A thermal protector with PTC as base

Abstract

The application relates to a thermal protector with a PTC base, characterized in that the thermal protector comprises a PTC base, a heat-bending conductive assembly, a movable contact, a first rivet, a second rivet, a fixed contact, a first wiring terminal and a second wiring terminal; the PTC base is provided with a first riveting hole and a second riveting hole; one end of the first wiring terminal is riveted on the first riveting hole through the first rivet; the fixed contact is arranged on the end surface of the first rivet; one end of the heat-bending conductive assembly and one end of the second wiring terminal are riveted on the second riveting hole through the second rivet; and the movable contact is arranged on the other end of the heat-bending conductive assembly and is in contact with the fixed contact. The application can simplify the structure of the thermal protector, manufacture a thermal protector with smaller volume, help to reduce the manufacturing difficulty and cost of the thermal protector, improve the application range of the thermal protector, and has high reliability, and can meet the requirements of actual use and has high applicability.

Description

Technical Field

[0001] This invention relates to the field of thermal protection technology, and in particular to a thermal protector. Background Technology

[0002] Currently, thermal protectors with PTCs generally consist of an insulating base, a bimetallic strip, a moving contact, a moving contact plate, a fixed contact, a fixed contact plate, a PTC block, conductive plates, voltage-conducting plates, and several rivets. The conductive and voltage-conducting plates are used to enable and limit the conduction of the PTC block. To facilitate a stable connection between the moving contact and the PTC block, numerous limiting holes and slots are formed in the insulating base to accommodate the installation and positioning of the PTC block, conductive plates, and voltage-conducting plates. This not only leads to an overly complex structure but also a larger size, increasing manufacturing difficulty and cost, and limiting the applicability of the thermal protector. Therefore, it is necessary to redesign the structure of thermal protectors.

[0003] Chinese patent CN202454497U discloses a thermal protector whose base is made of insulating material and has a three-tiered stepped structure from high to low, allowing for a more rational arrangement of components on the base. While this technical solution achieves a certain degree of structural compactness, its base structure remains relatively complex and does not involve PTC functionality.

[0004] Chinese patent CN103515146A discloses a button-type temperature current trigger, which sets the thermistor (PTC) as an independent functional element on an insulating base. However, the insulating base still needs to provide structural support, thus failing to achieve functional integration between the PTC element and the structural base. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned problems and shortcomings, and to provide a thermal protector that uses a PTC base as a base. This thermal protector adopts a PTC base and a first rivet with fixed contacts. The insulating base, fixed contacts, conductive plates and voltage-conducting plates can be directly omitted from the thermal protector, which simplifies the structure of the thermal protector, thereby making it easier to manufacture a smaller thermal protector. This helps to reduce the manufacturing difficulty and cost of the thermal protector, and also improves the applicability of the thermal protector. Moreover, the reliability of this protector is very high, which can well meet the needs of actual use, and its applicability is very strong.

[0006] The technical solution of this invention is implemented as follows: A thermal protector using a PTC as a base, characterized in that it includes a PTC base, a heat-bending conductive component, a moving contact, a first rivet, a second rivet, a fixed contact, a first terminal, and a second terminal. The PTC base has a first riveting hole and a second riveting hole at both ends. Both the first and second rivets are metal rivets. One end of the first terminal is riveted to the first riveting hole via the first rivet. The fixed contact is located on the end face of the first rivet. One end of the heat-bending conductive component and one end of the second terminal are both riveted to the second riveting hole via the second rivet. The moving contact is located on the other end of the heat-bending conductive component and contacts the fixed contact. The outer surface of the PTC base is covered with an insulating layer. The circumferential surface of the first rivet is pressed tightly against the wall of the first riveting hole, and the circumferential surface of the second rivet is pressed tightly against the wall of the second riveting hole.

[0007] Preferably, the insulating layer has a first contact port and a second contact port extending through to the surface of the PTC base, and the first contact port and the second contact port are located at the opening of the first riveting hole and the opening of the second riveting hole, respectively. The width of the first contact port is greater than the width of the opening of the first riveting hole, and the width of the second contact port is greater than the width of the opening of the second riveting hole. The first terminal is pressed tightly against the PTC base inside the first contact port, and the second terminal is pressed tightly against the PTC base inside the second contact port.

[0008] Preferably, the shortest distance between the wall of the first riveting hole and the wall of the second riveting hole is 5 to 6 mm.

