Method for manufacturing metallic cooling member

Abstract

The present invention prevents the occurrence of water leakage from a cooling flow passage.　Provided is a method for manufacturing a metallic cooling member 1 in which: a cooling flow passage 5 through which cooling water passes is formed between a metallic main body 33 and a cover plate 44 that are joined to each other; a supply port 6 for supplying the cooling water to the cooling flow passage 5 is provided at a first end 5a of the cooling flow passage 5; and a discharge port 7 for discharging the cooling water from the cooling flow path 5 is provided at a second end 5b of the cooling flow passage 5. In the method, one among the supply port 6 and the discharge port 7 is used as a suction port and the other is used as a measurement port, a suction device 51 is connected to the suction port to reduce the pressure inside the cooling flow passage 5, a pressure measurement device 52 is connected to the measurement port to measure the pressure inside the cooling flow passage 5, and the main body 33 and the cover plate 44 are welded along the cooling flow passage 5 in this state.

Description

Method for manufacturing a metal cooling member

[0001] The present invention relates to a method for manufacturing a metal cooling member having a cooling channel.

[0002] For example, in order to cool a battery, a cooling channel is provided in a metal member on which the battery is placed. Cooling water is flowed through the cooling channel, and the battery is cooled by the cooling water to suppress a temperature rise.

[0003] When such a metal cooling member is composed of two members, a cooling channel can be formed between the opposing surfaces of the two members. That is, by welding and joining the two members together, a cooling channel is formed between the opposing surfaces.

[0004] However, due to a temperature rise of the member during welding and a subsequent temperature drop, the member is likely to be distorted and welding defects are likely to occur. When welding defects occur, a desired sealing performance cannot be obtained, which causes water leakage.

[0005] In Patent Documents 1 to 3 below, it is proposed to reduce the pressure inside the container during welding. However, since the cooling member is provided with a long cooling channel, the length and path length of the section where the members are welded are long. Therefore, such a pressure reduction method in the container is not sufficient.

[0006] Japanese Patent Application Laid-Open No. 2013-188787, Japanese Patent Application Laid-Open No. 2012-200768, Japanese Patent Application Laid-Open No. 2001-79660

[0007] An object of the present invention is to prevent the occurrence of water leakage from the cooling channel.

[0008] The present invention relates to a method for manufacturing a metal cooling member, comprising a first metal member and a second metal member joined to each other, having a cooling channel through which cooling water passes between the first and second members, a supply port for supplying cooling water to the cooling channel provided at the first end of the cooling channel, and a discharge port for discharging cooling water from the cooling channel provided at the second end of the cooling channel, wherein one of the supply port and the discharge port is designated as a suction port and the other as a measurement port, a suction device is connected to the suction port to reduce the pressure in the cooling channel, and a pressure measuring device is connected to the measurement port to measure the pressure in the cooling channel, and in that state the first member and the second member are welded along the cooling channel.

[0009] In this method, the supply port and discharge port are provided at both ends of the cooling channel. That is, the supply port is provided at the first end of the cooling channel, and the discharge port is provided at the second end on the opposite side. When welding the first and second members, for example, the supply port is used as a suction port. A suction device can be connected to the suction port to reduce the pressure in the cooling channel. The discharge port is used as a measurement port. By connecting a pressure measuring device to the measurement port, the pressure in the cooling channel can be measured. Taking the case where the suction port is located at the first end of the cooling channel and the measurement port is located at the second end as an example, it is easy to determine whether the suction force from the suction port has reliably reached the measurement port on the opposite side, that is, whether it has reached the second end of the cooling channel. In this way, by providing the measurement port at the point furthest from the suction port, the pressure reduction state of the cooling channel can be easily determined along the entire length of the cooling channel.

[0010] By reducing the pressure in the cooling channel, the first and second members can be attracted to each other and brought into close contact. Furthermore, since welding is performed while monitoring the pressure value at a measurement port located at the end opposite the suction port, if the first or second member becomes distorted during welding along the cooling channel and a gap occurs between the two members, the gap can be easily detected by the pressure value, allowing welding to be stopped and welding defects to be prevented. Moreover, since the measurement port utilizes the supply or discharge port of the cooling channel, there is no need to provide a separate measurement port. In addition, because the measurement port is located at the end of the cooling channel and on the end opposite the suction port, the pressure in the cooling channel can be accurately grasped along its entire length.

[0011] In particular, the first member is a casting, and the second member is a metal plate of constant thickness. The first member has a groove for forming a cooling channel, a supply port, and an outlet. It is preferable to overlap the second member on the first member so as to cover the groove for the cooling channel, and then weld them by irradiating them with a laser from the second member side. With this method, the groove for the cooling channel can be formed when the first member is formed by casting. Also, by making the second member a metal plate of constant thickness, the structure of the second member can be simplified, and the second member can be easily manufactured. By overlapping the second member on the first member, the opening of the groove for the cooling channel can be easily closed by the second member. On the other hand, since the second member is a metal plate, it tends to bend slightly under reduced pressure and try to enter the groove for the cooling channel. Therefore, the second member can be easily adsorbed and tightly attached to the opening edge of the groove for the cooling channel, increasing the sealing performance at the opening edge of the groove for the cooling channel. In this state, high watertightness can be obtained by welding the peripheral edge of the groove for the cooling channel by irradiating it with a laser from the second member side.

