Heating plate assembly of vehicle cooling liquid heater and heater

Abstract

The invention relates to a heating plate assembly of a vehicle cooling liquid heater and the heater. The heating plate assembly is composed of a heating substrate and a heating resistance material layer. The heating substrate is of an aluminum cold heading integrally-formed structure, protrusions are densely distributed on the front face of the heating substrate, and the sides, making contact with cooling liquid, of the protrusions of the heating substrate are the sides, making contact with cooling liquid, of the heating substrate. The heating resistance material layer is printed on the back surface of the heating substrate; the heater comprises a main shell, a top cover, a bottom cover, a heating plate assembly, a control plate assembly, a terminal strip, an IGBT (Insulated Gate Bipolar Translator) fixing plate, an insulating spacer, a low-voltage wire harness assembly and a high-voltage wire harness assembly; the edge part of the heating substrate is welded with the inner wall of the main shell, so that a closed fluid cavity is formed between the front surface of the heating plate assembly and a fluid cavity top plate part which is transversely arranged in the main shell; and a liquid inlet and a liquid outlet are respectively arranged on the front side wall of the main shell corresponding to the two sides of the fluid cavity. According to the heater, the heat exchange efficiency and reliability are improved, and the lightweight and miniaturized design is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coolant electric heaters, and relates to a heating plate assembly and a heater for a vehicle coolant heater. Background Art

[0002] As a core component of the integrated thermal management system (ITMS), the coolant electric heater plays a key role in the field of automotive thermal management. Currently, the main heating methods of vehicle electric heaters are PTC ceramic chip heating, metal film heating, and resistance wire heating. Among them, most of the heating elements of metal film heating adopt stainless steel heating substrates, and the heating substrate and the liquid path are sealed by a sealing ring. This design has many defects: the risk of coolant leakage is relatively high, which may cause equipment failure and even pose safety problems; the appearance design of the heater is bulky, and the weight exceeds the industry standard, which is not conducive to the lightweight design and overall layout of the vehicle. In addition, the heat dissipation method of the stainless steel heating substrate is the reflow welding of the heating substrate and the fin belt, and the reliability is relatively low, and good heat dissipation uniformity cannot be guaranteed, which affects the heating efficiency and the heating effect of the coolant. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides a heating plate assembly and a heater for a vehicle coolant heater with good reliability, uniform heat dissipation, light weight, and small occupied space.

[0004] One of the above objects of the present invention is achieved by the following technical solutions:

[0005] A heating plate assembly for a vehicle coolant heater, the heating plate assembly is composed of a heating substrate and a heating resistance material layer; the heating substrate adopts an aluminum cold heading integral forming structure, the front surface of the heating substrate is densely provided with protrusions, and the side of the heating substrate with protrusions is the side in contact with the coolant; the heating resistance material layer is printed on the back surface of the heating substrate.

[0006] Another of the above objects of the present invention is achieved by the following technical solutions:

[0007] A heater for a heating plate of a vehicle coolant heater, including a main housing, a top cover, a bottom cover, a heating plate assembly, a control board assembly, a terminal block, an IGBT fixing plate, an insulating gasket, a low-voltage wire harness assembly, and a high-voltage wire harness assembly; the heating plate assembly is the heating plate assembly of the above-mentioned vehicle coolant heater;

[0008] The main housing is a square housing formed by integral casting. The upper and lower ends of the main housing are respectively and fixedly connected to the top cover and the bottom cover in a sealed manner. A fluid chamber top plate is transversely arranged inside the main housing, dividing the inner cavity of the main housing into upper and lower chambers. The upper chamber is an electrical chamber, and the lower chamber is a heat exchange chamber. A relief slot hole is arranged in the middle of one end of the fluid chamber top plate. The middle part of the fluid chamber top plate protrudes downward to form a heating plate support surface. The shape of the heating plate assembly matches the shape of the fluid chamber top plate. The heating plate assembly is arranged in the heat exchange chamber of the main housing. The protrusions on the heating substrate are in contact with the heating plate support surface, and the edges of the heating substrate are welded to the inner wall of the main housing, so as to form a closed fluid chamber between the front surface of the heating plate assembly and the fluid chamber top plate. Liquid inlets and outlets are respectively arranged at two positions corresponding to the two sides of the fluid chamber on the front side wall of the main housing. The side of the fluid chamber corresponding to the liquid inlet is the liquid inlet side, and the side corresponding to the liquid outlet is the liquid outlet side.

