JP7844613B2 - Pressure regulating valve - Google Patents

Description

This invention relates to a pressure regulating valve equipped with a pressure-sensitive member and a valve opening spring.

In pressure regulating valves, the valve opening degree has traditionally been controlled by driving a pressure-sensitive element connected to the valve member in response to pressure fluctuations. However, even when the set pressure conditions for valve opening were met, it was difficult to achieve smooth valve opening operation in these pressure regulating valves due to static friction acting on the stationary valve member, the weight of the valve member, and the valve closing force caused by foreign objects getting caught in the valve member.

Therefore, for example, Patent Document 1 describes a conventional pressure regulating valve (hereinafter referred to as "conventional pressure regulating valve") that comprises a valve member that can move closer to or further away from the valve seat, a pressure-sensitive member that drives the valve member in accordance with the primary pressure, and employs a valve opening spring that biases the valve member in the valve opening direction. In conventional pressure regulating valves, the valve opening spring constantly biases the valve member in the valve opening direction, thereby reducing the influence of static friction force acting on the stationary valve member, the weight of the valve member, and the valve closing fixing force, and as a result, the valve opening operation is performed smoothly.

Japanese Patent Publication No. 2001-116403

However, in conventional pressure regulating valves, the valve opening spring is located within the fluid path. This can lead to problems such as foreign objects becoming lodged between the spring wires and noise caused by vibrations in the spring (hereinafter referred to as "conventional problems (foreign object lodged in the valve opening spring and noise due to vibration)"). As a result, even when the set valve opening pressure conditions are met, the valve opening operation may not proceed smoothly.

The objective of this invention is to provide a pressure regulating valve that eliminates foreign matter jamming and noise caused by vibration in the valve opening spring by suppressing the flow of fluid through the fluid path into the valve opening spring, thereby enabling smooth valve opening operation.

To solve the above problems, the pressure regulating valve comprises a valve housing having a first port provided radially around the axis, a second port, a valve port, an intermediate chamber communicating with the first port, and a pressure-sensitive member housing chamber, which communicate sequentially from one side to the other, and a cylindrical guide portion provided in the intermediate chamber and erected around the valve seat formed at the other end of the valve port, defining a valve chamber on the inner circumference and communicating the valve chamber and the intermediate chamber radially around the axis, with at least one radial linkage The valve member comprises a guide portion having a through hole, a valve portion provided in the valve chamber within the guide portion and capable of approaching or separating from the valve seat, and a guide shaft portion extending to the other side and slidably guided by the guide portion; a pressure-sensitive member that displaces the valve portion in response to the pressure in the pressure-sensitive member housing chamber; and a valve opening spring provided on the outer circumference of the guide portion that biases the valve portion in the valve opening direction, wherein one end of the valve opening spring is positioned on the other side of the valve housing beyond the other end of the radial communication hole.

Furthermore, the pressure regulating valve may further include a valve seat member in which the guide portion and the valve seat portion having the second port and the valve port are integrally formed, and the valve seat member is fixed to a through hole that penetrates axially at one end of the valve housing.

Furthermore, in the above-described pressure regulating valve, the inner circumference of the guide portion of the valve seat member may have a sliding portion that slides with the guide shaft portion, and the sliding portion and the valve port may be coaxially machined.

Furthermore, in the above-mentioned pressure regulating valve, the inner circumference of the guide portion further has a relief portion adjacent to one side of the sliding portion and continuously connected to the inner diameter portion of the radial communication hole,
The inner diameter of the relief portion may be larger than the inner diameter of the sliding portion.

Furthermore, in the above-described pressure regulating valve, one end of the valve opening spring may be supported on the outer circumference of the guide portion, and the other end of the valve opening spring may be supported on the other end of the guide shaft portion.

Furthermore, the above-described pressure regulating valve may further include a one-side spring support portion having an annular portion, wherein the outer circumference of the guide portion has a stepped portion that narrows in diameter from one side to the other, and the annular portion of the one-side spring support portion engages with the stepped portion of the guide portion and supports the one-side end of the valve opening spring.

Furthermore, in the above-described pressure regulating valve, the one-side spring receiving portion may be erected from the inner circumference of the annular portion, engage with the outer circumference of the guide portion, and further have a cylindrical portion that guides the inner diameter of the valve opening spring.

Furthermore, in the above-described pressure regulating valve, the intermediate chamber and the pressure-sensitive member housing chamber may be connected via an annular gap between the outer peripheral end of the one-side spring receiving portion and the inner wall of the intermediate chamber.

Furthermore, in the above-mentioned pressure regulating valve, the area of the annular gap may be smaller than the sum of the opening areas in the radial communication holes.

Furthermore, in the above-described pressure regulating valve, the one end of the one-side spring support portion may be positioned at a distance from the inner wall of the intermediate chamber facing the one end of the one-side spring support portion, with respect to the central axis of the first port.

Furthermore, in the above-mentioned pressure regulating valve, the central axis of the first port and the central axis of the radial communication hole facing the first port 11 may be common.

Furthermore, the above-described pressure regulating valve may further include a ball support member fixed to the inner circumferential surface of the valve housing and having an annular shape, and a ball housed in the ball support member, wherein the ball is positioned between the valve member and the pressure-sensitive member, and the diameter of the ball may be larger than the gap on one side between the valve member and the valve housing.

Furthermore, in the above-mentioned pressure regulating valve, the pressure-sensitive member may be a pressure-sensitive bellows.

Furthermore, the above-mentioned pressure regulating valve may be configured such that the flow direction is from the first port to the second port, and the diameter of the valve port is smaller than the average inner diameter of the pressure-sensitive bellows.

According to the present invention, by suppressing the flow of fluid through the fluid path into the valve opening spring, it is possible to eliminate foreign matter jamming and noise caused by vibration in the valve opening spring, thereby providing a pressure regulating valve that enables smooth valve opening operation.