[0012] Furthermore, it is preferable that the depth of the flow channel groove is smaller than its width, and that the supply port and discharge port open to the bottom surface of the flow channel groove. With this method, since the flow channel groove is configured as a shallow groove, the first member can be easily made thinner. Also, since the flow channel groove can be made wider compared to a deep groove configuration, the second member can be easily curved toward the bottom surface of the flow channel groove by reduced pressure, improving the adhesion force and further enhancing watertightness.

[0013] Furthermore, the first member has an annular outer circumference and a partition portion extending inward in a plan view from the outer circumference, with respect to the upper surface forming a groove for a flow path. The welding process includes a first welding step of welding the second member to the entire circumference of the outer circumference of the first member, and a second welding step of welding the second member to the partition portion of the first member after the first welding step. Preferably, in the first welding step, the first member is welded without bending it toward the second member while the cooling flow path is depressurized, and in the second welding step, the first member is welded with the cooling flow path depressurized and it is bent toward the second member. According to this method, the first welding step of welding the second member to the outer circumference of the first member and the second welding step of welding the second member to the partition portion of the first member are performed under different conditions. The outer circumference weld is formed by the first welding step, and the partition weld is formed by the second welding step. The outer circumference weld is formed in an annular shape along the outer circumference, and the partition weld extends along the partition portion and is connected to the outer circumference weld.

[0014] In the first welding process, welding is performed without bending the first member toward the second member. In the first welding process, the cooling channel is depressurized. Since the first member is not bent, its outer circumference can be easily brought into close contact with the second member over its entire circumference, the cooling channel can be easily and reliably depressurized, and the first and second members can be welded under depressurized conditions.

[0015] On the other hand, in the second welding process, the first member is bent towards the second member for welding. The cooling channel is also depressurized in the second welding process, but in the first welding process, the outer circumference is already welded all the way around, and the cooling channel is sealed. Therefore, even if the first member is bent towards the second member, the sealed state of the cooling channel is maintained, and the cooling channel can be reliably depressurized. Also, since the laser is irradiated from the second member side, the temperature of the second member rises more easily than that of the first member during welding. Consequently, the second member expands more thermally than the first member during welding. Then, as the temperature decreases after welding, the first and second members contract, but the contraction of the second member is greater than that of the first member. Therefore, after the first welding process, the first and second members are bent downwards. If the second member were welded without bending it towards the first member in the second welding process, the first and second members would be bent even further downwards after the second welding process. When the first and second members are bent downwards in this manner, it becomes difficult to reliably weld the second member to the partition in the second welding process, and partial welding defects are likely to occur in the partition weld. When welding defects occur, water leakage will occur from those areas. In the present invention, in the second welding process, the first member is bent toward the second member. This allows the second member to be firmly attached to the partition, and the second member to be reliably welded to the partition. Therefore, the occurrence of welding defects can be prevented, and water leakage can be prevented.

[0016] In particular, during the second welding process, it is preferable to spot-press multiple points along the entire length of the corresponding area on the lower surface of the first member corresponding to the partition towards the second member. With this method, instead of pressing linearly along the entire length of the corresponding area on the lower surface of the first member corresponding to the partition, multiple points are pressed spot-like. Therefore, the second member can be bent more effectively toward the first member compared to when the entire length is pressed linearly.

[0017] As described above, by using one of the supply and discharge ports as a suction port and the other as a measurement port, the pressure in the cooling channel is reduced while being measured at the end of the cooling channel, thereby suppressing the occurrence of welding defects and preventing water leakage from the cooling channel.

[0018] A cross-sectional view showing a metal cooling member in the first embodiment of the present invention. A cross-sectional view showing the manufacturing process of the cooling member. A cross-sectional view showing the manufacturing process of the cooling member. A cross-sectional view showing the manufacturing process of the cooling member. A cross-sectional view showing a metal cooling member in the second embodiment of the present invention. A cross-sectional view showing the manufacturing process of the cooling member. A cross-sectional view showing the manufacturing process of the cooling member. A cross-sectional view showing the manufacturing process of the cooling member. A plan view showing a metal cooling member in the third embodiment of the present invention. A cross-sectional view along A-A in Figure 9. A plan view showing the first member of the cooling member in its standalone state. A cross-sectional view showing the manufacturing process of the cooling member. A cross-sectional view showing the first welding process in the manufacturing process of the cooling member. A plan view showing the state of the cooling member after the first welding process. A plan view showing the second welding process in the manufacturing process of the cooling member. A cross-sectional view showing the second welding process in the manufacturing process of the cooling member. A plan view showing the second welding process in the manufacturing process of the cooling member. A cross-sectional view showing the second welding process in the manufacturing process of the cooling member. A plan view showing the second welding process in the manufacturing process of the cooling member. A cross-sectional view showing the second welding process in the manufacturing process of the cooling member.

[0019] The following describes a metal cooling member according to one embodiment of the present invention and a method for manufacturing the same, with reference to the drawings. The cooling member is made by joining two metal members. That is, the cooling member comprises a first member and a second member. The first member and the second member are joined together at a predetermined joint. The first member has a first opposing surface, and the second member has a second opposing surface. The first opposing surface and the second opposing surface face each other. The first opposing surface and the second opposing surface are joined together. The first opposing surface is the first joining surface, and the second opposing surface is the second joining surface.

[0020] The cooling member may take various forms, and the forms of the first and second members may also take various forms. Figures 1 to 4 show a cooling member of the first embodiment. In this embodiment, the cooling member 1 is a tray for batteries. As shown by the dashed line in Figure 1, batteries 2 are placed on the cooling member 1. The number of batteries 2 placed is arbitrary. The shape of the cooling member 1 in plan view may take various forms, but it is preferably rectangular, and is either rectangular or square.

[0021] The cooling member 1 consists of a first member, the main body 3, and a second member, the cover plate 4. The main body 3 is made of cast material, specifically die-cast, and more specifically, aluminum die-cast. The cover plate 4 is a metal plate, preferably a wrought aluminum alloy.

[0022] A cooling channel 5 for flowing cooling water is formed between the first and second opposing surfaces. The cooling channel 5 has a continuous shape from its first end 5a to its second end 5b. The number of cooling channels 5 is arbitrary. In this embodiment, there is one cooling channel 5, but there may be multiple. The cooling channel 5 is provided with a supply port 6 and an outlet port 7. The supply port 6 and the outlet port 7 are provided at both ends of the cooling channel 5. The supply port 6 is provided at the first end 5a of the cooling channel 5, and the outlet port 7 is provided at the second end 5b of the cooling channel 5.

[0023] The supply port 6 is a water supply opening for supplying cooling water to the cooling channel 5. The discharge port 7 is a drainage opening for discharging cooling water from the cooling channel 5 to the outside. Piping is connected to both the supply port 6 and the discharge port 7. Cooling water is supplied from the supply side piping through the supply port 6 to the cooling channel 5, flows through the cooling channel 5 from its first end 5a to its second end 5b, and is then discharged through the discharge side piping via the discharge port 7. The dimension of the cooling channel 5 in the short direction (width dimension) is greater than the dimension of the cooling channel 5 in the vertical direction (height dimension). The longitudinal direction of the cooling channel 5 is the direction normal to the paper in Figure 1, and the short direction of the cooling channel 5 is the left-right direction in Figure 1. The cross-sectional shape of the cooling channel 5 is rectangular, specifically, a rectangle that is long in the horizontal direction.

[0024] The overall shape of the cooling channel 5 in plan view is arbitrary; for example, it may be a straight line from the first end 5a to the second end 5b, or it may be folded at one or more points. In this embodiment, the overall shape of the cooling channel 5 in plan view is folded at a total of three points. That is, the cooling channel 5 has three folded sections (not shown). When the cooling channel 5 has folded sections, the cooling channel 5 has a plurality of sections 8 arranged in a predetermined direction. In this embodiment, the cooling channel 5 has three folded sections and four sections 8 arranged in the left-right direction in Figure 1. Each section 8 is formed in a straight line; therefore, the sections 8 are straight sections and are parallel to each other. Adjacent sections 8 are connected at the folded sections. The supply port 6 is provided at the end of the section 8 located on the far right in Figure 1, and the discharge port 7 is provided at the end of the section 8 located on the far left in Figure 1.

[0025] As shown in Figure 2, the main body 3 has a bottom surface 10 and a peripheral wall 11 rising from the periphery of the bottom surface 10. The upper surface 10a of the bottom surface 10 is the first opposing surface. The height of the upper surface 10a of the bottom surface 10 is lower than the height of the upper end surface 11a of the peripheral wall 11. A flow channel groove 12 is formed in the bottom surface 10, recessed downward from the upper surface 10a of the bottom surface 10. The flow channel groove 12 opens upward. The flow channel groove 12, together with the cover plate 4, is for forming a cooling channel 5. The cross-sectional shape of the flow channel groove 12 is rectangular, specifically, a rectangle that is long horizontally. The width W of the flow channel groove 12 becomes the width of the cooling channel 5, and the depth D of the flow channel groove 12 becomes the height of the cooling channel 5. The depth D of the flow channel groove 12 is smaller than the width W of the flow channel groove 12. That is, the flow channel groove 12 is a shallow groove. The supply port 6 and the discharge port 7 are both formed in the main body 3, and more specifically, they are formed on the bottom surface 12a of the flow path groove 12. The supply port 6 and the discharge port 7 open to the bottom surface 12a of the flow path groove 12 and also open to the lower surface 10b of the bottom surface portion 10, and penetrate the bottom surface portion 10 of the main body 3 in the vertical direction.

