JP2001319537A - Electromagnetic relay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve contacting reliability by stabilizing the contact resistance of contacts of an electromagnetic relay and keeping the continuity lag of the contacts smaller during ON-operation. SOLUTION: The electromagnetic relay for opening and closing contacts with the excitation and demagnetizing control of an operating electromagnet has a fixed contact 9 and a movable contact 1 having surfaces coarsened to be aventurine planes 13 on the surfaces of which a liquid lubricant 14 such as a fluorine oil is applied. Thus, the contact resistance is stabilized by utilizing the function of the lubricant. Protruded portions of the aventurine planes formed on the surfaces of the contacts break through a lubricant film coveting the surfaces of the contacts during ON-operation of the contacts and a point contact pressure between the contacts is increased for connection without a continuity lag. Therefore, the operating/resetting time of the electromagnetic relay is shortened to obtain contacting reliability sufficiently applicable to a high contact opening and closing frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic relay applied to a power control panel or the like.

[0002]

2. Description of the Related Art First, the configuration of the electromagnetic relay described above is shown in FIG.
Shown in In the figure, 1 is an insulating base, 2 is a box-shaped cover made of transparent resin, 3 is a coil of an operating electromagnet, 4 is a yoke,
5 is an armature (movable iron core), 6 is a return spring, 7 is a movable contact support made of an insulator fixed to the armature 5, 8
Is a movable contact spring one end of which is supported by the support base 7, 9 is a movable contact mounted on both ends of a movable contact spring 8, and 10 is one end fixed to the base 1 and arranged on both front and back sides of the movable contact spring 8. The fixed contact terminal, 11 is a fixed contact provided at the tip of the fixed contact terminal 10 facing the movable contact 9, and 12 is a lead wire connected between the movable contact spring 8 and the movable contact terminal (input terminal).

The operation of the electromagnetic relay having such a configuration is well known. When the operating electromagnet is not energized, the movable contact 9 is in contact with one fixed contact (b contact) 11 as shown in the figure. Here, when the coil 3 of the operating electromagnet is excited, the armature 5 is attracted, and the movable contact spring 8 reverses following this, and the movable contact 9 contacts the other fixed contact (a contact). When the excitation of the coil 3 is released, the armature 5 is returned by the spring force of the return spring 6, and the movable contact 9 is switched from the contact a to the contact b.

On the other hand, in order to stabilize the contact resistance of the contacts, the viscous liquid lubricant (for example, fluororesin) is applied to the smooth surfaces of the movable contact 9 and the fixed contact 11 shown in FIG. Oil) has been conventionally applied very thinly. This lubrication material protects the contacts from corrosive gas, etc., and even when dust adheres to the surface of the contacts, the dust accompanies the fluid lubricant when the contacts come into contact during the ON operation. It is pushed away from the local contact portion between the contacts and acts to prevent contact failure of the contacts. The lubricant film adhering to the surfaces of the contacts is broken down by the voltage applied between the contacts, and the contact between the contacts becomes conductive due to the so-called coherer phenomenon.

[0005]

By the way, the frequency of opening and closing the above-mentioned electromagnetic relay may be as high as 1800 times / hour, depending on the purpose of use. Electromagnetic relays that are used at such a high switching frequency, in addition to the durability of the contact mechanism, the stable contact resistance of the contacts, and the fact that the movable contacts actually operate and return from the time when the movable It is required that the conduction delay until the contact becomes conductive becomes as low as possible.

[0006] In this regard, in the conventional relay contact in which the lubricant is applied to the smooth contact surface as described above, the contact resistance can be stabilized, but the actual distance between the contacts after the switching (operation and return) of the contacts is improved. Time delay (ms
(ec order), which is a factor that hinders the quick operation response of the electromagnetic relay. Then, the present inventors have investigated the cause of the conduction delay, and found that a smooth contact (for example, a spherical contact) has a film formed between the contacts that have been turned ON without breaking the lubricant applied to the surface. The film remains as it is, causing a time delay until the film is broken down by the coherer phenomenon and the contacts become conductive, and furthermore, the movable contact attached to the contact spring switches between the a contact and the b contact. It was found that there was a phenomenon that the contact was not separated smoothly due to the viscosity of the lubricant and the adhesion force due to the interfacial tension.

The present invention has been made in view of the above-mentioned points, and based on the above-described research results, it is possible to ensure that the contact is stable and that the power is supplied with almost no conduction delay at the time of operation and return of the contact while maintaining the contact resistance. It is an object of the present invention to provide an electromagnetic relay in which contacts are improved so that it can cope with a high switching frequency.

