JPH0133019B2 - - Google Patents

Description

Detailed Description of the Invention The present invention has a multi-pole contact interposed between a power source and a load, and when an abnormality is detected in the load, all of the multi-pole contacts are opened to connect the power source to the load. This invention relates to a multi-pole circuit breaker that can cut off power supply.

Conventional multi-pole circuit breakers have an independent contact breaking mechanism for each pole, and the latch plates in each contact breaking mechanism arranged in parallel with each other, that is, rotate by input from a bimetal, etc., to close the contacts. The latch plate that performs the shutoff operation is connected with an interlocking rod,
When the latch plate of one pole rotates, the latch plate of the other pole also rotates, so that the contact breaking operation of each pole is performed simultaneously. However, in such conventional examples, the structure of the latch plate and the size of the casing cannot be shared with single-pole circuit breakers, and therefore molds, production lines, etc. cannot be shared. Therefore, there was a problem that efficient production could not be carried out.

The present invention has been made to solve these problems of the conventional example, and provides a contact breaking mechanism for each circuit breaker with a simple configuration by arranging a plurality of single-pole type circuit breakers in parallel. It is an object of the present invention to provide a multi-pole circuit breaker which can be made to work in conjunction with each other and which can improve productivity by sharing parts.

The configuration of the present invention will be described below with reference to illustrated embodiments. FIG. 1 shows the appearance of _a single-pole circuit breaker that is _the basis of the present invention. It is constructed by tightening and fixing with fixing tools 3 such as rivets, and a handle 4 for opening and closing the circuit is provided protruding from the upper surface of the circuit breaker body 1. Figure 2 shows the state in which the fixture 3 has been removed and one casing 2 ₁ has been removed from the other casing 2 ₂ . As shown in the figure, there is a pair of casings 2 ₁ and 2 ₂ between them. External connection terminal 5
₁ and 5 ₂ , a movable contactor 6, and an arc extinguishing device 7. 3 and 4 individually show the parts required for the operation of the circuit breaker, and FIGS.
The figure shows the cross-sectional structure of the circuit breaker. In each of the above figures, 8 is a movable contact attached to the tip of the movable contact 6, and is designed to open and close the main circuit by contacting and separating from the fixed contact 10 attached to one terminal plate ₉₁ . It's getting old. A tightening screw 13 is attached to each terminal plate 9 ₁ , 9 ₂ via a washer 11 and a spring washer 12 , thereby forming a pair of external connection terminals 5 ₁ , 5 ₂ . The engaging hole 15a of the bimetal 15 for overcurrent detection is fitted into the protruding piece 14 protruding from the terminal plate ₉₂ , so that the protruding piece 14 is inserted and the bimetal 15 is fixed to the terminal plate ₉₂ . It's summery. One end of the braided wire 16 is welded to the free end side of the bimetal 15, and the other end of the braided wire 16 is welded to the movable contact 6.
The movable contact 6 is connected to a movable arm 17, and the movable arm 17 is adapted to be fitted into a bottom opening 18a of a movable frame 18. 19
is a rotating shaft for pivotally supporting the handle 4, the movable arm 17, and the movable frame 18, and the central portion 19a of the rotating shaft 19 is bent into a substantially U-shape.
It is adapted to fit into a groove 4a in the handle 4. Further, both ends 19b of the rotating shaft 19 are fitted into a U-shaped groove 20 that serves as a fulcrum of the movable arm 17, and are also fitted into a shaft support hole 21 and a U-shaped groove 22 of the movable frame 18. It's becoming like that. 23 is a tension spring for urging the handle 4 to the on position and the off position. One end of the tension spring 23 is engaged with the central portion 19a of the rotating shaft 19, and the other end is engaged with a pin 25 whose both ends are supported in the shaft hole 24 of the movable arm 17. Therefore, the handle 4 is biased to the on position or the off position at the point where the tension spring 23 crosses the rotation center P of the rotating shaft 19, as shown in FIGS. 5 and 7. . In addition, the above tension spring 2
The movable arm 17 and the movable frame 18 are moved by the tensile force of 3.
