PTC heater structure

Abstract

The utility model discloses a PTC heater structure, including a plurality of PTC heating tube, a plurality of radiating fins and mounting seat, a plurality of PTC heating tube installation is positioned on mounting seat, and a plurality of radiating fins interval arrangement sets up on PTC heating tube, still be provided with corrugated elastic metal sheet between a plurality of radiating fins and mounting seat, the corrugated elastic metal sheet is nickel base alloy material quality, a plurality of radiating fins and mounting seat are all aluminum material quality, the contact surface of a plurality of radiating fins is close to PTC heating tube and has coated nano alumina heat conduction coating, like this, through the elastic deformation absorption vibration energy, and gradient thermal expansion design, reduce the thermal stress, reduce the mechanical stress between mounting seat and fin aluminum pipe, prevent the connection loose after long -term use.

Description

Technical Field

[0001] This utility model relates to the field of PTC heaters, and in particular to a PTC heater structure. Background Technology

[0002] PTC heating element is a new type of constant-temperature heating element. It consists of two metal plates attached to both sides of the PTC heating element and two wires leading to it as current-carrying electrodes, eliminating the need for additional temperature control devices.

[0003] Among them, the PTC heater is composed of PTC ceramic heating element and aluminum tube; this type of PTC heating element has the advantages of low thermal resistance and high heat exchange efficiency, and is an automatic constant temperature and energy-saving electric heater; its outstanding feature is its safety performance, and it will not produce the surface "red" phenomenon of electric heating tube heaters under any application conditions, thus avoiding safety hazards such as burns or fires.

[0004] Existing ceramic PTC heaters typically include a base, heat dissipation fins, and a PTC heating element. The PTC heating element is secured to the base with screws, and the heat dissipation fins are spaced outside the PTC heating element. The heat dissipation fins are strip-shaped. The screw-secured method for the heat dissipation fins and the base has the following drawbacks: For example, due to the significant difference in thermal expansion coefficients, long-term thermal cycling generates mechanical stress. Long-term stress accumulation may cause fatigue damage at the connection points, leading to loose bolts, weld cracking, or material deformation, ultimately affecting the stability and service life of the heater.

[0005] Therefore, a new technical solution needs to be researched to address the above problems. Utility Model Content

[0006] In view of this, the present invention addresses the deficiencies of the existing technology, and its main purpose is to provide a PTC heater structure. Through the design of heat dissipation fins, mounting base and corrugated elastic metal sheet, a corrugated elastic metal sheet made of nickel-based alloy is also provided between several heat dissipation fins and mounting base. The elastic deformation absorbs vibration energy, and the gradient thermal expansion design (aluminum-nickel-based alloy-ceramic) reduces thermal stress, reduces mechanical stress between mounting base and finned aluminum tube, and prevents loosening of the connection after long-term use.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A PTC heater structure includes a plurality of PTC heating elements, a plurality of heat dissipation fins, and a mounting base. The plurality of PTC heating elements are mounted and positioned on the mounting base, and the plurality of heat dissipation fins are arranged at intervals on the PTC heating elements. A corrugated elastic metal sheet, made of nickel-based alloy, is also disposed between the plurality of heat dissipation fins and the mounting base. The corrugated elastic metal sheet includes a main body and a connecting portion extending along one end of the main body, forming a through cavity between the main body and the connecting portion. One end of the main body is mounted and positioned on the mounting base, and one end of the connecting portion is connected to one end of the heat dissipation fins. The plurality of heat dissipation fins and the mounting base are both made of aluminum. The contact surfaces of the plurality of heat dissipation fins near the PTC heating elements are coated with a nano-alumina thermally conductive coating.

[0009] As a preferred embodiment, the main body of the corrugated elastic metal sheet is fixed to the mounting base by laser welding, and the connecting part is connected to the root of the heat dissipation fin by interference fit or riveting.

[0010] As a preferred embodiment, the corrugated elastic metal sheet is Ω-shaped.

[0011] As a preferred embodiment, an airflow channel is formed between the adjacent heat dissipation fins, and the through cavity of the corrugated elastic metal sheet is disposed opposite to the airflow channel.

