JPH047545Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] Industrial application field The present invention relates to a particularly small super heat switch used in a refrigeration system to control an expansion valve by detecting the degree of superheating at the outlet of an evaporator. It is.

Conventional technology A super heat switch is attached to a refrigerant circulation pipe of a refrigeration system, and operates a pressure-responsive member based on the difference between the refrigerant pressure in the pipe and the refrigerant pressure sealed in a pressure-responsive member such as a diaphragm. The operation of the member is transmitted to the microswitch via the operating shaft.

By the way, a micro switch requires a contact adjustment mechanism, and as is well known, if this is provided at the contact part, it becomes impossible to miniaturize the micro switch. A technology has been developed to incorporate it into the board.

FIG. 4A shows such a conventional example, in which an adjustment screw c is provided for the drive plate portion b of the movable contact plate a in the micro switch, and the adjustment screw c is in point contact with the operating axis e of the diaphragm d. . In this case, since the adjusting screw c and the operating axis e coincide in the axial direction, the contact end portion of the adjusting screw c during operation is in a direction that intersects with the axial direction due to the cantilevered structure of the movable contact plate a. The frictional force when sliding is at its maximum, and if the contact end of the adjustment screw c does not slide on the operating shaft e, the drive plate b will bend as shown in Figure 4B. Normal operation will no longer occur.

The present invention focuses on the above-mentioned points and reduces the frictional force at the contact point between the adjustment screw provided in the drive part of the movable contact plate and the operating shaft of the diaphragm, thereby reducing the size of the super heat switch and improving its operation. This is to ensure stability.

[Structure of the idea]

Means for Solving Problems In the present invention, an adjustment screw is provided on the drive plate portion of the movable contact plate of the micro switch to bring it into point contact with the operating shaft of the diaphragm, and at this time, the operating direction in the axial direction of the operating shaft is By providing the adjustment screw with a diagonal clearance angle, the frictional force at the contact point between the adjustment screw and the operating shaft is reduced, and at this time, the adjustment screw is installed with an oblique relief angle. A stopper mechanism is provided on the operating shaft to prevent movement.

Embodiments Below, embodiments of the present invention will be described with reference to the drawings. Reference numeral 1 denotes a main body of a super heat switch, which has a connecting spiral portion 1b forming a pressure introduction port 1a at its lower part. A bottom plate 4 of a diaphragm 3 is provided at the bottom of the main body 1 via a bottom plate 2. A pair of diaphragms 3 and 3' are supported on the bottom plate 4, and a through hole 4a of the bottom plate 4 is connected to the diaphragm. 3,
It communicates with room R inside 3'. A capillary tube 5 is connected to the lower metal part 4, and the connecting screw part 1b
It extends outward through the tube and has a temperature sensing portion 5' at its tip.

A temperature-sensitive gas is sealed in the room R, and the bottom plate 2
This counteracts the refrigerant pressure introduced from the space 2a between the bottom plate 4 and the bottom plate 4.

An operating shaft 6 abuts on the diaphragm 3' and is guided by a hole 7a in a stopper 7 to move up and down. The operating shaft 6 is provided with a flange portion 6a that abuts against the stopper 7. An adjustment screw 8 of the micro switch S comes into contact with the upper surface of the operating shaft 6.

In the micro switch S, the mounting base plate 9a of the movable contact plate 9 is fixed to the switch case 11 by rivets 10, and the movable contact 9' at the free end faces the fixed contact 12' on the fixed contact plate 12.

The movable contact plate 9 is provided with forked arm portions 9b, 9b for the mounting board portion 9a, and the forked arm portions 9b,
A movable contact mounting portion 9d is provided at the end of the movable contact mounting portion 9b via diagonal connecting portions 9c, 9c that protrude in mutually opposing directions. A driving plate portion 9e is provided on the base plate portion 9a between the forked arm portions 9b, 9b.

Since the movable contact plate 9 is formed by punching out a phosphor bronze flat plate, the ends of the forked arm parts 9b, 9b are contracted inward due to the presence of the diagonal connecting parts 9c, 9c, and the movable contact mounting part 9d, and strain occurs in the proximal end portions 9f, 9f of the bifurcated arm portions 9b, 9b.

Therefore, by moving the drive plate portion 9e up and down during use, the movable contact fixed through the mounting hole _9d1 of the movable contact mounting portion 9d is rapidly reversed.

As clearly shown in FIG. 3, the adjusting screw 8 is tilted at an angle α with a relief angle such that the contact end 8a is directed toward the free end of the movable contact plate 9 with respect to the operating direction line l in the axial direction of the operating shaft 6. It is set up in a shape.

When the operating shaft 6 rises in the open state of the micro switch S shown in FIG.
a rises while sliding slightly in the direction of arrow P in FIG. 3, and when it passes the dead point, the movable contact plate 9 is rapidly reversed to bring the movable contact 9' into contact with the fixed contact 12'.

At a position beyond the dead point, the flange 6a of the actuating shaft 6 abuts against the stopper 7 to prevent movement, thereby preventing the drive plate 9e from being deformed more than necessary.

The movable contact plate 9 is provided slightly obliquely upward at the fixed contact 12', and in the process of closing the switch S, the movable contact plate 9' contacts the fixed contact 12' and the movable contact plate 9 Slight sliding toward the free end and mutual polishing of the contacts 9' and 12' are performed to ensure good electrical contact at all times.

〔effect〕

As described above, the present invention includes an operating shaft 6 that contacts the diaphragms 3 and 3' that respond to fluid pressure, and a flange 6a that abuts against a stopper 7 that guides the movement of the operating shaft 6. A movable contact 9' is provided at the free end of the movable contact plate 9 constituting the switch S, and a drive plate portion 9 of the movable contact plate 9 is provided.
An adjusting screw 8 is provided at the contact end 8a with respect to the operating direction line l in the axial direction of the operating shaft 6.
relief angle α toward the free end of the movable contact plate 9
The driving plate portion 9e quickly reverses the movable contact plate 9 in response to the movement of the diaphragms 3, 3', brings the movable contact plate 9' into contact with the fixed contact 12', and also rotates the operating shaft. The flange 6a of 6 is the stopper 7
Therefore, it is necessary to make the super heat switch as small as possible and ensure stable operation by reducing the frictional force at the point of contact between the adjustment screw and the operating shaft. It has the feature of being able to

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.
FIG. 2 is a perspective view of the movable contact plate, FIG. 3 is an enlarged view of the main parts of the same, and FIGS. 4A and 4B are explanatory views of a conventional example. 3...Diaphragm, 6...Operating shaft, 7...Stopper, 8...Adjustment screw, 9...Movable contact plate,
9e...Drive plate part, 9'...Movable contact, 12'...
Fixed contact.

Claims (1)

[Scope of utility model registration request] A movable switch S constituting the switch S is provided with an operating shaft 6 that contacts the diaphragms 3 and 3' that respond to the pressure of the fluid, and a flange 6a that abuts against a stopper 7 that guides the movement of the operating shaft 6. A movable contact 9' is provided at the free end of the contact plate 9, and an adjustment screw 8 is provided at the drive plate portion 9e of the movable contact plate 9, and the adjustment screw 8 is brought into contact with the actuation direction line l in the axial direction of the actuation shaft 6. The end 8a is provided obliquely with a relief angle α toward the free end of the movable contact plate 9, and the drive plate portion 9e is provided in response to the movement of the diaphragms 3, 3'.
quickly reverses the movable contact plate 9 and moves the movable contact plate 9'
A super heat switch characterized in that the flange 6a of the actuating shaft 6 abuts against a stopper 7 to prevent movement thereof.