[0009] The control board assembly is supported and fixed in the electrical chamber. The high-voltage wire harness assembly and the low-voltage wire harness assembly are respectively fixedly connected to the corresponding interfaces on the front side wall and the corresponding interfaces on the rear side wall of the main housing. The lead end of the high-voltage wire harness assembly is connected to the control board assembly. The low-voltage wire harness assembly is connected to the control board assembly through a connector. The terminal block is arranged at the relief slot hole of the main housing. The upper end of the terminal block is connected to the control board assembly, and the lower end of the terminal block is connected to the heating plate assembly by reflow soldering.

[0010] A heat dissipation platform is arranged below the position corresponding to the IGBT on the control board assembly on the fluid chamber top plate of the main housing. The IGBT fixing plate is fixedly connected to the main housing, so that the lower end of the IGBT is closely attached to the front surface of the heat dissipation platform through an insulating gasket.

[0011] Moreover, two liquid temperature sensors are welded on the control board assembly. The temperature sensing parts of the two liquid temperature sensors are respectively installed on the liquid inlet side and the liquid outlet side of the fluid chamber through thermal conductive silicone grease.

[0012] Moreover, criss-cross heat dissipation ribs are arranged on the back surface of the heat dissipation platform.

[0013] Moreover, a surface gel layer is coated on the back surface of the heating plate assembly.

[0014] Moreover, a reduced-edge groove is arranged on the back side edge of the heating substrate.

[0015] The advantages and positive effects of the present invention are as follows:

[0016] 1. High product qualification rate: The heating substrate adopts an integrally formed structure by cold heading process, which solves the problems such as high defect rate of welding fins in the heat exchange unit of traditional thick film heaters.

[0017] 2. Achieve better heat exchange effect: The heating substrate is densely covered with protrusions, which improves the strength of the substrate, increases the heat exchange area, enhances the heat exchange efficiency, and prevents the heating unit from dry burning.

[0018] 3. Realize the lightweight design of the product: The heating substrate of the heating plate adopts an integrally formed structure by cold heading process, significantly reducing the weight of a single board, effectively reducing the overall weight of the product, and conforming to the development trend of automotive lightweight.

[0019] 4. Realize the compact and small design: The overall volume of the heater product is small, occupying less space, and facilitating flexible layout in the limited space inside the vehicle.

[0020] 5. Achieve high sealing performance: The heating plate assembly and the main housing are connected by aluminum-aluminum laser welding, greatly reducing the risk of coolant leakage and improving the reliability and safety of the product.

[0021] 5. Achieve multiple protections: The product has multiple protection functions. In addition to the common overvoltage and overcurrent protections, an over-temperature protection function is added, effectively ensuring the safety of the product and personnel and enhancing the stability of the product.

[0022] 6. Wide applicability: This heat exchanger is applicable to high-voltage platforms of 390V - 925V, can meet the requirements of different vehicle models, and has a wider application range. Description of the Drawings

[0023] Figure 1 is an exploded view of the heating plate of the vehicle coolant heater of the present invention;

[0024] Figure 2 is a structural diagram of the heating substrate of the heating plate of the vehicle coolant heater of the present invention, 2a, plan view, 2b, A - A cross-sectional view;

[0025] Figure 3 is an exploded view of a traditional heating plate;

[0026] Figure 4 is an exploded view of the vehicle coolant heater of the present invention;

[0027] Figure 5 is a three-dimensional view of the main housing of the present invention;

[0028] Figure 6 is a schematic external view of the vehicle coolant heater of the present invention;

[0029] Figure 7 is a comparison diagram of improving welding stress of the present invention;

[0030] Figure 8 is a flow velocity distribution diagram of the coolant in the fluid cavity using the present invention;

[0031] Figure 9It is the temperature distribution diagram of the heating resistance material layer of the heater of the present invention. Detailed implementation mode

[0032] The structure of the present invention will be further described below in conjunction with the drawings and through embodiments. It should be noted that this embodiment is narrative rather than restrictive.

