Instantaneous trip device for wiring circuit breakers

Abstract

The present invention relates to an instantaneous trip device for a molded case circuit breaker, and more particularly to an instantaneous trip device for a molded case circuit breaker having increased magnetic attraction force and improved interruption performance. In an instantaneous trip device for a molded case circuit breaker according to one embodiment of the present invention, a heater is formed in a solenoid shape, so that a circular current is generated. Therefore, the direction of the magnetic field generated in the magnet coincides with the direction of movement of the armature, thereby strengthening the instantaneous attraction force.

Description

[Technical Field]

[0001] The present invention relates to an instantaneous trip device for a molded case circuit breaker, and more particularly to an instantaneous trip device for a molded case circuit breaker having increased magnetic attraction force and improved interrupting performance. [Background technology]

[0002] Generally, a molded case circuit breaker (MCCB) is an electrical device that protects the circuit and load by automatically shutting off the circuit in the event of an electrical overload or short circuit. Normally, molded case circuit breakers are often used in low-voltage systems.

[0003] A molded case circuit breaker generally comprises a terminal section connected to the power source side or the load side, a contact section including a fixed contact and a movable contact that opens and closes the circuit by moving it, a switching mechanism that operates the movable contact to supply the power necessary to open and close the circuit, a trip section that detects overcurrent or short-circuit current flowing in the circuit and induces the trip operation of the switching mechanism, and an arc-extinguishing section that extinguishes the arc that occurs when an abnormal current is interrupted.

[0004] Fault currents can be broadly divided into several categories, but typically, a current of 130% or more of the rated current is called an overcurrent, and a sudden current of 10 times or more the rated current is called an instantaneous fault current. Furthermore, sudden large currents, including instantaneous currents, are called short-circuit currents.

[0005] In the overcurrent region, the main method used is to trip the circuit breaker by demagnetizing a bimetal. For instantaneous currents of approximately 10 times the rated current, a conductor (heater) is placed between the magnet and armature. When a current greater than the set current flows through the conductor, a magnetic path is formed, and the armature is attracted to the magnet, tripping the circuit breaker.

[0006] Thus, the molded case circuit breaker includes an overcurrent trip device that responds to the rated overcurrent and an instantaneous trip device that responds to the instantaneous current.

[0007] FIG. 1 shows a conventional molded case circuit breaker 1, and FIG. 2 shows a trip section (trip device) 10.

[0008] A trip unit 10 for detecting an abnormal current flowing through the circuit and tripping the switching mechanism is provided inside the housing 2. The trip unit 10 is usually provided on the load side. The trip unit 10 includes a heater 11 connected to the load side terminal unit 9, a bimetal (not shown) coupled to the heater 11 to detect heat and bend in response to the amount of heat, a magnet 13 and an armature 14 installed around the heater 11, a crossbar 15 installed so as to be rotatable by contact with the bimetal or armature 14, and a chute 16 that is constrained or released by rotation of the crossbar 15 and that constrains or releases a nail 18 of the switching mechanism 20.

[0009] Normally, during a small current delayed cutoff, the heat generated in the heater 11 bends the bimetal, causing the crossbar 15 to rotate and the opening / closing mechanism to operate, and during a large current instantaneous cutoff, the magnetic force excited in the magnet 13 attracts the armature 14, causing the crossbar 15 to rotate and the opening / closing mechanism 20 to operate.

[0010] The operation of the instantaneous trip device is shown in Figures 3 and 4. When a large fault current such as a short circuit current occurs in the circuit in which the molded case circuit breaker 1 is installed, an induced current is generated in the magnet 13, and at that time, the magnetic field of the magnet 13 attracts the armature 14, pushing and rotating the crossbar 15, which in turn rotates the chute 16 and causes the switching mechanism 20 to trip.

[0011] In the trip section, when a fault current occurs, a magnetic field is generated around the heater 11 through which current flows, and an attractive force acts on the magnet 13, attracting the armature 14.

[0012] When a normal current is flowing, this attractive force is weaker than the tension of the instantaneous spring 12 of the armature 14, so it is unable to pull the armature 14. However, when a fault current occurs, the magnetic field force increases, and the attractive force of the magnet 13 becomes stronger than the tension of the instantaneous spring 12, so that the armature 14 can be attracted.

