JPH0260019A - Operation retainer for electromagnetic contactor - Google Patents

Abstract

PURPOSE:To eliminate an increase in load on the side of an electromagnetic contactor and further prevent burning of a coil by connecting a latch piece to a movable contact support, forcing a latch lever to press the latch piece through a roller, and further rataining a built-in contact demagnetizing a closing coil in a opened state until a continuous opening contact of the electromagnetic contactor is closed. CONSTITUTION:In a retaining operation, since a latch piece 23 connected to a movable contact support 12 is lowered with the support 12 when an electromagnetic contactor is closed, a spring for pressing the latch piece 23 against the support 12 and forcing the latch piece to follow the support is not used. A latch lever 22 is pressed against the latch piece 23 by a latch spring 30, but contact between the latch lever and the latch piece 23 is a rolling contact through a roller 28, so that frictional forces acting on the latch piece 23 from the latch lever 22 is small. Further, when a return of the latch piece 23 reaches a distance sufficient to open contacts 36a, 36b, engagement of an engaging piece 23d with an engaging bar 35 is ended to close a contact-mechanism 25. Thus, simultaneous excitation of a closing coil 36 and a trip coil 24b does not occur.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an operation holder for an electromagnetic contactor that mechanically maintains an electromagnetic contactor whose closing coil is energized to be closed even after the closing coil is demagnetized. [Conventional technology]

As an operation retainer for this type of electromagnetic contactor,
The one described in Japanese Patent No. 45649 is known. This is because the push rod, which is constantly pressed against the movable contact support by the force of the closing spring attached to the operation display rod, moves to follow the movable contact support when the electromagnetic contactor is turned on, and is thereby connected to the push rod. The movable piece is locked by a lock piece that receives the force of a latch spring, and the closed state of the electromagnetic contactor is maintained.

[Problem to be solved by the invention]

By the way, the spring force of the closing spring needs to be strong enough to make the operation indicator rod, movable piece, and push rod follow the movement of the movable contact support when the electromagnetic contactor is turned on, and the movable piece also needs to be strong enough to follow the movement of the movable contact support when the electromagnetic contactor is turned on. During this process, the latch spring makes sliding contact with the lock piece pressed against the tip of the movable piece, so the spring force of the closing spring takes into account the frictional force during the sliding contact. On the other hand, the electromagnetic contactor in the closed state is released when the movable piece is unlocked by the action of the electromagnetic mechanism. At this time, the movable contact 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. In other words, in the operation retainer of the electromagnetic contactor described in the above publication, since a closing spring is provided for making the push rod follow, the spring force of the return spring of the magnetic contactor is reduced by the amount that opposes the closing spring. I have to make it stronger. Furthermore, the spring force of the closing spring includes a component for overcoming the frictional force caused by direct contact between the movable piece and the lock piece pressed against it by the latch spring. Therefore, conventionally, when a motion retainer is used, the spring force of the return spring must be made larger than when the motion retainer is not used, and the capacity of the operating electromagnet must be correspondingly increased. However, this requires parts with special specifications such as a closing coil, and there is also the problem that the life of each part of the electromagnetic contactor is shortened as the operating force increases. In addition, in the operation retainer for the electromagnetic contactor described in the above publication, the closing coil demagnetization contact, which is opened by the lock piece at the same time as the movable piece is locked when the electromagnetic contactor is turned on, is closed by the movable piece when the electromagnetic contactor is released. The circuit closes as soon as the lock is released. Therefore, the closing coil of the electromagnetic contactor and the tripping coil of the motion retainer are excited at the same time, and there is a risk that the coils will be burnt out due to the fluttering operation. This invention eliminates the need for a spring for making the components of the motion retainer follow the movable contact support, and reduces the influence of the latch spring, thereby reducing the load on the electromagnetic contactor side due to the attachment 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 voltage and also prevents simultaneous excitation of a closing coil and a tripping coil, thereby preventing a coil burnout accident.

