An improved normally closed ablation protection thermal protector
By employing improved sealing components, integral injection molding structures, and laminated welded bimetallic strips, the problems of sealing performance, contact erosion, and temperature response in traditional thermal protectors have been solved, achieving highly efficient protection of electrical equipment.
Patent Information
- Application Number
- CN202522145056.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-11
- Publication Date
- 2026-11-06
- Estimated Expiration
- 2035-10-11
AI Technical Summary
Traditional thermal protectors suffer from insufficient sealing performance, significant contact erosion problems, and poor temperature response and action accuracy, leading to equipment failure and safety hazards.
By employing technologies such as sealing components, integral injection molding structure, stacked welded bimetallic sheets, and moisture-proof paint, we can ensure airtightness, reduce contact resistance, improve thermal conductivity, and enhance temperature control accuracy.
It effectively blocks moisture and dust, prevents component corrosion, reduces contact erosion, quickly cuts off the circuit, ensures safe and stable operation of the equipment, and extends its service life.
Smart Images
Figure CN224946733U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of electrical safety protection devices, and in particular to an improved normally closed type anti-ablation heat protector. Background Technology
[0002] During the long-term operation of electrical equipment, temperature overload is one of the key causes of equipment failure. Therefore, as the core component for temperature overload protection, the performance of the thermal protector directly determines the safety level and service life of the electrical equipment. However, traditional thermal protectors still have many shortcomings in practical applications that urgently need to be addressed: First, insufficient sealing performance. The connection between the connecting wires and the main body of traditional thermal protectors often uses simple sockets or ordinary glue seals, which are prone to sealing gaps due to temperature changes, vibrations, and other factors. This allows moisture, dust, and other impurities in the air to enter the internal cavity, causing the metal parts such as the stationary contact and moving contact to become damp, corroded, or contaminated. This not only increases contact resistance but may also cause poor circuit contact, and in severe cases, lead to the failure of the thermal protector. Second, contact erosion is a prominent problem. The stationary contact and the base of existing products are often connected by post-assembly, resulting in unavoidable connection gaps. Moreover, the contact surface often lacks special protective treatment. When current passes through, the excessive contact resistance can easily generate local high temperatures, leading to oxidation and erosion of the contact surface, shortening the service life of the thermal protector. Third, poor temperature response and action accuracy. The bimetallic strip and heat-conducting components of some thermal protectors are loosely connected, resulting in low heat conduction efficiency. This causes a lag in response when the temperature reaches the preset action threshold, and the action temperature tolerance range is large, making it difficult to accurately adapt to the differentiated temperature protection needs of different electrical equipment. Utility Model Content
[0003] To address some of the problems existing in the prior art, this utility model provides an improved normally closed ablation protection thermal protector. This thermal protector can be widely used in electrical equipment requiring temperature overload protection, such as household appliances, industrial motors, and electronic components. It can quickly cut off the power supply circuit of the equipment when the temperature rises abnormally during operation, preventing damage to internal components due to continuous overheating. It can also prevent safety accidents such as fires and leakage caused by overheating. After the equipment temperature drops to a safe range, it can automatically reset and restore normal circuit conduction, ensuring the safe and stable operation of electrical equipment.
[0004] To achieve the above objectives, this utility model provides an improved normally closed ablation-resistant thermal protector, comprising a thermal protector body and connecting wires. A sealing assembly is tightly fitted onto the thermal protector body, and the connecting wires pass through the sealing assembly and connect to internal components of the thermal protector body, forming a transmission circuit. The thermal protector body includes a shell, inside which a cavity is formed for accommodating components. A base, a stationary contact, and a temperature calibration plate are fitted within the cavity, the base and stationary contact being integrally injection molded. A bimetallic strip is provided on the temperature calibration plate, and a moving contact is provided on the bimetallic strip. Multiple terminals are also provided within the cavity, one end of each terminal being electrically connected to the temperature calibration plate and the stationary contact, and the other end being connected to the connecting wires. The moving contact is tightly fitted to the stationary contact by the pre-tightening pressure of the bimetallic strip, keeping the circuit closed and conductive. The bimetallic strip undergoes bending deformation due to the difference in thermal expansion coefficients, causing the moving contact to quickly separate from the stationary contact, thus cutting off the circuit.
