JP2002222624A - Tripping device for circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tripping device for a circuit breaker, with which miniatur ization is realized. SOLUTION: The tripping device 1 is equipped with a fixed ion core 2 fixed to a housing 20 of the circuit breaker, a fixed member 3 turnably supported by the fixed iron core 2, a movable iron core 4 fixed to the fixing member 3 so as to oppose to the fixed iron core 2, and a resetting spring 5 mounted between the fixed iron core 2 and the fixed member 3 for driving the fixed member 3 in the abutting direction of a stopper 3d of the fixed member 3 against the fixed iron core 2. At the tip part opposing a fixed member main body 3a of the stopper 3d, a spring hook part 3h is formed, which is composed of a protrusion protruding in a direction nearly orthogonal to the extension direction of the stopper 3d, and to which the end part of the setting spring 5 is hooked and fixed. Because a spring hook part 3h is formed at the stopper 3d, it is not necessary to form the spring hook part 3h for fixing the resetting spring 5 and the stopper 3d in the other side of the fixed member 3, miniaturization, compared with conventional examples can be devised at and the material layout of the stopper 3d is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker for releasing a circuit breaker by attracting a movable core to a fixed iron core by electromagnetic attraction due to an overcurrent and forcibly opening a main contact. It concerns the device.

[0002]

2. Description of the Related Art As a conventional circuit breaker trip device,
For example, there is one described in JP-A-8-96689. The tripping device disclosed in the above publication fixes a fixed core 30 to a fixing member 31 made of a non-magnetic material having a U-shaped groove 31c and a stopper 31a as shown in FIG. Pivot 39 and U-shaped groove 31
The spring hook portion 3 attached to the pivot point of the movable iron core 39 and provided on the fixed member 31 with respect to the bottom surface of the c and the stopper 31a
It is configured to be constantly pressed into contact by a spring 40 hooked on 1b.

In the above conventional example, since the fixed iron core 30 and the movable iron core 39 are integrally assembled via the fixing member 31, the gap between the fixed iron core 30 and the movable iron core 39 becomes constant, and the suction characteristics are stabilized. Can be done.

[0004]

However, in the above-mentioned conventional example, the movable iron core 39 is pivotally supported.
Since the spring hooks 31b and the stoppers 31a are formed at both ends of the fixing member 31 in the longitudinal direction with the groove 31c as the center, the length of the fixing member 31 in the longitudinal direction increases, and the fixing member becomes large. was there.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a circuit breaker tripping device that can be downsized.

[0006]

According to a first aspect of the present invention, in order to achieve the above object, a movable iron core is attracted to a fixed iron core by an electromagnetic attraction force caused by an overcurrent to forcibly open a main contact. A tripping device that opens a circuit breaker by means of a fixed core fixed to the circuit breaker and a non-magnetic material, is rotatably supported by the fixed core, and rotates by contacting the fixed core. A fixed member having a stopper that is regulated, a movable core fixed to the fixed member so as to face the fixed core, and a stopper of the fixed member mounted between the fixed core and the fixed member abuts on the fixed core. A return spring for urging the fixing member in the direction, a spring hook portion for hooking and fixing the other end side of the return spring fixed at one end side to the fixed iron core at the one end side to the stopper. That it formed And symptoms, it is not necessary to form another part of the fixed member the spring hook portion and a stopper for fixing the return spring, even better blank cutout of the fixing member downsizing as compared with the prior art can be achieved.

A second aspect of the present invention is characterized in that, in the first aspect of the present invention, the return spring is a compression spring, and the return spring can be easily mounted as compared with the tension spring.

According to a third aspect of the present invention, in the second aspect of the present invention, the fixed iron core includes a pair of opposing pieces opposing each other in a direction substantially orthogonal to the rotation direction of the fixing member, and a connecting piece connecting the pair of opposing pieces. The fixing member is pivotally supported by each opposing piece and the movable member is fixed to the fixing member main body, and the fixing member extends from the fixing member main body to the side opposite to the surface facing the movable core in the connecting piece. Equipped with a stopper,
It is characterized by comprising a projection projecting in a direction substantially perpendicular to the direction in which the stopper extends, and the spring hook portion can be easily formed.

