JPH0618101B2 - Thermal overcurrent relay - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermal overcurrent relay used for the purpose of protection against overload burning of a load such as a motor, and more particularly to an improvement in the structure of a thermal element. is there.

[Conventional technology]

FIG. 14 is a front view showing a conventional thermal overcurrent relay, FIG. 15 is a sectional view taken along the line AA of FIG. 14, and FIG.
FIG. 17 is a sectional view taken along the line BB of FIG. 17, FIG. 17 is a sectional view taken along the line CC of FIG. 14, FIG. 18 is a perspective view of the main part of the reversing mechanism, FIG. 19 is a perspective view of the movable contactor, and FIG. FIG. 6 is a perspective view of an operating lever.

In the figure, (1) shows a case and (2) shows a cover.
(3) is a bimetal provided for each phase, and is heated by a heater (4) that generates heat when a main circuit current flows,
It is curved and deformed as shown by the broken line in the figure. (5) is a load side main circuit terminal, and the upper end of the bimetal (3) is joined and fixed to the tongue portion (5a).

The load side main circuit terminal (5) is fixed to the case (1) by a tightening screw (6), and its one end (5b) is fixed.
Is a terminal screw (7) for connecting the load side main circuit (external circuit)
Is screwed on.

In FIG. 17, (40) is a main circuit terminal on the power source side, and one end (40a) thereof has an upper end portion (4a) of the heater (4).
Are mechanically and electrically connected by means such as welding. In addition, the left end portion (40) of the main circuit terminal (40) on the power source side
b) is screwed to a terminal of a power supply circuit such as an electromagnetic contactor (not shown).

In FIG. 14, (8) is an interlocking plate for transmitting the varying motion of the bimetal (3), which abuts on the tip of the bimetal (3) of each pole, and at the left end of FIG. It is arranged to press the lower end.

(10) is an actuating lever, which is fixed to the upper end of the temperature compensating bimetal (9) and is rotatably arranged around the shaft (11). FIG. 20 shows a perspective view of the operating lever. The shaft (11) is supported at both ends by lever supports (12) as shown in FIG. The lever support (12) has its L-bending inside corner (12a) as shown in FIG.
The case (1) is in contact with the edge part (1a) and is supported by a fulcrum, and is pressed against the adjusting screw (13) by the first tongue part (12b), and the second tongue part (12c) is a plate. Spring (14)
Thus, the urging force is applied to the left in FIG. Accordingly, by rotating the adjusting knob (15) put on the adjusting screw (13), the lever support (12) is moved to the edge part (1) in FIG.
Rotate about a) and the shaft (11) moves to the 14th
In the figure, the position is changed substantially in the left-right direction, the operating current is changed, and the adjustment operation is performed. (16) is a movable contact,
It is made of a thin metal plate having elasticity and conductivity, and is punched into a shape composed of an inner beam portion (16a) and an outer beam portion (16b) as shown in FIG. 19, and the tip of the inner beam portion (16a) and the outer beam. A U-shaped leaf spring (17) is engaged with the portion (16b) so as to press and urge it.

Further, the contact portion (16c) of the movable contactor (16) faces the normally-closed contact-like fixed contactor (18) in an abutting arrangement and constitutes a normally-closed contact.

Further, the lower end portion (16) of the movable contactor (16) shown in FIG.
e) is caulked and fixed to the normally closed movable side terminal (19) shown in FIG. 14 by the hole (16g).

The normally closed movable side terminal (19) is fixed to the case (1) by a tightening screw (20) as shown in FIG.

The inner beam portion (16a) of the movable contactor (16) is inserted through a substantially T-shaped hole (10a) provided at the tip of the actuating lever (10) shown in FIG. Movable contact (1
6) Upper beam part (16f) connected to the outer beam part (16b)
Is engaged with a groove (21a) provided at the left end of the crossbar (21).

The crossbar (21) is guided by a case (1) which is movable in the left-right direction in FIG.

(22) and (23) in FIG. 15 are normally open contact terminals,
4 and 15, (24) is a normally open fixed contact,
(25) shows a normally open movable contact.

The normally open fixed and movable contacts of (24) and (25) are made of a thin metal plate having spring property and conductivity, and are caulked to the normally open contact terminals (22) and (23), respectively.

The back surface (25a) of the upper end of the normally open movable contact (25) in FIG. 14 is disposed in contact with the protruding piece (21g) of the crossbar.

Reference numeral (26) denotes a reset bar, and in FIG. 14, it is slidably held by the case (1) so as to be movable in the vertical direction, and the edge portion (26c) applies an upward pressing force to the return spring (27). In response, it is urged upward and stops at the upper limit stop point.

