KR100503102B1 - Heat sensitive switch - Google Patents

Abstract

An object of the present invention is to provide a structure of a thermally actuated switch that is easy to assemble and to prevent rotation of a bimetal piece when performing ultrasonic welding.

In order to solve the said subject, the housing 1 of a user shape (bottom-shaped), the fixed contact 3 arrange | positioned at the inner bottom surface of this housing 1, and the inversion part 5a which can be reversed according to temperature And a bimetal piece 5 having a fixed contact 3 and a movable contact 6 separated from the fixed contact 3, and the other end of the bimetal piece 5 being overlapped and fixed in a cantilever shape and simultaneously housing The fixed terminal 4 is provided in the inner bottom surface of (1), and the said fixed terminal 4 abuts the outer edge part of the bimetallic piece 5, and the bimetallic piece 5 is this inversion part 5a. A restricting member 4d made of a metal material for restricting rotational movement in the direction intersecting with the reversal direction of?) Was formed.

Description

Thermal Reactive Switch {HEAT SENSITIVE SWITCH}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermally active switch, and more particularly, to a structure of a switch in which a movable contact is inverted by opening and closing an electrical contact by thermal vibration of a bimetal piece.

The thermally active switch comprises a movable electrode having a movable element (bimetal) in which a plurality of metals having different thermal expansion coefficients are superimposed on the movable piece, and the movable electrode forms a normally closed contact circuit. A fixed electrode is formed and connected to the circuit of the electric device to protect the electric device.

In other words, the thermally active switch connected to the circuit of the electric equipment has a structure in which the switch contact is separated by the bimetal bending reversal action when excessive current flows or the ambient temperature becomes very high. The power supply to the electrical equipment is cut off. As the ambient temperature decreases due to the interruption of the power supply to the electric equipment, the bimetal automatically returns, and the switch contact is reconnected to resume the power supply. It is possible to operate in a predetermined temperature range.

The structure of this conventional thermally active switch is shown in FIGS. 8 and 9. 8 is a plan view of the cover removed, and FIG. 9 is a plan view of the bimetal piece.

As a structure of the conventional thermally actuated switch, a pair of fixed terminals 22, 23 made of conductive metal are provided at regular intervals on the inner bottom surface of the housing 21 formed in a user's box shape with an insulating material such as synthetic resin. They are arranged to face each other. On the other hand, a fixed contact 24 is formed on the fixed terminal 22, and a bimetal piece 26 having a movable contact 25 fixed to one end is fixed to the cantilever shape on the other fixed terminal 23. It is.

In addition, the movable contact 25 is disposed to face the fixed contact 24 at regular intervals so as to be separated from each other, and the bimetal piece 26 has a dome-shaped inverting portion 26a at the center thereof. Is formed, and the inverting portion 26a is formed so as to be invertible in accordance with the change of temperature. In the normal state, the movable contact 25 is in contact with the fixed contact 24, and the switch circuit is in an on state.

The bimetal piece 26 is fixed on the fixed terminal 23 by a method such as laser welding, and the position where the laser welding is performed is opposed to the movable contact 25 with the inverting portion interposed therebetween. It is formed on the other end side. Moreover, although not shown in figure, the plate-shaped cover is attached so that the said bimetal piece 26 may cover the opening part of the housing 21 accommodated.

In the case where the bimetal piece 26 is fixed on the fixed terminal 23, the bimetal piece 26 to which the movable contact 25 is fixed is used for the housing 21 by using a bimetal suction tag or the like. ) Was positioned at a predetermined position, and was superimposed on the fixed terminal 23, and then assembled by laser welding from the upper surface side of the housing 21 by a laser irradiation device in the next step.

In this case, the bimetal piece 26 is the inversion part 26a by the position control groove part 21a formed in the said housing 21, and the position control protrusion part 26b formed in the said bimetal piece 26. The rotational movement in a direction intersecting with the reverse direction of the was regulated.

