JP2002313203A - Electromagnetic relay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic relay having proper cutting an arc, in spite of a movable contact supporting body bounding, when it hits a stopper. SOLUTION: (1) For the electromagnetic relay 10 forming an arc-cutting magnetic field between a fixed contact 16 and a movable contact 17, the strength of the magnetic field is made stronger than the strength making the arc 28 move from the contacting position to the arc cutting position, before the movable contact support body 18 hits the stopper 29, when the electromagnetic relay is disconnected. (2) The electromagnetic relay is a both-side cutting plunger type electromagnetic relay. (3) The electromagnetic relay is use for an electric power system for driving an electric vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic relay having improved cutoff characteristics.

[0002]

2. Description of the Related Art Japanese Patent Laying-Open No. 7-235248 discloses the structure of a typical conventional double-cut type plunger type electromagnetic relay having left and right terminal mounting portions. The conventional double-cut type plunger-type electromagnetic relay has left and right fixed contacts and left and right movable contacts that come into contact with and separate from the fixed contacts, and the left and right movable contacts are formed on the left and right portions of one movable contact support. It is supported by. The movable contact support is biased toward the plunger by a spring wound around a stopper on the opposite side of the movable contact support from the plunger. When the coil is energized, the plunger is attracted to the fixed core by the electromagnetic force generated in the coil. At this time, the movable contact support pressed against the plunger by the spring also moves to the fixed contact side, and the movable contact contacts the fixed contact. The electromagnetic relay connects. When the power to the coil is turned off, the plunger is moved away from the fixed core by the return spring, and at this time, the movable contact support is also pushed by the plunger and moves in the direction away from the fixed contact, so that the movable contact separates from the fixed contact, The electromagnetic relay is shut off.
When the movable contact is in contact with the fixed contact, current flows from one of the left and right fixed contacts to the corresponding one of the movable contacts, from one movable contact to the other movable contact through the movable contact support, and to the other. From the movable contact to the other fixed contact corresponding thereto, and the electromagnetic relay is connected. When the left and right movable contacts separate from the corresponding left and right fixed contacts, the electromagnetic relay is shut off. When the electromagnetic relay shifts from the connected state to the cutoff state, an arc is generated between the fixed contact and the movable contact moving in a direction away from the fixed contact, and current flows through the electromagnetic relay while the arc is present. Relays are not interrupted. Conventionally, the N pole and S pole of the permanent magnet are arranged at a position sandwiching the space between the fixed contact and the movable contact in the direction orthogonal to the direction connecting the fixed contact and the movable contact in order to improve the breaking characteristics of the electromagnetic relay Then, a magnetic force is applied to the arc in a direction orthogonal to the arc, a Lorentz force is applied to the arc in a direction according to Fleming's left hand rule, and the arc is moved from the contact portion to an arc runner curved at the left and right outer ends of the movable contact support, The arc length is increased so that the arc can be cut smoothly.

[0003]

However, in the conventional double-cut type plunger-type electromagnetic relay, when the electromagnetic relay shifts from a state in which the contacts are connected to a state in which the contacts are disconnected, the return spring biases the electromagnetic relay away from the fixed contact. When the moving movable contact support hits the stopper, it bounces to the fixed contact side, the movable contact temporarily approaches the fixed contact, the arc returns from the arc runner to the movable contact, and the arc breaks worse, that is, cutoff The problem that the property was not good occurred. SUMMARY OF THE INVENTION An object of the present invention is to provide an electromagnetic relay in which the arc can be easily cut, and therefore has good cut-off performance, regardless of whether the movable contact support bounces when hitting the stopper.

[0004]

The present invention to achieve the above object is as follows. (1) In an electromagnetic relay in which a magnetic field for arc cutting is formed between a fixed contact and a movable contact, the strength of the magnetic field is determined by moving the arc to a contact position before the movable contact support supporting the movable contact hits the stopper when the electromagnetic relay is cut off. An electromagnetic relay characterized in that it has a strength at which the arc is moved to a position at which the arc is cut off. (2) The electromagnetic relay according to (1), wherein the electromagnetic relay is a double-cut plunger type electromagnetic relay. (3) The electromagnetic relay according to (1), wherein the electromagnetic relay is an electromagnetic relay used in a power supply system for driving an electric vehicle.

In the electromagnetic relays of (1), (2) and (3), the magnetic field strength is moved from the contact position to a position where the arc is cut off before the movable contact support hits the stopper when the electromagnetic relay is cut off. Since the strength was not less than the strength, the arc was already cut when the movable contact support hit the stopper when the electromagnetic relay was cut off. Once the arc breaks, the arc is not regenerated even if the movable contact approaches the fixed contact, so that the arc is not regenerated even if the movable contact support hits the stopper and bounces. Therefore, the arc breaks well, and the breaking characteristics of the electromagnetic relay are improved.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the electromagnetic relay according to the present invention will be described below with reference to FIGS. First, the general structure and operation of the electromagnetic relay 10 according to the embodiment of the present invention will be described. The electromagnetic relay 10 according to the embodiment of the present invention is of a plunger type (a method in which a movable contact is opened and closed by a plunger).
In particular, it is a plunger type electromagnetic relay of a double-cut type (a type having contacts on both the left and right sides with respect to the center line of the electromagnetic relay). The electromagnetic relay 10 is provided, for example, in a circuit that connects a battery and an inverter of a power supply system for driving a hybrid vehicle, but the use destination is not limited to this.

