Temperature protector with mechanical action control

Abstract

The invention relates to the technical field of thermal protectors, in particular to a temperature protector with mechanical action control, which comprises an insulating protective shell; the PTC heating body is of a rectangular frame structure and is provided with a hollow cavity. The first connecting plate and the second connecting plate are correspondingly assembled on two end surfaces of the hollow cavity to form a closed cavity; the fixed end of the movable contact piece is connected to the first connecting plate, the free end of the movable contact piece is connected with a movable contact, and the second connecting plate is provided with a static contact. The ends, far away from each other, of the two bimetallic strips of the temperature sensing element are installed on the opposite inner side walls of the hollow cavity respectively. And the actuating block is arranged in an area below the movable contact piece, is positioned between the free ends of the two bimetallic strips, and is integrally formed by adopting a ceramic material. Through a cooperative linkage structure of the temperature sensing element, the actuating block and the movable contact piece, accurate conversion from a temperature signal to mechanical on-off action is realized, and high temperature sensing accuracy and rapid action response performance are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of thermal protector technology, and more particularly to a temperature protector with mechanical action control. Background Technology

[0002] Temperature protectors are widely used in household electric heating appliances and similar electrical equipment such as transformers and motors. Their core function is to sense and follow changes in ambient temperature in real time, and accurately execute the circuit cutting-off and closing actions at preset temperature points, thereby achieving temperature control and safety protection for electrical equipment and avoiding malfunctions, damage or even safety hazards caused by overheating.

[0003] In related technologies, temperature protectors often use built-in temperature-sensing moving contacts to achieve temperature response and circuit on / off control. The working principle is as follows: when the temperature of the circuit or equipment rises to a critical value, the two metal sheets deform differently due to the difference in thermal expansion, causing the moving contact to bend, which in turn causes the moving contact to move and separate from the stationary contact, thus achieving the purpose of disconnecting the circuit. When the temperature drops to a safe range, the temperature-sensing moving contact returns to its original shape, causing the moving contact and stationary contact to close again, and the circuit resumes conduction.

[0004] However, the moving contact end of the moving contact piece is mostly suspended. This structure is prone to vibration due to the slight deformation fluctuation of the temperature-sensing moving contact piece near the critical trigger temperature. This can lead to repeated switching between the moving and stationary contacts, causing the moving contact to bounce repeatedly. This not only results in unstable power cut-off and loss of protection when overheating, but also impacts the electrical circuit and causes secondary faults, affecting the stability and safety of equipment operation. Summary of the Invention

[0005] This invention provides a temperature protector with mechanical action control, which can effectively solve the problems in the prior art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A temperature protector with mechanical action control includes: Insulating protective casing; The PTC heating element is housed within the insulating protective shell and has a rectangular frame structure with a hollow cavity extending along the thickness direction. The first connecting plate and the second connecting plate are respectively assembled on the two end faces of the hollow cavity of the PTC heating element, together forming a closed cavity, and are respectively connected to the first lead and the second lead; A movable contact piece is housed in the enclosed cavity. Its fixed end is connected to the first connecting plate, and its free end is connected to a movable contact. A stationary contact is provided on the second connecting plate at a position corresponding to the movable contact. The temperature sensing element includes two bimetallic strips symmetrically arranged relative to the moving contact piece, with the ends of the two bimetallic strips being respectively mounted on the opposite inner walls of the hollow cavity of the PTC heating element. The actuator block is located in the area below the moving contact piece, between the free ends of the two bimetallic sheets, and is integrally formed from ceramic material.

[0007] Furthermore, the PTC heating element has grooves on both ends of its hollow cavity that are adapted to the first connecting plate and the second connecting plate; Furthermore, the outer surfaces of the first connecting plate and the second connecting plate are flush with the two end faces of the PTC heating element.

[0008] Furthermore, a crossbeam is provided inside the hollow cavity for the PTC heating element; The crossbeam is located below the temperature sensing element, and the extension direction of the crossbeam is parallel to the setting direction of the temperature sensing element. The bottom surface of the temperature sensing element is in contact with the upper surface of the crossbeam.

[0009] Furthermore, the bimetallic sheet is continuously bent along its length to form a fixed section, an adjusting section, and a deformable section in sequence; The fixed section is disposed on the inner side wall of the hollow cavity of the PTC heating element, the deformation section is in contact with the upper surface of the crossbeam, and the adjustment section is connected between the fixed section and the deformation section and is inclined along the length direction of the crossbeam.

[0010] Furthermore, the PTC heating element is provided with positioning grooves on the side walls at both ends of the crossbeam, and each positioning groove is provided with a pressure block that is compatible with the positioning groove. The fixing section of the bimetallic sheet is placed in the positioning groove, and the side of the pressure block facing the fixing section is integrally formed with a positioning post. The fixing section has a through hole corresponding to the position of the positioning post. The side of the pressure block away from the bimetallic strip abuts against the first connecting plate.