The lower vertical surface (26d) of the reset bar is in contact with the curved portion (24a) provided on the back surface of the normally open fixed contactor (24). The slope portion (26a) is moved downward in the reset bar (26) to cause the curved portion (24a).
It is arranged so that the normally open fixed contactor (24) is deformed and moved to the right in FIG. 14 by slidingly pressing.

(26b) shows a locking hole provided in the reset bar (26). When the overcurrent relay is used with the automatic reset method, the reset bar (26) is pushed downward, the switching plate (30) is moved to the left in FIG. 14, and the switching plate (3
The tip of the reset bar (26) is inserted into the locking hole (26b) to restrain the reset bar (26) from returning upward.

The conventional thermal overcurrent relay is configured as described above and operates as follows.

In FIG. 17, the main circuit current is the main circuit terminal (4
0) to the load side main circuit terminal (5) through the heater (4), the bimetal (3). An electric wire (not shown) is connected to the terminal screw (7) screwed to one end (5b) of the load side main circuit terminal (5), and a load (not shown) of an electric motor or the like is connected to the end thereof. It is connected to the. Therefore, the main circuit current is the same as the current flowing in the load.

Now, the bimetal (3) is heated by the Juule heat generated by the main circuit current flowing through the heater (4) and the bimetal (3), and is bent as shown by the broken line in FIG.

When the above-mentioned load is in an overloaded state, the main circuit current increases, so that the curvature of the bimetal (3) shown by the broken line in FIG. 14 becomes even larger, so that the interlocking plate (8) becomes larger than the bimetal (3). It is pushed by the tip and moves to the left in FIG.

Therefore, when pressed by the left end of the interlocking plate (8), the connection body of the temperature compensating bimetal (9) and the operating lever (10) rotates clockwise about the shaft (11), and the operating lever (10). T-shaped hole (10a) with the tip of
The inner beam portion (16) of the movable contactor (16) that abuts around the
a) is also bent to the right in FIG.

Then, the inner beam is reached up to the dead point caused by the relationship between the direction of the urging force of the U-shaped leaf spring (17) and the spring force of the outer contact (16b) of the movable contactor (16) trying to return to its original position. When the part (16a) is bent and moved, the movable contact (16) is rapidly inverted, and in FIG. 14, the outer beam part (16b) jumps to the left and the inner beam part (16a) jumps to the right.

Accordingly, the contact portion (16c) and the fixed contact for the normally closed contact (1
The normally-closed contact that was kept in electrical contact with the contact with 8) is opened.

Further, the crossbar (21) is pulled by the upper end portion (16f) of the outer beam portion (16b) to move to the left side in FIG. 14, and the protruding piece (21g) deforms the normally open movable contactor (25) to the left. Let Therefore, the normally open movable contact (25) comes into contact with and comes into contact with the normally open fixed contact (24) to turn on the normally open contact.

By connecting the normally-closed contact in series to the operation coil circuit of the electromagnetic contactor (not shown) that opens and closes the main circuit current,
When a load (not shown) such as an electric motor is overloaded, the main circuit can be cut off and protected. Further, by connecting a circuit such as an alarm lamp (not shown) in series with the normally open contact, an overload alarm signal can be issued.

After the main circuit current is cut off and the bimetal (3) returns to its original state, the normally open and normally closed contacts can be restored to their original state by manually operating the reset bar (26) as shown in FIG. It is done by pushing down. The reset bar (26) is manually returned to the downward direction in FIG. 14 by the spring (2
If you push down while resisting the reaction force of 7), the slope (26
a) is a curved part (24) on the back surface of the normally open fixed contact (24)
a) is pushed to the right, which causes the normally open stationary contact (2
4) The protrusion (26g) of the crossbar (26) is pushed rightward in FIG. 14 via the normally open movable contactor (25) in contact with the crossbar (26), and the crossbar (26) moves to the right. .

[Problems to be solved by the invention]

In the conventional thermal overcurrent relay as described above, since the power source side main circuit terminal (40) is held by welding to the heater (4), the power source side main circuit terminal (40) is electromagnetically contacted. When it is vibrated by a shock such as opening and closing of a container (not shown), stress is applied to the welded portion of the main circuit terminal (40) on the power source side and the heater (4), and the heater (4) may be broken. I got it.

Further, the tips of the bimetals (3) of each phase must be in contact with the interlocking plate (8) at the same time, and in order to do this, the load side main circuit in which the upper ends of the bimetals (3) are joined and fixed. The tongue portion (5a) of the terminal (5) must be plastically deformed to adjust the tip of the bimetal (3), which requires time for adjustment and increases the assembly cost.

