Motor protection circuit breaker having instantaneous pre-adjustment unit

Abstract

The present invention relates to a motor protection circuit breaker and, more specifically, to a motor protection circuit breaker having an instantaneous pre-adjustment unit that comprises: a trip plate connected to a trip unit so as to operate when an instantaneous current occurs in a circuit; a gap adjustment member coupled to an enclosure so as to be vertically movable; and an adjustment unit spring that is connected between the trip plate and the gap adjustment member and can extend and contract therebetween. According to an embodiment of the present invention, the motor protection circuit breaker having the instantaneous pre-adjustment unit enables modification of a set value for instantaneous operating current by having the instantaneous operating current pre-adjustment unit equipped therein.

Description

Circuit breaker for motor protection with instantaneous adjustment

[0001] The present invention relates to a circuit breaker for motor protection, and more particularly, to a circuit breaker for motor protection having an instantaneous adjustment unit.

[0002] In general, a motor protection circuit breaker (MMS; Manual Motor Starter) is a device used in an electric circuit with a rated insulation voltage of 690 V AC (frequency 50 Hz or 60 Hz) or less. It is installed in front of the motor and operates when an accident current occurs due to overcurrent, phase loss, phase reverse, short circuit, ground fault, etc., thereby protecting the system and load equipment by cutting off the system.

[0003] Fig. 1 shows an external perspective view of a circuit breaker for motor protection according to the prior art, and Fig. 2 shows an internal perspective view of a circuit breaker for motor protection according to the prior art.

[0004] The above motor protection circuit breaker is equipped with a detecting unit (trip unit) (30) that detects when an accident current such as overcurrent, phase loss, phase reverse, short-circuit current, or ground fault occurs inside the housing (2), an operating mechanism (20) that trips the circuit breaker according to a detection signal of the detecting unit, a contact unit (10) that opens and closes a line while interlocking with the operation of the operating mechanism, and an arc extinguishing unit (40) that extinguishes an arc generated when the contacts of the contact unit separate during breaking and discharges it to the outside. In addition, an auxiliary contact unit that sends a control signal to an accessory device according to the operation of the operating mechanism may also be equipped.

[0005] In the above motor protection circuit breaker, when the current is normally supplied, the moving contact (12) and the fixed contact (11) of the contact portion (10) are connected to supply terminal (3) to supply current to the load terminal (4). However, when an accident current occurs, the detection portion (30) detects this and operates the switching mechanism (20). As a result of the operation of the switching mechanism (20), the moving contact (12a) of the moving contact (12) is separated from the fixed contact (11a) of the fixed contact (11), thereby blocking the current from flowing to the load side.

[0006] The detection unit (trip unit) (30) of a circuit breaker for motor protection according to the prior art has the following configuration.

[0007] The detection unit (30) has a trip unit body (31) forming the base of the detection unit (30), a fixed contact (11) coupled to the lower portion of the trip unit body (31), a heater assembly (bimetal (39) and a heater (38) and a bimetal supporter (40)) coupled to the upper portion of the trip unit body (31) and detecting heat, an instantaneous coil (35) coupled to the upper portion of the bimetal supporter (40), a core portion (fixed core (32), a movable core (33) and a core spring (34)) inserted into the instantaneous coil (35), a terminal rod (41) coupled to the fixed core (32) and the trip unit body (31), and an instantaneous trip lever (36) rotatably coupled to the trip unit body (31).

[0008] At this time, the instantaneous operation of the detection unit (30) is as follows.

[0009] When a momentary current is applied to the circuit, the current flows to the momentary coil (35) through the terminal load (41), and the fixed core (32) is magnetized by the magnetic force.

[0010] As the fixed core (32) is magnetized, the movable core (33) is attracted to the fixed core (32) and moves upward. As the movable core (33) moves upward, it pushes one end of the instantaneous trip lever (36) to rotate the instantaneous trip lever (36). The other end of the instantaneous trip lever (36) moves downward and pushes the trip plate (25) downward. The trip plate (25) pushes the latch holder (23) of the switching mechanism (20) to operate the switching mechanism (20) and pushes the crossbar (29) to open the movable contact (12a) and the fixed contact (11a).

[0011] Here, the instantaneous operation refers to the function of rapidly cutting off when a huge instantaneous current flows due to a short circuit of the load or lightning strike, and the instantaneous set current is set from 2 times to as much as 20 times the rating. If the detection unit detects an abnormal current exceeding the instantaneous set current, the circuit breaker performs the cutting operation in a very short time.

