Current limiting double breakpoint molded case circuit breaker

Abstract

The present invention discloses a current-limiting double-break molded case circuit breaker. The present invention sets a variable resistor component. When the moving contact and the static contact are closed to make the main circuit conductive, the resistance value of the variable resistor component tends to zero, which does not affect the normal temperature rise of the heating conductive part. When the main circuit is short-circuited and an excessive current is generated, the moving contact and the static contact are separated and disconnected, and the moving contact faces the direction away from the static contact. Under the action of the repulsion driving force of the moving contact and the static contact, the resistance value of the variable resistor component is increased through the linkage component. Thereby, the overall resistance of the main circuit is increased, so as to play a current limiting role in the main circuit, that is, the resistance of the main circuit will increase when the circuit breaker is disconnected, and the increase in the resistance of the main circuit is equivalent to increasing the arc voltage, which is more conducive to arc extinguishing. It solves the problem that the circuit breaker in the prior art uses a fixed resistor with a very small resistance value to increase the current limiting resistor, which is not conducive to arc extinguishing.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breakers, and in particular to a current limiting double-breakpoint molded case circuit breaker. Background Art

[0002] Molded case circuit breakers are switch devices that can close, carry and interrupt current under normal circuit conditions; and can close, carry and interrupt current under abnormal circuit conditions (including short circuit conditions) within a specified time. Molded case circuit breakers are widely used in industry, agriculture, transportation, mining, civil construction and national defense. They play a great role in the transmission and distribution of electricity and the protection of motors. They are the most widely used products in low-voltage electrical appliances.

[0003] The operating mechanism of the circuit breaker is operated by a button extending out of the housing, and the moving contact and the static contact in the circuit breaker are driven to make contact or disconnect through multi-stage linkage. When the moving contact and the static contact are in contact, power can be supplied to the load connected to the circuit breaker.

[0004] The existing methods of increasing the current limiting resistance of circuit breakers usually include: 1. Designing the static contact of the circuit breaker into a coiled serpentine shape, increasing the length from the connection row to the static contact, thereby increasing the resistance; but this method is difficult to process; 2. Connecting the connection row and the static contact together through an S-shaped heating resistor alloy to increase the resistance; but this method increases the installation process and reduces reliability. In addition, the method of increasing the current limiting resistance of circuit breakers in the prior art using a fixed resistor with a very small resistance value is not conducive to arc extinguishing. Summary of the invention

[0005] The main purpose of the present invention is to provide a current limiting double-breakpoint molded case circuit breaker, aiming to solve the problem in the prior art that the circuit breaker increases the current limiting resistor by using a fixed resistor with a very small resistance, which is not conducive to arc extinguishing.

[0006] To achieve the above purpose, the technical solution proposed by the present invention is:

[0007] A current-limiting double-break molded case circuit breaker comprises a heating conductive member, a stationary contact, a moving contact, a variable resistor assembly and a linkage assembly; one end of the variable resistor assembly is electrically connected to the heating conductive member, the other end of the variable resistor assembly is electrically connected to the moving contact, the moving contact is used to be electrically connected to the stationary contact, so as to be connected in series in the main circuit of the circuit breaker; the variable resistor assembly has a first state in which the resistance value tends to zero when the moving contact is connected to the stationary contact, and a second state in which the resistance value increases through the linkage assembly under the action of the repulsive driving force of the moving contact and the stationary contact when the current of the main circuit is too large; when the variable resistor assembly is in the first state, the variable resistor assembly does not limit the current of the main circuit; when the variable resistor assembly is in the second state, the variable resistor assembly limits the current of the main circuit.

[0008] Preferably, it also includes an outer shell; a first inner cavity is formed in the outer shell; the variable resistor component is arranged in the first inner cavity; the variable resistor component includes a column, a resistance wire and a sliding sleeve; the first inner cavity includes an inner wall; the column is vertically connected to the inner wall; the resistance wire is wound around the middle of the column; the heat-generating conductive element is electrically connected to the column, and the connection point between the heat-generating conductive element and the column is located on the side of the resistance wire away from the inner wall; the sliding sleeve is slidably mounted on the column and is in sliding contact with the resistance wire; the moving contact and the sliding sleeve are electrically connected; the column and the sliding sleeve are both conductive components; the linkage component is used to drive the sliding sleeve to slide under the action of the repulsive driving force of the moving contact and the static contact, so as to change the resistance value of the variable resistor component.

