JPH0668765A - Contact point opening and closing device - Google Patents

Abstract

PURPOSE:To stabilize operation voltage, prevent welding of a low resistance contact point when a long time rush current is opened or closed, prevent a temperature rise in a contact point closed condition, and realize downsizing and cost reduction. CONSTITUTION:Terminals 7a and 7b are connected electrically to each other, and terminals 8a and 8b are connected electrically to each other. A leaf spring 2 is fixed to the terminal 7a, and a movable arc contact point 1 is fixed to the tip part of the leaf spring 2 by calking. A leaf spring 5 is fixed to the terminal 7b, and a low resistance movable contact point 4 is fixed to the tip part of the leaf spring 5 by calking. A fixed arc contact point 3 is fixed to the terminal 8a, and a low resistance fixed contact point 6 is fixed to the terminal 8b. An arc contact point driving card 9a is positioned between the movable arc contact point 1 and the terminal 7a, and drives the leaf spring 2. A low resistance contact point driving card 9b is positioned on the contact point central axis of the low resistance movable contact point 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact switching device used for a relay for switching a load having a large inrush current such as lighting control.

[0002]

2. Description of the Related Art Conventionally, as a contact switching device used in an electromagnetic relay, a fixed contact is fixed to a fixed contact plate, and a movable contact plate is driven by a driving member connected to a movable member such as an electromagnet device. It has a structure in which is fixed. By the way, a large inrush current flows when opening and closing a load such as a capacitor load or a lamp load. If the above contact switchgear is used to open and close such a load, there is a risk of contact welding due to the arc generated by the inrush current, so as a countermeasure against this, use a material with good welding resistance, such as tungsten. Has been. However, since such a contact material has a large resistance value, the temperature rises in the closed contact state.

Therefore, a contact opening / closing device of a double contact mechanism using both arc contacts having good welding resistance and low resistance contacts is disclosed in Japanese Utility Model Publication No. 51-23863 and Japanese Utility Model Publication 55-42.
No. 341, JP 61-233919, JP 62-71137, and JP 62-71138. Fig. 9 shows the actual Kosho 51-2386.
3A and 3B show the contact opening / closing device of FIG. 3, in which FIG. 3A is a perspective view of the contact portion, FIG. In FIG. 9, 31 is a movable contact consisting of an arc and a low resistance contact, 32 is a fixed contact for arc, and 3 is a fixed contact.
3 is a low resistance fixed contact, 34 is a movable contact plate, and 35 is a fixed contact plate. FIG. 10 shows a contact switchgear disclosed in Japanese Utility Model Publication No. 55-42341, (a) is a perspective view of the contact part, and (b) is a view showing the opened state. In FIG. 10, 41 is a movable contact consisting of an arc and a low resistance contact, 42 is a fixed contact for arc, 43 is a low resistance fixed contact, 44 is a movable contact plate, and 45 is a fixed contact plate. In addition, FIG.
It is a figure which shows the open state of the contact switchgear of Unexamined-Japanese-Patent No. 1-233919. In FIG. 11, 51 is a movable contact for arc and low resistance contact, 52 is a fixed contact for arc, and 53 is a fixed contact for arc.
Is a low resistance fixed contact.

In these contact switching devices, the arc contacts first come into contact with each other during the closing operation, the arc contacts come apart from each other during the opening operation, and the low resistance contacts come into contact with each other in the closed state. is there. As a result, the arc contacts bear the arc when the contacts are opened and closed, and a current flows through the low resistance contacts in the closed state to prevent a temperature rise.

[0005]

FIG. 1 shows the matching characteristics of the attraction force of the electromagnet and the spring load in the above-mentioned conventional contact switching device.
2 and the operating characteristics are shown in FIG. Further, FIG. 14 is a waveform diagram of each part. In FIG. 12, the vertical axis F is the attraction force and spring load of the electromagnet, the horizontal axis x is the contact stroke, is the attraction force at the time of setting, is the attraction force at the time of reset,
Indicates spring load.

