JPH0648731Y2 - pressure switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention] Industrial field of application The present invention relates to a pressure switch used in a refrigerating apparatus and the like, and in particular for shutting off a power supply circuit by detecting an abnormal decrease or rise in fluid pressure The present invention relates to a two-operation switch for security.

2. Description of the Related Art A high pressure switch and a low pressure switch have been used in combination in order to protect the equipment by shutting off the power circuit of the compressor when the refrigerant pressure abnormally drops or rises in a refrigeration circuit, etc. A two-action switch in which one switch is also used has been proposed.

As a switch of this kind, for example, in the one disclosed in Japanese Utility Model Laid-Open No. 59-82935 (FIG. 6), a diaphragm 11 is mounted in contact with a reversing disk 12, and the reversing disk 12 is a coil spring. It is supported by a piston 14 which is urged toward the diaphragm 11 by 13. Then, when the diaphragm 11 receives pressure, first the piston 14 moves to push the contact point 15 and the contact points 15 and 16 come into contact with each other,
When the diaphragm 11 is further subjected to a high pressure of a predetermined value or more, the reversing disk 12 is reversed and the driving rod 17 is pushed up, so that the contacts are opened.

Further, in the pressure switch disclosed in Japanese Utility Model Laid-Open No. 61-99340 (FIG. 7), a side support piece 25 of a contact plate 24 having a movable contact 23 at one end is provided with a protrusion 22 provided at a piston 21. Press,
Movable contact with the protrusion 26 on the inner wall of the housing as the fulcrum
23 is brought into contact with the fixed contact 27, and the action of the reversing disk 29 provided between the piston 21 and the diaphragm 28 is configured to be exactly the same as the above-mentioned technique.

Further, Japanese Utility Model Laid-Open No. 61-127543 discloses an improved pressure switch (Fig. 8). The diaphragm 31 is provided in contact with the piston 35 biased by the disc spring 32 via the holder 33 and the reversing disc 34, and the reversing disc 34
The movement of the movable contact plate 37 is performed by the rod 36 provided so as to penetrate through the guide hole at the center of the disc spring 32 and the holder 33.
Is being communicated to. In this pressure switch, when pressure is applied to the diaphragm 31, the piston 35 moves, the movable contact 38 comes into contact with the fixed contact 39 via the reversing disc 34 and the rod 36, and the diaphragm 31 has a predetermined amount or more. When a high pressure is applied, the reversing disc 34 is reversed to open the movable contact 38.

Problems to be Solved As described above, the conventional pressure switch opens and closes quickly during high pressure operation, but has a drawback that chattering is likely to occur because the contacts slowly come into contact with and separate from each other during low pressure operation.

Therefore, the present invention is intended to provide a two-action pressure switch in which the contacts open and close rapidly not only during high-voltage operation but also during low-voltage operation, and chattering does not occur. The aim is to realize a compact pressure switch with little wear and long life.

[Constitution of device]

Means for Solving the Problems In order to achieve the above-mentioned object, a two-action pressure switch of the present invention has a diaphragm provided by a spring means in a switch body having a movable contact for opening and closing an electric circuit. A responding body urged in the opposite direction and a switch driving body that is sequentially driven by the movement and reversal of the pressure reversing plate that slidably penetrates through the responding body and is supported by the responding body are accommodated,
The movable contact is provided on the contact plate that can be reversed by the switch driver, and the fixed contact is provided opposite to the switch driver side of the contact plate, and the moving distance of the switch driver required for reversing the contact plate. The responder locking means for restricting the above-mentioned movement of the responder is provided, and the spring strength of the spring means is set to a value that allows the move of the responder at the low operating pressure set value and the spring of the pressure reversal plate. The strength is configured as a value that allows reversal at the high working pressure set value.

Action In the pressure switch of the present invention, when the pressure is applied to the diaphragm, the pressure reversing plate and the responding body move upward as a unit, and accordingly, the switch driving body also moves and reverses the contact plate to perform the snap action. To close the contact.
Then, when the pressure applied to the diaphragm further exceeds a predetermined value, the pressure reversal plate is reversed, and the switch driver pushes up the contact plate and operates to instantly open the contact.

EXAMPLE An example of the pressure switch of the present invention is shown in FIGS.

A is a switch main body, B is a lid, and C is an annular packing. At the bottom of the switch main body A, a terminal 3 connected to a contact plate 2 provided with a movable contact 1 and an upward fixed contact 4 are provided. The terminal 5 is fixed through. 6 is a diaphragm
Reference numeral 7 is a pressure reversal plate, 8 is a responder formed so as to be able to support the edge portion of the pressure reversal plate 7, and 9 is a switch driver provided so as to freely slide through the central hole of the responder 8. ,
Reference numeral 8b is a spring that presses and urges the responding body 8 toward the diaphragm 6, and 8c is a spring frame.

