JP5248982B2 - Release-type electromagnet device - Google Patents

Description

  The present invention relates to a release-type electromagnet device that is applied to a tripping device such as a circuit breaker for wiring or a circuit breaker.

  As is well known, a circuit breaker such as a circuit breaker for wiring or a circuit breaker (hereinafter referred to as a circuit breaker) is used when a short circuit or a circuit leakage occurs in a circuit to which the circuit breaker is connected. Based on a trip signal generated by detecting this, the trip mechanism automatically trips and shuts off the circuit described above. Such a circuit breaker includes a release-type electromagnet device having an electromagnetic coil energized based on a trip signal and a plunger that is released when the electromagnet coil is energized, and a plan for the release-type electromagnet device. The tripping mechanism is tripped by the movement of the jar to shut off the circuit.

  Conventionally, as a release type electromagnet device used for a circuit breaker, a plunger guide made of a non-magnetic material is provided inside a through hole opened in an end yoke, and the plunger guide is used as a sliding bearing. Has been proposed to slidably guide and support, a technique for reducing the deviation of the magnetic resistance due to the adsorption of the through holes of the plunger and the end yoke, and ensuring stable release characteristics (for example, Patent Document 1). reference).

JP 2005-166429 A

  In the case of the conventional release electromagnet device disclosed in Patent Document 1, the plunger guide needs to be fixed to the through hole of the end yoke. There are several methods for fixing the plunger guide, such as welding and adhesion. However, in these fixing methods, the plunger guide may be offset toward the side wall of the through hole of the end yoke, and the operation axis of the plunger is eccentric. However, there is a problem that the release characteristics of the release type electromagnet device are not stable due to the occurrence of bias in the magnetic resistance.

  The present invention has been made to solve the above-mentioned problems in the conventional release-type electromagnet device, and provides a release-type electromagnet device having a stable release characteristic by stabilizing the magnetic resistance between the plunger and the end yoke. It is intended to provide.

A release type electromagnet device according to the present invention includes an electromagnetic coil wound around an outer peripheral surface of a bobbin having a through hole in a central portion, an opening at one end in an axial direction, and the electromagnetic coil and the bobbin accommodated therein. A main yoke made of a magnetic material, a permanent magnet fixed to the inner wall of the other axial end of the main yoke, and a transfer yoke provided between the permanent magnet and the axial end surface of the bobbin An end yoke having a through hole fixed to the opening of the main yoke and connected to the through hole of the bobbin; and a magnetic material, and inserted into the through hole of the bobbin and the through hole of the end yoke. A plunger portion provided with a plunger, and a release spring that constantly urges the plunger portion in a direction away from the transfer yoke. Is held at the contact position based on the attractive force of the permanent magnet when it is in contact with the transfer yoke, and the attractive force is reduced when the electromagnetic coil is energized to attach the release spring. A release-type electromagnet apparatus configured to be released and moved in a direction away from the transfer yoke based on a force, wherein the plunger portion forms a through hole of the plunger and the end yoke. The plunger includes a plunger guide that secures a magnetic gap between the inner peripheral surface and serves as a sliding bearing that slides on the inner peripheral surface of the end yoke, and the plunger has an inner diameter of a through hole of the end yoke. A large-diameter portion having a smaller outer shape and at least a portion inserted into the through-hole of the bobbin, and at least a portion having an outer shape smaller than the large-diameter portion and the end yoke The plunger guide includes a medium diameter portion inserted into the through hole, and a small diameter portion having an outer shape smaller than the outer shape of the medium diameter portion and at least a portion disposed outside the through hole of the end yoke. The outer diameter is substantially equal to the outer diameter of the large-diameter portion and is fitted to at least a part of the outer peripheral surface of the medium-diameter portion, and one end portion in the axial direction is bent radially inwardly to form the medium-diameter portion It is characterized by corresponding to the end face .

  The release-type electromagnet device according to the present invention provides a sliding bearing that secures a magnetic gap between the plunger and the inner peripheral surface forming the through hole of the end yoke and slides on the inner peripheral surface of the end yoke. Since the plunger guide is provided in the plunger section, the amount of eccentricity of the operating shaft of the plunger section is reduced, and the bias of the magnetic resistance between the plunger and the end yoke can be reduced, thus ensuring stable release characteristics. It becomes possible.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view of a release electromagnet device according to Embodiment 1 of the present invention, and FIG. 2 is a configuration diagram of a plunger portion of the release electromagnet device according to Embodiment 1 of the present invention. In FIG. 1, a bobbin 2 having a through hole 21 at the center is made of a non-magnetic material, and flanges 22 and 23 are formed at both ends in the axial direction. The electromagnetic coil 3 is wound around the outer peripheral portion of the bobbin 2 sandwiched between the flange portions 22 and 23.