[0009] Preferably, a first silver plating layer is provided on the wall of the first rivet hole where the first copper sleeve is embedded or the first rivet hole is fitted, and the first rivet is pressed tightly against the inner wall of the first copper sleeve or the first silver plating layer; a second silver plating layer is provided on the wall of the second rivet hole where the second copper sleeve is embedded or the second rivet hole is fitted, and the second rivet is pressed tightly against the inner wall of the second copper sleeve or the second silver plating layer.

[0010] Preferably, the radial cross-sections of the first rivet hole and the second rivet hole are both non-circular, the first rivet matches the first rivet hole, and the second rivet matches the second rivet hole.

[0011] Preferably, the heat-bending conductive component includes a movable contact, a bimetallic strip, and a support pad. A limiting protrusion is provided on the top surface of the support pad. The support pad, the bimetallic strip, and the movable contact are stacked sequentially on the top surface of the PTC base, with the middle part of the bimetallic strip pressing on the limiting protrusion. One end of the second terminal is placed on the bottom surface of the PTC base. The second rivet passes sequentially through one end of the movable contact, one end of the bimetallic strip, one end of the support pad, the second rivet hole, and one end of the second terminal before being riveted. The movable contact is located on the other end of the movable contact.

[0012] Preferably, the heat-bending conductive component includes a movable contact, a bimetallic strip, and a support pad. A limiting protrusion is provided on the top surface of the support pad, and a vertically penetrating clearance hole is provided in the middle of the movable contact. The support pad, movable contact, and bimetallic strip are stacked sequentially on the top surface of the PTC base, and the limiting protrusion passes through the clearance hole and rests on the middle of the bottom surface of the bimetallic strip. One end of the second terminal is placed on the bottom surface of the PTC base. The second rivet passes sequentially through one end of the bimetallic strip, one end of the movable contact, one end of the support pad, the second riveting hole, and one end of the second terminal before being riveted. The other end of the bimetallic strip is connected to the other end of the movable contact, and the movable contact is located on the other end of the movable contact.

[0013] Preferably, the other end of the movable contact piece is provided with at least one folded edge, which is bent upward and then pressed onto the top surface of the other end of the bimetallic sheet.

[0014] Preferably, the fixed contact is silver-plated.

[0015] The beneficial effects of this invention are as follows: The thermal protector of this invention employs a PTC base, and the fixed contacts are directly disposed on the end face of the first rivet. This PTC base can directly serve as the base of the thermal protector, while the first rivet can serve as the fixed contact. This eliminates the need for an insulating base, fixed contacts, conductive plates, and voltage-conducting plates in the thermal protector, thereby simplifying its structure and facilitating the manufacture of a smaller thermal protector, thus reducing manufacturing difficulty and cost. The application of this thermal protector offers advantages such as saving raw materials, saving installation space, reducing assembly steps, and saving labor. The thermal protector has excellent applicability.

[0016] Specifically, compared with the prior art, the present invention has at least the following significant technical advancements: (1) The invention realizes the dual function integration of PTC material as a structural base and PTC functional element. This invention breaks through the conventional thinking in the field that PTC material is only used as a functional element (such as a thermistor mounted on an insulating base) and must rely on an independent insulating base for structural support. For the first time, PTC material is used as both the structural base and PTC functional element of the thermal protector, fundamentally reconstructing the architecture of the thermal protector.

[0017] (2) By covering the outer surface of the PTC base with an insulating layer and pressing the circumferential surface of the rivet against the wall of the riveting hole, the two key technical problems faced by the PTC base as a structural base are solved: one is the insulation isolation problem of the outer surface of the PTC base (by covering it with an insulating layer), and the other is the reliable conductive contact between the rivet and the PTC base (by pressing the circumferential surface of the rivet against the wall of the hole).

[0018] (3) The number of parts is greatly reduced and the structure is significantly simplified. The present invention eliminates the four components of the traditional thermal protector: the insulating base, the fixed contact, the conductive plate, and the voltage-conducting plate. The first rivet also serves as a fixed connector, a conductive path, and a fixed contact carrier, further reducing the number of parts. This is a technical effect that is not taught or implied in any single prior art document or combination of multiple prior art documents.

[0019] (4) Significantly reduced size. Since the PTC base does not require complex hole and slot structures, only a reasonable creepage distance needs to be met, the overall size of the thermal protector can be significantly reduced. By optimizing the shortest distance between the wall of the first riveting hole and the wall of the second riveting hole to 5-6 mm, the length of the thermal protector can be shortened by about 1 / 3 compared to the existing small thermal protectors.

[0020] (5) Improved thermal response performance. Since the heat-bending conductive component is directly mounted on the PTC base, when the PTC base participates in the operation and generates heat, its heat can be applied to the heat-bending conductive component (bimetallic sheet) more directly and efficiently. This avoids the path loss of PTC heat transfer through multiple layers in the traditional structure, making the PTC function more fully and reliably performed.

[0021] Since the PTC base does not require complex hole and slot structures, only a reasonable creepage distance needs to be met. This allows for a smaller size of the thermal protector, thereby expanding its applicability. By employing a heat-bending conductive component, the moving contact can not only disengage from the fixed contact upon heating but also conduct electricity, ensuring a stable connection between the moving and fixed contacts to the protected circuit. This contributes to improving the reliability and applicability of the thermal protector.

[0022] Because the first terminal is riveted to the first riveting hole by the first rivet, and both the heat-bending conductive component and the second terminal are riveted to the second riveting hole by the second rivet, and the fixed contact and moving contact are located on the first rivet and the heat-bending conductive component respectively, the fixed contact and moving contact can be installed in place very accurately and stably, and the accuracy and stability of the moving contact's operation can be guaranteed. This helps to improve the reliability of the thermal protector.

[0023] By using both the first and second rivets as metal rivets, not only is the stability and reliability of the riveting ensured, but the PTC base can also be stably connected to the circuit, allowing the thermal protector to function optimally. This results in more reliable performance and more accurate response from the thermal protector, thus improving its reliability and applicability and better meeting the needs of practical applications.

[0024] By placing the fixed contact on the end face of the first rivet, not only is the machining of the fixed contact easier, but it also facilitates a stable and reliable contact between the moving contact and the fixed contact, which helps to further improve the reliability of the thermal protector.

[0025] Since there is no obstruction between the heat-bending conductive component and the PTC base, when the PTC base is engaged in operation and generates heat, the heat emitted by the PTC base can be better applied to the heat-bending conductive component, thus enabling the PTC to function better. The reliability of this thermal protector is very high. Attached Figure Description

[0026] Figure 1 This is a three-dimensional structural diagram of the first type of thermal protector in this invention.

[0027] Figure 2 This is a three-dimensional structural diagram of the second type of thermal protector in this invention.

[0028] Figure 3 This is a three-dimensional structural diagram of the third type of thermal protector in this invention.

[0029] Figure 4 This is a three-dimensional structural diagram of the fourth type of thermal protector in this invention.

[0030] Figure 5 This is a three-dimensional structural diagram of the fifth type of thermal protector in this invention.

[0031] Figure 6 This is a three-dimensional structural diagram of the sixth type of thermal protector in this invention.

[0032] Figure 7 This is a schematic diagram of the disassembled structure of the first thermal protector in this invention.

[0033] Figure 8 This is a schematic diagram of the split structure of the second type of thermal protector in this invention.

[0034] Figure 9 This is a schematic diagram of the split structure of the third type of thermal protector in this invention.

[0035] Figure 10 This is a schematic diagram of the split structure of the fourth type of thermal protector in this invention.

[0036] Figure 11 This is one of the three-dimensional structural diagrams of the PTC base in this invention.

[0037] Figure 12 This is the second three-dimensional structural diagram of the PTC base in this invention.

[0038] Figure 13 This is the third schematic diagram of the three-dimensional structure of the PTC base in this invention.

[0039] Figure 14 This is a cross-sectional view of the PTC base in this invention.

[0040] Figure 15 This is one of the structural schematic diagrams of the moving contact riveted to the moving contact piece in this invention.

[0041] Figure 16 This is the second schematic diagram of the structure in this invention where the moving contact is riveted to the moving contact piece.

[0042] Figure 17 This is one of the structural schematic diagrams of the moving contact welded onto the moving contact piece in this invention.

[0043] Figure 18 This is the second schematic diagram of the structure in this invention where the moving contact is welded onto the moving contact piece.

[0044] Figure 19 This is one of the schematic diagrams of the assembly structure of the thermal protector and the protective box in this invention.

[0045] Figure 20 This is one of the schematic diagrams of the assembly structure of the thermal protector and the protective box in this invention. Detailed Implementation

[0046] like Figure 1 and Figure 7As shown, the present invention discloses a thermal protector using a PTC as a base, comprising a PTC base 1, a heat-bending conductive component 2, a moving contact 3, a first rivet 4, a second rivet 5, a fixed contact 6, a first terminal 7, and a second terminal 8. The PTC base 1 has a first riveting hole 11 and a second riveting hole 12 at both ends. Both the first rivet 4 and the second rivet 5 are metal rivets. One end of the first terminal 7 is riveted to the first riveting hole 11 via the first rivet 4. The fixed contact 6 is disposed on the end face of the first rivet 4. One end of the heat-bending conductive component 2 and one end of the second terminal 8 are both riveted to the second riveting hole 12 via the second rivet 5. The moving contact 3 is disposed on the other end of the heat-bending conductive component 2 and contacts the fixed contact 6.

[0047] The thermal protector of this invention employs a PTC base 1, with the fixed contact 6 directly disposed on the end face of the first rivet 4. The PTC base 1 can directly serve as the base of the thermal protector, while the first rivet 4 can serve as the fixed contact. This eliminates the need for an insulating base, fixed contact, conductive sheet, and voltage-conducting sheet, simplifying the thermal protector structure and facilitating the manufacture of a smaller thermal protector, thereby reducing manufacturing difficulty and cost. The application of this thermal protector offers advantages such as saving raw materials, saving installation space, reducing assembly steps, and saving labor, making it highly versatile. Since the PTC base 1 does not require complex slot structures, only a reasonable creepage distance needs to be met. This allows for a smaller thermal protector size, thereby expanding its applicability.

[0048] By employing the heat-bending conductive component 2, not only can the moving contact 3 be disengaged from the fixed contact 6 after being heated, but it also serves to conduct electricity, so that the moving contact 3 and the fixed contact 6 can be stably connected to the circuit that needs protection. This helps to improve the reliability and applicability of the thermal protector.

[0049] Since the first terminal 7 is riveted to the first riveting hole 11 by the first rivet 4, and both the heat-bending conductive component 2 and the second terminal 8 are riveted to the second riveting hole 12 by the second rivet 5, and the fixed contact 6 and the moving contact 3 are located on the first rivet 4 and the heat-bending conductive component 2 respectively, the fixed contact 6 and the moving contact 3 can be installed in place very accurately and stably, and the accuracy and stability of the movement of the moving contact 3 can be guaranteed. This helps to improve the reliability of the thermal protector.

[0050] By using both the first rivet 4 and the second rivet 5 as metal rivets, not only is the stability and reliability of the riveting guaranteed, but the PTC base 1 can also be stably connected to the circuit, allowing the thermal protector to function effectively. This results in more reliable performance and more accurate response from the thermal protector, which in turn improves its reliability and applicability, better meeting the needs of practical applications.

[0051] By placing the fixed contact 6 on the end face of the first rivet 4, not only is the machining of the fixed contact 6 easier, but it also facilitates a stable and reliable contact between the moving contact 3 and the fixed contact 6, which helps to further improve the reliability of the thermal protector.

[0052] Since there is no obstruction between the heat-bending conductive component 2 and the PTC base 1, when the PTC base 1 is working and generating heat, the heat emitted by the PTC base 1 can be better applied to the heat-bending conductive component 2, thus better fulfilling the function of the PTC. The reliability of this thermal protector is very high.

[0053] Both the first rivet 4 and the second rivet 5 are copper rivets. This not only facilitates riveting but also ensures that both the first rivet 4 and the second rivet 5 have excellent electrical conductivity, thereby helping to improve the reliability of the thermal protector.

[0054] like Figure 19 and Figure 20 As shown, in actual use, the thermal protector can be protected by a protective box 10 with one open side and a cover 20. The PTC base 1 is embedded in the protective box 10, and the other ends of the first terminal 7 and the second terminal 8 are placed outside the protective box 10. The cover 20 is fastened to the protective box 10. This provides good protection for the thermal protector.