[0012] As a preferred embodiment, the mounting base includes a mounting plate and a positioning edge extending from one end of the mounting plate, with a magnet disposed on the outer side of the positioning edge.

[0013] As a preferred embodiment, the bottom surface of the mounting plate is provided with a fuse and a thermostat, the plurality of PTC heating elements are connected with leads, the thermostat is connected with a temperature control line, the leads and the temperature control line are connected together, and the fuse is connected to the thermostat.

[0014] As a preferred embodiment, the bottom surface of the mounting plate is also provided with a wire guard.

[0015] As a preferred embodiment, the mounting base includes an upper mounting base and a lower mounting base, with the upper and lower ends of the plurality of PTC heating tubes respectively connected to the upper mounting base and the lower mounting base. The magnet is disposed on the lower mounting base, and the upper mounting base includes a positioning plate and a positioning piece extending upward from the upper end of the self-positioning plate. The positioning piece has a positioning hole.

[0016] Compared with the prior art, this utility model has obvious advantages and beneficial effects. Specifically, as can be seen from the above technical solution, it mainly uses the design of heat dissipation fins, mounting base, and corrugated elastic metal sheet. The heat dissipation fins and mounting base are all made of aluminum, and the corrugated elastic metal sheet is made of nickel-based alloy. The PTC heating tubes are mounted and positioned on the mounting base, and the heat dissipation fins are arranged at intervals on the PTC heating tubes. In this way, a corrugated elastic metal sheet made of nickel-based alloy is also provided between the heat dissipation fins and the mounting base. Through elastic deformation, vibration energy is absorbed, and the gradient thermal expansion design (aluminum-nickel-based alloy-ceramic) reduces thermal stress, reduces mechanical stress between the mounting base and the aluminum tube fins, and prevents the connection from loosening after long-term use.

[0017] Secondly, a nano-alumina thermally conductive coating is applied to the contact surface of the heat sink fins to fill the interface gaps and form a continuous thermally conductive channel. Furthermore, the through cavity of the corrugated sheet is aligned with the airflow channel of the heat sink fins to form a directional airflow structure, thereby reducing airflow pressure loss.

[0018] To more clearly illustrate the structural features and effects of this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0019] Fig. 1 This is a perspective view of an embodiment of the present utility model;

[0020] Fig. 2 This is a top view of an embodiment of the present utility model;

[0021] Fig. 3 This is a side view of an embodiment of the present utility model;

[0022] Fig. 4 This is a bottom view of an embodiment of the present utility model.

[0023] Explanation of reference numerals in the attached diagram:

[0024] 10. PTC heating element; 11. Nano-alumina thermally conductive coating

[0025] 20. Heat dissipation fins

[0026] 30. Mounting bracket 31. Mounting plate

[0027] 32. Positioning edge; 33. Magnet

[0028] 34. Wire protection strip; 40. Corrugated elastic metal sheet. Detailed Implementation

[0029] Please refer to Figs. 1 to 4 As shown, it illustrates the specific structure of an embodiment of the present invention.

[0030] In the description of this utility model, it should be noted that the directional terms such as "up", "down", "front", "back", "left", and "right" indicate the orientation and positional relationship based on the accompanying drawings or the orientation or positional relationship shown when wearing and using the device normally. 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. They should not be construed as limiting the specific protection scope of this utility model.

[0031] A PTC heater structure includes a plurality of PTC heating tubes 10, a plurality of heat dissipation fins 20 and a mounting base 30.

[0032] The plurality of PTC heating elements 10 are mounted and positioned on the mounting base, and the plurality of heat dissipation fins 20 are arranged at intervals on the PTC heating elements 10; a corrugated elastic metal sheet 40 is also provided between the plurality of heat dissipation fins 20 and the mounting base, the corrugated elastic metal sheet 40 being made of nickel-based alloy; preferably, the corrugated elastic metal sheet 40 is Ω-shaped, and its Ω-shaped corrugated structure (its wave height is 4mm and its wave pitch is 12mm) can absorb axial displacement ≥0.5mm, and through gradient thermal expansion design (aluminum-nickel-based alloy-ceramic), thermal stress is reduced. Axial deformation absorption (along the corrugation extension direction): When the corrugated sheet is subjected to axial tension or compression, the side wings will be elastically bent, and the concave part of the arc will also slightly stretch or compress. The vertical (or inclined) structure of the side wings provides axial freedom, allowing the corrugated sheet to stretch and contract in the length direction, which can offset the axial displacement caused by thermal expansion (such as the expansion difference between the PTC heating tube and the heat sink fin 20). The elastic deformation of the concave part of the arc can help disperse axial stress and avoid mechanical stress concentration caused by rigid connection.

