AU2022200844A1 - Dc circuit breaker - Google Patents

Abstract

A DC circuit breaker is provided. The DC circuit breaker comprises a first housing and a second housing, wherein the first housing and the second housing jointly define an accommodation space, and a stationary contact assembly and a mechanism assembly are arranged in the accommodation space, the mechanism assembly being able to move between an on position and an off position. The mechanism assembly comprises a center plate and a moving contact assembly. The center plate is rotatably supported, at both sides of the center plate, by the first housing and the second housing respectively. The moving contact assembly is rotatably installed on the center plate by a moving shaft arranged on the center plate. The moving contact assembly is configured to rotate relative to the center plate during a rotation of the center plate relative to the first housing and the second housing. An elastic component of the mechanism assembly is configured to act between the moving contact assembly and the first housing. 1 10 13 11 6 14 21 17 20 (1 4 FIG. 1 1/35

Description

10 13 11 6 14 21

17 20

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4

FIG. 1

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DC CIRCUIT BREAKER PRIORITY

[0001] This application claims priority from Chinese Patent Application No

202110181405.X filed on 9 February 2021. The entire content of the priority application is

hereby incorporated by reference.

TECHNICAL FIELD

[0002] The present disclosure relates to a DC circuit breaker. A double contact

mechanism is designed in the DC circuit breaker and has the function of quick closing and

large spacing, meeting the requirements of contact pressure of high current level, tripping

force and element strength of existing accessories. The double contact mechanism can

reliably adapts to accessories, and has a moving contact point which opens quickly.

BACKGROUND

[0003] Under large current level, the contact pressure of direct current (DC) circuit

breaker is required to be very high. If the single-axis fixed-axis rotation and split-axis

fixed-axis rotation structure of existing DC product mechanism are used, the tripping force

will be correspondingly increased proportionally, resulting in the circuit breaker being unable

to use the existing accessory products. At the same time, the existing single contact structure

has insufficient current limiting ability for the required large short-circuit current.

SUMMARY

[0004] In order to solve one or more defects in the existing art, according to an aspect

of the present disclosure, a DC circuit breaker, comprising a first housing and a second

housing, wherein the first housing and the second housing jointly define an accommodation

space, and a stationary contact assembly and a mechanism assembly are arranged in the

accommodation space, the mechanism assembly being able to move between an on position

and an off position.

[0005] In some embodiments, the mechanism assembly comprises a center plate and a moving contact assembly.

[0006] In some embodiments, the center plate is rotatably supported, at both sides of the center plate, by the first housing and the second housing respectively.

[0007] In some embodiments, the moving contact assembly is rotatably installed on the center plate by a moving shaft arranged on the center plate.

[0008] In some embodiments, the moving contact assembly is configured to rotate relative to the center plate during a rotation of the center plate relative to the first housing and the second housing.

[0009] In some embodiments, an elastic component of the mechanism assembly is configured to act between the moving contact assembly and the first housing.

[0010] In some embodiments, the moving contact assembly comprises a moving contact point assembly.

[0011] In some embodiments, the moving contact point assembly is U-shaped.

[0012] In some embodiments, two moving contact points are connected in series by the U-shaped moving contact point assembly.

[0013] In some embodiments, the moving contact point assembly is connected to the moving contact assembly by a fastener.

[0014] In some embodiments, according to the above aspects of the present disclosure the DC circuit breaker further comprises an operating handle, a handle connecting rod and a handle return spring.

[0015] In some embodiments, the operating handle is configured to rotate around a handle shaft arranged on the first housing.

[0016] In some embodiments, the handle return spring is sleeved on the handle shaft.

[0017] In some embodiments, during a movement of the operating handle, one end of the handle return spring acts on a handle spring limiting rib on the first housing, and the other end of the handle return spring always acts on the operating handle.

[0018] In some embodiments, one end of the handle connecting rod is connected to the operating handle.

[0019] In some embodiments, the other end of the handle connecting rod is connected to the mechanism assembly.

[0020] In some embodiments, the mechanism component further comprises a tripping hook.

[0021] In some embodiments, the tripping hook is provided with a tripping hook through-hole, a tripping hook through-hole groove, a tripping hook torsion spring limiting

portion and a tripping hook notch.

[0022] In some embodiments, the other end of the handle connecting rod passes through the tripping hook through-hole groove.

[0023] In some embodiments, a center plate first shaft and a center plate first stopper are arranged on the center plate.

[0024] In some embodiments, the tripping hook is rotatably installed on the center plate through a cooperation of the center plate first shaft and the tripping hook through-hole.

[0025] In some embodiments, the center plate first stopper is configured to be fitted in the tripping hook notch.

[0026] In some embodiments, the center plate is further provided with a center plate blind groove.

[0027] In some embodiments, the other end of the handle connecting rod passing through the tripping hook through-hole groove is fitted in the center plate blind groove.

[0028] In some embodiments, the center plate comprises a center plate base, and a first branch and a second branch extending from the center plate base.

[0029] In some embodiments, the first branch and the second branch are parallel to each other and spaced apart.

[0030] In some embodiments, the center plate first shaft, the center plate first stopper and the center plate blind groove are arranged on the first branch.

[0031] In some embodiments, the first branch is further provided with a center plate first supporting shaft.

[0032] In some embodiments, the second branch is provided with a center plate second supporting shaft.

[0033] In some embodiments, the center plate first supporting shaft and the center plate second supporting shaft are coaxially arranged.

[0034] In some embodiments, the moving shaft is connected between the first branch

I and the second branch.

[0035] In some embodiments, the center plate is rotatably supported on the second housing and the first housing by the center plate first supporting shaft and the center plate

second supporting shaft respectively.

[0036] In some embodiments, a center plate spacing stopper is arranged on a side of the second branch facing the first branch.

[0037] In some embodiments, the center plate spacing stopper is configured to cooperate with the moving contact assembly to control a spacing between the moving contact

assembly and the stationary contact assembly.

[0038] In some embodiments, the first branch is further provided with a first branch tripping plate supporting shaft.

[0039] In some embodiments, the second branch is further provided with a second branch tripping sensor supporting shaft.

[0040] In some embodiments, the first branch tripping plate supporting shaft and the second branch tripping sensor supporting shaft are coaxially arranged.

[0041] In some embodiments, the mechanism assembly further comprises a tripping plate and a tripping sensor.

[0042] In some embodiments, the tripping plate is provided with a tripping plate slot.

[0043] In some embodiments, one end of the tripping sensor is provided with a tripping sensor hook.

[0044] In some embodiments, the tripping sensor hook is fitted in the tripping plate slot, so that the tripping sensor and the tripping plate are connected together.

[0045] In some embodiments, the tripping plate is further provided with a tripping plate convex column.

[0046] In some embodiments, a convex column through-hole is arranged in the tripping plate convex column.

