Vehicle air heater core and heater

Abstract

The invention relates to the technical field of air heater core bodies, in particular to a vehicle air heater core body and a heater, the vehicle air heater core body comprises a heating body and heat dissipation fins, the heating body is a heating wire formed by etching metal foil or a heating wire formed by printing thick film resistance paste, and the heat dissipation fins are arranged on the heating body. The head end and the tail end of the heating wire are each provided with an electrode plate, the upper side and the lower side of the heating wire are each provided with a piece of insulation paper, and the upper side insulation paper and the lower side insulation paper are fixed to the heating wire in a press fit mode. And radiating fins are arranged on one side or two sides of the upper and lower insulating paper far away from the direction of the heating wire. The heating wire and the electrode plate can be packaged between the two layers of insulation paper at the same time, the whole structure is light and thin, and the requirement of the automobile heater for compact design is met.

Description

Technical Field

[0001] The present invention relates to the technical field of air heater cores, and particularly to a vehicle air heater core and a heater. Background Art

[0002] An air heater is a device that heats air through electric heating elements and is widely used in industrial drying, heating, ventilation, air conditioning and other fields. Its core components include heating elements (resistance wires / ceramic PTC chips, etc.), fans and temperature control systems, and achieve efficient heat exchange through forced convection. It has the characteristics of fast heating, controllable energy consumption, high safety, etc.

[0003] A PTC (Positive Temperature Coefficient) heater is an intelligent electric heating device using a positive temperature coefficient ceramic material. Its core principle is: when the temperature of the PTC heating element is lower than the Curie point, the resistivity of the PTC material is low, and it quickly generates heat after being powered on; when the PTC heating element approaches the Curie temperature, the resistance increases sharply, automatically limiting the current to achieve constant temperature without an external temperature control device.

[0004] Due to its high safety and self-limiting temperature characteristics, PTC heaters are widely used in household appliances, medical and automotive fields. However, in automotive applications, due to the limited space inside the vehicle, special attention needs to be paid to the thermal efficiency ratio when integrating air heaters - that is, how to achieve a greater heating power within a smaller volume and weight. The structure of traditional vehicle PTC air heaters has obvious deficiencies: its heating element needs to wrap the PTC ceramic chip and the electrode chip together in multiple layers of insulating films, then install them in an aluminum shell and match with heat dissipation fins. This multi-layer structure results in a relatively large overall volume and weight, which does not match the design requirements of modern automotive lightweight and compactness. Additionally, due to the general problem of power attenuation of ceramic PTC chips in PTC heaters after long-term use (usually after 1000 consecutive hours, the power attenuates by 5 - 10%), this will affect the long-term stability in automotive applications. Summary of the Invention

[0005] The purpose of the present invention is to provide a vehicle air heater core and a heater to solve the problems raised in the above background art.

[0006] To achieve the above purpose, the present invention provides the following technical solution. A vehicle air heater core includes a heating element, the heating element includes a heating wire etched from a metal foil or a heating wire formed by screen printing a thick film resistor paste. An electrode chip is respectively arranged at the head and tail ends of the heating wire, and an insulating paper is respectively arranged on the upper and lower sides of the heating wire, and the upper and lower insulating papers are press-fitted and fixed. Heat dissipation fins are arranged on the sides of the upper and lower insulating papers away from the heating wire.

[0007] Preferably, as the above technical solution, the heating wire etched from a metal foil is made of iron-chromium-aluminum, stainless steel or copper.

[0008] Preferably, as the above technical solution, the heating wire formed by printing and shaping a thick film resistor paste uses a PTC resistor paste so that the heating wire has a self-limiting temperature function during operation.

[0009] Preferably, as the above technical solution, a PTC heating element module made by a thick film process is also integrated on a small part area of the heating wire for self-limiting temperature operation of the heating wire.

[0010] Preferably, as the above technical solution, the heat dissipation fins are arranged on one side or both sides of the heating wire, and the heat dissipation fins are attached to the insulating paper so that the heat generated by the heating wire can be quickly conducted to the heat dissipation fins and finally dissipated into the air; the material of the heat dissipation fins is aluminum or copper.

