JPS6136038Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a circuit breaker that is mainly equipped with a manual operating means for opening and closing a circuit by manual operation and a free tripping means for automatically interrupting the circuit when an abnormal current occurs in the circuit. It relates to circuit switching devices. In such a circuit breaker, there are problems in terms of safety and reliability when the circuit is opened and closed by manual operation. In other words, when a so-called closing operation is performed to close a circuit by operating the switching device of a circuit breaker, an abnormal current may flow in the circuit at the same time as this closing operation, so opening and closing the circuit should be performed to the minimum necessary level. There is a risk of danger if the manual operation is not performed with sufficient force and operating speed, but in the case of manual operation, the manual operating force and operating speed vary depending on the person, so it may be necessary in some cases. It may not be possible to obtain the operating force and operating speed, and there is a risk that danger may occur. Therefore, such a circuit breaker requires a mechanism that always opens and closes the circuit with a constant operating force and operating speed, regardless of the strength of the manual operating force or the slow operating speed.

The present invention satisfies the above-mentioned requirements by simplifying the switching device and making it special, while also maximizing the elastic force of the spring that counters the electromagnetic repulsive force between the contacts when the circuit is closed. It is an object of the present invention to provide a circuit switching device such as a circuit breaker that can be made small.

An example of implementing the present invention will be described with reference to the attached drawings. Reference numeral 1 denotes a movable contact rod having one side fixed to a shaft 3 rotatably attached to a frame 2, and an elongated hole of a predetermined length is provided at the end of the movable contact rod 1 on the side opposite to the shaft 3. 4 is bored therein, and a movable contact 5 is attached to the shaft 3 via a bracket to face a fixed contact 6. A roller 7 is fitted into the elongated hole 4 of the movable contact rod so as to be movable along the length direction while rotating within the elongated hole.
One end of a link 9 is rotatably fitted to a central shaft 8 inserted through the center of the link. The other end of the link 9 is pivotally connected via a pin 12 to a support fitting 11 of a free tripping means rotatably attached to the frame 2 via a shaft 10. 13
is an operating lever whose one end is rotatably fitted into a recess of a bearing 14 fixed to the frame 2, and is rotatably supported relative to the frame 2 around the bearing 14; A protrusion 15 for pushing one end of the support fitting 11 is formed at the end opposite to the center of the movement, and a pin 16 is attached.
A tension spring 17 is stretched between the roller 7 and the center axis 8 so as to prevent rotation of the roller 7 from being hindered.
The free tripping means is configured to prevent abnormal current from occurring in the support fitting 11 and the latch fitting 21 and the circuit that engages with the end portion of the support fitting opposite to the center of rotation thereof to prevent rotation of the support fitting 11. When the latch fitting 21 is activated,
It consists of an electromagnet or the like (not shown) that disengages the support fitting 11 from its engagement. A notch 19 is formed at the tip of the support fitting 11 on the opposite side from the center of rotation.
The latch fitting 2 is rotatably attached via the
1 is engaged with a roller 22 provided at the tip of the supporting member 11 to prevent counterclockwise rotation about the shaft 10 of the supporting member 11, and an operating lever 13 is provided on the intermediate outer surface of the supporting member 11. A protrusion 23 facing the protrusion 15 is formed. 24 is the movable contact rod 1
This is a stopper for stopping the rotation of the contact in the opening direction (clockwise in the drawing) at a predetermined angle.

The operation of the apparatus according to the above embodiment will now be explained. First, in FIG. 1, the support fitting 1
1 is prevented from rotating counterclockwise by engagement with the latch 21, and since the tension spring 17 is located on the left side of the link 9, the tensile force of the tension spring 17 causes the link 9 to move against the pin 12. It acts as a force to rotate counterclockwise around the center.
Therefore, a clockwise rotational force about the shaft 3 is applied to the movable contact rod 1 via the roller 7, and the movable contact 5 connected to the shaft 3 is separated from the fixed contact 6 and connected to the circuit. It has become a state. When the movable contact rod 1 rotates clockwise, it comes into contact with a stopper 24, and rotation beyond that position is stopped.

