JPH06105584B2 - Electromagnetic contactor motion retainer - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to an operation retainer for an electromagnetic contactor that excites a closing coil and mechanically holds the electromagnetic contactor in the closed state even after the closing coil is demagnetized.

[Prior art]

As a motion retainer for this type of electromagnetic contactor,
The one described in Japanese Patent No. 649 is known. this is,
The push bar that is constantly pressed against the movable contact support by the force of the closing spring attached to the operation indicator rod moves following the movable contact support when the electromagnetic contactor is turned on, and the movable piece connected to the push rod by it. Is locked by a lock piece that receives the force of the latch spring to maintain the electromagnetic contactor in the closed state.

[Problems to be Solved by the Invention]

By the way, the spring force of the closing spring is required to have a strength that allows the operation indicating rod, the movable piece and the push rod to follow the movement of the movable contact support when the electromagnetic contactor is closed. Since the latch spring makes sliding contact with the lock piece that is pressed against the tip of the movable piece in the process of reaching, the spring force of the closing spring takes into consideration the frictional force at the time of the sliding contact. On the other hand, the electromagnetic contactor in the closed state is released when the locking of the movable piece is released by the action of the electromagnet mechanism. At that time, the movable contactor support is pushed up against the closing spring by the return spring. Therefore, the spring force of the return spring must be stronger than the closing spring. That is, in the operation retainer of the electromagnetic contactor described in the above publication, since the closing spring for making the push rod and the like follow is provided, the spring force of the return spring of the electromagnetic contactor is increased by an amount corresponding to the closing spring. I have to be strong. Moreover, the spring force of the closing spring includes a component for overcoming the frictional force due to the direct contact between the movable piece and the lock piece pressed by the latch spring. Therefore, conventionally, when the motion retainer is used, it is necessary to increase the spring force of the return spring and to increase the capacity of the operating magnetic stone accordingly, compared with the case where the motion retainer is not used. However, for that purpose, parts with special specifications such as a closing coil are required, and there is a problem that the life of each part of the electromagnetic contactor is shortened as the operating force increases. Further, in the operation retainer of the electromagnetic contactor described in the above publication, the closing coil degaussing contact that is opened by the lock piece at the same time as the locking of the movable piece is one-point disconnection, so the voltage is high in the case of DC operation. In that case, there is a risk that the closing of the closing circuit may occur and the closing coil may be burnt out. The present invention eliminates the need for a spring to follow the components of the motion retainer and the movable contact support, and reduces the influence of the latch springs to reduce the load on the electromagnetic contactor accompanying the mounting of the motion retainer. It is an object of the present invention to provide an operation retainer for an electromagnetic contactor which eliminates an increase in the number of contacts and further improves the breaking performance of the closing coil degaussing contact to prevent a burning accident of the closing coil.

[Means for Solving the Problems]

In order to achieve the above object, a motion retainer for an electromagnetic contactor according to the present invention includes a latch piece connected to a movable contact support of the electromagnetic contactor and a two-point disconnection for demagnetizing a closing coil of the electromagnetic contactor. A contact mechanism having a normally closed contact, and when a latch spring constantly presses the latch piece through a roller to turn on an electromagnetic contactor, the roller rides on a shoulder portion of the latch piece and locks the latch piece. A latch lever for opening the contact mechanism and an electromagnet mechanism for rotating the latch lever against the spring force of the latch spring to unlock the latch piece.

[Action]

Since the latch piece for holding the electromagnetic contactor in the closed state is connected to the movable contact support, the spring for causing the latch piece to follow the movable contact support is unnecessary. Further, since the latch lever for locking the latch piece is pressed against the latch piece via the roller by the latch spring, the frictional force between the latch lever and the latch piece becomes small. Further, since the built-in contact for degaussing the closing coil is cut at two points, the breaking performance is improved and the closing coil can be reliably demagnetized.