Ultrasonic welding may be used in the case of attaching a thermally active switch to an electrical apparatus, or in attaching another component to an electrical apparatus provided with a thermally active switch. In this case, although the conventional thermally actuated switch is performing the fixing of the bimetal piece 26 by laser welding, since the welding point is small in structure, the bimetal piece 26 is rotated by the vibration of ultrasonic wave and the resin In contact with the inner wall of the said housing 21, there existed a problem that the contact part melt | dissolves due to vibration energy, or the said movable contact 25 peels. In addition, there is a problem that assembling is complicated when the welding part is increased so as not to rotate by vibration.

Accordingly, an object of the present invention is to provide a structure of a thermally activated switch that can solve the above-described problems and prevent the rotation of the bimetal piece during ultrasonic welding and can be easily assembled.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, in this invention, as a 1st means, it has a user-shaped housing, the fixed contact arrange | positioned at the inner bottom surface of this housing, and the movable contact which isolate | separates and connects with the said fixed contact which has the inverting part reversible according to temperature. In the thermally-actuated switch provided with the bimetal piece fixed to the one end side and the other end side of this bimetal piece overlapping and fixing in a cantilever shape, and having fixed terminals arranged on the inner bottom surface of the housing, the fixed terminal includes: A regulating member made of a metal material is formed in contact with the outer edge portion of the bimetal piece to restrict the bimetal piece from rotating in a direction intersecting with the reversal direction of the inversion part.

Further, as the second means, the restricting member is formed near the fixing portion on the other end side fixed in a cantilever shape to the fixed terminal on the side opposite to the movable contact fixed to the one end side of the bimetal piece.

Further, as a third means, the regulating member is formed integrally with the fixed terminal.

Further, as a fourth means, the bimetal piece is rotatably moved by forming a protruding piece that is bent downward and an opening in which a part of the fixed terminal is cut out, and engaging the protruding piece with the opening. It is characterized by that what is regulated.

In addition, as a fifth means, a pair of arm portions that face the openings of the fixed terminals are formed, and the arm portions are deformed in the direction of the protruding pieces of the bimetal piece so as to sandwich the protruding pieces into the arm parts. do.

Embodiment of the invention

Hereinafter, the Example of this invention is shown in FIGS. 1 is a plan view of the state in which the cover of the thermally activated switch is removed, FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, FIG. 3 is a sectional view taken along line 3-3 of FIG. 1, and FIG. 4 is a movable contact. 5 is a front view similarly, FIG. 6 is a top view of a fixed terminal, and FIG. 7 is a front view similarly.

In the figure, the housing 1 is formed in the shape of a box with an upper surface opened by an insulating material such as synthetic resin. Each terminal mentioned later is provided in the inner bottom part of this housing 1, and one end of each terminal is led outward from both side surfaces of the said housing 1. As shown in FIG. Further, at the center of the inner bottom surface of the housing 1, a support projection 1a protruding in a hemispherical shape from the inner bottom surface is formed.

Moreover, the rectangular groove part 1b is formed in the one end side of the said housing | casing 1, The support piece part 5b of the bimetallic piece 5 mentioned later is engaged and guided by this groove part 1b.

In the bottom portion of the housing, guide holes 1c and 1d extending from the outer bottom surface side to the back surface of each terminal described later are formed. These guide holes 1c and 1d are pinters of guide pins formed in a molding die for positioning each terminal when inserting each terminal into the housing 1.

The first terminal 2 is formed in a flat plate shape with a conductive metal material such as brass. On one end side of the first terminal 2, a fixed contact 3, which is formed of a small circular plane, which is exposed on the inner bottom surface of the housing 1, is formed, and on the other end side of the first terminal 2, The connection terminal part 2b which is led outward from the side part of the said housing 1 and connected to the circuit etc. of another electric apparatus is formed.

Further, in the first terminal 2, a wide window portion 2c is provided near the fixed contact 3 between the fixed contact 3 and the connection terminal portion 2b. Formed. This window hole part 2c is formed on the center line which passes the said fixed contact 3 of the longitudinal direction of the said 1st terminal 2, and is further in the width direction of the said 1st terminal 2, The window hole portion 2c is formed to have a width larger than the outer circumferential width of the fixed contact 3. In addition, the window hole 2c is cut out so as to rotate around the outer periphery of the fixed contact 3.

