JPH0594754A - Electromagnetic contactor - Google Patents

Abstract

PURPOSE:To remove gravitational influence upon a movable part when an electromagnetic contactor is installed on the floor surface or on the ceiling surface. CONSTITUTION:A lever 14 turnable around a fulcrum shaft 15 is provided, and its one end is linked to a contact point support 5 through a pin 17, and a balance weight 16 having weight W corresponding to weight W of a movable part composed of a movable iron core 3, the contact point support 5 and a movable contact point 7 is installed on the other end. Thereby, since gravity acted upon the movable part when an electromagnetic contactor is installed on the floor surface or on the ceiling surface is negated by the weight of the balance weight 16, an increase or a decrease in spring load force against electromagnetic sucking force is eliminated, so that even a single back spring 12 can cope with various kinds of installation postures.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic contactor which excites an electromagnetic coil to open and close a movable contact, and more particularly to an electromagnetic contactor in which the influence of gravity on a mounting posture is removed.

[0002]

2. Description of the Related Art FIG. 7 is a vertical sectional view showing a conventional electromagnetic contactor. In the figure, a fixed iron core 2 is fixed to a frame 1, and a movable iron core 3 is arranged so as to face the fixed iron core 2. An electromagnetic coil 4 is attached to the fixed iron core 2, and a contact support 5 made of an insulating material is connected to the movable iron core 3. A support 6 is slidably inserted in the contact support 5 in the axial direction,
The movable contact 7 is held between the head and the end face of the contact support. A contact spring 8 made of a compression spring is inserted between the end of the support 6 and the contact support 5, and the movable contact 7 is interposed between the head of the support 6 and the end face of the contact support 5 by its spring force. It is sandwiched.

A base 9 is attached to the upper portion of the frame 1, and a fixed contact 10 is fixed to the base 9. Further, the contact support 5 is slidably guided by the guide surface 11 of the frame 1, and the back spring 12 which is a compression spring inserted between the contact support 5 and the frame 1 moves the movable contact 7 in a non-excited state of the electromagnetic coil 4. It is separated from the fixed contact 10.

When the electromagnetic coil 4 is excited, the movable iron core 3 is attracted to the fixed iron core 2 and the movable contact 7 held by the contact support 5 contacts the fixed contact 10. Even when the movable contact 7 comes into contact with the fixed contact 10, the movable iron core 3 is further attracted until it comes into contact with the fixed iron core 2, during which the contact spring 8 is compressed and moved, and a required contact pressure is generated between the fixed contacts 7 and 10. Given. When the excitation of the electromagnetic coil 4 is cut off, the movable contact 7 returns to the position shown in the figure by the force of the back spring 12 and the contact spring 8.

FIG. 8 shows the load characteristics of the above-mentioned electromagnetic contactor. The horizontal axis shows the fixed force, the opening between the movable iron cores 2 and 3, and the vertical axis shows the attraction force acting on the movable iron core 3 and the load force against it. .. In the figure, the load force B of the back spring 12 gradually increases as the movable iron core 3 is attracted, but when the movable contact 7 comes into contact with the fixed contact 10, the contact spring 8 contacts this.
Load force P is added, and the load force is the sum (B + P) of these as a whole. Thereafter, this load force gradually increases until the movable iron core 3 contacts the fixed iron core 2. On the other hand, the attraction force M changes as shown by the curve, and moves the movable iron core 3 toward the fixed iron core 2 against the load force. Therefore, the suction force M must exceed the load force (B + P).

[0006]

By the way, when the electromagnetic contactor is mounted on a switchboard or the like, it is generally mounted horizontally on a vertical mounting surface 13 as shown in FIG. However, it may be mounted vertically on a horizontal floor or ceiling due to the mounting space and wiring. However, if the electromagnetic contactor for mounting on the vertical surface is mounted on the horizontal surface as it is, the following problems occur. That is, in the case of mounting on a vertical surface, the weight of movable parts such as the movable iron core 3 and the contact support 5 is supported by the guide surface 11 and does not affect the restoring force of the back spring 12. Since the weight of the movable portion works against the back spring 12, the restoring force of the movable portion is insufficient and normal operation cannot be performed. On the other hand, in the case of mounting on the ceiling surface, the weight of the movable portion is applied in the same direction as the back spring, contrary to the case of mounting on the floor surface, so the load force increases and normal operation cannot be performed.