[0013] That is, when a normal current is applied, the magnetic attraction force of the magnet 13 is smaller than the tension of the instantaneous spring 12, so the armature 14 does not move.

[0014] However, when a fault current flows, the magnetic attraction force of the magnet 13 becomes greater than the tension of the spring 12, causing the armature 14 to operate, which activates the mechanism and causes a tripping action.

[0015] However, in low-rated circuit breakers, the magnitude of the current is small, so the magnetic attraction force of the magnet when a fault current occurs is insufficient, and the armature may not operate within the instantaneous reference range.

[0016] Therefore, in order to increase the instantaneous attractive force, the magnet must be made larger, but there is a limit to how large the magnet can be made due to spatial constraints, which imposes a limit on the attractive force.

[0017] Figure 5 shows a perspective view of a heater according to the prior art. It shows the direction of the current flowing through the heater 11 and the direction of the magnetic field. A magnetic field is formed according to the right-hand screw rule, with the current flowing through the heater at the center.

[0018] Figure 6 shows a perspective view of a heater and magnet according to the prior art. It shows the magnetic field formed around magnet 13 by current flowing through heater 11. The magnet is formed in a U-shape, covering the heater. Therefore, a magnetic field directed backward is formed on one side of the magnet, and a magnetic field directed forward is formed on the other side of the magnet. However, because the direction of these magnetic fields is offset from the direction of movement of armature 14, the effect of increasing the magnetic attraction force is not significant. Summary of the Invention [Problem to be solved by the invention]

[0019] The present invention has been made to solve the above problems, and has as its object to provide an instantaneous trip device for a molded case circuit breaker which increases the instantaneous attractive force so that the armature can trip properly even at low ratings. [Means for solving the problem]

[0020] An instantaneous trip device for a molded case circuit breaker according to one embodiment of the present invention includes a heater connected to a circuit, a magnet installed adjacent to the heater, and an armature that is rotatably installed and is attracted to the magnet when the magnet is magnetized, wherein a magnetic hole is formed in the center of the heater, and the magnet has a protrusion that is inserted into the magnetic hole and protrudes toward the armature.

[0021] Here, the heater includes a power supply side heater section connected to the power supply side, a load side heater section arranged so that a portion of the heater section overlaps the power supply side heater section, and an insulating member interposed between the power supply side heater section and the load side heater section.

[0022] The power supply side heater portion also includes a power supply side connection terminal connected to the power supply side, a power supply side first vertical plate portion connected to the power supply side connection terminal and extending downward, a power supply side intermediate portion extending laterally from the power supply side first vertical plate portion, and a power supply side coupling portion connected to the power supply side intermediate portion.

[0023] Furthermore, the load side heater section includes a load side connecting section connected to the power supply side connecting section, a load side first vertical plate section extending upward from the load side connecting section, a load side intermediate section extending horizontally from the load side first vertical plate section, a load side second vertical plate section extending downward from the load side intermediate section and arranged parallel to the load side first vertical plate section, a load side flat plate section extending by being bent from the load side second vertical plate section, and a load side terminal section connected to the load side flat plate section.

[0024] Furthermore, the width of the power supply side first vertical plate portion is formed to be less than half the width of the power supply side connection terminal.

[0025] Furthermore, the widths of the load side first vertical plate portion and the load side second vertical plate portion are formed to be less than half the width of the load side flat plate portion.

[0026] Furthermore, the load-side second vertical plate portion and the power-source-side first vertical plate portion are arranged to overlap with each other via the insulating member.

[0027] Furthermore, the magnetic hole is formed between the load side first vertical plate portion and the load side second vertical plate portion.

[0028] Furthermore, the insulating member includes an insulating vertical plate portion and an insulating horizontal plate portion.

[0029] Furthermore, the magnet includes a fixed plate portion fixed to the trip portion case, and a protrusion portion that protrudes perpendicularly from the fixed plate portion and is inserted into the magnetic force hole.

[0030] Furthermore, the fixing plate portion is formed with a fixing groove for fixing to the trip portion case. [Effects of the Invention]

[0031] In the instantaneous trip device for a molded case circuit breaker according to one embodiment of the present invention, the heater is formed in a solenoid shape, so that a circular current is generated. Therefore, the direction of the magnetic field generated in the magnet coincides with the direction of the armature movement, thereby strengthening the instantaneous attractive force.