  The cylindrical main yoke 4 made of a magnetic material has a U-shaped cross section and has an opening 41 at one axial end thereof (in the following description, the main yoke 4 is referred to as a “U-shaped yoke”). Called). The electromagnetic coil 3 and the bobbin 2 are housed in the inner space of the U-shaped yoke 4 with the axial centers thereof matching the axial center of the yoke 4.

  The end yoke 5 made of a magnetic material is fitted into the opening 41 of the U-shaped yoke 4 and is in contact with the axial end of the bobbin 2. The end yoke 5 is fixed to the U-shaped yoke 4 by a method such as caulking. The end yoke 5 is formed with a cylindrical portion 51 having a through hole 5a at the center thereof. The through hole 5 a of the tubular part 51 is connected to the through hole 21 of the bobbin 2 with its axis centering on the extension line of the shaft center of the through hole 21 of the bobbin 2.

  Next, the structure of the plunger part 6 is demonstrated. 1 and 2, the plunger portion 6 includes a columnar plunger 6a made of a magnetic material. The plunger 6a includes a large diameter portion 6a1, a medium diameter portion 6a2, and a small diameter portion 6a3. The cylindrical plunger guide 6b made of a nonmagnetic material includes an end edge 6b1 whose one end in the axial direction is bent inward in the radial direction.

  The plunger guide 6b is fitted to the outer peripheral surface of the medium diameter part 6a2 of the plunger 6a, and the inner wall of the end edge part 6b1 is in contact with the end surface of the medium diameter part 6a2 of the plunger 6a. The outer diameter of the plunger guide 6 b is formed to be substantially equal to the outer diameter of the large diameter portion 6 a 1 of the plunger 6 a and is set slightly smaller than the inner diameter of the cylindrical portion 51 of the end yoke 5. The plunger guide 6 b secures a magnetic gap between the plunger 6 a and the inner peripheral surface of the cylindrical portion 51 of the end yoke 5.

  The plate 6c is attached to the small-diameter portion 6a3 of the plunger 6a so as to be movable in the axial direction, but is prevented from moving upward in the drawing by coming into contact with the fixing ring 6e. The plate spring 6d formed of a compression spring is disposed in a compressed state between the plate 6c and the end edge 6b1 of the plunger guide 6b, and separates the plunger guide 6b and the plate 6c from each other. Energized in the direction. The plunger guide 6b is fixed to the plunger 6a by the end edge 6b1 being pressed by the plate spring 6d.

  The plunger 6a of the plunger portion 6 configured as described above is inserted into the through hole 21 of the bobbin 2 and the through hole 5a of the end yoke 5 as shown in FIG. In this state, the plunger guide 6 b is located in the through hole 5 a of the end yoke 5, and the outer peripheral surface of the plunger guide 6 b slides with the inner peripheral surface of the cylindrical portion 51 of the end yoke 5. It operates as a sliding bearing for the plunger portion 6.

  In FIG. 1, the permanent magnet 7 magnetized in the thickness direction is positioned by a fixed plate 8 and is fixed to the bottom which is the inner wall of the other axial end of the U-shaped yoke 4. The transfer yoke 9 made of a magnetic material is installed between the permanent magnet 7 and the end surface of the bobbin 2, and faces the end surface of the plunger 9a. The plunger 6 a is configured to be attracted by the magnetic force of the permanent magnet 7 and attracted to the transfer yoke 9.

  The release spring 10 composed of a compression spring is provided such that one end thereof is in contact with the end yoke 5 and the other end is in contact with the plate 6 c of the plunger portion 6. The state shown in FIG. 1 shows a state where the plunger 6 a is attracted to the transfer yoke 9 by the magnetic force of the permanent magnet 7. In this state, the release spring 10 is in a compressed state and urges the plunger portion 6 in the direction of the anti-transfer yoke 9, but the plunger 6a and the transfer yoke 9 are in contact with each other. Since the attracting force of both of them is set to be larger than the urging force of the release spring 10 against the plunger portion 6, the plunger portion 6 is kept at a position in contact with the transfer yoke 9.

  Next, the operation of the release type electromagnet device according to Embodiment 1 of the present invention configured as described above will be described. When the plunger portion 6 is pushed into the reset position shown in FIG. 1 by a reset operation of a circuit breaker (not shown), the plunger portion 6 is attracted to the transfer yoke 9 by the magnetic force Fm of the permanent magnet 7 in FIG. Held in the position shown. In this state, the magnetic flux φm of the permanent magnet 7 returns from the N pole of the permanent magnet 7 to the S pole via the transfer yoke 9, the plunger 6 a, the end yoke 5, and the U-shaped yoke 4. Assuming that the spring force of the release spring 10 is Fs, the plunger portion 6 is attracted to the transfer yoke 9 with a force of [Fm−Fs].

