JPS595513A - Both-side switching type contact switching device - 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 Application) The present invention relates to a double-cut contact opening/closing device having contacts at both ends of a contact plate.

(Problems with the Prior Art) This type of contact opening/closing device uses a spring located in a horizontal hole of a movable stand made of an insulator to push the movable contact to the fixed contact, that is, to apply contact pressure.

Therefore, if the contact wears out after long-term use, the contact pressure will decrease unless the amount of push of the spring toward the fixed contact is increased accordingly.

This phenomenon is illustrated in Figure 3. If the vertical axis is the contact load (contact pressure) and the horizontal axis is the pushing amount, the return spring of the movable table itself acts until the point is reached from point a, and the point is not reached. Since the contacts are joined and the spring that presses the movable contact plate up to point C acts, only the contact pressure of the contacts increases without changing the pushing amount. Thereafter, the pushing amount and contact pressure increase proportionally up to point d.

However, when the contact wears out, the amount of pushing decreases (b-C'-(), so the contact pressure naturally decreases, causing an increase in contact resistance and a heat generation phenomenon.

(Purpose) The present invention has been made in view of the above points, namely:
The purpose is to attract the movable contact plate with the magnetic flux of the permanent magnet, and when the contact wears out, the magnetic flux of the permanent magnet acting on the movable contact plate compensates for the negative amount.

(Example) The present invention will be described below based on the drawings as an example. Reference numeral 1 denotes a movable base made of an insulator, which has a horizontal hole 2 passing through it and can be moved horizontally. Reference numeral 3 denotes a movable contact plate having movable contacts 4 at both ends, which is inserted into the horizontal hole 2 of the movable base 1.

5 is a fixed contact plate having a fixed contact 6 that separates from the movable contact 4; 7 is a spring for contact pressure of the movable contact plate 3;
It is interposed between one inner wall 2@, that is, the side opposite to the fixed contact 6, and the movable contact plate 3, and always presses the movable contact plate 3 toward the fixed contact 6. A permanent magnet 8 is interposed between the other inner wall 2b of the horizontal hole 2, that is, the fixed contact 6 side and the movable contact plate 3. Therefore, the magnetic flux of the permanent magnet 8 acts in a direction that promotes the spring pressure of the spring 7. Reference numeral 9 denotes a magnetic plate that is attached when the movable contact plate 3 is made of copper, which is a non-magnetic material.

By causing the magnetic flux of this permanent magnet 8 to act on the movable contact plate 3, the change in contact pressure and pushing amount is
It is shown in FIG.

Figure 4 shows the state before the contacts wear out, a - b - C -
d is the characteristic line of the return spring of the movable base and the spring 7 of the movable contact plate 3, e-f is the attractive force exerted by the permanent magnet 8 on the movable contact plate 3, l l-C'-i is the above λ-b-c -d to e
-f superimposed characteristic line, Fig. 5 is a -b -c -d
is the same as that shown in FIG. 4, and GC'-d is the characteristic line of contact wear. That is, compared to the $3 figure, its Cd and CI J
The spread between the two is small, and the reduction in contact pressure is improved compared to the conventional method.

(Effect) In the present invention, as described above, the movable contact plate 3 is attracted to the fixed contact side by the permanent magnet 8, so if the contact wears out, the negative contact pressure is compensated for by the magnetic flux of the permanent magnet acting on the movable contact plate. It has the effect of compensating for

[Brief explanation of drawings]

The drawings show an embodiment of the double-cut contact switching device of the present invention, with Fig. 1 being a front view, Fig. 2 being an exploded perspective view, and Fig. 3 showing contact pressure.
The general characteristic diagram of the pushing amount, FIGS. 4 and 5 are characteristic diagrams according to the present invention. 1...Movable base, 2...Horizontal hole, 3...Movable contact plate,
4... Movable contact, 5... Fixed contact plate, 6... Fixed contact, 7... Spring, 8... Permanent magnet. Patent applicant Matsushita Electric Works Co., Ltd. Patent attorney Toshimaru Takemoto (and 2 others) Figure 1

Claims (1)

[Claims] A horizontally transitionable movable base made of an insulator having a horizontal hole passing through both sides, a movable contact having movable contacts at both ends that is inserted into the horizontal hole and protruding from the horizontal hole, and the movable contact plate. a spring located between one inner wall of the horizontal hole and pressing the movable contact toward the fixed contact; and a spring located between the other side wall of the horizontal hole and the movable contact plate to push the movable contact plate toward the fixed contact. A double-cut contact opening/closing device characterized by a permanent magnet that acts as an attraction on the side.