As can be seen from FIG. 12, the double contact mechanism
By doing so, the two spring load and suction force characteristics are matched,
Since the opening / closing operation voltage is determined, it is possible to avoid variations in spring load.
Therefore, there is a drawback that the operating voltage greatly varies. Well
Also, as can be seen from FIG. 12 and FIG.
With the same flexure method, the points and low resistance contacts are turned on.
The low resistance contact is turned on after the arc contact is turned on.
Transition until₂Cannot be made too large, and
The contact was turned on after the movable member of the magnet was sufficiently accelerated.
Therefore, the time difference Δt between both contacts ₂Becomes shorter. So
Therefore, if an inrush current flows for a long time,
When a bounce as shown in Fig.
An arc is generated due to the bounce of the resistance contact, and the low resistance contact
Has the drawback of being welded.

Circuit diagrams are shown in FIGS. 15 (a) and 15 (b).
As shown in Figs. 15 (a) and 15 (b), theoretically the arc contacts
S₁Contact resistance R_AIs high, the arc contact S₁The
Arc contact S₁Contact resistance R_A
Voltage drop V between contacts_AHas a low resistance contact S₂The smallest of
Voltage V_minGreater than (ie V_A> V
_minCase), as shown in FIG. 15 (c), the low resistance contact S
₂Low resistance contact S when turning on₂The bounce of the arc
Occurs, low resistance contact S₂Has the drawback of being welded.

Even when the bounce of the single contact is reduced when the double contact mechanism is not used, in the case of the inrush current of the capacitor load, dielectric breakdown occurs before the contacts make contact,
An arc occurs. However, in the case of the double contact mechanism, since the inter-contact voltage between the low resistance contacts is small when the arc contact is turned on, the arc due to the dielectric breakdown does not occur. Further, in the case of the double contact mechanism, there is a drawback that the contact portion becomes large and the cost becomes high.

A first object of the present invention is to stabilize the operating voltage, prevent the low resistance contact from being welded when opening and closing a long-time inrush current, and increase the temperature when the contact is closed. It is to provide a contact switchgear capable of preventing the above. Further, a second object is to provide a contact opening / closing device which can be reduced in size and cost in addition to the first object.

[0010]

According to a first aspect of the present invention, there is provided a contact switchgear which is electrically connected to an arc contact composed of an arc movable contact and an arc fixed contact having good welding resistance, and the arc movable contact. Low resistance contact consisting of a fixed low resistance contact and a fixed low resistance contact electrically connected to the fixed contact for arc, and a low resistance movable contact after the movable contact for arc and the fixed contact for arc are contacted during closing operation. Drive the arc movable contact so that the arc movable contact and the arc fixed contact are separated after the low resistance movable contact and the low resistance fixed contact are separated during the opening operation. A second driving means for driving the driving means and the low resistance movable contact;
And a second driving means is displaced on the central axis of the low resistance contact, and the terminal for fixing the low resistance fixed contact is made of a rigid body.

According to a second aspect of the present invention, there is provided a contact opening / closing device, wherein the arc contact is composed of a movable contact for arc and a fixed contact for arc having good welding resistance, and a low resistance fixed contact electrically connected to the movable contact for arc. And a low resistance contact consisting of a low resistance movable contact electrically connected to the arc fixed contact and the low resistance movable contact and low resistance fixed contact after the arc movable contact and the arc fixed contact come into contact during the closing operation. Contact,
Equipped with a driving means for driving the movable contact for arc and the movable contact for low resistance so that the movable contact for arc and the fixed contact for arc are separated after the low resistance movable contact and the low resistance fixed contact are separated during the opening operation. , The fixed contact for arc and the low resistance movable contact which are integrally formed between the movable contact for arc and the low resistance fixed contact are inserted, and the drive means is displaced on the central axis of the low resistance contact to fix the low resistance fixed contact. The terminal to be connected is made of a rigid body.

[0012]

According to the first and second aspects of the present invention, when the card of the movable part of the electromagnet device is used as the driving means, the contact pressure of the low resistance contact point is constituted by the holding force of the electromagnet, so that the spring load is the arc. Only the spring load of the contact is used, and the variation in operating voltage can be made similar to that of the single contact. It also opens and closes large inrush currents that take a long time. After the contact for arc is turned on, the movable portion is displaced by the amount of OT of the contact for arc and the low resistance contact is turned on, so that the difference in the making time can be lengthened and the contact welding phenomenon can be eliminated. Further, since the low resistance contact is attracted by the holding force of the electromagnet, the spring coefficient is very large (ideally a rigid body collision) and the contact does not bounce and contact bounce does not occur. Therefore, even when the contact resistance of the arc contact becomes large and the voltage between the contacts becomes high, the low resistance contact does not bounce, so that no arc is generated at the low resistance contact and stable contact resistance is obtained without wear or welding. The temperature rise can be prevented.

