JP2003059379A - Thermosensitive switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermosensitive switch capable of preventing another spark between the contacts by absorbing the impact of the reversion of a thermally-actuated plate when the contact is opened. SOLUTION: A buffer plate 16 composed of a metallic plate having elasticity is fixed to a thermally-actuated plate support 10. The back side of the thermally-actuated plate is brought into contact with a contacting part 16A arranged on the tip of the free end part of the buffer plate 16 when the thermally-actuated plate 12 is reversed. The buffer plate 16 restricts the moving distance of a movable contact 14 by supporting the thermally-actuated plate 12 from the back when the thermally-actuated plate 12 is reversed, absorbs collision energy when it is reversed and suppresses a rebound of the movable contact. Accordingly the consumption of the contacts can be suppressed by restricting the distance between the contacts, suppressing arc energy and preventing another spark, therefore, the life of the switch 1 can be extended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of durability of contacts in a heat-actuated switch used in a hermetic three-phase electric compressor or the like.

[0002]

2. Description of the Related Art Various conventional three-phase thermally actuated switches have been proposed, and as one example, Japanese Patent Application Laid-Open No. 1-10.
There are two types of thermal protectors shown in 5435, and one having a particularly large current capacity is disclosed in Japanese Patent Laid-Open No.
Those shown in FIGS. 1-4 of -105435 are suitable. This thermal protector is connected to the midpoint of the winding of the three-phase motor and separates each winding of the three-phase motor from each other by opening and closing each of the two movable contacts fixed on the thermal plate. The power is cut off. This thermal protector had a structure in which the three-phase protector earlier opened and closed three sets of contacts, but by using two sets of contacts, the number of parts was reduced and manufacturing became easier.

However, in this thermal protector, there has been a problem of contact wear due to arcs generated when the contacts are opened. In such a switch, it is usually unavoidable that an arc is generated between the contacts when the contacts are opened, but the distance between the contacts when the contacts are opened becomes important especially when the switching current is large. This is related to the size of the arc when the contacts open, and not only is the arc less likely to break when the distance between contacts is too small, but the distance between contacts that has momentarily increased when the distance between contacts is too large. The energy of the arc increases against the resistance. Therefore life of the thermally responsive switch by damage to the surrounding contact with also severe wear of the contacts, etc. In either case there is a problem that becomes shorter. In particular, this protector has a problem in that the structure has a large space between the contacts and a large arc energy.

A heat-actuated switch which solves this problem will be described with reference to FIGS. The heat-actuated switch 101 has two sets of contacts and is used to protect a three-phase motor or the like. This heat-responsive switch 101
The metal-made dome-shaped housing 102 and the cover plate 103 constitute an airtight container. The lid plate 103 is a metal plate 104 provided with a rib 104A for increasing strength near the center.
The conductive pins 105 made of metal are respectively passed through the two through-holes formed in the hole and are airtightly fixed by an electrically insulating material such as glass.

A fixed contact 107 is conductively connected to the tip of the conductive pin 105 on the inner side of the closed container through a fixed contact support 106. The fixed contact support 106 is held and fixed by interposing an electrical insulator 108 such as an insulator or ceramics with the metal plate 104.

A metallic heat responsive plate support 109 is fixed to the metal plate 104 of the cover plate 103. The heat responsive plate support 109 has a plurality of legs 109A and a metal plate supported by the legs. Main surface portion 1 arranged substantially parallel to the surface of 104
And 09B. The elastic plate 11 is provided on the main surface portion 109B.
The heat responsive plate 112 is electrically conductively fixed to the heat responsive plate 112 via the fixing pieces 111 and 0, and the two movable contacts 113 fixed to the heat responsive plate 112 face the fixed contact 107. The heat responsive plate 112 is draw-formed in a shallow dish shape so as to make a sudden reversal at a predetermined temperature, and an adjustment screw 114 arranged on the main surface portion 109B of the heat responsive plate support 109 is used to adjust the vicinity of the center of the heat responsive plate. The reversal temperature is set by pressing and adjusting the pressure between the contacts.

