JPH0547836U - Pressure detector - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a pressure detecting device capable of absorbing variations in biasing force of a biasing member that presses a diaphragm. [Structure] A diaphragm chamber 52 is formed in a housing formed by an upper case 10 and a lower case 11, and the diaphragm chamber 12 is divided by a diaphragm 13 into an atmosphere chamber 14 and a negative pressure chamber 15, and a diaphragm 13 is formed. A switch plate that connects the rod 22 and fixes a pair of terminals 27 to the atmosphere chamber 14, and contacts the terminal 27 with the diaphragm 13 in a steady state, and moves away from the terminal 27 by moving the diaphragm 13 to the negative pressure chamber 15 side. 21, a load adjusting nut 23 is fixed to the rod 22, a spring 25 is provided between the load adjusting nut 23 and the upper case 10, and the outer peripheral edge portion of the load adjusting nut 23 is biased by the spring 25. A thin elastic body 26 that is deformed by.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a pressure detecting device, and more particularly to a pressure detecting device suitable for detecting a slight pressure difference between atmospheric pressure and negative pressure.

[0002]

[Prior Art]

 Conventionally, a pressure detection device shown in FIG. 4 has been known as a pressure detection device for detecting a minute pressure. In this device, a diaphragm 53 is located in a diaphragm chamber 52 formed by an upper case 50 and a lower case 51, and a peripheral edge portion of the diaphragm 53 is clamped and fixed by the upper case 50 and the lower case 51.

A center plate 54 is fixed to the center of the diaphragm 53, and a support plate 56 is connected to the center plate 54 via a switch plate 55. A rod 57 is integrally connected to the support plate 56, a load adjusting nut 58 is screwed to the rod 57, and a spring 59 is provided between the load adjusting nut 58 and the upper case 50. It is installed.

When the diaphragm chamber 2 is at atmospheric pressure, the urging force of the spring 59 acts on the rod 57 to bring the diaphragm 53 into the state shown in the figure, and the switch plate 55 contacts the pair of terminals 60, 60. The terminals 60, 60 are electrically connected.

On the other hand, when the diaphragm chamber 52 becomes a negative pressure and the pressure exceeds the set pressure, the diaphragm 53 descends, the switch plate 55 separates from the terminals 60, 60, and the terminals 60, 60 become non-conductive. Be in contact. As a result, the terminals 60, 60 are brought into an electrically non-conducting state, and a pressure above a predetermined level can be detected by a signal from the terminals 60, 60. The detected pressure can be adjusted by rotating the load adjusting nut 58 to change the screwing position with respect to the rod 57.

Therefore, conventionally, when a large amount of pressure detecting devices are produced, as shown in FIG. 5, the load adjusting nut 58 is rotated and positioned so that the spring 59 has a constant height. A decision is being made.

[0007]

[Problems to be solved by the device]

 However, in the conventional pressure detection device, even if the height H of the spring 59 is adjusted to a constant value, the biasing force of the spring 59 differs depending on the spring 59, so that the variation in the biasing force of the spring 59 causes a variation in the detected pressure. May occur.

That is, when a large amount of the spring 59 is produced, even if the height H of the spring 59 is adjusted to a constant value, variations in the biasing force of the spring 59 are about 5 to 10% in manufacturing. Therefore, the detected pressure will vary by about 5 to 10%.

In addition, in order to suppress the variation in the detected pressure, the manufacturing cost is increased if the spring 59 is manufactured so that the biasing force of the spring 59 does not vary, and the height of the spring 59 is slightly adjusted by the load adjusting nut 58. Although it is possible to adjust the height, adjusting the height of the spring 59 for each device is complicated because it requires a lot of time for the adjustment work.

An object of the present invention is to provide a pressure detecting device that can absorb variations in the biasing force of a biasing member that applies a biasing force to a diaphragm, reduce manufacturing costs, and facilitate adjustment work. To do.

[0011]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention is, as a first invention, a housing that forms a diaphragm chamber, a diaphragm that is fixed to the housing and divides the diaphragm chamber into an atmospheric chamber and a negative pressure chamber, and is inserted into the atmospheric chamber. Connected to approximately the center of the diaphragm, a pair of signal generating terminals that are placed in the diaphragm chamber and form one element of the electric circuit, and connected to the diaphragm to make contact with each signal generating terminal during normal operation. Then, the switch member that separates from each signal generation terminal due to the movement of the diaphragm toward the negative pressure chamber, the load adjusting member that is fixed to the rod so as to be movable along the axial direction, the load adjusting member, and the housing. And a biasing member that is mounted between the load adjusting member and biases the load adjusting member in a direction away from the diaphragm. It was composed of thin-walled elastic body you modified in accordance with the contact portion between the urging member Chi the biasing force of the biasing member is obtained by the pressure sensing device according to claim.