[0005] In operation, under normal working conditions, the connecting wire passes through the through hole in the sealing cover of the sealing assembly. The through hole size is adapted to the connecting wire, and the outer walls of the two are filled with high-temperature resistant sealant to maintain a seal within the range of -40℃ to 200℃. The current is transmitted through the connecting wire to multiple terminals inside the thermal protector body, and then conducted to the temperature calibration plate and stationary contact plate electrically connected to the terminals. The stationary contact plate and the base are integrally injection molded. The fixed end of the stationary contact plate is pre-embedded into the injection mold cavity of the base to form an inseparable structure. The contact end extends into the cavity and is plated with a 5μm silver layer. At this time, the bimetallic strip, which is "layer-welded" with the temperature calibration plate, makes its laser-welded moving contact tightly fit with the stationary contact plate under the pre-tightening pressure, keeping the circuit closed and conductive. At the same time, the internal cavity of the outer shell... The inner wall, the non-contact area of the stationary contact, and the side wall of the moving contact are coated with polyurethane-modified epoxy resin moisture-proof paint to prevent moisture intrusion. The product information label on the surface of the thermal protector body displays the model, parameters, and other information. When the ambient temperature rises to the preset operating temperature range of the bimetallic strip, the bimetallic strip bends due to the difference in thermal expansion coefficients, causing the moving contact to quickly separate from the stationary contact within ≤1ms, and the contact gap after separation is ≥50μm, thus cutting off the circuit. When the temperature drops to the preset reset temperature of the bimetallic strip, the bimetallic strip returns to its initial shape, the moving contact resets and re-contacts the stationary contact, and the circuit is restored to closed conduction. If the sealing cover is damaged, it can be disassembled and replaced separately to maintain the sealing effect of the sealing assembly on the thermal protector body and prevent moisture and dust from entering the cavity and contaminating or damaging the internal components.
[0006] The beneficial effects of this utility model are as follows: By setting a sealing assembly consisting of a sealing cap and high-temperature resistant sealant, the sealing cap is tightly fitted to the end of the outer shell, and the space between the through hole and the connecting wire is filled with sealant. This maintains excellent sealing performance within a temperature range of -40℃ to 200℃, effectively preventing moisture and dust from entering the cavity, avoiding moisture corrosion or contamination of internal metal parts, and extending the product's service life. The stationary contact piece and the base adopt an integral injection molding structure, eliminating the connection gap of traditional assembly methods and significantly improving connection strength. Simultaneously, the contact end of the stationary contact piece is plated with a silver layer, significantly reducing contact resistance and minimizing localized heating during current flow, fundamentally preventing contact point burning due to overheating. The bimetallic strip and the temperature calibration plate adopt... The bimetallic strip is fixed with a "layered welding" structure, and the free end of the bimetallic strip is laser-welded to the moving contact to form an integrated structure, which improves thermal conductivity and structural stability, precisely controls the preset operating temperature of the bimetallic strip, shortens the reaction time of contact separation, increases the contact distance after separation, ensures rapid circuit cutoff in case of abnormal temperature, and prevents damage to the contacts by arc discharge. The inner wall of the cavity, the non-contact area of the stationary contact, and the side wall of the moving contact are coated with polyurethane modified epoxy resin moisture-proof paint to further enhance the moisture-proof performance, enabling the product to work stably in humid environments such as bathroom appliances and outdoor equipment. The surface of the thermal protector body is marked with product information, which facilitates quick identification of product model, parameters and production information, and improves management convenience.
[0007] As a further improvement of this utility model, in order to effectively prevent moisture and dust from entering the interior and enhance the sealing reliability under wide temperature environments, the sealing assembly includes a sealing cover. The sealing cover is tightly fitted to the end of the outer shell to achieve a sealed connection. The sealing cover can be disassembled and replaced individually. The sealing cover has several through holes for connecting wires to pass through, and the size of the through holes is adapted to the connecting wires. The space between the through holes and the outer wall of the connecting wires is filled with high-temperature resistant sealant to maintain sealing performance within a temperature range of -40℃ to 200℃, effectively preventing moisture and dust from entering the cavity and avoiding moisture or contamination of internal components.