[0012] The instantaneous current setting of conventional motor protection circuit breakers is fixed. For example, the instantaneous current value is designed to operate at 13 times the rated current.

[0013] When an instantaneous current is applied to the circuit, a magnetic force exceeding the load of the core spring (34) is generated through the instantaneous coil (35), causing the movable core (33) to move toward the fixed core (32). However, since the elements that can control the magnetic force, namely the fixed core (32), movable core (33), core spring (34), and instantaneous coil (35), are all fixed, it is difficult to change the instantaneous operating current.

[0014] Therefore, for motor loads such as chillers and large fans where the current flows more than 13 times during operation, a general motor protection circuit breaker cannot be used, and a dedicated motor protection circuit breaker made for special purposes (more than 20 times instantaneously) must be used, which is inconvenient.

[0015] The present invention has been devised to solve the above-mentioned problems, and its purpose is to provide a circuit breaker for motor protection having an instantaneous adjustment unit capable of adjusting instantaneous operating current.

[0016] A circuit breaker for motor protection having an instantaneous adjustment unit according to one embodiment of the present invention comprises: a trip plate connected to a trip unit and operated when an instantaneous current occurs in a circuit; a gap adjustment member connected to an enclosure so as to be able to move up and down; and an adjustment spring connected between the trip plate and the gap adjustment member and configured to be elastic.

[0017] Here, the upper part of the trip plate has an instantaneous adjustment part formed with an upper coupling part to which the adjustment part spring is coupled.

[0018] In addition, the outer case has an instantaneous adjustment part formed with an insertion part into which the gap adjustment member is inserted.

[0019] Additionally, the gap adjustment member has an instantaneous adjustment member that is rotatably coupled to the insertion member along a vertical axis.

[0020] Additionally, a screw hole is formed in the insertion portion, and the gap adjustment member is screwed into the screw hole.

[0021] Additionally, a tool groove is formed on the upper surface of the gap adjustment member.

[0022] Additionally, the upper part of the gap adjustment member is exposed to the outside of the outer case.

[0023] Additionally, a guide portion is formed in the outer case to guide the up-and-down movement of the trip plate.

[0024] Additionally, the guide portion is formed as a straight wall arranged in an up-down direction.

[0025] And, the upper part of the adjustment spring is coupled to the lower part of the gap adjustment member.

[0026] According to a motor protection circuit breaker having an instantaneous adjustment unit according to one embodiment of the present invention, an instantaneous operating current adjustment unit is provided so that the instantaneous operating current setting value can be changed.

[0027] Additionally, the upper part of the gap adjustment member for changing the load of the trip plate is exposed to the outside of the case so that the user can easily manipulate it using a tool.

[0028] Additionally, the gap adjustment member is screw-jointed to the outer case so that the changed setting value remains constant.

[0029] In addition, the up-and-down movement of the gap adjustment member is guaranteed as a linear movement by the insertion part of the upper frame, and the up-and-down movement of the trip plate is guaranteed as a linear movement by the guide part of the middle frame, so the change characteristic of the set current value according to the expansion and contraction of the adjustment part spring is consistent.

[0030] Fig. 1 is an external perspective view of a circuit breaker for motor protection according to the prior art.

[0031] Fig. 2 is an internal perspective view of a circuit breaker for motor protection according to the prior art.

[0032] Fig. 3 is an external perspective view of a circuit breaker for motor protection according to one embodiment of the present invention.

[0033] Fig. 4 is an internal perspective view of a circuit breaker for motor protection according to one embodiment of the present invention. It shows the On state.

[0034] Fig. 5 is a cross-sectional view of a circuit breaker for motor protection according to one embodiment of the present invention. It shows the off state.

[0035] Figures 6 to 8 are operation diagrams of a switching mechanism in a motor protection circuit breaker according to one embodiment of the present invention. Figure 6 shows the Off state, Figure 7 shows the On state, and Figure 8 shows the Trip state.

[0036] Figures 9 and 10 are diagrams illustrating the operation of an instantaneous trip device in a circuit breaker for motor protection according to one embodiment of the present invention. Figure 9 shows the energized state (On state), and Figure 10 shows the open state (Off state).

[0037] Fig. 11 is a perspective view of a rating adjustment part of a motor protection circuit breaker according to one embodiment of the present invention.

[0038] Figures 12 and 14 are operational diagrams of an instantaneous rating adjustment unit of a motor protection circuit breaker according to one embodiment of the present invention. Figure 12 shows a state in which the instantaneous current setting value is low, Figure 13 shows a state in which the instantaneous current setting value is medium, and Figure 14 shows a state in which the instantaneous current setting value is high.

