JPH0586016B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a circuit protector.

[Background technology] 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 solenoid, and the main contact is opened. However, the tripping mechanism was complex, and there were limits 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 has been 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. is to provide.

[Disclosure of the Invention] The 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, a trip lever 9 which is pulled out and driven by a plunger 14 of the short circuit sensor 1, and a slide plate 10 which is releasably engaged with the trip lever 9. By moving the slide plate 10, the main contact 11 is fixed to the fixed contact 1.
A movable contactor 13 and the like to be separated from the contactor 2 is provided. 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 in the left and right directions in the figure. A coil 4 inserted in series with the main contact circuit is wound around the outer periphery of the yoke 2. The plunger 14 has a circumferential projection 5 on its outer periphery.
A bias spring 6 is provided between one side of the circumferential projection 5 and the bottom 3a of the cylindrical body 3.
Further, a shape memory alloy spring 7 wound into a coil is compressed between the other side surface of the circumferential protrusion 5 and a step portion 3b formed at the opening of the cylinder body 3. Normally, the plunger 14 is biased toward the right in the figure by the bias spring 6, and moves to a position where the other side surface of the circumferential projection 5 abuts the engagement step 8 formed at the center inside the cylinder 3. ing. 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 outside the cylinder 3 together with one end of the plunger 14, and the tip of the rod 14b at the other end slightly protrudes outward through the bottom 3a. The release lever 9 is composed of arm pieces 9a and 9b extending at a substantially right angle.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 plunger 14. The tip of the contact spring plate 30 is placed opposite to the rod 4b, and its tip 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 the body A
The approximately central part is fitted into and supported by a horizontal groove 16 provided in the upper part of the inner part so as to be movable in the left and right direction, and an upward locking piece provided at the tip of the arm piece 9b of the above-mentioned tripping lever 9 is provided at one end side. A locking hole 18 is provided in which the movable contact 17 is releasably locked, and a hole 19 in which the upper end of the above-mentioned movable contact 13 engages is bored at the other end. The movable contactor 13 has a main contact point 11 on the side surface of the lower end, and the rod body 14a of the plunger 14 is penetrated and engaged in the center part, and the surface between this penetration position and the upper end and the container body. A contact pressure spring 20 that applies contact pressure is installed between the contact pressure spring 20 and the inner wall of A, and the constantly movable contact 13 is given a rotational force in the counterclockwise direction in the drawings around the engagement point at the upper end. The main contact 11 is brought into contact with the fixed contact 12 of the fixed contact plate 21. The movable contactor 13 has a forked tip as shown in FIG.
A main contact 11 is provided on each of the divided pieces 13a, 13a, and a fixed contact plate 21 is provided in correspondence with the main contact 11.
Two fixed contact plates 21 are arranged in parallel, and one fixed contact plate 21 is integrally extended and electrically connected to one end of the above-mentioned coil 4 via a conductive plate 22, and one fixed contact plate 21 is connected downward from the other fixed contact plate 21. Terminal 2 extending and protruding outside the device body A
3. Fixed terminal plate 21, one fixed contact 12, one main contact 11, movable contact 13, other main contact 1
1, the other fixed contact 12, the fixed contact plate 21, the conductive plate 22, the coil 4, and the terminal 24 connected to the other end of the coil 4 and protruding outside the body A constitute a main contact circuit. The reset button 25 is arranged so as to be able to protrude into a hole 29 provided on the side surface of the container A.
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.