Further, in the first terminal 2, an inclined portion (not shown) is formed in a portion including the window hole portion 2c, and the fixed contact 3 and the connection terminal portion (through the inclined portion) are formed. 2b) is connected. When the first terminal 2 is mounted on the housing 1, the inclined portion is embedded in the inner bottom of the housing 1 and mounted.

Similarly, the second terminal 4 as the fixed terminal is formed in a flat plate shape with a conductive metal material such as brass. On one end side of the second terminal 4, a protrusion 4a is formed by knitting with a press or the like, and the protrusion 4a serves as a welded portion for fixing one end of the bimetal piece 5 described later. have. In addition, on the other end side of the second terminal 4, a connection terminal portion 4b which is led outward from the side surface portion of the housing 1 and connected to a circuit of another electric device or the like is formed.

The second terminal 4 has a wide window hole in the vicinity of the protruding portion 4a between the protruding portion 4a and the connecting terminal portion 4b for fixing the bimetal piece 5 described later. (4c) is formed. This window hole part 4c is formed on the centerline which passes the said projection part 4a which is the longitudinal direction of the said 2nd terminal 4, and is the said window hole in the width direction of the said 2nd terminal 4; The width of the portion 4c is formed to be larger than the width of the protruding portion 4a. In addition, the window hole portion 4c is cut out so as to rotate substantially around the outer periphery of the protruding portion 4a.

Moreover, the said window hole part 4c is provided with the pair of arm parts 4d and 4d which protruded toward the window hole part 4c from the outer periphery of the said projection part 4a, and this pair of arm parts Between 4d and 4d, the opening part 4e cut | disconnected in square shape is formed. That is, the pair of arm portions 4d and 4d are formed in the window hole portion 4c with the opening portion 4e interposed therebetween. The protruding piece 5c of the bimetallic piece 5 mentioned later is inserted in the said opening part 4e, and is engaged with the pair of arm parts 4d and 4d.

Incidentally, the inclined portion 4f is formed in the second terminal 4 at the portion including the window hole portion 4c, and the bimetallic piece 5 described later is fixed through the inclined portion 4f. The protrusion 4a and the connection terminal 4b are connected. In the case where the second terminal 4 is mounted to the housing 1, the inclined portion 4f is embedded in the inner bottom of the housing 1.

The bimetallic piece 5 is formed by laminating and bonding at least two or more kinds of metal materials having different thermal expansion coefficients, for example, between a high expansion material made of a material having a high electrical resistance and a low expansion material made of a material having a low electrical resistance. have. On one end of the bimetal piece 5, the movable contact 6 made of silver oxide or the like separated from the fixed contact 3 is fixed by a method such as electric welding. The protrusion 4a formed on the second terminal 4 is fixed by a method such as laser welding. In this case, since the coupling point between the second terminal 4 and the other end side of the bimetal piece 5 is partially engaged with the protruding portion 4a rather than the entire surface, the bimetal piece 5 is inverted. The operating characteristics are not impaired.

Moreover, the dome-shaped inversion part 5a which expanded in order to promote reversal action is formed in the center part of the said bimetallic piece 5, The temperature of the said bimetal piece 5 is formed by forming this inversion part 5a. In other words, the inversion operation according to the temperature can be reliably performed.

Moreover, on the other end side of the said bimetal piece 5, the support piece part 5b which extends and protrudes to the opposite side to the formation position of the said inversion part 5a outside the fixing position with the said 2nd terminal 4 is provided. Formed. The support piece 5b is formed in a state of protruding a pair in a direction orthogonal to each other in the direction perpendicular to the center line connecting the fixing portion between the movable contact 6 and the second terminal 4 and in the plane direction. have.

Further, at the center of the support piece 5b, a protruding piece 5c bent downward at a right angle is formed, and the protruding piece 5c is exposed to the groove part 1b of the housing 1. By inserting into the opening part 4e formed in the window hole part 4c of the second terminal 4 and engaging with the pair of arm parts 4d and 4d, the bimetallic piece 5 causes the housing 1 ) Is positioned.