[0039] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, these drawings are intended to provide a detailed description sufficient to enable those skilled in the art to easily practice the invention, and are not intended to limit the technical spirit or scope of the present invention.

[0040] The terms “absence” or “part” used to refer to components in the present invention are not used for any limiting purpose and may be omitted.

[0041] Fig. 3 is an external perspective view of a motor protection circuit breaker according to one embodiment of the present invention, Fig. 4 is an internal perspective view of a motor protection circuit breaker according to one embodiment of the present invention, and Fig. 5 is a longitudinal cross-sectional view of a motor protection circuit breaker according to one embodiment of the present invention. Here, Fig. 4 shows the On state, and Fig. 5 shows the Off state.

[0042] A circuit breaker for motor protection having an instantaneous adjustment unit according to each embodiment of the present invention will be described in detail with reference to the drawings.

[0043] A motor protection circuit breaker having an instantaneous adjustment unit according to one embodiment of the present invention comprises: a trip plate (156) connected to a trip unit (150) and operated when an instantaneous current occurs in a circuit; a gap adjustment member (170) connected to an outer case (101, 102, 103) so as to be able to move up and down; and an adjustment spring (180) connected between the trip plate (156) and the gap adjustment member (170) and elastically extending.

[0044] A motor protection circuit breaker having an instantaneous adjustment unit according to one embodiment of the present invention includes a detecting unit (or trip unit) (150) that detects and trips when an accident current such as an overcurrent, a phase loss, a phase reverse, a short-circuit current, or a ground fault occurs, an operating mechanism (140) that trips the circuit breaker according to a detection signal of the trip unit (150), a contact unit (110) that opens and closes a line in conjunction with the operation of the operating mechanism (140), and an arc extinguishing unit (120) that extinguishes an arc generated when the contacts of the contact unit (110) are separated during a circuit break and discharges it to the outside.

[0045] The housing (101) of the circuit breaker for motor protection installs and supports the components or elements inside. The housing (101) may be formed of a synthetic resin material.

[0046] The outer case (101, 102, 103) is composed of an upper frame (101), a middle frame (102), and a lower frame (103).

[0047] A part of the opening / closing mechanism (140) is inserted and installed inside the upper frame (101), and a handle (141) is installed on the upper surface of the upper frame (101) to receive the user's operating force.

[0048] An opening / closing mechanism (140) and a trip unit (150) are installed inside the intermediate frame (102). In addition, terminal units (105, 106) are configured at both longitudinal ends of the intermediate frame (102) and are connected to a power source or a load. Meanwhile, a fixed contact (111) in the contact unit (110) is fixedly installed on the lower surface of the intermediate frame (102).

[0049] A contact part (110) and a contact part (120) are installed in the lower frame (103).

[0050] Let's take a look at each component unit (part).

[0051] The contact portion (110) includes a fixed contact (111) that is fixedly installed on a part of the outer case (101, 102, 103) and connected to a power terminal portion (105) or a load terminal portion (106), and a movable contact (113) that makes contact with or is separated from the fixed contact (111) to conduct or cut off the circuit.

[0052] Fixed contacts (111) are respectively positioned adjacent to the terminal portions (105, 106). Each fixed contact (111) is provided with a fixed contact (112). Each fixed contact (111) is provided with a fixed contact (112) formed of a material having excellent electrical conductivity and high heat resistance.

[0053] The movable contact (113) is positioned at a predetermined distance from the fixed contact (111). The movable contact (113) is installed on a guide mover (115) and can move linearly (up and down) toward the fixed contact (111) together with the guide mover (115). The movable contact (113) is provided with a movable contact (114) formed of a material having excellent electrical conductivity and high heat resistance.

[0054] A contact spring (117) is arranged at the bottom of the movable contact (113) to provide elasticity to the movable contact (113) or the guide mover (115).

[0055] An arc extinguishing portion (120) is provided around the contact portion (110). The arc extinguishing portion (120) is provided to extinguish an arc generated at the contact portion (110) when breaking.

[0056] The arc-conducting portion (120) is provided with a side plate (121) and a plurality of grids (123) coupled thereto. An arc plate (125) that guides an arc to the arc-conducting portion (120) is provided at the bottom of the contact portion (110).

[0057] A detection unit or trip unit (150) is provided to detect and trip abnormal currents such as overcurrent or fault current flowing in a circuit. The trip unit (150) includes a delay trip unit that detects overcurrent and an instantaneous trip unit that detects fault current (short-circuit current).

