JPH01200530A - Thermostat - Google Patents

Abstract

PURPOSE:To simplify constitution and stabilize characteristics by providing a set lever on an operation board and holding the operation board at a set position at the time of thermostat setting. CONSTITUTION:At the time of the cooling operation of a refrigerator, an operation board 2 and a set lever 2d are in the predetermined conditions wherein the operation board 2 presses an operation axis 16, thereby making a movable contact point 12 in contact with a cooling contact point 13. Then, in defrosting the inside of the refrigerator, the operation board 2 is turned in a clockwise direction via the set lever 2d and a U-shape quick reverse spring 7 is reversed. A spring force available therefrom resists a bellows 3 and the operation board 2 retains the condition thereof. Then, the operation board 2 releases the pressing force of the operation axis 16 and a movable contact point 12 is change over to a defrosting contact point 14 via a drive board 15 tending 10 return to the home position thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermostat used for defrosting refrigerators, protecting boilers, etc.

In conventional gas pressure thermostats for refrigerators, the actuating plate that contacts the bellows as a pressure-responsive member is pressed against the bellows by a push button shaft to a temperature above the normal set temperature (pressure) for defrosting. The contact is actuated, and the frictional engagement between the operating plate and the push button shaft is released due to the pressure increase upon completion of defrosting, and the return spring returns the push button shaft to its original position.

1) The above conventional technology requires a push button shaft and a return spring for defrosting, as well as a means for frictionally securing the actuating plate, resulting in a complicated structure. When the push button shaft and the actuating plate disengage from each other at the end of defrosting, the degree of frictional force between them acts, causing variations in characteristics.

The present invention has been made with attention to the above-mentioned points, and it is an object of the present invention to provide a thermostat with a simplified configuration and stable characteristics.

In order to achieve the above-mentioned object of adjusting i, the present invention transmits the movement of the bellows in the gas pressure sensor section to the switch via an actuation plate, and provides a set lever on the actuation plate and an adjustment mechanism. A configuration is adopted in which a reversing spring of a snap action having a snap action is engaged, and during setting, the reversing spring resists the bellows and holds the actuating plate at the set position.

In the drawing, an abbreviated operating plate 2 is provided in a main body case 1 having a bracket 1a so as to be rotatable within a certain range about a fulcrum 2a. A pivot 2b+ is provided on the horizontal plate portion 2b of the L-shaped actuating plate 2, and is in contact with the free end portion 3a of the bellows 3, which serves as a pressure-responsive member that converts temperature into pressure. The coil spring 4 within the bellows 3 is used when the operating pressure is negative. A capillary tube 5 communicating with a temperature sensing section (not shown) is connected to the bottom plate 1b of the main body case 1 so as to open into the bellows 3. A gas pressure sensor section is constructed from the temperature sensing section to the bellows 3.

A known substantially U-shaped rapid reversal spring 7 is locked between the end 2b of the horizontal plate portion 2b of the actuating plate 2 and an elastic adjustment plate 6 provided on the side plate 1c of the main body case 1. The U-shaped rapid reversal spring 7 is a so-called double snap action that rapidly reverses in both directions. An adjustment screw 8 is screwed onto the side plate 1C to change the extrusion position of the elastic adjustment plate 6 and adjust the reversal position of the rapid reversal spring 7. A set lever 2d is connected to the vertical plate portion 2c of the actuating plate 2, and a hole 1a in the plaquette 2a is connected to the vertical plate 2c.
, are derived more externally.

A switch box 9 is fixed to one side of the main body case 1. In the switch box 9, as is well known, a micro switch S having a U-shaped rapid reversal spring 10 is provided, and a movable contact 12 provided at the free end of a movable contact plate 11 is separated from a cooling contact 13. It selectively approaches and separates from the frost contact 14.

An operating shaft 16 is fixed to a drive plate 15 that is connected to the movable contact plate 11 via the reversing spring 10 .

The actuating shaft 16 passes through the hole 9a of the switch box 9, enters the case body 1, and faces the vertical plate portion 2c of the actuating plate 2.

In the above configuration, during the cooling operation of the refrigerator, the actuating plate 2
The set lever 2d is in the state shown in FIG.
presses the operating shaft 16 to move the movable contact 12 to the cooling contact 13
is in contact with.

When a large amount of frost adheres to the evaporator of the refrigerator and defrosting is required (5°C), the actuating plate 2 is rotated clockwise via the set lever 2d, and the U-shaped rapid reversing spring is activated. 7 is reversed as shown in FIG. 2, and this state is maintained against the bellows 3 by the spring pressure of the reversed U-shaped sudden rotation reversing spring 7. At this time, the actuating plate 2 is moved against the actuating shaft 1.
6 is released, the movable contact 12 is switched to the defrosting contact I4 by the drive plate 15, which has a tendency to return to the state shown in FIG.

When the temperature inside the refrigerator rises (10°C) due to the progress of defrosting,
The bellows 3 overcomes the spring pressure of the U-shaped rapid reversal spring 7 and rotates the actuating plate 2 counterclockwise, and the reversal spring 7 is reversed to the state shown in FIG.

In this case, since the actuating plate 2 comes into contact with the actuating shaft 16 after the reverse return, the switch box 9 side does not affect the actuating value, and sufficient clearance is maintained between the actuating plate 2 and the actuating shaft 16. As a result, the timing adjustment for the reversal of the U-shaped rapid reversal spring 7 and the movable contact 12 turning OFF the defrosting contact 14 can be ignored, and the pivot of the actuating plate 2 in contact with the bellows 3 can be ignored. The end 2b of the actuating plate 2 and the end 6a of the elastic adjustment plate 6 that come into contact with the
Since all of them are knife-shaped, the influence of frictional force is extremely small.

As described above, the present invention transmits the movement of the bellows in the gas pressure sensor section to the switch via the actuating plate, and the actuating plate is provided with a cut lever and a snap-action reversing spring having an adjustment mechanism. The reversing spring holds the actuating plate in the center position against the bellows when set, so the structure can be greatly simplified and the operation can be stabilized. It has the advantage of being able to

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the cooling operation state of one embodiment, and FIG. 2 is a sectional view showing the defrosting operation state of the same embodiment. 2...Operation +L 2 d...Set lever -13...
・Bellows, 7... Reversing spring, S... Sui Sochi. Patent applicant: Saginomiya Seisakusho Co., Ltd. Figure 1

Claims (1)

[Claims] The operation of the bellows in the gas pressure sensor section is transmitted to the switch via the actuating plate, and the actuating plate is provided with a set lever and engaged with a snap-action reversing spring having an adjustment mechanism. A gas pressure thermostat characterized in that the actuating plate is held in a set position against a bellows.