JPH0737480A - Electromagnetic contactor - Google Patents

Abstract

(57) [Summary] [Purpose] Excludes the effect of gravity on moving parts when an electromagnetic contactor is attached to the floor or ceiling. [Structure] An end of the back spring 11 that gives a restoring force to movable parts such as a movable iron core 3 and a contact support 5 is supported by a pedestal 13 that moves in the axial direction of the back spring 11 by operating an adjusting cam 14. The set length of the back spring 11 can be changed. Thus, the back spring 11 can be operated by operating the adjusting cam 14 even when the floor surface is mounted so that gravity against the movable portion acts against the back spring 11 or conversely when the ceiling surface is mounted in the same direction as the force of the back spring 11. Load force can be matched in the case of normal vertical surface mounting, and it is not necessary to replace the back spring 11 depending on the mounting posture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic contactor that 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 the 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 mounted on 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 composed 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 1a of the frame 1, and the back spring 11 formed of a compression spring inserted between the contact support 5 and the frame 1 causes the movable contact 7 to move while the electromagnetic coil 4 is not excited. 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 comes into contact with 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 to move, 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 11 and the contact spring 8.

FIG. 8 shows the load characteristics of the above 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 11 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 of is added, and the load force becomes 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 an electromagnetic contactor is installed on a switchboard or the like, it is usually mounted horizontally on a vertical mounting surface 12 as shown in FIG. However, it may be installed vertically on a horizontal floor or ceiling due to the installation space and wiring. However, if the electromagnetic contactor for vertical surface mounting is directly mounted on the horizontal surface, the following inconvenience occurs. That is, in the case of mounting on a vertical surface, the weight of movable parts such as the movable core 3 and the contact support 5 is supported by the guide surface 1a and does not affect the restoring force of the back spring 11 in the case of mounting on a vertical surface. Since the weight of the movable portion works against the back spring 11, the restoring force to 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 force of the back spring, which is opposite to the case of mounting on the floor surface, so that the load force increases and normal operation cannot be performed.

Therefore, conventionally, in the case of floor surface mounting or ceiling surface mounting, an electromagnetic contactor different from that for vertical surface mounting, that is, a floor surface mounting in which the back spring is replaced with one in which the influence of the weight of the movable portion is corrected, is used. I used an electromagnetic contactor for ceiling mounting only. However, in such conventional measures, it is necessary to prepare electromagnetic contactors having different specifications depending on the mounting posture, and the management is complicated. Also, since there are relatively few cases of floor mounting and ceiling mounting, the electromagnetic contactor for that purpose became a special item, 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]

In order to achieve the above object, the present invention relates to the set length of the back spring, that is, the length of the back spring when it is set in the electromagnetic contactor. A means for changing it according to the above shall be provided. In order to change the set length of the back spring, it is preferable to support the end portion on the side opposite to the movable portion by a pedestal that moves in the axial direction of the back spring by operating the adjustment cam. In that case, the adjustment is facilitated by providing an arrow mark on the operation surface of the cam that always points in a fixed direction regardless of the mounting posture of the electromagnetic contactor.

[0009]

[Operation] By changing the set length of the back spring, the spring force is increased or decreased in the mounting posture in which the movable part is affected by gravity to correct the effect, and the restoring force or load force of the movable part is mounted on the vertical surface. It can be adjusted in the same manner as in. In that case, the end length of the back spring on the side opposite to the movable portion is supported by a pedestal provided so as to be movable in the axial direction, and the set length can be easily changed by moving this pedestal with an adjusting cam. The influence of gravity on the movable part becomes larger as the mounting angle becomes larger with reference to the vertical surface mounting, and becomes the maximum in the ceiling surface mounting or the floor surface mounting.
Therefore, the shape of the cam is set so that the rate of change of the set length of the back spring due to the change of the rotation angle of the adjustment cam and the rate of change of the influence of gravity on the movable part due to the change of the attachment angle of the electromagnetic contactor match. By doing so, the absolute orientation of the adjustment cam can be made constant regardless of the mounting posture of the electromagnetic contactor.If an arrow mark pointing vertically downward is displayed on the operation surface of the adjustment cam, this arrow The set length of the back spring can be adjusted properly simply by aligning the mark with that direction.

