JP6864579B2 - Contactor - Google Patents

Description

The present invention relates to a contactor using an electromagnet.

A contactor is a power device that opens and closes a power circuit for starting and stopping a power device such as an electric motor, and is used, for example, in a railway vehicle. In the contactor, physical contact occurs between the iron cores used for the electromagnet used when the main contact is turned on. Since the iron core is worn and impacted by this physical contact, a mechanism for reducing the wear and impact is required.

For example, Patent Document 1 includes a fixed iron core in which a coil is wound and fixed to a case, and a movable iron core that faces the fixed iron core and comes into contact with the excitation of the coil, and is energized by contacting and separating the fixed iron core and the movable iron core. Alternatively, in an electromagnetic contactor that shuts off, it is disclosed that an insulating ceramic film is coated on a portion facing a fixed iron core and a movable iron core.

JP-A-5-282984

As a result of diligent studies by the inventor of the present application on miniaturization of the contactor while reducing wear and impact due to physical contact between the fixed iron core and the movable iron core, the following findings have been obtained.

In the contactor according to Patent Document 1, the movable iron core is excited and wear of the iron core caused by contact with the fixed iron core can be prevented, but the impact when the movable iron core comes into contact with the fixed iron core is dealt with. It is difficult.

On the other hand, even if an attempt is made to cushion the impact by interposing a cushioning material between the fixed iron core and the movable iron core, the interposition of the cushioning material creates a gap at the time of adsorbing the iron core, which reduces the attractive force of the electromagnet. There is a problem that the size of the electromagnet is increased.

Therefore, an object of the present invention is to provide a contactor that can be miniaturized while alleviating wear and impact between the fixed core and the movable core of the electromagnet when the main contact is turned on.

In order to solve such a problem, in the present invention, a cushioning material containing a magnetic material is provided between the fixed iron core of the electromagnet and the movable iron core of the operating portion.

According to the present invention, it is possible to realize a contactor that can be miniaturized while alleviating wear and impact between the fixed core and the movable core of the electromagnet when the main contact is turned on.

It is a circuit diagram which shows the drive system of the AC railroad vehicle equipped with a contactor. It is a conceptual diagram which shows the schematic structure of the contactor in the contact open state by this embodiment. It is a conceptual diagram which shows the schematic structure of the contactor in the contact contact state by this embodiment. It is the attractive force characteristic figure of the electromagnet by this embodiment. It is a conceptual diagram which shows the relationship between the fixed iron core and the distance between a fixed iron core and a movable iron core by this embodiment. It is a figure which shows the arrangement place of the cushioning material by another embodiment.

FIG. 1 shows a block diagram relating to an example of a drive system for an AC railroad vehicle. The drive system includes a contactor according to the present invention. When the railroad vehicle travels, the drive system 1 takes in the single-phase AC power from the overhead line 2 connected to the substation, which is a single-phase AC power source, by the current collector 3, and closes the circuit breaker 4. A current is passed through the transformer 5, and the overhead wire voltage of the overhead wire 2 is stepped down by the transformer 5. One end of the primary winding on the input side of the transformer 5 is connected to a circuit breaker 4 that cuts off a large current such as an accident current, and the other end is connected to a wheel that contacts (grounds) the rail via a grounding brush 6. To do.

One end of the secondary winding on the output side of the transformer 5 is connected to the AC input end (u phase) of the single-phase converter 9 via the contactor 20, and the other end is the AC input end (v) of the single-phase converter 9. Phase) is connected. The auxiliary contactor 7 and the charging resistor 8 are connected in parallel with the contactor 20. A high voltage is applied to the input side of the transformer at the upper level, and a lower voltage is applied to the output side because the voltage is stepped down.

The contactor 20 is a device that physically opens and closes a power circuit for starting and stopping a power device, and disconnects a device (located on the right side in FIG. 1) that is potentially lower than the contactor 20. The high potential side of the contactor 20 is the A end, and the low potential side is the B end. Further, the auxiliary contactor 7 for charging the filter capacitor 10 and the charging resistor 8 for suppressing the charging current are connected in series. When the filter capacitor 10 is charged, the contactor 20 is closed, and the single-phase converter 9 and the three-phase inverter 11 start controlling the electric motor 12 that drives the railway vehicle. The DC input end of the filter capacitor 10 and the three-phase inverter 11 is connected to the DC output end of the single-phase converter 9. Further, an electric motor 12 is connected to the AC output end of the three-phase inverter 11.

