JP2005339934A - Circuit breaker for electric power - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit breaker for electric power capable of preventing adhesion of contacts due to high frequency and large current by restraining chattering period, in case that the circuit breaker is used as a switch of a capacitor circuit. <P>SOLUTION: For the circuit breaker for electric power having a fixed electrode 24 and a movable electrode 23, intermediate conductors 37a, 37b are arranged between an upper conductor 30 and the fixed electrode 24, so as to be able to move toward a movement direction of the movable electrode 23. At collision of the fixed electrode 24 and the movable electrode 23, the intermediate conductors 37a, 37b move somewhat upward to absorb impact force at the collision. Further, the upper conductor 30 and the intermediate conductors 37a, 37b are released of their engagement only at the time of collision of the fixed electrode 24 and the movable electrode 23, and at completion of pole closing and at pole opening, get engaged with restoring force of returning springs 33a, 33b or the like arranged at top parts of the intermediate conductors 37a, 37b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a power circuit breaker, and more particularly to a power circuit breaker such as a vacuum circuit breaker in which a main contact has a butt structure.

  Some conventional power circuit breakers have a structure in which a fixed electrode and a movable electrode are abutted. As this kind of power circuit breaker, since the break and disconnect functions are performed smoothly, movable conductors and slide contacts in the vacuum vessel are omitted, the number of processes in the manufacturing process is reduced, and the work is simplified. The thing is proposed (for example, refer patent document 1).

  The main contact of this type of conventional power breaker has a fixed electrode and a movable electrode, but has a breaking performance and an energization performance. Due to the butt structure, chattering, that is, rebounding occurs when the contact is closed. In this phenomenon, the contact bounces several times in 1 to 4 msec. This chattering phenomenon was not regarded as a problem in Japan. The reason is that in Japan, when applying a capacitor to improve the power factor, the fifth (or seventh) harmonic contained in the power supply causes resonance due to the inductance of the phase advance capacitor and the circuit. In order to prevent this, a reactor having a capacitor capacity of 6% to 13% is inserted to prevent destruction of the equipment due to the resonance. As an incidental effect, there is also an effect that a high-current transient current close to a short-circuit current is limited at a high frequency (1 kHz to several kHz) that flows when the circuit breaker of the phase advance capacitor circuit is turned on. On the other hand, in countries other than Japan, there is a case where a reactor for suppressing harmonics is not inserted, or there is a case where a current-limiting reactor is not inserted in a back-to-back capacitor bank defined in IEC 62271-100 (International Electrotechnical Commission). When closed, a large current (several tens of kA) may flow at a high frequency (several kHz). At that time, when chattering occurs at the contact, the current has a crest value, and the current flows to the contact. Therefore, the contact is melted and welded between the contacts and cannot be removed. For this reason, in the People's Republic of China (hereinafter referred to as China), there is a power station (corresponding to an electric power company in Japan) that specifies the contact chattering time as 2 msec or less. Actually, in the case of a vacuum circuit breaker, the rated current value applicable to the capacitor circuit is 1200 A or less, but the power station in China may require a chattering time of 2 msec or less for all rated currents. When the rated current is increased, the size of the conductor and the movable part conductor and the movable contact of the vacuum switch tube are increased in order to secure the energizing current. As energy increases, the natural frequency of the vacuum switch tube section decreases and the chattering frequency also decreases. In the 1200A rated product, the frequency of about 1500 Hz is lowered to about 500 Hz. In the case of high-current rated products, once chattering occurs, it becomes 4 msec or more, which makes it impossible to satisfy the requirements of the power station.

JP 2003-7179 A

  In a conventional power circuit breaker, a 6% or 13% reactor is inserted in a power factor correction capacitor bank in Japan to suppress harmonics. However, the above reactor is not inserted in countries other than Japan. When there are many cases or when a vacuum circuit breaker is used for opening and closing for a back-to-back capacitor bank, there is a problem that a large current rush current flows at a high frequency and contact welding may occur.

