JPS61104532A - Circuit protector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field] The present invention relates to a circuit protector.

[Background technology 1] Conventionally, this type of circuit protector has a structure in which the trip mechanism is tripped by the thermal response of a bimetal installed in the main contact circuit or the electromagnetic attraction force by an electromagnetic twist/id, and the main contact is opened. However, the trip mechanism was complicated, and there was a limit to miniaturization of the device. There was also the problem that the tripping speed was slow and it was not possible to disconnect quickly in the event of a short circuit.

[Object of the Invention] The present invention was made in view of the above-mentioned problems, and its purpose is to provide a circuit protector that has a simple structure, is easy to downsize, and has a fast main contact tripping speed. It is on offer.

[Disclosure 1 of the Invention The present invention will be explained below with reference to drawings of embodiments. The body A of the circuit protector has a short circuit sensor 1 inside, one tripping lever that is driven to be tripped by the plunger 14 of the short circuit sensor 1, and a slide plate 10 that is removably locked to the tripping lever 9. By moving the slide plate 10, the main contact 11
A movable contact 13 and the like are provided to separate the contact from the fixed contact 12. The short-circuit sensor 1 has a cylindrical body 3 made of a non-magnetic material inserted into the center of a cylindrical yoke 2, and a plunger 14 made of a magnetic material is inserted into the cylindrical body 3 so as to be movable left and right in the figure. A coil 4 inserted in series with the main contact circuit is wound around the outer periphery of the yoke 2. Plunger 1
4 is provided with a circumferential protrusion 5 on the outer periphery, and a bias spring 6 is compressed between one side of the circumferential protrusion 5 and the bottom portion 3a of the cylindrical body 3.

Moreover, a shape memory alloy spring 7 wound in a coil shape is provided between the other side surface of the circumferential protrusion 5 and the stepped portion 3b formed at the opening of the cylinder body 3.
is being reduced. Normally, the plunger 14 is biased rightward in the figure by the bias spring 6 and moved to a position where the other side surface of the circumferential protrusion 5 abuts the engagement step 8 formed at the center inside the cylinder 3. There is. The plunger 14 has small diameter rods 14a and 14b protruding in the axial direction from both ends, respectively.
In the above normal state, the rod 14a protrudes to the right along with one end of the plunger 14 outside the cylinder 3, and the rod 14a on the other end side
The tip of b slightly protrudes outward through the bottom portion 3a. The release lever 9 consists of arm pieces 9a and 9b extending at a substantially right angle to each other.The connection point of the lever 9 is rotatably supported at the upper part of the container body A, and the arm piece 9a hanging downward is connected to the upper part of the vessel A. It is opposed to the rod body 4b of the plunger 14, and its tip end is in elastic contact with an auxiliary contact spring plate 30 that is normally embedded and supported in the container body A. The slide plate 10 is supported by being fitted into a horizontal groove 16 provided in the upper part of the container body A so as to be able to move freely in the left and right directions at approximately the center, and on one end side there is an arm piece 9b of the pull lever 9. A locking hole 18 is provided in which the upward locking piece 17 provided at the tip is removably locked, and a hole 19 is provided at the other end in which the upper end of the above-mentioned movable contact 13 engages. has been done. The movable contact 13 has a main contact 11 on the side surface of its lower end, and a rod 14 of the plunger 14 is located in the medium heat section. A is penetrated and engaged, and a contact pressure spring 20 is compressed to apply contact pressure between the surface between this penetration position and the upper end and the inner wall of the container A, and the constantly movable contact 13 A rotational force is applied in a counterclockwise direction in the drawings around the engagement point at the upper end to bring the main contact 11 into contact with the fixed contact 12 of the fixed contact plate 21.

The tip of the movable contact 13 is divided into two as shown in FIG. 2, and each divided piece 13a, 13a is provided with a main contact and a contact 11, and two fixed contact plates 21 are also provided in parallel to correspond to this. One fixed contact plate 21 is electrically connected to one end of the above-mentioned coil 4 via an integrally extending conductive plate 22, and is extended downward from the other fixed contact plate 21 to connect to the body A.
Terminal 23 protruding outward, fixed terminal plate 21, one fixed contact 12, one main contact, α11, movable contact 13, other main contact 11, other fixed contact 12, fixed contact plate 21, conductive plate 22 , coil 4, which is connected to the other end of the coil 4 and connected to the body A
The circuit with the terminal 24 protruding outside constitutes a main contact circuit. The reset button 25 is arranged so as to protrude freely into a hole 29 provided on the side surface of the container A, and a hole 26 is bored inside the container A through which the tip of the rod 14a of the plunger 14 can freely enter and exit. When the main contact 11 is closed, the tip 25a is in contact with the movable contact 13.

Therefore, when the main contact 11 and the fixed contact 12 are in contact, the first
As shown in the figure, the reset button 25 is pressed by the movable contact 13 and its head protrudes from the hole 29 to the outside of the container A, and the locking piece 17 of the lever 9 is attached to the slide plate 10. It is locked in the locking hole 18 to restrict the movement of the slide plate 10 against the bias of the contact pressure spring 20, and to maintain the closed state of the main contact 11. At this time, the locking piece 17 faces the window hole 27 opened on the top surface of the container body A, and indicates to the outside that the container is not in the detached state. Next, when an excessive current flows through the main contact circuit, a large electromagnetic attraction force is generated by the coil 4, and the plunger 14 is attracted and moved to the left against the bias spring 6, causing the rod 14a to move. The removal stopper 28 provided at the tip engages with the movable contact plate 13 and the movable contact plate 13
At the same time, the arm piece 9 of the lever 9 is applied with the tip of the rod 14b.
Push a in the direction of rotating it clockwise.

