A circuit breaker thermal overload adjustable device

Abstract

A thermal overload adjustable device for circuit breakers belongs to the field of low-voltage electrical appliance technology. The circuit breaker includes an operating mechanism, a housing, a traction rod, a trip unit, and the thermal overload adjustable device. The operation of the operating mechanism enables the circuit breaker to close or open. The trip unit detects the current flowing in the circuit and triggers an action, actuating the traction rod to unlock the operating mechanism, thus disconnecting the circuit breaker. The thermal overload adjustable device includes a knob and a push rod. The push rod is slidably mounted on the housing, and the knob is mounted on the housing and rotates to drive the push rod to slide. The key feature is that the thermal overload adjustable device also includes an adjusting element with an actuating part. The adjusting element is mounted on the traction rod and rotates synchronously with it. The adjusting element cooperates with the push rod; under the push of the push rod, the adjusting element slides axially along the traction rod, causing different gaps between the actuating part and the corresponding actuating part on the bimetallic strip of the trip unit, thereby achieving different overload current requirements. Advantages: It avoids the adverse effects of the thermally adjustable traction rod on phase-to-phase insulation, ensuring good phase-to-phase insulation capability.

Description

Technical Field

[0001] This invention belongs to the field of low-voltage electrical appliance technology, specifically relating to a circuit breaker thermal overload adjustable device. Background Technology

[0002] In existing low-voltage circuit breakers, to adapt to different loads, the protection functions of the circuit breakers are required to be diversified. For example, adjustable overload protection and short-circuit protection are needed to meet the protection needs of different loads. The common implementation of adjustable overload protection is as follows: a mechanical traction rod is installed on the operating mechanism to unlock it, and a thermally adjustable traction rod is installed on the mechanical traction rod for adjusting the overload current. When the current is overloaded, the thermally adjustable traction rod drives the mechanical traction rod to rotate and unlock. By rotating a knob, the thermally adjustable traction rod moves axially, synchronously adjusting the idle travel of each phase, thus achieving overload adjustability. However, in high-voltage applications, due to the high phase-to-phase voltage and the large amount of metallic gas generated during breaking, there are high requirements for phase-to-phase insulation capacity. Since the thermally adjustable traction rod requires axial displacement, the common method of improving phase-to-phase insulation capacity through traction rod flanges is ineffective.

[0003] In view of the aforementioned existing technology, it is necessary to make reasonable improvements to the structure of the existing adjustable thermal overload device for circuit breakers. To this end, the applicant has made a beneficial design, and the technical solution described below arises from this background. Summary of the Invention

[0004] The objective of this invention is to provide a circuit breaker thermal overload adjustable device, which, by setting an adjustable overload current adjustment component and adding a push rod located outside the housing to synchronously push each phase adjustment component, avoids the adverse effects of the thermally adjustable traction rod on phase-to-phase insulation and ensures good phase-to-phase insulation capability.

[0005] The present invention achieves its objective by providing a thermal overload adjustable device for a circuit breaker. The circuit breaker includes an operating mechanism, a housing, a traction rod, a trip unit, and the thermal overload adjustable device. The operating mechanism's operation enables the circuit breaker to close or open. The trip unit detects the current flowing through the circuit and triggers an action, actuating the traction rod to unlock the operating mechanism, thus opening the circuit breaker. The thermal overload adjustable device includes a knob and a push rod. The push rod is slidably mounted on the housing, and the knob, mounted on the housing, rotates to drive the push rod to slide. The device further includes an adjusting component with an actuating part. The adjusting component is mounted on the traction rod and rotates synchronously with it. The adjusting component cooperates with the push rod; under the push rod's influence, the adjusting component slides axially along the traction rod, causing different gaps between the actuating part and the corresponding actuator on the bimetallic strip of the trip unit, thereby achieving different overload current requirements.

[0006] In a specific embodiment of the present invention, the adjusting member is provided with an opening, and the opening extends along one side of the axial direction of the traction rod and is provided with a sliding groove. The traction rod is provided with a sliding rod, which passes through the opening of the adjusting member and slides into the sliding groove to install the adjusting member onto the traction rod. The relative sliding of the sliding rod and the sliding groove enables the adjusting member to slide along the axial direction of the traction rod.

