JP2007329088A - Dc electromagnetic relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a DC electromagnetic relay which is prevented from forming projections like burrs on contacts, and can perform stable conduction and breakage of direct current. <P>SOLUTION: The DC electromagnetic relay 1 comprises a movable contact holder 5 and a pair of fixed contact holders 6 etc. A plus side fixed contact 61A has a primary curved surface periphery 612 on the periphery of its contact surface 611. The plane outline of the plus side fixed contact 61A is larger than that of a minus side movable contact 51B. The primary curved surface periphery 612 of the plus side fixed contact 61A is faced to a profile line C of the plane outline of the minus side movable contact 51B. A plus side movable contact 51A has a secondary curved surface periphery 512 on the periphery of its contact surface 511. The plane outline D1 of the plus side movable contact 51A is larger than that of a minus side fixed contact 61B. The secondary curved surface periphery 512 of the plus side movable contact 51A is faced to a profile line C of the plane outline of the minus side fixed contact 61B. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a DC electromagnetic relay that conducts or interrupts a DC current by contacting or retracting a pair of contacts.

In a DC electromagnetic relay that conducts or interrupts a direct current by contacting or retracting a pair of contacts, the pair of movable contacts are moved by a magnetic attraction force and contacted with a pair of fixed contacts that respectively face each movable contact The contact state is formed.
In addition, the shapes of the contact surfaces of the pair of movable contacts and the contact surfaces of the pair of fixed contacts are all formed in a planar shape (flat shape) for ease of manufacturing management. Also, taking into account the wear that occurs between the contacts, the size of the planar outer shape of the pair of movable contacts is made different from the size of the planar outer shape of the pair of fixed contacts.
For example, in the plunger type electromagnetic relay of Patent Document 1, the planar outer shape of the pair of fixed contacts and the planar outer shape of the pair of movable contacts are made larger.

  However, in a DC electromagnetic relay, each contact has a positive or negative polarity. Specifically, one of the fixed contacts is a plus-side fixed contact, one of the movable contacts in contact with this is a minus-side movable contact, and the other of the movable contacts is a plus-side movable contact. The other of the contacting fixed contacts is a negative fixed contact. When the pair of movable contacts and the pair of fixed contacts come into contact or retract, arc discharge occurs from each minus side contact to each plus side contact.

  For this reason, particularly, the contact surface of the plus side contact is heavily consumed, and a burr-like protrusion may be formed on the outer peripheral portion of the plus side contact surface. When this burr-like projection is formed, the current blocking ability may be reduced, and in some cases, the contacts may be fixed.

JP 2002-245916 A

  The present invention has been made in view of such conventional problems, and a DC electromagnetic relay capable of preventing a burr-like protrusion from being formed at a contact and stably conducting and interrupting a direct current is provided. It is something to be offered.

The present invention includes an exciting coil that generates magnetic flux when energized,
A magnetic path forming member that generates a magnetic attractive force by passing the magnetic flux generated by the excitation coil;
A plunger that is inserted into the inner peripheral hole of the excitation coil and slides upon receiving the magnetic attraction force;
A movable contact holder disposed on the plunger and provided with a pair of movable contacts;
A pair of fixed contact holders arranged to face the movable contact holder, each provided with a fixed contact facing the movable contact;
A case for accommodating the movable contact holder and the fixed contact holder;
The movable holder includes an interrupted state in which the pair of movable contacts are retracted from the pair of fixed contacts, and a pair of the movable contacts in contact with the pair of fixed contacts. It is configured to form a contact state in which current flows from one fixed contact holder to the other fixed contact holder,
In the DC electromagnetic relay configured so that one of the shut-off state and the contact state is formed by sliding the plunger by the magnetic attractive force, and the other is formed by a spring.
The positive fixed contact disposed on the one fixed contact holder forms a curved first curved outer peripheral portion on the outer periphery of the contact surface, and the flat outer shape is fixed on the positive fixed side of the pair of movable contacts. The outer contour of the negative movable contact facing the contact is larger than the planar outer shape, and the contour of the planar outer contour of the negative movable contact is opposed to the outer periphery of the first curved surface.
The plus side movable contact facing the minus side fixed contact disposed on the other fixed contact holder of the pair of movable contacts forms a curved second curved outer peripheral portion on the outer periphery of the contact surface, and A DC electromagnetic relay characterized in that a planar outer shape is larger than a planar outer shape of the negative fixed contact, and a contour line of the planar external shape of the negative fixed contact is opposed to the outer periphery of the second curved surface. (Claim 1).

