JPH0350595Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Technical field of the invention This invention is a structure that protects an electromagnetic relay, especially the surrounding wall surface from arc heat caused by switching between contacts, and realizes miniaturization and increased capacity of the electromagnetic relay. Regarding.

(b) Background of the technology An electromagnetic relay that operates a movable contact by operating an armature using the magnetic attraction force of an electromagnet is a
Like various electronic components, they are becoming smaller year by year, but due to the desire for larger capacity, efforts are being made to make the internal space as narrow as possible in structural design and to increase resistance to arc heat generated by load shedding of contacts. .

(c) Prior Art and Problems FIG. 1 is an external perspective view showing an example of a conventional configuration of an electromagnetic relay, and FIG. 2 is a plan view of the electromagnetic relay with the cover removed.

In FIG. 1, a relay 1 houses an electromagnet, a contact spring assembly, etc., and is composed of a main body part 2 from which a plurality of lead terminals 4 are led out from the bottom surface, and a cover 3 that covers the opening top surface of the main body part 2. There is.

In Fig. 2, 5 is an electromagnetic coil, 6 is a bobbin with 5 coils wound around it, 7 is an L-shaped yoke, 8 is an iron core that passes through the center through hole of the bobbin 6 and one end is fixed to the yoke 7, and 9 is a rocker. A movable armature, 10 a leaf spring supporting the bent portion of the armature 9, 11 a movable contact spring, 1
2 and 13 are fixed contact terminals, 14 and 15 are movable contacts, 16 and 17 are fixed contacts, 18 is a body made of molded plastic, and a leaf spring 10
One end of each of the movable contact springs 11 and 11 is fitted into the cover body 18, while the intermediate portions of the fixed contact terminals 12 and 13 are inserted into the cover body 18, and the lead terminal portion 4 thereof protrudes from the bottom surface of the cover body. .

In the relay 1 configured in this manner, the contacts 14 and 16 and 15 and 17 are alternately opened and closed by passing a predetermined current through the coil 5 and cutting off the power. However, while it is advantageous to make the space around the contacts 14 to 17 as narrow as possible in order to downsize the relay 1, it is necessary to make the space appropriately wide in order to increase the capacity. As a result, for example, a small relay designed with a rating of 1A can be
When used in A, the insulation of the surrounding wall of the contact portion of the cover 3 and the housing 18 is damaged due to contact arcing, etc., and the surrounding wall is filled with harmful gases, which not only deteriorate the characteristics but also cause significant damage. A scorch hole sometimes penetrated the peripheral wall.

Therefore, it is difficult to miniaturize large-capacity electromagnetic relays, and there is also the inconvenience that the body and cover must be made of expensive plastic (such as diallyl phthalate resin), which has excellent heat resistance. Ta.

(d) Purpose of the invention The purpose of the invention is to eliminate the above-mentioned problems and to increase the capacity and downsize the electromagnetic relay.

(e) Structure of the device The above object is to house at least an electromagnet, a movable contact spring operated by the electromagnet, and a fixed contact opposite to the movable contact fixed to the movable contact spring in a container, and to mold plastic. This is achieved by an electromagnetic relay characterized in that the container, which is made up of a shell and a cover, is formed with a heat-resistant insulating layer on the inner surface around at least the facing portion of the movable contact and the fixed contact. .

(f) Embodiment of the invention An electromagnetic relay according to an embodiment of the invention will be described below using the drawings.

Fig. 3 is a plan view of the main body of an embodiment in which the present invention is applied to the electromagnetic relay described above, with the cover removed, and Fig. 4 is a side view of the applied relay with a portion of the cover removed. be.

In FIGS. 3 and 4, in which the same parts as in the previous figure are denoted by the same reference numerals, the shield body 21 is connected to the contact points 14 to 4.
A series of heat-resistant insulating layers 21a and 21b are formed on a bottom surface surrounding the bottom surface of the cover 17 and a part of an inner wall connected to the bottom surface. It has a series of heat-resistant insulating layers 31a and 31b. As a result, relay 20
The heat-resistant insulating layers 21a, 21b, 3 reduce the arc heat and scattering of the contact members when the contacts are operated under load.
1a and 31b are received by a body 21 and a cover 31 made of molded plastic.
is no longer directly affected by the arc heat and the scattering of contact members, and in one embodiment using an existing relay and a relay to which the present invention is applied, the life of the wall surrounding the contact can be increased by 1.5 to 2 times. Life has been extended.