This is a cross-sectional view showing the valve closed state of a pressure regulating valve according to the first embodiment of the present invention. Figure 1 is an enlarged view of the valve member side of the pressure regulating valve. This is an enlarged view of the valve member side of the pressure regulating valve according to the second embodiment. This is an enlarged view of the valve member side of the pressure regulating valve according to the third embodiment.

Embodiments of the present invention will be described in detail with reference to Figures 1 to 4. However, the present invention is not limited to the embodiments described herein.

<About Terminology>
In this specification, “up,” “down,” “left,” and “right” refer to the directions shown in Figures 1 to 4. In this specification and the claims, “one side” and “the other side” refer to the “valve seat side” and the “adjustment spring unit side.” In this specification and the claims, “effective pressure-receiving area of the pressure-sensitive bellows” refers to the pressure-receiving area as an approximate value calculated based on the average inner diameter of the minimum inner diameter of the bellows shape (the inner diameter of the “valve” portion of the bellows shape projecting toward the central axis side of the pressure-sensitive bellows) and the maximum inner diameter (the inner diameter of the “peak” portion of the bellows shape projecting away from the central axis side of the pressure-sensitive bellows). In this specification and the claims, “guideable” includes “slidable.” In this specification and the claims, “concave-concave engagement” refers to a shape that is recessed in the axial direction and a shape that protrudes, respectively, that engage with each other. In this specification, “intermediate chamber” refers to “space other than the pressure-sensitive member housing chamber and the valve chamber.” In this specification, "spring aspect ratio" refers to "free length of spring / average spring diameter". In this specification, "average spring diameter" refers to "(inner spring diameter + outer spring diameter) / 2".

(First embodiment)
<About the configuration of the pressure regulating valve>
A pressure regulating valve 100a according to the first embodiment of the present invention will be described using Figure 1. The pressure regulating valve 100a mainly consists of a valve body 5, a valve seat member 30, a valve member 40, a pressure-sensitive unit 50, an adjustment spring unit 60, a lower connecting means 70, and an upper connecting means 80. The components of the pressure regulating valve 100a will be described in order below. In the pressure regulating valve 100a, the valve seat member 30, the valve member 40, the lower connecting means 70, the pressure-sensitive unit 50, the upper connecting means 80, and the adjustment spring unit 60 are assembled to the valve body 5 in an indirectly engaged state from one side to the other, in the order of valve seat member 30, valve member 40, lower connecting means 70, pressure-sensitive unit 50, upper connecting means 80, and adjustment spring unit 60. In this embodiment, for the purpose of explanation, the direction of the fluid path will be assumed to be from the first joint pipe 1 (first port 11) to the second joint pipe 2 (second port 12), but it is not limited to this, and depending on the application, for example, it may be from the second joint pipe 2 (second port 12) to the first joint pipe 1 (first port 11). As will be explained in detail later, in this embodiment, by positioning the valve opening spring 6, which biases the valve member 40 in the valve opening direction, in a position that does not interfere with the fluid path, the conventional problems (foreign matter getting caught in the valve opening spring and noise due to vibration) can be eliminated.

<About the valve body>
The valve body 5 consists of a valve housing 10 connected to the first joint pipe 1 and the second joint pipe 2, and a spring case 20 attached to the other end of the valve housing 10 by crimping or the like. The valve body 5 is made of an appropriate material such as brass, iron, aluminum, stainless steel, or resin material such as polyphenylene sulfide (PPS).

The valve housing 10 is a hollow cylindrical member with a through-hole extending along its axis L. This through-hole contains a second port 12 for connecting to the second joint pipe 2, an intermediate chamber 13, and a bellows housing chamber (pressure-sensitive member housing chamber) 16, all of which are interconnected. The inner wall of the intermediate chamber 13 is provided with an annular, one-sided spring-receiving step 18 that widens in diameter from one side to the other along the axis L.

Furthermore, the valve housing 10 is made of stainless steel and has a through-hole that extends radially from the intermediate chamber 13. A first port 11, which connects to the first joint pipe 1, is provided in this through-hole. This configuration allows the primary pressure P1 to be introduced into the intermediate chamber 13, the valve chamber 15 (described later), and the bellows housing chamber 16 via the first port 11 when the valve is closed.

The spring case 20 is a hollow cylindrical member having a through hole that penetrates along the axis L, and is provided with a spring housing chamber 21. Furthermore, a female threaded portion 22 is provided on the inner circumference of the other end of the spring case 20, and is screwed into a male threaded portion 62c provided on the outer circumference of the adjustment screw member 62 so as to be movable in the direction of the axis L. Air is constantly introduced into the spring housing chamber 21 through this screwed portion.

<Regarding valve seat components>
The valve seat member 30 is made of stainless steel and is a hollow cylindrical member having a through hole that penetrates along the axis L. It is composed of a valve seat portion 31 and a guide portion 32 that are integrally formed. After being press-fitted into the through hole that penetrates in the direction of the axis L at one end of the valve housing 10, it is fixed by brazing. In this way, by integrally forming the valve seat portion 31 and the guide portion 32 in the valve seat member 30 of this embodiment, costs can be reduced, the number of parts can be reduced, and the effort required for inventory management can be reduced.

The valve seat portion 31 has a valve port 31a that extends along the axis L and has an annular valve seat 31c formed at its other end, and an internal passage 31b that has a larger inner diameter than the valve port 31a and defines the second port 12.

The guide section 32 is provided in the intermediate chamber 13 and has a cylindrical shape that rises from around the other end of the valve seat section 31. It defines a valve chamber 15 (see Figure 2) on its inner circumference and has four radial communication holes 32a (see Figure 2) arranged at equal intervals in the circumferential direction, allowing communication between the valve chamber 15 and the intermediate chamber 13 in the radial direction centered on the axis L. While the radial communication holes 32a in this embodiment are arranged at equal intervals in the circumferential direction, the number and arrangement of the radial communication holes 32a can be appropriately set according to the intended use of the pressure regulating valve 100a.

