JP2004178953A - Magnetic arc-extinguishing type switching device and magnetic arc-extinguishing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic arc-extinguishing type switching device and a magnetic arc-extinguishing method whereby consumption of a cathode contact can be reduced since the consumption of a contact is restricted only to the consumption of an anode contact. <P>SOLUTION: In this switching device 10 (magnetic arc-extinguishing type switching device), a fixed contact 20 (anode contact) and a movable contact 30 (cathode contact) are provided so that they can be brought into contact with and separated from each other, and an arc generated between both contacts when both contacts are separated is magnetically extinguished. In addition, the switching device is provided with a magnet 40 to apply a magnetic field to the arc with magnetic flux density of 85 mT. As a result, the consumption of the contact is restricted only to the consumption of the anode contact, and the consumption of the cathode contact can be reduced. Accordingly, the consumption of the movable contact 30 caused by arcing can be prevented. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a magnetic arc extinguishing switch device and a magnetic arc extinguishing method.
[0002]
[Prior art]
For example, when a high voltage (42 V), large current load is interrupted by a switch, a persistent arc is generated when the contacts are opened. If this arc is stopped halfway through contact opening, the arc is maintained, the contact is greatly consumed, and the switch life is shortened.
[0003]
The arc generated when the electric contact is separated as described above is a metal phase arc maintained by the metal vapor from the electrode immediately after the separation, and the density of the metal vapor decreases as the contact gap increases. It is known that gas ions transition to a gas phase arc that plays a role in maintaining the arc.
[0004]
It is also known that the contact wear is the anode contact wear in the case of the metal phase arc and the cathode contact wear in the case of the gas phase arc (Non-Patent Document 1).
[0005]
[Non-patent document 1]
IEICE Transactions C-II Vol. J79-C-II No. 7 pp. 349-357 July 1996 [0006]
[Problems to be solved by the invention]
As described above, the wear of the contacts is inevitable due to the occurrence of the arc, but it is desired to reduce the wear of the contacts.
[0007]
In particular, even if it is unavoidable that a metal phase arc maintained by the metal vapor from the electrode immediately after the breakage occurs, if the arc is extinguished at the stage where the transition from the metal phase arc to the gas phase arc occurs, the contact It is preferable because the consumption is only the anode consumption and the cathode contact is not consumed.
[0008]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetic arc extinguishing switch device and a magnetic arc extinguishing method that can reduce the consumption of the cathode contact by consuming only the anode contact.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 provides an anode contact and a cathode contact so as to be able to contact and separate from each other, and magnetically extinguishes an arc generated between the contacts when the contacts are opened. A magnetic arc extinguishing switch device according to claim 1, further comprising a magnet for applying a magnetic flux density of 85 mT or more to the arc.
[0010]
According to a second aspect of the present invention, in the first aspect, the magnet is disposed so that a magnetic field is applied perpendicularly to the arc.
According to a third aspect of the present invention, in the first or second aspect, the anode contact is a fixed contact and the cathode contact is a movable contact.
[0011]
According to a fourth aspect of the present invention, in any one of the first to third aspects, the cathode contact is a plated contact.
The invention according to claim 5 is characterized in that when an anode contact and a cathode contact which are provided so as to be able to be separated from each other are opened, a magnetic field having a magnetic flux density of 85 mT or more is formed with respect to an arc generated between the contacts. The gist of the magnetic arc extinguishing method is as follows.
[0012]
The invention of claim 6 is characterized in that, in claim 5, the anode contact is a fixed contact and the cathode contact is a movable contact.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment in which the present invention is embodied in a light-load magnetic arc-extinguishing switch device will be described below with reference to FIGS.
[0014]
Here, the light-load magnetic arc-extinguishing switch device is, for example, a switch device used for an electric load driven under the voltage of a vehicle-mounted battery or the like (voltage of 12 to 42 V).
[0015]
FIG. 1 is a schematic diagram of a magnetic arc-extinguishing switch device (hereinafter, referred to as a switch device 10).
