JPS638570B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to circuit breakers and breakers, and is particularly characterized by comprising an electromagnetic device having both current transformation means and instantaneous tripping means.

In summary, this invention consists of a pair of yokes and a magnetic core connecting between the pair of yokes, and a single electromagnetic device in which the primary and secondary coils are wound coaxially to drive the secondary coil into a bimetallic device for timed tripping. It is configured to have two functions: a current transformation means electrically connected to the air gap magnetic path, and an instantaneous tripping means using a movable iron piece for instantaneous tripping placed in the air gap magnetic path.

To explain the background of the present invention, in recent years, low-voltage circuit breakers, especially wiring breakers, have been required to have the following protection functions in addition to the usual electric circuit protection.

The first is a function that protects the motor starter from short circuits for the purpose of starting/stopping the motor and overload protection.The second is the function of starting/stopping the motor, protecting the motor from overload, and preventing short circuits using the low voltage circuit disconnector itself. functions to protect, etc.

The first requirement to satisfy these functions is that the minimum rated current of general thermal and electromagnetic trip type wiring breakers is 15A as determined by JIS (Japanese Industrial Standard) C-8370. Therefore, in practice, the lower limit of operation is 10A. Therefore, the instantaneous trip value is approximately 10 times the rated current. In this case, for example, if a wiring sheath disconnector with a rated current of 10 A and an instantaneous trip value of 100 A is used for short-circuit protection in a motor starter with a full load current of 1 A, the overload current guaranteed by the thermal overload relay can be The allowable multiplier is usually about 10 to 15 times, so even if an overcurrent exceeding this flows, it is far from the current that would cause instantaneous tripping of a wiring or disconnector, and it would not cause a thermal overload while a short circuit current is flowing. This resulted in burnout and melting of the relay. Therefore, the instantaneous tripping of the wiring liner and disconnector does not work at the normal motor starting current, and the instantaneous tripping value is set at the motor starter's full load current in order to quickly disconnect the fault current that exceeds the normal motor starting current. It is preferable to set it to 12 times or more and 15 times or less. Thermal or electromagnetic tripping type wiring breakers have a small rated current, and the instantaneous tripping current is a constant value that satisfies the above-mentioned preferable conditions relative to the rated current. Equipment is desired.

The second requirement is that the overload trip current setting of the wiring cutter is compatible with the full load current, which varies depending on the motor capacity, rated voltage, applicable frequency, number of poles, protection method, and manufacturer. The setpoints must be adjustable within a certain range, and coordination must be maintained so that the wiring liner and disconnector can prevent the motor from burning out in the event of any overload. In order to make the setting of the overload tripping current adjustable, the bimetal tripping method is easier and more practical than the dart pot tripping method. The setting of the overload tripping current of this wiring cutter is required to be extremely small, with a practical minimum value of approximately 1A, in order to protect even small capacity motors. Although it is possible to adjust the overload trip current to a small value with the conventional dart pot type electromagnetic type wiring breakers, it is difficult to adjust the tripping current; For those with a bimetal tripping method, it is difficult to reduce the overload tripping current value to about 1A, which is a major obstacle, and this problem needs to be solved.

The third requirement is also related to the first requirement above, but the wiring sheath breaker does not trip at the starting current of the motor, but trips as quickly as possible at a fault current that exceeds this. It is desirable to
For this reason, it is required that the instantaneous tripping operation be performed within the range of 12 to 15 times the overload tripping setting value of the wiring sheath breaker. Wiring switches and disconnectors whose instantaneous tripping is several tens of times or more than the overload tripping setting value are undesirable because they increase the risk of damage to the motor.

In view of the above-mentioned current situation, the first purpose of the present invention is to make it possible to manufacture a bimetallic tripping system with any small rated current, with the practical minimum value of about 1A, and even if the rated current is small, Instead of increasing the resistance value of the bimetal to ensure the amount of heat generated, as was done previously, various main circuit currents can be converted to a constant secondary current by the current transformation means of the electromagnetic device, which is the main part of this invention. It is an object of the present invention to provide a convertible circuit and disconnector.