Further, since the load side main circuit terminal (5) to which the bimetal (3) is joined and fixed is only fixed to the case (1) by the tightening screw (6), the resin may be changed due to, for example, aging. When the size of the case (1) made is reduced, the tightening screw (6) is loosened and the position of the bimetal (3) is changed, so that the operating current is changed.

The present invention has been made to solve the above-mentioned problems. The main circuit terminal on the power supply side, the bimetal support, and the bimetal are integrally fixed to reduce the possibility of heater breakage due to vibration or shock, and the position of the bimetal. It is an object of the present invention to obtain a thermal dynamic overcurrent relay that can be adjusted quickly.

The present invention further provides a highly reliable thermal overcurrent relay by preventing the operating current from changing even if the resin case is slightly reduced in size due to aging or the tightening screw is loosened. The purpose is to get.

[Means for solving problems]

The thermal overcurrent relay according to the present invention includes a first groove portion which holds and fixes one main circuit terminal, a second groove portion which holds and holds a joint portion between one end of the bimetal support and one end of the bimetal, and a bimetal support. Provide a heater support body made of an insulating material having a pin that is inserted and locked in the drilled hole.Furthermore, the pin tip of the heater support body that is inserted in the hole drilled in the bimetal support is used as a hole drilled in the case. It is configured such that the tip of the pin of the heater support and the peripheral portion of the hole of the case are fixed with an adhesive resin and the bimetal support is fixed to the case with a tightening screw.

[Work]

In the present invention, the main circuit terminal on the power supply side and the joining portion of the bimetal support and the bimetal on which the heater is attached are integrated by a heater support formed of an insulating material, and the main circuit terminal on the power supply side is electrically connected to the heater. Connected to each other,
Even if the main circuit terminal is vibrated by an opening / closing impact of an electromagnetic contactor or the like, the stress is applied to the heater support, and therefore the heater attached to the bimetal is less affected.

In still another aspect of the invention, a heater support body in which a pin tip of a heater support body inserted through a hole of a bimetal support is inserted through a hole formed in a case to integrate a power source side main circuit terminal, a bimetal support and a bimetal However, the position of the tip of the bimetal with respect to the interlocking plate can be easily adjusted by rotating the heater support during assembly. In addition, since the tip of the heater support and the peripheral part of the hole of the case are fixed with adhesive resin after assembly, the size of the case shrinks due to aging, and the bimetal support is fixed to the case. Even if the screw loosens, the bimetal support is fixed to the case, and the bimetal integrated with the bimetal support does not change its position.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

1 is a front view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line U-U of FIG. 1, FIG. 3 is a sectional view taken along the line VV of FIG. 1, and FIG. 1 is a sectional view taken along line WW, FIG. 5 is a sectional view taken along line XX of FIG. 1, FIG. 6 is a side view of FIG. 5, and FIG. 7 is a front view showing a combined state of heating element portions. FIG. 8 is a plan view of the same, FIG. 9 is a side view of the same, FIG. 10 is an exploded perspective view of parts of a normally open contact and a reset device part, and FIG. 11 is an exploded view of parts of a normally closed contact and a reversing mechanism part. FIG. 12 is a perspective view of the first lever, and FIG. 13 is a perspective view of the second lever. In the figure, the same numbers as in the conventional example indicate the same parts or corresponding parts.

In the figure, (1) shows a case and (2) shows a cover.
Reference numeral (3) denotes a bimetal provided for each phase, which is heated by a heater (4) which generates heat when a main circuit current flows and is bent and deformed as shown by a broken line in FIG.

In FIG. 5, (5) is a load-side main circuit terminal, which is L-shaped. A terminal screw (7) for connecting a load side main circuit (external circuit) is screwed to one side (5b) of the L shape, and a bimetal support (50) is attached to the other side (5c) by welding or the like. ) Is electrically and mechanically joined. The upper end of the bimetal (3) is electrically and mechanically joined and fixed to the tongue portion (50a) of the bimetal support (50) by means such as welding. In FIGS. 5 and 7 to 9,
(40) is a main circuit terminal on the power source side, and the upper end portion (4a) of the heater (4) is electrically connected to one end (40a) thereof by means such as welding. In addition, the main circuit terminal (4
The left end portion (40b) of 0) is screwed to a terminal of a power supply circuit such as an electromagnetic contactor (not shown).

