A welding fixture and a method of welding bipolar plates

Abstract

The application discloses a welding tool and a welding method of a bipolar plate. The welding tool comprises a first pressing plate, a second pressing plate and a bottom plate. The first pressing plate and the second pressing plate are respectively provided with a plurality of first through holes and a plurality of second through holes which are distributed along the circumference of the welding tool. The projections of the first through holes on the bottom plate and the projections of the second through holes on the bottom plate are alternately arranged along the circumference of the welding tool in the height direction of the welding tool, and the end portions of adjacent projections overlap. When the first pressing plate is matched with the bottom plate, a welding device forms a first weld on a component to be welded. When the second pressing plate is matched with the bottom plate, the welding device forms a second weld on the component to be welded. Along the circumference of the welding tool, the two ends of the second weld are at least respectively overlapped on the end portions of adjacent two first welds to form an annular closed weld for sealing the outer edge of the component to be welded. The heat input during laser welding is dispersed, the adverse effects such as uneven thermal deformation are inhibited, and the welding quality and controllability are improved.

Description

Technical Field

[0001] The present application relates to the technical field of welding equipment, and in particular to a welding tool and a welding method for bipolar plates. Background Art

[0002] As a core component of fuel cells, bipolar plates primarily provide structural support and safety isolation, placing high demands on their structural strength and sealing performance. Prior art typically uses laser welding to securely connect two plates together. However, during laser welding, the weld seam can become too long, preventing the laser energy from maintaining stability throughout the entire weld. This can cause fluctuations in the molten pool temperature, leading to poor weld formation (e.g., uneven surfaces, irregular ripples, etc.), and ultimately, poor weld quality. Summary of the Invention

[0003] In view of this, the present application provides a welding tool and a welding method for bipolar plates to solve the technical problem of poor weld formation when welding long welds in the prior art.

[0004] The present application provides a welding tool for welding components to be welded, and the welding tool includes an upper tool and a lower tool; the upper tool includes a first pressure plate and a second pressure plate, the first pressure plate is provided with a plurality of first through holes, and the second pressure plate is provided with a plurality of second through holes, and the plurality of first through holes and the plurality of second through holes are all distributed at intervals along the circumference of the welding tool; the lower tool includes a bottom plate, and along the height direction of the welding tool, the projections of the first through holes on the bottom plate and the projections of the second through holes on the bottom plate are alternately arranged along the circumference of the welding tool, and the ends of adjacent projections overlap.

[0005] Among them, when the first pressure plate is matched with the base plate, the first through-hole guides the welding equipment to form a first weld on the component to be welded, and when the second pressure plate is matched with the base plate, the second through-hole guides the welding equipment to form a second weld on the component to be welded, and along the circumference of the welding tooling, the two ends of the second weld are at least respectively overlapped with the ends of the two adjacent first welds to form an annular closed weld for sealing the outer edge of the component to be welded.

[0006] In the embodiment of the present application, the first pressure plate and the second pressure plate are sequentially matched with the base plate, so that the welding equipment can perform segmented laser welding processing on the assembly to be welded, so that the first weld and the second weld formed on the assembly to be welded are both short welds, so that the long weld can be formed by connecting multiple short welds, so as to effectively disperse the heat input during laser welding and significantly suppress adverse effects such as uneven thermal deformation during laser welding. Furthermore, while ensuring that each first weld and each second weld are connected to form an annular closed weld, the welding quality and controllability of the annular closed weld can be improved, so that it has good sealing reliability, which is conducive to improving the production yield of bipolar plates.

[0007] In a possible embodiment, the first pressure plate includes a first pressure block and multiple first protective devices. Along the circumference of the welding tool, the multiple first protective devices are spaced apart on the outside of the first pressure block, and a first through hole is provided between the first pressure block and the first protective devices.

[0008] The second pressing plate includes a second pressing block and a plurality of second protection devices. Along the circumference of the welding tool, the plurality of second protection devices are spaced apart on the outside of the second pressing block, and a second through hole is provided between the second pressing block and the second protection devices.

