EP4117010A1

EP4117010A1 - Miniature circuit breaker

Info

Publication number: EP4117010A1
Application number: EP21765252.8A
Authority: EP
Inventors: Zaiwei CHEN
Original assignee: Zhejiang Chint Electrics Co Ltd
Current assignee: Zhejiang Chint Electrics Co Ltd
Priority date: 2020-03-06
Filing date: 2021-02-12
Publication date: 2023-01-11
Also published as: WO2021175113A1; EP4117010A4; AU2021229961A1; CN113363120A; ZA202208519B; AU2021229961B2

Abstract

A miniature circuit breaker comprises a housing and a handle, wherein an overload protection device and an operating mechanism connected to a moving contact are arranged in the housing; the overload protection device includes a temperature control assembly equipped with a bimetal sheet; an incoming wire connecting terminal connected to the moving contact is arranged on one side, close to the moving contact, inside the housing; a static contact that cooperates with the moving contact is arranged on one side of the moving contact, and the temperature control assembly is arranged on the other side of the moving contact; when overloaded, the temperature control assembly drives a temperature control protection device arranged on the housing to trigger the circuit breaker to trip; the temperature control protection device includes a partition plate and a thermal tripping rod, wherein the partition plate separates the moving contact and the thermal tripping rod in two different planes; and the temperature control assembly includes a bimetal sheet and a current-carrying conductor. When the circuit breaker is overloaded, a movable end of the bimetal sheet drives the thermal tripping rod to rotate to trigger the circuit breaker to trip. According to the miniature circuit breaker of the present invention, the length of the current-carrying conductor of the temperature control assembly is shortened, which reduces the internal resistance and heat generation, thereby avoiding a damage to the parts caused by the overheating of the temperature control assembly.

Description

TECHNICAL FIELD

The present invention relates to the technical field of low-voltage electrical appliances, and more particularly to a miniature circuit breaker.

BACKGROUND ART

For an overload protection device in a low-voltage terminal type miniature circuit breaker, delay calibration characteristics of rated currents of 100A and above are not easily controlled, which is mainly reflected in the inability to take into account the delay calibration time and temperature rise. At present, the most common method used by circuit breakers is to shunt a current of the overload protection device, thereby reducing the influence on the temperature rise of the circuit breaker by reducing the heating of a bimetal component, but the biggest influence of the current shunting on the overload protection device is that the short-delay calibration time is long and relatively discrete, which increases the production efficiency and greatly reduces a qualified rate.

