JPH0355225Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention is a pressure switch that is installed in a limited area, such as an automobile air conditioner, and is a type of switch that operates depending on high and low pressures. Regarding.

(Prior Art) A conventional pressure switch with two stages of high and low pressure operation has two sets of springs for high pressure and low pressure, as shown in FIG. A built-in structure is adopted, and in this structure,
When adjusting the high pressure after adjusting the low pressure by adjusting the spring, the low pressure adjustment value may shift, and it is difficult to provide an adjustment mechanism such as a screw to adjust the high and low pressure, making the structure complicated and requiring a large number of assembly steps. However, there were problems in that the installation space was large and the size was large.

Therefore, as shown in Fig. 7 of the above-mentioned Japanese Patent Application Laid-Open No. 1983-1983, a single spring is used to respond to high and low pressures, instead of using two sets of springs for high and low pressures. Although such a structure is also known, this structure has the problem that high and low pressure cannot be adjusted.

The present invention was developed in view of the above-mentioned problems, and provides a pressure switch that has a simple structure with two-stage operation of high and low pressures, is easy to adjust high and low pressures, can be constructed compactly, and can be installed even in narrow places. It is something to do.

[Structure of the idea]

(Means for Solving the Problems) The pressure switch of the present invention includes a case 2 having a pressure detection opening 1 at one end, and a case 2 installed in the case 2 facing the pressure detection opening 1. A diaphragm 5 that forms a pressure chamber 3 on the side of the pressure detection opening 1 and a switch chamber 4 on the opposite side, and a first piston that is provided in the switch chamber 4 so as to be able to move forward and backward and that comes into contact with the diaphragm 5. 6, a second piston 7 that is fitted concentrically with the first piston 6 and moves forward and backward independently of the first piston 6, and a threaded shaft formed on the second piston that is adjustable. This second piston 7 is screwed into
a holder 8 that moves forward and backward in the switch chamber 4 integrally with the switch; a spring 9 that biases the first piston and second piston 7 in the direction of contacting the diaphragm 5 through the holder 8; A pair of fixed contacts 10, 1 provided in the chamber 4
0, and this first piston 6 is provided with a
As the piston 6 advances and retreats, the pair of fixed contacts 1
0 and 10, respectively, and a second movable contact 12, which is provided on the holder 8 and is connected to and separated from the pair of first movable contacts 11, 11. It is something.

(Function) In the pressure switch of the present invention, pressure changes inside the control body of the pressure controlled body are transmitted to the pressure detection opening 1 of the case 2, and the diaphragm 5 connects the first movable contacts 11, 11 and the second movable The diaphragm 5 is pushed and deformed against the spring 9 due to contact with the contact point 12 and the increase in the pressure inside the control body of the pressure-controlled body, which is moved back and forth against the spring 9 through the holder 8 or by the spring 9. The first piston 6 retreats, and the first movable contacts 11, 11 and the second
The second piston 7 also retreats through contact with the movable contact 12 of the fixed contact 10 and the first movable contact 1.
1, second movable contact 12, first movable contact 11,
Upon contact of the fixed contact 10, the switch is closed and a low pressure rise is detected. Moreover, when the pressure inside the control of the pressure-controlled main body further increases, the second piston 7 retreats further, and as the holder 8 retreats, the second movable contact 12 separates from the first movable contacts 11, 11, and the switch is turned off. is opened and a rise in pressure is detected. Moreover, when the pressure inside the control body of the pressure controlled body decreases, the pressure applied to the diaphragm 5 decreases.
The second piston 7 is advanced by the spring 9, and the second movable contact 12 is moved forward by the first movable contact 11,
11 and closes the switch, and when the pressure inside the control body of the pressure controlled body further decreases, the first
The piston 6 is advanced and the first movable contact 11,
11 is separated from the fixed contacts 10, 10, and the switch is opened. The low pressure value is adjusted by selectively adjusting the elastic force of the spring 9, and the high pressure value is adjusted by adjusting the threaded shaft portion 24 of the second piston 7 so that the second piston 7 is attached to the holder 8. It can be adjusted by moving it forward or backward.

(Example) The configuration of an example of the present invention will be described with reference to the drawings.

2 is a case, this case 2 is Packing 20
It is composed of a first case member 21 and a second case member 22 that are connected via a . And this case 2
A diaphragm 5 is installed inside the pressure detection opening 1, and a pressure chamber 3 is formed on the pressure detection opening 1 side by the diaphragm 5, and a switch is installed on the opposite side of the pressure chamber 3. A chamber 4 is formed. A first piston 6 that comes into contact with the diaphragm 5 is provided in the switch chamber 4 so as to be able to move forward and backward with respect to the diaphragm 5.
A fitting hole 23 is passed through the center of the piston 6, and a second piston 7, which moves back and forth concentrically with the first piston 6, is fitted into the fitting hole 23.
A threaded shaft portion 24 integrally formed on the second piston 7 is screwed into a holder 8 molded from an insulating material. This holder 8 is urged by a spring 9 in the direction of contacting the diaphragm 5.