[0009] In a possible embodiment, a side wall of each pressing block facing each protective device is provided with an exhaust surface, the exhaust surface is inclined relative to the top surface of the pressing block, and a first angle α is formed between the exhaust surface and the top surface of the pressing block, and α satisfies 30°≤α<60°.

[0010] In a possible embodiment, a side wall of the pressing block facing the protective device is further provided with a stepped surface, and the exhaust surface is connected to the top surface of the pressing block via the stepped surface.

[0011] In one possible embodiment, each protective device is provided with an air intake channel and a first exhaust channel, the first exhaust channel is connected to the air intake channel, and the first exhaust channel is inclined relative to the surface of the component to be welded, and there is a second angle β between the first exhaust channel and the surface of the component to be welded, and β satisfies 30°≤β<60°.

[0012] In a possible embodiment, the protective device is further provided with a second exhaust channel, which is connected to the air inlet channel. Along the height direction of the welding tooling, the second exhaust channel is located on the side of the first exhaust channel away from the component to be welded, and the second exhaust channel is arranged parallel to the surface of the component to be welded.

[0013] In a possible embodiment, the protection device is further provided with an air accommodating cavity and an air delivery channel that are interconnected, the other end of the air accommodating cavity is connected to the air inlet channel, and the other end of the air delivery channel is respectively connected to the first exhaust channel and the second exhaust channel.

[0014] Among them, along the transmission direction of the protective gas, the flow cross-sectional area of ​​the gas containing cavity is S1, the flow cross-sectional area of ​​the gas transmission channel is S2, the flow cross-sectional area of ​​the first exhaust channel is S3, and the flow cross-sectional area of ​​the second exhaust channel is S4, and S1, S2, S3, and S4 meet at least one of the following conditions: S1>S2, S2>S3, S2>S4, S3≥S4.

[0015] In a possible embodiment, the protection device also includes a diverter block, which is installed at the outlet of the gas transmission channel. The diverter block is provided with a sharp corner on the side facing the gas chamber. The angle of the sharp corner is γ, and γ satisfies 30°≤γ<60°.

[0016] In a possible embodiment, the first pressure plate is further provided with a plurality of third through holes, and the plurality of third through holes and the plurality of first through holes are alternately arranged and spaced apart along the circumference of the welding tooling, and along the height direction of the welding tooling, the projections of the third through holes on the base plate and the projections of the second through holes on the base plate are distributed along the length direction and width direction of the welding tooling, and the ends of adjacent projections overlap.

[0017] When the first pressure plate is matched with the base plate, the third through hole guides the welding equipment to form a third weld on the component to be welded, and along the length and width directions of the welding tooling, the two ends of the second weld overlap with the two ends of the adjacent third weld respectively to form an annular closed weld for sealing the cavity area of ​​the component to be welded.

[0018] In a possible embodiment, the first pressure plate also includes a first pressure block, multiple first protective devices and multiple third protective devices. Along the circumference of the welding tooling, the multiple third protective devices are alternately arranged with the multiple first protective devices and are spaced apart on the outside of the first pressure block. There is a third through hole between the first pressure block and the third protective device.

[0019] In a possible embodiment, the bottom plate is provided with a groove, and along the height direction of the welding tool, the projections of the first through hole, the second through hole, and the third through hole are located within the projection range of the groove.

[0020] In one possible embodiment, the base plate is provided with a welding area for placing the components to be welded, and the base plate is also provided with a slide groove. Along the circumference of the welding tool, multiple slide grooves are spaced apart on the outside of the welding area. The welding tool also includes a slider, which slides along the extension direction of the slide groove to limit the movement of the components to be welded along the length and width directions of the welding tool.

[0021] The present application also provides a bipolar plate welding method, wherein the welding tool as described in any one of the above items is used to weld the assembly to be welded, and the welding method comprises:

[0022] Place the components to be welded on the base plate.