Note that the heat-resistant insulating layers 21a, 21b, 31a, 3
For 1b, apply a commercially available coating agent mainly composed of SiO ₂ , Al ₂ O ₃ , etc. with a brush (or air spray, etc.)
After that, the insulating layer 21a and the like are formed by heating at about 100°C for 20 minutes, and the coating agent turns into ceramic and not only withstands high temperatures of 1000°C or more, but also has excellent adhesion to the base member and Since it has the ability to follow thermal expansion, it exhibits sufficient resistance even when the relay 20 is operated continuously.

In addition to the above-mentioned inorganic type, commercially available similar coating agents include an organic type mainly composed of fluororesin and an inorganic/organic mixed type that is an appropriate blend of inorganic and organic types. It can be used in the same way as the inorganic type to form an insulating layer with the same effect.

FIG. 5 is a plan view of an electromagnetic relay according to another embodiment of the present invention, with the cover partially cut away, FIG. 6 is a side view with the cover and shield body of the relay partially cut away, and FIG. 7 FIG. 8 is a perspective view for explaining a structure for mounting a ceramic component on a predetermined portion of the cover, and FIG. 8 is a perspective view for explaining a structure for mounting a ceramic component on a predetermined portion of the cover.

In FIGS. 5 and 6, the relay 41 is constructed by fitting a cover 43 onto a relay body 42 on which a movable contact spring 44, fixed contact terminals 45, 46, and coils (not shown) are mounted in the same manner as in the prior art. However,
Ceramic parts 51 and 52 are attached to the opposite sides of the movable contact 47 and the fixed contact 49 and the movable contact 48 and the fixed contact 50 by heat caulking of the body protrusion 42a or the cover protrusion 43a.

However, the ceramic component 51 has an L-shape in a side view as shown in FIG.
The tip of the protrusion 43a is heat caulked and fixed, and the ceramic component 52, which has a flat plate shape as shown in FIG. . Since the ceramic parts 51 and 52 surround the sides of the contact facing parts that are not covered by the fixed contact terminals 45 and 46, the side walls 42 and cover 43 are protected against arc heat caused by opening and closing of the contacts. It will protect you from.

(g) Effects of the invention As explained above, the electromagnetic relay according to the invention is:
By making the contact surrounding wall made of plastic heat resistant and arc resistant, the effect of increasing capacity or reducing the size by allowing the contact surrounding wall and contact to be brought closer together is remarkable.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view showing a conventional example of an electromagnetic relay, Fig. 2 is a plan view of the electromagnetic relay with the cover removed, and Fig. 3 is an electromagnetic relay according to an embodiment of the present invention with the cover removed. 4th plan view of the main body
The figures are a side view with a part of the cover attached to the main body of Fig. 3 cut away, Fig. 5 is a plan view of an electromagnetic relay according to another embodiment of the present invention with a part of the cover cut out, and Fig. 6. 5 is a partially cutaway side view of the relay body and cover shown in FIG. FIG. 8 is a perspective view illustrating a configuration for attaching ceramic parts to the cover shown in FIG. 6. In the figure, 1, 20, 41 are electromagnetic relays,
3, 31, 43 are covers, 11, 44 are movable springs, 14, 15, 47, 48 are movable contacts, 16,
17, 49, 50 are fixed contacts, 18, 21, 42
21a, 21b, 31a, 31b are heat-resistant insulating layers, and 51, 52 are ceramic parts.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) At least an electromagnet, a movable contact spring operated by the electromagnet, and a fixed contact opposite to the movable contact fixed to the movable contact spring are housed in a container, and the plastic is An electromagnetic relay characterized in that the container, which is made up of a molded body and a cover, has a heat-resistant insulating layer formed on the inner surface around at least the facing portion of the movable contact and the fixed contact. (2) The electromagnetic relay according to claim 1, wherein the heat-resistant insulating layer is formed of a thin film obtained by coating and drying a heat-resistant insulating coating agent. (3) The electromagnetic relay according to claim 1, wherein the heat-resistant insulating layer is made of a thin ceramic component.