The second object of the present invention is related to the first object, and the secondary current is limited by the saturation phenomenon in the event of a short circuit by an electromagnetic device having a transformation means, so that the rated current of a circuit or a circuit breaker can be reduced. To provide a circuit or disconnection device in which an overcurrent tripping element is not overheated and burned out for all currents that reach a large rated current or a disconnection current.

The third object of the present invention is to use a motor starter protection shield breaker or a motor protection shield breaker that is particularly extremely small, regardless of the magnitude of the full load current of the motor starter or the rated current of the circuit breaker. It is an object of the present invention to provide a circuit and a disconnector having an instantaneous trip value that can obtain an instantaneous trip setting current value of approximately the same preferred magnification even in the case of a rated current.

The fourth object of this invention is to provide a bimetallic tripping system in which the setting of the overload tripping current value can be adjusted relatively easily. The goal is to provide the following.

The fifth object of this invention is that in order to satisfy each of the above objects, the electromagnetic device that forms the main part of this invention is used for multiple functions, so it is small and inexpensive to manufacture considering its high performance and multipurpose. The purpose is to provide circuit breakers and disconnectors.

The following is an explanation based on the drawings showing one embodiment of the circuit breaker and disconnector of the present invention.The circuit breaker main body 1 includes a mold base 2 made of a molded insulator and a part of the bottom cover of the mold base 2. 2' and a molded cover 3, it is formed into a box shape, and covers all the live parts of the circuit and disconnector except the terminal part, and the molded base 2 and molded cover 3 contain the main components of each pole and the operation. Each electrode chamber 4 and each electrode chamber 4 partitioned by an insulating partition wall that houses a mechanism part.
An opening/closing operation mechanism chamber 5 is provided adjacently to one side, and the opening/closing operation mechanism chamber 5 includes an opening/closing operation mechanism 5A,
A tripping mechanism 5B and a rated current adjustable mechanism 5C are housed.

Regarding the common parts of the respective poles, only one pole will be described for the sake of brevity.

As shown in FIG. 4, terminals 6 and 6' are provided at both ends of each pole, and terminal tap plates 6 and 6' are respectively provided.
It is made from a conductive material together with a and 6'a,
It is inserted and attached to the mold base 2. The terminal conductive plates 7, 7' are connected to the terminals 6, 6', and together with the terminal chamber end plates 4a, 4'a made of an insulating material form the end wall of the receiving groove of each electrode chamber. One end of a flexible lead 8 made of a conductive material is connected to one terminal conductive plate 7, and the adjacent terminal 6 has an introduction piece 6c extending inward from the end partition wall of the mold base 2 and has an inner tip. Movable arc horn 9
is connected.

As can be seen from Figures 12a and 12b, the contact crossbar 10 made of a molded insulator that penetrates from the opening/closing mechanism chamber 5 to each pole has two tongue-like pieces for each pole that are integrally molded therewith. The contact holder member 10a has a contact holder member 10a, and a protruding shaft 11a protruding from both wings of a movable contact rod 11 bent in a U-shape is fitted into a fitting groove 10b provided in the contact holder member 10a. As a result, the movable contact rod 11 is rotatably mounted between the two contact holder members 10a. The contact spring 12 is connected to the contact crossbar 1
0 and the movable contact rod 11, and normally applies contact pressure to the movable contact rod 11 in a counterclockwise direction. In addition, movable contact rod 1
A flexible lead 8 from a terminal 6 is connected to 1, and a movable contact 13 is attached to the free end.

