A heating plate assembly and heater for an automotive coolant heater

Abstract

This utility model relates to a heating plate assembly and heater for an automotive coolant heater. The heating plate assembly consists of a heating substrate and a heating resistor material layer. The heating substrate is a cold-forged aluminum integral structure, with protrusions densely distributed on the front side, the side with the protrusions being the side in contact with the coolant. The heating resistor material layer is printed on the back side of the heating substrate. The heater 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 wiring harness assembly, and a high-voltage wiring harness assembly. The edge of the heating substrate is welded to the inner wall of the main housing, forming a closed fluid cavity between the front side of the heating plate assembly and the top plate of the transversely arranged fluid cavity inside the main housing. An inlet and an outlet are respectively provided on the front side wall of the main housing corresponding to the two sides of the fluid cavity. This heater improves heat exchange efficiency and reliability, and achieves a lightweight and miniaturized design.

Description

Technical Field

[0001] This utility model belongs to the technical field of coolant electric heaters, and relates to a heating plate assembly and heater for an automotive coolant heater. Background Technology

[0002] As a core component of the Integrated Thermal Management System (ITMS), the coolant electric heater plays a crucial role in automotive thermal management. Currently, the main heating methods for automotive electric heaters include PTC ceramic chip heating, metal film heating, and resistance wire heating. Among these, metal film heating elements mostly use stainless steel heating substrates, with the heating substrate and fluid circuit sealed by a sealing ring. This design has several drawbacks: a high risk of coolant leakage, potentially leading to equipment failure and even safety issues; a bulky heater design, exceeding industry standards in weight, which is detrimental to lightweight automotive design and overall layout. Furthermore, the heat dissipation method for stainless steel heating substrates involves reflow welding of the heating substrate and fins, resulting in low reliability and inconsistent heat dissipation, affecting heating efficiency and coolant heating effect. Utility Model Content

[0003] This utility model addresses the shortcomings of existing technologies by proposing a heating plate assembly and heater for an automotive coolant heater that features high reliability, uniform heat dissipation, light weight, and small space occupation.

[0004] One of the above-mentioned objectives of this utility model is achieved through the following technical solution:

[0005] A heating plate assembly for an automotive coolant heater, the heating plate assembly comprising a heating substrate and a heating resistor material layer; the heating substrate adopts an aluminum cold-forged integral structure, the front side of the heating substrate is densely covered with protrusions, and the side with the protrusions is the side in contact with the coolant; the heating resistor material layer is printed on the back side of the heating substrate.

[0006] The second objective of this utility model is achieved through the following technical solution:

[0007] A heater for a heating plate of an automotive coolant heater includes a main housing, a top cover, a bottom cover, a heating plate assembly, a control board assembly, a terminal block, an IGBT mounting plate, an insulating gasket, a low-voltage wiring harness assembly, and a high-voltage wiring harness assembly; the heating plate assembly is the aforementioned heating plate assembly for an automotive coolant heater.

[0008] The main housing is a square housing integrally cast. The upper and lower ends of the main housing are sealed and fixedly connected to the top cover and bottom cover, respectively. A fluid cavity top plate is arranged horizontally inside the main housing, dividing the inner cavity of the main housing into upper and lower chambers. The upper chamber is the electrical chamber, and the lower chamber is the heat exchange chamber. A clearance slot is provided in the middle of one end of the fluid cavity top plate. The middle of the fluid cavity top plate 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. The heating plate assembly is set in the heat exchange chamber of the main housing. The protrusion on the heating plate contacts the heating plate support surface. The edge of the heating plate is welded to the inner wall of the main housing, so that the front of the heating plate assembly and the fluid cavity top plate form a closed fluid cavity. An inlet and an outlet are respectively provided on the front side wall of the main housing corresponding to the two sides of the fluid cavity. The side of the fluid cavity corresponding to the inlet is the inlet side, and the side corresponding to the outlet is the outlet side.

[0009] The control board assembly is supported and fixed in the electrical cavity. The high-voltage wiring harness assembly and the low-voltage wiring 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 wiring harness assembly is connected to the control board assembly. The low-voltage wiring harness assembly is connected to the control board assembly through connectors. The terminal block is set in the clearance slot 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 reflow soldered to the heating plate assembly.