(51) indicates a heater support made of a heat-resistant resin. The heater support (51) has a first groove (51
a) the power source side main circuit terminal (40), and the second groove portion (51b), the tongue portion (50) of the bimetal support (50).
Hold the joint between a) and the top of the bimetal (3) respectively.
It is fixed. Further, the heater support (51) has a cylindrical pin (51c) formed at the right end thereof inserted into a hole (50c) formed at the upper end of the bimetal support (50). As can be seen in FIG. 7, the heater support (51) connects the main circuit such as the power source side main circuit terminal (40), the bimetal support (50), the bimetal (3), the heater (4) and the heating element peripheral parts 1 It has the function of embodying. Now, the heating element portion (52) thus integrated and assembled as shown in FIG. 7 is housed in the case (1). At this time, the tip of the pin (51c) of the heater support is inserted into the hole (1X) of the case (1) shown in FIG.
The heating element part (52) is freely rotated around the center, and the tip of the bimetal (3) is adjusted to be equal to the interlocking plate (8), and then the tightening screw (6) shown in FIG. The lower end (50b) of the bimetal support (50) is fixed to the case (1). Next, after assembling the heating element portion (52) in the case (1), the pin (51) of the heater support (51) is
The tip of c) and the peripheral portion of the hole (1X) of the case (1) are fixed with an adhesive resin (53) as shown in FIG. Further, the adhesive resin (53) is filled in the hole (1y) formed in the portion corresponding to the corner portion (50d) of the bimetal support (50) of the case (1) shown in FIG.
When the adhesive resin (53) is hardened in the space shown by the hatching in FIG. 6 formed between the corner (50d) of 0) and the hole (1y), the corner (50d) of the bimetal support (50) is The case (1) is fixed, and the position of the bimetal (3) in the rotation direction in FIG. 1 is completely fixed.

Reference numeral (8) is an interlocking plate for transmitting the heat deformation operation of the bimetal (3), which comes into contact with the tip of the bimetal (3) of each pole,
At the left end of the interlocking plate (8) in the figure, the temperature compensation bimetal (5
It is arranged so as to press the lower end portion (54c) of 4).

In FIG. 3, (55) is a lever support, a pair of first fulcrum parts (55a) at the lower part thereof and a pair of second fulcrum parts at the upper part thereof.
Fulcrum portion (55b) is formed.

Reference numeral (56) indicates a movable contact made of a conductive thin metal plate.

A pair of edge portions (54a) formed substantially in the center of the compensating bimetal (54) is formed on the first fulcrum portion (55a) of the lever support (55) and below the movable contactor (56). The pair of edges (56a) is the second of the lever support (55).
Of the compensating bimetal (5
4) A hole (54b) drilled in the upper part and a movable contactor (56)
A tension coil spring (57) between the hole (56b) drilled in
Is stretched.

The lever support (55) abuts against the edge portion (1a) of the case at its L-bending inside corner (55c) and is supported as a fulcrum.
Further, the first tongue portion (55d) is pressed against the adjustment screw (13), and the second tongue portion (55e) is biased to the left in FIG. 1 by the leaf spring (14). It is configured like this. Therefore, by rotating the adjusting knob (15) put on the adjusting screw (13), the lever support (55) rotates about the edge portion (1a) of the case (1) in FIG. In operation, the lower end (54c) of the temperature-compensating bimetal changes its position in the substantially left-right direction in FIG. 1 to change and adjust the operating current.

In FIG. 11, (58) shows a normally closed fixed side terminal.
(59) is a normally closed fixed contact, which is made of a thin metal plate having spring properties and conductivity, and is electrically and mechanically connected to the normally closed fixed side terminal (58) at its lower part (59a) by means such as caulking. It is fixed. In addition, the contact (59
In b), the contact (56c) provided on the upper part of the movable contactor (56) is arranged to face the contact, and the contact and separation of these contacts form a normally closed contact.

The normally closed fixed side terminal (58) is press-fitted and fixed to the case (1) as shown in FIG.

Reference numeral (60) shown in FIG. 11 is a normally-closed movable side terminal, which is press-fitted and fixed to the case (1), and its tongue portion (60a) is
It is in contact with the first spring portion (61a) of the contact spring (61) attached to the first tongue portion (55d) of the lever support (55).

Since the contact spring (61) is made of a thin metal plate having conductivity and elasticity, the normally closed movable side terminal (60) → contact spring (61) → lever support (55) → movable contact (56) Power is supplied to the movable side of the normally-closed contact through the path.

In FIGS. 1 and 2, (22) is a normally open fixed-side terminal, and (2)
3) is a normally-open movable side terminal which is press-fitted and fixed to the case (1). (24) shows a normally open fixed contact, and (25) shows a normally open movable contact. Each of the normally open fixed and movable contacts of (24) and (25) is made of a thin metal plate having spring property and conductivity, and is connected to the normally open fixed side terminal (22) and the normally open movable side terminal (23). The right end of each is electrically and mechanically connected and fixed by means such as caulking.

Further, the normally open fixed contact (24) and the normally open movable contact (25) are provided with contacts (24a) and (25a) facing each other at substantially left ends thereof. , (25a) abut / separate to form a normally open contact.

