Battery box and manufacturing method thereof

Abstract

The present invention provides a battery case and a manufacturing method thereof, wherein the battery case includes a liquid cooling plate, the liquid cooling plate includes a bottom plate and a front plug, a flow channel is provided in the bottom plate, a flow channel groove is provided in the front plug, a connecting port connected to the flow channel in the bottom plate is provided on the side of the flow channel groove, a plug is provided at the connecting port, the plug has an extending portion and a protruding portion, the surrounding side of the protruding portion is fixed to the side of the liquid cooling plate by arc welding to form a circle of plug weld and seal the connecting port, an avoidance groove is provided on the left plate and / or the right plate to avoid the protruding portion and the plug weld, the thickness of the plug weld in the vertical direction is greater than the height of the stirring head of the stir friction welding, and the width of the plug weld in the left and right direction is less than the weld width of the stir friction welding. Beneficial effect: When the left plate and / or the right plate are subsequently welded by stir friction welding, the stirring head will not completely destroy the plug weld, thereby ensuring that the sealing effect of the plug weld on the connecting port is not destroyed and that the coolant does not leak.

Description

Technical Field

[0001] The present invention relates to a battery box and a manufacturing method thereof. Background Art

[0002] To meet lightweight requirements, profile enclosures are widely used in the new energy industry. With the widespread adoption of large battery cells and fast charging, heat dissipation issues are becoming increasingly prominent, leading to the emergence of profile enclosures with integrated liquid cooling capabilities.

[0003] like Figure 1 The figure shows a battery box in the prior art, which includes a liquid cooling plate at the bottom and a left side plate 4, a right side plate 5, a front side plate 2 and a rear side plate 3 fixed around the liquid cooling plate. The liquid cooling plate is an assembly, including a bottom plate 1 and a front plug 7 connected together. Figure 3 As shown, a flow channel 1-1 for the circulation of cooling liquid is provided in the bottom plate 1. Figure 2 As shown, two flow grooves 72 are provided at the left and right ends of the front plug 7. The rear ends of the two flow grooves 72 are connected with the flow channel 1-1 in the bottom plate 1, and the front ends extend into the boss 71. The boss 71 is connected with the water nozzle 6. Therefore, the coolant can be input into the bottom plate 1 through the water nozzle 6 and the flow groove 72 at one end. The coolant flows in the bottom plate 1 to dissipate heat for the battery pack, and then flows out of the box through the flow groove 72 and the water nozzle 6 at the other end.

[0004] During the manufacturing process of the battery case, the front plug 7 and the bottom plate 1 need to be welded together. Currently, friction stir welding is usually used. However, since the flow channel 72 is machined on the front plug 7, that is, the location where the flow channel 72 is located is hollow, when welding to this location, deformation is likely to occur. Therefore, to avoid deformation, a filling block is usually inserted into the flow channel 72 to temporarily fill the flow channel 72. Therefore, the side of the flow channel 72 must be set to an open structure to accommodate the filling block, that is, the rear and side of the flow channel 72 are open.

[0005] After the front plug 7 and the bottom plate 1 are welded and fixed, the filling block needs to be removed, and then the left side plate 4, the right side plate 5, the front plug 7 and the bottom plate 1 need to be welded and fixed. That is to say, after the bottom plate 1 is welded to the front plug 7 and the rear side plate 3, a connecting port connected to the flow channel in the bottom plate 1 will be left on the side of the assembled liquid cooling plate. At present, this connecting port is blocked by the left side plate 4 and the right side plate 5 when welding them to prevent leakage. However, this method relies on the close fit between the side plate and the side of the liquid cooling plate, which is actually difficult to achieve. Therefore, the seal is unreliable and leakage is prone to occur. In addition, the left side plate 4 and the right side plate 5 need to have a high surface quality, and the bottom plate 1 and the front plug 7 also need to have a high side quality. This not only increases the manufacturing difficulty and the manufacturing cost of the box, but also makes welding more difficult. Summary of the Invention

[0006] The object of the present invention is to provide a battery case with a relatively good sealing effect and capable of avoiding leakage; the object of the present invention is also to provide a method for manufacturing a battery case with a relatively good sealing effect and capable of avoiding leakage.