[0009] Preferably, the variable resistor assembly also includes a support plate and a sliding rod; the support plate is connected to one end of the column away from the inner wall; the sliding rod is connected between the support plate and the inner wall; the sliding rod is parallel to the column; the sliding rod is a plastic sliding rod; the sliding sleeve is provided with a through hole that cooperates with the sliding rod; the sliding rod is passed through the through hole.

[0010] Preferably, the linkage assembly includes a fixed seat, a first rotating shaft, a second rotating shaft, a rack and a first connecting arm; the fixed seat is connected to the inner wall, and the fixed seat is located on the side of the column away from the heat-generating conductive member; the moving contact is hinged to the fixed seat; the first rotating shaft is rotatably passed through the fixed seat; the second rotating shaft is rotatably connected to the column; the rack is slidably connected to the column, and the rack is parallel to the column; the sliding sleeve is connected to the rack; the moving contact is used to drive the first rotating shaft to rotate; the first rotating shaft is used to drive the second rotating shaft to rotate synchronously; the second rotating shaft is used to drive the rack to slide, so as to drive the sliding sleeve to slide.

[0011] Preferably, the linkage assembly also includes a first gear, a second gear, a first groove wheel, a second groove wheel and a belt; the first gear is coaxially connected to the rotating shaft between the moving contact and the fixed seat; the second gear is coaxially connected to the first rotating shaft; the first gear is meshed with the second gear; the first groove wheel is coaxially connected to the first rotating shaft; the second groove wheel is coaxially connected to the second rotating shaft; the second gear and the first groove wheel are respectively located on both sides of the fixed seat; and the belt is tautly wound between the first groove wheel and the second groove wheel.

[0012] Preferably, the linkage assembly also includes a second connecting arm and a third gear; the second connecting arm is connected to the column; the second rotating shaft is rotatably arranged through the second connecting arm; the second rotating shaft is located on the side of the column away from the heat-generating conductive element; the third gear is coaxially connected to the second rotating shaft; and the third gear is meshed with the rack.

[0013] Preferably, the linkage assembly also includes a first connecting rod, a second connecting rod, a third connecting arm, a fourth connecting arm, a first sleeve and a second sleeve; the first connecting rod and the second connecting rod are respectively connected to the two ends of the rack; the first connecting rod and the second connecting rod are located in the same straight line; the first connecting rod and the second connecting rod are both parallel to the column; one end of the third connecting arm is connected to the column, and the other end of the third connecting arm is connected to the first sleeve; one end of the fourth connecting arm is connected to the column, and the other end of the fourth connecting arm is connected to the second sleeve; the first connecting rod is slidably inserted into the first sleeve; the second connecting rod is slidably inserted into the second sleeve.

[0014] Preferably, the linkage assembly further comprises a U-shaped plate; the U-shaped plate comprises a first plate and a second plate vertically connected to each other; the first plate is connected to the back of the rack; and the first connecting arm is connected to the second plate.

[0015] Preferably, the moving contact is electrically connected to the sliding sleeve via a flexible wire.

[0016] Preferably, a second inner cavity is formed in the outer shell; and the static contact is arranged in the second inner cavity.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] The current-limiting double-break molded case circuit breaker proposed by the present invention; by setting a variable resistor component, when the moving contact and the static contact are closed to make the main circuit conductive, the resistance value of the variable resistor component tends to zero, and does not affect the normal temperature rise of the heating conductive part; when the main circuit is short-circuited and an excessive current is generated, the moving contact and the static contact are separated and disconnected, and the moving contact faces away from the static contact. Under the action of the driving force of the moving contact and the static contact, the resistance value of the variable resistor component is increased through the linkage component. Thereby, the overall resistance of the main circuit is increased, thereby playing a current limiting role for the main circuit, that is, the resistance of the main circuit will increase when the circuit breaker is disconnected, and the increase in the resistance of the main circuit is equivalent to increasing the arc voltage, which is more conducive to arc extinguishing; it solves the problem in the prior art that the circuit breaker increases the current-limiting resistor by using a fixed resistor with a very small resistance value, which is not conducive to arc extinguishing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0020] Figure 1 A schematic structural diagram of a first state of an embodiment of a current limiting double-breakpoint molded case circuit breaker proposed by the present invention;

