Breaker thermal release

Abstract

The utility model belongs to the technical field of low-voltage electric appliances, and discloses a thermal release of a circuit breaker, the circuit breaker comprises a base, a cover body, a moving contact assembly, a transmission mechanism and a thermal release, the base and the cover body are combined to form a containing cavity, the moving contact assembly, the transmission mechanism and the thermal release are arranged in the containing cavity, and the thermal release is arranged in the containing cavity. The thermal release comprises a traction rod, a thermal adjustable push rod, a bimetallic strip and an axial driving assembly. According to the thermal tripper of the circuit breaker, the sensitivity of the thermal tripper to different temperatures can be adjusted in a large range by adjusting the initial distance and the contact position between the delay screw on the bimetallic strip and the second transmission part on the thermal adjustable push rod, so that the protection action can be triggered under a proper temperature condition according to specific application scenes and requirements, and the safety of the circuit breaker is ensured. Therefore, different load characteristics and protection requirements are met, and safe operation of circuits and equipment is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of low-voltage electrical appliances, in particular to a thermal release of a circuit breaker. Background Art

[0002] Circuit breakers play a very important role in the transmission and distribution of electric power and the protection of motors. They are products with a large usage quantity and a wide application range among low-voltage electrical appliances. A circuit breaker mainly consists of a contact arc extinguishing system, a transmission mechanism, and a release. The release is an important mechanism in the circuit breaker. The function of the release is to convert electrical energy into mechanical action, and when receiving a release signal, it makes the circuit breaker trip, realizing the protection of the circuit breaker against overload or short-circuit faults.

[0003] Common releases are divided into two types: electronic and thermal-magnetic. Electronic releases perform excellently in providing high-precision and adjustable protection functions, but they have a high cost; thermal-magnetic releases have a low cost and stable performance, but their protection functions are relatively simple, only providing magnetic protection (short-circuit protection) and thermal protection (overload protection). Especially for the thermal release, its action value error is relatively large, its thermal sensitivity is non-adjustable or has limited adjustment ability, and it is greatly affected by the environment, thereby affecting the comprehensiveness and reliability of the protection function of the release. Summary of the Utility Model

[0004] Based on the above problems, the purpose of the utility model is to provide a thermal release of a circuit breaker, optimize the internal structure of the release, and realize a wider range of thermal adjustable functions.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A thermal release of a circuit breaker, the circuit breaker includes a base, a cover, a moving contact assembly, a transmission mechanism, and a thermal release. The base and the cover are combined to form a cavity. The moving contact assembly, the transmission mechanism, and the thermal release are arranged in the cavity. The thermal release includes a traction rod, a thermally adjustable push rod, a bimetal, and an axial drive assembly, wherein:

[0007] The traction rod is used to drive the transmission mechanism to act, realizing the tripping function of the circuit breaker;

[0008] The thermally adjustable push rod is provided with a first transmission part, a second transmission part, and a third transmission part. The first transmission part is used to drive the traction rod to rotate. The second transmission part is provided with a contact surface that changes along the axial height of the thermally adjustable push rod;

[0009] The bimetal is located on one side of the thermally adjustable push rod and is electrically connected to the moving contact assembly. The bimetal bends towards the thermally adjustable push rod after being heated. The bimetal is provided with a delay screw. The delay screw is used to press against the contact surface to drive the thermally adjustable push rod to rotate after the bimetal bends. The distance from the delay screw to the contact surface before the bimetal bends is adjustable;

[0010] The axial driving assembly acts on the third transmission part to drive the thermal adjustable push rod to move axially, thereby changing the position where the delay screw presses on the contact surface.

