JPH06260070A - Electromagnetic relay - Google Patents

Abstract

PURPOSE:To provide an electromagnetic relay capable of increasing the contact time difference between arc contacts and low-resistance contacts, capable of prolonging the contact life, and not enlarged so much. CONSTITUTION:When the first and second moving members 17, 18 are attracted to the opposite piece 12a of a yoke 10, both moving members 17, 18 are integrally operated until the first moving member 17 faces the first contact section 12c, and arc contacts 3, 7 are brought into contact. After the first moving member 17 is brought into contact with the first contact section 12c, only the second moving member 18 is operated until it is brought into contact with the second contact section 12d, and low-resistance contacts 4, 9 are brought into contact.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic relay suitable for opening and closing an electric circuit to which a lighting device through which a large inrush current flows is connected.

[0002]

2. Description of the Related Art In a general contact device such as an electromagnetic relay, a movable contact provided in a movable contact spring is brought into contact with and separated from a fixed contact provided in a fixed contact plate. In this case, if opening / closing of the electric line to which the lighting equipment is connected, the electric line is
Since it is a load, a large inrush current flows as shown in FIG. As a result, an arc is generated between the contacts, and welding is likely to occur.Thus, it is desirable to use Sn-based oxide contacts or tungsten contacts to improve the welding resistance, but then the contact resistance of the contacts increases and the temperature rises. The rise is a problem. That is, there is a trade-off between increasing the welding resistance and suppressing the temperature rise of the contacts.

Therefore, in order to improve the anti-welding performance and suppress the temperature rise of the contact, various proposals have been proposed in which an arc contact and a low resistance contact are used in accordance with the respective purposes (for example, Japanese Patent Laid-Open Publication No. Sho. 61-233919, JP 62-7113
7, JP-A-62-71138, etc.). These are used when an inrush current is generated by contacting the arc contact first and then the low resistance contact, and then opening the low resistance contact first and then the arc contact. Is made to flow to the contact for arc, and when it becomes a steady current, it is made to flow to the low resistance contact.

[0004]

The above-mentioned combination use of the arc contact and the low resistance contact gives good results when the change in current and the time difference operation of both contacts are matched. Matching is not always easy. That is, since the difference in contact time between the arc contact and the low resistance contact is structurally reduced, the difference in contact time is further reduced due to variations in component dimensions, or even when there is no variation, the time for the inrush current to flow is reduced. When it is long, there is a risk that an inrush current will flow through the low resistance contact and this will lead to welding. Moreover, these are difficult to apply to electromagnetic relays, which are complicated in structure or large in size and thus are strongly required to be downsized.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make the contact time difference between the arc contact and the low resistance contact large so that the contact life can be lengthened and not so large. In the provision of electromagnetic relay.

[0006]

In order to solve such a problem, an electromagnetic relay according to the present invention has a fixed contact plate provided with arc contacts and low resistance contacts, and a first contact provided with arc contacts.
A movable contact spring, a second movable contact spring provided with a low resistance contact, a movable contact plate in which the base ends of both movable contact springs are fixed so that the arc contacts and the low resistance contacts come into contact with each other, and a magnetic path A yoke having first and second armatures that form a part and determine two different operating positions, a coil that causes a magnetic flux to flow through the yoke, and a remaining part of the magnetic path are formed.
A first movable contact spring for moving the first movable contact spring into and out of contact with
A movable member; and a second movable member that forms the remaining portion of the magnetic path and that is in contact with and separated from the second armature portion and that drives the second movable contact spring. When the first movable member contacts the first armature portion, both movable members operate integrally, and after the first movable member contacts the first armature portion, the first movable member contacts the first armature portion. Only the two movable members are configured to operate until they contact the second armature.

More specifically, both movable members are of a plunger type that reciprocates in the inner space of the coil, the first movable member is cylindrical with an armature, and most of the second movable member is the first.
The movable member is formed into a rod shape having an armature portion housed inside.

Further, it is preferable to provide a buffer member on the first contact portion. Further, it is preferable that both movable contact springs are arranged in parallel so as to face each other, and an insulating member is interposed between both movable contact springs.