In this heat-actuated switch 101, a protrusion is provided on the main surface portion 109B of the heat-actuated plate support 109 as a portion for restricting the movement distance of the contacts so that the distance between the contacts does not become too wide when the heat-actuated plate 112 is reversed. 109C is provided, and when the heat responsive plate 112 is turned over, the moving end of the heat responsive plate has the protrusion 1
By making contact with 09C, the distance between the contact points is set to be an appropriate distance without being excessively widened.

[0008]

However, the heat responsive plate support 109 is a metal plate having sufficient strength to support the heat responsive plate, and the movable side of the heat responsive plate 112 has a mass. Since the large movable contact is fixed, if the thermal reaction plate 112 comes into contact with the projection 109C during the sudden jump reversal, the kinetic energy cannot be sufficiently canceled due to the collision between the rigid bodies and the movable contact 113 bound by the reaction is generated. The fixed contact 107 may be approached and the arc may re-ignite between the contacts. In particular, immediately after the arc is extinguished, metal vapor due to the arc drifts in the space between the contacts and it is easy to re-ignite, so when such a phenomenon occurs,
Since the arc is repeated when the contact is opened, there is a problem that the deterioration of the contact progresses and the welding of the contact is likely to occur, and the durability of the thermally responsive switch deteriorates. In particular, in the case of multiple moving contacts with a large number of moving contacts such as a three-phase thermal responding switch, it is necessary to support a large thermal responding plate in order to pass a large current, and the rigidity of the thermal responding plate support is required. When it is raised, the kinetic energy of the contact is more difficult to be absorbed and the amount of rebound becomes larger.

Therefore, even if the heat responsive plate is upsized, it is possible to prevent re-ignition of the arc due to the bouncing of the movable contact portion when the contacts are opened, and to keep the distance between the contacts appropriately when opened. Is required.

[0010]

SUMMARY OF THE INVENTION In view of the above, the present invention relates to a heat-responsive switch in which a heat-responsive plate is disposed inside a metal airtight container via a heat-responsive plate support having high rigidity. Above the movable end side of the heat responsive plate, there is a part that regulates the movement distance during reversal.This regulated part is compared with the heat responsive plate support in order to reduce the impact at the time of contact due to reversal of the heat responsive plate. It is characterized by having sufficient elasticity.

According to the present invention, it is possible to prevent the contact gap between the movable contact and the fixed contact from becoming too wide at the time of reversing the heat responsive plate by the restricting portion, and it is possible to set an appropriate distance, and at the same time, the heat responsive plate contact is provided at the restricting portion. By elastically absorbing the impact at the time of contact, it is possible to prevent re-ignition of the arc between the contacts due to the rebound of the movable contact. Therefore, it is possible to prevent the contact from being worn away by the arc, extend the life of the contact, and improve the durability of the switch.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
Description will be given with reference to the drawings. 1 is a longitudinal sectional view showing an embodiment of a heat-actuated switch of the present invention, and FIG. 2 is a perspective view showing the heat-actuated switch of FIG. 1 with a housing removed.
FIG. 3 is an exploded view for clearly showing the component configuration of FIG. 2. The heat-actuated switch 1 is used to protect a three-phase motor or the like and has two sets of contacts. The heat-actuated switch 1 constitutes an airtight container with a metallic dome-shaped housing 2 and a cover plate 3. The cover plate 3 has two through holes 4A formed in the metal plate 4 through which conductive pins 5 made of metal are inserted, respectively, and an electrically insulating material 6 such as glass or ceramics 6 is formed.
It is fixed airtightly. A rib 4B for increasing pressure resistance strength is provided near the center of the metal plate 4.