[0011] As an alternative solution, the axial driving assembly includes a fixed bracket, a slider and a knob, where:

[0012] The fixed bracket is fixed on the cover body;

[0013] The slider is slidably arranged on the fixed bracket, and the sliding direction of the slider is the same as the axial direction of the thermal adjustable push rod;

[0014] The knob is rotatably arranged on the fixed bracket, and an eccentric post is arranged at the lower end of the knob;

[0015] A first limiting groove perpendicular to the axial direction of the thermal adjustable push rod is arranged on the third transmission part;

[0016] One end of the slider is provided with a linkage rod inserted into the first limiting groove, and the other end of the slider is provided with a second limiting groove for the eccentric post to be inserted.

[0017] As an alternative solution, a convex block is arranged on the outer edge of the knob, and a stop block is arranged on the fixed bracket. The two stop blocks limit the stroke on both sides of the convex block, thereby restricting the rotation angle of the knob.

[0018] As an alternative solution, a plurality of gear position grooves distributed around the circumference of the knob are formed on the surface of the fixed bracket in contact with the knob, and convex points are arranged on the surface of the knob in contact with the fixed bracket. The convex points can slide in and out of each gear position groove.

[0019] As an alternative solution, the upper end of the knob protrudes from the cover body, and an arrow groove is arranged on the upper end surface of the knob. The arrow groove is used to display the current angle of the knob and is for a screwdriver to be inserted to drive the knob to rotate.

[0020] As an alternative solution, a concave cavity for installing the slider is arranged on the fixed bracket, convex ribs arranged along the sliding direction of the slider are arranged on the side wall of the concave cavity, and a sliding groove matched with the convex ribs is formed on the slider.

[0021] As an alternative solution, a return torsion spring is sleeved on the thermal adjustable push rod. One end of the return torsion spring abuts against the base, and the other end of the return torsion spring abuts against the second transmission part.

[0022] As an alternative solution, a right-angle part is arranged on the third transmission part and on one side of the thermal adjustable push rod. When the right-angle part abuts against the base, the rotation of the thermal adjustable push rod under the action of the return torsion spring is restricted.

[0023] As an alternative, the second transmission part includes a high potential region, a low potential region, and a ramp region connecting the high potential region and the low potential region, and the contact surface is the upper surface of the high potential region, the upper surface of the ramp region, and the upper surface of the low potential region.

[0024] As an alternative, a fixing nut is provided on the bimetallic strip, and the delay screw is threadedly connected to the fixing nut.

[0025] The beneficial effects of the present utility model: By adjusting the initial distance and contact position between the delay screw on the bimetallic strip and the second transmission part on the thermally adjustable push rod of the circuit breaker thermal release, the sensitivity of the thermal release to different temperatures can be adjusted within a wide range, so that the protection action can be triggered under appropriate temperature conditions according to specific application scenarios and requirements, to adapt to different load characteristics and protection requirements, and ensure the safe operation of the circuit and equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is the structural external view of the circuit breaker provided by the embodiment of the present utility model;

[0027] Figure 2 is the structural schematic diagram of the circuit breaker in the closed state provided by the embodiment of the present utility model Figure 1 ;

[0028] Figure 3 is the structural schematic diagram of the circuit breaker in the closed state provided by the embodiment of the present utility model Figure 2 ;

[0029] Figure 4 is the structural schematic diagram of the circuit breaker in the tripped state provided by the embodiment of the present utility model;

[0030] Figure 5 is the schematic diagram of the circuit breaker thermal release provided by the embodiment of the present utility model Figure 1 ;

[0031] Figure 6 is the schematic diagram of the circuit breaker thermal release provided by the embodiment of the present utility model Figure 2 ;

[0032] Figure 7 is the structural schematic diagram of the knob in the circuit breaker thermal release provided by the embodiment of the present utility model;

[0033] Figure 8 is the structural schematic diagram of the slider in the circuit breaker thermal release provided by the embodiment of the present utility model;

[0034] Figure 9 is the structural schematic diagram of the thermally adjustable push rod in the circuit breaker thermal release provided by the embodiment of the present utility model.

