JPH11329198A - Contact mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the discharge between the exposed surface of a fixed contact and the free edge of a movable contact piece and provide a contact having high withstand voltage by covering the exposed surface of a fixed terminal exposed from a base with an insulating material, and further covering the free end part of a movable contact piece with an insulating material. SOLUTION: A shallow recessed part 25 is provided on the upper surface of a base block 20, and a fixed contact 23a is provided on the exposed upper end part 23b of a fixed contact terminal in the corner part of the recessed part 25. The exposed upper end part 23b of the fixed contact terminal is covered with an insulating material 29 such as synthetic resin. The insulating material 29 may be the resin used for the molding of the base 20. A movable contact piece 32, which is formed by punching a conductive leaf spring material, has movable contacts 32b on divided pieces on both ends formed by laterally dividing it. The free end part of each divided piece is covered with an insulating material 29 such as synthetic resin. The insulating material 29 may be the molding resin used for the formation of a movable block.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact mechanism, and more particularly to an electromagnetic relay having a contact mechanism with a high withstand voltage.

[0002]

2. Description of the Related Art Conventionally, as a contact mechanism of an electromagnetic relay, for example, as shown in FIG.
And a movable contact piece 5 provided on a lower surface of a free end with a movable contact 4 opposing the fixed contact 3 so as to be able to contact and separate therefrom.

However, according to the above-described contact mechanism of the electromagnetic relay, the distance between the movable contact 3 and the fixed contact 4 is reduced due to the miniaturization of the device, and the withstand voltage is apt to be reduced. In particular, the free edge of the movable contact piece 5 and the fixed contact terminal 2
Discharge is likely to occur even between the end portion 2a and the withstand voltage.

In view of the above problems, an object of the present invention is to provide a contact mechanism having a high withstand voltage.

In order to achieve the above object, an electromagnetic relay according to the present invention has a fixed contact provided on an exposed surface of a fixed terminal exposed from a base and a free contact provided on a free end of a movable contact piece. In the contact mechanism in which the movable contact is opposed to the movable contact so that the exposed surface of the fixed terminal is covered with an insulating material. Also, the free end of the movable contact piece may be covered with an insulating material, or the exposed surface of the fixed terminal is covered with an insulating material, and the free end of the movable contact piece is covered with an insulating material. May be.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the accompanying drawings of FIGS. That is, the present embodiment is applied to an electromagnetic relay, and generally includes a base block 20 formed by subjecting the electromagnet block 10 to secondary molding, a movable block 30, and a case 40.
It consists of: By the way, the external dimensions of this electromagnetic relay (width x height x height) are 10mm x 6.5mm x
5 mm.

The electromagnet block 10 is formed by winding a coil 14 around a substantially U-shaped iron core 11, as shown in FIGS. As a method for manufacturing the electromagnet block 10, first, a spool 12 is formed by subjecting a substantially U-shaped iron core 11 to primary molding. This spool 12 is shown in FIG.
As shown in FIG. 2, the iron core 11 has flanges 13 formed on both ends thereof. Then, a coil 14 is wound around an intermediate portion of the iron core 11, and a lead wire of the relay terminal 1 is insert-molded into the flange 13 on one side.
5 (FIG. 3) and soldered. Further, a pair of connecting pieces 16 protruding from both side surfaces of the other flange portion 13 are provided.
Extend along the axial direction.

The base block 20 is formed by subjecting the electromagnet block 10 connected to a lead frame (not shown) to secondary molding. In the lead frame, a common terminal 21, fixed contact terminals 22, 23 and a coil terminal 24 are cut out and bent. However, fixed contacts 22a and 23a are provided in advance on the upper ends 22b and 23b of the fixed contact terminals 22 and 23, respectively.

The relay terminal 1 of the electromagnet block 10
5 is welded and integrated with the free end of the coil terminal 24 provided on the lead frame, and the connecting piece 16 is welded and integrated with the lead frame. Do. Then, the connecting piece 16 is cut from the lead frame, and each of the terminals 21 to 24 is cut.
The base block 20 is cut off and bent.
Is completed. At this time, the bases of the terminals 21 to 24 are substantially flush with the outer surface of the base block 20.

