JPS61104530A - 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 Field of the Invention: 1. Field of the Invention The present invention relates to a circuit protector which opens a cut-off contact inserted in series in a main current-carrying path when an overcurrent flows therethrough.

[Background Art 1] In general, a circuit protector of type 5-5 has a cutoff contact composed of a fixed contact and a movable contact, and a detection element on the top of a solenoid that drives an armature due to overcurrent inserted in series in the main current-carrying path. By connecting a movable contact plate equipped with a movable contact to the armature via a trip mechanism, the balance of the trip mechanism is disrupted by utilizing the movement of the armature outside when an overcurrent flows in the main current-carrying path. , the cut-off contact is opened. By the way, as shown in FIGS. 6 and 8, the conventional trip mechanism has a long hole 41 that supports both ends of a rotation shaft 4.0 provided at the center of the movable contact plate 4. A frame 42, an opening spring 11' which biases the movable contact plate 4' in the direction in which the breaking contact A is opened, and a latch link 43 that engages with one end of the movable contact plate 4'. A trip plate 45 that is attracted by an electromagnet 44 as an overcurrent detection element and presses the latch link 43 in a direction in which the engagement with the movable contact plate 4' is released when an overcurrent flows in the main current-carrying path. Here, the trip plate 45 is rotatably supported by the frame 42, and the trip plate 45 is urged away from the latch link 43 by a return spring 46. When current flows, one end of the trip plate 45 is attracted by the electromagnet and the other end of the trip plate kicks the launch link 43, as shown in FIG. The closed state is released, and the movable contact plate 4' is rotated around the rotation shaft 41 by the spring force of the opening spring 11', and the breaking contact A is opened. The problem with such a trip mechanism is that it has a complicated structure and requires a large number of components, such as a double trip mechanism.

[Objective of the Invention 1 The present invention has been made in view of the points mentioned in 1. The object thereof is to provide a circuit protector having a relatively small number of component parts, and has no other purpose. The purpose of this invention is to provide a circuit protector that has a fast response speed when an overcurrent passes through it.

[Disclosure 1 of the Invention (Embodiment) Figures 1 and 2 show an embodiment of the present invention. A fixed contact 3 is provided at the other end of the terminal plate 2 . A movable contact 5 is provided at one end of the movable contact plate 4 at a position corresponding to the fixed contact 3 and constitutes a breaking contact A together with the fixed contact 3.
is electrically connected to one end of the coil 7 via a connecting wire 6.

One end of the coil 7 is electrically connected to a second terminal plate 8 protruding from the casing 1 .

That is, the cutoff contact A and the coil 7 are inserted in series into the main current path formed between the first terminal board 2 and the second terminal board 8. One end of the movable contact plate 4 on the side opposite to the movable contact 5 is loosely fitted into the trip plate 9 so as to be able to swing up and down, and a locking piece 13 is provided at the tip of the movable contact plate 4 to prevent removal. is formed. Both ends of the trip plate 9 in the middle direction are slidably accommodated in guide grooves 10 provided in the casing 1 and running in the vertical direction, and are restricted so that the trip plate 9 can only move in the vertical direction. Also, the movable contact plate 4
An opening spring 11 is disposed at one end, one end of which abuts against a rib 12 provided on the casing 1, and the opening spring 11 urges the movable contact plate 4 toward -L. One end of the movable contact plate 4 is in contact with the lower end of a reset button 30 that protrudes freely forward and backward from the casing 1 at the center thereof. The opening is stopped and the lower part is tapered. An engagement hole 14 is formed in the lower end of the trip plate 9, and the tip of an armature 16 of a solenoid 15 serving as a detection element is inserted into the engagement hole 14. The solenoid 15 includes a fill 7, a coil bobbin 17 around which the coil 7 is wound, an armature 16 inserted into the coil bobbin 17 so as to be able to move forward and backward, a yoke 18 that forms a magnetic path together with the armature 16, and a coil bobbin 17. A bias spring 19 is installed inside the coil bobbin 17 and biases the armature 16 outwardly to protrude from the coil bobbin 17.A bias spring 19 is installed inside the coil bobbin 17 and expands outward against the spring force of the bias spring 19 when heated above the transformation temperature. The coil bobbin 1 of the armature 16 is composed of a coil spring 20 made of a shape memory alloy material.
An outer flange 21 is formed at one end inserted into 7, and the armature 16 such as the bias spring 19 and the coil spring 20 is biased by sandwiching the outer flange 21. Furthermore, a fitting hole 22 is formed in a T& shape further below the trip plate 9, into which one end portion of an auxiliary contact plate 23 formed of an elastic conductive material is inserted. That is, the auxiliary contact plate 23 is bent into a substantially IJ shape that is open downward, and an engagement piece 24 that is accommodated in the fitting hole 22 extends from the tip of one vertical piece, and the other side (This is the one in which the contact 25 is provided, and the other vertical piece is extended to the outside of the casing 1 to form a terminal plate. Contact 2
5 is disposed opposite to a contact 27 provided on a terminal plate 26 fixed at a fixed position in the casing 1, and together with the contact 27 constitutes an auxiliary contact. This auxiliary contact is used to control an alarm means that notifies that the circuit protector is activated and the cutoff contact A is opened due to an overcurrent flowing through the main current path. In addition, the auxiliary contact plate 2
3 and the terminal board 26 is an insulating layer 28 such as synthetic resin.
is interposed to prevent a short circuit between the auxiliary contact plate 23 and the terminal plate 26, which are arranged close to each other, outside the casing 1.

