JPH0260010A - Direct current switch - Google Patents

Abstract

PURPOSE:To prevent defective continuity of contact parts by using an organic material made of non-glass fiber as a reinforcing material of polyester premix forming an arc distinguish chamber and its peripheral members. CONSTITUTION:An arc distinguish chamber 11 is arranged so as to surround a movable contact 7 and a fixed contact 10, and its outside is covered by an arc distinguish chamber-cover 12. The arc distinguish chamber 11 is formed by polyester premix using cotton fabric chips instead of using glass fiber as a reinforcing material. When an electromagnetic coil 4 is energized, a moving core 3 is attracted to left hand in the drawing, toward a fixed core 2, and the movable contact 7 is pressed against the fixed contact 10 to close a direct current electromagnetic contactor. When the electromagnetic coil 4 is deenergized, the moving core 3 is returned to the right by forces of a return spring to separate the movable contact 7 from the fixed contact, and an arc 13 is generated between contacts 6, 9. As shown in the drawing, the arc 13 is pulled into the arc distinguish chamber 11, cooled and distinguished. At this time, the arc distinguish chamber 11 is exposed to high temperatures of the are 13, but the arc distinguish chamber 11 and its peripheral members are made of non-glass fiber, so that glass-melts due to heat of the arc are not generated, and thereby defective continuity of the contacts does not occur.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a DC switch such as a DC electromagnetic contactor,
In particular, it relates to the configuration of the arc extinguishing chamber or its surroundings.

[Conventional technology]

It has been known that the arc extinguishing chamber and its surrounding area of a DC switch are made of polyester premix, which is a molding material with excellent arc resistance. Glass fiber is generally used as a reinforcing material for polyester premix.

[Problem to be solved by the invention]

However, in such a DC switch, a conduction failure may occur at the contact portion. When the cause of this was investigated, it was discovered that the poor continuity of the DC switch was caused by the glass fibers used as the reinforcing material. In other words, DC switches have a longer arc time when opening than AC switches, so the glass fibers in the polyester premix used in the arc extinguishing chamber and its surroundings melt and fall off due to the arc heat, causing damage to the contacts. It adheres to the surface and causes poor conductivity. The object of the present invention is to provide a DC switch which does not suffer from poor conduction due to melted adhesion of glass fibers, and which is comparable in strength, wear due to arcing, electrical characteristics, etc.

[Means to solve the problem]

In order to achieve the above object, the DC switch of the present invention has the following features:
The arc extinguishing chamber or its surrounding area is constructed of a polyester premix using an organic material as a reinforcing material. As the reinforcing material for the organic material, cloth chips or pulp are suitable, and synthetic fibers can also be used.

[For use]

Since non-glass fiber is used as the reinforcing material, conduction defects caused by glass fiber do not occur. Furthermore, it was confirmed that the organic reinforcing material is comparable to the glass fiber reinforcing material in terms of strength, wear due to arcing, and electrical properties.

【Example】

Embodiments of the present invention applied to a DC electromagnetic contactor will be described below. FIG. 1 is a sectional view of a DC magnetic contactor, and this DC magnetic contactor has a rated current carrying capacity of 60A. In FIG. 1, an operating electromagnet consisting of a fixed core 2, a movable core 3, and an electromagnetic coil 4 is housed in a main body case 1, and a movable contact 6 is connected to a movable contact support 5 connected to the movable core 3. A movable contactor 7 provided thereon is supported. 8
is a contact spring inserted into the back surface of the movable contactor 7. A fixed contact 10 having a fixed contact 9 facing the movable contact 7 is screwed onto the main body case 1. Further, an arc extinguishing chamber 11 is arranged to surround the movable contact 7 and the fixed contact 10, and the outside thereof is covered with an arc extinguishing chamber cover 12. The arc extinguishing chamber 11 is made of a polyester premix using rice cloth chips as a reinforcing material instead of glass fiber. In such a configuration, when the electromagnetic coil 4 is excited, the movable core 3 is attracted toward the fixed core 2 in the left direction in the figure, and the movable contact 7 is thereby pressed against the fixed contact 10 and the DC electromagnetic contactor is activated. It will be in the input state. Next, when the electromagnetic coil 4 is de-energized, the movable core 3 is returned to the illustrated state by a not-shown return spring, and at the same time, the movable contactor 7 is also opened to the illustrated state. At that time, the movable/fixed contact 6
An arc 13 occurs between 9 and 9. This arc 13 is drawn into the arc extinguishing chamber 11 as shown in the figure, and is cooled and extinguished, but the arc extinguishing chamber 11 is exposed to the high heat of the arc 13. In conventional arc extinguishing chambers, the glass fibers in the arc extinguishing chamber parts exposed to the arc melt and fall off, causing the movable and fixed contacts 6
．． It adhered to part 9, causing poor continuity. Table 1 shows the test results of the embodiments of this invention.
These are the measured values after conducting a 500,000-cycle switching test at the rated capacity for the 10 DC magnetic contactors shown in the figure. Table 1 Here, the component strength is measured by fixing the arc extinguishing chamber component 11a on a stand 15 with a bottle 14 and applying a load in the direction of arrow F, as shown in FIG. 2, and measuring the strength at which it breaks. It is. As shown in Table 1, among the 10 units tested, there were 2 units in which the contact resistance of the contacts was significantly increased, whereas this occurred in 2 units with the conventional product, but not at all with the example. It was recognized that this method is effective in preventing poor conduction in the parts. In addition, the same results as conventional glass fiber-containing polyester premix were obtained in terms of parts wear due to arcing, insulation resistance, withstand voltage, and strength.

【Effect of the invention】

According to this invention, by using a non-glass fiber organic material as a reinforcing material for the polyester premix constituting the arc extinguishing chamber or its surrounding area, the generation of insulation products (glass melt) due to arc heat can be eliminated. It is possible to prevent conduction defects in the contact portions, and to satisfy other arc resistance performance equivalent to that of conventional products.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the DC electromagnetic contactor, and FIG. 2 is a side view illustrating a method of measuring the strength of the arc extinguishing chamber components in FIG. 1. 6... Movable contact, 9... Fixed contact, 11... Arc extinguishing chamber, 13... Arc.

Claims (1)

[Claims] 1) A DC switch characterized in that the arc extinguishing chamber or its surrounding area is made of a polyester premix using an organic material as a reinforcing material.