Each of the terminals 21 to 24 protruding from the side surface of the base block 20 has a narrow base.
Therefore, when the terminals 21 to 24 are bent downward, the terminals 21 to 24 can be bent with high dimensional accuracy from a predetermined position without using a mold for forming a reference surface, and the bending positions do not vary. As a result, the terminals 21 to 24 are connected to the base block 20.
Are fitted into the shallow grooves provided on the outer surfaces of the first and second surfaces, and these outer surfaces are substantially flush with each other. When the thickness of each of the terminals 21 to 24 is, for example, 0.15 mm, the distance from the side surface of the base block 20 before bending to each narrow portion is 0 to 0.
What is necessary is just 05 mm.

As shown in FIG. 1, the base block 20 obtained by the above-mentioned secondary molding has a shallow recess 25 on the upper surface thereof. Protrusions 26a and 26b are protruded. One convex part 26
“a” has a long ridgeline such that the top thereof is in line contact with a movable block 30 described later. The other convex portion 26b is
In order to absorb variations in dimensional accuracy in the width direction, the protrusion 26
It has a ridge top that is shorter than a.

A fixed contact terminal 2 is provided at a corner of the recess 25.
2 and 23 are fixed to the exposed upper ends 22b and 23b.
2a and 23a are provided respectively. And FIG.
As shown, the exposed upper end portions 22b and 23b of the fixed contact terminals 22 and 23 are covered with an insulating material 29 such as a synthetic resin shown in a dotted pattern. The insulating material 29 may be a molding resin used when molding the base 20. Coating with a molding resin has the advantage of reducing the number of production steps. The magnetic pole portions 11a and 11b of the iron core 11 are exposed between the adjacent fixed contacts 22a and 22a and between the adjacent fixed contacts 23a and 23a, respectively. Further, the magnetic pole portions 11a and 11b of the iron core 11 are separated from the fixed contacts 22a and 23a by insulating walls 27 having a substantially U-shaped plane. The opposite outer surface of the insulating wall 27 is a tapered surface (FIG. 6). Then, of the opening edges of the base block 20, the connection receiving portions 21
a is exposed.

As shown in FIGS. 1 and 4, a projection 28 is provided at the center of both end faces of the base block 20. As shown in FIG. As shown in FIG. 5, the protrusion 28 protrudes forward from the uncut ends 16c, 23c and 24c of the connecting piece 16, the fixed contact terminal 23 and the coil terminal 24. This is to prevent, for example, the end portion 23c and the end portion 24c from climbing over or catching with each other when the base block 20 is continuously transported.

As shown in FIGS. 1, 2 and 5 and 6, the movable block 30 has movable contact pieces 32, 32 arranged on both sides of a permanent magnet 31 and a movable iron piece 33 on one surface of the permanent magnet 31. Are superimposed, an insulating table 34 is formed by resin molding, and integrated.

The permanent magnet 31 is narrower than the movable iron piece 33, and is superposed on a so-called drooping surface of the movable iron piece 33. This is to prevent the permanent magnet 31 from contacting the so-called burr generated when the movable iron piece 33 is subjected to press working, so that no gap is generated between the two.

Further, after partially joining the edge of the joint surface between the permanent magnet 31 and the movable iron piece 33, resin molding may be performed. As the temporary fixing method, for example, an existing method such as laser welding, welding with a gas burner, spot welding, or the like can be used. Alternatively, a joining metal thin film formed on a joining surface of both may be melted and integrated. As a metal thin film for bonding,
For example, a simple substance such as nickel, zinc, cadmium, tin, copper, chromium, lead, silver, gold, and palladium or an alloy thereof may be used. In addition, as a method for forming the bonding metal thin film, existing methods such as plating, vapor deposition, and coating can be selected. Further, the bonding metal thin film may be formed on the entire bonding surface, or may be formed only on the edge of the bonding surface or only on the center. Examples of the method for melting the bonding metal thin film include laser irradiation, heating using a gas burner, and an existing heating method using electric resistance.

The movable contact piece 32 is formed by stamping a conductive thin plate spring material. The movable contacts 32a, 32a are respectively attached to the divided pieces at both ends formed by being divided in the width direction.
b are provided respectively. In addition, the movable contact piece 32
Has a substantially T-shaped connecting portion 32c extending laterally from a substantially central portion of the side. In addition, the free end of each split piece
It is covered with an insulating material 29 such as a synthetic resin. The insulating material 29 may be a molding resin used when molding the movable block 30. If covered with molding resin,
There is an advantage that the number of production steps is reduced.