[0055] like Figure 1 and Figure 11As shown, the outer surface of the PTC base 1 is covered with an insulating layer 13. The circumferential surface of the first rivet 4 is pressed tightly against the wall of the first riveting hole 11, and the circumferential surface of the second rivet 5 is pressed tightly against the wall of the second riveting hole 12. The insulating layer 13 serves as a covering and isolation layer to prevent the conductive component 2 from directly contacting the outer wall of the PTC base 1 when it is bent by heat. This ensures that the part of the PTC base 1 that participates in the operation is the PTC base 1 between the first riveting hole 11 and the second riveting hole 12. This eliminates the need to reserve a creepage distance on the surface of the PTC base 1; only the distance between the first riveting hole 11 and the second riveting hole 12 needs to be considered to ensure sufficient creepage distance. This allows the PTC base 1 to be made smaller, thereby further improving the applicability of the thermal protector. Furthermore, this prevents conductive debris on the outer wall of the PTC base 1 from affecting the working performance of the thermal protector, which helps to further improve the reliability of the thermal protector.

[0056] The insulating layer 13 is a high-temperature resistant insulating plastic layer (e.g., using the same material as the plastic insulating base of existing thermal protectors). During production, the insulating plastic layer can be formed on the surface of the PTC base 1 by immersing the PTC base 1 in molten insulating plastic and then removing it and cooling it.

[0057] like Figure 1 , Figures 12 to 14 As shown, the insulating layer 13 has a first contact port 131 and a second contact port 132 extending through to the surface of the PTC base 1. The first contact port 131 and the second contact port 132 are located at the openings of the first riveting hole 11 and the second riveting hole 12, respectively. The width of the first contact port 131 is greater than the width of the opening of the first riveting hole 11, and the width of the second contact port 132 is greater than the width of the opening of the second riveting hole 12. The first terminal 7 is pressed tightly against the PTC base 1 inside the first contact port 131, and the second terminal 8 is pressed tightly against the PTC base 1 inside the second contact port 132. The opening of the first contact port 131 and the second contact port 132 facilitates contact between the first terminal 7 and the second terminal 8 and the outer surface of the PTC base 1, thereby improving the convenience and stability of connecting the PTC base 1 to the thermal protector. This allows the PTC base 1 to better perform the functions of the PTC, further improving the reliability and applicability of the thermal protector.

[0058] like Figure 14As shown, both the first riveting hole 11 and the second riveting hole 12 penetrate the PTC base 1. In actual manufacturing, the first contact opening 131 can be formed on the insulating layer 13 on the outer sides of both openings of the first riveting hole 11, or it can be formed only on the insulating layer 13 on the outer side of one of the openings of the first riveting hole 11. Similarly, the second contact opening 132 can be formed on the insulating layer 13 on the outer sides of both openings of the second riveting hole 12, or it can be formed only on the insulating layer 13 on the outer side of one of the openings of the second riveting hole 12.

[0059] The shortest distance between the wall of the first riveting hole 11 and the wall of the second riveting hole 12 is 5-6 mm. This ensures a reasonable creepage distance between the first riveting hole 11 and the second riveting hole 12 while also allowing the PTC base 1 to have a very small volume, reducing its length by 1 / 3 compared to existing small thermal protectors. This facilitates the use of the thermal protector in a smaller space, thereby helping to further improve the applicability of the thermal protector.

[0060] like Figure 1 As shown, when the insulating layer 13 has a first contact port 131 and a second contact port 132, the shortest distance between the contact point of the first terminal 7 and the PTC base 1 and the contact point of the second terminal 8 and the PTC base 1 is 5-6 mm. This allows for good control of the overall size of the thermal protector.

[0061] like Figure 1 , Figures 12 to 14 As shown, the first rivet hole 11 is fitted with a first copper sleeve 111 or a first silver plating layer 112 is provided on the wall of the first rivet hole 11, and the first rivet 4 is pressed tightly against the inner wall of the first copper sleeve 111 or the first silver plating layer 112; the second rivet hole 12 is fitted with a second copper sleeve 121 or a second silver plating layer 122 is provided on the wall of the second rivet hole 12, and the second rivet 5 is pressed tightly against the inner wall of the second copper sleeve 121 or the second silver plating layer 122. The copper sleeve or silver plating layer improves the stability and reliability of the electrical connection between the first rivet 4, the second rivet 5 and the PTC base 1, thereby helping to further improve the reliability and applicability of the thermal protector. Furthermore, the copper sleeve protects the rivet hole from movement.

[0062] like Figure 8As shown, the radial cross-sections of both the first riveting hole 11 and the second riveting hole 12 are non-circular. The first rivet 4 matches the first riveting hole 11, and the second rivet 5 matches the second riveting hole 12. This structure ensures that the first rivet 4 and the second rivet 5 are tightly fitted into the first riveting hole 11 and the second riveting hole 12, respectively. This prevents the first rivet 4 and the second rivet 5 from rotating, thus avoiding rotation of the parts fixed by them. This improves the stability and reliability of the parts' installation and positioning, thereby further enhancing the reliability of the thermal protector.

