JPS645334Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a thermal overcurrent relay used to prevent burnout due to overload of industrial three-phase induction motors (hereinafter referred to as motors). , and particularly relates to an improved contact operating mechanism.

[Prior art] Figure 8 is a front view of a conventional thermal overcurrent relay.
FIG. 9 is an exploded perspective view of a main part of the reversing mechanism in the same overcurrent relay. In the figure, 1 is a case, and 3 is a bimetal provided in each phase, which is heated by a heater 4 that generates heat when a main circuit current flows, and is bent and deformed as shown by the broken line in the figure. 5 is a fixed terminal, and one end of the bimetal 3 is bonded and fixed to the tongue portion 5a of the fixed terminal. Further, the fixed terminal 5 is fixed to the case 1 by a tightening screw (not shown). Reference numeral 8 denotes an interlocking plate that transmits the deformation motion of the bimetal 3, and is arranged so as to abut the tip of the bimetal 3 of each pole and press the lower end of the temperature compensating bimetal 9 at the other end. Reference numeral 10 denotes an operating lever, which is fixed to the upper end of the temperature compensating bimetal 9 and is arranged to be freely rotatable about a shaft 11. The lever support 12 is supported such that its neck portion 112a is vertically supported by a support plate 150, and rotatably supported in the rotational direction around the edge portion 1a of the case 1.
12b is pressably abutted against the adjustment screw 13, and its second tongue portion 112c is configured to receive a clockwise biasing force from the leaf spring 14 about the edge portion 1a. Therefore, by rotating the adjustment knob 15 placed over the adjustment screw 13, the lever support 112 is moved to the eighth position.
In the figure, it rotates around the edge portion 1a, and the shaft 1
Reference numeral 1 in FIG. 8 performs an adjusting action of changing the operating current by changing the position in the substantially left-right direction. 116 is a movable contact made of a conductive metal plate, and as shown in FIG.
16a, and this edge portion 116a is the first fulcrum portion 1 formed on the normally closed movable side terminal 119.
19a in an abutting relationship. Reference numeral 151 denotes an operating plate, and as shown in FIG.
It is placed in contact with the fulcrum portion 119b. Further, a tension coil spring 152 is stretched between a hole 151b bored at the tip of the operating plate 151 and a hole 116b at the center of the movable contact 116. The movable contact 116 has a contact portion 116c attached to its tip by means such as welding, and faces the normally closed fixed terminal 118, thereby forming a normally closed contact. 153 is an operation panel made of an insulator such as thermoplastic plastic;
As shown in the figure, a protrusion 15 formed at the center of the
3a into the hole 116d of the movable contact 116,
It is integrated with the movable contact 116 by means such as thermal caulking. Further, the protrusion 153b of the operation plate 153 is arranged to press the normally open movable contact 125. Reference numeral 124 denotes a normally open fixed contact, which is disposed opposite to the normally open movable contact 125 and constitutes a normally open contact. Normally open movable contact 125 and normally open fixed contact 1
24 is composed of a metal thin plate having conductivity and elasticity, and the upper end portions of each are fixed to the normally open fixed side terminal 122 and the normally open movable side terminal 123 by means such as caulking. 126 is a reset bar, its lower end surface 1
26a is arranged to press a slope portion 124a formed on the back surface of the normally open fixed contact 124, and is normally urged upward by a return spring 127 and stopped at an upper stopping point.

Next, the operation of the conventional example will be explained.

In FIG. 8, the bimetal 3 is heated by the main circuit current flowing through the heater 4, causing it to curve and deform as shown by the broken line in FIG. The deformation becomes even larger, so that the interlocking plate 8 is pressed by the bimetal 3 and moves to the left in FIG. Therefore, the joint between the temperature compensating bimetal 9 and the operating lever 10 is rotated clockwise in FIG. 15
Press 1c to the right in FIG. For this reason,
The operating plate 151 rotates clockwise around its edge 151a, and the axis of the tension coil spring 152 stretched between the hole 151b of the operating plate 151 and the hole 116b of the movable contact 116 aligns with the normally closed movable side terminal 1.
19, the direction of the force applied by the tension coil spring 152 to the movable contact 116 suddenly reverses, and the movable contact 116 jumps clockwise in FIG. 8 around its edge 116a. Invert. This reversal action of the movable contact 116 causes the operation plate 153 fixed to the movable contact 116 to
The protrusion 153b presses the normally open movable contact 125. As described above, normally closed contacts open and close, and normally open contacts close.