[0008] As a further improvement of this utility model, in order to eliminate connection gaps, improve thermal conductivity and structural stability, reduce contact resistance, reduce local heating, and avoid overheating and erosion of the stationary contact piece; the bimetallic strip and the temperature calibration plate adopt a "layer welding" connection structure, with one end fixed to the temperature calibration plate by resistance spot welding; the other end of the bimetallic strip is a free end, which is laser-welded with the moving contact to form an integrated structure; the stationary contact piece and the base adopt an integral injection molding structure, with the fixed end of the stationary contact piece pre-embedded in the injection mold cavity of the base to form an inseparable integrated structure, used to eliminate connection gaps and improve connection strength; the contact end of the stationary contact piece extends into the cavity, and the surface of the contact end is plated with a silver layer with a thickness of 5μm, used to reduce contact resistance, reduce local heating when current passes through, and avoid the stationary contact piece from being eroded due to overheating.
[0009] As a further improvement of this utility model, in order to enhance the corrosion resistance in humid environments and extend the service life, the inner wall of the cavity, the non-contact area of the stationary contact piece, and the side wall of the moving contact are all coated with a moisture-proof paint. The moisture-proof paint is a polyurethane modified epoxy resin paint, which is formed into a uniform coating with a thickness of 12μm by spraying process.
[0010] As a further improvement of this utility model, in order to improve temperature control accuracy, optimize bimetallic strip driving efficiency, and simultaneously take into account rapid protection and automatic reset functions, thereby enhancing safety and convenience; the preset operating temperature range of the bimetallic strip is 45℃~150℃, and its operating temperature tolerance is ±5K; the reaction time of the bimetallic strip driving the moving contact to separate from the stationary contact is ≤1ms, and the contact distance after the moving contact and the stationary contact are separated is ≥50μm; when the temperature of the bimetallic strip drops to the preset reset temperature, it can return to its initial form, and the moving contact resets and re-contacts the stationary contact, and the circuit returns to the closed state.
[0011] As a further improvement of this utility model, in order to facilitate users to quickly identify product specifications and applicable scenarios, and optimize the user experience and maintenance efficiency, a product information label is provided on the surface of the thermal protector body to identify the product model, parameters and production information. Attached Figure Description
[0012] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the overall structure of this utility model.
[0013] Figure 2 This is a cross-sectional schematic diagram of the thermal protector body and sealing assembly in this utility model.
[0014] Figure 3 This is a schematic diagram of the working state when the circuit of this utility model is cut off.
[0015] The components include: 1. Thermal protector body, 11. Housing, 12. Cavity, 13. Base, 14. Static contact, 15. Moving contact, 16. Bimetallic strip, 17. Temperature calibration plate, 18. Terminal block, 2. Sealing assembly, 21. Sealing cover, 22. Through hole, 3. Connecting wire, and 4. Product information label. Detailed Implementation
[0016] To enable those skilled in the art to better understand the technical solutions in this utility model, the following description is provided in conjunction with the appendix. Figure 1-3 The present invention will be further described below. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the protection scope of the present invention.