[0032] Furthermore, the protrusions aligned with the direction of movement of the armature increase the magnetic attraction force of the magnet.

[0033] Therefore, even with a low rated current, the armature operates within the instantaneous reference range.

[0034] The heater is composed of a double plate consisting of a power supply side heater section and a load side heater section connected thereto, so that a circular current is formed.

[0035] An insulating member is interposed between the power supply side heater section and the load side heater section, so that current flows smoothly between the double plates. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 1 is a diagram showing a conventional molded case circuit breaker. [Figure 2] FIG. 1 is a diagram showing a trip section of a conventional molded case circuit breaker. [Figure 3] FIG. 1 is a diagram illustrating the operation of an instantaneous trip mechanism in a trip section of a conventional molded case circuit breaker, showing a current-carrying state. [Figure 4] FIG. 1 is a diagram illustrating the operation of an instantaneous trip mechanism in a trip section of a conventional molded case circuit breaker, showing a tripped state. [Figure 5] FIG. 1 is a perspective view of a heater according to the prior art. [Figure 6] FIG. 1 is a perspective view of a heater and magnet according to the prior art. [Figure 7] 1 is a cross-sectional view of the interior of a molded case circuit breaker according to an embodiment of the present invention. [Figure 8] 1 is a perspective view of a trip portion applied to a molded case circuit breaker according to an embodiment of the present invention, viewed from one direction; [Figure 9] 10 is a perspective view of the trip unit applied to the molded case circuit breaker according to the embodiment of the present invention, viewed from another direction. FIG. [Figure 10] 1 is a perspective view of a heater and a magnet applied to a trip unit of a molded case circuit breaker according to an embodiment of the present invention; [Figure 11] FIG. 11 is an exploded perspective view of the heater and magnet shown in FIG. 10. [Figure 12] FIG. 11 is an exploded perspective view of the heater shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0037] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, which are provided to explain the present invention in detail and are not intended to limit the technical spirit and scope of the present invention.

[0038] The terms "member" or "portion" used to indicate components in the present invention are not used for any limiting purpose and may be omitted.

[0039] An instantaneous trip device for a molded case circuit breaker according to each embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 7 shows an internal cross-sectional view of a molded case circuit breaker according to one embodiment of the present invention.

[0040] The instantaneous trip device of the molded case circuit breaker 100 according to one embodiment of the present invention includes a trip section case 280, a heater 210 that is installed in the trip section case 280 and connected to the circuit, a magnet 250 that is installed adjacent to the heater 210, an armature 260 that is rotatably installed on the heater 210 and is attracted when the magnet 250 is magnetized, and a crossbar 270 that rotates due to the action of the armature 260 and trips the opening / closing mechanism 125. A magnetic hole 213 is formed in the center of the heater 210, and the magnet 250 is provided with a protrusion 254 that is inserted into the through hole and protrudes toward the armature 260.

[0041] First, a molded case circuit breaker 100 according to an embodiment of the present invention will be described.

[0042] The housing 101 accommodates and supports the components of the molded case circuit breaker. The housing 101 is generally formed in a box shape. A handle 127 is exposed on the top surface of the housing 101. The handle 127 operates the opening / closing mechanism 125 by manual operation by the user.

[0043] Terminals 108, 218 connected to a power source or a load are provided on the front and rear of the housing 101. Terminals 108, 218 are provided for each phase (or each pole). For example, in a three-phase, four-pole molded-circuit breaker, four terminals are provided on each of the power source side and the load side. Terminals 108, 218 are composed of a power source side terminal 108 and a load side terminal 218.

[0044] A base assembly 102 is inserted into the housing 101. The base assembly 102 incorporates a contact unit and an arc-extinguishing unit. A base assembly 102 is provided for each phase. For example, in a three-phase system, the base assembly 102 is composed of an R phase, an S phase, and a T phase. An opening / closing mechanism unit 125 is installed in the S-phase base assembly 102.

