Overload thermal protection structure of molded case circuit breaker

Abstract

The utility model discloses an overload thermal protection structure of a molded case circuit breaker, which is mounted on a circuit breaker body, the circuit breaker body comprises an upper chamber and a lower chamber, and the overload thermal protection structure comprises a draw bar accommodated in the upper chamber; the bimetallic strip is accommodated in the lower cavity and is connected with the electrical loop; the lower end of the linkage mechanism is matched with the bimetallic strip, and the upper end of the linkage mechanism is matched with the traction rod. According to the structure, by means of the principle that a lever amplifies action force and expands the range, protection within the accurate time and current load range is achieved through the heat effect of the bimetallic strip, the structure has the advantages of being higher in response speed, higher in response precision and wider in adjustable range, and the protection requirement under the load condition can be more accurately matched. In addition, enough space is reserved from the rear of the operating mechanism to the leading-out end, limitation existing in the design of a bimetallic strip in the prior art is effectively solved, larger space is provided from the rear of the circuit breaker mechanism to the leading-out end, and expansion of other functions is facilitated.

Description

Technical Field

[0001] The utility model relates to the field of electrical technology, in particular to an overload thermal protection structure of a molded case circuit breaker. Background Art

[0002] In order to achieve the protection effect of the electrical circuit, the molded case circuit breaker will be equipped with a bimetallic strip inside the circuit breaker. The bimetallic strip is connected to the electrical circuit. When an overload occurs in the electrical circuit, the current in the electrical circuit increases, and the bimetallic strip heats up and deforms under the action of the current. The deformed bimetallic strip drives the operating mechanism of the circuit breaker to achieve the effect of tripping and opening the circuit breaker.

[0003] The existing bimetallic strip is placed on the side of the base facing the middle cover, and the bimetallic strip is arranged vertically to the bottom surface of the base. The problem with this structure is that the bimetallic strip and the operating mechanism will occupy too much space on the side of the base facing the middle cover, affecting the space from the rear of the operating mechanism to the outlet. Utility Model Content

[0004] Therefore, the technical problem to be solved by the utility model is how to adjust the position distribution between the bimetallic strip and the operating mechanism and improve the space utilization. To this end, an overload thermal protection structure of a molded case circuit breaker is installed on the circuit breaker body, and the circuit breaker body includes an upper chamber and a lower chamber. The overload thermal protection structure includes:

[0005] a traction rod, the traction rod being accommodated in the upper chamber;

[0006] A bimetallic strip, the bimetallic strip is accommodated in the lower chamber and connected to an electrical circuit;

[0007] A linkage mechanism, wherein the lower end of the linkage mechanism cooperates with the bimetallic strip, and the upper end of the linkage mechanism cooperates with the traction rod.

[0008] The linkage mechanism comprises a connecting rod, the lower end of the connecting rod cooperates with the bimetallic strip, and the upper end of the connecting rod is linked with the traction rod.

[0009] The linkage mechanism also includes a seesaw, which is accommodated in the lower chamber and rotates relative to the lower chamber. One end of the seesaw close to the rotating connection is located on the deformation track of the bimetallic strip, and the connecting rod cooperates with one end of the seesaw away from the rotating connection.

[0010] The connecting rod is linked with the rocker plate, and the connecting rod and the rocker plate are adjustable.

[0011] The linkage mechanism further comprises a fastener, and the connecting rod passes through the rocker plate and is threadedly connected to the fastener.

[0012] The linkage mechanism also includes a fixing part and a fixing spring. The fixing part cooperates with the connecting rod. The fixing part abuts against the top surface of the lower chamber. The fixing spring is sleeved on the connecting rod. One end of the fixing spring abuts against the fixing part, and the other end of the fixing spring abuts against the seesaw.

[0013] The seesaw is provided with a first through hole, and a contact surface is provided at one end of the seesaw away from the rotation, the contact surface is located above the first through hole, and the bimetallic strip passes through the first through hole and is located below the contact surface.

[0014] The circuit breaker body is provided with an energy storage cavity, which is communicated with the upper chamber and the lower chamber respectively. The linkage mechanism also includes an energy storage component, which is accommodated in the energy storage cavity. The connecting rod passes through the energy storage component and drives the energy storage component to operate.

[0015] A driving part is arranged at one end of the connecting rod that cooperates with the traction rod.