[0021] Figure 2 A structural schematic diagram of a second state of an embodiment of a current limiting double-breakpoint molded case circuit breaker proposed by the present invention;

[0022] Figure 3 for Figure 1 A magnified diagram of the details in the middle.

[0023] Description of reference numerals:

[0024] 110, outer shell; 120, first inner cavity; 130, second inner cavity; 140, moving contact; 150, static contact; 160, inner wall; 170, heating conductive member; 180, column; 190, operating mechanism; 210, fixed seat; 220, first gear; 230, belt; 240, resistance wire; 250, sliding sleeve; 260, sliding rod; 270, support plate; 280, first connecting arm; 29 0, first plate; 310, second plate; 320, rack; 330, first connecting rod; 340, second connecting rod; 350, third connecting arm; 360, first sleeve; 370, fourth connecting arm; 380, second sleeve; 390, first rotating shaft; 410, second gear; 420, first groove wheel; 430, second rotating shaft; 440, second groove wheel; 450, third gear; 460, third connecting arm.

[0025] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0028] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0031] The invention provides a current limiting double-breakpoint molded case circuit breaker.

[0032] Please refer to the attached Figure 1 -Attached Figure 3In one embodiment of a current limiting double breakpoint molded case circuit breaker proposed by the present invention, the current limiting double breakpoint molded case circuit breaker includes a heating conductive member 170, a stationary contact 150, a moving contact 140, a variable resistor component and a linkage component; one end of the variable resistor component is electrically connected to the heating conductive member 170, and the other end of the variable resistor component is electrically connected to the moving contact 140, and the moving contact 140 is used to be electrically connected to the stationary contact 150 to be connected in series in the main circuit of the circuit breaker; the variable resistor component has a first state in which the resistance value tends to zero when the moving contact 140 and the stationary contact 150 are turned on, and a second state in which the resistance value increases through the linkage component under the action of the repulsive driving force of the moving contact 140 and the stationary contact 150 when the current of the main circuit is too large; when the variable resistor component is in the first state, the variable resistor component does not limit the current of the main circuit; when the variable resistor component is in the second state, the variable resistor component limits the current of the main circuit.

[0033] The current limiting double breakpoint molded case circuit breaker proposed by the present invention; by setting a variable resistor component, when the moving contact 140 and the static contact 150 are closed to make the main circuit conductive (as shown in the attached Figure 3 As shown in the figure, the resistance value of the variable resistor component tends to zero, which does not affect the normal temperature rise of the heating conductive member 170; when a short circuit occurs in the main circuit and an excessive current is generated, the moving contact 140 and the stationary contact 150 are repelled and disconnected, and the moving contact 140 moves away from the stationary contact 150. Under the action of the repelling driving force of the moving contact 140 and the stationary contact 150, the resistance value of the variable resistor component increases through the linkage component (as shown in the figure). Figure 2 As shown). The overall resistance of the main circuit is increased, so that the main circuit has a current limiting effect, that is, the resistance of the main circuit will increase when the circuit breaker is disconnected, and the increase in the resistance of the main circuit is equivalent to increasing the arc voltage, which is more conducive to arc extinguishing; the problem that the circuit breaker in the prior art increases the current limiting resistance by using a fixed resistor with a very small resistance value is not conducive to arc extinguishing is solved.