[0058] The configuration outline of the trip device is as follows.

[0059] The delay trip device includes a bimetal (161) that is connected to a load-side terminal (106) or a heater (163) and bends due to heat generated when an overcurrent flows, a moving plate (134) that moves due to the bending of the bimetal (161), a moving plate lever (135) that is installed on the moving plate (134) and moves, and a compensation bimetal (136) that rotates due to the moving plate lever (135). In the delay trip device, the compensation bimetal (136) moves the latch holder (147) of the opening / closing mechanism (140) through sequential interlocking movements of the bimetal (161), the moving plate (134), the moving plate lever (135), and the compensation bimetal (136).

[0060] The instantaneous trip device includes an instantaneous coil (157) that generates an induced electromagnetic force when a fault current flows in the load-side terminal portion (106), a fixed core (152) fixedly installed inside the instantaneous coil (157), a movable core (153) that moves by the induced electromagnetic force, an instantaneous trip lever (155) that moves by receiving the force of the movable core (153), and a trip plate (156) that moves in conjunction with the instantaneous trip lever (155) and moves a latch holder (147).

[0061] Let’s take a closer look at the trip section (150).

[0062] A trip unit body (151) is provided. Delay trip unit components and instantaneous trip unit components are installed in the trip unit body (151).

[0063] A heater assembly (161, 162, 163) is provided. The heater assembly (161, 162, 163) includes a bimetal (161), a heater (163), and a bimetal support plate (162).

[0064] The bimetal (161) is bent by heat flowing to the terminal (106) or heater (163). The bimetal (161) can be formed integrally with the bimetal support plate (162).

[0065] The temperature of the heater (163) rises due to the heat flowing to the terminal (106).

[0066] The bimetal support plate (162) is connected to the trip body (151).

[0067] The heater assembly (161, 162, 163) is used as a delay trip device.

[0068] Let's take a look at the instantaneous trip mechanism. The instantaneous trip mechanism includes an instantaneous coil (157), a movable core (153), a fixed core (152), a core spring (154), an instantaneous trip lever (155), and a trip plate (156).

[0069] An instantaneous coil (157) is provided. The instantaneous coil (157) generates an induced electromagnetic force according to the amount of change in the current occurring in the terminal portion (106). The instantaneous coil (157) is mounted on the trip portion body (151). The instantaneous coil (157) generates an induced electromotive force to generate a magnetic force in the fixed core (152) and the movable core (153).

[0070] A core part (152, 153, 154) is provided. The core part includes a fixed core (152), a movable core (153), and a core spring (154). The core part is inserted and installed inside an instantaneous coil (157).

[0071] A fixed core (152) is provided. The fixed core (152) is fixed by having its upper end fitted into a terminal rod (160). At this time, the fixed core (152) can be fixedly fitted into the terminal rod (160) by a screw connection method or the like.

[0072] A movable core (153) is provided. The movable core (153) is arranged to be spaced apart from the fixed core (152) and is capable of linear movement. When there is no external force, the movable core (153) is spaced apart from the fixed core (152) by the core spring (154). When an induced electromagnetic force is generated in the instantaneous coil (157), a magnetic force is generated between the movable core (153) and the fixed core (152), and the movable core (153) overcomes the force of the core spring (154) and is pulled toward the fixed core (152).

[0073] A lever pressure portion (153a) is formed at the lower end of the movable core (153) to operate the instantaneous trip lever (155). The lever pressure portion (153a) may be formed in the shape of a pin protruding from the lower surface of the movable core (153). When the movable core (153) rises, the plate portion of the lever pressure portion (153a) can push up the instantaneous trip lever (155).

[0074] A core spring (154) is inserted between the fixed core (152) and the movable core (153). The core spring (154) places the movable core (153) in a position spaced apart from the fixed core (152) in a normal case where no external force is applied.

[0075] The terminal load (160) connects between the trip unit (150) and the terminal unit. The terminal load (160) is connected to the load-side terminal (106). The terminal load (160) is fixedly connected to the trip unit body (151).

[0076] The terminal rod (160) may be formed in a stepped plate shape. A fixed core (152) may be fitted to the upper surface of the terminal rod (160). The upper surface of the terminal rod (160) is positioned above the instantaneous coil (157). The lower surface of the terminal rod (160) may form a load-side terminal portion (106).

[0077] An instantaneous trip lever (155) is provided. The instantaneous trip lever (155) has a rotating shaft formed therein and is fitted into the trip body (151). The instantaneous trip lever (155) rotates around the rotating shaft.