  The present invention has been made to solve such a problem, and an object thereof is to obtain a power circuit breaker capable of preventing contact welding due to high frequency and large current by suppressing chattering time. And

  The present invention is a power circuit breaker having a fixed electrode and a movable electrode, and is provided between the upper conductor and the fixed electrode so as to be movable in the same direction with respect to the moving direction of the movable electrode. And an intermediate conductor for absorbing impact force at the time of collision between the fixed electrode and the movable electrode.

  According to this invention, it is a power circuit breaker having a fixed electrode and a movable electrode, and can move in the same direction with respect to the moving direction of the movable electrode between the upper conductor and the fixed electrode. Provided with an intermediate conductor for absorbing impact force at the time of collision between the fixed electrode and the movable electrode, so that when using a circuit breaker as a switch of a capacitor circuit, by suppressing chattering time It is possible to prevent contact welding due to high frequency and large current.

Embodiment 1 FIG.
Hereinafter, the circuit breaker for electric power which concerns on Embodiment 1 of this invention is demonstrated about a figure. FIG. 1 is a perspective view of the circuit breaker, FIG. 2 is a circuit breaker open state, and FIG. 3 is a circuit breaker closed state. FIG. 4 is a view seen from the CC direction in FIG. 2 and shows a circuit breaker open state. FIG. 5 is a view as seen from the DD direction in FIG. However, FIG. 5 shows a state at the moment when the fixed electrode and the movable electrode collide.

  As shown in these drawings, an operation mechanism 2 is mounted on the carriage 1. The operating mechanism 2 is provided with a closing spring 3 that stores the throwing input, an opening spring 4 that stores the opening force, and an output lever 5 that transmits the throwing input and opening force to the outside. The output lever 5 is provided so as to be rotatable about an output shaft 6. Further, as shown in FIGS. 2 and 3, a cam shaft 14 is provided that is pivotably suspended with respect to an operation mechanism frame 7 that houses the operation mechanism 2 therein. A cam 15 is fixed to the cam shaft 14, and a large gear 8 is attached to the end of the cam 15. A shaft 9 is attached to the large gear 8. On the shaft 9, a closing spring rod 10 is pivotally attached to the shaft 9. At the lower end of the closing spring rod 10, the closing spring 3 is disposed between the closing spring seat 10 a and the carriage 1 disposed coaxially with the threaded portion at the lower end of the closing spring rod. The large gear 8 meshes with the gear portion 9a at the end of the shaft 9, and rotates in synchronization with the gear portion 9a. The gear portion 9a is provided with a small gear 11 that rotates coaxially. It is assumed that the radius of the small gear 11 is larger than the radius of the gear portion 9a. The small gear 11 has a clutch structure in which the closing spring 3 moves in the axial direction toward the operating mechanism frame 7 when storing energy and does not rotate simultaneously with the shaft 9. The small gear 11 has a structure that meshes with the gear 13 of the output shaft of the electric motor 12. When the gear 13 is rotated in the clockwise direction by the driving force of the electric motor 12, the large gear 8 is also turned through the small gear 11 and the gear portion 9a. Rotate in the direction. Due to the clockwise rotation of the large gear 8, the closing spring rod 10 attached to the large gear 8 rotates clockwise around the output shaft 6, and is attached to the other end of the closing spring rod 10 via the gear 13. The closing spring 3 is stored. The closing spring 3 engages with a closing latch (not shown) upon completion of energy storage, and at the same time interrupts the current by a limit switch (not shown) for stopping the output of the electric motor 12. At the same time, the drive force of the electric motor 12 is not transmitted to the shaft 9 due to the contact and separation between the shaft 9 and the small gear 11, whereby the energy storage of the closing spring 3 is completed.