[0016] The bimetallic strip is accommodated in the lower chamber in a transverse and tilted manner.

[0017] The technical solution of the utility model has the following advantages:

[0018] 1. The utility model provides an overload thermal protection structure for a molded case circuit breaker, which adopts a lower bimetallic strip setting, and then realizes the upper and lower linkage effect through a linkage mechanism, so that the traction rod and the operating mechanism in the upper chamber can have a larger space, and the function expansion of the circuit breaker can be increased according to actual needs.

[0019] 2. The utility model provides an overload thermal protection structure for a molded case circuit breaker, and the setting of the connecting rod forms an upper and lower matching effect. The connecting rod forms a transmission effect between the bimetallic strip and the traction rod.

[0020] 3. The utility model provides an overload thermal protection structure for a molded case circuit breaker, in which a seesaw and a lower chamber form a rotation effect, and both sides of the seesaw form a rotation with the lower chamber. The bimetallic strip and a connecting rod are arranged at both ends of the seesaw, forming a lever-driven effect. The deformation of the bimetallic strip is amplified by the seesaw, thereby increasing the vertical movement stroke of the connecting rod and also increasing the action force of the connecting rod, thereby realizing the thermal action of the bimetallic strip and realizing the tripping and opening operation of the traction rod.

[0021] 4. The utility model provides an overload thermal protection structure for a molded case circuit breaker. Through an adjustable setting, since the seesaw forms an effect of amplifying the stroke, precise adjustment can be achieved by adjusting the position between the connecting rod and the seesaw. Different currents generate heat to cause the bimetallic strip to bend at different angles, thereby achieving a tripping control effect within an adjustable range.

[0022] 5. The utility model provides a molded case circuit breaker overload thermal protection structure, the threaded connection of the fastener makes the connecting rod adjustment more convenient, and the effect of precise adjustment can be achieved through the number of turns of the thread or the rotation angle of the connecting rod. Here, the seesaw is also provided with a fixing groove adapted to the fastener.

[0023] 6. The utility model provides an overload thermal protection structure for a molded case circuit breaker. The setting of the fixing piece and the fixing spring forms a fastening effect on the other end of the seesaw, so that the seesaw can be better linked with the connecting rod.

[0024] 7. In the overload thermal protection structure of a molded case circuit breaker provided by the utility model, the arrangement of the first through hole and the force-contacting surface increases the deformation space of the bimetallic strip, so that the bimetallic strip can better cooperate with the seesaw.

[0025] 8. The utility model provides an overload thermal protection structure for a molded case circuit breaker. The arrangement of the energy storage chamber and the energy storage component forms an energy storage reset effect, so that when no force is applied to the connecting rod, the connecting rod can be quickly reset.

[0026] 9. The utility model provides an overload thermal protection structure for a molded case circuit breaker. The setting of the driving part can improve the adjustment effect of the connecting rod. The driving part can be a groove, a protrusion, a ring structure, or a disc structure.

[0027] 10. The utility model provides an overload thermal protection structure for a molded case circuit breaker, which is arranged to be laterally inclined so that the bimetallic strip can form a better accommodation effect and reduce the height of the circuit breaker body. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A schematic diagram of the structure of the overload thermal protection structure provided by the utility model in cooperation with the base;

[0030] Figure 2 A schematic diagram of the structure of the overload thermal protection structure provided by the utility model in cooperation with the base;

[0031] Figure 3 A cross-sectional view of the overload thermal protection structure provided by the utility model in cooperation with the base;

[0032] Figure 4A bottom view of the overload thermal protection structure provided by the utility model in cooperation with the base;

[0033] Figure 5 A schematic diagram of the structure of an overload thermal protection structure of a molded case circuit breaker provided by the utility model;

[0034] Figure 6 A schematic diagram of the structure of an overload thermal protection structure of a molded case circuit breaker provided by the utility model;

[0035] Figure 7 A side view of an overload thermal protection structure of a molded case circuit breaker provided by the utility model;

[0036] Figure 8 A side view of an overload thermal protection structure of a molded case circuit breaker provided by the utility model.