The contact plate 2 is press-molded from an elastic metal thin plate in a shape as shown in FIG. 4, has a hole 2a for fixing the movable contact 1 at the tip portion, and is fixed to the terminal 3 at the base portion. A hole 2b for forming is formed. A tongue-shaped piece having a convex portion 2d in contact with the switch driving body 9 in the central portion of the contact plate 2.
2c is formed by punching, and stepped portions 2e are formed by pressing on both sides of the hole 2a at the tip portion.
When pushing up 2d from below, the contact plate 2 reverses and the hole 2a
The movable contact 1 attached to is configured to move downward.

The pressure switch of this example is in a state as shown in FIG. 1 when no pressure is applied to the diaphragm 6, but when the pressure corresponding to the lower working pressure is applied, the diaphragm 6 is pushed upward and the spring 8b is compressed. As a result, the responder 8 moves upward together with the pressure reversing plate 7. At the same time, the switch driver 9 also moves upward, and the contact plate 2 is pushed by the switch driver 9 and inverted as shown in FIG.
Contact the fixed contact 4 instantaneously.

When the pressure applied to the diaphragm 6 is further increased, the shoulder 8a of the responder 8 is locked by the step a in the switch body A and does not move any further, and exceeds a predetermined high working pressure. After that, the pressure reversal plate 7 is reversed. Then, as shown in FIG. 3, the switch driver 9 pushes up the contact plate 2, and the movable contact 1 is separated from the fixed contact 4 instantly.

The pressure switch of this example operates by the snap action when the pressure decreases, as well as when the pressure switch increases by the snap action. The state of this operation is shown in FIG. 5, but the switch driving body 9 moves according to the pressure as shown in FIG. 5A, and the contacts are quickly opened and closed by raising and lowering the pressure as shown in FIG. .

[Effect of device]

The pressure switch of the present invention is constructed such that the contact plate is instantly inverted even when the switch driver slowly moves in the low pressure operation, and the switch driver is driven by the inversion operation of the pressure inversion plate in the high pressure operation. Since the contact plate is rapidly moved to drive the contact plate, in any case, the contact is quickly opened and closed to prevent chattering. Therefore, not only does it operate reliably, but the service life of the contacts is long.

In addition, since a contact plate having a reversing function is assembled in advance in the switch body and then moving parts are inserted to assemble, the number of assembly parts is small and the assembly workability is improved. There are advantages to be obtained.

[Brief description of drawings]

1 to 3 are sectional views of an example of the pressure switch of the present invention, showing states corresponding to low, medium and high operating pressures, respectively. FIG. 4 shows a contact plate in the switch, (a) is a plan view, (b) is a sectional view, and (c) is a side view. FIG. 5 is a diagram showing the relationship between the pressure and the operating state in the switch, (a) shows the movement of the switch driver, and (b) shows the opening and closing of the contacts. 6 to 8 are sectional views of conventional pressure switches. ... switch body, B ... lid, C ... annular packing,
1 ... Movable contact, 2 ... Contact plate, 4 ... Fixed contact, 6 ...
… Daifya ram, 7 …… Pressure reversal plate, 8 …… Reactor, 8b
...... Spring, 9 ...... Switch driver, 11 ...... Diaphragm, 12 ...... Inverted disk, 14 ...... Piston, 15,16 ...... Contact point, 17 ...... Drive rod, 21 ...... Piston, 23 ...... Movable contact,
24 …… contact plate, 27 …… fixed contact, 28 …… diaphragm,
29 …… Inverted disk, 31 …… Daifyaram, 32 …… Disc spring,
33 …… holder, 34 …… inverted disk, 35 …… piston, 36
...... Rod, 37 …… Movable contact plate, 38 …… Movable contact, 39…
… Fixed contacts.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A switch body having a movable contact for opening and closing an electric circuit, wherein a responder urged toward a diaphragm by a spring means and a slide body penetrating the responder in a freely sliding manner. A switch driver that is sequentially driven by the movement and reversal of the pressure reversal plate supported by the body is accommodated,
The movable contact is provided on the contact plate that can be reversed by the switch driver, and the fixed contact is provided opposite to the switch driver side of the contact plate, and the moving distance of the switch driver required for reversing the contact plate. The responder locking means for restricting the above-mentioned movement of the responder is provided, and the spring strength of the spring means is set to a value that allows the move of the responder at the low operating pressure set value and the spring of the pressure reversal plate. A two-action pressure switch, wherein the strength is set to a value that allows reversal at a high working pressure set value.