JP2002270061A - Switch member - Google Patents

Abstract

(57) [Problem] To provide a novel switch member which has excellent performance and can be obtained at low cost. SOLUTION: In a switch member 1 comprising a cord cover 3 for accommodating a cord switch 2 and a base part 4 to which the cord cover 3 is attached, the cord cover 3 is formed of thermoplastic urethane rubber, and the base part 4 is formed. Is formed from a thermoplastic rubber such as a thermoplastic olefin rubber. This makes it possible to exhibit properties equal to or higher than those of a conventional crosslinked rubber and to eliminate the need for a cumbersome crosslinking step or molding process as in the case of a crosslinked rubber, so that it can be obtained easily and at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch member as one of safety mechanisms provided in an automatic opening / closing mechanism such as a store door or a garage shutter.

[0002]

2. Description of the Related Art Conventionally, many doors and garage shutters of a store, glass windows of automobiles, and the like are provided with an automatic opening and closing mechanism for automatically opening and closing them.

[0003] These automatic opening / closing mechanisms are designed to automatically operate opening / closing equipment such as a motor by detecting the presence of a human by a sensor or the like or by remote control. In general, a safety mechanism such as a pressure-sensitive sensor is provided in order to prevent a pinching accident or the like caused by a switch member. One of the safety mechanisms is a switch member 1 as shown in FIG.
Has been adopted.

As shown in the figure, a switch member 1 includes a cord switch 2 having a pair of cord-shaped conductive members 2b, 2b at a predetermined interval on the inner surface of a tubular insulator 2a, And a base portion 4 for attaching the code cover 3 to a mounting portion such as a shutter or a door. The base portion 4 is, for example, an end portion of the shutter. When a certain amount of pressure is applied to the cord switch 2 in the cord cover 3 when a person or an object is caught and the cord switch 2 is closed when these are closed, the conductive members 2b inside the cord switch 2 are connected to each other. It comes into contact with electricity,
In this way, the operation of the opening / closing device for driving the shutter or the like is stopped or caused to recoil so as to prevent a trapped accident from occurring.

The cord switch 2 housed in the cord cover 3 has a circular cross section as shown in FIG. 5, and four conductive members 2b, 2b, 2b, 2b are arranged at equal intervals. There has been proposed a sensor which can reliably detect not only the pressure in the opening and closing direction but also the pressure in an oblique direction. Further, as the base portion 4 to which the code cover 3 is attached, in addition to a base having a rectangular cross section in order to stick and fix along an edge portion surface of a shutter or a door, the edge portion is fitted as shown in FIG. Various shapes have been proposed according to the form of the mounting portion, such as those having the groove 5 and the like.

[0006]

By the way, in such a conventional switch member 1, each constituent member, that is, the insulator 2a of the cord switch 2, the cord cover 3,
The base portion 4 is generally formed of a crosslinked rubber such as ethylene propylene rubber or chloroprene rubber, which is excellent in shock absorption and resilience and has a low material cost.

However, these cross-linked rubbers must be extruded into a predetermined shape and then subjected to a cross-linking step. In addition, when a mounting portion such as a shutter is bent, the cross-linked rubber is bent in accordance with the shape. Since molding must be performed again after crosslinking to impart a habit, there is an inconvenience that labor and cost are required in manufacturing.

On the other hand, as described above, the switch using four conductive members 2b, 2b, 2b, 2b as the code switch 2 housed in the code cover 3 is only for the pressure from the opening / closing direction of the shutter or the like. However, it is possible to reliably detect the pressure from an oblique direction. However, since a large amount of the expensive conductive member 2b is used,
There is a disadvantage that the cost is higher than that of a pair of conductive members 2b, 2b.

Furthermore, since these crosslinked rubbers are difficult to reuse, there is also a disadvantage that when they reach the end of their life, they remain in large quantities as waste.

Accordingly, the present invention has been devised in order to effectively solve such a problem, and an object of the present invention is to provide a novel switch member which has excellent performance and can be obtained at low cost. Is provided.

[0011]

According to the present invention, there is provided a switch comprising a cord cover for accommodating a cord switch and a base for mounting the cord cover. In the member, the cord cover is made of thermoplastic urethane rubber,
The base is made of a thermoplastic rubber other than a thermoplastic urethane rubber such as a thermoplastic olefin rubber or a thermoplastic styrene rubber.

As a result, it is possible to exhibit characteristics equal to or higher than those of the conventional crosslinked rubber, and it is not necessary to perform a troublesome cross-linking step or molding process as in the case of the crosslinked rubber.

