JPS62163221A - Circuit breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 〔Technical field〕 This invention relates to a circuit breaker.

[Background technology]

A conventional example of cutting off and extinguishing the arc by inserting an arc-extinguishing shield plate between the movable contact and the fixed contact in the event of an abnormal current, such as a short circuit (Japanese Patent Laid-Open No. 196440/1983)
is shown in FIG. 12, but it had the following drawbacks. That is, since the shielding plate 101 moves between the fixed contact 102 and the movable contact 103 in conjunction with the opening/closing operation of the movable contact 100 by the operation of the link mechanism section of the opening/closing/tripping means 104, the shielding plate 101 is moved between the fixed contact 102 and the movable contact 103, so that the shielding plate 101 is moved between the fixed contact 102 and the movable contact 103. There is a delay time of about 2 to 4 minutes due to the operation of the link mechanism of the opening/closing/tripping means 104 until the contact 103 starts to open, and moreover, the movable contact 10
Approximately 3~5+n from the time 3 starts to open until the complete open
s, it takes approximately 5 to 1Qms from the occurrence of a short circuit until the temporary shielding lot completes its operation.

FIG. 7 shows the arc waveform when the spring force of the opening spring is set high and the shielding plate 101 completes its operation in about 5 ms. Ql is contact arc voltage, Q2 is breaking current,
Q3 is the estimated short circuit current.

In this way, even if the spring force of the opening spring is set high and the temporary shielding 101 is operated, there is a delay of approximately 5 ms, so the short circuit current reaches its peak value, and as a result, contact damage due to arcing and contact Surrounding molded products and shielding plate 1
01 is severely damaged.

In addition, if the spring force of the opening spring is increased, the load for operating the handle increases, resulting in an operational burden.

As a result, the time required for the temporary shield 101 to complete its operation cannot be shortened, and a large number of new customers cannot be obtained.

[Purpose of the invention]

An object of the present invention is to provide a circuit breaker that can increase the number of new customers by shortening the time from the occurrence of a short circuit to the completion of operation of the shield plate without increasing the operating load of the handle. It is.

[Disclosure of the invention]

The circuit breaker of the present invention includes a fixed contact having a fixed contact, a movable contact having a movable contact that opens and closes with respect to the fixed contact, an electromagnet for detecting an abnormal current of a load, and an operation of the electromagnet. an arc-extinguishing shielding plate that enters between the movable contact and the fixed contact in a closed state in conjunction with a detection unit that opens and closes the movable contact with a handle and detects abnormal current in the load. opening/closing to trip open the movable contactor opened by the shielding plate;
It is equipped with a trip means.

According to the configuration of the present invention, when an abnormal current such as a short circuit current flows, the shielding plate is inserted between the fixed contact and the movable contact in conjunction with the operation of the electromagnet and without the operation of the opening/closing/tripping means. Therefore, there is no effect of delay time due to the operation of the opening/closing/trip means, and the time from the occurrence of abnormal current until the shielding plate completes its operation can be shortened. Therefore, the arc cutoff time can be shortened, resulting in a large number of new customers. can be realized. Furthermore, since there is no need to increase the size of the opening spring of the opening/closing/tripping means, there is no need to increase the operating load of the handle.

Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 to 6. That is, this circuit breaker includes a fixed contact 2 having a fixed contact I, a movable contact 4 having a movable contact 3 that opens and closes with respect to the fixed contact 1, and an electromagnet 5 that detects abnormal current of the load. In conjunction with the operation of the electromagnet 5, an arc-extinguishing shielding plate 9 enters between the movable contact 3 and the fixed contact l in the open state, and the movable contact 4 is opened and closed by the handle 6, and the load is removed. It is provided with opening/closing/tripping means 8 for tripping and opening the movable contact 4 which is opened by the shielding temporary 9 in conjunction with a detection section that detects an abnormal current.

In FIG. 1, 10 has an opening (not shown) on the side surface (perpendicular to the paper surface of FIG. 1) for incorporating parts, and
The case has a structure of poles, and when configuring a multi-pole circuit breaker, the cases 10 are arranged in parallel and connected by passing a caulking pin (not shown) through the connection hole 13. 11 is a load side terminal provided at one end of the case 10, 12 is a power supply side terminal provided at the other end of the case 10, and 14 is a case mounting groove.