  In the closed state shown in FIG. 3, a roller 16 is provided at a position where the output lever 5 abuts. A connecting rod 17 is rotatably attached to the output lever 5. A three-phase lever 18 is rotatably provided at the lower end of the connecting rod 17. A contact pressure link 19 is provided at the other end of the three-phase lever 18. A contact pressure spring 20 is attached to the upper part of the contact pressure link 19. An insulating rod 21 is provided so that the contact pressure spring 20 is accommodated therein, and a movable electrode 23 of a vacuum switch tube 22 is connected to the insulating rod 21 via a movable electrode rod 28 and a flexible conductor 40. Screws are fastened. Further, a fixed electrode 24 is provided to face the movable electrode 23. In the opened state of FIG. 2, the movable electrode 23 and the fixed electrode 24 are separated from each other. In the closed state of FIG. And the fixed electrode 24 abut. An upper conductor 30 and an upper spring retainer 31 are provided on the upper portion of the fixed electrode 24. The upper conductor 30 is fixed, and the fixed electrode 24 of the vacuum switch tube 22 is fixed to the upper conductor 30 with a screw. In the present embodiment, however, intermediate conductors 37a and 37b (not shown in FIGS. 2 and 3) that move slightly upward when the fixed electrode 24 and the movable electrode 23 collide will be described later with reference to FIGS. ) Is provided between the upper conductor 30 and the fixed electrode 24. One end of the upper conductor 30 is fixed to the operating mechanism frame 7 via a support insulator 25a, and the upper main circuit terminal 25 is fixed to the other end. Reference numeral 45 denotes a lower conductor, one end of which is fixed to the operating mechanism frame 7 via a support lever 25b, and the lower main circuit terminal 27 is fixed to the other end. A flexible conductor 40 having flexibility is connected to the lower conductor 45 and the movable electrode rod 28 of the vacuum switch tube 22, and the flexibility of the flexible conductor 40 is maintained even when the movable electrode rod 28 moves in the AB direction. Therefore, the flexible conductor 40 and the movable electrode bar 28 can be electrically connected.

  As shown in FIGS. 4 and 5, intermediate conductors 37 a and 37 b are provided inside the upper conductor 30. Since the intermediate conductors 37a and 37b are configured to be movable in the same direction with respect to the moving direction of the movable electrode 23, the intermediate conductors 37a and 37b move slightly upward when the fixed electrode 24 and the movable electrode 23 collide. The impact force at the time of collision between the fixed electrode 24 and the movable electrode 23 is absorbed or alleviated. The upper spring retainer 31 is screwed to the upper conductor 30 with bolts 36a, 36b, 36c (not shown) and 36d (not shown). Bolts 34 a, 34 b, 34 c, 34 d, 34 e (not shown), 34 f (not shown), 34 g (not shown), 34 h (not shown) are provided on the side surface of the upper conductor 30. 38b, 38c, 38d, 38e (not shown), 38f (not shown), 38g (not shown), 38h (not shown) are penetrated to the bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, and 34h are screwed to the intermediate conductors 37a and 37b. The oblong holes 38a, 38b, 38c, 38d, 38e (not shown), 38f (not shown), 38g (not shown), 38h (not shown) are defined in the vertical direction (AB). This is a vertically long elliptical hole whose inner diameter is larger than the inner diameter in the horizontal direction (direction perpendicular to the AB direction). As a result, the bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, and 34h can be slightly moved in this direction as long as the inner diameter in the AB direction permits. Since the inner diameter of the oval hole in the horizontal direction is substantially the same as the outer diameter of the shafts of the bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, and 34h, The movement of the bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, and 34h in the horizontal direction is restricted. The bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, 34h are coaxially connected to springs 35a, 35b, 35c, 35d, 35e (not shown), 35f (not shown), 35g (not shown). 35h (not shown) are disposed, and the contact surfaces of the upper conductor 30 and the intermediate conductors 37a and 37b are compressed and electrically connected with a predetermined force. Thus, the intermediate conductors 37a and 37b and the upper conductor 30 have a structure having a constant contact pressure by the springs 35a, 35b, 35c, 35d, etc. and the bolts 34a, 34b, 34c, 34d, etc., and have energization performance. It has a structure.