[0033] Radial deformation absorption (along the radius of the corrugated sheet cross section): When the system expands radially due to temperature changes (such as the radial expansion of heat dissipation fins 20), the concave part of the arc will bulge outward or contract inward. By adapting to the radial displacement through curvature changes, the flexibility of the arc structure allows the corrugated sheet to deform radially (perpendicular to the length direction), avoiding compression or cracking caused by radial expansion.

[0034] When the aluminum heat sink fins 20 and the mounting base expand axially due to temperature rise, the elastic bending of the Ω-shaped side wings can offset the difference in expansion between the two, preventing the connection from becoming loose; Radial compensation: When the fins expand radially, the Ω-shaped arc recessed part expands outward, absorbing radial stress through structural deformation, preventing contact failure between the fins and the PTC heating element; Thermal conductivity and buffering balance: The high elasticity of the nickel-based alloy combined with the thermal conductivity of the nano-alumina coating ensures both heat conduction efficiency and buffers mechanical stress through the Ω-shaped structure.

[0035] In this embodiment, the coefficient of thermal expansion of the nickel-based alloy corrugated sheet is between that of aluminum (mount / heat sink fins 20, 23 × 10). -6 / ℃) and ceramic (PTC heating element 10, 5×10 -6 Between / ℃, a gradient thermal expansion transition is formed; when the temperature rises, the expansion of the aluminum component is greater than that of the ceramic heating tube, and the corrugated sheet offsets the difference through elastic deformation.

[0036] The corrugated elastic metal sheet 40 includes a main body and a connecting part extending along one end of the main body. The main body and the connecting part (also referred to as the arc structure) form a through cavity. One end of the main body is mounted on a mounting base, and one end of the connecting part is connected to one end of the heat dissipation fins 20. The plurality of heat dissipation fins 20 and the mounting base are all made of aluminum. The contact surfaces of the plurality of heat dissipation fins 20 near the PTC heating tube 10 are coated with a nano-alumina thermally conductive coating 11. The nano-alumina coating reduces the contact thermal resistance, thereby improving the heat transfer efficiency from the heating tube to the fins. Nano-alumina has a high thermal conductivity, and when added to the coating, it can form an effective heat transfer channel, accelerate heat transfer, effectively improve the heat dissipation efficiency of the substrate, and prevent the equipment from degrading or being damaged due to overheating.

[0037] In this embodiment, the corrugated structure (similar to a metal expansion joint) has axial or radial elastic deformation capability, and can absorb the relative displacement of the aluminum part caused by temperature difference through its own bending, stretching or compression, thus avoiding stress concentration.

[0038] Preferably, the main body of the corrugated elastic metal sheet 40 is fixed to the mounting base by laser welding, and the connecting part is connected to the root of the heat dissipation fin 20 by interference fit or riveting.

[0039] Preferably, an airflow channel is formed between the adjacent heat dissipation fins 20, and the through cavity of the corrugated elastic metal sheet 40 is arranged opposite to the airflow channel to form a directional flow guiding structure, which reduces airflow resistance. The through cavity guides the airflow through the bottom of the heating tube, which enhances natural convection and improves the overall heat dissipation power.

[0040] Preferably, the mounting base includes a mounting plate 31 and a positioning edge 32 extending from one end of the mounting plate 31, and a magnet 33 is provided on the outer side of the positioning edge 32.

