JPS641726Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved high pressure switch for high fluid pressure applications in which pressure switches sense fluid pressure to open and close electrical signal circuits.

A pressure switch applies fluid pressure to one side of a pressure-responsive part such as a diaphragm, bellows, or pressure-sensitive reversing plate, and has a main shaft elastically pressed against the other side of the pressure-responsive part. When the spindle is displaced by action, it is common to open and close an electrical signal circuit through mechanical means.

As can be understood from the above, this type of pressure switch has mechanical components and electrical components, and appropriate materials are selected for these components. In particular, plastic is used for the electrical part, that is, the configuration of the switch chamber, because of its ability to provide suitable electrical insulation, and it is also selected in consideration of its characteristics of appropriate mechanical strength and moldability. There is. It is common to use metal materials for electrical circuit elements and elastic spring materials.

In pressure switches for high fluid pressures, for example up to 300 atmospheres, the mechanical strength of the elements constituting each part of the pressure switch and the selection of materials therefor are important issues.

As a pressure responsive part for high fluid pressure, it is advantageous to use a pressure responsive plate made of a stack of pressure sensitive reversal plates made of thin metal plates, since it also has the feature of rapid reversal at a predetermined pressure. When using the above-mentioned pressure-responsive plate, the plate itself absorbs the pressure, and the elastic spring for stabilizing the main shaft only needs to be used for the purpose of holding, so it can be constructed in a small and simple manner. .

The main shaft abuts against the back surface of the pressure-responsive plate, extends its other end into the switch chamber, and is elastically pressed by the elastic spring.

It is advantageous to use plastic with good electrical insulation for the electrical elements of the electrical circuit that opens and closes using the displacement of the main shaft as the operating source, but it is advantageous to use plastic with good electrical insulation. has a drawback in terms of mechanical strength, and as a result it has the disadvantage of requiring wall thickness and size.

In view of the above circumstances, it is an object of the present invention to provide a high pressure switch that is small, lightweight, has a simple structure, and has been improved to be suitable for use at high fluid pressures.

The basis of the pressure resistance of the pressure switch of the present invention is that a flat pressure-resistant part contacts the end face of a plastic cup-shaped switch case, and a skirt part extending from the periphery of the flat plate part wraps around the upper end of the switch case. The idea is to incorporate a metal pressure-resistant reinforcing plate around it.

Next, embodiments of the present invention will be described with reference to the drawings.

The pressure-responsive plate 3, which is constructed by laminating a required number of pressure-sensitive reversing plates made of thin metal plates, has a stopper plate 6 on the back side and a connecting cup 2 on the front side, and their peripheral edges are fixed by welding or the like. The above connection cup 2 is the connection pipe 1
A pressure chamber 2a is provided on the front surface of the pressure responsive plate 3. The stopper plate 6 is formed into a hollow shape in order to accommodate the reversal of the front bulge of the pressure responsive plate 3, and has a hole in its center so as to pass through the main shaft 8.

A metal pressure-resistant reinforcing plate 5 is disposed on the back side of the stopper plate 6 and between the switch case 9 and the switch case 9.
The pressure-resistant reinforcing plate 5 has a flat plate part 5a that comes into contact with the lower end surface of the switch case, and a skirt part 5b extending from the peripheral edge of the flat plate part 5a. It is wrapped around the outer circumferential surface and caulked tightly. Further, a screw portion is provided on the outer peripheral portion 5c of the pressure-resistant reinforcing plate 5, and the cylindrical portion 4a of the metal cap 4 is screwed into the outer cylindrical portion 4a.
The tip of a is crimped and tightly attached.

Note that the entire cylindrical portion 4a of the metal cap 4 may be crimped to the outer circumferential portion 5c without providing a screw portion on the outer circumferential portion 5c of the pressure-resistant reinforcing plate 5.

The metal cap 4 is fixed to the connection cup 2, the pressure-responsive plate 3, the stopper plate 6, and the pressure-resistant reinforcing plate 5. The pressure-resistant reinforcing plate 5 has an opening in the center and passes through the main shaft 8.