[0037] Description of reference numerals:

[0038] 11. Upper chamber; 12. Lower chamber; 13. Base; 14. Drawbar; 15. Bimetallic strip; 16. Connecting rod; 17. Rocker; 18. Insert; 19. Fastener; 20. Fixing piece; 21. Fixing spring; 22. Energy storage chamber; 23. Energy storage piece; 121. Rotating shaft hole; 122. Rotating shaft groove; 141. Notch; 161. Driving unit; 171. Rotating shaft; 172. Fixing groove; 173. First through hole; 174. Force surface. DETAILED DESCRIPTION

[0039] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0040] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "laterally inclined", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, 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 therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] Example 1

[0044] This embodiment provides an overload thermal protection structure for a molded case circuit breaker, as shown in the attached Figure 1-8 As shown, it is installed on the circuit breaker body, and the circuit breaker body includes an upper chamber 11 and a lower chamber 12. Here, the upper chamber 11 is specifically a middle cover and a base 13. The operating mechanism and the traction rod 14 are both accommodated in the upper chamber 11. There is also an upper cover above the upper chamber 11 to form a closed effect. This is a prior art, so it is not described in detail in this embodiment. The lower chamber 12 is a base 13 and a bottom plate. The lower chamber 12 opens downward and forms a closed effect through the bottom plate.

[0045] The overload thermal protection structure includes:

[0046] The traction rod 14 is accommodated in the upper chamber 11, and cooperates with the operating mechanism to achieve the effect of tripping and opening the gate. The linkage structure between the traction rod 14 and the operating mechanism is the prior art, so it is not described in detail in this embodiment.

[0047] Bimetallic strip 15, bimetallic strip 15 will be deformed under the action of large current. Different currents generate heat and cause the bimetallic strip 15 to bend at different angles. This is a prior art, so this embodiment will not be described in detail. Bimetallic strip 15 is accommodated in lower chamber 12, and bimetallic strip 15 is connected to the electrical circuit. Bimetallic strip 15 can cooperate with the input end to form an electrical connection effect, and bimetallic strip 15 can also cooperate with the output end to form an electrical connection effect. The number of bimetallic strips 15 can be set according to actual needs. In this embodiment, the number of bimetallic strips 15 corresponds to the number of phase lines of the circuit breaker, and one phase line is electrically connected to one bimetallic strip 15.

[0048] The linkage mechanism is a linkage mechanism that runs through the base 13 from top to bottom. The lower end of the linkage mechanism cooperates with the bimetallic strip 15. Under the action of the current, the bimetallic strip 15 deforms and bends, and the bimetallic strip 15 drives the linkage mechanism to move. The upper end of the linkage mechanism cooperates with the traction rod 14. When the bimetallic strip 15 moves, the traction rod 14 is driven to move through the linkage mechanism to achieve the effect of tripping and opening the gate. The linkage mechanism here can be a connecting rod structure, and the movement of the traction rod 14 is achieved through the vertical up and down movement of the connecting rod. The linkage mechanism can also be a rack structure, or a slide rail structure, or a pull rope structure.

[0049] The bimetallic strip 15 is placed downwardly, and the linkage mechanism is used to achieve the upper and lower linkage effect, so that the traction rod 14 and the operating mechanism in the upper chamber 11 can have a larger space, and the function expansion of the circuit breaker can be increased according to actual needs.

[0050] Specifically, as attached Figure 1-8 As shown, the linkage mechanism includes a connecting rod 16, the lower end of which cooperates with the bimetallic strip 15. The lower end of the connecting rod 16 can be located on the deformation trajectory of the bimetallic strip 15, and the lower end of the connecting rod 16 can also be connected to the deformed end of the bimetallic strip 15 to form a linkage effect between the two. The upper end of the connecting rod 16 is linked with the traction rod 14 to form a synchronous action. Here, the connecting rod 16 passes through the base 13 to form an effect of upper and lower connection, so the connecting rod 16 moves vertically up and down. Here, the connecting rod 16 can move downward to drive the traction rod 14 to rotate, thereby achieving the effect of tripping and opening the gate; the connecting rod 16 can also move upward to drive the traction rod 14 to rotate, thereby achieving the effect of tripping and opening the gate. The setting of the connecting rod 16 forms an effect of upper and lower cooperation. The transmission effect between the bimetallic strip 15 and the traction rod 14 is formed through the connecting rod 16. In addition, it can also be a rack structure, that is, the lower chamber 12 is provided with a gear or an incomplete gear that cooperates with the bimetallic strip 15, the rack passes through the base 13 to form an up-and-down penetration effect, and the gear and the rack are meshed to form an effect that the rack drives the traction rod 14 to rotate. It can also be a pull rope structure, the lower end of the pull rope cooperates with the bimetallic strip 15, the upper end of the pull rope cooperates with the traction rod 14, and the lower end of the pull rope cooperates with the bimetallic strip 15. It can also be a slide rail structure, etc., which will not be described in detail in this embodiment.