[0007] To achieve the above objectives, the battery box of the present invention adopts the following technical solutions:

[0008] A battery box comprises a liquid cooling plate and a left side plate, a right side plate, a front side plate and a rear side plate respectively welded and fixed to the liquid cooling plate, the liquid cooling plate comprises a bottom plate and a front plug welded and fixed to the front side of the bottom plate, a flow channel for cooling liquid to circulate is provided in the bottom plate, and the left and right ends of the front plug are respectively provided with flow channel grooves connected to the flow channel in the bottom plate, one of the two flow channel grooves is for external cooling liquid to flow into the bottom plate, and the other is for cooling liquid in the bottom plate to flow out of the liquid cooling plate, a connecting port connected to the flow channel in the bottom plate is provided on the side surface of the junction part of at least one flow channel groove with the bottom plate, a plug for sealing the connecting port is provided at the connecting port, the plug having an extending portion extending into the connecting port and a extending portion located outside the connecting port, and a gap is formed between the upper surface of the extending portion and the upper surface of the liquid cooling plate. A set distance is set, and / or there is a set distance between the lower surface of the protruding part and the lower surface of the liquid cooling plate, the surrounding side surfaces of the protruding part and the side surfaces of the liquid cooling plate are fixed by arc welding to form a circle of plug welds and seal the connecting port, and the left plate and / or the right plate are provided with avoidance grooves for avoiding the protruding part and the plug welds, the liquid cooling plate and the left plate and / or the right plate are fixed by stir friction welding, the thickness of the plug weld in the up and down direction is greater than the height of the stirring head of the stir friction welding to avoid the plug weld being completely destroyed by the stirring head of the stir friction welding, and the width of the plug weld in the left and right directions is less than the weld width of the stir friction welding, so that the weld of the stir friction welding can cover the plug weld and the edge of the liquid cooling plate and the left plate or the right plate.

[0009] The beneficial effect of the technical solution of the battery box is that: a plug is inserted into the communication port, and an extended portion is left outside the communication port. The distance between the upper surface of the extended portion and the upper surface of the liquid cooling plate can ensure that there is sufficient space for the plug weld to be formed here. Similarly, the distance between the lower surface of the extended portion and the lower surface of the liquid cooling plate can ensure that there is also sufficient space for the plug weld to be formed here, and the thickness of the plug weld in the vertical direction is greater than the height of the stirring head of the stir friction welding. In this way, when the liquid cooling plate and the left plate and / or the right plate are subsequently welded by stir friction welding, The plug weld will not be completely destroyed, thereby ensuring that the sealing effect of the plug weld on the connecting port is not destroyed, thereby ensuring that the coolant will not leak, and the sealing effect is better; and the avoidance grooves provided on the left plate and / or the right plate can ensure that the left plate and / or the right plate are aligned with the liquid cooling plate, and at the same time, the width of the plug weld in the left and right directions is smaller than the weld width of the friction stir welding, so that the weld of the friction stir welding can cover the plug weld and the edge of the liquid cooling plate and the left plate or the right plate, and successfully complete the welding and fixation between the liquid cooling plate and the left plate or the right plate.

[0010] Furthermore, in order to control the insertion degree of the plug and facilitate the installation of the plug, a stopper edge is provided on the protruding portion of the plug to cooperate with the side stopper of the liquid cooling plate.

[0011] Furthermore, in order to facilitate the processing and manufacturing of the plug, sufficient space is left between the upper and lower surfaces of the protruding part and the side of the liquid cooling plate to form the plug weld. The plug is T-shaped, and there are two stopping edges, which are respectively located at the front and rear ends of the protruding part. The upper and lower surfaces of the protruding part are flush with the upper and lower surfaces of the inserted part.

[0012] Furthermore, in order to facilitate the installation of the plug, the end of the extending portion is provided with a guiding slope for facilitating the plug to be inserted into the communicating port.

[0013] Furthermore, in order to ensure the welding seal between the bottom plate and the rear side plate, and to prevent the sealing effect from being destroyed by subsequent stir friction welding, corner cuts are respectively provided at the left and right ends of the rear part of the bottom plate, and a corner groove is formed between the corner cuts and the rear side plate. The corner cuts and the rear side plate are fixed by arc welding to form a corner weld in the corner groove. The length of the corner weld in the up and down directions is greater than the height of the stirring head of the stir friction welding to prevent the corner weld from being completely destroyed by the stirring head of the stir friction welding.