[0063] like Figures 7 to 10 As shown, in the actual manufacturing process, the cross-sections of the first riveting hole 11 and the second riveting hole 12 can be made into rectangles, pentagons, hexagons, ellipses, etc. This effectively prevents the rivets from rotating.

[0064] like Figure 1 , Figure 3 , Figure 7 , Figure 9 , Figure 15 and Figure 17As shown, the heat-bending conductive assembly 2 includes a movable contact 21, a bimetallic strip 22, and a support pad 23. A limiting protrusion 231 is provided on the top surface of the support pad 23. The support pad 23, bimetallic strip 22, and movable contact 21 are stacked sequentially on the top surface of the PTC base 1, with the middle portion of the bimetallic strip 22 pressing against the limiting protrusion 231. One end of the second terminal 8 is placed on the bottom surface of the PTC base 1. The second rivet 5 passes sequentially through one end of the movable contact 21, one end of the bimetallic strip 22, one end of the support pad 23, the second rivet hole 12, and one end of the second terminal 8 before being riveted. The movable contact 3 is located on the other end of the movable contact 21. The structure of this heat-bending conductive assembly 2 is very simple and reliable, which not only facilitates manufacturing but also improves the accuracy and stability of the movable contact 3's operation. The support pad 23 not only facilitates the machining of the limiting protrusion 231, but also elevates the moving contact 21, ensuring sufficient space between the moving contact 3 and the PTC base 1 for the installation of the fixed contact. This avoids overly complex designs for the moving contact 21, bimetallic strip 22, and PTC base 1, thus simplifying the thermal protector structure. The limiting protrusion 231 effectively limits the center of the bimetallic strip 22, preventing it from moving downwards when deformed by heat. This ensures the other end of the bimetallic strip 22 acts more quickly on the moving contact 21, improving the stability, accuracy, and reliability of the moving contact 21's operation, thereby enhancing the thermal protector's reliability and applicability. The second rivet 5 secures the bimetallic strip 22, preventing it from detaching and ensuring safety.

[0065] like Figure 2 , Figures 4 to 6 , Figure 8 , Figure 10 , Figure 16 and Figure 18As shown, the heat-bending conductive component 2 includes a movable contact 21, a bimetallic strip 22, and a support pad 23. A limiting protrusion 231 is provided on the top surface of the support pad 23. A vertical through-hole 211 is provided in the middle of the movable contact 21. The support pad 23, movable contact 21, and bimetallic strip 22 are stacked sequentially on the top surface of the PTC base 1, and the limiting protrusion 231 passes through the through-hole 211 and rests on the middle of the bottom surface of the bimetallic strip 22. One end of the second terminal 8 is placed on the bottom surface of the PTC base 1. The second rivet 5 passes sequentially through one end of the bimetallic strip 22, one end of the movable contact 21, one end of the support pad 23, the second riveting hole 12, and one end of the second terminal 8 before being riveted. The other end of the bimetallic strip 22 is connected to the other end of the movable contact 21. The movable contact 3 is provided on the other end of the movable contact 21. The structure of the heat-bending conductive component 2 is very simple and reliable, which not only facilitates manufacturing but also improves the accuracy and stability of the movement of the moving contact 3. The support pad 23 facilitates the machining of the limiting protrusion 231 and also elevates the moving contact 21, ensuring sufficient space between the moving contact 3 and the PTC base 1 for the installation of the fixed contact. This avoids overly complex designs for the moving contact 21, bimetallic strip 22, and PTC base 1, thus simplifying the thermal protector structure. The limiting protrusion 231 effectively limits the middle of the bimetallic strip 22, preventing it from moving downwards when deformed by heat. This ensures the other end of the bimetallic strip 22 acts more quickly on the moving contact 21, improving the stability, accuracy, and reliability of the moving contact 21's movement, thereby further enhancing the reliability and applicability of the thermal protector. By riveting the bimetallic strip 22 with the second rivet 5, it can be prevented from falling off and safety can be ensured.

[0066] like Figures 7 to 10 As shown, the above structure allows for convenient and rapid processing of the support pad 23 and the limiting protrusion 231 through stamping, thereby improving the ease of processing.