[0051] Specifically, as attached Figure 2-8As shown, the linkage mechanism also includes a seesaw 17, which is accommodated in the lower chamber 12. The seesaw 17 rotates relative to the lower chamber 12. The seesaw 17 may be provided with a rotating shaft 171, and the lower chamber 12 may be provided with a rotating shaft hole 121. The rotating shaft 171 cooperates with the rotating shaft hole 121 to form a relative rotation effect. Alternatively, the seesaw 17 may be provided with a rotating shaft hole 121, and the lower chamber 12 may be provided with a rotating shaft 171, so that the rotation effect can also be achieved. In this embodiment, the seesaw 17 is a flat plate-like structure, and a rotating shaft 171 is provided on its short side wall. Two rotating shaft holes 121 are symmetrically provided on the side wall of the lower chamber 12, so as to achieve a relative rotation effect between the seesaw 17 and the lower chamber 12. In this embodiment, the position where the rotating shaft 171 cooperates with the rotating shaft hole 121 is the rotation connection. The seesaw 17 includes two long side walls, and one end of the seesaw 17 close to the rotation connection is located on the deformation track of the bimetallic strip 15, and this end is one of the long side walls. When the bimetal 15 is deformed, the bimetal 15 drives the seesaw 17 to rotate. The connecting rod 16 cooperates with one end of the seesaw 17 away from the rotating connection, and this end is another long side wall. The rotating connection forms a fulcrum rotation effect. Taking the attached figure as an example, the bimetal 15 cooperates with the left end of the seesaw 17, and the connecting rod 16 cooperates with the right end of the bimetal 15. The distance from the left end of the seesaw 17 to the rotating connection is less than the distance from the right end of the seesaw 17 to the rotating connection, that is, the rotating connection is close to the left end of the seesaw 17. The distance ratio between the two ends here can be adjusted according to actual needs. This structure forms a lever amplification effect, which amplifies the deformation of the bimetal 15 through the seesaw 17, thereby increasing the movement stroke of the connecting rod 16 in the vertical direction, and also increases the action force of the connecting rod 16, thereby realizing the thermal action of the bimetal 15 and realizing the tripping and opening operation of the traction rod 14. Here, the deformation of the bimetallic strip 15 causes the left end of the seesaw 17 to move upward, thereby the right end of the seesaw 17 drives the connecting rod 16 to move downward, and the connecting rod 16 drives the traction rod 14 to rotate. Alternatively, the deformation of the bimetallic strip 15 causes the left end of the seesaw 17 to move downward, thereby the right end of the seesaw 17 drives the connecting rod 16 to move upward, and the connecting rod 16 drives the traction rod 14 to rotate. In this embodiment, the connection between the bimetallic strip 15 and the incoming line end is located above the seesaw 17, so the deformation of the bimetallic strip 15 causes the left end of the seesaw 17 to move upward. Here, when the space of the lower chamber 12 is sufficient, the deformation of the bimetallic strip 15 can also be used to drive the left end of the seesaw 17 to move downward. Here, each phase line corresponds to a bimetallic strip 15. Taking three phase lines as an example, the three bimetallic strips 15 are distributed at equal intervals. The three bimetallic strips 15 cooperate with the same seesaw 17 to form a linkage effect, which can also form an isolation chamber effect for the lower chamber 12. Each small chamber is correspondingly provided with a bimetallic strip 15 and a seesaw 17 to form a corresponding linkage effect.

[0052] Specifically, one end of the bimetallic strip 15 is electrically connected to the incoming line end, and the other end of the bimetallic strip 15 is deformed. Taking the accompanying figure as an example, the right end of the bimetallic strip 15 is located above the right end of the seesaw 17, and the left end of the bimetallic strip 15 extends obliquely to cooperate with the left end of the seesaw 17. Here, the bimetallic strip 15 is bolted to the incoming line end. In addition, the bimetallic strip 15 can also be electrically connected to the output end, and those skilled in the art can adjust it according to actual needs.

