JPS63141228A - Thermostat - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a thermostat that controls, for example, a compressor, by opening and closing a switch by sensing a change in temperature.

(Prior art) A conventional thermostat of this type is, for example, the
The configuration described in Publication No. 44687 is known. This conventional thermostat has a bellows connected to a power element connected to an RS thermostat, and a bellows rotatably attached to this bellows by a support shaft. One end of the lever is in contact. The other end of the bellows lever is provided with a spring whose strength can be adjusted freely by a screw that biases one end of the bellows lever in a direction in which it contacts the bellows, and the switch is activated by rotating the bellows lever against the spring. It is configured to open and close the contacts of the switch by pressing the lever and via the toggle rock structure.

Then, the bellows is expanded and contracted by the movement of the power element caused by the pressure change inside the temperature sensing tube that detects the outside temperature, and this bellows presses one end of the bellows lever, causing the bellows lever to rotate around the support shaft against the spring. let The other end of the bellows lever is brought into sliding contact with the switch lever to open and close the contacts of the switch via a toggle mechanism.

(Problems to be Solved by the Invention) However, the conventional thermostat described above requires a toggle mechanism to open and close the switch contacts with a snap action, whereas the lever moves slowly. The problem was that it was complicated, had a large number of parts, and was expensive. Furthermore, since the contacts are exposed to the outside air, the contacts are contaminated by oil applied to the toggle mechanism and are likely to cause contact failures, resulting in the problem of low reliability of the switch.

The present invention was made in view of the above problems, and an object of the present invention is to provide a highly reliable thermostat that performs snap action with an aS structure.

[Structure of the invention]

(Means for Solving the Problems) The thermostat of the present invention includes a bellows that expands and contracts due to temperature changes, one end of which is in contact with the bellows, and a driving magnet that is fixed to the other end of the bellows. A lever biased by a spring and rotatably attached to a support shaft, a driven magnet provided with poles that repel the driving magnet facing each other, and a lever provided near the driven magnet. The switch is operated by a driven magnet.

(Function) In the present invention, the bellows expands and contracts depending on the temperature, and this expansion and contraction causes the lever, which is biased by a spring, to rotate so as to always come into contact with the bellows. When this lever rotates, the driving magnet at the other end of the lever repulses and moves the driven magnet, thereby operating the switch.

(Example) Hereinafter, one example of the thermostat of the present invention will be described with reference to the drawings.

In the figure, reference numeral 1 denotes a box-shaped vessel body, to which is fixed a power element 3 that expands and contracts a bellows 2 attached to its tip in response to changes in the pressure inside the temperature-sensing tube that detects the outside temperature. A contact portion 7 at one end of a bellows lever 6 rotatably mounted on a support shaft 5 is brought into contact with the operating port 4 at the upper part of the bellows 2, and a free end side of the other end of the bellows lever 6 is brought into contact with is provided with a driving magnet 8 with the S pole located on the tip side, and a holding plate portion 10 that locks one end of a spring 9 that urges the contact portion 7 of the bellows lever 6 in the direction of the bellows 2. are integrally provided.

A hook part 11 provided at one end of the spring 9 is hooked into a hole 12 of a retaining plate part 10 of the bellows lever 6, and the other end of the spring 9 is hooked into a hole 12.
It is locked to an adjustment tube 15 that is attached by screwing into a screw 14 inserted into a screw hole 13 provided in the.

Reference numeral 16 denotes a driven magnet, and the driven magnet 1G has an S pole on the side facing the driving magnet 8 so as to repel the driving magnet 8, and both magnets 8 and 16 have the same polarity. The driven magnets 16 face each other, and the driven magnets 16 are fixed to the tip of an actuating plate 17 rotatably attached to the support shaft 5.

Reference numeral 21 denotes an insulator, and a reed switch 22 that opens and closes by sensing the position of the driven magnet 16 is attached to the insulator 21 via a terminal piece 23.

Reference numerals 24 and 25 are adjustment screws for regulating the rotation range of the operating plate 17, and the open position adjustment screw 24 is located at the bending portion 2 of the container body 1.
6, and when the driven magnet 16 comes into contact with the tip of the open position adjustment screw 24, the reed switch 22
Adjust with the adjustment hole 28 of the container body 1 so that it is open. Further, the closed position adjusting screw 25 is screwed into a screw hole 29 of the insulator 21, and when the driven magnet 16 comes into contact with the tip of the closed position adjusting screw 25, the reed switch 22 is closed.

Next, the operation of the above embodiment will be explained.

First, the biasing force of the bead O's lever 6 is adjusted by rotating the screw 14 and moving the adjustment tube 15 forward and backward to change the position of the spring 9.

Next, when the driven magnet 16 comes into contact with the tip of the open position adjustment screw 24, the reed switch 22 rotates the same @mlO screw 24 from the adjustment hole 28 to move it forward and backward to adjust it. When the driven magnet 16 comes into contact with the tip of the closed position adjusting screw 25, the reed switch 23 is adjusted by rotating the closed position adjusting screw 25 so that it moves forward or backward.

Then, the external temperature is sensed by the power element 3. For example, when the temperature is high, the bellows 2 expands, and the operating surface 4 presses the contact part of the bellows lever 6, and the bellows lever 6 is moved against the support shaft against the spring 9. 5 and push down the driving magnet 8. When the driving magnet 8 crosses the actuation straight line, which is the dead center position, the driven magnet 16 is repelled by the driving magnet 8, and the actuating plate 17 rotates around the support shaft 5 with a snap action, and the driven magnet 16 is brought into contact with the closed position adjustment screw 25.

At this time, the reed switch 22 is closed by the driven magnet 16.

On the other hand, when the temperature becomes low, the bellows 2 contracts, the operating surface 4 lowers, and the spring 9 rotates the bellows lever 6 about the support shaft 5, pushing up the driving magnet 8.

When the driving magnet 8 crosses the actuation straight line, which is the dead center, the driven magnet 16 is repelled by the driving magnet 8, and the actuating plate 17 rotates around the support shaft 5 with a snap action, and the driven magnet 16 is brought into contact with the same level i\J4 node screw 24. At this time, the reed switch 22 is opened by the driven magnet 16.

In this way, the temperature of, for example, a compressor connected to the terminal piece 23 is controlled.

(Effects of the Invention) According to the present invention, since the repulsive force of the magnet is used, snap action can be performed with a simple structure, and the operation is reliable, and since it does not depend on the mechanical structure of the toggle mechanism, a paper-type switch can be performed. It can be used with high reliability.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of one embodiment of the thermostat of the present invention, and FIG. 2 is a top sectional view of the same. 2. Bellows, 5. Support shaft, 6. Lever, 8.
Driving magnet, 9... Spring, 16... Driven magnet, 22... Switch.

Claims (1)

[Claims] (1) A bellows that expands and contracts due to temperature changes, one end of which is in contact with the bellows, a driving magnet is fixed to the other end of the bellows, and is biased by a spring in the direction of contacting the bellows and is rotatably attached to a support shaft. a lever attached to the drive magnet; a driven magnet provided with a pole repelling the driving magnet facing the driven magnet; and a switch provided near the driven magnet and operated by the driven magnet. A thermostat characterized by: