Heating unit structure of automotive air heating heater and preparation method of heating unit structure

Abstract

The invention relates to a heating unit structure of a vehicle air heating heater and a preparation method of the heating unit structure. The heating unit structure is composed of a heating main body part, an outer protection element and a terminal. The heating main body part is in a strip-shaped thin plate shape, is of a multi-layer structure and is composed of a heating substrate, an insulating layer, a resistance layer, a conductor layer and a protection layer. The heating substrate adopts an aluminum alloy plate, the insulating layer is in printed sintering connection with one side of the heating substrate, the resistance layer and the conductor layer are in printed sintering connection with the insulating layer, the resistance layer is composed of resistance strips, the conductor layer is used for realizing series connection of the resistance strips, the conductor layer and the resistance strips form a composite layer, and a tin soldering pad is reserved on the resistance layer; the protective layer and the composite layer are printed, sintered and connected; the outer protection element is fixed outside the heating main body part and is insulated and isolated from the heating main body; and the terminal strip is welded and connected with a tin soldering pad reserved on the resistance layer. The heat exchanger is high in heat exchange efficiency, small in size and light in weight.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle air heaters, and in particular relates to a heating unit structure of a vehicle air heater and a preparation method thereof. Background Art

[0002] With the development and popularization of new energy vehicles, additional heating equipment is needed for vehicle heating, and the existing PTC air heaters just meet this demand. In the existing technology, a PTC air heater heat exchange core needs to be equipped with a large number of PTC ceramic heating chips. Due to its structural limitations, its assembly process is complicated, its weight is large, and its heat exchange efficiency is low, which seriously restricts the development of air heaters towards miniaturization and lightweight. Summary of the invention

[0003] In view of the above technical problems, the present invention proposes a heating unit structure of a vehicle air heater with high heat exchange efficiency, small size and light weight, and a preparation method thereof.

[0004] One of the above-mentioned purposes of the present invention is achieved by the following technical solution:

[0005] A heating unit structure of a vehicle air-heater is composed of a heating main body, an external protection element and a terminal; the heating main body is in the shape of a strip thin plate, and the heating main body is a multi-layer structure, consisting of a heating substrate, an insulating layer, a resistor layer, a conductor layer and a protective layer; the heating substrate is made of an aluminum alloy plate, the insulating layer is connected to one side of the heating substrate by printing and sintering, the resistor layer and the conductor layer are connected to the insulating layer by printing and sintering, the resistor layer is composed of a resistor bar, the conductor layer is used to realize the series connection of the resistor bars, the resistor layer and the conductor layer are connected to form a composite layer, and the resistor layer is reserved with a tin soldering pad; the protective layer is connected to the resistor layer and the conductor layer by printing and sintering.

[0006] The external protection element is fixed outside the heating body and forms insulation isolation with the heating body, and the terminal row is welded and connected with the tin soldering pad reserved in the resistance layer.

[0007] Moreover, the insulating layer is centrally arranged above the heating substrate, and the insulating layer is smaller than the length and width dimensions of the heating substrate in the length and width directions respectively; the composite layer composed of the resistance layer and the conductor layer is centrally arranged above the insulating layer, and the composite layer is smaller than the length and width dimensions of the insulating layer in the width and length directions; the size of the protective layer is consistent with the size of the insulating layer, and the edges are aligned; the external protection element includes an external protection plate and a thick film insulation layer printed on one side of the external protection plate; the external protection element is bonded to the heating main body part by high-temperature resistant thermal conductive adhesive and rolled to fix it in such a way that the thick film insulation layer contacts the protective layer of the heating main body part, and the bonding and rolling positions are located at the periphery of the composite layer.

[0008] Moreover, the insulating layer is centrally arranged above the heating substrate, and the insulating layer is smaller than the length and width dimensions of the heating substrate in the length and width directions respectively; the composite layer composed of the resistance layer and the conductor layer is centrally arranged above the insulating layer, and the composite layer is smaller than the length and width dimensions of the insulating layer in the width and length directions; the size of the protective layer is consistent with the size of the insulating layer, and the edges are aligned; the external protection element includes a protective tube and an insulating film, the insulating film is wrapped around the outside of the heating main body, the heating main body wrapped with the insulating film is inserted into the protective tube, and the two are press-connected, and sealant is filled at the end of the protective tube away from the terminal row.