[0007] In another specific embodiment of the present invention, the adjusting member is provided with a sliding surface, and the main shaft of the traction rod is provided with a contact surface at the position corresponding to the sliding surface. The slide rod is composed of a straight arm and a bent part. The width of the bent part is greater than the width of the straight arm. The two ends of the straight arm are respectively connected to the contact surface and the bent part. The width of the opening is greater than the width of the bent part. The groove width of the slide is adapted to the straight arm.

[0008] In another specific embodiment of the present invention, the adjusting member is provided with a locking part perpendicular to the slide groove in the extension direction of the slide groove, and the push rod is provided with a transmission part at the position corresponding to the locking part, and the transmission part is fitted and assembled with the locking part.

[0009] In another specific embodiment of the present invention, a sliding part is provided on the housing at the position corresponding to the body of the push rod, the body of the push rod is engaged in the sliding part and slides along the sliding part, and a hole is provided on the housing along the sliding direction of the push rod at the position corresponding to the transmission part of the push rod, the transmission part passes through the hole and cooperates with the engaging part on the adjusting member.

[0010] In another specific embodiment of the present invention, the housing is provided with multiple sets of symmetrically spaced bosses along the sliding direction of the push rod, and the space between each set of bosses constitutes a sliding part.

[0011] In a further specific embodiment of the present invention, one end of the push rod is provided with a rack portion, and the knob is provided with a gear portion that cooperates with the rack portion. The knob and the push rod mesh with the rack portion through the gear portion.

[0012] In a further specific embodiment of the present invention, a knob support is provided at the lower part of the gear portion of the knob, and the knob is assembled with the housing by means of the knob support extending into the knob mounting hole provided on the housing.

[0013] In yet another specific embodiment of the present invention, when the actuating part on the adjusting member is a wedge-shaped boss, the actuating member is a corresponding adjusting screw; when the actuating part on the adjusting member is a cylindrical boss, the actuating member is a corresponding wedge-shaped cover.

[0014] In yet another specific embodiment of the present invention, the number of adjusting elements is the same as the number of poles of the circuit breaker.

[0015] The present invention has the following advantages due to the above-mentioned structure: First, by setting an adjustable overload current adjustment component on each phase and adding a push rod to synchronously push the adjustment components of each phase, multi-phase linkage is achieved, avoiding the adverse effects of the adjustment components on the interphase insulation; Second, since the push rod is installed outside the housing, the housing can effectively block the metal gas and metal particles generated during the break-off, preventing the push rod from being contaminated and causing a decrease in insulation capacity, thereby ensuring the interphase insulation capacity. Attached Figure Description

[0016] Figure 1 This is an exploded view of the assembly of the circuit breaker described in this invention;

[0017] Figure 2 This is an exploded view of the assembly of the adjusting component and the traction rod described in this invention;

[0018] Figure 3 This is an exploded view of the assembly of the knob, push rod, and housing described in this invention;

[0019] Figure 4 This is an assembly diagram of the knob, push rod, adjusting component, traction rod, and release device described in this invention.

[0020] In the diagram: 1. Base; 2. Operating mechanism; 21. Mechanism handle; 3. Housing; 31. Hole; 32. Sliding part; 33. Boss; 34. Knob mounting hole; 4. Knob; 41. Gear part; 42. Knob support part; 5. Push rod; 51. Transmission part; 52. Rack part; 53. Body; 6. Adjusting component; 61. Sliding surface; 62. Opening; 63. Slide groove; 64. Snap-fit ​​part; 65. Actuating part; 66. Protrusion; 7. Traction rod; 71. Contact surface; 72. Slide rod; 721. Straight arm part; 722. Bending part; 8. Trip device; 81. Bimetallic strip; 811. Actuating component. Detailed Implementation

[0021] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the description of the embodiments is not a limitation on the technical solution. Any formal but not substantive changes made based on the concept of the present invention should be considered within the scope of protection of the present invention.

