JP2007109470A - Electromagnetic relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize operation to open a contact, and improve shut off performance and welding resistance of the contact in an electromagnetic relay equipped with a diaphragm 8. <P>SOLUTION: A plunger 15 has a recessed part 21 having a circular cross section formed in the central part on the end surface on an anti-iron core side, and one end part of a bush 5 is slidably inserted into the recessed part 21. When the plunger 15 is moved by being sucked with a fixed iron core 13, a moving contact 4 abuts on a set of fixed contacts 3, only the plunger 15 is singly moved with the bush 5 left, and movement of the bush 5 is made small. When the plunger 15 is pushed back in the anti-iron core direction, resistance caused by the deformation of the diaphragm 8 and air resistance caused by volume change of a contact chamber 7 are not applied until the plunger 15 collides with the bush 5, and high shut off performance can be kept without dropping the moving speed of the plunger 15. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electromagnetic relay that closes a contact by attracting a plunger with an electromagnet.

Conventionally, an electromagnetic relay 100 shown in FIG. 5 is known (see Patent Document 1).
The electromagnetic relay 100 includes a set of fixed contacts 110 connected to an electric circuit, a movable contact 120 that connects and disconnects between the set of fixed contacts 110, and magnetizes the fixed iron core 140 when the electromagnetic coil 130 is energized. 150 includes a solenoid 160 that sucks 150.
When energization of the electromagnetic coil 130 is stopped, the plunger 150 is pushed back in the anti-fixed iron core direction (upward direction in the drawing) by the return spring 170, so that the movable contact 120 is connected via the bush 180 fixed to the plunger 150. Is pushed upward in the figure and is pulled away from the set of fixed contacts 110 to open an electric circuit.
Further, when the electromagnetic coil 130 is energized and the fixed iron core 140 is magnetized, the plunger 150 is attracted to the fixed iron core 140 and moves downward in the figure against the urging force of the return spring 170, and therefore the contact pressure spring 190. The movable contact 120 biased by the contact with the set of fixed contacts 110 closes the electric circuit.

In the electromagnetic relay 100 described above, for example, abrasion powder is generated when the movable contact 120 repeatedly collides with the set of fixed contacts 110 or the current is interrupted, and the abrasion powder is generated inside the solenoid 160, particularly the plunger 150. Intrusion into the sliding gap may cause malfunction of the plunger 150. In addition, when foreign matter enters the inside of the solenoid 160 during assembly or the like and the foreign matter enters the contact chamber 200 in which the pair of fixed contact 110 and movable contact 120 is arranged, there is a risk of causing contact failure between the contacts. .
Therefore, as shown in FIG. 6, the contact chamber 200 and the interior of the solenoid 160 (the winding chamber in which the electromagnetic coil 130 and the like are arranged) are separated by a diaphragm 210, and the wear powder on the contact chamber 200 side is separated from the winding chamber side. There is known a technique for preventing a foreign matter on the winding chamber side from entering the contact chamber 200 side.
JP 2005-63741 A

However, in the known technique using the diaphragm 210, the central portion of the diaphragm 210 is fixed to the bush 180, and the bush 180 is fixed to the plunger 150. Therefore, the diaphragm 210 must be deformed by the moving stroke of the plunger 150. I must. In this case, for example, when the electromagnetic coil 130 is switched from ON to OFF, that is, when the movable contact 120 is disconnected from the set of fixed contacts 110, air resistance due to volume change on the contact chamber 200 side and deformation of the diaphragm 210 are caused. Since the resistance is large, the moving speed of the plunger 150 decreases. Due to the decrease in the speed of the plunger 150, the impact force when the bush 180 collides with the movable contact 120 is reduced. As a result, the behavior of the movable contact 120 when the contact is opened becomes unstable, and there is a possibility that the breaking performance and the contact welding resistance are deteriorated.
The present invention has been made based on the above circumstances, and its purpose is to stabilize the behavior of the movable contact when the contact is opened in an electromagnetic relay including a diaphragm that separates the contact chamber and the winding chamber. The purpose is to improve the breaking performance and the welding resistance of the contacts.

