JP2003115243A - Power circuit breaker - Google Patents

Abstract

(57) [Problem] To provide a power circuit breaker with reduced size and high reliability by reducing the impact at the end of the closing operation. The outer shape of a cam (3) is provided with a maximum radius of curvature centered on a rotation axis and a radius of curvature smaller than the curvature adjacent to the cam (3). It was configured to be guided along. At the moment when the cam 3 separates from the main lever 5, the main lever 5
The roller 7 is configured to substantially contact the second cut-off latch 8. According to the present invention, the impact force at the end of the closing operation is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power circuit breaker, and more particularly to a structure of a circuit breaker operating device suitable for improving energy efficiency and downsizing the entire device.

[0002]

2. Description of the Related Art The demand for high speed, small size and light weight circuit breakers is increasing due to the increase in power demand, and the demand for operating devices using springs as power means in terms of maintainability, noise / vibration and safety. Is expanding. A conventional circuit breaker operating device using a spring transmits a closing spring force to a breaking spring side via a cam and a main lever during a closing operation, as described in, for example, Japanese Patent Application Laid-Open No. 9-106742. The contact is closed while the blocking spring is compressed.

As the spring, a compression coil spring, which generally has a linear relationship between displacement and force, is often used, and the breaking spring force is determined so as to satisfy the breaking performance. On the other hand, in the closing operation, since the contacts are driven while compressing the breaking spring, it is necessary to make the driving force of the closing spring larger than the breaking spring force in the entire region. In this case, it may be possible to configure the closing spring force to exceed the breaking spring force in the entire region, but the spring force becomes too large and the parts become large. The force is designed to be larger than the breaking spring force.

Japanese Unexamined Patent Publication (Kokai) No. 62-82615 describes a configuration in which the cam plate has a reduced angle.

[0005]

At the end of the closing operation, the cam separates from the main lever, and the main lever and the lever of the breaking control section are engaged to hold the breaking spring force, and prepare for the next breaking operation. However, the energy of the breaking spring causes the main lever to move abruptly and collide with the lever of the breaking control unit, resulting in a large impact force, which may cause instability in engagement. There is a possibility that the operation may be broken and a malfunctioning cutoff operation may result. Further, it is necessary to design in consideration of impact, and there are problems that the parts become large and it is difficult to reduce the size of the entire operating device, and the responsiveness decreases.

An object of the present invention is to eliminate the impact on the lever of the breaking control unit of the main lever at the end of the closing operation,
Another object of the present invention is to provide a circuit breaker for electric power which can be reduced in size to realize downsizing of the entire circuit breaker and improvement in reliability.

[0007]

In order to achieve the above object, according to the present invention, the cam outer shape has a large radius of curvature centered on the rotation axis, for example, a maximum radius of curvature portion, and a radius of curvature adjacent to this portion. The main lever is configured to be guided along the outer shape of the cam during the first step, which is the closing operation.

The main lever and the strain energy holding means of the breaking elastic body are in contact with each other at the second stage when the closing operation is completed.

With this construction, the impact force at the end of the closing operation can be made smaller than in the prior art, so that the mechanical parts can be made smaller and lighter, and therefore the circuit breaker as a whole can be made smaller and its reliability improved. It will be possible.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a diagram showing a closed state of the circuit breaker,
Both the shutoff spring 26 and the closing spring 28 are compression coil springs, and both are in a compressed state. These springs may be other elastic elements, such as disc springs, spiral springs, leaf springs, etc. Reference numeral 29 denotes a contact point of the breaking portion, and a movable contactor 32 having one end rotatably connected to the lever 33 is provided. The other end of the lever 33 is attached to the main shaft 4 of the operating device. The main shaft 4 is rotatably supported by the housing 1, and a main lever 5 is attached to the main shaft 4. In other words, the rotation of the main lever 5 causes the lever 33 to operate so that the movable contact 32 is separated from the contact 29. A lever or a link that amplifies the stroke length of the movable contact may be provided between the lever 33 and the movable contact 32. A blocking spring link 25 that transmits the load of the blocking spring 26 is attached to one end of the main lever 5.

