JPH0117069Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a pressure switch that detects abnormally high pressure or abnormally low pressure of a pressure fluid such as a refrigerant used in refrigeration equipment, and opens the contacts of the compressor to stop the compressor.

Conventional pressure switches of this type include, for example, the
- Something like the one shown in No. 82935 broke out. (See Fig. 5.) However, in the case of abnormally high pressure, such a pressure switch switches the second contact 4 on one switch lever 3 via the rod 2 by the action of the reversing plate 1 to the second contact 4 on the other switch lever 5. If the pressure is abnormally low, the holder 9 pushes down the piston 7 by the elasticity of the spring 8, thereby separating the first contact 6 from the second contact 4 and stopping the compressor.

With this kind of configuration, two movable switch levers are required in a narrow space, there are many parts, it is troublesome to assemble, and it is not only large and expensive, but also requires a lot of man-hours for dimensional control because there are many moving parts. The drawback was that it took a long time.

The present invention has been devised in view of the above drawbacks, and the object of the present invention is to provide a pressure switch that is small in size, easy to assemble, and inexpensive.

This project was devised to achieve the above objectives, and includes a switch body with a passage for pressure fluid, a cylindrical case that is hermetically connected to this body and has a pair of terminals, and a switch that slides inside this case. a disc-shaped receiver having an opening in the center and two protrusions at positions offset from the center; and a spring receiver that abuts against the receiver via the legs in the case with spring pressure. One end of the center plate part is fixed to one terminal, a movable contact is provided at the tip of the plate part, and each part is separated from the tip of the center plate part toward the fixed part, and each free end has a support piece that comes into contact with the protruding part. A fulcrum is provided opposite to the inside of the case so as to support each support piece on the side of the movable contact and opposite to the contact portion between the switch lever and the protrusion of each of the support pieces. a reversing plate whose peripheral edge is supported by the receiver on the side; a diaphragm whose peripheral edge is airtightly attached between the main body and the case so as to cover the reversing plate; and a reversing plate between the reversing plate and the switch lever. When the pressure of the fluid consisting of the rod provided in the opening is normal, the receiver moves and its protrusion operates the support piece of the switch lever to close the contact, and when the pressure is abnormally high, the reversing plate reverses. Then, move the rod by operating the center plate of the switch lever to open the contact, and when the pressure is abnormally low, the spring receiver moves due to the spring pressure, and the receiver is moved in the opposite direction via its legs. Since the protrusion and the support piece of the switch lever are released from contact, the movable contact of the switch lever is separated from the fixed contact due to the elasticity of the switch lever.

An embodiment of the present invention shown in the drawings will be described below. Reference numeral 11 denotes a switch body, which has a passage 12 in its center through which a pressurized fluid such as a refrigerant passes. 13
is a cylindrical case with a bottom and is airtightly attached to the main body. 14 indicates the packing provided between the two.

The case 13 has a large-diameter chamber 16 and a small-diameter chamber 17 with a stepped portion 15 interposed therebetween. A disk-shaped receiver 18 is housed in the large-diameter chamber 16 so as to be able to slide within the chamber. And in the center of this receiver there is an opening 1.
It has 8a. The case 13 side of this receiver has two protrusions 19 (only one is shown) at off-center positions. These protrusions are in contact with the free ends of both support pieces of the switch lever, which will be described later.

The outer periphery of the reversing plate 20 is held by the peripheral edge of the receiver 18 on the side opposite to the protrusion. A diaphragm 21 is provided on the outside of the reversing plate 20, and its outer periphery is held airtight between the switch body 11 and the case 13.

A spring receiver 22 is installed in the small diameter chamber 17 of the case 13.
is provided, and due to the elasticity of the ridge 23 provided between the spring receiver and the bottom of the small diameter chamber 17, the receiver 18 is moved through two legs 24 (only one is shown) provided on the spring receiver. is in contact with. These legs are provided spaced apart from each other at the front and back of the page so as to sandwich the center of the receiver.

Terminals 25 and 26 are embedded in the case 13 at a distance from each other, one terminal supports a fixed contact 27, and the other terminal supports one end of a center plate portion 29 of a switch lever 28.

A movable contact 30 is provided at the other end of the center plate portion 2 of the switch lever so as to face the fixed contact 27.

Two support pieces 31 and 32 are provided on both sides from the other end (free end) of the center plate portion 29 and in the direction of the support portion at one end of the center plate portion. The tips of the respective protrusions of the receiver are in contact with the free ends of both support pieces. Furthermore, two legs of the spring receiver 22 face the space formed by the center plate 29 and both support pieces 31 and 32.