[0022] In the following description, all directional or orientational concepts involving up, down, left, right, front, and back are based on the positions shown in the corresponding figures, and therefore should not be construed as a special limitation on the technical solutions provided by this invention.

[0023] Please see Figure 1This invention relates to a circuit breaker thermal overload adjustable device. The circuit breaker includes a base 1, an operating mechanism 2, a housing 3, a traction rod 7, and a trip unit 8. The traction rod 7 is rotatably hinged to the clamps on both sides of the operating mechanism 2 for unlocking the operating mechanism 2. The operating mechanism 2 is mounted on the base 1 and is driven by a mechanism handle 21 mounted on the operating mechanism 2. After the operating mechanism 2 is activated, it drives the rotating shaft of the circuit breaker (not shown in the figure) to move. The rotating shaft drives the moving contact (not shown in the figure) of the circuit breaker to rotate, so as to achieve contact or separation with the stationary contact (not shown in the figure) of the circuit breaker, thereby realizing the opening and closing of the circuit breaker. The trip unit 8 detects the current flowing in the circuit and gives a trigger action, actuating the traction rod 7 to unlock the operating mechanism 2, thereby realizing the opening of the circuit breaker. The thermal overload adjustable device includes a knob 4, a push rod 5, and an adjusting member 6. The push rod 5 is slidably mounted on the circuit breaker housing 3. The knob 4 is mounted on the circuit breaker housing 3 and rotates to drive the push rod 5 to slide. The adjusting member 6 is provided with an actuating part 65. The adjusting member 6 is mounted on the traction rod 7 and rotates synchronously with the traction rod 7. The adjusting member 6 cooperates with the push rod 5. Under the push of the push rod 5, the adjusting member 6 slides along the axial direction of the traction rod 7, causing the actuating part 65 to have a different gap with the actuating member 811 on the bimetallic strip 81 mounted on the trip unit 8, thereby meeting the requirements of different overload currents.

[0024] When the circuit breaker requires an adjustable current function, the push rod 5 on the housing 3 can be slid by rotating the knob 4 on the housing 3. The sliding of the push rod 5 causes the adjusting member 6 on the traction rod 7 to slide. This can be achieved by the actuator 65 on the adjusting member 6 corresponding to the actuator 811 on the bimetallic strip 81 on the trip unit 8.

[0025] like Figures 2 to 4As shown, the adjusting member 6 includes a sliding surface 61 and the aforementioned actuating part 65. The sliding surface 61 cooperates with the traction rod 7, and the actuating part 65 cooperates with the actuating element 811 on the bimetallic strip 81 of the trip unit 8. In this embodiment, the sliding surface 61 has a "┐" shaped structure, and a contact surface 71 is provided on the main shaft of the traction rod 7 at the position corresponding to the sliding surface 61 of the adjusting member 6. An opening 62 is provided on the upper part of the sliding surface 61, and a groove 63 extends from the opening 62 along one side of the axial direction of the traction rod 7. A sliding rod 72 is provided on the traction rod 7 at the position corresponding to the groove 63 of the adjusting member 6. The sliding rod 72 passes through the opening 62 of the adjusting member 6 and slides into the groove 63 to install the adjusting member 6 onto the traction rod 7. The sliding surface 61 and the contact surface 71 are in contact, and the relative sliding of the sliding rod 72 and the groove 63 enables the adjusting member 6 to slide along the axial direction of the traction rod 7. Specifically, the slide rod 72 consists of a straight arm portion 721 and a bent portion 722. The width of the bent portion 722 is greater than the width of the straight arm portion 721. The two ends of the straight arm portion 721 are respectively connected to the mating surface 71 and the bent portion 722, so the slide rod 72 is inverted L-shaped or T-shaped. In this embodiment, it is preferably inverted L-shaped. The width of the opening 62 is greater than the width of the bent portion 722, so that the bent portion 722 can pass through the opening 62 to the adjusting member 6. The groove width of the sliding groove 63 of the adjusting member 6 is smaller than the width of the bent portion 722, but it is adapted to the straight arm portion 721 of the slide rod 72, so that the adjusting member 6 can slide relative to the straight arm portion 721 and rotate synchronously with the traction rod 7, and will not fall off due to the obstruction of the bent portion 722.