The opening/closing/tripping means 8 includes a handle 6, a frame 15, an operation link 19, an operating shaft 20, and a movable frame 30.
, a latch link 23 , a trip link 24 , an opening spring 42 , and the above-mentioned detection section, which uses the electromagnet 5 as an example. The frame 15 is held within the case IO. The handle 6 is rotatably provided at the first upper end of the frame 15 by a fixed shaft 16, and is attached to the case 10.
A part of the case 10 is exposed through the handle hole 17 on the top surface of the case 10.
A reset protrusion is formed on the inside of the 6th.

A movable shaft 18 is provided at the inner end of the handle 6.
One end of the operating link 19 is connected to the link 8, and the operating shaft 2 is connected to the other end.
0 is concatenated. Further, a handle return spring 22 having a tensile action is suspended between the movable shaft 18 and a spring receiver 21 provided below the handle 6 of the frame 15, and is attached so that the handle 6 is in the neutral position shown in FIG. It is strong. The upper end of the latch link 23 is rotatably connected to the fixed shaft 16, and the operating shaft 20 is slidably abutted on one side of the lower end of the launch link 23. A trip link 24 is rotatably provided on the frame 15 at a position opposite to the operating shaft 20 of the latch link 23 by a fixed shaft 25.

This trip link 24 has a latch portion 24a at the tip,
It includes a short-circuit response section 27 in the middle, an overcurrent response section 26 extending upward from the fixed shaft 25, and a return spring 28. The return spring 28 has a wound portion supported by the fixed shaft 25, one end of which engages with the overcurrent response section 26, and the other end of which engages with the frame 15 to rotate the trip link 24 clockwise in FIG. It is biased and positioned at the position shown in FIG. 1 by a stopper (not shown) provided on the frame 15. Further, this state is a latched state in which the latch portion 24a abuts and locks the lower end of the latch link 23, and prevents the latch link 23 from rotating counterclockwise about the fixed shaft 16.

A pair of guides 29 are provided on the side wall of the case 10 below the operation link 19, and a movable rod 30 is guided between the guides 29 so as to be slidable in the vertical direction in FIG. Movable rod 3
0 has a recess 31 (see FIG. 5) formed in the upper end of the bearing, and the bearing can be held in the recess 31 to prevent the operating shaft 20 from moving downward.

The electromagnet 5 is of a plunger type, and includes a movable part 7 as a plunger, a coil cylinder 33 having the movable part 7 inside, a yoke 40 spanning both ends of the coil cylinder 33, and a coil cylinder inside the yoke 40. 33, a fixed core 41 facing the movable part 7 within the coil tube 33, a return spring (not shown) interposed between the movable part 7 and the fixed core 41, and an operating link 35. It consists of

The yoke 40 is fixed below the trip link 24 of the frame 15. The movable part 7 is provided with a movable rod 7a integrally or separately that penetrates the fixed iron core 41, and has a collar-shaped retaining part 34 at the upper end of the movable part 7.
are opposed so as to engage with the short-circuit response portion 27 of the trip link 24 by the operation of the electromagnet 5. The operating link 35 is attached to the case 10 by a fixed shaft 36 below the movable rod 7a.
° Rotatably held. This working link 3
5 has an L-shape and has a fixed shaft 36 at its bent part, a winding part of a return spring 37 is hung on the fixed shaft 36, one end of the return spring 37 is locked to the bottom of the case 10, and the other end is connected to an operating link. 35
, the operating link 35 is urged clockwise, and one end 35a of the operating link 35 is engaged with the movable rod 7 due to the spring action.
Press the lower end of a upward so that the stepped part of the movable part 7
The position is determined by being locked to the inner stepped portion of the upper end of 3. Note that the return spring (not shown) is the return spring 28°3.
7 can also be used.

The electromagnet 5 detects short-circuit current by setting the spring force of a return spring (not shown), and a bimetal 38 is provided in the case 10 to detect overcurrent. The base end of the bimetal 38 is fixed to the load-side terminal 11, and a gap adjustment screw 39 is provided at the distal end, with the distal end of the gap adjustment screw 39 facing the overcurrent response section 26.