In the DC electromagnetic relay of the present invention, the shape of the pair of movable contacts arranged in the movable contact holder and the shape of the pair of fixed contacts arranged in the fixed contact holder are devised.
That is, in the present invention, at the contact position between each movable contact and each fixed contact, the planar outline of each plus contact located upstream of the DC current flow is changed to each minus contact located downstream. The outline of the planar outline of each negative contact is opposed to the curved outer peripheral portion of each positive contact.

  More specifically, the planar outline of the plus side fixed contact is made larger than the planar outline of the minus side movable contact, and the outline of the plane outline of the minus side movable contact is opposed to the outer periphery of the first curved surface of the plus side fixed contact. In addition, the planar outline of the plus side movable contact is made larger than the planar outline of the minus side fixed contact, and the outline of the plane outline of the minus side fixed contact is opposed to the second curved outer peripheral portion of the plus side movable contact. Yes.

When the contact state is formed by bringing the pair of movable contacts into contact with the pair of fixed contacts, the direct current flows from the plus side fixed contact to the minus side movable contact, and after flowing through the movable contact holder, the plus side Flows from the movable contact to the negative fixed contact.
When the above contact state is formed, arc discharge occurs between the inner part of the curved outer peripheral portion of the contact surface of each plus side contact and the contact portion of each minus side contact surface, A gap is formed between the outer peripheral portion of the curved surface on the contact surface of the plus side contact and the outer periphery of the contact surface of each minus side contact, and arc discharge does not occur.

In addition, when switching from the contact state to the shut-off state in which the pair of movable contacts are retracted from the pair of fixed contacts, the curved surface outer periphery of the contact surface of each plus-side contact is the same as when the contact state is formed. A gap is formed between the contact portion and the outer peripheral portion of the contact surface of each negative contact, and arc discharge does not occur. Thereby, it can prevent that the burr | flash-shaped protrusion is formed in the outer peripheral part of each positive side contact.
Therefore, according to the present invention, it is possible to provide a DC electromagnetic relay that can prevent a burr-like protrusion from being formed at a contact point and can stably conduct and interrupt a DC current.

A preferred embodiment of the present invention described above will be described.
In the present invention, the contact surface of the plus side fixed contact is formed in a flat shape on the inner side of the outer peripheral portion of the first curved surface, and the contact surface of the minus side movable contact is formed in a flat shape, The contact surface of the plus side movable contact is preferably formed so that the inner part of the outer peripheral portion of the second curved surface is flat, and the contact surface of the minus side fixed contact is formed flat. Item 2).

  In this case, the flat portion on the contact surface of the plus side fixed contact can be stably brought into contact with the flat contact surface of the minus side movable contact, and the flat surface on the contact surface of the plus side movable contact can be obtained. Can be stably brought into contact with the flat contact surface of the negative fixed contact. Therefore, the direct current can be energized and interrupted more stably.

The movable contact holder has a slide reference portion on one side surface orthogonal to the slide direction, and the case has the slide reference portion along the slide direction on one inner peripheral surface thereof. Only when the minus-side movable contact in the movable contact holder is opposed to the plus-side fixed contact in the one fixed contact holder. Is preferably configured to be guided by the guide reference portion (claim 3).
In this case, when the movable contact holder is opposed to the pair of fixed contact holders and assembled in the case, the movable contact holder aligns the formation direction of the slide reference portion with the formation direction of the guide reference portion in the case. Can be assembled. For this reason, it is possible to easily prevent an assembly error of the movable contact holder.