As a second invention including the first invention, a housing that forms a diaphragm chamber, a diaphragm that is fixed to the housing and divides the diaphragm chamber into an atmospheric chamber and a negative pressure chamber, and is inserted into the atmospheric pressure. A rod connected to approximately the center of the diaphragm, a pair of signal generating terminals that are arranged in the diaphragm chamber and form one element of an electric circuit, and a signal connecting terminal that is connected to the diaphragm and is stationary. The switch member that comes into contact with and separates from each signal generation terminal by moving the diaphragm toward the negative pressure chamber, the load adjusting member that is fixed to the rod so as to be movable along its axial direction, the load adjusting member, and the housing. A biasing member that is mounted between the biasing member and biases the load adjusting member in a direction away from the diaphragm. A pressure detecting device is characterized in that an elastic body that deforms according to the urging force of the urging member is attached to at least one of the urging member and the housing. ..

[0013]

[Action]

 According to the above-mentioned means, since the contact portion of the pressure adjusting member with the biasing member is made of the thin elastic body, the thin elastic body is deformed according to the biasing force of the biasing member. Even if the length is constant, it is possible to absorb the variation in the biasing force of the biasing member, and it is possible to suppress the variation in the detected pressure.

Further, if an elastic body is mounted between the biasing member and the load adjusting member or between the biasing member and the housing, the elastic body is deformed according to the biasing pressure of the biasing member, It is possible to absorb variations in the urging force of the urging body and suppress variations in the detected pressure.

[0015]

【Example】

 An embodiment of the present invention shown in the drawings will be described below.

In FIG. 1, the upper case 10 and the lower case 11 are configured as a housing, and the upper case 10 and the lower case 11 form a diaphragm chamber 12.

A diaphragm 13 is located inside the diaphragm chamber 12, and a peripheral edge of the diaphragm 13 is mounted between the upper case 10 and the lower case 11 so as to be sandwiched and fixed by the upper case 10 and the lower case 11. Has been done. As a result, the diaphragm chamber 12 is divided into the atmosphere chamber 14 and the negative pressure chamber 15 by the diaphragm 53, and the negative pressure chamber 15 is communicated with the outside through the negative pressure passages 16 and 17.

A center plate 18 is fixed to the central portion of the diaphragm 53 in a state of penetrating therethrough, and a shaft-shaped protrusion 19 is bulged at the central portion of the center plate 18. .. A support plate 20 is fitted on the outer peripheral side of the protrusion 19. An annular switch plate 21 as a switch member is mounted between the diaphragm 13 and the support plate 20.

A rod 22 is integrally connected to the top side of the support plate 20, and a threaded portion 24 is formed on the outer peripheral side of the rod 22. A load adjusting nut 23 as a load adjusting member is screwed into the screw portion 24. A spring 25 as a biasing member is mounted between the outer peripheral edge of the load adjusting nut 23 and the recess 32 of the upper case 10.

As shown in FIG. 2, the spring 25 is in contact with a thin elastic body 26 formed on the outer peripheral edge of the load adjusting nut 23. The thin elastic body 26 is configured to be deformable by the urging force of the spring 25, and when the length of the spring 25 is constant, the urging force of the spring 25 is the same as that shown in FIG. 2A, the thin elastic body 26 moves upward, and when the biasing force of the spring 25 is small, as shown in FIG. 2C, The thin elastic body 26 is adapted to deform downward.

Further, a pair of terminals 27, 27 are fixed to the wall surface of the atmosphere chamber 14 so as to face the switch plate 11, and each terminal 27, 27 is a lead for generating a pressure detection signal. It is connected to the lines 28, 28.

In the above structure, when both the atmosphere chamber 14 and the negative pressure chamber 15 are in the atmospheric pressure state, the urging force of the spring 25 acts on the rod 22 via the load adjusting nut 23, and the diaphragm 13 Is in the illustrated state.

Therefore, at this time, the switch plate 21 contacts the terminals 27, 27, and the terminals 27, 27 are in a short-circuited state. Therefore, no signal is generated from the lead wires 28, 28, so that no pressure is detected.

On the other hand, when a negative pressure is introduced into the negative pressure chamber 15 via the negative pressure passages 16 and 17, a force for lowering the diaphragm 13 acts on the diaphragm 13. When this negative pressure exceeds the set pressure, the diaphragm 13 is lowered against the biasing force of the spring 25. As a result, the switch plate 21 is separated from the terminals 27 and 27, the terminals 27 and 27 are brought into an electrically non-conducting state, and a pressure detection signal is output from the terminals 27 and 27. This makes it possible to detect the pressure.

Therefore, when the pressure detecting device according to the present invention is mass-produced, even if the height of the spring 25 is adjusted to be constant, the thin elastic body 26 is deformed according to the biasing force of the spring 25. It is possible to prevent the detected pressure from varying due to the variation in the biasing force of the spring 25.

