JPH0122204Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a contact buffer device for a switchgear in which a movable contact is brought into contact with a fixed contact at high speed when the contact is turned on.

[Conventional technology]

In many vacuum switchgears, a fixed contact and a movable contact are butted against each other to make surface contact.This butt-type contact has a simple structure, but it does not need to be inserted as required for general switchgear. If the speed is increased, an excessive impact force will be applied to the contactor or structural members near the contactor, which may damage it, or cause the movable contactor to chatter, causing damage to the contactor or the electrical circuit in which it is inserted. or To prevent this, this type of switchgear is equipped with a contact buffer device.

FIG. 1 is a side view showing an example of a vacuum switch. In FIG. 1, a vacuum valve 1 is installed on an insulating support insulator 5 on a frame 4 together with one terminal plate 3 led out from a fixed contact 2 thereof. A movable contact 6 facing the fixed contact 2 is attached to the tip of a movable contact bar 7.
is led out of the vacuum valve 1 via the bellows 8, and the other terminal plate 10 is connected to the movable contact bar 7 via the flexible conductor 9, and when both contacts 2 and 6 come into contact, both ends The electric circuit connected between the daughter boards 3 and 10 is energized. The rear end of the movable contact rod 7 is connected to an operating rod 12 via an insulating connector 11, and the operating rod 12 is connected to a spring receiver 14 fixed to the operating rod 12.
The movable contact 6 is biased in the direction of the arrow R by a closing spring 13 provided around the operating rod 12, but is pulled up against the closing spring 13 by an operation mechanism (not shown), and moves the movable contact 6 to the fixed contact. It is locked by a locking device 15 in a state where it is separated from 2. The shock absorber includes a collision piece 16 attached to the operating rod 12;
It is composed of a buffer body 18, an oil dump pot 17, and the like.

If this switch does not have a shock absorber, locking device 1
5 is unlocked, the elastic energy of the closing spring 13 is converted into kinetic energy, and the operating rod 12 starts moving in the direction of arrow R, and the movable contact 6 at the tip of the operating rod 12 finally contacts the fixed contact 2. do. The kinetic energy E _k of the movable part including the operating rod 12 and the movable contact 6 just before this is E _k =mV ² /2, where m is the mass of the movable part and v is the speed. When the movable contact 6 of the operating rod 12 contacts the fixed contact 2 with this kinetic energy E _x , the repulsive energy E _r is equal to the kinetic energy E _k multiplied by the repulsion coefficient α. Therefore, if materials with the same coefficient of repulsion α are used, the amount of rebound of the movable contact due to the repulsive energy E _r of the movable part becomes smaller as the mass m of the movable part is smaller and the input speed v is slower. It is also known that the greater the force with which the movable part pushes the fixed contact after the movable contact contacts the fixed contact, the smaller the amount of rebound of the movable part becomes. However, as already mentioned, switchgears generally require a fast closing speed, and in addition, it is difficult to reduce the mass m of the moving parts in order to maintain sufficient mechanical strength of the contacts and other surrounding structural members. . There is also a limit to the force with which the movable part pushes the fixed contact. Therefore, such opening/closing devices have conventionally been provided with a buffer device. In other words, the shock absorber consists of a collision piece fixed to the operating rod and a shock absorber attached to the frame, and the switchgear makes the collision piece collide with the shock absorber just before both contacts come into contact, thereby reducing the kinetic energy of the movable part. Most of it is absorbed by the buffer, and the speed of the operating rod is slowed down before it is introduced.

[The problem that the idea aims to solve]

By the way, in conventional shock absorbers, a shock absorber faces the collision piece and receives it, and an elastic material or an oil dash pot connected to the rear of the shock absorber absorbs the kinetic energy of the operating rod. . In this case, if an elastic body is used, there is a drawback that the compressed elastic body acts as a reaction force and reduces the contact pressure of the contact in the closed state. In order to eliminate this drawback, a shock absorbing device using an oil dart pot has been devised and put into practical use; however, due to its structure, when the point of collision between the collision piece and the shock absorber approaches the contact position of the contact, the operating rod is The disadvantage is that the speed cannot be reduced sufficiently. Furthermore, these shock absorbers have the disadvantage that the loading speed varies because the elastic modulus, oil viscosity, etc. are affected by the surrounding environment.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, and to provide a contact buffer device for a switch which does not cause the movable contact to jump even when the switch closing speed is high, and which has a simple structure. do.