[0035] In the drawings:

[0036] 1. Drawbar

[0037] 2. Heat-adjustable push rod; 21. First transmission part; 22. Second transmission part; 221. High-potential area; 222. Low-potential area; 223. Slope area; 23. Third transmission part; 231. First limit groove; 232. Right-angle part; 24. Reset torsion spring

[0038] 3. Bimetallic strip; 31. Delay screw; 32. Fixed nut

[0039] 4. Axial drive assembly; 41. Fixed bracket; 411. Stop block; 412. Gear position groove; 413. Convex rib; 42. Slide block; 421. Linking rod; 422. Second limit groove; 423. Slide groove; 43. Knob; 431. Eccentric column; 432. Convex block; 433. Convex point; 434. Arrow groove

[0040] 5. Base

[0041] 6. Cover body

[0042] 7. Moving contact assembly

[0043] 8. Transmission mechanism; 81. Sub-lock Detailed implementation mode

[0044] The present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model, rather than limiting the present utility model. In addition, it should be noted that for the convenience of description, only parts related to the present utility model rather than all structures are shown in the drawings.

[0045] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0046] In the present utility model, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may also include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on the top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under" and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0047] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "left" and "right" are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for differentiation in description and have no special meanings.

[0048] Please refer to Figures 1 to 4 As shown, this preferred embodiment provides a circuit breaker thermal release, wherein the circuit breaker includes a base 5, a cover 6, a moving contact assembly 7, a transmission mechanism 8 and a thermal release. The base 5 and the cover 6 are combined to form a cavity, and the moving contact assembly 7, the transmission mechanism 8 and the thermal release are arranged in the cavity. Whether it is an electronic circuit breaker or a thermal-magnetic circuit breaker, the base 5 and the cover 6 here can be universal.

[0049] Specifically, the thermal release here includes a traction rod 1, a thermally adjustable push rod 2, a bimetallic strip 3 and an axial drive assembly 4, as detailed in Figure 5 wherein:

[0050] The traction rod 1 is used to drive the transmission mechanism 8 to act and realize the tripping function of the circuit breaker;

[0051] The thermally adjustable push rod 2 is provided with a first transmission part 21, a second transmission part 22 and a third transmission part 23. The first transmission part 21 is used to drive the traction rod 1 to rotate, and the second transmission part 22 is provided with a contact surface that changes along the axial height of the thermally adjustable push rod 2;

[0052] The bimetallic strip 3 is located on one side of the thermally adjustable push rod 2 and is electrically connected to the moving contact assembly 7. The bimetallic strip 3 bends towards the thermally adjustable push rod 2 after being heated. The bimetallic strip 3 is provided with a delay screw 31, and the delay screw 31 is used to press against the contact surface of the second transmission part 22 to drive the thermally adjustable push rod 2 to rotate after the bimetallic strip 3 bends, and the distance from the delay screw 31 to the contact surface before the bimetallic strip 3 bends is adjustable;

[0053] The axial drive assembly 4 acts on the third transmission part 23 to drive the thermal adjustable push rod 2 to axially move, thereby changing the position where the delay screw 31 presses on the contact surface.

[0054] Thus, by adjusting the initial distance and contact position between the delay screw 31 on the bimetal 3 and the second transmission part 22 on the thermal adjustable push rod 2, the sensitivity of the thermal release to different temperatures can be adjusted within a wide range. Therefore, according to specific application scenarios and requirements, it can ensure that the protection action is triggered under appropriate temperature conditions to adapt to different load characteristics and protection requirements, ensuring the safe operation of the circuit and equipment.

