JPS583350B2 - screw terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a screw terminal that is screwed and press-welded to an end device to make an electrical connection. At the same time, a gap is formed near the tip of the arm so that the set screw can be inserted from the radial direction, and when the set screw is tightened and the earthen arm is deformed, the gap becomes narrower than the diameter of the set screw. Regarding screw terminals such as

Conventional screw terminals include round screw terminals 1 as shown in Figures 1A and B, or tip-open type (also called Y-type) screw terminals as shown in Figures 2A and B. 2 are known.

These screw terminals 1 and 2 are connected to pressure contact parts 3 and 4, respectively.
and connecting portions 5 and 6, and is mechanically and electrically connected to a terminal device 1 as shown in FIG. 3, for example, by a set screw 8.

The pressure contact portion 3 of the round terminal 1 is formed into an annular shape having an insertion hole 9 for inserting the set screw 8 at the center of the cheek of the disc, and the pressure contact portion 4 of the pre-opening type terminal 2 is Arm portions 1o and 10 parallel to each other form a set screw guide groove 11.

These pressure contact parts 3 and 4 are connected to the conductive metal fitting 1 of the terminal device 1.
An electrical connection is made by press-contacting with the second or the like.

Further, the connection parts 5 and 6 of each screw terminal 1 and 2 are connected to an external lead wire 13, for example, the first
The lead wire 13 is formed into a tubular shape as shown in FIG. As shown in FIGS. 3 and 4, the tubes are crushed and crimped to mechanically and electrically connect these screw terminals 1, 2 and lead wires 13.

Such terminals 1 and 2 are generally called crimp terminals.

In addition, the above connection portion may be connected to the lead wire 13 by soldering.

The terminal device 7 to which these screw terminals 1 and 2 are attached is
For example, it may be installed as a part of electrical/electronic equipment such as an electromagnetic relay or earth leakage breaker, or it may be used as an independent relay terminal or terminal block.

A conductive metal fitting 12 fixed to the base etc. of this terminal device I
For example, as shown in FIG. 4, a female screw hole 14 is formed into which a set screw 8 is screwed, and a tongue piece 15 extending inwardly of the terminal device 7 is provided with an internal lead wire. Holes 16 and the like are formed for soldering and fixing.

Furthermore, a washer 17 arranged to face the conductive metal fitting 12 has a hole 18 through which the set screw 8 is inserted, and the screw terminals 1 and 2 are provided between the conductive metal fitting 12 and the washer 17.
By inserting and arranging the press-contact parts 3 and 4 and tightening the set screw 8, the press-contact parts 3 and 4 of the screw terminals 1 and 2 are brought into pressure contact with the conductive metal fitting 12, thereby establishing an electrical connection.

By the way, when using these screw terminals 1 and 2, important issues include ease of installation, stability and reliability after connection and fixation.

However, in the case of the conventional round terminal 1, it is necessary to completely remove each set screw 8 during installation work.
Furthermore, after inserting the set screw 8 into the insertion hole 9 of the pressure contact part 3,
It is necessary to screw each set screw 8 to the tightening position, and this work is troublesome and takes a long time, especially when there are a large number of round terminals to be attached or when the length of the set screw 8 is long. vinegar.

Furthermore, the set screw 8 must be inserted in the order of the washer 17, the round terminal 1, and the conductive metal fitting 12, and if this order is incorrect, it takes time and effort to re-insert the screw.

Further, if the removed setscrews 8 and the like fall into the inside of the device, it is necessary to take out the setscrews 8 and the like to the outside to prevent failure, further deteriorating the efficiency of the terminal attachment work.

In addition, in the case of the conventional pre-opening type terminal 2, it is not necessary to remove the set screw 8. Loosen the set screw 8 halfway and connect the two arms 10, 10 of the pressure welding part 4 to the conductive metal fitting 12. Washer 1
7 and guide the set screw 8 into the guide groove 11, and then tighten the set screw 8 to attach the terminal.

However, if the set screw 8 loosens even slightly due to vibration or the like after it has been installed and fixed in this way, the pre-opening type terminal 2 will easily fall off the set screw 8, and at the same time, the electrical connection will be cut off or the connection will be poor. This may have a negative impact on electrical equipment that is in operation, and may even cause a major accident.

Furthermore, during installation, temporary fixing will not be possible, and if the setscrews 8 are not tightened to the final position, the pre-opened terminals 2 will easily fall off, making it necessary to tighten the screws for each individual piece. , it's a hassle.