[0011] Preferably, as the above technical solution, the heating element is of a planar structure, a temperature control part is arranged on the heat dissipation fins, the temperature control part includes a PTC ceramic chip, the PTC ceramic chip is adhesively fixed on the heat dissipation fins, a wire is arranged on the PTC ceramic chip, a current relay is arranged on the wire, and the PTC ceramic chip and the current relay are electrically connected through the wire.

[0012] Preferably, as the above technical solution, the heating element is of a barrel structure, the heat dissipation fins are arranged on the outer surface side of the heating element, a temperature control part is arranged on the inner surface side of the heating element, the temperature control part includes a PTC ceramic chip, the PTC ceramic chip is adhesively fixed on the insulating paper on the inner surface side of the heating element, a wire is arranged on the PTC ceramic chip, a current relay is arranged on the wire, and the PTC ceramic chip and the current relay are electrically connected through the wire.

[0013] A heater uses the vehicle air heater core body in Embodiment 3. An installation shell is arranged outside the heat dissipation fins. A fan part is bolt-fixed at the rear of the installation shell. A main board is screw-fixed at the rear of the fan part. The current relay is adhesively fixed at the rear of the main board. A temperature fuse is adhesively fixed on the inner wall of the installation shell. The temperature fuse is electrically connected to the main board through the wire. A wire management opening is provided on the installation shell.

[0014] Preferably, as the above technical solution, the PTC ceramic chip is a cylinder, and its outer surface fits with the inner surface of the heating element.

[0015] Preferably, as the above technical solution, a support base is arranged at the rear side of the PTC ceramic chip.

[0016] The present invention provides a vehicle air heater core and a heater, having the following beneficial effects: 1. Since the traditional vehicle air heater core uses a PTC ceramic sheet as the heating element, to meet the heat generation requirement, the PTC ceramic sheet needs to maintain a relatively large thickness, and at the same time, metal electrode sheets must be attached to both sides. This combined structure makes it impossible to use the glue / pressing process for encapsulating the PTC ceramic sheet + electrode sheet: Due to the large thickness and heavy mass of the PTC ceramic sheet + electrode sheet assembly, if the glue / pressing process is used, it is easy for the insulating paper to separate and fall off. Therefore, only the winding and wrapping method can be selected, and multiple layers of winding are often required to ensure insulation reliability, ultimately resulting in a bulky overall structure and making it difficult to meet the requirements of modern automotive radiators for compact design. The heating wire is etched from metal foil, resulting in a small thickness of the heating wire. In this way, the heating wire and the electrode sheet can be encapsulated between two layers of insulating paper at the same time, and the overall structure is light and thin, meeting the requirements of automotive radiators for compact design.

[0017] 2. Since the heating element and the heat conduction part are made of metals and polymer materials with high bending strength, it can be bent into a barrel-shaped structure, where the heating element is completely wrapped in the sandwich layer of the heat conduction part. This cylindrical design has a larger heat generation and heat dissipation surface area than the traditional planar structure under the same volume, and at the same time occupies less space, which is particularly suitable for application scenarios with high space utilization requirements such as automobiles.

