JPH0596630U - Diaphragm for oil pressure switch - Google Patents

Abstract

(57) [Summary] [Structure] The diaphragm A for an oil pressure switch includes a base cloth 1 and a rubber plate 2 in which the base cloth 1 is embedded. The base cloth 1 is formed by knitting a twisted yarn made of long fibers. Since the twisted yarn made of long fibers has excellent tensile strength, the yarn diameter can be reduced. [Effect] The base cloth 1 and the rubber plate 2 can be made thin, and the followability to changes in hydraulic pressure can be improved. It is possible to prevent fluffing of the end surface of the rubber plate 2, prevent deterioration of the rubber due to this, and improve durability.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a diaphragm of an oil pressure switch used as a switch for an oil warning light of an automobile or the like.

[0002]

[Prior Art]

 In automobiles and the like, when the oil pressure of engine oil drops below a predetermined value, the oil warning light is turned on to inform the driver of the abnormality. As an oil pressure switch that connects and disconnects the oil warning light, a diaphragm that is displaced according to the oil pressure of the engine oil is provided, and the energization is interrupted depending on whether the displacement of the diaphragm exceeds a predetermined amount. A diaphragm type oil pressure switch is generally used.

Conventionally, the above-mentioned diaphragm has been formed of fluororubber or the like in which a base fabric woven of threads is embedded.

[0004]

[Problems to be solved by the device]

However, the yarn forming the above-mentioned base cloth is usually a twisted yarn made of short fibers having a length of about 50 to 70 mm. As described above, it is necessary to increase the diameter of the twisted yarn made of short fibers in order to secure a predetermined tensile strength. For this reason, the thickness of the base cloth is increased (for example, about 0.25 to 0.27 mm), and the thickness of the entire diaphragm is increased. Therefore, the rigidity of the diaphragm becomes high and the followability to changes in hydraulic pressure deteriorates, and the operating pressure of the oil pressure switch fluctuates (for example, fluctuates in the range of 0.1 to 0.4 kg / cm ² ) and the sensitivity is There was a problem of getting worse.

Further, in the case of a twisted yarn of short fibers, there is also a problem that fluffing occurs due to the above short fibers on the end surface of the cut rubber, oil permeates from this fluffing portion, and the rubber is likely to swell and deteriorate. there were. It is an object of the present invention to solve the above technical problems and to realize a diaphragm for an oil pressure switch that is thin, has strength, has good followability to changes in hydraulic pressure, and has excellent durability.

[0006]

[Means for Solving the Problems]

 An oil pressure switch diaphragm according to claim 1 for achieving the above object is provided in an oil pressure switch that intermittently energizes in accordance with hydraulic pressure, and is reinforced in an oil pressure switch diaphragm that displaces in accordance with hydraulic pressure. It is made of a plate-shaped rubber plate including a base cloth for use in the above, and the base cloth is formed by knitting a twisted yarn made of long fibers.

[0007]

[Action]

 Since the twisted yarn forming the base fabric is made of long fibers, it is possible to secure a predetermined tensile strength even when the twisted yarn is made smaller in diameter than when the twisted yarn is made of short fibers. Therefore, it is possible to reduce the thickness of the entire rubber plate including the base fabric as well as the thickness of the base fabric, and it is possible to suppress the rigidity to be low while ensuring the strength. Since the rigidity is low, it has good followability to changes in hydraulic pressure.

Since the twisted yarn is composed of long fibers, it is difficult for the cut rubber plate to have fluffing due to the fibers on the end surface thereof, and therefore it is possible to prevent the deterioration of the rubber from the end surface due to the fluffing. ..

[0009]

【Example】

 Embodiments will be described in detail below with reference to the accompanying drawings. FIG. 1 shows a diaphragm A according to an embodiment of the present invention, and FIG. 2 is a sectional view of an essential part of an oil pressure switch B including the diaphragm A. With reference to FIG. 1, in this oil pressure switch, a diaphragm A includes a base cloth 1 and an annular rubber plate 2 in which the base cloth 1 is embedded.