【Example】

1 to 4 show an embodiment of the present invention, FIG. 1 (A) is a cross-sectional view of a motion retainer released by an electromagnetic contactor, and FIG. 2 is a perspective view of a latch lever, FIG. 3 is a perspective view of a latch piece, and FIG. 4 is a perspective view of a contact mechanism. In the figure, reference numeral 10 is an electromagnetic contactor, and an operation retainer is provided above the electromagnetic contactor.
20 is installed. The figure shows the front of the electromagnetic contactor 10, and 11 is a terminal screw. The electromagnetic contactor 10 has a well-known structure, and although not shown, the electromagnetic contactor 10 has an operation electromagnet including a movable core, a fixed core, and a closing coil for driving the movable core, which is connected to the movable core. The movable contact support 12 has a movable contact and a contact spring incorporated therein. Then, the movable core is attracted by the excitation of the closing coil, and when the excitation is cut off, the movable core is returned to the released state by a return spring (not shown) incorporated in the movable contact support if the operation holder is not provided. . On the other hand, the motion retainer 20 is configured such that the case 21 accommodates the latch lever 22, the latch piece 23, the electromagnet mechanism 24, the contact mechanism 25, and the like. The case 21 made of a mold resin has a groove 21a having a T-shaped cross section at the bottom, and the groove 21a has a cross section T of the electromagnetic contactor 10.
Insert the character-shaped protrusion 10a to attach the motion retainer 20 to the electromagnetic contactor 1
It is designed to be attached to 0. The latch lever 22 is formed of a mold resin into a prismatic shape as shown in FIG. 2, and is rotatably supported by a pin 27 on a mounting bracket 26 having a U-shaped arm. At the tip of the latch lever 22, a bifurcated operation end 22a for operating the contact mechanism 25 is formed.
Are integrally formed, and rollers 28 are attached by pins 29 on both sides of the base. Also, the latch lever
A latch spring 30 which applies a force to the latch lever 22 in the counterclockwise direction in FIG. In addition, 22b is an operation display rod integrally formed with the latch lever 22, and a display window 21b opened at the top of the case 21.
It projects from (Fig. 1) and displays the released and put-in state of the electromagnetic contactor 10. The latch piece 23 is also made of molding resin, and its detailed shape is as shown in FIG. The latch piece 23 has a T-shaped portion 23a at the lower end, and by inserting the T-shaped portion 23a into the T groove 12a (FIG. 1) at the upper end of the movable contact support 12, a movable contact is formed. It is connected to the child support 12. On one side of the latch piece 23, square shoulders 23b on which the roller 28 of the latch lever rides are formed at two front and rear positions, as will be described later. The mounting bracket 26 supporting the latch lever 22 is screwed to the side wall of the case 21. The latch lever 22 faces one side of the latch piece 23 in the case 21 as shown in FIG. 1, and in the electromagnetic contactor released state of FIG. It is in contact with the side surface of the portion 23b. The electromagnet mechanism 24 is composed of a plunger 24a, a trip coil 24b wound around the plunger 24a, and a yoke 24c, and the plunger 24a is held at the illustrated position by a back spring (not shown) when not excited. The electromagnet mechanism 24 is screwed to the side wall of the case 21 close to the other side of the latch piece 23, and in this state, the tip of the plunger 24a faces the latch lever 22 via the upper cutout 23c of the latch piece 23. It has become. As shown in FIG. 4, the contact mechanism 25 has two points in which a pair of fixed contacts 32 are embedded in a frame 31 made of mold resin and a movable contact 33 is arranged so as to bridge the fixed contacts 32. It is configured as a normally closed contact. Movable contact 33
Is inserted into a U-shaped contact support portion 31a integral with the frame 31, and is constantly pressed against the fixed contact 32 by the contact spring 34. The contact mechanism 25 is placed on the bottom of the case 21 and arranged below the latch lever 22, and is screwed to the side wall of the case 21 by a mounting piece 31b. FIG. 5 shows an operation circuit for the electromagnetic contactor 10 and the motion retainer 20. Between the power supply P and N, the closing coil 35 of the electromagnetic contactor 10, the normally closed contact of the contact mechanism 25, and the closing switch 36. The normally open contact and the normally closed contact of the release switch 37 are connected in series,
Furthermore, the trip coil of the motion retainer 20 is connected between the power supply P and N.
24b, a built-in normally open contact (auxiliary contact) 35a of the electromagnetic contactor 10, a normally closed contact of the closing switch 36 and a normally open contact of the release switch 37 are connected in series. Now, in such a configuration, the closing switch of FIG.
When 36 is turned on to close the excitation circuit of the closing coil 35, the latch piece 23 moves together with the movable contact support 12 downward in the figure. Therefore, when the shoulder portion 23b of the latch piece 23 passes the roller 28, the latch lever receiving the force of the latch spring 30.
22 rotates counterclockwise in the figure, and the roller 28 rides on the shoulder portion 23b of the latch piece 23 as shown in FIG. At this time, the operating end 22a of the latch lever 22 directly pushes both shoulders of the movable contact 33 of the contact mechanism 25 to open it. As a result, the exciting circuit of the closing coil 35 is opened to close the closing coil 35.
Is demagnetized. However, the latch piece 23 is locked by the latch lever 22 in the state shown in FIG. 1 (B), and the electromagnetic contactor 10 is held in the closed state. In FIG. 1 (B) showing the holding state, the contact point 38 between the roller 28 and the shoulder portion 23b is
The dead point of the reaction force from the shoulder 23b with respect to the fulcrum (pin 27) of the latch lever 22 is set slightly to the right in the figure, and even if the spring force of the latch spring 30 is small, vibration or impact causes the roller to move. The engagement between 28 and the shoulder portion 23b is prevented from being disengaged. In the holding operation, the latch piece 23 connected to the movable contact support 12 descends together with the movable contact support 12 when the electromagnetic contactor is turned on. No spring is used to press and follow it. Therefore, the return spring of the movable contactor support 12 does not need to have a particularly large spring force as compared with the case where the motion retainer is not used. Further, the latch lever 22 is pressed against the latch piece 23 by the latch spring 30, but since the contact with the latch piece 23 is a rolling contact via the roller 28, the latch lever 22 is pushed from the latch lever 22 during the closing process of the electromagnetic contactor 10. The frictional force acting on the latch piece 23 is small. From these things, according to the configuration shown in the figure, even if the motion retainer 20 is mounted, the closing operation force of the electromagnetic contactor 10 does not particularly increase, and the closing coil may be a standard coil. To release the electromagnetic contactor 10 from the holding state of FIG. 1 (B), the release switch 37 is turned on in FIG.
Energize 24 trip coils 24b. The electromagnetic contactor 10
The built-in normally-open contact 35a is closed in the operation holding state of the electromagnetic contactor 10. As a result, the plunger 24a is attracted and moves to the left in the figure, and the latch lever 22 is rotated in the clockwise direction in the figure against the force of the latch spring 30. As a result, the latch piece 23 is unlocked and returns to the state of FIG. 1 (A) by the return spring (not shown) together with the movable contact support 12. FIG. 6 is an exploded perspective view showing a main configuration of the latch lever 22 that facilitates fine adjustment of the vertical position of the roller 28. That is, in FIG. 6, a square hole 22c penetrating in the front-rear direction is formed in the upper portion of the latch lever 22, and a nut plate 39 having a screw hole is press-fitted therein. On the other hand, attach the latch lever 22
The insertion hole 22d for the pin 27 to be supported by the 26 is a vertically long slot, and the adjustment screw 40 is screwed into the pin 27 and the nut plate 39.
A cushion spring 41 is inserted between and. With such a configuration, by turning the adjusting screw 40, the latch lever 22 can be moved up and down within the range of the gap between the elongated hole 22c and the pin 27. As a result, fine adjustment of the opening of the operation electromagnet of the electromagnetic contactor 10 becomes possible, and the reliability of the motion retainer 20 becomes higher.