The electromagnetic device 14, which constitutes the main body of this invention, is located in the center together with its auxiliary devices, and has a primary coil 15 and a secondary coil 16. The cross-sectional area of the winding and the number of turns are selected appropriately according to the current.
Also, the number of ampere turns is selected to be constant with respect to the rated current. The secondary coil 16 is also made of an insulated winding, and is wound inside the primary coil 15 via an insulator 17.
a and 16b are connected to the overcurrent response device 18. The cross-sectional area and number of turns of the secondary coil 16 may be constant regardless of the rated current. The fixed core 19 is formed by stacking silicon steel plates to form a block, and is insulated from the secondary coil 16 by an insulator. That is, the secondary coil 16 is wound around the fixed core 19, and the primary coil 15 is further wound coaxially on the outside thereof. A yoke 20 made of several laminated steel plates is attached to both sides of the fixed core 19. The fixed core 19 and the yoke 20 form an H-shaped magnetic core, and this yoke 20 connects the primary coil 15 and the secondary coil. A current transformer is constructed by surrounding the next coil 16, and is further expanded to extend over the contact portion 20a, the arc extinguishing chamber portion 20b, and the instantaneous tripping portion 20c. Yoke insulation plate 21
is attached to the inside of the yoke 20, and the yoke 2
0 part of the contact part 20a and arc extinguishing chamber part 20b
It is formed in a large size so as to protrude from the outer periphery. On the contact side of the yoke 20, engaging protrusions 22a provided on both side edges of the fixed contact base 22 made of an insulating plate so as to close the space between the corresponding pair of yoke insulating plates 21 are connected to the respective pairs of yoke insulating plates 21. The contact base 22 extends through engagement holes 21a and 20d provided in the yokes 20, and a fixed contact base 22 is supported between the pair of yokes 20. A fixed contact rod 23 made of a conductive material is bent into an L shape and held on a fixed contact base 22, has a fixed contact 24 at a position corresponding to the movable contact 13, and has a primary coil at one end. 15 lead wires 15a are connected thereto, and a fixed side arc horn 25 made of a metal material is connected to the other end. Fixed side arc horn 2
5 may be formed by being bent integrally with the fixed contact rod 23 or separately, passing near the lower side of the primary coil 15 and bending at the end of the arc extinguishing chamber 26 to form an end bent engagement piece 25a. is engaged with and supported by a fitting groove 2b provided in a partition wall 2a of the tripping element housing portion of the mold base 2. An arc insulating plate 23a is attached to the fixed contact 23. Further, the fixed side arc horn 25 is provided so as to almost completely partition the gap between the pair of yoke insulating plates 21 provided correspondingly, and the arc extinguishing chamber 26 is connected to the primary and secondary coils 1.
5 and 16, and the overcurrent response device 18 is isolated by the partition wall 2a of the mold base 2.

The arc extinguishing grid group 27, 27' is formed by a large number of magnetic plates 28, 28' housed in the arc extinguishing chamber 26, and is connected to the fixed side arc horn 25 provided horizontally below the primary coil 15. An arc extinguishing grid group 27 is arranged below, and an arc extinguishing grid group 27' is arranged next to the movable arc horn 9 provided at one end of the arc extinguishing chamber 26 facing the bottom wall of the mold base 2. An L-shaped intermediate arc runner 29 is provided to connect the movable arc horn 9, the fixed arc horn 25, and the arc extinguishing grid groups 27, 27' to strengthen the extinguishing magnetic flux.
Fixed side arc horn 25 and intermediate arc runner 2
The arc extinguishing grid group 27 is arranged horizontally between one side of the arc extinguishing grid 27 and the arc extinguishing grid group 27 has a large number of magnetic plates 28.
Letter-shaped notches 28a are provided, and are arranged in parallel at equal intervals so that the left and right sides are alternately replaced. In addition, a mold base 2 is provided between the movable arc horn 9 and the other side of the intermediate arc runner 29.
The arc-extinguishing grid group 27' is arranged at a slight inclination towards the bottom wall of the arc-extinguishing grid, and has a number of magnetic plates 28' having notches 28'a for drawing the arc on the contact side, as shown in FIG. , and a notch 28'b is provided on the lower end side, and both ends of the notch 28'a are formed to have a long leg 28'c and a short leg 28'd of the magnetic plate 28', and the left and right sides are They are arranged in parallel at equal intervals so that they alternate. A buffer plate 30 made of an insulating material is provided so as to partition one end of the arc extinguishing chamber 26 over the tip side of the arc extinguishing grid group 27.
Therefore, the arc gas flowing out from the arc extinguishing grid groups 27, 27' moves from the vent hole 30a of the buffer plate 30 to the arc gas exhaust expansion chamber 31 provided on the bottom wall 2' side of the mold base 2, and further flows into the mold base 2. The arc gas is led to the outside through an outlet 32 of the mold base 2 provided between the poles of one of the connecting terminals 6'.