SUMMARY OF THE INVENTION

An objective of the present invention is to overcome the defects of the prior art and provide a miniature circuit breaker with a simple structure and high reliability.
To achieve the above object, the present invention adopts the following technical solution:
A miniature circuit breaker, comprising a housing and a handle arranged on the housing, wherein an overload protection device and an operating mechanism connected to a moving contact are arranged in the housing; the overload protection device comprises a temperature control assembly equipped with a bimetal sheet; an incoming wire connecting terminal connected to the moving contact is arranged on one side, close to the moving contact, inside the housing; a static contact matched with the moving contact is arranged on one side of the moving contact, and the temperature control assembly is arranged on the other side of the moving contact; the overload protection device further comprises a temperature control protection device; when overloaded, the temperature control assembly drives the temperature control protection device arranged on the housing to trigger the circuit breaker to trip; and the temperature control protection device comprises a partition plate and a thermal tripping rod, wherein the thermal tripping rod can be rotated on the partition plate to trigger the circuit breaker to trip; the partition plate separates the moving contact and the thermal tripping rod in two different planes; the temperature control assembly comprises a bimetal sheet and a current-carrying conductor; a fixed end of the bimetal sheet is located on the housing on one side close to the moving contact; the bimetal sheet is connected to the incoming wire connecting terminal through the current-carrying conductor; and when the circuit breaker is overloaded, the bimetal sheet is heated and bent, such that a movable end of the bimetal sheet drives the thermal tripping rod to rotate to trigger the circuit breaker to trip and cut off.
Further, the temperature control assembly further comprises a support on which the bimetal sheet and the current-carrying conductor are fixedly arranged; one end of the support is connected to a fixed end of the bimetal sheet, and the other end of the support forms a bifurcated structure with the movable end of the bimetal sheet; and the other end of the support is used for connection with an adjusting member arranged on one side of the housing.
Further, the partition plate is provided with a first critical point, a second critical point and a limiting portion, wherein the first critical point and the second critical point are used for being in limiting fit with the thermal tripping rod; the middle part of the thermal tripping rod is rotatably mounted on the partition plate; one end of the thermal tripping rod is used as an unlocking end to pass through a gap between the first critical point and the second critical point and to cooperate with an operating mechanism; the other end of the thermal tripping rod is used as a driving end to cooperate with the movable end of the bimetal sheet; and the limiting portion is used for being in limiting fit with the bimetal sheet.
Further, the partition plate is of a right-angled triangle as a whole; a mandrel for the thermal tripping rod to be rotatably mounted is arranged on the upper part of the partition plate; two protrusions are arranged on one side of the mandrel close to the operating mechanism as the first critical point and the second critical point, respectively, wherein the first critical point is located on one side close to the temperature control assembly, and the second critical point is located on one side away from the temperature control assembly; a longitudinal rib is arranged on the partition plate, wherein a groove serving as a limiting portion is formed in the middle of the rib; and the movable end of the bimetal sheet passes through the groove and used for cooperating with the driving end of the thermal tripping rod.
Further, the current-carrying conductor comprises a current-carrying plate, a first flexible conductor and a second flexible conductor; one end of the current-carrying plate is connected to the incoming wire connecting terminal, and the other end of the current-carrying plate is connected to the second flexible conductor; the first flexible conductor is connected to the moving contact; the first flexible conductor is connected to the second flexible conductor; and one end of the first flexible conductor is connected to the bimetal sheet, and the other end of the first flexible conductor is connected to the moving contact.