[0026] The flow channel groove 12 has a continuous shape from its first end to its second end. The flow channel groove 12 has three groove return sections corresponding to the return sections of the cooling channel 5, and four groove sections arranged side by side in the left-right direction in Figure 2, corresponding to sections of the cooling channel 5. Each groove section is formed in a straight line and is parallel to the others.

[0027] Furthermore, a circumferential groove 13 is formed on the periphery of the bottom surface 10. The circumferential groove 13 is formed around the entire circumference, adjacent to the inside of the circumferential wall 11, and encircles it. The lower surface 10b of the bottom surface 10 is a flat surface. The thickness (thickness in the vertical direction) of the bottom surface 10 is relatively thin in the portion with the flow channel groove 12, and relatively thick in the portion without the flow channel groove 12, with the difference corresponding to the depth D of the flow channel groove 12. It is also relatively thin in the portion with the circumferential groove 13. The portion of the bottom surface 10 in which neither the flow channel groove 12 nor the circumferential groove 13 is formed is the main bottom surface 14, and the thickness of the main bottom surface 14 is the thickest in the bottom surface 10. The thickness of the main bottom surface 14 is the basic thickness of the bottom surface 10. Furthermore, the upper surface of the main bottom surface 14 is the first opposing surface.

[0028] A cover plate 4 is placed on and welded to the upper surface 10a of the bottom portion 10, specifically the upper surface of the main bottom portion 14. The battery 2 is placed on the upper surface 4a of the cover plate 4. Therefore, the upper surface 4a of the cover plate 4 becomes the battery mounting surface. The cover plate 4 is a thin plate of constant thickness. The upper surface 4a of the cover plate 4 is lower than the upper end surface 11a of the peripheral wall portion 11 of the main body 3. By attaching the cover plate 4 to the upper surface of the main bottom portion 14 of the main body 3, the opening of the flow channel groove 12 is closed. A cooling channel 5 is formed by the flow channel groove 12 of the main body 3 and the cover plate 4. The battery 2 is cooled by the cooling water flowing through the cooling channel 5.

[0029] The cover plate 4 is joined and integrated with the main body 3 by laser welding. The lower surface 4b of the cover plate 4 is superimposed on the upper surface of the main bottom portion 14 of the bottom portion 10 of the main body 3. The lower surface 4b of the cover plate 4 is the second opposing surface. The circumferential groove 13 is located around the cover plate 4. A weld bead 15 (welded area) is formed at the welded location. The peripheral edge of the cover plate 4 is overlapped and fillet welded to the main body 3. In the areas between adjacent sections 8 in the cooling channel 5, the cover plate 4 is overlapped and welded to the main body 3. The welded area extends around the entire circumference of the cooling channel 5.

[0030] Figures 2 and 3 show the state before joining. As shown in Figure 2, for example, the cover plate 4 is sucked up by the sucker 50 and moved to the top of the main body 3, and as shown in Figure 3, the cover plate 4 is placed on the upper surface of the bottom main body 14. One of the supply port 6 and discharge port 7 of the main body 3 is designated as a suction port and the other as a connection port. For example, if the supply port 6 is designated as a suction port and the discharge port 7 is designated as a connection port, the suction device 51 is connected to the supply port 6 and the pressure measuring device 52 is connected to the discharge port 7.

[0031] Then, with the cover plate 4 held in place by the sucker 50, the suction device 51 sucks air from the cooling channel 5 through the supply port 6 to reduce the pressure in the cooling channel 5 to a predetermined value. When the pressure in the cooling channel 5 is reduced to the predetermined value, the sucker 50 releases its hold and returns the sucker 50 to its original position. With the pressure in the cooling channel 5 reduced to the predetermined value, the laser 53 is irradiated from the cover plate 4 side as shown in Figure 4 to perform welding. The laser 53 is moved along the channel groove 12 and irradiated onto the cover plate 4 to weld around the channel groove 12.

[0032] The pressure measuring device 52 measures the pressure in the cooling channel 5 and continues to measure and monitor the pressure in the cooling channel 5 even during welding. Whether or not the pressure in the cooling channel 5 has been reduced to a predetermined value can be easily determined from the measurement results of the pressure measuring device 52. For example, by connecting the pressure measuring device 52 to a personal computer, the pressure in the cooling channel 5 can be automatically determined. If the pressure has not reached the predetermined value, welding can be stopped, or if the pressure exceeds the predetermined value during welding, i.e., if it has not been reduced to the predetermined value, the welding process can be stopped midway.