According to a third aspect of the present invention, the thermoplastic urethane rubber constituting the cord cover has a rubber hardness of 60 to 90, and the thermoplastic rubber constituting the base has a rubber hardness of 60 to 60. By setting to ~ 95,
The characteristics required for the switch member can be exhibited in a well-balanced manner.

According to a fifth aspect of the present invention, the cord switch comprises a tubular insulator and at least one pair of conductive members held on the inner surface of the insulator. By arranging the inner surface in a spiral shape at regular intervals, it is possible to reliably detect not only the opening / closing direction of a shutter or the like to which it is attached but also oblique or lateral pressure.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a switch member 1 according to the present invention. As in the prior art, a cord switch 2, a cord cover 3 for accommodating the same, and the cord cover 3 are attached. It is mainly composed of a base 4.

The cord switch 2 has a pair of cord-shaped conductive members 2b, 2b housed in a tube-shaped insulator 2a having a rectangular cross section so as to face each other at a predetermined interval. In addition, when the insulator 2a is pressurized and crushed, the conductive members 2b and 2b come into contact with each other to be in an energized state. As shown in FIG. 3, the conductive members 2b, 2b are arranged spirally at regular intervals along the inner surface of the insulator 2a.

The cord cover 3 is formed as a hollow tube having a rectangular cross section. The cord switch 2 is inserted into and accommodated in the hollow portion of the tube.
The cord switch 2 is effectively protected from direct contact with moisture, dust and the like.

The base portion 4 is formed in the shape of a solid square member having a rectangular cross section. The code cover 3 accommodating the code switch 2 is integrally attached and supported on the upper surface thereof, and is automatically opened and closed. It is designed to be attached to the shutter or door edge.

In the switch member 1 of the present invention having such a configuration, the cord cover 3 is made of thermoplastic urethane rubber, and the base portion 4 is made of thermoplastic rubber other than thermoplastic urethane rubber. For example, it is composed of thermoplastic olefin rubber or thermoplastic styrene rubber.

That is, the thermoplastic urethane rubber has good impact absorption and durability, and has a small compression set to some extent. Therefore, the material of the cord cover 3 is equal to or more than that of the conventional crosslinked rubber. It does not require a troublesome cross-linking step unlike conventional cross-linked rubber. In addition, this thermoplastic urethane rubber can be easily deformed according to its shape only by heating, even when the mounting portion such as a shutter is bent, so that it is not crosslinked after crosslinking, as in a conventional crosslinked rubber. There is no need for such a troublesome process that molding and the like must be performed again to impart a bending habit.

On the other hand, thermoplastic rubbers such as thermoplastic olefin rubber and thermoplastic styrene rubber constituting the base portion 4 are also used.
It has a shock absorption and durability similar to that of the thermoplastic urethane rubber, has a small compression set, and has an appropriate strength to be fixed to a mounting part such as a shutter. In addition to exhibiting properties equal to or higher than those of conventional crosslinked rubber, it does not require a cumbersome crosslinking step as in conventional crosslinked rubber.

Here, the hardness of the thermoplastic urethane rubber forming the cord cover 3 varies depending on the application case, but generally, the hardness is preferably in the range of 60 to 90. That is, if the rubber hardness exceeds 90, the cord switch 2 becomes too hard and is hardly deformed even when pressure is applied from the outside, so that the reactivity of the cord switch 2 is impaired. Is technically difficult, and the range of 65 to 85 is optimal.

The rubber hardness of the thermoplastic rubber forming the base portion 4 also varies depending on the application case, but in general, a range of 60 to 95 is appropriate. The reason is,
If the rubber hardness exceeds 95, the rubber becomes too hard and loses rubber-like properties, resulting in impaired shock absorption and durability. In addition, it is technically difficult to produce rubber having a rubber hardness of 60 or less. More specifically, when the rubber cover 3 is bent and attached, 60 to 70
It is desirable to have a rubber hardness as low as possible, and it is desirable to have a rubber hardness as high as about 80 to 95 in order to secure a certain level of strength in the case where an impact is applied.
Further, when both performances are obtained in a well-balanced manner, 70
It is desirable to have a rubber hardness of about 80.

As described above, in the switch member 1 of the present invention, the cord cover 3 is formed of thermoplastic urethane rubber, and the base portion 4 is formed of thermoplastic rubber such as thermoplastic olefin rubber or thermoplastic styrene rubber. Therefore, it is possible to produce easily and at low cost, because it is possible to exhibit the same or better characteristics as the conventional crosslinked rubber, and it is not necessary to perform a cumbersome crosslinking step or mold processing such as a crosslinked rubber.