[Means to solve the problem]

According to the present invention, the present invention comprises a buffer body supported by a frame, an operating rod to which a movable contact that contacts a fixed contact and a collision piece that collides with the buffer are respectively fixed, and the operating rod moves in its axial direction to cause the collision piece to collide with the buffer body immediately before the movable contactor contacts the fixed contactor to reduce the speed of the first operating rod,
A collision surface inclined toward the rear end is provided at the tip of the collision piece, and the shock absorber is arranged diagonally so that the collision surface at the tip faces the collision surface of the collision piece parallel to and spaced apart from. A return spring for biasing the shock absorber toward the collision surface and an oil dash pot for braking the shock absorber are disposed on the rear end surface of the shock absorber. This can be achieved by

〔Example〕

Next, embodiments of the present invention will be described in detail based on the drawings. Since the switch to which the shock absorber according to the present invention is attached is exactly the same as the conventional one, it will be omitted and only the shock absorber will be described. In FIG. 2, the collision piece 16 is made of a material with higher rigidity than the electrically conductive member of the switchgear, such as iron, and has a collision surface 16a that is inclined rearward with its tip pointing in the direction in which the operating rod 12 is inserted.
It is fixed to the operating rod 12. The shock absorber 18 is cut out around the front end surface perpendicular to its axis, and the remaining part is a collision surface 18a. It is a cylindrical body with a large mass and is made of a rigid material such as iron and has a rear end surface 18b parallel to the collision surface 18a. This rigid body forms the main part of the shock absorber. This buffer body 18 is provided with two elongated holes 19 which intersect at right angles to the axis thereof and whose major diameters are in the axial direction, separated in the axial direction near the leading end and near the rear end. The buffer body 18 is movably supported in the axial direction by fixing pins 20 inserted into the long holes 19, respectively. A rear end surface 18b of the buffer body 18 is supported by a return spring 21. Buffer 18
is arranged obliquely with respect to the moving direction of the operating rod 12 so that the collision surface 18a at its tip is parallel to the collision surface 16a of the collision piece 16 with a distance _G1 ,
As the switch is turned on, when the shock absorber 18 is farthest from the collision piece 16, the shock absorber 18 moves toward the collision piece 1.
It is attached at a distance F from the side surface of 6. An oil dash pot 22 for braking is provided on the rear end surface 18b side of the shock absorber 18 at a slight distance so that it collides with the shock absorber 18 when it retreats. The position adjustment is performed using an adjustment screw 23 that is screwed in the axial direction toward the collision surface using a window 18c provided in the center of the buffer body 18. The tip of this screw 23 comes into contact with a pin 20 inserted into the elongated hole 19. Therefore, when the adjusting screw 23 is advanced, the tip of the adjusting screw 23 that appears in the elongated hole pushes the pin 20, and conversely, the movable shock absorber 18 itself pushes against the collision piece 16.
The collision piece 16 moves in the direction away from the shock absorber ₁₈ , widening the gap G1 and thus increasing the stroke G until the collision piece 16 collides with the buffer body 18. Conversely, when the adjustment screw 23 is moved backward, the position of the buffer body 18 is moved in the direction in which the stroke G becomes smaller. Mass adjustment is performed using a screw thread 25 provided on the outer periphery of the shock absorber 18 made of a columnar body.
A removable adjustment piece 24 for mass adjustment fitted in
It will be held in That is, by changing the number or size of the adjusting pieces 24, the mass of the entire shock absorber is adjusted, and thereby the magnitude of the kinetic energy absorbed from the movable part is adjusted. A nut can also be used as the adjustment piece 24.