[0033] As described above, when welding the cover plate 4 to the main body 3, the supply port 6 is used as a suction port and the discharge port 7 is used as a measurement port. Since the measurement port is located at the end of the cooling channel 5 opposite to the suction port, it is easy to determine whether the suction force from the suction port has reliably reached the measurement port located at the opposite end of the cooling channel 5. Therefore, welding can be performed with suction force reliably applied to the end of the cooling channel 5 opposite to the suction port, preventing welding defects near the measurement port. In addition, by reducing the pressure in the cooling channel 5, the lower surface 4b of the cover plate 4 can be brought into close contact with the upper surface of the main bottom portion 14 of the main body 3. Therefore, welding can be performed in a tightly fitted state.

[0034] Furthermore, welding is performed while measuring and monitoring the reduced pressure state at a measurement port located at the end opposite the suction port. Therefore, if the main body 3 or cover plate 4 becomes distorted during welding along the cooling channel 5, causing a gap to form between the two components and weakening the reduced pressure state, this can be easily detected. This allows welding to be stopped to prevent welding defects and thus prevent water leakage caused by welding defects. In particular, since the cover plate 4 is a thin plate and the laser 53 is irradiated from the cover plate 4 side, the thin cover plate 4 is prone to distortion due to heat. However, since the pressure in the cooling channel 5 is continuously checked through the measurement port even during welding, welding defects due to gap formation can be quickly detected. Moreover, since the measurement port utilizes the supply port 6 or discharge port 7 of the cooling channel 5, there is no need to provide a separate measurement port. Furthermore, since the measurement port is located, for example, at the second end 5b of the cooling channel 5, on the end opposite the suction port, the pressure in the cooling channel 5 can be accurately grasped along its entire length.

[0035] The flow channel grooves 12 can be formed simultaneously when the main body 3 is formed by casting. Furthermore, since the cover plate 4 is made of a metal plate of uniform thickness, the cooling channel 5 can be easily formed. In particular, by placing the cover plate 4 on the upper surface of the main bottom portion 14 of the main body 3, the opening of the flow channel grooves 12 can be easily closed by the cover plate 4.

[0036] On the other hand, because the cover plate 4 is thin, the reduced pressure in the cooling channel 5 causes the cover plate 4 to flex slightly and fit into the channel groove 12. In particular, since the supply port 6 and discharge port 7 are formed in the channel groove 12, the cover plate 4 can be easily adsorbed and tightly fitted to the opening edge of the channel groove 12. As a result, the sealing performance at the opening edge of the channel groove 12 is enhanced, and by irradiating the cover plate 4 side with a laser 53 and welding the peripheral edge of the channel groove 12 in this state, high watertightness can be ensured.

[0037] Furthermore, since the flow channel groove 12 is shallow and the supply port 6 and discharge port 7 are formed on the bottom surface 12a of the flow channel groove 12, the main body 3 can be easily made thinner. Also, because the flow channel groove 12 is wide, the inside of the cooling channel 5 is depressurized, making it easier to curve the cover plate 4 toward the bottom surface 12a of the flow channel groove 12, allowing the cover plate 4 to be tightly adhered to the opening edge of the flow channel groove 12, improving welding strength and further enhancing watertightness.

[0038] Next, a second embodiment will be described. However, a detailed explanation of the configuration, which is the same as that of the first embodiment, will be omitted. Figures 5 to 8 show the cooling member 1 in this embodiment. The cooling member 1 in this embodiment is a tray, similar to the cooling member 1 in the first embodiment, but it is deeper than the tray in the first embodiment. The flow path groove 12 is formed on the lower surface 10b of the bottom surface 10 of the main body 3 and opens downwards. The cover plate 4 is joined to the lower surface 10b of the bottom surface 10. Therefore, in this embodiment, the lower surface 10b of the bottom surface 10 of the main body 3 is the first opposing surface, and the upper surface 4a of the cover plate 4 is the second opposing surface. The battery 2 is placed on the upper surface 10a of the bottom surface 10 of the main body 3. Therefore, the upper surface 10a of the bottom surface 10 of the main body 3 is the battery mounting surface. Note that the upper surface 10a of the bottom surface 10 of the main body 3 is lower than the upper end surface 11a of the peripheral wall 11 of the main body 3.

[0039] The cooling channel 5 has one return section and two sections 8, the two sections 8 being parallel to each other. The supply port 6 is provided at the end of one section 8, and the discharge port 7 is provided at the end of the other section 8. The channel groove 12 has one groove return section and two groove sections, the two groove sections being parallel to each other.

[0040] Figures 6 and 7 show the state before joining. The main body 3 is shown in an inverted state, with the lower surface 10b of the bottom surface 10 of the main body 3 facing upwards. The suction cup 50 picks up the cover plate 4 and places the cover plate 4 on the lower surface 10b of the bottom surface 10 of the main body 3. At this time, a positioning member 54 may be placed to position the cover plate 4 horizontally. After the cooling channel 5 is depressurized, the laser 53 is irradiated as shown in Figure 8. When irradiating with the laser 53, it is preferable to move the positioning member 54 from the positioning position shown in Figure 7 to a retracted position located laterally from the positioning position so that the positioning member 54 does not obstruct the laser irradiation.

