JP7760907B2 - electromagnetic contactor - Google Patents

Description

The present invention relates to an electromagnetic contactor that opens and closes a main circuit.

A known conventional electromagnetic contactor is a device that includes a contact mechanism in which a pair of fixed contacts with fixed contacts and a long movable contact that can be attached to and detached from each of the pair of fixed contacts are housed in a housing case made of insulating material; an electromagnet unit that drives the movable contact of the contact mechanism in the direction in which the movable contact moves toward and away from the pair of fixed contacts; and a rotation restriction unit that restricts the rotation of the movable contact when it moves toward and away from the pair of fixed contacts.

The rotation restriction section is composed of four metal sliding guides that are arranged in two pairs, spaced apart in the longitudinal direction of the movable contactor and sandwiching the movable contactor from the lateral direction, and extend in the direction in which the movable contactor moves forward and backward. When the movable contactor moves in the contact and separation direction, the four sliding guides come into contact with the lateral sides of the movable contactor, restricting its rotation and preventing poor conductivity when opening and closing the main circuit, thereby improving reliability.

Japanese Patent Application Laid-Open No. 2021-118111

However, the electromagnetic contactor in Patent Document 1 has four metal sliding guides located near the movable contact, which means that the insulation between the contact points of the movable contact is likely to deteriorate. Furthermore, the arc generated by the opening movement of the movable contact is likely to short-circuit to the sliding guides, which creates problems with interruption performance.

The present invention aims to provide an electromagnetic contactor that regulates the rotation of the movable contactor, thereby preventing poor conductivity when opening and closing the main circuit, improving reliability, while also resolving issues such as reduced insulation between the contacts of the movable contactor and reduced interrupting performance.

To achieve the above objective, an electromagnetic contactor according to one aspect of the present invention comprises a pair of fixed contacts having fixed contacts, a long movable contactor having a pair of movable contacts that can be moved toward and away from the fixed contacts of the pair of fixed contacts, and an electromagnet unit that drives a movable plunger connected to the movable contactor via a movable contactor support portion, thereby driving the movable contactor in a direction that moves it toward and away from the pair of fixed contacts, and a rotation restriction portion is disposed near the movable contactor support portion to restrict rotation of the movable contactor as it moves toward and away from the pair of fixed contacts.

The electromagnetic contactor of the present invention has a rotation restriction section that restricts rotation of the movable contact as it moves back and forth, located near the movable contact support section that connects the movable contact and the movable plunger, which is located away from the contacts of the pair of fixed and movable contacts. This restricts the rotation of the movable contact, preventing poor conductivity when opening and closing the main circuit and improving reliability, while also preventing a decrease in insulation between the contacts of the movable contact and a decrease in interrupting performance.

1 is a cross-sectional view of an electromagnetic contactor according to a first embodiment of the present invention. 1 is a perspective view showing an internal structure of an electromagnetic contactor according to a first embodiment, excluding an upper case and a lower case that fix a pair of fixed contacts; 1 is a plan view showing a main part of an electromagnetic contactor according to a first embodiment; FIG. FIG. 4 is a view taken along the line IV-IV in FIG. 3. FIG. 10 is a perspective view showing the internal structure of an electromagnetic contactor according to a second embodiment, excluding an upper case and a lower case that fix a pair of fixed contacts. FIG. 10 is a plan view showing a main part of an electromagnetic contactor according to a second embodiment. FIG. 7 is a view taken along the line VII-VII in FIG. 6.

Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc., may differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, it goes without saying that the drawings may include parts with different dimensional relationships and ratios.
Furthermore, the embodiments shown below are merely examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention does not limit the materials, shapes, structures, arrangements, etc. of the components to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims.
In addition, terms indicating directions such as "upper,""lower,""left,""right,""front,""rear,""longitudinaldirection," and "shortitudinal direction" used in the following description are used with reference to the directions in the accompanying drawings.
[First embodiment]

An electromagnetic contactor according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG.
As shown in FIG. 1, the electromagnetic contactor 1 of this embodiment includes a contact mechanism 2 and an electromagnet unit 3 that drives a movable contact of the contact mechanism 2, which will be described later.
The contact mechanism 2 and the electromagnet unit 3 are housed in a sealed state in the same space within a storage case 6. The storage case 6 is composed of a resin upper case 4 and a resin lower case 5 joined to the upper case 4. Arc-extinguishing gas is sealed into the storage case 6 through a gas inlet pipe 7. After the arc-extinguishing gas is sealed into the storage case 6, the gas inlet pipe 7 is cut midway and the opening is closed. The upper case 4 of the storage case 6 is provided with an attachment portion 8 for attaching to another member.

The contact mechanism 2 comprises a pair of fixed contacts 11, 12 (hereinafter referred to as the first fixed contact 11 and the second fixed contact 12) fixed to the upper case 4 by insert molding, and a movable contact 13 that can be brought into contact with and separated from these first fixed contact 11 and second fixed contact 12.
The first fixed contact 11 and the second fixed contact 12 are made of a conductive metal material and fixed at a predetermined distance in the left-right direction to the upper case 4. A fixed contact 11a is formed on the lower end surface of the first fixed contact 11 on the left side, and a fixed contact 12a is formed on the lower end surface of the second fixed contact 12 on the right side.
The movable contactor 13 is a conductive plate made of conductive metal and extending long in the left-right direction, and is supported by a contact support 14, a contact spring 15, and a spring retainer 16 connected to a movable plunger 21 (described later) of the electromagnet unit 3. The contact support 14, the contact spring 15, and the spring retainer 16 correspond to the movable contactor support portion in the present invention.
A movable contact 13a that contacts the fixed contact 11a of the first fixed contact 11 on the left side is formed on the upper surface of the left end of the movable contact 13, and a movable contact 13b that contacts the fixed contact 12a of the second fixed contact 12 on the right side is formed on the upper surface of the right end of the movable contact 13. The lower part of the contact support 14 is fixed to the upper end of the movable plunger 21, and a pair of legs 16b of a spring presser 16 that has a top plate 16a and a pair of legs 16b extending downward from both ends of the top plate 16a is fixed to the upper part of the contact support 14. The movable contact 13 is arranged to penetrate between the top plate 16a of the spring presser 16 and the contact support 14 in the left-right direction, and is sandwiched between the top plate 16a of the spring presser 16 and the contact spring 15 in a state where it is constantly biased upward by the contact spring 15 that is arranged between the movable contact 13 and the contact support 14, thereby supporting the movable contact 13.

As shown in FIG. 1, the electromagnet unit 3 includes a movable plunger 21, an armature 22, a spool 24, an excitation coil 25, an excitation yoke 31, an auxiliary yoke 32, a permanent magnet 33, and a return spring 34, and is disposed below the contact mechanism 2 inside the storage case 6.
The movable plunger 21 is a round shaft-shaped member made of a magnetic material and extending in the vertical direction. An armature 22 made of a disk-shaped magnetic material with a diameter larger than that of the movable plunger 21 is fixed to the lower end of the movable plunger 21. The contact support 14 fixed to the upper end of the movable plunger 21 moves upward as the movable plunger 21 moves upward, and moves downward as the movable plunger 21 moves downward. The movable contactor 13 moves upward as the contact support 14 moves upward, and moves downward as the contact support 14 moves downward. A cylindrical sliding collar 26 is disposed below the outer periphery of the movable plunger 21, and a cylindrical plunger ring 27 is disposed above it.
The excitation yoke 31 includes a U-shaped upper yoke body 35 with an opening facing downward, and a lower yoke body 36 that is connected to the upper yoke body 35 and closes the opening of the upper yoke body 35. Movable plunger through-holes 37a and 37b through which the movable plunger 21 passes are formed in an upper plate 35a of the upper yoke body 35 and the lower yoke body 36.