[0067] like Figures 15 to 18As shown, the moving contact 3 includes a conductive block 31 and a silver-plated surface 32. The conductive block 31 is welded or riveted to the bottom surface of the other end of the moving contact piece 21, and the silver-plated surface 32 is disposed on the lower surface of the conductive block 31. This not only ensures that the moving contact 3 has excellent conductivity, but also facilitates the manufacturing and processing of the moving contact 3 and allows for easy contact with the fixed contact 6, which helps improve the reliability of the thermal protector. When using welding to install the conductive block 31, it is not necessary to make the conductive block 31 too large, nor is it necessary for the conductive block 31 to pass through the moving contact piece 21. This avoids the conductive block 31 occupying the installation space of the bimetallic strip 22, which not only makes it easier to make the moving contact piece 21 shorter, but also makes it easier to make the bimetallic strip 22 slightly larger, thereby improving the reliability of the thermal protector.

[0068] like Figure 1 , Figure 2 , Figure 7 , Figure 8 , Figure 15 and Figure 16 As shown, the conductive block 31 is riveted to the movable contact piece 21. Figures 3 to 6 , Figure 9 , Figure 10 , Figure 17 and Figure 18 As shown, the conductive block 31 is welded onto the moving contact piece 21.

[0069] When there is an insulating layer 13 on the PTC base 1, the support pad 23 can be made of either a non-insulating material (e.g., copper or steel sheet) or an insulating material (e.g., rubber). When there is no insulating layer 13 on the PTC base 1, in order to control the overall size of the thermal protector, the support pad 23 is made of a high-temperature resistant insulating material (e.g., rubber). This ensures that the moving contact 21 can only be connected to the PTC base 1 through the second rivet 5, which facilitates control of the working parts on the PTC base 1. Consequently, it is possible to make the thermal protector as small as possible while meeting the creepage distance requirements.

[0070] like Figure 2 , Figures 4 to 6 , Figure 8 , Figure 10 , Figure 16 and Figure 18As shown, the other end of the movable contact 21 is provided with at least one folded edge 212. The folded edge 212 is bent upwards and then pressed against the top surface of the other end of the bimetallic strip 22. This makes it very convenient to connect the other end of the bimetallic strip 22 with the other end of the movable contact 21, thereby improving the ease of manufacturing and processing of the thermal protector. Furthermore, this limiting effect is very reliable, contributing to the improved reliability of the thermal protector. Moreover, this structure not only facilitates shortening the length of the movable contact 21 but also allows for increasing the width of the bimetallic strip 22 during manufacturing, thus facilitating the reduction of the thermal protector's size and improving its reliability.

[0071] like Figure 4 As shown, the width of the folded edge 212 can be made the same as the width of the movable contact piece 21. Figure 6 As shown, when using a folded edge 212, and the width of the folded edge 212 is less than the width of the movable contact piece 21, the folded edge 212 is located at the center of the end face of the movable contact piece 21. Figure 5 As shown, when two folded edges 212 are used, and the sum of the widths of the two folded edges 212 is less than the width of the movable contact piece 21, the two folded edges 212 are located on the front and rear ends of the end face of the movable contact piece 21, respectively. Figure 2 As shown, when two folded edges 212 are used, the two folded edges 212 can be located on the two sides of the other end of the moving contact piece 21, respectively. The above structures can achieve a very good connection effect between the moving contact piece 21 and the bimetallic strip 22.

[0072] By using PTC base 1, the functions of a PTC can be realized. During operation, the bimetallic strip 22 is guaranteed not to reset; it will only reset after the power is disconnected and the circuit is left idle for a period of time. This thermal protector is reusable.

[0073] The fixed contact 6 is silver-plated. This ensures that the fixed contact 6 has excellent conductivity, thereby helping to further improve the reliability of the thermal protector.

Claims

1. A thermal protector that uses a PTC as a base, characterized in that: The device includes a PTC base (1), a heat-bending conductive component (2), a moving contact (3), a first rivet (4), a second rivet (5), a fixed contact (6), a first terminal block (7), and a second terminal block (8). The PTC base (1) has a first riveting hole (11) and a second riveting hole (12) at both ends. The first rivet (4) and the second rivet (5) are both metal rivets. One end of the first terminal block (7) is riveted to the first riveting hole (11) by the first rivet (4). The fixed contact (6) is located on the end face of the first rivet (4). One end of the heat-bending conductive component (2) and one end of the second terminal block (8) are riveted to the second riveting hole (12) by the second rivet (5). The moving contact (3) is located on the other end of the heat-bending conductive component (2) and is in contact with the fixed contact (6). The outer surface of the PTC base (1) is covered with an insulating layer (13), the circumferential surface of the first rivet (4) is pressed tightly against the wall of the first rivet hole (11), and the circumferential surface of the second rivet (5) is pressed tightly against the wall of the second rivet hole (12).