[0010] A heat dissipation platform is provided on the top plate of the fluid cavity of the main housing, below the IGBT mounting position on the control board assembly. The IGBT mounting plate is fixedly connected to the main housing, so that the lower end of the IGBT is in close contact with the front of the heat dissipation platform through an insulating gasket.

[0011] In addition, two liquid temperature sensors are soldered onto the control board assembly. The temperature sensing parts of the two liquid temperature sensors are installed on the inlet and outlet sides of the fluid cavity respectively through thermal grease.

[0012] In addition, there are crisscrossing heat dissipation fins on the back of the heat dissipation platform.

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

[0014] Furthermore, a reduction groove is provided on the back side edge of the heating substrate.

[0015] The advantages and positive effects of this utility model are as follows:

[0016] 1. High product qualification rate: The heating substrate adopts a one-piece molding structure through cold forging process, which solves the problem of high defect rate of welding fins in the heat exchange unit of traditional thick film heater.

[0017] 2. Achieve better heat exchange effect: The densely distributed protrusions on the heating substrate improve the substrate strength, increase the heat exchange area, improve the heat exchange efficiency, and prevent the heating unit from burning dry.

[0018] 3. Achieved lightweight product design: The heating substrate adopts a one-piece molding structure using cold forging process, which significantly reduces the weight of a single board and effectively reduces the overall weight of the product, in line with the trend of automotive lightweighting.

[0019] 4. Achieved a compact and small design: The heater product has a small overall size and occupies little space, making it easy to be flexibly arranged in the limited space inside the car.

[0020] 5. High sealing performance is achieved: The heating plate assembly is connected to the main housing by aluminum-aluminum laser welding, which greatly reduces the risk of coolant leakage and improves the reliability and safety of the product.

[0021] 5. Multiple protections: The product has multiple protection functions. In addition to common overvoltage and overcurrent protection, it also has an overtemperature protection function, which effectively ensures the safety of the product and personnel and improves the stability of the product.

[0022] 6. Wide applicability: This heat exchanger is suitable for high voltage platforms of 390V-925V, which can meet the needs of different vehicle models and has a wider range of applications. Attached Figure Description

[0023] Figure 1 This is an exploded view of the heating plate of the automotive coolant heater of this utility model;

[0024] Figure 2 This is a structural diagram of the heating plate of the automotive coolant heater of this utility model, including a plan view (2a) and a sectional view (2b, AA).

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

[0026] Figure 4 This is an exploded view of the automotive coolant heater of this utility model;

[0027] Figure 5 This is a perspective view of the main housing of this utility model;

[0028] Figure 6 This is a schematic diagram of the exterior of the vehicle coolant heater of this utility model;

[0029] Figure 7 This is a comparison diagram of the welding stress improvement of this utility model;

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

[0031] Figure 9 This is a temperature distribution diagram of the heating resistor material layer in the heater of this utility model. Detailed Implementation

[0032] The structure of this utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that these embodiments are descriptive and not limiting.

[0033] Please refer to the heating plate assembly of an automotive coolant heater. Figures 1-9 The heating element is composed of a heating substrate 13.2 and a heating resistor material layer 13.1. The heating substrate adopts an integrated aluminum cold-forged structure, and the front side of the heating substrate is densely covered with protrusions 13.2.2. The side with the protrusions is the side in contact with the coolant. The protrusions have several functions: 1. They can improve the strength of the aluminum cold-forged heating substrate, which is beneficial for resisting impact and vibration; 2. They can increase the heat exchange area and improve the heat exchange efficiency; 3. The turbulence effect formed between the protrusions can effectively reduce the formation of eddies and avoid dry burning of the heating unit; 4. The protrusions can also suppress the bubbles formed when the coolant boils, which can effectively reduce dry burning and noise problems caused by bubbles.

[0034] The shape of the protrusions on the cold heading heating substrate is not limited to the hexagon shown in the attached figure. Any structure with a similar principle, such as a cone or a wave groove, is within the scope of protection of this patent.