[0011] Furthermore, the actuating block has an I-shaped structure, including a top plate, a bottom plate, and a vertical plate connecting the two; The top plate, bottom plate, and vertical plate enclose two symmetrically distributed semi-enclosed cavities, and the deformed sections of the two bimetallic sheets are respectively housed in the two semi-enclosed cavities; Along the length of the beam, the length of the bottom plate is less than the length of the top plate; In the initial state, the distance between the free ends of the two deformed segments is less than the length of the bottom plate. After the bimetallic strip is heated and deformed, the distance between the free ends of the two deformed segments is less than the length of the top plate.

[0012] Furthermore, the top plate is inclined on the corresponding driving surfaces of the two deformation segments; The two driving surfaces are symmetrically distributed and gradually spread outwards in the direction away from the top plate. The ends of the deformed sections of the two bimetallic sheets are integrally formed with arc-shaped contacts, which slide in contact with the corresponding driving surfaces.

[0013] Furthermore, the actuating block also includes a plunger, which is disposed through the vertical plate in a direction perpendicular to the top plate and the bottom plate; One end of the plunger extends out of the top plate and corresponds to the protrusion on the movable contact piece, while the other end extends out of the bottom plate and is fitted into the through hole of the crossbeam. The side of the crossbeam that contacts the two bimetallic strips extends along its length toward the movable contact piece to form side guards. The bottom plate is placed between the two side guards, and the top plate abuts against the top surface of the two side guards.

[0014] Furthermore, the first connecting plate protrudes outward at the position corresponding to the movable contact piece, forming a cavity for movement; The protruding portion of the first connecting plate is recessed inward on the side facing the closed cavity to form a first support platform, and one end of the movable contact piece is fixed on the first support platform; The second connecting plate is recessed inward on the side facing the closed cavity corresponding to the position of the stationary contact to form a second support platform, and the stationary contact is fixed on the second support platform.

[0015] Furthermore, the insulating protective shell consists of an inner protective cover and two outer protective covers; The inner protective cover covers one side wall of the PTC heating element in the width direction, including a side plate and four pressure strips formed by bending and extending along the four corners of the upper and lower edges of the side plate. The four pressure strips are respectively set at the joint positions of the first connecting plate and the second connecting plate with the corresponding groove. Two outer protective covers are provided on the two side walls along the length of the PTC heating element. Each of the two inner walls of the outer protective covers is provided with a retaining strip, which abuts against the pressure strip. The two ends of the pressure strips at opposite corners of the inner cover are bent and extended to form a first limiting edge. The two outer covers are provided with a second limiting edge at the position corresponding to the first limiting edge. After assembly, the first limiting edge covers the outside of the second limiting edge.

[0016] The technical solution of this invention can achieve the following technical effects: Through the coordinated linkage structure of the temperature sensing element, actuator block, and moving contact, the temperature signal is accurately converted into mechanical on / off action. This not only ensures high temperature sensing accuracy and fast action response performance, allowing for timely circuit cutoff when the circuit overheats, but also effectively avoids equipment damage and safety risks caused by malfunctions or delays. Furthermore, by using the PTC heating element's own structure to provide assembly space for the sensing components, there is no need for additional external or internal mounting brackets, significantly reducing redundant gaps between components. At the same time, the integrated assembly structure formed by the first connecting plate, the second connecting plate, and the PTC heating element effectively reduces the total number of parts, simplifies the assembly process, shortens assembly time, and significantly reduces manufacturing and maintenance costs.

[0017] This invention incorporates a first connecting plate and a second connecting plate attached to both ends of the hollow cavity of a PTC heating element. The PTC heating element passively senses temperature anomalies caused by overcurrent or overload in the working circuit and forms a stable micro-thermal environment within the hollow cavity through multi-faceted circumferential temperature sensing. The cavity temperature is maintained in dynamic equilibrium through the heat convection effect of air conduction. Simultaneously, the contact conduction between the PTC heating element and the sensing element achieves stable heat transfer, forming a dual heat conduction mechanism of air heat storage and contact heat replenishment. This significantly improves heat transfer efficiency, effectively avoids protection delays caused by untimely temperature sensing, and further ensures the reliability and stability of circuit protection.