[0023] Mate the first pressure plate with the bottom plate.

[0024] The component to be welded is welded through the first through hole to form a first weld.

[0025] Mate the second pressure plate with the bottom plate.

[0026] The component to be welded is welded through the second through hole to form a second weld.

[0027] Wherein, along the circumference of the welding tool, both ends of the second weld are respectively overlapped with the ends of at least two adjacent first welds to form an annular closed weld for sealing the outer edge of the assembly to be welded.

[0028] In an embodiment of the present application, after the components to be welded are stacked and placed on the base plate, the first pressure plate and the base plate are controlled to clamp the components to be welded along the height direction of the welding tooling, so that the welding equipment processes a first weld on the components to be welded through the first pressure plate. After multiple first welds are processed, the first pressure plate is separated from the base plate, and the second pressure plate and the base plate are controlled to clamp the components to be welded along the height direction of the welding tooling, so that the welding equipment processes a second weld on the components to be welded through the second pressure plate. In the process of laser welding the components to be welded by the welding equipment through the second pressure plate, the two ends of the second weld can be respectively overlapped with the ends of two adjacent first welds, so that the first welds and the second welds alternately arranged along the circumference of the welding tooling are connected to form an annular closed weld for sealing the outer edge of the bipolar plate.

[0029] Through such a design, the welding equipment can use a segmented processing method to perform laser welding on the assembly to be welded. Not only can the time for replacing the tooling (i.e., the time for the first pressure plate and the second pressure plate to replace each other) be used to dissipate the heat of the pre-formed weld to reduce the possibility of overall heat input accumulation, but the first through holes and the second through holes distributed at intervals can also be used to shorten the processing time of the welding equipment for each first weld and each second weld, so as to avoid the accumulation of heat input in each weld while ensuring that the length of each weld is short, thereby reducing the possibility of long welds in the process of laser welding the assembly to be welded, avoiding the risk of uneven thermal deformation of the assembly to be welded due to heat input accumulation, and reducing the possibility of warping of the assembly to be welded during laser welding, which is beneficial to improving the welding quality of the first weld and the second weld, so as to ensure the sealing reliability of the annular closed weld, improve the production yield of the bipolar plate, and better meet actual production needs.

[0030] In a possible implementation, during the process of welding the component to be welded through the first through hole to form the first weld, the welding method further includes:

[0031] The component to be welded is welded through the third through hole to form a third weld.

[0032] Wherein, along the length direction and width direction of the welding tool, the two ends of the second weld are overlapped with the two ends of the adjacent third weld respectively to form an annular closed weld for sealing the cavity area of ​​the component to be welded.

[0033] In a possible implementation, before the first pressing plate is mated with the bottom plate, the welding method further includes:

[0034] The components to be welded are clamped by the slider to limit the movement of the components to be welded along the length and width directions of the welding tooling.

[0035] It should be understood that the foregoing general description and the following detailed description are merely illustrative and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0037] Figure 1 This is an exploded view of an embodiment of the welding tool provided in this application;

[0038] Figure 2 This is a schematic diagram of the specific structure of the first pressing plate provided in this application in one embodiment;

[0039] Figure 3 yes Figure 2 A partial enlarged view of

[0040] Figure 4 This is a schematic diagram of the specific structure of the second pressing plate provided in this application in one embodiment;

[0041] Figure 5 This is a schematic diagram of the specific structure of the base plate provided in this application in one embodiment;

[0042] Figure 6 is a cross-sectional view of an embodiment of the protection device provided by the present application;

[0043] Figure 7 This is a schematic diagram of the specific structure of the slider provided in this application in one embodiment;

[0044] Figure 8 Schematic diagram of the structure of the bipolar plate provided in this application in one embodiment.