[0035] The back side of the heating substrate is used to fix a heating resistor material layer, which is fixed to the back side of the heating substrate by printing. The heating resistor material layer constitutes the heating film surface.

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

[0037] Compared with traditional heating plate assemblies which are made of stainless steel heating substrate and fins through reflow welding, the heating substrate of this utility model is integrally formed from aluminum cold heading heating substrate, which has higher reliability.

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

[0039] The main housing 15 is manufactured using a one-piece casting process and is a square housing. A fluid cavity top plate is laterally arranged inside the main housing, dividing the inner cavity into upper and lower chambers. The upper chamber is the electrical chamber, and the lower chamber is the heat exchange chamber. A clearance slot 15-5 is provided at the center of one end of the fluid cavity top plate for terminal block installation. The center of the fluid cavity top plate protrudes downwards, forming a heating plate support surface 15-3. The shape of the heating plate assembly matches the shape of the fluid cavity top plate. The heating plate assembly is disposed within the heat exchange chamber of the main housing. The protrusion on the heating plate contacts the heating plate support surface, and the edge of the heating plate is connected to the inner wall of the main housing by laser welding, forming a closed fluid cavity between the front of the heating plate assembly and the fluid cavity top plate.

[0040] To reduce the impact of welding stress between the heating substrate and the main housing on the heating resistor material, a reduction groove is provided on the back edge of the heating substrate. The width of the reduction groove is 2-5 mm, and the thickness F of the reduction groove is 2-5 mm. For improvements in welding stress, see [link to relevant documentation]. Figure 7 As shown in the figure, the horizontal axis represents the test points, and the vertical axis represents the stress values ​​at different test points.

[0041] A liquid inlet 15-1 and a liquid outlet 15-2 are respectively provided on the front side wall of the main housing, 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 flow path of the coolant is as follows: it enters the fluid cavity from the liquid inlet 15-1, and during the process of flowing from one side to the other in the fluid cavity, it is heated by the heating resistor material layer on the heating plate assembly. Finally, the fluid that meets the temperature requirements flows out through the liquid outlet 15-2, satisfying the thermal management requirements of the entire vehicle.

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

[0043] The control board assembly (PCBA) 4 is supported and fixed within the electrical cavity. The lead ends of the high-voltage wiring harness assembly 14 are connected to the control board assembly (PCBA) 4 via a bolt and nut structure, wherein the nut 17 can be a flange bolt. The low-voltage wiring harness assembly 7 is connected to the control board assembly (PCBA) 4 via a connector. The terminal block 10 is located at the clearance slot 15-5 of the main housing. The upper end of the terminal block 10 is connected to the control board assembly (PCBA) 4 via a fisheye pin, and the lower end of the terminal block 10 is soldered to the heating plate assembly 13 via reflow soldering and connected to the main housing via hex socket head cap screws 11, thereby enabling the PCBA to precisely control the heating element.

[0044] In terms of power supply and system control, the high-voltage wiring harness assembly 14 is connected to the vehicle's high-voltage power supply system to provide the required power to the heater; the low-voltage wiring 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, a heat dissipation platform is installed on the top plate of the main housing fluid cavity, corresponding to the IGBT mounting position on the control board assembly (PCBA). The IGBT mounting plate is fixed to the main housing with screws, ensuring that the lower end of the IGBT is in close contact with the front of the heat dissipation platform through an insulating gasket 5. The insulating gasket provides electrical isolation between the two. Further, crisscrossing heat dissipation fins 15-4 are provided on the back of the heat dissipation platform, achieving a better heat dissipation effect.

[0046] In terms of safety protection measures, in addition to overvoltage and overcurrent protection functions, this product also features overtemperature protection. The liquid temperature sensor is directly soldered onto the control board assembly (PCBA) 4, and its sensing element is installed on both the inlet and outlet sides of the main housing 8 via thermally conductive silicone grease. It can collect the inlet and outlet liquid temperatures in real time and transmit them to the control board assembly (PCBA) 4. A plate temperature sensor is soldered onto the heating plate assembly, which transmits the collected plate temperature data to the control board assembly (PCBA) 4, achieving comprehensive temperature monitoring and protection for the heater.

