JP4534777B2 - Magnetic contactor - Google Patents

Description

  The present invention relates to an electromagnetic contactor equipped with a hinge type electromagnet as an operation electromagnet.

As an electromagnet for operation of an electromagnetic contactor, an E-shaped fixed core with a magnetic pole surface facing upward and a resin-molded product in which an operation coil is wound and inserted into the center leg of the fixed core Adopting an electromagnet consisting of a spool and a hinge-type movable core pivotally supported on a bearing formed on the upper end of the spool and placed on a fixed core, the movable core is attracted (rotated) by the excitation of the operating coil. ), A contactor holder is driven in the lateral direction to open and close the contacts (for example, see Patent Document 1 and Patent Document 2).
Next, based on the configuration disclosed in Patent Document 2, the structure and operation of a conventional electromagnetic contactor will be described with reference to FIGS. In each figure, 1 is a resin mold case of an electromagnetic contactor having a two-part structure of an upper case 1a and a lower case 1b, 2 is an E-shaped fixed core incorporated in the lower case 1b, and 3 is an operation coil 4 wound around. The spool is a resin-molded product inserted into the center leg 2a (2b, 2c is the outer leg) of the fixed core 2 and 5 is pivotally supported by a bearing formed at the upper end of the spool 3 and placed on the fixed core. The hinged movable core 6 is connected to the movable core 5 and is a laterally sliding contact holder built in the upper case 1a, 7 is a bridge-shaped movable contactor mounted and held on the contact holder 6, and 8 is fixed. A contact 9 is a return spring (compression coil spring) inserted between the contact holder 6 and the upper case 1a.

Here, as shown in FIG. 6, a step 1c that is one step higher than the bottom is formed at an end (right side in the drawing) corresponding to the hinge side of the movable core 5 at the bottom of the lower case 1b. The yoke end of the fixed core 2 is placed on the part 1c, and the fixed core is assembled in the case. The cantilever is supported so that the fixed core 2 can be slightly tilted to the left with the edge of the step 1c as a fulcrum. is doing. Further, as will be described later, an engagement groove portion 1d and a support base portion 1e for holding the spool 3 in a fixed position are provided inside the case.
On the other hand, the spool 3 to be a resin molded product is provided with flanges 3a. A bearing portion 3c that has a hinge shaft portion 5a formed on the movable core 5 and is pivotally supported is formed on one end side of both blade wall portions that rise from the upper flange portion 3a. Further, in order to latch and hold the spool 3 on the lower case 1b, the lower flange portion 3b has an engagement protrusion 3d fitted into an engagement groove portion 1d formed in the lower case 1b, and the upper wing wall portions have the above-mentioned A support arm 3e to be carried on the support base 1e of the lower case 1b is integrally formed at the end opposite to the bearing 3c.

The movable core 5 has an L shape with an operating arm 5b rising upward from the rear part of the hinge shaft 5a as shown in the figure, and the tip of the operating arm 5b is connected to the contact holder 6 as shown in FIG. .
With the above configuration, when the operation coil 4 is in a non-excited state, as shown in FIG. 2, the contact holder 6 is retracted to the right by receiving the spring force of the return spring 9, and the movable core 5 connected to the contact holder 6 is connected. Is pivoted clockwise with the hinge shaft 5a as a fulcrum and is waiting at a release position away from the contact surface of the fixed core 2.
Here, when the operation coil 4 is excited based on an external command, the movable core 5 rotates counterclockwise around the hinge shaft 5a by a magnetic attractive force acting between the fixed / movable cores, as shown in FIG. Then, the contact holder 6 is driven to the left at the same time as being attracted to the contact surface of the fixed core 2, whereby the contact of the movable contact 7 / the fixed contact 8 is switched.

Further, in the adsorption operation process of the movable core 5, as shown in FIG. 4, the fixed core 2 receives the load when the movable core 5 collides with the magnetic pole surface of the fixed core 2, and the fixed core 2 is stepped on the lower case 1b. The movable core 5 overshoots counterclockwise while tilting slightly counterclockwise with the edge portion P of 1c as a fulcrum, and the return spring 9 is compressed via the contact holder 6. As a result, the collision energy accompanying the adsorption operation of the movable core is absorbed and relaxed, and unnecessary bounce of the movable core 5 is suppressed to prevent chattering between the fixed / movable contacts.
JP-A-4-280025 JP-A-10-223431