[0018] 3. The heat generated at the heat dissipation fins is blown out by the fan part to quickly heat the external air and dissipate heat from the heating wire. Since the temperature fuse is set on the inner wall of the installation shell, it can monitor in real time whether the temperature of the heating element exceeds the safety threshold. When the temperature of the heating element is too high, the temperature fuse melts. Since the temperature fuse is connected in series with the power module of the main board through a wire, the melting of the temperature fuse will disconnect the power module on the main board and cut off the power supply of the entire device, protecting against potential safety hazards caused by overheating of the device. In this way, with the current relay as the primary open circuit protection and the temperature fuse as the secondary open circuit protection, under such double protection, the open circuit protection is first carried out by the current relay during overheating. If the current relay fails, the temperature fuse will play the role of secondary protection at this time, greatly improving the safety of the device. When the temperature fuse triggers the open circuit protection, a warning module is set on the main board to remind the user that the temperature fuse has triggered the open circuit protection and the device cannot work, and the current relay and the temperature fuse should be detected or replaced in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural view of the heating element in the present invention; Figure 2 is Figure 1 an exploded view of Figure 3Schematic diagram of the structure of the PTC heating element module in the present invention; Figure 4 Schematic diagram of the structure when the heat dissipation fins in the present invention are arranged on both sides; Figure 5 For Figure 4 exploded view; Figure 6 Schematic diagram of the structure when the heat dissipation fins in the present invention are arranged on one side; Figure 7 Schematic diagram of the connection relationship between the heating element and the heat dissipation fins and the temperature control part when the heating element in the present invention is in a planar structure; Figure 8 Schematic diagram of the connection relationship between the heating element and the heat dissipation fins and the temperature control part when the heating element in the present invention is in a barrel structure; Figure 9 Schematic diagram of the structure of a preferred heater in the present invention; Figure 10 For Figure 9 exploded view; Figure 11 For Figure 9 schematic diagram of the main board in; Figure 12 For Figure 9 another schematic diagram of the PTC ceramic in; Figure 13 For Figure 12 schematic diagram of the PTC ceramic in.

[0020] In the figure: 1. Heating element; 11. Heating wire; 12. Electrode plate; 13. Insulating paper; 14. PTC heating element module; 15. Heat dissipation fins; 2. Temperature control part; 21. PTC ceramic; 22. Wire; 23. Current relay; 24. Support matrix; 3. Installation shell; 31. Wire management port; 4. Fan part; 5. Main board; 51. Thermal fuse. Detailed implementation manners

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0022] Embodiment 1: As Figures 1-6 shown, a vehicle air heater core, the heating element 1 includes a heating wire 11, and an electrode plate 12 is respectively arranged at the head and tail ends of the heating wire 11, and an insulating paper 13 is respectively arranged on the upper and lower sides of the heating wire 11, and the upper and lower insulating papers 13 are press-fitted and fixed; The insulating paper 13 is provided with heat dissipation fins 15 on the side away from the heating wire 11.

[0023] It should be noted that since the traditional vehicle air heater core uses PTC ceramic sheets as the heating element, to meet the heat generation requirement, the PTC ceramic sheets need to maintain a relatively large thickness, and at the same time, metal electrode sheets must be adhered to both sides. This combined structure makes it impossible to use the glue / pressing process for encapsulating the PTC ceramic sheets + electrode sheets with insulating paper: Due to the large thickness and heavy mass of the PTC ceramic sheets + electrode sheet assembly, if the glue / pressing process is used, it is easy for the insulating paper to separate and fall off. Therefore, only the winding and wrapping method can be selected, and multiple layers of winding are often required to ensure insulation reliability, which ultimately leads to a bulky overall structure and is difficult to meet the requirements of modern automotive radiators for compact design.

[0024] In specific implementation, the heating wire 11 is etched from metal foil or formed by screen-printing thick film resistor paste, resulting in a small thickness of the heating wire 11 and the electrode sheet 12. In this way, the heating wire 11 and the electrode sheet 12 can be encapsulated between two layers of insulating paper 13 at the same time, and the overall structure is light and thin, meeting the requirements of automotive radiators for compact design.

[0025] Furthermore, the material of the heating wire etched from metal foil is iron-chromium-aluminum, stainless steel or copper; for the heating wire formed by screen-printing thick film resistor paste, the thick film resistor paste uses PTC resistor paste so that the heating wire has a self-limiting temperature function during operation.

[0026] It should be further noted that the traditional PTC heater core wraps the PTC ceramic sheet and the metal electrode sheet assembly with multiple layers of insulating paper, and then embeds the entire coated body into an aluminum shell. This design leads to two key defects: First, multiple layers of insulating materials form an obvious physical isolation between the heating element and the aluminum shell, preventing the PTC ceramic sheet from making direct contact with the aluminum shell; second, the remaining air gaps between the insulating layers seriously hinder heat transfer. This structural design with excessive thermal resistance directly causes three adverse consequences: slow thermal response (it takes 3 - 5 minutes from startup to stable operation), low energy utilization rate (about 30% of the heat remains inside the heating element), and accelerated aging of the PTC ceramic sheet due to local overheating (the failure rate increases by more than 40%).