A fixed contact 8 is conductively connected to a tip of the conductive pin 5 on the inner side of the closed container through a fixed contact support 7. The fixed contact point support 7 is an electrical insulator 9 such as ceramics or heat resistant synthetic resin that is elastically sandwiched between the metal plate 4 and the fixed contact point support 7 and fixed to the conductive pin 5. The insulator 9 is fixed on the cover plate. Further, since the tip side of the fixed contact support 7 to which the fixed contact 8 is fixed is elastically adhered to the electric insulator 9, the electric insulator 9
By defining the thickness of the fixed contact 8, the height of the fixed contact 8 from the lid plate surface can be made uniform to a predetermined value. Further, a projecting bearing 9A is provided at one end of the electric insulator 9, and a heat responsive plate described later is supported by the two fixed contacts 8 and the bearing 9A described above. In this example, the fixed contact support 7 has a reduced cross-sectional area so as to generate heat when energized, so that the rigidity is also lowered. Therefore, the fixed contact support 7 elastically sandwiches the electrical insulator 9 to allow the metal plate 4 to move. The fixed contacts are aligned with respect to the fixed contacts and at the same time support the fixed contacts. However, in the case where the cross-sectional area of the fixed contact support 7 can be increased to sufficiently increase the rigidity, or when the fixed contact 8 is directly fixed to the end face of the conductive pin 5, electrical insulation for determining the position of the fixed contact is provided. The body 7 can be omitted. Further, in the embodiment, the support portion 9A for supporting the heat responsive plate is provided as a part of the electric insulator 9. However, if a bypass current flows through this support portion, it does not matter and the tip of the support portion is insulated. When interposing paper or the like, the support portion may be formed of a metal plate or the like.

On the metal plate 4 of the cover plate 3, a metal heat responsive plate support 10 is electrically conductively fixed. The heat responsive plate support 10 has a plurality of legs 10A and a main surface portion 10B supported by the legs. In this embodiment, the main surface portion 10B is arranged substantially parallel to the surface of the metal plate 4, and the fixed end 1 of the elastic plate 11 is provided on the surface facing the metal plate 4.
1A is fixed by welding or the like. The heat responsive plate 12 is electrically conductively fixed to the free end 11B of the elastic plate 11. In addition, a through hole 11C for inserting a screw for operating temperature calibration, which will be described later, is provided near the center. In the present embodiment, the heat responsive plate 12 is elastic via a fixing piece 13 which is previously fixed to the support portion 12A before the temperature calibration work of the heat responsive plate so that the heat and strain during welding do not affect the operating characteristics. Although it is fixed to the free end 11B of the plate 11, the heat responsive plate 12 is fixed to the elastic plate 11 unless it has a substantial effect on the operating temperature.
It may be directly fixed to. In this case, the shape of the free end 11B of the elastic plate 11 does not have to be the widened shape as shown.

Two movable contacts 14 are fixed to the heat responsive plate 12, and the two movable contacts 14 are fixed to the heat responsive plate 12.
The support portions 12A are arranged so as to form an isosceles triangle, and each face the fixed contact 8 described above so as to be openable and closable. Further, the heat responsive plate 12 is formed by drawing a shallow dish shape in the vicinity of the center of the plate so as to make a sudden jump reversal at a predetermined temperature, and the side that normally becomes convex is the surface that contacts the adjusting screw 15.
After assembly, the reversing temperature is set by pressing the vicinity of the center of the heat responsive plate with the adjusting screw 15 to adjust the contact pressure. Moreover, the pressing force by the adjusting screw 15 is
The two movable contacts 14 fixed to the supporting portion 12A of the heat responsive plate 12 are supported at three points, that is, the supporting portion 9A of the electric insulator 9 and the fixed contact 8 as described above. Since the heat responsive plate 12 is elastically held and fixed by the elastic plate 11 as described above, the positional relationship between the movable contact and the fixed contact is not aligned due to the inclination between the components due to assembly, etc. Then, even if the contact pressure between the contacts is not uniform, the actual contact pressure between the contacts can be automatically uniformed by slightly bending the elastic plate if the amount of inclination of the component is less than or equal to a predetermined amount.