The switch case 9 is made of plastic and has a cup shape, and electrical signal terminals 11 and 12 are provided by penetrating the upper plate.
A fixed contact 14 is provided on the upper plate portion of the case 9 connected to the terminal 2, and a movable contact 13 is provided at the tip of an elastic spring 10 extending from the other terminal 11. The elastic spring 10 engages with the rear end surface of the main shaft 8, presses the main shaft 8 against the pressure-responsive plate 3, and elastically holds the main shaft 8.

The guide plate 7 is fitted and attached to the lower part of the switch case 9, and the skirt portion 5 of the pressure-resistant reinforcing plate 5 is
Coupled with the tightening from the outside by b, the connection of the entire pressure switch is strengthened. Above guide plate 7
has an appropriate thickness and has an opening in the center, through which the main shaft 8 is supported. An example is shown in which the pressure switch assembly described above is further housed in a plastic case 15.

In the above pressure switch, when the fluid pressure exceeds the elastic strength of the pressure responsive plate 3, the pressure responsive plate 3 is reversed. This reversal is completed instantaneously and its operation is reliable. The main shaft 8 is displaced by the reversal of the pressure-responsive plate 3, and this displacement pushes the elastic spring 10, causing the movable contact 13 to come into contact with the fixed contact 14.

When the fluid pressure decreases to a predetermined pressure, the pressure responsive plate 3 reverses again to displace the main shaft 8 forward, and the movable contact 13 opens.

In order to withstand use under high fluid pressure, especially considering the pressure-resistance reliability of the switch case 9, the metal case must be replaced by insulation processing. This is doable. However, there are significant disadvantages compared to the case where plastic materials could be used. In the present invention, by attaching the above-described pressure-resistant reinforcing plate 5, the advantages of plastic material can be fully utilized.

As described above, the present invention comprises a pressure responsive plate provided facing the pressure fluid, a metal cap housing a connecting cup provided on the front surface of the pressure responsive plate and a stopper plate provided on the back surface, and a metal cap that accommodates a fixed contact point. A pressure switch is constructed by stacking and connecting a switch case containing a guide plate that pivotally supports a main shaft that operates a movable contact with a metal pressure-resistant reinforcing plate interposed; one end of the main shaft is The pressure-resistant reinforcing plate is in contact with the back surface of the plate and passes through the stopper plate, the pressure-resistant reinforcing plate, and the guide plate so as to be freely movable back and forth, and the pressure-resistant reinforcing plate has its flat plate portion abutted against the end face of the switch case and extends from the periphery of the flat plate portion. The skirt portion is wrapped around the outer peripheral surface of the switch case and is in close contact with the switch case, and the metal cap is connected with its cylindrical portion to the outer peripheral surface of the metal pressure-resistant reinforcing plate. It has the advantage of being able to manufacture a high-pressure type pressure switch suitable for use with a simple structure, small size, and light weight.

[Brief explanation of the drawing]

The figure is a sectional view of an embodiment of the high pressure switch of the present invention. 3...Pressure responsive plate, 4...Metal cap, 5...
...Pressure reinforcing plate, 6...Stopper plate, 7...Guide plate, 8...Main shaft, 9...Switch case, 10
... Elastic spring, 11, 12 ... Terminal, 13 ... Movable contact, 14 ... Fixed contact.

Claims (1)

[Scope of utility model registration request] A metal cap that accommodates a pressure response plate provided facing the pressure fluid, a connection cup provided on the front side of the pressure response plate, and a stopper plate provided on the back side, and a main shaft that operates the movable contact relative to the fixed contact. A pressure switch is constructed by stacking and connecting a switch case containing a supporting guide plate with a metal pressure reinforcing plate interposed; one end of the main shaft is in contact with the back surface of the pressure responsive plate, and the stopper board,
The pressure-resistant reinforcing plate passes through a pressure-resistant reinforcing plate and a guide plate so as to be freely movable back and forth, and the flat plate portion of the pressure-resistant reinforcing plate abuts the end face of the switch case, and a skirt portion extending from the periphery of the flat plate portion touches the outer circumferential surface of the switch case. 1. A high-pressure pressure switch, characterized in that the metal cap is rotated in close contact with the metal cap and its cylindrical portion is connected to the outer circumferential surface of the metal pressure-resistant reinforcing plate.