When using the timed tripping bimetal 34 as the tripping element of the timed tripping device 33 of the overcurrent response device 18, the bimetal 34 is bent into a J shape as shown in FIGS. It is divided by a dividing groove 35 at the center of the width, leaving the upper end connecting part 34a of the long side, and the dividing ends 34b and 34c of the parallel opposing short sides have an output wire 16a for leading out and introducing the current of the secondary coil 16. , 16b are connected. The bimetal 34 includes a bottom cylindrical projection 2d in the tripping element storage recess 2c of the mold base 2;
It is attached to the cylindrical projection 2d by a mounting screw 37 passing through a mounting hole 34e provided in the clamping portion 34d and the bimetal insulating piece 36. Also, the bimetal adjustment screw 38 is attached to the tongue piece 39 of the trip bar 39 at the upper end connecting portion 34a of the bimetal 34.
It is provided opposite to a.

The trip bar 39 is made of a molded insulator and extends from the opening/closing operation mechanism chamber 5 to each pole of the mold base 2.
The tongue piece 39a provided for each pole extends through the vicinity of the joint between the mold cover 3 and the mold cover 3, and an inclined surface 40 is integrally formed on one side of the tongue piece 39a. It is provided facing the screw 38, so that the gap between the bimetal adjusting screw 38 and the tongue piece 39a can be set at an appropriate position by adjustment work. Trip bar 3
9 is supported so as to be movable in the direction across the multipole, and the position of the inclined surface 40 of the tongue piece 39a can be changed by a rated current adjustable mechanism 5c provided in the opening/closing operation mechanism chamber 5, which will be described later. The set current can be adjusted by increasing/decreasing the gap between the corresponding bimetal adjusting screws 38. The lead-in piece 7a on one side of the terminal conductive plate 7' is connected to the primary coil 15.
It is connected to the lead wire 15b at one end, and the other side is connected to the terminal 6' by a lead-out piece 7b extending through the end partition wall of the mold base 2.

The instantaneous tripping device 41 of the overcurrent response device 18 has a movable iron piece 42 for instantaneous tripping, and this movable iron piece 42 has an ear piece 42a in the center that connects to the pair of yokes 2.
0 and the small frame 43 installed between these yokes 20
It is rotatably supported by the yoke 20 by a support shaft 44 that passes through the yoke 20, and an enlarged wing portion 42b extending between the pair of yokes 20 is provided at one end so as to correspond to a part of the outer peripheral edge of the yoke 20. The tail portion 42c at the other end is provided to correspond to the protruding piece 39b of the trip bar 39. One end of the leaf spring 45 is attached to the movable iron piece 42, and the enlarged wing portion 42b of the constantly movable iron piece 42 is attached to the pair of yokes 20.
It is constructed so that it acts in the direction of separation from.
The instantaneous trip adjustment screw 46 is screwed into a small frame 43 attached to the yoke 20, and its penetrating tip abuts the other end of the leaf spring 45, causing the instantaneous trip adjustment cover 3' of the mold cover 3 to be adjusted. The instantaneous trip setting value can be adjusted to a desired value by removing it and changing the amount of deflection of the leaf spring 45 by rotating the adjustment screw 46 through the adjustment hole 3a with a screwdriver or the like. Furthermore, a stopper piece 43a of the movable iron piece 42 is provided at one end of the small frame 43.

As shown in FIGS. 8 to 12, the opening/closing operation mechanism chamber 5 is provided with an opening/closing operation mechanism 5A and a tripping device 5B in association with the contact crossbar 10 and the trip bar 39. It is equipped to control automatic tripping in response to overcurrent tripping. The opening/closing operation mechanism 5A includes a pair of left and right fixed frames 48 fixed to the mold base 2.
A handle 47 made of molded insulator is supported by a handle shaft 49, and an operating knob 47a of the handle 47 projects from the opening 3b of the molded cover 3 so that the handle 47 can be rotated. In Figures 8 to 10, the handle 4
The handle spring 50, which constitutes a torsion spring, is located between the fixed frame 48 and the handle 47. The handle 47 is always biased in the off direction, that is, in the clockwise direction. One end of an operating link 52 is connected to the handle 47 by a pin 51.
The other end of the operation link 52 is loosely connected to a long groove hole 54a of a trip lever 54 by a pin 53. The trip lever 54 is rotatably supported by a trip lever shaft 55 fixed to the fixed frame 48. The contact link 56 has a pin 53 engaged with the long slot 54a of the trip lever 54.
One end is connected to the operating link 52, and the other end is connected by a pin 57 to a crossbar operating piece 10f formed integrally with the contact crossbar 10. One end of the blade spring 58 is hung on the pin 57 at the other end of the contact link 56, and the other end of the blade spring 58 is hung on a spring hanging piece 59 attached to the mold base 2, so that the contact cross is always connected. The bar 10 is biased clockwise.