Hereinafter, embodiments of the DC electromagnetic relay 1 of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the DC electromagnetic relay 1 of this example includes the following exciting coil 2, magnetic path forming member 3, plunger 4, movable contact holder 5, a pair of fixed contact holders 6, and a case 7. ing.
The exciting coil 2 is formed by winding a bobbin 21 and generating a magnetic flux when energized. The magnetic path forming member 3 is disposed in the inner peripheral hole 22 and the outer periphery of the exciting coil 2, and is configured to pass a magnetic flux generated by the exciting coil 2 to generate a magnetic attractive force.

  As shown in FIG. 1, the plunger 4 is inserted into the inner peripheral hole 22 of the exciting coil 2 and is slid by receiving the magnetic attraction force. The movable contact holder 5 is disposed at the tip of the plunger 4 and has a pair of movable contacts 51 on its surface. Each of the fixed contact holders 6 is disposed to face the movable contact holder 5, and includes a fixed contact 61 that faces the movable contact 51. The case 7 is connected to the magnetic path forming member 3 and accommodates the movable contact holder 5 and the fixed contact holder 6.

  In addition, the movable contact holder 5 has a pair of movable contacts 51 retracted from a pair of fixed contacts 61, as shown in FIG. 3, and a pair of movable contacts 51, as shown in FIG. Each of the pair of fixed contact holders 6 is brought into contact with the fixed contact 61 to form a contact state 102 in which a current flows from one fixed contact holder 6 to the other fixed contact holder 6. Further, one of the blocking state 101 and the contact state 102 is formed by sliding the plunger 4 by a magnetic attractive force, and the other is formed by a spring 41.

  As shown in FIGS. 3 and 4, the positive side fixed contact 61 </ b> A disposed in the one fixed contact holder 6 has a curved first curved outer peripheral portion 612 on the outer periphery of the contact surface 611. . The planar outer shape (planar outer diameter) D1 of the plus side fixed contact 61A is larger than the planar outer shape (planar outer diameter) D2 of the minus side movable contact 51B facing the plus side fixed contact 61A of the pair of movable contacts 51. is there. Further, the contour line (corner portion) C of the planar outer shape of the minus side movable contact 51B is opposed to the first curved surface outer peripheral part 612 of the plus side fixed contact 61A.

  The positive movable contact 51A facing the negative fixed contact 61B disposed on the other fixed contact holder 6 of the pair of movable contacts 51 has a curved second curved outer peripheral portion on the outer periphery of the contact surface 511. 512. The planar outer shape (planar outer diameter) D1 of the plus side movable contact 51A is larger than the planar outer shape (planar outer diameter) D2 of the minus side fixed contact 61B. Further, the outline (corner portion) C of the planar outer shape of the negative fixed contact 61B is opposed to the second curved surface outer periphery 512 of the positive movable contact 51A.

Below, it demonstrates in full detail with FIGS. 1-6 about the direct current | flow electromagnetic relay 1 of this example.
As shown in FIG. 6, the DC electromagnetic relay 1 of this example includes a high-voltage battery (a high-voltage DC power source used as a drive source for a hybrid vehicle or an electric vehicle) 81 in a vehicle and an inverter circuit 82 for driving the vehicle. It is arranged and used for wiring between. Further, the DC electromagnetic relay 1 is arranged on both the plus side wiring 841 and the minus side wiring 842 to constitute a pair of main relays 1 and receives a signal from an ECU (electronic control unit) 85 of the vehicle, and is excited. The coil 2 is energized and used to turn on / off the drive of the inverter circuit 82.

  Further, in order to prevent a large inrush current at the time of power-on from flowing to the capacitor 821 in the inverter circuit 82, a precharge relay 831 and a resistor 832 are connected between the high voltage battery 81 and the inverter circuit 82. It is. Then, precharge relay 831 and main relay 1B are driven by a signal from ECU 85, and after charging of capacitor 821 is completed, main relay 1A is driven by a signal from ECU 85. When the inverter circuit 82 is driven, the main relays 1A and 1B are maintained in the energized state.