Next, when manually closing the circuit, the operating lever 13 in the state shown in FIG. 1 is rotated in the direction of arrow A, that is, counterclockwise, about the end that contacts the bearing 14. As the operating lever 13 rotates, the tension spring 17 also rotates counterclockwise around the attachment point to the center shaft 8 of the roller, but the tension spring 17 overlaps the link 9 (the center shaft 8 and pin 12 (matches on the connecting line)
Until then, tension spring 17 is applied to link 9.
Since a counterclockwise rotational force is applied around the pin 12, the circuit is in an open state. However, when the tension spring 17 moves beyond the position where it overlaps with the link 9 due to further rotation of the operating lever 13 and comes to be located on the right side of the link 9, the support bracket 11 is stationary and the position of the pin 12 remains unchanged. Therefore, a clockwise rotational force about the pin 12 is applied to the link 9 by the tension spring 17, and the roller 7 attached to the link 9 rotates inside the elongated hole 4 of the movable contact rod 1. while moving to the right along the long hole 4. Therefore, due to the rotational movement of the roller 7 within the elongated hole 4, a rotational force in the counterclockwise direction about the shaft 3 acts on the movable contact rod 1, and the movable contact 5 connected to the shaft 3 As the shaft 3 rotates counterclockwise, it comes into contact with the fixed contact 6, and the circuit is closed as shown in the second diagram.

If the circuit is to be opened manually from this state, the operation is the reverse of the above. That is, if the operating lever 13 in FIG. 2 is rotated clockwise about the end in contact with the bearing 14, the state shown in FIG. 1 will be achieved, and the circuit will be in a closed state.

Next, a case will be described in which the circuit is automatically cut off when an abnormal current occurs in the circuit. Second
If an abnormal current occurs in the circuit in the closed circuit state shown in the figure, it is detected by a detection device (not shown), and its output is applied to a circuit breaker tripping electromagnet (not shown). Due to the operation of the tripping electromagnet, etc., a force in the direction of arrow B in FIG. The engagement between the latch fitting 21 and the support fitting 11 is released by the movement. Then, the support fitting 11 rotates counterclockwise around the shaft 10 via the link 9 due to the tensile force of the tension spring 17, and the pin 12 and therefore the link 9 also rotate counterclockwise around the central axis 8. Tension spring 1 for rotational movement in the direction
The tensile force 7 no longer acts as a rotational force that rotates the link 9 clockwise about the pin 12, and therefore the movable contact rod 1 is rotated about the shaft 3 via the roller 7 attached to the link 9. The movable contact 5 is separated from the fixed contact 6 and becomes the open state shown in FIG. 3. At this time, by rotating the support metal fitting 11 in the counterclockwise direction, the protrusion 23 of the support metal fitting 11 and the protrusion 15 of the operating lever 13 are arranged in close proximity to each other in a facing state. In order to manually close the circuit from this state, that is, to reset the circuit to the state shown in FIG. 1, the operating lever 13 is rotated in the direction of arrow C in FIG. 3, that is, clockwise. Then, as the operating lever 13 is rotated clockwise, the protrusion 15 of the operating lever pushes the protrusion 23 of the support fitting 1.
1 also rotates clockwise together with the operating lever 13, so that the notch 19 at the tip of the support fitting 11
When engaged with the roller 22 at the tip of the latch 21, the state shown in FIG. 1 is achieved, and manual closing operation becomes possible again. In this case, after the circuit is interrupted by the free tripping means, the tripping electromagnet etc. are deenergized and the latch fitting 21 returns to its original position.

In the above embodiment, the movable contact 5 in the movable contact is attached via a bracket to the shaft 3 that rotates together with the movable contact bar 1, but it may be attached directly to the movable contact bar 1 with insulating means. Alternatively, the shaft 3 and the movable contact rod 1 may not be fixed, but the movable contact rod 1 may be rotatably attached to a shaft fixed to the frame 2; The same applies to Furthermore, although the embodiment has been shown to be applied to a circuit breaker, the present invention is not limited to this and can be applied to other circuit switching devices.