[0053] Specifically, as attached Figure 2-8 As shown, it also includes a plug-in 18, and the number of plug-in 18 is two. In order to facilitate the installation and fixation of the seesaw 17, a shaft groove 122 is provided on both sides of the lower chamber 12, and the shaft groove 122 extends downward. The shaft hole 121 is located at the top of the shaft groove 122. When the seesaw 17 is installed, the shaft 171 enters the shaft hole 121 along the shaft groove 122, and then the plug-in 18 cooperates with the shaft groove 122 to achieve the fixing effect of the shaft 171 and prevent the rotation connection from being offset. The plug-in 18 and the shaft groove 122 are plug-in fits. The plug-in 18 can be set independently, and the plug-in 18 can also cooperate with the bottom plate. When the bottom plate cooperates with the base 13, the fixing effect of the rotation connection can also be achieved. The plug-in 18 and the shaft groove 122 can also be matched with a dovetail groove to improve the fixing strength. Here, the plug-in 18 and the shaft groove 122 can be interference fit. In addition, the seesaw 17 can also directly cooperate with the lower chamber 12 to form a relative rotation effect.

[0054] Specifically, as attached Figure 2-8 As shown, the connecting rod 16 is linked with the seesaw 17, and the seesaw 17 rotates, driving the connecting rod 16 to move vertically up and down. In this embodiment, when the seesaw 17 cooperates with the connecting rod 16 to move downward at one end, the connecting rod 16 moves vertically downward, so that the traction rod 14 is actuated, thereby achieving the effect of tripping and opening the gate. The connecting rod 16 and the seesaw 17 are adjustable. The connection position of the connecting rod 16 and the seesaw 17 can be adjusted, specifically referring to the different connection positions of the connecting rod 16 and the seesaw 17 being linked, and it can also be considered that the length of the connecting rod 16 passing through the seesaw 17 is different. The connecting rod 16 and the seesaw 17 can be threadedly connected or elastically matched. Through the adjustable setting, since the seesaw 17 forms an effect of amplifying the stroke, precise adjustment can be achieved by adjusting the position between the connecting rod 16 and the seesaw 17. Different currents generate heat to cause the bimetallic strip 15 to bend at different angles, thereby achieving a tripping control effect within an adjustable range.

[0055] Specifically, as attached Figure 3-4As shown in Figures 7 and 8, the linkage mechanism also includes a fastener 19, and the connecting rod 16 passes through the seesaw 17 and is threadedly connected to the fastener 19. The fastener 19 is located below the seesaw 17, and the fastener 19 here can be a nut. The end of the connecting rod 16 passing through the seesaw 17 is provided with an external thread, so the connecting rod 16 and the fastener 19 form a threaded connection. The threaded connection of the fastener 19 makes it easier to adjust the connecting rod 16. Since the stroke of the connecting rod 16 is enlarged, the matching position between the connecting rod 16 and the seesaw 17 is adjusted by adjusting the number of turns of the thread or the rotation angle of the connecting rod 16. Through testing or data calculation, the bending angle of the bimetallic strip 15 and the parameter relationship between the seesaw 17 and the connecting rod 16 under different currents can be obtained, and the effect of precise adjustment can be achieved through the calculation formula. Here, it is specifically to adjust the distance between the force surface and the bimetallic strip 15. By precisely adjusting the direction of the connecting rod 16 and the number of turns, the seesaw 17 can be driven to adjust so that the contact surface of the seesaw 17 can be moved up and down close to or away from the bimetal 15 at a precise distance, so that different currents passing through the molded case circuit breaker generate heat, and the bimetal 15 bends at different angles, which can accurately pull the connecting rod 16 to trip and disconnect the molded case circuit breaker. In addition, the connecting rod 16 can also be directly threadedly connected to the seesaw 17, and the adjustment effect can also be achieved through the threaded hole of the seesaw 17. In addition to this embodiment, the connecting rod 16 and the seesaw 17 can be elastically matched, that is, one gear corresponds to one current position. The seesaw 17 can also be provided with a semicircular hole, and the connecting rod 16 can be provided with a plurality of gear protrusions. At a certain angle, the gear protrusion can pass through the seesaw 17, and the connecting rod 16 is rotated, and the gear protrusion and the seesaw 17 are offset to form a gear limiting effect.