[0009] The second object of the present invention is achieved by the following technical solution:

[0010] Step 1, arranging and processing the heating main body; at the same time, making an outer protection plate, arranging and printing thick film insulation layers on the outer protection plate corresponding to the heating main body, and multiple rows of thick film insulation layers correspond to multiple rows of heating main body parts one by one;

[0011] Step 2: Coat the protective layer of the heating main body assembly and the insulating layer of the protection element assembly respectively, and buckle and press the surfaces coated with the thermal conductive adhesive of the two to form a fixed connection;

[0012] Step 3, a set of terminal blocks are installed corresponding to each row of heating main body parts, wherein the copper tinned terminals of the terminal blocks are connected to the tin soldering pads reserved on the corresponding heating main body parts, and the insulating shells of the terminal blocks are connected to the corresponding heating substrates by snap-fitting. After the terminal blocks are installed, reflow soldering is performed to form a complete heating unit group structure;

[0013] Step 4: Make the final monomer heating unit structure by cutting or breaking.

[0014] Moreover, in step 2, the single-side width L of the rolling is 2 to 3 mm; the difference between the thickness T2 of the rolled part and the thickness T1 of the unrolled part is -0.5 mm to -0.2 mm; the thickness t of the connection between the combined parts of adjacent rows after rolling is 0.5 mm to 1 mm.

[0015] A method for preparing a heating unit structure of a vehicle air heater, characterized in that:

[0016] Step 1: Assemble and process the heating main body;

[0017] Step 2: Install a set of terminal blocks corresponding to each row of heating main body parts, wherein the copper tinned terminals of the terminal blocks are connected to the tin soldering pads reserved on the corresponding heating main body parts, and the insulating shells of the terminal blocks are connected to the corresponding heating substrates by snap-fitting. After the terminal blocks are installed, reflow soldering is performed to form a complete heating unit group structure.

[0018] Step 3, cutting to produce a single heating main body with welded terminal blocks;

[0019] Step 4: Wrap one or two layers of insulating film on the surface of the monomer heating main body and insert it into the protective tube;

[0020] Step 5: Finally, press-fit the main heating body to fit tightly against the protective tube, and fill the end of the protective tube away from the terminal row with sealant to achieve sealing, thus finally forming a complete single-unit heating unit structure.

[0021] The third object of the present invention is achieved by the following technical solution:

[0022] A heat exchange core comprises a heating unit and a heat dissipation strip. The heating unit adopts the above-mentioned heating unit structure. A plurality of groups of heating units and a plurality of heat dissipation strips are fixedly connected by bonding or welding in an alternating contact manner to form the heat exchange core.

[0023] The present invention has the advantages and positive effects:

[0024] 1. The heating unit structure of the present invention has high heating efficiency, which can reach more than 95%.

[0025] 2. The heating unit of the present invention has a simple structure and light weight. Compared with the PTC air heater of the same specification, it can reduce 60% of the parts and reduce the weight by more than 40%.

[0026] 3. The heating unit structure of the present invention has a simple preparation process and can be mass-produced at a low cost.

[0027] 4. The heating unit structure of the present invention is applicable to a wide voltage range and can match the heating power according to different needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure A1 This is a schematic diagram of the heating unit form A of the present invention;

[0029] Figure A2 This is a schematic diagram of the heating unit type A arrangement of the present invention;

[0030] Figure A3 It is a schematic diagram of the arrangement of heating elements in the heating unit form A of the present invention;

[0031] Figure A4 It is an exploded view of the heating element arrangement in the heating unit form A of the present invention;

[0032] Figure A5 It is a schematic diagram of the arrangement of the outer and inner protection elements in the heating unit type A of the present invention;

[0033] Figure A6It is an exploded view of the arrangement of the outer and inner protective elements of the heating unit type A of the present invention;

[0034] Figure A7 It is a schematic diagram of the assembly and rolling of the heating unit group in the heating unit form A of the present invention;

[0035] Figure A8 It is a transverse cross-sectional view of the heating unit group assembly and rolling in the heating unit type A of the present invention;

[0036] Figure A9 It is an enlarged view of the position M in A8 in the figure;

[0037] Figure A10 This is a schematic diagram of the terminal row connection structure in the heating unit form A of the present invention;

[0038] Figure B1 Schematic diagram of heating unit form B of the present invention;

[0039] Figure B2 An exploded view of a heating unit form B in a heating unit form B of the present invention;

[0040] Figure B3 Schematic diagram of terminal block welding in heating unit form B of the present invention;

[0041] Figure B4 A cross-sectional view of the end of the heating unit form B in the heating unit form B of the present invention;

[0042] Figure C1 This is a schematic diagram of the assembly of a heat exchange core body composed of a heating unit of the present invention;

[0043] Figure C2 It is an exploded view of the heat exchange core composed of the heating unit of the present invention. DETAILED DESCRIPTION

[0044] The structure of the present invention is further described below with reference to the accompanying drawings and by way of examples. It should be noted that the present examples are descriptive rather than restrictive.