Therefore, conventionally, in the case of floor mounting or ceiling mounting, a magnetic contactor different from that for vertical mounting, that is, floor mounting or ceiling mounting using a back spring with the weight of moving parts corrected Used a magnetic contactor. However, in such conventional measures, it was troublesome to prepare electromagnetic contactors having different specifications depending on the mounting posture. Also, since there are relatively few cases of floor mounting or ceiling mounting, the electromagnetic contactor for that purpose was a special product, resulting in higher prices and longer delivery times. Therefore, an object of the present invention is to provide an electromagnetic contactor that can be used as it is even if the mounting posture changes.

[0008]

To achieve the above object, the present invention provides a rotatable lever having one end connected to a movable portion of an electromagnetic contactor, and the other end of the lever is provided with the movable portion. A balance weight commensurate with the weight should be attached.

[0009]

The weight of the movable portion and the weight of the balance weight are balanced with each other with the turning fulcrum of the lever interposed therebetween. As a result, in the mounting posture in which the movable portion is subjected to the action of gravity, the balance weight is also subjected to the same action, so that the actions of both are offset and the influence of gravity does not affect the back spring.

[0010]

1 is a vertical sectional view showing an embodiment of the present invention. The same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted. The illustrated embodiment differs from the prior art in that a lever 14 is rotatably supported on a frame 1 by a fulcrum shaft 15, one end of which is connected to a contact support 5 and a balance weight 16 is attached to the other end. That is the point. The connection between the lever 14 and the contact support 5 is performed by engaging the pin 17 implanted in the contact support 5 with the end of the lever 14 through the notch 14a. Further, in the illustrated state in which the electromagnetic contactor is mounted on the vertical surface, the centers of gravity of the pin 17, the fulcrum shaft 15 and the balance weight 16 are arranged on the vertical line.

Here, the movable parts of the electromagnetic contactor are the movable iron core 3, the contact support 5, the support 6, the movable contact 7 and the contact spring 8, and the total weight of these is called the movable part weight. The pin 17 is attached to the center of gravity of the movable part. The weight of the movable part is W ₁ , the length of the arm from the fulcrum shaft 15 to the pin 17 is L ₁ , and the balance weight 1 is the same.
Balance weight 1 if arm length up to 6 is L _2.
The weight W ₂ of 6 is set to be approximately W ₁ × L ₁ = W ₂ × L ₂ . The load characteristics of the electromagnetic contactor having such a configuration will be described below for each mounting posture.

First, FIG. 3 shows a constitutional model in a normal case in which an electromagnetic contactor is mounted on a vertical surface as shown in FIG. 1. The back spring force B, the contact spring force P, the moving part weight W ₁ and the balance are shown. The weight weight W ₂ acts in the directions shown in the drawings. In this case, the weight W ₁ of the movable part is supported by the guide surface 11, and there is a frictional force from the guide surface 11 as a load force, but the friction coefficient is 0.1 to 0.2, which is minute, and therefore omitted here. Also, the electromagnetic contactor usually has auxiliary contacts, which are omitted here for the sake of simplicity.

Now, assuming that the movable iron core 3 is attracted and the lever 14 is tilted to the position of the broken line, the balance weight 1
Assuming that the horizontal movement distance of 6 is L ₃ as shown in the figure, the load force F by the balance weight 16 is approximately (W ₂ × L ₃ ) /
L ₁ is added to the back spring force B. This is shown in the load characteristic diagram as shown in FIG.

That is, in the case of mounting on a vertical surface, a load force F is newly generated, but this load force is zero at the start of suction and increases with suction, and becomes maximum when the movable iron core 3 contacts the fixed iron core 2. Become. Therefore, there is no problem in the initial stage of the injection when the suction force is small, and there is no problem because the suction force is extremely large at the time of the completion of the maximum injection. Movable iron core 3
In general, when the abutment contacts the fixed iron core 2, the suction force tends to be excessive as compared with the load force as shown in the figure, and it can be said that the increase of the load force is rather preferable from the viewpoint of impact mitigation.