The operation of the embodiment will be specifically explained below.

No, Figure 1 shows the ON state set Y, and Figure 2 shows the lip state. First, when set, the fixed contact 3 and the movable contact 5 are in contact with each other, as shown in Figure 1. Breaking contact A is closed. In this state, the opening pole 211 is compressed by the movable contact plate 4, the trip plate 9 is positioned one position below, and one end of the armature 16 of the solenoid 15 is inserted into the engagement hole 14 of the trip plate 5. . Therefore, the trip plate 9 is prohibited from moving in the -1 direction, the cutoff contact A is maintained in the closed state, and the contact 25.2 is kept closed.
The auxiliary contact constituted by 7 is opened. When an overcurrent flows through the coil 7 in this state, as shown in FIG.
0 extension causes the armature 16 to be drawn into the solenoid 15. Here, amateur 16 has magnetic force,
When the coil spring 20 expands, a resultant force with the external force acts, so the armature 16 is pulled in with a large force.
It moves steeply. Furthermore, since the coil spring 20 is of an indirect heating type that is heated indirectly by the coil 7, and the coil spring 20 is housed inside the fill 7, the overcurrent detection element can be made smaller. This allows the arc extinguishing chamber inside the casing 1 to be completely removed. When the armature 16 is pulled into and out of the solenoid 15, the engagement between the trip plate 9 and the armature 16 is released, the trip plate 9 moves upward, and one end of the movable contact plate 4 is connected to the opening spring 11. It is flipped upward by the force of the spring. Since the lower end of the reset button 30 is in contact with the center of the movable contact plate 4, the movable contact plate 4 rotates using the lower end of the reset button 30 as a fulcrum, and the movable contact 5 is separated from the fixed contact 3. do. That is, the cutoff contact A is opened. During this time, the three components that move are the armature 16, the trip plate 9, and the movable contact plate 4.
Since there are only two parts, the time from when an overcurrent flows to the coil 7 until the breaking contact A opens is extremely short (1), and the breaking characteristics are excellent. With the trip plate 9 moved upward, the auxiliary contact plate 23 is bent, and the auxiliary contact is closed. In order to return to the original state from the tripped state, the reset button 30 is pressed downward. In other words, when the reset button 30 is pressed downward,
The movable contact plate 4 moves downward, the opening spring 11 is compressed, and the trip plate 9 also moves downward. and,
Immediately after tripping, the coil spring 20 radiates heat and becomes below the transformation temperature, so when the engagement hole 14 is lowered to the position corresponding to the armature 16, the spring force of the bias spring 19 lowers the armature 16. The tip protrudes from the solenoid 15 and fits into the engagement hole 14. When the reset button 30 is pressed, the engagement hole 1 of the trip plate 9
・Even if the tip of the armature 16 is fitted to 1, is the movable contact plate 4 pressed downward and the cutoff contact ＼ open? To do (
As a result, the breaking contact A is brought into a closed state by the pressing force of the opening spring 11, and the contact pressure is increased by the opening spring 11.

By the way, the movable contact plate 4a may be formed into a bifurcated shape as shown in FIG. Contact 5
Fixed contacts 3a, 31] are formed corresponding to a, 51). Then, the other end of the first fixed contact plate 2a provided with the fixed contact 3a at one end protrudes from the casing 1, and -
A coil 7 is connected to the other end of the second fixed contact plate 21 provided with a fixed contact 31 at its end. Therefore, the connecting wire is not required here, and there is no risk of the connecting wire breaking or the connecting wire coming into contact with the fixed terminal board 3 and causing the breaking contact A to short-circuit. Furthermore, if the height positions of the fixed contacts 3a, 3+] are made different in the direction in which the breaking contact A opens, and a step is provided for both the fixed contacts 3a, 31], the movable contacts 5a, 51] and the fixed contact 3a, 31
This is done by always keeping the opening order of the contacts 31] and 5b constant, and by making the contact area of the contacts 31] and 5b that leave first to be larger than the contact areas of the other contacts 3a and 5a. , which effectively absorbs and removes the arc that occurs when the contact is opened.