Upward movement of the movable plunger 21 is restricted by the armature 22 abutting against the lower periphery of the movable plunger through-hole 37b in the lower yoke body 31b, while downward movement of the movable plunger 21 is restricted by the armature 22 abutting against the upper surface of the auxiliary yoke 32. The spool 24 is a cylindrical member extending in the vertical direction and surrounding the outer periphery of the movable plunger 21. An excitation coil 25 that drives the movable plunger 21 is wound around the outer periphery of the spool 24. This excitation coil 25 is electrically connected to terminal 38. The permanent magnet 33 is an annular member and is installed below the lower yoke body 36 of the excitation yoke 31 and around the armature 22 of the movable plunger 21. An annular plate-shaped auxiliary yoke 32 made of a magnetic material is installed below this permanent magnet 33. The permanent magnet 33 is attached to the lower surface of the lower yoke body 36, and the auxiliary yoke 32 is installed while being attached to the lower surface of the permanent magnet 33. The return spring 34 is installed between the lower end surface of the sliding collar 26 and the armature 22 fixed to the movable plunger 21 so as to surround the movable plunger 21, and separates the movable contact 13 from the first fixed contact 11 and second fixed contact 12 when the excitation coil 25 is de-energized.

Fig. 2 shows the internal structure of the electromagnetic contactor 1 excluding the upper case 4 (first fixed contact 11, second fixed contact 12) and the lower case 5. Fig. 3 shows the internal structure of Fig. 2 from above, and Fig. 4 shows a cross section of the internal structure shown in Fig. 2.
The contact support 14 of this embodiment is a resin member formed in a substantially rectangular shape when viewed from above, as shown in Figures 2 and 3. As shown in Figure 4, the upper end of the movable plunger 21 is fixed to the lower part of the contact support 14 by insert molding, and the lower ends of the pair of legs 16b of the spring retainer 16 are fixed to the upper part of the contact support 14 by insert molding. The movable contactor 13 is sandwiched between the top plate 16a of the spring retainer 16 and the contact spring 15 while penetrating in the left-right direction, and is arranged with a small gap between its front-rear side and the pair of legs 16b of the spring retainer 16.

As shown in Figure 3, a sliding member 40 made of non-magnetic metal plate is fixed to the side of the contact support 14 by insert molding. This sliding member 40 is formed by bending a strip of metal into a U-shape and includes a pair of opposing sliding portions 40a, 40b and a connecting portion 40c that connects the pair of sliding portions 40a, 40b. The pair of sliding portions 40a, 40b are fixed to the side surfaces of the contact support 14 facing the front-to-rear direction, and the connecting portion 40c is fixed to the side surface of the contact support 14 facing to the right.

As shown in FIG. 2, a rotation restricting member 41 made of a non-magnetic metal plate is fixed to the upper plate 35a of the upper yoke body 35 that constitutes the excitation yoke 31 of the electromagnet unit 3. This rotation restricting member 41 includes a pair of fixed portions 42 spaced apart in the left-right direction and crimped to the upper plate 35a, and a pair of flat rotation restricting portions 43a, 43b that rise upward and are connected to the front-to-rear edges of the pair of fixed portions 42. As shown in FIG. 4, a through-hole 41a through which the plunger ring 27 is inserted is formed in the center of the rotation restricting member 41. As shown in FIG. 3, the pair of rotation restricting portions 43a, 43b face a pair of sliding portions 40a, 40b of a sliding member 40 fixed to the side of the contact support 14.