[0041] Next, a third embodiment will be described. However, a detailed explanation of the configuration similar to that of the above embodiment will be omitted. Figures 9 to 20 show the cooling member 1 and its manufacturing method in this embodiment. The cooling member 1 in this embodiment is a flat plate. The main body 3 is plate-shaped and thicker than the cover plate 4. A flow channel groove 12 is formed on the upper surface 3a of the main body 3. The upper surface 3a of the main body 3 is a flat surface with a constant height except for the flow channel groove 12. The cover plate 4 is joined to the upper surface 3a of the main body 3. The upper surface 3a of the main body 3 is the first opposing surface, and the lower surface 4b of the cover plate 4 is the second opposing surface. The battery 2 is placed on the cover plate 4.

[0042] The cooling channel 5 has three folded sections 9 and four sectioned sections 8, similar to the first embodiment. Figure 11 shows a plan view of the main body 3. The channel groove 12 has three groove folded sections 20 and four grooved sectioned sections 21. The upper surface 3a of the main body 3 has an annular outer periphery 22 and three partition sections 23. The outer periphery 22 is provided on the periphery of the upper surface 3a of the main body 3. If the region of the upper surface 3a of the main body 3 in which the channel groove 12 is formed is called the groove-forming region, then the outer periphery 22 is located outside the groove-forming region in a plan view. The outer periphery 22 surrounds the groove-forming region from the outside in a plan view.

[0043] The partition portion 23 extends inward in a plan view from the outer peripheral portion 22. The partition portion 23 may extend linearly or may be curved. The first end portion 23a of the partition portion 23 is connected to the outer peripheral portion 22, and the second end portion 23b is separated from the outer peripheral portion 22. Therefore, the first end portion 23a of the partition portion 23 is a connection end portion, and the second end portion 23b of the partition portion 23 is a free end portion. The partition portion 23 separates adjacent groove section portions 21 from each other. Therefore, a pair of groove section portions 21 are provided on both sides of the partition portion 23. The number of partition portions 23 corresponds to the groove section portions 21. In the present embodiment, a total of three partition portions 23 are provided. When distinguishing the three partition portions 23, the partition portion 23 on the right in FIG. 11 is referred to as the first partition portion 231, the central partition portion 23 is referred to as the second partition portion 232, and the left partition portion 23 is referred to as the third partition portion 233. The height of the partition portion 23 is the same as the height of the outer peripheral portion 22, and the partition portion 23 and the outer peripheral portion 22 are flush with each other and constitute one continuous plane.

[0044] The cover plate 4 is welded to the upper surface 3a of the main body 3, whereby the concave groove 12 for the flow path is closed by the cover plate 4, and the cooling flow path 5 is formed. The welding process will be sequentially described. The welding process is roughly divided into two processes, including the first welding process and the second welding process performed after the first welding process. In the first welding process, the peripheral edge portion of the cover plate 4 is overlapped with the outer peripheral portion 22 and fillet welded, and in the second welding process, the cover plate 4 is overlapped and welded to the three partition portions 23 respectively.

[0045] As shown in FIG. 12, the main body 3 is placed on the support base 60. The support base 60 supports the peripheral edge portion of the lower surface 3b of the main body 3. The central portion of the lower surface 3b of the main body 3 other than the peripheral edge portion is not supported and is open. Also, the peripheral edge portion of the upper surface 3a of the main body 3 is fixed by the clamp member 61. The peripheral edge portion of the main body 3 is clamped vertically by the clamp member 61 and the support base 60. Therefore, the height of the peripheral edge portion of the main body 3 is kept constant.

[0046] For example, the cover plate 4 is placed on the upper surface 3a of the main body 3 by the soccer ball 50. Then, similar to the first embodiment, the suction device 51 is connected to the supply port 6, and the pressure measuring device 52 is connected to the discharge port 7 to decompress the cooling flow path 5. In this decompressed state, the laser 53 is irradiated to the peripheral portion of the cover plate 4. By moving the laser 53 along the peripheral portion of the cover plate 4, the entire circumference of the peripheral portion of the cover plate 4 is welded to the outer peripheral portion 22 of the main body 3. The above steps are the first welding step, and the annular outer peripheral welding portion 30 is formed by the first welding step. The groove forming region is sealed by the outer peripheral welding portion 30. In the first welding step, the pressing member 62 described later is in the retracted position and does not press the lower surface 3b of the main body 3.

