JP2003338238A - Motor protective device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a motor protective device which is used for a sealed motor compressor and has a function to detect an abnormal refrigerant pressure together with an over-current and an overheat. <P>SOLUTION: A pressure-proof container is constituted of a container 2 and a cover plate 3 in the motor protective device 1. A stationary contact point 9 is adhered to one electroconductive terminal pin 8A insert-penetrating and fixed to the cover plate 3. A thermally-actuating plate 5 is connected with and fixed to the inner face of the container 2, and the movable contact point 6 is arranged open-close free with the stationary contact point 9. In the motor protective device 1, because a thermally-actuating plate fixing position 2A of the container 2 is flattened and deformed, the pressure between the contact points is adjusted, and the operated temperature is calibrated. A displacement part 2B which is made easier to deform by making the plate thickness thinner than that of its peripheral part is installed in the vicinity of the thermally- actuated plate fixing position. The operating temperature of the thermally- actuated plate can be reduced because the displacement part 2B of the container is deformed in the smashed direction if it is exposed to a high pressure state. Therefore, the current supply can be cut off under a high pressure. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention [Industrial applications]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor protection device, and more particularly to an electric motor protection device arranged in a refrigerant atmosphere in a closed container of a hermetic electric compressor in a refrigerator, an air conditioner or the like.

[0002]

2. Description of the Related Art Conventionally, as a motor protection device used in a hermetically-sealed electric compressor, there is a heat responsive switch described in Japanese Patent Publication No. 2519530. As shown in FIG. 8 and FIG. 9 which is a cross-sectional view taken along the line CC of FIG. 8, the thermoresponsive switch 101 forms an airtight container from a long dome-shaped pressure-resistant container 102 and a lid 103, and inside the airtight container, a bimetal or the like is used. Contact opening / closing mechanism using the heat responsive plate 104 and heater 105
have. The heat responsive plate 104 has one end at the container 102.
To the movable contact, which is the other end.
06 is fixed and can be brought into contact with and separated from the fixed contact 107. The fixed contact 107 is fixed to a conductive terminal pin 108A which is fixed to the cover plate 103 by an insulating filling material 109 such as glass in an airtight and electrically insulated state. The heater 105 has one end connected to the cover plate 103 and the other end connected and fixed to the conductive terminal pin 108B.

This heat-responsive switch 101 is used by connecting one of the two conductive terminal pins 108A and 108B to the winding of the electric motor and the other end to a power source, and the temperature around the heat-responsive switch 101 becomes abnormally high. When an abnormal current flows through the electric motor, the heat responsive plate 104 reverses to open the contacts. Further, by providing the fusing part 105A in which the cross-sectional area of a part of the heater (heating element) 105 is smaller than the cross-sectional area of the other part, in the unlikely event that the guaranteed number of operations of the heat-responsive switch is exceeded, welding of contacts occurs. In addition, the fusing part 105A of the heater can be fused and the electric circuit can be cut off.

[0004]

SUMMARY OF THE INVENTION The above-mentioned heat-responsive switch is designed to invert the heat-responsive plate or fuse the heater by overheating in the hermetically sealed container of the compressor or internal heat generation due to overcurrent flowing in the motor. It is possible to prevent the situation such as burnout by cutting off the power supply to.

In recent years, a hermetic compressor has been required to have a function of detecting an abnormal rise in refrigerant pressure in a hermetic container in addition to a function of detecting overheat and overcurrent. Conventionally, in order to protect against pressure rise of the refrigerant, a pressure switch is provided in the hermetic compressor to stop the electric motor, or a safety valve is provided to release the refrigerant into the atmosphere, etc. There were things that were set so as not to reach a level where danger could occur.

[0006] In particular, due to the change of the refrigerant by replacement with a specific CFC, the refrigerant pressure during the steady operation of the hermetic compressor is higher than that of the conventional one, and the detection of the pressure rise at the time of abnormality becomes more important. ing.

Due to its structure, the hermetic electric compressor needs to be protected not only from an abnormal rise in refrigerant pressure but also from overcurrent and overheat as described above. It is necessary to provide a pressure switch. However, the miniaturization of hermetic electric compressors has made it difficult to obtain a place for mounting these plural protective devices.