  In the state shown in FIG. 1, when a release current is applied to the electromagnetic coil 3 based on the trip signal of the circuit breaker, the magnetic flux φi generated by the electromagnetic coil 3 is transferred so as to cancel the holding force Fm of the permanent magnet 7. It flows through the path of the yoke 9, the U-shaped yoke 4, the end yoke 5, and the plunger 6a, and the holding force Fm of the permanent magnet 7 is reduced. As a result, the spring force Fs of the release spring 10 overcomes the holding force Fm of the permanent magnet 7, and the plunger portion 6 integrated with the plunger guide 6 b serving as a sliding bearing is released from the adsorption with the transfer yoke 9. Projects upward in the figure.

  When the plunger part 6 protrudes by the urging force of the release spring 10, a tripping mechanism (not shown) of the circuit breaker is triggered by the plunger part 6 to disengage the movable contact from the fixed contact, thereby interrupting the circuit. It is.

  If the tripping mechanism is reset to close the circuit breaker after the plunger portion 6 has been protruded by the urging force of the release spring 10, an actuator (not shown) provided in the circuit breaker during the reset operation. Presses the plate 6c of the plunger portion 6 and moves the plunger portion 6 downward in FIG. Thereby, the release type electromagnet device 1 is reset. Since the plate 6c is operable in the axial direction of the plunger 6a, the actuator is prevented from pushing the plate 6c too much and destroying the plate 6c when the actuator of the circuit breaker is reset.

  In the case of the above-described conventional apparatus, when the plunger guide 6b is fixed to the end yoke 5 by welding or the like by welding or the like, the operation axis of the plunger is decentered and the magnetic resistance is biased. Although there was a problem that the release characteristics of the release-type electromagnet device were not stable, according to the release-type electromagnet device according to Embodiment 1 of the present invention, the plunger guide 6b is fixed to the plunger 6a. The operation axis of the plunger 6a is not decentered. Therefore, the bias of the magnetic resistance is eliminated, and a stable release characteristic can be ensured. Furthermore, since the plunger guide 6b is fixed by pressing the plunger guide 6b against the plunger 6a by the plate spring 6d, the plunger guide 6b can be fixed without adding any parts, and the assembly is easy. It is.

It is sectional drawing of the release type electromagnet apparatus by Embodiment 1 of this invention. It is a block diagram of the plunger part of the release type electromagnet apparatus in Embodiment 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Release type electromagnet apparatus 2 Bobbin 21 Bobbin through-hole 3 Electromagnetic coil 4 U-shaped yoke 41 U-shaped yoke opening 5 End yoke 5a End yoke through-hole 6 Plunger part 6a Plunger 6a1 Large diameter part 6a2 Medium Diameter portion 6a3 Small diameter portion 6b Plunger guide 6b1 Plunger guide end edge 6c Plate 7 Permanent magnet 8 Fixed plate 9 Transfer yoke 10 Release spring

Claims (3)

A main yoke composed of an electromagnetic coil wound around the outer peripheral surface of a bobbin having a through hole in the center, and a magnetic material having an opening at one axial end and housing the electromagnetic coil and the bobbin inside A permanent magnet fixed to the inner wall of the other axial end of the main yoke, a transfer yoke provided between the permanent magnet and the axial end surface of the bobbin, and fixed to the opening of the main yoke An end yoke having a through hole connected to the through hole of the bobbin, and a plunger portion that is made of a magnetic material and is inserted into the through hole of the bobbin and the through hole of the end yoke. And a release spring that constantly urges the plunger portion in a direction away from the transfer yoke, and the plunger portion has the plunger abutting against the transfer yoke. The transfer yoke is held at the abutting position based on the attracting force of the permanent magnet when the magnet is energized, and the attracting force is reduced when the electromagnetic coil is energized and based on the biasing force of the release spring. A release-type electromagnet device configured to move by being released in a direction away from
The plunger portion serves as a sliding bearing that secures a magnetic gap between the plunger and an inner peripheral surface forming a through hole of the end yoke and slides on the inner peripheral surface of the end yoke. With a plunger guide ,
The plunger has an outer shape smaller than an inner diameter of the through hole of the end yoke, and at least a part thereof is inserted into the through hole of the bobbin, and an outer shape smaller than the large diameter part and at least a part of the plunger. A medium-diameter portion that is inserted into the through-hole of the end yoke, and a small-diameter portion that has an outer shape that is smaller than the outer shape of the medium-diameter portion and that is at least partially disposed outside the through-hole of the end yoke,
The plunger guide has an outer diameter substantially equal to the outer diameter of the large-diameter portion and is fitted to at least a part of the outer peripheral surface of the medium-diameter portion, and one end in the axial direction is bent radially inward. Corresponding to the end face of the medium diameter part,
Release electromagnetic device characterized by that.   The plunger portion includes a plate that holds the release spring, and a plate spring that is provided between the plate and the plunger guide and constantly presses the plunger guide against the plunger. The release electromagnet device according to claim 1.   The release type electromagnet device according to claim 2, wherein the plate is provided so as to be movable in a direction in which the plate spring is compressed.

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