[0045] Description of reference numerals:

[0046] 1- Put on work clothes

[0047] 11- first pressing plate;

[0048] 111-first through hole;

[0049] 112-first pressing block;

[0050] 113-first protection device;

[0051] 114-third through hole;

[0052] 115-third protection device;

[0053] 12- second pressing plate;

[0054] 121- second through hole;

[0055] 122-second pressing block;

[0056] 123-Second protection device;

[0057] 2-Lower work clothes

[0058] 21- bottom plate;

[0059] 211-welding area;

[0060] 212-groove;

[0061] 213-chute;

[0062] 3- Bipolar plates;

[0063] 31-first weld;

[0064] 32- second weld;

[0065] 33-third weld;

[0066] 41-exhaust surface;

[0067] 42-stepped surface;

[0068] 51-intake passage;

[0069] 52-first exhaust passage;

[0070] 53- second exhaust passage;

[0071] 54-air chamber;

[0072] 55-gas transmission channel;

[0073] 56- diverter block;

[0074] 6- Slider;

[0075] 7-Welding equipment.

[0076] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. DETAILED DESCRIPTION

[0077] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0078] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0079] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0080] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0081] The embodiment of the present application provides a welding tool for welding components to be welded, such as Figure 1 and Figure 8 As shown, the welding tool includes an upper tool 1 and a lower tool 2 distributed along its height direction, and the component to be welded is located between the upper tool 1 and the lower tool 2, so that the welding tool can clamp the component to be welded along its height direction for welding processing.

[0082] Optionally, the assembly to be welded may be two monopolar plates stacked along the height direction of the welding tool, so as to be welded into a bipolar plate 3 by laser welding.

[0083] Specifically, if Figure 1 、 Figure 2 and Figure 4 As shown, the upper tooling 1 includes a first pressing plate 11 and a second pressing plate 12. The first pressing plate 11 is provided with a plurality of first through holes 111, and the second pressing plate 12 is provided with a plurality of second through holes 121. The plurality of first through holes 111 and the plurality of second through holes 121 are distributed at intervals along the circumference of the welding tooling.

[0084] Specifically, if Figure 1 and Figure 5 As shown, the lower tooling 2 includes a bottom plate 21 , and along the height direction of the welding tooling, the projection of the first through hole 111 on the bottom plate 21 and the projection of the second through hole 121 on the bottom plate 21 are staggered along the circumference of the welding tooling.

[0085] Among them, such as Figure 6As shown, when the first pressure plate 11 cooperates with the base plate 21, the first through hole 111 guides the welding equipment 7 to form a first weld 31 on the assembly to be welded, and when the second pressure plate 12 cooperates with the base plate 21, the second through hole 121 guides the welding equipment 7 to form a second weld 32 on the assembly to be welded, and along the circumference of the welding tooling, the two ends of the second weld 32 are at least respectively overlapped with the ends of the two adjacent first welds 31 to form an annular closed weld for sealing the outer edge of the assembly to be welded.

[0086] In the embodiment of the present application, the upper tooling 1 includes a first pressing plate 11 and a second pressing plate 12, and the lower tooling 2 includes a base plate 21. During the process of laser welding the assembly to be welded by the welding equipment 7, the first pressing plate 11 and the second pressing plate 12 can cooperate with the base plate 21 in sequence (i.e., clamp the assembly to be welded along the height direction of the welding tooling), so that the welding equipment 7 can first process the first weld 31 on the assembly to be welded through the first pressing plate 11, and then process the second weld 32 on the assembly to be welded through the second pressing plate 12, so that the welding equipment 7 can process multiple short welds (i.e., the first weld 31 and the second weld 32) on the assembly to be welded in batches, and connect the two adjacent short welds end to end to form a long weld (i.e., an annular closed weld) for sealing the outer edge of the bipolar plate 3.