[0045] A heating unit structure of a car air heater, see Figure A1-Figure B4 The invention point is: it is mainly composed of a heating main body, an external protection element and a terminal row. The heating main body is in the shape of a strip thin plate, and the heating main body is a multi-layer structure, mainly composed of a heating substrate, an insulating layer, a resistance layer, a conductor layer and a protective layer. The heating substrate is made of an aluminum alloy plate, and the insulation layer is connected to one side of the heating substrate by printing and sintering. The resistance layer is composed of a resistance bar, and the conductor layer is used to realize the series connection of the resistance bars. The resistance layer is reserved with a tin soldering pad; the protective layer is connected to the resistance layer and the conductor layer by printing and sintering.

[0046] The external protection element is fixed outside the heating body and forms insulation isolation with the heating body, and the terminal row is welded and connected with the tin soldering pad reserved in the resistance layer.

[0047] The following two embodiments are specifically adopted for the heating unit structure of the vehicle air heater of the present invention:

[0048] Example 1, see Figures A1-A10 :

[0049] The heating unit structure A consists of a heating main body 1, an external protection element 2, and a terminal block 3. Figure A1 , A2 As shown. The surface of the heating main body is printed with thick film heating resistor material, which is a heat source; the external protection element includes an external protection plate, on the surface of which thick film insulating material is printed, and its main function is to protect the thick film heating resistor on the surface of the heating main body and conduct heat; the terminal row is composed of copper electrodes arranged inside, one end of which is connected to the heating main body, which plays the role of electrical connection.

[0050] The main heating body part is composed of a heating substrate 1.1, an insulating layer 1.2, a resistor layer 1.3, a conductor layer 1.4, and a protective layer 1.5, wherein the insulating layer is centrally arranged above the heating substrate, and the length and width of the insulating layer are respectively smaller than the length and width of the heating substrate; the composite layer composed of the resistor layer and the conductor layer is centrally arranged above the insulating layer, and the width and length of the composite layer are respectively smaller than the length and width of the insulating layer; the size of the protective layer is consistent with the size of the insulating layer, and the edges are aligned.

[0051] like Figure A4 The preparation method is as follows:

[0052] Each heating body part can be assembled and processed, such as Figure A3 , A4 As shown. First, a sintered insulating layer is printed on the heating substrate, which mainly isolates the electrical connection between the resistor layer and the heating substrate. The heating substrate is formed by cutting an aluminum alloy plate. Secondly, a sintered resistor layer and a conductor layer are printed on the insulating layer, wherein the resistor layer is a heating element and provides heat. The conductor layer connects the resistor strips on the resistor layer in series. Finally, a sintered protective layer is printed on the resistor layer and the conductor layer to provide insulation protection from the outside world.

[0053] The following should be emphasized:

[0054] ① The arrangement of the heating main parts in the figure is for reference only. The number of heating main parts in the arrangement can be adjusted according to the space of the production equipment.

[0055] The protection element 2 is composed of a protection substrate 2.1 and an insulating layer 2.2, and can also be formed by arranging protection units, such as Figure A5 , A6 First, a sintered insulating layer 2.2 is printed on the protective substrate 2.1, the main function of which is to form an insulating protective layer. The material of the protective substrate 2.1 is formed by cutting an aluminum alloy plate.

[0056] After the heating main body assembly and the protection element assembly are printed and sintered, high temperature resistant thermal conductive adhesive is coated on the protection layer of the heating main body assembly and the insulation layer of the protection element assembly respectively, and the surfaces coated with thermal conductive adhesive are buckled together and rolled. After rolling, the structure is as follows Figure A7 After rolling, install the terminal block, as shown in Figure A10 As shown, the copper tinned terminal 3.1 of the terminal row is connected to the tin soldering pad reserved on the heating main body assembly, and the insulating shell 3.2 of the terminal row is connected to the heating substrate by clamping. After the terminal row is installed, reflow soldering is performed. Finally, a complete heating unit assembly is formed. Figure A2 As shown, the final single heating unit form A can be manufactured by cutting or "breaking" the single heating unit.