Further, the middle part of the thermal tripping rod is circular and is used for rotational connection with the partition plate; one end of the thermal tripping rod is used as the driving end to cooperate with the movable end of the bimetal sheet; the end part of the driving end is bluntly rounded; the other end of the thermal tripping rod is used as the unlocking end, and the end part of the other end is bent to one side for triggering the circuit breaker to trip.
Further, the partition plate is of a right-angled triangle as a whole; the thermal tripping rod is rotatably mounted on the upper part of the partition plate; one end of the thermal tripping rod is used as the unlocking end to extend out of the partition plate and to cooperate with the operating mechanism, and the other end of the thermal tripping rod is used as the driving end to be located in the middle of the partition plate; the temperature control assembly comprises a bimetal sheet, a current-carrying conductor and a support, wherein the support is used to fix the current-carrying conductor and the bimetal sheet between the incoming wire connecting terminal and the moving contact; the movable end of the bimetal sheet extends to the driving end on the partition plate for driving the driving end ofthe thermal tripping rod; the support is obliquely arranged along a hypotenuse edge of the partition plate and used for connection with the adjusting member on one side of the housing; and the adjusting member is inclined toward the hypotenuse of the partition plate.
Further, the operating mechanism comprises a contact support, and a jump buckle and a lock catch which are pivotally arranged on the contact support, respectively; the contact support is connected to the moving contact; the jump buckle and one end of the lock catch are lapped and connected to each other; a connecting rod for connection with the handle is arranged at the other end of the jump buckle; and an unlocking portion that cooperates with the thermal tripping rod is arranged at the other end of the lock catch.
Further, the unlocking portion is located at the edge of one side of the lock catch close to the incoming wire connecting terminal; the unlocking portion is of a protruding structure that protrudes from the edge of the lock catch; an arc-striking plate for introducing an electric arc into an arc-extinguishing chamber is also arranged on the current-carrying conductor; and the arc-striking plate and the moving contact are located on the same plane.
Further, the housing is provided with the arc extinguishing chamber inside, wherein the arc extinguishing chamber is located on one side of the moving contact away from the temperature control assembly, and is located below the static contact; and the partition plate is located on one side of the arc extinguishing chamber close to the moving contact.
Compared with the existing scheme, the miniature circuit breaker of the present invention does not need to perform current shunting on a temperature control assembly, only by additionally providing the partition plate in the housing and arranging the moving contact and the thermal tripping rod in two different planes respectively, the bimetal sheet that is originally in the same plane as the moving contact is also in two planes with the moving contact under the separation of the partition plate. In addition, the temperature control assembly is then mounted in a space close to the moving contact, which shortens the length of the current-carrying conductor of the temperature control assembly, reduces the internal resistance and reduces heat generation, thereby avoiding a damage to parts caused by the overheating of the temperature control assembly.
In addition, by arranging the first critical point, the second critical point and the limiting portion on the partition plate, the circuit breaker will not be interfered by the thermal tripping rod during normal operation under the restriction of the first critical point and the second critical point, wherein the limiting portion is used to limit a movement range of the bimetal sheet to avoid interfering the normal operation of the circuit breaker.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-3 are schematic structural diagrams of a miniature circuit breaker of the present invention;
FIG. 4 is a schematically exploded view of FIG. 2;
FIG. 5 is a schematic structural diagram of a temperature control assembly in the circuit breaker of the present invention;
FIG. 6 is a schematic structural diagram of a partition plate in the miniature circuit breaker of the present invention; and
FIG. 7 is a schematic structural diagram of a current-carrying conductor in the miniature circuit breaker of the present invention.