Further, as shown in FIG. 2, the contactor 20 includes a main contact 23, an operation unit 26, an electromagnet 31 and a control device 33, and is a single-phase converter 9 which is a device potentially lower than the contactor 20. It is controlled based on the information from the control device 33 that monitors the three-phase inverter 11 and the electric motor 12.

When the control device 33 confirms that the filter capacitor 10 is charged and there is no abnormality in the device potentially lower than the contactor 20, a voltage equal to or higher than a predetermined value is applied to the electromagnet 31 via the power supply 32. When a voltage equal to or higher than a predetermined value is applied, the electromagnet 31 attracts the operation unit 26 as shown in FIG. The operation unit 26 closes the main contact 23 by being attracted by the electromagnet 31.

When the main contact 23 is closed, the contactor 20 supplies a current to a device at a potential lower than that of the contactor 20. When the voltage applied to the electromagnet 31 is smaller than a predetermined value, the attractive force of the electromagnet 31 is weakened, and the main contact 23 is opened by the return spring provided in the movable iron core 27, and the potential is higher than that of the contactor 20. No current is supplied to the lower equipment.

The main contact 23 is composed of a fixed main contact 21 and a movable main contact 24 facing each other, which are sealed in a vacuum interrupter 22 having a vacuum inside. When the movable main contact 24 interlocking with the operation unit 26 comes into contact with the fixed fixed main contact 21, the main contact 23 is closed.

The operation unit 26 is a portion for operating the open / closed state of the main contact 23, and is composed of an insulating joint 25 and a movable iron core 27. The surface of the insulating joint 25 is, for example, covered with a polyester resin, and electrically cuts off the circuit on the main contact 23 side to which a high voltage is applied and the circuit on the electromagnet 31 side to which a low voltage is applied. The movable iron core 27 is connected to the insulating joint 25 and interlocks with the movable main contactor 24 via the insulating joint 25.

The electromagnet 31 is composed of an exciting coil 30 in which a coil is wound around a cylindrical bobbin and a fixed iron core 29 fixed to the exciting coil 30. The exciting coil 30 is connected to the power supply 32, and a voltage is applied to the electromagnet 31 via the exciting coil 30. The exciting coil 30 is excited when a voltage is applied, and the movable iron core 27 is attracted by an electromagnetic force via the fixed iron core 29.

A cushioning material 28 is provided between the movable core 27 and the fixed core 29 so as to cover the contact surface between the movable core 27 and the fixed core 29 and the space between the two fixed cores 29. The cushioning material 28 softens the impact when the movable iron core 27 is sucked and comes into contact with the fixed iron core 29. The main material of the cushioning material 28 needs to be a low elastic body such as resin in order to soften the impact. However, if a resin material is provided between the movable iron core 27 and the fixed iron core 29, the movable iron core when the main contact 23 is turned on is provided. Since the gap between the 27 and the fixed iron core 29 increases, the magnetic resistance increases, and thus the attractive force of the electromagnet 31 decreases. The cushioning material 28 is arranged on the fixed iron core 29, for example.

Therefore, in the contactor 20, the cushioning material 28 uses resin as the main material to ensure impact resistance and contains a magnetic material, so that the movable iron core 27 and the fixed iron core 29 when the main contact 23 is inserted are used. The increase in magnetic resistance is suppressed and the attractive force of the electromagnet 31 is maintained. For example, the magnetic material is any one of ferromagnetic materials such as electromagnetic soft iron, structural carbon steel, cast steel, ferrite and silicon steel plate. Since the contactor 20 is used in an environment subject to the vibration of a moving vehicle, it goes without saying that the parts used for the contactor 20 are those that do not fall off due to vibration.

(2) Effect of the present embodiment As described above, the contactor 20 of the present embodiment contains a magnetic material while ensuring shock mitigation or shock absorption by using resin as the main material for the cushioning material 28. By doing so, the increase in magnetic resistance is suppressed. As shown in FIG. 4, which shows the attractive force characteristics of the electromagnet 31 with the distance between the movable iron core 27 and the fixed iron core 29 being 8 mm, when the cushioning material 28 is only a resin material, as shown in Graph 35, the main contact 23 Immediately before charging (immediately before the amount of movement of the movable iron core reaches 8 mm), the suction force becomes about 1200 N. On the other hand, when the cushioning material 28 contains a magnetic material, the suction force becomes about 1500 N immediately before the main contact 23 is turned on (immediately before the moving amount of the movable iron core becomes 8 mm) as shown in Graph 36.

