JP7215790B1 - dispenser - Google Patents

Abstract

A new dispenser is provided that reduces wear on parts. A dispenser (20) has a housing (28) having a piston (22), a columnar measuring chamber (24) filled with a liquid material containing particles, and a piston chamber (26) in which the piston (22) projecting into the measuring chamber (24) reciprocates. and a sealing member 30 that seals between the inner peripheral surface 26 a of the piston chamber 26 and the piston 22 . The piston 22 reciprocates inside a measuring chamber 24, and the measuring chamber 24 has a gap G formed between an outer peripheral surface 22a of the protruding piston 22 and an inner peripheral surface 24a of the measuring chamber 24. As shown in FIG. [Selection drawing] Fig. 3

Description

TECHNICAL FIELD The present invention relates to a dispenser, and for example, to a dispenser that ejects liquid material.

BACKGROUND ART Conventionally, a so-called uniaxial eccentric screw pump has been devised as a discharge device for stably discharging a fixed amount of a highly viscous liquid material such as an adhesive or a metal paste. This pump consists of a rotor with a male thread and a stator with a female thread. A closed space called a cavity formed between the stator and rotor moves to the discharge side, and a certain amount of liquid is sucked into the cavity. can be discharged (see Patent Document 1).

Japanese Patent Application Laid-Open No. 2021-38740

However, in the above-mentioned ejection device, if you try to eject a liquid material in which particles are dispersed, the particles caught between the stator and the rotor will wear out each part, so regular maintenance and replacement of parts will cause downtime. This leads to an increase in time and an increase in equipment operating costs. Therefore, development of a new dispenser that suppresses downtime is required.

SUMMARY OF THE INVENTION It is in view of this situation that one of the exemplary objects of the present invention is to provide a new dispenser that reduces wear of parts due to particles contained in liquid materials.

In order to solve the above problems, the dispenser of one aspect of the present invention includes a piston, a columnar measuring chamber filled with a liquid material containing particles, and a piston chamber in which the piston projecting into the measuring chamber reciprocates. and a sealing member that seals between the inner peripheral surface of the piston chamber and the piston. The piston reciprocates inside the measuring chamber, and the measuring chamber has a gap formed between the outer peripheral surface of the projecting piston and the inner peripheral surface of the measuring chamber.

According to this aspect, a gap is formed between the outer peripheral surface of the projecting piston and the inner peripheral surface of the measuring chamber, and the pressure applied to the gap is less than the pressure applied to the tip surface of the piston pushed out into the measuring chamber. can be reduced. Therefore, the pressure applied to the sealing member provided in the piston chamber at the tip of the gap is also reduced, and particles are less likely to enter between the sealing member and the inner peripheral surface of the piston chamber or the piston. As a result, abrasion (wear) of the sealing member and the piston due to particles is reduced, and an increase in cost due to replacement of parts and stoppage of the apparatus can be suppressed.

The housing may have an opening connecting the metering chamber and the piston chamber. The inner diameter of the opening is smaller than the inner diameter of the metering chamber. Thereby, the gap between the piston and the inner peripheral surface of the measuring chamber can be increased.

The piston chamber may have an annular groove formed on the inner peripheral surface. The sealing member may be mounted in the groove.

The housing may have a filling port for filling the measuring chamber with the material, and a discharge port for discharging the material filled in the measuring chamber according to the movement of the piston. The filling port may be formed on the inner peripheral surface of the weighing chamber. The discharge port may be formed in a region farther from the piston chamber than the filling port. As a result, part of the material is less likely to stay in the region of the measuring chamber on the piston chamber side.

The measuring chamber may have irregularities formed on the inner peripheral surface thereof to change the movement of the material. As a result, when the material is moved within the measuring chamber by the reciprocating motion of the piston, an effect of stirring the material can be obtained, and the particles contained in the material can be easily maintained in a well-dispersed state.

A first valve that opens and closes the filling port, a second valve that opens and closes the discharge port, a drive source that reciprocates the piston, opening and closing timings of the first valve and the second valve, and a drive source. A control unit for controlling the driving of the may further be provided. The control unit drives the drive source in the direction in which the piston is retracted from the measurement chamber at the timing when the first valve is opened and the second valve is closed, and at the timing when the first valve is closed and the second valve is opened. , the driving source may be driven in the direction in which the piston advances into the measuring chamber. Thereby, a constant volume of material can be repeatedly discharged.

The piston may have a diameter of 1-30 mm and a gap of 2-5 mm.