DETAILED DESCRIPTIONOF THE PREFERRED EMBODIMENTS

The specific implementation of the miniature circuit breaker of the present invention will be further described below with reference to the embodiments given in FIGS. 1 to 7. The miniature circuit breaker of the present invention is not limited to the description of the following embodiments.
A miniature circuit breaker, comprising a housing 1 and a handle 2 arranged on the housing 1, wherein an overload protection device and an operating mechanism connected to a moving contact 8 are arranged in the housing 1; the overload protection device comprises a temperature control assembly equipped with a bimetal sheet 61; an incoming wire connecting terminal connected to the moving contact 8 is arranged on one side, close to the moving contact 8, inside the housing 1; a static contact matched with the moving contact 8 is arranged on one side of the moving contact 8, and the temperature control assembly is arranged on the other side of the moving contact 8;the overload protection device further comprises a temperature control protection device; when overloaded, the temperature control assembly drives the temperature control protection device arranged on the housing 1 to trigger the circuit breaker to trip; andthe temperature control protection device comprises a partition plate 41 and a thermal tripping rod 42, wherein the thermal tripping rod 42 can be rotated on the partition plate 41 to trigger the circuit breaker to trip; the partition plate 41 separates the moving contact 8 and the thermal tripping rod 42 in two different planes; the temperature control assembly 61 comprises a bimetal sheet 61 and a current-carrying conductor; a fixed end of the bimetal sheet 61 is located on the housing 1 on one side close to the moving contact 8; the bimetal sheet 61 is connected to the incoming wire connecting terminal through the current-carrying conductor; and when the circuit breaker is overloaded, the bimetal sheet 61 is heated and bent, such that a movable end 611 of the bimetal sheet 61 drives the thermal tripping rod 42 to rotate to trigger the circuit breaker to trip and cut off.
Compared with the existing scheme, the miniature circuit breaker of the present invention does not need to perform current shunting on a temperature control assembly, and the operating mechanism, the overload protection device, and the moving contact 8 are all located in the same cavity of the housing 1, by additionally providing the partition plate 41 in the housing 1 and arranging the moving contact 8 and the thermal tripping rod 42 in two different planes respectively, the bimetal sheet 61 that is originally in the same plane as the moving contact 8 is also in two planes with the moving contact 8 under the separation of the partition plate 41. In addition, the temperature control assembly is then mounted in a space close to the moving contact 8, which shortens the length of the current-carrying conductor of the temperature control assembly, reduces the internal resistance and reduces heat generation, thereby avoiding a damage to parts caused by the overheating of the temperature control assembly.
In conjunction with an embodiment provided in FIGS. 1 to 4, a miniature circuit breaker includes a housing 1 and a handle 2 arranged on the housing 1, wherein an overload protection device and an operating mechanism connected to a moving contact 8 are arranged in the housing 1; the overload protection device includes a temperature control assembly equipped with a bimetal sheet 61, and a temperature control protection device; the operating mechanism includes a contact support, and a jump buckle 31 and a lock catch 32 which are pivotally arranged on the contact support respectively; the contact support is connected to the moving contact 8; the jump buckle 31 and one end of the lock catch 32 are lapped and connected to each other; a connecting rod 33 for connection with the handle 2 is arranged at the other end of the jump buckle 31; the handle 2 and the operating mechanism are located at the upper part of the housing 1; a static contact that cooperates with the moving contact 8 is arranged on one side of the moving contact 8; the static contact is arranged on a static contact plate 9; the temperature control assembly is arranged on the other side of the moving contact 8; an incoming wire connecting terminal (not shown) connected to the moving contact 8 is arranged on one side, close to the moving contact 8, inside the housing 1; an outgoing wire connecting terminal (not shown) is arranged on one side, close to the static contact, inside the housing 1; the temperature control assembly is arranged on one side of the moving contact 8 close to the incoming wire connecting terminal; the temperature control assembly drives the temperature control protection device arranged in the housing 1 to trigger the unlocking of the operating mechanism to trip and cut off the circuit breaker; the temperature control protection device includes a partition plate 41 and a thermal tripping rod 42, wherein the thermal tripping rod 42 can be rotated on the partition plate 41 to trigger the operating mechanism to unlock; the partition plate 41 separates the moving contact 8 and the thermal tripping rod 42 in two different planes, and preferably, the