Therefore, the present invention proposes a protection device that integrates these functions to facilitate the attachment of the protection device and to reliably detect an abnormality.

[0009]

Therefore, in the motor protection device of the present invention, a pressure-proof airtight container is formed by a metal pressure-tight container and a lid plate that is airtightly fixed to the opening end of the container. A fixed contact or a heat responsive plate is fixed to the conductive terminal pin that is airtightly insulated and fixed to the through hole, and the heat responsive plate or fixed contact is conductively connected and fixed inside the pressure vessel.
In a motor protection device in which a movable contact of a heat responsive plate is releasably connected to the fixed contact, and the operating temperature is calibrated by displacing the fixed position of the heat responsive plate or fixed contact of the pressure resistant container with a jig or the like. In the vicinity of the fixed position of the pressure-resistant container, a displacing portion that is more easily deformed than the peripheral portion is formed, and the displacing portion is displaced in a direction in which the contact pressure between the movable contact and the fixed contact increases when pressure is applied from the outside of the container. It is characterized by that.

According to the present invention, it is possible to detect an abnormally high pressure state by making a slight modification to the conventional motor protection device, and to protect the equipment to be protected from overheating, overcurrent and high pressure. You can

Further, the maximum displacement position of the displacement portion is arranged so as to be closer to the tip end of the heat responsive plate than the fixed position of the heat responsive plate. Further, the fixed contact is fixed to the contact fixing position via the fixed contact support, and the maximum displacement position of the displacement portion is arranged in the fixed contact direction rather than the contact fixing position.
With this structure, when the container receives high pressure, the heat responsive plate and the fixed contact support are displaced so that the movement in the direction of the tip becomes large. Even if the amount is large, the pressure between the contacts can be sufficiently increased to cause a change in the operating temperature of the heat responsive plate, and a protective operation against the pressure can be reliably performed.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An electric motor protection device of the present invention will be described below with reference to the drawings. 1 and 2 are a side view and a plan view of this embodiment, FIG. 3 is a sectional view taken along the line AA of FIG. 2, FIG. 4 is a sectional view taken along the line BB of FIG. 3, and FIG.
FIG. 4 is a partially enlarged view of FIG. 3. Electric motor protection device 1 of the present invention
Is a pressure-resistant container 2 made by pressing and shaping an iron plate, etc.
The container 2 has a long dome shape having substantially spherical portions on both sides and connecting both ends by a semicircular central portion. The shape of the pressure-resistant container 2 is not limited to such a long dome shape, and if a predetermined pressure-resistant strength is obtained by, for example, providing a rib along the longitudinal direction of the container, it does not necessarily have a spherical portion. You don't have to. A lid plate 3 formed by forming an iron plate having a thickness greater than that of the container 2 is hermetically sealed by ring projection welding or the like in the opening of the container 2, and the both constitute a hermetic container.

One end of the heat responsive plate 5 is connected and fixed to the inside of the heat responsive plate fixing position 2A provided at one end of the container 2 via a support 4 made of a suitable metal plate. The heat responsive plate 5 is formed by drawing a bimetal, a trimetal, or the like into a shallow dish shape to set the operation reversal temperature in advance, and is arranged so as to be substantially parallel to the inner surface of the container. A movable contact 6 is fixed to the other end of the heat responsive plate 5.

Through holes 3A and 3B are formed in the cover plate 3, and electrically conductive terminal pins 8 are provided in the through holes by an electrically insulative filler 7 such as glass in consideration of the coefficient of thermal expansion.
A and 8B are airtightly insulated and fixed. A fixed contact 9 is fixed near the tip of one of the conductive terminal pins 8A on the inner side of the airtight container, and is arranged so as to face the movable contact 6 and be separated from it. In this embodiment, as the fixed contact 9, a contact in which the contact portion is clad on the substrate is directly fixed to the conductive terminal pin, but the fixed contact 9 may be fixed via a fixed piece.