  The spring guides 32a, 32b, 32c (not shown) and 32d (not shown) have four through holes 39a, 39b, 39c (not shown) provided at one end of the spring retainer 31. , 39d (not shown) is slidably disposed with respect to the other end, and holes 41a (see FIG. 8), 41b (see FIG. 8), 41c (see FIG. 8) provided in the intermediate conductors 37a and 37b. (Not shown) and 41d (not shown) are fitted to restrict the radial movement of the spring guides 32a, 32b, 32c and 32d. The spring guides 32a, 32b, 32c (not shown), 32d (not shown) are coaxially provided with return springs 33a, 33b, 33c (not shown), 33d (not shown). The return spring 33a and the like are compressed with a predetermined force to restrict the movement of the intermediate conductors 37a and 37b in the B direction to a certain value, and the stepped portion of the upper conductor 30 when the closing is completed. 30a, 30b and the stepped portions 37aa, 37bb of the intermediate conductors 37a, 37b abut.

  The stepped portion will be described. As shown in FIGS. 4 and 5, the intermediate conductors 37 a and 37 b have a substantially inverted L-shaped cross-sectional shape, and stepped portions 37 aa and 37 bb are provided in the upper part. The stepped portions 37aa and 37bb are projected outward. On the other hand, the upper conductor 30 has a substantially L-shaped cross-sectional shape, and stepped portions 30a and 30b are provided in portions slightly above the intermediate position in the height direction. The stepped portions 30a and 30b protrude inward. That is, the intermediate conductors 37a and 37b and the upper conductor 30 both have an L-shaped cross-sectional shape and are provided in opposite directions to each other. 30a and 30b and stepped part 37aa and 37bb contact | abut.

  Due to the configuration provided with the stepped portions, the intermediate conductors 37a and 37b move slightly when the fixed electrode 24 and the movable electrode 23 collide at the time of closing, so that the stepped portions 37aa and 37bb of the intermediate conductors 37a and 37b The stepped portions 30a and 30b of the upper conductor 30 are separated from the stepped portions 30a and 30b as shown in FIG. 5 only at the moment of collision. Thereafter, when the closing is completed, the return springs 33a, 33b, 33c and 33d The stepped portions 37aa and 37bb and the stepped portions 30a and 30b of the upper conductor 30 are engaged with each other to complete the closing. Further, at the time of opening, the stepped portions 30a and 30b of the fixed upper conductor 30 and the stepped portions 37aa and 37bb of the intermediate conductors 37a and 37b are engaged, so that the fixed electrode 24 of the vacuum switch tube 22 is engaged. Since the downward movement is restricted, it is possible to generate a tripping force even for the tripping during contact welding.

  Next, the operation will be described. In the closing operation, the engagement of the closing latch (not shown) and the large gear 8 causes the large gear 8 to rotate counterclockwise by the driving force of the closing spring 3. As a result of the counterclockwise rotation of the large gear 8, the cam shaft 14 and the cam 15 rotate counterclockwise. As a result, the rotatable roller 16 comes into contact with the cam 15 and is attached to the output lever 5. The output lever 5 rotates around the output shaft 6 in the clockwise direction. As a result, the connecting rod 17 rotatably attached to the output lever 5 is pushed down in the A direction, and the three-phase lever 18 rotates counterclockwise. The contact pressure link 19 attached to the other end of the three-phase lever 18 pushes up the contact pressure spring 20 and the insulating rod 21 in the B direction. After the movable electrode 23 of the vacuum switch tube 22 screwed to the insulating rod 21 is also pushed up in the B direction and comes into contact with the fixed electrode 24 of the vacuum switch tube 22, the contact pressure spring 20 is compressed by a predetermined dimension, and then the cam After the roller 16 is pushed up with the maximum outer shape of 15, the output lever 5 is held at the closing completion position by a latch mechanism (not shown) and the charging is completed. By this operation, the release spring 4 is stored via the release spring rod 29 that is pivotally attached to the other end of the output lever 5, and the insertion is completed.

  In the opening operation, the output lever 5 is rotated counterclockwise by the release spring force and the contact pressure spring force by disengaging the latch mechanism (not shown), and the connecting rod 17, the three-phase lever 18, the contact pressure link. 19, the insulating rod 21, the contact pressure spring 20, and the movable electrode 23 of the vacuum switch tube 22 perform the reverse operation to the closing operation.