[0014] To achieve the above objectives, the battery case manufacturing method of the present invention adopts the following technical solutions:

[0015] A method for manufacturing a battery case includes the steps of welding a bottom plate and a front plug to form a liquid cooling plate. Subsequently, before welding the liquid cooling plate to the left plate and / or the right plate, a plug is inserted into the communication port left on the side of the liquid cooling plate, so that a portion of the plug extends into the communication port to form an extending portion, and the remaining portion is located outside the communication port to form an extending portion. At the same time, a set distance is maintained between the upper surface of the extending portion and the upper surface of the liquid cooling plate, and / or a set distance is maintained between the lower surface of the extending portion and the lower surface of the liquid cooling plate. Then, arc welding is used to weld the surrounding side surfaces of the extending portion to the side surfaces of the liquid cooling plate to form a circle of plug welds to seal the communication port. Correspondingly, it is necessary to pre-process an avoidance groove on the left plate and / or right plate to avoid the protruding part and the plug block weld; then the left plate and the right plate are aligned with the liquid cooling plate respectively, and the liquid cooling plate is welded and fixed to the left plate and the right plate by using stir friction welding, and the thickness of the plug block weld in the up and down directions is controlled so that its thickness is greater than the height of the stirring head of the stir friction welding, thereby avoiding the plug block weld from being completely destroyed by the stirring head of the stir friction welding; at the same time, by controlling the width of the plug block weld in the left and right directions so that its width is less than the weld width of the stir friction welding, the weld of the stir friction welding can cover the plug block weld and the edge of the liquid cooling plate and the left plate or the right plate.

[0016] The beneficial effect of the technical solution of the above-mentioned battery box manufacturing method is that: a plug is inserted into the connecting port, and an extended portion is left outside the connecting port, and the distance between the upper surface of the extended portion and the upper surface of the liquid cooling plate can ensure that there is sufficient space for the plug weld to be formed here. Similarly, the distance between the lower surface of the extended portion and the lower surface of the liquid cooling plate can ensure that there is also sufficient space for the plug weld to be formed here, and the thickness of the plug weld in the vertical direction is greater than the height of the stirring head of the stir friction welding, so that when the liquid cooling plate and the left plate and / or the right plate are subsequently welded by stir friction welding, , the plug weld will not be completely destroyed, thereby ensuring that the sealing effect of the plug weld on the connecting port is not destroyed, thereby ensuring that the coolant will not leak, and the sealing effect is better; and setting an avoidance groove on the left plate and / or the right plate in advance can ensure that the left plate and / or the right plate are aligned with the liquid cooling plate, and at the same time, the width of the plug weld in the left and right directions is smaller than the weld width of the friction stir welding, so that the weld of the friction stir welding can cover the plug weld and the edge of the liquid cooling plate and the left plate or the right plate, and successfully complete the welding and fixation between the liquid cooling plate and the left plate or the right plate.

[0017] Furthermore, in order to facilitate the installation of the plug, a stopper edge that cooperates with the side stopper of the liquid cooling plate is provided on the protruding portion of the plug when the plug is manufactured, so as to control the insertion degree of the plug.

[0018] Furthermore, in order to facilitate the processing and manufacturing of the plug, and at the same time leave sufficient space for the plug weld to form between the upper and lower surfaces of the protruding part and the side of the liquid cooling plate, when manufacturing the plug, the plug is processed into a T shape, so that the stop edge is located at the front and rear ends of the protruding part, and the upper and lower surfaces of the protruding part are flush with the upper and lower surfaces of the protruding part, respectively, thereby leaving sufficient space for the plug weld to form between the upper and lower surfaces of the protruding part and the side of the liquid cooling plate.

[0019] Furthermore, in order to facilitate the installation of the plug, when manufacturing the plug, a guiding inclined surface is processed at the end of the extending portion to facilitate the plugging of the plug into the communicating port.