[0078] The front end of the instantaneous trip lever (155) is inserted into the through hole of the trip plate (156). Therefore, when the instantaneous trip lever (155) rotates, the trip plate (156) is operated downward.

[0079] A driven part (155a) is provided at the rear end of the instantaneous trip lever (155) and is placed in the space formed by the lever pressing part (153a) of the movable core (153). When the movable core (153) moves upward, it pushes the driven part (155a) and the instantaneous trip lever (155) rotates, and accordingly, the front end of the instantaneous trip lever (155) descends and moves the trip plate (156) downward.

[0080] The switching mechanism will be described. Further reference will be made to the switching mechanism illustrated in FIGS. 6 to 8. FIGS. 6 to 8 are diagrams illustrating the operation of the switching mechanism in a motor protection circuit breaker according to one embodiment of the present invention. FIG. 6 illustrates the Off state, FIG. 7 illustrates the On state, and FIG. 8 illustrates the Trip state.

[0081] A switching mechanism (140) is provided. The user operates the switching mechanism (140) to open and close the contact (110) to turn the circuit on or off.

[0082] The opening / closing mechanism (140) is provided with a handle (141), a joint gear (142) that converts the movement of the handle (141) in an orthogonal axial direction, a first U pin (149), a latch (143), a second U pin (144), and a push link (145) that are sequentially connected and interlocked from the joint gear (142).

[0083] The first U-pin (149) is provided between the joint gear (142) and the latch (143) and pushes or pulls the latch (143) according to the movement of the joint gear (142).

[0084] The second U-pin (144) is provided between the push link (145) and the latch (143) to mediate interaction. That is, the second U-pin (144) pushes or pulls the latch (143) according to the movement of the push link (145), or pushes or pulls the push link (145) according to the movement of the latch (143).

[0085] The latch (143) moves according to the relative movement of the first U-pin (149) and the second U-pin (144), and has an on-off engaging portion (143a) that contacts the latch holder (147).

[0086] The on / off engaging portion (143a) is a portion where the latch (143) is restrained by the latch holder (147) during on / off operation. The on / off engaging portion (143a) is formed to protrude from a portion of the body of the latch (143). The on / off engaging portion (143a) has an on / off contact surface that meets the side surface of the latch holder (147) at an acute angle.

[0087] The push link (145) presses the crossbar (146), and the crossbar (146) moves the guide mover (115) to open and close the contact point (110).

[0088] The latch holder (147) binds or releases the latch (143). In normal operation, the latch holder (147) binds the on-off engaging portion (143a) of the latch (143), and when an overcurrent or short-circuit current occurs, it releases the binding of the on-off engaging portion (143a) of the latch (143) to cause a trip operation.

[0089] The operation of the opening / closing mechanism (140) and the trip unit (150) is as follows.

[0090] First, let's look at the normal operation without intervention of the trip unit (150) as follows. When the user turns the handle (141) in the Off state as shown in FIG. 6 so that the joint gear (142) rotates clockwise, the on-off engaging portion (143a) of the latch (143) is caught on the side of the latch holder (147) and is in a restrained state, so that the latch (143) rotates around the on-off engaging portion (143a), and the first U-pin (149) and the second U-pin (144) are pushed to the left in the drawing, so that the push link (145) rotates counterclockwise. When the push link (145) rotates counterclockwise, the force that was pressing down the crossbar (146) is removed, and the movable contact (113) contacts the fixed contact (111) by the elastic force of the contact spring (117), so that the circuit is energized and the handle is in the On state. That is, it switches to the state of FIG. 7. The state of the contact point can be seen in Fig. 4.

[0091] At this time, the latch holder (147) maintains the energized state by restraining the latch (143). That is, the on / off engaging portion (143a) of the latch (143) is in a state where it is caught by the latch holder (147). The switching mechanism (140) maintains the state of Fig. 7 in a normal circuit energized state.

[0092] Likewise, when the user turns the handle (141) in the opposite direction to switch from the on state to the off state, the on / off catch (143a) of the latch (143) is caught in the latch holder (147).

[0093] That is, in a normal on / off operation by the user's operation, the on / off engaging portion (143a) of the latch (143) is caught by the latch holder (147) and is in a restrained state, that is, in a normal on / off operation, it moves between the states of FIG. 6 and FIG. 7.

[0094] Next, let's examine the trip operation. First, let's examine the overcurrent trip process.