Therefore, according to the contactor 20, the attractive force of the electromagnet 31 can be maintained while ensuring impact mitigation or shock absorption, and the impact generated by the movable iron core 27 and the fixed iron core 29 on the contactor 20 and the peripheral devices of the contactor 20. It is possible to reduce the size and weight of the contactor 20 by reducing the adverse effect of the contactor 20.

Further, the chattering generated at the main contact 23 at the time of charging due to the impact generated by the movable iron core 27 and the fixed iron core 29 generates an arc at the main contact 23. This arc carbonizes and deteriorates the main contact 23. By suppressing the impact generated by the movable iron core 27 and the fixed iron core 29, chattering generated at the time of charging at the main contact 23 can be suppressed, deterioration of the main contact 23 can be suppressed, and the durability of the contactor 20 can be improved.

Further, by suppressing the impact generated by the movable iron core 27 and the fixed iron core 29, the mechanical fatigue of the main contact 23 can be reduced, and the durability of the contactor 20 can be improved.

Further, since the attractive force of the electromagnet 31 is increased, the number of times the coil wound around the exciting coil 30 is wound can be reduced, and the exciting coil 30 can be made smaller and lighter. This also makes it possible to reduce the size and weight of the contactor 20. It becomes. When the attractive force of the electromagnet 31 increases, the current for exciting the exciting coil 30 (hereinafter referred to as the coil exciting current) can be reduced, and the contactor 20 can operate at a smaller voltage.

While the vehicle is running, it is necessary to pass a coil exciting current in order to maintain the contactor 20 in the closed state, but this coil exciting current raises the temperature of the exciting coil 30 and may cause a failure or the like. is there. By reducing the coil exciting current, the temperature rise of the exciting coil 30 can be suppressed, and the reliability of the contactor 20 can be improved.

Further, by suppressing the impact generated by the movable iron core 27 and the fixed iron core 29, the impact sound due to this impact can be suppressed, and the quietness is improved. The impact sound generated at the main contact 23 can be suppressed in the same manner.

(3) Other Embodiments In the above-described embodiment, the case where the main contact 23 is provided in vacuum has been described, but the present invention is not limited to this, and the main contact 23 may be provided in air. In addition, it can be widely applied to various contactors.

Further, in the above-described embodiment, the case where the bobbin of the exciting coil 30 has a cylindrical shape has been described, but the present invention is not limited to this, and the bobbin of the exciting coil 30 may have a square columnar shape.

Further, in the above-described embodiment, the case where the exciting coil 30 is a bobby coil has been described, but the present invention is not limited to this, and the exciting coil 30 may be a molded coil.

Further, in the above-described embodiment, the case where the operation unit 26 is provided with the rotation mechanism and the operation unit 26 is rotated by the spring to return the main contact 23 to the open state has been described, but the present invention is not limited to this. Instead, the main contact 23 may be returned to the open state by the spring provided in the movable iron core 27.

Further, in the above-described embodiment, the case where the number of fixed iron cores 29 is two has been described, but the present invention is not limited to this, and the number of fixed iron cores 29 may be three or more.

Further, in the above-described embodiment, the case where the thickness of the cushioning material 28 is uniform has been described, but the present invention is not limited to this, and the thickness of the cushioning material 28 may differ from place to place.

Further, in the above-described embodiment, as shown in FIGS. 3 and 5A, a case where the movable iron core 27 and the fixed core 29 facing each other are parallel to each other when the main contact is closed has been described. The present invention is not limited to this, and as shown in FIG. 5B, when the main contact is closed, the surfaces of the movable iron core 27 and the fixed iron core 29 facing each other do not have to be parallel to each other.

It is desirable to reduce the leakage of magnetic flux between the fixed cores 29 by making the distance D1 between the fixed cores 29 larger than the sum of the distances D2 and D3 between the movable cores 27 and the fixed cores 29.

