Thermal relay and combined structure of thermal relay and contactor

Abstract

The utility model discloses a thermal relay and a combined structure of the thermal relay and a contactor. A rear cover plate; the penetrating pipes are fixed and arranged on the outer wall face of the rear cover plate in a protruding mode, the rod type terminals are arranged in the penetrating pipes in a penetrating mode, one ends of the rod type terminals are connected with the thermal tripping mechanism, and the other ends of the rod type terminals are located outside the penetrating pipes; the lower buckles are fixedly arranged on the outer wall face of the rear cover plate at intervals, the lower buckles and the penetrating pipes are located at the two ends of the rear cover plate in the length direction respectively, and buckling parts buckled with the ends of the lower buckles are arranged on a shell of the contactor; when the rod type terminal is connected with a wiring terminal of the contactor and the lower buckle is buckled with the buckling part, the penetrating pipe is in contact with the contactor shell, and the penetrating pipe and the lower buckle support the rear cover plate at the same time, so that a connection gap is kept between the rear cover plate and the contactor shell, and the connection gap is used for heat dissipation of the thermal relay. The strength of the connection structure between the combined thermal relay and the contactor is improved, heat dissipation of the thermal relay is facilitated, and action response and reset time of the thermal relay are ensured to accord with set parameters.

Description

Technical Field

[0001] This utility model relates to the field of electrical equipment technology, and in particular to a thermal relay and its combination structure with a contactor. Background Technology

[0002] The main function of a thermal relay is to provide overload protection for circuits or motors. Thermal relays are usually used in combination with contactors. The thermal relay and contactor can be fixed by independent installation and then connected to the terminals of the thermal relay and the contactor by wires. Alternatively, the thermal relay terminals can be directly plugged into the corresponding contactor terminals to combine the thermal relay and contactor, reducing the space occupied by the installation.

[0003] However, in the above-mentioned combination structure of thermal relay and contactor, the connection force between thermal relay and contactor is mainly provided by the contactor terminals. The housing of thermal relay and contactor provides support, resulting in poor connection strength and affecting the heat dissipation of thermal relay. The action response and reset time of relay deviate. Utility Model Content

[0004] In view of the shortcomings of the existing production technology, the applicant provides a thermal relay and its combination structure with a contactor, thereby improving the strength of the connection structure between the combined thermal relay and the contactor, while maintaining a certain distance between the thermal relay and the contactor housing to facilitate heat dissipation of the thermal relay and ensure that the action response and reset time of the thermal relay meet the set parameters.

[0005] The technical solution adopted in this utility model is as follows:

[0006] A thermal relay, comprising,

[0007] The housing structure houses the thermal tripping mechanism.

[0008] The rear cover plate is installed at the opening of the housing structure to enclose the thermal release mechanism within the housing structure.

[0009] Multiple through-tubes are fixedly installed on the outer wall surface of the rear cover plate and protrude from the outer wall surface of the rear cover plate.

[0010] The rod-type terminals correspond one-to-one with the tubes and are installed inside the tubes. One end is connected to the thermal tripping mechanism, and the other end is located outside the tube and is used to connect to the contactor's wiring terminals.

[0011] The lower buckles are multiple and fixedly installed at intervals on the outer wall of the rear cover plate. The lower buckles and the through tube are located at both ends of the length direction of the rear cover plate. The outer shell of the contactor is provided with a fastening part that engages with the end of the lower buckle.

[0012] When the rod-type terminal is connected to the wiring terminal of the contactor and the lower buckle is fastened to the fastening part, the tube contacts the housing of the contactor. The tube and the lower buckle simultaneously support the rear cover plate, so that a connection gap is maintained between the rear cover plate and the housing of the contactor. The connection gap is used for heat dissipation of the thermal relay.

[0013] As a further improvement to the above technical solution:

[0014] The contactor housing is provided with support portions that correspond one-to-one with the through-tubes, and the support portions are rib structures that protrude from the contactor housing.

[0015] The rear cover plate is provided with ventilation holes that connect the inner and outer spaces of the housing structure. The thermal release mechanism includes a bimetallic strip, and the ventilation holes correspond to the bimetallic strip.

[0016] The fastening part is a groove provided on the upper surface of the bottom plate of the contactor. The structure of the lower buckle includes a first extension connected to the rear cover plate. A first protrusion is provided on one side of the end of the first extension, and the first protrusion is fastened to the fastening part.