partition plate 41 is of a right-angle triangle arranged in the middle of the housing 1; the thermal tripping rod 42 is rotatably mounted on the upper part of the partition plate 41; one end of the thermal tripping rod 42 is used as an unlocking end 421 to extend out of the partition plate 41 and to cooperate with the operating mechanism, and the other end of the thermal tripping rod 42 is used as a driving end 422 to be located in the middle of the partition plate 41; the temperature control assembly includes a bimetal sheet 61 and a current-carrying conductor; a fixed end of the bimetal sheet 61 is located on the housing 1 on one side close to the moving contact 8; and the bimetal sheet 61 is connected to the incoming wire connecting terminal through the current-carrying conductor. When the circuit breaker is overloaded, the bimetal sheet 61 is heated and bent, such that a movable end 611 of the bimetal sheet 61 drives the thermal tripping rod 42 to rotate to trigger the operating mechanism to trip and cut off; and the movable end 611 of the bimetal sheet 61 is located above the partition plate 41. In this embodiment, the tripping rod cooperates with the lock catch 32 of the operating mechanism, the jump buckle 31 and the lock catch 32 of the operating mechanism are lapped and connected to each other, and the thermal tripping rod 42 rotates to drive the lock catch 32 to rotate, such that the lock catch 32 releases the lapped connection from the jump buckle 31, thereby tripping and cutting off the circuit breaker.
It should be noted that the significance of adding the partition plate 41 in the housing 1 is to fully separate a space near the moving contact 8 and increase its space utilization rate, such that the temperature control assembly is mounted on the space near the moving contact 8. Of course, the temperature control assembly can also be mounted near the moving contact 8 by increasing a size of the housing 1 to increase the space between the moving contact 8 and the incoming wire connecting terminal, but this is not conducive to the miniaturized design of the circuit breaker.
In addition, said incoming wire connecting terminal and outgoing wire connecting terminal can be adjusted as the outgoing wire connecting terminal and the incoming wire connecting terminal according to the change in the user's wiring mode.
As shown in FIG. 5, the temperature control assembly specifically includes a bimetal sheet 61, a current-carrying conductor and a support 63, wherein the support 63 is used to fix the current-carrying conductor and the bimetal sheet 61 between the incoming wire connecting terminal and the moving contact 8; one end of the support 63 is connected to a fixed end of the bimetal sheet 61, and the other end of the support 63 forms a bifurcated structure with the movable end 611 of the bimetal sheet 61, the other end of the support 63 is used for connection with an adjusting member 7 arranged on one side of the housing 1, and preferably, the support 63 is obliquely arranged along a hypotenuse edge of the partition plate 41 and used for connection with the adjusting member 7 on one side of the housing 1; and the adjusting member 7 is obliquely arranged toward the hypotenuse of the partition plate 41, which further shortens the length of the support 63. A current-carrying conductor structure shown in FIG. 7 is provided. The current-carrying conductor includes a current-carrying plate 623, a first flexible conductor 621 and a second flexible conductor 622; one end of the current-carrying plate 623 is connected to the incoming wire connecting terminal, and the other end of the current-carrying plate 623 is connected to the second flexible conductor 622; the first flexible conductor 621 is connected to the moving contact 8; and one end of the first flexible conductor 621 is connected to the bimetal sheet 61, and the other end of the first flexible conductor 621 is connected to the moving contact 8. Of course, the first flexible conductor 621 and the second flexible conductor 622 can be combined into one flexible conductor. This flexible conductor only needs to connect the current-carrying plate 623, the movable contact 8 and the bimetal sheet 61 together, and its specific form is not limited. The movable end 611 of the bimetal sheet 61 extends to the driving end 422 on the partition plate 41 for driving the thermal tripping rod 42. Further, preferably, an arc-striking plate 64 for introducing an electric arc into the arc extinguishing chamber is connected to the current-carrying conductor, and the arc-striking plate 64 is in the same plane as the moving contact 8. The adjusting member 7 is a screw.
