JP2860517B2 - Thermal responsive switch and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermally responsive switch using a thermally responsive plate, such as a bimetal, which deforms in response to a change in temperature and using its movement to open and close contacts.

[0002]

2. Description of the Related Art A conventional thermally responsive switch is disclosed, for example, in Japanese Patent Application Laid-Open No. Hei 5-36335. This thermal responsive switch will be described with reference to FIGS. 11A and 11B. The thermal responsive switch 101 is used for protecting a well-known electric motor used in, for example, a hermetic electric compressor. A cover plate 5 in which a conductive terminal pin 3 is hermetically penetrated and fixed in a hole formed in a conductive metal plate 2 such as iron by an electrically insulating filler 4 such as glass, and a metal housing 6. An airtight container having pressure resistance is formed by hermetically fixing the opening and the opening by ring projection welding or the like. At the end of the conductive terminal pin 3 on the inside of the container, a metal fixed contact support 7 having strength like iron is provided.
The fixed contact 8 made of silver or silver alloy is fixed to the other end of the fixed contact support 7.

One end of a thermally responsive plate 9 such as a bimetal drawn in a dish shape is conductively fixed to the inner surface of the housing 6 via a thermally responsive plate support 10. A movable contact 11 similar to a fixed contact is fixed to the other end of the thermally responsive plate 9, and the movable contact 11 is arranged so as to be able to contact and separate from the fixed contact 8.

[0004] The operation of the thermal responsive switch 101 will be described.
11A is curved in a direction in which the movable contact 11 and the fixed contact 8 are brought into contact with each other as shown by a solid line in FIG. 11 (A). At this time, the conductive terminal pin 3-fixed contact support 7-fixed contact 8-movable contact 1
An electric path is constituted by a path of 1-thermal response plate 9-thermal response plate support 10-housing 6. When the temperature of the thermally responsive plate reaches the first temperature due to an increase in the ambient temperature around the thermally responsive switch 101 or an increase in the current value flowing inside, the thermally responsive plate 9 rapidly changes its bending direction. FIG. 11 (A)
The movable contact 11 and the fixed contact 8 are separated by reversing as shown by a dotted line in FIG.

When the temperature of the inverted thermal responsive plate 9 drops to a predetermined second temperature, it returns suddenly, returns its bending direction to the initial direction, and brings the movable contact 11 and the fixed contact 8 into contact with each other. Restore the electrical circuit.

[0006]

In such a thermoresponsive switch, the calibration of the operating temperature is performed by the calibration unit 6 of the housing 6.
By deforming A and displacing the root of the thermally responsive plate support 10, the contact pressure between the movable contact 11 and the fixed contact 8 is calibrated by the principle of a roller.

[0007] Therefore, in welding the contacts, FIG.
When the contact height h ₀ in the ideal welding state as shown in FIG. 12 varies depending on the welding state and the amount of crushing of the welded portion and the inclination of the contact appear as shown in FIGS. Since the value h changes with respect to the reference value h ₀ as indicated by h ₁ or h ₂ , the initial contact pressure between the contacts after assembly varies for each product. Therefore, there is a problem that the amount of deformation of the calibration portion 6A of the housing 6 at the time of temperature calibration is not uniform and the calibration operation becomes difficult. In particular, in the case where the operating temperature is configured by partially deforming the container after forming the closed container as in the present embodiment, if an abnormality in the contact height is overlooked, the contact pressure between the contacts before the operating temperature configuration is established. Is too high or too low, it may not be possible to calibrate the temperature after construction of the closed container. Furthermore, due to the difference in contact height,
There has been a problem that the distance between the contacts at the time of opening is varied and the withstand voltage value between the contacts is not uniform.

Conventionally, the fixed contact and the movable contact both use a spherical contact whose contact surface has a relatively large curvature, so that the positional relationship between the two contacts before and after temperature calibration may be changed due to an error during assembly. Even if the distance is slightly deviated, there is a variation that has a considerable effect on the initial contact pressure between the contacts and the distance between the contacts after opening.