[0034] In addition, the current limiting double breakpoint molded case circuit breaker also includes an outer shell 110; a first inner cavity 120 is formed in the outer shell 110; the variable resistor assembly is arranged in the first inner cavity 120; the variable resistor assembly includes a column 180, a resistance wire 240 and a sliding sleeve 250; the first inner cavity 120 includes an inner wall 160; the column 180 is vertically connected to the inner wall 160; the resistance wire 240 is wound around the middle of the column 180; the heating conductive element 170 is electrically connected to the column 180, The connection point between the heating conductive element 170 and the column 180 is located on the side of the resistance wire 240 away from the inner wall 160; the sleeve 250 is slidably mounted on the column 180 and is in sliding contact with the resistance wire 240; the moving contact 140 and the sleeve 250 are electrically connected; the column 180 and the sleeve 250 are both conductive components; the linkage assembly is used to drive the sleeve 250 to slide under the action of the repulsive driving force of the moving contact 140 and the static contact 150, so as to change the resistance value of the variable resistor assembly.

[0035] That is, the resistance wire 240 is wound around the middle of the column 180 to form a sliding resistor, and the sliding sleeve 250 is slidably mounted on the column 180, and the sliding sleeve 250 contacts the resistance wire 240 to change the resistance value of the variable resistor component, thereby changing the resistance value of the main circuit of the circuit breaker.

[0036] Meanwhile, the variable resistor assembly further includes a support plate 270 and a slide bar 260; the support plate 270 is connected to the end of the column 180 away from the inner wall 160; the slide bar 260 is connected between the support plate 270 and the inner wall 160; the slide bar 260 is parallel to the column 180; the slide bar 260 is a plastic slide bar 260; the slide sleeve 250 is provided with a through hole (not shown) that matches the slide bar 260; the slide bar 260 is passed through the through hole. In this way, the sliding direction of the slide sleeve 250 is consistent with the axial direction of the column 180.

[0037] In addition, the linkage assembly includes a fixed seat 210, a first rotating shaft 390, a second rotating shaft 430, a rack 320 and a first connecting arm 280; the fixed seat 210 is connected to the inner wall 160, and the fixed seat 210 is located on the side of the column 180 away from the heating conductive member 170; the moving contact 140 is hinged to the fixed seat 210; the first rotating shaft 390 is rotatably arranged in the fixed seat 210; the second rotating shaft 430 is rotatably connected to the column 180; the rack 320 is slidably connected to the column 180, and the rack 320 is parallel to the column 180; the sliding sleeve 250 is connected to the rack 320; the moving contact 140 is used to drive the first rotating shaft 390 to rotate; the first rotating shaft 390 is used to drive the second rotating shaft 430 to rotate synchronously; the second rotating shaft 430 is used to drive the rack 320 to slide, so as to drive the sliding sleeve 250 to slide. Through the above technical solution, the structure of the linkage assembly is improved, that is, the first rotating shaft 390 drives the second rotating shaft 430 to rotate synchronously, and the second rotating shaft 430 drives the rack 320 to slide, thereby driving the sliding sleeve 250 to slide.

[0038] At the same time, the linkage assembly also includes a first gear 220, a second gear 410, a first groove wheel 420, a second groove wheel 440 and a belt 230; the first gear 220 is coaxially connected to the rotating shaft between the moving contact 140 and the fixed seat 210; the second gear 410 is coaxially connected to the first rotating shaft 390; the first gear 220 is meshed with the second gear 410; the diameter of the first gear 220 is greater than the diameter of the second gear 410, and the number of teeth of the first gear 220 is greater than the number of teeth of the second gear 410; the first groove wheel 420 is coaxially connected On the first rotating shaft 390; the second groove wheel 440 is coaxially connected to the second rotating shaft 430; the second gear 410 and the first groove wheel 420 are respectively located on both sides of the fixed base 210; the rotating shaft between the moving contact 140 and the fixed base 210, the first rotating shaft 390 and the second rotating shaft 430 are parallel to each other; the belt 230 is tightly wound between the first groove wheel 420 and the second groove wheel 440; the first rotating shaft 390 is closer to the inner wall 160 than the second rotating shaft 430, and the second rotating shaft 430 is farther away from the inner wall 160 than the resistance wire 240.