[0057] The following should be emphasized:

[0058] ① After rolling, the cross section in the middle of the group is as follows Figure A8 , A9 As shown, the single-side width L of the rolling is 2 to 3 mm to ensure a sufficient sealing end surface; the difference between the thickness T2 of the rolled part (corresponding to the outer part of the composite layer) and the thickness T1 of the unrolled part (corresponding to the composite layer) is between -0.5 mm and -0.2 mm to ensure the rolling strength while avoiding rolling deformation; the thickness t of the connection between the combined parts of adjacent rows after rolling is between 0.5 mm and 1 mm to ensure that the subsequent process will not break easily, and a "chocolate block" structure can be formed, which is convenient for the subsequent formation of a separate heating unit.

[0059] ② The thermal conductive adhesive can be cured at high temperature while reflow soldering the terminal block, which improves production efficiency and saves unit production costs.

[0060] ③ High temperature resistant thermal conductive adhesive, its function is to fix the heating main part and the external protection element so that the two fit closely, secondly, it has excellent thermal conductivity, so that the heat generated by the heating main part can be quickly transferred to the external protection element, and thirdly, it seals the circumference of the heating unit form A to prevent water vapor from entering and improve the waterproof performance.

[0061] For example 2, please see Figures B1-B4 :

[0062] The heating unit structure B is composed of a heating main body 1, a terminal block 3, an insulating film 4, and a protective tube 5. Figure B1, B2 As shown. The surface of the heating main body is printed with thick film heating resistor material, which is a heat source; the insulating film 4 is made of polyacetamide film, which mainly serves as insulation; the terminal row is composed of copper electrodes arranged inside, one end of which is connected to the heating main body to play the role of electrical connection; the protection tube 5 is made of drawn aluminum tube, which mainly serves to protect the heating main body and conduct the heat generated by it.

[0063] Among them, the heating main body part and the terminal row structure and preparation method are the same as method A.

[0064] The assembly sequence is as follows:

[0065] After the printed sintered thick film heating resistors are assembled in the heating main body, the terminal block is installed and reflow soldering is performed; after soldering, the heating main body is cut to form a single heating main body; one or two layers of insulating film are wrapped on the surface of the heating main body; the heating main body is inserted into the protective tube and finally pressed to fit the heating main body tightly to the protective tube. Figure B3 , B4 As shown, the ends thereof are sealed with sealant to finally form a complete heating unit form B.

[0066] The following should be emphasized:

[0067] ①The number of insulating film wrapping layers is based on the product insulation withstand voltage requirements, generally 1 to 2 layers.

[0068] ② At the end of the heating unit type B, the sealant potting depth d1 is 5 to 10 mm to ensure the end is sealed.

[0069] ③ The insulating film at the end of the heating unit type B should extend out of the heating main part, and its d2 value should be between 2 and 5 mm to ensure electrical insulation between the heating main part and the protective tube.

[0070] The above two preparation methods can realize the preparation of the heating unit structure. The heating unit structure A / B is fixed to the heat dissipation strip 6 by bonding to finally form a heat exchange core. Figure C1 , C2 shown.

[0071] The heat exchange core of this invention has a simple structure, few parts and light weight. Compared with existing PTC air heaters, it can reduce 60% of parts and reduce weight by more than 40%. The preparation process of the heating unit is simple, the cost is low, and mass production can be achieved.

[0072] The implementation cases described in the present invention are applicable to a voltage range (high voltage DC: 200~840V, low voltage DC: 9~16V) and a rated power range (3000~10000W); they solve the problems of complex structure and high cost of existing PTC air heaters, and greatly reduce product size, weight and cost.

[0073] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A heating unit structure of a vehicle air heater, characterized in that: It is composed of a heating main body, an external protection element and a terminal; the heating main body is in the shape of a strip thin plate, and the heating main body is a multi-layer structure, consisting of a heating substrate, an insulating layer, a resistance layer, a conductor layer and a protective layer; the heating substrate is made of an aluminum alloy plate, the insulating layer is connected to one side of the heating substrate by printing and sintering, the resistance layer and the conductor layer are connected to the insulation layer by printing and sintering, the resistance layer is composed of a resistance bar, the conductor layer is used to realize the series connection of the resistance bars, the resistance layer and the conductor layer are connected to form a composite layer, and the resistance layer is reserved with a tin soldering pad; the protective layer is connected to the composite layer by printing and sintering. The external protection element is fixed outside the heating body and forms insulation isolation with the heating body, and the terminal row is welded and connected with the tin soldering pad reserved in the resistance layer.