[0041] Preferably, a fuse and a thermostat are provided on the bottom surface of the mounting plate 31, the plurality of PTC heating elements 10 are connected to leads, the thermostat is connected to a temperature control wire, the leads and the temperature control wire are connected together, and the fuse is connected to the thermostat to form overheat protection. Preferably, a wire protection piece 34 is also provided on the bottom surface of the mounting plate 31.

[0042] Preferably, the mounting base includes an upper mounting base and a lower mounting base, and the upper and lower ends of the plurality of PTC heating tubes 10 are respectively connected to the upper mounting base and the lower mounting base. The magnet 33 is disposed on the lower mounting base, and the upper mounting base includes a positioning plate and a positioning piece extending upward from the upper end of the positioning plate. The positioning piece has a positioning hole.

[0043] The key design feature of this invention lies in its design of heat dissipation fins, mounting base, and corrugated elastic metal sheet. The heat dissipation fins and mounting base are made of aluminum, while the corrugated elastic metal sheet is made of a nickel-based alloy. Several PTC heating elements are mounted on the mounting base, and the heat dissipation fins are arranged at intervals on the PTC heating elements. Furthermore, a corrugated elastic metal sheet made of nickel-based alloy is placed between the heat dissipation fins and the mounting base. This absorbs vibration energy through elastic deformation, and the gradient thermal expansion design (aluminum-nickel-based alloy-ceramic) reduces thermal stress, decreases mechanical stress between the mounting base and the aluminum tube fins, and prevents loosening of the connection after long-term use.

[0044] Secondly, a nano-alumina thermally conductive coating is applied to the contact surface of the heat sink fins to fill the interface gaps and form a continuous thermally conductive channel. Furthermore, the through cavity of the corrugated sheet is aligned with the airflow channel of the heat sink fins to form a directional airflow structure, thereby reducing airflow pressure loss.

[0045] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the technical scope of the present utility model. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A PTC heater structure, characterized in that: The device includes several PTC heating elements, several heat dissipation fins, and a mounting base. The PTC heating elements are mounted on the mounting base, and the heat dissipation fins are arranged at intervals on the PTC heating elements. A corrugated elastic metal sheet, made of nickel-based alloy, is also provided between the heat dissipation fins and the mounting base. The corrugated elastic metal sheet includes a main body and a connecting part extending from one end of the main body, forming a through cavity between the main body and the connecting part. One end of the main body is mounted on the mounting base, and one end of the connecting part is connected to one end of the heat dissipation fins. Both the heat dissipation fins and the mounting base are made of aluminum. The contact surfaces of the heat dissipation fins near the PTC heating elements are coated with a nano-alumina thermally conductive coating.

2. The PTC heater structure according to claim 1, characterized in that: The main body of the corrugated elastic metal sheet is fixed to the mounting base by laser welding, and the connecting part is connected to the root of the heat dissipation fins by interference fit or riveting.

3. The PTC heater structure according to claim 1, characterized in that: The corrugated elastic metal sheet is Ω-shaped.

4. The PTC heater structure according to claim 1, characterized in that: An airflow channel is formed between the plurality of heat dissipation fins, and the through cavity of the corrugated elastic metal sheet is arranged opposite to the airflow channel.

5. The PTC heater structure according to claim 1, characterized in that: The mounting base includes a mounting plate and a positioning edge extending from one end of the mounting plate, with a magnet disposed on the outer side of the positioning edge.

6. The PTC heater structure according to claim 5, characterized in that: The bottom surface of the mounting plate is provided with a fuse and a thermostat. The plurality of PTC heating elements are connected with leads. The thermostat is connected with a temperature control line. The leads and the temperature control line are connected together. The fuse is connected to the thermostat.

7. The PTC heater structure according to claim 6, characterized in that: The bottom surface of the mounting plate is also provided with a wire protection plate.

8. The PTC heater structure according to claim 5, characterized in that: The mounting base includes an upper mounting base and a lower mounting base. The upper and lower ends of the plurality of PTC heating tubes are respectively connected to the upper mounting base and the lower mounting base. The magnet is disposed on the lower mounting base. The upper mounting base includes a positioning plate and a positioning piece extending upward from the upper end of the self-positioning plate. The positioning piece has a positioning hole.

Images