In FIG. 1, (62) indicates the first lever. The first lever has a perspective shape as shown in FIG. 12, and has a cylindrical portion (62a) at the center thereof, and a protruding shaft (1) provided on the case (1).
Z) and is rotatably held. The first lever (62) has a first arm (62b) and a second arm (62c) extending in three directions around the cylindrical portion (62a).
And a third arm (62d), the first arm (62b) is divided into two projecting pieces (62e) and (62f) at the tip, and these projecting pieces (62e) and (62f)
Holds the tip portion (56d) of the movable contactor (56). The second arm (62c) also has a tip (62g),
It is divided into two projecting pieces (62g), and the normally open movable contact (25) is provided between these projecting pieces (62g) and (62h).
The tip of is arranged.

The tip of the third arm (62d) is bent as shown in Fig. 12 to form a display piece (62J). The display piece (62J) is attached to the window 1W of the case (1). It projects to the corresponding position.

Reference numeral (63) shows the second lever in FIG. 13, which is a half-notched cylinder in the substantially central portion so that it is rotatably held with respect to the protruding shaft (1Z) of the same case (1) as the first lever (62). It has a portion (63a), and has a shape including a first arm (63b) and a second arm (63c) extending in two directions with the portion (63a) as the center.

The tip of the first arm (63b) has protruding pieces (63d), (6
3e), and a normally closed fixed contact (59) in the gap.
The front end (59c) of the above is sandwiched and arranged. Further, the tip end (63f) of the second arm (63c) is arranged so as to be pressed by the reset bar described later.

The second spring portion (61b) provided on the contact spring (61) shown in FIG. 11 has a structure in which the substantially central portion of the first arm (63b) of the second lever is pushed leftward in FIG. Therefore, the second lever (63) receives an urging force in the counterclockwise direction about the protruding shaft (1Z), and stops by contacting the case (1) at the stopper portion (1V) of the case (1). .

In FIG. 10, (64) is a reset bar, and (65) is a switching plate. Both parts are assembled in the reset bar case of (66) and then mounted in the case (1).

Both sides of the reset bar (64) are slidably supported by the guides (66a) and (66b) of the reset bar case (66), and are configured to be movable up and down in FIG.
The spring receiving portion (64a) and the reset bar case (66)
The return spring (67) is assembled by compressing and assembling it between the spring receiving portions (66c) provided in the above, and the reset bar (64) is urged upward by the return spring (67).

Also, the first protrusion (64) at the bottom of the reset bar (64)
b) is arranged so as to oppose the upper surface of the normally open fixed contactor (24), and the second protrusion (64c) is arranged to press the tip (63f) of the second arm (63c) of the second lever. ing.

Further, the switching plate (65) is a component for switching the recovery method after the contact operation of the device from manual recovery to automatic recovery. The switching plate (65) is provided in the shaft hole (66d) of the reset bar case (66). The front split shaft (65a) is fitted and assembled, and the switching plate (65) rotates around this shaft hole. Reference numeral (66e) is a guide hole for fixing the switching plate (65) at the manual return position and the automatic return position, and is a substantially dharma hole.

The projection pair (65b) of the switching plate (65) is configured to fit into the guide hole (66e). FIG. 1 shows the state of manual restoration. At the time of automatic return, the switching plate is rotated counterclockwise, and at that time, the tip end (65c) is configured to push down the upper surface of the normally open fixed contact (59).

Next, the operation of the embodiment will be described.

In FIG. 5, the main circuit current is the main circuit terminal (4
0) to the load side main circuit terminal (5) through the heater (4), the bimetal (3) and the bimetal support (50). An electric wire (not shown) is fastened and connected by a terminal screw (7) screwed to one side (5b) of the L-shape of the load side main circuit terminal (5), and the tip of the wire is a load such as an electric motor. (Not shown). Therefore, the main circuit current is the same as the current flowing in the load.

It is similar to the conventional example that the bimetal (3) is heated by the Juule heat generated by the main circuit current flowing through the heater (4) and the bimetal (3) and curved as shown by the broken line in FIG. Is.

When the above-mentioned load is in an overloaded state, the main circuit current increases, so that the curvature of the bimetal (3) shown by the broken line in FIG. 1 becomes even larger, so that the interlocking plate (8) becomes the tip of the bimetal (3). It is pushed by and moves to the left in FIG.

Therefore, the lower end (54c) of the interlocking plate (8) is attached to the left end of the interlocking plate (8).
The temperature compensating bimetal (54), which is pressed to the left, rotates clockwise around the first fulcrum portion (55a) of the lever support (55).