【The invention's effect】

According to the present invention, a spring for making the components of the motion retainer follow the movable contact support of the electromagnetic contactor is unnecessary,
In addition, by rolling the contact between the latch piece and the latch lever to reduce the frictional force, the load of the closing coil of the electromagnetic contactor does not increase even if the motion retainer is mounted, and the closing coil of special specifications etc. Is unnecessary and
The life of the electromagnetic contactor can be extended and the cost can be reduced. Further, by making the contacts for degaussing the closing coil into two points, it is possible to reliably cut off even at a high DC operating voltage and prevent burning of the closing coil. Also, since the latch piece is directly connected to the movable contact support, it has good followability,
The reliability of operation holding is also high.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, and FIG. 1 (A) is a sectional view of a motion retainer in a state where an electromagnetic contactor is released, and FIG. 1 (B).
Is a cross-sectional view of the motion retainer with the electromagnetic contactor turned on; FIG. 2 is a perspective view of the latch lever of FIG. 1, FIG. 3 is a perspective view of the latch piece of FIG. 1, and FIG. FIG. 5 is a perspective view of the contact mechanism shown in FIG. 5, FIG. 5 is an operation circuit diagram of the electromagnetic contactor and the motion retainer of FIG. 1, and FIG. .. 10 ... Electromagnetic contactor, 12 ... Movable contactor support, 20 ... Motion retainer, 22 ... Latch lever, 22a ... Latch lever operation end, 2
3 ... Latch piece, 23b ... Latch piece shoulder, 24 ... Electromagnetic mechanism,
25 ... Contact mechanism, 28 ... Roller, latch spring ... 30,33
… Movable contact of the contact mechanism, 35… closing coil.

Claims (1)

[Claims] 1. A latch piece connected to a movable contact support of an electromagnetic contactor, a contact mechanism having a two-point open normally closed contact for demagnetizing a closing coil of the electromagnetic contactor, and a roller by a latch spring. When the electromagnetic contactor is constantly pressed by the latch piece and the electromagnetic contactor is closed, the roller rides on the shoulder portion of the latch piece to lock the latch piece and open the contact mechanism, and the spring of the latch spring. An operation retainer for an electromagnetic contactor, comprising an electromagnet mechanism for rotating the latch lever against a force to unlock the latch piece.