[0045] The fixed contacts 120, 121 are fixedly provided inside the housing 101. The fixed contacts 120, 121 are connected to the terminal portions 108, 218. In a dual-contact type molded-case circuit breaker, the fixed contacts 120, 121 are provided on the power supply side and the load side, respectively. That is, a power supply side fixed contact 120 and a load side fixed contact 121 are provided. Here, the power supply side fixed contact 120 may be directly connected to the power supply side terminal portion 108 or may be formed integrally therewith. The load side fixed contact 121 is connected to the load side terminal portion 218 via a trip mechanism (particularly, a heater 210).

[0046] An arc-extinguishing section (arc-extinguishing device) 105 is provided near the contact section (fixed contact and movable contact) to extinguish the arc that occurs during circuit breaking. In a double-contact type molded-case circuit breaker, the arc-extinguishing section 105 is provided on both the power supply side and the load side. The arc-extinguishing section 105 is composed of a pair of side walls and a plurality of grids that are connected to the side walls at predetermined intervals. The arc that occurs at the contact section is divided by the plurality of grids.

[0047] A trip unit 200 for detecting an abnormal current flowing through the circuit and tripping the switching mechanism is provided in a part of the housing 101. The trip unit 200 is usually provided on the load side. The trip unit 200 includes a heater 210 connected to the load-side terminal 218, a bimetal 240 coupled to the heater 210 to detect heat and bend in response to the amount of heat, a magnet 250 installed around the heater 210 to generate a magnetic field in the event of a fault current, an armature 260 rotatably installed on the heater 210 and attracted by the magnetic force of the magnet 250, a crossbar 270 rotatably installed by contact with the bimetal 240 or the armature 260, and a chute 275 that is constrained or released by rotation of the crossbar 270 and that constrains or releases the nail 118 of the switching mechanism 125.

[0048] Normally, during a small current delayed cutoff, the heat generated in the heater 210 bends the bimetal 240, causing the crossbar 270 to rotate and the opening / closing mechanism 125 to operate, and during a large current instantaneous cutoff, the magnetic force excited in the magnet 250 attracts the armature 260, causing the crossbar 270 to rotate and the opening / closing mechanism 125 to operate.

[0049] The operating force of the user is transmitted to the opening and closing mechanism 125 via a handle 127. In order to transmit the power of the opening and closing mechanism 125 to each phase, a pair of rotating pins 104 are installed in the opening and closing mechanism 125. The rotating pins 104 are formed to a length that spans all of the phases, and are installed in a shaft assembly (or a mover assembly) 130.

[0050] A shaft assembly 130 is provided, and a rotating pin 104 is inserted through the shaft assembly 130. The shaft assembly 130 rotates when the opening and closing power of the opening and closing mechanism 125 is transmitted by the rotating pin 104. When the shaft assembly 130 rotates, the movable contact 140 also rotates, and moves toward and away from the fixed contacts 120 and 121.

[0051] The shaft assembly 130 includes a shaft body 131 , a movable contact 140 , a shaft pin 165 , and a spring 160 .

[0052] The movable contact 140 is inserted into the opening 133 of the shaft body 131. The movable contact 140 rotates counterclockwise or clockwise together with the shaft body 131 or independently, and moves in and out of contact with the fixed contacts 120 and 121 to energize or cut off the line.

[0053] Movable contacts 141 are provided at both ends of the movable contactor 140, respectively, to come into contact with the fixed contacts 122 and 123 of the fixed contactors 120 and 121. The movable contacts 141 are made of a material with excellent conductivity and durability, such as a chromium-copper (Cr-Cu) alloy.

[0054] A fixing protrusion 142 capable of locking one end of a spring 160 is protruded from the side of the movable contactor 140. When one end of the spring 160 is fixed to the fixing protrusion 142, the movable contactor 140 receives a force that rotates it counterclockwise in the drawing. Therefore, the movable contactor 140 maintains its inserted state in the shaft body 131 due to the biasing force of the spring 160 unless an external force is applied.

[0055] In general, the movable contact 140 rotates together with the shaft body 131 during small or large current interruption, but during current-limiting interruption, the movable contact 140 rotates independently due to a sudden electromagnetic repulsive force. In this case, the movable contact 140 stops rotating when it comes into contact with the shaft pin 165 in the opening. A locking groove (not shown) that comes into contact with the shaft pin 165 is formed on the back surface of the movable contact 140.

