JPS648407B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disconnection switch for cutting off the load current or excitation current of a transformer in order to disconnect the transformer from or connect it to the line in a power system.

Traditionally, this type of switch has been used to provide a power circuit breaker for the purpose of interrupting fault current, or a circuit breaker to open and close a line in a no-current state, so as to have the ability to disconnect the current. A spring-operated mechanism was used, making the structure complicated and expensive.

The present invention provides an inexpensive disconnect switch by configuring the spring force that presses the movable contact against the fixed contact for energization to also be used as the contact opening force.

FIG. 1 is an embodiment of the present invention, and FIG. 2 is a diagram for explaining the operation of this embodiment. In the figure, 1
is, for example, a fixed contact connected to the line end of a transformer,
2 is a connection lead connected to the power system line, 3
5 is a roller-shaped movable contact for electrically connecting the fixed contact 1 and the connection lead 2; 4 is a roller holding arm for rotatably holding the movable roller contact 3;
6 is a drive arm for driving the roller holding arm 4, and 6 is a drive arm 5 that is driven by rotational force transmitted from a drive source (not shown), such as an electric motor or a manual handle shaft.
The drive arm 5 is slidably supported in the radial direction with respect to the main shaft 6. The drive arm 5 and the roller holding arm 7 are connected between the main shaft 6 and the roller holding arm 4. A push spring 8 arranged concentrically and wound into a coil is attached to the drive arm 5 to prevent the drive arm 5 from jumping out from the main shaft 6 when the movable contact 3 is detached from the fixed contact 1, that is, in the open state. A stopper 9 is a gap provided between the main shaft 6 and the stopper 8 when the movable contact 3 and the fixed contact 1 are in contact, 10 is an operating shaft connected to a drive source (not shown), and 11 is an end of the operating shaft 10 A protrusion 12 having an appropriate angle is formed in the radial direction of the operating shaft 10 and the concentric disk by a coupling cam provided in the section. 13 is a coupling fixed to the end of the main shaft 6; 14 is a coupling cam 11 inside the coupling 13;
a cam hole configured to be loosely fitted concentrically with the protrusion 12 and connected with the projection 12 with a predetermined play in the rotational direction;
15 is the angle of play between the protrusion 12 and the cam hole 14 in the rotational direction.

In Figure 1, current flows from a transformer (not shown) to the power system line through fixed contacts 1 - movable contacts 3 -
It flows via the roller holding arm 4, the driving arm 5, and the connecting lead 2. Now, when a rotational force is transmitted to the operation shaft 10 to break the circuit, the protrusion 12 on the coupling cam 11 idles until it fills up the play with the cam hole 14, and then the main shaft 6 rotates and is driven. arm 5
The roller holding arm 4 and movable contact 3 are rotated about the main shaft 6. The movable contact 3 is driven in the direction of separation from the fixed contact 1 while rotating around its center and rolling on the surface of the fixed contact 1. Figure 2 shows the situation during this period. As shown in FIG. 2, when the movable contact 3 is in the fixed position (position A in FIG. 2), the surface of the fixed contact 1 is machined into a circumferential surface centered on the rotation center of the main shaft 6, and the movable contact 3 The area near the point where the contact 1 separates from the fixed contact 1 is machined into a plane parallel to the central axis of the main shaft 6. Therefore,
In FIG. 2, when the movable contact 3 is in the fixed position, all of the force P by the push spring 7 becomes a force Q that presses the fixed contact 1, but near the point where the movable contact 3 separates from the fixed contact (at the (B position in Figure 2), the second
As shown in the figure, the force P exerted by the push spring 7 is generated by being divided into a force Q that presses the movable contact 3 against the fixed contact 1 and a force F that causes the movable contact 3 to separate. When the force F driving this movable contact 3 becomes large enough to overcome the rotational friction torque of the main shaft 6, the main shaft 6 rotates in the direction already being driven by the force F, filling up the play 15 shown in FIG. It runs on its own until it reaches the final stage.
Therefore, even if the drive arm becomes blind during operation, once it starts moving on its own, the operation will be completed at a speed determined by the force F and the inertia and friction of the rotational dynamic system. The force P or the contact parts of the movable contact 3 and the fixed contact 1 are applied so that the rotation speed is adjusted to a speed that corresponds to the atmosphere in which the disconnect switch is placed (for example, insulating oil) and the voltage and current that must be disconnected. cos ^-1 determined by shape (P/
It is sufficient to adjust the magnitude of Q) and the moment of inertia of the movable system. In addition, if there is a reason such as the need to withstand the transformer's input current even when the contact is closed, place another fixed contact 1 at the location corresponding to the open position as shown in Figure 2. By applying a rotation opposite to that described above to the operating shaft, early injection is possible.

As is clear from the above explanation, if the disconnection switch of the present invention is used, there is no need to provide a spring operation mechanism separate from the contact part, and the structure is configured simply by utilizing the force of the spring to give current carrying ability to the contact. It is possible to provide a highly economical disconnect switch with a small number of parts.

In addition, since a roller-shaped movable contact is used as the bow contact, the torque required for operation is small, and since the movable contact itself rotates when the contact opens, the foot of the arc generated when the contact opens moves. This has the effect of making cutting easier.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is an explanatory diagram illustrating the operating principle of FIG. 1.
In the figure, 1 is a fixed contact, 3 is a movable contact, 5 is a driving arm, 6 is a main shaft, and 7 is a spring. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A main shaft that is rotatably driven, a drive arm supported by the main shaft and movable a predetermined distance in a direction substantially perpendicular to the center line of the main shaft, and a drive arm rotatably supported by the drive arm substantially parallel to the center line of the main shaft. a movable contact, a spring that presses the drive arm in a direction that moves the movable contact away from the center line of the main shaft, and the movable contact can roll at a predetermined radius from the center line of the main shaft against the spring; A disconnecting switch comprising a fixed contact having a contact surface and a release surface that is farther from the centerline of the main shaft than the contact surface.