[0095] When the bimetal (161) of the trip unit (150) is bent by the heat generated when an overcurrent flows through the circuit in a energized state as shown in Fig. 7, the compensation bimetal (136) rotates the latch holder (147) of the switching mechanism (140) counterclockwise through the sequential interlocking movement of the moving plate (134), the moving plate lever (135), and the compensation bimetal (136). Accordingly, the restraint on the latch (143) is released. When the restraint of the latch holder (147) is released, the restraint force of the main spring (148) is removed from the latch (143), and the latch (143) returns to its original state. By receiving the restoring force of the main spring (148), the push link (145) rotates clockwise, and the second U-pin (144) is pulled. The latch (143) rotates counterclockwise by the second U-pin (144). At this time, the push link (145) presses the crossbar (146), so that the movable contact (113) is separated from the fixed contact (111), and the circuit is cut off. (Transition to the state of Fig. 8)

[0096] Afterwards, the joint gear (142) rotates further counterclockwise by the restoring force of the joint gear spring (142a), and the latch (143) rotates clockwise via the first U-pin (149) to return to the Off position. (Transition to the state of Fig. 6)

[0097] Next, let's examine the short-circuit current (fault current) trip process. Refer to FIGS. 9 and 10 for further details. FIGS. 9 and 10 are diagrams illustrating the operation of an instantaneous trip device in a motor protection circuit breaker according to one embodiment of the present invention. FIG. 9 shows a energized state (On state), and FIG. 10 shows an open state (Off state, trip state).

[0098] When a short-circuit current flows through the circuit in a energized state as shown in Fig. 7, an induced electromagnetic force is generated in the instantaneous coil (157). The movable core (153) is attracted to the fixed core (152) by this induced electromotive force. In conjunction with the movement of the movable core (153), the instantaneous trip lever (155) rotates counterclockwise and the trip plate (156) moves downward to press the trip action part (147a) of the latch holder (147) to rotate the latch holder (147) counterclockwise (see Fig. 8). Accordingly, the restraint on the latch (143) is released. When the restraint on the latch holder (147) is released, the latch (143) rotates counterclockwise by the force of the main spring (148). Under the force of the main spring (148), the push link (145) rotates clockwise and the second U-pin (144) is pulled. The latch (143) is rotated counterclockwise by the second U-pin (144). At this time, the push link (145) presses the crossbar (146), so that the movable contact (113) is separated from the fixed contact (111), and the circuit is cut off. The state is changed to that of Figs. 8 and 10.

[0099] Afterwards, the joint gear (142) moves by the restoring force of the joint gear spring (142a) and the latch (143) rotates clockwise via the first U-pin (149) to return to the Off position. (Transition to the state of Fig. 6)

[0100] Fig. 11 is a perspective view of a rating adjustment part of a motor protection circuit breaker according to one embodiment of the present invention.

[0101] An instantaneous trip current adjustment unit is provided. The instantaneous trip current adjustment unit is provided to adjust the set value of the instantaneous trip current.

[0102] The instantaneous trip current adjustment unit includes a gap adjustment member (170) rotatably coupled to the upper frame (101), a trip plate (156) connected to and operating the trip unit (150), and an adjustment unit spring (180) provided between the gap adjustment member (170) and the trip plate (156).

[0103] A trip plate (156) is interposed between the opening / closing mechanism (140) and the trip unit (150). The trip plate (156) may be formed in a plate shape. The trip plate (156) is provided to operate the latch holder (147) of the opening / closing mechanism (140).

[0104] A lever hole (156a) is formed at the bottom of the trip plate (156) into which the front end of the instantaneous trip lever (155) is inserted. Since the lever hole (156a) is provided for each phase, a plurality of lever holes are provided.

[0105] The front end of the instantaneous trip lever (155) is inserted into the lever hole (156a), and when the instantaneous trip lever (155) rotates, the trip plate (156) is pressed down.

[0106] A holder insertion hole (156b) is formed on the upper portion of the trip plate (156) into which the trip action part (147a) of the latch holder (147) is inserted. When the trip plate (156) moves downward, the trip action part (147a) inserted into the holder insertion hole (156b) moves downward, and accordingly, the latch holder (147) rotates to release its restraint on the latch (143).

[0107] An upper coupling portion (156c) is provided at the upper end of the trip plate (156) to which an adjustment spring (180) is coupled. The upper coupling portion (156c) may be formed to protrude from the upper end of the trip plate (156). A through hole is formed in the upper coupling portion (156c) so that the lower end of the adjustment spring (180) can be fitted therein.