The partition plate 41 is specifically shown in FIG. 6. The partition plate 41 is provided with a first critical point 411, a second critical point 412 and a limiting portion 413, wherein the first critical point 411 and the second critical point 412 are used for being in limiting fit with the thermal tripping rod 42. Under the limiting action of the first critical point 411 and the second critical point 412, the thermal tripping rodwill not interfere with the operating mechanism when the circuit breaker works normally. The middle part of the thermal tripping rod 42 is rotatably mounted on the partition plate 41; one end of the thermal tripping rod 42 is used as an unlocking end 421 to pass through a gap between the first critical point 411 and the second critical point 412 and to cooperate with an operating mechanism; the other end of the thermal tripping rod 42 is used as a driving end 422 to cooperate with the movable end 611 of the bimetal sheet 61; and the limiting portion 413 is used for being in limiting fit with the bimetal sheet 61. The bimetal sheet 61 is bent within a limited space under the action of the limiting portion 413, and the limiting space of the limiting portion 413 is related to a bending degree of the bimetal sheet 61 when overloaded.
According to an optimal scheme of the partition plate 41 provided in FIG. 6, the partition plate 41 is of a right-angled triangle as a whole; a mandrel for the thermal tripping rod 42 to be rotatably mounted is arranged on the upper part of the partition plate 41; two protrusions are arranged on one side of the mandrel close to the operating mechanism as the first critical point 411 and the second critical point 412, respectively, wherein the first critical point 411 is located on one side close to the temperature control assembly, and the second critical point 412 is located on one side away from the temperature control assembly. When the circuit breaker is not overloaded, the thermal tripping rod 42 is located on one side close to the first critical point 411; and when the circuit breaker is overloaded, the thermal tripping rod 42 is driven by the bimetal sheet 61 to approach the second critical point 412, and meanwhile, the unlocking end 421 of the thermal tripping rod 42 trips the operating mechanism, thereby tripping and cutting off the circuit breaker. A longitudinal rib is arranged on the partition plate 41, wherein a groove serving as a limiting portion 413 is formed in the middle of the rib; and the movable end 611 of the bimetal sheet 61 passes through the groove and is used for cooperating with the driving end 422 of the thermal tripping rod 42. When the circuit breaker is not overloaded, the movable end 611 of the bimetal sheet 61 is close to the lower side wall of the groove; and when the circuit breaker is overloaded, the movable end 611 of the bimetal sheet 61 approaches the upper side wall of the groove to drive the thermal tripping rod 42 to rotate. A comb-shaped groove which is used for cooperating with an arc-extinguishing grate of the arc-extinguishing chamber to adjust an air pressure of the arc-extinguishing chamber is formed in a right-angle side on one side of the partition plate 41 close to the arc-extinguishing chamber. A circular groove that is mounted in cooperation with the static contact is formed above the comb-shaped groove.
The arc-extinguishing chamber is located on one side of the moving contact 8 away from the temperature control assembly, and is located below the static contact. The moving contact 8 swings so that the moving contact at one end is in contact with or separated from a static contact point on the static contact. The static contact point extends to an arc entry side of the arc extinguishing chamber. The partition plate 41 is located on one side of the arc-extinguishing chamber close to the moving contact 8, and corresponds to a swing space of the moving contact 8. Only the swing space of the moving contact 8 needs to be separated, such that the movable contact 8 is separated from the thermal tripping rod 42 and the movable end 611 of the bimetal sheet 61 on different planes, without occupying the space of the arc-extinguishing chamber and affecting the arc-extinguishing capability.
The thermal tripping rod 42 mounted on the partition plate 41 is preferably as shown in FIGS. 2-4. The thermal tripping rod 42 is a rod body with one thick end and one thin end. The middle part of the thermal tripping rod 42 is circular and is used for rotational connection with the partition plate 41; one thin end of the thermal tripping rod 42 is used as the driving end 422 to cooperate with the movable end 611 of the bimetal sheet 61; the end part of the driving end 422 is bluntly rounded; and the thick end of the thermal tripping rod 42 is used as the unlocking end 421, and the end part of the thick end is bent to one side for triggering the circuit breaker to trip.
Preferably, an unlocking portion 321 which cooperates with the unlocking end 421 of the thermal tripping rod 42 is arranged at one end of the lock catch 32 of the operating mechanism. The unlocking portion 321 is located on an edge of one side of the lock catch 32 close to the incoming wire connecting terminal, and the unlocking portion 321 is of a protruding structure that protrudes from the edge of the lock catch 32. The unlocking end 421 of the thermal tripping rod 42 is located on the side opposite to the unlocking portion 321.
We have made further detailed description of the present invention mentioned above in combination with specific preferred embodiments, but it is not deemed that the specific embodiments of the present invention is only limited to these descriptions. A person skilled in the art can also, without departing from the concept of the present invention, make several simple deductions or substitutions, which all be deemed to fall within the protection scope of the present invention.