[0047] In some embodiments, the first branch tripping plate supporting shaft is configured to pass through the convex column through-hole and is fitted in the convex

column through-hole, so that the tripping plate is able to rotate relative to the center plate.

[0048] In some embodiments, the other end of the tripping sensor is provided with a

A sensor through-hole and a sensor convex column.

[0049] In some embodiments, the second branch tripping sensor supporting shaft is configured to pass through the sensor through-hole and is fitted in the sensor through-hole, so

that the tripping sensor and the tripping plate can integrally rotate relative to the center plate.

[0050] In some embodiments, the tripping plate is further provided with a tripping plate locking surface.

[0051] In some embodiments, the tripping hook is provided with a tripping hook locking surface.

[0052] In some embodiments, upon the mechanism assembly being in the on position, the tripping hook locking surface is not in contact with the tripping plate locking surface.

[0053] In some embodiments, during a movement of the mechanism assembly from the on position to the off position, the tripping hook locking surface comes into contact with

the tripping plate locking surface.

[0054] In some embodiments, upon the mechanism assembly being in the off position, the tripping hook locking surface keeps in contact with the tripping plate locking surface.

[0055] In some embodiments, the moving contact assembly comprises a bracket skirt portion, a bracket connecting portion and a bracket tension spring connecting portion.

[0056] In some embodiments, the bracket connecting portion and the bracket tension spring connecting portion are located between the first branch and the second branch.

[0057] In some embodiments, the moving contact point assembly is partially arranged in the bracket skirt portion.

[0058] In some embodiments, the bracket connecting portion is provided with a connecting portion through-hole, and the moving shaft passes through the connecting portion

through-hole.

[0059] In some embodiments, one end of a tension spring of the moving contact assembly is connected to the bracket tension spring connecting portion.

[0060] In some embodiments, the other end of the tension spring of the moving contact assembly is connected to a tension spring spindle arranged on the first housing.

[0061] In some embodiments, the moving contact assembly further comprises a bracket quick-closing cooperating portion.

[0062] In some embodiments, the bracket quick-closing cooperating portion is located between the first branch and the second branch.

[00631 In some embodiments, the bracket quick-closing cooperating portion is configured to cooperate with a quick-closing structure arranged inside the first housing, so

that, during a closing process of the moving contact assembly, the quick-closing structure

applies a force on the bracket quick-closing cooperating portion to accelerate closing of the moving contact assembly.

[0064] In some embodiments, the bracket quick-closing cooperating portion is provided with a bracket spacing cooperating surface;

[0065] In some embodiments, the center plate spacing stopper is configured to cooperate with the bracket spacing cooperating surface, so as to control the spacing between the moving contact assembly and the stationary contact assembly.

[0066] In some embodiments, the first housing is provided with a driving torsion spring fitting convex column.

[0067] In some embodiments, the driving torsion spring fitting convex column is provided with a fitting convex column blind hole.

[0068] In some embodiments, the center plate second supporting shaft is rotatably inserted into the fitting convex column blind hole.

[0069] In some embodiments, a driving torsion spring is sleeved on an outer surface of the driving torsion spring fitting convex column.

[0070] In some embodiments, one end of the driving torsion spring is configured to act on the driving torsion spring housing limiting rib arranged in the first housing.

[0071] In some embodiments, upon the moving contact assembly being in the on position, the other end of the driving torsion spring is not in contact with the tripping sensor,

but in contact with a rib of the first housing.

[0072] In some embodiments, during a movement of the mechanism assembly from the on position to the off position, a sensor convex column of the tripping sensor acts on the

other end of the driving torsion spring.

[0073] In some embodiments, the tripping hook is provided with a tripping hook torsion spring limiting portion.

[0074] In some embodiments, the tripping plate is provided with a tripping plate torsion spring limiting portion.

[0075] In some embodiments, a tripping torsion spring is sleeved on an outer surface of the tripping plate convex column of the tripping plate.

[0076] In some embodiments, one end of the tripping torsion spring is connected to the tripping plate torsion spring limiting portion.

[0077] In some embodiments, the other end of the tripping torsion spring acts on the tripping hook torsion spring limiting portion.

[0078] In some embodiments, during the movement of the mechanism assembly from the on position to the off position, the tripping torsion spring is configured to apply a force to

keep the tripping hook locking surface in contact with the tripping plate locking surface.

[0079] In some embodiments, the DC circuit breaker further comprises a front panel and a fault indicator.

[0080] In some embodiments, the front panel is provided with a fault display window.

[0081] In some embodiments, the front panel is connected to the first housing and the second housing by panel connection slots arranged in the first housing and the second housing.

[0082] In some embodiments, the fault indicator is configured to slide relative to the first housing and the second housing by cooperating with fault connection slots arranged in the first housing and the second housing.

[0083] In some embodiments, the front panel is configured to cover the fault indicator.

[0084] In some embodiments, the tripping hook is provided with a tripping hook fault stopper.

[0085] In some embodiments, the center plate is provided with a center plate fault stopper.

[0086] In some embodiments, the fault indicator is provided with an indicator tongue.

[0087] In some embodiments, in a normal working state of the DC circuit breaker, neither the tripping hook fault stopper nor the center plate fault stopper pushes the indicator

tongue.

'7

[00881 In some embodiments, upon the DC circuit breaker having a magnetic fault or a thermal fault, the tripping hook fault stopper pushes the indicator tongue, so that the fault

indicator appears in a fault display window.

[00891 In some embodiments, upon the magnetic fault or the thermal fault of the DC circuit breaker being eliminated, the center plate fault stopper pushes the indicator tongue, so

that the fault indicator no longer appears in the fault display window.

[0090] In some embodiments, the quick-closing structure comprises a closing cam which is rotatably installed relative to the first housing and a closing cam return spring.

[0091] In some embodiments, the closing cam comprises a cam cooperating portion having an arc surface and a cam concave portion.

[0092] In some embodiments, the closing cam return spring is sleeved on the tension spring spindle.

[0093] In some embodiments, one end of the closing cam return spring acts on the first housing.

[0094] In some embodiments, the other end of the closing cam return spring is abutted and fitted in the cam concave portion.

[0095] In some embodiments, according to the above aspects of the present disclosure, the bracket quick-closing cooperating portion of the moving contact assembly of the DC

circuit breaker comprises a first cooperating surface and a second cooperating surface.

[0096] In some embodiments, the first cooperating surface and the second cooperating surface are connected together through a bracket circular arc surface.

[0097] In some embodiments, upon the moving contact assembly of the DC circuit breaker being in the on position relative to the stationary contact assembly of the DC circuit

breaker, under an action of the closing cam return spring, the closing cam abuts against an inner surface of the first housing, and a circular arc surface of the cam cooperating portion is

not in contact with the first cooperating surface.