Further, for example, when a flat contact is used as the fixed contact, the movable contact and the fixed contact have no commonality as parts, and the difference in welding conditions and the inclination of the contact cause the height of the contact after welding. I couldn't get it all together.

[0010]

According to the present invention, there is provided a method of manufacturing a thermally responsive switch, comprising: a cover plate in which a conductive terminal is fixed in a hole formed in a conductive metal plate in an airtight manner with an electrically insulating filler; ,
A hermetic container is formed by fixing the opening end surface of the housing to the cover plate, and the inside of the hermetic container is rapidly reversed in a bending direction at a predetermined first temperature to form a second container. A conductive thermo-responsive plate set in advance to make a jump return at a temperature of one end, one end of the thermo-responsive plate is electrically connected to one of the housing or the conductive terminal, A movable contact is fixed to an end, and the movable contact can be brought into contact with or separated from the conductive terminal or a fixed contact electrically connected to the housing, and can open and close an electric path between the conductive terminal and the housing. In the switch, at least a portion of the fixed contact that comes into contact with the movable contact after the fixed contact is welded to the fixed contact support is subjected to a plastic deformation process so that the height of the fixed contact from a predetermined portion of the fixed contact support is set to a predetermined value. Together with that contact The characterized in that it into a predetermined shape.

The thermal responsive switch of the present invention further comprises a cover plate having one or more holes formed in a conductive metal plate and having a conductive terminal hermetically penetrated with an electrically insulating filler. A fixed contact support body having a housing made of a metal, and having an open end surface of the housing fixed to the lid plate to form an airtight container, and a conductive contact terminal disposed substantially parallel to the metal plate inside the container. One end of the fixed contact is conductively connected and a fixed contact is fixed to the other end of the fixed contact support,
An electrically insulating spacer such as ceramic is provided between the fixed contact support and the metal plate, and a back surface of the fixed contact support on the fixed contact fixing side is brought into contact with the fixed contact support.
One end of a conductive thermally responsive plate preset to jump-reverse the bending direction at a predetermined first temperature and return to a jump at a second temperature is electrically connected to the inner surface of the housing. The other end of the thermally responsive plate is fixed to a movable contact corresponding to the fixed contact and capable of being separated from and separated from the thermally responsive plate, and is capable of opening and closing an electric path between the conductive terminal and the housing. The back surface of the contact support is configured to apply a biasing force so as to always press the contact portion with the spacer, and the position of the fixed contact is always kept constant.

In another thermal responsive switch according to the present invention, the fixed contact support and the spacer abut only near the distal end of the fixed contact support, and a gap for thermal insulation is provided in other portions. It is characterized by having.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. The thermal responsive switch 1 of FIG. 1 is the thermal responsive switch of the present invention, and the same parts as those of the above-described conventional example are denoted by the same reference numerals and description thereof is omitted. In the thermally responsive switch 1, the fixed contact 12 is formed by welding a spherical contact made of a material having good spreadability, such as silver or a silver alloy, to the fixed contact support 7 by a method such as projection welding and then pressing. As shown in FIG. 2, the height H is adjusted, and at the same time, the contact surface 12A with the movable contact 11 is made to have a predetermined shape, in this embodiment, a flat shape. The operation of the thermally responsive switch 1 is the same as that of the conventional example, and the description is omitted.