[0026] like Figure 2 , Figure 4 As shown, the adjusting member 6 has a locking part 64 perpendicular to the slide groove 63 extending in the direction of the slide groove 63. The push rod 5 has a transmission part 51 corresponding to a pair of locking parts 64, and the transmission part 51 is inserted into the locking part 64. In this embodiment, the locking part 64 is formed by the space between a pair of symmetrically arranged protrusions 66, and the transmission part 51 is a circular boss. Of course, their positions can be interchanged. The opening 62 and the slide groove 63 are adjacent and their positions can be interchanged. The locking part 64 can be located on the left side of the opening 62 or the right side of the slide groove 63, or vice versa. Preferably, the locking part 64 is located on the right side of the slide groove 63.

[0027] like Figure 3As shown, a sliding part 32 is provided on the housing 3 at the position corresponding to the body 53 of the push rod 5. The body 53 of the push rod 5 is engaged in the sliding part 32 and slides along the sliding part 32. A hole 31 is provided on the housing 3 along the sliding direction of the push rod 5, corresponding to the position of the transmission part 51 of the push rod 5. The transmission part 51 passes through the hole 31 and is inserted into the engaging part 64 of the adjusting member 6. Preferably, the hole 31 is a square hole. In this embodiment, multiple sets of symmetrically spaced protrusions 33 are provided on the housing 3 along the sliding direction of the push rod 5, and the space between each set of protrusions 33 constitutes the sliding part 32. Of course, the sliding part 32 can also be composed of a long strip-shaped track.

[0028] like Figure 3 , Figure 4 As shown, one end of the push rod 5 is provided with a rack portion 52, and the knob 4 is provided with a gear portion 41 that meshes with the rack portion 52. The knob 4 and the push rod 5 are connected by the gear portion 41 and the rack portion 52. The lower part of the gear portion 41 of the knob 4 is provided with a knob support portion 42, which is inserted into the knob mounting hole 34 provided on the housing 3 to assemble the knob 4 with the housing 3.

[0029] like Figure 3 , Figure 4 As shown, the actuating part 65 is located below the sliding surface 61 of the adjusting member 6. The actuating part 65 is disposed opposite to the actuating member 811 on the bimetallic strip 81 of the circuit breaker trip unit 8. When the actuating part 65 on the adjusting member 6 is a wedge-shaped boss, the actuating member 811 is a corresponding adjusting screw. When the actuating part 65 on the adjusting member 6 is a cylindrical boss (not shown in the figure), the actuating member 811 is a corresponding wedge-shaped cover (not shown in the figure). In this embodiment, the actuating part 65 is a wedge-shaped boss, and the actuating member 811 is an adjusting screw. When the circuit breaker current setting needs to be adjusted, the push rod 5 is slid by rotating the knob 4. At the same time, the push rod 5 drives the adjusting member 6 to slide. The overload current is changed by changing the gap between the actuating part 65 on the adjusting member 6 and the actuating member 811 on the bimetallic strip 81.

[0030] The number of adjusting elements 6 is determined by the number of poles of the circuit breaker, i.e., it is the same as the number of poles of the circuit breaker. When the circuit breaker has 2 poles, there are 2 adjusting elements 6; when the circuit breaker has 3 poles, there are 3 adjusting elements 6; when the circuit breaker has 4 poles, there are 4 adjusting elements 6. The figure shows a three-pole circuit breaker, i.e., the number of adjusting elements 6 is 3.