When the main contact 11 and the fixed contact 12 are in contact with each other, the reset button 25 is pushed by the movable contact 13 and the head is projected from the hole 29 to the outside of the body A, as shown in FIG. Also, the locking piece 17 of the lever 9 is connected to the locking hole 18 of the slide plate 10.
The main contact 11 is held in a closed state by restricting movement of the slide plate 10 against the bias of the contact pressure spring 20. 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 biasing force of the bias spring 6.
A retainer 28 provided at the tip of the rod 14a engages with the movable contact plate 13 and applies a force to the movable contact plate 13 to rotate clockwise around its upper end, and the tip of the rod 14b pulls it out. The arm piece 9a of the lever 9 is pushed in a clockwise direction. Therefore, the locking piece 17 of the lever 9 is released from the locking hole 18 of the slide plate 10, and the movable contact plate 13 rapidly rotates clockwise due to the biasing force of the contact pressure spring 20 of the slide plate 10. to separate the main contact 11 from the fixed contact 12. At the same time, movable contact plate 1
3 indicates that the slide plate 10 is moved to the right in the figure at the upper end to close the window hole 27 and that the removal operation has been performed. In addition, due to excessive current, coil 4
As the shape memory alloy spring 7 tries to return to its original shape and pushes the plunger 14 to the left against the bias spring 6, 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 release lever 9 has an arm piece 9a and an auxiliary contact spring plate 30.
is pressed to bring the auxiliary contact 31 into contact with the auxiliary fixed contact 32 and output the operational output to the outside via the auxiliary terminals 33 and 34. The insulator 35 is the auxiliary terminal 33, 34
It is an insulator that isolates 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 also be dealt 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, when the reset button 25 is pushed into the container A with the finger 15 as shown in FIG. Move the slide plate 10 to the left at the upper end of the plate 13 until the hole 27 is exactly connected to the locking piece 17 of the arm piece 9b of the lever 9.
When the lever 9 reaches the position shown in FIG. 4, the lever 9 is rotated counterclockwise by the biasing force of the auxiliary contact spring plate 30, and the engagement piece 17 is engaged with the engagement hole 18 as shown in FIG. When the pressing force of the reset button 25 is released in this state, the movable contact plate 13 rotates counterclockwise around its upper end due to the biasing force of the contact pressure spring 20, bringing the main contact 11 into contact with the fixed contact 12 and making the first It can be reset to the original state shown in the figure.

[Effects of the Invention] The present invention includes a short-circuit sensor that moves a plunger by 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 engaged with the release lever and is 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 extending substantially perpendicularly to the direction of movement of the plate, with the other end of the plunger penetratingly engaging in the intermediate portion, and a main contact corresponding to the fixed contact provided on the front end surface of the other end of the plunger. a reset button disposed in front of the other end of the plunger, one end of which is provided so as to protrude outside the vessel body, and the other end of which faces the movable contact plate so as to be able to push the movable contact plate; The movable contact plate is provided 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 resists the bias of the contact pressure spring. The tripping lever and slide plate can be detached while applying force to force the movable contact plate to rotate. As a result, the movable contact plate can be detached quickly and the main contact can be opened. It has the effect of being able to be released quickly, and the structure is simple because it only requires a locking structure between the release lever and the slide plate.
This has the effect of making it possible to downsize the entire configuration.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the present invention, Fig. 2 is an exploded perspective view of the main parts of the above, Figs. 1 is a coil, 7 is a shape memory alloy spring, 9 is a release lever, 10 is a slide plate, 11 is a main contact, 12 is a fixed contact, 13 is a movable contact plate, and 14 is a plunger.

Claims (1)

[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, and a trip lever that is pushed at one end of the plunger when the plunger moves. , a slide plate whose one end is removably engaged with a tripping lever and is movable in a direction parallel to the plunger; and a slide plate whose one end is movably engaged with the other end of the slide plate. a movable contact plate extending substantially perpendicularly to the direction of movement of the plunger, the other end of the plunger penetratingly engaging the intermediate portion thereof, and a main contact corresponding to the fixed contact provided on the front end surface of the other end of the plunger; and a reset button disposed in front of the other end of the plunger, 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, and the plunger is in penetrating engagement with the reset button. 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 position and the engagement position with respect to the slide plate. 2. Claims characterized in that a short-circuit sensor is used, in which a shape memory alloy spring that returns to its original shape when the transformation temperature is reached 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.