According to this embodiment, the height of the contact is adjusted after the fixed contact 12 is fixed to the fixed contact support 7, so that the height H can be made uniform with high dimensional accuracy. The temperature adjustment work is easy to perform because the variation in each temperature is reduced. According to the experiment, when the fixed contact is welded as in the conventional case, the reference height from the back surface of the fixed contact support to the contact surface of the contact is ± 0.2 mm with respect to 1.4 mm.
Although the above error occurred, in this embodiment, 1.15 mm +
The height could be made uniform within the range of 0 mm to -0.05 mm. In addition, since the contact surface 12A of the fixed contact 12 is flat, even if the positional relationship between the fixed contact 12 and the movable contact 11 is shifted in the front-rear and left-right directions within the plane, a change in the contact pressure of the contact can be eliminated. . Therefore, it is not impossible to calibrate the temperature due to the defective contact pressure after the construction of the closed container. Further, in the case where the fixed contact 12 is fixed to the fixed contact support 7 by projection welding or the like, the contact area between the fixed contact 12 and the fixed contact support 7 is increased by crushing the vicinity of the welded portion at the time of pressing. The heat of the fixed contact 12 heated by the arc generated at the time of opening becomes easy to escape to the fixed contact support 7 side, and the heat generation at the welded portion due to the instantaneous large current at the time of opening the contact is suppressed, and the life of the contact is reduced. Can be longer.

In this embodiment, the height H of the fixed contact 12 is defined from the back surface 7A of the fixed contact support 7, but may be defined from the front surface 7B. When the positional relationship between the movable contact and the fixed contact is not shifted or the influence of the shift is small, the shape of the contact surface of the fixed contact may be a predetermined shape such as a spherical shape.

Next, another embodiment will be described. In the thermally responsive switch 21 shown in FIG. 3, a closed container is constituted by a lid plate 22 and a housing 23. The cover plate 22 is made of a metal plate 2 such as iron.
The conductive terminal pins 25 are air-tightly fixed in the holes formed in 4 by an electrically insulating filler 26. One end 27A of a thermally responsive plate support 27 is conductively fixed to an end of the conductive terminal pin 25 on the inner side of the sealed container, and a calibration piece 28 made of an electrically insulating material such as ceramic is attached to the other end 27B of the housing 23. It is fixed so as to contact the inner surface of the. One end of a thermally responsive plate 30 such as a bimetal is electrically connected to and fixed to the thermally responsive plate support 27 via a welding plate 29 for welding. The thermally responsive plate 30 is drawn in a dish shape, and is set so that it jumps over at a predetermined first temperature and returns at a second temperature. A movable contact 31 is provided at the other end of the thermally responsive plate 30.
Is fixed. A fixed contact 32 is fixed to the metal plate 24 as a fixed contact support so as to be able to contact and separate from the movable contact 31. After the fixed contact 32 is fixed to the metal plate 24 by welding or the like, the height is adjusted by the above-described method or the like, and the contact surface 32A of the movable contact 32 is made flat.

The operation of the thermally responsive switch 21 will be described. Until the temperature reaches a predetermined first temperature, the thermally responsive plate 30 is turned on.
Is curved in the direction in which the movable contact 31 and the fixed contact 32 come into contact with each other as shown in FIG.
-Thermal response plate support 27-Thermal response plate 30-Movable contact 31-
An electric path is constituted by a path between the fixed contact 32 and the metal plate 24. When the temperature of the thermally responsive plate reaches the first temperature due to an increase in the ambient temperature around the thermally responsive switch 21 or an increase in the current flowing inside, the thermally responsive plate 30 rapidly changes its bending direction. By reversing, the movable contact 31 and the fixed contact 32 are separated, and the electric circuit is reliably cut off. When the temperature of the inverted thermoresponsive plate 30 decreases to a predetermined second temperature, it returns suddenly, returns its bending direction to the initial direction, and brings the movable contact 31 and the fixed contact 32 into contact with each other to restore the electric circuit. Let it.

The operating temperature is calibrated by deforming the vicinity of the calibrating portion 23A of the housing 23. At this time, the end portion 27B of the thermally responsive plate support via the calibration piece 28
Is displaced, but the portion 27C closer to the conductive terminal pin than the fixed portion of the thermally responsive plate is made narrower than the other portions, so that the thermally responsive plate support 27 around the portion 27C becomes The movable contact is rotated and pressed against the fixed contact to calibrate the contact pressure.