[0017] The contactor housing has two parallel upright plates. The upright plates extend along the length of the rear cover plate and are connected to the bottom plate of the contactor. When the contactor is connected to the thermal relay, the ends of the upright plates face the outer wall of the rear cover plate. Each upright plate has a fastening block on a single side. The two fastening blocks are located on the sides facing different upright plates. The rear cover plate has an upper buckle that engages with the fastening blocks.

[0018] One side of each upright panel is attached to an upper clip, and the other side is attached to a lower clip.

[0019] The upper buckle includes a second extension connected to the rear cover plate. A second protrusion is provided on one side of the end of the second extension. The second protrusion is engaged with the buckle block. The buckle block is provided with a guide slope to guide the second protrusion past the buckle block and hook onto the buckle block. After the second protrusion hooks onto the buckle block, the second extension comes into contact with the buckle block.

[0020] The shell structure includes a main shell and an auxiliary shell connected to the main shell. The main shell and the auxiliary shell are arranged in the same direction as the length direction of the rear cover plate. The bimetallic sheet is installed inside the main shell. The rear cover plate is an integral structure and is connected to both the main shell and the auxiliary shell. The inner wall of the rear cover plate is provided with multiple fins. The length direction of the fins is the same as the length direction of the rear cover plate, and the length of the fins is adapted to the length of the rear cover plate.

[0021] The main housing is provided with multiple partitions, which divide the main housing into cavities that correspond one-to-one with the bimetallic strips. The number of fins is the same as that of the partitions and they correspond one-to-one. The fins are in surface contact with the corresponding partitions.

[0022] One end of the rear cover is connected to the opening of the auxiliary housing via a slot-type fastening structure, and the other end of the rear cover is connected to the opening of the main housing via a hook-and-groove fastening structure.

[0023] It also includes a connecting cover that fits against one side surface of the auxiliary housing, the connecting cover having a buckle that snaps onto the end of the rear cover plate, and a plug plate that inserts into the auxiliary housing.

[0024] A combined structure of a thermal relay and a contactor includes the thermal relay described in any of the above claims. The contactor has a snap-fit ​​portion on its housing. The lower snap-fit ​​end is snapped into the snap-fit ​​portion. A through tube contacts the housing of the contactor. The through tube and the lower snap-fit ​​simultaneously support the rear cover plate, so that a connection gap is maintained between the rear cover plate and the housing of the contactor. The connection gap is used for heat dissipation of the thermal relay.

[0025] The beneficial effects of this utility model are as follows:

[0026] This utility model has a compact and reasonable structure and is easy to operate. Two supporting connection structures are set at both ends along one length of the relay's rear cover plate, namely the through tube and the lower buckle, to support the rear cover plate and connect the thermal relay and the contactor together with the rod terminal. A connection gap is formed between the rear cover plate and the contactor, which improves the strength of the connection structure between the combined thermal relay and the contactor. At the same time, it maintains a certain distance between the thermal relay and the contactor housing to facilitate heat dissipation of the thermal relay and ensure that the thermal relay's action response and reset time meet the set parameters.

[0027] This utility model also has the following advantages:

[0028] (1) A pair of upper buckles are symmetrically arranged, and a pair of lower buckles are symmetrically arranged. The upper and lower buckles are connected and contacted with the vertical plate to limit the thermal relay along the length direction perpendicular to the rear cover plate. A buckling connection structure is added between the lower buckle and the rod terminal to improve the strength of the connection structure between the rear cover plate and the contactor.

[0029] (2) The integrated rear cover makes the assembly of the thermal relay more convenient. Multiple fins are set in the length direction of the rear cover, which not only strengthens the structure but also increases the inner surface area of ​​the rear cover, improving the efficiency of heat transfer from the main housing to the rear cover and enhancing the heat dissipation effect. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the combined structure of the thermal relay and contactor of this utility model.

[0031] Figure 2 This is a schematic diagram of the combined structure of the thermal relay and contactor of this utility model (from another perspective).

[0032] Figure 3 This is a schematic diagram (front view) of the combined structure of the thermal relay and contactor of this utility model.

[0033] Figure 4 This is an exploded view of the combined structure of the thermal relay and contactor of this utility model.

[0034] Figure 5 This is a schematic diagram of the contactor of this utility model.

[0035] Figure 6 This is a schematic diagram of the structure of the rear cover plate of this utility model.

[0036] Figure 7 This is a schematic diagram of the structure of the rear cover plate of this utility model (from another perspective).