In addition, the contact can be reset by using the reset bar 12 from the outside.
6 is pushed down against the return spring 127, the lower end surface 126a of the reset bar 126 presses the slope 124a of the normally open fixed contact 124, and the normally open fixed contact 124 is moved to the right side in FIG. This is done by

Furthermore, the operation check by manual operation is performed using the interlocking plate 8.
This is done by pressing the portion 8a protruding from the case 1 toward the left in FIG.

[Problems to be solved by the invention] In the conventional thermal overcurrent relay as described above,
A heater 4 through which a main circuit current flows and a bimetal 3 that curves when heated by the heater 4 are arranged on the right side of the case 1 in FIG. 8, and a normally open fixed contact 124 is placed on the left side of the case 1 in FIG. The movable contact 1 with the contact of the normally open movable contact 125 and the operation plate 153 attached
16, a normally closed movable terminal 119, an operating plate 151, and a tension coil spring 152, and an adjustment mechanism including a lever support 112, a support plate 150, and an adjustment knob 15. Therefore, there was a problem in that the external dimensions in the left-right direction in FIG. 8 became large.

In addition, a movable contact 1 constituting a part of the reversing mechanism
A heavy operation panel 153 is attached to 16, and the panel surface (not shown) on which the device is attached is in the horizontal direction of the lower surface in FIG. This is the vertical direction in the figure, and this vertical impact causes the operation plate 15 to
Edge 116 due to inertia based on the weight of 3
Since the moment around a induces malfunction of the movable contactor 116, there is a problem that the movable contact 116 is vulnerable to external shocks and the contact malfunctions frequently.

This invention was devised to solve these problems, and the purpose is to reduce the external dimensions in the width direction and to obtain a highly accurate thermal eddy current relay that does not malfunction contacts even when subjected to external impact. shall be.

[Means for Solving the Problems] The thermal eddy current relay according to this invention has an inner beam portion and an outer beam portion formed on a movable contact made of an elastic thin metal plate, and the outer beam portion and the inner beam portion are connected to each other. A reversing mechanism is located on one side of the case that engages a U-shaped pressing plate spring between the beam and operates the inner beam or outer beam by bending the bimetal due to the heating of the heater through which the main circuit current flows. let it form,
The heater and the bimetal are placed on the other side of the case, and an operating rod that engages with the end of the reversing beam and is movable in parallel in the direction of movement of the reversing beam is placed above the heater and the bimetal. The normally open contact can be moved in the same direction as the operating rod by the operating rod to close the circuit.

[Function] In this device, a reversing mechanism consisting of a movable contact having an inner beam and an outer beam, and a U-shaped pressing leaf spring that engages with the outer beam and the inner beam is placed on one side of the case. and a heater and a bimetal for operating the inner beam or the outer beam are placed on the other side of the case,
Since the operating rod that engages with the end of the reversing beam and is movable in parallel in the direction of movement of the reversing beam is placed above the heater and the bimetal, the contact operation consisting of the reversing mechanism and the operating rod, etc. The space occupied by the mechanism inside the case is shaped like an inverted L when viewed from the front of the case, and the external dimensions of the case in the width direction are greatly reduced. In addition, since the operating direction of the normally open contact that can be closed by the operating rod is parallel to the mounting board surface, the normally open contact will be directed vertically against vertical vibrations and shocks transmitted from the outside to the board surface. It is difficult to move.

[Example] An example of this invention will be described with reference to the drawings.

1 to 7 show an embodiment of this invention.

In Figures 1 and 2, 1 is a case, 2
indicates a cover. Reference numeral 3 denotes a bimetal provided in each phase, which is heated by a heater 4 that generates heat when the main circuit current flows, and is bent and deformed as shown by the broken line in the figure.
5 is a fixed terminal, and one end of the bimetal 3 is bonded and fixed to the tongue portion 5a of the fixed terminal. Further, the fixed terminal 5 is fixed to the case 1 by a tightening screw 6, and a terminal screw 7 for connecting an external circuit (main circuit) is attached to one end of the fixed terminal 5.
is installed.