Further, according to the second aspect of the invention, since the arc fixed contact and the low resistance movable contact which are integrally formed between the arc movable contact and the low resistance fixed contact are inserted,
Miniaturization and cost reduction can be achieved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. 1 is a configuration diagram of a contact portion of a contact opening / closing device according to a first embodiment of the present invention, and FIG. 2 is a plan view of the contact opening / closing device specifically mounted on a relay. 1 and 2,
1 is a movable contact for arc, 2 and 5 are leaf springs, 3 is a fixed contact for arc, 4 is a low resistance movable contact, 6 is a low resistance fixed contact,
7a, 7b, 8a and 8b are terminals made of a rigid body, 9a is an arc contact drive card (first drive means) of the movable part of the electromagnet, and 9b is a low resistance contact drive card (second drive means).
Is. The movable contact 1 for arcs and the fixed contact 3 for arcs serve as arc contacts having good welding resistance, and the low resistance movable contact 4 and the fixed contact 6 for low resistance serve as low resistance contacts.

In this contact switchgear, terminals 7a and 7b are electrically connected, and terminals 8a and 8b are electrically connected. A leaf spring 2 is fixed to the terminal 7a, and an arc movable contact 1 is fixed to the tip end of the leaf spring 2 by caulking. A leaf spring 5 is fixed to the terminal 7b, and a low resistance movable contact 4 is fixed to the tip end of the leaf spring 5 by caulking. The arc fixed contact 3 is fixed to the terminal 8a, and the low resistance fixed contact 6 is fixed to the terminal 8b. The arc contact drive card 9a is positioned between the arc movable contact 1 and the terminal 7a and drives the leaf spring 2. The low resistance contact drive card 9b is positioned on the contact center axis of the low resistance movable contact 4.

FIG. 3 is a diagram showing the operating principle of this contact switching device when a bistable electromagnet is used. In FIG. 3, the electromagnet has two sides of the iron core 24 as magnetic pole portions, and two armatures 21 and 22 sandwiching the permanent magnet 23 perform contact and separation operations so as to sandwich the iron core 24. In Fig. 3 (a), the movable part of the electromagnet is in the initial position. When a current flows through the coil, the movable portion is displaced, the arc contact drive card 9a drives the leaf spring 2, and the low resistance contact drive card 9b drives the low resistance movable contact 4. Then, as shown in FIG. 3 (b), the movable contact 1 for arc contacts the fixed contact 3 for arc, and an inrush current flows. After that, the arc contact drive card 9a further pushes the leaf spring 2 to apply the arc contact pressure, the low resistance movable contact 4 contacts the low resistance fixed contact 6 as shown in FIG. 3 (c), and the electromagnet stops. , The contact pressure of the low resistance contact is added by the holding force of the electromagnet. That is, _a gap x _a is created between the armature 21 of the electromagnet and the iron core 24. This is the same as the case where the Resiliency Plate (used to cut the rise in the suction force at the final end of the suction force) is added. During the opening operation, the movable contact 4 for arc and the fixed contact 3 for arc are separated after the movable contact 4 for low resistance and the fixed contact 6 for low resistance are separated.

FIG. 4 shows the matching characteristics of the attractive force of the electromagnet and the spring load, and FIG. 5 shows the operating characteristics. In FIG. 4, the vertical axis F is the attraction force and spring load of the electromagnet, the horizontal axis x is the contact stroke, is the attraction force at setting, is the attraction force at reset, and is the spring load. As can be seen from FIG. 4, the alignment is similar to the single contact mechanism and the holding force Δ
f ₁ becomes the contact pressure of the low resistance contact. The actual stroke ST0 is different from the actual stroke ST0 of the electromagnet.
1 becomes short.