The switch device 10 is an oscillating switch, and includes a fixed contact 20, a movable contact 30 arranged so as to be able to contact and separate from the fixed contact, and a magnet 40 arranged near both contacts. The movable contact 30 is formed from a metal piece whose central part is bent, and one end of the metal piece extends toward the fixed contact 20. A contact portion 30 a is formed on a side surface on one end side of the movable contact 30. On one end side, the movable contact 30 is engaged with the fulcrum member 50 as a fulcrum at a position near the center, and the contact portion 30a is disposed so as to be able to contact and separate from the fixed contact 20 as shown in FIG. ing.
[0016]
When the movable contact 30 is pressed from above one end of the movable contact 30 via a pressing element (not shown), the movable contact 30 swings around the fulcrum member 50 as a fulcrum and comes into contact with the fixed contact 20. When the pressing of the pressing element is released, the movable contact 30 is separated from the fixed contact 20 by the urging force of a spring or the like, as shown in FIG.
[0017]
The contact portion 30a is a plated contact plated with a metal such as Ag or a silver alloy. Therefore, the cost is reduced as compared with the case where the contact portion 30a of the movable contact 30 is formed of a rubber material.
[0018]
On the other hand, the fixed contact 20 is made of a metal material such as Ag, a silver alloy, or a gold alloy.
In the present embodiment, the fixed contact 20 is an anode contact, and the movable contact 30 is a cathode contact.
[0019]
In the present embodiment, the magnet 40 is formed of a permanent magnet, and is fixed to a mounting member (not shown) in the vicinity of the two contacts. The magnet 40 is magnetized so as to form a magnetic field having a magnetic flux density of 85 mT or more in a gap between the contact portion 30a and the fixed contact formed when the contact portion 30a is separated from the fixed contact 20. Have been. That is, the magnet 40 is magnetized so that the magnetic field is applied perpendicularly to the arc 60 generated when the contacts are separated and the magnetic flux density is 85 mT or more.
[0020]
(Operation of the embodiment)
FIG. 2 is a characteristic diagram obtained from a test example in which an arc reduction effect by a magnetic field was confirmed. In the figure, the vertical axis indicates the intensity of the arc energy, and the horizontal axis indicates the magnetic flux density acting on the arc.
[0021]
The switch device used in the test example has the same configuration as the two contacts of the switch device 10 of the present embodiment, and magnets are provided so that the magnetic flux density in the gap between the separated contact portion 30a and the fixed contact 20 differs. It is possible to change the strength of the magnetic field by exchange. The test was performed by turning on and off the switch device 10 in a circuit (test circuit) in which the switch device was electrically connected to an electric load.
[0022]
In FIG. 2, resistors 3A, 7A, and 10A are examples in which an electric load is used as a resistive load and load currents of 3A, 7A, and 10A flow through the test circuit. In FIG. 2, the P / W motor is an example in which a power window driving motor used for a power window is used as an electric load, that is, an example of an inductive load, in which a load current of 6.5 A flows. ing.
[0023]
As shown in FIG. 2, it can be seen that the higher the magnetic flux density, the lower the arc energy. That is, an arc generated when the movable contact 30 of the switch device 10 is separated from the fixed contact 20 is subjected to a magnetic field in a vertical direction, so that the arc is curved by Fleming's law. As a result, the arc is extinguished in a short time, with the same effect as the contact gap is rapidly expanded. FIG. 2 also shows that there is an arc reducing effect even when the magnetic flux density is weak.
[0024]
FIGS. 3 (a) to 3 (c) show the current flowing in the test circuit during arc generation and the two contacts when the switch device of the test circuit is turned off with the magnetic flux densities being different from each other. 3 shows a change in voltage between the two.