As shown in Figure 2, the inner circumference of the guide portion 32 has a sliding portion 32b that slides with the guide shaft portion 42 along the axis L direction from one side to the other, and a relief portion 32c adjacent to the sliding portion 32b and continuously connected to the inner diameter portion of the radial communication hole 32a. In this embodiment, the inner diameter of the relief portion 32c is set to be larger than the inner diameter of the sliding portion 32b, thereby suppressing the physical direct interference of the opening end of the radial communication hole 32a on the valve chamber 15 side with the valve member 40. As a result, even if machining burrs or the like are present at the opening end of the radial communication hole 32a on the valve chamber 15 side, contact with the valve member 40 is avoided by the relief portion 32c, and as a result, the operability of the valve member 40 can be improved.

In this embodiment, the sliding portion 32b of the guide portion 32 and the valve port 31a of the valve seat portion 31 are coaxially machined. As a result, the valve member 40 is guided stably in the axial direction L by the sliding portion 32b, and the center positions of the valve member 40 and the valve seat 31c, as viewed from the axial direction L, always coincide. This reduces the sliding resistance of the valve member 40 against the sliding portion 32b, thereby reducing hysteresis, ensuring low valve leakage, and improving flow stability. Furthermore, since the guide portion 32 and the valve seat portion 31 are integrally formed, there is no risk of assembly errors that would inevitably occur if they were separate parts. Therefore, coaxial management of the sliding portion 32b and the valve port 31a can be performed relatively easily and with extremely high precision.

<Regarding valve components>
The valve member 40 is provided on one side and comprises a valve portion 41 having a substantially conical shape and a cylindrical guide shaft portion 42 extending to the other side in the axial direction L. The guide shaft portion 42 is positioned on the inner circumference side of the guide portion 32, except for the other end. An annular groove portion 42a is formed on the outer circumferential surface of the other end of the guide shaft portion 42. The other spring receiving portion 7 is made of a ring-shaped thin plate having a plurality of protrusions on its inner circumference and engages with the annular groove portion 42a via these multiple protrusions.

The guide shaft portion 42 of the valve member 40 is positioned to guide within the guide portion 32 of the valve seat member 30 in the axial direction L. Here, the gap G1 (see Figure 2) formed between the outer diameter of the guide shaft portion 42 and the inner diameter of the sliding portion 32b (see Figure 2) is set to be relatively small. Furthermore, the valve member 40 is constantly biased in the valve opening direction by a valve opening spring 6 sandwiched between the other-side spring receiving portion 7, which engages with the annular groove portion 42a of the valve member 40, and the one-side spring receiving step portion 18 of the valve housing 10.

The movement of the valve member 40 in the axial direction L will be described in detail later, but it is caused by the pressure difference between the primary pressure P1 and the secondary pressure P2, the biasing force of the pressure-sensitive bellows (pressure-sensitive member) 51 and adjustment spring 63 acting on the other end of the valve member 40, and the biasing force of the valve opening spring 6 acting on the other spring receiving portion 7. These external forces cause the valve portion 41 to move closer to or further away from the valve seat 31c, determining the valve opening degree. Here, as will be described in detail later, the stepped portion 55c of the connecting rod 55 contacts the bellows upper cover 53, thereby defining the maximum valve lift amount from the valve closed state to the fully open state (maximum valve lift). In this embodiment of the pressure regulating valve 100a, in addition to the fully open state (maximum valve lift), there is a fully open state where a specified flow rate is achieved, just before the stepped portion 55c of the connecting rod 55 contacts the bellows upper cover 53.

<About the pressure-sensitive unit>
The pressure-sensitive unit 50 consists of a pressure-sensitive bellows 51, which is a pressure-sensitive member; a bellows upper cover 53; and a connecting rod 55 having one end and the other end that extend along the axis L. The pressure-sensitive bellows 51 has its one end and the other end that extend along the axis L connected to the one end of the connecting rod 55 and the bellows upper cover 53, respectively. Here, the elastic force of the pressure-sensitive bellows 51 itself biases the valve member 40 in the valve closing direction. The pressure-sensitive unit 50 is made of metal such as stainless steel and is housed in the bellows housing chamber 16 of the valve housing 10.

The pressure-sensitive bellows 51 is connected to one end of the connecting rod 55 and the bellows upper cover 53, thereby constantly introducing the primary side pressure P1 into the external space of the pressure-sensitive bellows 51 via the intermediate chamber 13 and the bellows housing chamber 16. Meanwhile, air is constantly introduced into the internal space of the pressure-sensitive bellows 51 through the gap formed between the small-diameter portion 55b of the connecting rod 55 and the insertion hole 53a of the bellows upper cover 53, and through the gap formed between the connecting member 83 and the contact portion 53c of the bellows upper cover 53. Furthermore, in this pressure-sensitive bellows 51, the dimensional relationship of each part is set such that the outer diameter of the peaks and the inner diameter of the valleys of the bellows shape are constantly non-contacting the valve housing 10 and the connecting rod 55, respectively. While the pressure-sensitive member in this embodiment is a pressure-sensitive bellows 51, it is not limited to this; for example, a diaphragm may also be used.

The connecting rod 55 comprises a substantially cylindrical, large-diameter portion 55a extending to one side in the axial direction L, and a substantially cylindrical, small-diameter portion 55b extending from the large-diameter portion 55a to the other side in the axial direction L. A flange portion 55d is formed at one end of the large-diameter portion 55a, projecting radially, and to which one end of the pressure-sensitive bellows 51 is connected by welding W. Furthermore, an annular stepped portion 55c is formed between the large-diameter portion 55a and the small-diameter portion 55b.