[0017] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0018] like Figure 1-3An improved normally closed ablation protection thermal protector is shown, comprising a thermal protector body 1 and connecting wires 3. A sealing assembly 2 is tightly fitted onto the thermal protector body 1. The connecting wires 3 pass through the sealing assembly 2 and connect to internal components of the thermal protector body 1, forming a transmission circuit. The thermal protector body 1 includes a housing 11, inside which a cavity 12 is formed for accommodating components. A base 13, a stationary contact 14, and a temperature calibration plate 17 are fitted within the cavity 12. The base 13 and the stationary contact 14 are integrally injection molded. A bimetallic strip 16 is provided on the temperature calibration plate 17, and a moving contact 15 is provided on the bimetallic strip 16. Multiple terminals 18 are also provided within the cavity 12. One end of 8 is electrically connected to the temperature calibration plate 17 and the stationary contact 14 respectively, and the other end is connected to the connecting wire 3; the moving contact 15 is tightly fitted to the stationary contact 14 by the pre-tightening pressure of the bimetallic strip 16, so that the circuit remains closed and conductive; the bimetallic strip 16 bends due to the difference in thermal expansion coefficient, causing the moving contact 15 to quickly separate from the stationary contact 14, thereby cutting off the circuit; the sealing assembly 2 includes a sealing cover 21, which is tightly fitted to the end of the outer shell 11 to achieve a sealed connection, and the sealing cover 21 can be disassembled and replaced separately; the sealing cover 21 has several through holes 22 for the connecting wire 3 to pass through, and the size of the through holes 22 is adapted to the connecting wire 3; the through holes 22 and The outer walls of the connecting wires 3 are filled with high-temperature resistant sealant to maintain sealing performance within a temperature range of -40℃ to 200℃, effectively preventing moisture and dust from entering the cavity 12 and avoiding moisture or contamination of internal components; the bimetallic strip 16 and the temperature calibration plate 17 adopt a "layer welding" connection structure, with one end fixed to the temperature calibration plate 17 by resistance spot welding; the other end of the bimetallic strip 16 is a free end, which is integrated with the moving contact 15 by laser welding; the stationary contact 14 and the base 13 adopt an integral injection molding structure, with the fixed end of the stationary contact 14 pre-embedded in the injection mold cavity of the base 13 to form an inseparable integrated structure, used to eliminate connection gaps and improve connection strength; the stationary contact 14 The contact end of 14 extends into the cavity 12, and the surface of the contact end is plated with a silver layer with a thickness of 5μm to reduce contact resistance, reduce local heating when current passes through, and prevent the stationary contact from burning due to overheating; the inner wall of the cavity 12, the non-contact area of the stationary contact 14, and the side wall of the moving contact 15 are all coated with a moisture-proof paint, which is a polyurethane modified epoxy resin paint, and a uniform coating with a thickness of 12μm is formed by spraying; the preset operating temperature range of the bimetallic strip 16 is 45℃~150℃, and its operating temperature tolerance is ±5K; the reaction time of the bimetallic strip 16 in separating the moving contact 15 from the stationary contact 14 is ≤1ms, and the contact distance after the moving contact 15 and the stationary contact 14 are separated is ≥50μm;When the bimetallic strip 16 cools to a preset reset temperature, it returns to its initial state. The moving contact 15 resets and re-engages with the stationary contact 14, restoring the circuit to a closed state. A product information label 4 is provided on the surface of the thermal protector body 1 to identify the product model, parameters, and production information.
[0019] In operation, under normal working conditions, the connecting wire 3 passes through the through hole 22 on the sealing cover 21 in the sealing assembly 2. The size of the through hole 22 is adapted to the connecting wire 3, and the outer walls of the two are filled with high-temperature resistant sealant to maintain a seal within the range of -40℃ to 200℃. The current is transmitted through the connecting wire 3 to multiple terminals 18 in the thermal protector body 1, and then conducted to the temperature calibration plate 17 and the stationary contact piece 14 electrically connected to the terminals 18. The stationary contact piece 14 and the base 13 are integrally injection molded. The fixed end of the stationary contact piece 14 is pre-embedded into the injection mold cavity of the base 13 to form an inseparable structure. The contact end extends into the cavity 12 and is plated with a 5μm silver layer. At this time, the bimetallic strip 16, which is "stacked" with the temperature calibration plate 17, makes its laser-welded moving contact 15 tightly fit with the stationary contact piece 14 under the pre-tightening pressure, and the circuit remains closed and conductive. At the same time, the outer shell 11 The inner wall of the internal cavity 12, the non-contact area of the stationary contact 14, and the side wall of the moving contact 15 are coated with polyurethane modified epoxy resin moisture-proof paint to prevent moisture intrusion. The product information label 4 on the surface of the thermal protector body 1 displays information such as model and parameters. When the ambient temperature rises to the preset operating temperature range of the bimetallic strip 16, the bimetallic strip 16 bends due to the difference in thermal expansion coefficients, causing the moving contact 15 to quickly separate from the stationary contact 14 within ≤1ms, and the contact distance after separation is ≥50μm, thus cutting off the circuit. When the temperature drops to the preset reset temperature of the bimetallic strip 16, the bimetallic strip 16 returns to its initial shape, and the moving contact 15 resets and re-contacts the stationary contact 14, restoring the circuit to closed conduction. If the sealing cover 21 is damaged, it can be disassembled and replaced separately to maintain the sealing effect of the sealing assembly 2 on the thermal protector body 1, preventing moisture and dust from entering the cavity 12 and contaminating or damaging the internal components.