[0020] Furthermore, in order to ensure the welding seal between the bottom plate and the rear side plate, and to avoid the sealing effect being destroyed by the subsequent stir friction welding, before the liquid cooling plate is welded to the left and right plates, the bottom plate and the rear side plate are first welded and fixed, and the left and right ends of the rear part of the bottom plate are respectively processed in advance to form a corner groove between the corner and the rear side plate, and then the corner and the rear side plate are welded and fixed by arc welding to form a corner weld in the corner groove, and the length of the corner weld in the up and down directions is controlled to be greater than the height of the stirring head of the stir friction welding to avoid the corner weld being completely destroyed by the stirring head of the stir friction welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural diagram of a battery box in the prior art;

[0022] Figure 2 for Figure 1 Structural diagram of the center front plug;

[0023] Figure 3 for Figure 1 Structural diagram of the midsole plate;

[0024] Figure 4 It is a three-dimensional structural diagram of the battery box in the present invention;

[0025] Figure 5 A top view of the battery box of the present invention;

[0026] Figure 6 for Figure 5 A partial enlarged view of the

[0027] Figure 7 This is a diagram of the battery box in the present invention after the bottom plate is welded to the front plug and the rear side plate (no repair welding is done at this time);

[0028] Figure 8 for Figure 7 Enlarged view of point A in the middle;

[0029] Figure 9 for Figure 8Structural diagram of the middle plug;

[0030] Figure 10 for Figure 7 Enlarged view of point B in the middle;

[0031] Figure 11 This is a state diagram of the battery box of the present invention after the bottom plate is welded to the front plug and the rear side plate (repair welding completed);

[0032] Figure 12 for Figure 11 Enlarged view of point C in the middle;

[0033] Figure 13 for Figure 11 Enlarged view of point D in the middle.

[0034] In the figure: 1. Bottom plate; 1-1. Flow channel; 2. Front side plate; 3. Rear side plate; 4. Left side plate; 5. Right side plate; 6. Water nozzle; 7. Front plug; 71. Boss; 72. Flow channel groove; 8. Left side plate; 9. Rear side plate; 10. Right side plate; 11. Bottom plate; 12. Water nozzle; 13. Front plug; 14. Front side plate; 15. Friction stir welding seam; 16. Plug weld; 17. Plug; 171. Guide slope; 172. Stop edge; 18. Connecting port; 19. Angle groove; 20. Angle weld. DETAILED DESCRIPTION

[0035] An embodiment of the battery box of the present invention is as follows Figure 4 and Figure 5 As shown, it includes a liquid cooling plate at the bottom and a left side plate 8, a right side plate 10, a front side plate 14, and a rear side plate 9 welded around the liquid cooling plate. The liquid cooling plate is an assembly, including a bottom plate 11 and a front plug 13 welded together by friction stir welding. The front plug 13 is welded to the front side of the bottom plate 11. The liquid cooling plate and the left side plate 8, the right side plate 10, and the rear side plate 9 are all fixed by friction stir welding, and the friction stir welding seam 15 formed is shown as follows. Figure 5 shown.

[0036] The bottom plate 11 is provided with a flow channel for the coolant to flow ( Figures 4 to 13 Not shown), the left and right ends of the front plug 13 are respectively provided with flow channel grooves ( Figures 4 to 13 (not shown), two flow channels are connected to the nozzle 12 respectively, one of which is for external coolant to flow into the bottom plate 11, and the other is for the coolant in the bottom plate 11 to flow out of the liquid cooling plate. Specifically, the structure of the bottom plate 11 and the front plug 13 in this embodiment is the same as that of the bottom plate and the front plug in the prior art (for details, refer to Figures 1 to 3), therefore, after the bottom plate 11 and the front plug 13 are welded and fixed, a connecting port 18 connected to the flow channel in the bottom plate 11 will be left on the side of each flow channel groove at the junction with the bottom plate 11. The rest of the structure is the same as the prior art and will not be repeated in this embodiment.

[0037] The difference is that a plug 17 for blocking the communication port 18 is provided at the communication port 18, such as Figure 8 and Figure 9 As shown, the plug is T-shaped, with a portion extending into the communication port to form an inserting portion, and the remaining portion located outside the communication port to form an extending portion. Stop edges 172 are provided at the front and rear ends of the extending portion to engage with the side stops of the liquid cooling plate. This allows the insertion depth of the plug to be controlled, facilitating installation of the plug 17. Furthermore, to facilitate insertion of the plug into the communication port, a guiding slope 171 is provided at the end of the extending portion.