(Invention of Claim 1)
The present invention includes a solenoid that magnetizes a fixed iron core by energizing an electromagnetic coil and attracts a plunger, a set of fixed contacts connected to an electric circuit, and a predetermined set on the side opposite to the plunger relative to the set of fixed contacts. A movable contact that is arranged with a gap and is driven by a solenoid to intermittently connect between a set of fixed contacts, a contact pressure spring that biases the movable contact toward the set of fixed contacts, and a set of fixed A diaphragm that separates the contact chamber in which the contact and the movable contact are arranged and the internal space of the solenoid, and a bush that is inserted through the center of the diaphragm and fixed to the diaphragm and disposed between the plunger and the movable contact. The electromagnetic relay is provided, and the bush is connected while the plunger is attracted to the fixed iron core and moved while the movable contact moves through the gap and contacts the set of fixed contacts. Receiving the reaction force of the pressure spring, it moves together with the movable contact, and the plunger moves independently from the bush until the movable contact contacts the set of fixed contacts and then collides with the fixed iron core. It is characterized by that.

According to said structure, when a plunger is attracted | sucked and moved to the magnetized fixed iron core, after a movable contact contact | abuts to a set of fixed contacts, a plunger separates from a bush and moves independently. In other words, after the movable contact contacts the set of fixed contacts, the bush does not move further with the plunger and stops separately from the plunger, so that the amount of deformation of the diaphragm fixed to the bush is small. Get smaller.
After that, when the plunger is pushed back toward the anti-fixed iron core by stopping energization of the electromagnetic coil, it does not receive the resistance due to the deformation of the diaphragm and the air resistance due to the volume change of the contact chamber until the plunger collides with the bush. Therefore, the moving speed of the plunger does not decrease due to the influence of the diaphragm.

As a result, compared with the above-mentioned known technology, the impact force when the bush collides with the movable contact is large, and the behavior of the movable contact when the contact is opened is stable, so that a good breaking performance can be maintained and the contact resistance of the contact can be maintained. The weldability is also improved.
Furthermore, since the amount of deformation of the diaphragm is small, the deterioration of the diaphragm is reduced and the life of the diaphragm is improved. In addition, since the amount of deformation of the diaphragm is small, the thickness of the diaphragm can be adjusted appropriately. For example, by making the diaphragm thicker than before, contact bounce that occurs when the movable contact and the fixed contact collide can be suppressed due to the damper effect of the diaphragm, so that the contact life and welding resistance are improved.

(Invention of Claim 2)
2. The electromagnetic relay according to claim 1, wherein the plunger has a recess formed in the center portion of the end surface on the anti-fixed iron core side, and the bush is slidably inserted in the recess formed in the end of the anti-movable contact side. It is characterized by being.
According to said structure, since the edge part of a bush is inserted in the recessed part of a plunger, the attitude | position of a bush can be hold | maintained, Therefore Even if it has the structure which isolate | separated the bush and the plunger, the opening / closing operation | movement of a stable contact is realizable.

(Invention of Claim 3)
3. The electromagnetic relay according to claim 1, wherein a contact cover fixed to the solenoid to form a contact chamber, one end side is connected to the electromagnetic coil inside the contact cover, and the other end side is taken out of the contact cover. And a packing that is disposed around the terminal inside the contact cover and seals between the contact cover and the terminal, and the packing is provided integrally with the diaphragm.
Thereby, since the number of parts can be reduced, assembly workability is improved.

  The best mode for carrying out the present invention will be described in detail with reference to the following examples.

FIG. 1 is a cross-sectional view of the electromagnetic relay 1.
The electromagnetic relay 1 shown in the first embodiment includes a set of fixed contacts 3 fixed to the contact cover 2, a movable contact 4 that is movable facing the set of fixed contacts 3, and the movable contact 4. A movable bush 5, a solenoid 6 that drives the movable contact 4 through the bush 5, and a diaphragm 8 that defines a contact chamber 7 in which the pair of fixed contact 3 and movable contact 4 are disposed inside the contact cover 2. Etc.
The set of fixed contacts 3 is connected to an electric circuit (not shown) via two terminal bolts 9 and 10 attached to the contact cover 2.
The movable contact 4 is arranged between a stopper portion 11 provided inside the contact cover 2 and a set of fixed contacts 3, and a set of fixed contacts by a contact pressure spring 12 arranged around the stopper portion 11. It is energized towards 3.

The solenoid 6 magnetizes the fixed iron core 13 when energized to form an electromagnet, the plunger 15 attracted to the magnetized fixed iron core 13, and the anti-fixed iron core when the attracting force of the electromagnet disappears. It comprises a return spring 16 and the like for pushing back in the direction (upward in FIG. 1).
The electromagnetic coil 14 is wound around the bobbin 17, accommodated inside the yoke 18, and energized from the outside through a terminal 19 (see FIG. 4) taken out of the contact cover 2.
The yoke 18 is provided in a cup shape having a bottom surface, forms a part of the magnetic circuit, and also serves as an outer case of the solenoid 6.
On the opening side of the yoke 18, a ground plate 20 (part of a magnetic circuit), which is a ferromagnetic material, is insert-molded on a resin bobbin 17.