[0018] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0019] Figure 1 An assembly diagram of a temperature protector with mechanical action control; Figure 2 An exploded view of a temperature protector with mechanical action control; Figure 3 This is a schematic diagram showing the installation of the moving contact piece on the first connecting plate; Figure 4 This is a schematic diagram showing the position of the crossbeam relative to the PTC heating element; Figure 5 This is a schematic diagram of the actuator block installation. Figure 6 A schematic diagram of two bimetallic sheets transitioning from their initial state to a deformed state. Figure 7 This is a schematic diagram of the deformation section and the top plate driving surface, as well as a partially enlarged schematic diagram; Figure 8A schematic diagram of the cross-sectional structure of a temperature protector with mechanical action control; Reference numerals: 1. Insulating protective shell; 11. Inner protective cover; 111. Pressure strip; 112. First limiting edge; 12. Outer protective cover; 121. Locking strip; 122. Second limiting edge; 2. PTC heating element; 21. Hollow cavity; 22. Groove; 23. Pressure block; 3. First connecting plate; 31. First support platform; 4. Second connecting plate; 41. Second support platform; 5. Moving contact piece; 51. Protrusion; 6. Moving contact; 7. Stationary contact; 8. Temperature sensing element; 81. Bimetallic strip; 81a. Fixed section; 81b. Adjusting section; 81c. Deformation section; 81d. Arc-shaped contact; 9. Actuating block; 91. Top plate; 91a. Driving surface; 92. Bottom plate; 93. Vertical plate; 94. Plunger; 10. Crossbeam; 101. Side guard. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] like Figures 1-8 As shown, this application provides a temperature protector with mechanical action control, including an insulating protective shell 1, a PTC heating element 2, a moving contact 5, a temperature sensing element 8, a first connecting plate 3, and a second connecting plate 4; The PTC heating element 2 is housed within an insulating protective shell 1 and has a rectangular frame structure with a hollow cavity 21 extending along the thickness direction. The first connecting plate 3 and the second connecting plate 4 are respectively assembled on the two end faces of the hollow cavity 21 of the PTC heating element 2, together forming a closed cavity, and are respectively connected to the first lead and the second lead; The movable contact 5 is housed in a closed cavity. Its fixed end is connected to the first connecting plate 3, and its free end is connected to the movable contact 6. A stationary contact 7 is provided on the second connecting plate 4 at a position corresponding to the movable contact 6. The temperature sensing element 8 includes two bimetallic strips 81 symmetrically arranged relative to the moving contact 5. The ends of the two bimetallic strips 81 that are far apart from each other are respectively mounted on the inner sidewalls of the hollow cavity 21 of the PTC heating element 2. The actuator block 9 is located in the area below the moving contact piece 5, between the free ends of the two bimetallic pieces 81, and is integrally molded from ceramic material.

[0023] In this invention, the PTC heating element 2 serves as both a heating element and a mounting carrier for internal components. Its assembly with the connecting plate and the temperature sensing element 8 forms a modular structure, which significantly optimizes the overall size of the protector and facilitates its adaptation in confined electrical installation environments. At the same time, the PTC heating element 2 itself has the characteristics of constant temperature heating and over-temperature self-limitation, which can assist in temperature regulation. Furthermore, the inner wall of the rectangular frame structure can be directly used as the mounting carrier for the temperature sensing element 8 without the need for additional mounting brackets, thus simplifying the overall structure.

[0024] The first connecting plate 3 and the second connecting plate 4 serve as the core carriers for circuit connection. By connecting the first lead and the second lead respectively, the protector can be stably connected to the target circuit, ensuring stable current transmission. On this basis, the first connecting plate 3 and the second connecting plate 4 are attached to the two end faces of the PTC heating element 2, forming a closed cavity. The PTC heating element 2 can passively sense the circuit temperature on the first connecting plate 3 and the second connecting plate 4, thereby obtaining the temperature regulation that causes the two bimetallic strips 81 to deform. In addition, the formed closed cavity can effectively prevent external dust and moisture from entering the contact area between the internal moving contact 6 and the stationary contact 7, avoiding contact oxidation and corrosion that could lead to failure of switching on and off, and ensuring the reliability of contact switching.

[0025] The temperature sensing element 8 is positioned perpendicular to the moving contact 5. The two bimetallic strips 81, with their ends facing away from each other, are fixed to opposite inner walls of the hollow cavity 21 of the PTC heating element 2. This structure allows the temperature sensing element 8 to fully contact the temperature environment within the cavity, ensuring a uniform temperature sensing range, high temperature sensing accuracy, and rapid response to temperature changes. The free ends of the two bimetallic strips 81 are connected to the actuator block 9, transmitting the force generated by their deformation to the actuator block 9. This ensures precise direction of movement for the actuator block 9, achieving efficient and accurate force transmission. The actuator block 9 is integrally molded from ceramic material. Utilizing the insulating properties of ceramic, the circuit between the temperature sensing element 8 and the moving contact 5 is effectively isolated, preventing short circuits and significantly improving the electrical safety of the equipment.

[0026] In this embodiment, the first connecting plate 3, the moving contact 5, the moving contact 6, the stationary contact 7, and the second connecting plate 4 together constitute the working circuit. When the protector is connected to the circuit, this working circuit is connected in parallel with the PTC heating element 2. The specific working process is as follows: Under normal operating temperature, the temperature sensing element 8 is in a natural state. At this time, the actuator block 9 is not pushed by the temperature sensing element 8. The moving contact 5, by virtue of its own structural characteristics, keeps the moving contact 6 at its free end in close contact with the stationary contact 7 on the second connecting plate 4. The working circuit is in a stable conducting state, and the target electrical equipment can work normally.

