JP2013235748A - Direct current switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a direct current switch that can secure a stable arc-extinguishing performance by placing a permanent magnet near a contact point without increasing the number of components or without providing extra space in an arc-extinguishing room.SOLUTION: A direct current switch is configured to accommodate a fixed contact 12 and a movable contact 9 moving parallel to a case division face inside a division-type case 1, and to place a permanent magnet 19 to extinguish arc in the vicinity of the contact position of these contacts. The permanent magnet 19 is housed in a magnet housing part 16 formed integrally with the case 1. The magnet housing part 16 comprises a wall part 17 covering at least a fixed contact side and a case inside, and comprises an insertion opening 18 for the permanent magnet at the opposite side of the fixed contact or the case opening side.

Description

  The present invention relates to a DC switch that improves the extinction performance of an arc generated when a contact is opened.

  A DC switch is a device that opens and closes a DC circuit by incorporating a movable contact interlocking with a handle into a case together with a fixed contact. When the current value increases, it is inevitable that an arc is generated between the contacts when the contact is opened and the DC current is interrupted, and it is necessary to extinguish the generated arc quickly in order to improve the interrupting ability. It is done. In particular, in recent years, with the improvement of photovoltaic power generation technology and battery performance, higher direct current voltages and higher currents have advanced, and there has been a strong demand for improvement in the breaking capability of direct current switches.

  Therefore, conventionally, a technique has been used in which a permanent magnet is disposed between the movable contact and the fixed contact to stretch the arc and quickly extinguish the arc. However, when the permanent magnet is disposed in the arc-extinguishing chamber, there is a problem that the magnetic extinguishing performance is gradually lowered due to exposure to the generated arc and the arc-extinguishing performance is lost.

  In order to solve this problem, there has been proposed a DC switch having a structure in which a permanent magnet is attached to an arc extinguishing plate and protected by an insulating plate as shown in Patent Document 1. This structure has the advantage that the permanent magnet is not directly exposed to the arc. However, on the other hand, there are problems that the number of parts of the insulating plate increases and the mounting work of the insulating plate occurs, leading to an increase in cost.

  In addition, there is a plastic part in which a permanent magnet is sealed, but there is a problem that the number of parts of the plastic part increases. Further, since it is necessary to secure a storage space for plastic parts in the arc extinguishing chamber, there is a problem that the installation space for the internal equipment is reduced and it is difficult to improve the shut-off capability.

JP 9-320375 A

  Therefore, the object of the present invention is to solve the above-mentioned conventional problems, and to arrange a permanent magnet near the contact without increasing the number of parts or providing an extra space in the arc extinguishing chamber, thereby providing stable arc extinguishing performance. It is to provide a DC switch that can be secured.

  The DC switch according to the present invention, which has been made to solve the above problems, houses a fixed contact and a movable contact that operates in parallel with the case dividing surface in a split type case, and also has a fixed contact. In a DC switch having a permanent magnet for extinguishing an arc in the vicinity of the contact position between the child and the movable contact, the permanent magnet is housed in a magnet housing portion formed integrally with the case, and The magnet housing portion is provided with a wall portion that covers at least the stationary contact side and the inside of the case, and has a permanent magnet insertion opening on the opposite side of the stationary contact or the case opening side. is there.

  It is preferable that an arc runner is extended at the tip of the stationary contact, and the magnet storage part is disposed at the tip of the arc runner, and the permanent magnet is positioned from both sides by a case. It is preferable to do.

  In the DC switch according to the present invention, since the permanent magnet is housed in the magnet housing portion formed integrally with the case, an extra plastic part for attaching the permanent magnet is unnecessary, and the number of parts can be reduced. In addition, the arc is extinguished by the permanent magnet, and of course, the magnet housing is provided with a wall covering at least the stationary contact side and the inside of the case, so the permanent magnet is not directly exposed to the arc. There is no decrease in magnetic force, and arc extinguishing performance does not decrease. In addition, since the permanent magnet insertion port is provided on the opposite side of the fixed contact or on the case opening side, the permanent magnet can be easily attached.

  In addition, if it is the structure which has arrange | positioned the said magnet storage part ahead of an arc runner, it can improve arc-extinguishing performance further, and if it is set as the structure where the position of the permanent magnet was regulated from both sides by a case, it is a simple structure However, the permanent magnet can be securely held.

It is an external appearance perspective view which shows the DC switch of embodiment. It is the perspective view which removed the near case on the near side and showed the internal structure. It is a perspective view which shows the insertion position of a permanent magnet. It is an expanded sectional view of a magnet storage part. It is a perspective view of a left case. It is explanatory drawing of the internal structure in an ON state. It is explanatory drawing of the internal structure in an OFF state.