The movable contact 4 is supported in a state where the middle part is biased upward by an opening spring 42, the movable contact 3 is fixed to the tip part, and the curved part 43 of the rear end part 43a is the lower end of the electromagnet 5. The lower end of the movable frame 30 is connected by a shaft 30a between the opening spring 42 and the movable contact 3, and the movable frame 30 causes the movable contact 3 to come into contact with the fixed contact l. The movable contact 4 is pressed in the direction of

Note that the spring force of the opening spring 42 is set to be larger than that of the handle return spring 22.

The shielding plate 9 is formed of an insulating member with a wedge-shaped tip 9a, and is slidably supported in a guide groove 46 formed in the case 10, as shown in FIG.
a is located laterally between the fixed contact 1 and the movable contact 3, and has an engagement hole 47 at its rear end, into which the other end 35b of the operating link 35 engages. ing. Further, a notch 65 is formed at the rear end of the shielding plate 9 to allow the movable rod 7a to pass therethrough. The shielding plate 9 is pulled by the operating link 35 by the return spring 37 and is located in the retracted position shown in FIG. When the movable rod 7a moves downward due to the operation of the electromagnet 5 and presses the operating link 35 against the return spring 37,
The operating link 35 rotates counterclockwise to move the shielding plate 9 forward using the other end 35b. As a result, the distal end portion 9a of the shielding plate 9 is connected to the movable contact 3 and the fixed contact 1 in the closed state.
It enters between the two and shields both of them in an open state. At this time, the movable contactor 4 performs an opening operation against the spring action of the contact pressure applied by the opening spring 42.

The fixed contact 2 is arranged on the lower side of a partition plate 66 that partitions the lower side of the opening/closing/tripping means 8 of the case IO,
The fixed contact 1 is passed through a notch 67 formed in the partition plate 66 and faces the opening/closing/tripping means 8 side. The base end of the fixed contact 2 having the fixed contact 1 at its tip extends halfway to the movable contact 4 1j! It has an extending portion 49 extending in the direction of the L end. As a result, when a current flows between the movable contact 4 and the fixed contact 2 while the movable contact 3 and the fixed contact 1 are in contact, an electromagnetic repulsive force is generated, and in the case of an abnormal current, the electromagnetic repulsive force becomes large. In order to push up the movable contact 3, the opening spring 42 is compressed to cause the movable contact 3 to perform an opening operation and assist the opening operation by the shield 9. Fixed contact 2
The base end portion extends from the extending portion 49 to the opposite side via a horizontal U-shaped bent portion 50, and this opposite side extending portion 44 has a curved portion 45 in the middle portion, and is provided in the case lO. A spring 56 is provided on the proximal end 49' side of the fixed shaft 48 to urge the fixed contact 1 away from the movable contact 3. The base end 49' is held fixed by a plunger 51 of a polar magnet 50.

The polarized electromagnet 50 is provided to provide a timer function by connecting a remote control or a timer circuit, and the plunger 51. Coil frame 5 wrapped with coil 52
5. York 53, 54. and a permanent magnet 69 (magnetic poles are indicated by N and S) interposed between the yokes 53 and 54, and the first armature 51a of the plunger 51
The state shown in FIG. 1 in which the second armature 51b contacts the yoke 54 and the second armature 51b contacts the yoke 54 is defined as a stable state. The proximal end 49' of the fixed contact 2 is inserted into the groove 57 of the protrusion of the plunger 51.
are engaged, and the fixed contact 1 is maintained in a fixed state as the fixed contact 1 by the holding force of the permanent magnet 69 via the plunger 51. When the coil 52 of the polarized IM stone 50 is energized, the plunger 51 moves to the opposite side due to excitation, and the fixed contact 2 rotates clockwise around the fixed shaft 48, so that the fixed contact 1 moves to the movable contact 2. Separate from.