[0027] In specific implementation, the light and thin structural design of the heating wire 11, the electrode sheet 12, and the insulating paper 13 enables them to be closely attached to the heat dissipation fins 15, so that the heat generated by the heating wire 11 can be quickly conducted to the heat dissipation fins 15 and finally dissipated into the air. The material of the heating wire 11 is iron-chromium-aluminum, stainless steel or copper, and the choice of different materials is mainly based on the heat generation requirement, and the expected heating performance is achieved by selecting appropriate raw materials.

[0028] Please refer to Figure 3, preferably, a small part of the heating wire 11 is also integrated with a PTC heating element module 14 made by the thick film process for self-limiting temperature operation of the heating wire. This design realizes a combined heating element of "pure resistive heating wire and PTC module", and the pure resistive heating wire can be a metal etched heating wire or a heating wire produced by printing thick film resistor paste. It can not only meet the self-limiting temperature requirement but also has the characteristics of low cost and high stability of the pure resistive heating wire.

[0029] Please continue to refer to Figure 5 and Figure 6 , preferably, the heat dissipation fins 15 are arranged on one side or both sides of the heating wire 11.

[0030] Embodiment 2: Please refer to Figure 7 , on the basis of Embodiment 1, in this embodiment, the heating element 1 is of a planar structure, and a temperature control part 2 is arranged on the heat dissipation fins 15. The temperature control part 2 includes a PTC ceramic sheet 21, the PTC ceramic sheet 21 is adhesively fixed on the heat dissipation fins 15, a wire 22 is arranged on the PTC ceramic sheet 21, and a current relay 23 is arranged on the wire 22. The PTC ceramic sheet 21 and the current relay 23 are electrically connected through the wire 22.

[0031] In specific implementation, the PTC ceramic sheet 21 is used as a temperature sensor to fit with the heat dissipation fins 15. In this way, when the temperature of the heat dissipation fins 15 is too high, the resistance value change in the PTC ceramic sheet 21 causes the current change in the wire 22. Finally, the current relay 23 can timely disconnect the entire heater circuit under the feedback of the current fluctuation in the wire 22 to ensure the safe operation of the equipment.

[0032] It should be noted that the detection circuit of the PTC ceramic sheet 21 and the current relay 23 is independently set. In this way, when the PTC ceramic sheet 21 operates under low voltage and low current conditions, its service life is greatly increased, and at the same time, no insulation protection is required, which saves more volume and cost. The detection and feedback mechanism of the current relay 23 and the PTC ceramic sheet 21 is based on the industry general technology and is the common knowledge in this field, so it will not be described in detail.

[0033] Embodiment 3: Please refer to Figure 8 , on the basis of Embodiment 1, in this embodiment, the heating element 1 is bent into a barrel-shaped structure, the heat dissipation fins 15 are arranged on the outer surface side of the heating element 1, and a temperature control part 2 is arranged on the inner surface side of the heating element 1. The temperature control part 2 includes a PTC ceramic sheet 21, the PTC ceramic sheet 21 is adhesively fixed on the insulating paper 13 on the inner surface side of the heating element 1, a wire 22 is arranged on the PTC ceramic sheet 21, and a current relay 23 is arranged on the wire 22. The PTC ceramic sheet 21 and the current relay 23 are electrically connected through the wire 22.

[0034] In specific implementation, since the heating wire 11, the electrode plate 12 and the insulating paper 13 are made of metals and polymer materials with high bending strength, they can be bent into a barrel-shaped structure. Compared with the traditional planar structure, this cylindrical design has a larger heat generation and dissipation surface area under the same volume, and at the same time occupies less space, which is particularly suitable for application scenarios with high requirements for space utilization such as automobiles.

[0035] The PTC ceramic sheet 21 is used as a temperature sensor and is attached to the insulating paper 13. In this way, when the temperature of the heating wire 11 is too high, the resistance change in the PTC ceramic sheet 21 causes the current in the wire 22 to change. Finally, the current relay 23 can timely disconnect the entire heater circuit under the feedback of the current fluctuation in the wire 22 to ensure the safe operation of the device.