Also in this thermally responsive switch 21, the fixed contact 32 is fixed to the metal plate 3 as a fixed contact support by welding or the like.
Since the height of the fixed contact from the predetermined surface of the metal plate is adjusted after welding to zero, there is little variation in the contact height and contact pressure for each product, and the temperature calibration work after assembly is easy. Become.

Next, still another embodiment will be described with reference to FIG. The thermally responsive switch 41 is used for protecting a well-known electric motor such as a hermetic electric compressor, for example, and includes a metal bottomed cylindrical housing 42 and a cover plate 4.
3 constitutes a closed container. The cover plate 43 has conductive terminal pins 45A in each of two holes formed in the metal plate 44.
And 45B are hermetically fixed through an electrically insulating filler 46. One conductive terminal pin 45A
One end of a thermally responsive plate support 47 is fixed to an inner end of the container, and a lug plate 48 for welding and an operation temperature calibration operation to be described later is attached to the other end of the thermally responsive plate support 47. One end of the heat responsive plate 49 is electrically connected to and fixed therethrough. A movable contact 50 is fixed to the free end of the thermally responsive plate 49, and is arranged so as to be able to contact and separate from a fixed contact described later. At the end of the other conductive terminal pin 45B on the inner side of the container, a metal fixed terminal support 5 having strength such as iron
The fixed contact support 51 has fixed contacts 5 fixed thereto.
2 is fixed. Reference numeral 53 denotes an insulator for protecting the filler 46 from an arc when the contact is opened, and reference numeral 54 denotes a heater connected between the metal plate 44 and the thermally responsive plate support 47. Reference numeral 55 denotes a screw used for temperature calibration described later.

Next, the operation when the thermally responsive switch 41 is used for an electric motor such as a hermetic electric compressor will be described. The conductive terminal pin 45A of the thermally responsive switch 41 is connected to the main winding of the motor (not shown) by the housing 42 or the metal plate 4.
4 is a conductive terminal pin 45B for an auxiliary winding for starting the motor.
Are connected to a power source (not shown). The other ends of the main winding and the auxiliary winding are shared and connected to a power supply. In normal use, the thermally responsive plate 49 is convex upward as shown in FIG. 4, and the movable contact 50 and the fixed contact 52 are in contact with each other. At this time, the conductive terminal pin 45B, the fixed contact support 51, the fixed contact 52, the movable contact 50, the thermally responsive plate 49, the lug plate 48, the thermally responsive plate support 47, and the conductive terminal pin 4
An electric path is formed in the order of 5A (or the heat responsive plate support 47-heater 54-metal plate 44-housing 42). The temperature of the thermally responsive plate 49 is increased by the abnormal current on the main winding side, the heat of the heater 54 by the abnormal current on the auxiliary winding side, and the temperature of the thermally responsive switch 49 due to the rise in the temperature of the mounting position of the thermally responsive switch and its surroundings. When the temperature reaches the first set temperature, the thermally responsive plate 49 jumps and reverses, separating the movable contact 50 and the fixed contact 52 to cut off the electric circuit. When the inverted temperature of the thermally responsive plate 49 falls to the second set temperature, the thermally responsive plate jumps back to the illustrated position and closes the electric circuit. Note that the heater 54 is not always necessary,
In some cases, the main winding and the auxiliary winding are omitted by being connected to the conductive terminal pin 45A.

The calibration of the operating temperature of the thermally responsive switch 41 will be described. The thermal response is performed by displacing the lug plate 48 with the screw 55 as a calibration member, which is performed before the housing 42 and the cover plate 43 constitute a closed container. The plate 49 is rotated about the vicinity of the fixed point between the lug plate 48 and the thermally responsive plate support 47. Therefore, the contact pressure between the movable contact 50 and the fixed contact 52 is adjusted, and calibration is performed so that the thermally responsive plate 49 is inverted at a predetermined operating temperature.