As shown in FIG. 1, the exciting coil 2 of this example is formed by winding a bobbin 21 made of resin. The bobbin 21 has a cylindrical portion 211 having an inner peripheral hole 22 at the center thereof, and has flange portions 212 protruding radially outward at both axial ends of the cylindrical portion 211. The winding constituting the exciting coil 2 is wound in a recess 213 formed between the pair of flange portions 212.
The magnetic path forming member 3 of this example is formed continuously on the fixed iron core 31 disposed in the inner peripheral hole 22 of the bobbin 21 of the exciting coil 2 and on one end side and the outer peripheral side of the exciting coil 2 and the bobbin 21 in the axial direction. The yoke 32 includes a fixed iron core 31, the excitation coil 2, and a plate 33 that holds the bobbin 21 and is disposed on the other axial end side of the excitation coil 2 and the bobbin 21. The fixed iron core 31, the yoke 32, and the plate 33 are all made of a magnetic material for forming a magnetic path.

As shown in the drawing, a part of the plunger 4 of this example is disposed in the inner peripheral hole 22 of the bobbin 21, and a slide return spring (on the axial end of the fixed iron core 31 ( Return spring) 41 is arranged. The plunger 4 is made of a magnetic material and is inserted into a center hole 321 formed at one end of the yoke 32 in the axial direction.
As shown in FIGS. 1 and 3, in the DC electromagnetic relay 1 of this example, when the excitation coil 2 is not energized, the pair of movable contacts 51 are separated from the pair of fixed contacts 61 by the biasing force of the spring 41. The shut-off state 101 is formed by retracting.
On the other hand, as shown in FIG. 4, in the DC electromagnetic relay 1 of this example, when the exciting coil 2 is energized, the plunger 4 slides against the biasing force of the spring 41, and the pair of movable contacts 51 are paired. The contact state 102 is formed in contact with the fixed contact 61.

As shown in FIG. 1, the case 7 of this example is fixed to the yoke 32 and a movable contact holder between the case body 71 having the pair of fixed contact holders 6 and the case body 71. 5 and a case cover 72 for accommodating the fixed contact holder 6 and the like. Inside the case main body 71, fixed contact holders 6 are arranged on both sides of the central portion where the plunger 4 is arranged.
A contact spring 53 is arranged inside the case cover 72 between the surface of the movable contact holder 5 on one end side in the axial direction. The contact spring 53 urges the movable contact holder 5 in a direction to approach the fixed contact holder 6.

As shown in FIG. 5, the movable contact holder 5 has a slide reference portion 551 on one side surface 55 orthogonal to the slide direction L thereof. Further, the case cover 72 has a guide reference portion 721 for guiding the slide of the slide reference portion 551 along the slide direction L (see FIG. 3) on one inner peripheral surface 720 thereof.
The movable contact holder 5 of this example has a first protrusion 551 formed on one of a pair of side surfaces 55 facing each other, and a second protrusion 552 smaller than the first protrusion 551 on the other side. Further, the case cover 72 of this example has a first guide groove 721 for guiding the slide of the first protrusion 551 on one of a pair of inner peripheral surfaces 720 facing each other, and the slide of the second protrusion 552 on the other. Has a second guide groove 722 for guiding. In this example, the first protrusion 551 is a slide reference portion 551, and the first guide groove 721 is a guide reference portion 721.

The case cover 72 of this example can be assembled to the case main body 71 only when the negative movable contact 51B in the movable contact holder 5 is opposed to the positive fixed contact 61A in one fixed contact holder 6. It has become.
That is, only when the minus side movable contact 51B in the movable contact holder 5 is opposed to the plus side fixed contact 61A in one fixed contact holder 6, the first protrusion 551 as the slide reference portion 551 in the movable contact holder 5 The first guide groove 721 as the guide reference portion 721 in the case cover 72 is opposed, the first protrusion 551 is guided by the first guide groove 721, and the second protrusion 552 is guided by the second guide groove 722. It has become.