and a rotating shaft 19 can be integrated. A protrusion 26 is formed at one end of the movable frame 18, and the concave groove 4b of the handle 4 can be engaged with the protrusion 26 as shown in FIG. This allows the handle 4 to move to arrow A during the assembly process of the circuit breaker.
The device is designed to prevent the device from flying out in the direction shown. Next, reference numeral 27 is a compression coil type spring for forcibly opening the movable contactor 6 during the trip operation, and the tip end 27a of this spring 27 is connected to the spring receiver of the movable frame 18 via a protective plate 28 for preventing arcing. It is adapted to be inserted into and engaged with an engagement hole 29 provided in the seat 31. This spring 27 is housed in the storage space 30 of both casings 2 ₁ and 2 ₂ , and the rear end 27 b of the spring 27 comes into contact with the inner bottom surface 30 a of the spring 27 . The arc protection plate 28 is the movable contactor 6
The spring 27 is caused by the arc generated when the movable contact 8 is separated from the fixed contact 10 of the terminal plate ₉₁ .
It prevents the front protection plate 28a from being melted and damaged, and is composed of a front protection plate 28a and a side protection plate 28b. Also, a spring 27 is attached to the front protection plate 28a.
A fitting hole 28c is provided for fitting the tip 27a. The front protection plate 28a and the spring seat 31 around the engagement hole 29 of the movable frame 18 are slightly inclined to improve contact with the spring 27. Reference numeral 32 denotes a yoke plate for short-circuit current detection formed of a magnetic material, and lateral protruding pieces 33 protruding from this yoke plate 32 are connected to respective engagement plates formed on the pair of casings 2 ₁ and 2 ₂ . It is designed to be fixed by a matching hole 34. The center piece 35 of the yoke plate 32 is adapted to be fixed to the terminal plate 9 ₂ , and side pieces 36 forming magnetic coupling paths extend vertically from both sides of the center piece 35 . 37 is a latch plate, and both ends of a pivot pin 39 inserted into the pivot hole 38 are supported by engagement holes 40 of both casings 2 ₁ and 2 ₂ , making the latch plate 37 rotatable. . This latch plate 37 is made of a magnetic material, and when an excessive current flows through the bimetal 15, the magnetic flux generated around the bimetal 15 flows to the center piece 35 and side pieces 36 of the yoke plate 32, and the latch plate 37
The magnetic adsorption piece 41 is adapted to be adsorbed to the side piece 36. Further, an abutment piece 42 is formed at the upper end of the latch plate 37, and is adapted to abut against the free end side of the bimetal 15. A locking step 44 is formed at the tip of each side piece 43 of the latch plate 37, and is adapted to abut against a locking portion 45 of the movable frame 18. Reference numeral 46 denotes a torsion spring that presses the contact piece 42 of the latch plate 37 toward the free end side of the bimetal 15, and as shown in FIGS. The other end contacts the handle 4 when it is in the off position, and contacts the casings 2 ₁ and 2 ₂ when it is in the on position, and is applied to the latch plate 37 depending on the state of the handle 4. changing power. Torsion spring 46
is rotatably supported by fitting into the shaft support boss 47 ₁ of the casing 2 ₁ on the one hand, and received by the shaft support boss 47 ₂ of the casing 2 ₂ on the other hand. Both casings 2 ₁ and 2 ₂ also have a rotating shaft 1
Pivot hole 48 for supporting both ends 19b of 9
, a hole 49 for inserting the fixture 3, and an exhaust hole 5 for exhausting gas generated when the circuit is interrupted.
0a, 50b, etc. are provided. Furthermore, 7 is an arc extinguishing device, which is formed by holding a plurality of arc extinguishing plates 51 made of magnetic material at appropriate intervals with side plates 52 made of insulating material.
The arc generated when the movable contact 8 and the fixed contact 10 are separated can be extinguished as quickly as possible. Each arc extinguishing plate 51 is provided with a notch 51a so that the movable contact 6 can pass therethrough. A substantially V-shaped cut groove 51b is formed at the lower end of the cutout 51a, and the gas accumulated around the contact is transferred to a gas retention part 53 formed behind the fixed contact 10 through the cut groove 51b. By discharging it, the blocking performance can be improved. Also, an arc extinguishing chamber 54 that stores the arc extinguishing device 7
A partition wall 56 is formed between the arc extinguishing chamber 54 and the interrupting mechanism section 55 that houses the spring 27, the movable frame 18, etc.
This prevents the intrusion into the 5.