[0008]

According to the present invention, in order to achieve the above object, according to the present invention, in an electromagnetic relay for opening and closing a contact by controlling the excitation and demagnetization of an operating electromagnet, the surface of the contact is roughened in a satin shape. Above, a liquid lubricant (for example, fluorine oil) is applied to the surface. By applying a lubricant after the surface of the contact is roughened like a matte surface in this way, the electromagnetic relay operates and returns, and the movable contact is formed on the surface when it comes into contact with the fixed contact on the other side As the contact pressure increases at the convex portion of the matte surface, the convex portion mechanically breaks through the lubricant film covering the surface of the contact and starts conduction with the mating contact. As a result, the concentrated resistance of the contacts is rapidly reduced, and the contacts are conducted with almost no delay in conduction. Also, from this state, even when the movable contact separates from the fixed contact that has been in contact with the next switching operation of the electromagnetic relay, the movable contact smoothly separates without being greatly affected by the viscosity and interfacial tension of the lubricant. I do. As a result, the contact resistance and the contact reliability of the contacts that can sufficiently cope with the operation and return of the electromagnetic relay having a high contact opening / closing frequency can be secured.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on illustrated embodiments. It should be noted that FIG.
Are given the same reference numerals, and detailed description thereof will be omitted. First, FIGS. 1A and 1B show the structure of a contact according to the present invention. That is, the surfaces of the fixed contact 9 and the movable contact 11 are roughened into a matte surface by, for example, electric discharge machining (surface roughness is, for example, about 7 μm), and then the matte surface 1 is formed.
Fluorine oil is applied as a lubricant 14 on the surface of 3 to form an extremely thin film. In this case, since the fluorine oil itself has a relatively high viscosity, in the coating process, the fluorine oil is diluted with a highly volatile solvent, coated by a dipping method or the like, and then the solvent is volatilized to form a thin film on the contact surface. Is coated with a lubricating film. In the drawing, the matte surface 13 and the irregularities thereof are schematically drawn so as to be easily understood.

When the above-mentioned contacts are employed as the movable contact 9 and the fixed contact 11 of the electromagnetic relay shown in FIG. 3 to operate the electromagnetic relay, as shown in FIG. In this state, the convex portions of the matte surface 13 of the contacts 9 and 11 mechanically break through the film of the lubricant 14 covering the contact surfaces, and come into contact with each other. Therefore,
Since the contact pressure of the protruding portion increases and the concentrated resistance of the contact rapidly decreases, conduction between the contacts 9 and 11 starts with almost no time delay without waiting for the start of conduction due to the so-called coherer phenomenon. The current i flows. In addition, even in the process in which the movable contact 9 is separated from the fixed contact 11 by the return operation of the electromagnetic relay from the state of FIG. The movable contact 9 is separated from the fixed contact 11 in a smooth manner without delay, almost without being affected by the viscosity and the interfacial tension of the lubricant.

[0011] Thus, the contact resistance of the contact is stabilized by utilizing the function of the lubricant, and the conduction delay of the contact at the time of the operation and return of the electromagnetic relay is suppressed to be high, so that it is possible to sufficiently cope with the high switching frequency. Can be secured. The inventor of the present invention made the electromagnetic relay shown in FIG. 3 by using a contact having a matte finish on the surface as described above and a conventional spherical contact having a smooth surface as a test contact and applying a lubricant to the contact surface. From the results of performance evaluation tests of operating characteristics adopted for
It has been confirmed that both the operation and the recovery time can be significantly improved as compared with the conventional product.

[0012]

As described above, according to the present invention, in an electromagnetic relay that opens and closes a contact by controlling the excitation and demagnetization of an operating electromagnet, the surface of the contact is roughened in a satin shape,
By applying a liquid lubricant such as fluorine oil on the surface, the contact resistance of the contact was stabilized by utilizing the function of the lubricant, and the lubricant was applied to the smooth contact surface even in the conductive surface. It is possible to provide a highly reliable electromagnetic relay which can sufficiently cope with a high contact opening / closing frequency by eliminating a contact conduction delay in operation / return of the electromagnetic relay which has been a problem with the conventional contact.

[Brief description of the drawings]

FIG. 1 is a structural view of a contact of an electromagnetic relay according to an embodiment of the present invention, wherein (a) and (b) are a sectional view and a plan view of the contact, respectively.

FIG. 2 is an operation explanatory diagram showing a conductive state at the time of an ON operation by the contact in FIG.

FIG. 3 is an overall configuration diagram of an electromagnetic relay to which the present invention is applied;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Operating electromagnet 8 Movable contact spring 9 Movable contact 10 Fixed contact 11 Fixed contact 13 Pear ground 14 Lubricant

Claims (2)

[Claims] 1. An electromagnetic relay for opening and closing a contact by controlling the excitation and demagnetization of an operating electromagnet, characterized in that the surface of the contact is roughened in a satin shape and a liquid lubricant is applied to the surface. Electromagnetic relay contact. 2. The electromagnetic relay according to claim 1, wherein the lubricant is fluorine oil.