[0055] Specifically, the axial drive assembly 4 can be implemented in various forms as long as it can simply drive the thermal adjustable push rod 2 to axially move. In this embodiment, one form is exemplified as follows. It includes a fixed bracket 41, a slider 42, and a knob 43. For details, see Figures 5 to 9 , wherein:

[0056] The fixed bracket 41 is fixed on the cover body 6;

[0057] The slider 42 is slidably arranged on the fixed bracket 41, and the sliding direction of the slider 42 is the same as the axial direction of the thermal adjustable push rod 2;

[0058] The knob 43 is rotatably arranged on the fixed bracket 41, and an eccentric post 431 is arranged at the lower end of the knob 43;

[0059] A first limiting groove 231 perpendicular to the axial direction of the thermal adjustable push rod 2 is arranged on the third transmission part 23;

[0060] One end of the slider 42 is provided with a linkage rod 421 inserted into the first limiting groove 231, and the other end of the slider 42 is provided with a second limiting groove 422 for the eccentric post 431 to be inserted.

[0061] Thus, through the cooperation between the eccentric post 431 and the second limiting groove 422, the rotation of the knob 43 is converted into the sliding of the slider 42. Through the cooperation between the linkage rod 421 and the first limiting groove 231, the sliding of the slider 42 is converted into the axial movement of the thermal adjustable push rod 2. Therefore, by rotating the knob 43, the relative position between the delay screw 31 and the second transmission part 22 is changed, playing the role of adjustable thermal release.

[0062] Optionally, for details, see Figure 6 , a convex block 432 is arranged on the outer edge of the knob 43, and a stop block 411 is arranged on the fixed bracket 41. The two stop blocks 411 limit the travel on both sides of the convex block 432, thereby restricting the rotation angle of the knob 43 and ensuring that the adjustment action is carried out normally within the set range.

[0063] Optionally, the knob 43 has several gears during rotation. In this embodiment, three gears are exemplified. For details, see Figure 6 andFigure 7 On the surface of the fixed bracket 41 that contacts the knob 43, three gear grooves 412 are provided and distributed around the circumference of the knob 43. On the surface of the knob 43 that contacts the fixed bracket 41, bump points 433 are provided. The bump points 433 can slide in and out of the respective gear grooves 412, so that the gear shift can be clearly felt during the rotation of the knob 43.

[0064] Furthermore, the upper end of the knob 43 protrudes from the cover 6, and an arrow groove 434 is provided on the upper end face of the knob 43. The arrow groove 434 is used to display the current angle of the knob 43 and is for a screwdriver to be inserted to drive the rotation of the knob 43, so as to facilitate the operation of rotating the knob 43 to the target gear position.

[0065] Optionally, a concave cavity for installing the slider 42 is provided on the fixed bracket 41. On the side wall of the concave cavity, convex ribs 413 are arranged along the sliding direction of the slider 42. A sliding groove 423 that cooperates with the convex ribs 413 is provided on the slider 42, so as to ensure that the slider 42 slides back and forth accurately on the fixed bracket 41.

[0066] Optionally, a return torsion spring 24 is sleeved on the heat adjustable push rod 2. One end of the return torsion spring 24 abuts against the base 5, and the other end of the return torsion spring 24 abuts against the second transmission part 22, so that when the heat adjustable push rod 2 is not affected by the delay screw 31, it can automatically reset.

[0067] Furthermore, a right-angle part 232 is provided on the third transmission part 23 and on one side of the heat adjustable push rod 2. See Figure 5 When the right-angle part 232 abuts against the base 5, the rotation of the heat adjustable push rod 2 under the action of the return torsion spring 24 is restricted, so as to avoid excessive rotation of the heat adjustable push rod 2 during reset.

[0068] Optionally, see Figure 9 The second transmission part 22 includes a high potential region 221, a low potential region 222, and a slope region 223 connecting the high potential region 221 and the low potential region 222. The contact surfaces are the upper surface of the high potential region 221, the upper surface of the slope region 223, and the upper surface of the low potential region 222. When the heat adjustable push rod 2 moves axially, the delay screw 31 correspondingly abuts against a certain position on the high potential region 221 or the low potential region 222 or the low potential region 222. Due to the different heights of the high potential region 221, the low potential region 222, and the slope region 223, the relative distance between the delay screw 31 and the second transmission part 22 changes, which means that the delay screw 31 can touch the second transmission part 22 only when the bimetal strip 3 has different bending degrees (i.e., different temperatures), so that the protection action can be triggered under the desired temperature conditions.