The configuration in which the slide reference portion 551 and the guide reference portion 721 are formed prevents the negative movable contact 51B in the movable contact holder 5 from being mistakenly opposed to the negative fixed contact 61B in the other fixed contact holder 6. can do. Therefore, it is possible to easily prevent the movable contact holder 5 from being assembled incorrectly.
Note that the slide reference portion 551 may be formed in a groove shape, and the guide reference portion 721 may be formed in a protrusion shape. In addition to the above-described configuration, various configurations can be adopted as the slide reference portion 551 and the guide reference portion 721.

As shown in FIG. 1, the movable contact holder 5 of this example is disposed on one end side in the axial direction of the plunger 4 via a shaft 42 made of resin. The pair of movable contacts 51 are disposed on both sides of the central portion of the DC electromagnetic relay 1 in which the plunger 4 is disposed on the surface on the other axial end side of the movable contact holder 5.
As shown in FIGS. 1 and 2, the pair of fixed contact holders 6 of this example are bent to the outer surface on one end side in the axial direction of the case cover 72 and pulled out. Bolts 601 are disposed on the outer end of the fixed contact holder 6 and an electric wiring attachment 60 for energization and interruption is formed. Then, the electrical wiring that is energized and interrupted by the DC electromagnetic relay 1 is connected to the mounting portion 60 in each fixed contact holder 6 by each bolt 601.

Further, as shown in FIG. 1, the solenoid portion 11 including the exciting coil 2, the magnetic path forming member 3, the plunger 4, the spring 41, and the like is connected to the direct current on the other axial end side (the side on which the plate 33 is disposed). It arrange | positions on the bracket 12 for installing the electromagnetic relay 1. FIG. The bracket 12 is provided with a conductive terminal 121 electrically connected to a winding end (lead wire) of the exciting coil 2 by insert molding or the like.
And the electric power for driving the exciting coil 2 from the exterior of the DC electromagnetic relay 1 is supplied to the conductive terminal 121 in response to a signal from the ECU 85.

The movable contact holder 5 and the fixed contact holder 6 are made of a good conductor metal, and the pair of movable contacts 51 and the pair of fixed contacts 61 are made of a good conductor metal having high corrosion resistance. The pair of movable contacts 51 and the pair of fixed contacts 61 have a circular shape in plan view.
Further, as shown in FIGS. 3 and 4, the first curved outer peripheral portion 612 of the plus side fixed contact 61A of the present example has an entire circumference formed in a cross-sectional R shape, and the contact surface 611 of the plus side fixed contact 61A. The inner part of the first curved outer peripheral part 612 is formed in a flat shape. Further, the contact surface 515 of the minus side movable contact 51B of this example is formed in a flat shape.
In addition, the second curved outer peripheral portion 512 of the plus side movable contact 51A of this example is formed in a cross-sectional R shape, and the contact surface 511 of the plus movable contact 51A is the second curved outer peripheral portion 512. The inner part of is formed flat. Further, the contact surface 615 of the minus side fixed contact 61B of this example is formed in a flat shape.

In the DC electromagnetic relay 1 of this example, the shape of the pair of movable contacts 51 arranged in the movable contact holder 5 and the shape of the pair of fixed contacts 61 arranged in the fixed contact holder 6 are devised.
In other words, in this example, the planar outer diameter D1 of the plus-side fixed contact 61A is made larger than the planar outer diameter D2 of the minus-side movable contact 51B, and the minus-side movable is moved to the first curved surface outer peripheral portion 612 of the plus-side fixed contact 61A. The contour line C of the planar outer shape of the contact 51B is opposed, and the planar outer diameter D1 of the plus side movable contact 51A is made larger than the planar outer diameter D2 of the minus side fixed contact 61B. The contour C of the flat outer shape of the negative fixed contact 61B is opposed to the curved outer peripheral portion 512.