The present invention has been made to eliminate these conventional drawbacks, and it is possible to attach a screw terminal without removing the set screw of the terminal device, and furthermore, the terminal does not come off once the set screw is tightened. The purpose of this invention is to provide a screw terminal that does not cause such problems.

Another object of the present invention is to provide a screw terminal that can be temporarily fixed by simply loosening the set screw and press-fitting the screw terminal, thereby greatly improving the efficiency of the terminal installation work. .

Further objects of the present invention will become apparent from the following description.

Hereinafter, some preferred embodiments of the present invention will be described with reference to the drawings.

First, FIGS. 5 to 7 show an embodiment of the present invention, in which a screw terminal 20 is formed by punching out a conductive metal plate such as Cu or AI, and then plastically deforming the plate.

That is, this screw terminal 20 includes a pressure contact portion 21 into which the aforementioned set screw 8 is inserted and tightened by the set screw 8 to make pressure contact with the conductive metal fitting 14 of the terminal device 7 to establish an electrical connection, and a lead wire. 13 for electrical connection.

The pressure contact portion 21 has two arc-shaped arm portions 23, 23, and these arm portions 23, 23 are symmetrical to each other and have an annular shape that surrounds the set screw insertion hole 24 as a whole. The set screw 8 is bent in the direction of the arrow A, which is the axial direction of the arm part 8, and is formed so that the set screw 8 can be guided into the insertion hole 24 through a gap between the tips of each of the arm parts 23, 23.

For this purpose, it is sufficient to make the gap size t larger than the diameter d of the set screw 8, but the gap size t may be slightly smaller than the diameter d, and in this case, the screw terminal 20
When the set screw 8 is press-fitted from the radial direction of the arrow B as shown in FIG. .

The connecting portion 22 of this screw terminal 20 is formed, for example, in a tubular shape as in the conventional case, and the conductor portion from which the sheathing has been removed at the tip of the lead wire 13 is inserted and guided inside the tube of the connecting portion 22. Mechanical and electrical connections are made by squeezing and crimping the bodies.

Such a screw terminal 20 is inserted between the conductive metal fitting 12 and the washer 17 of the terminal device 7 as described above in the radial direction of the set screw 8, that is, in the direction of arrow B, as shown in FIG. At this time, the set screw 8 is guided into the insertion hole 24 through the gap near the tips of the arms 23, 23 (see Fig. 1).
.

In this state, by screwing the set screw 8 in the direction of arrow A and clamping the pressure contact part 21 of the screw terminal 20 between the washer 11 and the conductive metal fitting 12, the arm parts 23 and 23 are connected as shown in FIGS. 5A to 5C. The cheeks transform into the shape shown by the two-dot chain line.

At this time, the gap between the arms 23 and 23 is the diameter d of the set screw 8.
It becomes narrower, and the screw terminal 20 is prevented from coming off from the set screw 8.

As is clear from the above explanation, without removing the set screw 8, simply loosen the set screw 8 to create a gap large enough to insert the screw terminal 20, and then insert the screw terminal 20. After that, by tightening the locking screw 8 and narrowing the gap between the arm parts 23 and 230, stable mounting and fixing without coming off can be achieved.

Furthermore, since the arms 23, 23 are bent in the axial direction of the set screw 8, when the set screw 8 is tightened, from the middle position,
A reaction occurs when the arm portions 23, 23 deform, so that complete tightening can be performed, and electrical connection by pressure welding can be stably performed, and the screw terminal 20 can be temporarily fixed even when tightening and in the middle position. can.

This temporary fixing or temporary fixing can also be done when inserting the terminal, because the arms 23, 23 are arcuate and engage with the set screw 8 at the tips, etc., so that they are difficult to come off.
Furthermore, in order to ensure temporary fixation, for example, the width t of the gap between the arms 23 and 23 may be made slightly narrower than the diameter d of the set screw 8, or when the set screw 8 is loosened in the axial direction, a conductive Just make sure that the distance between the metal fitting 12 and the washer 17 is slightly narrower than the width 1 of the screw terminal 20 in the same direction. Temporary fixation of the terminal can be reliably performed by the reaction and restoring force accompanying the deformation of the arm portions 23, 23.

Therefore, when attaching a plurality of terminals, for example, each terminal can be compressed one after another and temporarily fixed, and then the screws can be tightened all at once, greatly improving work efficiency.