The metering chamber may have a volume of 0.1-200 ml and a piston stroke of 1-300 mm.

The material may comprise particles with an average particle size of 1-100 μm and a viscosity of 5000-500000 CPS.

It should be noted that any combination of the above-described components, and conversion of the expressions of the present invention between methods, devices, systems, etc. are also effective as aspects of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the new dispenser which reduces wear of components can be provided.

It is a schematic diagram which shows schematic structure of the dispenser which concerns on a reference example. 2 is an enlarged view of area A in FIG. 1; FIG. It is a schematic diagram showing a schematic configuration of a dispenser according to the present embodiment. 4 is an enlarged view of the B area of FIG. 3; FIG. FIG. 4 is a schematic diagram for explaining the movement of each part of the dispenser when filling the weighing chamber with the material; FIG. 4 is a schematic diagram for explaining movements of parts of the dispenser when discharging material from the weighing chamber;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described based on embodiments with reference to the drawings. The same or equivalent constituent elements, members, and processes shown in each drawing are denoted by the same reference numerals, and duplication of description will be omitted as appropriate. Moreover, the embodiments are illustrative rather than limiting the invention, and not all features and combinations thereof described in the embodiments are necessarily essential to the invention. The dispenser according to the present embodiment is a device that repeatedly transfers a constant amount of fluid liquid containing dispersed powder particles based on a metering chamber change type volume metering (plunger pump) method.

First, the outline of the plunger pump will be explained. A plunger pump utilizes the volume change that occurs when a cylindrical piston (plunger) makes linear reciprocating motion through a seal (sealing part) inside a compartment (small room) in the pump housing. It is a device that moves the An advantage of this device is the ability to accurately and repeatedly dispense a given amount of material.

However, when the material to be metered is a particle dispersion such as solder/copper/silver paste or silica (silicon), wear at the contact points between the elements that make up the plunger pump can damage or break parts and seals. It has become clear that this is likely to occur. Therefore, the inventors of the present application have earnestly studied the reasons for this and arrived at the following considerations.

FIG. 1 is a schematic diagram showing a schematic configuration of a dispenser according to a reference example. FIG. 2 is an enlarged view of area A in FIG. The plunger pump 10 shown in FIG. 1 linearly reciprocates a piston 14 inside a cylindrical compartment 12 . An O-ring 16 for sealing between the outer peripheral surface 14a of the piston 14 and the inner peripheral surface 12a of the compartment 12 is mounted in an annular groove 14b formed in the outer peripheral surface 14a of the piston 14 .

In this state, the piston tip surface 14c and the seal surface 16a pushed out toward the compartment 12 by the driving force of the piston drive source are subjected to pressure equivalent to the stress generated by the piston drive source. Therefore, when the compartment 12 is filled with the particle dispersion 18 (fluid containing solid matter) and weighed, the solid particles 18b dispersed in the liquid binder 18a enter the seal surface 16a, and the O-ring 16 is broken. Considered to be damaged. Damage to the O-ring 16 leads to deterioration of the sealing performance, so frequent replacement of the O-ring 16 is required, which leads to deterioration of work efficiency.

Therefore, the inventors of the present application devised the following new dispenser in view of the phenomenon that causes damage to the O-ring. FIG. 3 is a schematic diagram showing a schematic configuration of a dispenser according to this embodiment. FIG. 4 is an enlarged view of area B in FIG.

The dispenser 20 shown in FIG. 3 includes a cylindrical piston 22, a cylindrical measuring chamber 24 filled with a liquid material containing particles, and a cylindrical piston chamber 26 in which the piston 22 projects into the measuring chamber 24 and reciprocates. and a sealing member 30 that seals between the inner peripheral surface 26 a of the piston chamber 26 and the piston 22 . The piston 22 reciprocates inside the metering chamber 24 . Further, the measuring chamber 24 has a gap G formed between the outer peripheral surface 22a of the protruding piston 22 and the inner peripheral surface 24a of the measuring chamber 24 . The diameter L1 of the piston 22 according to this embodiment is, for example, 1-30 mm, preferably 2-8 mm, and more preferably 3-6 mm. Also, the gap G is preferably 2 to 5 mm. The sealing member 30 is, for example, an O-ring or packing.