By the way, the electromagnetic contactor having the above configuration has the following problems in terms of operation and function. That is, in the conventional structure, the impact load accompanying the adsorption operation of the movable core is absorbed and relaxed by the tilting of the fixed core and the compression of the return spring, so that the movable core is positioned from the position where it hits the contact surface of the fixed core. Furthermore, it will rotate in the direction of overshoot.
In this case, the fixed core 2 is inclined with the lower end of the yoke as a fulcrum (arrow P), while the movable core 5 is rotated around the hinge shaft 5a. For this purpose, the magnetic pole surface of the fixed core 2 slides while being overlapped with the movable core 5 after being attracted, and the magnetic material powder generated by the abrasion of the attracting surface is scattered and adhered to the inside of the case for insulation. May deteriorate.
On the other hand, magnetic contactor products are required to have high dimensions and assembly accuracy in order to ensure the specified quality. Especially for fixed and movable contacts, high accuracy of ± 0.2mm is required for parts and assembly positions. Imposed. In this respect, when the core attracting surface of the electromagnet is worn as described above, the operating position of the contact holder 6 is changed, and the characteristics of the contact opening / closing operation are affected. Moreover, the inclination of the fixed core 2 varies depending on the magnitude of the impact load when the movable core 5 is attracted, with the position where the end opposite to the tilting fulcrum of the core abuts against the bottom wall of the lower case 1b as the maximum inclination. Also, the opening / closing operation of the fixed / movable contact becomes unstable and the reliability of the product is lowered. In addition, if the overshoot of the movable core 5 during the adsorption operation increases, the bending allowance of the movable contact becomes large when the movable contact is in contact with the fixed contact. Accelerates.

Note that the spool having the conventional structure has a sufficient clearance between the component and the fixed core at the assembly position of the spool so as to release the inclination of the fixed core due to the attracting operation of the electromagnet as described in Patent Document 2. To avoid contact between the spool and the fixed core.
The present invention has been made in view of the above points, and skillfully absorbs and reduces the collision load associated with the adsorption operation of the electromagnet without adding a significant change such as adding a new part to the conventional structure. An object of the present invention is to provide a highly reliable electromagnetic contactor which is improved so as to stabilize the operation characteristics while suppressing the influence on the opening / closing position.

In order to achieve the above object, according to the present invention, an E-shaped fixed core built in a lower case with a magnetic pole surface facing upward, and an operation coil are wound and inserted into the center leg of the fixed core. A spool with a hook that becomes a resin molded product, a hinge-shaped movable core that is pivotally supported on a bearing formed at one end of the upper portion of the spool, and is disposed on the fixed core, and is connected to the movable core and is installed in the upper case. Assembly of a laterally sliding contact holder, a movable contact mounted on the contact holder, a fixed contact facing the movable contact, and a return spring that urges the movable core in a direction to release it from the fixed core It is an electromagnetic contactor that has a structure and operates the contact holder holder to open and close the contact by attracting the movable core by exciting the operating coil, and the fixed core has a yoke end corresponding to the hinge side of the movable core at the lower case Formed at the bottom of The spool is mounted on the difference portion and cantilevered. The spool is loosely fitted to the center leg of the fixed core and is held by the lower case. The spool is assembled in the assembled state in which the fixed core and the spool are housed in the lower case. As shown in FIG. 2, the upper side flange portion of the fixed core is opposed to be close to the hinge-side leg portion of the fixed core so as to face each other, and the spool is formed of a molded part of a thermoplastic resin having flexibility, and is assembled to the lower case. The overhang dimension of the heel part is set so that the minimum clearance necessary for assembling the parts is left between the peripheral edge of the upper heel part and the hinge-side leg part of the fixed core at the position. 1).

  According to the above configuration, when the movable core is attracted to the magnetic pole surface of the fixed core by the excitation of the electromagnet, and the fixed core that receives the impact load tries to tilt with the step portion of the lower case as a fulcrum, The leg is inserted into the central leg and hits the tip of the flange portion of the spool held in the lower case, and the inclination of the fixed core is restricted, and the spool made of thermoplastic resin is bent to absorb and reduce the impact load of the movable core. That is, the flange portion of the spool functions as a buffer stopper. As a result, the movable core does not overshoot as in the conventional structure. In addition, the pushing load applied from the fixed core to the flange portion of the spool is in a direction (downward) that the movable core collides with the magnetic pole surface of the fixed core (horizontal direction), and the movable core is applied to the bearing portion formed on the spool. Since it is pivotally supported, there is almost no occurrence of relative sliding between the movable core and the magnetic pole surface of the fixed core, and the problem caused by core wear due to sliding friction, which has been a problem in the conventional structure, can be solved.

  Further, since there is almost no overshoot of the movable core, the operation position of the contact holder connected to the movable core does not vary, and the opening / closing operation of the contact is stabilized and the reliability is improved.