[0027] When an overcurrent or overload fault occurs in the working circuit, the circuit temperature will rise abnormally. When the temperature rises to a preset threshold, the PTC heating element 2 will indirectly sense and respond to the temperature abnormality caused by the overcurrent or overload in the working circuit. The PTC heating element 2 senses the heat of the circuit, and the heat will first be transferred to its own cavity sidewall, and then radiated and conducted to the interior of the hollow cavity 21 through the sidewall, so that a high-temperature environment matching the temperature of the PTC heating element is formed inside the cavity. The temperature sensing element 8 is assembled inside the hollow cavity 21 and deforms by directly sensing the high-temperature environment inside the cavity. Since one end of the two bimetallic strips 81 is fixed to the inner sidewall of the hollow cavity 21, their free... The end is connected to the actuator block 9. During the deformation process, a driving force is generated in the direction perpendicular to the moving contact 5. This driving force pushes the actuator block 9 upward to push the free end of the contact 5. Under the pushing force of the actuator block 9, the moving contact 5 swings around its fixed end, causing the moving contact 6 to separate from the stationary contact 7. The working circuit is cut off, and the target device stops working, thereby realizing the over-temperature and over-current protection functions. After the moving contact 6 and the stationary contact 7 are disconnected, the holding current in the circuit will flow through the parallel PTC heating element 2, causing the PTC heating element 2 to start heating itself and continue to maintain the high temperature environment in the hollow cavity 21, ensuring that the temperature sensing element 8 is always in a deformed state, forming a self-locking protection. Until the circuit power is cut off and the ambient and equipment temperatures drop to a safe range, the deformation of the temperature sensing element 8 gradually recovers, the driving force on the actuator block 9 disappears, and the moving contact 5 swings in the opposite direction around its fixed end based on its own elastic reset capability. The moving contact 6 at the free end re-makes close contact with the stationary contact 7 on the second connecting plate 4, the working circuit is restored to conduction, and the target electrical equipment can work normally again.

[0028] Through the coordinated linkage structure of the temperature sensing element 8, the actuator block 9, and the moving contact piece 5, the temperature signal is accurately converted into mechanical on / off action. This not only ensures high temperature sensing accuracy and fast action response performance, but also allows for timely circuit cutoff when the circuit overheats, effectively avoiding equipment damage and safety risks caused by malfunctions or delays. Furthermore, the PTC heating element 2 itself provides assembly space for the sensing components, eliminating the need for additional external or internal mounting brackets and significantly reducing redundant gaps between components. At the same time, the integrated assembly structure formed by the first connecting plate 3, the second connecting plate 4, and the PTC heating element 2 effectively reduces the total number of parts, simplifies the assembly process, shortens assembly time, and significantly reduces production and maintenance costs.

[0029] In this invention, a first connecting plate 3 and a second connecting plate 4 are attached to both ends of the hollow cavity 21 of the PTC heating element 2. The PTC heating element 2 can passively sense temperature anomalies caused by overcurrent and overload in the working circuit, and form a stable micro-thermal environment in the hollow cavity 21 through circumferential multi-faceted temperature sensing. The cavity temperature is maintained in dynamic equilibrium by means of the heat convection effect of air conduction. At the same time, the contact conduction between the PTC heating element 2 and the sensing element realizes stable heat transfer, forming a dual heat conduction mechanism of air heat storage and contact heat supplementation, which greatly improves the heat transfer efficiency, effectively avoids the protection delay problem caused by untimely temperature sensing, and further ensures the reliability and stability of circuit protection.

[0030] In a preferred embodiment of the present invention, the PTC heating element 2 has grooves 22 on both ends of the cavity 21 corresponding to the first connecting plate 3 and the second connecting plate 4; and the outer surfaces of the first connecting plate 3 and the second connecting plate 4 are flush with the two ends of the PTC heating element 2.

[0031] The groove 22 provides a precise assembly positioning reference for the first connecting plate 3 and the second connecting plate 4, allowing them to be accurately embedded and effectively avoiding offset or misalignment during assembly. This further ensures the relative positional accuracy of the moving contact 6 and the stationary contact 7. In addition, the design of the outer surfaces of the first connecting plate 3 and the second connecting plate 4 being flush with the PTC heating element 2 minimizes the overall thickness of the protector after assembly, making the overall structure of the product flatter and more compact, and further enhancing the product's adaptability to narrow electrical installation environments.

[0032] As a preferred embodiment of the present invention, the PTC heating element 2 has a crossbeam 10 disposed in the hollow cavity 21; the crossbeam 10 is located below the temperature sensing element 8, and the extension direction of the crossbeam 10 is parallel to the setting direction of the temperature sensing element 8; the bottom surface of the temperature sensing element 8 is in contact with the upper surface of the crossbeam 10.

[0033] The crossbeam 10 and the PTC heating element 2 are integrally molded, saving installation steps. The crossbeam 10 also acts as a reinforcing rib of the PTC heating element 2's frame structure, effectively improving the overall structural strength and deformation resistance of the PTC heating element 2. Simultaneously, the temperature sensing element 8 is directly attached to the upper surface of the crossbeam 10, allowing the crossbeam 10 to directly transfer the heat generated by the PTC heating element 2 to the temperature sensing element 8. Combined with the connection between the two ends of the temperature sensing element 8 and the inner wall of the hollow cavity 21, a multi-directional heat transfer path is formed, enabling the temperature sensing element 8 to detect temperature changes more quickly and evenly, further improving temperature response speed and ensuring timely over-temperature protection. It should be noted that the crossbeam 10 located below the temperature sensing element 8 may only contact the second connecting plate 4; therefore, it will not form a second parallel branch when energized. Furthermore, the crossbeam 10 can be made of ceramic material alone and assembled into the hollow cavity 21 of the PTC heating element 2 using a riveting process.