[0098] In some embodiments, during the movement of the moving contact assembly from the on position to the off position relative to the stationary contact assembly, the first

cooperating surface is in frictional contact with the circular arc surface of the cam

cooperating portion and a contact position between the first cooperating surface and the

Q circular arc surface of the cam cooperating portion changes with a rotation of the moving contact assembly, and the frictional contact slows down a closing movement of the moving contact assembly.

[0099] In some embodiments, upon the circular arc surface of the cam cooperating portion being out of contact with the first cooperating surface and coming into contact with

the bracket circular arc surface, the force applied by the moving contact assembly to the

closing cam causes the closing cam to press the first housing.

[00100] In some embodiments, upon the circular arc surface of the cam cooperating portion being out of contact with the bracket circular arc surface, under an action of torque

generated by the pressure of the bracket circular arc surface, the closing cam quickly hits the second cooperating surface, so that the moving contact assembly quickly reaches the off

position, and the closing cam return spring is in a compressed state at this time.

[00101] In some embodiments, with a continuous closing action of the operating handle of the DC circuit breaker, the circular arc surface of the cam cooperating portion rests

on the second matching surface.

[00102] In the DC circuit breaker according to the present disclosure, the mechanism uses a double moving contact point series structure such that the contact points are quickly

opened under the action of a tension spring, the electric arc is lengthened twice, and the

current limiting ability meets the breaking requirements.

[001031 In the DC circuit breaker according to the present disclosure, the moving shaft of the moving contact assembly is designed on the center plate which moves around a fixed axis, and the tripping force can meet the requirements by adjusting the force arm of the

tension spring to the moving shaft and the force arm of the moving shaft to the first

supporting shaft and the second supporting shaft of the center plate. Under the action of tension spring, the moving contact opens at a high speed.

[00104] In order to reduce the tripping force and increase the releasing force, a driving torsion spring and its special working state are designed in the DC circuit breaker according to the present disclosure: the driving torsion spring is initially installed on the first housing,

and upon the product being closed to a certain angle, the tripping sensor is in contact with one

end of the driving torsion spring, and the driving torsion spring acts on the first housing and

a the tripping sensor until the product is completely closed, and the force of the driving torsion spring is designed to ensure that the closing process of the product does not slip. Upon the product being opened, the driving torsion spring always acts on the tripping sensor before the other pole or accessory trips, which plays the function of increasing the releasing force of the product, and reducing the tripping force.

[00105] The DC circuit breaker according to the disclosure meets the requirements of high contact pressure and low tripping force, and ensures the reliable tripping of the product under the influence of pollutants such as dust after breaking short-circuit current.

[00106] In the DC circuit breaker according to the present disclosure, because the quick-closing structure is not installed on the operating handle, the quick-closing structure and the functional surface of the moving contact assembly will not occupy the space of the

magnetic assembly, which can give more space for the design of the magnetic assembly size,

element arrangement and the like, so as to meet the requirements of the product for high breaking performance.

[00107] The quick-closing structure according to the present disclosure requires less space and saves space. The moving contact point assembly always moves when realizing the quick-closing function, thereby reducing the friction force of the working face and lowering

the material strength requirement. The quick-closing function increases the releasing force of

products and reliably drives multipolar products and accessory products. The quick-closing structure according to the present disclosure is easy to assemble, simple in structure and

reliable in performance. Fast closing can effectively reduce contact ablation and prolong service life.

[00108] So far, in order that the detailed description of the disclosure here can be better understood, and in order that the contribution of the disclosure to the existing art can be better recognized, the disclosure has outlined the content of the disclosure quite extensively. Of

course, embodiments of the present disclosure will be described below and will form the

subject of the appended claims.

[00109] Likewise, those skilled in the art will recognize that the concept on which the present disclosure is based can easily be used as a basis for designing other structures,

methods and systems for carrying out several purposes of the present disclosure. Therefore, it

1n is important that the appended claims should be regarded as including such equivalent structures as long as they do not go beyond the spirit and scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

[00110] Those skilled in the art will have a better understanding of the present disclosure through the following drawings, and the advantages of the present disclosure can

be more clearly reflected. The drawings described here are only for illustrative purposes of selected embodiments, not all possible embodiments, and are intended not to limit the scope

of the present disclosure.

[00111] Fig. 1 shows an interior of a DC circuit breaker according to the present disclosure, wherein the mechanism assembly is in the on position;

[00112] Fig. 2 shows an interior of a DC circuit breaker according to the present disclosure, wherein the mechanism assembly is in the off position;

[001131 Fig. 3 shows relative positions of an operating handle, a handle connecting rod and a moving contact assembly in an open state according to the present disclosure;

[00114] Fig. 4 shows relative positions of an operating handle, a handle connecting rod and a moving contact assembly in a closed state according to the present disclosure;

[00115] Fig. 5 and Fig. 6 illustrate a center plate according to the present disclosure;

[00116] Fig. 7 and Fig. 8 illustrate a tripping hook according to the present disclosure;

[00117] Fig. 9 and Fig. 10 illustrate a tripping plate according to the present disclosure;

[00118] Fig. 11 and Fig. 12 illustrate a moving contact assembly according to the present disclosure;

[00119] Fig. 13 and Fig. 14 illustrate a tripping sensor according to the present disclosure;

[00120] Fig. 15 shows a moving contact assembly, a tension spring and a moving contact assembly according to the present disclosure;

[00121] Fig. 16 and Fig. 17 show a relative positional relationship between a center plate and a moving contact assembly in the open state and the closed state, respectively;

[00122] Fig. 18 and Fig. 19 show a relative positional relationship of a center plate, a tripping plate and a moving contact assembly in an open state and a closed state, respectively;

1 1

[00123] Fig. 20 and Fig. 21 show a relative positional relationship of a center plate, a tripping hook, a tripping plate and a moving contact assembly in an open state and a closed

state, respectively;

[00124] Fig. 22 and Fig. 23 show a relative positional relationship of a center plate, a tripping plate and a moving contact assembly in an open state and a closed state, respectively,

especially show cooperating surfaces of the tripping hook and the tripping plate;

[00125] Fig. 24 and Fig. 25 show a relative positional relationship of a center plate, a tripping sensor and a moving contact assembly in an open state and a closed state in a plan side view, respectively;

[00126] Fig. 26 and Fig. 27 are perspective views showing a relative positional relationships of a center plate, a tripping hook, a tripping plate, a tripping sensor and a

moving contact assembly in an open state and a closed state, respectively;

[00127] Fig. 28 and Fig. 29 show states of a driving torsion spring and a handle return spring in an open state and a closed state, respectively;

[00128] Fig. 30 and Fig. 31 illustrate a front panel according to the present disclosure;

[00129] Fig. 32 and Fig. 33 illustrate a fault indicator according to the present disclosure;

[00130] Fig. 34 shows a panel connection slot and a fault connection slot provided on a first housing and a second housing according to the present disclosure;

[00131] Fig. 35 shows a cooperation of a fault indicator with a first housing according to the present disclosure;

[00132] Fig. 36 shows relative positions of a quick-closing assembly and a moving contact assembly in an open state according to the present disclosure;

[00133] Fig. 37 shows relative positions of a quick-closing assembly and a moving contact assembly in a closed state according to the present disclosure; and

[00134] Fig. 38 shows an internal structure of a first housing according to the present disclosure.