[0038] The upper and lower surfaces of the protruding portion are flush with the upper and lower surfaces of the protruding portion, respectively. Thus, when the plug is inserted into the connecting port 18, a certain distance is formed between the upper surface of the protruding portion and the upper surface of the liquid cooling plate. This distance ensures that there is sufficient space for the plug weld to be formed. Similarly, a certain distance is formed between the lower surface of the protruding portion and the lower surface of the liquid cooling plate. This distance also ensures that there is sufficient space for the plug weld to be formed. The surrounding side surfaces of the protruding portion and the side surfaces of the liquid cooling plate are fixed by arc welding to form a circle of plug welds 16, as shown in FIG. Figure 11 and Figure 12 As shown, the plug weld 16 completely seals the communication port 18 to ensure that the coolant does not leak, and the sealing effect is relatively good.

[0039] Since the plug 17 has a protruding portion and there is a plug weld around the protruding portion, in order to ensure that the left plate 8 and the right plate 10 can be aligned with the liquid cooling plate, avoidance grooves are provided on the left plate 8 and the right plate 10, such as Figure 6 shown.

[0040] Since both the left side plate 8 and the right side plate 10 are welded to the liquid cooling plate by friction stir welding, that is, the stirring head of the friction stir welding will be inserted into the joint between the liquid cooling plate and the left side plate 8 or the right side plate 10, in order to prevent the stirring head from completely destroying the welded plug weld 16 during movement, thereby affecting the sealing effect, it is necessary to control the thickness of the plug weld 16 in the vertical direction during the formation process. Specifically, while ensuring that the plug weld 16 on the upper side of the protruding portion is flush with the upper surface of the liquid cooling plate as much as possible, it is also necessary to ensure that its thickness is greater than the height of the stirring head. In this way, even if the stirring head passes through the position of the upper plug weld 16, it will not completely destroy the plug weld 16, thereby maintaining the sealing of the connecting port 18.

[0041] Similarly, since the liquid cooling plate and the upper and lower surfaces of the left and right plates 8 and 10 all require friction stir welding, while ensuring that the plug weld 16 on the lower side of the extension is flush with the lower surface of the liquid cooling plate as much as possible, it is also necessary to ensure that its thickness is greater than the height of the stirring head. This ensures that even if the stirring head passes through the position of the lower plug weld 16, it will not completely destroy the plug weld 16, thereby maintaining the sealing of the connecting port 18. In addition, the vertical length of the plug welds 16 on the left and right sides of the extension is equal to the thickness of the liquid cooling plate (obviously, the vertical thickness is much greater than the height of the stirring head). As long as the upper and lower plug welds are not completely destroyed, the left and right plug welds can also ensure the sealing of the connecting port 18.

[0042] In order to ensure that the liquid cooling plate can be welded and fixed to the left plate 8 or the right plate 10, it is also necessary to control the width of the plug weld 16 in the left and right directions, that is, to control the width of the protruding portion in the left and right directions, to ensure that its width is smaller than the width of the friction stir welding seam 15, so that the friction stir welding seam 15 can cover the plug weld 16 and the edge of the liquid cooling plate and the left plate 8 or the right plate 10, as shown in FIG. Figure 6 shown.

[0043] In this embodiment, the rear end of the bottom plate 11 is closed, and the bottom plate 11 and the rear side plate 9 are in end-to-end contact. When welding, a stir friction welding process is required on the upper and lower surfaces of the bottom plate 11 and the rear side plate 9, respectively. This achieves a seal on the upper and lower sides where the bottom plate 11 and the rear side plate 9 are in contact. In order to further ensure the sealing of the battery box, it is necessary to also achieve a seal on the left and right sides where the bottom plate 11 and the rear side plate 9 are in contact. To this end, a cut corner is provided at the left and right ends of the rear portion of the bottom plate 11, and a corner groove 19 is formed between the cut corner and the rear side plate 9. The cut corner and the rear side plate 9 are fixed by arc welding to form a fillet weld 20 in the corner groove 19. Figure 13 shown.

[0044] Since friction stir welding will be performed between the liquid cooling plate and the left plate 8 and the right plate 10 later, in order to prevent the fillet weld 20 from being completely destroyed by the stirring head of the friction stir welding and to ensure that the sealing effect is not affected, it is necessary to control the length of the fillet weld 20 in the up and down directions to ensure that its length is greater than the height of the stirring head. In this way, even if the stirring head passes through the position of the fillet weld 20, the fillet weld 20 will not be completely destroyed.