The bellows upper cover 53 extends concentrically along the axis L and includes an insertion hole 53a through which the small-diameter portion 55b of the connecting rod 55 is inserted, a bellows upper cover joint portion 53b to which the other end of the pressure-sensitive bellows 51 is connected, and a cylindrical contact portion 53c that extends concentrically along the axis L, has an inner diameter larger than the insertion hole 53a, through which the small-diameter portion 55b of the connecting rod 55 is inserted, and through which the connecting member 83 slides. Here, the pressure-sensitive unit 50 is fixed to the valve body 5 so as to be unable to move relative to it, by welding or other means to the other ends of the bellows upper cover 53 and the valve housing 10.

<About the adjustment spring unit>
The adjustment spring unit 60 consists of a spring receiving member 61, an adjustment screw member 62, and an adjustment spring 63 sandwiched between the spring receiving member 61 and the adjustment screw member 62, which biases the valve portion 41 in the valve closing direction. The spring receiving member 61 and the adjustment screw member 62 are made of a suitable material such as brass, iron, aluminum, stainless steel, or resin material such as polyphenylene sulfide (PPS), and are housed in the spring housing chamber 21 of the spring case 20. The spring receiving member 61 has a boss portion 61a extending to the other side in the axial direction L, and a flange portion 61b provided on one side in the axial direction L, on which one end of the adjustment spring 63 is seated. The adjustment screw member 62 has an annular wall portion 62a extending to one side in the axial direction L, and an upper surface portion 62b provided on the other side, on which the other end of the adjustment spring 63 is seated. A male threaded portion 62c is provided on the outer circumference of the adjustment screw member 62, while a female threaded portion 22 is provided on the inner circumference of the other end of the spring case 20. By screwing the male threaded portion 62c and the female threaded portion 22 together and moving the adjustment screw member 62 in the direction of the axis L, the biasing force of the adjustment spring 63 can be adjusted, and the pressure (set value) at which the valve member 40 opens can be adjusted. In this embodiment, a multi-wound wave spring is used as the adjustment spring 63, but it is not limited to this, and for example, a coil spring may also be used.

<Regarding the lower connection means>
The lower connecting means 70 consists of a pair of recesses 71 and 72 formed on opposing surfaces in the axial direction L of the valve member 40 and the pressure-sensitive unit 50, and a ball 73 that is sandwiched between the pair of recesses 71 and 72 to form a recessed engagement. The pair of recesses 71 and 72 are formed on the axial center of the other end face of the guide shaft 42 and the one end face of the large diameter portion 55a, and consist of a conical lower recess 71 and an upper recess 72. This conical shape has a base formed concentrically with the axis L and an apex located on the axis L. The ball 73 is made of a metal such as stainless steel.

As a result, the guide shaft portion 42 of the valve member 40 is positioned within the guide portion 32 of the valve seat member 30 so as to be guided along the axis L, and the center position of the lower recess portion 71 is always positioned near the axis L. Furthermore, the center position of the upper recess portion 72 is independently positioned near the axis L because a centripetal force acts on the upper recess portion 72 via the lower recess portion 71 and the ball 73.

<Regarding the upper connection means>
The upper connecting means 80 consists of a pair of engaging portions 81 and 82 formed on the axial direction L-facing surfaces of the connecting rod 55 and the spring receiving member 61, and a spherical connecting member 83 sandwiched between the pair of engaging portions 81 and 82 to form a concave-concave engagement. The pair of engaging portions 81 and 82 are formed on the other end face of the small diameter portion 55b and on the axial center of one end face of the spring receiving member 61, and consist of a conical lower engaging portion 81 and an upper engaging portion 82. This conical shape has a base formed concentrically with the axis L and a vertex located on the axis L. The connecting member 83 is made of a metal such as stainless steel.

Here, viewed from the direction of axis L, the radius of the circular side portion of the connecting member 83 is set to be slightly smaller than the radius of the contact portion 53c. Therefore, the center position of the connecting member 83 is always located near axis L. Furthermore, the center positions of the lower engaging portion 81 and the upper engaging portion 82 are independently located near axis L because a centripetal force acts on them via the connecting member 83, which restricts radial movement. In addition, the small-diameter portion 55b of the connecting rod 55 is set to be inserted through the insertion hole 53a along axis L in a non-contact state.

<Details regarding the support mechanism for the valve opening spring>
Conventional pressure regulating valves have the valve opening spring located in the fluid path, which leads to the conventional problems (foreign objects getting caught in the valve opening spring and noise due to vibration). As a result, even when the set pressure conditions for valve opening are met, there is still a risk that the valve opening operation will not be performed smoothly.

In contrast, in the support means for the valve opening spring 6 in the first embodiment, as shown in Figure 2, one end of the valve opening spring 6 is supported by the one-side spring receiving step 18 of the valve housing 10, while the other end of the valve opening spring 6 is supported by the other-side spring receiving portion 7, which engages with the annular groove portion 42a of the valve member 40. In this case, viewed from the axial direction L, the other end of the valve opening spring 6 is supported so as to overlap with the other-side spring receiving portion 7 around its entire circumference. Here, viewed from the central axis C of the radial communication hole 32a, the one-side spring receiving step 18 of the valve housing 10, that is, the one end of the valve opening spring 6, is positioned on the other side of the valve housing 10 than the other end of the radial communication hole 32a. In this way, in the first embodiment, by positioning the valve opening spring 6 in a location that does not interfere with the fluid path, the conventional problems (foreign object jamming in the valve opening spring and noise due to vibration) can be eliminated.

Furthermore, in the valve opening spring 6, if the aspect ratio of the spring, i.e., the ratio of free length to average spring diameter, increases, buckling in the radial direction around the axis L is more likely to occur, potentially resulting in a load below the design load. In contrast, in the first embodiment, buckling can be suppressed by guiding the outer diameter portion of the valve opening spring 6 with an inner wall erected from the outer circumference of the spring support step 18 on one side of the valve housing 10. Note that the average spring diameter is defined as (spring inner diameter + spring outer diameter) / 2.