According to a fourth aspect of the present invention, in the third aspect of the present invention, a notch portion is provided at a position where the stopper comes into contact with the return spring at a peripheral edge of the spring hooking portion. The allowance between the spring hook portion and the spring hook portion increases, and the return spring can be hardly detached from the spring hook portion.

The invention of claim 5 is characterized in that, in the invention of claim 3 or 4, an opening for accommodating the return spring is provided in the connecting piece of the fixed core, and the return spring and the fixed core overlap. The size can be reduced by the thickness of the connecting piece.

The invention of claim 6 is the invention of claim 3 or 4 or 5
In the invention of the above, a step portion protruding outward in the facing direction of the pair of opposing pieces, and a shaft portion having a smaller diameter than the step portion and protruding outward from the step portion are formed on each opposing piece, and each shaft portion The fixing member body is provided with a leg that is rotatably supported on the fixing member main body. The number of contact parts can be reduced. Therefore, the friction between the two can be reduced, and the fixing member can be smoothly rotated,
Thus, the tripping operation can be smoothly performed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 7 is a partially cutaway side view of a circuit breaker using the trip device of the present embodiment. The circuit breaker has a main contact (FIG. 7) electrically connected between input and output terminals. (Not shown) is housed inside a synthetic resin housing 20, and the trip device 1 operates when an overcurrent such as a short-circuit current flows in an electric circuit between the input and output terminals. , The tripping member 2 of the opening / closing mechanism by the tripping device 1
5 is driven, a trip operation (trip operation) is performed, and the main contact is forcibly opened. In addition,
The closing operation, the opening operation, and the resetting operation (the operation of releasing the tripping state by the tripping device 1) of the main contact are performed by a handle 24 provided on the front surface of the housing 20 so as to be able to move up and down.

The main contact is fixedly connected to a fixed contact (not shown) electrically connected to the input terminal, and is fixed to one longitudinal end of a movable contact 26 made of a conductive strip-shaped metal plate. And a movable contact (not shown) that comes in contact with and separates from the movable contact. The other end of the movable contact 26 in the longitudinal direction is locked by the locking piece 21 protruding from the inner bottom surface of the housing 20, and the end locked by the locking piece 21 and the movable contact are fixed. A portion between the end portion and the opening / closing mechanism portion (not shown) is connected. Further, a portion between the connection portion and the end portion locked by the locking piece 21 is connected to the housing 2 by a coil spring 22.
0 (upward in FIG. 7). One end of the coil spring 22 is inserted into a projection 23 protruding from the vicinity of the locking piece 21 on the inner bottom surface of the housing 20, and the other end is in contact with the movable contact 26.

The opening / closing mechanism is in a direction to open the main contact (FIG. 7).
A latch member (not shown) which is elastically urged to drive the movable contact 26 in the upward direction and is latched by the trip member 25 in a state where the main contact is closed (closed state) by the closing operation of the handle 24. The latching member is latched by the tripping member 25 to maintain the closed state, and the opening operation of the handle 24 allows the main contact to be opened to be in the open state. Tripping member 2
5 is a driving piece 25a pushed by the trip device 1.
And a latch piece 25b projecting from the lower end of the drive piece 25a in a direction substantially orthogonal to the drive piece 25a, and are integrally formed.
A scissor-shaped spring, which is rotatably disposed about a pivot (not shown) inserted into a bearing 25c formed at the lower end of the driving piece 25a and is mounted around the bearing 25c. (Not shown), the latch piece 25b is urged in a direction (clockwise in FIG. 7) in which the latch piece 25b contacts the latch member and latches. Since the configuration of the opening / closing mechanism other than this can be realized by using a conventionally known technique, illustration and detailed description are omitted. When the driving piece 25a is pushed and driven by the trip device 1 in a state where the main contact is closed (closed state), the trip member 25 rotates counterclockwise in FIG. The latch between the latch member 25b and the latch member is released, and the movable contact 26 moves upward in FIG. 7 by the spring force of the coil spring 22 or the like, and the main contact is forcibly opened.