Next, the operation of the single-pole type circuit breaker will be explained with reference to FIGS. 5 to 8. First, FIG. 5 shows a state in which the circuit breaker is turned off, and in this state, the movable contact 8 and the fixed contact 10 are separated. At this time, the movable contact 6 is biased by the tensile force of the tension spring 23, and the movable contact 6 is biased at the bottom opening 1 of the movable frame 18
It is separated to a position where it abuts the opening edge of 8a. Further, the handle 4 is similarly biased by the tensile force of the tension spring 23 and is stopped at a position where the groove 4b engages with the protrusion 26. Further, since one end of the torsion spring 46 is pressed by the outer peripheral surface of the handle 4, the other end of the torsion spring 46 strongly presses the back side of the abutting piece 42 of the latch plate 37.
Therefore, the locking portion 45 of the movable frame 18 is connected to the latch plate 3.
It is securely engaged with the locking step portion 44 of No.7. Further, due to this engagement, the spring 27 for tripping operation remains compressed within the storage space 30. 6th
The figure shows a cross-sectional view taken along the line X-X in FIG. I can understand the situation clearly. Next, Figure 7 shows the state when the circuit breaker is turned on.
In this state, the movable contact 6 is pulled by the tension spring 23.
The movable contact 8 is stopped at a position where it is pressed against the fixed contact 10. Further, the handle 4 is similarly biased by the tensile force of the tension spring 23, and is stopped at a position where the operating portion of the handle 4 is in contact with the casings 2 ₁ and 2 ₂ . In this manner, the direction in which the movable contactor 6 and the operating portion of the handle 4 are biased is reversed at the point where the tension spring 23 crosses the rotation center P of the rotation shaft 19. Therefore, when the circuit breaker is on, one end of the torsion spring 46 is no longer pressed against the outer peripheral surface of the handle 4, as shown in FIG.
The pressing force of the latch plate 37 at the other end against the abutment piece 42 is weaker than in the off state, so that a desired force is applied to the abutment piece 42. Therefore, if the bimetal 15 is deformed by an overcurrent and presses against the abutting piece 42, or if the yoke plate 32 is magnetized by a short-circuit current flowing through the bimetal 15 and attracts the magnetic attraction piece 41, the latch will not be activated. The plate 37 is designed to rotate around the pivot pin 39, whereby the locking step portion 44 and the locking portion 45 are disengaged, the spring 27 is expanded, and the movable frame 18 is adapted to rotate about the rotation center P of the rotating shaft 19. FIG. 8 shows a state in which such a tripping operation is performed, and as shown in the figure, the movable frame 18 is moved by the spring 2.
Since it is pressed and rotated by the movable contact 6
is pushed by the opening edge of the bottom opening 18a of the movable frame 18 and is forcibly driven in the contact opening direction. When the movable contact 6 is separated by a predetermined distance, it is further driven in the direction of contact separation by the tensile force of the tension spring 23, and finally the movable arm 17 comes into contact with the pivot pin 39, and the movable arm 17
is stopped, and the handle 4 is stopped at a position where the groove 4b is engaged with the protrusion 26 of the movable frame 18. At this time, since the movable frame 18 is tilted, the operating portion of the handle 4 stops approximately at the center between the on position and the off position, indicating that a trip operation has been performed. When such a tripping operation is performed, unless the handle 4 is returned to the OFF position and the engagement between the locking step portion 44 and the locking portion 45 is restored as shown in FIG.
cannot be stopped at the ON position. As is clear from a comparison between FIG. 5 and FIG. 7, the bottom opening 18 of the movable frame 18
The opening width of a is longer than the opening/closing stroke of the movable contact 6. Therefore, when a trip operation is not performed such as during manual opening/closing operation, the movable contact 6 is moved by the spring 27 or the movable frame 18. Also, it is not affected by contact breaking mechanisms such as the latch plate 37. Further, in this embodiment, since one end of the torsion spring 46 is separated from the handle 4, the abutment piece 42 of the latch plate 37 is
Since the handle 4 is strongly pressed, it is possible to reduce the possibility that the locking step portion 44 and the locking portion 45 will come out of engagement due to vibrations when the handle 4 is manually opened and closed.