[0033] For a heating plate assembly of a vehicle coolant heater, please refer to Figures 1-9 , which is composed of a heating substrate 13.2 and a heating resistance material layer 13.1. The heating substrate adopts an integrally cold-heading aluminum structure, and the front surface of the heating substrate is densely provided with protrusions 13.2.2. The side of the heating substrate with protrusions is the side in contact with the coolant. The setting of the protrusions has multiple functions: 1. It can improve the strength of the integrally cold-heading aluminum heating substrate, facilitating resistance to impact and vibration; 2. It can increase the heat exchange area and improve the heat exchange efficiency; 3. A turbulent flow effect is formed between the protrusions, which can effectively reduce the formation of eddy currents and avoid dry burning of the heating unit; 4. The protrusions can also suppress the bubbles formed during the cold boiling of the coolant, effectively reducing the dry burning and noise problems caused by the bubbles.

[0034] The shape of the protrusions of the cold-heading heating substrate is not limited to the hexagon shown in the drawings. Any structure with a similar principle, such as a cone, a wavy groove, etc., belongs to the protection scope of this patent.

[0035] The back surface of the heating substrate is used to fix the heating resistance material layer, and the heating resistance material layer is fixed to the back surface of the heating substrate by printing. The heating resistance material layer constitutes the heating film surface

[0036] The overall width W of the heating plate assembly is between 20 - 300 mm, the height H is between 20 - 300 mm, the thickness B of the plate body part 13.2.1 of the heating substrate is between 1 - 6 mm, the thickness C of the protrusion part is between 1 mm - 20 mm, the distance D between the protrusions is between 1 - 5 mm, and the width E of the protrusions is between 1 - 5 mm.

[0037] Compared with the traditional heating plate assembly composed of a stainless-steel heating substrate and fin reflow welding, the heating substrate of the present invention is integrally formed by cold-heading aluminum, and the process has higher reliability.

[0038] For a heater using the above heating plate assembly, please refer to Figures 4-6 , which mainly includes a top cover 2, an IGBT fixing plate 3, a control board assembly 4, an insulating gasket 5, a rubber sealing ring 6, a low-voltage wire harness assembly 7, a grounding bolt 8, a surface gel layer 9, a terminal block 10, a bottom cover 12, a heating plate assembly 13, a high-voltage wire harness assembly 14, a main housing 15, a breather valve 16, and a flange nut 17.

[0039] The main housing 15 is manufactured by an integral casting process and is a square housing. A fluid chamber top plate is horizontally arranged inside the main housing, dividing the inner cavity of the main housing into upper and lower chambers. The upper chamber is an electrical chamber, and the lower chamber is a heat exchange chamber. A relief slot hole 15-5 is provided at the middle position of one end of the fluid chamber top plate for installing the terminal block. The middle part of the fluid chamber top plate protrudes downward to form a heating plate support surface 15-3. The shape of the heating plate assembly matches the shape of the fluid chamber top plate. The heating plate assembly is arranged in the heat exchange chamber of the main housing. The protrusions on the heating substrate contact the heating plate support surface, and the edges of the heating substrate are connected to the inner wall of the main housing by laser welding, so as to form a closed fluid chamber between the front surface of the heating plate assembly and the fluid chamber top plate.

[0040] To reduce the influence of the welding stress between the heating substrate and the main housing on the heating resistance material, a reduced-edge groove is provided at the back side edge of the heating substrate. The width of the reduced-edge groove is 2-5 mm, and the thickness F of the reduced-edge groove is 2-5 mm. For the improvement of the welding stress, see Figure 7 as shown, where the abscissa is the test point and the ordinate is the stress value of different test points.

[0041] On the front side wall of the main housing, a liquid inlet 15-1 and a liquid outlet 15-2 are respectively provided at two positions corresponding to both sides of the fluid chamber. The side of the fluid chamber corresponding to the liquid inlet is the liquid inlet side, and the side corresponding to the liquid outlet is the liquid outlet side. The flow path of the coolant is: entering the interior of the fluid chamber from the liquid inlet 15-1, being heated by the heating resistance material layer end on the heating plate assembly during the process of flowing from one side to the other side in the fluid chamber, and finally the fluid meeting the temperature requirement flows out through the liquid outlet 15-2 to meet the needs of vehicle thermal management.