The adjusting screw 15 is held by an adjusting screw holding portion arranged on the main surface portion 10B of the heat responsive plate support 10, and the adjusting screw holding portion is constituted by the two beams 1 in the embodiment.
It is composed of 0C. The adjusting screw 15 is attached while forming a screw groove near the center of the slit-shaped gap 10D sandwiched between the beams 10C. At this time, the adjusting screw 15 attempts to spread the beams 10C on both sides, but the screws are held so as not to loosen by being elastically tightened by the reaction force of the beams 10C. Therefore, it is not necessary to prepare a special screw stopper.

The adjusting screw 15 is inserted through the above-mentioned insertion hole 11C of the elastic plate 11 and its tip is in contact with the surface of the heat responsive plate 12 which is normally the convex side, and the heat is adjusted by adjusting the screwing amount. The pressing force on the response plate is adjusted. By pressing the convex surface of the heat responsive plate 12 in this way, the reversal temperature of the heat responsive plate set by drawing can be finely adjusted and calibrated.

The main surface portion of the heat responsive plate support 10 is made of a metal plate having sufficient elasticity as compared with the heat responsive plate support, as a portion for restricting the moving distance of the movable contact when the heat responsive plate is reversed. The buffer plate 16 is fixed. This buffer plate 16 is made of a material having flexibility, such as rolled steel plate or phosphor bronze, and has an abutting portion 16A provided at the tip of a spring-like portion 16B extending in an arm shape when the heat responsive plate 12 is inverted. It is arranged so as to come into contact with the vicinity of the back surface of the movable contact fixing position of the plate. Further, the cushioning plate 16 is arranged such that the side of the abutting portion 16A is spaced apart from the main surface portion 10B of the heat responsive plate support body by a predetermined distance. The entire 16B is designed to be flexible. In this embodiment, one buffer plate 16 is provided with two spring-shaped portions and abutting portions, but two independent buffer plates may be provided with abutting portions. Furthermore, a buffer plate may be welded to the fixed end 11A side of the elastic plate 11 so that the abutting portion abuts on the movable end side of the heat responsive plate.

Next, the operation of this heat-actuated switch will be described. This heat-actuated switch 1 is connected to the middle point of a so-called Y-connection three-phase electric compressor, and includes a metal plate 4 of a cover plate 3 and two conductive pins 5 insulated and fixed to the metal plate. The terminals are connected to each winding of the three-phase motor.

Here, a current path from one conductive pin 5 to the other conductive pin 5 through the fixed contact support 7 and the fixed contact 8, the movable contact 14, the heat responsive plate 12, and each conductive pin 5.
In the same way, through the heat responsive plate 12, the fixing piece 13 and the elastic plate 1
1. With respect to the current path that reaches the metal plate 4 through the heat responsive plate support 10, the heat generated by each component on each electric path and the heat generated by the heat responsive plate itself have substantially the same effect on the heat responsive plate 12. Is set. Therefore, the thermal responsive plate can be reliably operated regardless of which winding of the three phases has an overcurrent.

When the heat responsive plate 12 reverses due to self-heating or the thermal influence from the surroundings, the heat responsive plate 12 is fixed to the plate 2
Each of the movable contacts 14 is separated from the fixed contact 8, and the heat-actuated switch 1 is deenergized. At this time, the heat-responsive plate 12 that has undergone the sudden jump reversal moves its movable end almost instantaneously to the main surface side of the heat-responsive plate supporter 10.