[0056] The movable contactor 140 rotates in the following three cases. In the first case, the user operates the handle 127, causing the opening / closing mechanism 125 connected to the handle 127 to rotate the shaft assembly 130, and the movable contactor 140 rotates together with the shaft body 131. In other words, the movable contactor 140 is constrained by the force of the spring 160 and moves together with the shaft body 131. In other words, in this case, the movable contactor 140 and the shaft body 131 of the shaft assembly 130 move together as a single unit.

[0057] In the second case, the trip unit 200 detects a fault current, and the switching mechanism 125 is released from its restraint, causing the shaft assembly 130 to rotate, which in turn causes the movable contactor 140 to rotate. In this case, the movable contactor 140 is also restrained by the force of the spring 160 and moves together with the shaft body 131.

[0058] In the third case, when a large fault current such as a short-circuit current occurs, the movable contact 140 rotates while being separated from the fixed contacts 120 and 121 due to an electromagnetic repulsive force (so-called current-limiting interruption). In this case, the movable contact 140 rotates independently from the shaft body 131. The movable contact 140 moves within the opening 133 of the shaft body 131. When the strong electromagnetic repulsive force causes the movable contact 140 to move clockwise, overcoming the biasing force of the spring 160, the movable contact 140 is separated from the fixed contacts 120 and 121. The movable contact 140 is separated from the fixed contacts 120 and 121 and is fixed in a state where the movable contact 140 is in contact with the shaft pin 165. That is, in this case (current-limiting interruption), only the movable contact 140 moves independently of the shaft assembly 130, while the shaft body 131 does not rotate.

[0059] 8 and 9 are perspective views of a trip section applied to a molded case circuit breaker according to one embodiment of the present invention, viewed from various directions; FIG. 10 is a perspective view of a heater and a magnet applied to the trip section; FIG. 11 is an exploded perspective view of the heater and the magnet; and FIG. 12 is an exploded perspective view of the heater.

[0060] A trip unit 200 for detecting an abnormal current flowing in the circuit and tripping the switching mechanism is provided in a part of the housing 101. Usually, the trip unit 200 is provided on the load side.

[0061] The trip unit 200 includes a trip unit case 280 that houses the components of the trip unit, a heater 210 connected to part of the circuit, a bimetal 240 that is coupled to the heater 210 to detect heat and bend according to the amount of heat generated, a magnet 250 and an armature 260 that are installed around the heater 210, a crossbar 270 that is installed so as to be rotatable by contact with the bimetal 240 or the armature 260, and a chute 275 that is constrained or released by rotation of the crossbar 270 and that constrains or releases the nail 118 of the opening and closing mechanism 125.

[0062] A trip unit case 280 is provided, and the trip unit case 280 accommodates and supports the components of the trip unit 200. The trip unit case 280 is made of a synthetic resin for insulation.

[0063] A contactor protection section 282 is provided to protrude from the front surface of the trip section case 280. The contactor protection section 282 covers the load side fixed contactor 121 to protect and insulate it.

[0064] A phase partition wall 284 for separating the phases is provided inside the trip unit case 280. The phase partition wall 284 is provided in the form of a double wall.

[0065] The rear surface of the trip unit case 280 is either open and the terminal unit is connected thereto, or is insulated by the housing 101 .

[0066] The heater 210 is provided as part of the circuit and generates heat or generates an induced current. The heater 210 is made of a conductor. The heater 210 is connected to the circuit to pass current. The upper end of the heater 210 is connected to the load-side fixed contact 121, and the lower end of the heater 210 is connected to the load-side terminal 218 to pass current. The heater 210 sends a signal to the trip unit when an overcurrent or large current flows. That is, when an overcurrent flows through the heater 210, heat is generated and transferred to the bimetal 240. Furthermore, when a large current flows through the heater 210, a magnetic field is formed by the induced current, which generates a magnetic attraction force on the magnet 250.

[0067] The heater 210 is configured to generate an induced current in a form that strengthens the magnetic attraction force of the magnet 250. That is, the heater 210 generates a circular current in the form of a coil, like a solenoid. Therefore, the heater 210 generates a circular current in the form of a coil so that a magnetic field is formed in a form that passes through the center of the circular current. This is an application of a magnetic field caused by a current flowing through a circular conductor.