Further, in the above-described embodiment, the case where the cushioning material 28 is provided so as to cover the contact surfaces of the movable iron core 27 and the fixed iron core 29 and the space between the two fixed iron cores 29 has been described, but the present invention is not limited to this. , As shown in FIGS. 6 (A) to 6 (G), the space between the two fixed iron cores 29 may not be covered with the cushioning material 28.

For example, as shown in FIG. 6 (A), the space between the two fixed iron cores 29 may simply not be covered with the cushioning material 28, or the thickness of the cushioning material 28 may be changed as shown in FIG. 6 (B). It may be thickened. The smaller the content of the magnetic material, the easier it is for the cushioning material 28 to absorb the impact. Further, the thicker the thickness, the easier it is for the cushioning material 28 to absorb the impact.

Further, as shown in FIGS. 6 (C) to 6 (E), the width of the cushioning material 28 is reduced with respect to the width of the surface of the fixed iron core 29, and the cushioning material 28 covers the side portion of the fixed iron core 29. You may do so. The larger the cross-sectional area of the cushioning material 28, the smaller the magnetic resistance and the stronger the attractive force of the electromagnet 31. From the viewpoint of not falling off due to vibration, an arrangement that is embedded in the fixed iron core 29 as shown in FIG. 6 (D) or an arrangement that covers the fixed iron core 29 as shown in FIG. 6 (E) is preferable.

Further, as shown in FIGS. 6 (F) and 6 (G), cushioning materials 28 and 40 having different magnetic permeabilitys may be used to form a multilayer structure. By arranging the cushioning material 28 having a high magnetic permeability on the movable iron core 27 side, the attractive force of the electromagnet 31 is strengthened. The cushioning material 40 does not have to contain a magnetic material.

Further, in the above-described embodiment, the case where the cushioning material 28 is arranged on the fixed iron core 29 has been described, but the present invention is not limited to this, and the cushioning material 28 may be arranged on the movable iron core 27. ..

1 ... Drive system, 2 ... Overhead wire, 3 ... Current collector, 4 ... Circuit breaker, 5 ... Transformer, 6 ... Grounding brush, 7 ... Auxiliary contactor, 8 ... Charging resistor, 9 ... Single-phase converter, 10 ... Filter capacitor, 11 ... 3-phase inverter, 12 ... Electric motor, 21 ... Fixed main contactor, 22 ... Vacuum interrupter, 23 ... Main contact, 24 ... Movable main Contactor, 25 ... Insulated joint, 26 ... Operation part, 27 ... Movable iron core, 28 ... Buffer material, 29 ... Fixed iron core, 30 ... Exciting coil, 31 ... Electromagnet, 32 ... Power supply, 33 …… Control device, 35, 36 …… Graph, 40 …… Buffer material.

Claims (7)

The fixed main contact and the movable main contact that make up the main contact,
An operation unit that has a movable iron core and works with the movable main contact
An electromagnet having a fixed iron core that attracts the movable iron core by electromagnetic force,
In a contactor that opens and closes the main contact by applying a voltage to the electromagnet.
Between the fixed core and the movable iron core, e Bei a buffer material containing a magnetic material,
A contactor characterized in that the electromagnet has the fixed iron core, and at least a part of the fixed iron core is not covered with the cushioning material. The fixed main contact and the movable main contact that make up the main contact,
An operation unit that has a movable iron core and works with the movable main contact
An electromagnet having a fixed iron core that attracts the movable iron core by electromagnetic force,
In a contactor that opens and closes the main contact by applying a voltage to the electromagnet.
Between the fixed core and the movable iron core, e Bei a buffer material containing a magnetic material,
Contactors thickness of the buffer material and wherein Rukoto different for each location. In the contactor according to claim 1 or 2.
A contactor characterized in that the fixed iron core includes the cushioning material. In the contactor according to any one of claims 1 to 3, the contactor
A contactor characterized in that the cushioning material is provided on the entire surface of the fixed iron core on the movable iron core side. In the contactor according to any one of claims 1 to 4, the contactor
A contactor characterized in that a part of the cushioning material is embedded in the fixed iron core. In the contactor according to any one of claims 1 to 5,
A contactor characterized in that the cushioning material is made of a resin material. In the contactor according to any one of claims 1 to 6,
A contactor characterized in that the cushioning material has a multi-layer structure of the cushioning materials having different magnetic permeability.

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