[0025]
FIG. 3A is a test example of the resistor 7A, in which the magnetic flux density indicated by α in FIG. 2 is 0. As shown in FIG. 3A, when the magnetic flux density is 0, that is, when the magnetic field is not applied to the arc, the generation continuation time of the gas phase arc after the generation of the metal phase arc is reduced. It can be seen that the time is longer than the duration of occurrence. Therefore, there is a problem of cathode consumption (in this example, electrode consumption on the movable contact side) due to the long-term occurrence of the gas phase arc.
[0026]
FIG. 3A shows a test example of the resistor 7A, but the same can be said for the example of the resistor 3A, the resistor 10A, and the P / W motor.
FIG. 3B is a test example of the resistor 7A, which is a case where the magnetic flux density indicated by β in FIG. 2 is 47 mT. When the magnetic flux density is 47 mT as shown in FIG. 3 (b), it can be seen from FIG. 3 (a) that the generation continuation time of the gas phase arc after the generation of the metal phase arc is shorter.
[0027]
However, also in this case, there is a problem of cathode consumption (in this example, electrode consumption on the movable contact side) due to the occurrence of the gas phase arc.
Although FIG. 3B is a test example of the resistor 7A, the same can be said for the example of the resistor 3A, the resistor 10A, and the P / W motor.
[0028]
FIG. 3 (c) is a test example of the resistance 7A in FIG. 2, and is a case where the magnetic flux density indicated by γ in FIG. 2 is 85 mT. As shown in FIG. 3C, when the magnetic flux density is 85 mT, it can be seen that after the metal phase arc is generated, the gas phase arc is not generated but disappears.
[0029]
In this case, while the metal phase arc is occurring, a magnetic field acts vertically, the arc is curved by Fleming's law, the contact gap is rapidly widened, and the phase shifts to a gas phase arc. It is presumed that the arc was extinguished a short time ago.
[0030]
Although FIG. 3C shows a test example of the resistor 7A, the same can be said for the example of the resistor 3A, the resistor 10A, and the P / W motor.
In the above embodiment, the magnetic flux density is set to 85 mT. However, when the magnetic flux density is set to 90 mT or more, it is expected that a gas phase arc will not be generated and the arc will be extinguished earlier in a shorter time.
[0031]
Therefore, according to the present embodiment, the following effects can be obtained.
(1) In the present embodiment, the fixed contact 20 (anode contact) and the movable contact 30 (cathode contact) are provided so as to be able to contact and separate from each other, and the arc generated between the two contacts when the two contacts are opened is magnetically extinguished. The switch device 10 (magnetic arc-extinguishing switch device) was used.
[0032]
And the magnet 40 applied to the arc with a magnetic flux density of 85 mT was provided.
As a result, the contact can be consumed only by the anode contact, and the consumption of the cathode contact can be reduced. It is possible to prevent the movable contact 30 from being consumed by the arc.
[0033]
(2) In the present embodiment, the magnet 40 is arranged so that a magnetic field is applied perpendicularly to the arc.
As a result, the magnetic field can be efficiently applied to the arc, and the magnetic arc can be efficiently extinguished.
[0034]
(3) In this embodiment, the anode contact is the fixed contact 20 and the cathode contact is the movable contact 30.
As a result, the movable contact 30 is not consumed by the arc, so that it is not necessary to form the movable contact 30, particularly the contact portion 30a, from a costly metal material such as a rubber material.
[0035]
(4) In the present embodiment, the contact portion 30a of the movable contact 30 is a plated contact.
As a result, since the movable contact side is prevented from being consumed by the arc, the contact portion 30a can be formed at low cost by using a plated contact that does not require cost.
[0036]
(5) In the present embodiment, when the fixed contact 20 (anode contact) and the movable contact 30 (cathode contact), which are provided to be able to contact and separate from each other, are separated from each other, an arc of 85 mT is generated between the two contacts. A magnetic field having a magnetic flux density was formed.
[0037]
As a result, the contact can be consumed only by the anode contact, and the consumption of the cathode contact can be reduced. It is possible to prevent the movable contact 30 from being consumed by the arc.
Note that the embodiment of the present invention may be modified as follows.