[Means to solve the problem]

In order to achieve the above object, the operation retainer of the electromagnetic contactor of the present invention includes a latch piece connected to a movable contact support of the electromagnetic contactor, and a normally closed contact for demagnetizing the closing coil of the electromagnetic contactor. a contact mechanism having a latch spring that is constantly pressed against the latch piece through a roller, and when the electromagnetic contactor is turned on, the roller rides on the shoulder of the latch piece to lock the latch piece and the contact mechanism It consists of a latch lever that opens the circuit, and an electromagnetic mechanism that rotates the latch lever against the spring force of the latch spring to unlock the latch piece, and the movable contact of the contact mechanism has an engaging claw at the tip. A locking rod having a locking rod is fixed, and this locking rod engages with the locked latch piece when the contact mechanism is opened by turning on the electromagnetic contactor, and
When the latch piece is unlocked by the operation of the electromagnetic mechanism, the contact mechanism is maintained in the open state by maintaining engagement with the latch piece until the normally closed contact of the electromagnetic contactor is opened. shall be.

[For use]

Since the latch piece that holds the electromagnetic contactor in the closed state is connected to the movable contact support, there is no need for a spring to cause the latch piece to follow the movable contact support. Further, since the latch lever that locks the latch piece is pressed against the latch piece via a roller by the latch spring, the frictional force between the latch lever and the latch piece is reduced. Further, since the built-in contact for demagnetizing the closing coil is held open until the normally closed contact of the electromagnetic contactor is opened, the phenomenon in which the closing coil and the tripping coil are simultaneously excited does not occur.