Therefore, the locking piece 17 of the lever 9 is attached to the slide plate 10.
The slide plate 10 is released from the locking hole 18 of the contact pressure spring 2.
Due to the biasing force of 0, the movable contact plate 13 rapidly rotates clockwise to separate the main contact 11 from the fixed contact 12. At the same time, the movable contact plate 13 moves the sliding plate 10 to the right in the figure at one end to close the window hole 27, thereby indicating that a detaching operation has been performed. In addition, coil 4 may be damaged due to excessive current.
When it heats up and exceeds the transformation temperature, the shape memory alloy spring 7 attempts to return to its original shape and pushes the plunger 14 to the left against the biasing force of the bias spring 6, so the plunger 14 rapidly moves to the left along with the electromagnetic force. direction and rapidly perform the tripping operation. In other words, the movable contact plate 13 is rotated quickly, and the main contact 11 and the fixed contact 12 are quickly disconnected to protect the load. This state is shown in FIG. Here, the tripping lever 9 presses the auxiliary contact spring plate 30 with the arm piece 9a, brings the auxiliary contact 31 into contact with the auxiliary fixed contact 32, and outputs the operating output to the outside via the auxiliary terminals 33 and 34. Insulator 35 is an insulator that isolates auxiliary terminals 33,34. Of course, if an overcurrent flows through the main contact circuit, the plunger 14 can be driven by the shape-returning force of the shape memory alloy spring 20, and the overcurrent can be coped with. Now, when the temperature falls below the transformation temperature after shutoff, the shape memory alloy spring 20 returns to its original state, and the plunger 14 also moves to its original position under the bias of the bias spring 6. Here, as shown in FIG. 4, when the reset button 25 is pushed into the container body A with the finger 15, the movable contact plate 1
3 can be pushed against the bias of the contact pressure spring 20, and when pushed, the slide plate 10 is moved to the left at the upper end of the movable contact plate 13, and the hole 27 is exactly connected to the arm piece 9b of the lever 9. When the locking piece 17 reaches the position shown in FIG. will be stopped. In this state, when the pressing force of the reset button 25 is released, the movable contact plate 13
is rotated counterclockwise about its upper end by the biasing force of the contact pressure spring 20, and the main contact 11 can be brought into contact with the fixed contact 12 and reset to the original state shown in FIG.

[Effects of the Invention] The present invention includes a short-circuit sensor that moves a plunger using electromagnetic force when an excessive current flows through a coil inserted in series in a main contact circuit, and a trip lever that is pushed at one end of the plunger when the plunger moves. A slide plate is arranged such that one end is removably locked to the release lever and movable in a direction parallel to the plunger, and the other end of the slide plate is movably engaged with the other end of the slide plate. A movable contact that extends substantially perpendicularly to the direction of movement of the plate, has the other end of the plunger penetratingly engaged with the intermediate portion, and has a main contact corresponding to the fixed contact on the front end surface of the other end of the plunger. a reset button, which is disposed in front of the other end of the plunger and has one end protruding from the container body and the other end facing the movable contact plate so as to be able to push the movable contact plate; and a plunger penetrating member. It is equipped with a contact pressure spring that biases the movable contact plate toward the other end of the plunger in the forward direction between the mating position and the engagement position with respect to the slide plate, so that when a short circuit occurs, the plunger will
The tripping lever and the slide plate can be removed while applying force to forcibly rotate the movable contact plate against the bias of the contact pressure spring, and as a result, the movable contact plate can be detached. It has the effect of being able to quickly open and release the main contact, and furthermore, the structure is simple and the overall structure can be made smaller because the tripping structure only requires a locking structure between the tripping lever and the slide plate. This has the effect of making it possible.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the present invention, FIG. 2 is an exploded perspective view of the main parts of the same, and FIGS. 3 and 4 are explanatory diagrams of the operation of the same.
1 is a container body, 1 is a short circuit sensor, 4 is a coil, 7 is a shape memory alloy spring, a collar release lever, 10 is a slide plate, 1
1 is a main contact, 12 is a fixed contact, 13 is a movable contact plate, 14
is a plunger.

Claims (2)

[Claims] (1) A short-circuit sensor that moves the plunger using electromagnetic force when an excessive current flows through a coil inserted in series in the main contact circuit, a trip lever that is pushed at one end of the plunger when the plunger moves, and a trip lever. A slide plate is arranged such that one end thereof is releasably engaged with the plunger and is movable in a direction parallel to the plunger, and one end of the slide plate is movably engaged with the other end of the slide plate and is movably moved in the direction of movement of the slide plate. a movable contact plate extending substantially perpendicularly to the plunger, the other end of the plunger penetratingly engaging the intermediate portion thereof, and having a main contact corresponding to the fixed contact on the front end surface of the other end of the plunger; The other end is a reset button arranged in front, one end of which is provided so as to freely protrude outside the container body, and the other end of which faces the movable contact plate so as to be able to push the movable contact plate, the plunger's penetrating engagement position, and the slide plate. A circuit protector comprising a contact pressure spring that biases a movable contact plate toward the other end of the plunger in the forward direction between the engagement position and the engagement position. (2) A patent claim characterized by using a short-circuit sensor in which a shape memory alloy spring that returns to its original shape when it reaches a transformation temperature is provided in the coil, and the plunger can be moved by the shape recovery force of this shape memory alloy spring. The circuit protector according to item 1.