Thus, in the dispenser 20 according to the present embodiment, the gap G is formed between the outer peripheral surface 22a of the protruding piston 22 and the inner peripheral surface 24a of the measuring chamber 24, and the piston 20 is extruded into the measuring chamber 24. The pressure P2 applied to the gap G can be reduced more than the pressure P1 applied to the tip surface 22b of the piston 22. Therefore, the pressure applied to the sealing member 30 provided in the piston chamber 26 at the end of the gap G is also reduced, and particles are trapped between the sealing member 30 and the inner peripheral surface 26a of the piston chamber 26 and the piston 22. difficult to enter. As a result, the wear (wear) of the sealing member 30 and the piston 22 due to particles is reduced, and the increase in cost associated with parts replacement and device stoppage can be suppressed.

The housing 28 has an opening 32 through which the metering chamber 24 and the piston chamber 26 are connected. The inner diameter L2 of the opening 32 is smaller than the inner diameter L3 of the housing 28 . Thereby, the gap G between the piston 22 and the inner peripheral surface 24a of the measuring chamber 24 can be increased.

The piston chamber 26 has an annular groove 26b formed in the inner peripheral surface 26a. The sealing member 30 is an O-ring mounted in the groove 26b.

The housing 28 has a filling port 34 for filling the measuring chamber 24 with the material, and a discharge port 36 for discharging the material filled in the measuring chamber 24 according to the movement of the piston 22. . The filling port 34 is formed in the inner peripheral surface 24a of the weighing chamber 24. As shown in FIG. The discharge port 36 is formed in a region farther from the piston chamber 26 than the filling port 34 . As a result, part of the material is less likely to stay in the region of the measuring chamber 24 on the piston chamber 26 side.

The dispenser 20 also includes a first valve 38 for opening and closing the filling port 34, a second valve 40 for opening and closing the discharge port 36, a driving source 42 for reciprocating the piston 22, and the first valve 38. and a control unit 44 that controls the opening/closing timing of the first valve 38 and the drive of the drive source 42 .

Various types of actuators such as mechanical, pneumatic, and electromagnetic actuators can be used as the drive source 42 . The actuator may be a mechanism capable of repeatedly reciprocating the piston 22, and preferably has a mechanism capable of changing the stroke and stroke speed. More specifically, in the case of variable metering, a ball screw mechanism driven by a motor can be used. In the case of fixed metering, an air cylinder or the like may be used. Both methods improve the dispensing accuracy of liquid dispensing by increasing the repeatability of the stroke working distance. The stroke of the piston 22 according to this embodiment is, for example, 1 to 300 mm. Also, the number of strokes may be 5 times/s or less, more practically 2 times/s or less.

FIG. 5 is a schematic diagram for explaining the movement of each part of the dispenser when filling the weighing chamber with the material. FIG. 6 is a schematic diagram for explaining the movement of each part of the dispenser when the material is discharged from the weighing chamber.

As shown in FIG. 5, the control unit 44 drives the drive source 42 in the direction in which the piston 22 is retracted from the measurement chamber 24 at the timing when the first valve 38 is opened and the second valve 40 is closed. As a result, the material corresponding to the volume of the portion where the piston 22 is retracted flows into the measuring chamber 24 from the measuring chamber 24 . For example, if the cylindrical piston 22 has a diameter of 6 mm and the retracting stroke of the piston 22 is 10 mm, π×3×3×10 [mm ³ ]=0.28 ml of the material flows from the filling port 34 into the measuring chamber 24 . flow into

After that, as shown in FIG. 6, at the timing when the first valve 38 is closed and the second valve 40 is opened, the driving source 42 is driven in the direction in which the piston 22 advances into the measurement chamber 24 . As a result, the material corresponding to the volume of the portion where the piston 22 has advanced into the measuring chamber 24 flows out from the measuring chamber 24 . For example, if the cylindrical piston 22 has a diameter of 6 mm and a stroke of 10 mm when the piston 22 advances, π×3×3×10 [mm ³ ]=0.28 ml of material is discharged from the discharge port 36 to the outside. be done. In this way, by controlling the opening/closing timing of the first valve 38 and the second valve 40 and the advancing/retreating timing of the piston 22, a constant volume of material can be repeatedly discharged. The volume of the weighing chamber 24 can be appropriately selected depending on the application of the dispenser 20 and the type of material.

A material such as a particle dispersion liquid according to the present embodiment contains particles with an average particle size of 1 to 100 μm, and has a viscosity of 5000 to 500000 CPS. For example, various particle dispersions such as solder, gold paste, silver paste, copper paste, and sealing material used in the manufacture of electronic substrates, foods (dressings containing spices), and building material cement can be used in this embodiment. It can be such a material. Dispersion solvents (binders) for dispersing the particles include organic solvents, physiological saline, water, and the like.

