JPH0112754Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the terminal structure of an electromagnetic contactor, and particularly to an improvement in the terminal structure of an electromagnetic contactor for connecting and fixing external wiring material terminals of an electric motor or the like.

Opening/closing control of electric circuits of electric motors, etc. is normally performed by controlling the opening/closing of main circuit contacts of electromagnetic contactors, and the fixed contact terminal board that forms this main circuit contact is equipped with terminals of external wiring materials of electric motors, etc. connection is fixed.

The wiring material terminals have been conventionally attached to the terminal board by screws because it is easy to attach and detach the wiring materials. This conventional terminal structure for mounting wiring materials includes a terminal screw with a washer rotatably attached to the lower end of the screw head, a fixed contact for the main circuit contact at one end, and a mounting surface for the wiring material terminal at the other end. a terminal board formed with a terminal board, wherein the terminal screw is screwed into a female screw formed on the terminal board or an insulating base on which the terminal board is placed, and the terminal of the wiring material is fixed between the terminal board and the washer. It consists of a structure that is The terminal of the wiring material is preferably a ring-shaped round crimp terminal that is used by being fitted into the screw portion and does not come off even if the screw becomes loose, from the viewpoint of preventing danger due to the terminal coming off.

However, with conventional terminal structures, when attaching and detaching the round crimp terminals, that is, when completely screwing the terminal screws out of the terminal board, the terminal screws cannot be held because human fingers cannot reach them. fell from the terminal board, resulting in the terminal screws becoming powdery, and the fallen terminal screws short-circuiting the electrical circuit.

Furthermore, in the conventional structure, great care must be taken to prevent the terminal screw from falling when attaching and detaching the round crimp terminal, making the operation of attaching and detaching the terminal extremely complicated.

The present invention has been devised in view of the above-mentioned conventional problems, and its purpose is to provide an improved terminal structure for attaching wiring materials that allows terminals such as round crimp terminals to be attached and detached extremely easily.

In order to achieve the above object, the present invention is an electromagnetic contactor that controls the opening and closing of electric circuits by bringing a movable core into and out of contact with a fixed core by excitation of a fixed core, in which a fixed contact is disposed at one end and an external wiring material is connected to the other end. The terminal board includes a terminal board having a terminal mounting surface, a terminal screw for screwing a terminal of a wiring material to the terminal mounting surface, and a terminal cover that covers the terminal board and the terminal screw. A guide wall is provided vertically to guide the vertical movement of the terminal screw, and a threaded protrusion is provided on the side surface of the head of the terminal screw. A thread is formed by cutting the terminal screw, and the terminal screw is held in the threaded portion of the guide wall while maintaining a predetermined gap between the lower end of the terminal screw and the terminal plate in an unthreaded state.

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 shows the structure of an electromagnetic contactor including a terminal structure according to the present invention, in which a fixed core 14 having an operating coil 12 mounted thereon is housed and held in a holding frame 10. On the other hand, a movable core 16 is provided at a position facing above the fixed core 14 so as to be movable up and down, and a cross bar 18 is attached to the movable core 16 . Therefore, the fixed core 1 by the operating coil 12
4, the movable iron core 16 is moved toward and away from the fixed iron core 14, and at this time, the crossbar 18 is moved up and down in conjunction with the movable iron core 16.

A movable contact 20 is provided on the cross bar 18, and a fixed contact 22 is disposed opposite the movable contact 20. That is, the holding frame 10
A conductive terminal plate 26 is placed and fixed on the insulating base board 24 , and a fixed contact 22 is disposed at one end of the terminal plate 26 to face the movable contact 20 .

On the other hand, a mounting surface for a wiring material terminal is formed at the other end of the terminal plate 26, and a wiring material terminal such as a motor (not shown) is fixed to the mounting surface with a terminal screw 28.

Therefore, as the movable iron core 16 is brought into contact with and removed from the fixed iron core 14, the movable contact 20 is brought into contact with and removed from the fixed contact 22, that is, the electric circuit of the electric motor or the like is opened and closed.

The mounting portion of the wiring material terminal, that is, the terminal board 2
6. Terminal screws 28 and wiring material terminals (not shown) are covered with terminal covers 38 for safety and dust prevention.
covered by.

The characteristic feature of the present invention is that the terminal structure of the electromagnetic contactor has a unique structure so that round crimp terminals etc. can be attached and detached extremely easily and reliably. A guide wall is provided vertically to guide the terminal screw, and a threaded protrusion is provided on the side surface of the head of the terminal screw, and as the terminal screw is unscrewed, the threaded protrusion cuts a thread on the circumferential surface of the guide wall. The formed terminal screw is configured to be held in the threaded portion of the guide wall while maintaining a predetermined gap between the lower end of the terminal screw and the terminal plate in an unthreaded state.

In this embodiment, an insertion hole for a terminal screw 28 is formed in the terminal mounting surface of the terminal board 26, and a female screw 30 is formed in the insulating base plate 24 corresponding to the insertion hole.
is provided.

On the other hand, the terminal screw 28 in this embodiment is shown in FIG.
As shown in FIG. 3, a plurality of threaded projections, in this embodiment, three threaded projections 32a, 32b, and 32c, are provided at equiangular intervals on the upper side of the head. These threaded projections 32a, 32b, 32c are formed so as to form a thread when the terminal screw 28 is unrotated.
32c are provided so as to be shifted in the axial direction by 1/3 pitch corresponding to one pitch of the threaded portion 34. Further, a washer 36 is rotatably and irremovably attached to the lower end of the head of the terminal screw 28.

