JPH0136264Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a pressure switch equipped with a ventilation mechanism.

(Prior art) A diaphragm pressure switch is, for example, disclosed in Japanese Patent Application Laid-open No. 51
- As described in Publication No. 87084, by attaching a film that allows only external gas to pass through the through hole communicating with the switch chamber, the switch chamber is brought to outside pressure and the diaphragm is operated by pressure sensing without gas compression. I can't find a pressure switch that would cause this.

(Problem to be solved by the invention/Objective of the invention) This invention is equipped with a movable contact and a fixed contact, and prevents water and mud from entering the switch chamber, which is normally sealed with a diaphragm. In addition to preventing defects, by attaching a film that allows only outside air to pass through the through hole formed in the pressure adjustment screw, ventilation is free and the outside pressure is maintained inside the switch chamber, allowing the diaphragm to operate normally. The object of this invention is to provide a ventilation mechanism that has a simple structure and is easy to assemble.

(Means for Solving the Problems) The present invention meets the above-mentioned objectives, and includes a body 1 provided with a pressure fluid inlet beak 3, an insulator fitted and fixed to the body 1, a diaphragm 8 whose peripheral edge is sandwiched and fixed between the body 1 and the insulator;
A pressure regulating screw 25 is provided which is screwed into the screw hole 14 of the insulator, a closed switch chamber 15 corresponding to the inner surface of the diaphragm 8 is provided, and one end of the pressure regulating screw 25 is provided in the switch chamber 15. A pressure regulating spring 27 is applied between the screw 25 and a sliding rod 19 whose other end corresponds to the inner surface of the diaphragm 8, and a movable contact is moved by the sliding rod 19 which is linked to the distortion of the diaphragm due to the pressure fluid. 21 and a fixed contact 17 are arranged, one end of the movable contact 21 is exposed in the switch chamber 15, and the other end is exposed to the atmosphere.An axial through hole 31 is formed in the pressure regulating screw 25. A through hole 31 that communicates between the switch chamber 15 of the pressure switch and the outside is provided in the through hole 31, and a film 34 that selectively allows only gas to pass through is attached to the through hole. The present invention relates to a pressure switch equipped with a ventilation mechanism that allows ventilation of the pressure switch 15 with the outside.

(Embodiment) A preferred embodiment of the present invention will be described with reference to the accompanying drawings.

In the figure, 1 is a body provided with a pressure inlet beak 3 with a mounting screw 4 cut on its outer periphery, and has a cylindrical case portion 2. The inner ring 5, which is a part of the insulator, and the insulators 6 and 7 are sequentially fitted into the case part 2, and the edges of the case part 2 are bent inward and caulked to connect the inner ring to the inner ring of the body 1. 5
The peripheral edge of the diaphragm 8 is sandwiched and fixed between them, and an inner plate 9 with a protrusion 10 protruding from the center is applied to the inner surface of the inner ring 5, so that the protrusion 10 is joined to the inner surface of the diaphragm 8. The insulator 6 is cylindrical and has an inwardly projecting ring 1 above it.
1 is provided to engage the engagement shoulder 12 of the insulator 7. The insulator 7 is roughly in the shape of a lid, and has a sliding hole 13 with a part of it as a screw hole 14 above its center, and the insulators 6 and 7 connect to the upper part of the inner plate 9. A switch chamber 15 is formed. In the switch chamber, both ends of the pressure spring 16 are hung between the protrusion ring 11 and the inner plate 9, and a rod-shaped fixed contact 17 and a spring hook 18 are protruded from symmetrical positions from the insulator 7 into the switch chamber 15. A movable contact 21 corresponding to the fixed contact 17 is mounted on an arm 20 fitted to a sliding rod 19 whose upper portion is slidably fitted into a movable hole 13 and whose lower end is pressed against the inner plate 9. A spring 22 connected to one end of the spring 22 is hung on the spring hanging piece 18. An insulator 23 made of resin is filled in the recessed part of the upper surface of the insulator 7 to make it flat, and a cylindrical enclosure 24 is provided around the upper part of the sliding hole 13. In addition, a head 26 is provided in the screw hole 14 of the sliding hole 13 from the outside of the tail end of the insulator 7, and a pressure regulating screw 25, which has one end exposed to the switch chamber 15 and the other end exposed to the atmosphere, is screwed into the screw hole 14 of the sliding hole 13. Then, a pressure regulating spring 27 is applied to the inner end of the screw 25 and the upper end of the sliding rod 19. The pressure regulating spring 27 acts on the movable contact 21 via the sliding rod 19.

In addition, 28 is a cord for connecting to the fixed contact 17 and the movable contact 21 or a lead wire, and 29 is a rubber cover.

In this embodiment, in the pressure switch illustrated above, a through hole 31 is provided in the center of the pressure regulating screw 25 to communicate the switch chamber 15 with the outside air, and an enlarged diameter hole 32 is formed in the head 26. A tetrafluoroethylene film (or a film of the same nature) that selectively allows only air to pass through the enlarged diameter hole 32 is stretched, a rubber washer 35 is placed on top of the film, and a pressing piece 33 is attached to the head 26.
Bend and fix. The outside air passing through the film 34 enters the switch chamber 15 through the through hole 31 and the gap between the sliding rod 19 and the through hole 13.

(Effects) As is clear from the above description, the present invention has the following effects:
A through hole 31 is provided in the pressure regulating screw 25 that communicates from the outside of the pressure switch to the internal sealed switch chamber, and a film 34, such as tetrafluoroethylene film, that selectively allows only air to pass through is provided in the through hole 31. With this configuration, the switch chamber 15 can always be kept at the external pressure to allow the diaphragm 8 to operate normally, and water and mud can be prevented from entering the switch chamber 15, thereby preventing poor contact between the contacts. Furthermore, since the film is attached to the through hole of the pressure regulating screw that communicates the outside air and the switch chamber, there is no need to provide a special passage in the body or insulator. It can be assembled into
This has the effect of making it easier to attach the film.

[Brief explanation of the drawing]

The accompanying drawings show one embodiment of the present invention, in which FIG. 1 is a longitudinal sectional front view, and FIG. 2 is a perspective view of a portion of FIG. 1. 1... Body, 3... Pressure inlet beak, 5... Inner ring, 6, 7... Insulator, 8... Diaphragm, 15... Switch chamber, 17... Fixed contact,
19...Sliding rod, 21...Movable contact, 25...Pressure adjustment screw, 27...Pressure adjustment spring, 34...Film.

Claims (1)

[Scope of utility model registration request] It consists of a body 1 provided with a pressure fluid inlet beak 3, an insulator fitted and fixed to the body 1, and a diaphragm 8 whose peripheral edge is sandwiched and fixed between the body 1 and the insulator. A pressure regulating screw 25 is provided which is screwed into the screw hole 14, and a sealed switch chamber 15 corresponding to the inner surface of the diaphragm 8 is provided. A sliding rod 19 is provided with a spring 27 applied thereto, the other end of which corresponds to the inner surface of the diaphragm 8, and a movable contact 21 is moved by the sliding rod 19 which is linked to distortion of the diaphragm 8 due to pressure fluid, and a fixed contact 17. are arranged, and one end is the switch chamber 15.
A through hole 31 in the axial direction is formed in the pressure regulating screw 25, the other end of which is exposed to the inside and the other end is exposed to the atmosphere, and a film 34 that selectively allows only gas to pass is attached to the through hole. A pressure switch equipped with a ventilation mechanism, characterized in that the switch chamber 15 is vented to the outside.