Welding method of die casting liquid cooling plate

Abstract

The invention discloses a welding method of a die casting liquid cooling plate, which improves the welding efficiency of the liquid cooling plate and reduces the welding cost of the liquid cooling plate on the premise of ensuring the performance of the liquid cooling plate. The shell and the upper cover which are manufactured through die casting are connected through annular light spot laser welding, and the shell and the upper cover form an integrated structure after welding connection.

Description

Technical Field

[0001] The invention relates to the technical field of liquid cooling plate manufacturing, in particular to a welding method for a die-casting liquid cooling plate. Background Art

[0002] With the penetration and popularization of intelligent and networked vehicles, the proportion of automotive electronic and electrical components in automobiles has gradually increased. Advanced driver assistance systems and in-vehicle multimedia entertainment systems have gradually become functional configurations that consumers pay attention to and influence their purchasing decisions. Increasingly complex systems have a demand for the number of sensors and electronic controllers (Electronic Control Unit, ECU), such as autonomous driving cameras, millimeter-wave radars, co-pilot entertainment screens for multimedia entertainment systems, HUD head-up display systems, ECM modules that control engine performance, BMS modules that manage new energy vehicle batteries, and AVM modules for 360-degree surround image fusion calculations.

[0003] Among them, the autonomous driving domain controller is responsible for realizing and controlling the autonomous driving function of the car. It needs to have the ability to receive image information, process and judge image information, process and calculate data, navigate and plan routes, and make quick judgments and decisions on real-time situations. It needs to process algorithms at the three levels of perception, decision-making, and control, and has the highest requirements for the domain controller's hardware and software.

[0004] For autonomous driving and cockpit domain controllers, the chip performance and operating system-level algorithm requirements are relatively high. Under the premise of meeting high performance, the chip production cost also brings tremendous pressure, and low-cost processing methods need to be considered to deal with it. When manufacturing existing liquid cooling plates, the shell and upper cover are first made through a die-casting process. The shell is provided with corresponding flow channels and bosses. Then the upper cover is installed on the corresponding open surface area of ​​the aluminum alloy shell, and then friction welding is performed to connect. During the friction welding process, it takes a relatively long time and the cost is relatively high. For this reason, it is urgent to develop a welding method that can improve welding efficiency and reduce welding costs while ensuring the performance of the liquid cooling plate. Summary of the invention

[0005] In view of the above problems, the present invention provides a welding method for a die-casting liquid cooling plate, which improves the welding efficiency of the liquid cooling plate and reduces the welding cost of the liquid cooling plate while ensuring the performance of the liquid cooling plate.

[0006] A method for welding a die-cast liquid cooling plate is characterized in that a shell and an upper cover made by die-casting are connected by annular spot laser welding, and after welding, the shell and the upper cover become an integrated structure.

[0007] It is further characterized by:

[0008] The shell is provided with a concave contour edge at the edge corresponding to the upper cover, and a stopper surface is provided on the inner side of the shell corresponding to the concave contour edge. The bottom edge of the upper cover is supported on the stopper surface at the corresponding position. The edge of the upper cover and the concave contour edge are tightly fitted and positioned. The tight fit gap between the edge of the upper cover and the concave contour edge is formed into an integrated structure by annular spot laser welding.

[0009] During annular spot laser welding, the annular + central beam emitted by the annular spot laser is routed around the tight fit gap between the edge of the upper cover and the concave contour edge. When the routing is completed, the welding is completed, which reduces the welding time and improves the welding efficiency.

[0010] The shell is provided with a flow channel and a plurality of upper convex columns inside. The flow channel is formed by a baffle bar. An upper convex positioning strip is provided on the upper surface of the baffle bar. The width of the upper convex positioning strip is smaller than that of the baffle bar. The upper cover is provided with a contoured concave positioning cavity at a position corresponding to the baffle bar. When the upper cover is mounted on the shell, the upper convex positioning strip is inserted into the contoured concave positioning cavity. The upper convex positioning strip and the contoured concave positioning cavity are tightly matched. The assembly alignment gap formed by the tight match is connected by annular spot laser welding.

[0011] According to the requirement of heat exchange power, at least one heat exchange module with stacked fins or shovel teeth structure is also locally arranged in the inner cavity of the shell. The heat exchange module includes a bottom plate and a stacked fin or shovel teeth structure on the upper surface. A sunken bottom plate positioning groove is arranged at a corresponding position of the bottom of the shell. The bottom plate is tightly fitted in the bottom plate positioning groove. Then, the annular + central light beam emitted by the annular spot laser is welded around the bottom plate positioning groove, so that the heat exchange module can be reliably welded to the shell to form an assembled shell structure.

[0012] The annular spot laser is an anti-high-reflection annular spot laser with a power of 6000W. When the annular spot laser performs annular spot laser welding, the laser power ramp-up time is 100ms, the laser power ramp-down time is 150ms, and the annular spot diameter is 0.1mm.