[0034] In this invention, the bimetallic sheet 81 is continuously bent along its length to form a fixed section 81a, an adjusting section 81b, and a deformable section 81c in sequence. The fixed section 81a is disposed on the inner side wall of the hollow cavity 21 of the PTC heating element 2, the deformable section 81c is in contact with the upper surface of the crossbeam 10, and the adjusting section 81b is connected between the fixed section 81a and the deformable section 81c and is inclined along the length of the crossbeam 10.

[0035] Two bimetallic strips 81 extend across the hollow cavity 21. Their fixed sections 81a are respectively positioned within the limiting grooves on the inner sidewalls of the hollow cavity 21 of the PTC heating element 2. The deformable section 81c contacts the upper surface of the crossbeam 10. Utilizing the heat conduction relationship between the crossbeam 10 and the PTC heating element 2, the bimetallic strips 81 quickly receive heat from the PTC heating element 2 through the deformable section 81c. Simultaneously, the contact heat conduction between the fixed section 81a and the sidewall of the hollow cavity 21 forms a dual-path heat transfer, enabling the bimetallic strips 81 to sense temperature changes more quickly and uniformly, effectively improving temperature sensing sensitivity. The tilted adjustment section 81b provides ample travel and buffer space for the deformation of the bimetallic strips 81. When the two bimetallic strips 81 deform under heat... The deformation section 81c swings upward around its connection with the adjustment section 81b. The two bimetallic strips 81 work together to form a beam structure with fixed ends and an arched center. The arched center directly drives the actuator block 9 to move towards the moving contact 5, thereby causing the moving contact 5 to move in tandem, separating the moving contact 6 from the stationary contact 7 and breaking the circuit. At the same time, the resistance of the PTC heating element 2 increases rapidly after being powered on, and its temperature rises synchronously. The increased temperature is directly transferred to the fixed section 81a of the bimetallic strip 81 on one hand, and indirectly transferred to the deformation section 81c of the bimetallic strip 81 through the crossbeam 10 on the other hand, forming a complete heat conduction closed loop circuit, which further accelerates the temperature response speed of the bimetallic strip 81 and ensures the timeliness and reliability of the over-temperature protection action.

[0036] In a further optimized structure, the PTC heating element 2 is provided with positioning grooves on the side walls at both ends of the crossbeam 10, and each positioning groove is provided with a pressure block 23 that is adapted to the positioning groove; the fixing section 81a of the bimetallic sheet 81 is placed in the positioning groove, and the side of the pressure block 23 facing the fixing section 81a is integrally formed with a positioning post, and the fixing section 81a is provided with a through hole at the position of the positioning post; the side of the pressure block 23 away from the bimetallic sheet 81 abuts against the first connecting plate 3.

[0037] The pressure block 23 is embedded in the positioning groove, and the positioning pin on the pressure block 23 passes through the through hole of the fixed section 81a, forming a pin-hole positioning structure. This structure can precisely constrain the relative position of the fixed section 81a, the pressure block 23, and the PTC heating element 2 in the horizontal direction, ensuring that the bimetallic strip 81 is always in the preset sensing position and preventing the bimetallic strip 81 from shifting left or right or tilting at an angle during assembly. This positioning structure ensures that the two bimetallic strips 81 always maintain a parallel and symmetrical assembly posture, ensuring that they arch synchronously and drive the actuator block 9 evenly when deformed, avoiding problems such as uneven driving force and motion jamming caused by posture deviation. The pressure block 23 locks the fixed section 81a with the pressing action of the first connecting plate 3. In addition, the bimetallic strip 81 can also be fixed by direct adhesive bonding. A high-temperature resistant and anti-aging adhesive must be selected to ensure that the fixed section 81a remains stable and prevents it from falling off in the high-temperature environment of the self-heating PTC heating element 2.

[0038] In the preferred structure of the present invention, the actuating block 9 has an I-shaped structure, including a top plate 91, a bottom plate 92 and a vertical plate 93 connecting the two; the top plate 91, the bottom plate 92 and the vertical plate 93 enclose two symmetrically distributed semi-closed cavities, and the deformation segments 81c of the two bimetallic sheets 81 are respectively housed in the two semi-closed cavities. Specifically, the actuator block 9 adopts an integrally molded I-beam structure, which effectively withstands periodic impact forces during the repeated deformation and reset cycles of the bimetallic strip 81, avoiding failures such as breakage and deformation. The two semi-enclosed cavities enclosed by the I-beam structure provide dedicated assembly and movement space for the deformation segment 81c of the bimetallic strip 81, which can constrain the deformation segment 81c from three directions: top, bottom, and sides. This not only prevents the two bimetallic strips 81 from interfering with each other during assembly or deformation, but also ensures that the actuating force of the two bimetallic strips 81 is precisely concentrated on the actuator block 9, achieving synchronous drive.