[0042] In terms of electrical connection and installation, a high-voltage wire harness assembly interface is provided on the front side wall of the main housing, and a low-voltage wire harness assembly interface is provided on the rear side wall of the main housing. The high-voltage wire harness assembly 14 and the low-voltage wire harness assembly 7 are installed together with the corresponding interfaces on the main housing 15 by screws. The breather valve 16 is installed on one side of the main housing. The top cover 2 is sealed with the upper end of the main housing by a rubber sealing ring 6 and is fixedly connected by an internal hexagonal screw 1. The bottom cover 12 is sealed with the lower end of the main housing by a rubber ring and is fixedly connected by an internal hexagonal screw to isolate the interior of the main housing from the outside.

[0043] The control board assembly (PCBA) 4 is supported and fixed in the electrical chamber. The lead end of the high-voltage harness assembly 14 is connected to the control board assembly (PCBA) 4 through a bolt-nut structure, where the nut 17 can be a flange nut. The low-voltage harness assembly 7 is connected to the control board assembly (PCBA) 4 through a connector. The terminal block 10 is arranged at the relief slot hole 15-5 of the main housing. The upper end of the terminal block 10 is connected to the control board assembly (PCBA) 4 through a fish-eye pin. The lower end of the terminal block 10 is welded to the heating plate assembly 13 through reflow soldering and is connected to the main housing through an internal hexagonal screw 11, so as to achieve precise control of the heating element by the PCBA.

[0044] In terms of power supply and system control, the high-voltage harness assembly 14 is connected to the vehicle's high-voltage power supply system to provide the required electrical energy for the heater; the low-voltage harness assembly 7 is connected to the vehicle's low-voltage system, and the vehicle end uses a 12V low-voltage circuit to control the 390-925V high-voltage system, thereby achieving comprehensive control of the heater.

[0045] In terms of heat dissipation and safety guarantee, a heat dissipation platform is arranged below the position corresponding to the IGBT on the control board assembly (PCBA) on the top plate of the fluid chamber of the main housing. The IGBT fixing plate is fixedly connected to the main housing through screws, so that the lower end of the IGBT is closely attached to the front of the heat dissipation platform through an insulating gasket 5. Among them, the insulating gasket realizes electrical isolation between the two. Further, criss-cross heat dissipation ribs 15-4 are arranged on the back of the heat dissipation platform, which can achieve a better heat dissipation effect.

[0046] In terms of safety protection measures, in addition to having overvoltage and overcurrent protection functions, this product also adds an over-temperature protection function. The liquid temperature sensor is directly welded on the control board assembly (PCBA) 4, and its temperature sensing part is installed on both sides of the inlet and outlet of the main housing 8 through thermal conductive silicone grease, which can collect the inlet and outlet liquid temperatures in real time and transmit them to the control board assembly (PCBA) 4. A board temperature sensor is welded on the heating plate assembly, which can transmit the collected board temperature data to the control board assembly (PCBA) 4 to achieve full-range temperature monitoring and protection of the heater.

[0047] In the structure of this heater, after the heating plate assembly 13 and the main housing 15 are laser welded to form a closed liquid circuit structure, a surface gel layer 9 is evenly coated on the back of the heating plate assembly 13. This surface gel layer 9 plays an important role. It can build an effective barrier between the heating plate assembly 13 and the external environment, realizing the direct isolation of liquid vapor from the heating plate assembly 13. During the operation of the vehicle, especially under the condition of coolant circulation heating, liquid vapor will inevitably be generated. If the liquid vapor contacts the heating resistance material layer on the heating plate assembly 13, it may cause safety hazards such as short circuit and electric leakage, affecting the normal operation of the heater and even threatening the safety of the vehicle and personnel. The good sealing and insulation properties of the surface gel layer 9 can effectively prevent the liquid vapor from contacting the heating resistance material layer, ensuring the safe and stable operation of the heating plate assembly in various complex environments, and greatly improving the safety and reliability of the product.

[0048] In addition, in this embodiment, the main housing, top cover and bottom cover of the heater are all made of metal materials, effectively solving the electromagnetic compatibility (EMC) problem of electronic components and ensuring the normal operation of automotive internal electronic devices.

[0049] Figure 8 It is the flow velocity distribution diagram of the coolant in the fluid cavity by adopting the solution of the present invention. Figure 8 The lines in the figure represent the flow trajectories of the fluid, that is, streamlines. The distribution of streamlines shows the flow path and direction of the fluid in a specific area, and streamlines of different colors reflect different velocity magnitudes. It can be seen from this figure that: the structure of the heating plate assembly of the present invention will evenly distribute the fluid flow velocity, which is beneficial to the heat dissipation of the heating resistance material.