[0047] Since the laser 53 is irradiated from the cover plate 4 side, the temperature of the cover plate 4 rises more easily than that of the main body 3. During welding, the cover plate 4 thermally expands more than the main body 3. On the other hand, when the welding is completed, as the temperature decreases, the main body 3 and the cover plate 4 contract, but the cover plate 4 contracts more than the main body 3. Therefore, at the stage when the first welding step is completed, the main body 3 and the cover plate 4 are in a state of being slightly warped downward.

[0048] Subsequently, the second welding step is performed. In the second welding step, the decompressed state of the cooling flow path 5 is continuously maintained from the first welding step. Note that the pressure of the cooling flow path 5 may be changed or set to the same value between the first welding step and the second welding step. In the second welding step, the three partition portions 23 are welded. The three partition weld portions 31 are formed by the second welding step. When distinguishing the three partition weld portions 31, the partition weld portion 31 of the first partition portion 231 is referred to as the first partition weld portion 311, the partition weld portion 31 of the second partition portion 232 is referred to as the second partition weld portion 312, and the partition weld portion 31 of the third partition portion 233 is referred to as the third partition weld portion 313. In the second welding step, the three partition portions 23 are welded one by one. Therefore, the second welding step includes a first partition welding step of welding the first partition portion 231, a second partition welding step of welding the second partition portion 232, and a third partition welding step of welding the third partition portion 233.

[0049] In the first partition welding process, as shown by the dashed line in Figure 15, the first partition portion 231 and the cover plate 4 are welded together to form the first partition welded portion 311. When welding the first partition portion 231, the lower surface 3b of the main body 3 is pushed toward the cover plate 4, as shown in Figure 16. On the underside of the main body 3, pressing members 62 are positioned below each of the partition portions from the first partition portion 231 to the third partition portion 233. The pressing members 62 are, for example, round bars. The pressing members 62 locally press the lower surface 3b of the main body 3 corresponding to the partition portion 23. That is, the pressing members 62 press in a spot manner. The pressing members 62 are provided to be movable vertically. The pressing members 62 can move vertically between a pressing position that presses the lower surface 3b of the main body 3 and a retracted position that is spaced downward from the lower surface 3b of the main body 3. As the pressing member 62 rises to the pressing position, the upper surface of the pressing member 62 pushes upward the portion of the lower surface 3b of the main body 3 that corresponds to the partition portion 23.

[0050] Furthermore, when distinguishing between the pressing members 62, the pressing member 62 located below the first partition 231 will be referred to as the first pressing member 621, the pressing member 62 located below the second partition 232 will be referred to as the second pressing member 622, and the pressing member 62 located below the third partition 233 will be referred to as the third pressing member 623. As shown in Figure 15, the first pressing members 621 are arranged at intervals in the longitudinal direction of the first partition 231 in a plan view, and in this embodiment, they are arranged at three locations. However, the locations and number of the first pressing members 621 are arbitrary. Similarly, the second pressing members 622 and the third pressing members 623 are arranged at equal intervals in the longitudinal direction of the second partition 232 and the third partition 233 in a plan view, as shown in Figures 17 and 19. If we refer to the points where the pressing member 62 applies pressure as pressing points, then in this embodiment, a total of nine pressing points are provided.

[0051] In the first partition welding process, as shown in Figure 16, the first pressing member 621 rises to the pressing position and pushes the lower surface 3b of the main body 3 upward. Specifically, the main body 3 is pushed upward so that the height of the first partition portion 231 is higher than the height of the outer circumference portion 22. The three first pressing members 621 rise together in conjunction, pushing the lower surface 3b of the main body 3 upward by the same amount. The clamp member 61 fixes the peripheral edge of the main body 3 and prevents the peripheral edge of the main body 3 from rising. As a result, the pressing member 621 pushes the lower surface 3b of the main body 3, causing the main body 3 to bend upward. In the first partition welding process, the second pressing member 622 and the third pressing member 623 do not rise but retract to a retracted position away from the lower surface 3b of the main body 3. In this way, the three first pressing members 621 push up the three pressing points on the lower surface 3b of the main body 3, causing the main body 3 to bend upward, and the first partition portion 231 is welded in that state. This forms the first partition weld portion 311.

[0052] The second partition welding process is performed following the first partition welding process. In the second partition welding process, as shown in Figures 17 and 18, the first pressing member 621 descends to a retracted position and moves away from the lower surface 3b of the main body 3, and the second pressing member 622 rises and pushes up the lower surface 3b of the main body 3, causing the main body 3 to bend upward. In this state, the second partition portion 232 is welded. This forms the second partition welded portion 312.

[0053] Next, the process moves to the third partition welding step. In the third partition welding step, as shown in Figures 19 and 20, the second pressing member 622 descends to its retracted position and moves away from the lower surface 3b of the main body 3, and the third pressing member 623 rises and pushes up the lower surface 3b of the main body 3, causing the main body 3 to bend upward. In this state, the third partition 233 is welded. This forms the third partition welded section 313.