[0039] Along the length of the crossbeam 10, the length of the base plate 92 is less than the length of the top plate 91. In the initial state, the two bimetallic strips 81 are in a natural, undeformed state, and the distance between the free ends of the two deformation segments 81c is less than the length of the base plate 92. The two deformation segments 81c are used to press the base plate 92 against the crossbeam 10 to form an initial limit on the actuator 9, so as to prevent the actuator 9 from moving unexpectedly due to the vibration of the protector. At this time, the top plate 91 and the moving contact 5 maintain a preset initial distance or slight contact, and the moving contact 6 at the free end of the moving contact 5 is in close contact with the stationary contact 7 of the second connecting plate 4, and the circuit is in a conducting state. When the temperature of the target electrical equipment or the ambient temperature rises above a preset threshold, the PTC heating element 2 heats up and transfers heat to the bimetallic strip 81. After the bimetallic strip 81 deforms due to heat, the two bimetallic strips 81 arch synchronously and push against the top plate 91 together, driving the entire I-shaped actuator block 9 to move upward in a direction perpendicular to the moving contact piece 5. During this process, the distance between the free ends of the two deformed segments 81c gradually increases, but the distance between the free ends of the two deformed segments 81c is still less than the length of the top plate 91, ensuring that even under maximum deformation, the driving effect of the bimetallic strip 81 can still effectively act on the top plate 91, and will not leave the force range of the actuator block 9 due to excessive deformation, thus ensuring the continuity and effectiveness of the driving action.

[0040] As a preferred embodiment of the above scheme, the top plate 91 is inclined to the corresponding driving surfaces 91a of the two deformation segments 81c; the two driving surfaces 91a are symmetrically distributed and gradually spread outward in the direction away from the top plate 91; the ends of the deformation segments 81c of the two bimetallic sheets 81 are integrally formed with arc-shaped contacts 81d, and the arc-shaped contacts 81d slide in contact with the corresponding driving surfaces 91a.

[0041] When the deformation section 81c of the bimetallic strip 81 deforms, the vertical arching force generated can be converted into a positive driving force for the actuator block 9 to move upward through the inclined driving surface 91a of the top plate 91. Compared with the planar driving structure, the inclined driving surface 91a can effectively reduce the lateral loss of force, so that the deformation energy of the bimetallic strip 81 can be more concentrated on the lifting and lowering motion of the actuator block 9, greatly improving the power transmission efficiency and ensuring that the actuator block 9 responds quickly and pushes the moving contact 5 to move. At the same time, as the arc-shaped contact 81d at the end of the deformation section 81c slides along the inclined driving surface 91a, the actuator block 9 will continuously climb along the inclined direction under the continuous pushing force generated by the bending deformation of the deformation section 81c, thereby ensuring that the actuator block 9 has sufficient lifting distance to ensure that the subsequent moving contact 5 can swing effectively, so that the moving contact 6 and the stationary contact 7 can be stably separated.

[0042] As a preferred structure of the present invention, the actuating block 9 further includes a plunger 94, which is disposed through the vertical plate 93 in a direction perpendicular to the top plate 91 and the bottom plate 92; one end of the plunger 94 extends out of the top plate 91 and corresponds to the protrusion 51 on the movable contact piece 5, and the other end extends out of the bottom plate 92 and is fitted into the through hole of the crossbeam 10; the design of the plunger 94 penetrating through the middle vertical plate 93 of the actuating block 9 and the lower end being embedded in the through hole of the crossbeam 10 can strictly constrain the movement trajectory of the actuating block 9 in the axial direction, ensuring that the actuating block 9 can only move up and down in a direction perpendicular to the movable contact piece 5, avoiding tilting, swaying or lateral movement during its movement, ensuring the precise docking of the actuating block 9 and the protrusion 51 of the movable contact piece 5, and ensuring that the pushing force is stably transmitted to the movable contact piece 5; The side of the crossbeam 10 that contacts the two bimetallic strips 81 extends along its length toward the movable contact piece 5 to form side guards 101. The base plate 92 is placed between the two side guards 101, and the top plate 91 abuts against the top surface of the two side guards 101. The side guards 101 of the crossbeam 10 provide lateral restraint to the base plate 92 of the actuator block 9 and also provide vertical restraint through the abutment of the top end with the top plate 91. Together with the guide structure of the plunger 94, they form a three-dimensional restraint system to prevent displacement deviation of the actuator block 9 during force-driven or reset processes. In addition, sound insulation cotton can be installed on the side guards 101 to effectively absorb the noise generated during the movement of the actuator block 9. Specifically, it can alleviate the impact noise between the top plate 91 and the top of the side baffle 101, as well as the sliding friction noise between the bottom plate 92 and the side baffle 101. At the same time, it can absorb the slight friction noise between the bimetallic strip 81 and the semi-enclosed cavity of the actuator block 9 when the bimetallic strip 81 deforms, reduce the operating noise during the operation of the temperature protector, and improve the comfort of using the product. It is especially suitable for noise-sensitive electrical equipment scenarios.

