JPH0237635A - High-pressure switch - Google Patents

Abstract

PURPOSE:To detect the absolute value and fluctuation of the high fluid pressure with high precision and high sensitivity by providing the first spring body exciting a reversal plate in the return direction against the fluid pressure adjustably for its support position and providing the second spring body exciting the reversal plate in the return direction only when the reversal plate is in the reverse attitude. CONSTITUTION:The pressure of the fluid guided from a pressure guiding coupler 9 pressurizes a reversal plate 7 via a piston 8, the reversal plate 7 is reversed when the load applied to the piston exceeds the total of the load of an adjusting spring 12 and an elastic arm 3b and the reversal limit load of the reversal plate 7, contacts 3a and 3c of a switch are closed. The switch operating pressure is adjusted by changing the load of the adjusting spring 12 with an adjusting screw 13 at this time. When the reversal plate 7 is reversed, the reversal plate 7 is brought into contact with a sleeve 10 to push it up, a dish spring 14 is compressed, a pressing force is generated in the return direction. The high pressure can be detected with high precision and high sensitivity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a pressure detection switch used for hydraulic control and the like.

[Prior Art] With the development of control systems that utilize hydraulic pressure, higher pressure of working fluid has been required. For this reason, pressure switches used to detect the pressure of the working fluid and control the operation of fluid pressurizing devices are also required to have a high operating point.

Conventional pressure switches, for example, receive fluid pressure with a pressure-responsive body such as a diaphragm, and open and close the switch by transmitting the displacement of the pressure-responsive body to a movable contact of the switch. In order to perform this quickly and reliably, there is a pressure-reversing plate that is used as a pressure-responsive body.

Although a pressure switch using such a pressure reversal plate has the advantage of being small and having good response sensitivity, when the fluid pressure increases, it is necessary to use a pressure reversal plate with a large load relative to the amount of displacement, which inevitably results in Since the variation in the reversal load of the pressure reversal plate itself and the difference between the reversal load and the return load become large, a problem arises in that not only the response accuracy of the switch but also the sensitivity is impaired.

[Problems to be Solved by the Invention] Therefore, an object of the present invention is to provide a high-pressure switch that can detect the absolute value of fluid pressure under high pressure and its fluctuation with high precision and high sensitivity.

(Means for Solving the Problems) The object of the present invention as described above is to provide a means for transmitting the displacement of a diaphragm subjected to fluid pressure to a reversing plate, and a means for transmitting the reversing and returning motion of the reversing plate to a movable contact of a switch. A pressure switch comprising: a first spring body that urges the reversing plate in the return direction against the fluid pressure; the support position of the first spring body is adjustable; a second urging the reversing plate in the return direction via a movable member that can come into contact with the reversing plate only when the reversing plate is in the posture;
This is achieved by a high-pressure switch characterized by being provided with a spring body.

〔Example〕

An embodiment of the high pressure switch of the present invention is shown in FIG.

In the figure, reference numeral 1 denotes a main body, on the top of which a fixed contact 3a and a movable contact 3C fixed to an elastic arm 3b are provided in a switch case 2, and a switch part A is sealed with a guide plate 4.
is installed.

Further, at the bottom of the main body 1, there are a diaphragm 6 held between a pedestal 5a and a diaphragm fixing ring 5b, and a circular reversing plate 7.
and a piston 8 which has a shape that contacts both the diaphragm 6 and the reversing plate 7 at the same time and is movable within the hole of the fixed ring 5b, and a pressure introducing joint 9 is attached to the pedestal 5a. It is.

A sleeve 1 having a flange portion is provided in the through hole 1a of the main body 1.
0 is slidably fitted and passes through the sleeve 10 and the guide hole 4a of the guide plate 4.
1a contacts the elastic arm 3b and its lower end 11b
It is provided so as to be in contact with the center portion of the reversing plate 7. Further, an adjustment spring 12 is held between a spring receiver 12a in contact with the upper end 11c of the actuating rod 11 and a spring seat 12b supported by an adjustment screw 13 screwed into the switch case 2, and can be adjusted by turning the adjustment screw 13. spring 12
The configuration is such that the degree of compression of the reversing plate 7 can be adjusted to change the magnitude of the force that presses the reversing plate 7 in the return direction via the actuating rod 11.