As shown in FIGS. 1 and 2, a tripping device 1 has a fixed core 2 fixed to a housing 20, a fixing member 3 rotatably supported by the fixed core 2, and a fixed core 2 facing the fixed core 2. A movable iron core 4 fixed to the fixing member 3 so that
The fixed member 3 is mounted between the fixed core 2 and the fixed member 3.
And a return spring 5 for urging the fixing member 3 in a direction in which the stopper 3d contacts the fixed iron core 2.

The fixed iron core 2 is made of a magnetic material, and is formed in a substantially L-shape to face a pair of opposing pieces 2a, 2a.
A connecting piece 2b connecting the two opposing pieces 2a, 2a at the distal end, a connecting piece 2c projecting from the rear end side of the connecting piece 2b via a step, and an opposing piece 2a from the side edge of the connecting piece 2b. Mounting piece 2d projecting in the opposite direction and having mounting screw hole 2e
Are integrally formed. The connecting piece 2b is formed with a substantially rectangular opening 2f in which the return spring 5 is housed as described later, and the end of the return spring 5 is inserted into the inner peripheral edge of the opening 2f on the distal end side. A spring receiving projection 2g to be attached and hooked is formed. Further, a pair of opposing pieces 2
a cylindrical step 2 projecting outward in the direction opposite to the direction a.
h, and a substantially cylindrical shaft portion 2i having a smaller diameter than the step portion 2h and protruding outward from the step portion 2h is formed at a distal end portion of each of the opposing pieces 2a.

The movable core 4 is formed of a magnetic material into a rectangular flat plate shape, and has a pair of fixing projections 4a, 4a for caulking and fixing to the fixing member 3 and protruding along the longitudinal direction. The fixing member 3 is made of a non-magnetic material, and has a rectangular flat plate-shaped fixing member main body 3a to which the movable iron core 4 is fixed, and a pair of bending members that are bent at substantially right angles from both longitudinally opposite edges of the fixing member main body 3a. 2b, a substantially L-shaped stopper 3d extending from one edge (lower edge in FIGS. 2 and 3) of one leg 3b, and the other edge of the same leg 3b (FIG. 2). And an arm piece 3f extending from the upper edge of FIG. 3). The fixing member main body 3a has two insertion holes 3 through which the fixing protrusions 4a of the movable iron core 4 are inserted.
e, 3e are perforated along the longitudinal direction, and the insertion holes 3
The movable iron core 4 is caulked and fixed to the fixed member main body 3a by caulking the tips of the fixed protrusions 4a, 4a inserted through e and 3e. The two leg pieces 3b, 3b are formed with bearing grooves 3c, 3c which are open to the lower end and have an upper end edge having a substantially arc shape. Thus, the shaft portions 2i, 2i formed in the bearing grooves 3c, 3c at the tips of the opposing pieces 2a, 2a of the fixed iron core 2.
Is inserted, the leg pieces 3b, 3b of the fixing member 3 are pivotally supported by the shaft portions 2i, 2i, and the fixing member 3 is attached to the fixed iron core 2 so as to be rotatable around the shaft portions 2i, 2i. At this time, since the step 2h is interposed between the leg 3b and the opposing piece 2a of the fixed iron core 2, even if the interval between the legs 3b, 3b is reduced, the step is brought into contact only with the steps 2h, 2h. Instead, the number of contact portions between the fixed iron core 2 and the fixed member 3 can be reduced, so that the friction between the two can be reduced and the fixed member 3 can be smoothly rotated.

The stopper 3d is formed in a substantially L-shape such that the stopper 3d is inclined downward as the distance from the fixing member main body 3a increases, and the tip side faces the fixing member main body 3a. At the tip of the stopper 3d facing the fixing member body 3a,
A spring hook portion 3h is formed, which comprises a projection projecting in a direction (upward in FIGS. 2 and 3) substantially perpendicular to the direction in which the stopper 3d extends, and to which the end of the return spring 5 is hooked and fixed. Here, since the spring hook 3h is constituted by a projection projecting in a direction substantially perpendicular to the extending direction of the stopper 3d, there is an advantage that the spring hook 3h can be easily formed.