In the trip mechanism 5B, the trip lever 54
The claw portion 54b at one end is a hooking portion 60 which is a semicircular notch of a trip pin 60 supported on the fixed frame 48.
It is engaged with a in normal closed and open circuit states. The trip pin arm 61 has a curved portion 61a along the circumference of the trip pin 60, and this curved portion 61a is provided with an elongated hole 61b, and the screw 62 is inserted into the elongated hole 6.
1b and is screwed into a tap hole provided in the trip pin 60, and the amount of engagement between the claw portion 54b of the trip lever 54 and the engaging portion 60a of the trip pin 60 is adjusted by rotating the trip pin 60. It is configured such that it can be adjusted to a desired position and fixed with a screw 62. One side 61 of the trip pin arm 61 attached integrally with the trip pin 60
One end of the bimetal 63 for ambient temperature correction is connected to c.
The other end of 3 is provided opposite to the protruding piece 39c of the trip bar 39.

The trip pin return spring 64 is connected to the trip pin arm 6.
The clockwise movement of the trip pin arm 61 is caused by the engagement projection piece 61 on the other side of the trip pin arm 61.
d is limited by engagement with a locking protrusion 48a provided on the fixed frame 48, and a stationary position in a steady state of clockwise rotation of the trip pin arm 61 is determined.

As shown in FIG. 5, one end of the trip bar 39 is connected by inserting a bearing pin 65 provided on the side wall of the mold base 2 of the opening/closing operation mechanism chamber 5 into a slide shaft hole 66 provided in the shaft core of the trip bar 39. It is rotatably and slidably supported in the axial direction, and the other end has an exposed portion 67 of a metal shaft integrally embedded with the trip bar 39, which is attached to the partition wall that separates the end pole chamber 4 from the adjacent pole. It is rotatably and slidably supported by a bearing plate 68 in the axial direction. The trip bar spring 69 has one end secured to the protruding piece 39c of the trip bar 39 and the other end secured to the spring mounting piece 70 of the fixed frame 48, and always biases the trip bar 39 clockwise.

As shown in FIGS. 8 to 11, the rated current adjustable mechanism 5c has a mounting member 7 fixed to the fixed frame 48.
2 has a rated current adjustable knob 71 made of a molded insulator and rotatably supported by the adjustable knob 7.
1 has its head exposed through the cutout hole 3c of the mold cover 3, and has an actuation piece 71a protruding at an eccentric position at the lower end, and the actuation piece 71a is inserted into the slot 39e of the trip bar 39. are mated,
By rotating the rated current adjustable knob 71 from the outside, the actuating member 71a moves in an arc, and the trip bar 39 is slid in the axial direction, so that the corresponding tongue with the bimetal adjusting screw 38 in each pole chamber is moved. The position of the inclined surface 40 of the piece 39a changes,
The gap between the adjustment screw 38 and the inclined surface 40 can be changed to adjust the set current. The trip push button 73 is provided so that its head is exposed through the cutout hole 3d of the mold cover 3, like the rated current adjustable knob 71, and its lower end is connected to the mounting members 72, 72'.
It passes through the upper side 74a of the U-shaped trip push button return spring 74 attached to the lower side of the mounting member and presses the protrusion piece 39d of the trip bar 39 via the trip push button return spring operating piece 74b on the lower side. It is set up accordingly.