[0037] Figure 8 This is a schematic diagram of the shell structure of this utility model.

[0038] Figure 9 This is a schematic diagram of the shell structure of this utility model (from another perspective).

[0039] in:

[0040] 1. Shell structure; 11. Main shell; 1101. Snap hole; 111. Partition; 12. Auxiliary shell; 1201. First slot; 1202. Second slot;

[0041] 2. Rear cover plate; 201. First insert block; 202. Second insert block; 203. Inner locking block; 204. Third slot; 21. Through tube; 22. Upper buckle; 221. Second extension; 222. Second protrusion; 23. Lower buckle; 231. First extension; 232. First protrusion; 24. Ventilation hole; 25. Fin plate;

[0042] 3. Rod-type terminal;

[0043] 4. Connecting cover; 401. Snap-on; 402. Insert plate;

[0044] 5. Contactor; 50. Base plate; 51. Support; 52. Fastener; 521. Guide slope; 53. Fastening part; 54. Vertical plate. Detailed Implementation

[0045] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0046] Example 1:

[0047] like Figures 1-6 As shown, the thermal relay of this embodiment includes a housing structure 1, a rear cover plate 2, a through tube 21, a rod-type terminal 3, and a lower buckle 23.

[0048] Housing structure 1, which internally houses a thermal tripping mechanism;

[0049] The rear cover plate 2 is installed at the opening of the housing structure 1 to enclose the thermal release mechanism in the housing structure 1;

[0050] Multiple through-tubes 21 are fixedly installed on the outer wall surface of the rear cover plate 2 and protrude from the outer wall surface of the rear cover plate 2.

[0051] The rod-type terminal 3 corresponds one-to-one with the tube 21 and is installed in the tube 21. One end is connected to the thermal tripping mechanism, and the other end is located outside the tube 21 for connection to the wiring terminal of the contactor 5.

[0052] The lower buckle 23 is in multiple pieces and is fixedly set at intervals on the outer wall of the rear cover plate 2. The lower buckle 23 and the through tube 21 are located at both ends of the length direction of the rear cover plate 2 respectively. The outer shell of the contactor 5 is provided with a fastening part 53 that is fastened to the end of the lower buckle 23.

[0053] When the rod terminal 3 is connected to the wiring terminal of the contactor 5 and the lower buckle 23 is fastened to the fastening part 53, the through tube 21 contacts the housing of the contactor 5. The through tube 21 and the lower buckle 23 simultaneously support the rear cover plate 2, so that the rear cover plate 2 and the housing of the contactor 5 maintain a connection gap L. The connection gap L is used for heat dissipation of the thermal relay.

[0054] Two supporting connection structures, namely through tube 21 and lower buckle 23, are provided at both ends along one length direction of the relay rear cover plate 2. These structures support the rear cover plate 2 and, together with the rod terminal 3, connect the thermal relay and the contactor 5. A connection gap L is formed between the rear cover plate 2 and the contactor 5 to improve the strength of the connection structure between the combined thermal relay and the contactor 5. At the same time, a certain distance is maintained between the housing of the thermal relay and the contactor 5 to facilitate heat dissipation of the thermal relay and ensure that the action response and reset time of the thermal relay meet the set parameters.

[0055] Furthermore, the outer casing of the contactor 5 is provided with support portions 51 that correspond one-to-one with the through tube 21. The support portions 51 are stiffener structures that protrude from the outer casing of the contactor 5.

[0056] The ribbed support section 51 facilitates air entry into the connection gap L, allowing heat to be carried away from the rear cover plate 2 through airflow, thus aiding in the heat dissipation of the thermal relay. Specifically, for example... Figure 5 As shown, the cross-section of the stiffener structure is cross-shaped.

[0057] Furthermore, the rear cover plate 2 is provided with ventilation holes 24 that connect the inner and outer spaces of the housing structure 1, and the thermal release mechanism includes a bimetallic strip, with the ventilation holes 24 corresponding to the bimetallic strip.

[0058] Ventilation holes 24 are provided on the rear cover plate 2 to prevent the bimetallic strip from overheating and affecting the accuracy of the action due to long-term operation. In particular, there are more ventilation holes 24 on the rear cover plate 2 corresponding to the bimetallic strip in the middle position, so that the heat dissipation conditions of each bimetallic strip in the corresponding spatial position are consistent, ensuring the accuracy of the thermal relay operation.