In FIGS. 1 and 3, reference numeral 8 denotes an interlocking plate that transmits the deformation motion of the bimetal 3, and is arranged so as to abut the tip of the bimetal 3 of each pole and press the lower end of the temperature-compensating bimetal 9 at the other end. ing.
Reference numeral 10 denotes an operating lever, which is fixed to the upper end of the temperature compensating bimetal 9 and is arranged to be rotatable around the case 11. The shaft 11 is supported at both ends by lever supports 12. The lever support 12 has an L-bent inner part 12a, and the edge part 1a of the case
The first tongue portion 12b is pressed against the adjustment screw 13, and the second tongue portion 12b is pressed against the adjustment screw 13.
2c is configured to receive biasing force in the left direction by a leaf spring 14. Therefore, by rotating the adjustment knob 15 placed over the adjustment screw 13, the lever support 12 is rotated around the edge portion 1a in FIG. It performs the function of changing and adjusting the operating current by making a change. 16 is a movable contact made of a thin metal plate having elasticity and conductivity;
As shown in the figure, the inner beam part 16a and the outer beam part 1
6b, and the inner beam part 16
As shown in FIGS. 1 and 3, a U-shaped leaf spring 1 is disposed between the tip of a and the outer beam 16b.
7 is engaged so as to be biased. Further, the contact portion 16c of the movable contactor 16 is connected to the normally closed fixed terminal 18.
facing each other, forming a normally closed contact.

Further, the lower end 16e of the movable contactor 16 is fixed to the normally closed movable side terminal 19. Normally closed movable side terminal 1
9 is fixed to the case 1 with a tightening screw 20. The inner beam portion 16a of the movable contactor 16 is approximately T provided at the tip of the actuating lever 10 shown in FIG.
It is inserted into the shape hole 10a. Movable contact 16
The upper end 16f of the operating rod 21 is engaged with a groove 21a provided at the left end of the operating rod 21.

The operating rod 21 is guided by the case 1 so as to be able to move unilaterally in the left-right direction in FIG. In FIG. 4, 22 and 23 are normally open contact terminals, 24 is a normally open fixed contact, and 25 is a normally open movable contact. Each of the contacts 24 and 25 is made by bending a metal thin plate having elasticity and conductivity into a U-shape, and the normally open contact terminal 2 is formed by the spring force of the U-shape.
2, 23, this normally open contact terminal 22, 2
It is configured to energize with No. 3. The tip of the normally open movable contact 25 is connected to the protruding piece 21 of the operating rod.
It is inserted through the approximately T-shaped hole 21b so as to come into contact with the holes 21b and 21c. In FIG. 1, a reset bar 26 is guided by the case 1 so as to be movable in the vertical direction in the figure, and is normally urged upward by a return spring 27 and stopped at a contact point. In addition, the slope 2 at the bottom of the reset bar
6a are arranged opposite to each other so as to push the apex angle 21e of the operating rod.

Next, the operation will be explained.

In Fig. 1, the bimetal 3 is heated by the main circuit current flowing through the heater 4, causing it to curve and deform as shown by the broken line in the figure. However, when the motor becomes overloaded, the main circuit current becomes large and the bimetal 3 deforms even further. As a result, the interlocking plate 8 is pressed by the bimetal and moves to the left in the figure. This tension is pushed by the interlocking plate 8 and the temperature compensation bimetal 9
The connecting body of the actuating lever 10 rotates clockwise in FIG. The beam 16a also moves to the right in FIG. When the force direction of the biasing force of the U-shaped plate spring 17 reaches the dead center caused by the relationship with the force of the movable contact 16 to return to its original position, the movable contact 16 rapidly reverses and In Figure 1, the outer beam 16b is on the left side, and the inner beam 1 is on the left side.
6a jumps to the right. Therefore, the contact portion 16
The normally closed contact, which had been maintaining electrical continuity, opens due to the contact between the normally closed fixed terminal 18 and the normally closed terminal 18. Further, the operating rod 21 is pulled by the tip 16f of the outer beam and the first
Moving to the left in the figure, the protruding piece 21c deforms the normally open movable contact 25 to the left. Therefore, the normally open movable contact 25 contacts the normally open fixed contact 24, and the normally open contact is turned on. By connecting the normally closed contact in series with the coil circuit of an electromagnetic contactor (not shown) that switches on and off the main circuit current, the main circuit can be cut off and protected when the motor is overloaded.
Further, by connecting an alarm buzzer (not shown) or a lamp (not shown) in series to the normally open contact, a motor overload alarm 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 are returned to their original positions by manually pushing the reset bar 26 downward in FIG. 1 from the outside. .