[0054] As described above, in the manufacturing method of this embodiment, the lower surface 3b of the main body 3 is not pressed by the pressing member 62 in the first welding step. That is, in the first welding step, welding is performed in a flat state without bending the main body 3 upward. Therefore, the cover plate 4 can be easily made to adhere tightly to the entire circumference of the outer peripheral portion 22 by reducing the pressure in the cooling passage 5. On the other hand, in the second welding step, the lower surface 3b of the main body 3 is pushed up by the pressing member 62 and the main body 3 is welded while bent upward. In the first welding step, the outer peripheral portion 22 has already been welded all around and the cooling passage 5 is sealed. Therefore, even if the main body 3 is bent, the sealed state and reduced pressure state of the cooling passage 5 are maintained, the partition portion 23 can be reliably welded to the cover plate 4, and the occurrence of welding defects can be prevented. Therefore, water leakage from the cooling member 1 can be prevented.

[0055] Furthermore, in the second welding process, the pressing points on the lower surface 3b of the main body 3 opposite each partition 23 are pressed in a spot manner by the pressing member 62, so that the upward force from the pressing member 62 can be effectively applied to the lower surface 3b of the main body 3. As a result, the main body 3 can be effectively bent upward.

[0056] Furthermore, in all of the first, second, and third partition welding processes, the first pressing member 621, the second pressing member 622, and the third pressing member 623 may all be raised to the pressing position to press the lower surface 3b of the main body 3. That is, all nine pressing points may be pressed. Alternatively, one of the nine pressing points may be pressed, or any multiple dispersed pressing points may be pressed.

[0057] In this embodiment, the case in which only one groove-forming region is provided on the upper surface 3a of the main body 3 has been described, but multiple groove-forming regions may be provided on the upper surface 3a of the main body 3. If multiple groove-forming regions are provided on the upper surface 3a of the main body 3, a cover plate 4 may be attached to each groove-forming region, or a single cover plate 4 may cover multiple groove-forming regions together.

[0058] 1 Cooling component 2 Battery 3 Main body (first component) 3a Top surface 3b Bottom surface 4 Cover plate (second component) 4a Top surface (second opposing surface) 4b Bottom surface (second opposing surface) 5 Cooling flow path 5a First end 5b Second end 6 Supply port 7 Discharge port 8 Section 9 Folded-over section 10 Bottom surface 10a Top surface (first opposing surface) 10b Bottom surface (first opposing surface) 11 Peripheral wall 11a Upper end surface 12 Flow path groove 12a Bottom surface 13 Peripheral groove 14 Main part of bottom surface 15 Weld bead 20 Folded-over groove section 21 Groove section 22 Outer circumference 23 Partition section 23a First end 23b Second end 231 First partition section 232 Second partition section 233 Third partition section 30 Outer circumference welded section 31 Partition welded section 311 First partition welded section 312 Second partition welded section 313 Third partition welded section 50 Suction device 51 Suction device 52 Pressure measuring device 53 Laser 54 Positioning member 60 Support base 61 Clamp member 62 Pressing member 621 First pressing member 622 Second pressing member 623 Third pressing member

Claims

1. A method for manufacturing a metal cooling member comprising a first and second metal member joined to each other, having a cooling channel through which cooling water passes between the first and second members, a supply port for supplying cooling water to the cooling channel provided at the first end of the cooling channel, and a discharge port for discharging cooling water from the cooling channel provided at the second end of the cooling channel, wherein one of the supply port and the discharge port is designated as a suction port and the other as a measurement port, a suction device is connected to the suction port to reduce the pressure in the cooling channel, and a pressure measuring device is connected to the measurement port to measure the pressure in the cooling channel, and in that state the first and second members are welded together along the cooling channel.

2. The method for manufacturing a metal cooling member according to claim 1, wherein the first member is a casting, the second member is a metal plate of constant thickness, the first member has a groove for forming a cooling channel, a supply port, and a discharge port formed therein, the second member is placed on top of the first member so as to cover the groove for forming the cooling channel, and the two members are welded by irradiating a laser from the second member side.

3. The method for manufacturing a metal cooling member according to claim 2, wherein the flow channel groove is less deep than it is wide, and the supply port and discharge port are opening to the bottom surface of the flow channel groove.

4. A method for manufacturing a metal cooling member according to claim 2, wherein the first member has an annular outer circumference and a partition portion extending inward in a plan view from the outer circumference so as to form a groove for a flow path on its upper surface, and comprises a first welding step of welding the second member to the entire circumference of the outer circumference of the first member, and a second welding step of welding the second member to the partition portion of the first member after the first welding step, wherein in the first welding step the first member is welded without bending it toward the second member while the cooling flow path is under reduced pressure, and in the second welding step the first member is welded while the cooling flow path is under reduced pressure and it is bent toward the second member.

5. The method for manufacturing a metal cooling member according to claim 4, wherein in the second welding step, multiple locations along the entire length of the corresponding portion on the lower surface of the first member corresponding to the partition portion are pressed towards the second member in a spot-like manner.

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