At this time, the fixed contact 52 is
The height is adjusted after welding with 1 and the contact surface is made flat, so that the contact pressure between the contacts before temperature calibration can be more uniform than the conventional one, and the temperature calibration work Becomes easier.

Still another embodiment will be described with reference to FIGS. The thermally responsive switch 61 shown in FIG. 5 is used for, for example, a three-phase induction motor, and is disclosed in Japanese Patent Application No. Hei.
No. 5684. The three-phase thermally responsive switch 61 forms a closed container from the cover plate 62 and the housing 63. In the cover plate 62, conductive terminal pins 65 A and 65 B are inserted into each of two holes formed in the metal plate 64, and the cover plate 62 is airtightly fixed by an electrically insulating filler 66. One ends of fixed contact supports 67A and 67B are fixed to the ends of the conductive terminal pins 65A and 65B on the inner side of the container, respectively, so as to be substantially parallel to the metal plate 64. The fixed contacts 68A and 68B are fixed. A spacer 69 made of an electrically insulating material such as ceramic is arranged between the fixed contact supports 67A and 67B and the metal plate 64 to support the fixed contact support and to electrically connect the fixed contact support to the metal plate. Maintain proper insulation.

A temperature calibration plate 70 is provided on the inner surface of the housing 63.
An end near a bent portion 70A described later is fixed, and one end of a thermally responsive plate support 71 having sufficient elasticity is fixed near the fixed portion. At the other end of the thermally responsive plate support 71, a substantially responsive, thermally responsive plate 73 drawn in a disk shape is fixedly connected via a highly rigid metal lug plate 72. . The lug plate 72 is in contact with the projecting support 69A of the spacer 69. The thermally responsive plate 73 has, for example, a planar shape as shown in FIG. 8, and the movable contacts 74A and 74B are symmetrical with respect to a center line 73B passing through a point 73A that contacts the support 69A via the lug plate 72. It is fixed. An electrically insulative calibration piece 75 such as a ceramic is disposed on the center line 73B of the surface of the thermally responsive plate 73 that is convex at normal temperature so as to be in contact with the thermally responsive plate support 71. The other is in contact with the temperature calibration plate 70 through the drilled hole.

The operation of this thermally responsive switch will be described. For example, it is used in a so-called star-connected three-phase induction motor used in a hermetic electric compressor or the like, and has conductive terminal pins 6.
Each of the 5A, 65B and the housing 63 is connected to three windings of a three-phase induction motor, and the midpoint thereof is simultaneously opened and closed. Although detailed description of the electric circuit is omitted, three paths are formed between each conductive terminal pin and the housing, and between both conductive terminals, and all the electric paths are designed to have substantially equal resistance values. Therefore, when the heat responsive plate 73 reaches a predetermined first operating temperature due to heat generation due to an overcurrent caused by an abnormality of the winding or a rise in ambient temperature, the bending direction is reversed by a jumping action, and At the same time to open the circuit.

The calibration of the operating temperature of the thermally responsive switch 61 will be described. The calibration of the temperature is performed by deforming the calibration section 63A of the housing 63. As a result, the right end of the temperature calibration plate 70 in the figure is displaced, and the temperature calibration plate 70 is rotated around a bent portion 70A whose width is reduced as compared with other portions. A force is applied to plate 73 to calibrate the operating temperature by adjusting the contact pressure between movable contact 74 and fixed contact 68.

At this time, since the thermally responsive switch 61 of this embodiment has two fixed contacts and two movable contacts, the contact pressure between the two pairs of contacts must be made substantially uniform. In other words, a so-called one-sided state occurs in which one of the contacts is separated earlier than the other. Therefore, the movable contact 7
Even if the method of applying the force to 4A and 74B is properly set, if the heights of the fixed contacts 68A and 68B are different, the contact pressures will not be uniform and a break will occur. In addition, since it is impossible to correct the occurrence of a break after the temperature calibration in order to perform the temperature calibration after forming the closed container, it is important to make the heights of the contacts uniform.