[0047] In this heater structure, 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 uniformly coated on the back of the heating plate assembly 13. This surface gel layer 9 plays an important role, as it can build an effective barrier between the heating plate assembly 13 and the external environment, achieving direct isolation between liquid vapor and the heating plate assembly 13. During vehicle operation, especially under the condition of coolant circulation heating, liquid vapor is inevitably generated. If liquid vapor comes into contact with the heating resistor material layer on the heating plate assembly 13, it may cause safety hazards such as short circuits and 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 liquid vapor from contacting the heating resistor material layer, ensuring that the heating plate assembly can operate safely and stably in various complex environments, 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, which effectively solves the electromagnetic compatibility (EMC) problem of electronic components and ensures the normal operation of electronic equipment inside the vehicle.

[0049] Figure 8 This is a flow velocity distribution diagram of the coolant in the fluid cavity using the solution of this utility model. Figure 8 The lines represent the fluid flow trajectory, i.e., streamlines. The distribution of streamlines shows the flow path and direction of the fluid within a specific area, with different colored streamlines reflecting different velocities. As can be seen from this diagram, the heating plate assembly structure of this invention achieves a uniform fluid velocity distribution, which is beneficial for heat dissipation of the heating resistor material.

[0050] Figure 9 The diagram shows the temperature distribution of the heating resistor material layer in the heater, where the lines represent the temperature distribution of the heating resistor material. It can be seen from the diagram that the temperature distribution of the heating surface is relatively uniform, which is mainly due to the uniform heat dissipation of the heating plate structure, which helps to extend the service life of the heating resistor material.

[0051] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations 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 plate assembly for an automotive coolant heater, characterized in that: The heating plate assembly is composed of a heating base plate and a heating resistance material layer; the heating base plate adopts an aluminum cold upsetting integrated structure, and the front surface of the heating base plate is densely provided with protrusions, one side of the protrusions being a side in contact with the cooling liquid; and the heating resistance material layer is printed on the back surface of the heating base plate.

2. An engine coolant heater characterized by: The main shell is a square shell integrally casted, the upper end and the lower end of the main shell are respectively sealingly and fixedly connected with the top cover and the bottom cover; a fluid cavity top plate part is transversely arranged in the main shell, and the main shell is divided into an upper chamber and a lower chamber by the fluid cavity top plate part, the upper chamber is an electrical chamber, the lower chamber is a heat exchange chamber, and a clearance slot hole is arranged at the middle of one end of the fluid cavity top plate part; the middle of the fluid cavity top plate part is concave, forming a heating plate support surface; the heating plate assembly is arranged in the heat exchange chamber of the main shell, the protrusions on the heating base plate are in contact with the heating plate support surface, and the edge of the heating base plate is welded to 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 the fluid cavity top plate part; a liquid inlet and a liquid outlet are respectively arranged on the front side wall of the main shell at positions corresponding to the two sides of the fluid cavity, one side of the fluid cavity corresponding to the liquid inlet being an inlet side, and the other side corresponding to the liquid outlet being an outlet side. 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 rear side wall of the main shell; 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 strip is arranged at the clearance slot hole of the main shell, the upper end of the terminal strip is connected to the control board assembly, and the lower end of the terminal strip is reflow soldered to the heating plate assembly. A heat dissipation platform is arranged below the position corresponding to the IGBT on the control board assembly on the fluid cavity top plate part of the main shell, and the IGBT fixing plate is fixedly connected to the main shell, so that the lower end of the IGBT is tightly attached to the front surface of the heat dissipation platform through the insulating pad. 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 inlet side and the outlet side of the fluid cavity through the heat-conducting silicone grease.

3. The coolant heater for vehicles according to claim 2, characterized by: Longitudinal and transverse heat dissipation ribs are arranged on the back surface of the heat dissipation platform.

4. The coolant heater for vehicles according to claim 2, characterized by: A surface gel layer is coated on the back surface of the heating plate assembly.

5. The coolant heater for vehicles according to claim 2, characterized by: An edge reduction slot is arranged on the back side edge of the heating base plate.

6. The coolant heater for vehicles according to claim 2, characterized by: ​

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