The fixed iron core 13 is disposed inside the electromagnetic coil 14, and the end surface (the lower surface in the drawing) on the side opposite to the plunger is in contact with and fixed to the bottom surface of the yoke 18.
The plunger 15 is disposed inside the electromagnetic coil 14 so as to face the fixed iron core 13, is urged toward the anti-fixed iron core by receiving the reaction force of the return spring 16, and the fixed iron core 13 is magnetized by energizing the electromagnetic coil 14. Then, the fixed iron core 13 is attracted and moved against the urging force of the return spring 16. A concave portion 21 having a circular cross section is formed in the center portion of the end surface on the side opposite to the fixed core (upper side in the drawing) of the plunger 15, and one end side end portion of the bush 5 having a columnar shape is slidably inserted into the concave portion 21. ing.

The bush 5 is disposed between the plunger 15 and the movable contact 4, and is urged toward the anti-fixed iron core integrally with the plunger 15 by the reaction force of the return spring 16, thereby resisting the urging force of the contact pressure spring 12. Thus, the movable contact 4 is pressed against the stopper portion 11 (see FIG. 1).
The diaphragm 8 is provided in the shape of a disk having a center hole in the central portion in the radial direction, the outer peripheral portion is closely fixed to the inner peripheral surface of the contact cover 2, and the bush 5 is inserted into the central hole. An inner peripheral portion is fixed to the bush 5. The diaphragm 8 separates the contact chamber 7 and the internal space of the solenoid 6 (referred to as a winding chamber 22), so that the wear powder on the contact chamber 7 side enters the winding chamber 22 side, or It has a function of preventing foreign matter on the winding chamber 22 side from entering the contact chamber 7 side.

Next, the operation of the electromagnetic relay 1 will be described.
When the electromagnetic coil 14 is energized and the fixed iron core 13 is magnetized, an attractive force acts between the fixed iron core 13 and the plunger 15, so that the plunger 15 acts on the fixed iron core 13 against the urging force of the return spring 16. Move by being sucked. When the plunger 15 moves to the fixed iron core 13 side, the force pressing the movable contact 4 against the stopper portion 11 via the bush 5 is released, so that the movable contact 4 that receives the reaction force of the contact pressure spring 12 is moved to the stopper portion 11. And abut against a set of fixed contacts 3 (see FIG. 2).
After the movable contact 4 comes into contact with the set of fixed contacts 3, the plunger 15 further moves independently to the fixed iron core 13 side and comes into contact with the end surface of the fixed iron core 13 and stops (see FIG. 3). Thereby, the movable contact 4 is pressed by the set of fixed contacts 3 by the reaction force of the contact pressure spring 12, and the electric circuit is closed.

  Thereafter, when the energization of the electromagnetic coil 14 is stopped and the attraction force of the electromagnet disappears, the plunger 15 is pushed back toward the anti-fixed iron core by the reaction force of the return spring 16, and the plunger 15 has a predetermined distance (clearance C). After moving and colliding with the bush 5, it further moves with the bush 5. At this time, since the impact force generated when the plunger 15 collides with the bush 5 is transmitted to the movable contact 4 via the bush 5, the movable contact 4 resists the reaction force of the contact pressure spring 12 and a set of fixed contacts. By moving away from 3, the electrical circuit is opened. After moving away from the set of fixed contacts 3, the movable contact 4 is further moved by being pushed by the bush 5 and comes into contact with the end face of the stopper portion 11 and stops (see FIG. 1).

(Effect of Example 1)
In the electromagnetic relay 1, one end of the bush 5 is slidably inserted into the recess 21 formed in the plunger 15, so that the plunger 15 is attracted to the fixed iron core 13 by energizing the electromagnetic coil 14. In this case, after the movable contact 4 comes into contact with the set of fixed contacts 3, the bush 5 does not move together with the plunger 15, and only the plunger 15 can move alone, leaving the bush 5. That is, when the plunger 15 is completely attracted to the fixed iron core 13, a clearance C (see FIG. 3) is generated between the bottom surface of the recess 21 formed in the plunger 15 and the one end side end surface of the bush 5. For this reason, compared with the known technique in which the bush 5 is fixed to the plunger 15, the amount of movement of the bush 5 is reduced by a distance corresponding to the clearance C.