[0068] To this end, the heater 210 is composed of a power supply side heater section 220, a load side heater section 211, and an insulating member 230 disposed therebetween. The power supply side heater section 220 and the load side heater section 211 form a double plate that partially overlaps with each other, realizing the shape of a coil.

[0069] The power supply side heater section 220 includes a power supply side connection terminal 221, a power supply side first vertical plate section 223, a power supply side intermediate section 225, and a power supply side coupling section 227. The current applied from the power supply section, i.e., the current that enters via the load side fixed contactor 121, travels through the power supply side connection terminal 221, the power supply side first vertical plate section 223, the power supply side intermediate section 225, and the power supply side coupling section 227 in this order.

[0070] The power supply side connection terminal 221 is coupled to the load side fixed contact 121. That is, the power supply side connection terminal 221 functions as a terminal portion or a connection portion. Therefore, the power supply side connection terminal 221 is connected to a circuit, and current supplied from the power supply flows through it.

[0071] The power supply side first vertical plate portion 223 is connected to the power supply side connection terminal 221, extends downward, and is formed long in the vertical direction. The power supply side first vertical plate portion 223 is formed so that its width is less than half the width of the power supply side connection terminal 221. In addition, the power supply side first vertical plate portion 223 is connected to one side of the power supply side connection terminal 221.

[0072] The power supply side intermediate portion 225 extends laterally from the lower end of the power supply side first vertical plate portion 223. The power supply side intermediate portion 225 connects the power supply side first vertical plate portion 223 and the power supply side coupling portion 227.

[0073] The power supply side coupling portion 227 is a portion where the power supply side heater portion 220 is coupled to the load side heater portion 211. The power supply side coupling portion 227 is arranged parallel to the power supply side first vertical plate portion 223. The power supply side coupling portion 227 has a predetermined distance from the power supply side first vertical plate portion 223. This distance is the portion where they are connected by the power supply side intermediate portion 225.

[0074] The power supply side coupling part 227 and the load side coupling part 212 are coupled to each other. The power supply side coupling part 227 and the load side coupling part 212 are coupled to each other with a bolt or a pin. The power supply side coupling part 227 and the load side coupling part 212 are respectively formed with coupling holes 227a and 212a into which the bolt or pin is inserted.

[0075] The load-side heater section 211 includes a load-side coupling section 212, a load-side first vertical plate section 214, a load-side intermediate section 215, a load-side second vertical plate section 216, a load-side flat plate section 217, and a load-side terminal section 218. The current entering from the power-source-side heater section 220 travels through the load-side coupling section 212, the load-side first vertical plate section 214, the load-side intermediate section 215, the load-side second vertical plate section 216, the load-side flat plate section 217, and the load-side terminal section 218 in this order.

[0076] The load-side coupling section 212 is coupled to the power-side coupling section 227 of the power-side heater section 220. The power-side heater section 220 and the load-side heater section 211 are directly coupled only at the power-side coupling section 227 and the load-side coupling section 212. Other than that, other components of the power-side heater section 220 and other components of the load-side heater section 211 are not directly connected to each other.

[0077] The load-side first vertical plate portion 214 extends upward from the load-side coupling portion 212. In the load-side first vertical plate portion 214, the current flowing from the power source-side heater portion 220 moves upward.

[0078] The load side intermediate portion 215 extends laterally from the upper end of the load side first vertical plate portion 214. The load side intermediate portion 215 connects the load side first vertical plate portion 214 and the load side second vertical plate portion 216 together.

[0079] The load side second vertical plate portion 216 extends downward from the load side intermediate portion 215. The load side second vertical plate portion 216 is disposed parallel to the load side first vertical plate portion 214. In the load side second vertical plate portion 216, the current flowing from the load side first vertical plate portion 214 and the load side intermediate portion moves downward.

[0080] The load side second vertical plate portion 216 is disposed at a predetermined distance from the load side first vertical plate portion 214. That is, a magnetic force hole 213 is formed between the load side first vertical plate portion 214 and the load side second vertical plate portion 216. This magnetic force hole 213 provides a space into which the protrusion 254 of the magnet 250 is inserted.