As shown in FIGS. 1 and 4, when the excitation coil 2 in the DC electromagnetic relay 1 is energized by a signal from the ECU 85, the magnetic flux generated by the excitation coil 2 is a fixed iron core as the magnetic path forming member 3. 31, the yoke 32 and the plate 33 pass through, and a magnetic attractive force acts on the plunger 4 from the fixed iron core 31. Then, the plunger 4 and the movable contact holder 5 slide, and the pair of movable contacts 51 in the movable contact holder 5 come into contact with the fixed contacts in the pair of fixed contact holders 6. Further, at this time, the pair of movable contacts 51 are stably brought into contact with the pair of fixed contacts 61 by being urged by the contact spring 53.
In this way, the contact state 102 is formed, and the electric wires connected to the attachment portions 60 in the fixed contact holders 6 can be conducted to conduct electricity.

At this time, as shown in FIG. 4, the direct current I flows from the positive fixed contact 61A to the negative movable contact 51B, flows through the movable contact holder 5, and then flows from the positive movable contact 51A to the negative fixed contact 61B. .
An arc discharge is generated between the inner portion of the first curved surface outer peripheral portion 612 of the contact surface 611 of the plus side fixed contact 61A and the contact portion of the contact surface 515 of the minus side movable contact 51B, while the plus side A gap S is formed between the first curved surface outer peripheral portion 612 of the contact surface 611 of the fixed contact 61A and the outer peripheral portion of the contact surface 515 of the minus side movable contact 51B, and no arc discharge occurs.

  In addition, arc discharge occurs between the inner portion of the second curved surface outer peripheral portion 512 on the contact surface 511 of the plus side movable contact 51A and the contact portion of the minus side fixed contact 61B with the contact surface 615, while the plus side A gap S is formed between the second curved surface outer peripheral portion 512 of the contact surface 511 of the movable contact 51A and the outer peripheral portion of the contact surface 615 of the negative side fixed contact 61B, and arc discharge does not occur.

  Next, as shown in FIGS. 1 and 3, when energization to the exciting coil 2 is interrupted by a signal from the ECU 85, the magnetic attraction force disappears, and the plunger 4 and the movable contact holder 5 apply the biasing force of the spring 41. Upon receipt, the slide returns. Then, the pair of movable contacts 51 in the movable contact holder 5 retracts from the fixed contacts in the pair of fixed contact holders 6. In this way, the interruption | blocking state 101 is formed and the conduction | electrical_connection of the electrical wiring each connected to the attaching part 60 in each fixed contact holder 6 can be interrupted | blocked.

  Further, when the contact state 102 is switched to the cut-off state 101, the first curved surface outer peripheral portion 612 on the contact surface 611 of the plus-side fixed contact 61A and the minus-side movable portion are formed as in the case of forming the contact state 102. A gap S is formed between the outer peripheral portion of the contact surface 515 of the contact 51B, and arc discharge does not occur. Also, a gap S is formed between the second curved surface outer peripheral portion 512 of the contact surface 511 of the plus side movable contact 51A and the outer peripheral portion of the contact surface 615 of the minus side fixed contact 61B, so that no arc discharge occurs. .

As described above, in this example, arc discharge does not occur in the first curved surface outer peripheral portion 612 of the plus side fixed contact 61A and the second curved surface outer peripheral portion 512 of the plus side movable contact 51A, and the outer peripheral portion of the plus side fixed contact 61A. In addition, burr-like protrusions can be prevented from being formed on the outer peripheral portion of the plus side movable contact 51A.
Therefore, according to the DC electromagnetic relay 1 of this example, it is possible to prevent the burr-like protrusions from being formed on the contacts 51A and 61A, and to stably conduct and interrupt the DC current I.