Embodiments of the present invention will be described below based on the examples shown in FIGS. 1 (a) and 1 (b). In addition, in the figure of an Example, the same code | symbol is attached | subjected to the member corresponding to FIG. 2, and the description is abbreviate | omitted.
That is, the electromagnetic contactor of the illustrated embodiment basically has the same assembly structure as that of the prior art, but the upper side flange 3a of the spool 3 made of a thermoplastic resin molded product is an electromagnet hinge in the illustrated embodiment. In the assembled state in which the distal end 3a-1 of the flange portion protruding toward the side is extended from the conventional structure and the fixed core 2 and the spool 3 are housed in the lower case 1b as illustrated, the distal end 3a-1 of the flange portion 3a is assembled. Is made to approach and face each other until it almost comes into contact with the leg surface of the outer leg 2c corresponding to the hinge side of the E-shaped fixed core 2, specifically, between the tip 3a-1 of the flange 3a and the outer leg 2c. The dimensions and assembly accuracy of the parts are controlled so that the clearance g is about 0.5 mm (the minimum clearance required for the parts assembly work).

  With the above configuration, the movable core 5 is attracted to the magnetic pole surface of the fixed core 2 by excitation of the operation coil 4, and the edge (arrow) of the step portion 1c formed on the bottom of the lower case 1b by the fixed core 2 receiving the impact load When trying to tilt counterclockwise with the point P) as a fulcrum, the upper side collar of the spool 3 in which the outer leg 2c of the E-shaped core is inserted into the center leg 2a and is held by the lower case 1c (see FIG. 6) 3, the inclination of the fixed core 2 is restricted, and the spool itself made of thermoplastic resin is bent to absorb and relax the impact load of the movable core 2. That is, the flange portion 3a of the spool 3 functions as a buffer stopper. This prevents the movable core 5 from overshooting as in the conventional structure described with reference to FIGS. In addition, the pushing load applied from the fixed core 2 to the flange portion 3a of the spool 3 is in a direction (downward) where the movable core 5 collides with the magnetic pole surface of the fixed core 2 (downward), and the movable core 5 is spooled. Since it is pivotally supported by a bearing portion 3c (see FIG. 6) formed in FIG. 3, there is almost no relative sliding between the movable core 5 and the magnetic pole surface of the fixed core 2, which is a problem in the conventional structure. Problems due to core wear due to sliding friction can be solved. Furthermore, since the overshoot of the movable core 5 hardly occurs, the operation positions of the contact holder 6 and the movable contact 7 connected to the movable core 5 do not vary, and the contact opening / closing operation is stabilized and electromagnetic contact is achieved. The reliability of the vessel is improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram of this invention Example, (a) is a longitudinal front view of the whole electromagnetic contactor, (b) is an enlarged view of the principal part in (a). Configuration diagram showing the released state of a conventional magnetic contactor The figure showing the input state of FIG. The figure showing the state at the time of a movable core colliding with the magnetic pole surface of a fixed core in the injection | throwing-in process from FIG. 2 to FIG. External perspective view of magnetic contactor Exploded perspective view of lower case, spool and movable core for explaining the assembly structure of the magnetic contactor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin mold case 1a Upper case 1b Lower case 1c Step part for cantilever support of fixed core 1d Engagement groove part of spool 1e Support base part of spool 2 E-shaped fixed core 2a Central leg 2c Hinge side outer leg 3 Spool 3a Upper part Side flange portion 3c Bearing portion 3d Engaging projection 3e Support arm 4 Operating coil 5 Movable core 5a Hinge shaft portion 6 Contact holder 7 Movable contact 8 Fixed contact 9 Return spring

Claims (1)

An E-shaped fixed core that is built in the lower case with the magnetic pole surface facing upward, a hooked spool that is a resin-molded product that is wound around the center leg of the fixed core by winding an operation coil, and an upper portion of the spool A hinge-type movable core pivotally supported by a bearing portion formed at one end and disposed on a fixed core, a laterally-sliding contact holder connected to the movable core and housed in an upper case, and the contact holder The assembled structure of the mounted movable contact, the fixed contact that faces the movable contact, and the return spring that urges the movable core in the direction to release it from the fixed core. The fixed core is cantilevered by placing the yoke end corresponding to the hinge side of the movable core on the step formed on the bottom of the lower case. The spool is fixed In the assembled state in which the fixed core and the spool are housed in the lower case, the tip of the upper side collar portion of the spool is on the hinge side of the fixed core. The spool is made of a thermoplastic resin molded part having flexibility so as to almost come into contact with the leg part, and at the assembly position to the lower case, the peripheral edge of the upper side collar part and the fixed core An electromagnetic contactor characterized in that an overhanging dimension of the flange portion is set so as to face the hinge side leg portion while leaving a minimum clearance necessary for assembly of parts .

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