Further, as can be seen from FIG. 5, after the arc contact is turned on, the movable portion is displaced by the OT amount of the arc contact, and then the low resistance contact is turned on.
It is possible to lengthen t ₁ . Further, since the holding force of the electromagnet is instantly applied to the low resistance contact to form the contact pressure, bounce does not occur. That is, no arc is generated at the low resistance contact.

As described above, according to this embodiment,
As a second drive means, a card (9
a, 9b) and the contact pressure of the low resistance contact is composed of the holding force of the electromagnet, so the spring load is only the spring load of the contact for arc, and the variation in operating voltage is the same as that of the single contact. be able to. In addition, when opening and closing a large inrush current for a long time, after the arc contact is turned on, the movable part is displaced by the OT amount of the arc contact and the low resistance contact is turned on. Therefore, the contact welding phenomenon can be eliminated. Further, since the low resistance contact is attracted by the holding force of the electromagnet, the spring coefficient is very large (ideally a rigid body collision) and the contact does not bounce and contact bounce does not occur. Therefore, even when the contact resistance of the arc contact becomes large and the voltage between the contacts becomes high, the low resistance contact does not bounce, so that no arc is generated at the low resistance contact and stable contact resistance is obtained without wear or welding. The temperature rise can be prevented.

Next, a second embodiment of the present invention will be described. 6A and 6B show the structure of a contact portion of a contact switchgear according to a second embodiment of the present invention. FIG. 6A is a perspective view thereof, and FIG. 6B is a plan view thereof. FIG. 7 is a partial explanatory view thereof, and FIG. 8 is a plan view in which the contact switchgear is specifically mounted on a relay. Figure 6
In FIG. 8, 11 is a movable contact for arc, and 12, 15
Is a leaf spring, 13 is a fixed contact for arc, 14 is a low resistance movable contact, 16 is a low resistance fixed contact, 17, 18a and 18b are terminals made of a rigid body, 19 is a contact drive card (driving means) for the movable part of the electromagnet Is. The movable contact for arc 11
The arc fixed contact 13 serves as an arc contact having good welding resistance, and the low resistance movable contact 14 and the low resistance fixed contact 16 serve as low resistance contacts.

This contact switching device has terminals 18a and 18b.
Are electrically connected. The leaf spring 12 is attached to the terminal 18a.
Is fixed, and the movable contact for arc 1 is attached to the tip of the leaf spring 12.
1 is caulked and fixed. The low resistance fixed contact 16 is fixed to the terminal 18b. A leaf spring 15 is fixed to the terminal 17, and an arc fixed contact 13 and a low resistance movable contact 14 are fixed to the tip of the leaf spring 15. The contact drive card 19 is positioned on the same axis as the contacts 11, 13, 14, and 16. As shown in FIG. 7, the fixed contact 13 for arc is caulked and fixed to the tip of the leaf spring 15 by using a low resistance contact material 14a such as Ag as a base metal, and the low resistance contact material 14a after caulking and fixation is low. The resistance movable contact 14 is configured.

In this contact switching device, during the closing operation,
The contact drive card 19 drives the leaf spring 12 to bring the arc movable contact 11 into contact with the arc fixed contact 13. Further, the contact drive card 19 drives and displaces the leaf springs 12 and 15, the low resistance movable contact 14 contacts the low resistance fixed contact 16, the electromagnet stops, and the contact pressure of the low resistance contact is added by the holding force of the electromagnet. To be done. During the opening operation, the low resistance movable contact 14 and the low resistance fixed contact 16 are separated, and then the arc movable contact 11 and the arc fixed contact 13 are separated.

According to this embodiment, the same effect as that of the first embodiment is obtained, and further, the movable contact 11 for the arc.
Since the arc fixed contact 13 and the low resistance movable contact 14 which are integrally formed between the low resistance fixed contact 16 and the low resistance fixed contact 16 are inserted,
Miniaturization and cost reduction can be achieved.