The cord cover 3 is made of thermoplastic urethane rubber, and the base portion 4 is made of thermoplastic rubber such as thermoplastic olefin rubber or thermoplastic styrene rubber. It can reduce the amount of waste and contribute to the effective use of resources.

Further, as shown in FIG. 3, the conductive members 2b, 2b of the cord switch 2 are formed into a tubular insulator 2a.
2 is arranged spirally while maintaining a constant gap therein, as shown in FIG. 2, generally without using a large number of expensive conductive members 2b, not only in the opening / closing direction of a shutter or the like, but also in a diagonal or lateral direction. It is possible to reliably detect the pressure, and the pressure reactivity can be improved at low cost.

The base portion 4 itself may be formed of thermoplastic urethane rubber as in the case of the cord cover 3, but this thermoplastic urethane rubber is considerably more expensive than other thermoplastic rubbers at present. In addition, since the base 4 itself uses a larger amount of material than the cord cover 3, it is not appropriate in view of cost.

In the present embodiment, the cord switch 2 and the rubber cover 3 for accommodating the cord switch 2 have been described as having a rectangular cross section. However, the present invention can also be applied to a circular switch having a circular cross section as shown in FIG. Further, the number of the code switches 2 may be one or more as shown in FIG. Further, in addition to the form in which the base portion 4 is adhered and fixed to the edge of a shutter or a door, etc., a groove 5 is formed as shown in FIG. It may be a form that can be attached with.

Further, the cord cover 3 and the base 4
As a method for producing the above, extrusion molding by an extruder is generally used, but when there is a bent portion or the like, molding by injection or the like may be used.

[0031]

EXAMPLES (Example 1) As a material of the cord cover 3,
Rubber hardness 8 manufactured by Takeda Birdish Urethane Industry Co., Ltd.
This is extruded at a temperature of 190 ° C. using a 28 mm extruder (L / D = 20) while using thermoplastic urethane having a rubber hardness of 85 manufactured by Mitsubishi Chemical Corporation as a base 4. Styrene rubber (Lavalon SE844
B.N) and this was extruded with a 50 mm extruder (L / D = 25)
And extruded at a temperature of 200 ° C. to simultaneously form two layers of the cord cover 3 and the base part 4 with a length of 1 m. A switch member 1 having a shape was formed.

The cord cover 3 of the switch member 1 was repeatedly hit at a temperature of 80 ° C. with a rod having a diameter of 4 mm at a force of 160 N at an interval of once every 2 seconds to perform an impact durability test. After the rotation, the state of the cord cover 3 was visually checked, and the impact durability was evaluated. (Example 2) Rubber hardness 7 manufactured by Nippon Milactran Co., Ltd.
In addition to using the thermoplastic urethane (Milactran E675MNAT) of No. 4 as a material of the code cover 3, a thermoplastic olefin rubber (Milastomer 9020N) with a rubber hardness of 90 manufactured by Mitsui Chemicals, Inc. was used as the material of the base part 4 shown in FIG. The cord cover 3 is connected to a 30 mm extruder (L / D = 2
0), at a temperature of 195 ° C., and a base 4 with a 40 mm extruder (L / D = 25) at a temperature of 200 ° C. and a length of 1 m.
After simultaneously extruding the layers, the code switch 2 was accommodated in the code cover 3 to form a switch member 1 having a circular cross section as shown in FIG.

The switch member 1 was subjected to a hitting durability test in the same manner as in Example 1 to evaluate the hitting durability. On the other hand, the cord cover 3 was preheated to 80.degree. A part of the cord cover 3 is fitted into a bent metal frame having a radius of 20 mm, the metal frame is sandwiched in a 70-ton press at a temperature of 180 ° C. for 20 seconds, heat is applied, and then cooled to 50 ° C. The state of the bent portion was visually evaluated. (Comparative Example 1) Thermoplastic urethane (Elastollan ET88) with a rubber hardness of 80 manufactured by Takeda Birdish Urethane Industry Co., Ltd.
After extruding one layer at 50 ° C. using a 50 mm extruder at a temperature of 190 ° C., the code switch 2 is housed in the code cover 3 to form a switch member 1 having a rectangular cross section as shown in FIG. Then, the impact durability was evaluated by the same test method as in Example 1. (Comparative Example 2) Thermoplastic styrene butadiene rubber (Sumitomo TPE-SB2710) having a rubber hardness of 75 manufactured by Sumitomo Chemical Co., Ltd. was used as a material of the cord cover 3 and the base portion 4. After extruding one layer at 190 ° C., the cord switch 2
To form a switch member 1 having a rectangular cross-section as shown in FIG. 1, and thereafter, the impact durability was evaluated by the same test method as in Example 1. (Comparative Example 3) 40 m of EPDM having the composition shown in Table 1 below was used.
After extruding at 105 ° C. with an extruder (L / D = 15) to produce an unvulcanized tube, the tube was vulcanized by a UHF (5 kw belt type) -HA continuous crosslinking line, and FIG. A code cover 3 of the type shown in FIG.
And the durability to impact was evaluated by the same test method as in Example 1.