[0069] Specifically, a fixing nut 32 is provided on the bimetal sheet 3, and the delay screw 31 is threadedly connected to the fixing nut 32, so that the initial distance between the delay screw 31 and the second transmission part 22 is adjustable. That is, it allows the thermal release to trigger the protection action after a certain time delay when reaching a certain temperature. In this way, it can better adapt to different load characteristics and protection requirements, and avoid misoperation or premature operation.

[0070] Specific installation structure:

[0071] The bimetal sheet 3 is fastened to the moving contact assembly 7 by screws, the moving contact assembly 7 and the outgoing terminal connecting plate are fastened by screws, and they are uniformly installed on the base 5; the delay screw 31 and the fixing nut 32 are assembled and installed on the bimetal sheet 3; the reset torsion spring 24 is installed into the thermally adjustable push rod 2, and after assembling the push rod and the installation part, the thermally adjustable push rod 2 is installed on the base 5, the base 5 and the cover 6 are assembled, the transmission mechanism 8 is fixed on the base 5 and the cover 6, and the fixing bracket 41 is combined with the slider 42 and the knob 43 and fastened on the cover 6.

[0072] Insert a flat-blade screwdriver into the arrow groove 434 to drive the knob 43 to rotate. The convex block 432 of the knob 43 cooperates with the two stoppers 411 of the fixing bracket 41 for limiting, so that the slider 42 is linked under the combined action of the eccentric column 431 of the knob 43 and the second limiting groove 422 of the slider 42 and under the combined action of the convex rib 413 of the fixing bracket 41 and the groove of the slider 42. Furthermore, the thermally adjustable push rod 2 moves left and right under the combined action of the linkage rod 421 of the slider 42 and the first limiting groove 231 on the third transmission part 23 of the thermally adjustable push rod 2, whereby the relative position of the contact surface between the delay screw 31 and the second transmission part 22 of the thermally adjustable push rod 2 changes.

[0073] When the circuit breaker carries an overload operating current (such as twice), a large amount of heat will be generated in the entire conductive part connecting plate. The bimetal sheet 3 is heated and bent, and the delay screw 31 pushes the second transmission part 22 of the thermally adjustable push rod 2 to make the thermally adjustable push rod 2 rotate. The first transmission part 21 of the thermally adjustable push rod 2 is linked to drive the traction rod 1 to rotate, so that the part of the traction rod 1 that locks the secondary latch 81 is unlocked, and the entire transmission mechanism 8 is tripped. For details, see Figure 3 and Figure 4 .

[0074] Obviously, the above-mentioned embodiments of the present invention are only examples for clearly explaining the present invention, and are not intended to limit the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. Circuit breaker thermal release, the circuit breaker includes a base (5), a cover (6), a moving contact assembly (7), a transmission mechanism (8) and a thermal release, the base (5) and the cover (6) are combined to form a cavity, the moving contact assembly (7), the transmission mechanism (8) and the thermal release are arranged in the cavity, characterized in that, The thermal release includes a traction rod (1), a thermally adjustable push rod (2), a bimetallic strip (3), and an axial drive assembly (4), where: The traction rod (1) is used to drive the transmission mechanism (8) to actuate, realizing the tripping function of the circuit breaker; The thermally adjustable push rod (2) is provided with a first transmission part (21), a second transmission part (22), and a third transmission part (23). The first transmission part (21) is used to drive the traction rod (1) to rotate, and the second transmission part (22) is provided with a contact surface that varies along the axial height of the thermally adjustable push rod (2); The bimetallic strip (3) is located on one side of the thermally adjustable push rod (2) and is electrically connected to the moving contact assembly (7). The bimetallic strip (3) bends towards the thermally adjustable push rod (2) when heated. A delay screw (31) is provided on the bimetallic strip (3). The delay screw (31) is used to press against the contact surface to drive the thermally adjustable push rod (2) to rotate after the bimetallic strip (3) bends. The distance from the delay screw (31) to the contact surface before the bimetallic strip (3) bends is adjustable; The axial drive assembly (4) acts on the third transmission part (23) to drive the thermally adjustable push rod (2) to move axially, thereby changing the position where the delay screw (31) presses against the contact surface.