【Example】

1 to 4 show embodiments of the present invention, and FIG. 1 (A
) is a cross-sectional view of the operating retainer with the electromagnetic contactor released,
Figure 1 (B) is a sectional view of the operating retainer with the electromagnetic contactor closed, Figure 2 is a perspective view of the latch lever, Figure 3 is a perspective view of the latch piece, and Figure 4 is a perspective view of the contact mechanism. It is a diagram. In the figure, reference numeral 10 denotes an electromagnetic contactor, and a motion retainer 20 is attached to the upper part of the electromagnetic contactor. The figure shows the front of the electromagnetic contactor IO, and 11 is a terminal screw. The electromagnetic contactor 10 has a well-known configuration. Although not shown, inside the electromagnetic contactor 10 there is an operating electromagnet consisting of a movable core, a fixed core, and a closing coil that drives the movable core, and is connected to the movable core. The movable contact support 12 includes a movable contact and a contact spring. When the movable core is attracted by the excitation of the closing coil, it enters the closed state, and when the excitation is turned off, if an operating retainer is not provided, it is returned to the released state by a return spring (not shown) built into the movable contact support. It will be done. On the other hand, the operation retainer 20 is configured by accommodating a latch lever 22, a latch piece 23, an electromagnet mechanism 24, a contact mechanism 25, etc. in a case 21. The case 21 made of molded resin has a groove 21a with a T-shaped cross section at the bottom, and the electromagnetic contactor 1 is inserted into this groove 21a.
The operation retainer 2 is fitted with a protrusion 10a having a T-shaped cross section.
0 is attached to the electromagnetic contactor 10. The latch lever 22 is formed of molded resin into a prismatic shape as shown in FIG.
It is rotatably supported by a bin 27. A bifurcated operating end 22a for operating the contact mechanism 25 is integrally provided at the tip of the latch lever 22, and an escape groove 22a is provided on the front surface of the operating end 22a.
b is formed. Furthermore, rollers 28 are attached to pins 29 on both sides of the base of the operating end 22a. Further, a latch spring 30 is provided between the latch lever 22 and the mounting bracket 26 to apply force to the latch lever 22 in the counterclockwise direction in FIG. Note that 22c is an operation display bar integrally formed with the latch lever 22, and the display window 21b opened at the top of the case 21.
(Fig. 1) and displays the open and closed states of the electric and magnetic contactor 10. The latch piece 23 is also made of molded resin, and its detailed shape is as shown in FIG. This latch piece 23 is
It is provided with a 1-shaped portion 23a at the lower end, and is connected to the movable contact support 12 by fitting this 1-shaped portion 23a into the T-groove 12a (FIG. 1) at the upper end of the movable contact support 12. ing. On one side of the latch piece 23, rectangular shoulders 23b on which the roller 28 of the latch lever rides are formed at two locations, front and rear, as will be described later. In addition, there is a piece-shaped window hole 23 in the center.
The corner edge of the window hole 23C is made thinner to form an engaging piece 23d. The mounting bracket 26 that supported the latch lever 22 is attached to the case 21.
is screwed to the side wall of the And latch lever 2
2 faces one side of the latch piece 23 in the case 21 as shown in FIG. is in contact with. The electromagnetic mechanism 24 includes a plunger 24a, a trip coil 24b wound around the outside of the plunger 24a, and a yoke 24c. When not energized, the plunger 24a is held at the illustrated position by a back spring (not illustrated). This electromagnetic mechanism 24 is located close to the other side of the latch piece 23 in the case 21.
In this state, the tip of the plunger 24a faces the latch lever 22 via the upper end 23e of the latch piece 23. As shown in FIG. 4, the contact mechanism 25 is a two-point structure in which a pair of fixed contacts 32 are embedded in a frame-like frame 31 made of molded resin, and a movable contact 33 is arranged to bridge the fixed contacts 32. It is configured as a normally closed contact. The movable contact 33 is inserted into a U-shaped contact support portion 31a that is integral with the frame 31, and is constantly pressed against the fixed contact 32 by a contact spring 34. A locking rod 35 is fixed to the movable contact 33 along the center of the contact spring 34 so as to move together with the movable contact 33. At the tip of the locking rod 33, a serrated engagement claw 35a with an inclined front surface is formed on one side, and the contact support part 35a is formed on one side.
It faces the window 31b on the end face of 1a. The contact mechanism 25 is placed on the bottom of the case 21 and below the latch lever 22, and is fixed to the side wall of the case 21 by a mounting piece 31b. Here, FIG. 5 shows the operation circuit of the electromagnetic contactor 10 and the operation holder 20, and between electric JP-N, the closing coil 36 of the electromagnetic contactor 10, the normally closed contact of the contact mechanism 25, and Normally open contact of closing switch 37 and normally open contact 3 of magnetic contactor
6a (auxiliary contact) is connected in series, and the tripping coil 2 of the operation retainer 20 is connected between the power supplies P and N.
4b1 Normally open contact 36b (auxiliary contact) of the electromagnetic contactor 10,
A normally closed contact 38 of a control relay (not shown) is connected in series. 6 and 7 show the operation end 2 of the latch lever 22.
2a shows the positional relationship between the contact mechanism 25 and the latch piece 23, and FIGS. 6(A) and 6(B) are a cross-sectional view and a vertical cross-sectional view, respectively, of the contact mechanism part in the released state of the electromagnetic contactor 10, and FIG. FIGS. 7(A) and (B) show the electromagnetic contactor 10
FIG. 6 is a cross-sectional view and a vertical cross-sectional view of a contact mechanism portion in a closed state. As shown in the figure, the latch lever 22