[0013] When controlling the surface diameter and melting depth of the weld, a V-shaped molten pool is presented by adjusting the laser power, defocusing amount, and feed speed.

[0014] After adopting the technology of the present invention, the shell and the upper cover made by die casting are connected by annular spot laser welding. After welding, the shell and the upper cover become an integrated structure. During welding, the annular + center light beam emitted by the annular spot laser travels in a single direction along the preset weld line, so that the annular + center light beam completely covers the preset weld position. The welding efficiency is high and the cost is reduced, which is 50% lower than the cost of friction welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the processing flow of the liquid cooling plate of a specific embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the weld routing during welding in step S2 of a specific embodiment of the present invention;

[0017] Figure 3 This is a schematic diagram of the weld routing during welding in step S3 of a specific embodiment of the present invention;

[0018] Figure 4 A partially enlarged schematic diagram of a laser weld formed in an embodiment of the present invention;

[0019] Figure 5 It is a reverse perspective view of the upper cover of a specific embodiment of the present invention;

[0020] The names corresponding to the serial numbers in the figure are as follows:

[0021] Shell 10, bottom plate positioning groove 11, concave contour edge 12, stop table 13, upper convex column 14, barrier strip 15, upper convex positioning strip 16, upper cover 20, contoured concave positioning cavity 21, heat exchange module 30, bottom plate 31, skiving structure 32, assembled shell structure 40, laser weld 50. DETAILED DESCRIPTION

[0022] A method for welding a die-cast liquid cooling plate: a shell 10 and an upper cover 20 manufactured by die-casting are connected by annular spot laser welding, and after the welding connection, the shell 10 and the upper cover 20 become an integrated structure.

[0023] Specific embodiments, see Figure 1-Figure 5 A heat exchange module 30 with a shovel-tooth structure is arranged in the inner cavity of the shell 10. The heat exchange module 30 includes a bottom plate 31 and a shovel-tooth structure 32 on the upper surface. A sunken bottom plate positioning groove 11 is arranged at a corresponding position of the bottom of the shell 10. An edge of the shell 10 corresponding to the upper cover 20 is provided with an inwardly concave profiling contour edge 12. A stop table 13 is arranged on the inner side of the shell 10 corresponding to the inwardly concave profiling contour edge 12. A flow channel and a plurality of upper convex columns 14 are arranged inside the shell 10. The formation of the flow channel is completed by a baffle bar 15. An upper convex positioning strip 16 is arranged on the upper surface of the baffle bar 15. The width of the upper convex positioning strip 16 is smaller than that of the baffle bar 15. A profiling inwardly concave positioning cavity 21 is arranged at a position of the upper cover 20 corresponding to the baffle bar 15.

[0024] In specific implementation, S1, a housing 10, an upper cover 20, and a heat exchange module 30 made of aluminum alloy are manufactured by die-casting in advance;

[0025] S2, the bottom plate 31 is tightly placed in the bottom plate positioning groove 11, and then the annular + center beam emitted by the annular spot laser circles the bottom plate positioning groove 11 for a circle to perform welding operation, and the wiring trajectory is shown in FIG. Figure 2 The guide mark position enables the heat exchange module 30 to be reliably welded to the shell 10 to form an assembled shell structure 40;

[0026] S3, the upper convex positioning strip 16 is inserted into the contoured concave positioning cavity 21, the upper convex positioning strip 16 and the contoured concave positioning cavity 21 are tightly matched, and at the same time, the bottom edge of the upper cover 20 is supported on the stop table 13 at the corresponding position, and the edge of the upper cover 20 and the concave contour edge 12 form a tight fit positioning, and the annular + center light beam emitted by the annular spot laser is routed around the tight fit gap between the edge of the upper cover 20 and the concave contour edge 12, and the tight fit gap between the upper convex positioning strip 16 and the contoured concave positioning cavity 21 (a straight line when the width is small and a closed circumference when the width is large) to complete the laser welding connection, and the routing trajectory is shown in FIG. Figure 2 The rear housing 10 and the upper cover 20 are welded together to form an integrated structure.

[0027] In the specific implementation, the annular spot laser is an anti-high-reflection annular spot laser with a power of 6000W. When the annular spot laser performs annular spot laser welding, the laser power ramp-up time is 100ms, the laser power ramp-down time is 150ms, and the annular spot diameter is 0.1mm.

[0028] When controlling the surface diameter and penetration depth of the weld spot, the welding power is adjusted to 3-4KW, the defocus distance is 200-300mm, and the feed speed is 15-25mm / s. Figure 4 The V-shaped molten pool shown forms a corresponding laser weld bead 50. The above laser welding parameters are adjusted to define the weld bead molten width G, molten height H, and molten depth S within the welding range to ensure the pressure resistance test of the die-cast aluminum alloy product after welding.