This movement causes the temperature compensating bimetal hole (54b) to move to the right in FIG. In FIG. 1, the straight line connecting the hole (54b) of the temperature compensating bimetal and the hole (56b) of the movable contact, that is, the axis of the tension coil spring (57) is the hole (56b) of the movable contact and the second fulcrum of the lever support. (55
When the temperature-compensating bimetal (54) is rotated until it crosses the straight line connecting to (b) to the right (dead point),
The tensile force of the tension coil spring (57) causes the movable contactor (56) to move.
The direction of the force for urging is changed, and the movable contactor (56) rapidly rotates clockwise around the second fulcrum portion (55b) of the lever support. At this time, until the dead point, the tension force of the tension coil spring (57) worked by acting on the movable contactor (56) as an urging force in the counterclockwise direction about the second fulcrum portion (55b), so that the contact ( 59b)
The normally closed stationary contact (59) is also pressed to the left in FIG. 1 by the contact between the contact point (56c) and the contact point (56c), and contacts the protruding piece (63e) of the second lever (63). It has stopped at. When the movable contactor (56) rapidly rotates clockwise beyond the dead point as described above, the tip (59c) of the normally closed fixed contactor (59) projects from the protruding piece (63d) of the second lever (63). ), The movable contact (56) follows the movable contact (56) and is constrained by the contact position (63d), and the movable contact (56) continues to rotate in the clockwise direction. The contact of 59b) is released, and the normally closed contact is opened.

Here, the normally closed fixed contact (59) is the second lever (63).
The dimension that follows the movable contactor (56) from the contact position of the protruding piece (63e) to the protruding piece (63d) is the overtravel dimension of the normally closed contact and improves the contact reliability of the normally closed contact. effective. As described above, when the movable contactor (56) rapidly rotates clockwise, the protruding piece (62f) is moved by the tip (56d) of the movable contactor (56).
1, the first lever (62) is rotated counterclockwise about the protruding shaft (1Z). Therefore, the normally open movable contact (25) is deformed by being pressed by the protruding piece (62g) of the first lever (62), and the contact (25a).
Comes into contact with the contact (24a) of the normally open fixed contact (24) to close the normally open contact. Here, since the normally open fixed contactor (24) is also made of a thin metal plate having a spring property, it is pushed by the protruding piece (62g) of the first lever (62) even after the contact is closed, and is normally opened. The movable contactor (25) is further deformed upward. The normally open fixed contact (24) is the reset bar (6
This deformation proceeds until it hits the first protrusion (64b) in 4), and stops at this position. Movable contact at this position (56)
The rotation operation of the first lever (62) is also stopped, and the reversing operation (trip) is completed. Contact points (24a) and (25a)
Of the normally open fixed contact (24) after closing the normally open contact (that is, the gap between the normally open fixed contact (24) and the first protrusion of the reset bar in the initial state of FIG. 1).
Is the overtravel dimension of the normally open contact, which has the effect of improving the contact reliability of the normally open contact.

Further, the contacts (24a) and (25a) are slid to each other in the left-right direction in FIG. 1 by the deformation operation of the normally open fixed contact (24) and the normally open movable contact (25) within this overtravel dimension. Since it has an action to remove dust, dust, oxides, etc. on the surface of each contact, it has the effect of further improving the contact reliability of the normally open contact.

In addition, as described above, in the state where the recoil operation (trip) is completed, the first lever (62) is fully rotated counterclockwise, so that the third arm (62d) is also rotated to the left side. The display piece (62J) at the tip was visible from the outside through the window (1W) of the case (1) in the initial state of FIG. 1, but after completion of the reversing operation, the wall (1) of the case (1)
It disappears in the shadow of S). That is, the display piece (62
When J) is seen from the outside through the window of the case, it indicates a non-inverted state (reset state), and when it is invisible, it indicates an inversion operation completed state (trip).
2J) has an operation display function. Further, this display piece (62J) has a function of a test trip operation portion in addition to the operation display function.

What is a test trip? When the overcurrent relay reverses due to overload, the normally closed and normally open contacts are connected to an external circuit to check whether or not they perform the required operation. In the case of this embodiment, the operation can be performed as follows. In the initial state of FIG. 1, the display piece (62
J) is artificially moved to the left in FIG. 1 from the outside,
By this operation, the first lever (62 rotates counterclockwise, but this rotation causes the protruding piece (62e) of the first lever (62) to move the movable contact (56) tip (56d) to the first position. 1 Push to the right in Fig. 1. Then, move the contact hole (56
b) is the first fulcrum part (55a) of the lever support (55)
And the second fulcrum portion (55b) are connected to the right side of the line, the force of the tension coil spring (57) suddenly changes to the opposite direction, and the movable contact (56) rapidly moves clockwise. The movable contactor is rotated and the movable contact and the first lever (62) are rotated in the same manner as the above-described inversion operation, and the inversion operation is completed (trip).