2. The circuit breaker thermal release according to claim 1, characterized in that: The axial drive assembly (4) includes a fixed bracket (41), a slider (42), and a knob (43), where: The fixed bracket (41) is fixed on the cover body (6); The slider (42) is slidably arranged on the fixed bracket (41), and the sliding direction of the slider (42) is the same as the axial direction of the thermally adjustable push rod (2); The knob (43) is rotatably arranged on the fixed bracket (41), and an eccentric post (431) is provided at the lower end of the knob (43); A first limiting groove (231) perpendicular to the axial direction of the thermally adjustable push rod (2) is provided on the third transmission part (23); One end of the slider (42) is provided with a linkage rod (421) inserted into the first limiting groove (231), and the other end of the slider (42) is provided with a second limiting groove (422) for the eccentric post (431) to be inserted into.

3. The thermal release of the circuit breaker according to claim 2, characterized in that, A convex block (432) is provided on the outer edge of the knob (43), and a stop block (411) is provided on the fixed bracket (41). The two stop blocks (411) limit the stroke on both sides of the convex block (432), thereby restricting the rotation angle of the knob (43).

4. The thermal release of the circuit breaker according to claim 3, characterized in that, A number of gear position grooves (412) distributed around the circumference of the knob (43) are formed on the surface of the fixed bracket (41) in contact with the knob (43). A convex point (433) is provided on the surface of the knob (43) in contact with the fixed bracket (41), and the convex point (433) can slide in and out of each of the gear position grooves (412).

5. The thermal release of the circuit breaker according to claim 4, characterized in that, The upper end of the knob (43) protrudes from the cover body (6), and an arrow groove (434) is provided on the upper end face of the knob (43). The arrow groove (434) is used to display the current angle of the knob (43) and is for a screwdriver to be inserted to drive the rotation of the knob (43).

6. The circuit breaker thermal release according to claim 2, characterized in that: A concave cavity for installing the slider (42) is provided on the fixed bracket (41). Convex ribs (413) arranged along the sliding direction of the slider (42) are provided on the side wall of the concave cavity, and a sliding groove (423) cooperating with the convex ribs (413) is formed on the slider (42).

7. The thermal release of the circuit breaker according to claim 1, characterized in that, A return torsion spring (24) is sleeved on the heat-adjustable push rod (2). One end of the return torsion spring (24) abuts against the base (5), and the other end of the return torsion spring (24) abuts against the second transmission part (22).

8. The circuit breaker thermal release according to claim 7, characterized in that: A right-angle part (232) is provided on the third transmission part (23) and on one side of the heat-adjustable push rod (2). When the right-angle part (232) abuts against the base (5), the rotation of the heat-adjustable push rod (2) under the action of the return torsion spring (24) is restricted.

9. The thermal release of the circuit breaker according to claim 1, wherein The second transmission part (22) includes a high-potential region (221), a low-potential region (222), and a slope region (223) connecting the high-potential region (221) and the low-potential region (222). The contact surface is the upper surface of the high-potential region (221), the upper surface of the slope region (223), and the upper surface of the low-potential region (222).

10. The thermal release of the circuit breaker according to claim 1, characterized in that, A fixing nut (32) is provided on the bimetallic strip (3). The delay screw (31) is threadedly connected to the fixing nut (32).

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