In order to form an internal electric path of this circuit breaker, the circuit breaker is connected between the bimetal 38 and the coil 32 of the 1i magnet 5, between the coil 32 and the movable contact 4, and between the fixed contact 2 and the power supply side terminal 1.
Flexible electric wires 57 to 59 are connected between the two. Therefore, when viewed from the load side terminal 11 side, the internal electric circuit is from load side terminal 11 to bimetal 38 to flexible electric wire 57.
- Coil 32 - Flexible wire 58 - Movable contact 4 - Movable contact 3 - Fixed contact 1 - Fixed contact 2 - Flexible T wire 59 - Power supply side terminal 12.

In addition, 60 is an energization indicator lamp which is an example of a light emitting diode connected to the coil 52 of the polarized electromagnet 50 to indicate the energization state, and 61 is provided in the window 62 of the case 10 in correspondence with the energization indicator lamp 60. A translucent display plate 63 is a cover plate provided on the window 64 of the case 10 in correspondence with the gap adjustment screw 39.

The operation of this circuit breaker will be explained.

That is, FIG. 1 shows the circuit breaker in the on state, and FIG. 3 shows the circuit breaker in the off state. When the handle 6 is tilted counterclockwise from the off state to the state shown in FIG. 1, the handle 6 rotates about the fixed shaft 16 and the movable shaft 18 rotates counterclockwise. Since the operating shaft 20 of the operating link 19 moves downward while sliding on the latch link 23, the operating link 19 rotates in a direction in which it assumes a vertical position. At this time, the handle return spring 22 is pulled. As the operating shaft 20 moves, the bearing engaged with the operating shaft 20 moves the movable frame 30 having the recess 31 downward as it is guided by the guide 29. Movable contact 4 is movable frame 3
0, the movable contact 3 contacts the fixed contact 1, and then the movable contact 3 contacts the fixed contact 1, and the movable contact 3
rotates clockwise around the fixed contact 1, and the opening spring 42
Contact pressure is applied by compressing the movable contact 2, and at the same time, the movable contact 2 rolls on the surface of the fixed contact 1, thereby destroying the welding bridge when contact welding occurs due to the arc at the time of closing. Also, since the opening spring 42 is compressed, its reaction force is applied to the operating link 19 via the movable frame 31, and the movable shaft 18 crosses the inversion dead center where it intersects the line connecting the fixed shaft 16 and the operating shaft 20. Then, the opening spring 42 pushes up the movable shaft 18 and biases the handle 6 in the direction in which it falls.

The movable shaft 18 is locked to a stopper (not shown), and the handle 6
maintains the state shown in FIG. Therefore, power supply side terminal 1
2 and the load-side terminal 7 are connected to a load on the line, a current will flow through the internal circuit.

When the handle 6 is tilted from the ON state shown in FIG. 1 to the state shown in FIG. 23 and moves upward, the movable frame 30 moves upward, and the movable contact 4 performs an opening/separating operation. When the curved portion 43 at the base end of the movable contact 4 comes into contact with the lower end of the electromagnet 5, the movable contact 4 rotates about the contact point as a fulcrum, and the movable contact 3 separates greatly from the fixed contact 1.

Figure 4 shows the state immediately after a short circuit current among the abnormal currents flows.
FIG. 5 shows a state in which the opening/closing/tripping means 8 has completed its operation. When a short circuit current flows through the internal circuit, the electromagnet 5 operates to rotate the trip link 24 about the fixed shaft 25 and release the launch link 23. At the same time, the operating link 35 is rotated at the lower end of the movable rod 7a, and the shielding plate 9 is moved forward, and the shielding plate 9 slides on the surface of the movable contact 3 with its tip 9a, prying the movable contact 3 open, and making the movable It enters between the contact 3 and the fixed contact 1. As a result, the shielding plate 9 interrupts the arc generated when the contacts are opened and reliably destroys the contact welding.