[0029] The present invention designs an annular spot laser welding optical system based on the vortex light principle. The index for measuring laser welding is the melting depth and melting width. The ratio of the annular laser and the central laser is used to control the temperature gradient and reduce cracks. At the same time, the stirring effect brought by the annular spot can help to remove the gas and reduce welding pores. The laser parameters are set by the laser: the equipment attribute power is 6000W / annular welding / anti-high reflection, the laser power ramp-up time is 100ms, the laser power ramp-down time is 150ms, and the annular spot diameter is 0.1mm; under the condition of controlling the surface diameter of the weld spot and the melting depth to a certain extent, by adjusting the laser power, pulse width, defocusing amount, and feed speed, a V-shaped molten pool is presented;

[0030] It uses laser welding technology for die-cast aluminum alloy liquid cooling plates, which has high welding efficiency. Compared with the friction welding process of the same product, it shortens the welding time and saves costs.

[0031] Moreover, this technology can design heat exchange modules with different structural shapes and small-pitch stacked fins and skived-tooth structures according to different power consumption, so as to perform matching annular spot laser welding on the local part of the die-cast aluminum alloy shell and the heat source, so as to make the heat transfer of the heating element faster and improve the performance;

[0032] After the annular spot laser welding is adopted, the heat exchange module is independently manufactured and then assembled and welded with the shell of the water-cooled plate. The water-cooled plate greatly improves the overall temperature uniformity and heat exchange efficiency. In terms of design, the upper cover contoured concave positioning cavity and the upper convex positioning strip of the die-cast aluminum alloy shell are tightly matched to reduce the outflow of the solution from the matching gap of the flow channel baffle; this welding method has high welding efficiency and reduces costs, and reduces the processing cost of the friction welding process by 50%. After the annular spot laser welding is adopted, the heat exchange module is independently manufactured and partially embedded in the inner cavity of the shell. The stacked fins and shovel teeth on the heat exchange module are independently designed and manufactured, which reduces the processing difficulty of the shell and the defective rate. The heat conduction method of the inner cavity of the liquid cooling plate can be multi-directional heat exchange and increase the area for heat exchange, which makes the heat absorption efficiency high. The entire technical product uses corrosion-resistant materials, which can provide more efficient heat conduction performance, reliability and life.

[0033] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0034] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for welding a liquid cooling plate of a die casting, characterized in that: The shell and the upper cover manufactured by die casting are connected by annular spot laser welding, and after welding, the shell and the upper cover become an integrated structure.

2. The method for welding a liquid cooling plate of a die casting according to claim 1, characterized in that: The shell is provided with a concave contour edge at the edge corresponding to the upper cover, and a stop table is provided on the inner side of the shell corresponding to the concave contour edge. The bottom edge of the upper cover is supported on the stop table at the corresponding position. The edge of the upper cover and the concave contour edge are tightly fitted and positioned, and the tight fit gap between the edge of the upper cover and the concave contour edge is formed into an integrated structure by annular spot laser welding.

3. A method for welding a liquid cooling plate of a die casting according to claim 2, characterized in that: During annular spot laser welding, the annular + central beam emitted by the annular spot laser is routed around the tight fit gap between the edge of the upper cover and the concave contour edge, and welding is completed when routing is completed.

4. The method for welding a liquid cooling plate of a die casting according to claim 3, characterized in that: The shell is provided with a flow channel and a plurality of upper convex columns inside, and the flow channel is formed by a baffle bar. An upper convex positioning strip is provided on the upper surface of the baffle bar, and the width of the upper convex positioning strip is smaller than that of the baffle bar. The upper cover is provided with a contoured concave positioning cavity corresponding to the position of the baffle bar. When the upper cover is installed on the shell, the upper convex positioning strip is inserted into the contoured concave positioning cavity. The upper convex positioning strip and the contoured concave positioning cavity are tightly fitted, and the assembly alignment gap formed by the tight fit is connected by annular spot laser welding.

5. The method for welding a liquid cooling plate of a die casting according to claim 1, characterized in that: According to the demand for heat exchange power, at least one heat exchange module with stacked fins or shovel teeth structure is locally arranged in the inner cavity of the shell. The heat exchange module includes a bottom plate and a stacked fin or shovel teeth structure on the upper surface. A sunken bottom plate positioning groove is arranged at a corresponding position on the bottom of the shell. The bottom plate is tightly fitted in the bottom plate positioning groove. Then, the annular + center light beam emitted by the annular spot laser is welded around the bottom plate positioning groove, so that the heat exchange module can be reliably welded to the shell to form an assembled shell structure.

6. A method for welding a liquid cooling plate of a die casting according to claim 2 or 5, characterized in that: The annular spot laser is an anti-high-reflection annular spot laser with a power of 6000W. When the annular spot laser performs annular spot laser welding, the laser power ramp-up time is 100ms, the laser power ramp-down time is 150ms, and the annular spot diameter is 0.1mm.

7. The method for welding a liquid cooling plate of a die casting according to claim 6, characterized in that: When controlling the surface diameter and melting depth of the weld, a V-shaped molten pool is presented by adjusting the laser power, defocusing amount, and feed speed.

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