[0045] The manufacturing method of the battery case is as follows:

[0046] Reference Figures 4 to 13As shown, when manufacturing the battery case, it is necessary to provide a flow channel within the base plate 11 and machine two flow channel grooves within the front plug 13. To facilitate friction stir welding between the base plate 11 and the front plug 13, filler blocks need to be inserted into the flow channel grooves before welding. Therefore, a connecting port 18 connecting to the flow channel within the base plate must be provided on the side of the flow channel groove where it meets the base plate. In this embodiment, there are two connecting ports 18. In addition, two T-shaped plugs 17 need to be machined, and an avoidance groove needs to be machined into both the left plate 8 and the right plate 10. Furthermore, it is necessary to machine corner cuts on the left and right ends of the rear portion of the base plate.

[0047] After the preparation work is done, the following is the welding order of the battery box:

[0048] First, the front side panel 14 and the front plug 13 can be welded together. Then, the front plug 13 and the bottom panel 11 can be welded together using friction stir welding. During this process, a filler block needs to be inserted into the communication port 18 to prevent deformation of the front plug 13. The filler block is removed after welding. Then, the bottom panel 11 and the rear side panel 9 are welded together using friction stir welding. It should be noted that both the top and bottom surfaces of the front plug 13 and the bottom panel 11, and the bottom panel 11 and the rear side panel 9 need to be welded.

[0049] Then start the repair welding operation. First, insert the processed T-shaped plug 17 into the connecting port 18. It should be noted here that the plug 17 is different from the filling block used before. The length of the filling block extending into the connecting port 18 is relatively long, and the flow channel groove needs to be completely filled to avoid deformation of the front plug, while the extending part of the plug 17 is relatively short to avoid affecting the normal circulation of the coolant.

[0050] After the plug 17 is installed, since friction stir welding cannot be used around the plug, arc welding (either electric arc welding or argon arc welding) is used to weld the surrounding sides of the plug's protruding portion to the side of the liquid cooling plate, forming a ring of plug welds 16 to seal the connection. The parameters of the plug welds 16 must be controlled. The plug welds on the upper and lower sides of the protruding portion are flush with the upper and lower surfaces of the liquid cooling plate, respectively, and their vertical thickness must be greater than the height of the friction stir welding head. The vertical length of the plug welds on the left and right sides of the protruding portion is equal to the thickness of the liquid cooling plate (which, of course, is also much greater than the height of the stirring head). Furthermore, the width of the plug welds 16 in the left and right directions must be controlled to be less than the width of the friction stir welding seam 15.

[0051] Then, the corner groove 19 formed between the cut corner of the bottom plate 11 and the rear side plate 9 is repaired by welding, and a corner weld 20 is formed in the corner groove 19 by arc welding (which can be electric arc welding or argon arc welding). Here, the length of the corner weld 20 in the vertical direction needs to be controlled to be greater than the height of the stirring head of the stir friction welding.

[0052] After repair welding at all four locations on the bottom plate 11, align the right side plate 10 with the liquid cooling plate. Friction stir welding is then performed along the seam between the right side plate 10 and the liquid cooling plate to secure the right side plate 10 to the liquid cooling plate. This ensures that the plug weld 16 is covered while also protecting the plug weld 16 and the fillet weld 20, thus ensuring a secure seal. It should be noted that welding is required on both the top and bottom surfaces of the right side plate 10 and the liquid cooling plate.

[0053] Finally, the bottom plate 11 and the left side plate 8 are welded and fixed in the same manner as the right side plate 10, thereby completing the welding operation of the box body.

[0054] In other embodiments of the battery case and the battery case manufacturing method, the bottom plate may be welded to the left side plate first and then to the right side plate; the bottom plate may be welded to the rear side plate first and then to the front plug; the bottom plate may be welded to the front plug first and then to the front side plate.

[0055] In other embodiments of the battery case and the battery case manufacturing method, the left and right ends of the rear portion of the bottom plate may not be processed and cut corners, and in this case, there is no need to perform fillet weld repair operations.

[0056] In other embodiments of the battery case and the method for manufacturing the battery case, when manufacturing the plug, the end of the plug's protruding portion may not be processed with a guide slope.