Wiring material terminals of electric motors, etc. are screwed to the terminal board 26. This screwing operation is performed by placing a round crimp terminal of the wiring material on the terminal mounting surface of the terminal board 26, and then tightening the threaded part 34 of the terminal screw 28. The wiring material terminal is fixed between the terminal plate 26 and the washer 36 by tightening the female screw 30.

After the wiring material terminals are screwed to the terminal board 26 as described above, the terminal cover 38 that covers the wiring material terminal mounting portion is attached to the upper part of the holding frame 10 to ensure safety and dustproofing.

A terminal screw 28 is inserted from the top wall of the terminal cover 38.
A guide wall 40 is provided vertically to guide the vertical movement of the terminal screw 28 when screwing on or unscrewing. This guide wall 40 is formed by a cylindrical wall or by arranging a plurality of arcuate plates facing each other. A stopper step 42 is provided on the upper inner circumferential surface of the guide wall 40 to determine the upper limit movement position of the terminal screw 28, and in this embodiment, the portion below this step 42 is provided with a washer for the terminal screw 28. 36 is formed to be slidable, and the inner diameter of the cylindrical wall in the upper part of the stepped portion 42 or the distance between the opposing plates is formed to be smaller than the diameter of the virtual cylindrical surface passing through each tip of the threaded projection 32a described above. , 32b, 32c to form a thread.

This embodiment has the above structure, and the following terminal screws 2
The thread cutting action on the circumferential surface of the guide wall 40 when the screw of No. 8 is unrotated, that is, when the wiring material terminal is removed, will be explained.

First, when removing the wiring material terminal from the terminal board 26, a tool is inserted into the guide wall 40 from outside from above and the terminal screw 28 is unscrewed and rotated. Due to this screw release rotation, the terminal screw 28 moves upward along the guide wall 40, and the threaded protrusion 32a reaches the position of the stopper step 42 at a position slightly before the terminal screw 28 comes out of the female screw 30, and at this time For the first time, the threaded protrusion 32a bites into the circumferential surface of the guide wall, and cutting and formation of the thread begins. When the terminal screw 28 is further unrotated and the terminal screw 28 is completely unscrewed from the female screw 30, the other threaded protrusions 32b and 32c have bitten into the circumferential surface of the guide wall 40, and the terminal screw 28 is unrotated. By continuing to cut the thread on the circumferential surface of the guide wall, the thread cutting progresses further and the terminal screw 28
It is only when the washer 36 engages with the stopper step 42 that the upward movement of the terminal screw 28 is prevented and the thread forming action is stopped. In this state, the terminal screw 28 is screwed into and held by the threaded part of the guide wall, and the lower end of the terminal screw 28 forms a predetermined gap with the terminal board 26, that is, a gap sufficient for the insertion and removal of the wiring material terminal. As a result, it is possible to attach and detach the round crimp terminal etc. extremely easily.

As explained above, according to the present invention, when the terminal screw 28 is unscrewed from the female screw 30, the terminal screw 28 forms a predetermined gap between the lower end of the terminal screw and the terminal plate 26, and the guide wall is closed. Because it is screwed into the threaded part, the terminal screw 2 is removed when attaching or detaching the wiring material terminal.
8 will not fall, and it is possible to attach and detach a round crimp terminal or the like to and from the terminal plate 26 extremely easily.

In this embodiment, each of the plurality of threaded protrusions formed on the side surface of the head of the terminal screw is formed so that threads can be cut. It is also possible to form a thread cutting guide protrusion for threading the thread formed thereon.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an electromagnetic contactor including a terminal structure according to the present invention, Fig. 2 is a front view of a terminal screw constituting the terminal structure of the electromagnetic contactor according to the present invention, and Fig. 3 is a diagram of the configuration of a magnetic contactor including a terminal structure according to the present invention. FIG. The same members in each figure are given the same reference numerals, 14 is a fixed core, 16 is a movable core, 22 is a fixed contact, 26
is a terminal board, 28 is a terminal screw, 32a, 32b, 3
2c is a threaded projection, 38 is a terminal cover, and 40 is a guide wall.

Claims (1)

[Scope of utility model registration request] In an electromagnetic contactor that controls opening and closing of an electric circuit by moving a movable core into and out of contact with a fixed core by excitation of a fixed core,
A terminal board having a fixed contact arranged at one end and a terminal mounting surface for external wiring material at the other end, a terminal screw for screwing the terminal of the wiring material to the terminal mounting surface, and a terminal board that covers the terminal board and the terminal screw. including a terminal cover;
A guide wall is provided vertically from the top wall of the terminal cover to guide the vertical movement of the terminal screw, and a threaded protrusion is provided on the side surface of the head of the terminal screw, so that when the terminal screw is unscrewed, the screw is rotated. A thread is cut and formed on the circumferential surface of the guide wall by the cutting protrusion, and the terminal screw is held in the threaded part of the guide wall while maintaining a predetermined gap between the lower end of the terminal screw and the terminal plate in the unthreaded state. Characteristic terminal structure of magnetic contactor.