  In the present embodiment, when a closing signal is input in the drawing, the closing latch (not shown) is disengaged, and the large gear 8 rotates counterclockwise by the throwing force of the closing spring 3. The force caused by the collision between the movable electrode 23 and the fixed electrode 24 tends to push up the intermediate conductors 37a and 37b screwed to the fixed electrode 24 through the fixed electrode 24 by several hundred μm. As a result, the intermediate conductors 37 and 37b move slightly upward to reduce the input impact force, and the input impact force is limited and transmitted by the frictional force between the intermediate conductors 37a and 37b and the upper conductor 30. Therefore, the amount of vibration energy transmitted to the intermediate conductors 37a and 37b and the upper conductor 30 is reduced, and the amplitude is reduced. This shortens the chattering time. FIG. 6 is a diagram in which the input impact force is related by frequency, and represents the input impact force of the conventional structure and the input impact force of the structure according to the present embodiment. The response frequency of the structure of the vacuum circuit breaker is a vibration mode in which chattering occurs, that is, a response in a mode in which the upper conductor 30 vibrates in the AB direction when the capacity of the vacuum circuit breaker increases as shown in FIG. In the frequency range where the contact point of 350 Hz to 1000 Hz chatters, the structure of the present invention reduces the input impact force, and the vibration amplitude of the upper conductor 30 due to the input impact force becomes small, and chattering hardly occurs.

  As described above, in the present embodiment, when the power circuit breaker is closed, the impact force from the movable electrode 23 of the vacuum switch tube 22 to the fixed electrode 24 is not transmitted directly to the fixed electrode 30. Intermediate conductors 37a and 37b attached to the fixed electrode 24 are provided so as to move upward. As a result, the stepped portions 37aa and 37bb of the intermediate conductors 37a and 37b and the stepped portions 30a and 30b of the upper conductor 30 fixedly provided only at the moment of collision between the fixed electrode 24 and the movable electrode 23. When the closing is completed, the stepped portions 30a of the upper conductor 30 provided with the stepped portions 37aa and 37bb of the intermediate conductors 37a and 37b fixed by the return springs 33a, 33b, 33c, and 33d. And 30b are engaged, and the closing is completed. Further, at the time of opening, the stepped portions 30a and 30b of the fixed upper conductor 30 and the stepped portions 37aa and 37bb of the intermediate conductors 37a and 37b are engaged, so that the fixed electrode 24 of the vacuum switch tube 22 is engaged. Since the downward movement is restricted, it is possible to generate a tripping force even for the tripping during contact welding. Further, the intermediate conductors 37a and 37b and the upper conductor 30 have a structure having a constant contact pressure and a current-carrying performance by the springs 35a, 35b, 35c and 35d and the bolts 34a, 34b, 34c and 34d. Yes. With this structure, the impact force is absorbed or alleviated by moving the intermediate conductors 37a and 37b attached to the fixed electrode 24 slightly upward when the main contact is closed, and the impact force is reduced with the intermediate conductors 37a and 37b. Since the transmission is limited by the frictional force with the fixed upper conductor 30, the vibration transmission energy of the fixed upper conductor 30 is small and the amplitude is small, and the chattering time is shortened. As a result, it is possible to prevent contact welding even when a large current and a high-frequency current flow.

Embodiment 2. FIG.
Next, another embodiment of the present invention will be described. Although the spring used in the first embodiment is a flat spring as an example, a spring having low friction and non-linearity such as a bamboo spring or a ring spring has the same effect.