[0039] In addition, the linkage assembly also includes a second connecting arm and a third gear 450; the second connecting arm is connected to the column 180; the second rotating shaft 430 is rotatably passed through the second connecting arm; the second rotating shaft 430 is located on the side of the column 180 away from the heat-generating conductive element 170; the third gear 450 is coaxially connected to the second rotating shaft 430; the third gear 450 is meshed with the rack 320.

[0040] Specifically, the moving contact 140 and the stationary contact 150 rotate under the action of the repulsive driving force, thereby driving the first gear 220 to rotate, the first gear 220 drives the second gear 410 to rotate, and then drives the first groove wheel 420 to rotate, the first groove wheel 420 drives the second groove wheel 440 to rotate through the belt 230, and then drives the rack 320 to slide through the third gear 450, so as to drive the sleeve 250 to slide along the axial direction of the column 180.

[0041] At the same time, the linkage assembly also includes a first connecting rod 330, a second connecting rod 340, a third connecting arm 460, a fourth connecting arm 370, a first sleeve 360 ​​and a second sleeve 380; the first connecting rod 330 and the second connecting rod 340 are respectively connected to the two ends of the rack 320; the first connecting rod 330 and the second connecting rod 340 are located in the same straight line; the first connecting rod 330 and the second connecting rod 340 are parallel to the column 180; one end of the third connecting arm 460 is connected to the column 180, and the other end of the third connecting arm 460 is connected to the first sleeve 360; one end of the fourth connecting arm 370 is connected to the column 180, and the fourth connecting arm 370 is connected to the first sleeve 360. 0 is connected to the other end of the second sleeve 380; the third connecting arm 460 is parallel to the fourth connecting arm 370; the third connecting arm 460 and the fourth connecting arm 370 are both perpendicular to the column 180; the third connecting arm 460 and the fourth connecting arm 370 are respectively located on both sides of the resistance wire 240; the first sleeve 360 ​​and the second sleeve 380 have a central axis; the first connecting rod 330 is slidably inserted into the first sleeve 360; the second connecting rod 340 is slidably inserted into the second sleeve 380; the outer shell 110, the support plate 270, the first connecting arm 280, the second connecting arm, the third connecting arm 460 and the fourth connecting arm 370 are all insulating components.

[0042] In addition, the linkage assembly further includes a U-shaped plate; the U-shaped plate includes a first plate 290 and a second plate 310 vertically connected to each other; the first plate 290 is connected to the back of the rack 320; and the first connecting arm 280 is connected to the second plate 310. Through the above technical solution, the structure and function of the linkage assembly are improved.

[0043] Specifically, the moving contact 140 is electrically connected to the sliding sleeve 250 through a flexible wire (not shown); the flexible wire is provided with an insulating layer (not shown) on its outer sleeve. The current limiting double breakpoint molded case circuit breaker further includes an operating mechanism 190 disposed on the outer shell 110; the operating mechanism 190 is used to operate the moving contact 140 and the static contact 150 to open or close the switch; a second inner cavity 130 is also formed in the outer shell 110; the static contact 150 is disposed in the second inner cavity 130.