By the way, when the movable contact 8 and the fixed contact 10 are opened and the main circuit is interrupted, an arc is generated between the movable contact 8 and the fixed contact 10, but this arc is caused by the arc extinguishing device 7. The arc is extinguished as quickly as possible by a plurality of arc extinguishing plates 51. As described above, a substantially V-shaped groove 51b is formed at the lower end of the notch 51a of the arc-extinguishing plate 51, and this groove 51b is located below the terminal plate ₉₁ as shown in FIG. It is arranged. Therefore, the gas generated around the contact when the circuit is interrupted is quickly discharged to the gas retention section 53 at the rear of the terminal plate ₉₁ through the cut groove 51b.
Further, since the gas discharged into the gas retention portion 53 is discharged from the exhaust hole 50a, the amount of arc ejected to the outside can be reduced. In addition to this exhaust hole 50a,
An exhaust hole 50b is also provided on the opposite side of the arc extinguishing device 7, and the efficiency of gas discharge from the arc extinguishing device 7 is improved by discharging gas in both directions.

Next, FIG. 9 is a sectional view showing a mechanism for adjusting the thermal response characteristics of the bimetal 15 of the single-pole circuit breaker as described above. Alternatively, the push-down jig 58 is inserted into the circuit breaker body 1 so that the thermal response characteristics of the bimetal 15 can be changed from the outside. In Fig. 9, 59 is the terminal plate 9 ₂
It is an adjustment piece formed at the lower end of the holder, and has a substantially L-shaped opening 60, a push-up engagement part 61, and a push-down engagement part 62. A projecting piece 14 is protruded from the end of the adjustment piece 59, and an engagement hole 15a of the bimetal 15 is fixed to this projecting piece 14. However, since the terminal plate ₉₂ is formed of a plate made of copper or copper alloy to improve conductivity, the adjustment piece 59 is relatively easily deformed, and the push-up jig 57 is pushed up into the engaging portion. 61 and pushes the adjustment piece 59 upward, the periphery of the approximately L-shaped opening 60 of the adjustment piece 59 is deformed, and the free end of the bimetal 15 is displaced in the direction shown by the arrow Q. Furthermore, when the push-down jig 58 is engaged with the push-down engagement portion 62 and the adjustment piece 59 is pushed down, the periphery of the approximately L-shaped opening 60 of the adjustment piece 59 is deformed in the opposite direction, causing the bimetal 15 to be free. The end is displaced in the direction opposite to arrow Q. Therefore, the free end of the bimetal 15 and the latch plate 37
The gap between the bimetal 15 and the contact piece 42 can be freely adjusted, thereby making it possible to adjust the thermal response characteristics of the bimetal 15.

Next, FIGS. 10 to 14 show a multi-pole type circuit breaker which is the gist of the present invention, in which three single-pole type circuit breakers B are arranged in parallel to form a three-phase AC multi-pole circuit breaker. The circuit breaker B is configured as a pole type circuit breaker, and as shown in FIG. 11, each circuit breaker B is fixed to each other by a long fixture 3. Further, a connecting cap 63 is attached to the operating portion of each handle 4, and a connecting shaft 65 is fitted into a horizontal hole 64 formed at the tip of each operating portion, thereby connecting each handle 4. are becoming interconnected. Both casings 2 ₁ and 2 ₂ of each circuit breaker B are each formed with a substantially fan-shaped ridge 66 as shown in FIG. 4. In the present invention, the inside of this ridge 66 is By appropriately punching, substantially fan-shaped openings 66a are formed in the mutually adjacent casings 2 ₁ and 2 ₂ of each circuit breaker B, and the interlocking plate 67 can be fitted into the openings 66a. Interlocking plate 67
The length in the longitudinal direction is slightly shorter than the thickness when three circuit breakers B are stacked. Further, the length of the interlocking plate 67 in the width direction is the approximately fan-shaped opening 6.
6a, and therefore, one end in the width direction of the interlocking plate 67 has a substantially fan-shaped opening 6.
6a, and the other end in the width direction can rotate along the arc of the substantially fan-shaped opening 66a. FIG. 12 shows the position of the movable contact 6 when the interlocking plate 67 is attached and the handle 4 is in the OFF position. As shown in the figure, in this state, the movable contact 6 is attached to the interlocking plate It is something that cannot be touched. On the other hand, in Figure 13, either one
The circuit breaker B is tripped and the movable contact 6 is opened. In this state, the interlocking plate 67 is pressed by the movable contact 6. The latch plate 37 of the other circuit breaker B is pressed by the interlocking plate 67 and rotates.
Therefore, the three circuit breakers B are designed to trip almost simultaneously.