The bifurcated operating end 22a faces the front surface of the movable contact 33, and the locking rod 35 of the contact mechanism 25 is inserted into the window hole 23 of the latch piece 23.
It is designed to face c. Now, in such a configuration, when the closing switch 37 shown in FIG. 5 is turned on to close the excitation circuit of the closing coil 36, the latch piece 23 moves downward in FIG. 1 together with the movable contact support 12. Therefore, when the shoulder portion 23b of the latch piece 23 passes the roller 28, the latch lever 22, which is receiving the force of the latch spring 30, rotates counterclockwise in the figure.
As shown in FIG. 1CB), the roller 28 is connected to the latch piece 23
The vehicle rides on the shoulder 23b of the vehicle. At this time, the operating end 22a pushes the movable contact 33 to open it as shown in FIG. At this time, interference between the operating end 22a and the upper corner 31c of the contact support part 31a is avoided by the escape groove 22b of the operating end 22a, and the operating ends 2, 2a can move forward despite the narrow space inside the case 21. By increasing the stroke, sufficient opening of the movable contact 33 can be obtained. When the movable contact 33 is released, the locking rod 35 also moves forward, and the inclined surface of the front surface of the engaging claw 35a abuts against the engaging piece 23d of the latch piece 23. As a result, the locking rod 35 is elastically deformed as shown by the chain line in FIG. 7(A) due to the wedge action, and when the engaging claw 35a crosses over the engaging piece 23d, the two are moved as shown in FIG. engage with each other. When the contact mechanism 25 is opened, the closing coil 36 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 39 between the roller 28 and the shoulder portion 23b of the latch lever 23 is the fulcrum (pin 27) of the latch lever 22.
The roller 28 is set at a position slightly beyond the dead center of the reaction force from the shoulder portion 23b toward the right in the figure, so that the engagement between the roller 28 and the shoulder portion 23b does not come off due to vibration or impact. In the above 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.
A spring is not used to press the movable contact support 12 against the movable contact support 12 and make it follow this. Therefore, the return spring of the movable contact support 12 does not need to have a particularly large spring force compared to the case where the motion retainer is not used. Furthermore, 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 rolling contact via the roller 28, the latch lever 22 is pressed against the latch piece 23 during the closing process of the electromagnetic contactor 10. Latch piece 2
The frictional force acting on 3 is small. For these reasons, according to the illustrated configuration, the closing operation force of the electromagnetic contactor 10 does not particularly increase even if the operation retainer 20 is attached, and the closing coil may be a standard one. To release the electromagnetic contactor 10 from the operation holding state shown in FIG. 1(B), turn the control relay (not shown) to 0F in FIG.
By turning ON the normally closed contact 38 of FL, the tripping coil 24b of the electromagnet mechanism 24 is energized. Note that the normally open contact 36b of the electromagnetic contactor 10 is closed when the electromagnetic contactor 10 is in an operation holding state. This allows plunger 2
4a is attracted and moves to the left in FIG. 1(B), and the latch lever 22 is rotated clockwise 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 shown in FIG. 1(A) together with the movable contact support 12 by a return spring (not shown). By the way, the normally open contacts 3.6a and 36b of the electromagnetic contactor 10 have an appropriate wipe amount. Therefore, in the release operation, the latch piece 23 is unlocked and the movable contact support 12 starts to rise, and even though the wipe amount remains, the contact 36. a is closed. However, conventionally, the closing coil demagnetizing contact (in the case shown, the contact of the contact mechanism 25) was closed at the same time as the latch piece 23 was unlocked. The coil 24b was sometimes excited at the same time. Therefore, in the illustrated configuration, even if the latch piece 23 is unlocked, the locking rod 35 is locked by the engaging piece 23d, so that the open state of the contact mechanism 25 is maintained. Then, the return of the latch piece 23 is at the contact points 36 a, 36
When the distance A in FIG. 7(B), which is sufficient to open the circuit, the engagement between the engagement piece 23d and the locking rod 35 is terminated, and the contact mechanism is closed as shown in FIG. 25 is closed. With this configuration, the 08 points of the normally open contact 33 for degaussing of the closing coil 36 are connected to the closing coil 3.
The OFF point of the normally open contacts 36a and 36b of the electromagnetic contactor inserted in the excitation circuit of 6 and the tripping coil 24b is always after the OFF point, and simultaneous excitation of the closing coil 36 and the tripping coil 24b does not occur. FIG. 8 is an exploded perspective view showing the main structure of the latch lever 22 that facilitates fine adjustment of the vertical position of the roller 28. That is, in FIG. 8, a square hole 22d is formed in the upper part of the latch lever 22 and penetrates in the front-rear direction, and a nut plate 40 having a screw hole is press-fitted into the square hole 22d. On the other hand, latch lever 2
2 is supported by the mounting bracket 26 through the insertion hole 22e of the pin 27.
is composed of a vertically long elongated hole, and a pin 27 and a nut plate 40
A cushion spring 42 is inserted between the adjustment screw 41 and the adjustment screw 41 screwed into. With this configuration, adjusting screw 4
1, the latch lever 22 is connected to the elongated hole 22e and the pin 27.
It can be moved up and down within the gap between. This makes it possible to finely adjust the opening of the operating electromagnet of the electromagnetic contactor 10, thereby increasing the reliability of the operating holder 20.