[0056] Specifically, as attached Figure 3-4 As shown, the seesaw 17 is also provided with a fixing groove 172 adapted to the fastener 19. When the fastener 19 is a nut, in particular a regular hexagonal nut. The fixing groove 172 can abut against two side surfaces of the nut to form a fixing effect, and the fixing groove 172 can also abut against all six side surfaces of the nut to form a fixing effect. When debugging, the nut will not slip, and the adjustment effect can be achieved by adjusting the connecting rod 16.

[0057] Specifically, as attached Figure 3As shown, the linkage mechanism also includes a fixing member 20 and a fixing spring 21. The fixing member 20 cooperates with the connecting rod 16. The fixing member 20 abuts against the top surface of the lower chamber 12. The fixing spring 21 is sleeved on the connecting rod 16. One end of the fixing spring 21 abuts against the fixing member 20, and the other end of the fixing spring 21 abuts against the seesaw 17. The fixing member 20 places the fixing spring 21 and extends into the base 13, specifically referring to the hole in the base 13 for the connecting rod 16 to pass through, so as to prevent the fixing spring 21 from extending into the hole. The fixing member 20 here can be a retaining spring or other structure. The setting of the fixing member 20 and the fixing spring 21 forms a fastening effect on the other end of the seesaw 17, so that the seesaw 17 can be better linked with the connecting rod 16. The fixing member 20 and the fixing spring 21 are located above the seesaw 17, and the fastener 19 is located below the seesaw 17, forming an upper and lower clamping effect, so that the linkage end connection of the connecting rod 16 and the seesaw 17 is more firmly and stably connected. In addition, the fixing member 20 may also be omitted, and only the stability of the fixing spring 21 needs to be ensured.

[0058] Specifically, the number of connecting rods 16 can be one or more, and the lower end of one connecting rod 16 is linked to the seesaw 17, and the upper end is linked to the traction rod 14, so as to achieve the effect of up and down transmission. There can also be two connecting rods 16, and the two connecting rods 16 are arranged in parallel, and their lower ends are connected to the seesaw 17, and their upper ends are connected to the traction rod 14. There can also be three connecting rods 16. In this embodiment, the number of connecting rods 16 is described by taking only one as an example. Here, the matching position of the connecting rod 16 and the traction rod 14 can also be adjusted according to actual needs, and can be the end position of the traction rod 14, or the middle area of ​​the traction rod 14. Those skilled in the art can adjust it according to actual needs.

[0059] Specifically, as attached Figure 5 , 7 As shown, the traction rod 14 is provided with a notch 141, and the notch 141 has only one opening direction. The rod size of the connecting rod 16 is smaller than the notch 141, and the top size of the connecting rod 16 is larger than the notch 141. It can be considered that the size of the brim position of the connecting rod 16 is larger than the notch 141. Therefore, during the installation process of the connecting rod 16 and the traction rod 14, the rod portion enters the notch 141 horizontally, so that the brim part is located above the notch 141, forming a fitting and fixing effect, thereby achieving the effect of driving the traction rod 14 to move. Further, the connecting rod 16 here can also be a simple screw structure.

[0060] Specifically, as attached Figure 4-8As shown, the seesaw 17 is provided with a first through hole 173, and a contact surface 174 is provided at one end of the seesaw 17 away from the rotation. The contact surface 174 is located above the first through hole 173, and the two side walls of the first through hole 173 extend toward the contact surface 174 and are connected to the contact surface 174, so that the contact surface 174 and the two side walls are connected to form an arched structure, and the bottom end of the contact surface 174 is higher than the top surface of the rest of the seesaw 17. It can also be considered that the contact surface 174 and the two side walls are in a bulge shape. The bimetallic strip 15 passes through the first through hole 173 and is located below the contact surface 174, that is, the left end of the bimetallic strip 15 passes through the first through hole 173 and extends to the bottom of the contact surface 174. The setting of the first through hole 173 and the contact surface 174 increases the deformation space of the bimetallic strip 15, so that the bimetallic strip 15 can better cooperate with the seesaw 17. Here, a certain gap is formed between the bimetallic strip 15 and the bottom end of the contact surface 174, and a precise adjustment effect is formed by precisely adjusting the gap between the bimetallic strip 15 and the contact surface 174. It should also be noted that the length of the first through hole 173 is greater than the length of the contact surface 174. Further, the contact surface 174 can be an inclined surface or a plane. In this embodiment, the contact surface 174 is an inclined surface, specifically inclined downward toward the left end of the seesaw 17. The inclined setting allows the bimetallic strip 15 to better cooperate with the contact surface 174 to form a driving effect, and it is convenient to adjust the distance between the bimetallic strip 15 and the contact surface 174.