<About the operation of the pressure regulating valve>
The operation of the pressure regulating valve 100a will be explained using Figure 2. Here, the pressure regulating valve 100a will be described as being used in a refrigerant circuit, but it is not limited to this. In the pressure regulating valve 100a, the first port 11 is connected to the first joint pipe 1 on the high-pressure (primary pressure P1) side, and the second port 12 is connected to the second joint pipe 2 on the low-pressure (secondary pressure P2) side.

(When the primary pressure P1 is lower than the set value)
When the primary pressure P1 is lower than the set value (for example, when the compressor discharge pressure has decreased), the valve section 41 is seated on the valve seat 31c, and the valve is closed. In this case, the primary pressure P1 is introduced into the space outside the pressure-sensitive bellows 51, which is the bellows housing chamber 16, via the intermediate chamber 13.

First, a force equal to the primary pressure P1 × effective pressure-receiving area S1 (see Figure 2) acts on the pressure-sensitive bellows 51 in the direction that opens the valve portion 41. Here, the effective pressure-receiving area S1 of the pressure-sensitive bellows 51 is the pressure-receiving area calculated based on the average inner diameter D1 of the minimum and maximum inner diameters of the bellows shape.

Next, the valve member 40 experiences a force acting in the direction that opens the valve section 41, which is the secondary pressure P2 × pressure-receiving area S2 (see Figure 2). Conversely, it experiences a force acting in the direction that closes the valve section 41, which is the primary pressure P1 × pressure-receiving area S2 (see Figure 2). Here, the pressure-receiving area S2 of the valve section 41 is the pressure-receiving area calculated based on the diameter D2 of the valve port 31a. Furthermore, the valve member 40 is subjected to a biasing force F1 from the valve opening spring 6 as a force acting in the direction that opens the valve section 41, while the valve member 40 is subjected to a biasing force F2 from the pressure-sensitive bellows 51 itself and a biasing force F3 from the adjustment spring 63 as forces acting in the direction that closes the valve section 41.

Therefore, the balance of external forces acting on the valve member 40 of the pressure regulating valve 100a can be expressed as follows.
P1×S1+P2×S2+F1=P1×S2+F2+F3 (Formula 1)
Here, P1: Primary pressure [N/ ^mm² ]
P2: Secondary pressure [N/ ^mm² ]
S1: Effective pressure-receiving area of pressure-sensitive bellows 51 [ ^mm² ]
S2: Pressure-receiving area of valve section 41 [ ^mm² ]
F1: Biasing force of valve opening spring 6 [N]
F2: Biasing force [N] due to the pressure-sensitive bellows 51 itself
F3: Biasing force of adjustment spring 63 [N]

Equation 1 can be rearranged to P1 × S1 + F1 = (P1 - P2) × S2 + F2 + F3.

Dividing both sides of this equation by S1, we can transform it into P1 + F1/S1 = (P1 - P2) × S2/S1 + (F2 + F3)/S1. Here, by setting the ratio of the pressure-receiving area S2 of the valve section 41 to the effective pressure-receiving area S1 of the pressure-sensitive bellows 51 to be extremely small (S1 >> S2), the first term on the right-hand side can be ignored. As a result, the influence of fluctuations in the secondary pressure P2 can be made extremely small. Specifically, it is preferable to set S2/S1 = 0.09 or less.

Here, since the area is proportional to the square of the inner diameter, in order to set the ratio of the pressure-receiving area S2 of the valve section 41 to the effective pressure-receiving area S1 of the pressure-sensitive bellows 51 to be extremely small, it is sufficient to set a small ratio of the diameter D2 of the valve port 31a to the average inner diameter D1 of the pressure-sensitive bellows 51. Specifically, it is preferable to set D2/D1 = 0.30 or less.

Furthermore, if S1 >> S2, the above equation becomes P1 × S1 = F2 + F3 - F1. Therefore, the pressure regulating valve 100a can be controlled to vary its opening in accordance with fluctuations in the primary pressure P1 by moving the adjustment screw member 62 in the axial direction L and appropriately setting the biasing force F3 of the adjustment spring 63. In addition, the dimensions of each part of the pressure regulating valve 100a can be set using the actual pressure-receiving area obtained through experiments, not limited to the pressure-receiving area (effective pressure-receiving area) as an approximate value calculated based on the average inner diameter of the minimum and maximum inner diameters of the bellows shape. Thus, in this embodiment, by setting the flow direction from the first port 11 to the second port 12 and setting the diameter D2 of the valve port 31a to be smaller than the average inner diameter D1 of the pressure-sensitive bellows 51, the influence of fluctuations in the secondary pressure P2 can be made extremely small. Furthermore, if the pressure regulating valve 100a in the first embodiment is to be used for low-flow rate control, this can be achieved by changing only the diameter D2 of the valve port 31a while maintaining the overall size.

(When the primary pressure P1 is higher than the set value)
When the primary pressure P1 is higher than the set value ((F2 + F3 - F1) / S1) (for example, when the compressor discharge pressure rises), the valve portion 41 is separated from the valve seat 31c, and the valve is in an open state (not shown). In this case, the valve opening degree increases as the primary pressure P1 rises. In this embodiment, the pressure regulating valve 100a uses a pressure-sensitive bellows 51 as a pressure-sensitive member, which allows the displacement amount (lift amount, stroke amount) of the pressure-sensitive member in the axial direction L, that is, the flow rate through the valve port 31a, to be increased.

(Second embodiment)
A pressure regulating valve 100b according to a second embodiment of the present invention will be described using Figure 3. The pressure regulating valve 100b of the second embodiment differs from the pressure regulating valve 100a of the first embodiment in that one end of the valve opening spring 6 is supported by a one-side spring receiving portion 8 via a stepped portion 32d formed on the outer circumference of the guide portion 32, and that a valve opening spring 6 with a longer free length is used (see Figures 2 and 3). However, the other basic configurations are the same as those of the first embodiment. Here, the same reference numerals are used for the same components, and redundant explanations are omitted.