DETAILED DESCRIPTION

[00135] Hereinafter, specific embodiments according to the present disclosure will

1) be described in detail with reference to Figs. 1 to 37.

[001361 As illustrated by Fig. 1 and Fig. 2, an embodiment of the present disclosure provides a DC circuit breaker 1, which includes a first housing 2 and a second housing 3

(referring to Fig. 34). The first housing 2 and the second housing 3 jointly define an accommodation space, in which a stationary contact assembly 4 and a mechanism

assembly 5 are arranged, and the mechanism assembly 5 is able to move between an on

position (as illustrated by Fig. 1, that is, an open state) and an off position (as illustrated by Fig. 2, that is, an off state).

[00137] Fig. 1 and Fig. 3 do not show a magnetic assembly, and Fig. 2 and Fig. 4 show a magnetic assembly. The first housing 2 is not shown in Fig. 3 and Fig. 4.

[00138] The mechanism assembly 5 includes a center plate 6 and a moving contact assembly 7.

[00139] The center plate 6 is rotatably supported, at both sides of the center plate, by the first housing 2 and the second housing 3 at both sides of the center plate 6 respectively.

[00140] The moving contact assembly 7 is rotatably installed on the center plate 6 through a moving shaft 8 (see Fig. 17) arranged on the center plate 6.

[00141] During the rotation of the center plate 6 relative to the first housing 2 and the second housing 3, the moving contact assembly 7 is able to rotate relative to the center

plate 6.

[00142] An elastic component of the mechanism assembly acts between the moving contact assembly 7 and the first housing 2.

[00143] According to the above embodiment of the present disclosure, the mechanism assembly 5 further includes a moving contact point assembly 9.

[00144] The moving contact point assembly 9 has a U shape.

[00145] As illustrated by Fig. 15, two moving contact points 9-1 are connected in series by the moving contact point assembly 9 having a U shape.

[00146] The moving contact point assembly 9 is connected to the moving contact assembly 7 by a fastener 9-3.

[00147] According to the above embodiments of the present disclosure, the DC circuit breaker 1 further includes an operating handle 10, a handle connecting rod 11 and a

1 2 handle return spring 12.

[00148] The operating handle 10 rotates around a handle shaft 13 provided on the first housing 2.

[00149] The handle return spring 12 is sleeved on the handle shaft 13.

[00150] During the movement of the operating handle 10, one end of the handle return spring 12 acts on a handle spring limiting rib (not shown) on the first housing 2, and

the other end of the handle return spring 12 always acts on the operating handle 10.

[00151] One end of the handle connecting rod 11 is connected to the operation handle 10.

[00152] The other end of the handle connecting rod 11 is connected to the mechanism assembly 5.

[001531 According to the above embodiments of the present disclosure, as illustrated by Figs. 7 and 8, the mechanism assembly 5 further includes a tripping hook 14.

[00154] The tripping hook 14 is provided with a tripping hook through-hole 14-1, a tripping hook through-hole groove 14-2, a tripping hook torsion spring limiting portion

14-3 and a tripping hook notch 14-4.

[00155] The other end of the handle connecting rod 11 passes through the tripping hook through-hole groove 14-2.

[00156] The center plate 6 is provided with a center plate first shaft 6-1 and a center plate first stopper 6-2.

[00157] The tripping hook 14 is rotatably installed on the center plate 6 through the cooperation of the center plate first shaft 6-1 and the tripping hook through-hole 14-1.

[00158] The center plate first stop 6-2 is able to be fitted in the tripping hook notch 14-4.

[00159] According to the above embodiments of the present disclosure, the center plate 6 is further provided with a center plate blind groove 6-3.

[00160] The other end of the handle connecting rod 11 passing through the tripping hook through-hole groove 14-2 is fitted in the center plate blind groove 6-3.

[00161] According to the above embodiments of the present disclosure, as illustrated by Figs. 5 and 6, the center plate 6 includes a center plate base 6-4, and a first branch 6-5

1A and a second branch 6-6 extending from the center plate base 6-4.

[00162] The first branch 6-5 and the second branch 6-6 are parallel to each other and spaced apart.

[001631 According to the above embodiments of the present disclosure, the center plate first shaft 6-1, the center plate first stopper 6-2 and the center plate blind groove 6-3

are arranged on the first branch 6-5.

[00164] The first branch 6-5 is further provided with a center plate first supporting shaft 6-7.

[00165] The second branch 6-6 is provided with a center plate second supporting shaft 6-8.

[001661 The center plate first supporting shaft 6-7 and the center plate second supporting shaft 6-8 are coaxially arranged.

[00167] The moving shaft 8 is connected between the first branch 6-5 and the second branch 6-6.

[001681 The center plate 6 is rotatably supported on the second housing 3 and the first housing 2 by the center plate first supporting shaft 6-7 and the center plate second

supporting shaft 6-8, respectively.

[001691 According to the above embodiments of the present disclosure, a center plate spacing stopper 6-6-1 is arranged on a side of the second branch 6-6 facing the first branch 6-5.

[00170] The center plate spacing stopper 6-6-1 cooperates with the moving contact assembly 7, thereby controlling the spacing between the mechanism assembly 5 (moving

contact point) and the stationary contact assembly 4 (stationary contact point).

[00171] According to the above embodiments of the present disclosure, the first branch 6-5 is further provided with a first branch tripping plate supporting shaft 6-9.

[00172] The second branch 6-6 is further provided with a second branch tripping sensor supporting shaft 6-10.

[001731 The first branch tripping plate supporting shaft 6-9 and the second branch tripping sensor supporting shaft 6-10 are coaxially arranged.

[00174] According to the above embodiments of the present disclosure, the

1CI~ mechanism assembly 5 further includes a tripping plate 15 (as illustrated by Fig. 9 and Fig. ) and a tripping sensor 16 (as illustrated by Fig. 13 and Fig. 14).

[00175] The tripping plate 15 is provided with a tripping plate slot 15-1.

[00176] One end of the tripping sensor 16 is provided with a tripping sensor hook 16-1.

[00177] The tripping sensor hook 16-1 is fitted in the tripping plate slot 15-1, so that the tripping sensor 16 and the tripping plate 15 are connected together.

[00178] According to the above-mentioned embodiments of the present disclosure, a tripping plate convex column 15-2 is further provided on the tripping plate 15.

[00179] A convex column through-hole 15-2-1 is arranged in the tripping plate convex column 15-2.

[00180] The first branch tripping plate supporting shaft 6-9 passes through the convex column through-hole 15-2-1 and is fitted in the convex column through-hole 15-2-1, so that the tripping plate 15 is able to rotate relative to the center plate 6.