[0036] It should be noted that the detection circuits of the PTC ceramic sheet 21 and the current relay 23 are independently set. In this way, when the PTC ceramic sheet 21 operates under low voltage and low current, its service life is greatly increased, and at the same time, no insulation protection is required, which saves more volume and cost. The detection and feedback mechanism of the current relay 23 and the PTC ceramic sheet 21 is based on the general technology in the industry and is common knowledge in this field, so it will not be described in detail.

[0037] Embodiment 4: As Figures 9-11 shown, a heater adopts the vehicle air heater core in Embodiment 3. An installation shell 3 is arranged outside the heat dissipation fins 15. A fan part 4 is bolted to the rear of the installation shell 3. A main board 5 is screwed to the rear of the fan part 4. A current relay 23 is bonded to the rear of the main board 5. A temperature fuse 51 is adhesively fixed to the inner wall of the installation shell 3. The temperature fuse 51 is electrically connected to the main board 5 through a wire 22.

[0038] In specific implementation, the heat discharged from the heat dissipation fins 15 is blown out by the fan unit 4, which is used to quickly heat the external air and dissipate heat from the heating wire 11. Since the temperature fuse 51 is arranged on the inner wall of the installation shell 3, it can monitor in real time whether the temperature of the heating element 1 exceeds the safety threshold. When the temperature of the heating element 1 is too high, the temperature fuse 51 will melt. Since the temperature fuse 51 is connected in series with the power module of the main board 5 through the wire 22, the melting of the temperature fuse 51 will disconnect the power module on the main board 5, cutting off the power supply of the entire device to provide protection against potential safety hazards caused by overheating of the device. In this way, with the current relay 23 as the primary open-circuit protection and the temperature fuse 51 as the secondary open-circuit protection, under such double protection, the open-circuit protection is first carried out by the current relay 23 during overheating. If the current relay 23 fails, at this time, the temperature fuse 51 plays the technical effect of secondary protection, greatly improving the safety of the device. When the temperature fuse 51 triggers the open-circuit protection, a warning module is arranged on the main board 5 to remind the user that the temperature fuse 51 has triggered the open-circuit protection and the device cannot work, and the current relay 23 and the temperature fuse 51 need to be detected or replaced in time.

[0039] It should be noted that the control circuit and detection feedback mechanism of the current relay 23 and the temperature fuse 51 are based on industry general technologies and are common knowledge in this field, so no further description will be given.

[0040] Furthermore, please refer to Figure 8 , a wire management port 31 is provided on the installation shell 3 for storing the wire 22, avoiding the aging and peeling of the insulation layer of the wire 22 caused by being in a high-temperature working environment for a long time.

[0041] As a further implementation of the present invention, please refer to Figure 12 and Figure 13 , the PTC ceramic sheet 21 is a cylinder, and its outer surface fits with the inner surface of the heating element 1. In this way, the PTC ceramic sheet 21 can support the heating wire 11 bent into a barrel shape, avoiding the deformation of the heating wire 11 caused by vibration during use, resulting in stress concentration and potential safety hazards.

[0042] Furthermore, a support matrix 24 is arranged at the rear of the PTC ceramic sheet 21, which can reduce the usage amount of the PTC ceramic sheet 21 while maintaining the support effect on the barrel-shaped heating wire 11, achieving the effects of weight reduction and cost reduction.