[0010]

1 is a vertical sectional view of an electromagnetic contactor showing an embodiment of the present invention, and FIG. 2 is a partially enlarged sectional view taken along the line II--II. The same reference numerals are used for the parts corresponding to those in the conventional example, and the description is omitted. In the conventional example of FIG. 7, the end 11a (FIG. 2) of the back spring 11 on the side opposite to the movable portion is directly supported by the flange 1b of the frame 1, whereas in the illustrated embodiment, it is movable in the axial direction. The pedestal 13 is supported, and the pedestal 13 is moved in the axial direction of the back spring 11 by rotating the adjusting cam 14. The pedestal 13 has a shape provided with a positioning protrusion 13a that fits into the end portion 11a of the back spring 11 at the center of a square plate body, and has three guide walls 1c raised on the flange 1b and a side wall 1d of the frame 1. Is slidably guided by.

The adjusting cam 14 has a shape in which a cam portion 14b is integrally formed at an intermediate portion of a rotary shaft having a stepped head portion 14a, is inserted into the frame 1 from the left and right side surfaces, and has a small diameter portion and a shaft end of the head portion 14a. And is rotatably supported by straddling the side wall 1d and the guide wall 1c of the frame 1, and the cam portion 14b is attached to the base 1
It is in contact with the bottom surface of 3. The chain line in FIG. 2 indicates the cam portion 14b.
The contour of is rotated by 90 degrees. That is, in the mounting state on the vertical surface shown in the drawing, the rotation position of the adjustment cam 14 is in the middle, and the rising height of the cam portion 14b is also in the middle.
A hook 14c and a slit 14d are provided at the shaft end of the adjusting cam 14.
And the hook 14c which has passed through the bearing hole of the guide wall 1c while escaping to the slit 14d side at the time of insertion is
The adjustment cam 14 is prevented from coming off by engaging with c. As shown in FIG. 3, a cross hole 14e for receiving the tip of a tool such as a driver and an arrow mark 15 which will be described later are provided on the upper surface of the head portion 14a of the adjustment cam 14 which is seen from the side surface of the frame 1. .

When the above-mentioned electromagnetic contactor is attached to the floor surface 16 as shown in FIG. 5, the gravity acting on the movable portion acts to the maximum against the back spring 11, and the load force is reduced by that amount, but the movable portion is reduced. Lacks the ability to recover. FIG. 4 shows the effect of the weight of the movable part on the load characteristic diagram in the case of vertical surface mounting which is also shown in FIG. 8, and the load force B of the back spring 11 is the level shown by the broken line for the weight W of the movable part. Falls to. Therefore, in such a case, the adjusting cam 14 is rotated 90 degrees from the state of FIG. 2, the rising height of the cam portion 14b is maximized and the set length of the back spring 11 is minimized, and its preload is movable. This is corrected by raising it by a value commensurate with the part weight W. As a result, the load force B can be increased to the solid line level (vertical surface mounting level) in FIG.

On the other hand, when the electromagnetic contactor is attached to the ceiling surface, the gravity W acting on the movable portion is the back spring 1
The force of 1 works in the same direction, and the load force B increases to the level shown by the chain line in FIG. In that case, the adjustment cam 14 is rotated 90 degrees in the opposite direction from the case of mounting on the floor from the state of FIG. 2 to minimize the rising height of the cam portion 14b and maximize the set length of the back spring 11. , Reduce its preload. This allows
Load force B is shown by the solid line level in Fig. 4 (vertical surface mounting level)
Can be lowered to.