The electromagnetic relay 10 includes a coil assembly 3
The contact chamber assembly 11 is assembled on the upper side of the housing. The contact chamber assembly 11 includes the coil assembly 3
A contact pole 15 is formed on the top of the pole 13 in cooperation with the resin pole 13 having an upper wall and a side wall and disposed on the pole 13 with a resin pole 13 disposed via a packing 12. A contact chamber cover 14 made of resin, a fixed contact 16 fixedly arranged in the contact chamber 15, and approaching and separating from the fixed contact 16 arranged in the contact chamber 15 (in FIG. The movable contact 17 for turning on and off the electric connection, and the movable contact 17 are supported on both left and right sides of the electromagnetic relay center line (including the case of integrally forming) and fixed by the return spring 38 of the coil assembly 30 when the electromagnetic relay is cut off. A movable contact support 18 made of a conductive material (for example, copper) pushed in a direction (upward in FIG. 1) away from the fixed core 34 by a plunger 35 urged away from the core 34; The plunger 35 across the support 18
A spring 19 which is disposed on the opposite side and is wrapped around a stopper 29 and constantly urges the movable contact support 18 toward the plunger 35 (downward in the figure); and a contact 20 made of a conductive material and connected to the fixed contact 16. , Contact 20
And a terminal 21 made of a conductive material connected to the terminal 21.
The fixed contact 16 and the movable contact 17 are provided on the left and right sides of the center line of the electromagnetic relay with respect to the center line of the electromagnetic relay, respectively, and constitute a double-cut type electromagnetic relay. The contacts 20 and the terminals 21 are also provided on the left and right sides of the center line of the electromagnetic relay. The cable side terminal is connected to the terminal 21 and fastened to the terminal 21.

The movable contact support 18 is formed of a single member extending left and right with respect to the center line of the electromagnetic relay, and has an arc runner 22 which is bent at both ends in a direction away from the fixed contact 16 (upward in FIG. 1). Then, the central portion abuts on the upper end of the plunger 35 of the coil assembly 30 (the upper end of the plunger rod 36 constituting a part of the plunger 35), is pressed against the plunger 35 from above by the spring 19, and is supported at the central portion. ing. The arc runner 22 is not in contact with the contact chamber cover 14 where the arc runner 22 faces.

In the contact chamber cover 14, N-pole and S-pole permanent magnets 25 oppose each other with a space between the fixed contact 16 and the movable contact 17 when the contacts are opened. When an arc is generated between the fixed contact 16 and the movable contact 17 when the contact is opened when the electromagnetic relay is cut off, a Lorentz force is applied to the arc 28 in a direction in accordance with Fleming's left hand rule. Is moved to the arc runner 22 side (arc 28 'in FIG. 1) by Lorentz force, and the arc length is extended to make the arc 28 easier to cut.

The coil assembly 30 includes a cylindrical yoke 31 having a bottom and a bobbin 3 installed in the yoke 31.
2, a coil 33 wound on the outer periphery of the bobbin 32, a fixed core 34 disposed on the inner periphery of the bobbin 32, and a fixed core 3
A plunger 35 arranged to be vertically movable above 4;
A plunger rod 36 for transmitting the vertical movement of the plunger 35 to the movable contact support 18 (the plunger rod 36 constitutes a part of the plunger 35), and the yoke 31, the fixed core 34, and the plunger 35 cooperate with each other when the coil is energized. A plate 37 that forms a circuit; a return spring 38 that is disposed between the fixed core 34 and the plunger 35 and constantly urges the plunger 35 upward; and a low spring that allows a low-voltage DC current (for example, 12 V) to flow through the coil 33. Voltage terminals,
Having. The yoke 31 and the plate 37 form a case 39 that covers the coil 33. This structure constitutes a plunger type electromagnetic relay.

The operation of the general components of the electromagnetic relay will be described. When a low voltage (for example, 12 V) DC current flows through the coil 33, a magnetic circuit is formed in the yoke 31, the plate 37, the fixed core 34, and the plunger 35, and the plunger 35 is moved with the compression of the return spring 38. The movable contact support 18, which is magnetically attracted to 34 and pressed against the plunger 35 by the spring 19, also moves downward, the movable contact 17 hits the fixed contact 16, and a high voltage current flows between the terminals 21. Movable contact 17
Is in contact with the fixed contact 16, a high-voltage current (for example, 250 V) flows from one terminal 21 to one fixed contact 16 via one contact 20, and from one fixed contact 16 to the corresponding one Flows from one movable contact 17 through the movable contact support 18 to the other movable contact 17, flows from the other movable contact 17 to the corresponding other fixed contact 16, and flows into the other fixed contact. 16 to the other terminal 21 via the other contact 20.