[0044] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A current limiting double breakpoint molded case circuit breaker, characterized in that: The invention comprises a heating conductive member, a static contact, a moving contact, a variable resistor component and a linkage component; one end of the variable resistor component is electrically connected to the heating conductive member, the other end of the variable resistor component is electrically connected to the moving contact, the moving contact is used to be electrically connected to the static contact, so as to be connected in series in the main circuit of the circuit breaker; the variable resistor component has a first state in which the resistance value tends to be zero when the moving contact is connected to the static contact, and a second state in which the resistance value increases through the linkage component under the action of the repulsive driving force of the moving contact and the static contact when the current of the main circuit is too large; when the variable resistor component is in the first state, the variable resistor component does not limit the current of the main circuit; When the variable resistor component is in the second state, the variable resistor component limits the current of the main circuit; It also includes an outer shell; a first inner cavity is formed in the outer shell; the variable resistor component is arranged in the first inner cavity; the variable resistor component includes a column, a resistance wire and a sliding sleeve; the first inner cavity includes an inner wall; the column is vertically connected to the inner wall; the resistance wire is wound around the middle of the column; the heat-generating conductive element is electrically connected to the column, and the connection point between the heat-generating conductive element and the column is located on the side of the resistance wire away from the inner wall; the sliding sleeve is slidably sleeved on the column and in sliding contact with the resistance wire; the moving contact is electrically connected to the sliding sleeve; the column and the sliding sleeve are both conductive components; The linkage assembly is used to drive the sliding sleeve to slide under the action of the repulsive driving force of the moving contact and the static contact, so as to change the resistance value of the variable resistor assembly; The linkage assembly includes a fixed seat, a first rotating shaft, a second rotating shaft, a rack and a first connecting arm; the fixed seat is connected to the inner wall, and the fixed seat is located on the side of the column away from the heat-generating conductive member; the moving contact is hinged to the fixed seat; the first rotating shaft is rotatably arranged in the fixed seat; the second rotating shaft is rotatably connected to the column; the rack is slidably connected to the column, and the rack is parallel to the column; the sliding sleeve is connected to the rack; the moving contact is used to drive the first rotating shaft to rotate; the first rotating shaft is used to drive the second rotating shaft to rotate synchronously; the second rotating shaft is used to drive the rack to slide, so as to drive the sliding sleeve to slide; The linkage assembly also includes a first gear, a second gear, a first groove wheel, a second groove wheel and a belt; the first gear is coaxially connected to the rotating shaft between the moving contact and the fixed seat; the second gear is coaxially connected to the first rotating shaft; the first gear is meshed with the second gear; the first groove wheel is coaxially connected to the first rotating shaft; the second groove wheel is coaxially connected to the second rotating shaft; the second gear and the first groove wheel are respectively located on both sides of the fixed seat; the belt is tightly wound between the first groove wheel and the second groove wheel; the first rotating shaft is closer to the inner wall than the second rotating shaft, and the second rotating shaft is farther away from the inner wall than the resistance wire; The linkage assembly further includes a second connecting arm and a third gear; the second connecting arm is connected to the column; the second rotating shaft is rotatably disposed through the second connecting arm; the second rotating shaft is located on a side of the column away from the heat-generating conductive element; the third gear is coaxially connected to the second rotating shaft; and the third gear is meshed with the rack; The variable resistor assembly further comprises a support plate and a slide rod; the support plate is connected to one end of the column away from the inner wall; the slide rod is connected between the support plate and the inner wall; the slide rod is parallel to the column; the slide rod is a plastic slide rod; the sliding sleeve is provided with a through hole matched with the slide rod; the slide rod is passed through the through hole; The linkage assembly also includes a first connecting rod, a second connecting rod, a third connecting arm, a fourth connecting arm, a first sleeve and a second sleeve; the first connecting rod and the second connecting rod are respectively connected to the two ends of the rack; the first connecting rod and the second connecting rod are located in the same straight line; the first connecting rod and the second connecting rod are both parallel to the column; one end of the third connecting arm is connected to the column, and the other end of the third connecting arm is connected to the first sleeve; one end of the fourth connecting arm is connected to the column, and the other end of the fourth connecting arm is connected to the second sleeve; the first connecting rod is slidably inserted into the first sleeve; the second connecting rod is slidably inserted into the second sleeve.

2. A current limiting double breakpoint molded case circuit breaker according to claim 1, characterized in that: The linkage assembly also includes a U-shaped plate; the U-shaped plate includes a first plate and a second plate vertically connected to each other; the first plate is connected to the back of the rack; and the first connecting arm is connected to the second plate.

3. A current limiting double breakpoint molded case circuit breaker according to claim 1, characterized in that: The moving contact is electrically connected to the sliding sleeve through a flexible wire.

4. A current limiting double breakpoint molded case circuit breaker according to claim 1, characterized in that: A second inner cavity is also formed in the outer shell; the static contact is arranged in the second inner cavity.

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