Next, the return operation will be described.

When the reversing operation is completed, the reset bar (64) is manually pushed downward in FIG. 1 against the reaction force of the return spring (67).

By this operation, the first protrusion (64b) of the reset bar
Will push down the projection piece (62g) of the first lever (62) through the normally open fixed contact (24) and the normally open movable contact (25) in the downward direction in FIG.

As a result, the first lever (62) rotates clockwise around the protrusion shaft (1Z), and is pushed by the protrusion piece (62f) to move the movable contactor (56) to the left. When the hole (56b) of the movable contact moves to the left side of the straight line connecting the first fulcrum part (55a) and the second fulcrum part (55b) of the lever support (55), the tension coil spring (57) The urging force of the movable contactor (56) due to the abrupt change from the clockwise direction to the counterclockwise direction, and the movable contactor (56) pivots counterclockwise so as to rapidly return to the initial state of FIG. .

As a result, the tip (56d) of the movable contact pushes the protruding piece (62e) of the first lever (62), and the first lever (6)
2) rapidly rotates clockwise and returns to the initial state (reset) of FIG. 1, the normally open contact is opened, and the normally closed contact is closed.

Next, the normally closed contact cutting operation will be described.

This operation is performed by pressing the reset bar (64) downward in FIG. 1 in the initial state of FIG.

By pushing down the reset bar (64) downward against the return spring (67), the second protrusion (64c) of the reset bar causes the second arm (63) of the second lever (63) to move.
It abuts against the tip (63f) of c) and is pushed down.

Therefore, the second lever (63) rotates clockwise about the protrusion shaft (1Z) against the resistance of the second spring portion (61b) of the contact spring (61). As a result, the protruding piece (63d) of the second lever (63) presses the tip (59c) of the normally closed fixed contact (59) to the left. Therefore, the normally closed fixed contact (59) is deformed to the left. At this time, the movable contactor (56) is also fixed in the normally closed state until the first lever (62) is rotatable clockwise, that is, the protruding piece (62g) abuts the stop piece of the case (1). Follows the contact (59), but thereafter the movable contact (56)
The tip (56d) of which is the protruding piece (62e) of the first lever.
When contacted with the contact 56
c) and the contact (59b) are opened. That is, the normally closed contact is opened. Then, by releasing the manual pressing force of the reset bar (64), the reset bar returns to the state shown in FIG.

Therefore, the second lever (63) is also released, and the first spring portion (61b) of the contact spring (61) is urged by the urging force of the first spring portion (61b).
Returning to the original state of the figure, the normally closed contact is closed.

Like the conventional example, the normally closed contact is connected in series to the operation coil circuit of the electromagnetic contactor (not shown) that opens and closes the main circuit current,
The normally open contact is used to open and close an alarm lamp or the like (not shown).

In this embodiment, the power source side main circuit terminal (40), the tongue piece (50a) of the bimetal support (50), and the joint at the upper end of the bimetal (3) to which the heater (4) is attached are made of insulating material. It is integrated by the formed heater support body (51), and the power source side main circuit terminal (40) is the heater (4).
Even if the power source side main circuit terminal (40) is vibrated by the opening / closing impact of the electromagnetic contactor, etc., the stress generated by the vibration is not electrically connected to the heater support. It directly affects the body (51) and has little influence on the heater (4) attached to the bimetal (3). Therefore, the heater (4) is not broken.

Furthermore, the tip of the pin (51c) of the heater support (51) that is inserted through the hole (50c) of the bimetal support (50) is inserted through the hole (1X) formed in the case (1), and the power source side main circuit terminal ( 40), by rotating the heater support (51) that integrates the bimetal support (50) and the bimetal (3), the position adjustment of the tip of the bimetal (3) with respect to the interlocking plate (8) can be performed quickly and easily. You can do it. Further, after the heater support (51) is assembled in the case (1), the tip of the heater support (51) and the peripheral portion of the hole (1X) of the case (1) are bonded as shown in FIG. Since the case (1) is fixed by resin, the size of the case (1) is reduced due to aging, and the tightening screw (6) fixing the lower end portion (50b) of the bimetal support (50) to the case (1) is loosened. In any case, the bimetal support (50) is fixed to the case (1), and the bimetal (3) integrated with the bimetal support (50) does not change its position. Therefore, the operating current never changed. As shown in FIG. 6, a hole (1Y) is formed in the case (1) corresponding to the corner (50d) of the bimetal support (50), and the adhesive resin (53) is placed in the hole (1Y). When filled, the adhesive resin (53) in the space shown by hatching in FIG. 6 is formed between the corner (50d) of the bimetal support (50) and the hole (1Y).
Is cured, and the bimetal support (50) is fixed to the case (1) by the adhesive resin (53). Therefore, even if the case (1) is reduced in size due to aging, the bimetal support (50) remains securely fixed to the case (1). Further, the fastening screw (6) for fixing the bimetal support (50) to the case (1) and the peripheral portion of the hole of the case (1) are fixed with an adhesive resin, whereby the bimetal support (50) is further improved. The case (1) is firmly fixed.