The arm piece 3f projects upward from the upper end edge of the leg piece 3b in a direction substantially parallel to the fixing member body 3a, and has at its tip a pressing projection 3g projecting in a direction opposite to the direction in which the stopper 3d extends. Are formed.

Thus, as described above, the bearing grooves 3c, 3c
The shafts 2i, 2i of the opposing pieces 2a, 2a of the fixed core 2 are inserted through the shafts 2i, 2i of the fixed member 3 with respect to the fixed core 2.
4, the movable core 4 fixed to the fixing member main body 3a is arranged to face the fixed core 2 as shown in FIG. 4, and the distal end of the stopper 3d is attached to the back of the fixed core 2 ( A spring hook 3h formed at the distal end of the stopper 3d is opposed to the fixed core 2 so as to face the side opposite to the side where the opposing piece 2a of the connecting piece 2b protrudes.
Is arranged near the opening 2f provided in the connecting piece 2b. Then, both ends of the return spring 5 composed of a compression spring are inserted into the spring receiving projection 2g and the spring hooking part 3h provided on the connecting piece 2b, respectively, and the spring force of the return spring 5 causes the pressing projection 3g at the tip of the arm 3f. The fixing member 3 is urged in the direction of rotation approaching the fixed core 2, and the stopper 3 d contacts the connecting piece 2 b of the fixed core 2, thereby restricting the rotation of the fixing member 3. Here, since the return spring 5 is a compression spring, there is an advantage that the return spring 5 can be easily mounted as compared with the tension spring. Further, since a notch 3i having a substantially U-shape is provided at a position where the stopper 3d comes into contact with the return spring 5 at the periphery of the spring hook 3h, the notch 3i allows the return spring 5 and the spring hook 3d to be connected to each other. There is also an advantage that the allowance increases, and the return spring 5 can be hardly disengaged from the spring hook 3d. Further, since the opening 2f in which the return spring 5 is housed is provided in the connecting piece 2b of the fixed iron core 2, the size of the trip device 1 is reduced by the thickness of the connecting piece 2b where the return spring 5 and the fixed iron core 2 overlap. There is an advantage that conversion can be realized.

As shown in FIGS. 3 and 4, a bimetal 6 is disposed in a space surrounded by the fixed core 2 and the fixed member 3 so as to face the fixed core 2 and the movable core 4.
The bimetal 6 is formed in a long rectangular plate shape, and its lower end is connected to the connecting piece 2c of the fixed iron core 2 and inserted between the opposing pieces 2a, 2a. At the upper end of the bimetal 6, a screw hole 6a penetrating in the bending direction of the bimetal 6 is formed, and an adjusting screw 6b is screwed into the screw hole 6a. Further, as shown in FIG. 7, an intermediate portion of the bimetal 6 is connected to an output terminal via a connection wire 7 made of a braided wire, and a lower end of the bimetal 6 is movable via a connection wire 8 also made of a braided wire. It is connected to the contact 26.
Therefore, when the main contacts are closed (closed state), a main circuit (main energizing circuit) through which a current flows through the input terminal-main contact-movable contact 26-bimetal 6-output terminal is formed. The connection wire 7 connecting the bimetal 6 and the output terminal is inserted into a through-hole of the toroidal core of the zero-phase current transformer CT housed in the right end of the housing 20 as shown in FIG. In the circuit breaker according to the embodiment, a zero-phase current transformer CT detects a leakage current such as a leakage current or a ground fault current flowing in the main circuit, and when the leakage current is detected, an opening / closing mechanism by an electromagnetic release device (not shown). The tripping member 25 is driven to perform a tripping operation, and the main contact is forcibly opened.

