JPS647579Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a terminal device for electrical wiring.

Conventionally, there are various types of terminal devices for electrical wiring depending on the structure and purpose of use of electrical equipment, and the ones illustrated in FIGS. 1 and 2 are known. In FIGS. 1 and 2, 1 is a terminal screw, and this terminal screw 1 is provided with a head 4 having a larger outer diameter than the screw shaft 2 through a neck 3 on the screw shaft 2. 4
A columnar protrusion 5 for connecting lead wires is provided protruding from the end surface opposite to the screw shaft 2. As shown in FIG. 2, a through hole 7 is formed in a base 6 made of an insulating material such as plastic, and the screw shaft 2 of the terminal screw 1 is passed through the through hole 7.
A nut 8a is screw-fitted to a portion protruding from the base 6 of the terminal screw 1 through a washer 10, and by tightening the nut 8a, the base 6 is sandwiched between this and the head 4 of the terminal screw 1. Nut 8 of the screw shaft portion 2
The end of one lead wire 9 is connected to the part protruding from a by tightening with another nut 8b via washers 11a and 11b on both sides, and the end of the other lead wire 12 is connected to the head of the terminal screw 1. It is connected to a protrusion 5 provided at 4 by soldering or the like.

In the conventional terminal device configured as above,
Copper alloy materials such as brass are often used for the terminal screw 1 in consideration of its electrical properties, and since thread processing methods such as header are used for threading the screw shaft portion 2, the neck portion 3 is It leaves a large residual stress. This residual stress accelerates stress corrosion cracking in the neck portion 3 over time due to tightening of the nut 8a or 8b, causing the terminal screw 1 to break from the neck portion 3, and the electrical connection between the lead wires 9 and 12 to be interrupted. It may become disconnected and lose its function as a terminal device. Note that residual stress is reduced by adding a radius to the neck between the screw shaft and head of the terminal screw, and by appropriately controlling the tightening torque of the nut. Even if this is done, residual stress cannot be eliminated. Although there is a low probability that a terminal screw will break due to stress corrosion cracking on the neck of the terminal screw caused by the residual stress mentioned above, there are many important circuits that cannot be disconnected from the connected electrical circuit, and such circuits Therefore, there is a need for countermeasures against stress corrosion cracking of terminal screws.

This invention is an attempt to meet the above-mentioned demands; one end is connected to the screw shaft of the terminal screw, the middle part is passed through a mounting member such as a base, and the other end is connected to the screw shaft of the terminal screw. By attaching a branch terminal that connects to the lead wire on the head side, the aim is to provide a terminal device that will not disconnect the electrical circuit even if the terminal screw breaks due to stress corrosion cracking at the neck. .

An embodiment of this invention will be described below with reference to FIGS. 3 and 4.

In FIGS. 3 and 4, 13 is a branch terminal, and this branch terminal 13 is a rectangular conductive metal plate that is formed into a substantially similar shape when viewed from the front. A hole 13a is formed at one end, and a hole 13a is formed at the other end. A notch 13b (or hole) is formed in the portion. Further, as shown in FIG. 4, in addition to the through hole 7, an insertion hole 14 into which the branch terminal 13 is inserted is formed in the base 6, which is a mounting member. In addition, in FIG. 4, the same parts as in FIG. 2 are given the same reference numerals, and the description thereof will be omitted.

Then, the screw shaft 2 of the terminal screw 1 is passed through the through hole 7 of the base 6, and the washer 10 is connected to the nut 8a screwed into the screw shaft 2 and the head 4 of the terminal screw 1.
The terminal screw 1 is fixed to the base plate 6 by sandwiching the base plate 6 therebetween. Further, the middle part of the branch terminal 13 is inserted into the insertion hole 14 of the base plate 6, and the hole 13a provided at one end of the branch terminal 13 is fitted into the part of the screw shaft part 2 protruding from the nut 8a. By arranging washers 11a and 11b on both sides of one end and one end of the lead wire 9 and tightening them together with a nut 8b, the lead wire 9
and connect the branch terminal 13 to the terminal screw 1. Furthermore, the end of the other lead wire 12 is connected to the branch terminal 13.
Pass the lead wire 12 through the notch 13b (or hole) provided at the other end, wrap it around the other end of the branch terminal 13, and solder it, and connect the end of the lead wire 12 extending from the branch terminal 13 to the head of the terminal screw 1. Wrap it around the protrusion provided on part 4 and solder it. In addition, in FIG. 4, 15 and 16 indicate solder.

In the terminal device of the embodiment configured as described above, the lead wires 9 and 12 are electrically connected via the screw shaft portion 2, neck portion 3, head portion 4, and projection portion 5 of the terminal screw 1. In addition, the screw shaft portion 2 and the branch terminal 13 are electrically connected to each other. Therefore, even if the neck 3 of the terminal screw 1 breaks due to stress corrosion cracking during use and the electrical connection between the screw shaft 2 and the protrusion 5 is broken, the screw shaft 2 and the branch terminal 13
Since the lead wires 9 and 12 are electrically connected via the lead wires 9 and 12, the electric circuit is not disconnected and the circuit works without any trouble.

Further, the branch terminal 13 has a simple structure, is easy to process, and is easy to incorporate into a terminal device. Furthermore, even if the terminal screw 1 is broken, since the electric circuit is electrically connected through the branch terminal 13 as described above, it can be dealt with when inspecting the equipment.

In addition, in this invention, as a branch terminal,
A conductive metal wire is formed into a shape and has an annular portion formed at one end, and the annular portion is fitted onto the screw shaft of the terminal screw to connect one end of the branch terminal to the screw shaft. However, the intermediate portion of the branch terminal may be passed through the mounting member, and the other end portion of the branch terminal may be connected to the lead wire on the head side of the terminal screw.

As explained above, in this invention, one end is connected to the screw shaft of the terminal screw, the middle part penetrates the mounting member such as the base, and the other end is connected to the lead wire on the head side of the terminal screw. It also has a branch terminal for connection, so even if the terminal screw breaks due to stress corrosion cracking due to residual stress during thread processing,
There is an effect that the circuit is not electrically disconnected at the branch terminal, and a highly reliable terminal device can be provided.

[Brief explanation of the drawing]

Fig. 1 is a front view of a terminal screw used in a conventional terminal device, Fig. 2 is a partially sectional front view showing a conventional terminal device, and Fig. 3 is a branch used in a terminal device according to an embodiment of this invention. FIG. 4 is a partially sectional front view showing a terminal device according to an embodiment of the present invention. 1...Terminal screw, 2...Screw shaft, 3...Neck, 4...Head, 5...Protrusion, 6...Base (mounting member), 7...Through hole, 8a, 8b... Natsuto,
9, 12... Lead wire, 13... Branch terminal, 14
...Insertion hole.

Claims (1)

[Scope of utility model registration request] The screw shaft of the terminal screw is passed through the mounting member, the mounting member is sandwiched between the nut screwed into the screw shaft and the head of the terminal screw, and the screw shaft and the head of the terminal screw are respectively inserted. In a terminal device for connecting lead wires, one end is connected to the screw shaft of the terminal screw, the intermediate portion passes through the mounting member, and the other end is connected to the lead wire on the head side of the terminal screw. A terminal device characterized by comprising a terminal.