Next, the operation of the electromagnetic contactor 1 of the first embodiment will be described with reference to FIG.
Now, assume that the excitation coil 25 of the electromagnet unit 3 is in a non-excited state, and the electromagnet unit 3 is in a released state where it is not generating an excitation force that moves the movable plunger 21 upward. In this released state, the movable plunger 21 is urged downward by the return spring 34, and the armature 22 is attracted to the auxiliary yoke 32 by the action of the permanent magnet 33. Therefore, the movable contactor 13 connected to the movable plunger 21 is spaced downward a predetermined distance from the first fixed contactor 11 and the second fixed contactor 12. Therefore, the current path between the first fixed contactor 11 and the second fixed contactor 12 is interrupted (open state of the contact mechanism 2).
When current is applied to the excitation coil 25 of the electromagnet unit 3 from this open state of the contact mechanism 2, an excitation force is generated in the electromagnet unit 3, which pushes the movable plunger 21 upward against the attraction force of the permanent magnet 33 to the auxiliary yoke 32 and the biasing force of the return spring 34, and the armature 22 is attracted to the underside of the lower yoke body 36 of the excitation yoke 31. As the movable plunger 21 moves upward in this manner, the movable contactor 13 connected to the movable plunger 21 also moves upward, and both contacts 13a, 13b of the movable contactor 13 come into contact with the fixed contact 11a of the first fixed contactor 11 and the fixed contact 12a of the second fixed contactor 12 with the contact pressure of the contact spring 15, and the current path between the first fixed contactor 11 and the second fixed contactor 12 is brought into a conducting state (closed state of the contact mechanism 2). When the energization of the excitation coil 25 of the electromagnet unit 3 is stopped from the closed state of the contact mechanism 2, the excitation force that moves the movable plunger 21 upward in the electromagnet unit 3 disappears, and the movable plunger 21 moves downward due to the biasing force of the return spring 34, and the armature 22 is attracted to the auxiliary yoke 32 by the action of the permanent magnet 33. When the movable plunger 21 moves downward, the movable contactor 13 connected to the movable plunger 21 moves downward away from the first fixed contactor 11 and the second fixed contactor 12, entering an opening start state.

When the movable contactor 13 moves downward due to the open contact state of the contact mechanism 2, both contacts 13a, 13b attempt to rotate in a direction away from the fixed contact 11a of the first fixed contactor 11 and the fixed contact 12a of the second fixed contactor 12. The rotation of the movable contactor 13 is transmitted to the contact support 14 via a pair of legs 16b of the spring retainer 16, which are located near the front-to-rear sides of the movable contactor 13. The rotation of the contact support 14 is restricted when a pair of sliding portions 40a, 40b of a sliding member 40 fixed to the side surface abuts against a pair of rotation restriction portions 43a, 43b of a rotation restriction member 41 that faces the pair of sliding portions 40a, 40b. In this way, when the movable contactor 13 attempts to rotate, the pair of sliding portions 40a, 40b of the sliding member 40 provided on the contact support 14 abuts and slides against the rotation restriction member 41 provided on the electromagnet unit 3, thereby restricting the rotation of the movable contactor 13. Furthermore, when the movable contactor 13 moves upward due to the contact mechanism 2 being in a closed state, the pair of sliding portions 40a, 40b of the sliding member 40 provided on the contact support 14 come into contact with and slide against the rotation restriction member 41 provided on the electromagnet unit 3, thereby restricting the rotation of the movable contactor 13.

Next, the effects of the electromagnetic contactor 1 of this embodiment will be described.
When the movable contactor 13 moves upward and downward, a pair of sliding portions 40a, 40b of the sliding member 40 fixed to the contact support 14 abuts and slides against rotation restricting portions 43a, 43b of the rotation restricting member 41 fixed to the upper plate 35a of the upper yoke body 35 of the electromagnet unit 3, thereby restricting the rotation of the movable contactor 13. As a result, the electromagnetic contactor 1 of this embodiment avoids poor conductivity between both contacts 13a, 13b of the movable contactor 13 and the fixed contact 11a of the first fixed contactor 11 and the fixed contact 12a of the second fixed contactor 12, thereby ensuring sufficient reliability of the main circuit.

In addition, the sliding member 40 and rotation restricting member 40 that restrict the rotation of the movable contactor 13 are positioned at positions that are sufficiently separated vertically from the contacts of the movable contactor 13 (contacts 13a, 13b of the movable contactor 13 and fixed contacts 11a of the first fixed contactor 11 and fixed contacts 12a of the second fixed contactor 12), so the insulation between the contacts of the movable contactor 13 is not reduced. Even if an arc is generated when the movable contactor 13 is opened, the arc does not short-circuit to the sliding member 40 and rotation restricting member 40, which are sufficiently separated vertically from the movable contactor 13, so interrupting performance can be fully ensured.

