JPH0356983Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Objective of the Invention] (Field of Industrial Application) The present invention relates to a diaphragm switch in which the airtight structure of a pressure chamber and a switch chamber partitioned by a diaphragm is improved.

(Prior Art) Conventionally, in a diaphragm switch, an annular seal ring is integrally formed on the outer periphery of a diaphragm, and this seal ring is held between an insulator and a body, which respectively constitute the main body of the diaphragm switch. The pressure chamber formed in the body is airtightly partitioned from the switch chamber formed in the insulator by a diaphragm, and the joint between the insulator and the body is hermetically closed using an O-ring. This is to prevent water from entering the switch room from outside.

(Problem to be solved by the invention) However, in the conventional configuration described above, an O-ring separate from the diaphragm is required to airtightly close the joint between the insulator and the body, which increases the number of parts and makes assembly difficult. The disadvantage was that the number of man-hours and parts management costs increased.

Accordingly, an object of the present invention is to provide a diaphragm switch that can reduce assembly man-hours and parts management costs.

[Structure of the invention] (Means for solving the problem) The present invention uses a fixed contact provided in the switch chamber on the outer periphery of a diaphragm that partitions the switch chamber provided in the insulator from the pressure chamber provided in the body. A first annular seal ring portion is provided between the outer periphery of the first seal ring portion and the end face of the body, and a second annular seal ring portion is provided on the outer periphery of the first seal ring portion via a thin wall portion. is integrally molded, and the second seal ring portion is sandwiched between the insulator and the end surface of the body.

(Function) According to the above means, the second seal ring portion for airtightly closing the joint between the insulator and the body is integrally provided outside the first seal ring portion provided on the outer periphery of the diaphragm. The number of parts is reduced compared to the conventional method using a diaphragm and a separate O-ring, and therefore the number of assembly steps and parts management costs can be reduced.

(Example) An example of the present invention will be described below with reference to the drawings. Reference numeral 1 denotes a plastic insulator with a connector part 2 integrally molded on the side thereof, a switch chamber 3 is recessed in the upper surface shown in the drawing, and a recess 4 communicating with the switch chamber 3 is formed in the lower surface shown in the drawing as will be described later. ing. Connection terminals 5 and 6 are insert-molded in the insulator 1, and are integrally formed with terminals 7 and 8 provided in the connector section 2. A ventilation hole 5a is formed in the connection terminal 5 to communicate the switch chamber 3 and the recess 4. Reference numeral 9 denotes a rubber stopper fitted into the recess 4, and a ventilation hole 9a formed approximately in the center of the plug so as to communicate with the switch chamber 3 via the ventilation hole 5a has air permeability and water repellency. Film 10 having
is pressed down by a cylindrical vent body 10a. This stopper 9 is covered with a waterproof and dustproof cover 11 from below in the figure. Further, a stepped portion 3a is provided at the opening edge of the switch chamber 3, and the outer peripheral portion of the annular fixed contact 12 is attached to this stepped portion 3a. 13 is a coil spring disposed between the fixed contact 12 and the connection terminal 6.
14 is a plastic body in which a pressure chamber 15 is formed;
is integrated into the insulator 1 by engaging with an engagement flange 17 provided on the insulator 1. 18 is switch chamber 3 and pressure chamber 15
An annular first seal ring portion 19 is provided on the outer periphery of the diaphragm, and a thin wall portion 20 is provided on the outer periphery of the first seal ring portion 19.
A second annular seal ring portion 21 is provided via the annular second seal ring portion 21 . And the first seal ring part 19
is sandwiched between the outer circumferential portion of the fixed contact 12 and the end surface of the body 14, and the fixed contact 12 is held by this first seal ring portion 19. The second seal ring portion 21 is held between the insulator 1 and the end face of the body 14, and the second seal ring portion 21 allows water to flow into the switch chamber 3 from the joint between the insulator 1 and the body 7. Prevents intrusion. That is, the second seal ring portion 21 hermetically closes the switch chamber 3 and the pressure chamber 15 from the outside. 2
2 is a hole 1 provided in the center of the diaphragm 18
The diaphragm 18 is inserted through the diaphragm 8a.
A movable contact 23 shown by a solid line in FIG. 1 is attached to a small-diameter portion 22a formed in the switch chamber 3, and this movable contact 23 is attached to a fixed contact from below as shown in the figure. It is facing 12. 24 is a coil spring disposed between the movable contact 23 and the connection terminal 5. On the other hand, 22b is a spring receiving part formed in the pressure chamber 15 of the contact holder 22, and a coil spring 26 is disposed between this and a spring plate 25 disposed in the pressure chamber 15. Reference numeral 27 denotes an adjustment screw screwed into a screw hole 28 of the body 14, and by screwing this screw forward and backward, the spring plate 25 can be moved in the vertical direction in the drawing to adjust the spring force of the coil spring 26 acting on the diaphragm 18. ing. In addition, 29 is a fluid packing filled in the screw hole 28 after adjustment of the adjustment screw 27, 30 is a connecting cylinder communicating with the pressure chamber 15,
A tube (not shown) communicating with a pressure source is connected to this.