[00181] According to the above embodiments of the present disclosure, the other end of the tripping sensor 16 is provided with a sensor through-hole 16-2 and a sensor convex column 16-3.

[00182] The second branch tripping sensor supporting shaft 6-10 passes through the sensor through-hole 16-2 and is fitted in the sensor through-hole 16-2, so that the tripping sensor 16 and the tripping plate 15 can integrally rotate relative to the center plate 6.

[00183] According to the above-mentioned embodiments of the present disclosure, as illustrated by Figs. 22 and 23, a tripping plate locking surface 15-3 is further provided on

the tripping plate 15.

[00184] The tripping hook 14 is provided with a tripping hook locking surface 14-5.

[00185] Upon the mechanism assembly 5 being in the on position, as illustrated by Fig. 22, the tripping hook locking surface 14-5 is not in contact with the tripping plate

locking surface 15-3.

[00186] During the movement of the mechanism assembly 5 from the on position to the off position, the tripping hook locking surface 14-5 comes into contact with the tripping

plate locking surface 15-3, as illustrated by Fig. 23.

1A

[001871 Upon the mechanism assembly 5 being in the off position, the tripping hook locking surface 14-5 keeps in contact with the tripping plate locking surface 15-3.

[00188] According to the above embodiments of the present disclosure, as illustrated by Figs. 15 and 16, the moving contact assembly 7 includes a bracket skirt portion 7-1, a

bracket connecting portion 7-2 and a bracket tension spring connecting portion 7-3 (these

three portions constitute a movable contact bracket).

[00189] The bracket connecting portion 7-2 and the bracket tension spring connecting portion 7-3 are located between the first branch 6-5 and the second branch 6-6.

[00190] The moving contact point assembly 9 is partially arranged in the bracket skirt portion 7-1.

[00191] The bracket connecting portion 7-2 is provided with a connecting portion through-hole 7-2-1, and the moving shaft 8 passes through the connecting portion

through-hole 7-2-1.

[00192] The elastic component includes but is not limited to a tension spring 17. One end of the tension spring 17 of the mechanism assembly 5 is connected to the bracket

tension spring connecting portion 7-3.

[00193] The other end of the tension spring 17 of the mechanism assembly 5 is connected to a tension spring spindle 18 arranged on the first housing 2.

[00194] According to the above-mentioned embodiments of the present disclosure, the moving contact assembly 7 further includes a bracket quick-closing cooperating portion

7-4.

[00195] The bracket quick-closing fitting 7-4 is located between the first branch 6-5 and the second branch6-6.

[00196] The bracket quick-closing cooperating portion 7-4 is configured to cooperates with a quick-closing structure arranged inside the first housing 2, so that, during

a closing process of the mechanism assembly 5, the quick-closing structure applies a force on the bracket quick-closing cooperating portion 7-4 to accelerate the closing of the

mechanism assembly 5.

[00197] According to the above embodiments of the present disclosure, the bracket quick-closing cooperating portion 7-4 is provided with a bracket spacing cooperating

1'7 surface 7-4-1.

[00198] The center plate spacing stopper 6-6-1 is configured to cooperate with the bracket spacing cooperating surface 7-4-1, so as to control the spacing between the

mechanism assembly 5 and the stationary contact assembly 4.

[00199] According to the above embodiments of the present disclosure, as illustrated by Fig. 38, the first housing 2 is provided with a driving torsion spring fitting convex

column 2-1.

[00200] The driving torsion spring fitting convex column 2-1 is provided with a fitting convex column blind hole 2-1-1.

[00201] The center plate second supporting shaft 6-8 is rotatably inserted into the fitting convex column blind hole 2-1-1.

[00202] As illustrated by Fig. 28, a driving torsion spring 19 is sleeved on the outer surface of the driving torsion spring fitting convex column 2-1.

[00203] One end of the driving torsion spring 19 acts on the driving torsion spring housing limiting rib arranged in the first housing 2.

[00204] Upon the mechanism assembly 5 being in the on position, the other end of the driving torsion spring 19 is not in contact with the tripping sensor 16, as illustrated by

Fig. 28.

[00205] During the movement of the mechanism assembly 5 from the on position to the off position, the sensor convex column 16-3 of the tripping sensor 16 acts on the other

end of the driving torsion spring 19, as illustrated by Fig. 29.

[00206] According to the above embodiments of the present disclosure, the tripping hook 14 is provided with a tripping hook torsion spring limiting portion 14-3.

[00207] The tripping plate 15 is provided with a tripping plate torsion spring limiting portion 15-4.

[00208] A tripping torsion spring 20 is sleeved on the outer surface of the tripping plate convex column 15-2 of the tripping plate 15.

[00209] One end of the tripping torsion spring 20 is connected to the tripping plate torsion spring limiting portion 15-4.

[00210] The other end of the tripping torsion spring 20 acts on the tripping hook

1Q torsion spring limit portion 14-3.

[00211] During the movement of the mechanism assembly 5 from the on position to the off position, the force applied by the tripping torsion spring 20 keeps the tripping hook

locking surface 14-5 in contact with the tripping plate locking surface 15-3.

[00212] According to the above embodiments of the present disclosure, as illustrated by Figs. 30 to 35, the DC circuit breaker further includes a front panel 21 and a fault

indicator 22.

[00213] The front panel 21 is provided with a fault display window 21-1.

[00214] The front panel 21 is connected to the first housing 2 and the second housing 3 through panel connection slots 23 arranged in the first housing 2 and the second housing 3.

[00215] The fault indicator 22 is able to slide relative to the first housing 2 and the second housing 3 by (for example, through its elastic arm 22-2) fitting with fault connecting slots 24 arranged in the first housing 2 and the second housing 3.

[00216] The front panel 21 covers the fault indicator 22.

[00217] According to the above embodiments of the present disclosure, the tripping hook 14 is provided with a tripping hook fault stopper 14-6.

[00218] The center plate 6 is provided with a center plate fault stopper 6-11.

[00219] The fault indicator 22 is provided with an indicator tongue 22-1.

[00220] In the normal working state of the DC circuit breaker 1, neither the tripping hook fault stopper 14-6 nor the center plate fault stopper 6-11 pushes the indicator tongue 22-1.

[00221] Upon the DC circuit breaker 1 having a magnetic fault or a thermal fault, the tripping hook fault stopper 14-6 pushes the indicator tongue 22-1, so that the fault indicator 22 appears in the fault display window 21-1.

[00222] Upon the magnetic fault or thermal fault of the DC circuit breaker 1 being eliminated, the center plate fault stopper 6-11 pushes the indicator tongue 22-1, so that the fault indicator 22 no longer appears in the fault display window 21-1.