2. The thermal protector using a PTC as a base according to claim 1, characterized in that: The insulating layer (13) is provided with a first contact port (131) and a second contact port (132) that penetrate to the surface of the PTC base (1). The first contact port (131) and the second contact port (132) are located at the opening of the first riveting hole (11) and the opening of the second riveting hole (12), respectively. The width of the first contact port (131) is greater than the width of the opening of the first riveting hole (11), and the width of the second contact port (132) is greater than the width of the opening of the second riveting hole (12). The first terminal (7) is pressed tightly against the PTC base (1) inside the first contact port (131), and the second terminal (8) is pressed tightly against the PTC base (1) inside the second contact port (132).

3. The thermal protector using a PTC as a base according to claim 1, characterized in that: The shortest distance between the wall of the first riveting hole (11) and the wall of the second riveting hole (12) is 5-6 mm.

4. The thermal protector using a PTC as a base according to claim 1, characterized in that: The first rivet hole (11) is fitted with a first copper sleeve (111) or a first silver plating layer (112) is provided on the wall of the first rivet hole (11), and the first rivet (4) is pressed tightly against the inner wall of the first copper sleeve (111) or the first silver plating layer (112); the second rivet hole (12) is fitted with a second copper sleeve (121) or a second silver plating layer (122) is provided on the wall of the second rivet hole (12), and the second rivet (5) is pressed tightly against the inner wall of the second copper sleeve (121) or the second silver plating layer (122).

5. The thermal protector using a PTC as a base according to claim 1, characterized in that: The radial cross sections of the first riveting hole (11) and the second riveting hole (12) are both non-circular. The first rivet (4) is matched with the first riveting hole (11), and the second rivet (5) is matched with the second riveting hole (12).

6. The thermal protector using a PTC as a base according to claim 1, characterized in that: The heat-bending conductive component (2) includes a movable contact (21), a bimetallic strip (22), and a support pad (23). A limiting protrusion (231) is provided on the top surface of the support pad (23). The support pad (23), the bimetallic strip (22), and the movable contact (21) are stacked sequentially on the top surface of the PTC base (1), and the middle part of the bimetallic strip (22) is pressed on the limiting protrusion (231). One end of the second terminal (8) is placed on the bottom surface of the PTC base (1). The second rivet (5) passes sequentially through one end of the movable contact (21), one end of the bimetallic strip (22), one end of the support pad (23), the second rivet hole (12), and one end of the second terminal (8) before being riveted. The movable contact (3) is provided on the other end of the movable contact (21).

7. The thermal protector using a PTC as a base according to claim 1, characterized in that: The heat-bending conductive component (2) includes a movable contact (21), a bimetallic strip (22), and a support pad (23). A limiting protrusion (231) is provided on the top surface of the support pad (23), and a vertically penetrating clearance hole (211) is provided in the middle of the movable contact (21). The support pad (23), movable contact (21), and bimetallic strip (22) are stacked sequentially on the top surface of the PTC base (1), and the limiting protrusion (231) passes through the clearance hole (211) and rests on the bimetallic strip. On the bottom center of the metal sheet (22), one end of the second terminal (8) is placed on the bottom surface of the PTC base (1). The second rivet (5) passes through one end of the bimetallic sheet (22), one end of the moving contact (21), one end of the support pad (23), the second rivet hole (12), and one end of the second terminal (8) in sequence and is then riveted. The other end of the bimetallic sheet (22) is connected to the other end of the moving contact (21). The moving contact (3) is set on the other end of the moving contact (21).

8. The thermal protector using a PTC as a base according to claim 7, characterized in that: The other end of the movable contact piece (21) is provided with at least one folded edge (212), which is bent upward and then pressed onto the top surface of the other end of the bimetallic sheet (22).

9. The thermal protector using a PTC as a base according to claim 1, characterized in that: The fixed contact (6) is silver-plated.

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