[0009]

According to this structure, until the first movable member comes into contact with the first armature, the movable members are attracted to each other by the magnetic attraction force and operate integrally, so that the arc contact is made first. The contact is made, and then the second movable member is attracted to the second armature to bring the low resistance contact into contact, so that the contact time difference between the arc contact and the low resistance contact can be made relatively large.

Further, when the buffer member is provided at the first armature, the movable members can be decelerated in the latter half of the operation, the contact time difference between the arc contact and the low resistance contact can be made larger, and the collision noise can be reduced. .

Further, by interposing an insulating member between the movable contact springs, it is possible to reduce the influence of the arc on the low resistance contact side.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

Reference numeral 1 is a base on which various members to be described later are placed,
By covering and fixing the cover (not shown), the housing is constructed together with the cover. 1a is a fixed contact plate,
1b is a support hole for fixing the movable contact plate through, 1c, 1c
Is a yoke positioning protrusion, 1d is a spring support wall, and 1e is an insulating wall.

Reference numeral 2 denotes a fixed contact plate, which has a U-shaped portion composed of opposing pieces 2a and 2b and a connecting piece 2c, and a terminal portion 2d which is connected from the center side end of the connecting piece 2c. The arc contact 3 is placed on one of the facing pieces 2a with the contact surface facing inward, and the other facing piece 2b.
The low resistance contacts 4 are fixed to each of the contacts with the contact surface facing outward. The arc contact 3 is made of a contact material having excellent welding resistance such as Sn-based oxide contact or tungsten contact, and the low resistance contact 4 is made of a low resistance contact material such as silver or silver alloy. In this fixed contact plate 2, the terminal portion 2d is fixed through the support hole 1a. In addition, the fixed contact plate 2
May be simultaneously molded.

Reference numeral 5 denotes a movable contact plate, which has a U-shaped portion composed of opposing pieces 5a and 5b and a connecting piece 5c, and a terminal portion 5d connected from the center side end of the connecting piece 5c. 6 is the first movable contact spring,
An arc contact 7 that contacts and separates from the arc contact 3 is provided at the tip. 8 is the second movable contact spring, which has a low resistance contact at the tip 4
A low resistance contact 9 that contacts and separates is provided. In this case, the second
The spring constant of the movable contact spring 8 is made smaller than that of the first movable contact spring 6. Both of these movable contact springs 6 and 8 are fixed at their base ends to the opposing pieces 5a and 5b of the movable contact plate 5 so that the arc contacts 3 and 7 and the low resistance contacts 4 and 9 come into contact with and separate from each other.
Therefore, these are juxtaposed so as to face each other. In the movable contact plate 5, the terminal portion 5d is fixed through the support hole 1b.
In this case, the insulating wall 1e of the base 1 is interposed between the two movable contact springs 6 and 8, and thus the insulating member is interposed between the two movable contact springs. The movable contact plate 5 may be simultaneously formed on the base 1.

Reference numeral 10 denotes a yoke, which is a U-shaped inner yoke piece 11,
The outer yoke piece 12 and the permanent magnet 13 sandwiched between the outer yoke pieces 12 form a part of the magnetic path. In the inner yoke piece 11, the outer surfaces of the facing pieces 11a and 11b serve as a contact pole portion that attracts a movable member described later. The outer yoke piece 12 is larger than the inner yoke piece 11, and the inner side surfaces of the facing pieces 12a and 12b serve as a contact portion that attracts a movable member described later. Therefore, between the opposing pieces 11a and 12a, 11b.12
Between b is a gap corresponding to the amount of displacement of the movable member.
Also, what is important in the yoke 10 is that the outer yoke piece is used in order to determine two different operating positions of the movable member, which will be described later.
The first and second armature portions 12c, 12d are provided on one of the facing pieces 12a of 12
Is to have. In this embodiment, the cushioning member 14 extending from the root to about half the height is attached to one of the facing pieces 12a, and the surface thereof is covered with the first contact piece 12c and the facing piece 12a.
The inner surface of a is the second armature portion 12d. Alternatively, the facing piece 12a may be stepped to form two armature portions.