[0038]
In the above embodiment, the present invention is embodied as a swing type switch. However, the present invention is not limited to the swing type switch, and may be embodied as a push switch or another type of switch.
In the above embodiment, the magnet 40 is formed of a permanent magnet, but may be formed of an electromagnet.
[0039]
In the above embodiment, the fixed contact is an anode contact and the movable contact is a cathode contact. However, the fixed contact may be a cathode contact and the movable contact may be an anode contact.
In this case, the movable contact 30 is formed of a rubber material made of at least a metal such as a silver alloy or a gold alloy.
[0040]
In the above-described embodiment, the movable contact 30 is a plated contact. However, the movable contact 30 may be formed of a silver alloy, a gold alloy or the like, instead of the plated contact. Also in this case, the wear of the movable contact serving as the cathode contact can be prevented.
[0041]
The configuration of the above-described embodiment may be embodied in, for example, a switch device that turns on and off electric power supplied to a drive motor of a power window mounted on a vehicle.
Further, such a switch device 10 may be applied to a switch device of another on-vehicle electrical component.
[0042]
That is, as in the above-described embodiment, the switch device of the on-vehicle electrical component has a load current of about several tens A at most. In such a switch device with a light load current, if a magnetic flux density of 85 mT or more, preferably 90 mT or more is applied to the arc, in the switch device with a light load current, the wear of the contacts is only the anode contact wear, The consumption of the cathode contact can be reduced.
[0043]
If the movable contact is a cathode contact, the production cost of the movable contact can be greatly reduced, and the effect of reducing the cost of parts is great.
The technical ideas other than the claims that can be grasped from the embodiment are described below.
[0044]
(1) The magnetic arc-extinguishing switch device according to any one of claims 1 to 4, wherein the switch device is a switch device for on-vehicle electrical equipment.
(2) The magnetic arc extinguishing method according to claim 5 or 6, wherein the cathode contact and the anode contact are a cathode contact and an anode contact of a switch device for in-vehicle electrical equipment.
[0045]
【The invention's effect】
As described above in detail, according to the first to fourth aspects of the present invention, the magnetic arc extinguishing swash plate switch device can reduce the consumption of the cathode contact only by the consumption of the anode contact. be able to.
[0046]
According to the fifth and sixth aspects of the present invention, it is possible to provide a magnetic arc extinguishing method capable of reducing the consumption of the cathode contact only by the consumption of the anode contact.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a switch device according to an embodiment of the invention.
FIG. 2 is a characteristic diagram obtained from a test example in which an arc reduction effect by a magnetic field was confirmed.
FIGS. 3A to 3C are explanatory diagrams showing a current flowing in the test circuit and a change in voltage between both contacts during arcing when a switch device of the test circuit is turned off.
[Explanation of symbols]
10. Switch device (magnetic arc-extinguishing switch device)
20: fixed contact (anode contact)
30 ... movable contact (cathode contact)
30a ... contact part 40 ... magnet 60 ... arc

Claims (6)

A magnetic arc extinguishing switch device for providing an anode contact and a cathode contact so as to be able to contact and separate from each other, and for magnetically extinguishing an arc generated between the two contacts when the two contacts are opened.
A magnetic arc-extinguishing switch device comprising a magnet for applying a magnetic flux density of 85 mT or more to the arc. The magnetic arc quenching switch device according to claim 1, wherein the magnet is arranged so as to apply a magnetic field perpendicularly to the arc. The magnetic arc-extinguishing switch device according to claim 1, wherein the anode contact is a fixed contact, and the cathode contact is a movable contact. 4. The magnetic arc quenching switch device according to claim 1, wherein the cathode contact is a plated contact. A magnetic arc extinguishing method characterized by forming a magnetic field having a magnetic flux density of 85 mT or more with respect to an arc generated between two contacts when an anode contact and a cathode contact which are provided so as to be able to contact and separate from each other are opened. The magnetic arc extinguishing method according to claim 5, wherein the anode contact is a fixed contact, and the cathode contact is a movable contact.

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