[00223] According to the above-mentioned embodiments of the present disclosure, as illustrated by Figs. 36 and 37, the quick-closing structure includes a closing cam 25 which is rotatably installed relative to the first housing 2 and a closing cam return spring 26.

[00224] The closing cam 25 includes a cam cooperating portion 25-1 having a circular arc surface and a cam concave portion 25-2.

[00225] The closing cam return spring 26 is sleeved on the tension spring spindle 18.

[00226] One end of the closing cam return spring 26 acts on the first housing 2.

[00227] The other end of the closing cam return spring 26 is abutted and fitted in the cam concave portion 25-2.

[00228] According to the above embodiments of the present disclosure, as illustrated by Figs. 11 and 12, the bracket quick-closing cooperating portion 7-4 of the moving contact assembly 7 of the DC circuit breaker 1 includes a first cooperating surface 7-4-2 and a

second cooperating surface 7-4-3.

[00229] The first cooperating surface 7-4-2 and the second cooperating surface 7-4-3 are connected together through a bracket circular arc surface 7-4-4.

[00230] According to the above embodiments of the present disclosure, upon the mechanism assembly 5 of the DC circuit breaker 1 being in the on position relative to the stationary contact assembly 4 of the DC circuit breaker 1, the closing cam 25 abuts against

an inner surface of the first housing 2 under the action of the closing cam return spring 26,

and the circular arc surface of the cam cooperating portion 25-1 is not in contact with the first cooperating surface 7-4-2, as illustrated by Fig. 36.

[00231] During the movement of the mechanism assembly 5 from the on position to the off position relative to the stationary contact assembly 4, the first cooperating surface

7-4-2 is in frictional contact with the circular arc surface of the cam cooperating portion

-1 and the contact position between the first cooperating surface and the circular arc surface of the cam cooperating portion changes with the rotation of the moving contact

assembly 7, and the the frictional contact slows down the closing movement of the

mechanism assembly 5.

[00232] Upon the circular arc surface of the cam cooperating portion 25-1 being out of contact with the first cooperating surface 7-4-2 and coming into contact with the bracket

circular arc surface 7-4-4, the force applied by the moving contact assembly 7 to the

InA closing cam 25 causes the closing cam 25 to press the first housing 2.

[00233] Upon the circular arc surface of the cam cooperating portion 25-1 being out of contact with the bracket circular arc surface 7-4-4, under an action of torque generated

by the pressure of the bracket circular arc surface 7-4-4, the closing cam 25 quickly hits the second cooperating surface 7-4-3, so that the mechanism assembly 5 can quickly reach the

off position, and the closing cam return spring 28 is in a compressed state.

[00234] With the continuous closing action of the operating handle 10 of the DC circuit breaker 1, the circular arc surface of the cam cooperating portion 25-1 rests on the

second cooperating surface 7-4-3, as illustrated by Fig. 37.

[00235] As illustrated by Figs. 18 to 27, when the DC circuit breaker according to the present disclosure is in the open state and the closed state:

[00236] 1. One end of the driving torsion spring 19 acts on the driving torsion spring housing limiting rib of the first housing 2, while the other end of the driving torsion spring 19 is not in contact with the tripping sensor 16.

[00237] 2. The tripping hook 14 and the tripping plate 15 are respectively installed on two posts of the center plate 6. One end of the handle connecting rod 11 is connected with the operating handle 10, and the other end of the handle connecting rod 11 is

connected with the tripping hook (tripping hook through-hole slot 14-2) and the center

plate (center plate blind slot 6-3).

[00238] 3. In the open state, the operating handle 10 is in contact with a rib on the first housing 2, and the center plate 6 is in contact with a rib on the second housing 2. One end of the tripping torsion spring 20 is connected with the tripping plate 15, and the other

end of the tripping torsion spring 20 is connected with the tripping hook 14. The tripping

torsion spring 20 is configured to make the tripping hook locking surface 14-5 of the tripping hook 14 contact with the tripping plate locking surface 15-3 of the tripping plate

during the closing process of the DC circuit breaker after the tripping plate 15 is tripped.

[00239] 4. Upon the DC circuit breaker being open, the tripping hook locking surface 14-5 of the tripping hook 14 is not in contact with the tripping plate locking surface

-3 of the tripping plate 15.

[00240] 5. The tripping plate 15 is provided with a tripping plate slot 15-1; one end

)1 of the tripping sensor 16 is provided with a tripping sensor hook 16-1; the tripping sensor hook 16-1 is fitted in the tripping plate slot 15-1, so that the tripping sensor 16 and the tripping plate 15 are connected together. The first branch 6-5 is further provided with a first branch tripping plate supporting shaft 6-9; the second branch 6-6 is further provided with a second branch tripping sensor supporting shaft 6-10; the first branch tripping plate supporting shaft 6-9 and the second branch tripping sensor supporting shaft 6-10 are coaxially arranged; the tripping sensor 16 and the tripping plate 15 can integrally rotate relative to the center plate 6.

[00241] 6. One end of the tension spring 17 of the mechanism assembly 5 is connected to the bracket tension spring connecting portion 7-3; the other end of the tension spring 17 of the mechanism assembly 5 is connected to the tension spring spindle 18

arranged on the first housing 2.

[00242] 7. The spacing is controlled by the structural features of the center plate 6 and of the moving contact assembly 7 and the moving contact assembly 7 is connected to the center plate 6 through the moving shaft 8. The moving shaft 8 is tightly connected with

the center plate 6, and the moving shaft 8 is in clearance fit with the moving contact assembly 7, so that the moving contact assembly 7 is able to rotate around the moving shaft

8.

[00243] 8. The quick-closing structure is assembled by the shaft 29 assembled on the first housing 2, and the tension spring 17 is assembled by the tension spring spindle 18

assembled on the first housing. The closing cam return spring 26 is installed below the tension spring spindle 18.

[00244] 9. The two contact points 9-1 are welded on the moving contact point assembly 9, for example, the two contacts 9-1 are riveted with the moving contact

assembly 7 through copper rivets, but are not limited thereto, so as to meet the requirements of high breaking performance of the product.

[00245] In the closing process, as illustrated by Figs. 1 to 2, the operating handle 10 rotates clockwise, and the handle connecting rod 11 is in contact with the tripping hook

through-hole groove 14-2 of the tripping hook and the center plate blind groove 6-3 of the

center plate 6. The tripping hook locking surface 14-5 of the tripping hook 14 is in contact

1) with the tripping plate locking surface 15-3 of the tripping plate 15. Upon the operating handle 10 being rotated by a certain angle, the driving torsion spring contacts the tripping sensor.

[00246] Before the quick-closing, the operating handle, the handle connecting rod, the tripping hook, the tripping plate, the center plate and the moving contact assembly move together. Upon the quick-closing starting, the operating handle, the handle

connecting rod, the tripping hook, the tripping plate and the center plate move together, while the moving contact assembly moves around the center plate at a slower speed. After

the quick closure is realized, the product is closed.