Moreover, between the inversion part 5a of the said bimetal piece 5 and the said support piece part 5b, the flat part 5d as a coupling part with the said 2nd terminal 4 is formed, and this flat part ( 5d) and the protrusion part 4a of the said 2nd terminal 4 are welded and fixed.

In this case, the supporting piece 5b extends on the side opposite to the formation position of the inverting section 5a via a fixing section with the second terminal 4, thereby forming the bimetal piece 5 above. When assembling to the housing 1, the deformation | transformation of the inversion part 5a of the said bimetallic piece 5 can be prevented, and assembly can be made easy.

Further, at the center of the support piece 5b, a projecting piece 5c bent downward at a right angle is formed, and the projecting piece 5c is provided at the window hole portion 4c of the second terminal 4. By being inserted into the formed opening portion 4e and engaging with the pair of arm portions 4d and 4d, the movement of the bimetal piece 5 in the rotational direction can be effectively suppressed, thereby improving positioning accuracy.

The projecting piece 5c, the opening portion 4e and the pair of arm portions 4d and 4d to which the mesh piece is engaged, are fixed to the movable contact 6 fixed to one end side of the bimetal piece 5. Since it is formed in the vicinity of the fixing part fixed to the cantilever shape of the opposite side, even when the said movable contact 6 side of the said bimetal piece 5 reversely moves, it does not rub together and becomes a malfunction, It is possible to regulate the location.

In addition, since the regulating portion for regulating the position in the rotational direction of the bimetallic piece 5 is formed integrally with the second terminal 4, which is a fixed terminal, there is no need to newly form a regulating member, and thus the number of parts The position control can be performed without increasing the cost, so the cost can be reduced.

Although not shown, a cover formed in an approximately plate shape from an insulating material such as synthetic resin is attached to an opening of the housing 1, and the first and second terminals (not shown) are disposed inside the housing 1. 2, 4), the bimetallic piece 5, the movable contact 6, the fixed contact 3, and the like prevent the influence of dust and gas.

Next, the assembly of the above-mentioned thermally active switch of the present invention will be described.

First, the first and second terminals 2 and 4 formed by press molding a strip-shaped metal plate having a discharge hole at predetermined intervals are integrally formed at the inner bottom of the housing 1 by a method such as insert molding. By embedding | throwing-in by this, the several housing | casing 1 forms the hoop material continuously formed in a belt shape.

Next, the flat contact portion 5d of the bimetal piece 5 is adsorbed and held by a bimetal assembly jig, and the fixed contact 3 and the movable contact 6 oppose the housing 1, The bimetallic piece 5 is assembled in a state where the protruding portion 4a of the two terminals 4 and the one end thereof overlap. At this time, the said bimetal piece 5 is provided with the support piece part 5b which extends and protrudes in the direction opposite to the fixing direction of the said movable contact 6, and orthogonal to a longitudinal direction, and this support piece part The bimetal piece 5 is guided to the housing 1 by engaging 5b with the groove 1b of the housing 1.

At this time, the protruding piece 5c formed on the bimetallic piece 5 is inserted into the opening portion 4e formed in the window hole portion 4c of the second terminal 4 so that the pair of arm portions 4d is provided. And 4d), the movement of the bimetal piece 5 in the rotational direction can be effectively suppressed, and the positioning accuracy is improved. Moreover, since the structure is simple, the workability of assembly is also improved.

At this time, if necessary, the pair of arm portions 4d and 4d are deformed in the direction of the protruding piece 5c of the bimetal piece 5 by a method such as a press, so that the arm portions 4d, By inserting the protruding pieces 5c in 4d), the gaps between each other can be reduced, and the rotation of the bimetal piece 5 can be more firmly regulated.