[0050] Figure 9 It is the temperature distribution diagram of the heating resistance material layer of the heater by adopting the solution of the present invention. The lines in the figure represent the temperature distribution of the heating resistance material. It can be seen from the figure that the temperature distribution on the heating surface is relatively uniform, which mainly benefits from the uniform heat dissipation of the heating plate structure and is beneficial to extending the service life of the heating resistance material.

[0051] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art can understand that: within the spirit of the present invention and the appended claims, various substitutions, changes and modifications are possible. Therefore, the scope of the present invention is not limited to the content disclosed in the embodiments and drawings.

Claims

1. A heating plate assembly for a vehicle coolant heater, characterized in that: The heating plate assembly is composed of a heating substrate and a heating resistance material layer; the heating substrate adopts an integrally cold-heading aluminum structure, with protrusions densely arranged on the front surface of the heating substrate, and the side of the heating substrate with protrusions is the side in contact with the coolant; the heating resistance material layer is printed on the back surface of the heating substrate.

2. A vehicle coolant heater, characterized in that: It includes a main housing, a top cover, a bottom cover, a heating plate assembly, a control board assembly, a terminal block, an IGBT fixing plate, an insulating gasket, a low-voltage wire harness assembly, and a high-voltage wire harness assembly; the heating plate assembly adopts the heating plate assembly of the vehicle coolant heater described in Claim 1. The main housing is a square housing formed by integral casting, and the upper and lower ends of the main housing are respectively sealed and fixedly connected to the top cover and the bottom cover; a fluid cavity top plate part is horizontally arranged inside the main housing, dividing the inner cavity of the main housing into upper and lower chambers. The upper chamber is an electrical chamber, and the lower chamber is a heat exchange chamber. A relief slot hole is provided in the middle of one end of the fluid cavity top plate part; the middle part of the fluid cavity top plate part protrudes downward to form a heating plate support surface; the shape of the heating plate assembly matches the shape of the fluid cavity top plate part. The heating plate assembly is arranged in the heat exchange chamber of the main housing, the protrusions on the heating substrate are in contact with the heating plate support surface, and the edges of the heating substrate are welded to the inner wall of the main housing, so as to form a closed fluid cavity between the front surface of the heating plate assembly and the fluid cavity top plate part; on the front side wall of the main housing, a liquid inlet and a liquid outlet are respectively provided at the two positions corresponding to the two sides of the fluid cavity. The side of the fluid cavity corresponding to the liquid inlet is the liquid inlet side, and the side corresponding to the liquid outlet is the liquid outlet side. The control board assembly is supported and fixed in the electrical chamber, and the high-voltage wire harness assembly and the low-voltage wire harness assembly are respectively fixedly connected to the corresponding interfaces on the front side wall and the rear side wall of the main housing; the lead end of the high-voltage wire harness assembly is connected to the control board assembly; the low-voltage wire harness assembly is connected to the control board assembly through a connector; the terminal block is arranged at the relief slot hole of the main housing, the upper end of the terminal block is connected to the control board assembly, and the lower end of the terminal block is connected to the heating plate assembly by reflow soldering. A heat dissipation platform is provided below the position corresponding to the IGBT on the control board assembly on the fluid cavity top plate part of the main housing. The IGBT fixing plate is fixedly connected to the main housing, so that the lower end of the IGBT is closely attached to the front surface of the heat dissipation platform through the insulating gasket.

3. The vehicle coolant heater according to claim 2, characterized in that: Two liquid temperature sensors are welded on the control board assembly, and the temperature sensing parts of the two liquid temperature sensors are respectively installed on the liquid inlet side and the liquid outlet side of the fluid cavity through thermal conductive silicone grease.

4. The vehicle coolant heater according to claim 2, characterized in that: Interlaced heat dissipation ribs are provided on the back surface of the heat dissipation platform.

5. The vehicle coolant heater according to claim 2, characterized in that: A surface gel layer is coated on the back surface of the heating plate assembly.

6. The vehicle coolant heater according to claim 2, characterized in that: A reduced-edge groove is provided at the back side edge of the heating substrate.

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