[00247] If there is no quick-closing function, the operating handle, the handle connecting rod, the tripping hook, the tripping plate, the center plate and the moving

contact assembly move together at the beginning. After the moving contact is closed,

before the product is closed, the operating handle, the handle connecting rod, the tripping hook, the tripping plate and the center plate move together, and the moving contact

assembly rotates around the moving shaft and the moving contact slides on the stationary

contact.

[00248] In the opening process, the operating handle rotates counterclockwise, and the moving contact assembly rotates around the moving shaft under the force of the tension

spring, and is in contact with the features controlling the spacing. Subsequently, the whole mechanism moves counterclockwise together under the action of the handle return spring,

and the product is opened.

[00249] The foregoing disclosure provides illustration and description, but it is not intended to be exhaustive or to limit the embodiments to the precise forms disclosed.

Modifications and changes can be made according to the above disclosure, or can be acquired from the practice of the embodiments.

[00250] Even though specific combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various embodiments. In fact, many of these features can be combined in

ways not specifically described in the claims and/or not specifically disclosed in the

specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of various embodiments includes each dependent claim combined with each other claim in the claim set.

[00251] Unless explicitly stated, any element, action or instruction used herein should not be interpreted as critical or necessary. In addition, as used herein, the terms "a"

and "an" are intended to include one or more items and can be used interchangeably with "one or more". In addition, as used herein, the term "the" is intended to include one or

more items cited in conjunction with the article "the" and can be used interchangeably with "one or more". In addition, as used herein, the term "set" is intended to include one or more

items (such as related items, unrelated items, a combination of related and unrelated items,

etc.), and can be used interchangeably with "one or more". If only one item is intended, use the phrase "only one item" or similar language. In addition, as used herein, the term "has"

and its variants are intended to be open-ended terms. In addition, the phrase "based on" is

intended to mean "at least partly based on", unless explicitly stated otherwise. In addition, as used herein, the term "or" is intended to be inclusive when used in series, and can be

used interchangeably with "and/or", unless otherwise explicitly stated (for example, if used

in combination with "or" or "one of them").

[00252] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that such prior art forms part of the

common general knowledge.

[002531 It will be understood that the terms "comprise" and "include" and any of their derivatives (e.g. comprises, comprising, includes, including) as used in this specification, and the claims that follow, is to be taken to be inclusive of features to which the term refers, and

is not meant to exclude the presence of any additional features unless otherwise stated or

implied.

Claims (23)

1. A DC circuit breaker, comprising a first housing and a second housing, wherein the

first housing and the second housing jointly define an accommodation space, and a stationary contact assembly and a mechanism assembly are arranged in the accommodation

space, the mechanism assembly being able to move between an on position and an off

position, characterized in that: the mechanism assembly comprises a center plate and a moving contact assembly;

the center plate is rotatably supported, at both sides of the center plate, by the first

housing and the second housing respectively.; the moving contact assembly is rotatably installed on the center plate by a moving shaft

arranged on the center plate; the moving contact assembly is configured to rotate relative to the center plate during a

rotation of the center plate relative to the first housing and the second housing; and

an elastic component of the mechanism assembly is configured to act between the

moving contact assembly and the first housing.

2. The DC circuit breaker according to claim 1, characterized in that: the moving contact assembly comprises a moving contact point assembly; the moving contact point assembly is U-shaped;

two moving contact points are connected in series by the U-shaped moving contact point assembly; the moving contact point assembly is connected to the moving contact assembly by a

fastener.

3. The DC circuit breaker according to claim 2, characterized in that:

the DC circuit breaker further comprises an operating handle, a handle connecting rod and a handle return spring,

wherein the operating handle is configured to rotate around a handle shaft arranged on

the first housing; wherein the handle return spring is sleeved on the handle shaft; wherein during a movement of the operating handle, one end of the handle return spring acts on a handle spring limiting rib on the first housing, and the other end of the handle return spring always acts on the operating handle; wherein one end of the handle connecting rod is connected to the operating handle and the other end of the handle connecting rod is connected to the mechanism assembly.

4. The DC circuit breaker according to claim 3, characterized in that:

the mechanism component further comprises a tripping hook;

the tripping hook is provided with a tripping hook through-hole, a tripping hook through-hole groove, a tripping hook torsion spring limiting portion and a tripping hook

notch;

the other end of the handle connecting rod passes through the tripping hook through-hole groove;

a center plate first shaft and a center plate first stopper are arranged on the center plate;

the tripping hook is rotatably installed on the center plate through a cooperation of the center plate first shaft and the tripping hook through-hole; and

the center plate first stopper is configured to be fitted in the tripping hook notch.

5. The DC circuit breaker according to claim 4, characterized in that:

the center plate is further provided with a center plate blind groove; and the other end of the handle connecting rod passing through the tripping hook

through-hole groove is fitted in the center plate blind groove.

6. The DC circuit breaker according to claim 5, characterized in that:

the center plate comprises a center plate base, and a first branch and a second branch

extending from the center plate base; and the first branch and the second branch are parallel to each other and spaced apart.

7. The DC circuit breaker according to claim 6, characterized in that: the center plate first shaft, the center plate first stopper and the center plate blind groove are arranged on the first branch; the first branch is further provided with a center plate first supporting shaft; the second branch is provided with a center plate second supporting shaft; the center plate first supporting shaft and the center plate second supporting shaft are coaxially arranged; the moving shaft is connected between the first branch and the second branch; and the center plate is rotatably supported on the second housing and the first housing by the center plate first supporting shaft and the center plate second supporting shaft respectively.

8. The DC circuit breaker according to claim 7, characterized in that:

a center plate spacing stopper is arranged on a side of the second branch facing the first

branch; and the center plate spacing stopper is configured to cooperate with the moving contact

assembly to control a spacing between the moving contact assembly and the stationary

contact assembly.

9. The DC circuit breaker according to claim 8, characterized in that:

the first branch is further provided with a first branch tripping plate supporting shaft; the second branch is further provided with a second branch tripping sensor supporting

shaft; and the first branch tripping plate supporting shaft and the second branch tripping sensor

supporting shaft are coaxially arranged.

10. The DC circuit breaker according to claim 9, characterized in that:

the mechanism assembly further comprises a tripping plate and a tripping sensor;

the tripping plate is provided with a tripping plate slot; one end of the tripping sensor is provided with a tripping sensor hook; and

the tripping sensor hook is fitted in the tripping plate slot, so that the tripping sensor and

the tripping plate are connected together.

1"7

11. The DC circuit breaker according to claim 10, characterized in that:

the tripping plate is further provided with a tripping plate convex column;

a convex column through-hole is arranged in the tripping plate convex column; and the first branch tripping plate supporting shaft is configured to pass through the convex

column through-hole and is fitted in the convex column through-hole, so that the tripping

plate is able to rotate relative to the center plate.