  Further, when the contact state 102 is formed, the flat portion 513 on the contact surface 611 of the plus side fixed contact 61A and the flat contact surface 515 of the minus side movable contact 51B can be stably contacted, Further, the flat portion 613 on the contact surface 511 of the plus side movable contact 51A and the flat contact surface 615 of the minus side fixed contact 61B can be stably brought into contact with each other. Therefore, the direct current I can be energized and interrupted more stably.

Cross-sectional explanatory drawing shown in the state which looked at the DC electromagnetic relay in the Example from the front. Cross-sectional explanatory drawing shown in the state which looked at the DC electromagnetic relay in the Example from the side. Cross-sectional explanatory drawing which shows the interruption | blocking state which evacuated a pair of movable contact in a Example from a pair of fixed contact. Cross-sectional explanatory drawing which shows the contact state which made a pair of movable contact contact a pair of fixed contact in an Example. Cross-sectional explanatory drawing shown in the state which looked at the periphery of the movable contact holder in the Example from the downward direction. Circuit explanatory drawing which shows the state which used the DC electromagnetic relay for the inverter circuit in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 DC electromagnetic relay 101 interruption | blocking state 102 contact state 2 exciting coil 22 inner peripheral hole 3 magnetic path formation member 31 fixed iron core 32 yoke 33 plate 4 plunger 41 spring 5 movable contact holder 51A plus side movable contact 512 2nd curved surface outer peripheral part 51B minus Side movable contact 6 fixed contact holder 61A plus side fixed contact 612 first curved surface outer peripheral part 61B minus side fixed contact 7 case

Claims (3)

An exciting coil that generates magnetic flux when energized;
A magnetic path forming member that generates a magnetic attractive force by passing the magnetic flux generated by the excitation coil;
A plunger that is inserted into the inner peripheral hole of the excitation coil and slides upon receiving the magnetic attraction force;
A movable contact holder disposed on the plunger and provided with a pair of movable contacts;
A pair of fixed contact holders arranged to face the movable contact holder, each provided with a fixed contact facing the movable contact;
A case for accommodating the movable contact holder and the fixed contact holder;
The movable holder includes an interrupted state in which the pair of movable contacts are retracted from the pair of fixed contacts, and a pair of the movable contacts in contact with the pair of fixed contacts. It is configured to form a contact state in which current flows from one fixed contact holder to the other fixed contact holder,
In the DC electromagnetic relay configured so that one of the shut-off state and the contact state is formed by sliding the plunger by the magnetic attractive force, and the other is formed by a spring.
The positive fixed contact disposed on the one fixed contact holder forms a curved first curved outer peripheral portion on the outer periphery of the contact surface, and the flat outer shape is fixed on the positive fixed side of the pair of movable contacts. The outer contour of the negative movable contact facing the contact is larger than the planar outer shape, and the contour of the planar outer contour of the negative movable contact is opposed to the outer periphery of the first curved surface.
The plus side movable contact facing the minus side fixed contact disposed on the other fixed contact holder of the pair of movable contacts forms a curved second curved outer peripheral portion on the outer periphery of the contact surface, and A DC electromagnetic relay characterized in that a planar outer shape is made larger than a planar outer shape of the minus side fixed contact, and a contour line of the planar outer shape of the minus side fixed contact is opposed to the outer peripheral portion of the second curved surface. 2. The contact surface of the positive fixed contact according to claim 1, wherein an inner portion of the outer peripheral portion of the first curved surface is formed flat, and a contact surface of the negative movable contact is formed flat. ,
The contact surface of the plus side movable contact is formed in a flat shape on the inner side of the outer peripheral portion of the second curved surface, and the contact surface of the minus side fixed contact is formed in a flat shape. DC electromagnetic relay. In Claim 1 or 2, the movable contact holder has a slide reference part on one side surface orthogonal to the slide direction,
The case has a guide reference portion that guides the slide of the slide reference portion along the slide direction on one inner peripheral surface thereof,
The slide reference portion is configured to be guided by the guide reference portion only when the minus side movable contact in the movable contact holder is opposed to the plus side fixed contact in the one fixed contact holder. DC electromagnetic relay characterized by that.

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