In the present embodiment, the fixed contacts 68 are fixed to the fixed contact support 67 by welding or the like, and then the contact height is adjusted by the method described above. The heights of the two contacts can be made uniform, so that the contact pressure between the two pairs of contacts can be easily made uniform, and the occurrence of a break can be suppressed. In addition, since the height of the fixed contacts for each product is also stable, it is easy to calibrate the contact pressure, that is, to calibrate the operating temperature, and it is easy to make the distance between the two contacts when the contacts are opened, and the variation in the withstand voltage between the contacts is reduced Disappears. Further, since the contact surfaces 68A1 and 68B1 of the two fixed contacts are flat, even if the positional relationship between the movable contact and the fixed contact is slightly shifted during assembly, the height of the fixed contact at the contact position does not change. The contact pressure and the withstand voltage between the contacts are not affected.

In the thermally responsive switch 61, the fixed contact support members 67A and 67B are in contact with the spacer near the back surface of the fixed point where the fixed contact support members 67A and 67B are fixed to the fixed contacts 68A and 68B. This operation will be described with reference to FIGS. 9 and 10. FIG. 9 shows one end 67D of the fixed contact support 67.
9 shows a state in which the fixed contact 68 is fixed to the contact hole. Ribs 6 for increasing rigidity are provided on both sides of the fixed contact support 67.
Although 7C is provided, it is not particularly necessary when the thickness of the material is sufficient and the strength can be obtained. The fixed portion 67E of the fixed contact support to the conductive terminal pin near the end opposite to the fixed contact side end 67D is slightly inclined by pressing. As shown in FIG. 10 assuming that the spacer 69 is removed, the fixed contact support 67 is inclined toward the metal plate 64 by fixing the fixing portion 67E to the end surface of the conductive terminal pin 65 by welding or the like. Actually, since the spacer 69 is provided between the fixed contact support 67 and the metal plate 64, the spacer 69 is pressed against the metal plate 64 by the fixed contact support 67 and the metal plate at the end 67D on the fixed terminal side. The distance from the spacer 64 is defined by the thickness of the spacer 69.

Therefore, since the positional accuracy of the fixed contact depends on the accuracy of the thickness of the spacer, it is possible to set the position of the contact with higher accuracy than the accuracy of normal assembly.

In such a thermally responsive switch, when operated by an abnormal current, or when the amount of heat generated by the thermally responsive plate 73 alone is insufficient, the thermal responsive plate support 71 or the fixed contact support is used. There may be a so-called indirectly heated type in which the resistance value of the body 67 is increased to increase the calorific value and heat the thermally responsive plate. At this time, the fixed contact support 67 is
If the entire surface is in close contact with the substrate 9, there is a problem that the heat of the fixed contact support is taken away by the spacer and does not sufficiently act as an indirect heat type.

Therefore, in this embodiment, the fixed contact support 67 and the spacer 69 are brought into contact only in the vicinity of the tip 68D of the fixed contact support, and a gap for thermal insulation is provided between the fixed contact support 67 and the spacer 69. 76 are provided. Therefore, the heat of the fixed contact support 67 is effectively given to the heat responsive plate 73 without being unilaterally deprived by the spacer 69. Also, since the vicinity of the fixed portion with the fixed contact 68 is in contact with the spacer 69, the heat of the fixed contact 68 heated by the arc generated when the contact is opened can be released to the spacer 69 side via the fixed contact support. it can. In this embodiment, a three-phase thermally responsive switch having two pairs of contacts has been described. However, it is needless to say that the same effect can be obtained even with one pair of contacts.