This motor protection device 1 adjusts the contact pressure between the movable contact 6 and the fixed contact 9 of the heat responsive plate 5 by crushing and deforming the heat responsive plate fixing position 2A of the pressure resistant container 2 from the outside to adjust the operating temperature. Calibrate. The shape of the support body 4 is not limited to that shown in the figure, and the support body 4 is not limited as long as it does not substantially affect the preset operation reversal temperature when fixing the heat responsive plate 5 to the pressure resistant container. Can be omitted.

In the embodiment, the other conductive terminal pin 8B
Heater 10 as a heating element near the tip of the inside of the airtight container
Of the heater 10 is fixed, and the other end of the heater 10 is fixed on the cover plate. The heater 10 is arranged substantially along the periphery of the conductive terminal pin 8B, and is also arranged substantially parallel to the heat responsive plate 5 so that the heat exchange relationship is improved. The heater 10 is provided with a fusing part 10A having a smaller cross-sectional area than other parts. During normal operation of the compressor, which is the controlled device, the fusing part 10 is driven by the operating current of the electric motor.
A does not melt, and when the electric motor is in a restrained state, the heat responsive plate 5 reverses in a short time to open the gap between the contacts, so that the melted portion does not melt in this case either. If the electric motor protection device is repeatedly opened and closed for a long period of time, the contacts may be welded after a certain number of guaranteed operations, and the contacts may not be opened. In that case, the temperature of the fusing part 10A rises due to the overcurrent due to the restrained state of the electric motor, which eventually leads to the fusing, so that the power supply to the electric motor can be reliably cut off.

Next, the operation of the motor protection device 1 will be described. The electric motor protection device 1 is arranged in a closed container of a hermetic electric compressor, and is fixed on, for example, a coil end of the electric motor or a conductive terminal of the closed container. Further, the electric motor protection device 1 is arranged in the discharge-side refrigerant which has a high pressure and which easily detects overheating of the electric motor and the compressor. Conductive terminal pins 8A, 8
One of B is connected to a power source and the other is connected to a main winding of an electric motor, and an operating current flows through the contacts of the electric motor protection device 1 during operation of the compressor. At this time, the heat responsive plate 5 of the motor protection device 1 self-heats and the heater 10 also heats, but the heat is taken away by the refrigerant flowing around the motor protection device 1, so that the heat responsive plate 5 is not removed during normal operation. The reversal operation temperature is not reached, and the energization is continued.

When the refrigerant temperature rises, the motor protection device 1 is no longer cooled, and the temperature of the heat responsive plate 5 also rises. When the operating temperature is reached, the heat responsive plate flips suddenly and opens the contacts to operate. Cut off the current. In this way, when the operation is stopped and the temperature of the refrigerant is lowered and the temperature of the heat responsive plate 5 is also lowered to the predetermined temperature, the heat responsive plate jumps back to bring the movable contact 6 into contact with the fixed contact 9 and restart the energization.

Further, for example, if the compressor is restrained for some reason or is temporarily overloaded, the current flowing through the motor increases and the coil temperature of the motor rises. At this time, the amount of heat generated by the heat responsive plate 5 and the heater 10 also increases as the current increases, so that the heat responsive plate 5 reaches the reversing operation temperature and undergoes a sudden jump reversal and opens the contacts to cause an operating current flowing through the motor. Shut off. By cutting off the current, the heat generation of the motor coil is stopped and the internal heat generation of the motor protection device is also stopped. In this way, when the temperature of the heat responsive plate 5 drops to a predetermined temperature, the heat responsive plate jumps back to resume energization.

Here, when the cause of restraint or overload of the compressor is removed by temporarily stopping the compressor,
The electric compressor can resume normal operation. Further, when the cause of restraint or the like is not removed, the electric motor protection device 1 operates again due to the overcurrent to cut off the energization. In this way, the electric motor is prevented from being burned while repeating energization and interruption. Normally, in such a state, the performance of the refrigerator and the air conditioner will not be exhibited, and the abnormality of the compressor will be noticed.