Following this operation, the third opening/closing process that leads to the state shown in FIG.
The tripping operation by the tripping means 8 is performed when the trip link 24 rotates counterclockwise and the latch portion 24a performs a releasing operation to move away from the side surface of the lower end of the latch link 23. The force of pressing the latch link 23 causes the latch link 23 to move to the fixed shaft 16.
The operating shaft 20 rotates counterclockwise around the movable frame 30.
The bearing leaves the recess 31. At the same time, the movable frame 30 moves upward due to the biasing force of the opening spring 42, and the movable contact 4 moves to open and separate, causing the curved portion 43 of the movable contact 4 to contact the lower end of the electromagnet 5, causing the curved portion 43 to move upward. The movable contact 4 rotates around the center, and the movable contact 3 further opens and separates from the opening position formed by the shielding plate 9. The open position of the movable contactor 4 is regulated by a stopper (not shown). Furthermore, when the operating shaft 20 leaves the recess 31, the bearing is not affected by the opening spring 42, so the action of the handle return spring 22 causes the movable shaft 18 to rotate clockwise, and the handle 6 assumes a neutral position. A trip display is performed with this neutral position of the handle 6.

When the current in the internal circuit is cut off by trip opening,
Since the attractive force of the electromagnet 5 disappears, the movable part 7 returns to its original position by a return spring (not shown), and at the same time, the shielding plate "σ" returns to its original position. However, the movable contact 4 is maintained in an open state by the operation of the opening/closing/tripping means 8.

To reset after repairing a short-circuit accident, move the handle 6 in the neutral position from the state shown in FIG. 5 to the OFF state shown in FIG. 3. Rotation of the handle 6 causes the movable shaft 18 to rotate clockwise, so the operating link 19 is pulled up and the operating shaft 20 is moved to the movable frame 30.
The bearing engages in the recess 31. Further, the reset protrusion 68 of the handle 6 causes the launch link 23 to rotate clockwise around the fixed shaft 18, and the return spring 28 causes the trip link 24 to return and the latch portion 24a to move the latch link 23.
The latch link 23 is engaged with the side surface of the lower end of the latch link 23, and the latch link 23 is placed in the launch state as shown in FIGS. 1 and 3. This turns it off.

Next, when an overcurrent flows in the internal circuit in the on state,
In the electromagnet 5, the movable part 7 does not operate because the return spring 37 has a spring force greater than the attractive force, but the bimetal 38 is self-heated and curved, and the overcurrent response of the trip link 24 occurs at the tip of the gap adjustment screw 39. 26, which rotates the trip link 24 and locks the latch link 23.
to be released. The subsequent tripping operation of the opening/closing/tripping means 8 is the same as described above.

In addition, in the on state shown in FIG. 1, the coil 52 of the seed magnet 50 is
When current is applied to , the plunger 51 moves upward in FIG. 1, the rear end portion 49 of the fixed contact 2 rotates clockwise, and the fixed contact 1 separates from the movable contact 3. therefore,
Even if the handle 6 is in the on position, the internal electric circuit is cut off. On the contrary, even if the fixed contact 1 is in the state shown in FIG. 1, it is turned off by tilting the handle 6 to the off position, so in either case, priority is given to off.

Because of this structure, according to this embodiment, when an abnormal current such as a short circuit current flows, the shielding plate 9 can be moved with respect to the fixed contact 1 in conjunction with the operation of the electromagnet 5 without the operation of the opening/closing/tripping means 8. Insert between contact point 3.

Therefore, there is no effect of the delay time caused by the operation of the opening/closing/tripping means 8, and the time from when an abnormal current occurs until the shielding plate 9 completes its operation can be shortened. Therefore, the arc cutoff time can be shortened, resulting in a large interruption. It is possible to realize the number of customers.

According to experiments, it took 2 ms for the shielding plate 9 to complete its operation. FIG. 6 shows an arc voltage waveform diagram at that time. Q5 is the estimated short circuit IT current, Q6 is the cutoff current, Q7
is the contact arc voltage, but since the breaking current is smaller compared to FIG. 7, the fixed contact 1. Movable contact 3. Case 10. It can be seen that the damage caused by the arc to the shielding plate 9, etc. is small.

Further, unlike in the prior art, there is no need to increase the operating speed of the shielding plate 9 by increasing the spring force of the opening spring 42, so there is no need to increase the operating load on the handle 6.

Furthermore, in this embodiment, after the trip link 24 is operated by the movable part 7 of the electromagnet 5 to trip the latch link 23, the shielding plate 9 is operated by the movable rod 7a. The load on the movable part 7 is reduced, the movable contact 4 is reliably opened, and even if contact welding occurs, it can be destroyed.