The pressure regulating valve 100a of the first embodiment requires flexible adaptation to various types of valve opening springs 6 (especially in terms of free length) depending on the application, taking into account the static friction force acting on the stationary valve member 40, the weight of the valve member 40, and the valve closing fixing force due to foreign matter jamming into the valve member 40, in order to ensure smooth valve opening operation. However, since one end of the valve opening spring 6 is supported by one side spring support step 18 of the valve housing 10, adapting to various types of valve opening springs 6 required preparing a valve housing 10 with the position of the spring support step 18 changed vertically or horizontally each time. Therefore, in the pressure regulating valve 100a of the first embodiment, the processing cost of the valve housing 10 was likely to be relatively high in order to adapt to various types of valve opening springs 6.

Furthermore, in the pressure regulating valve 100a of the first embodiment, as shown in Figure 2, fluid communication is established between the intermediate chamber 13 and the bellows housing chamber 16 via a connecting passage. Although the flow rate itself is not insignificant, as this connecting passage is provided for pressure transmission, the space between the wires of the valve opening spring 6 constitutes part of the connecting passage. Therefore, in the pressure regulating valve 100a of the first embodiment, there was a risk of even slight foreign matter becoming lodged between the wires of the valve opening spring 6.

In contrast, the pressure regulating valve 100b of the second embodiment employs a stepped portion 32d formed on the outer circumference of the guide portion 32, as shown in Figure 3, instead of the one-sided spring receiving step portion 18 formed on the valve housing 10 in the pressure regulating valve 100a of the first embodiment, and further includes a one-sided spring receiving portion 8. Furthermore, the pressure regulating valve 100b of the second embodiment will be described as employing a valve opening spring 6 with a longer free length compared to the pressure regulating valve 100a of the first embodiment, as an example of accommodating various types of valve opening springs 6.

Specifically, the outer circumference of the guide portion 32 has a stepped portion 32d that tapers in diameter from one side to the other. The one-side spring receiving portion 8 comprises an annular portion 8a and a cylindrical portion 8b that rises from the inner circumference of the annular portion 8a. Here, one end of the valve opening spring 6 is supported by the annular portion 8a of the one-side spring receiving portion 8, which engages with the stepped portion 32d of the guide portion 32. In this case, viewed from the axial direction L, the one end of the valve opening spring 6 is supported so as to overlap with the annular portion 8a of the one-side spring receiving portion 8 around its entire circumference. Because the annular portion 8a and the cylindrical portion 8b have a relatively long engagement region along the axial direction L relative to the outer circumference of the guide portion 32, a more robust engagement can be achieved. Note that the engagement of the one-side spring receiving portion 8 with the stepped portion 32d in this embodiment may be by locking or press-fitting. Furthermore, the other end of the valve opening spring 6 is supported by the other spring receiving portion 7, which engages with the annular groove portion 42a of the valve member 40, similar to the first embodiment.

Therefore, in the pressure regulating valve 100b of the second embodiment, when employing various types of valve opening springs 6 (especially those with different free lengths), simply providing a valve seat member 30 with a stepped portion 32d formed at a position corresponding to the valve opening spring 6 allows for flexible adaptation and high versatility. Furthermore, the concern about high processing costs associated with the pressure regulating valve 100a of the first embodiment is resolved.

In this case, the aspect ratio of the valve opening spring 6 becomes larger, making it prone to buckling in the radial direction around the axis L. However, buckling can be suppressed by guiding the inner diameter portion of the valve opening spring 6 with the outer circumferential surface of the cylindrical portion 8b of the spring receiving portion 8 on one side.

Furthermore, when adjusting the position of the stepped portion 32d in the axial direction L, the stepped portion 32d of the guide portion 32, that is, one end of the valve opening spring 6, is positioned on the other side of the valve housing 10, relative to the central axis C of the radial communication hole 32a, compared to the other end of the radial communication hole 32a. This allows the valve opening spring 6 to be positioned in a location that does not interfere with the fluid path, thereby eliminating the conventional problems (foreign object jamming in the valve opening spring and noise due to vibration) in the second embodiment as in the first embodiment.

Furthermore, in the pressure regulating valve 100b of the second embodiment, fluid communication occurs between the intermediate chamber 13 and the bellows housing chamber 16 via an annular gap Gc between the outer peripheral end of the annular portion 8a of the one-side spring receiving portion 8 and the inner wall of the intermediate chamber 13. Therefore, the communication passage between the intermediate chamber 13 and the bellows housing chamber 16 can be separated from the outer diameter portion of the valve opening spring 6, thus eliminating the concern in the pressure regulating valve 100a of the first embodiment where the spaces between the wires of the valve opening spring 6 become part of the communication passage.

Furthermore, in the pressure regulating valve 100b of the second embodiment, the area of the annular gap Gc between the outer peripheral end of the one-side spring receiving portion 8 and the inner wall of the intermediate chamber 13 is set to be smaller than the sum of the opening areas of the (for example, four) radial communication holes 32a. Note that in the pressure regulating valve 100b of the second embodiment, for illustrative purposes, a configuration with four radial communication holes 32a is shown as an example; however, the number of radial communication holes 32a can be appropriately set according to the intended use of the pressure regulating valve 100a. Therefore, since the flow resistance through the annular gap Gc is higher than the fluid resistance through the four radial communication holes 32a, the fluid flowing from the first port 11 into the intermediate chamber 13 flows to the four radial communication holes 32a in a manner that avoids passing through the annular gap Gc. As a result, in the second embodiment, the fluid flowing through the fluid path does not actively flow towards the valve opening spring 6, thus further eliminating the conventional problems (foreign object jamming in the valve opening spring and noise due to vibration) compared to the first embodiment.