[0081] The load-side second vertical plate portion 216 overlaps with the power-source-side first vertical plate portion 223. That is, they are arranged to form a double plate. However, the load-side second vertical plate portion 216 and the power-source-side first vertical plate portion 223 are arranged so that a predetermined gap is provided between them by the insulating member 230. Therefore, current does not flow directly from the power-source-side first vertical plate portion 223 to the load-side second vertical plate portion 216.

[0082] The load side flat plate portion 217 is bent and extends from the load side second vertical plate portion 216. The load side flat plate portion 217 is connected to the load side terminal portion 218.

[0083] The widths of the load side first vertical plate portion 214 and the load side second vertical plate portion 216 are formed to be less than half the width of the load side flat plate portion 217. In addition, the widths of the load side first vertical plate portion 214 and the load side second vertical plate portion 216 are formed to be less than half the width of the power supply side connection terminal 221.

[0084] The load-side terminal portion 218 extends from the load-side flat plate portion 217. The load-side terminal portion 218 forms a terminal portion to which a load is connected. A current applied from a power source to the heater 210 flows to the load via the load-side terminal portion 218.

[0085] A support portion 219 is provided on the lower surface of the load side terminal portion 219.

[0086] The insulating member 230 is interposed between the power source side heater section 220 and the load side heater section 211. The insulating member 230 is made of insulating paper. Specifically, the insulating member 230 is formed in an inverted L shape. That is, the insulating member 230 is composed of an insulating vertical plate section 231 and an insulating horizontal plate section 232. The insulating member 230 prevents the power source side heater section 220 and the load side heater section 211 from being directly connected to each other except at the joint section. The insulating vertical plate section 231 is interposed between the power source side first vertical plate section 223 and the load side second vertical plate section 216. The insulating horizontal plate section 232 is interposed between the upper end section of the power source side first vertical plate section 223 (or one side surface of the power source side connection terminal 221) and the load side intermediate section 215.

[0087] When the current flows from the power supply side heater 220 to the load side heater 211, it rotates about two times in an elliptical shape to form a circular current. This generates a magnetic field that penetrates the circular current. This magnetic field passes through the magnetic hole 213. Figures 10 and 12 show the direction of the current flowing through the heater.

[0088] The bimetal 240 is made of two bonded metal plates with different thermal conductivities, and bends when heat is generated. The bimetal 240 is in contact with the heater 210, and when heat is transferred, it bends and rotates the crossbar 270. The bimetal 240 functions as an overcurrent tripping element.

[0089] The armature 260 is installed in the heater 210. Specifically, the armature 260 is installed in the load-side flat plate portion 217 of the load-side heater portion 211. The armature is shown in FIGS.

[0090] The armature 260 is installed by an armature support 262 and a return spring 264. The armature 260 is made of a magnetic material, and when the magnetic force of the magnet 250 is stronger than the elastic resistance of the return spring 264, the armature 260 overcomes the magnetic force and is attracted (rotates) toward the magnet 250.

[0091] The magnet 250 is installed behind the heater 210. When a sudden change in current occurs in the heater 210, the magnetic attraction force of the magnet 250 increases due to the magnetic field caused by the induced current. The magnet is clearly shown in Figures 10 and 11.

[0092] The magnet 250 is formed in a T-shape when viewed from above.

[0093] The magnet 250 is composed of a fixed plate portion 251 and a protrusion portion 254 .

[0094] The fixing plate portion 251 has a fixing groove 252 formed therein, and is fixed to the trip portion case 280. The fixing plate portion 251 is disposed on the rear surface of the heater 210 (contact portion side).

[0095] The protruding portion 254 protrudes in a direction perpendicular to the fixing plate portion 251. The protruding portion 254 is inserted into the magnetic hole 213 of the heater 210. That is, the protruding portion 254 penetrates between the power supply side first vertical plate portion of the power supply side heater portion 220 and the load side first vertical plate portion of the load side heater portion 211. The protruding portion 254 is also inserted into the gap between the load side first vertical plate portion and the load side second vertical plate portion.

[0096] The crossbar 270 is rotated by the bimetal 240 and the armature 260, releasing the constraint of the chute 275 and activating the opening and closing mechanism 125. The crossbar 270 is provided with an adjustment screw 272 for adjusting the distance between the crossbar 270 and the bimetal 240.