On the other hand, an annular disc spring 14 is inserted between the upper surface of the sleeve 10 and the lower surface of the guide plate 4, and is configured to be able to push the sleeve 10 downward, that is, in the direction in which the reversing plate 7 returns. . Further, when the flange portion 10a of the sleeve 10 is in a state of being locked to the step portion 1b of the through hole 1a, the lower end surface of the sleeve 10 protrudes from the lower end of the through hole 1a, but the reversing plate 7 in the restored state The structure is such that it does not come into contact with the top surface.

In the high pressure switch of the present invention having such a structure, the pressure of the fluid introduced from the pressure introduction joint 9 pushes the lower surface of the diaphragm 6 and passes through the piston 8 to the reversing plate 7.
Apply pressure in the reverse direction. The inversion Fi,7 receives the pressing force of the adjustment spring 12 via the actuating rod 11, and the adjustment spring 1
When the load by the piston exceeds the sum of the load of 2, the load of the elastic arm 3b, and the reversal limit load of the reversing plate 7, the reversing plate 7 reverses for the first time, compressing the adjustment spring 12 a little and simultaneously By pushing up the elastic arm 3b, the contacts 3a and 3c of the switch are closed. At this time, the absolute magnitude of the fluid pressure that causes the switch to close can be counteracted by the total load of the reversing plate 7 and the adjustment spring 12, so the reversing plate 7 should have a relatively small reversing limit load. ,t
By changing the load of the in-spring 12 with the adjusting screw 13, the switch operating pressure can be adjusted and the setting accuracy can be improved.

Further, when the reversing plate 7 is reversed in this way, the reversing plate 7 contacts the sleeve 10 and pushes it up, causing the disk spring 1
Compress 4. Therefore, the disc spring 14 does not act in the same way on the reversing plate 7 until the reversal starts, but after it is reversed, it generates a pressing force in the direction of return, so the reversing limit load of the reversing plate 7 is It is possible to reduce the pressure difference between opening and closing of the switch.

The operating characteristics of the high pressure switch of the present invention are shown in FIG.

In a switch having a conventional structure, as shown by curve A, the difference between the reverse operation pressure and the return operation pressure reaches about 30% of the absolute value of the reverse operation pressure. On the other hand, when a switch is adjusted using a reversing plate and an adjustment spring so that the reversing operating pressure is the same, and a disc spring is added to assist the reversing plate, the difference in operating pressure is significantly reduced as shown by curve B. Ru.

Furthermore, by adjusting the adjustment spring, the operating pressure can be set with high precision to the desired value.

(Effects of the Invention) The high pressure switch of the present invention is configured as a pressure switch suitable for detecting high pressure by reducing the difference between the reversal limit pressure and the return limit pressure of the reversing plate, and sets the fluid pressure to be detected. Not only could the value be changed significantly, but the difference in the operating pressure for opening and closing the switch could be significantly reduced.

Therefore, it is highly accurate and sensitive, and has characteristics suitable for precise control of fluid pressure.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an example of the high pressure switch of the present invention, and FIG. 2 is a graph comparing the operating characteristics of the high pressure switches. DESCRIPTION OF SYMBOLS 1... Main body, 6... Diaphragm, 7... Reversing plate, 8... Piston, 10... Sleeve, 11...
Operating rod, 12... Adjustment spring, 13... Adjustment screw, 1
4... Disc spring.

Claims (1)

[Claims] A pressure switch comprising means for transmitting displacement of a diaphragm subjected to fluid pressure to a reversing plate, and means for transmitting reversing and returning movements of the reversing plate to a movable contact of the switch, wherein the reversing plate resists the fluid pressure. A first spring body is provided so that its supporting position can be adjusted and biased in the return direction, and a movable member that can come into contact with the reversing plate only when the reversing plate is in the reversing position is provided. A high pressure switch characterized in that a second spring body is provided for biasing the reversing plate in the return direction.