Embodiment 3 FIG.
Next, another embodiment of the present invention will be described. FIG. 7 is a diagram showing the vacuum switch tube 22 and the upper conductor portion in the circuit breaker open state, and FIG. 8 is a diagram showing the circuit breaker closed state. However, FIG. 8 shows a state at the moment when the fixed electrode and the movable electrode collide. In the upper conductor 30, intermediate conductors 37 a and 37 b are disposed as in the first and second embodiments. The upper spring retainer 31 is screwed to the upper conductor 30 by bolts 36a, 36b, 36c (not shown), 36d (not shown). Bolts 34a, 34b, 34c, 34d, 34e (not shown), 34f (not shown), 34g (not shown), 34h (not shown) are provided on the side surfaces of the upper conductor 30 as oblong holes 38a, 38b. , 38c, 38d, 38e (not shown), 38f (not shown), 38g (not shown), 38h (not shown), the bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g and 34h are screwed to the intermediate conductors 37a and 37b. In addition, the said oblong hole 38a etc. are the oblong elliptical holes in which the internal diameter of AB direction is larger than the internal diameter of a horizontal direction (direction perpendicular | vertical to AB direction). As a result, the bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, 34h can be slightly moved in the AB direction. In addition, since the inner diameter of the smaller one of the oblong holes is substantially the same size as a little larger than the outer diameter of the shafts of the bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, 34h, The movement of the bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, and 34h in the horizontal direction is restricted. The bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, 34h are provided on the same axis with springs 35a, 35b, 35c, 35d, 35e (not shown), 35f (not shown), 35g (shown). 35h (not shown) are disposed, and the contact surfaces of the upper conductor 30 and the intermediate conductors 37a and 37b are compressed and electrically connected with a predetermined force.

  The spring guides 32a, 32b, 32c (not shown) and 32d (not shown) have four through-hole portions 39a, 39b, 39c (not shown) provided in the spring retainer 31 at one end. 39d (not shown) is slidably disposed, and the other end is fitted with holes 41a, 41b, 41c (not shown), 41d (not shown) provided in the intermediate conductors 37a, 37b. In combination, the radial movement of the spring guides 32a, 32b, 32c (not shown) and 32d (not shown) is restricted. The spring guides 32a, 32b, 32c (not shown), 32d (not shown) are coaxially provided with return springs 33a, 33b, 33c (not shown), 33d (not shown). During closing, at the moment of collision between the fixed electrode 24 and the movable electrode 23, the return spring 33a and the like are compressed with a predetermined force, and the movement of the intermediate conductors 37a and 37b in the B direction during the closing is constant. Regulate by value. Further, when the closing is completed and opened, the intermediate conductors 37a and 37b are urged in the A direction by the urging force in the A direction by the return force of the return springs 33a, 33b, 33c, and 33d. Since the lower portions of the circular holes 38a, 38b, 38c, 38d, 38e, 38f, 38g, 38h and the bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, 34h abut, the bolts 34a, 34b, 34c, 34d , 34e, 34f, 34g, and 34h, the movement of the intermediate conductors 37a and 37b and the fixed electrode 22 of the vacuum switch tube 22 in the A direction are restricted.

  As described above, in the present embodiment, when the power circuit breaker is closed, the impact force from the movable electrode 23 of the vacuum switch tube 22 to the fixed electrode 24 is not transmitted directly to the fixed electrode 30. Intermediate conductors 37a and 37b attached to the fixed electrode 24 are provided so as to move upward. Thereby, only at the moment of collision between the fixed electrode 24 and the movable electrode 23, the lower part of the oval hole of the upper conductor 30 and the bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, 34h are slightly separated, When the closing is complete, the return springs 33a, 33b, 33c, 33d allow the lower portions of the oblong holes 38a, 38b, 38c, 38d, 38e, 38f, 38g, 38h of the upper conductor 30 and the bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, and 34h come into contact with each other to complete the closing. At the time of opening, the bottom of the oblong holes 38a, 38b, 38c, 38d, 38e, 38f, 38g, 38h of the upper conductor 30 and the bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, 34h are engaged. Therefore, since the movement of the vacuum switch tube 22 below the fixed electrode 24 is restricted, a tripping force can be generated even when the contact is welded. Further, the intermediate conductors 37a and 37b and the upper conductor 30 have a structure having a constant contact pressure and a current-carrying performance by the springs 35a, 35b, 35c and 35d and the bolts 34a, 34b, 34c and 34d. Yes. With this structure, the impact force is absorbed or alleviated by moving the intermediate conductors 37a and 37b attached to the fixed electrode 24 slightly upward when the main contact is closed, and the impact force is reduced with the intermediate conductors 37a and 37b. Since the transmission is limited by the frictional force with the fixed upper conductor 30, the vibration transmission energy of the fixed upper conductor 30 is small and the amplitude is small, and the chattering time is shortened. As a result, it is possible to prevent contact welding even when a large current and a high-frequency current flow. As described above, in the present embodiment, the upper conductor and the intermediate conductor are engaged with each other by the body of the bolts 34a, 34b, 34c, 34d, 34e, 34f, 34g, 34h instead of the stepped portion. In this case, the same effects as those of the first and second embodiments are obtained.