Next, in the state where the dam plate which fixes and heat-absorbs the bimetal piece 5 at the time of welding is contacted from the upper surface opening side of the said housing 1 to the upper surface of the one end part of the said bimetal piece 5, A laser beam for welding is irradiated from the guide hole 1c formed on the bottom surface of 1) to the bottom surface of the fixed terminal 4 by a laser irradiation device, and the bimetal piece 5 is fixed to the fixed terminal 4. Is attached to the protruding portion 4a.

Next, assembling is completed by attaching a cover to the upper surface side of the opening of the housing 1, cutting and separating the respective thermally active switches from the hoop material.

Next, the operation | movement of the thermally active switch of this invention mentioned above is demonstrated.

At normal temperature and normal use temperature, the movable contact 6 and the fixed contact 3 which are disposed to face each other are in contact with each other and the contact is in an on state. When the temperature rises for some reason from this state, the inversion part 5a formed in the bimetallic piece 5 to which the movable contact 6 is fixed performs the inversion operation in accordance with the increase in temperature. At this time, the movable contact 6 fixed to the bimetallic piece 5 is driven together with the bimetallic piece 5 to be spaced apart from the fixed contact point 3 so that the contact is turned off. In this case, the swelling part inverts the said inverting part 5a of the inverted bimetallic piece 5, and protrudes in the direction of the said fixed contact 3, ie, the direction of the inner bottom surface of the said housing 1. .

Moreover, when temperature falls from this state and returns to original normal temperature, the said inversion part 5a of the said bimetallic piece 5 will invert and return according to the fall of temperature, and will be opposite to the direction of the said fixed contact 3 By projecting in the direction of, the movable contact 6 comes into contact with the fixed contact 3 so that the contact is turned on and returns to the initial state.

In the structure of the thermally actuated switch of the present invention described above, a dome-shaped inverting portion 5a is formed at the central portion of the bimetal piece 5 in order to promote the reversing action when inverting according to the temperature. Therefore, the inversion operation is surely performed.

In addition, the support protrusion 1a is formed on the inner bottom surface of the housing 1. Therefore, when the inversion part 5a returns without being inverted by the temperature change (slow cooling) gradually at the time of temperature fall, the said inversion part 5a is this support protrusion part 1a. ), The contact between the movable contact 6 and the fixed contact 3 is maintained in a spaced apart state, and the movable contact 6 and the fixed contact 3 in the case of reversing again when the temperature rises. The occurrence of chattering of the contact can be prevented.

According to the configuration of the above embodiment, the protruding piece 5c formed by bending a part of the bimetal piece 5 on a part of the second terminal 4 that is a fixed terminal disposed on the housing 1. A pair of arm portions 4d and 4d and an opening 4e for abutting the bimetal piece 5 to restrict rotation of the bimetal piece 5 in a direction intersecting with the reversal direction of the inverted portion 5a. Therefore, by the combination of the metal second terminal 4 and the bimetallic piece 5, the contact portions of the engaging portions for restricting the rotational movement of the bimetallic piece 5 are formed to be metals. .

Therefore, even when ultrasonic welding is used when the thermal oscillation switch is mounted on an electrical apparatus or when another component is attached to an electrical apparatus provided with the thermal oscillation switch, the bimetal piece ( 5) Since it rotates, the part which contacts the inner wall of the said resin housing 1 made of resin, and touches with vibration energy does not melt | dissolve, or the said movable contact 6 peels off, and it does not rotate by vibration, It is not necessary to increase the welding position with the second terminal 4, which is a fixed terminal, so that assembly can be performed easily.

As described above, the thermally actuated switch of the present invention has a user-shaped housing, a fixed contact disposed on an inner bottom surface of the housing, and a movable contact having a reverse contact that can be inverted depending on temperature, and a movable contact for disconnecting from the fixed contact. A bimetal piece fixed to the side and a fixed terminal disposed on the inner bottom surface of the housing while being superimposed on the other end side of the bimetal piece and fixed in a cantilever shape, the fixed terminal abuts against the outer edge of the bimetal piece Since a restricting member made of a metal material restricts rotational movement in a direction intersecting with the inverting direction of the inverting portion, a contacting portion is formed between metals by a combination of a metal restricting member and a bimetallic piece. Contact point with the fixed terminal is not melted. Thereby preventing a rotational movement bimetal convenience. Moreover, since there is no need to increase a welding location, assembly can be made easy.