Further, a pair of first movable contacts 11, 11, which are brought into contact with and separated from a pair of fixed contacts 10, 10 provided in the switch chamber 4, are connected to the first piston 6.
The first movable contacts 11, 11 are provided in the fixed contacts 10, 10 as the first piston 6 moves back and forth.
are separated from each other. Further, the first
An annular second movable contact 12 that is brought into contact with and separated from the movable contacts 11 and 11 is provided. The movement range of this holder 8 is restricted by the spring 9 at the fixed contacts 10, 10.

Next, the operation of this embodiment will be explained.

Pressure changes within the control body of the pressure-controlled body are transmitted to the pressure detection opening 1 of the case 2, and the diaphragm 5 is moved back and forth against or by the spring 9. When the diaphragm 5 is pressed and deformed against the spring 9 due to an increase in the pressure inside the control body of the pressure-controlled body from the state shown in FIG. 1, the first piston 6 retreats. The holder 8 is pressed through the engagement between the first movable contacts 11, 11 and the second movable contact 12, and the second piston 7 is also retracted, so that the first movable contact 11, 11 is fixed contact 1
0 and 10, an electric path is formed between the fixed contact 10, the first movable contact 11, the second movable contact 12, the first movable contact 11, and the fixed contact 10, and the switch is turned on at point a in FIG. is closed and a rise in pressure is detected. Further, when the pressure inside the control body of the pressure controlled body further increases, the pressure applied to the diaphragm 5 pushes the second piston 7 further and retreats. As the holder 8 moves back, the second movable contact 12 moves back to the first
The switch is separated from the movable contacts 11, 11, and the switch is opened at point b in FIG. 7, and it is detected that the pressure inside the control body of the pressure controlled body has become high pressure. Also,
When the control internal force of the pressure controlled body decreases, the pressure applied to the diaphragm 5 decreases, and the spring 9
As a result, the holder 8 is advanced, and the switch is closed again by the contact between the second movable contact 12 and the first movable contacts 11, 11. Furthermore, when the control internal force of the pressure controlled body decreases, the second movable contact 12 of the holder 8 and the first movable contacts 11, 11 come into contact with each other due to the biasing force of the spring 9, and the first piston 6 The second piston 7 is advanced, the first movable contacts 11, 11 are separated from the fixed contacts 10, 10, and the switch is released.

Further, the high pressure setting is adjusted by moving the second piston 7 forward and backward with respect to the holder 8, and the low pressure setting is set by selecting the spring 9.

[Effect of idea]

According to the present invention, it is possible to perform two-stage operation of high pressure and low pressure with a simple configuration, and the pressure switch configuration is simple and can be miniaturized.
Low pressure settings can also be easily adjusted.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a pressure switch showing one embodiment of the present invention, Fig. 2 is a sectional view of the same in a low pressure state, and Fig. 3 is a sectional view of the pressure switch in a low pressure state.
The figure is a sectional view in a high pressure state, Figure 4 is a bottom view of the first piston as above, Figure 5 is a front view of the holder as above,
FIG. 6 is a sectional view of the same as above, and FIG. 7 is a characteristic diagram of the same pressure switch. 1... Pressure detection opening, 2... Case, 3...
...Pressure chamber, 4...Switch chamber, 5...Diaphragm, 6...First piston, 7...Second piston, 8...Holder, 9...Spring, 10...
...Fixed contact, 11...First movable contact, 12...
Second movable contact, 24...screw shaft portion.

Claims (1)

[Scope of utility model registration request] A case having a pressure detection opening at one end, and a case installed in the case facing the pressure detection opening to form a pressure chamber on the side of the pressure detection opening and a switch chamber on the opposite side. a diaphragm; a first piston that is provided in the switch chamber so as to be movable back and forth and abuts the diaphragm; and a first piston that is fitted concentrically with the first piston and that moves back and forth independently of the first piston. 2 piston, and a holder in which a threaded shaft portion formed on the second piston is screwed together in an adjustable manner, and the holder moves forward and backward in the switch chamber integrally with the second piston; a spring that biases the first piston and the second piston in the direction of contacting the diaphragm; a pair of fixed contacts provided in the switch chamber; and a spring provided on the first piston that urges the first piston to move back and forth a pair of first movable contacts that are respectively brought into contact with and separated from the pair of fixed contacts; and a pair of second movable contacts provided on the holder.
and a second movable contact that is brought into contact with and separated from the movable contact.