[0043] The present invention provides a vehicle air heater core and a heater, and the specific working principle is as follows: The heat derived from the heat dissipation fins 15 is blown out by the fan unit 4, which is used to quickly heat the external air and dissipate the heat of the heating wire 11. Since the thermal fuse 51 is arranged on the inner wall of the installation shell 3, it can monitor in real time whether the temperature of the heating element 1 exceeds the safety threshold. When the temperature of the heating element 1 is too high, the thermal fuse 51 will melt. Since the thermal fuse 51 is connected in series to the power module of the main board 5 through the wire 22, the melting of the thermal fuse 51 will disconnect the power module on the main board 5, cutting off the power supply of the entire device, which can prevent potential safety hazards caused by overheating of the device. In this way, with the current relay 23 as the primary open circuit protection and the thermal fuse 51 as the secondary open circuit protection, under such double protection, the open circuit protection is first carried out by the current relay 23 during overheating. If the current relay 23 fails, at this time, the thermal fuse 51 plays the technical effect of secondary protection, greatly improving the safety of the device. When the thermal fuse 51 triggers the open circuit protection, a warning module is arranged on the main board 5 to remind the user that the thermal fuse 51 has triggered the open circuit protection and the device cannot work, and the current relay 23 and the thermal fuse 51 should be detected or replaced in time.

[0044] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A vehicle air heater core, comprising a heating element (1), characterized in that: The heating element (1) includes a heating wire (11). The heating wire (11) is a resistance heating circuit formed by etching a metal foil or a resistance heating circuit formed by printing a thick film resistor paste. An electrode plate (12) is provided at each of the head and tail ends of the heating wire (11). An insulating paper (13) is provided on each of the upper and lower sides of the heating wire (11), and the upper and lower insulating papers (13) are press-fitted and fixed together. A heat dissipation fin (15) is provided on the side of the insulating paper (13) away from the heating wire (11).

2. The vehicle air heater core according to claim 1, characterized in that: The heating wire (11) is a resistance heating circuit formed by etching a metal foil, and the material of the metal foil is iron-chromium-aluminum, stainless steel or copper.

3. The vehicle air heater core according to claim 1, wherein: The heating wire (11) is a resistance heating circuit formed by printing a thick film resistor paste, and the thick film resistor paste used is a PTC resistor paste.

4. The vehicle air heater core according to claim 2, characterized in that: A PTC heating element module (14) made by a thick film process is integrated on the heating wire (11).

5. The vehicle air heater core according to claim 4, characterized in that: The heat dissipation fin (15) is provided on one or both sides of the heating wire (11). The heat dissipation fin (15) is attached to the insulating paper (13), and the material of the heat dissipation fin (15) is aluminum or copper.

6. The vehicle air heater core according to claim 2, wherein: The heating element (1) has a planar structure. A temperature control part (2) is provided on the heat dissipation fin (15). The temperature control part (2) includes a PTC ceramic sheet (21). The PTC ceramic sheet (21) is adhesively fixed to the heat dissipation fin (15). A wire (22) is provided on the PTC ceramic sheet (21), and a current relay (23) is provided on the wire (22). The PTC ceramic sheet (21) and the current relay (23) are electrically connected through the wire (22).

7. The vehicle air heater core according to claim 2, wherein: The heating element (1) has a barrel-shaped structure. The heat dissipation fin (15) is provided on the outer surface side of the heating element (1). A temperature control part (2) is provided on the inner surface side of the heating element (1). The temperature control part (2) includes a PTC ceramic sheet (21). The PTC ceramic sheet (21) is adhesively fixed to the insulating paper (13) on the inner surface side of the heating element (1). A wire (22) is provided on the PTC ceramic sheet (21), a current relay (23) is provided on the wire (22), and the PTC ceramic sheet (21) and the current relay (23) are electrically connected through the wire (22).

8. A heater, comprising a vehicle air heater core as described in claim 7, characterized in that: An installation shell (3) is provided outside the heat dissipation fin (15). A fan part (4) is bolt-fixed to the rear part of the installation shell (3). A main board (5) is screw-fixed to the rear part of the fan part (4). The current relay (23) is adhesively fixed to the rear part of the main board (5). A temperature fuse (51) is adhesively fixed to the inner wall of the installation shell (3). The temperature fuse (51) is electrically connected to the main board (5) through the wire (22). A wire management port (31) is provided on the installation shell (3).

9. The heater according to claim 8, characterized in that: The PTC ceramic sheet (21) is a cylinder, and its outer surface fits with the inner surface of the heating element (1).

10. A heater according to claim 9, characterized in that: A support matrix (24) is provided at the rear side of the PTC ceramic sheet (21).

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