For example, when the abnormality of the compressor is not noticed for a long time of more than half a month, the thermal response plate 1 exceeds its endurance limit, the operating temperature is changed, and the contacts are welded to cause the current to flow. May not be cut off. In particular, if the current is not cut off, the coil temperature of the electric motor will continue to rise and eventually burn out. In view of this, in the present embodiment, the heater 10 is provided with a fusing part 10A having a smaller cross-sectional area than the other parts, and when an overcurrent continues to flow, the fusing part 10A is melted to reliably cut off the electric circuit and to prevent the electric motor. Can be prevented from burning.

Further, in the present invention, the operation can be stopped even when the pressure in the closed container rises abnormally. This will be described below. Example motor protection device 1
As described above, the operating temperature is calibrated by adjusting the contact pressure between the movable contact 6 and the fixed contact 9 of the heat responsive plate 5 by crushing and deforming the heat responsive plate fixing position 2A of the container 2 from the outside. . The crushing amount itself for this temperature calibration is small, and the operating temperature can be lowered by increasing the crushing amount and increasing the contact pressure within the adjustable range. Therefore, in the present invention, when the container is exposed to an abnormally high pressure, the heat responsive plate fixing position 2A is deformed in the direction of being crushed to lower the operating temperature of the heat responsive plate.

During normal operation, the heat responsive plate 5 of the motor protection device 1 maintains a temperature lower than the operating temperature by about 10 to 20 ° C. due to heat from the surroundings and self-heating, but when the refrigerant pressure rises, the compressor operates. Since the overload operation state is set, the operating current of the electric motor also increases and the temperature of the heat responsive plate also rises.
At this time, if the temperature of the heat responsive plate 5 rises to the operating temperature due to the electric current, the motor protection device can operate to cut off the power supply to the motor and stop the operation of the compressor. However, the increase in current due to overload is not necessarily large, and depending on the conditions, the increase in operating current alone may result in insufficient temperature rise to operate the thermal actuator plate. If it is continued, the refrigerant pressure may reach a dangerous state.

Here, due to the abnormal pressure, the heat responsive plate fixing position 2A of the container 2 is deformed in the crushing direction, so that the operating temperature of the heat responsive plate 5 is lowered in the same manner as the temperature calibration work is performed on the motor protection device. Therefore, the heat responsive plate can reliably perform the reversing operation by the self-heating due to the overload current to interrupt the electric path. Further, in this embodiment, the fixed position on the base side of the heat responsive plate is deformed.Furthermore, the fixed position is not moved in parallel, but is displaced so that the heat responsive plate is slightly tilted toward the contact side. The tip side of the plate can be largely displaced. Therefore, even if the displacement is small, the amount of movement on the fixed contact side can be sufficiently secured, and the operating temperature of the heat responsive plate can be sufficiently lowered.

The vicinity of the container 2 including the heat responsive plate fixing position 2A is processed by pressing and cutting separately from the drawing work so as to be thinner than other parts. Therefore, the container 2 itself is a pressure resistant container and has a high allowable pressure resistance performance, but only the displacement portion 2B surrounded by a diagonal line in FIG. 2 is slightly deformed by pressure. In this example, as shown in FIG.
The center 2C of this displacement portion 2B is located closer to the tip end side of the heat responsive plate 5 than the heat responsive plate fixing position 2A, while being removed from the center 2C which is the maximum displacement position. Therefore, the displacement part 2B
When is deformed by the pressure, the heat responsive plate 5 is displaced so as to incline the tip end direction while inclining from the normal posture shown by the broken line in FIG. Therefore, the movable contact side can be largely moved with respect to the displacement amount of the displacement portion 2B.

Here, the displacing portion may have a structure that elastically deforms or a structure that plastically deforms, depending on the protection means against pressure. For example, when the displacement portion is elastically bent with respect to pressure, the operating temperature slightly fluctuates because it is slightly deformed with respect to the pressure applied in normal use, but within the normal pressure range. If there is, the fluctuation remains within 1 to 2 ° C., so there is practically no problem. If the pressure in the hermetically sealed container rises excessively due to some abnormality, the displacement amount of the displacement portion 2B becomes large and the operating temperature of the heat responsive plate 5 is greatly lowered to cause a reversal operation, and the electric power to the electric motor of the electric compressor is cut off to operate. Can be canceled.