In addition, since the restricting member is formed near the fixing part on the other end side fixed in the cantilever shape to the fixed terminal on the opposite side to the movable contact fixed on one end side of the bimetal piece, even when the movable contact side of the bimetal piece reverses movement. It is not rubbed and malfunctions, and position can be regulated reliably.

In addition, since the restricting member is formed integrally with the fixed terminal, the position can be regulated without increasing the number of parts, and the cost response can be achieved.

In addition, the bimetal piece was formed to protrude downwardly, and at the same time, the fixed terminal was formed with an opening cut out a part of the bimetal piece to engage the protruding piece with the opening to restrict the rotation of the bimetal piece. This becomes easy, and the assembly workability can be improved.

In addition, since a pair of arm portions opposed to the openings of the fixed terminals were formed, the arm portions were deformed in the direction of the protruding pieces of the bimetal piece, and the protruding pieces were fitted into the arm parts, thereby making it possible to reduce the gap between them. The rotation of the bimetal piece can be firmly regulated.

1 is a plan view illustrating a state in which a cover of a thermally active switch that is an embodiment of the present invention is removed.

It is sectional drawing in the 2-2 line of FIG. 1 of this invention.

3 is a cross-sectional view taken along line 3-3 of FIG. 1 of the present invention.

It is a top view which shows the bimetal piece of the state which fixed the movable contact of this invention.

It is a front view which shows the bimetal piece in the state which fixed the movable contact of this invention.

6 is a plan view showing a fixed terminal of the present invention.

7 is a front view showing the fixed terminal of the present invention.

8 is a plan view showing a state in which a cover of a conventional thermal switch is removed.

It is a top view which shows the bimetal piece of the state which fixed the conventional movable contact.

* Description of the symbols for the main parts of the drawings *

1 Housing 1a Supporting projection

1b groove 1c, 1d guide hole

2 1st terminal 2b connection terminal part

2c window hole 3 fixed contact

4 2nd terminal (fixed terminal) 4a protrusion

4b connection terminal part 4c window hole part

4d arm part (regulator) 4e opening

4f slope 5 bimetal edition

5a inverted part 5b support piece

5c protrusion 5d flat

6 movable contacts

Claims (5)

The housing 1 of a user shape (bottom-shaped), a fixed contact 3 disposed on the inner bottom surface of the housing 1, and an inverting portion 5a that can be inverted according to temperature, and the fixed contact ( 3) and the bimetal piece 5 in which the movable contact 6 separated from each other is fixed to one end, and the other end side of the bimetal piece 5 are overlapped and fixed in a cantilever shape and the housing 1 In the thermally actuated switch having a fixed terminal 4 disposed on the inner bottom surface of the biaxial piece 5, the fixed terminal 4 abuts against an outer edge of the bimetal piece 5 so that the bimetal piece 5 is connected to the fixed terminal 4. A thermally active switch, characterized in that a restricting member (4d) is formed of a metal material for restricting rotational movement in a direction intersecting with an inverting direction of the inverting portion (5a). The other end side according to claim 1, wherein the restricting member (4d) is fixed in a cantilever shape to the fixed terminal (4) on the side opposite to the movable contact (6) fixed to one end side of the bimetal piece (5). The thermally active switch, characterized in that formed in the vicinity of the fixing portion. 3. The thermally active switch according to claim 2, wherein the restricting member (4d) is formed integrally with the fixed terminal (4). 4. The bimetal piece 5 is provided with a protruding piece 5c bent downward, an opening 4e having a portion cut out in the fixed terminal 4, and the opening. A thermally active switch characterized in that the bimetal piece (5) is regulated to rotate by engaging the protruding piece (5c) with (4e). A pair of arm portions 4d are formed in the opening portion 4e of the fixed terminal 4, and the arm portions 4d are protruded in the direction of the bimetallic piece 5. And the projecting piece (5c) is inserted into the arm portion (4d).