[0034]

According to the present invention, after the fixed contact is welded to the fixed contact support, at least a portion of the fixed contact which comes into contact with the movable contact is subjected to a plastic deformation process such as pressing to remove the fixed contact from a predetermined portion of the fixed contact support. By setting the height of the fixed contact to a predetermined value and making the contact surface a predetermined shape such as a flat surface or a spherical shape, the welding conditions of the fixed contact and the inclination of the contact, etc. Substantial variations in the contact height can be eliminated, and the temperature calibration operation becomes easier. Therefore, in particular, when the operation temperature calibration is performed by deforming a part of the container after the closed container is formed, the pressure between the contacts before the temperature calibration can be adjusted to a predetermined range. It is possible to prevent the generation of products whose operating temperature cannot be calibrated. In a device having two or more pairs of contacts, so-called disconnection can be prevented by adjusting the contact pressure between the contacts.

Further, by using the same movable contact and fixed contact and deforming only necessary contacts, the commonality of parts can be maintained.

Further, by increasing the fixing area between the fixed contact and the fixed contact support by applying pressure, heat generation at the fixed portion is avoided,
The heat of the fixed contact can be quickly released to the fixed contact support.

The fixed contact support is welded to the conductive terminal pins so as to be slightly displaced in the direction of the cover plate toward the tip end so that the back surface of the fixed contact support always presses the contact portion with the spacer. By providing the biasing force, it is possible to suppress variation in the position of the fixed contact from product to product and to obtain high assembly accuracy.

Also, the fixed contact support and the spacer abut only in the vicinity of the tip of the fixed contact support, and other portions are provided with gaps for thermal insulation. Is given to the thermally responsive plate without being unilaterally deprived by the spacer, so that a reliable operation can be obtained even in the indirectly heated type thermally responsive switch. In addition, since the vicinity of the fixed portion with the fixed contact is in contact with the spacer, the heat of the fixed contact, which is heated by the arc generated when the contact is opened, can be released to the spacer side via the fixed contact support, so that the contact Life can be extended.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a thermally responsive switch according to the manufacturing method of the present invention.

FIG. 2 is a diagram showing a method for manufacturing a contact according to the present invention.

FIG. 3 shows another embodiment of the thermally responsive switch according to the manufacturing method of the present invention.

FIG. 4 shows another embodiment of the thermally responsive switch according to the manufacturing method of the present invention.

FIG. 5 is an embodiment of a three-phase thermally responsive switch of the present invention.

FIG. 6 shows an embodiment of a three-phase thermoresponsive switch according to the present invention.

FIG. 7 shows an embodiment of a three-phase thermally responsive switch of the present invention.

FIG. 8 is a view showing a bimetal used for a three-phase thermoresponsive switch.

FIG. 9 is an embodiment of a fixed contact support of the thermally responsive switch of the present invention.

FIG. 10 is an explanatory view showing a welding state of the fixed contact support of the present invention.

FIG. 11 shows an embodiment of a thermally responsive switch according to a conventional manufacturing method.

FIG. 12 is a diagram showing a contact portion of a thermally responsive switch according to a conventional manufacturing method.

[Explanation of symbols]

1, 21, 41, 61: thermoresponsive switch 2, 44, 64: metal plate 3, 25, 45A, 45B, 65A, 65B: conductive terminal pin 4, 26, 46, 66: electrically insulating filler 5, 22, 43, 62: lid plate 6, 23, 42, 63: housing 7, 51, 67A, 67B: fixed contact support 12, 32, 52, 68A, 68B: fixed contact 9, 30, 49, 73: heat Response plate 11, 31, 50, 74A, 74B: Movable contact 24: Metal plate (fixed contact support) 27, 47, 71: Thermal response plate support 28, 75: Calibration piece 69: Spacer 69A: Support part 70: Temperature calibration plate