As shown in Figures 3, 8, 12a and 12b, the crossbar 10 is integrally formed with an opening/closing indicator piece 10c on the opposite side of the crossbar operating piece 10f, and around the opening/closing indicator piece 10c there are two grooves 10d, For example, one groove 10d is colored green and the other groove 10e is colored red, so that when the circuit is connected from the display window 3e of the mold cover 3 and the disconnector is closed, the red groove 10e is provided. In the open state, the open/closed state of the circuit or disconnector can be directly determined by visually observing the green groove 10d.

Next, the opening/closing operation of the circuit breaker and disconnector of the present invention constructed in this way will be explained. In the normal OFF state shown in FIGS. 8 and 13, the operation knob 47a of the handle 47 is The claw portion 54b of the trip lever 54 is tilted to the right.
is configured to be able to engage with the engaging portion 60a of the trip pin 60, and is in a state of preparation for closing the circuit or disconnector. If the operating knob 47a is moved leftward to the on side from this OFF state, the pin 53 will be pushed into the long groove hole 54 of the trip lever 54 via the operating link 52.
As a result, the contact crossbar 1 is moved through the contact link 56 to the right.
0 is rotated counterclockwise, the shear spring 58 is pulled and the tensile force is increased, and in the final loading process, the line connecting the handle shaft 49, pin 51, and pin 53 is overcentered, and the 9th As shown in the figure, the handle 47 and the operating link 52 are held stationary in this state. Accordingly, the contact crossbar 10 is in the state shown in FIG. 4 in which the movable contact 13 of the movable contact rod 11 is kept in the on state in which the movable contact 13 of the movable contact rod 11 is pressed against the fixed contact 24.
From this ON state, the operation knob 47 can be turned on by assisted operation.
If you move a clockwise to the right, operation link 5
2, the pin 53 is moved to the left in the long groove hole 54a of the trip lever 54.
is rotated clockwise, contact crossbar 1
0 separates the movable contact 13 from the fixed contact 24 and enters the OFF state.

In addition, in the case of automatic disconnection due to the activation of an overcurrent tripping device due to overcurrent flowing, for example, the bimetal 34 of the overcurrent response device 18 causes the trip bar to
9 is rotated clockwise, the ambient temperature correction bimetal 63, the trip pin arm 61, and the trip pin 6c are integrally rotated counterclockwise by the projection piece 39c of the trip bar 39. The engagement between the engaging portion 60a of the trip pin 60 and the claw portion 54b of the trip lever 54 is released,
The trip lever 54 is rotated counterclockwise,
The pin 53 is pushed to the left along the long groove hole 54a of the trip lever 54 by the spring force of the slit spring 58 via the contact link 56, and the slit spring 58 is contracted and the contact cross bar 10 is moved. When the movable contact 13 is rotated clockwise, the movable contact 13 is separated from the fixed contact 24, and the current is briefly cut off (Fig. 10). As the operation link 52, trip lever 54, and contact link 56 are pulled up in the direction shown in FIG. returned to the engaged off state.

Furthermore, when an excessive current such as a short circuit current flows, the magnetic field generated in the primary coil 15, which is arranged so that the current flows in the same direction as the fixed contact rod 23, interlinks with the movable contact rod 11, and this electromagnetic force While the contact crossbar 10 is held in the open position by the action force of the contact spring 12, the movable contact rod 11 is rotated clockwise using the protrusion shaft 11a that engages with the contact holder member 10a as a fulcrum, and is movable. The contact 13 is prematurely separated from the fixed contact 24 and is broken,
The state shown in FIG. 14, in which the contact spring 12 is held in the open position by reversing the acting force of the contact spring 12, is achieved.
After this activation, the overcurrent response device 18 is activated, and as described above, the trip bar 39 rotates, causing the trip pin engaging portion 60a to engage the trip lever 54.
is disengaged from the claw portion 54b, the opening/closing operation mechanism is collapsed, the contact crossbar 10 is rotated counterclockwise, and the shaft 11 of the movable contact rod 11 is
a is moved, the acting force of the contact spring 12 is reversed again, the movable contact rod 11 is returned to the normal position, and the handle spring 50 causes the claw portion 54b of the trip lever 54 to be moved.
The switch is returned to the OFF state shown in FIGS. 8 and 13, in which the switch is engaged with the engaging portion 60a of the trip pin and preparation for loading is completed.