(Third embodiment)
A pressure regulating valve 100c according to a third embodiment of the present invention will be described using Figure 4. The pressure regulating valve 100c of the third embodiment differs from the pressure regulating valve 100b of the second embodiment in that it employs a valve opening spring 6 with a shorter free length (see Figures 3 and 4), the one-sided spring receiving portion 8' does not have a cylindrical portion 8b, and a ring-shaped ball support member 9 is provided. However, the other basic configurations are the same as those of the second embodiment. Here, the same reference numerals are used for the same components, and redundant explanations are omitted.

In the second embodiment, for example, if the position of the stepped portion 32d is shifted to one side in the axial direction L to accommodate a valve opening spring 6 with a long free length, the one end of the valve opening spring 6 may be affected by fluid pulsation or other factors due to its proximity to the fluid path, even if it is not located in the fluid path.

In contrast, in the pressure regulating valve 100c of the third embodiment, by devising the material of the wires of the valve opening spring 6 and adopting a shorter free length, the position of the stepped portion 32d can be positioned on the other side in the axial direction L compared to the pressure regulating valve 100b of the second embodiment. In this case, since the free length of the valve opening spring 6 is short and there is no need to suppress buckling, the cylindrical portion 8b of the spring receiving portion 8' on one side can be omitted.

Specifically, the length l1 of the perpendicular from one end of the spring support portion 8' to the central axis C of the first port 11 is set to be longer than the length l2 of the perpendicular from the inner wall 19 of the intermediate chamber 13 facing the one end of the spring support portion 8' to the central axis C of the first port 11.

Therefore, in the pressure regulating valve 100c of the third embodiment, the lengths l1 and l2 of the perpendiculars from one end of the one-side spring receiving portion 8' and the inner wall 19 of the intermediate chamber 13 facing one end of the one-side spring receiving portion 8' to the central axis C of the first port 11 are set such that l1 > l2. As a result, with respect to the central axis C of the first port 11, one end of the one-side spring receiving portion 8' is positioned further away from the inner wall 19 of the intermediate chamber 13 facing one end of the one-side spring receiving portion 8'. In other words, the fluid flowing from the first port 11 into the intermediate chamber 13 is less likely to flow to one end of the one-side spring receiving portion 8', that is, to one end of the valve opening spring 6. As a result, in the third embodiment, the issue of one end of the valve opening spring 6 being close to the fluid path, which was a concern in the pressure regulating valve 100b of the second embodiment, can be resolved. Furthermore, since the fluid flowing through the fluid path does not actively flow towards the valve opening spring 6, the conventional problems (foreign object jamming in the valve opening spring and noise due to vibration) can be reliably eliminated compared to the second embodiment.

Furthermore, in the pressure regulating valve 100c of the third embodiment, the first port 11 and the radial communication hole 32a facing the first port 11 share a common central axis C. As a result, the fluid flowing from the first port 11 into the intermediate chamber 13 flows smoothly into the radial communication hole 32a, which shares a common central axis C with the first port 11, while not actively flowing into the valve opening spring 6. Therefore, compared to the second embodiment, the conventional problems (foreign matter jamming in the valve opening spring and noise due to vibration) can be reliably eliminated.

Furthermore, in the pressure regulating valve 100c of the third embodiment, a stepped portion 17 is formed on the inner circumferential surface of the valve housing 10, which tapers in diameter from one side to the other. A ring-shaped ball support member 9 is engaged with this stepped portion 17. This ball support member 9 is positioned to accommodate the ball 73 of the lower connecting means 70.

Specifically, the gap G1 formed between the guide shaft portion 42 and the sliding portion 32b is set to be smaller than the gap G2 between the ball support member 9 and the ball 73. Therefore, the guide shaft portion 42 has a relatively narrow gap G1 (<G2) between it and the sliding portion 32b, and the center position of the ball 73 is independently positioned near the axis L due to a centripetal force acting on the ball 73 via the lower recess portion 71 formed in the guide shaft portion 42. In addition, the gap G2 between the ball support member 9 and the ball 73 allows the ball support member 9 to restrict the radial movement of the ball 73 around the axis L, even if some external impact is applied.

Therefore, in the pressure regulating valve 100c of the third embodiment, the biasing force generated by the pressure-sensitive bellows 51 and the adjustment spring 63, which does not follow the axis L, can be suppressed from being transmitted to the valve member 40 via the ball 73. As a result, the sliding resistance of the valve member 40 against the sliding part 32b is reduced, and hysteresis can be reduced. Therefore, even when the valve opening start pressure (primary side pressure P1) is slightly less than the set value ((F2 + F3 - F1) / S), low valve leakage can be ensured.

Furthermore, in the pressure regulating valve 100c of the third embodiment, the diameter Db of the ball 73 is set to be larger than the gap Go on one side between the valve member 40 and the valve housing 10. Here, the lower connecting means 70 assembles the valve member 40, the ball 73, and the ball support member 9 in that order, through a through hole that penetrates along the axis L of the valve housing 10, from one side to the other. In this case, even if the ball 73 has, for example, a small diameter Db and is positioned outside the lower recess 71 formed in the guide shaft portion 42, it is prevented from falling into the gap Go on one side, thus allowing for smooth assembly.

<Other>
It goes without saying that the pressure regulating valves 100a, 100b, and 100c of this embodiment are applicable not only to the exemplified refrigerant circuit but to all fluid devices and fluid circuits. Furthermore, the present invention is not limited to the above-described forms, embodiments, or modifications, and can be appropriately modified or altered without departing from the technical spirit of the present invention.

