JPS6328843Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure switch that is opened and closed in response to fluid pressure, particularly the internal pressure of a conduit for flammable gas or combustible liquid.

Conventionally, as this type of switch device, a switch system linked to a pressure gauge, a reed switch system, etc. have been used industrially. However, the former device is complicated and expensive because it requires a pressure gauge and a reading device for the pressure gauge. Therefore, a method was proposed in which a damper that changes the open/close position by fluid pressure is placed in the fluid conduit as a simple fluid pressure responsive switch, and a switch mechanism is connected to this damper. It has the disadvantage that it is thin and increases the pressure loss inside the pipe. In addition, the reed switch method has the disadvantage that the position at which the contact turns ON varies, and the bag-shaped diaphragm itself has hysteresis, making it impossible to operate with high precision.

The present invention solves the above-mentioned conventional drawbacks.
It is an object of the present invention to provide a pressure switch with a simple configuration that accurately detects changes in fluid pressure and operates reliably.

The present invention will be explained in detail below based on an example of implementation shown in the drawings.

In the drawings, reference numeral 1 denotes a body portion having a fluid passage hole 12 connected to a fluid conduit, etc. A flat diaphragm 3 that expands and contracts due to fluid pressure is disposed on the body portion 1, and a bonnet is mounted on the diaphragm 3. 2 are arranged, and the body part 1 and the bonnet 2 are fastened together with a screw 7 to become one body.

A shell 5 having contact projections 4 is attached to the bonnet 2 side of the diaphragm 3. Also, the set screw 6 is inserted through the bonnet 2.
is attached, and the end of this set screw 6 is located at a position corresponding to the contact protrusion 4 of the shell 5.

Set Screw 6 has Set Screw 6.
A spring retaining nut 8, which is axially movable and rotationally locked, is screwed into the spring retaining nut 8. The locking of the rotation of the spring retaining nut 8 to allow the axial movement of the set screw 6 is achieved by forming the inner wall of the bonnet 2 into a hexagonal shape that matches the shape of the spring retaining nut 8. It is something that exists. A spring 9 is held between this spring holding nut 8 and the shell 5 described above. The set screw 6 is freely rotatable with respect to the bonnet 2 and is constantly pressed outward by the spring 9 via the spring retaining nut 8. The flange 13 engages with the inner surface of the bonnet 2 to prevent it from popping out. Therefore, by the engagement of the flange portion 13 with the inner surface of the bonnet 2,
The position of the tip of the set screw 6 is always held constant, and when the set screw 6 is rotated, the spring retaining nut 8 screwed into it is moved up and down in the figure, and the compressive force of the spring 9 is It is designed to be adjustable. Further, reference numeral 10 denotes a lock bolt, which is used to fix the set screw 6 after appropriately setting the compression force of the spring 9.

Spring retaining nut 8 and set screw 6
The space between the springs 9 and 9 is insulated.
and the lead wires 11 and 1 to the set screw 6, respectively.
1 is connected. Therefore, the fluid pressure transmitted through the fluid passage hole 12 causes the diaphragm 3 to
When the contact protrusion 4 of the shell 5 and the tip of the set screw 6 bulge upward in the figure and come into contact, both lead wires 11, 11 are connected via the spring 9, the shell 5, and the set screw 6. . Conversely, when the fluid pressure decreases and the diaphragm 3 moves downward, the contact protrusion 4 of the shell 5 and the set screw 6
When the tips of the two lead wires 11, 11 are separated, the connection between the two lead wires 11, 11 is released.

Next, the effects of the present invention will be listed.

1. The compression force of the spring can be adjusted by turning the set screw, so the working fluid pressure can be set freely.

2. For the same reason, even if there is some variation in the spring or diaphragm, a product with a constant working fluid pressure can be obtained.

3. In particular, since the structure of the movable part is simple, a compact and robust product can be provided at low cost.

[Brief explanation of drawings]

The drawing is an explanatory cross-sectional view showing an example of the implementation of the pressure switch according to the present invention. 1...Body part, 2...Bonnet, 3...Diaphragm, 4...Contact projection, 5...Ciel, 6
...Set screw, 7...Screw, 8...Spring retaining nut, 9...Spring, 10...
Lock nut, 11... Lead wire, 12... Fluid hole, 13... Flange.

Claims (1)

[Scope of utility model registration request] A diaphragm is disposed between the body portion in which the fluid passage hole is bored and the bonnet, and a shell having a contact protrusion is attached to the bonnet side of the diaphragm, and an end portion of the bonnet is positioned in correspondence with the contact protrusion of the shell. A set screw is inserted through the bonnet so as to be freely rotatable, and a spring retaining nut which is movable in the axial direction of the set screw and whose rotation is locked is screwed onto the set screw. A pressure switch characterized in that a spring is sandwiched between shells, a spring retaining nut and a set screw are insulated, and lead wires are connected to the spring and the set screw, respectively.