[0020] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.
Claims
1. An improved normally closed type ablation protection thermal protector, comprising a thermal protector body (1) and connecting wires (3), characterized in that: A sealing assembly (2) is tightly fitted onto the thermal protector body (1). The connecting wire (3) passes through the sealing assembly (2) and is connected to the internal components of the thermal protector body (1) to form a transmission circuit. The thermal protector body (1) includes a shell (11), and a cavity (12) for accommodating components is formed inside the shell (11). A base (13), a stationary contact plate (14), and a temperature calibration plate (17) are fitted inside the cavity (12). The base (13) and the stationary contact plate (14) are integrally injection molded. The temperature calibration plate (17) is provided with a bimetallic strip (16), and the bimetallic strip (16) is provided with a moving contact (15); the cavity (12) is also provided with a plurality of terminals (18), one end of the terminals (18) is electrically connected to the temperature calibration plate (17) and the stationary contact (14) respectively, and the other end is connected to the connecting wire (3); the moving contact (15) is tightly fitted to the stationary contact (14) by the pre-tightening pressure of the bimetallic strip (16), so that the circuit remains closed and conductive; the bimetallic strip (16) is provided with a bimetallic strip (16) and a moving contact (15) is provided with a moving contact (15); ... provided with a plurality of terminals (18), one end of the terminals (18) is electrically connected to the temperature calibration plate (17) and the stationary contact (14) respectively, and the moving contact (15) is connected to the stationary contact (14) respectively, so that the circuit remains closed and conductive; the bimetallic strip (16) is provided with a bimetallic strip (16) and a moving contact (15) is provided with a moving contact (15); the cavity (12) is provided with a plurality of terminals (18), one end of the terminals (18) is electrically connected to the temperature calibration plate (17) and the stationary contact (14) respectively, and the moving contact ( The sheet (16) bends and deforms due to the difference in thermal expansion coefficients, causing the moving contact (15) to quickly separate from the stationary contact sheet (14), thus cutting off the circuit; the sealing assembly (2) includes a sealing cover (21), which is tightly fitted to the end of the outer shell (11); the sealing cover (21) has several through holes (22) for the connecting wires (3) to pass through, and the size of the through holes (22) is adapted to the connecting wires (3); there is also a gap between the through holes (22) and the outer wall of the connecting wires (3). It is filled with high-temperature resistant sealant; the bimetallic strip (16) and the temperature calibration plate (17) adopt a "layer welding" connection structure, one end of which is fixed to the temperature calibration plate (17) by resistance spot welding; the other end of the bimetallic strip (16) is a free end, which is integrated with the moving contact (15) by laser welding; the stationary contact piece (14) and the base (13) adopt an integral injection molding structure, the contact end of the stationary contact piece (14) extends into the cavity (12), and the surface of the contact end is plated with a silver layer with a thickness of 5μm.
2. The improved normally closed type ablation protection thermal protector according to claim 1, characterized in that: The inner wall of the cavity (12), the non-contact area of the stationary contact (14) and the side wall of the moving contact (15) are all coated with moisture-proof paint. The moisture-proof paint is a polyurethane modified epoxy resin paint, which is formed by spraying to form a uniform coating with a thickness of 12μm.
3. The improved normally closed type ablation protection thermal protector according to claim 1, characterized in that: The bimetallic strip (16) has a preset operating temperature range of 45℃~150℃ and an operating temperature tolerance of ±5K; the reaction time of the bimetallic strip (16) driving the moving contact (15) to separate from the stationary contact (14) is ≤1ms, and the contact distance after the moving contact (15) and the stationary contact (14) are separated is ≥50μm.
4. The improved normally closed type ablation protection thermal protector according to claim 1, characterized in that: The surface of the thermal protector body (1) is provided with a product information label (4) for identifying the product model, parameters and production information.