The positional relationship between the main lever 5 and the shutoff lever of the shutoff controller will be described. The shutoff lever includes various latch components.

A breaking spring 26 as strain energy holding means
The strain energy stored in is held and released by the means described below. That is, when the main lever 5 rotates, the roller 7 provided at the other end of the main lever 5 is engaged with and held by the slope 61 of the second cutoff latch 8 which is rotatably supported by the roller 7. Have been thwarted. The rotation of the second cutoff latch 8 is engaged with and held by the slope 62 of the cutoff latch 11 which is rotatably supported by the roller 10 provided at the other end of the second cutoff latch 8. Have been blocked by. Further, the cutoff latch 11 is prevented from rotating by the roller 13 provided at the other end of the cutoff latch 11 being engaged and held by the end surface 63 of the cutoff trigger 14 which is rotatably supported by the roller 13. Has been done. These shut-off latches 8, 11 and shut-off trigger 14 are return springs 9,
12, 15 and the return springs 9, 12, 15 are always elastically biased. The shutoff solenoid 17 is attached to the housing 1, and a plunger 72 of the shutoff solenoid 17 extends through the housing 1 to a position near the end of the shutoff trigger 14. On the other hand, the large gear 52 and the cam 3 are fixed to the rotatable cam shaft 2.
Reference numeral 51 is a small gear, which meshes with the large gear 52. As will be described later, the cam 3 is configured so that its outer shape has a large curvature portion 81 and a small curvature portion 82, and one end of the closing spring link 27 is connected thereto. The other end of the closing spring link 27 is connected to the closing spring 28 via a spring receiver 35. The closing operation means is configured as shown below. That is, the cam 3 is driven by the energy of the closing spring 28.
Is given a counterclockwise rotational force, but the roller 18 provided at one end of the cam 3 is engaged with and held by the inclined surface 64 of the closing latch 19 which is rotatably supported by the roller 18. The rotation is blocked by. Closing latch 19
The rotation is blocked by the roller 21 attached to the other end of the closing latch 19 being held by the end surface 65 of the closing trigger 22 which is rotatably supported by the roller 21. The closing solenoid 24 is attached to the housing 1, and a plunger 71 thereof penetrates the housing 1 and extends to the vicinity of an end portion of the closing trigger 22.

Next, the structure and operation of the blocking section will be described. First, in the breaking operation, when the breaking command is input in FIG.
Protrudes, presses the cutoff trigger 14, rotates the cutoff trigger 14 counterclockwise against the biasing force of the return spring 15, and releases the engagement between the cutoff trigger 14 and the roller 13 of the cutoff latch 11. Since the cutoff latch 11 is freely rotatable, it is rotated by the contact force of the second cutoff latch 8 from the roller 10, and the engagement between the cutoff latch 11 and the second cutoff latch 8 is released. Then, the second breaking latch 8 becomes free to rotate and is rotated by the contact force from the main lever 5, and the engagement between the main lever 5 and the second breaking latch 8 is released. Isolation spring 26
The main lever 5 rotates counterclockwise around the main shaft 4 due to the driving force of, the release spring 26 is released, and the contact 29 is closed. FIG. 2 shows a state in which the breaking operation is completed. A roller 6 provided at one end of the main lever 5 stands still in a state of substantially abutting the outer surface of the cam 3. The cutoff spring 26 is in a full stroke state.

Next, the construction and operation of the closing operation section will be described. When a closing command is input in FIG. 2, the closing solenoid 24 is excited and the plunger 71 protrudes to press one end of the closing trigger 22. Then, the closing trigger 22 rotates counterclockwise around the shaft against the urging force of the return spring 23. Next, the closing latch 19 is also rotated counterclockwise by the contact force from the roller 18 provided on the cam 3. Then, the closing spring 28 causes the cam 3 to rotate counterclockwise. Along with this rotation, the cam 3 comes into contact with the roller 6 provided on the main lever 5 to rotate the main lever 5 clockwise, and the contact 29 is closed while the blocking spring 26 is compressed.