Furthermore, since the electromagnet 5 also serves as the detection section for detecting abnormal current, the configuration is simplified.

A second embodiment of the invention is shown in FIGS. 8-11. That is, in the above embodiment, the electromagnet 5 also serves as the detection section, but in this embodiment, the bimetal 38 for detecting overcurrent is used. In this case, when a short circuit current flows, the bimetal 38 operates later than the electromagnet 5 operates. Therefore, when a short circuit occurs, the movable contact 3 is opened by the shield plate 9 as shown in FIG.
11, the bimetal 38 operates the trip link 24, trips the launch link 23, and trips the opening/closing/tripping means 8. As shown in FIG. The rest is the same as the first embodiment.

In the above embodiment, the movable frame 30 and the movable contact 4 were connected by the shaft 30a, but the movable frame 30 may simply be brought into contact with the movable contact 4. In addition, the leading end 9a of the shielding plate 9 is tapered to allow the shielding plate 9 to enter between the contacts. It is a good thing. Furthermore, although in the above embodiment the shielding plate 9 is driven by the electromagnet 5 via the actuating link 35, it may be driven directly.

Further, in the present invention, the opening/closing/tripping means is not limited to the above embodiment. For example, it can be applied to a retraction quick-acting type and a reversing spring-type quick-acting quick-in type configured with a link mechanism of the same type as the embodiment. Regarding abnormal current, although the above embodiment deals with short circuit current, it can also be applied to overload current where arcing occurs.

〔Effect of the invention〕

According to the circuit breaker of the present invention, when an abnormal current such as a short circuit current flows, the shielding plate is inserted between the fixed contact and the movable contact in conjunction with the operation of the electromagnet and without the operation of the opening/closing/tripping means. . Therefore, there is no effect of delay time caused by the operation of the opening/closing/tripping means, and the time from when an abnormal current occurs until the shielding plate completes its operation can be shortened. Therefore, the arc cutoff time can be shortened, so a large amount of cutoff is required. It can be realized. Moreover, it opens and closes.
The opening spring of the trip means is made thicker (because it is not necessary to
This has the effect of not increasing the operating load of the handle.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the first embodiment of the present invention in the on state;
Figure 2 is a partial perspective view of the shield plate, Figure 3 is a cross-sectional view in the off state, Figure 4 is a cross-sectional view showing the operating state of the shield plate immediately after tripping, and Figure 5 is a state in which the trip operation is completed. FIG. 6 is an arc voltage waveform diagram of this embodiment, FIG. 7 is an arc voltage waveform diagram of the conventional example, and FIG. 8 is a diagram of the second arc voltage waveform.
9 is a sectional view of the embodiment in the on state, FIG. 9 is a sectional view of the off state, FIG. 10 is a sectional view showing the operating state of the shield plate immediately after tripping, and FIG. 11 is a sectional view showing the state where the tripping operation is completed. 12 are partial sectional views of the conventional example. DESCRIPTION OF SYMBOLS 1... Fixed contact, 2... Fixed contact, 3... Movable contact, 4... Movable contact, 5... Electromagnet, 6...
Handle, 7... Movable part, 8... Opening/closing/tripping means, 9... Shielding plate Patent applicant Matsushita Electric Works Co., Ltd. F,'-,','So゛,''-+-:;',, , , 5,4゜Representative Patent Attorney Akio Kanai, ;; Figure 2 - Pr FJI (msec) Figure 7 1 hour (msec) Figure 6

Claims (3)

[Claims] (1) A fixed contact having a fixed contact, a movable contact having a movable contact that opens and closes with respect to the fixed contact, an electromagnet that detects abnormal current of the load, and a closed state in conjunction with the operation of this electromagnet. an arc-extinguishing shielding plate that enters between the movable contact and the fixed contact; and the movable contact is opened and closed by a handle, and the shielding plate opens and closes the movable contact in conjunction with a detection unit that detects abnormal current in the load. A circuit breaker comprising an opening/closing/tripping means for tripping and opening the movable contact that is polarized. (2) The circuit breaker according to claim (1), wherein the detection section of the opening/closing/tripping means is the electromagnet. (3) The circuit breaker according to claim (1) or (2), wherein the shielding plate has a wedge-shaped tip.