  Accordingly, when the plunger 15 is pushed back in the anti-fixed iron core direction by the reaction force of the return spring 16 due to the energization stop of the electromagnetic coil 14, until the plunger 15 collides with the bush 5, the resistance due to the deformation of the diaphragm 8 and the contact Since the air resistance due to the volume change of the chamber 7 is not received, the moving speed of the plunger 15 does not decrease due to the influence of the diaphragm 8. As a result, when compared with the above-mentioned known technology, the impact force when the bush 5 collides with the movable contact 4 is increased, and the behavior of the movable contact 4 when the contact is released is stabilized, so that a good breaking performance is maintained. And the welding resistance of the contact is improved.

Further, when the movement amount of the bush 5 is reduced, the deformation amount of the diaphragm 8 fixed to the bush 5 is also reduced, so that the deterioration of the diaphragm 8 is reduced and the life of the diaphragm 8 is improved.
Furthermore, since the deformation amount of the diaphragm 8 is small, the thickness of the diaphragm 8 can be adjusted appropriately. For example, by making the thickness of the diaphragm 8 thicker than before, contact bounce that occurs when the movable contact 4 and the fixed contact 3 collide can be suppressed by the damper effect of the diaphragm 8, improving contact life and welding resistance. To do.

FIG. 4 is a cross-sectional view of the electromagnetic relay 1 according to the second embodiment.
In the electromagnetic relay 1 shown in the second embodiment, as shown in FIG. 4, a packing 23 is disposed around the terminal 19 inside the contact cover 2, and the packing 23 is provided integrally with the diaphragm 8. Features. The terminal 19 is inserted through the packing 23, one end side is taken out of the contact cover 2, and the other end side is insert-molded on the bobbin 17 and connected to the electromagnetic coil 14.
In the present embodiment, the number of parts can be reduced by integrating the packing 23 with the diaphragm 8, so that the assembly workability is improved.

(Example 1) which is sectional drawing (off state) of an electromagnetic relay. (Example 1) which is sectional drawing (in the middle of operation | movement) of an electromagnetic relay. (Example 1) which is sectional drawing (an ON state) of an electromagnetic relay. (Example 2) which is sectional drawing (an ON state) of an electromagnetic relay. It is sectional drawing (on state) of an electromagnetic relay (prior art). It is sectional drawing (on state) of the electromagnetic relay which has a diaphragm (prior art).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electromagnetic relay 2 Contact cover 3 A set of fixed contact 4 Movable contact 5 Bush 6 Solenoid 7 Contact chamber 8 Diaphragm 12 Contact pressure spring 13 Fixed iron core 14 Electromagnetic coil 15 Plunger 19 Terminal 21 Recess 22 formed in the plunger 22 Winding chamber 23 Packing

Claims (3)

A solenoid that magnetizes the fixed iron core by energizing the electromagnetic coil and attracts the plunger;
A set of fixed contacts connected to the electrical circuit;
A movable contact that is arranged with a predetermined gap on the side opposite to the plunger with respect to the set of fixed contacts, and is driven by the solenoid to intermittently connect between the set of fixed contacts,
A contact pressure spring that biases the movable contact toward the set of fixed contacts;
A diaphragm that separates a contact chamber in which the set of fixed contacts and the movable contact are disposed, and an internal space of the solenoid;
An electromagnetic relay comprising a bush inserted through the center of the diaphragm and fixed to the diaphragm, and disposed between the plunger and the movable contact,
The bush receives the reaction force of the contact pressure spring while the movable contact moves through the gap and contacts the set of fixed contacts when the plunger is moved by being attracted to the fixed iron core. Move together with the movable contact,
The plunger moves independently from the bush until the plunger contacts the fixed iron core after the movable contact contacts the set of fixed contacts. The electromagnetic relay according to claim 1,
The plunger is formed with a recess in the center portion of the end surface on the side opposite to the fixed core,
The bush is slidably inserted into a recess formed in the plunger at an end on the side opposite to the movable contact. The electromagnetic relay according to claim 1 or 2,
A contact cover fixed to the solenoid to form the contact chamber;
A terminal having one end connected to the electromagnetic coil inside the contact cover and the other end taken out from the contact cover;
It is arranged around the terminal inside the contact cover, and has a packing for sealing between the contact cover and the terminal, and the packing is provided integrally with the diaphragm. Electromagnetic relay.

Images