[0057] In other embodiments of the battery case and the battery case manufacturing method, when manufacturing the plug, stop edges can also be set at the four upper, lower, front and rear ends of the plug. At this time, it is necessary to ensure that there is sufficient distance between the upper stop edge and the upper surface of the liquid cooling plate, and between the lower stop edge and the lower surface of the liquid cooling plate to form a plug weld that meets the requirements.

[0058] In other embodiments of the battery case and the battery case manufacturing method, when manufacturing the plug, the stopper edge may not be provided on the plug, for example, the plug is a rectangular or cube-shaped plug.

[0059] In other embodiments of the battery case and the battery case manufacturing method, a connecting port can be provided on only one of the flow channel sides of the left end flow channel or the right end flow channel, and the other side is closed. In this case, only one plug needs to be prepared. Of course, in this case, only an avoidance groove needs to be provided on one of the side panels of the left plate or the right plate. In addition, in this case, only the side panel with the avoidance groove and the liquid cooling plate need to be fixed by stir friction welding, while the other side panel does not have an avoidance groove, and there is no connecting port and plug on the corresponding side of the liquid cooling plate. There is no need to consider whether the plug weld will be destroyed by the stirring head. Therefore, stir friction welding, argon arc welding or brazing can be used between the side panel and the liquid cooling plate.

[0060] In other embodiments of the battery case and the battery case manufacturing method, when the thickness of the liquid cooling plate is large enough, if the connecting port is relatively high, it is only necessary to ensure that there is a set distance between the upper surface of the protruding portion of the plug and the upper surface of the liquid cooling plate, that is, to ensure that the thickness of the upper plug weld meets the requirements. Since the distance between the lower surface of the protruding portion and the lower surface of the liquid cooling plate is relatively large, the stirring head will not contact the lower plug weld at all. At this time, there is no need to consider the distance between the lower surface of the protruding portion and the lower surface of the liquid cooling plate, that is, there is no need to consider Consider the thickness of the lower plug weld; of course, when the thickness of the liquid cooling plate is large enough and the connecting port is relatively low, it is only necessary to ensure that there is a set distance between the lower surface of the protruding part of the plug and the lower surface of the liquid cooling plate, that is, to ensure that the thickness of the lower plug weld meets the requirements. Since the distance between the upper surface of the protruding part and the upper surface of the liquid cooling plate is relatively large, the stirring head will not contact the upper plug weld at all. At this time, there is no need to consider the distance between the upper surface of the protruding part and the upper surface of the liquid cooling plate, that is, there is no need to consider the thickness of the upper plug weld.

[0061] In other embodiments of the battery case and the battery case manufacturing method, argon arc welding or brazing may also be used between the liquid cooling plate and the front plug and the rear side plate.

Claims

1. A battery case, comprising a liquid cooling plate and a left side plate, a right side plate, a front side plate, and a rear side plate respectively welded to the liquid cooling plate, the liquid cooling plate comprising a bottom plate and a front plug welded to the front side of the bottom plate, a flow channel for cooling liquid to flow within the bottom plate being provided within the bottom plate, and flow channel grooves communicating with the flow channel within the bottom plate being provided at the left and right ends of the front plug, one of the two flow channel grooves being provided for external cooling liquid to flow into the bottom plate, and the other for cooling liquid within the bottom plate to flow out of the liquid cooling plate, and a communication port communicating with the flow channel within the bottom plate being provided on the side surface of the junction portion of at least one flow channel groove with the bottom plate, characterized in that: A plug for sealing the connecting port is provided at the connecting port, the plug having an extending portion extending into the connecting port and a protruding portion located outside the connecting port, a set distance between the upper surface of the protruding portion and the upper surface of the liquid cooling plate, and / or a set distance between the lower surface of the protruding portion and the lower surface of the liquid cooling plate, the surrounding side surfaces of the protruding portion and the side surfaces of the liquid cooling plate are fixed by arc welding to form a circle of plug welds and seal the connecting port, and an avoidance groove for avoiding the protruding portion and the plug weld is provided on the left plate and / or the right plate, the liquid cooling plate and the left plate and / or the right plate are fixed by friction stir welding, the thickness of the plug weld in the up and down direction is greater than the height of the stirring head of the friction stir welding to avoid the plug weld being completely destroyed by the stirring head of the friction stir welding, and the width of the plug weld in the left and right directions is less than the weld width of the friction stir welding, so that the weld of the friction stir welding can cover the plug weld and the edge of the liquid cooling plate and the left plate or the right plate.