Subsequently, by the latter half of the closing operation, the cam 3 makes a half rotation, and the roller 6 of the main lever 5 in the maximum radius of curvature portion.
Abut. Since the main lever 5 is configured to overstroke from the position in the closing and holding state, a gap g1 is formed between the roller 7 of the main lever 5 and the one side 61 of the second shutoff latch 8 as shown in FIG. As a result, the second breaking latch 8 is returned to its original position by the return spring 9, and then the breaking latch 11 is returned to its original position by the return spring 12. Finally, the cutoff trigger 14 is returned to its original position by the return spring 15. Generally, the closing operation takes a longer time as compared with the shut-off operation, and the closing trigger 2
2. The closing lever 19 is also returned to its original position by each return spring. Furthermore, the cam 3 rotates and separates from the main lever 5. At this time, in the prior art, the cam 3 is connected to the main lever 5
When separated from, the main lever 5 starts to rotate counterclockwise due to the breaking spring force 26, and the gap g1 rapidly decreases,
The roller 7 of the main lever 5 is engaged and held with the second breaking latch 8. At this time, the impact force is transmitted to the cutoff latch 11, the cutoff trigger 14, and the housing 1 to generate vibration. In the case of the present embodiment, the outer shape of the cam is as shown in FIG. Adjacent to the maximum radius of curvature R1 centered on the heart,
It is configured by providing a portion having a radius of curvature R2 smaller than the maximum radius of curvature. According to the study by the inventors, these R1 and R2
It is preferable that the angular range θ0 including the above parts is around 30 °. When the cam 3 further rotates from the state of FIG. 3, the main lever 5 starts to rotate counterclockwise due to the breaking spring force, but the roller 6 of the main lever 5 follows the outer shape of the cam 3 at a portion having a small radius of curvature R ₂ . Since it is further guided, the gap g1 is gradually reduced, and at the moment when the cam 3 separates from the main lever 5, the roller 7 is almost in contact with the second cutoff latch 8, and the closing of the closing shown in FIG. Reach the state. The radius of curvature R ₂ need not be a geometrical radius of curvature,
It may be a pseudo radius, and may have a substantially small radius of curvature. In this way, the main lever 5 is guided along the outer shape of the cam in the first stage, and the lever of the shutoff control unit is operated by the main lever 5 at the end of the closing / closing operation in the second stage.
It is in a positional relationship of being in contact with the strain energy holding means of the blocking elastic body via. When the cam 3 moves away from the main lever 5,
The impact force acts from the roller 7 to the second cutoff latch 8,
Since the rotation speed of the main lever 5 is sufficiently suppressed,
The impact force is smaller than that in the conventional technique, the operation for holding the breaking spring force is stable, and the reliability is improved. Further, it is possible to reduce the size and weight of the breaking latch and the breaking trigger, and it is possible to reduce the size and weight of the circuit breaker as a whole. Further, according to the present embodiment, since there is no impact force or the impact force can be reduced, it is possible to reduce the vibration of the housing 1 as well. Stable and improved reliability. Along with this, the housing 1 can be made smaller.

After the closing operation is completed, it is necessary to compress the closing spring. The closing spring 28 is compressed by starting an electric motor (not shown), rotating the small gear 51 counterclockwise, and rotating the large gear 52 and the cam 3 meshing with the small gear counterclockwise. When the cam 3 makes a half turn, the electric motor stops,
Although the closing spring force begins to release, the cam roller 18 engages the closing lever 19 and the closing lever 19 engages the closing trigger 22 to hold the closing spring force.