Here, the movable end of the heat responsive plate 12 is brought into contact with an abutting portion 16A provided at the tip of the buffer plate 16 which is a restricting portion, so that the shock at the time of contact of the movable portion is caused by the buffer plate 16. By elastically deforming, it is relieved and the rebound of the movable contact can be prevented. Further, in the embodiment, at least a part of the abutting portion 16A at the tip of the buffer plate 16 pushed by the heat responsive plate 12 comes into contact with the main surface portion 10B of the heat responsive plate supporter 10 to cause the movable end of the heat responsive plate 12 to move. The movement is restricted to prevent the distance between the movable contact and the fixed contact from becoming excessive. In this way, by restricting the moving distance of the movable contact when the contacts are opened by the buffer plate 16, it is possible to prevent the distance between the contacts from being unnecessarily widened when the contacts are opened, and to suppress the arc energy within an appropriate range. The contact life can be extended.

Further, the buffer plate 16 absorbs the kinetic energy when the heat responsive plate 12 is reversed to prevent the arc between the contacts from being re-ignited. That is, when the heat responsive plate 12 is inverted, the movable side of the heat responsive plate vigorously heats the heat responsive plate supporter 10.
However, in the present invention, the buffer plate 16 is elastically deformed by the movable end of the heat responsive plate contacting the abutting portion 16A having the V-shaped tip of the buffer plate 16 having sufficient elasticity. The heat-responsive plate 12 is received to soften the impact at the time of a collision due to sudden reversal of the heat-responsive plate 12. Therefore, the rebound of the movable end side is suppressed when the heat responsive plate is turned over, and the situation where the movable contact that was generated in the conventional one with a moving distance restriction part by a rigid body approaches the fixed contact enough to re-ignite the arc It can be surely prevented. Further, in the case of the embodiment, not only the elasticity due to the buffer plate which is the movement restricting portion of the movable contact, but also the tip end portion of the contact plate that abuts against the heat responsive plate causes sliding friction when it comes into contact with the heat responsive plate support. The heat-responsive plate 12 can be more efficiently brought into contact with the heat-responsive plate supporter.
Can absorb the kinetic energy of.

Next, another embodiment of the present invention will be described with reference to FIG. In this embodiment, the same parts as those in the above-mentioned embodiment are designated by the same reference numerals and detailed description thereof will be omitted. FIG. 4 shows the assembled state excluding the housing of the heat-actuated switch. In this embodiment, the heat-actuated plate support 20 welds and fixes a plurality of legs 20A to the metal plate 4 as in the previous embodiments. Has been done. The main surface portion 20B of the heat responsive plate support 20 is provided with a notch 20C at a portion where the abutting portion 26A at the tip of the buffer plate 26, which is a restriction portion, is arranged, and the vicinity of the tip of the buffer plate 26 is provided at the heat responsive support body. It is designed not to touch 20.

The shape of the buffer plate 26, which is the regulating portion, may be the same as that of the above-described embodiment, but the tip end portion of the buffer plate is arranged so as to be spaced a predetermined distance from the main surface portion 20B of the heat responsive plate support. This affects not only the processing accuracy of each component but also the accuracy at the time of assembly and a slight deformation due to welding, etc., which is problematic in terms of ease of manufacturing work. Therefore, in the present embodiment, the entire buffer plate 26 is arranged along the main surface portion 20B of the heat responsive plate support, and the vicinity of its tip is a free cantilever. Therefore, it is easy to match the dimensions during manufacturing. Further, the buffer plate is not fixed at the base of the tip portion, and the spring-like portion (not shown) similar to the above-described example is also set in a free state, so that the heat responsive plate 12 causes the tip portion 2 to move.
The buffer plate 26 has a notch 20C when the vicinity of 6A is bent.
The spring-like portion can be bent into an arch shape with the contact point with the fulcrum as a fulcrum, and the impact during collision can be easily absorbed. In this case, the distance between the movable contact and the fixed contact at the time of opening can be determined by the material, thickness and width of the buffer plate, and the amount of protrusion from the notch at the tip.