Reference numeral 15 denotes a coil frame, which has a tubular portion 15a and collar portions 15b and 15c at both ends thereof, and a coil 16 for flowing a magnetic flux to the yoke 10 is wound around the tubular portion 15a. One collar part
A coil terminal 16a is formed at the same time on 15b, and recesses 15d, 15d for positioning the inner yoke piece 11 are formed at the inner ends of the flanges 15b, 15c.

Reference numeral 17 denotes a first movable member, which has a cylindrical shape that reciprocates in the inner space of the coil 16, that is, the coil frame 15, and is sandwiched between the opposing pieces 11a, 12a and 11b.12b at both ends thereof. It has the armature pieces 17a and 17b located. The two armature pieces 17a and 17b are
The respective contact pieces are alternately contacted and separated from each other, and in particular one contact piece 17a is arranged to contact and separate from the first contact portion 12c of the outer yoke piece 12. In addition, one armature piece 17a has a first
Drive piece 17 made of insulating material for driving the movable contact spring 6
c is attached. 18 is the second movable member, most of which is the first
The armature piece 18 is formed in a rod shape that is housed inside the movable member and reciprocates, and is located at one end of the pole piece between the opposing pieces 11a and 12a.
have a. The contact piece 18a is alternately brought into contact with and separated from the facing pieces 11a and 12a, and particularly, is brought into contact with and separated from the second contact portion 12d of the outer yoke piece 12. Also this armature piece 18a
A drive piece 18c made of an insulating material for driving the second movable contact spring 8 is attached to this. Reference numeral 19 is a coil spring for cushioning the first movable member 17, and is attached to the spring support wall 1d.

Both movable members 17 and 18 are of the plunger type that reciprocates in the inner space of the coil frame 16 as described above, and thus form a magnetic path with the yoke 10 and one of the armature pieces 17a and 18a.
Are located in a polymerized manner. As a result, when the coil 16 is energized and a magnetic flux flows in the magnetic path, the two contact pole pieces 17a and 18a attract each other and a specific section (the contact pole piece 17a contacts the first armature portion 12c and then the contact piece 18a is contacted). Is an area where is polarized to the second armature part 12d)
It works together except. That is, when the coil 16 is energized with both movable members 17 and 18 in the return position (contact open state) as shown in FIG. 1, both movable members 17 and 18 move integrally to the left in the figure. First, the driving piece 17c drives the first movable contact spring 6 to bring the arc contacts 3 and 7 into contact with each other, and eventually the armature piece 17a contacts the first armature portion 12c so that the first movable member 17 moves. Stop. Next, the armature piece 18a is connected to the second armature portion 12
Only the second movable member 18 is further moved by being attracted by d, and first the driving piece 18c drives the second moving contact spring 8 to bring the low resistance contacts 4 and 9 into contact with each other, and eventually the contact piece 18a moves to the second contact piece. Armature part 12
The second movable member 18 also stops by contacting with d.

FIGS. 3A, 3B and 3C schematically show the construction and show the operation thereof. In (a), as in FIG. 1, both movable members 17, 18 are in the return position (contact open state), and the state is maintained by the magnetic flux of the permanent magnet 12. In this state, when the coil 16 is energized so that the magnetic flux of the permanent magnet 12 flows in a direction that cancels the magnetic flux of the permanent magnet 12, the armature pieces 17a, 18a are attracted to the armature portions 12c, 12d and both movable members 17, 18 move to the left. First, the driving piece 17c drives the first movable contact spring 6 so that the arc contacts 3 and 6 come into contact with each other, and eventually the contact piece as shown in (b).
The first movable member 17 stops when 17a contacts the first armature 12c. Next, only the armature piece 18a is attracted to the second armature part 12d, and only the second movable member 18 moves further to the left. First, the driving piece 18c drives the second movable contact spring 8 to make a low resistance contact. 4,9 come into contact with each other, and eventually the armature piece 18a becomes the second as shown in (c).
The second movable member 18 also stops by contacting the armature 12d of the second movable member 17, and both movable members 17, 18 are in the operating position (contact contact state). In this state, even if the power supply to the coil 16 is stopped, the state is maintained by the magnetic flux of the permanent magnet 12. When returning from the operating position to the return position, if the coil 16 is energized in the reverse direction, the operation substantially reverse to the above is performed and the state (a) is obtained.