When the pressure of the pressure source decreases and the pressure inside the pressure chamber 15 becomes negative, the diaphragm 18 is displaced together with the contact holder 22 in the direction toward the pressure chamber 15 against the spring force of the coil spring 26. Accordingly, the movable contact 23 comes into contact with the fixed contact 12 due to the spring force of the coil spring 24, and the diaphragm switch is closed.

According to the above configuration, the first and second seal ring parts 19 and 21 are integrally formed on the outer circumference of the diaphragm 18.
The first seal ring part 19 holds the fixed contact 12, and the second seal ring part 21 seals the switch chamber 3 and the pressure chamber 15.
Since it is closed from the outside, there is no need for an O-ring, which was conventionally provided separately, and the number of parts is reduced, thereby reducing assembly man-hours and parts management costs.

Furthermore, since the first seal ring part 19 and the second seal ring part 21 are integrally molded with the thin wall part 20 in between, the outer peripheral part of the fixed contact 12 and the second seal ring part 19 are in pressure contact with each other. Even if there is a step between the end surface of the insulator 1 and the end surface of the insulator 1 to which the first seal ring portion 21 comes into pressure contact due to manufacturing dimensional errors, the step is absorbed by the thin wall portion 20 and the first seal ring portion 19 is fixed. The second seal ring portion 21 is in close contact with the outer periphery of the contact 12 and the end face of the insulator 1, so that the sealing properties of the respective seal ring portions 19 and 21 are maintained well.

Note that, instead of the movable contact 23, a movable contact 31 shown by a broken line in FIG. 1 may be provided so that it is separated from the fixed contact 12 and turned off when the pressure inside the pressure chamber 15 becomes negative pressure.

[Effects of the invention] As is clear from the above explanation, the present invention integrally molds the second seal ring part on the outer periphery of the first seal ring part provided on the outer periphery of the diaphragm, which is not necessary in the conventional structure. It is possible to eliminate the need for a separate O-ring and reduce the number of parts, which has the excellent effect of reducing assembly man-hours and parts management costs.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a longitudinal sectional side view, FIG. 2 is a side view, and FIG. 3 is a side view seen from a different direction from FIG. 2. In the figure, 1 is an insulator, 3 is a switch chamber,
12 is a fixed contact, 14 is a body, 15 is a pressure chamber, 18 is a diaphragm, 19 is a first seal ring portion, 20 is a thin wall portion, 21 is a second seal ring portion, and 23 is a movable contact.

Claims (1)

[Scope of utility model registration request] an insulator having a switch chamber; a body having a pressure chamber communicating with a pressure source; a fixed contact provided within the switch chamber and having an outer peripheral portion attached to the opening edge of the switch chamber; a diaphragm disposed between the insulator and the body so as to partition the body; and the fixed contact, which is integrally molded on the outer periphery of the diaphragm and is sandwiched between the outer periphery of the fixed contact and the end surface of the body. The switch chamber and the pressure chamber are held between an annular first seal ring portion that holds the insulator and the end surfaces of the insulator and the body that are integrally molded on the outer peripheral portion of the first seal ring portion. A diaphragm comprising: an annular second seal ring portion that is airtightly closed from the outside; and a movable contact disposed within the switch chamber so as to move toward and away from the fixed contact in response to displacement of the diaphragm. Switch.