[0059] Specifically, in this embodiment, the fastening part 53 is a groove provided on the upper surface of the base plate 50 of the contactor 5. The structure of the lower buckle 23 includes a first extension 231 connected to the rear cover plate 2. A first protrusion 232 is provided on one side of the end of the first extension 231, and the first protrusion 232 is fastened to the fastening part 53.

[0060] When the first protrusion 232 is engaged in the fastening part 53 of the groove structure, the first extension 231 limits the rear cover plate 2 to form a connection gap L. After the rod terminal 3 is connected to the wiring terminal of the contactor 5, the relative position between the rear cover plate 2 and the contactor 5 is fixed.

[0061] Example 2:

[0062] Based on Embodiment 1, in order to further improve the strength of the connection structure between the rear cover plate 2 and the contactor 5, the housing of the contactor 5 in this embodiment is provided with two parallel vertical plates 54. The vertical plates 54 extend along the length of the rear cover plate 2 and are connected to the bottom plate 50 of the contactor 5. When the contactor 5 is connected to the thermal relay, the end of the vertical plate 54 faces the outer wall surface of the rear cover plate 2. Each vertical plate 54 has a fastening block 52 on a single side. The two fastening blocks 52 are located on the sides facing different vertical plates 54. The rear cover plate 2 is provided with an upper buckle 22 that is fastened to the fastening block 52.

[0063] One side of each upright panel 54 is attached to an upper clip 22, and the other side is attached to a lower clip 23.

[0064] like Figure 5 As shown, a pair of symmetrically arranged upper latches 22 and a pair of symmetrically arranged lower latches 23 are connected to and contact the vertical plate 54 to limit the thermal relay along the length direction perpendicular to the rear cover plate 2. A latching connection structure is added between the lower latches 23 and the rod terminal 3 to improve the strength of the connection structure between the rear cover plate 2 and the contactor 5.

[0065] Specifically, such as Figure 6As shown, the upper buckle 22 in this embodiment includes a second extension 221 connected to the rear cover plate 2. A second protrusion 222 is provided on one side of the end of the second extension 221. The second protrusion 222 is fastened to the buckle block 52. The buckle block 52 is provided with a guide slope 521 to guide the second protrusion 222 to pass over the buckle block 52 and hook onto the buckle block 52. After the second protrusion 222 hooks onto the buckle block 52, the second extension 221 contacts the buckle block 52.

[0066] like Figures 6-9 As shown, the shell structure 1 includes a main shell 11 and an auxiliary shell 12 connected to the main shell 11. The arrangement direction of the main shell 11 and the auxiliary shell 12 is consistent with the length direction of the rear cover plate 2. A bimetallic sheet is installed inside the main shell 11. The rear cover plate 2 is an integral structure and is connected to both the main shell 11 and the auxiliary shell 12. The inner wall surface of the rear cover plate 2 is provided with multiple fins 25. The length direction of the fins 25 is consistent with the length direction of the rear cover plate 2, and the length of the fins 25 is adapted to the length of the rear cover plate 2.

[0067] The integrated rear cover plate 2 makes the assembly of the thermal relay more convenient. Multiple fins 25 are provided along the length of the rear cover plate 2, which not only strengthen the structure but also increase the inner surface area of ​​the rear cover plate 2, thereby improving the efficiency of heat transfer from the main housing 11 to the rear cover plate 2 and enhancing the heat dissipation effect.

[0068] Control terminals and other related components are installed inside the auxiliary housing 12.

[0069] Furthermore, such as Figure 8 , Figure 9 As shown, the main housing 11 is provided with multiple partitions 111, which divide the main housing 11 into cavities corresponding to the bimetallic strips. The number of fins 25 is the same as that of the partitions 111 and they correspond one-to-one. The fins 25 are in surface contact with the corresponding partitions 111.

[0070] A partition 111 is provided inside the main housing 11 to isolate each bimetallic strip from each other, thereby reducing the impact of a single phase temperature rise on the temperature of adjacent bimetallic strips and improving the relay's operating response accuracy.

[0071] In this embodiment, one end of the rear cover plate 2 is connected to the opening of the auxiliary housing 12 through a slot-type fastening structure, and the other end of the rear cover plate 2 is connected to the opening of the main housing 11 through a hook-and-groove fastening structure.

[0072] It also includes a connecting cover 4 that fits against one side surface of the auxiliary housing 12. The connecting cover 4 is provided with a buckle 401 that is fastened to the end of the rear cover plate 2, and a plug plate 402 that is inserted into the auxiliary housing 12.