[0024]

According to the contact opening / closing device according to the first and second aspects of the present invention, when a card of the movable part of the electromagnet device is used as the driving means, the contact pressure of the low resistance contact is constituted by the holding force of the electromagnet. The load is only the spring load of the contact for arc, and it is possible to make the variation of the operating voltage similar to that of the single contact. In addition, when opening and closing a large inrush current for a long time, after the arc contact is turned on, the movable part is displaced by the OT amount of the arc contact and the low resistance contact is turned on. Therefore, the contact welding phenomenon can be eliminated. Further, since the low resistance contact is attracted by the holding force of the electromagnet, the spring coefficient is very large (ideally a rigid body collision) and the contact does not bounce and contact bounce does not occur. Therefore, even when the contact resistance of the arc contact becomes large and the voltage between the contacts becomes high, the low resistance contact does not bounce, so that no arc is generated at the low resistance contact and stable contact resistance is obtained without wear or welding. The temperature rise can be prevented.

Further, according to the contact opening / closing device of the present invention, the fixed arc contact and the low resistance movable contact, which are integrally formed between the arc movable contact and the low resistance fixed contact, are inserted. -Cost can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a contact portion of a contact opening / closing device according to a first embodiment of the present invention.

FIG. 2 is a plan view in which the contact opening / closing device of the first embodiment is specifically mounted on a relay.

FIG. 3 is a diagram showing the operating principle of the contact switching device of the first embodiment.

FIG. 4 is a matching characteristic diagram of the attraction force of the electromagnet and the spring load in the first embodiment.

FIG. 5 is an operation characteristic diagram in the first embodiment.

FIG. 6 is a configuration diagram of a contact portion of a contact switchgear according to a second embodiment of the present invention.

FIG. 7 is a partial explanatory view of the contact switching device of the second embodiment.

FIG. 8 is a plan view in which the contact opening / closing device of the second embodiment is specifically mounted on a relay.

FIG. 9 is a view showing a contact opening / closing device of Japanese Utility Model Publication No. 51-23863 which is a conventional example.

FIG. 10 is a view showing a contact opening / closing device of Japanese Utility Model Publication No. 55-42341 which is a conventional example.

FIG. 11 is a view showing a conventional contact opening / closing device disclosed in Japanese Patent Laid-Open No. 61-233919.

FIG. 12 is a matching characteristic diagram of the attraction force of the electromagnet and the spring load in the conventional contact opening / closing device.

FIG. 13 is an operation characteristic diagram in a conventional example.

FIG. 14 is a waveform chart of each part in the conventional example.

FIG. 15 is an explanatory diagram of a problem in the conventional example.

[Explanation of symbols]

 1 movable contact for arc 3 fixed contact for arc 4 low resistance movable contact 6 low resistance fixed contact 8b terminal 9a contact drive card for arc (first drive means) 9b low resistance contact drive card (second drive means) 11 arc Movable contact 13 fixed arc contact 14 low resistance movable contact 16 low resistance fixed contact 18b terminal 19 contact drive card (drive means)

Claims (2)

[Claims] 1. An arc contact composed of an arc movable contact and an arc fixed contact having good welding resistance, a low resistance movable contact electrically connected to the arc movable contact, and the arc fixed contact. During the closing operation, the low resistance contact, which is a low resistance fixed contact electrically connected, and the arc movable contact and the arc fixed contact come into contact with each other, and then the low resistance movable contact and the low resistance fixed contact come into contact with each other. A first drive for driving the arc movable contact so that the arc movable contact and the arc fixed contact are separated after the low resistance movable contact and the low resistance fixed contact are separated during the opening operation. Means and a second drive means for driving the low resistance movable contact, wherein the second drive means is displaced on the central axis of the low resistance contact, and the terminal for fixing the low resistance fixed contact is a rigid body. Contact switchgear consisting of. 2. An arc contact composed of an arc movable contact and an arc fixed contact having good welding resistance, a low resistance fixed contact electrically connected to the arc movable contact, and the arc fixed contact. During the closing operation, the low resistance contact, which is a low resistance movable contact electrically connected, contacts the arc movable contact and the arc fixed contact, and then the low resistance movable contact contacts the low resistance fixed contact. During the opening operation, the arc movable contact and the low resistance movable contact are arranged so that the arc movable contact and the arc fixed contact are separated after the low resistance movable contact and the low resistance fixed contact are separated. Driving means for driving, wherein the arc fixed contact and the low resistance movable contact integrally formed between the arc movable contact and the low resistance fixed contact are inserted, and the driving means Is a contact opening / closing device in which the terminal for fixing the low resistance fixed contact is made of a rigid body and is displaced on the central axis of the low resistance contact.