12. The DC circuit breaker according to claim 11, characterized in that:

the other end of the tripping sensor is provided with a sensor through-hole and a sensor convex column; and

the second branch tripping sensor supporting shaft is configured to pass through the

sensor through-hole and is fitted in the sensor through-hole, so that the tripping sensor and the tripping plate can integrally rotate relative to the center plate.

13. The DC circuit breaker according to claim 12, characterized in that: the tripping plate is further provided with a tripping plate locking surface;

the tripping hook is provided with a tripping hook locking surface;

upon the mechanism assembly being in the on position, the tripping hook locking surface is not in contact with the tripping plate locking surface;

during a movement of the mechanism assembly from the on position to the off position, the tripping hook locking surface comes into contact with the tripping plate locking surface;

and

upon the mechanism assembly being in the off position, the tripping hook locking surface keeps in contact with the tripping plate locking surface.

14. The DC circuit breaker according to claim 9, characterized in that: the moving contact assembly comprises a bracket skirt portion, a bracket connecting

portion and a bracket tension spring connecting portion;

the bracket connecting portion and the bracket tension spring connecting portion are

IQ9 located between the first branch and the second branch; the moving contact point assembly is partially arranged in the bracket skirt portion; the bracket connecting portion is provided with a connecting portion through-hole, and the moving shaft passes through the connecting portion through-hole; one end of a tension spring of the moving contact assembly is connected to the bracket tension spring connecting portion; the other end of the tension spring of the moving contact assembly is connected to a tension spring spindle arranged on the first housing.

15. The DC circuit breaker according to claim 14, characterized in that: the moving contact assembly further comprises a bracket quick-closing cooperating

portion;

the bracket quick-closing cooperating portion is located between the first branch and the second branch;

the bracket quick-closing cooperating portion is configured to cooperate with a

quick-closing structure arranged inside the first housing, so that, during a closing process of the moving contact assembly, the quick-closing structure applies a force on the bracket

quick-closing cooperating portion to accelerate closing of the moving contact assembly.

16. The DC circuit breaker according to claim 15, characterized in that:

the bracket quick-closing cooperating portion is provided with a bracket spacing cooperating surface; the center plate spacing stopper is configured to cooperate with the bracket spacing

cooperating surface, so as to control the spacing between the moving contact assembly and the stationary contact assembly.

17. The DC circuit breaker according to claim 13, characterized in that: the first housing is provided with a driving torsion spring fitting convex column;

the driving torsion spring fitting convex column is provided with a fitting convex

column blind hole; the center plate second supporting shaft is rotatably inserted into the fitting convex column blind hole; a driving torsion spring is sleeved on an outer surface of the driving torsion spring fitting convex column; one end of the driving torsion spring is configured to act on the driving torsion spring housing limiting rib arranged in the first housing; upon the moving contact assembly being in the on position, the other end of the driving torsion spring is not in contact with the tripping sensor, but in contact with a rib of the first housing; during a movement of the mechanism assembly from the on position to the off position, a sensor convex column of the tripping sensor acts on the other end of the driving torsion spring.

18. The DC circuit breaker according to claim 13, characterized in that:

the tripping hook is provided with a tripping hook torsion spring limiting portion;

the tripping plate is provided with a tripping plate torsion spring limiting portion; a tripping torsion spring is sleeved on an outer surface of the tripping plate convex

column of the tripping plate;

one end of the tripping torsion spring is connected to the tripping plate torsion spring limiting portion;

the other end of the tripping torsion spring acts on the tripping hook torsion spring limiting portion;

during the movement of the mechanism assembly from the on position to the off position,

the tripping torsion spring is configured to apply a force to keep the tripping hook locking surface in contact with the tripping plate locking surface.

19. The DC circuit breaker according to claim 13, characterized in that: the DC circuit breaker further comprises a front panel and a fault indicator;

the front panel is provided with a fault display window;

the front panel is connected to the first housing and the second housing by panel connection slots arranged in the first housing and the second housing; the fault indicator is configured to slide relative to the first housing and the second housing by cooperating with fault connection slots arranged in the first housing and the second housing; and the front panel is configured to cover the fault indicator.

20. The DC circuit breaker according to claim 19, characterized in that: the tripping hook is provided with a tripping hook fault stopper;

the center plate is provided with a center plate fault stopper;

the fault indicator is provided with an indicator tongue; in a normal working state of the DC circuit breaker, neither the tripping hook fault

stopper nor the center plate fault stopper pushes the indicator tongue;

upon the DC circuit breaker having a magnetic fault or a thermal fault, the tripping hook fault stopper pushes the indicator tongue, so that the fault indicator appears in a fault display

window;

upon the magnetic fault or the thermal fault of the DC circuit breaker being eliminated, the center plate fault stopper pushes the indicator tongue, so that the fault indicator no longer

appears in the fault display window.

21. The DC circuit breaker according to claim 15, characterized in that:

the quick-closing structure comprises a closing cam which is rotatably installed relative to the first housing and a closing cam return spring;

the closing cam comprises a cam cooperating portion having an arc surface and a cam

concave portion; the closing cam return spring is sleeved on the tension spring spindle;

one end of the closing cam return spring acts on the first housing; and

the other end of the closing cam return spring is abutted and fitted in the cam concave portion.

22. The DC circuit breaker according to claim 21, characterized in that: the bracket quick-closing cooperating portion of the moving contact assembly of the DC circuit breaker comprises a first cooperating surface and a second cooperating surface; and the first cooperating surface and the second cooperating surface are connected together through a bracket circular arc surface.

23. The quick-closing structure according to claim 22, characterized in that:

upon the moving contact assembly of the DC circuit breaker being in the on position relative to the stationary contact assembly of the DC circuit breaker, under an action of the

closing cam return spring, the closing cam abuts against an inner surface of the first housing,

and a circular arc surface of the cam cooperating portion is not in contact with the first cooperating surface;

during the movement of the moving contact assembly from the on position to the off

position relative to the stationary contact assembly, the first cooperating surface is in frictional contact with the circular arc surface of the cam cooperating portion and a contact

position between the first cooperating surface and the circular arc surface of the cam

cooperating portion changes with a rotation of the moving contact assembly, and the frictional contact slows down a closing movement of the moving contact assembly;

upon the circular arc surface of the cam cooperating portion being out of contact with

the first cooperating surface and coming into contact with the bracket circular arc surface, the force applied by the moving contact assembly to the closing cam causes the closing cam

to press the first housing; upon the circular arc surface of the cam cooperating portion being out of contact with

the bracket circular arc surface, under an action of torque generated by the pressure of the

bracket circular arc surface, the closing cam quickly hits the second cooperating surface, so that the moving contact assembly quickly reaches the off position, and the closing cam

return spring is in a compressed state at this time;

with a continuous closing action of the operating handle of the DC circuit breaker, the circular arc surface of the cam cooperating portion rests on the second matching surface.