As mentioned above, the present invention is mainly used to manually open and close a circuit in a circuit breaker, and the present invention is not intended to open and close the contacts of a contactor using only manual force, but rather to use an operating lever that can be rotated manually. The movable contact rod is connected via a link and a tension spring, and the release force of the tension spring, which is generated based on a change in relative position between the tension spring and the link due to rotation of the operating lever, is used as a driving force to drive the contact. Since the contacts are made to open and close, the circuit can be opened and closed with a constant operating force and operating speed, regardless of the strength of the manual operating force used to operate the operating lever, or whether the operating speed is slow or slow. Can be opened and closed safely and reliably.

In addition, in circuit breakers, etc., after contacts make contact, electromagnetic repulsion, etc. strongly acts between the contacts, so in order to prevent the contacts from opening due to this electromagnetic repulsion, the contacts must be countered against the electromagnetic repulsion, etc. It is necessary to provide a spring or the like to apply a strong pressure force between the contacts of the contactor, but the present invention makes it possible to use the elastic force of the spring to counter the electromagnetic repulsive force between the contacts when the circuit is closed. can be made smaller. That is, the present invention does not simply rotate the movable contact rod to close the circuit using only the tensile force of the tension spring that connects the operating lever and the movable contact rod; The movable contact rod is rotated in the contact closing direction via a roller that moves while rotating within the long hole of the movable contact rod as the link rotates. The distance l between the roller moving in the elongated hole of the contact rod and the rotating shaft of the movable contact rod approaches the position where the contacts make contact as the movable contact rod rotates, as shown in Figure 4. Therefore _, by applying the lever principle of a movable contact rod with the rotating _shaft as a _fulcrum , and
Since the electromagnetic repulsive force is generated after the contacts make contact, it is strongly required that the spring counteracts the electromagnetic repulsive force by applying pressure contact force to the contact over the entire stroke of the movable contact until it comes into contact with the fixed contact. The movable contact only needs to act strongly from just before it comes into contact with the fixed contact.
Even if the elastic force of the tension spring that applies rotational force to the movable contact rod and therefore the link is as small as possible, it is sufficient to apply a pressing force between the contacts to counter the electromagnetic repulsion force.

[Brief explanation of the drawing]

The drawings show an example of the implementation of the present invention, and FIG. 1 is an explanatory diagram of the operation of the switching device when the circuit is opened;
Fig. 2 is an explanatory diagram of the operation of the switchgear when the circuit is closed by manual operation, Fig. 3 is an explanatory diagram of the operation of the switchgear when the circuit is interrupted by the free tripping means, and Fig. 4 is an explanatory diagram of the operation of the switchgear when the circuit is closed by manual operation.
The figure is an explanatory view showing the positional relationship between the roller and the rotating shaft of the movable contact rod when the circuit is closed by manual operation. 1...Movable contact rod, 2...Frame, 3...
Shaft, 4... Elongated hole, 5... Movable contact, 6... Fixed contact, 7... Roller, 8... Center shaft, 9... Link, 10... Shaft, 11... Support metal fitting, 12... Pin, 13...operation lever, 14...bearing.

Claims (1)

[Scope of utility model registration request] A movable contact rod has a movable contact facing a fixed contact on one side, a long hole on the other side, and is rotatably attached to a frame via an axis; A roller that is fitted into an elongated hole and is movable while rotating within the elongated hole, one end of which is pivotally connected to the central axis of the roller, and the other end of which is freely tripped.One end of the roller is connected to the frame. a link pivotally attached to a support bracket rotatably attached to the frame via a shaft; an operating lever rotatably attached to the frame around one end; and a central axis of the roller and the operating lever. It consists of a tension spring stretched between the center of rotation of the lever and a pin provided on the opposite side, and the tension generated due to changes in the relative position of the tension spring and the link due to rotation of the operating lever. The releasing force of the spring is used as a driving force, and the movable contact rod is rotated through a link that rotates due to the releasing force of the tension spring and a roller that rotates within the long hole of the movable contact rod as the link rotates. A circuit opening/closing device such as a circuit breaker, which is characterized by opening and closing contacts by moving the contacts.