The present invention is not limited to the embodiment described above, and the same effect can be obtained even if the present invention is constituted by a plurality of closing springs and breaking springs. In addition, the larger the gap between the main lever and the interruption latch in the overstroke state, the longer the time required for the interruption latch and the interruption trigger to return to their original positions, and the more stable engagement holding operation can be realized. . Further, in the present embodiment, the number of the cutoff latches is two, but the cutoff trigger 14 may be used alone or a plurality of cutoff latches may be formed. Similarly, on the closing side, the same effect can be obtained even if there is no closing latch or if the closing latch is composed of a plurality of closing latches.

[0019]

As described above, according to the present invention, the main lever in the overstroke state is guided along the outer shape of the cam at the end of the closing operation, and the gap between the main lever and the breaking lever including the breaking latch is reduced. Since the roller of the main lever is almost in contact with the breaking lever at the moment when the cam is gradually reduced and the cam separates from the main lever, the impact force is reduced and the reliability is improved. Further, it becomes possible to reduce the size and weight of parts such as the breaking latch and the breaking trigger, and it is possible to reduce the size and weight of the circuit breaker as a whole.

[Brief description of drawings]

FIG. 1 is a structural diagram showing a state in which both a breaking spring and a closing spring are compressed in a closing state of a power circuit breaker according to an embodiment of the present invention.

FIG. 2 is a structural diagram showing the cutoff state of FIG.

FIG. 3 is a structural diagram showing a state in which the closing spring is in the released state in the closed state of FIG. 1;

FIG. 4 is a structural diagram showing a state at a moment when the cam is separated from the main lever in the closing state of FIG.

FIG. 5 is an external configuration diagram of a cam according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Casing, 3 ... Cam, 5 ... Main lever, 8 ... 2nd cutoff latch, 11 ... Cutoff latch, 14 ... Cutoff trigger, 17 ... Cutoff solenoid, 19 ... Closure latch, 22 ... Closure trigger, 2
4 ... closing solenoid, 25 ... breaking spring link, 26 ... breaking spring, 27 ... closing spring link, 28 ... closing spring, 29
... contacts, 32 ... movable contacts.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hideo Kawamoto             1-1-1 Kokubuncho, Hitachi-shi, Ibaraki Stock             Hitachi, Ltd. Electric Systems Division (72) Inventor Kenichi Okubo             1-1-1 Kokubuncho, Hitachi-shi, Ibaraki Stock             Hitachi, Ltd. Electric Systems Division F-term (reference) 5G028 AA17

Claims (2)

[Claims] 1. A shutoff unit for shutting off and turning on electric power by opening and closing a contact consisting of a fixed contact and a movable contact.
It has a breaking elastic body and a closing elastic body that opens and closes the contact by releasing the strain energy, and closes the contact by releasing the strain energy stored in the closing elastic body. However, a power circuit breaker is configured to compress the breaking elastic body via the cam and the main lever to engage the main lever with the lever of the breaking control unit, and the outer shape of the cam is centered on the rotation axis. Has a large radius of curvature and a radius of curvature adjacent to it that is smaller than the radius of curvature, and at the end of the closing operation, the main lever is guided along the contours of the large radius of curvature and the small radius of curvature of the cam. A circuit breaker for electric power, characterized in that, when the guide moves from a large radius of curvature portion to a small radius of curvature portion, the gap between the main lever breaking control lever and the lever is reduced. 2. A shutoff unit for shutting off and turning on electric power by opening and closing a contact consisting of a fixed contact and a movable contact.
An elastic body for closing and an elastic body for closing for opening and closing the contact by releasing strain energy, and means for holding and releasing strain energy stored in the elastic body for closing and the elastic body for closing, By releasing the strain energy stored in the closing elastic body, the breaking spring for compression is compressed via the cam and the main lever while closing the contact, and the main lever is engaged with the lever of the breaking control unit. In the electric power circuit breaker, the main lever is guided along the outer shape of the cam in the first step, and the lever of the interruption control section is in the second step, the elastic body for interruption via the main lever. The circuit breaker for electric power, wherein the circuit breaker is guided along the outer shape of the cam so as to be in contact with the strain energy holding means.