JPH0638355Y2 - Contact structure of electromagnetic relay - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of the Invention> The present invention relates to a contact structure of an electromagnetic relay used for opening and closing various electric circuits, and particularly to a contact structure suitable for being applied to a ground contact of an electromagnetic relay for high frequency current.

《Summary of device》 This device has a contact structure of an electromagnetic relay, and a large contact pressure can be obtained due to a combination shape of a movable contact member and a fixed contact member, and a high contact request can be obtained with good durability. It is something to do.

<< Prior Art and its Problems >> As one of small electromagnetic relays used for opening and closing a high frequency current circuit, an electromagnetic means and a magnetically attracted by the electromagnetic means causes displacement, for example, rotational displacement. A movable iron piece, a fixed contact member, and a movable contact member, which is provided so as to be movable in parallel or rotatable about one pivot axis, carries a movable contact member, abuts on the movable iron piece, and is displaced according to the displacement of the movable iron piece, The movable contact holding member is made of an electrically insulating material such as a synthetic resin that separates the movable contact member from the fixed contact member, and a leaf spring that positions the movable contact holding member at a predetermined return rotation position. A type of electromagnetic relay having a return spring is already known, which is shown, for example, in Japanese Utility Model Publication No. 57-150442.

As the contact structure for conducting current in the electromagnetic relay of the type described above, a movable bar member and a fixed contact member are both plate-shaped and are configured to be in line contact with each other. And a rivet contact type in which both of them are made of a combination of a flat plate and a hemispherical projection, and the two are in point contact with each other. In the case of the cross bar contact type, contact contact may be unstable and sufficient contact pressure may not be obtained, whereas in the case of the rivet contact type, sufficient contact pressure may not be obtained. You get
Since it is a one-point contact, if any trouble occurs in the contact portion, a contact failure will occur immediately and durability reliability tends to be poor.

<Purpose of Invention> The present invention was made in view of the above-mentioned problems, and the purpose thereof is to obtain a sufficient contact pressure,
Moreover, it is to provide an improved contact structure for an electromagnetic relay that has excellent durability and reliability.

<< Structure and Effect of the Invention >> In order to achieve the above-mentioned object, the invention has a contact structure of an electromagnetic relay that has a movable contact member and a fixed contact member, and the contact between them makes the both conductive. The movable contact member is formed of a bifurcated plate-shaped body, and the fixed contact portion has a hemispherical projection having an apex at a position aligned between the two forks of the movable contact portion. .

According to the above-mentioned structure, the movable contact member straddles the hemispherical projection of the fixed contact member at the bifurcated portion and abuts against the hemispherical projection, thereby making a two-point contact between them. As a result, a sufficient contact pressure can be obtained as compared with the conventional crossbar contact type, and since it is a two-point contact, durability reliability is doubled as compared with the one-point contact rivet contact type.

<< Description of Embodiments >> Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 4 show an embodiment of a contact structure of an electromagnetic relay according to the present invention.

In these figures, 10 is a substrate made of an electrically insulating material such as synthetic resin, and 12 is its box-like cover.

On the substrate 10, a bobbin 14 made of synthetic resin, a coil 16 wound around the outer periphery of the bobbin, a rod-shaped fixed iron core 18 provided through the center of the bobbin 14, and a fixed iron core 18 at one end An L-shaped yoke 20 which is connected and extends around the bobbin 14 is fixedly mounted as one assembly.

A hinge protrusion 22 is provided at the tip of the yoke 20,
A hinge hole 26 of a movable iron piece 24 is loosely fitted in the hinge protrusion 22. The movable iron piece 24 has a hinge hole 26 and a hinge projection 22.
In a loosely fitted state, the engaging portion is rotatably carried by the yoke 20 by using the engaging portion as a hinge portion, and the engaging portion of the bobbin 14 is also provided.
The return spring 28, which also functions as a metal fitting, is engaged with the bobbin 14 by being engaged with the bobbin 14 so as to prevent the disengagement from the assembly and to provide a restoring force. The movable iron piece 24 is magnetically attracted to the end surface of the fixed iron core 18 so as to rotate in the direction of arrow A in FIG. 1 against the spring force of the return spring 28 with the hinge portion as the center of rotation. Has become.

The movable iron core 24 is integrally provided with an extension arm portion 30, and a pressing end portion 32 is provided at a tip portion of the extension arm portion 30.

A metal shield case 36 having ground terminals 34, 35 on its inner surface is fixed to the substrate 10 adjacent to the assembly. A neutral fixed contact member 38, a normally closed fixed contact member 40, and a normally open fixed contact member 42, which are located inside the shield case 36, are mounted on the substrate 10 in a fixed state.

The shield case 36 has a pair of hinge pieces 44 on both sides thereof, and the hinge pieces 44 are provided with bearing holes 46 on the same axis. In the bearing hole 46, shaft-like protrusions 50 provided on the same axis line with each other on both sides of a rotating member 48 as a movable contact carrying member are fitted. The rotating member 48 is made of an electrically insulating material such as synthetic resin in the form of a plate piece as a movable contact carrying member, and has a shaft-like projection 50 on one end side thereof, and the shaft-like projection serves as a bearing hole 46. Mating with the shield case
It is rotatably supported by 36.