As shown in FIG. 6, the weighing chamber 24 may have irregularities 46 formed on the inner peripheral surface 24a to change the movement of the material. As a result, when the material is moved within the measuring chamber 24 by the reciprocating motion of the piston 22, an effect of stirring the material can be obtained, and the particles contained in the material can be easily maintained in a well-dispersed state. The irregularities 46 can be, for example, annular protrusions, spiral protrusions, or randomly arranged protrusions. Alternatively, the inner peripheral surface 24a may be wavy unevenness 46 . The reason why such unevenness 46 is provided is that a gap G is provided between the piston 22 and the inner peripheral surface 24 a of the measuring chamber 24 .

In addition, since there is a gap G between the measuring chamber 24 and the piston 22, abrasion of the inner peripheral surface 24a of the measuring chamber 24 and the piston 22 due to the particle dispersion is reduced. Therefore, the housing 28 and the piston 22 can be selected from materials with relatively low hardness (for example, relatively inexpensive stainless steel). In addition, it becomes possible to omit processing such as surface coating and quenching for increasing hardness and wear resistance, thereby expanding options for low-cost materials. In addition, since there is no need to consider the contact between the inner peripheral surface 24a of the measuring chamber 24 and the piston 22, the machining accuracy required for each member may be low, leading to a reduction in machining costs.

Although the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments, and can be applied to any suitable combination or replacement of the configurations of the embodiments. It is included in the present invention. Further, it is also possible to appropriately rearrange the combinations and the order of processing in the embodiments based on the knowledge of a person skilled in the art, and to add modifications such as various design changes to the embodiments. Embodiments described may also fall within the scope of the present invention.

20 Dispenser 22 Piston 22a Outer peripheral surface 22b Tip surface 24 Measuring chamber 24a Inner peripheral surface 26 Piston chamber 26a Inner peripheral surface 26b Groove 28 Housing 30 Sealing member 32 Opening 34 Filling port 36 Discharge port 38 First valve 40 Second valve 42 Drive source 44 Control unit 46 Unevenness L1 diameter L2 inner diameter L3 inner diameter.

Claims (5)

a piston;
a housing having a columnar measuring chamber filled with a liquid material containing particles with an average particle diameter of 1 to 100 μm, and a piston chamber in which the piston protruding into the measuring chamber reciprocates;
A sealing member that seals between the inner peripheral surface of the piston chamber and the piston,
The piston reciprocates inside the measuring chamber,
a first gap is formed between the protruding outer peripheral surface of the piston and the inner peripheral surface of the measuring chamber ;
The housing includes an opening connecting the measuring chamber and the piston chamber, a filling port for filling the measuring chamber with the material, and a material filled in the measuring chamber according to the movement of the piston. and an ejection port through which is ejected,
The piston chamber has an annular groove formed on its inner peripheral surface, and a second gap into which the particles enter is formed between the outer peripheral surface of the piston and the inner peripheral surface of the piston chamber. and
The sealing member is mounted in the concave groove,
The filling port is formed on the inner peripheral surface of the measuring chamber within a stroke range of the piston,
The discharge port is formed in a region farther from the piston chamber than the filling port,
The inner diameter of the opening is smaller than the inner diameter of the measuring chamber,
The piston has a diameter of 1 to 30 mm,
The first gap is 2 to 5 mm,
A dispenser , wherein the particles are metal or ceramics . 2. The dispenser according to claim 1, wherein the measuring chamber has irregularities formed on the inner peripheral surface thereof to change the movement of the material. a first valve that opens and closes the filling port;
a second valve that opens and closes the discharge port;
a drive source for reciprocating the piston;
a control unit that controls opening/closing timings of the first valve and the second valve, and driving of the drive source;
The control unit
driving a drive source in a direction in which the piston is retracted from the measuring chamber at the timing when the first valve is opened and the second valve is closed;
3. The dispenser according to claim 1 , wherein the driving source is driven in the direction in which the piston advances to the measuring chamber at the timing when the first valve is closed and the second valve is opened. The measuring chamber has a volume of 0.1 to 200 ml,
A dispenser according to claim 1 or 2, characterized in that the stroke of said piston is 1-300 mm. A dispenser according to claim 1 or 2 , characterized in that said material has a viscosity of 5000-500000 CPS.

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