In the above-described circuit breakers and disconnectors, the electromagnetic device 14, which is the main subject of the present invention, can be selected so that the primary coil 15 that conducts current in the main circuit has a constant number of ampere turns for various rated currents.
It can be manufactured to any rated current no matter how small. However, for a practical motor protection circuit or disconnector, the minimum value is around 1A.

On the other hand, the secondary coil 16 may be selected so as to keep the secondary current constant for each rated current, and of course the response current of the overcurrent response device 18 connected to the secondary coil 16 is the same as that of the primary coil 15. It may be constant regardless of the rated current.

The fact that the secondary current can be set constant regardless of the rated current makes it easy to keep the electrical energy supplied at the time of overcurrent trip constant when the overcurrent response device 18 is a bimetal thermal type. Moreover, it becomes easy to maintain the value to the minimum necessary value. For example, keeping the bimetal 34 for timed tripping constant and maintaining it at the minimum necessary constant value generated by the bimetal is due to the difference in rated current of the conventional method in which the primary current is passed directly to the bimetal. There is no hassle of selecting and changing resistance, curvature constant, width, thickness, etc., and there is no need for the amount of power required for operation to vary depending on the rated current. There is no need to use high resistance.

In the embodiment of this invention, the winding ratio calculation of the secondary current is
The current is set at around 5A, which is close to the lowest standard value for the response current of a directly heated bimetal with a simple structure, but it is important to minimize the mechanical force and stroke required for tripping. This is a value that can be designed. Therefore, the winding ratio is selected so that the secondary current is multiplied when the rated value of the primary current is less than 5 A, and is decreased when the rated value exceeds 5 A.
This makes it possible to use a bimetal tripping system even when the primary current is a minute current of less than 5A, and all bimetallic tripping devices can have the same structure regardless of the rated current of the circuit or disconnector. , the same tripping time characteristics are obtained.

Connecting the bimetal 34 of the overcurrent response device 33 to the secondary side by the above-mentioned transformation means of the electromagnetic device 14 is important because of the magnetic saturation phenomenon of the electromagnetic device 14, no matter how large the short circuit current flowing through the primary coil 15 is. The current on the next side does not increase accordingly, which naturally prevents the bimetal 34 from burning out due to short-circuit current, which eliminates one of the obstacles in increasing the rated and disconnection currents. Electromagnetic device 1
4 is provided in an irregular open core shape in order to function as the above-mentioned transformation means as well as the instantaneous tripping means described later. In the overcurrent region of metamorphosis, it was difficult to set the secondary current to a certain fixed magnification relative to the respective rated primary current, but arc-extinguishing grid groups 27 and 2
The magnetic plates 28, 28' of 7' are used as part of the magnetic path of the magnetic device 14, and the secondary coil 1 is
By efficiently interlinking with 6, the improvement was achieved to the extent that there is no problem in practical use. That is, primary coil 1
5. By coaxially winding the secondary coil 16, leakage magnetic flux could be reduced. It is more preferable to wind the primary coil 15 outside the secondary coil 16, and the length of the winding of the primary coil 15 will inevitably become longer and the resistance will increase. It has a limiting effect and contributes to short circuits. In particular, the effect becomes greater for those with a minute rated value of the rated current number A. In addition, since the winding length of the secondary coil 16 is inevitably short and the resistance value is low, the electromagnetic device 14 as a current transformation means
The burden will be reduced.

Furthermore, a pair of yokes 20 of the electromagnetic device 14 are mounted thereon.
A movable iron piece 42 for instantaneous tripping is arranged along with a setting spring 45 so as to correspond to a part of the outer peripheral edge of the yoke 20 over the instantaneous tripping part 20c, and the movable iron piece 42 is moved to the yoke 20 in response to a predetermined primary current. The trip bar 39 that is operatively connected to the magnet is rotated to collapse the opening/closing operation mechanism 5A, and the multi-pole movable contacts are simultaneously opened and separated instantly, and is actuated by the excitation magnetic flux generated by the primary current. be done. Since the primary coil 15 is wound with a constant number of ampere turns depending on each rated current, the movable iron piece attraction force with respect to the load factor remains unchanged even when the rated currents differ.
Therefore, in any case, the instantaneous trip setting value can be set to a desired substantially constant multiplier. As a result, with conventional thermal electromagnetic circuit breakers, it was impossible to set the instantaneous trip value to 12 to 15 times the full load current for small-capacity motors, for example, when the full load current was 1A. I was able to make things possible.