[0043] In a preferred embodiment of the present invention, the first connecting plate 3 protrudes outward from the position corresponding to the movable contact piece 5 to form a movable cavity; the movable cavity provides sufficient space for the swinging action of the movable contact piece 5, so that the swinging action of the movable contact piece 5 is unrestricted.

[0044] The protruding part of the first connecting plate 3 is recessed inward toward the side of the closed cavity to form a first support platform 31, and one end of the moving contact piece 5 is fixed on the first support platform 31; the second connecting plate 4 is recessed inward toward the side of the closed cavity corresponding to the position of the stationary contact 7 to form a second support platform 41, and the stationary contact 7 is fixed on the second support platform 41.

[0045] The first support platform 31 and the second support platform 41 provide precise assembly reference surfaces for the moving contact 5 and the stationary contact 7, respectively, making the fixed positions of the moving contact 5 and the stationary contact 7 more accurate and effectively limiting their displacement in the horizontal or vertical direction. At the same time, the support platform can increase the fixed contact area, improve the connection strength, and prevent the moving contact 5 and the stationary contact 7 from loosening or shifting during equipment vibration or long-term use, ensuring the stability of their relative positions and thus improving the reliability of circuit switching. In addition, the protrusion of the first connecting plate 3 forms a movable cavity, and the reverse concave shape forms the support platform, which is an integrally molded structure. The support platform of the second connecting plate 4 is also an integral protruding structure, which simplifies the structural design, minimizes internal redundant space, and improves the adaptability to narrow installation environments.

[0046] In a preferred embodiment of the present invention, the insulating protective shell 1 is composed of an inner protective cover 11 and two outer protective covers 12; the inner protective cover 11 covers one side wall of the PTC heating element 2 in the width direction, including a side plate and four pressure strips 111 formed by bending and extending along the four corner positions of the upper and lower edges of the side plate, and the four pressure strips 111 are respectively set at the joint positions of the first connecting plate 3 and the second connecting plate 4 and the corresponding groove 22; the two outer protective covers 12 cover the two side walls of the PTC heating element 2 in the length direction, and the two inner walls of the outer protective covers 12 are provided with retaining strips 121, which abut against the pressure strips 111; The ends of the two diagonally opposite pressure strips 111 of the inner cover 11 are bent and extended to form a first limiting edge 112. The two outer covers 12 are provided with a second limiting edge 122 at the position corresponding to the first limiting edge 112. After assembly, the first limiting edge 112 covers the outside of the second limiting edge 122.

[0047] The insulating protective shell 1 adopts a combined structure of an inner cover 11 and two outer covers 12, which can be assembled in stages, reducing the assembly difficulty. Specifically, the inner cover 11 is first assembled into place, and its four pressure strips 111 are attached to the joint of the first connecting plate 3, the second connecting plate 4 and the corresponding groove 22. With the help of the assembly pre-tightening force, the two connecting plates are subjected to auxiliary pressing, which further consolidates the fixed state of the first connecting plate 3 and the second connecting plate 4 in the groove 22 and prevents the connection from loosening. Then, the two outer covers 12 are assembled to complete the overall coverage. The retaining strips 121 of the outer cover 12 relative to the inner wall can accurately abut against the inner wall of the pressure strips 111, forming a cooperative limiting of the inner and outer covers 12, effectively restraining the relative displacement of the two, and significantly improving the assembly stability of the overall protective shell.

[0048] The insulating protective shell 1 only covers the frame of the PTC heating element 2. On the one hand, it enables the PTC heating element 2 to more efficiently absorb and concentrate ambient heat when the working circuit is operating normally, ensuring that the heat is mainly concentrated in the body of the PTC heating element 2, which provides a guarantee for the subsequent accurate heat transfer to the bimetallic strip 81. It effectively strengthens the heat conduction link between the PTC heating element 2 and the bimetallic strip 81 and avoids temperature sensing delay caused by heat dispersion. On the other hand, the frame covering design allows the first connecting plate 3 and the second connecting plate 4 to remain exposed or in good contact with the external environment, making full use of the metal thermal conductivity of the first connecting plate 3 and the second connecting plate 4 to achieve efficient heat dissipation. This not only prevents the PTC heating element 2 from excessive heat accumulation and affecting its service life, but also balances the operating temperature of the entire device.

[0049] Although this application has been described in conjunction with specific features and embodiments, it is apparent that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and accompanying drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of this application and its equivalents, this application is intended to include such modifications and modifications.