In the tripping device 1 of the present embodiment configured as described above, as shown in FIG. 7, the mounting piece 2d of the fixed iron core 2 is mounted on the mounting base 27 projecting from the bottom surface of the housing 20. And a screw insertion hole 27a opened on the top surface of the mounting base 27.
Screw 28 inserted from the outside of the bottom surface of the housing 20
Is screwed into the screw hole 2e of the mounting piece 2d to be fixed at a fixed position inside the housing 20. At this time, the connection piece 2c of the fixed iron core 2 is
7 and the mounting table 27 (FIG. 7).
reference). In a state where the tripping device 1 is fixed at the fixed position, the pressing projection 3g provided on the arm piece 3f of the fixing member 3 and the adjusting screw 6b of the bimetal 6 as shown in FIG. It faces the driving piece 25a.

When a current flows between the input and output terminals in a state where the main contact is closed, a magnetic field is generated by the current flowing through the bimetal 6, and the magnetic resistance of the magnetic path passing through the fixed core 2 and the movable core 4 is reduced. As described above, when the attractive force (electromagnetic attractive force) acts between the movable iron core 4 and the fixed iron core 2 and the passing current of the bimetal 6 is an excessive current such as a short-circuit current, FIG. As shown, the movable core 4 approaches the fixed core 2 against the spring force of the return spring 5, that is, the fixed member 3 rotates counterclockwise in FIG. The driving piece 25a is pushed to rotate the tripping member 25 counterclockwise in FIG. 6 to forcibly open the main contact.

On the other hand, if the passing current of the bimetal 6 is lower than the short-circuit current such as the overload current but is higher than the rated current of the circuit breaker, the bimetal 6 bends due to the heat due to the overcurrent, and the bimetal 6 is bent. The driving member 25a of the tripping member 25 is pushed and driven by the tip end of the adjusting screw 6b screwed to the upper end of the tripping member 6, thereby turning the tripping member 25 counterclockwise in FIG. Is forcibly opened. Here, since the degree of curvature (operation sensitivity) of the bimetal 6 with respect to the passing current changes depending on the variation of the material of the bimetal 6 and the connection positions of the connection lines 7 and 8, the operation sensitivity of the opening / closing mechanism (ie, the operation sensitivity)
Current passing through the main circuit when the switching mechanism trips)
In order to prevent the variation, the amount of the adjustment screw 6b screwed to the bimetal 6 projecting from the bimetal 6 toward the trip member 25 may be adjusted.

The tripping device 1 of the present embodiment is constructed as described above, and has a spring hook 3h for hooking and fixing the other end of a return spring 5 fixed at one end to the fixed iron core 2. Since the stopper 3d is formed, the spring hook 3h for fixing the return spring 5 and the stopper 3d do not need to be formed in different portions of the fixing member 3, so that the size can be reduced and the fixing member can be reduced as compared with the conventional example. There is an advantage that the material removal of No. 3 is also improved.

[0027]

According to the first aspect of the present invention, there is provided a tripping device which opens a circuit breaker by attracting a movable iron core to a fixed iron core by electromagnetic attraction due to an overcurrent and forcibly opening a main contact. A stationary member fixed to the circuit breaker, and a fixing member made of a non-magnetic material and having a stopper rotatably supported by the stationary core and abutting against the stationary core to restrict rotation. A movable core fixed to the fixed member so as to face the iron core, and a return spring mounted between the fixed core and the fixed member to bias the fixed member in a direction in which a stopper of the fixed member comes into contact with the fixed core. In the tripping device for a circuit breaker provided with the stopper, a spring hook portion for hooking and fixing the other end side of the return spring having one end hooked and fixed to the fixed iron core is formed in the stopper. And stopper It is not necessary to form a different site in the constant member, as compared with the conventional example has the effect that with even better blank cutout of the fixing member size can be reduced.

According to the second aspect of the present invention, since the return spring is a compression spring in the first aspect of the invention, there is an effect that the return spring can be easily mounted as compared with the tension spring.

According to a third aspect of the present invention, in the second aspect of the present invention, the fixed iron core includes a pair of opposing pieces opposing each other in a direction substantially perpendicular to the rotating direction of the fixing member, and a connecting piece connecting the pair of opposing pieces. The fixing member is pivotally supported by each opposing piece and the movable member is fixed to the fixing member main body, and the fixing member extends from the fixing member main body to the side opposite to the surface facing the movable core in the connecting piece. Equipped with a stopper,
Since the projection is formed in a direction substantially perpendicular to the direction in which the stopper extends, there is an effect that the spring hook portion can be easily formed.