FIG. 4 shows the displacement amount x with respect to the passage of time t (s).
(mm), speed v (m / s), load current I (A)
Is the displacement of the first movable member 17, x2 is the displacement of the second movable member 18,
v1 is the speed of the first movable member 17, v2 is the speed of the second movable member 18, Ip is the peak current, Io is the steady current, t1 is the contact point of the arc contact, and t2 is the contact point of the low resistance contact. As is clear from this characteristic diagram, the difference in the contact time between t1 and t2 can be made large by the change in the displacement amount or speed becoming small during the operation.

In carrying out such an operation, some consideration must be given to the following points in design. That is, in the state of FIG. 3B, the magnetic resistance between the armature piece 18a and the facing piece 12a is made smaller than the magnetic resistance between the armature piece 17a and the facing piece 12a.

In the embodiment, both movable members are of the plunger type which reciprocates in the inner space of the coil.
It can also be applied to the clapper format. If the operation noise does not matter, the cushioning member may be a rigid member. Further, if the arc generated between the arc contacts is not so large, the insulating member between the two movable contact springs may be omitted.

[0024]

According to the electromagnet device of the present invention, until the first movable member comes into contact with the first armature, both movable members are attracted to each other by the magnetic attraction force and operate integrally, so that the arc is performed first. The contact for contact, and then the second movable member is attracted to the second contact to make contact with the low resistance contact, so that the contact time difference between the arc contact and the low resistance contact is relatively large, and therefore the contact life is long. Can be made longer, and will not be so large.

[Brief description of drawings]

FIG. 1 is a plan view showing a first embodiment of the present invention.

FIG. 2 is an exploded perspective view thereof.

3 (a), (b) and (c) are schematic operation explanatory views.

FIG. 4 is a displacement / velocity characteristic curve with time.

FIG. 5 is a waveform diagram of a general inrush current.

[Explanation of symbols]

1 Base 2 Fixed contact plate 3 Arc contact 4 Low resistance contact 5 Moving contact plate 6 1st moving contact spring 7 Arc contact 8 2nd moving contact spring 9 Low resistance contact 10 Yoke (11 Inner yoke piece, 12 Outer) (Yoke piece, 13 permanent magnet) 12c First armature portion 12d Second armature portion 14 Buffer member 15 Coil frame 16 Coil 17 First movable member 18 Second movable member

Claims (4)

[Claims] 1. A fixed contact plate having an arc contact and a low resistance contact, a first movable contact spring having an arc contact, a second movable contact spring having a low resistance contact, and arc contacts. And a movable contact plate in which the base ends of both movable contact springs are fixed so that the low resistance contacts come into contact with and separate from each other, and first and second contact poles that form a part of the magnetic path and determine two different operating positions. A yoke having a portion, a coil that causes a magnetic flux to flow through the yoke, a first movable member that forms the remaining portion of the magnetic path and that is in contact with and separated from the first armature portion and that drives the first movable contact spring.
A second movable member that forms the remaining part of the magnetic path and that is in contact with and separated from the second armature portion and that drives the second movable contact spring, and when both movable members are in contact with both armature poles. , Both movable members operate integrally until the first movable member contacts the first armature portion, and only the second movable member after the first movable member contacts the first armature portion. An electromagnetic relay that operates until the pole contacts the second armature. 2. Both of the movable members are of a plunger type that reciprocates in the inner space of the coil, the first movable member is cylindrical with an armature, and most of the second movable member is the first movable member. The electromagnetic relay according to claim 1, wherein the electromagnetic relay is formed in a rod shape having an armature portion housed inside. 3. The electromagnetic relay according to claim 1, wherein a buffer member is provided on the first contact portion. 4. The electromagnetic relay according to claim 1, wherein the movable contact springs are arranged in parallel so as to face each other, and an insulating member is interposed between the movable contact springs.