2. The heating unit structure of the vehicle air heater according to claim 1 is characterized in that: The insulating layer is centrally arranged above the heating substrate, and the insulating layer is smaller in length and width than the heating substrate, respectively; the composite layer composed of the resistance layer and the conductor layer is centrally arranged above the insulating layer, and the composite layer is smaller in width and length than the insulating layer; the size of the protective layer is consistent with that of the insulating layer, and the edges are aligned; the external protection element includes an external protection plate and a thick film insulating layer printed on one side of the external protection plate; The outer protection element is bonded and fixedly connected with the heating main body part by high temperature resistant heat conductive adhesive in a manner that the thick film insulation layer contacts the protection layer of the heating main body part and is rolled.

3. The heating unit structure of the vehicle air heater according to claim 1 is characterized in that: The insulating layer is centrally arranged above the heating substrate, and the insulating layer is smaller than the length and width of the heating substrate in the length and width directions respectively; the composite layer composed of the resistance layer and the conductor layer is centrally arranged above the insulating layer, and the composite layer is smaller than the length and width of the insulating layer in the length and width directions; the size of the protective layer is consistent with the size of the insulating layer, and the edges are aligned; the external protection element includes a protective tube and an insulating film, the insulating film is wrapped around the outside of the heating main body, the heating main body wrapped with the insulating film is inserted into the protective tube, and the two are pressed and connected, and sealant is filled at the end of the protective tube away from the terminal row.

4. A method for preparing the heating unit structure of the vehicle air heater as claimed in claim 2, characterized in that: The steps include: Step 1, arranging and processing the heating main body; at the same time, making an outer protection plate, arranging and printing thick film insulation layers on the outer protection plate corresponding to the heating main body, and multiple rows of thick film insulation layers correspond to multiple rows of heating main body parts one by one; Step 2: Coat the protective layer of the heating main body assembly and the insulating layer of the protection element assembly respectively, and buckle and press the surfaces coated with the thermal conductive adhesive of the two to form a fixed connection; Step 3, a set of terminal blocks are installed corresponding to each row of heating main body parts, wherein the copper tinned terminals of the terminal blocks are connected to the tin soldering pads reserved on the corresponding heating main body parts, and the insulating shells of the terminal blocks are connected to the corresponding heating substrates by snap-fitting. After the terminal blocks are installed, reflow soldering is performed to form a complete heating unit group structure; Step 4: Make the final monomer heating unit structure by cutting or breaking.

5. The method for preparing the heating unit structure of the vehicle air heater according to claim 4, characterized in that: In step 2, the single-side width L of the rolling is 2 to 3 mm; the difference between the thickness T2 of the rolled part and the thickness T1 of the unrolled part is -0.5 mm to -0.2 mm; the thickness t of the connection between the joints of adjacent rows after rolling is 0.5 mm to 1 mm.

6. A method for preparing the heating unit structure of the vehicle air heater as claimed in claim 3, characterized in that: The steps include: Step 1: Assemble and process the heating main body; Step 2: Install a set of terminal blocks corresponding to each row of heating main body parts, wherein the copper tinned terminals of the terminal blocks are connected to the tin soldering pads reserved on the corresponding heating main body parts, and the insulating shells of the terminal blocks are connected to the corresponding heating substrates by snap-fitting. After the terminal blocks are installed, reflow soldering is performed to form a complete heating unit group structure. Step 3, cutting to produce a single heating main body with welded terminal blocks; Step 4: Wrap one or two layers of insulating film on the surface of the monomer heating main body and insert it into the protective tube; Step 5: Finally, press-fit the main heating body to fit tightly against the protective tube, and fill the end of the protective tube away from the terminal row with sealant to achieve sealing, thus finally forming a complete single-unit heating unit structure.

7. A heat exchange core, comprising a heating unit and a heat dissipation strip, characterized in that: The heating unit adopts the heating unit structure described in claim 1 or 2, and a plurality of groups of heating units and a plurality of heat dissipation strips are fixedly connected by bonding in an alternating contact manner to form the heat exchange core.

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