When the temperature of the heat responsive plate 5 of the motor protection device 1 is lowered to the reset temperature, the heat responsive plate suddenly recovers and the electric compressor is started and the electric compressor is restarted. To do. When the displacement portion 2B has a structure that elastically deforms, the normal operation can be resumed if the pressure in the closed container is reduced. If the pressure in the closed container has not dropped, the operating temperature of the heat responsive plate 5 remains lowered, and the heat responsive plate reverses in a short time even after restarting the operation until the pressure drops and the operation is stopped. To be done.

Further, in the case where the displacement portion 2B has a structure in which plastic deformation is caused when an excessive pressure is applied, when the abnormal pressure is once generated, the thermal response plate is reversed in a short time even after the operation is restarted, and the operation is performed. Since it stops, it is possible to avoid the risk of increasing the pressure again.

Further, the displacement portion 2B is made to have a shape which is slightly bulged to the outside in advance so as to cause a snap displacement due to excessive pressure or abrupt displacement due to buckling, until a region where protection is required is reached. The operating temperature of the thermal actuator plate can be kept near the desired calibration value with almost no displacement during this period, and the operating temperature can be drastically lowered when the pressure reaches the level at which protection is required to interrupt the electrical circuit. it can.

In the above-described embodiment, the heat responsive plate is fixed to the container via the support, but there is no problem that the operating temperature of the heat responsive plate does not substantially change during the fixing work. If so, the heat responsive plate may be directly fixed to the container without the support. The heater may be omitted if the self-heating of the heat responsive plate against electric current is sufficient.

Further, the motor protection device of the present invention is not limited to the long dome type pressure resistant container as shown in the above-mentioned embodiment, but may be a deep drawing type. This example will be described with reference to FIG. This motor protection device 2
1 has a deep-drawing pressure-resistant metal container 22 made of metal, and a lid plate 23 made of metal is welded to an opening at one end of its cylindrical shape to form an airtight container.

In the container 22, a heat-responsive plate 25 is formed by sandwiching a metal-made contact plate 24 on the inner surface of the heat-responsive plate fixing position 22A.
One end of is connected and fixed. Similar to the above-mentioned example, the heat responsive plate 25 is formed by drawing a bimetal, a trimetal or the like into a shallow dish and setting the operation reversal temperature in advance. The movable contact 26 is fixed to the end opposite to the fixed end. ing.

A through hole is formed in the cover plate 23, and the conductive terminal pin 27 is airtightly fixed by an electrically insulating filling material. A fixed contact 29 is arranged in the vicinity of the tip of the conductive terminal pin 27 inside the airtight container via a fixed contact support 28 so that the fixed contact 29 can be separated from the movable contact 26.

In this motor protection device 21, the container 2
The operation temperature is calibrated by adjusting the contact pressure of the movable contact with the fixed contact by deforming the vicinity of the displacement portion 22B including the heat-responsive plate fixing position 22A of No. 2 by a predetermined amount by a jig. The displacement portion 22B has a thinner plate thickness than the other portions of the container 22 and is deformed inward of the container when the ambient pressure becomes abnormally high. Therefore, the contact pressure between the contacts is increased, the operating temperature of the heat responsive plate can be substantially lowered, and the abnormal high voltage state can be detected and the energization of the electric motor can be cut off as in the above-described example. Further, the pressure can be similarly detected when another conductive terminal pin is fixed to the cover plate of this embodiment by penetrating and a heater is provided between the cover and the fixed contact.

Still another embodiment will be described with reference to FIG. The electric motor protection device 31 constitutes an airtight container by a deep-drawing metal pressure-resistant container 32 and a metal lid plate 33 welded to an opening at one end thereof.

In this embodiment, unlike the above-mentioned embodiments, a fixed contact is connected and fixed to the container 32. Specifically, a fixed contact 35 is connected and fixed to the inner surface of the contact fixing position 32A provided in the container 32 via a metal contact support 34. The contact support 34 is arranged substantially parallel to the inner surface of the container, and has one end fixed to the contact fixing position and the other end fixed to the fixed contact.