The cord cover 3 was bent in the same manner as in Example 2, and the state of the bent portion was visually evaluated.

[0035]

[Table 1]

(Comparative Example 4) In order to bend the cord cover 3 obtained in Comparative Example 3, the radius 2 was preheated to 60 ° C.
A part of the code cover 3 is fitted into a mold metal frame having a bent shape of 0 mm, 2 g of the compounded rubber shown in Table 2 below is weighed and put into the metal frame, and the metal frame is heated to 80 ° C. 70 tons. The mold portion was vulcanized by leaving it for 10 minutes without pressing, and the state of the bent portion was visually evaluated.

[0037]

[Table 2]

Table 3 below shows the evaluation results of Examples 1 and 2 and Comparative Examples 1 to 4.

[0039]

[Table 3]

As can be seen from this table, Examples 1 and 2 according to the present invention were both excellent in impact strength, bending workability and bending part formation state (the bending part was properly formed with a radius of 20 mm). ) Was good. In addition, in each of these examples, the material cost was low and the vulcanization step was not required, so that it was possible to easily manufacture it at low cost.

On the other hand, the code cover 3 and the base 4
Each of Comparative Examples 1 and 2 made of thermoplastic urethane rubber exhibited excellent impact strength as in Examples 1 and 2, but the material cost was high and the cost was disadvantageous. Was.

In the case of Comparative Example 2 in which a thermoplastic rubber other than the thermoplastic urethane rubber was used as the cord cover 3, the material cost was reduced, but cracks occurred in the cord cover 3 after the impact test. The impact strength was poor.

In Comparative Example 3 using the vulcanized rubber, the impact strength and the material cost were good.
The radius of the bent part after bending is 10
It spread to 0 mm, and the bent part formed state deteriorated. On the other hand, in Comparative Example 4 using the rubber compounded with the mold, the bent portion was formed in a good condition, but the bending property was poor. In addition, all of Comparative Examples 3 and 4 had to go through a cumbersome vulcanization step, and required a lot of time for production.

[0044]

In summary, according to the present invention, the cord cover accommodating the cord switch is formed of thermoplastic urethane rubber, and the base for fixing the cord cover is formed of thermoplastic rubber. In addition to exhibiting the same or better characteristics as cross-linked rubber, it also eliminates the need for complicated cross-linking steps and mold processing such as cross-linked rubber, so it exhibits excellent effects such as easy and low-cost production. Can be.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a switch member according to the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the switch member according to the present invention.

FIG. 3 is a longitudinal sectional view showing another embodiment of the switch member according to the present invention.

FIG. 4 is a partially cutaway perspective view showing an example of a conventional switch member.

FIG. 5 is a partially cutaway perspective view showing an example of a conventional switch member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Switch member 2 Code switch 2a Insulator 2b Conductive member 3 Code cover 4 Base part 5 Groove

Claims (5)

[Claims] 1. A switch member comprising a cord cover for accommodating a cord switch and a base for mounting the cord cover, wherein the cord cover is made of thermoplastic urethane rubber and the base is made of thermoplastic rubber. A switch member characterized by the above-mentioned. 2. The switch member according to claim 1, wherein the thermoplastic rubber forming the base portion is a thermoplastic olefin rubber or a thermoplastic styrene rubber. 3. The switch member according to claim 1, wherein the thermoplastic urethane rubber constituting the cord cover has a rubber hardness of 60 to 90. 4. The thermoplastic rubber constituting the base portion has a rubber hardness of 60 to 95.
4. The switch member according to any one of 3. 5. The cord switch includes a tubular insulator, and a pair of conductive members held on an inner surface of the insulator, and the conductive members are spaced apart from each other on the inner surface of the insulator. The switch member according to any one of claims 1 to 4, wherein the switch member is arranged in a spiral shape.