As a method of forming the movable block 30, for example, after the movable contacts 32a and 32b are provided, the movable contact pieces 32 and 32 cut out from a lead frame (not shown) by press working are positioned in a mold. Next, there is a method in which the temporarily fixed permanent magnet 31 and the movable iron piece 33 are positioned in the mold, and then integrated by an insulating table 34 formed of a resin mold. The movable iron piece 33 has the same configuration as that of the iron core 11 except for a portion in contact with the magnetic pole portions 11a and 11b.
The entire surface may be resin-molded to enhance the insulating properties.

Then, the movable block 30 is dropped into the base block 20 from above. Thereby, a pair of concave portions 34a and 34b provided on the lower surface of the insulating base 34 (FIG. 2).
Are convex portions 26a projecting from the upper surface of the base block 30,
26b, the movable block 30 is automatically positioned. Further, by welding the connection portion 32c of the movable contact piece 32 to the connection receiving portion 21a of the common terminal 21, the movable block 30 is rotatably supported.

In this embodiment, the concave portions 34 a and 34 b provided on the lower surface of the insulating table 34 are
a and 26b to be fitted and supported. For this reason,
For example, even if there is a variation in the distance between the convex portions 26a and 26b due to the processing tolerance, the ridgeline at the top of the convex portion 26b is shorter than that of the convex portion 26a, and the variation in the processing tolerance can be absorbed. As a result, it is possible to avoid a malfunction due to a variation in processing tolerance. Also, the recesses 34a, 34b of the insulating table 34
And the contact portion between the base block 20 and the convex portions 26a and 26b are located on substantially the same plane as the connecting portion 32c serving as the rotation axis. For this reason, there is no play due to the variation of the rotation axis, and a smooth rotation can be obtained. Further, FIG.
As shown in the figure, the upper ends 22b, 2 of the fixed terminals 22, 23
Since both the free ends of the movable contact piece 3b and the movable contact piece 32 are covered with the insulating material 29, there is an advantage that the discharge is eliminated and the withstand voltage is improved.

In this embodiment, two convex portions 26 are provided.
Although the case where a and 26b are formed has been described, the present invention is not limited to this, and one or two or more may be formed. The shape of the projections 26a and 26b is not limited to the above-described one, and the top may be a triangular prism, a cone, or a hemisphere. Furthermore, while the tops of the protrusions 26a and 26b are formed to have an acute angle, and the bottoms of the recesses 34a and 34b are formed to have an obtuse angle, it is possible to provide a structure in which the rotation fulcrum hardly rattles.

In this electromagnetic relay, the spatial distance between the movable contact piece 32 and the movable iron piece 33 is about 0.9 mm. However, as shown in FIGS. 11 and 14, as a result of assembling the movable block 30 to the base block 20, the substantially U-shaped insulating wall 27 separates the movable iron piece 33 and the movable contact piece 32. For this reason, the creepage distance between the two becomes long, and the insulation characteristics are high. Then, both ends 34 of the insulating table 34
c and 34 d extend long and overlap the insulating wall 27. For this reason, the extension distance between the two becomes even longer,
There is an advantage that the insulation characteristics are improved.

The case 40 has a box shape that can be fitted to the base block 20, as shown in FIGS. As shown in FIG. 6, the case 40 has an insulating rib 41 protruding from the ceiling surface. One end of the insulating rib 41 is continuous with the inner surface of the case 40, and the joining surface joining the insulating wall 27 of the base block 20 is a tapered surface.

Then, the case 40 is assembled and fitted to the base block 20 to which the movable block 30 is assembled.
Thereby, as shown in FIG. 6, the insulating ribs 41 of the case 40 abut on the outer surface of the insulating wall 27 provided on the base block 20. For this reason, the creepage distance between the two becomes longer, and the insulation characteristics are improved. Further, since the joining surfaces of both the insulating wall 27 and the insulating rib 43 are tapered, there is an advantage that a smooth assembly is possible and the assembling work is facilitated. Note that the insulating ribs 41 may be in contact with the opposing inner surfaces of the insulating wall 27.

Next, the base block 20 and the case 40
After sealing the joint surface with the gas outlet, the internal gas is evacuated from the gas vent hole of the case 40, and the gas vent hole is heat-sealed to complete the assembling operation.

Next, the operation of the electromagnetic relay having the above-described structure will be described. First, when no voltage is applied to the coil 14 of the electromagnet block 10, one end 33 a of the movable iron piece 33 is attracted to the magnetic pole 11 a of the iron core 11 by the magnetic force of the magnetic flux of the permanent magnet 31, and the magnetic circuit is closed. And the movable contact 32a of the movable contact piece 32 is in contact with the fixed contact 22a.