Protrusions 33 and 34 are provided to face each other and protrude inward toward the center of the case 13, and the protrusions 19
Each support piece 31, 32 is supported on the side opposite to the contact surface of the support piece 31, 32. 35 is a rod that fits into the opening 18a in the center of the receiver 18 and also connects the switch lever 28.
and the reversing plate 20. The end of this rod on the switch lever side faces the center of the center plate portion 29 of the switch lever. Reference numeral 36 indicates an adjustment screw for adjusting the elasticity of the spring 23.

Next, the operation of such a pressure switch will be explained. When a pressurized fluid such as a refrigerant is in a no-pressure or abnormally low-pressure state, no or almost no fluid pressure is applied to the passage 12, and the spring receiver 22 moves downward due to the elasticity of the spring 23. . Therefore, the receiver 18 is pressed in the same direction by the leg portion 24 of the spring receiver 22, and the protrusion 19 of the receiver 18 and the support pieces 31, 32 of the switch lever 28 are released from contact. The movable contact 30 with the switch lever is the fixed contact 2
Since the movable contact 30 has elasticity in the direction of moving away from the fixed contact 27, the elasticity causes the movable contact 30 to move away from the fixed contact 27, and the electric circuit is turned off, thereby avoiding unnecessary operation of the compressor, etc.

Next, when the fluid reaches a predetermined pressure, the fluid pressure overcomes the elasticity of the spring 23, so that the receiver 1
8 rises in the large diameter chamber 16 of the case 13 as shown in the figure and comes into contact with the stepped portion 15 . In this state, the spring receiver 22 rises through the legs 24 against the elasticity of the spring 23, and the spring receiver 22
The protruding parts 19 of 8 are both support pieces 3 of the switch lever 28.
The free ends of 1 and 32 will be pressed. When the support pieces 31 and 32 of the switch lever are pressed in this way, the support pieces rotate about the protrusions 33 and 34 as fulcrums, and the movable contact 30 comes into contact with the fixed contact 27. (Fig. 3) Therefore, the air circuit is turned on and the compressor starts operating.

Furthermore, if the refrigerant or other fluid reaches an abnormally high pressure in the state shown in FIG. Push up the plate portion 29. Due to this movement of the center plate portion 29, the support pieces 31 and 32 also move upward in the figure while being supported by the protrusions 33 and 34 and the protrusion portion 19, so that the movable contact 30 provided on the center plate portion 29 is moved by the fixed contact 27. When separated, the air circuit is turned off, the compressor is stopped, and no unnecessary load is placed on the compressor.
(Fig. 4) When the abnormally high pressure is released, the reversing plate 20 returns to the state shown in Fig. 3, and with this return, the switch lever also returns to its old position, the movable contact contacts the fixed contact again, and the compressor starts operating. Resume driving.

As described above, according to the present invention, a single switch lever is used to open the contacts in the case of abnormally low fluid pressure or abnormally high pressure, and the number of parts is small and assembly is easy and inexpensive. Not only is it easy to manufacture, but it also has the advantage of requiring less man-hours for dimensional control because there are fewer moving parts.

[Brief explanation of the drawing]

The drawings show one embodiment of the pressure switch of the present invention, and Fig. 1 is a schematic vertical cross-sectional view when the fluid is in a state of no pressure or abnormally low pressure, Fig. 2 is a plan view of the switch lever as seen from the switch body side, and Fig. 3 4 is a schematic longitudinal sectional view when the fluid is at a predetermined pressure, FIG. 4 is a similar longitudinal sectional view when the fluid is at an abnormally high pressure, and FIG. 5 is a similar longitudinal sectional view of a conventional pressure switch. 11... Switch body, 12... Passage, 13...
...Case, 18...Receiver, 18a...Opening, 19
...Protrusion, 20...Reversing plate, 21...Diaphragm, 22...Spring receiver, 23...Spring, 24...
... Legs, 25, 26 ... Terminals, 27 ... Fixed contacts, 28 ... Switch levers, 29 ... Center plate parts, 30 ... Movable contacts, 31, 32 ... Support pieces,
33, 34... protrusion, 35... rod.

Claims (1)

[Scope of utility model registration request] A switch body has a passage for pressure fluid, a cylindrical case is hermetically connected to the body and has a pair of terminals, and a cylindrical case that slides inside the case and has an opening in the center and is located at a position offset from the center.
a disk-shaped receiver having a protruding part; a spring receiver that abuts against the receiver via the spring pressure in the case; one end of the center plate part is fixed to one terminal; A switch lever having a movable contact point at the tip of the central plate portion, separate from the tip of the center plate portion toward the fixed portion side, and each free end of which has a support piece that abuts the protrusion, and a contact portion between the protrusion of each of the support pieces. and a reversing plate whose periphery is supported by the receiver on the opposite side from the switch lever; A pressure switch comprising a diaphragm whose periphery is airtightly attached between the main body and the case so as to cover the reversing plate, and a rod provided in the opening of the receiver between the reversing plate and the switch lever.