Hereinafter, preferred embodiments of the present invention will be described.
FIG. 1 is an external view showing a DC switch according to an embodiment of the present invention. The case 1 is made of resin and includes a central case 2, a right case 3, and a left case 4 that are divided into three in the width direction. The DC switch of this embodiment includes a two-pole contact mechanism, 5 is a handle, 6 is a power supply side terminal, and 7 is a load side terminal.

  FIG. 2 is a perspective view showing the internal structure by removing the right case 3 on the front side of the drawing. The central case 2 stores opening / closing mechanism portions 8 in the internal spaces on both sides of the central partition. These opening / closing mechanisms 8 operate the movable contact 9 in parallel with the split surface of the case 1 in conjunction with the upper handle 5. A movable contact 10 is provided at the tip of the movable contact 9. The movable contact 9 is connected to the load side terminal 7 by a stranded wire 11.

  In addition, a stationary contact 12 is disposed integrally with the power supply side terminal 6 at the end of the case 1 on the power supply side. The fixed contact 12 includes a fixed contact 14 on an inclined portion 13 that extends toward the center of the case. The tip of the inclined portion 13 is an arc runner 15 extending in parallel with the bottom surface of the case 1.

  A magnet housing portion 16 formed in a flat box shape is disposed at the tip of the arc runner 15. As shown in FIG. 3, the magnet storage portion 16 is formed integrally with the bottom portion of the central case 2 and includes a wall portion 17 that covers the fixed contact 12 side and the case inner side. An insertion opening 18 for the permanent magnet 19 is formed on the front side of the case opening in FIG. Since the magnet storage portion 16 is formed in parallel with the bottom portion of the central case 2, it does not hinder the arc gas injection. In addition, since the magnet housing portion 16 has a structure in which the side of the stationary contact 12 that contacts the arc and the inside of the case are covered with the wall portion 17, the permanent magnet 19 can be prevented from coming into direct contact with the arc. For this reason, the permanent magnet 19 does not decrease in magnetic force, and the interruption performance can be maintained.

  If the permanent magnet 19 is inserted into the magnet housing portion 16 formed in the central case 2 as shown in FIG. 3 and the right case 3 and the left case 4 are attached to both sides thereof, as shown in the cross-sectional view of the main part in FIG. In addition, the position of the permanent magnet 19 is restricted from both sides by the right case 3 and the left case 4 and does not come off. Such a structure is advantageous in simplifying the mold structure for molding the case 1. FIG. 5 shows the right case. Reference numeral 20 denotes a portion that presses the side surface of the magnet storage portion 16. FIG. 6 shows the internal structure in the on state, and FIG. 7 shows the internal structure in the off state.

  If the magnetic pole of the permanent magnet 19 is installed toward the moving path of the movable contact 10, the arc gas can be bent by the magnetic force and reliably extinguished. Needless to say, the surface of the permanent magnet 19 is covered with the resin wall 17 and the magnetic force is not affected.

  Note that the extension lines of the movable contact 10 and the fixed contact 14 are covered with a box-shaped magnet storage portion 16 so that the mating surfaces of the cases are not positioned on the extension line. Further, since the lower surface of the magnet housing portion 16 is also used as the bottom surface of the case, it is effective in terms of space.

  In the above-described embodiment, a DC switch without an overcurrent interruption function is shown. However, a breaker function may be provided for tripping the movable contact 9 by an overcurrent to interrupt the circuit.

  Further, in the above-described embodiment, the two-pole opening / closing mechanism is stored in the three-divided case 1 composed of the central case 2, the right case 3, and the left case 4. However, the present invention includes two right and left cases. It can also be applied to a two-split type.

DESCRIPTION OF SYMBOLS 1 Case 2 Center case 3 Right case 4 Left case 5 Handle 6 Power supply side terminal 7 Load side terminal 8 Opening and closing mechanism part 9 Movable contact 10 Movable contact 11 Strand 12 Fixed contact 13 Inclined part 14 Fixed contact 15 Arc runner 16 Magnet Storage part 17 Wall part 18 Insertion slot 19 Permanent magnet 20 The part which presses the side of a magnet storage part

Claims (3)

To accommodate the stationary contact and the movable contact that operates in parallel with the case split surface inside the split case, and to extinguish the arc near the contact position between the fixed contact and the movable contact In a DC switch with permanent magnets
The permanent magnet is housed in a magnet housing portion formed integrally with the case, and the magnet housing portion includes a wall portion covering at least the stationary contact side and the inside of the case, and the opposite side of the stationary contact or the case A DC switch comprising a permanent magnet insertion opening on the opening side.   2. The DC switch according to claim 1, wherein an arc runner is extended at the tip of the stationary contact, and the magnet housing portion is disposed at the tip of the arc runner.   The DC switch according to claim 2, wherein the position of the permanent magnet is regulated by a case from both sides.

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