[0073] Specifically, such as Figures 7-9As shown, the slot-type fastening structure includes a first insert 201 and a second insert 202 located at one end of the inner wall of the rear cover plate 2. The side wall of the opening of the auxiliary housing 12 is provided with a first slot 1201, and the middle of the opening of the auxiliary housing 12 is provided with a second slot 1202. When the first insert 201 is inserted into the first slot 1201, the end protrusion of the first insert 202 engages with the recess in the first slot 1201. When the second insert 202 is inserted into the second slot 1202, the end protrusion of the second insert 201 engages with the recess in the second slot 1202. The end of the rear cover plate 2 is flush with the corresponding outer surface of the auxiliary housing 12.

[0074] Specifically, such as Figures 7-9 As shown, the hook-and-groove fastening structure includes a pair of spaced inner locking blocks 203 located at one end of the inner wall of the rear cover plate 2, and a pair of locking holes 1101 provided on the side wall of the main housing 11. The ends of the inner locking blocks 203 are hook-shaped and inserted into the locking holes 1101.

[0075] Specifically, such as Figure 4 , Figure 7 As shown, the end of the rear cover plate 2 is provided with a third slot 204. When the buckle 401 is inserted into the third slot 204, the end of the buckle 401 is engaged with the recess in the third slot 204. There are three insert plates 402, corresponding to the gap between the auxiliary terminal partitions on the auxiliary housing 12. The connecting cover 4 serves as a protective cover outside the auxiliary housing 12 and strengthens the connection between the rear cover plate 2 and the auxiliary housing 12.

[0076] Example 3:

[0077] This embodiment provides a combined structure of a thermal relay and a contactor, including the thermal relay described in any of the above embodiments. The housing of the contactor 5 is provided with a fastening part 53, and the end of the lower buckle 23 is fastened to the fastening part 53. The through tube 21 contacts the housing of the contactor 5. The through tube 21 and the lower buckle 23 simultaneously support the rear cover plate 2, so that a connection gap L is maintained between the rear cover plate 2 and the housing of the contactor 5. The connection gap L is used for heat dissipation of the thermal relay.

[0078] The assembly process of the thermal relay and contactor 5 in this embodiment is as follows:

[0079] Connect the rod-type terminal 3 of the thermal relay to the wiring terminal of the contactor 5.

[0080] As the rod terminal 3 continues to be inserted, the first protrusion 232 at the end of the lower latch 23 engages with the latching part 53 on the contactor 5, at which point the thermal relay is in a slightly tilted state.

[0081] During the process of aligning the thermal relay, the second protrusion 222 at the end of the upper buckle 22 contacts the guide slope 521. The second protrusion 222 slides along the guide slope 521 to the rear side of the buckle block 52. When the second protrusion 222 hooks the buckle block 52, the thermal relay is in the aligning state. The tube 21 contacts the support part 51. The two symmetrical upper buckles 22 are respectively attached to a vertical plate 54. The two symmetrical lower buckles 23 are distributed and attached to the other side of the vertical plate 54.

[0082] Then, screws are used to secure the rod terminal 3 to the wiring terminal of the contactor 5.

[0083] The above description is an explanation of the present utility model and not a limitation thereof. The scope of the present utility model is defined by the claims. Within the protection scope of the present utility model, any form of modification may be made.

Claims

1. A thermal relay, characterized in that: include, The housing structure (1) contains a thermal tripping mechanism; The rear cover plate (2) is installed at the opening of the housing structure (1) to enclose the thermal release mechanism in the housing structure (1); Multiple through-tubes (21) are fixedly installed on the outer wall surface of the rear cover plate (2) and protrude from the outer wall surface of the rear cover plate (2). The rod-type terminal (3) corresponds one-to-one with the tube (21) and is installed in the tube (21). One end is connected to the thermal tripping mechanism, and the other end is located outside the tube (21) for connection to the wiring terminal of the contactor (5). The lower buckle (23) is in multiple pieces and is fixedly set at intervals on the outer wall of the rear cover plate (2). The lower buckle (23) and the through tube (21) are located at both ends of the length direction of the rear cover plate (2). The outer shell of the contactor (5) is provided with a fastening part (53) that is fastened to the end of the lower buckle (23). When the rod terminal (3) is connected to the wiring terminal of the contactor (5) and the lower buckle (23) is fastened to the fastening part (53), the tube (21) contacts the outer shell of the contactor (5), and the tube (21) and the lower buckle (23) simultaneously support the rear cover plate (2), so that the rear cover plate (2) and the outer shell of the contactor (5) maintain a connection gap (L), which is used for heat dissipation of the thermal relay.