The base cloth 1 is formed by knitting a twisted yarn made of long fibers such as aramid fibers. The base cloth 1 has the same strength as a conventional product with a thickness of about 0.25 to 0.27 mm. It is possible to exemplify those having a thickness of about 0.15 to 0.17 mm. The rubber plate 2 is made of fluororubber or the like. The rubber plate 2 has a thick and annular outer peripheral edge portion 2a and a similarly thick and annular inner peripheral edge portion 2b.

Referring to FIGS. 1 and 2, the outer peripheral edge portion 2 a of the rubber plate 2 forming the diaphragm A is sandwiched between the metal case 3 and the resin case 4 to be in a liquid-tight state. At the same time, one contact member 5 is liquid-tightly attached to the inner peripheral edge portion 2b of the rubber plate 2. The other contact member 6 is arranged below the one contact member 5. Both contact members 5 and 6 are arranged in series with the warning lamp 7 and the power source 8 via the lead wire, and the warning lamp 7 is turned on / off by contact / separation of the contact members 5 and 6.

The hydraulic pressure from the direction indicated by the hollow arrow in the drawing acts to push up the diaphragm A and the contact member 5 in the drawing upward, and conversely, the compression coil spring 9 moves the contact member 5 downward. I am urged. When the hydraulic pressure is larger than the pressing load applied by the compression coil spring 9, both contact members 5 and 6 are separated from each other. When the hydraulic pressure decreases, the compression coil spring 9 pushes the contact member 5 downward, The members 5, 6 are brought into contact.

According to this embodiment, since the twisted yarn constituting the base fabric 1 is made of long fibers, a predetermined tensile strength can be ensured even when the twisted yarn is made thinner than the case where the twisted yarn is made of short fibers. can do. Therefore, it is possible to reduce the thickness of the base cloth 1, and thus the thickness of the rubber plate 2 as a whole, and the rigidity can be suppressed to be low while the strength of the diaphragm A is secured. Since the rigidity is low, the ability to follow changes in hydraulic pressure is good, and the sensitivity of the oil pressure switch can be increased. In this example, the variation range of the operating pressure was 0.1 to 0.2 kg / cm ² , and the variation of the operating pressure could be about 1/3 of that of the conventional product.

Further, since the twisted yarn is made of long fibers, it is difficult for the cut rubber plate 2 to have fluffing due to the fibers on the end surface of the cut rubber plate 2. It is possible to prevent the deterioration of rubber. The present invention is not limited to the above embodiment, and various modifications may be made within the scope not changing the gist of the present invention, such as application to an oil pressure switch for hydraulic equipment other than automobiles. It is possible.

[0015]

[Effect of the device]

 As described above, according to the diaphragm for the oil pressure switch of the present invention, it is possible to reduce the diameter of the twisted yarn while ensuring a predetermined tensile strength.Thus, the base cloth and the rubber plate including the same can be made thin. The rigidity can be lowered. Since the rigidity is low, it can follow the change in hydraulic pressure well, and the sensitivity of the oil pressure switch can be improved. In addition, since fluffing due to fibers is unlikely to occur on the end surface of the rubber plate, it is difficult for oil to enter from the end surface, and durability can be improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a diaphragm for an oil pressure switch according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a schematic configuration of an oil pressure switch.

[Explanation of symbols]

 1 Base cloth 2 Rubber plate A Diaphragm B Oil pressure switch

Claims (1)

[Scope of utility model registration request] 1. A diaphragm for an oil pressure switch, which is provided in an oil pressure switch that is turned on and off according to hydraulic pressure and is displaced according to hydraulic pressure, is made of a rubber plate containing a reinforcing base fabric, and the base fabric is A diaphragm for an oil pressure switch, which is formed by knitting a twisted yarn made of long fibers.