Claims

1. A temperature protector with mechanical action control, characterized in that, include: Insulating protective casing; The PTC heating element is housed within the insulating protective shell and has a rectangular frame structure with a hollow cavity extending along the thickness direction. The first connecting plate and the second connecting plate are respectively assembled on the two end faces of the hollow cavity of the PTC heating element, together forming a closed cavity, and are respectively connected to the first lead and the second lead; A movable contact piece is housed in the enclosed cavity. Its fixed end is connected to the first connecting plate, and its free end is connected to a movable contact. A stationary contact is provided on the second connecting plate at a position corresponding to the movable contact. The temperature sensing element includes two bimetallic strips symmetrically arranged relative to the moving contact piece, with the ends of the two bimetallic strips being respectively mounted on the opposite inner walls of the hollow cavity of the PTC heating element. The actuator block is located in the area below the moving contact piece, between the free ends of the two bimetallic sheets, and is integrally formed from ceramic material.

2. The temperature protector with mechanical action control according to claim 1, characterized in that, The PTC heating element has grooves on both ends of its cavity that are adapted to the first connecting plate and the second connecting plate. Furthermore, the outer surfaces of the first connecting plate and the second connecting plate are flush with the two end faces of the PTC heating element.

3. The temperature protector with mechanical action control according to claim 1, characterized in that, The PTC heating element is provided with a crossbeam inside the hollow cavity; The crossbeam is located below the temperature sensing element, and the extension direction of the crossbeam is parallel to the setting direction of the temperature sensing element. The bottom surface of the temperature sensing element is in contact with the upper surface of the crossbeam.

4. The temperature protector with mechanical action control according to claim 3, characterized in that, The bimetallic sheet is continuously bent along its length to form a fixed section, an adjusting section and a deformation section in sequence. The fixed section is disposed on the inner side wall of the hollow cavity of the PTC heating element, the deformation section is in contact with the upper surface of the crossbeam, and the adjustment section is connected between the fixed section and the deformation section and is inclined along the length direction of the crossbeam.

5. The temperature protector with mechanical action control according to claim 4, characterized in that, The PTC heating element has positioning grooves on the side walls at both ends of the crossbeam, and each positioning groove is equipped with a pressure block that is compatible with the positioning groove. The fixing section of the bimetallic sheet is placed in the positioning groove, and the side of the pressure block facing the fixing section is integrally formed with a positioning post. The fixing section has a through hole corresponding to the position of the positioning post. The side of the pressure block away from the bimetallic strip abuts against the first connecting plate.

6. The temperature protector with mechanical action control according to claim 4, characterized in that, The actuating block has an I-shaped structure, including a top plate, a bottom plate, and a vertical plate connecting the two. The top plate, bottom plate, and vertical plate enclose two symmetrically distributed semi-enclosed cavities, and the deformed sections of the two bimetallic sheets are respectively housed in the two semi-enclosed cavities; Along the length of the beam, the length of the bottom plate is less than the length of the top plate; In the initial state, the distance between the free ends of the two deformed segments is less than the length of the bottom plate. After the bimetallic strip is heated and deformed, the distance between the free ends of the two deformed segments is less than the length of the top plate.

7. The temperature protector with mechanical action control according to claim 6, characterized in that, The top plate is inclined on the corresponding driving surfaces of the two deformation segments. The two driving surfaces are symmetrically distributed and gradually spread outwards in the direction away from the top plate. The ends of the deformed sections of the two bimetallic sheets are integrally formed with arc-shaped contacts, which slide in contact with the corresponding driving surfaces.

8. The temperature protector with mechanical action control according to claim 6, characterized in that, The actuating block further includes a plunger, which is disposed through the vertical plate in a direction perpendicular to the top plate and the bottom plate; One end of the plunger extends out of the top plate and corresponds to the protrusion on the movable contact piece, while the other end extends out of the bottom plate and is fitted into the through hole of the crossbeam. The side of the crossbeam that contacts the two bimetallic strips extends along its length toward the movable contact piece to form side guards. The bottom plate is placed between the two side guards, and the top plate abuts against the top surface of the two side guards.

9. The temperature protector with mechanical action control according to claim 1, characterized in that, The first connecting plate protrudes outward from the position corresponding to the movable contact piece, forming a cavity for movement; The protruding portion of the first connecting plate is recessed inward on the side facing the closed cavity to form a first support platform, and one end of the movable contact piece is fixed on the first support platform; The second connecting plate is recessed inward on the side facing the closed cavity corresponding to the position of the stationary contact to form a second support platform, and the stationary contact is fixed on the second support platform.

10. The temperature protector with mechanical action control according to claim 2, characterized in that, The insulating protective shell consists of an inner protective cover and two outer protective covers; The inner protective cover covers one side wall of the PTC heating element in the width direction, including a side plate and four pressure strips formed by bending and extending along the four corners of the upper and lower edges of the side plate. The four pressure strips are respectively set at the joint positions of the first connecting plate and the second connecting plate with the corresponding groove. Two outer protective covers are provided on the two side walls along the length of the PTC heating element. Each of the two inner walls of the outer protective covers is provided with a retaining strip, which abuts against the pressure strip. The two ends of the pressure strips at opposite corners of the inner cover are bent and extended to form a first limiting edge. The two outer covers are provided with a second limiting edge at the position corresponding to the first limiting edge. After assembly, the first limiting edge covers the outside of the second limiting edge.

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