〔The invention's effect〕

As described above, the present invention has a main circuit terminal on the power supply side,
The stress generated in the main circuit terminal when the bimetal support and the joining part of the bimetal to which the heater is attached are integrated by the heater support made of an insulating material and vibrated by the opening and closing impact of the electromagnetic contactor etc. Is applied to the heater support, the effect of the stress on the heater attached to the bimetal is small, and there is an effect that the heater is not broken.

Further, the pin tip of the heater support body inserted through the hole of the bimetal support is inserted into the hole formed in the case, and the heater support body is rotatable around the pin, so that the heater support body is rotated at the time of assembly. As a result, the position of the bimetal tip with respect to the interlocking plate can be adjusted quickly and easily. In addition, the tip of the heater support and the peripheral part of the hole of the case are fixed with adhesive resin after assembly, and the size of the case has been reduced over time and the bimetal support is fixed to the case. Since the bimetal support is fixed to the case even if the screw is loosened, the bimetal integrated with the bimetal support does not change its position, and the operating current does not change.

[Brief description of drawings]

1 is a front view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line U-U of FIG. 1, FIG. 3 is a sectional view taken along the line VV of FIG. 1, and FIG. 1 is a sectional view taken along line WW, FIG. 5 is a sectional view taken along line XX of FIG. 1, FIG. 6 is a side view of FIG. 5, and FIG. 7 is a front view showing a combined state of heating element portions. FIG. 8 is a plan view of the same, FIG. 9 is a side view of the same, FIG. 10 is an exploded perspective view of parts of a normally open contact and a reset device part, and FIG. 11 is an exploded view of parts of a normally closed contact and a reversing mechanism part. Fig. 12 is a perspective view of the first lever, Fig. 13 is a perspective view of the second lever, and Fig. 14 is a front view showing a conventional thermal overcurrent relay.
5 is a sectional view taken along the line AA of FIG. 14, FIG. 16 is a sectional view taken along the line BB of FIG. 14, FIG. 17 is a sectional view taken along the line CC of FIG. 14, and FIG. 19 is a perspective view of a movable contactor, and FIG. 20 is a perspective view of an operating lever. In the figure, (1) is a case, (1X) is a hole, (1Y)
Is a hole, (3) is a bimetal, (4) is a heater, (5) is a load side main circuit terminal, (6) is a tightening screw, (40) is a power side main circuit terminal, (50) is a bimetal support, (50c)
Is a hole, (51) is a heater support, (51a) is a first groove, (51b) is a second groove, (51c) is a pin, and (5)
3) is an adhesive resin.

Claims (2)

[Claims] 1. A normally closed contact means, an actuating means for opening and closing the normally closed contact means, a plurality of bimetals for driving the actuating means via interlocking plates, and either of the power supply side or the load side attached to each bimetal. A case that is electrically connected to one of the main circuit terminals and that causes a displacement of the bimetal during heat generation, and a bimetal support that fixes one end of the bimetal and is electrically connected to the other main circuit terminal In the thermal overcurrent relay provided inside, a first groove portion sandwiching and fixing one of the main circuit terminals, a second groove portion sandwiching and fixing a joint portion of the bimetal support and the bimetal, and a hole drilled in the bimetal support A thermal overcurrent relay, characterized in that a heater support formed of an insulating material having a pin inserted through and locked in is provided. 2. A normally-closed contact means, an actuating means for opening and closing the normally-closed contact means, a plurality of bimetals for driving the actuating means via interlocking plates, and a bimetal attached to each of the bimetals, either on the power supply side or the load side. A case that is electrically connected to one of the main circuit terminals and that causes a displacement of the bimetal during heat generation, and a bimetal support that fixes one end of the bimetal and is electrically connected to the other main circuit terminal In the thermal overcurrent relay provided inside, the first groove part which holds and fixes one main circuit terminal, the second groove part which holds and fixes the joint part of the bimetal support and the bimetal, and the bimetal support are drilled A heater support formed of an insulating material having a pin inserted and locked in the hole is provided, and the pin tip of the heater support inserted through the hole of the bimetal support is inserted through the hole formed in the case, And a peripheral portion of the hole of the pin tip and the case of the data carrier fixed with adhesive resin, thermally activated overcurrent relay, characterized in that fixing the bimetallic support to the chassis with the screw tightening.