Next, FIGS. 5 and 6 show another embodiment of the present invention. Since the basic structure of these examples is the same as that used in the first embodiment when a heat-actuated switch is used, a diagram showing the entire structure is omitted and a buffer plate is attached to the heat-actuated plate supporter 10. Shown only in the closed state. The spring-like portion 36A of the buffer plate 36 shown in FIG. 5 is attached as a regulating portion similarly to the buffer plate 16 described above, and a V-shaped contact portion 36B near the tip end.
Is provided. Further, the spring-like portion 46A of the buffer plate 46 shown in FIG. 6 is provided with an abutting portion 46B by bending so as to raise the vicinity of its tip.

These cushioning plates 36 and 46 are in a state in which the movable-side end portions 36C and 46C of the spring-shaped portions 36A and 46A are in contact with the main surface portion 10B of the heat responsive plate support 10, respectively, but are in contact with each other. The angle from the portion to the tip with respect to the heat responsive plate support main surface portion 10B is 60 degrees or less, more preferably 45 degrees or less. Therefore, when the heat responsive plate is turned over and comes into contact with the abutting portion, the tip side of the spring-like portion having a relatively high rigidity instantly falls toward the abutting portion around the tips 36C and 46C. At this time, the entire spring-shaped portions 36A and 46C are bent to absorb the impact of the contact with the thermal responsive plate and prevent the movable contact from rebounding. Particularly in the example of FIG. 5, the impact portion 36 of the buffer plate 36
By making B a V-shape, a force is applied to the surface of the spring-shaped portion 36C at a deeper angle, so that the spring-shaped portion can be easily bent. Further, by making the contact angle of the tip portions 36C and 46C of the buffer plate with the principal surface portion 10B of the heat responsive plate support 10 shallow, the tip portions 36C and 46C are located on the principal surface portion 10B when the abutting portions 36B and 46B are pressed. It becomes easier to slide on, and the amount of this sliding is small, but the energy at the time of impact of the heat responsive plate is effectively absorbed. Furthermore, each buffer plate 36,
Since 46 is assembled in a state where the tip end portion is in contact with the main surface portion of the heat responsive plate 10, the distance between the heat responsive plate and the abutting portion, and the distance between the fixed contact and the movable contact when the heat responsive plate is reversed. It becomes easy to prescribe.

Further, another embodiment of the present invention will be described with reference to FIGS. This heat-responsive switch 51
Also, most of the parts are common to the first embodiment described above,
The same parts are designated by the same reference numerals and detailed description thereof will be omitted. The heat responsive plate support 50 of the heat responsive switch 51 is held and fixed by the legs 50A as in the above-mentioned example, and a notch 50C is provided on the side surface of the main surface 50B. The front end of the buffer plate 56, which is a restriction portion, is inserted into the notch 50C. As shown in FIG. 9, the buffer plate 56 has a hook-shaped planar shape at the tip of the spring-shaped portion 56A, and the tip portion is 90 degrees with respect to the plane of the spring-shaped portion 56A.
It is bent once.

In the present embodiment, the upper end surface 56B1 of the bent base portion 56B of the tip portion is the spring portion 56.
It is higher than the A side. Therefore, when the heat responsive plate 12 is turned over, the heat responsive plate 12 and the main surface portion 5 of the heat responsive plate support 50 are determined by the positional relationship between the upper end surface 56B1 and the abutting portion 56B2.
The distance to 0B is defined, so that the maximum distance between the contacts is reliably defined. The spring-like portion 56A is the heat responsive plate support 5
A biasing force is applied in the direction of separating the tip of the main surface portion 50B of 0. An extension portion 56C extending upward from the base portion 56B in the drawing is inserted through the notch 50C described above, and the locking portion 56D provided at the tip is in contact with the main surface portion 50B by the biasing force described above. Due to the function of this locking portion, the spring-like portion 56A of the buffer plate 56 approaches the thermal responsive plate 10 more than necessary or the abutting portion 56 even if the above-mentioned biasing force is applied.
B2 never touches. Further, in this embodiment, the distance between contacts at the time of reversing the heat responsive plate can be determined by the machining accuracy of the parts, such as the planar shape near the tip of the buffer plate or the notch shape of the heat responsive plate support. Higher accuracy can be obtained as compared with the above-mentioned example in which the positional relationship of the contacts is determined by the bending angle, the mounting accuracy to the heat responsive plate support, and the like.