In addition, the contact support 14 of this embodiment, which is made of resin, functions as an insulating member that separates the main circuit flowing through the first fixed contactor 11, the second fixed contactor 12, and the movable contactor 13 from the drive circuit flowing through the electromagnet unit 3, thereby making it possible to provide an electromagnetic contactor 1 that ensures a sufficient insulation distance between the main circuit and the drive circuit.
In this embodiment, the sliding member 40 formed by bending a strip-shaped metal body into a U-shape is fixed to the side of the contact support 14, but the same effect can be achieved by fixing the sliding member 40 formed by bending a strip-shaped metal body into a U-shape to the side of the contact support 14.

Second Embodiment
Next, Fig. 5 shows the internal structure of the electromagnetic contactor of the second embodiment, excluding the upper case 4 (first fixed contact 11, second fixed contact 12) and the lower case 5. Fig. 6 shows the internal structure of Fig. 5 from above, and Fig. 7 shows a cross section of the internal structure shown in Fig. 6. Components that are the same as those in the first embodiment are given the same reference numerals, and descriptions thereof will be omitted.
5 and 6, the member designated by the reference numeral 44 is the resin contact support 44 of the second embodiment. As shown in Fig. 7, the lower ends of the pair of legs 16b of the spring retainer 16 are fixed to the upper part of the contact support 44 by insert molding. In addition, a pair of sliding members 45 formed from a non-magnetic metal plate material are fixed to the lower part of the contact support 44 by insert molding. The pair of sliding members 45 are plate materials bent into an L shape and include a connecting portion 46 that extends in the front-rear direction and connects to the upper part of the movable plunger 21, and a sliding portion 47 that rises from the end of the connecting portion 46.

As shown in FIG. 5, a rotation restricting member 50 made of a non-magnetic metal plate is fixed to the upper plate 35a of the upper yoke body 35 that constitutes the excitation yoke 31 of the electromagnet unit 3. This rotation restricting member 50 has a fixed portion 52 that is crimped to the upper plate 35a and has a through hole 51 formed therein for inserting the plunger ring 27, and a pair of flat rotation restricting portions 53a, 53b that rise from the edge of the through hole 51. As shown in FIG. 6, the pair of rotation restricting portions 53a, 53b face the sliding portions 47 of a pair of sliding members 45 that are fixed to the contact support 44 and the movable plunger 21.

In the electromagnetic contactor 1 of this embodiment, when the movable contactor 13 moves downward due to the open state of the contact mechanism 2, if both contacts 13a, 13b attempt to rotate in a direction away from the fixed contact 11a of the first fixed contactor 11 and the fixed contact 12a of the second fixed contactor 12, the rotation of the movable contactor 13 is transmitted to the contact support 44 via a pair of legs 16b of the spring retainer 16 located close to the front-to-rear sides of the movable contactor 13. The sliding portions 47 of a pair of sliding members 45 fixed to the contact support 44 come into contact with a pair of rotation restriction portions 53a, 53b of the rotation restriction member 50 that face them, thereby restricting the rotation. In this way, when the movable contactor 13 attempts to rotate, the sliding portions 47 of the pair of sliding members 45 fixed to the contact support 44 come into contact with and slide against the pair of rotation restricting portions 53a, 53b of the rotation restricting member 50 fixed to the electromagnet unit 3, thereby restricting the rotation of the movable contactor 13. Furthermore, when the movable contactor 13 moves upward due to the closed state of the contact mechanism 2, the sliding portions 47 of the pair of sliding members 45 of the contact support 44 come into contact with and slide against the pair of rotation restricting portions 53a, 53b of the rotation restricting member 50, thereby restricting the rotation of the movable contactor 13.