In the description of the embodiments of the present invention, an overcurrent detection mechanism made of a bimetal 15 and a short-circuit current detection mechanism made of a yoke plate 32 and a magnetic adsorption piece 41 were shown as a load abnormality detection mechanism, but instead of these, It is also possible to use an earth leakage detection mechanism, an open phase detection mechanism, or the like.

The present invention is constructed as described above, in which a plurality of single-pole circuit breakers are arranged in parallel, and when one of the circuit breakers operates to break, the movable contactor driven in the contact opening direction Interlocking plates that come into contact with each other to operate the contact breaking mechanisms of other circuit breakers are provided, and these interlocking plates are fitted into substantially fan-shaped openings formed in mutually adjacent casings of each circuit breaker. Therefore, it is possible to interlock each contact breaking mechanism of a single-pole circuit breaker with an extremely simple configuration, and therefore, by stacking an appropriate number of single-pole circuit breakers. With this, a multi-pole circuit breaker with the desired number of poles can be constructed.
This has the advantage of significantly improving production efficiency since it can share molds, production lines, etc. with single-pole circuit breakers. Further, in the present invention, the interlocking plate is inserted into the substantially fan-shaped opening, so that one end in the width direction of the interlocking plate contacts the center of the substantially fan-shaped opening, and the other end in the width direction contacts the center of the substantially fan-shaped opening. Since it is designed to be able to rotate along the arc-shaped part, there is no need to provide special members such as a pivot pin for the interlocking plate, and the structure is simple, and the interlocking plate pivot mechanism is free from failure. This has the advantage that it can be reduced.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the appearance of a single-pole circuit breaker that is the basis of the present invention, Fig. 2 is a perspective view of the same with both casings opened, and Figs. 3 and 4 are the same configuration as above. A perspective view showing parts; FIG. 5 is a cross-sectional view of the above circuit breaker in the OFF state; FIG. 6 is a cross-sectional view taken along line X-X of the above; FIG. 7 is a cross-sectional view of the above circuit breaker in the ON state. , FIG. 8 is a cross-sectional view of the above circuit breaker in a trip state, FIG. 9 is a cross-sectional view showing a mechanism for adjusting the thermal response characteristics of a bimetal used in the above circuit breaker, and FIG. 10 is a summary of the present invention. A perspective view of a multipolar circuit breaker, No. 11
The figure is an exploded perspective view of the same as the above, and FIGS. 12 and 13 are cross-sectional views of the same in the off state and trip state, respectively. 2 ₁ and 2 ₂ are casings, 4 is a handle, 6 is a movable contact, 8 is a movable contact, 10 is a fixed contact, 15
is a bimetal, 66a is an opening, and 67 is an interlocking plate.

Claims (1)

[Claims] 1. A rotatable movable contact with a movable contact attached to one end, a fixed contact that comes into contact with the movable contact and opens when the movable contact rotates, and the movable contact and the fixed contact open when a load abnormality is detected. A plurality of single-pole circuit breakers are arranged in parallel, each having a contact breaking mechanism inside the casing that drives the movable contact in the direction in which the movable contact is rotated, and a handle for rotating the movable contact protruding from the casing. An interlocking plate is provided that comes into contact with the movable contact driven in the contact opening direction when one of the circuit breakers operates to break the contact, and operates the contact breaking mechanism of the other circuit breaker. The interlocking plate is fitted into substantially fan-shaped openings formed in mutually adjacent casings of the circuit breaker, so that one end in the width direction of the interlocking plate contacts the center of the substantially fan-shaped opening, and the other end in the width direction contacts the substantially fan-shaped opening. 1. A multi-pole circuit breaker, characterized in that the circuit breaker is rotatable along an arcuate portion of the section.