Further, a through hole is formed in the cover plate 33, and the conductive terminal pin 36 is airtightly fixed by an electrically insulating filling material. One end of a heat responsive plate 38 is connected and fixed to the inside of the airtight container of the conductive terminal pin 36 via a heat responsive plate support 37. Similarly to the above-mentioned example, this heat-responsive plate 38 is also formed by drawing a bimetal, trimetal or the like into a shallow dish shape and setting the operation reversal temperature in advance, and the movable contact 39 is fixed to the end opposite to the fixed end. Has been done. The movable contact 39 is arranged so as to be separable from the fixed contact 35 described above.

In the electric motor protection device 31, the contact fixing position 32A is crushed and deformed from the outside to adjust the contact pressure from the fixed contact side to calibrate the operating temperature. Further, in the embodiment, the fixed contact support 34
Since the position of the fixed contact 35 can be separated from the fixed contact position 32A through the fixed contact support member 34,
By displacing the contact fixing position so as to slightly incline, the displacement amount on the fixed contact side can be increased by the principle of leverage as in the above example.

The portion of the container 32 including the contact fixing position 32A is a displacement portion 32B having a thinner plate thickness than the surroundings, and when the motor protection device is exposed to an abnormally high pressure, the displacement portion 32B is formed. By displacing inward, the pressure between the contacts is increased and the effective operating temperature is lowered. In this embodiment, the contact fixing position 32A is removed from the center of the maximum displacement position of the displacement portion 32B, and the center of this displacement portion 32B is located closer to the tip side of the fixed contact support 34 than the contact fixing position 32A. Therefore, when the displacing portion 32B is deformed by the pressure, the fixed contact support 34 is displaced so as to incline the tip end of the fixed contact support 34 slightly. Therefore, the movement of the position of the fixed contact can be increased with respect to the displacement amount of the displacement portion 32B to cause a sufficient change in the contact pressure and a change in the operating temperature accordingly.

In the present embodiment, the deep-drawing type pressure-resistant container has the fixed contacts connected and fixed via the fixed contact support, but the structure is such that the displacement part of the container is sufficiently displaced. In some cases, the fixed contact may be directly fixed to the container. Further, in the case where the dome type pressure resistant container is used as in the above-mentioned example or the example in which the heater is built in, the fixed contact can be connected and fixed to the container instead of the heat responsive plate.

In each of the above-mentioned embodiments, the case where it is arranged in the high-pressure container of the hermetic electric compressor has been described as an example, but various protective devices for detecting current, temperature and pressure in the high-pressure container are used. Needless to say, it can be used.

[0042]

According to the motor protection device of the present invention, by disposing one device in the hermetically sealed container of the hermetic electric compressor, overheating of the refrigerant and the like, overcurrent to the motor, and excessive refrigerant pressure can be prevented. The hermetic electric compressor can be protected from rising.

Further, the heat-responsive plate fixing position is deformed by the pressure so as to incline the end of the heat-responsive plate and the front end of the fixed contact support, so that the heat-responsive plate has sufficient strength against normal pressure but is slightly deformed by abnormal pressure. The operating temperature of the heat responsive plate can be lowered sufficiently.

[Brief description of drawings]

FIG. 1 is a side view of a motor protection device of the present invention.

FIG. 2 is a plan view of the motor protection device of FIG.

3 is a sectional view taken along the line AA in the plan view of FIG.

FIG. 4 is a cross-sectional view taken along the line BB in the cross-sectional view of FIG.

5 is a partially enlarged view of the cross-sectional arrow view of FIG.

FIG. 6 is a vertical cross-sectional view of another embodiment of the motor protection device of the present invention.

FIG. 7 is a vertical cross-sectional view of another embodiment of the motor protection device of the present invention.

FIG. 8 is a vertical sectional view of a conventional motor protection device.

9 is a sectional view taken along the line CC of the motor protection device of FIG.