[0061] Specifically, as attached Figure 1-3 As shown, the circuit breaker body is provided with an energy storage chamber 22, specifically, the base 13 is provided with an energy storage chamber 22. The energy storage chamber 22 is communicated with the upper chamber 11 and the lower chamber 12 respectively, and the energy storage chamber 22 here is the part of the hole of the base 13 for the connecting rod 16 to pass through. The cross-section of the energy storage chamber 22 is larger than the lower end size of the hole, so a stepped structure is formed, and the energy storage chamber 22 is close to the upper chamber 11. The linkage mechanism also includes an energy storage member 23, and the energy storage member 23 is accommodated in the energy storage chamber 22. The connecting rod 16 passes through the energy storage member 23 and the connecting rod 16 drives the energy storage member 23 to move. It can be considered that the energy storage member 23 is sleeved on the connecting rod 16. When the connecting rod 16 moves vertically downward, the connecting rod 16 will exert force on the energy storage member 23, so that the energy storage member 23 is compressed to store energy. The setting of the energy storage chamber 22 and the energy storage member 23 forms the effect of energy storage reset, so that when no force is applied to the connecting rod 16, the connecting rod 16 can be quickly reset. In this embodiment, the energy storage member 23 can be a straight spring or a conical spring. A positioning protrusion is provided on the connecting rod 16, and the positioning protrusion drives the energy storage member 23 to move to achieve an energy storage effect.

[0062] Specifically, as attached Figure 4-8As shown, a driving part 161 is provided at one end of the connecting rod 16 that cooperates with the traction rod 14. The setting of the driving part 161 can improve the adjustment effect of the connecting rod 16, and the operator can drive the driving part 161 to rotate the connecting rod 16. In this embodiment, the lower end of the connecting rod 16 and the fastener 19 are threadedly connected as an example for description. When the driving part 161 is driven, the connecting rod 16 rotates. Since the fastener 19 is in a fixed state, the connecting rod 16 can move vertically downward or vertically upward, thereby achieving the adjustment effect. The driving part 161 can be driven by a tool. For example, the driving part 161 can be a groove, such as a slot, a cross slot, a Pozi slot, or a hexagon socket, etc., and the rotation effect of the connecting rod 16 can be achieved by driving with a tool; the driving part 161 can also be a protrusion, such as a regular triangular prism, a regular quadrangular prism, a regular pentagonal prism, or a regular hexagonal prism, and the driving effect can also be achieved by tools such as sleeves. The driving part 161 can also be manually driven. For example, the driving part 161 is a ring structure, that is, the driving part 161 is a ring part, and the ring part is connected to the top of the connecting rod 16. The connecting rod 16 is driven to rotate by twisting the ring part. The driving part 161 can also be a disc-shaped structure, and can also be manually rotated.

[0063] Specifically, the seesaw 17 and the bimetallic strip 15 are installed from below. When the connecting rod 16 cooperates with the traction rod 14, the connecting rod 16 passes through the base 13 and extends into the lower chamber 12. Then, the spring 21, the seesaw 17, and the bimetallic strip 15 are installed and fixed to form an assembly effect. There will be no interference between them and the upper chamber 11, which improves the convenience of installation, makes installation simpler, and is also conducive to assembly line operation.

[0064] Specifically, as attached Figure 1-8 As shown, the bimetallic strip 15 is tilted transversely and accommodated in the lower chamber 12. By tilting the bimetallic strip 15 transversely, the bimetallic strip 15 can better form an accommodation effect and reduce the height of the circuit breaker body. When the number of the bimetallic strips 15 is three, the structures of the three bimetallic strips 15 are offset, and their left ends are tilted downward to the bottom of the contact surface 174, and their right ends are electrically connected to the electrical circuit in the circuit breaker. The transverse tilt forms a horizontal installation design. The horizontal installation design of the bimetallic strip 15 leaves more space from the rear of the circuit breaker mechanism to the outlet terminal, making the circuit breaker smaller in size and convenient for installation and use.

[0065] Specifically, the bimetallic strip 15 also includes a foolproof structure, which can form a positioning and fixing effect to prevent the bimetallic strip 15 from being installed in the wrong direction during installation. The foolproof structure can be a foolproof groove or a foolproof protrusion.