Further, in the above-described embodiment, the thin elastic body 26 absorbs the variation in the biasing force of the spring 25, but as shown in FIG. 3, the load adjusting nut 29 of the load adjusting nut 29 is used. It is also possible to form the concave portion 30 in the outer peripheral edge portion, mount the elastic body 31 in the concave portion 30, and absorb the variation in the biasing force of the spring 25 by deforming the elastic body 31.

That is, when the urging force of the spring 25 has a central value, the elastic body 31 as shown in FIG. 3B is used, and when the urging force of the spring 25 is large, it is shown in FIG. As shown in (C), when the elastic body 31 is contracted, and when the biasing force of the spring 25 is small, the elastic body 31 is expanded as shown in (C). Variations can be absorbed.

It should be noted that the same effect can be obtained even if the elastic body 31 is provided in the recess 32 of the upper case 10 without being provided in the recess 30 formed in the outer peripheral edge of the load adjusting nut 29. There is.

[0029]

[Effect of the device]

 As described above, according to the present invention, the contact portion of the load adjusting member with the biasing member is formed of a thin elastic body that deforms according to the biasing force of the biasing member. Can be absorbed by the thin elastic body, and it is possible to prevent variations in the detected pressure due to variations in the urging force of the urging member, which can contribute to improvement in detection accuracy.

Further, since the deformable elastic body is arranged at the contact portion with the biasing member, this elastic body can absorb the variation in the biasing force of the biasing member, and therefore the manufacturing is easy and the manufacturing cost is low. It has the effect of making it cheaper.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a diagram for explaining a method of absorbing a variation in biasing force of a spring 25.

FIG. 3 is an explanatory view showing another embodiment for absorbing the variation in the biasing force of the spring.

FIG. 4 is a vertical sectional view of a conventional example.

FIG. 5 is an enlarged view of a main part of a conventional example.

[Explanation of symbols]

 10, 50 ... upper case 11, 51 ... lower case 12, 52 ... diaphragm chamber 13, 53 ... diaphragm 14 ... atmosphere chamber 15 ... negative pressure chamber 16, 17 ... negative pressure passage 18, 54 ... ... Center plate 19 ... Projections 20,56 ... Support plates 21,55 ... Switch plates 22,57 ... Rods 23,29,58 ... Load adjustment nuts 24 ... Screw portions 25,59 ... Springs 26 ... Thin-walled elastic body 27, 60 ... Terminal 28 ... Lead wire 30, 32 ... Recessed portion 31 ... Elastic body

Claims (2)

[Scope of utility model registration request] 1. A housing (10, 11) forming a diaphragm chamber (12), and a diaphragm chamber (12) fixed to the housing (10, 11) to form an atmosphere chamber (14) and a negative pressure chamber (15). A diaphragm (13) divided into
A rod (22) inserted into the atmosphere chamber (14) and connected to a substantially central portion of the diaphragm (13), and a pair of signal generators arranged in the diaphragm chamber (12) and constituting one element of an electric circuit. Connected to the terminals (27, 27) and the diaphragm (13), each signal generating terminal (27,
27) and the negative pressure chamber (1) of the diaphragm (13).
To the switch member (21) and the rod (22) which are separated from the respective signal generating terminals (27, 27) by moving to the 5) side.
A load adjusting member (23) fixed so as to be movable along the axial direction, the load adjusting member (23) and the housing (1
0) and a biasing member (2) for biasing the load adjusting member (23) in a direction away from the diaphragm (13).
5) In the pressure detecting device including: a thin-walled member in which a contact portion of the load adjusting member (23) with the biasing member (25) is deformed according to the biasing force of the biasing member (25). A pressure detecting device comprising an elastic body (26). 2. A housing (10, 11) forming a diaphragm chamber (12), and a diaphragm chamber (12) fixed to the housing (10, 11) to form an atmosphere chamber (14) and a negative pressure chamber (15). A diaphragm (13) divided into
A rod (22) inserted into the atmospheric pressure (14) and connected to a substantially central portion of the diaphragm (13), and a pair of signals arranged in the diaphragm chamber (12) and constituting one element of an electric circuit. The signal generating terminals (27, 27) and the diaphragm (13) are connected to each signal generating terminal (27, 27) in a steady state.
27) and the negative pressure chamber (1) of the diaphragm (13).
To the switch member (21) and the rod (22) which are separated from the respective signal generating terminals (27, 27) by moving to the 5) side.
A load adjusting member (29) fixed so as to be movable along the axial direction, the load adjusting member (29) and the housing (1
0) and a biasing member (2) for biasing the load adjusting member (29) in a direction away from the diaphragm (13).
5) A pressure detecting device comprising: a biasing member (25) and a load adjusting member (29); or a biasing member (25) and a housing (10). A pressure detecting device, characterized in that an elastic body (31) that is deformed according to the urging force of the urging member (25) is mounted.