Next, FIGS. 4 and 5 show cases of floor surface mounting and ceiling surface mounting, respectively. In the case of mounting on the floor of FIG. 4, the weight W ₁ of the movable portion acts so as to reduce the load force, and a counterclockwise moment is generated around the fulcrum shaft 15. On the other hand, the weight W ₂ of the balance weight 16 acts so as to increase the load force, and similarly a clockwise moment is generated. However, there is a relationship of W ₁ × L ₁ = W ₂ × L ₂ ,
Since these moments cancel each other out, the influence of the weight W ₁ of the movable portion on the load is eliminated, and the load characteristics are the same as in the case of the conventional vertical surface mounting shown in FIG. On the other hand, also in the case of mounting on the ceiling surface of FIG. 5, the weight W _{1 of} the movable portion that acts to increase the load force is similarly offset by the weight W ₂ of the balance weight 16 that acts in the opposite way, and the load characteristics are also shown in FIG. It is equivalent to the conventional vertical surface mounting.

FIG. 6 shows the case of mounting on an inclined surface having an inclination angle θ from the vertical surface. Normally, such a mounting method is not used, but when mounted on a ship, such a state may occur even when mounted on a vertical surface. In the illustrated state, the component force of the moving part weight W ₁ acting in the same direction as the back spring force B is W ₁
× H ₁ / L ₁ On the other hand, the force F exerted on the pin 17 in the opposite direction by the weight W ₂ of the balance weight 16 is W ₂ × H ₂ / L ₁ . However, W ₁ × L
_{Since 1} = W ₂ × L ₂ to W ₁ × H ₁ = W ₂ × H ₂ , the above two forces are balanced and the load force becomes equivalent to that in the conventional vertical surface mounting of FIG.

As described above, according to the embodiment shown in FIGS.
In any of the floor surface mounting, the ceiling surface mounting, and the inclined surface mounting shown in FIG. 6, the influence of gravity acting on the movable portion is canceled by the balance weight 16, and the load force does not change.
Further, in the illustrated embodiment, in the case where the electromagnetic contactor is mounted on the vertical surface, the connecting point (pin 17) between the lever 14 and the movable portion and the rotation fulcrum of the lever 14 (fulcrum shaft 15 when the electromagnetic coil 4 is not excited). ) And the center of gravity of the balance weight 16 are positioned on the vertical line, the load force at the start of suction is not affected by the balance weight 16 even in the case of normal vertical surface mounting, and when the suction is completed. The matching of the suction force and the load force is improved. In addition, in the state of FIG.
Is on the right side of the position shown, and the balance weight 16
Is configured so that its center of gravity is located on the left side of the illustrated position, that is, the lever 14 is tilted to the right, and the load force is reduced by the counterclockwise moment by the balance weight 16 at the start of suction, and the load force increases with suction. It is also possible to do so.

[0018]

According to the present invention, a balance weight having a weight commensurate with the weight of a movable part is provided, and the balance weights are balanced with each other through a lever, so that the back spring can be replaced even when the floor surface or the ceiling surface is mounted. The standard electromagnetic contactor can be used in any mounting posture.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention.

FIG. 2 is a load characteristic diagram of the electromagnetic contactor of FIG.

FIG. 3 is a diagram showing a configuration model when the electromagnetic contactor of FIG. 1 is mounted on a vertical surface.

FIG. 4 is a diagram showing a structural model when the electromagnetic contactor of FIG. 1 is mounted on a floor.

5 is a diagram showing a configuration model when the electromagnetic contactor of FIG. 1 is mounted on a ceiling surface.

6 is a diagram showing a configuration model when the electromagnetic contactor of FIG. 1 is attached to an inclined surface.

FIG. 7 is a vertical sectional view of a conventional example.

FIG. 8 is a load characteristic diagram of the electromagnetic contactor of FIG.

[Explanation of symbols]

 2 fixed iron core 3 movable iron core 4 electromagnetic coil 5 contact support 7 movable contact 8 contact spring 10 fixed contact 12 back spring 14 lever 15 fulcrum shaft 16 balance weight 17 pin

Claims (2)

[Claims] 1. An electromagnetic contactor for driving a movable part including a movable iron core by exciting an electromagnetic coil to open and close a movable contact, is provided with a rotatable lever whose one end is connected to the movable part. An electromagnetic contactor, characterized in that a balance weight corresponding to the mass of the movable portion is attached to the end. 2. When the electromagnetic contactor is mounted on a vertical surface,
2. The electromagnetic contactor according to claim 1, wherein the connection point between the lever and the movable portion, the pivotal fulcrum of the lever, and the center of gravity of the balance weight are located on the vertical line when the electromagnetic coil is not excited. ..