As the reset bar 26 moves downward, the lower slope 26a pushes the apex angle 21e of the operating rod 21 to the right in FIG. In order to move the movable contact 16 beyond the dead center of the movable contact 16
rapidly recovers and returns to the state shown in Figure 1.

If you want to check the circuit by activating the contacts of the overcurrent relay without energizing the main circuit, manually move the external protrusion 21f of the operating rod 21 to the left and remove the movable contact. This can be done by inverting 16. Further, depending on the position of the external protruding piece 21f, the operation and downward operation of the overcurrent relay can be identified from the outside.

[Effect of the invention] As explained above, this invention forms an inner beam portion and an outer beam portion on a movable contact made of a thin elastic metal plate, and a U-shaped portion is formed between the outer beam portion and the inner beam portion. A reversing mechanism is located on one side of the case, which engages a pressing leaf spring and operates the inner beam or outer beam by bending the bimetal due to heating of the heater through which the main circuit current flows, and the heater and the bimetal are connected to each other. An operating rod is disposed on the other side of the case, engages with an end of the reversing beam, and is movable in parallel in the operating direction of the reversing beam, and is provided above the heater and the bimetal; Since the space inside the heater occupied by the contact operating mechanism section consisting of the reversing mechanism and the operating rod etc. forms an inverted L-shape with respect to the front of the case, the outer dimensions of the case in the width direction can be greatly reduced. be.

In addition, an operating rod that engages with the end of the reversing beam and can move parallel to the direction of movement of the reversing beam allows the normally open contact to move in the same direction as the operating rod to close the circuit. The operating direction of is parallel to the mounting board surface (bottom surface in Figure 1), so
Even if vertical vibrations or shocks are transmitted from the outside to the panel surface, the normally open contacts are difficult to move vertically, so contact malfunctions are extremely rare, resulting in a highly accurate thermal eddy current relay. There is an effect.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of this invention, Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1, Fig. 3 is a cross-sectional view taken along line B-B in Fig. 1, and Fig. 4 is a cross-sectional view taken along line A-A in Fig. 1. 1 is a cross-sectional view taken along the line C-C in Fig. 1, Fig. 5 is a perspective view showing a movable contact in an embodiment of this invention, Fig. 6 is a perspective view showing an actuating lever in an embodiment of this invention, and Fig. 7 is a perspective view showing a movable contact in an embodiment of this invention. FIG. 8 is a front view of a conventional thermal overcurrent relay, and FIG. 9 is an exploded perspective view of a main part of the reversing mechanism of the overcurrent relay. In the figure, 1... Case, 3... Bimetal, 4... Heater, 16... Movable contact, 16a
...Inner beam part, 16b...Outer beam part, 17...
... U-shaped leaf spring, 21 ... Operation rod, 22, 2
3... Normally open contact terminal, 24... Normally open fixed contact,
25... Normally open movable contact. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims for Utility Model Registration] (1) An inner beam portion and an outer beam portion are formed on a movable contact made of a thin elastic metal plate, and a U-shaped press is formed between the outer beam portion and the inner beam portion. A reversing mechanism that engages a leaf spring and operates the inner beam or outer beam by bending the bimetal due to heating of the heater through which the main circuit current flows is formed by being located on one side of the case, and the heater and the bimetal are connected to the case. An operating rod is disposed on the other side and engages with an end of the reversing beam, and is movable in parallel in the direction of movement of the reversing beam, and is provided above the heater and the bail metal;
A thermal eddy current relay characterized in that the normally open contact can be moved in the same direction as the operating rod by the operating rod to close the circuit. (2) The heating device according to claim 1 of the utility model registration, characterized in that the operating rod is capable of returning a closed normally open contact by pressing a reset bar disposed perpendicularly to the operating rod. Dynamic eddy current relay.