According to a fourth aspect of the present invention, in the third aspect of the present invention, a notch portion is provided at a position where the stopper comes into contact with the return spring on the periphery of the spring hook portion. This has the effect of increasing the margin of engagement with the part and making it difficult for the return spring to come off from the spring hook part.

According to a fifth aspect of the present invention, in the third or fourth aspect of the present invention, the opening for accommodating the return spring is provided in the connecting piece of the fixed iron core. There is an effect that the size can be reduced by the thickness.

The invention of claim 6 is the invention of claim 3 or 4 or 5
In the invention of the above, a step portion protruding outward in the facing direction of the pair of opposing pieces, and a shaft portion having a smaller diameter than the step portion and protruding outward from the step portion are formed on each opposing piece, and each shaft portion The fixed leg body is provided on the fixing member main body so that it can rotate freely so that it can only contact the stepped portion even if the distance between the leg pieces is narrow, and the contact portion between the fixed iron core and the fixing member can be reduced. Therefore, the friction between the two members can be reduced, and the fixing member can be smoothly rotated, so that the tripping operation can be smoothly performed.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the same as seen from another direction.

FIG. 3 is a perspective view of the same.

FIG. 4 is a perspective view of the same as seen from another direction.

FIG. 5 is a side view of the above-mentioned inactive state.

FIG. 6 is a side view of the same operating state.

FIG. 7 is a partially broken side view showing the circuit breaker using the above.

FIG. 8 is an exploded perspective view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tripping device 2 Fixed core 2a Opposing piece 2b Connecting piece 2g Spring receiving protrusion 3 Fixing member 3d Stopper 3g Pressing protrusion 4 Movable core 5 Return spring

Claims (6)

[Claims] 1. A trip device for opening a circuit breaker by attracting a movable core to a fixed iron core by an electromagnetic attraction force due to an overcurrent and forcibly opening a main contact, wherein the trip device is fixed to the circuit breaker. A fixed member having a stopper made of a non-magnetic material, rotatably supported by the fixed iron core, and having a stopper that abuts on the fixed core and regulates rotation, and is fixed so as to face the fixed iron core. A movable iron core fixed to the member,
In a tripping device for a circuit breaker having a return spring mounted between a fixed core and a fixed member and biasing the fixed member in a direction in which a stopper of the fixed member comes into contact with the fixed core, one end of the circuit breaker is connected to the fixed core. A tripping device for a circuit breaker, wherein a spring hooking portion for hooking and fixing the other end side of a return spring hooked and fixed is formed in a stopper. 2. The trip device for a circuit breaker according to claim 1, wherein the return spring is a compression spring. 3. The fixed iron core includes a pair of opposing pieces facing each other in a direction substantially orthogonal to the rotation direction of the fixing member, and a connecting piece connecting the pair of opposing pieces. A fixed member main body that is pivotally supported and to which the movable core is fixed; and a stopper that extends from the fixed member main body to a surface of the connecting piece opposite to the surface facing the movable iron core, and the spring hook portion includes a stopper. 3. The tripping device for a circuit breaker according to claim 2, comprising a projection projecting in a direction substantially perpendicular to the extending direction. 4. The tripping device for a circuit breaker according to claim 3, wherein a notch is provided at a portion of the stopper at the periphery of the spring hooking portion, the portion being in contact with the return spring. 5. The tripping device for a circuit breaker according to claim 3, wherein an opening for accommodating the return spring is provided in the connecting piece of the fixed iron core. 6. A step portion protruding outward in a direction opposite to the pair of opposing pieces, and a shaft portion having a smaller diameter than the step portion and protruding outward from the step portion are formed on each opposing piece, respectively.
6. The tripping device for a circuit breaker according to claim 3, wherein a leg piece rotatably supported on each shaft portion is provided on the fixing member main body.