【Effect of the invention】

According to this invention, there is no need for a spring that causes the components of the motion retainer to follow the movable contact support of the electromagnetic contactor;
In addition, by making the contact between the latch piece and the launch lever a rolling contact and reducing the frictional force, the load on the closing coil of the electromagnetic contactor does not increase even when the operating retainer is attached, and it is possible to use special specifications for closing coils, etc. is no longer necessary, and
It can extend the life of magnetic contactors and reduce costs. Further, by closing the closing coil demagnetizing contact after the normally open contact of the electromagnetic contactor is opened, it is possible to prevent a coil burnout accident due to simultaneous excitation of the closing coil and the tripping coil. Further, since the latch piece is directly connected to the movable contact support, it has good followability and reliability in maintaining operation is also high.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention; FIG. 1(A) is a sectional view of the operating retainer with the electromagnetic contactor released; FIG. 1(B)
2 is a sectional view of the operating retainer with the electromagnetic contactor closed; FIG. 2 is a perspective view of the latch lever in FIG. 1; FIG. 3 is a perspective view of the latch piece in FIG. 1; FIG. 5 is an operation circuit diagram of the electromagnetic contactor and operation retainer shown in FIG. 1, FIG. 6 (A) is a cross-sectional view of the contact mechanism part of FIG. Figure 6 (B) is its longitudinal cross-sectional view, Figure 7 (A)
is a cross-sectional view of the contact mechanism part in Figure 1 (B), and Figure 7 (B
) is a longitudinal sectional view thereof, and FIG. 8 is an exploded perspective view of a main part of a different embodiment of the latch lever. 10...Magnetic contactor, 12...Movable contact support, 2
0... Operation retainer, 22... Latch lever 23.
...Latch piece, 23b...Shoulder of latch piece, 24...
- Electromagnetic mechanism, 24b... tripping coil, 25...
Contact mechanism, 28...roller, latch spring...
30.33... Movable contact of contact mechanism, 35... Locking rod, 35a... Locking claw, 36... Closing coil, 36
a, 36b... Normally open contact of the electromagnetic contactor. (A) (B) Figure Figure

Claims (1)

[Claims] 1) A latch piece connected to the movable contact support of the electromagnetic contactor, a contact mechanism having a normally closed contact for demagnetizing the closing coil of the electromagnetic contactor, and a latch spring that is connected to the latch piece via a roller at all times. When pressed and the electromagnetic contactor is turned on, the roller rides on the shoulder of the latch piece, locking the latch piece and opening the contact mechanism, and against the spring force of the latch spring. It consists of an electromagnetic mechanism that rotates the latch lever to unlock the latch piece, and a locking rod having an engaging claw at the tip is fixed to the movable contact of the contact mechanism, and this locking rod is attached to the electromagnetic contactor. When the contact mechanism is opened by closing, the latch piece is engaged with the locked latch piece, and when the latch piece is unlocked by the operation of the electromagnetic mechanism, the normally open contact of the electromagnetic contactor is opened. An operation retainer for an electromagnetic contactor, characterized in that the contact mechanism is maintained in an open state by maintaining engagement with the latch piece until the end of the operation.