[0097] In the instantaneous trip device for a molded case circuit breaker according to one embodiment of the present invention, the heater is formed in a solenoid shape, so that a circular current is generated. Therefore, the direction of the magnetic field generated in the magnet coincides with the direction of the armature movement, thereby strengthening the instantaneous attraction force.

[0098] Therefore, the armature operates within the instantaneous reference range even at a low rated current.

[0099] The heater is composed of a double plate consisting of a power supply side heater section and a load side heater section connected thereto, so that a circular current is formed.

[0100] An insulating member is interposed between the power supply side heater section and the load side heater section, so that current flows smoothly between the double plates.

[0101] The above-described embodiments are examples of implementing the present invention, and a person skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate the technical idea of ​​the present invention, but are not intended to limit the scope of the technical idea of ​​the present invention. In other words, the scope of protection of the present invention should be interpreted by the scope of the claims, and any technical idea within the scope equivalent thereto should be interpreted as being included in the present invention. [Explanation of symbols]

[0102] 100 Circuit breaker 101 Case 108 Power supply side terminal section 218 Load side terminal 120,121 Fixed contact 125 Opening and closing mechanism 130 Shaft Assembly 140 Movable contact 200 Trip Section 210 Heater 211 Power supply side heater 220 Load side heater section 230 Insulating materials 240 Bimetal 250 Magnets 251 Fixed plate part 254 Protrusion 260 Armature 270 Crossbar 275 Shooter 280 Trip section case

Claims

1. a heater connected to the circuit; a magnet installed adjacent to the heater; an armature that is rotatably disposed and that is attracted to the magnet when the magnet is magnetized; a magnetic hole is formed in the center of the heater, and the magnet is provided with a protrusion that is inserted into the magnetic hole and protrudes toward the armature; Instantaneous trip device for wiring circuit breakers.

2. The heater is a power supply side heater portion connected to a power supply side; a load-side heater section disposed so as to overlap a portion of the power-source-side heater section; an insulating member interposed between the power supply side heater section and the load side heater section; 2. The instantaneous trip device for a molded case circuit breaker according to claim 1.

3. The power supply side heater section is a power supply side connection terminal to be connected to the power supply side; a power supply side first vertical plate portion connected to the power supply side connection terminal and extending downward; a power supply side intermediate portion extending laterally from the power supply side first vertical plate portion; a power supply side coupling portion connected to the power supply side intermediate portion, 3. The instantaneous trip device for a molded case circuit breaker according to claim 2.

4. The load side heater section includes: a load-side coupling portion coupled to the power-source-side coupling portion; a load side first vertical plate portion extending upward from the load side coupling portion; a load side intermediate portion extending laterally from the load side first vertical plate portion; a load side second vertical plate portion extending downward from the load side intermediate portion and arranged parallel to the load side first vertical plate portion; a load side flat plate portion bent and extending from the load side second vertical plate portion; a load side terminal portion connected to the load side flat plate portion, 4. The instantaneous trip device for a molded case circuit breaker according to claim 3.

5. The width of the power supply side first vertical plate portion is formed to be less than half the width of the power supply side connection terminal.

4. The instantaneous trip device for a molded case circuit breaker according to claim 3.

6. The widths of the load side first vertical plate portion and the load side second vertical plate portion are formed to be less than half the width of the load side flat plate portion.

5. The instantaneous trip device for a molded case circuit breaker according to claim 4.

7. the load-side second vertical plate portion and the power-source-side first vertical plate portion are arranged to overlap with each other via the insulating member; 5. The instantaneous trip device for a molded case circuit breaker according to claim 4.

8. The magnetic hole is formed between the load side first vertical plate portion and the load side second vertical plate portion.

5. The instantaneous trip device for a molded case circuit breaker according to claim 4.

9. The insulating member includes an insulating vertical plate portion and an insulating horizontal plate portion.

3. The instantaneous trip device for a molded case circuit breaker according to claim 2.

10. The magnet is a fixed plate portion fixed to the trip portion case; a protrusion protruding from the fixing plate portion in a direction perpendicular to the fixing plate portion and inserted into the magnetic hole, 2. The instantaneous trip device for a molded case circuit breaker according to claim 1.

11. The fixing plate portion has a fixing groove formed therein for fixing to the trip portion case.

11. The instantaneous trip device for a molded case circuit breaker according to claim 10.

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