[0108] An insertion portion (107) is provided in the upper frame (101). The insertion portion (107) may be formed as a circular tube. A screw hole (108) is formed through the insertion portion (107). A gap adjustment member (170) is screw-connected to the screw hole (108).

[0109] The gap adjustment member (170) is movably connected to the screw hole (108) of the insertion portion (107). Since the gap adjustment member (170) is supported by the screw hole (108) of the insertion portion (107), it can maintain its position at an arbitrarily set height. Accordingly, the changed instantaneous current operation setting value is maintained.

[0110] A screw thread is formed on the outer surface of the gap adjustment member (170) and is screw-connected to a screw hole (108). Accordingly, the gap adjustment member (170) can be moved up and down by rotation.

[0111] A tool groove is formed in the head of the gap adjustment member (170) to enable rotation using a work tool such as a driver. The user can easily adjust the instantaneous current setting value by rotating the gap adjustment member (170) using a tool from the outside of the outer case (101, 102, 103).

[0112] An example in which the gap adjustment member (170) is formed in a screw shape has been given, but other members capable of lifting and lowering movement may also be applied.

[0113] The intermediate frame (102) is provided with a guide portion (102a) that guides the up-and-down movement of the trip plate (156) (see Fig. 12). The guide portion (102a) may be provided with a pair of straight walls arranged in the up-and-down direction. The trip plate (156) is guided by the guide portion (102a) of the intermediate frame (102) to move up and down in the vertical direction. Since the up-and-down linear movement of the trip plate (156) is guaranteed, the set value changes according to a certain displacement when adjusting the instantaneous current, thereby ensuring the consistency of the adjustment. Even when the adjustment portion spring (180) is in a free state, the up-and-down linear movement of the gap adjustment member (170) and the trip plate (156) is guaranteed, thereby ensuring the consistency of the change in the set value according to the displacement of the gap adjustment member (170) when setting the instantaneous current.

[0114] An adjustment spring (180) is provided between the gap adjustment member (170) and the trip plate (156).

[0115] The upper part of the adjustment spring (180) is fixed to the gap adjustment member (170), and the lower part of the adjustment spring (180) is fixed to the upper connecting part (156c) of the trip plate (156).

[0116] As the position of the gap adjustment member (170) changes due to the elevation of the gap adjustment member (170), the gap between the gap adjustment member (170) and the trip plate (156) changes, causing the adjustment spring (180) to expand. Accordingly, the tension (load) of the adjustment spring (180) changes. Accordingly, the force capable of moving the trip plate (156) changes, and accordingly, the instantaneous trip current setting value can be adjusted.

[0117] The operation of adjusting the instantaneous operating current setting value of a circuit breaker for motor protection using the instantaneous adjustment unit of the present invention will be described with reference to FIGS. 12 to 14 as examples.

[0118] Figures 12 and 14 are operational diagrams of an instantaneous rating adjustment unit of a motor protection circuit breaker according to one embodiment of the present invention. Figure 12 shows a state in which the instantaneous current setting value is low, Figure 13 shows a state in which the instantaneous current setting value is medium, and Figure 14 shows a state in which the instantaneous current setting value is high.

[0119] For example, Fig. 12 shows a state in which the instantaneous operating current value is set to 10 times the rated current, Fig. 12 shows a state in which the instantaneous operating current value is set to 13 times the rated current, and Fig. 12 shows a state in which the instantaneous operating current value is set to 20 times the rated current.

[0120] Fig. 12 shows a state in which the load of the adjustment spring (180) between the gap adjustment member (170) and the trip plate (156) is at a minimum. The adjustment spring (180) is not extended. When an abnormal current flows in the circuit and the trip unit (150) operates, the instantaneous trip lever (155) rotates to apply downward pressure to the trip plate (156). The trip plate (156) operates according to the load value of the core unit (152, 153, 154), etc.

[0121] Fig. 13 shows a state in which the gap adjustment member (170) is raised upward by a predetermined distance. This shows a state in which the gap adjustment member (170) and the trip plate (156) are separated, the adjustment spring (180) is extended, and a load is applied to the adjustment spring (180). Accordingly, the operating pressure of the trip plate (156) increases, and the load applied to the trip unit (150) is combined with the load caused by the operation of the trip plate (156), so that the instantaneous operation set current value increases.

[0122] Fig. 14 shows a state in which the load of the adjustment spring (180) between the gap adjustment member (170) and the trip plate (156) is applied to the maximum. This shows a state in which the gap adjustment member (170) and the trip plate (156) are opened to the maximum, the adjustment spring (180) is extended to the maximum, and the maximum load is applied to the adjustment spring (180). The operating pressure of the trip plate (156) increases to the maximum, and the maximum load at which the trip plate (156) operates is added to the load applied to the trip unit (150), so that the instantaneous operation set current value increases to the maximum.