Therefore, in the electromagnetic contactor 1 of the second embodiment, the rotation of the movable contactor 13 when it moves upward and downward is restricted, thereby avoiding poor conductivity between both contacts 13a, 13b of the movable contactor 13 and the fixed contact 11a of the first fixed contactor 11 and the fixed contact 12a of the second fixed contactor 12, and fully ensuring the reliability of the main circuit.
Furthermore, the sliding portions 47 of the pair of sliding members 45 that restrict the rotation of the movable contactor 13 and the pair of rotation restricting portions 53a, 53b are positioned at positions that are sufficiently spaced apart in the vertical direction from the contacts of the movable contactor 13, so that the insulation between the contacts of the movable contactor 13 is not reduced, and even if an arc is generated when the movable contactor 13 is opened, the arc does not short-circuit to the sliding portions 47 of the pair of sliding members 45 and the pair of rotation restricting portions 53a, 53b, which are sufficiently spaced apart in the vertical direction from the movable contactor 13, so that interrupting performance can be sufficiently ensured.

In addition, because the connecting portions 46 of the pair of sliding members 45 are connected to the top of the movable plunger 21, the impact force of the sliding portions 47 when they come into contact with the pair of rotation restriction portions 53a, 53b can be dissipated to the movable plunger 21. This improves the durability of the resin contact support 44, which is less susceptible to impact force.

1 Electromagnetic contactor 2 Contact mechanism 3 Electromagnet unit 4 Upper case 5 Lower case 6 Storage case 7 Gas inlet pipe 8 Mounting portion 11 First fixed contact 11a Fixed contact 12 Second fixed contact 12a Fixed contact 13 Movable contacts 13a, 13b Movable contact 14 Contact support 15 Contact spring 16 Spring holder 16a Top plate portion 16b Leg portion 21 Movable plunger 22 Armature 24 Spool 25 Excitation coil 26 Sliding collar 27 Plunger ring 31 Excitation yoke 32 Auxiliary yoke 33 Permanent magnet 34 Return spring 35 Upper yoke body 35a Upper plate 36 Lower yoke body 37a, 37b Movable plunger through hole 38 Terminal 40 Sliding member 40a, 40b Sliding portion 40c Connecting portion 41 Rotation restricting member 41a Through hole 42 Fixed portion 43a, 43b Rotation restricting portion 44, contact support 45, sliding member 46, connecting portion 47, sliding portion 50, rotation restricting member 51, through hole 52, fixing portions 53a, 53b, rotation restricting portion

Claims (3)

a pair of fixed contacts having fixed contacts;
a long movable contactor having a pair of movable contacts that can be brought into contact with and separated from the fixed contacts of the pair of fixed contacts;
an electromagnet unit that drives a movable plunger connected to the movable contactor via a movable contactor support portion to drive the movable contactor in a direction toward or away from the pair of fixed contactors,
a rotation restricting portion that restricts rotation of the movable contact when the movable contact moves forward and backward is disposed near the movable contact supporting portion ;
The movable contactor support portion comprises a resin contact support fixed to one end of the movable plunger, a spring presser having a top plate portion and a pair of legs extending parallel to each other from both ends of the top plate portion and fixed to the contact support, and a contact spring that biases a longitudinal center portion of the movable contactor disposed inside the spring presser toward the top plate portion,
the electromagnet unit includes an excitation coil that generates a magnetic force by being excited to drive the movable plunger, and an excitation yoke that surrounds the excitation coil;
An electromagnetic contactor characterized in that the rotation regulating portion comprises a flat metallic sliding portion fixed to the side of the contact support along the rotation direction, and a flat metallic rotation regulating portion fixed to the excitation yoke and arranged opposite the sliding portion . 2. The electromagnetic contactor according to claim 1, wherein the sliding portion is fixed to the side surface of the contact support at least in two places, and the rotation restricting portion is disposed at at least in two places opposite the sliding portion at least in two places . 3. The electromagnetic contactor according to claim 1, wherein a connecting portion is formed integrally with the sliding portion, and the connecting portion is fixed to the movable plunger .