100a, 100b, 100c Pressure regulating valve 1 First joint pipe 2 Second joint pipe 5 Valve body 6 Valve opening spring 7 Other side spring receiving part 8, 8' One side spring receiving part 8a Annular part 8b Cylindrical part 9 Ball support member 10 Valve housing 11 First port 12 Second port 13 Intermediate chamber 15 Valve chamber 16 Bellows housing chamber (pressure-sensitive member housing chamber)
17 Stepped section 18 One-sided spring support step section 19 Inner wall of intermediate chamber facing one end of one-sided spring support section 20 Spring case 30 Valve seat member 31 Valve seat section 31a Valve port 31b Internal passage 31c Valve seat 32 Guide section 32a Radial communication hole 32b Sliding section 32c Relief section 32d Stepped section 40 Valve member 41 Valve section 42 Guide shaft section 42a Annular groove section 50 Pressure-sensitive unit 51 Pressure-sensitive bellows (pressure-sensitive member)
53 Bellows upper cover 55 Connecting rod 60 Adjustment spring unit 61 Spring receiving member 62 Adjustment screw member 63 Adjustment spring 70 Lower connecting means 71 Lower recess 72 Upper recess 73 Ball 80 Upper connecting means

C Central axis D1 Diameter of valve port D2 Average inner diameter of pressure-sensitive bellows Db Diameter of ball F1 Biasing force of valve opening spring F2 Biasing force by pressure-sensitive bellows itself F3 Biasing force of adjustment spring G1 Gap formed between the outer diameter of the guide shaft and the inner diameter of the sliding part Gc Gap between the ball support member and the ball Annular gap Go between the outer peripheral end of the annular part of the one-side spring receiving part and the inner wall of the intermediate chamber One-side gap l1 Between the valve member and the valve housing Length of the perpendicular from one end of the one-side spring receiving part to the central axis of the first port l2 Length of the perpendicular from the inner wall of the intermediate chamber to the central axis of the first port L Axis P1 Primary pressure P2 Secondary pressure S1 Effective pressure-receiving area of pressure-sensitive bellows S2 Pressure-receiving area of the valve part

Claims (14)

A valve housing having a first port provided radially around an axis corresponding to the longitudinal direction of the pressure regulating valve, and a second port, a valve port, an intermediate chamber communicating with the first port, and a pressure-sensitive member housing chamber, which are sequentially communicating from one side to the other.
A cylindrical guide portion provided in the intermediate chamber and erected around the valve seat formed at the other end of the valve port, the guide portion having a valve chamber defined on its inner circumference and at least one radial communication hole that connects the valve chamber and the intermediate chamber in the radial direction centered on the axis,
A valve member having a valve portion provided in the valve chamber within the guide portion and capable of moving closer to or further away from the valve seat, and a guide shaft portion extending to the other side and slidably guided by the guide portion,
A pressure-sensitive member that displaces the valve portion in accordance with the pressure inside the pressure-sensitive member housing chamber,
A valve opening spring is provided on the outer circumference of the guide portion and biases the valve portion in the valve opening direction,
It has,
One end of the valve opening spring is positioned on the other side of the valve housing than the other end of the radial communication hole.
A pressure regulating valve characterized in that an annular connecting passage is formed between the intermediate chamber and the bellows housing chamber with respect to the axis, and when viewed from the axial direction corresponding to the longitudinal direction of the pressure regulating valve, all areas of the connecting passage do not overlap with the valve opening spring. The valve seat member further comprises the guide portion and a valve seat portion having the second port and the valve port, which are integrally formed.
The pressure regulating valve according to claim 1, characterized in that the valve seat member is fixed to a through hole that penetrates axially at one end of the valve housing. The pressure regulating valve according to claim 2, characterized in that the inner circumference of the guide portion of the valve seat member has a sliding portion that slides with the guide shaft portion, and the sliding portion and the valve port are coaxially machined. The inner circumference of the guide portion is adjacent to one side of the sliding portion and further has a relief portion that is continuously connected to the inner diameter portion of the radial communication hole.
The pressure regulating valve according to claim 3, characterized in that the inner diameter of the relief portion is larger than the inner diameter of the sliding portion. One end of the valve opening spring is supported on the outer circumference of the guide portion.
The pressure regulating valve according to claim 1, characterized in that the other end of the valve opening spring is supported at the other end of the guide shaft. It further comprises a one-sided spring receiving portion having an annular portion,
The outer circumference of the guide portion has a stepped portion that decreases in diameter from one side to the other.
The pressure regulating valve according to claim 5, characterized in that the annular portion of the one-side spring receiving portion engages with the stepped portion of the guide portion and supports one end of the valve opening spring. The pressure regulating valve according to claim 6, characterized in that the one-side spring receiving portion is erected from the inner circumference of the annular portion, engages with the outer circumference of the guide portion, and further has a cylindrical portion that guides the inner diameter of the valve opening spring. The pressure regulating valve according to claim 6, characterized in that the intermediate chamber and the pressure-sensitive member housing chamber are in communication via an annular gap between the outer peripheral end of the one-side spring receiving portion and the inner wall of the intermediate chamber. The pressure regulating valve according to claim 8, characterized in that the area of the annular gap is smaller than the sum of the opening areas in the radial communication holes. The pressure regulating valve according to claim 9, characterized in that, with respect to the central axis of the first port, one end of the one-side spring support portion is positioned at a distance greater than the inner wall of the intermediate chamber facing the one end of the one-side spring support portion. The pressure regulating valve according to claim 10, characterized in that the central axis of the first port and the central axis of the radial communication hole facing the first port are common. The valve housing further comprises a ball support member fixed to the inner circumferential surface and having an annular shape, and a ball housed in the ball support member.
The pressure regulating valve according to claim 11, wherein the ball is disposed between the valve member and the pressure-sensitive member, and the diameter of the ball is larger than the gap on one side between the valve member and the valve housing. The pressure regulating valve according to any one of claims 1 to 12, characterized in that the pressure-sensitive member is a pressure-sensitive bellows. The flow direction is from the first port to the second port,
The pressure regulating valve according to claim 13, characterized in that the diameter of the valve port is smaller than the average inner diameter of the pressure-sensitive bellows.