When the operating rod 12 of the switch is unlocked, the operating rod 12
starts moving in the direction of the arrow R, and the collision piece 16 moves along with the operating rod 12 by an amount G from the open position 0 point toward the closed position point C, and collides with the buffer body 18 at point P, which is l this side of the closed position. do. Then, the collision piece 16 gives a part of the kinetic energy of the movable part to the buffer body 18, so that the movable part reaches the closed position point C at a slower speed than before due to the decrease of its kinetic energy, and the movable part contacts The child 6 is brought into contact with the fixed contact 2. Therefore, the movable contact comes into contact with the fixed contact without applying a large impact to the contact or the structural members in the vicinity, so that no jumping phenomenon occurs. At this time, the buffer body 18 is collided with the collision piece 16, absorbs a part of the kinetic energy possessed by the movable part, is guided by the pin 20, moves in the direction of the arrow H, and separates from the collision piece 16 and becomes independent. exercise. However, the shock absorber 18 immediately collides with the oil dumpster pot 22 attached to the rear end surface.
The speed is rapidly reduced and the robot moves to the position shown in FIG. 3, where it once stops. At this time, the distance between the collision piece 16 and the buffer body 18 is F. Therefore, the shock absorber 18 does not affect the operating rod 12 after colliding with the collision piece 16. After the buffer body 18 stops, it is urged by the return spring 21 and the collision piece 16 is moved again.
is returned in the direction of However, since the elasticity of the return spring 21 is weak, the return speed of the shock absorber 18 is slow, and as shown in FIG. 16. At this time, the buffer body 18 brings its notch into contact with the side surface of the collision piece 16, so the operating rod 1
2 or prevent movement of the operating rod 12 when opening the switch.

[Effect of idea]

As described above, the contact shock absorber for a switchgear according to the present invention is equipped with a shock absorber made of a rigid body with a large mass, and when a collision piece fixed to the operating rod of the switchgear collides with this shock absorber, the shock absorber moves. Obtains the kinetic energy of the body and moves independently. The movable part is decelerated by giving a part of its kinetic energy to the buffer, and the movable contact at the tip comes into contact with the fixed contact. Therefore, the movable contact does not move and does not apply shocks that could damage the contact and structural members in the vicinity of the contact. Therefore, it becomes possible to increase the speed of the movable part. Moreover, the entire shock absorber is made up of a rigid body, and the shock absorbing effect is achieved by using the mass of a solid, rather than by using the viscosity of a fluid like in an oil dumpster. A constant damping characteristic is always obtained regardless of the location of the collision point. Therefore, even if the collision position of the collision piece and the buffer body approaches the contact position of the contact, the movable part can be sufficiently decelerated, and the impact when the contact part is inserted can be reduced. In addition, the buffer body is not affected by the surrounding environment such as temperature unlike conventional oil dump pots, so it can always maintain stable buffer properties, which has the effect of keeping the charging speed constant. There is.

[Brief explanation of the drawing]

Figure 1 is a side view showing the configuration of the vacuum switch, Figure 2 is a side view showing the configuration of the vacuum switch.
The figure is a side view showing an embodiment of the contact buffer device for a switchgear according to the present invention, and FIGS. 3 and 4 are views showing the operating process of the present invention, respectively. 2... Fixed contact, 4... Frame, 6... Movable contact, 12... Operating rod, 16... Collision piece, 1
6a... Collision surface of collision piece, 18... Buffer, 18
a...Collided surface of shock absorber, 18b... Rear end surface, 1
9...Oval hole of buffer body, 20...Pin, 21...
Return spring, 22...braking unit, 23...adjustment screw,
24...Adjustment piece.

Claims (1)

[Scope of utility model registration request] It includes a buffer body supported by a frame, and an operating rod to which a movable contact that contacts a fixed contact and a collision piece that collides with the buffer are respectively fixed, and the operating rod moves in its axial direction to Immediately before the movable contactor contacts the fixed contactor, the collision piece collides with the buffer body to reduce the speed of the operating rod, wherein the collision piece has a collision surface inclined toward the rear end at the tip thereof. the shock absorber is disposed diagonally so that the collision surface at the tip faces the collision surface of the collision piece parallel to and spaced apart from each other, and supports the shock absorber so as to be movable in the axial direction; 1. A contact shock absorbing device for a switchgear, characterized in that a return spring for urging the shock absorber toward the collision surface and an oil dump pot for braking the shock absorber are disposed on the rear end side.