Claims

A miniature circuit breaker, comprising a housing (1) and a handle (2) arranged on the housing (1), wherein an overload protection device and an operating mechanism connected to a moving contact (8) are arranged in the housing (1); the overload protection device comprises a temperature control assembly equipped with a bimetal sheet (61); an incoming wire connecting terminal connected to the moving contact (8) is arranged on one side, close to the moving contact (8), inside the housing (1); a static contact matched with the moving contact (8) is arranged on one side of the moving contact (8), and the temperature control assembly is arranged on the other side of the moving contact (8);
the overload protection device further comprises a temperature control protection device; when overloaded, the temperature control assembly drives the temperature control protection device arranged on the housing (1) to trigger the circuit breaker to trip; and

the temperature control protection device comprises a partition plate (41) and a thermal tripping rod (42), wherein the thermal tripping rod (42) can be rotated on the partition plate (41) to trigger the circuit breaker to trip; the partition plate (41) separates the moving contact (8) and the thermal tripping rod (42) in two different planes; the temperature control assembly (61) comprises a bimetal sheet (61) and a current-carrying conductor; a fixed end of the bimetal sheet (61) is located on the housing (1) on one side close to the moving contact (8); the bimetal sheet (61) is connected to the incoming wire connecting terminal through the current-carrying conductor; and when the circuit breaker is overloaded, the bimetal sheet (61) is heated and bent, such that a movable end (611) of the bimetal sheet (61) drives the thermal tripping rod (42) to rotate to trigger the circuit breaker to trip and cut off.
The miniature circuit breaker according to claim 1, wherein the temperature control assembly further comprises a support (63) on which the bimetal sheet (61) and the current-carrying conductor are fixedly arranged; one end of the support (63) is connected to a fixed end of the bimetal sheet (61), and the other end of the support (63) forms a bifurcated structure with the movable end (611) of the bimetal sheet (61); and the other end of the support (63) is used for connection with an adjusting member (7) arranged on one side of the housing (1).
The miniature circuit breaker according to claim 1, wherein the partition plate (41) is provided with a first critical point (411), a second critical point (412) and a limiting portion (413), wherein the first critical point (411) and the second critical point (412) are used for being in limiting fit with the thermal tripping rod (42); the middle part of the thermal tripping rod (42) is rotatably mounted on the partition plate (41); one end of the thermal tripping rod (42) is used as an unlocking end (421) to pass through a gap between the first critical point (411) and the second critical point (412) and to cooperate with an operating mechanism; the other end of the thermal tripping rod (42) is used as a driving end (422) to cooperate with the movable end (611) of the bimetal sheet (61); and the limiting portion (413) is used for being in limiting fit with the bimetal sheet (61).
The miniature circuit breaker according to claim 3, wherein the partition plate (41) is of a right-angled triangle as a whole; a mandrel for the thermal tripping rod (42) to be rotatably mounted is arranged on the upper part of the partition plate (41); two protrusions are arranged on one side of the mandrel close to the operating mechanism as the first critical point (411) and the second critical point (412), respectively, wherein the first critical point (411) is located on one side close to the temperature control assembly, and the second critical point (412) is located on one side away from the temperature control assembly; a longitudinal rib is arranged on the partition plate (41), wherein a groove serving as a limiting portion (413) is formed in the middle of the rib; and the movable end (611) of the bimetal sheet (61) passes through the groove and used for cooperating with the driving end (422) of the thermal tripping rod (42).
The miniature circuit breaker according to claim 1, wherein the current-carrying conductor comprises a current-carrying plate (623), a first flexible conductor (621) and a second flexible conductor (622); one end of the current-carrying plate (623) is connected to the incoming wire connecting terminal, and the other end of the current-carrying plate (623) is connected to the second flexible conductor (622); the first flexible conductor (621) is connected to the moving contact (8); the first flexible conductor (621) is connected to the second flexible conductor (622); and one end of the first flexible conductor (621) is connected to the bimetal sheet (61), and the other end of the first flexible conductor (621) is connected to the moving contact (8).
The miniature circuit breaker according to claim 1, wherein the middle part of the thermal tripping rod (42) is circular and is used for rotational connection with the partition plate (41); one end of the thermal tripping rod (42) is used as the driving end (422) to cooperate with the movable end (611) of the bimetal sheet (61); the end part of the driving end (422) is bluntly rounded; the other end of the thermal tripping rod (42) is used as the unlocking end (421), and the end part of the other end is bent to one side for triggering the circuit breaker to trip.
The miniature circuit breaker according to claim 1, wherein the partition plate (41) is of a right-angled triangle as a whole; the thermal tripping rod (42) is rotatably mounted on the upper part of the partition plate (41); one end of the thermal tripping rod (42) is used as the unlocking end (421) to extend out of the partition plate (41) and to cooperate with the operating mechanism, and the other end of the thermal tripping rod (42) is used as the driving end (422) to be located in the middle of the partition plate (41); the temperature control assembly comprises a bimetal sheet (61), a current-carrying conductor and a support (63), wherein the support (63) is used to fix the current-carrying conductor and the bimetal sheet (61) between the incoming wire connecting terminal and the moving contact (8); the movable end (611) of the bimetal sheet (61) extends to the driving end (422) on the partition plate (41)for driving the driving end (422)ofthe thermal tripping rod (42); the support (63) is obliquely arranged along a hypotenuse edge of the partition plate (41) and used for connection with the adjusting member (7) on one side of the housing (1); and the adjusting member (7) is inclined toward the hypotenuse of the partition plate (41).
The miniature circuit breaker according to claim 1, wherein the operating mechanism comprises a contact support, and a jump buckle (31) and a lock catch (32) which are pivotally arranged on the contact support, respectively; the contact support is connected to the moving contact (8); the jump buckle (31) and one end of the lock catch (32) are lapped and connected to each other; a connecting rod (33) for connection with the handle (2) is arranged at the other end of the jump buckle (31); and an unlocking portion (321) that cooperates with the thermal tripping rod (42) is arranged at the other end of the lock catch (32).
The miniature circuit breaker according to claim 8, wherein the unlocking portion (321) is located at the edge of one side of the lock catch (32) close to the incoming wire connecting terminal; the unlocking portion (321) is of a protruding structure that protrudes from the edge of the lock catch (32); an arc-striking plate (64) for introducing an electric arc into an arc-extinguishing chamber is also arranged on the current-carrying conductor; and the arc-striking plate (64) and the moving contact (8) are located on the same plane.
The miniature circuit breaker according to claim 1, wherein the housing (1) is provided with the arc extinguishing chamber inside, wherein the arc extinguishing chamber is located on one side of the moving contact (8) away from the temperature control assembly, and is located below the static contact; and the partition plate (41) is located on one side of the arc extinguishing chamber close to the moving contact (8).