2. The thermal relay as described in claim 1, characterized in that: The outer shell of the contactor (5) is provided with support portions (51) that correspond one-to-one with the through tube (21). The support portions (51) are stiffener structures that protrude from the outer shell of the contactor (5).

3. The thermal relay as described in claim 1, characterized in that: The rear cover plate (2) is provided with ventilation holes (24) that connect the inner and outer spaces of the housing structure (1). The thermal release mechanism includes a bimetallic strip, and the ventilation holes (24) correspond to the bimetallic strip.

4. The thermal relay as described in claim 1, characterized in that: The fastening part (53) is a groove provided on the upper surface of the base plate (50) of the contactor (5). The structure of the lower buckle (23) includes a first extension (231) connected to the rear cover plate (2). A first protrusion (232) is provided on one side of the end of the first extension (231). The first protrusion (232) is fastened to the fastening part (53).

5. The thermal relay as described in claim 1, characterized in that: The contactor (5) has two parallel vertical plates (54) on its housing. The vertical plates (54) extend along the length of the rear cover plate (2) and are connected to the bottom plate (50) of the contactor (5). When the contactor (5) is connected to the thermal relay, the end of the vertical plate (54) faces the outer wall of the rear cover plate (2). Each vertical plate (54) has a buckle (52) on a single side. The two buckles (52) are located on the sides facing different vertical plates (54). The rear cover plate (2) has an upper buckle (22) that is fastened to the buckle (52). One side of each upright panel (54) is attached to an upper buckle (22), and the other side is attached to a lower buckle (23).

6. The thermal relay as described in claim 5, characterized in that: The upper buckle (22) includes a second extension (221) connected to the rear cover plate (2). A second protrusion (222) is provided on one side of the end of the second extension (221). The second protrusion (222) is fastened to the buckle block (52). The buckle block (52) is provided with a guide slope (521) to guide the second protrusion (222) to pass over the buckle block (52) and hook onto the buckle block (52). After the second protrusion (222) hooks onto the buckle block (52), the second extension (221) contacts the buckle block (52).

7. The thermal relay as described in claim 3, characterized in that: The shell structure (1) includes a main shell (11) and an auxiliary shell (12) connected to the main shell (11). The arrangement direction of the main shell (11) and the auxiliary shell (12) is consistent with the length direction of the rear cover plate (2). The bimetallic sheet is installed inside the main shell (11). The rear cover plate (2) is an integral structure. The rear cover plate (2) is connected to both the main shell (11) and the auxiliary shell (12). The inner wall surface of the rear cover plate (2) is provided with multiple fins (25). The length direction of the fins (25) is consistent with the length direction of the rear cover plate (2), and the length of the fins (25) is adapted to the length of the rear cover plate (2).

8. The thermal relay as described in claim 7, characterized in that: The main housing (11) is provided with multiple partitions (111). The partitions (111) divide the main housing (11) into cavities corresponding to the bimetallic strips. The number of fins (25) is the same as that of the partitions (111) and they correspond one-to-one. The fins (25) are in surface contact with the corresponding partitions (111).

9. The thermal relay as described in claim 7, characterized in that: One end of the rear cover plate (2) is connected to the opening of the auxiliary housing (12) through a slot-type fastening structure, and the other end of the rear cover plate (2) is connected to the opening of the main housing (11) through a hook-and-groove fastening structure. It also includes a connecting cover (4) that fits against one side surface of the auxiliary housing (12), the connecting cover (4) having a buckle (401) that snaps into the end of the rear cover plate (2), and a plug plate (402) that plugs into the auxiliary housing (12).

10. A combined structure of a thermal relay and a contactor, characterized in that: The thermal relay includes any one of claims 1-9, wherein the outer casing of the contactor (5) is provided with a fastening part (53), the end of the lower buckle (23) is fastened to the fastening part (53), the through tube (21) contacts the outer casing of the contactor (5), and the through tube (21) and the lower buckle (23) simultaneously support the rear cover plate (2), so that a connection gap (L) is maintained between the rear cover plate (2) and the outer casing of the contactor (5), and the connection gap (L) is used for heat dissipation of the thermal relay.

Images