Furthermore, by making the arms 23, 23 symmetrical,
Since the gap is formed on the extension line of the connecting portion 22,
When inserting the crimping part 21 in the radial direction of the set screw 8 (in the direction of arrow B) while supporting the connecting part 22 by hand, the direction of the force is in a straight line, and the insertion work (compression work) can be performed easily. .

In addition, since the shape is symmetrical, the contact parts with the conductive metal fittings 12 and the washer 11, such as the ends and outer peripheral edges of the arm parts 23, 23, are in a straight line almost parallel to the terminal insertion direction (direction of arrow B). This also reduces frictional force during insertion, contributing to easier insertion.

In addition, by bending the arm portions 23, 23 in the axial direction of the set screw 8, the external diameter W of the pressure contact portion generally becomes narrower than the external width W before bending (or after tightening the set screw). Even if the terminal device has a conductive metal fitting placed inside the recess or hole, when inserting the screw terminal 20 into the recess or hole, the terminal should be installed smoothly without getting caught on the side wall, etc. This will make it easier.

Furthermore, since the lower edge of the side surface of the doki arm is formed into an arc shape, the insertion angle when viewed from the side when inserting the terminal can be selected arbitrarily. Even when inserting into a hole, it is possible to smoothly insert the arcuate portion while making contact with each other.

Moreover, since the entire cheek-arm part is displaced relative to its original position (double-dashed line in Figure 5) so as to reduce the external width W, the deforming force when screwing is dispersed over the entire arm part. The pressure contact portion can be deformed with less tightening force than when the force is concentrated locally, such as when only a portion of the arm portion is locally bent.

In addition, in the present invention, since the side surface of the arm is formed to bulge out in a downward arc, the point of application of force when screwing (approximately the tip of the arm) and the fulcrum (approximately the tip of the arm) The point of action and fulcrum are concentrated at the tip of the pre-opened terminal, for example, in cases where only the tip of the arm is bent and deformed, the point of action and fulcrum are concentrated at the tip of the pre-opened terminal. It is possible to cause deformation with less acting force due to a type of lever action compared to those that do.

Further, according to the present invention, by the above-mentioned displacement of the entire arm, the amount of movement of the tip of the arm due to deformation during screw tightening can be increased, the gap between the tips after tightening the screw can be narrowed, and reliable fixation can be achieved.

Next, FIG. 8 shows another embodiment of the present invention, in which the outer periphery of the connecting portion 22 of the screw terminal 20 of the above-described embodiment is covered with an insulating tube 40 serving as an insulating layer to form a screw terminal 20'.
It consists of

According to the embodiment shown in FIG. 8, it not only has the effects of the embodiment shown in FIGS. A terminal 20' can be provided.

[Brief explanation of the drawing]

FIG. 1 shows a round screw terminal 1 as a conventional example.
A is a plan view, and B is a side view. FIG. 2 shows a pre-opening type screw terminal 2 as another conventional example, in which A is a plan view and B is a side view. FIG. 3 is a perspective view showing an example of a terminal device. FIG. 4 is an exploded perspective view showing essential parts of the terminal device 1 of FIG. 3. FIG. 5 shows a first embodiment of the present invention, where A is a plan view;
B is a side view, and C is a front view. FIG. 6 and FIG. γ are schematic diagrams showing the process of attaching the screw terminal 20 of FIG. 5 to the terminal device 7. FIG. 8 is a perspective view showing another embodiment of the present invention. 20, 20'... Screw terminal, 21...
... Pressure welding part, 22... Connection part, 23...
・Arms.

Claims (1)

[Claims] 1. A press-contact portion into which a set screw is inserted and tightened by the set screw to make pressure contact with a conductive metal fitting of a terminal device to establish an electrical connection, and a pressure contact portion that is coupled to a lead wire to establish an electrical connection. In the screw terminal, the pressure welding part has a pair of arcuate arms, and by bending the entirety of these arcuate arms in the same direction in the axial direction of the set screw, the pressure welding can be performed. The outer width W of the arm part is formed to be narrower than the same width W before bending (w<W), so that the outer peripheral edge of the arm part bulges downward in an arc shape when viewed from the side. The arm portion can be inserted from the radial direction of the set screw through a gap near the tip, and can be deformed by tightening the set screw so that the gap becomes narrower than the diameter of the set screw. A screw terminal characterized by: 2. The screw terminal according to claim 1, wherein the press-contacting part is made up of two arm parts formed by cutting an annular plate into a shape symmetrical to the cut part. 3. The screw terminal according to claim 1 or 2, wherein the outer periphery of the connecting portion is coated with an insulating layer.