As shown in FIG. 6, when the electromagnetic contactor is mounted on the inclined surface between the vertical surface mounting and the floor surface mounting, the gravity acting on the movable portion corresponds to the inclination angle of the inclined surface 17. The force acts against the back spring 11. Further, when the electromagnetic contactor is mounted on the inclined surface between the vertical surface mounting and the ceiling surface mounting, the gravity acting on the movable portion acts in the same direction as the force of the back spring 11 with a component force corresponding to the tilt angle. To do. Therefore, in the case of mounting on these inclined surfaces, if the rotational position of the adjusting cam 14 is adjusted according to the inclination angle with reference to the mounting on the vertical surface, the load force of the back spring 11 is always matched in the case of mounting on the vertical surface. be able to.

Here, the arrow mark 15 of the adjustment cam 14 is provided so as to face vertically downward. That is, the electromagnetic contactor is in a state rotated by 90 degrees from the vertical surface mounting in FIG. 1 in the floor surface mounting in FIG. 5, but at that time, if the adjusting cam 14 is simultaneously rotated in the opposite direction by 90 degrees, the electromagnetic contactor can be mounted in the vertical surface. The arrow mark 15 which was facing vertically downward still faces vertically downward. This also applies to the case of mounting on the ceiling surface, and the adjustment cam 1 is rotated at the same time when the electromagnetic contactor is rotated 90 degrees in the opposite direction from the case of mounting on the vertical surface from the state of mounting on the vertical surface.
Since 4 also rotates 90 degrees in the opposite direction, the arrow mark 15 also faces vertically downward.

This relationship is due to the change rate of the influence of gravity on the movable part due to the change of the attachment angle of the electromagnetic contactor when the inclined surface is attached, and the back spring 11 due to the change of the rotation angle of the adjusting cam 14 for correcting this. By setting the shape of the cam portion 14b so as to match the rate of change of the set length, it can be always established regardless of the mounting angle of the electromagnetic contactor. The mark 15 shows such an example. If there is such an arrow mark 15, the adjustment cam 14 can always be set at an appropriate position only by making it point vertically downward.
The direction of the arrow mark 15 is not limited to the vertically downward direction, but can be set arbitrarily.

[0017]

As described above, according to the present invention, by providing the means for changing the set length of the back spring according to the mounting posture of the electromagnetic contactor, the load force of the back spring can be set in any mounting posture. By aligning with the case of vertical mounting, one type of magnetic contactor can be used for all mounting postures.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an electromagnetic contactor showing an embodiment of the present invention in a state of being mounted on a vertical surface.

FIG. 2 is a partially enlarged sectional view taken along the line II-II of FIG.

FIG. 3 is a top view of the head of the adjustment cam in FIG.

4 is a diagram illustrating load characteristics of the electromagnetic contactor of FIG. 1 in a floor-mounted state and a ceiling-mounted state.

5 is a side view showing a state in which the electromagnetic contactor of FIG. 1 is attached to a floor surface.

6 is a side view showing a state in which the electromagnetic contactor of FIG. 1 is attached to an inclined surface.

FIG. 7 is a vertical cross-sectional view of a conventional electromagnetic contactor.

FIG. 8 is a load characteristic diagram of the electromagnetic contactor of FIG. 7.

[Explanation of symbols]

 1 Frame 2 Fixed Iron Core 3 Movable Iron Core 4 Electromagnetic Coil 5 Contact Support 11 Back Spring 13 Pedestal 14 Adjustment Cam 15 Arrow Mark

Claims (3)

[Claims] 1. An electromagnetic contactor in which a movable part including a movable iron core is driven by an electromagnetic coil to be driven against a back spring to open and close a movable contact, and a set length of the back spring is set to a mounting attitude of the electromagnetic contactor. An electromagnetic contactor, characterized in that it is provided with a means for changing it according to. 2. The electromagnetic contactor according to claim 1, wherein an end of the back spring on the side opposite to the movable portion is supported by a pedestal that moves in the axial direction of the back spring by operating an adjusting cam. 3. The electromagnetic contactor according to claim 2, wherein an arrow mark that always indicates a fixed direction is provided on the operation surface of the adjustment cam regardless of the mounting posture of the electromagnetic contactor.