Claims

1. A thermal overload adjustable device of a circuit breaker, the circuit breaker comprising an operating mechanism (2), a housing (3), a traction rod (7), a release (8) and a thermal overload adjustable device, the operating mechanism (2) being actuated to realize the closing of the circuit breaker, the release (8) detecting the current flowing in the circuit to give a trigger action, actuating the traction rod (7) to unlock the operating mechanism (2) to realize the breaking of the circuit breaker, the thermal overload adjustable device comprising a knob (4) and a push rod (5), the push rod (5) being slidingly arranged on the housing (3), the knob (4) being arranged on the housing (3) and being rotated to drive the push rod (5) to slide, characterized in that: The thermal overload adjustable device further comprises an adjusting member (6) arranged on each phase, and an actuating portion (65) is arranged on the adjusting member (6); the adjusting member (6) is arranged on a traction rod (7) and rotates synchronously with the traction rod (7); the adjusting member (6) cooperates with the push rod (5), and under the pushing of the push rod (5), the adjusting member (6) slides axially along the traction rod (7), so that the actuating portion (65) is different from the gap corresponding to the actuating member (811) on the bimetallic strip (81) arranged on the release (8), thereby achieving the requirement of different overload currents; the number of the adjusting members (6) is the same as the number of poles of the circuit breaker. ​ 2. A thermal overload adjustable device for a circuit breaker according to claim 1, characterized in that: An opening (62) is arranged on the adjusting member (6), and a sliding groove (63) is arranged on one side of the opening (62) along the axial direction of the traction rod (7); a sliding rod (72) is arranged on the traction rod (7), the sliding rod (72) passes through the opening (62) of the adjusting member (6) and slides into the sliding groove (63) to mount the adjusting member (6) to the traction rod (7), and the relative sliding of the sliding rod (72) and the sliding groove (63) realizes the axial sliding of the adjusting member (6) along the traction rod (7).

3. A thermal overload adjustable device for a circuit breaker according to claim 2, characterized in that: A sliding surface (61) is arranged on the adjusting member (6), a matching surface (71) is arranged on the main shaft of the traction rod (7) at a position corresponding to the sliding surface (61), the sliding rod (72) is composed of a straight arm portion (721) and a bent portion (722), the width of the bent portion (722) is greater than the width of the straight arm portion (721), the two ends of the straight arm portion (721) are connected to the matching surface (71) and the bent portion (722) respectively, the width of the opening (62) is greater than the width of the bent portion (722), and the groove width of the sliding groove (63) is adapted to the straight arm portion (721).

4. A circuit breaker thermal overload adjustable device according to claim 3, characterized in that: The adjusting member (6) is provided with a clamping portion (64) perpendicular to the sliding groove (63) in the extension direction of the sliding groove (63), and a transmission portion (51) is arranged on the push rod (5) at a position corresponding to the clamping portion (64).

5. A circuit breaker thermal overload adjustable device according to claim 4, characterized in that: A sliding portion (32) is arranged on the shell (3) at a position corresponding to the body (53) of the push rod (5), the body (53) of the push rod (5) is clamped in the sliding portion (32) and slides along the sliding portion (32), and a hole (31) is arranged on the shell (3) at a position corresponding to the transmission portion (51) of the push rod (5) along the sliding direction of the push rod (5), the transmission portion (51) passes through the hole (31) and cooperates with the clamping portion (64) on the adjusting member (6).

6. A circuit breaker thermal overload adjustable device according to claim 5, characterized in that: A plurality of groups of bosses (33) are arranged on the shell (3) along the sliding direction of the push rod (5) and are symmetrically and spaced apart, and the space between each group of bosses (33) forms the sliding portion (32).

7. The adjustable thermal overload device for a circuit breaker of claim 1 wherein: One end of the push rod (5) is provided with a rack portion (52), and a gear portion (41) is arranged on the knob (4) and cooperates with the rack portion (52), and the knob (4) and the push rod (5) are engaged through the gear portion (41) and the rack portion (52).

8. A thermal overload adjustable device for a circuit breaker according to claim 7, characterized in that: The lower part of the gear part (41) of the knob (4) is provided with a knob supporting part (42), and the knob (4) is assembled with the shell (3) by the knob supporting part (42) penetrating into the knob mounting hole (34) provided on the shell (3).

9. The adjustable thermal overload device for a circuit breaker of claim 1 wherein: When the actuating part (65) on the adjusting part (6) is a wedge-shaped boss, the actuating part (811) is a correspondingly arranged adjusting screw; when the actuating part (65) on the adjusting part (6) is a cylindrical boss, the actuating part (811) is a correspondingly arranged wedge-shaped housing.

Images