2. The battery box according to claim 1, characterized in that: The protruding portion of the plug is provided with a stop edge which cooperates with the side surface of the liquid cooling plate.

3. The battery case according to claim 2, wherein: The plug is T-shaped, has two stopping edges and is respectively located at the front and rear ends of the protruding part, and the upper and lower surfaces of the protruding part are respectively flush with the upper and lower surfaces of the protruding part.

4. The battery case according to any one of claims 1 to 3, characterized in that: The end of the extending portion is provided with a guiding inclined surface for facilitating the plugging of the plug into the communicating port.

5. The battery case according to any one of claims 1 to 3, characterized in that: Cut corners are provided at the left and right ends of the rear part of the bottom plate respectively, and a corner groove is formed between the cut corners and the rear side plate. The cut corners and the rear side plate are fixed by arc welding to form a corner weld in the corner groove. The length of the corner weld in the up and down direction is greater than the height of the stirring head of the stir friction welding to avoid the corner weld being completely destroyed by the stirring head of the stir friction welding.

6. A method for manufacturing a battery box, characterized in that: The method comprises the steps of welding and fixing the bottom plate and the front plug to form a liquid cooling plate, and then before welding the liquid cooling plate to the left plate and / or the right plate, first inserting a plug into the communication port left on the side of the liquid cooling plate, so that a part of the plug is inserted into the communication port to form an inserting portion, and the remaining part is located outside the communication port to form an extending portion, and at the same time, a set distance is set between the upper surface of the extending portion and the upper surface of the liquid cooling plate, and / or a set distance is set between the lower surface of the extending portion and the lower surface of the liquid cooling plate; then arc welding is used to weld and fix the surrounding side surface of the extending portion to the side surface of the liquid cooling plate to form a circle of plug weld to seal the communication port, and the corresponding needs An avoidance groove for avoiding the protruding part and the plug block weld is processed in advance on the left plate and / or the right plate; then the left plate and the right plate are aligned with the liquid cooling plate respectively, and the liquid cooling plate is welded and fixed to the left plate and the right plate by using stir friction welding, and the thickness of the plug block weld in the up and down directions is controlled so that its thickness is greater than the height of the stirring head of the stir friction welding, thereby avoiding the plug block weld from being completely destroyed by the stirring head of the stir friction welding; at the same time, the width of the plug block weld in the left and right directions is controlled so that its width is less than the weld width of the stir friction welding, so that the weld of the stir friction welding can cover the plug block weld and the edge of the liquid cooling plate and the left plate or the right plate.

7. The method for manufacturing a battery case according to claim 6, wherein: When manufacturing the plug, a stopper edge is provided on the protruding portion of the plug to cooperate with the side stopper of the liquid cooling plate to control the insertion degree of the plug.

8. The method for manufacturing a battery case according to claim 7, wherein: When manufacturing the plug, the plug is processed into a T shape, so that the stop edge is located at the front and rear ends of the protruding part, and the upper and lower surfaces of the protruding part are flush with the upper and lower surfaces of the protruding part, respectively, so as to leave sufficient space for the plug weld to form between the upper and lower surfaces of the protruding part and the side of the liquid cooling plate.

9. The method for manufacturing a battery case according to any one of claims 6 to 8, wherein: When manufacturing the plug, a guiding slope is machined at the end of the protruding portion to facilitate the plug to be inserted into the communicating port.

10. The method for manufacturing a battery case according to any one of claims 6 to 8, wherein: Before welding the liquid cooling plate to the left and right plates, the bottom plate and the rear side plate are first welded and fixed, and the left and right ends of the rear part of the bottom plate are respectively cut in advance to form a corner groove between the cut corner and the rear side plate. Then, the cut corner and the rear side plate are welded and fixed by arc welding to form a fillet weld in the corner groove. The length of the fillet weld in the vertical direction is controlled to be greater than the height of the stirring head of the stir friction welding to avoid the fillet weld being completely destroyed by the stirring head of the stir friction welding.

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