[Explanation of symbols]

1, 21, 31: Motor protection device 2, 22, 32: Container 2A, 22A: Fixed position of thermal plate 2B, 22B, 32B: Displacement part 2C: Maximum displacement position 3, 23, 33: lid plate 4: Support 5, 25, 38: Thermal plate 6, 26, 39: Moving contact 8A, 8B, 27, 36: Conductive terminal pin 9, 29, 35: Fixed contact 10: Heater 10A: Fusing part 32A: contact fixing position 34: Fixed contact support

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01H 37/54 H01H 37/54 D H02K 11/00 H02K 11/00 DF term (reference) 3H003 AA01 AB01 AC03 CF00 CF01 3H045 AA02 AA09 AA12 AA27 BA42 BA43 CA01 CA21 CA24 DA02 EA13 EA16 EA20 EA26 5G041 AA04 BB02 BB03 CC01 CC02 DA02 DA12 DB01 DC02 5H611 AA01 AA03 BB01 PP01 QQ04 SS01 UA01 UB01

Claims (5)

[Claims] 1. A pressure-resistant airtight container is constituted by a metal pressure-resistant container and a lid plate that is airtightly fixed to an opening end of the container, and a conductive terminal pin is airtightly insulated and fixed to a through hole formed in the lid plate.
A fixed contact is fixed to the conductive terminal pin, a movable contact is fixed to one side inside the pressure vessel, and the center is drawn in the shape of a dish to form a thermo-responsive plate that is set to suddenly reverse at a predetermined temperature. , The movable contact of the thermal responsive plate is connected to the fixed contact so as to be separable from the fixed contact, and the operating temperature is calibrated by displacing the fixed position of the thermal responsive plate of the pressure resistant container. The vicinity of the fixed position of the heat responsive plate of the container is a displacement part that is more easily deformed than the surrounding part,
The motor protection device is characterized in that the displacement portion is displaced so as to move the heat responsive plate in a direction in which the contact pressure between the movable contact and the fixed contact increases when pressure is applied from the outside of the container. 2. A pressure-resistant airtight container is constituted by a metal pressure-resistant container and a lid plate which is airtightly fixed to its opening end, and two conductive terminal pins are airtightly insulated and fixed in a through hole formed in the lid plate. A fixed contact is fixed to one conductive terminal pin, one end of the heater is fixed to the other conductive terminal pin, the other end of the heater is connected and fixed to the lid plate, and one side is movable inside the pressure vessel. The contact point is fixed and the center area is drawn in the shape of a dish, and the thermo-responsive plate set so as to make a sudden flip at a predetermined temperature is conductively connected and fixed. The movable contact of the thermo-responsive plate can be separated from the fixed contact. In a motor protection device whose operating temperature is calibrated by displacing the heat-responsive plate fixing position of the pressure-resistant container, the displacement in the vicinity of the heat-responsive plate fixing position of the pressure-resistant container is more easily deformed than the surrounding area. The displacement part is the outside of the container. An electric motor protection device, which is displaced so as to move a heat responsive plate in a direction in which a contact pressure between a movable contact and a fixed contact increases when a pressure from is received. 3. The electric motor protection device according to claim 1, wherein the maximum displacement position of the displacement portion is arranged so as to be closer to the front end of the heat responsive plate than the fixed position of the heat responsive plate. 4. A pressure-resistant airtight container is constituted by a metal pressure-resistant container and a lid plate which is airtightly fixed to an opening end thereof, and a conductive terminal pin is airtightly insulated and fixed to a through hole formed in the lid plate.
A movable contact is fixed to one side of the conductive terminal pin, and a thermo-responsive plate that is formed by drawing in the shape of a dish near the center and set so as to make a sudden flip at a predetermined temperature is conductively connected and fixed. A fixed contact is fixedly connected, the fixed contact is releasably connected to the movable contact of the heat responsive plate, and the operating temperature is calibrated by displacing the contact fixing position of the pressure resistant container. The vicinity of the contact fixing position is a displacement part that is more easily deformed than the surrounding part, and this displacement part moves the fixed contact in the direction in which the contact pressure between the movable contact and the fixed contact increases when pressure from the outside of the container is received. An electric motor protection device characterized in that it is displaced as described above. 5. The fixed contact is fixed at a fixed contact position via a fixed contact support, and the maximum displacement position of the displacement portion is arranged in the fixed contact direction rather than the fixed contact position. The electric motor protection device according to claim 4.