When the low-voltage direct current of the coil 33 is cut off, the magnetic circuit disappears, and the movable contact support 18 moves upward by the bias of the return spring 38, and the movable contact 1
7 is separated from the fixed contact 16 and the high voltage current between the terminals 21 is cut off. When the movable contact support 18 moves upward, the spring 19 bends on the compression side and stops against the stopper 29. When the movable contact support 18 hits the stopper 29, it may bounce due to the rebound and the pressing force of the spring 19, and when it does, the movable contact 17 approaches the fixed contact 16 temporarily, and the following configuration of the present invention is adopted. If there is no arc, the arc 28 moving from the point of contact to the arc runner 22 will return to the point between the points of contact again, making it difficult for the arc 28 to be cut.

Next, the configuration and operation of a portion unique to the present invention will be described. In the present invention, in the electromagnetic relay 10 in which a magnetic field for turning off the arc 28 is formed between the fixed contact 16 and the movable contact 17, the magnetic field strength of the permanent magnet 25 is such that the movable contact 17 supports the movable contact 17 when the electromagnetic relay 10 is shut off. The strength is set to move the arc 28 from the contact position A to the position B where the arc is cut before the support 18 hits the stopper 29. Since the moving speed of the arc 28 increases as the magnetic field strength of the permanent magnet 25 increases,
The magnetic field strength of the permanent magnet is gradually changed to a stronger one, so that even when the movable contact support 18 bounces, a good arc break (interruptability of the electromagnetic relay) can be obtained. By selecting 25, the magnetic field strength can be easily set to a desired magnetic field strength.

With regard to the operation of the electromagnetic relay 10 of the present invention, the magnetic field strength of the permanent magnet 25 is changed by moving the arc 28 from the contact position to the position where the arc is cut off before the movable contact support 18 hits the stopper 29 when the electromagnetic relay is cut off. Fixed contact 1 when the electromagnetic relay is cut off.
Movable contact support 18 moving in a direction away from 6
When the strikes the stopper 29, the arc 28 has already been cut. Once the arc 28 is cut off, even if the movable contact 17 approaches the fixed contact 16, the arc 28 is not regenerated. Therefore, even if the movable contact support 18 hits the stopper 29 and gets close to the fixed contact 16, the broken arc. 28 does not regenerate, and the arc regenerative does not connect the electromagnetic relay. Therefore, even if the movable contact support 18 hits the stopper 29 and bounces, the arc 28 is well cut and the electromagnetic relay 1
0 is improved.

[0015]

According to the electromagnetic relay of the first, second and third aspects, the magnetic field strength is determined by the position at which the arc is cut from the contact position before the movable contact support hits the stopper when the electromagnetic relay is cut off. When the movable contact support hits the stopper when the electromagnetic relay is cut off, the arc has already been cut. Once the arc breaks, the arc is not regenerated even if the movable contact approaches the fixed contact, so that the arc is not regenerated even if the movable contact support hits the stopper and bounces. Therefore, the arc breaks well, and the breaking characteristics of the electromagnetic relay are improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an electromagnetic relay according to an embodiment of the present invention.

FIG. 2 is a plan view of the electromagnetic relay according to the embodiment of the present invention.

FIG. 3 is a front view of the vicinity of a contact and an arc of the electromagnetic relay according to the embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 electromagnetic relay 11 contact chamber assembly 12 packing 13 pole (lower casing) 14 contact chamber cover (upper casing) 15 contact chamber 16 fixed contact 17 movable contact 18 movable contact support 19 spring 20 contact 21 terminal bolt 22 arcrunner 25 permanent magnet 28 , 28 'arc 29 stopper 30 coil assembly 31 yoke 32 bobbin 33 coil 34 fixed core 35 plunger 36 plunger rod 37 plate 38 return spring 39 case

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazunori Yamada 14 Iwatani, Shimowakaku-cho, Nishio-shi, Aichi F-term in Japan Automobile Parts Research Laboratory (reference) 5G027 AA03 BB01 BB03

Claims (3)

[Claims] 1. An electromagnetic relay in which a magnetic field for arc cutting is formed between a fixed contact and a movable contact, wherein the magnetic field strength is
An electromagnetic relay characterized in that the arc has a strength to move the arc from the contact position to a position at which the arc is cut off before the movable contact support supporting the movable contact hits the stopper when the electromagnetic relay is cut off. 2. The electromagnetic relay according to claim 1, wherein said electromagnetic relay is a double-sided plunger type electromagnetic relay. 3. The electromagnetic relay according to claim 1, wherein the electromagnetic relay is an electromagnetic relay used in a power supply system for driving an electric vehicle.