The rotating member 48 is provided with two contact carrier portions 52 and 54 at the rotating tip end portion which is farther away from the shaft-like protrusion 50. The contact carrier portions 52 and 54 are respectively located in the shield case 36 and carry the strip-shaped movable contact members 56 and 58 each having both ends formed in a bifurcated shape in a stepwise manner in the thickness direction. . Movable contact member 56
Selectively contacts the neutral fixed contact member 38 and the normally closed fixed contact member 40 to electrically connect them, and the other movable contact member 58 is a neutral fixed contact member 38 and a normally open fixed contact member 42. And are selectively brought into contact with each other to selectively electrically connect the both.

The ground terminals 34 and 35 are formed as hemispherical projections by embossing or the like, as shown in FIGS. 3 and 4, and are aligned between the forked portions 57 and 59 of the movable contact members 56 and 58, respectively. It has a vertex at the position.

A staple-shaped mounting portion 62 of the return spring 60 is fixed to the center of the rotating member 48 in a pinching manner. The return spring 60 is
The whole is made of a metal plate having an appropriate spring property, and has a pair of leaf spring piece portions 64 that engage with the spring receiving pieces 37 of the shield case 36 at the tip. The leaf spring piece portion 64 is provided between the rotating member 48 and the shield case 36, and the rotating member 48 is provided.
In the figure, the turning force in the clockwise direction is applied to the turning member 48.
Is positioned at a predetermined rotation return position.

The mounting portion 62 of the return spring 60 has a planar piece portion 66 on which the rotary member 48 overlaps with the surface portion of the movable iron piece 24 facing the pressing end portion 32. As shown in FIG. 3, a ridge-shaped projection 68 having a semicircular cross section extending along an axis parallel to the rotation axis of the rotation member 48 is formed by embossing or the like.

The ridge-shaped projection 68 faces a pressing end portion 32 provided at the tip of the extension arm portion 30 of the movable iron piece 24, and the pressing end portion 32 abuts the ridge-shaped projection 38 so that the rotating member 48 is a shaft-shaped projection. It is designed to be driven to rotate about the central axis of 50.

When the electromagnetic coil 16 is not energized and the fixed iron core 18 is not excited, the movable iron piece 24 is caused by the spring force of the return spring 28, and the rotating member 48 is moved by the leaf spring piece portion 64 of the return spring 60.
They are in the return position due to the spring force. At this time, the movable contact member 56 contacts the neutral fixed contact member 38 and the normally open fixed contact member 40 to electrically connect them, and the other movable contact member 58 is the neutral fixed contact member 38 and the normally open fixed member. It is separated from the contact member 42 and is in contact with the ground terminal 35 provided on the inner surface of the shield case 36.

When the electromagnetic coil 16 is energized and the fixed iron core 18 is excited, the movable iron piece 24 is magnetically attracted to the end face of the fixed iron core 18, and the movable iron piece 24 rotates the hinge portion including the engaging portion of the hinge protrusion 20 and the hinge hole 26. As a center, it is rotated and displaced in the direction of arrow A in FIG. 1 against the spring force of the return spring 28. By this rotational displacement of the movable iron piece 24, the pressing end surface 32 presses the ridge-shaped projection 68 of the return spring 60, and this pressing causes the rotating member.
48 rotates counterclockwise in the figure against the spring force of the leaf spring piece portion 64 about the central axis of the axial projection 50. Due to the rotation of the rotating member 48, the movable contact member 56 is separated from the neutral fixed contact member 38 and the normally open fixed contact member 40, and the shield case.
The other movable contact member 58 contacts the ground terminal 34 provided inside 36, and the other movable contact member 58 is the ground terminal of the shield case 36.
Separated from 35, neutral fixed contact member 38 and normally open fixed contact member 42
And comes into contact with each other to electrically connect them.

As described above, the contact structure according to the present invention is embodied as a ground contact structure, and the movable contact member 56 makes two-point contact with the forked portion 57 on the hemispherical protrusion of the ground contact 34 so as to straddle it. The movable contact member 58 has a ground contact at the forked portion 59.
Two hemispherical projections of 35 are contacted so that they straddle them.

[Brief description of drawings]

1 is an exploded perspective view showing an embodiment of an electromagnetic relay having a contact structure according to the present invention, and FIG. 2 is a part of an electromagnetic relay having a contact structure according to the present invention shown in FIG. FIG. 4 is a cutaway front view, FIG. 3 is an enlarged perspective view showing a main part of the electromagnetic relay according to the present invention shown in FIGS.
The figure is a sectional view thereof. 16 …… Coil 18 …… Fixed iron core 24 …… Movable iron piece 32 …… Pressing end 34, 35 …… Ground contact 36 …… Shield case 38 …… Neutral fixed contact member 40 …… Normally closed fixed contact member 42 …… … Normally open fixed contact member 48 …… Rotating member 56, 58 …… Moveable contact member 60 …… Return spring 66 …… One part 68 …… Ridge-shaped projection

Claims (1)

[Scope of utility model registration request] 1. A contact structure of an electromagnetic relay, comprising a movable contact member and a fixed contact member, wherein the contact between the movable contact member and the fixed contact member makes the movable contact member a bifurcated plate-like member. The fixed contact portion has a hemispherical protrusion having an apex at a position aligned with the fork of the movable contact portion, and the contact structure of the electromagnetic relay.