[0030]

As described above, according to the thermal responsive switch of the present invention, the movement of the movable side of the thermal responsive plate is regulated when the thermal responsive plate is reversed by the regulating portion provided on the thermal responsive plate support. By doing so, it is possible to prevent the contact distance between the movable contact and the fixed contact from becoming too wide when the contacts are opened, and to set an appropriate distance so that the energy of the arc does not become excessive. Further, since the restriction portion elastically absorbs the impact when the heat responsive plate comes into contact, the movable contact can be prevented from rebounding and the re-ignition of the arc due to the reduction of the distance between the contacts immediately after opening the contacts can be prevented. In this way, the durability of the switch can be improved by preventing the contact from being worn due to the arc between the contacts.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a heat-actuated switch according to the present invention.

FIG. 2 is a perspective view showing an assembled state of the thermoresponsive switch of FIG. 1 excluding a housing.

FIG. 3 is an exploded perspective view of FIG.

FIG. 4 is a perspective view showing an assembled state excluding a housing in another embodiment of the present invention.

FIG. 5 is a side view showing the main part of another embodiment of the present invention.

FIG. 6 is a side view showing a main part in another embodiment of the present invention.

FIG. 7 is a longitudinal sectional view showing an embodiment of a heat-actuated switch according to the present invention.

8 is a perspective view showing an assembled state of the thermoresponsive switch shown in FIG. 7 excluding a housing.

9 is a perspective view of a buffer plate used in the heat-actuated switch of FIG. 7. FIG.

FIG. 10 is a vertical sectional view showing an example of a conventional heat-actuated switch.

11 is a perspective view showing an assembled state of the thermoresponsive switch of FIG. 10 excluding a housing.

[Explanation of symbols]

1, 51: Thermally actuated switch 2: Housing 3: lid plate 4: Metal plate 5: Conductive pin 6: Electrically insulating material 7: Fixed contact support 8: Fixed contact 9: Electrical insulator 10, 20, 50: Heat-responsive plate support 11: Elastic plate 12: Thermal plate 13: Fixed piece 14: Moving contact 15: Adjustment screw 16, 26, 36, 46, 56: Buffer plate (regulating portion) 16A, 36B, 46B, 56B2: Abutting part 16B, 36A, 46A, 56A: Spring portion

Claims (3)

[Claims] 1. A lid plate in which two conductive pins are airtightly fixed through a metal plate in an electrically insulated state, and a metal housing constituting an airtight container by fixing an opening to a peripheral portion of the lid plate. And a heat-responsive plate is disposed on the metal plate via a heat-responsive plate support having high rigidity inside the airtight container, and the heat-responsive plate is drawn at a predetermined temperature by being drawn into a dish shape. The curving direction is suddenly reversed and returned, and one end of the heat responsive plate is a fixed end that is electrically connected and fixed to the metal plate, and the movable end that forms an isosceles triangle with this fixed end as a vertex. Two movable contacts are fixed to the portion, and the movable contacts are fixed contacts that are conductively connected to the conductive pins, and the movable contacts can be opened and closed. When the response plate is inverted, the contact gap between the movable contact and the fixed contact becomes wider. In order not to overload, the moving end side of the heat responsive plate is provided with a part that regulates the moving distance at the time of reversing. A thermally responsive switch characterized by having sufficient elasticity in comparison. 2. The heat-responsive opening / closing according to claim 1, wherein the movement restricting portion is formed of a metal plate, and an abutting portion with which the heat-responsive plate abuts is formed on a part of the metal plate. vessel. 3. The heat-actuated switch according to claim 2, wherein the abutting portion is arranged on the back side of each movable contact.