[0123] Here, the up-and-down movement of the gap adjustment member (170) is ensured as a linear movement by the insertion part (107) of the upper frame (101), and the up-and-down movement of the trip plate (156) is ensured as a linear movement by the guide part (102a) of the middle frame (102), so the change characteristic of the set current value according to the expansion and contraction of the adjustment part spring (180) is consistent.

[0124] According to a motor protection circuit breaker having an instantaneous adjustment unit according to one embodiment of the present invention, an instantaneous operating current adjustment unit is provided so that the instantaneous operating current setting value can be changed.

[0125] Additionally, the upper part of the gap adjustment member for changing the load of the trip plate is exposed to the outside of the case so that the user can easily manipulate it using a tool.

[0126] Additionally, the gap adjustment member is screw-jointed to the outer case so that the changed setting value remains constant.

[0127] In addition, the up-and-down movement of the gap adjustment member is guaranteed as a linear movement by the insertion part of the upper frame, and the up-and-down movement of the trip plate is guaranteed as a linear movement by the guide part of the middle frame, so the change characteristic of the set current value according to the expansion and contraction of the adjustment part spring is consistent.

[0128] The embodiments described above are illustrative of the best possible implementations of the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention. Therefore, these embodiments are not intended to limit the technical spirit of the present invention, but rather merely to illustrate it. Therefore, it should be understood that the scope of the technical spirit of the present invention is not limited by these embodiments. In other words, the scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included within the scope of the rights of the present invention.

[0129] [Explanation of symbols]

[0130] 101 Upper Frame

[0131] 102 middle frame

[0132] 103 Lower Frame

[0133] 105 Power side terminal

[0134] 106 Load side terminal

[0135] 110 contact point

[0136] 111 fixed contacts

[0137] 113 movable contact

[0138] 120 Sohobu

[0139] 140 Switching mechanism

[0140] 141 handle

[0141] 142 joint gear

[0142] 143 latch

[0143] 144 2nd U-pin

[0144] 145 Push Link

[0145] 146 crossbar

[0146] 147 Latch Holder

[0147] 148 main spring

[0148] 149 1st U-pin

[0149] 150 trips

[0150] 152 fixed cores

[0151] 153 movable cores

[0152] 154 core spring

[0153] 155 Instantaneous trip lever

[0154] 156 trip plate

[0155] 157 instantaneous coil

[0156] 160 Terminal Road

[0157] 161 Bimetal

[0158] 163 heater

[0159] 170 No gap adjustment

[0160] 180 degree adjustment spring

Claims

1. A trip plate connected to the trip section and operated when a momentary current occurs in the circuit; A gap adjustment member that is connected to the outer case so that it can be moved up and down; and A circuit breaker for motor protection having an instantaneous adjustment part including an adjustment part spring that is connected between the above trip plate and the gap adjustment member and is elastic.

2. A motor protection circuit breaker having an instantaneous adjustment part in which an upper coupling part to which the adjustment part spring is coupled is formed at the upper part of the trip plate in the first paragraph.

3. A motor protection circuit breaker having an instantaneous adjustment part in which an insertion part is formed in the outer case through which the gap adjustment member is inserted.

4. A motor protection circuit breaker in the third paragraph, wherein the gap adjustment member has an instantaneous adjustment member that is rotatably coupled to the insertion part along a vertical axis.

5. A motor protection circuit breaker in accordance with paragraph 4, wherein a screw hole is formed in the insertion portion and the gap adjustment member has an instantaneous adjustment portion that is screw-connected to the screw hole.

6. A motor protection circuit breaker having an instantaneous adjustment part in which a tool groove is formed on the upper surface of the gap adjustment member in the fifth paragraph.

7. A motor protection circuit breaker in accordance with paragraph 5, wherein the upper part of the gap adjustment member has an instantaneous adjustment part exposed to the outside of the housing.

8. A motor protection circuit breaker having an instantaneous adjustment part in which a guide part for guiding the up-and-down movement of the trip plate is formed in the outer case in the first paragraph.

9. A circuit breaker for motor protection having an instantaneous adjustment part formed by a straight wall arranged in an up-down direction in the 8th paragraph.

10. A motor protection circuit breaker having an instantaneous adjustment part in which the upper part of the adjustment part spring is coupled to the lower part of the gap adjustment member in the 9th paragraph.

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