As described above, the present invention makes it possible to manufacture circuits and circuit breakers with bimetal for timed tripping of any small rated current by using a single electromagnetic device having both current transformation means and instantaneous tripping means. It is possible to set the instantaneous trip value to a desirable setting value according to the rated current, and various effects are achieved to achieve the above-mentioned object.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a circuit breaker showing an embodiment of the present invention, FIG. 2 is a right side view of the circuit breaker shown in FIG. 1, and FIG. 3 is a top view of the circuit breaker shown in FIG. A plan view of the disconnector with the mold cover removed, Figure 4 is the same as 4 in Figure 1.
- A cross-sectional view of the polar chamber viewed along line 4 in the direction of the arrow,
Figure 5 is a cross-sectional view taken along the line 5-5 in Figure 1 in the direction of the arrow, Figure 6 is a back view of the mold base in Figure 1 with the bottom cover partially removed, and Figure 7 is this. FIGS. 8 to 10 are exploded perspective views of the main parts of the electromagnetic device for circuit breakers and circuit breakers of the invention, and are cross-sectional views of the opening/closing operation mechanism chamber viewed in the direction of the arrows along line 8-8 in FIG. 8th
9 shows a similar diagram showing the on state, and FIG. 10 shows the off and reset states of the circuit breakers.
Figure 11 shows a similar diagram showing the process of the trip instant.
The figure is an exploded perspective view of the rated current adjustment mechanism, No. 12.
Figures a and b are side views and cross-sectional views showing the attachment relationship between the contact crossbar and the movable contact, Figure 13 is a cross-sectional view of the electrode chamber showing the off state, and Figure 14 is a cross-sectional view of the electrode chamber showing the off state.
The figure is a cross-sectional view of the electrode chamber showing the process of shorting and breaking. In the figure, 1: main body, 2: mold base, 3:
Mold cover, 4: Pole chamber, 5A: Opening/closing operation mechanism, 5B: Tripping mechanism, 6, 6': Terminal, 9: Arc horn, 10: Contact crossbar, 1
1: Movable contact rod, 12: Contact spring, 13: Movable contact, 14: Electromagnetic device, 1
5: Primary coil, 16: Secondary coil, 18: Overcurrent response device, 19: Fixed core, 20: Yoke, 2
3: Fixed contact rod, 24: Fixed contact, 2
5: Arc horn, 26: Arc extinguishing chamber, 27,2
7': arc extinguishing grid group, 28, 28': magnetic plate, 3
0: Buffer plate, 32: Discharge port, 33: Timed trip device, 34: Bimetal, 39: Trike bar, 4
1: Instantaneous tripping device, 42: Movable iron piece, 45: Leaf spring, 47: Handle, 52: Operation link, 5
4: Triple lever, 56: Contact link,
61: Trip pin arm, 71: Adjustable knob, 7
3: Trip push button.

Claims (1)

[Scope of Claims] 1. A circuit breaker for wiring equipped with a fixed contact rod having a fixed contact and a movable contact rod facing the fixed contact rod and having a movable contact at its free end, comprising: a fixed contact made of a magnetic material; A current transformer consisting of a core, plate-shaped yokes provided on both sides of the fixed core, yoke insulating plates provided inside each yoke, and a primary coil and a secondary coil wound around the fixed core. A device, a bimetal provided on one side of the yoke and provided outside the primary and secondary coils and connected to the secondary coil, and a bimetal provided on the other side of the yoke and supported to form a magnetic path with the yoke. A circuit characterized by comprising: a movable iron piece rotatably supported by a shaft; and a trip bar with which a part of the movable iron piece engages at one end and is pressed by the bimetal at the other end. Shiya disconnector.