[0066] Specifically, this embodiment uses the principle of mechanical levers to amplify the action force and expand the range, and uses the thermal effect of the bimetallic strip 15 to achieve protection within a precise time and current load range. It has the characteristics of faster response speed, higher response accuracy, and a wider adjustable range, and can more accurately match the protection requirements under load conditions. At the same time, sufficient space is left from the rear of the operating mechanism to the outlet terminal. This structure effectively solves the limitations of the bimetallic strip 15 design in the prior art, can adapt to a wider range of load conditions, and provides a larger space from the rear of the circuit breaker mechanism to the outlet terminal, facilitating the expansion of other functions.

[0067] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. A thermal overload protection structure for a molded case circuit breaker, mounted on a circuit breaker body, wherein the circuit breaker body comprises an upper chamber (11) and a lower chamber (12), characterized in that: The overload thermal protection structure includes: A traction rod (14), wherein the traction rod (14) is accommodated in the upper chamber (11); A bimetallic strip (15), the bimetallic strip (15) being accommodated in the lower chamber (12), and the bimetallic strip (15) being connected to an electrical circuit; A linkage mechanism, wherein the lower end of the linkage mechanism cooperates with the bimetallic strip (15), and the upper end of the linkage mechanism cooperates with the traction rod (14).

2. The overload thermal protection structure of the molded case circuit breaker according to claim 1, characterized in that: The linkage mechanism comprises a connecting rod (16), the lower end of the connecting rod (16) cooperates with the bimetallic strip (15), and the upper end of the connecting rod (16) is linked with the traction rod (14).

3. The overload thermal protection structure of the molded case circuit breaker according to claim 2, characterized in that: The linkage mechanism also includes a seesaw (17), the seesaw (17) is accommodated in the lower chamber (12), the seesaw (17) rotates relative to the lower chamber (12), one end of the seesaw (17) close to the rotating connection is located on the deformation track of the bimetallic strip (15), and the connecting rod (16) cooperates with one end of the seesaw (17) away from the rotating connection.

4. The overload thermal protection structure of the molded case circuit breaker according to claim 3, characterized in that: The connecting rod (16) and the rocker (17) are linked together, and the connecting rod (16) and the rocker (17) are adjustable.

5. The overload thermal protection structure of the molded case circuit breaker according to claim 4, characterized in that: The linkage mechanism also includes a fastener (19), and the connecting rod (16) passes through the rocker plate (17) and is threadedly connected to the fastener (19).

6. The overload thermal protection structure of the molded case circuit breaker according to claim 3, 4 or 5, characterized in that: The linkage mechanism further comprises a fixing member (20) and a fixing spring (21), wherein the fixing member (20) cooperates with the connecting rod (16), the fixing member (20) abuts against the top surface of the lower chamber (12), the fixing spring (21) is sleeved on the connecting rod (16), one end of the fixing spring (21) abuts against the fixing member (20), and the other end of the fixing spring (21) abuts against the seesaw (17).

7. The overload thermal protection structure of the molded case circuit breaker according to claim 3, 4 or 5, characterized in that: The seesaw (17) is provided with a first through hole (173), and a contact surface (174) is provided at one end of the seesaw (17) away from the rotation, the contact surface (174) is located above the first through hole (173), and the bimetallic strip (15) passes through the first through hole (173) and is located below the contact surface (174).

8. The overload thermal protection structure of the molded case circuit breaker according to claim 2, 3, 4 or 5, characterized in that: The circuit breaker body is provided with an energy storage chamber (22), the energy storage chamber (22) being communicated with the upper chamber (11) and the lower chamber (12) respectively, the linkage mechanism further comprising an energy storage component (23), the energy storage component (23) being accommodated in the energy storage chamber (22), the connecting rod (16) passing through the energy storage component (23), and the connecting rod (16) driving the energy storage component (23) to operate.

9. The overload thermal protection structure of the molded case circuit breaker according to claim 2, 3, 4 or 5, characterized in that: A driving portion (161) is provided at one end of the connecting rod (16) that cooperates with the traction rod (14).

10. The overload thermal protection structure of the molded case circuit breaker according to claim 1, 2 or 3, characterized in that: The bimetallic strip (15) is accommodated in the lower chamber (12) in a transversely inclined manner.

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