Continuation of the front page (56) References JP-A-49-26763 (JP, A) JP-A-5-47428 (JP, A) JP-A-5-36335 (JP, A) , U) Shokai Sho 57-138226 (JP, U) Shokai Sho 59-53717 (JP, U) Japanese Patent Publication No. 45-40818 (JP, B1) (58) Fields surveyed (Int. Cl. ⁶ , DB Name) H01H 1/06-1/10 H01H 11/00-11/06 H01H 37/00-37/56 H01H 37/64-37/70

Claims (5)

(57) [Claims] 1. A cover plate in which a conductive terminal is hermetically passed through and fixed to a hole formed in a conductive metal plate with an electrically insulating filler, and a metal housing. An airtight container is formed by being fixed to the lid plate. Inside the airtight container, a conductive material set in advance so as to rapidly reverse the bending direction at a predetermined first temperature and return to a jump at a second temperature. A thermally responsive plate, one end of which is electrically connected to one of the housing or the conductive terminal;
A movable contact is fixed to the other end of the thermally responsive plate, and the movable contact can be brought into contact with or separated from the conductive terminal or a fixed contact electrically connected to the housing, and can open and close an electric path between the conductive terminal and the housing. In the thermally responsive switch, the fixed contact is welded to the fixed contact support, and then at least a portion of the fixed contact that comes into contact with the movable contact is subjected to plastic deformation processing to reduce the height of the fixed contact from a predetermined portion of the fixed contact support. A method for manufacturing a thermally responsive switch, characterized in that a predetermined value and a contact surface thereof are formed in a predetermined shape. 2. A cover plate in which conductive terminals are air-tightly fixed with an electrically insulating filler in each of a plurality of holes formed in a conductive metal plate, and a metal housing. An airtight container is formed by fixing the opening end surface to the lid plate, and the inside of the airtight container is preset so that the bending direction jumps at a predetermined first temperature and returns at a second temperature. One end of the thermally responsive plate is electrically connected to one of the housing or the conductive terminal, and a movable contact is fixed to the other end of the thermally responsive plate. The movable contact is configured to be able to contact and separate from a fixed contact electrically connected to another conductive terminal or the housing to which the thermally responsive plate is connected, and to be able to open and close an electric path between the conductive terminal and the housing. Fixed contacts are welded to the fixed contact support After that, at least the portion of the fixed contact that comes into contact with the movable contact is subjected to plastic deformation processing so that the height of the fixed contact from a predetermined portion of the fixed contact support is set to a predetermined value, and the contact surface is formed to a predetermined shape. A method for manufacturing a thermally responsive switch. 3. A cover plate in which a conductive terminal is air-tightly fixed to each of one or a plurality of holes formed in a conductive metal plate with an electrically insulating filler, and a metal housing, An airtight container is formed by fixing the open end surface of the housing to the cover plate, and one end of a fixed contact support substantially parallel to the metal plate is conductively connected to the conductive terminal inside the container. The fixed contact is fixed to the other end of the fixed contact support, and an electrically insulating space is provided between the fixed contact support and the metal plate.
And a back surface of the fixed contact support on the side where the fixed contact is fixed is brought into contact with the fixed contact support. One end of a conductive thermally responsive plate set in advance to make a jump return is electrically connected, and the other end of the thermally responsive plate has a movable contact corresponding to the fixed contact and made detachable. In a thermally responsive switch, which is fixed and capable of opening and closing an electric path between a conductive terminal and a housing, it is configured such that a back surface of a fixed contact support always applies a biasing force so as to press a contact portion with a spacer. A thermally responsive switch characterized in that the position of the fixed contact is always kept constant. 4. The thermally responsive opening and closing according to claim 3, wherein the fixed contact support is fixed so as to be slightly displaced in the direction of the cover plate toward the tip of the fixed contact support so as to be pressed against the spacer. vessel. 5. The fixed contact support and the spacer abut only in the vicinity of the tip of the fixed contact support, and a gap for thermal insulation is provided in other portions.
Or the thermally responsive switch of claim 4.