In the above-mentioned example, the locking piece 13 is formed as a stop for the movable contact plate 1 to come off from the trip plate 9, or as shown by the imaginary line in FIG. Alternatively, a locking link 3a may be provided, or a shaft 131" may be provided protruding from the medium heat portion of the movable contact plate 4, and the end of this shaft 131) may be inserted into the guide groove 13c provided in the casing 1. It's okay.

Further, in the above embodiment, the solenoid 15 is used as the detection means.
Instead, an oil dashpot or an ordinary electromagnetic slide without the fill spring 20 may be used.

The ones shown in Figures 1 and 5 have different lateral contacts for the auxiliary contact, where ' is the trip plate 9.
A contact drive plate 33 is provided protrudingly from a portion of the contact drive plate 33, and a pair of contacts 34 and 35 constituting the auxiliary contacts are arranged to face each other in the direction perpendicular to the plane of FIG. 4. Each contact 34.35
Each of the contact plates 36 and 37 provided here has elasticity, and in the set state, the contact drive plate 33 or one of the contact plates 36 is pressed from the outside to close between the two contacts 34 and 35. When the trip plate 9a is moved to one side, the contact drive plate 33 is removed from the stepped portion 3 provided on the contact plate 36.
7, the pressing force acting on the contact plate 36 from the contact drive plate 33 is released, and the contacts 34, 35
It is intended to be open for a while.

1 Effects of the Invention 1 The present invention, as described in -F, comprises a casing, a fixed contact fixed at a fixed position on the casing, a movable contact plate including a movable contact that constitutes a breaking contact together with the fixed contact, and a movable contact. an opening spring that biases the plate in the direction in which the interrupting contact opens;
An overcurrent detection element that is inserted in series with the cutoff contact into the main current carrying path and trips the armature when an overcurrent passes through it, and an opening spring that swingably supports the movable contact plate at one end of the movable contact plate. With the spring force stored, the above amateur =
12- Consisting of a trip plate that engages with the tour, and a reset button that abuts the movable contact plate at one end and protrudes from the casing so that it can move forward and backward as the movable contact plate moves at the other end. When an overcurrent passes through the electrical circuit, the engagement between the armature and the trip plate is released and the breaking contact is opened by the spring force of the opening spring, resulting in a simple structure and a reduced number of components. It has the advantage of being less.

In addition, when an overcurrent flows, the breaking contact opens only by the movement of the armature, the trip plate, and the movable contact plate, and the response from when the overcurrent flows until the breaking contact opens. It has the advantage of being fast.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing the configuration and operation of one embodiment of the present invention, FIG. 3 is an exploded perspective view showing an embodiment of the pond of the present invention, and FIG. 4 is a further embodiment of the present invention. FIG. 5 is a partially exploded perspective view of the same example, FIG. 6 and FIG. 7 are cross-sectional views showing the configuration and operation of the conventional example, and FIG. be. 1 is a casing, 3 is a fixed contact, 1 is a movable contact plate, 5
9 is a movable contact, 9 is a triumph plate, 11 is an opening spring, 14 is an engagement hole, 15 is a solenoid, 16 is an armature, 30
is a reset button, and ＼ is a cutoff contact. Agent Patent Attorney Ai Ishi Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (3)

[Claims] (1) A casing, a fixed contact fixed to a fixed position on the casing, a movable contact plate including a movable contact that together with the fixed contact constitutes a breaking contact, and the movable contact plate is biased in the direction in which the breaking contact opens. an overcurrent detection element that is inserted in series with the cutoff contact into the main current-carrying path and draws in the armature when the overcurrent passes; A trip plate engages the armature with the opening spring storing spring force, one end of which abuts the movable contact plate, and the other end of which protrudes freely forward and backward from the casing as the movable contact plate moves. When an overcurrent passes through the main energizing path, the engagement between the armature and the trip plate is released and the interrupting contact is opened by the spring force of the opening spring. A circuit protector with special features. (2) The movable contact plate is formed into a bifurcated shape, and
A patent claim characterized in that a movable contact is provided at each tip of the two prongs, a fixed contact is provided corresponding to each movable contact, and a pair of cutoff contacts are inserted in series in the main current-carrying path. The circuit protector according to item 1. (3) Claims characterized in that at least one of the pair of movable contacts and the pair of fixed contacts is arranged at different positions in the direction in which one of the pair of breaking contacts opens. The circuit protector described in item 2.