When a voltage is applied to the coil 14 of the electromagnet block 10 so that a magnetic flux for canceling the magnetic flux of the permanent magnet 31 is generated, the movable iron piece 33 rotates against the magnetic force of the permanent magnet 31, and The movable contact piece 32 rotates. For this reason, after the movable contact 32a is separated from the fixed contact 22a, the movable contact 32b contacts the fixed contact 23a, and the other end 33b of the movable iron piece 33 is connected to the magnetic pole 1 of the iron core 11.
Adsorb to 1b. And even if the application of the above-mentioned voltage is released, the movable block 30
Hold that state.

Further, when a voltage in a direction opposite to the above-described application direction is applied to the coil 16, the coil 16 resists the magnetic force of the permanent magnet 31,
The movable iron piece 33 rotates in the direction opposite to the above-described rotation direction, and accordingly, the movable contact piece 32 also rotates. Therefore, the movable contact 32b is separated from the fixed contact 23a, and the movable contact 32a
After contacting with the fixed contact 22a, one end 33a of the movable iron piece 33 is attracted to the magnetic pole portion 11a of the iron core 11 and returns to the original state.

Although the self-holding type electromagnetic relay has been described in the above embodiment, the present invention is not limited to this.
Needless to say, the present invention may be applied to a self-recovering type electromagnetic relay or another contact switch.

[0029]

As is apparent from the above description, according to the first aspect of the electromagnetic relay according to the present invention, the exposed surface exposed from the base is covered with the insulating material. Therefore, there is no discharge between the exposed surface of the fixed contact terminal and the free edge of the movable contact piece, and a contact mechanism with high withstand voltage can be obtained. According to the second aspect, since the free end of the movable contact piece is covered with the insulating material, a contact mechanism with high withstand voltage can be obtained as described above. According to the third aspect, since both the exposed surface of the fixed terminal and the free end of the movable contact piece are covered with the insulating material, there is an effect that a contact mechanism with a higher withstand voltage can be obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an electromagnetic continuity device according to the present invention.

FIG. 2 is a perspective view of the movable block shown in FIG. 1 from different angles.

FIG. 3 is a sectional view showing a state where a movable block is assembled to a base block.

FIG. 4 is a partial plan sectional view showing a state where a movable block and a case are assembled to a base block.

FIG. 5 is a partial front sectional view showing a state where a movable block and a case are assembled to a base block.

FIG. 6 is a partial side sectional view showing a state where the movable block and the case are assembled to the base block.

FIG. 7 is an enlarged perspective view of a main part showing an electromagnetic relay according to the present invention.

FIG. 8 is an enlarged perspective view of a main part showing an electromagnetic relay according to a conventional example.

[Explanation of symbols]

10: electromagnet block, 11: iron core, 11a, 11b ...
Magnetic pole part, 12 ... Spool, 13 ... Flange part, 14 ... Coil,
15 ... relay terminal, 16 ... connecting piece, 16c ... end, 20 ...
Base block, 21 common terminal, 21a connection receiving part, 22, 23 fixed contact terminal, 22a, 23a fixed contact, 22b, 23b upper end, 22c, 23c end, 24 coil terminal, 24c End, 25 ... recess, 2
6a, 26b: convex, 27: insulating wall, 28: protruding, 29
... insulating material, 30 ... movable block, 31 ... permanent magnet, 32
... Movable contact pieces, 32a and 32b ... Movable contacts, 32c ... Connections, 33 ... Movable iron pieces, 34 ... Insulating tables, 34a and 34b
... recesses, 40 ... cases, 41 ... insulating ribs.

Claims (3)

[Claims] 1. A contact mechanism in which a fixed contact provided on an exposed surface of a fixed terminal exposed from a base and a movable contact provided on a free end of a movable contact piece are detachably opposed to each other. A contact mechanism whose surface is covered with an insulating material. 2. A contact mechanism in which a fixed contact provided at an end of a fixed terminal exposed from a base and a movable contact provided at a free end of a movable contact piece are detachably opposed to each other. A contact mechanism having a free end covered with an insulating material. 3. A contact mechanism in which a fixed contact provided on an exposed surface of a fixed terminal exposed from a base and a movable contact provided on a free end of a movable contact piece are detachably opposed to each other. A contact mechanism, wherein a surface is covered with an insulating material, and a free end of the movable contact piece is covered with an insulating material.