It is a perspective view which shows the circuit breaker for electric power which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the opening state of the circuit breaker for electric power which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the closing state of the circuit breaker for electric power which concerns on Embodiment 1 of this invention. It is detailed sectional drawing which shows the open circuit state of the circuit breaker for electric power which concerns on Embodiment 1 of this invention. It is a detailed sectional view showing a power circuit breaker according to Embodiment 1 of the present invention. It is explanatory drawing which showed this invention and the conventional input impact force by the relationship between a frequency and energy spectral density. It is sectional drawing which shows the opening state of the circuit breaker for electric power which concerns on Embodiment 3 of this invention. It is sectional drawing which shows the closing state of the circuit breaker for electric power which concerns on Embodiment 3 of this invention.

Explanation of symbols

  1 bogie, 2 operating mechanism, 3 closing spring, 4 release spring, 5 output lever, 6 output shaft, 7 operating mechanism frame, 8 large gear, 9 shaft, 10 closing spring rod, 11 small gear, 12 electric motor, 13 gear, 14 Cam shaft, 15 Cam, 17 Connecting rod, 18 Three-phase lever, 19 Contact pressure link, 20 Contact pressure spring, 21 Insulating rod, 22 Vacuum switch tube, 23 Movable electrode, 24 Fixed electrode, 25a Support insulator, 25b Support insulator , 25 Upper main circuit terminal, 27 Lower main circuit terminal, 28 Movable electrode, 29 Flexible conductor, 30 Upper conductor, 31 Upper spring retainer, 30a, 30b Gap, 32a, 32b, 32c, 32d Spring guide, 33a, 33b, 33c, 33d return spring, 34a, 34b, 34c, 34d bolt, 35a, 35b, 35c, 35d, 35e, 3 5f, 35g, 35h Spring, 36a, 36b Bolt, 37a, 37b Intermediate conductor, 38a, 38b, 38c, 38d, 38e, 38f, 38g, 38h Oval hole, 41a, 41b, 41c, 41d Hole, 45 Lower conductor .

Claims (4)

A power circuit breaker having a fixed electrode and a movable electrode,
Between the upper conductor and the fixed electrode, provided so as to be movable in the same direction with respect to the moving direction of the movable electrode, in order to absorb the impact force at the time of collision between the fixed electrode and the movable electrode A power circuit breaker characterized by comprising an intermediate conductor.   The upper conductor and the intermediate conductor are disengaged only when the fixed electrode and the movable electrode collide, and when the closing is completed and when the opening is completed, a return force of a spring provided on the upper portion of the intermediate conductor is used. The power circuit breaker according to claim 1, wherein the power circuit breaker is engaged.   The upper conductor and the intermediate conductor each have a step portion, and the step portion of the upper conductor and the step portion of the intermediate conductor are separated only when the fixed electrode and the movable electrode collide, 2. The power circuit breaker according to claim 1, wherein the power breaker is engaged by a restoring force of a spring provided on an upper portion of the intermediate conductor at the time of completion and opening. The intermediate conductor is attached to the upper conductor by a spring and a bolt, and the contact surface between the intermediate conductor and the upper conductor is always kept at a constant pressure by the spring so that electrical connection is maintained. The power circuit breaker according to claim 1, wherein the power circuit breakers are pressed against each other.

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