[0087] Through such a design, the welding equipment 7 can use a segmented processing method to perform laser welding on the assembly to be welded. Not only can the time for replacing the tooling 1 (i.e., the time for the first pressure plate 11 and the second pressure plate 12 to replace each other) be used to dissipate the heat of the previously formed weld to reduce the possibility of overall heat input accumulation, but the first through holes 111 and the second through holes 121 distributed at intervals can also be used to shorten the processing time of the welding equipment 7 for each first weld 31 and each second weld 32, so as to avoid heat input accumulation in each weld while ensuring that the length of each weld is short, thereby reducing the possibility of long welds in the process of laser welding the assembly to be welded, avoiding the risk of uneven thermal deformation of the assembly to be welded due to heat input accumulation, and reducing the possibility of warping of the assembly to be welded during laser welding, which is beneficial to improving the welding quality of the first weld 31 and the second weld 32, so as to ensure the sealing reliability of the annular closed weld, improve the production yield of the bipolar plate 3, and better meet actual production needs.

[0088] It should be noted that during the laser welding process of the assembly to be welded by the welding device 7, the first pressing plate 11 can be first engaged with the base plate 21, and then the second pressing plate 12 can be engaged with the base plate 21, or the second pressing plate 12 can be first engaged with the base plate 21, and then the first pressing plate 11 can be engaged with the base plate 21. This application does not impose any restrictions on this. The following description will be based on the order in which the first pressing plate 11 is engaged with the base plate 21 first, and the second pressing plate 12 is engaged with the base plate 21 later.

[0089] Specifically, the first pressing plate 11 is provided with a plurality of first through holes 111 spaced apart along the circumference of the welding tool. During the laser welding process of the welding device 7 on the assembly to be welded, the first through holes 111 can guide the welding device 7 to form a plurality of first welds 31 on the assembly to be welded, and the plurality of first welds 31 can be spaced apart along the circumference of the welding tool.

[0090] This design approach allows the length of the first weld 31 to be constrained by the size of the first through-hole 111, which helps improve the control accuracy of the length of the first weld 31 and reduces the possibility of the first weld 31 being too long, resulting in a long weld. Furthermore, by distributing the welds 31 at intervals along the circumference of the welding tool, the risk of adjacent first welds 31 connecting in a molten state to form a long weld can be avoided, further reducing the possibility of warping of the first weld 31 during laser welding, improving the welding quality and controllability of the first weld 31, and thus increasing the pass rate of the first weld 31. In the subsequent laser welding process, the first weld 31 can form a high-quality annular closed weld together with the second weld 32, ensuring the overall sealing reliability of the bipolar plate 3 and improving the production yield of the bipolar plate 3.

[0091] Specifically, the second pressing plate 12 is provided with a plurality of second through holes 121 spaced apart along the circumference of the welding tool. During the process of laser welding the assembly to be welded by the welding device 7, the second through holes 121 are used to guide the welding device 7 to form a plurality of second welds 32 on the assembly to be welded, and to enable the plurality of second welds 32 to be spaced apart along the circumference of the welding tool.

[0092] This design approach allows the length of the second weld 32 to be constrained by the size of the second through-hole 121, which helps improve the control accuracy of the length of the second weld 32, reduces the possibility of the second weld 32 being too long and interfering with other areas, and reduces the possibility of the second weld 32 being too short and unable to connect two adjacent first welds 31, thereby improving the connection reliability between adjacent first welds 31 and second welds 32. Furthermore, by distributing the welds at intervals along the circumference of the welding fixture, each first weld 31 and each second weld 32 can be interconnected along the circumference of the welding fixture to form the required annular closed weld. This further improves the welding quality and controllability of the annular closed weld, ensuring good sealing reliability, and thus further improving the production yield of the bipolar plate 3.

[0093] In the height direction of the welding fixture, the projections of the first through holes 111 on the bottom plate 21 and the projections of the second through holes 121 on the bottom plate 21 are alternately arranged along the circumference of the welding fixture, and the ends of adjacent projections overlap.

[0094] This design allows the projections of the first through-holes 111 and the second through-holes 121 on the base plate 21 to be arranged alternately along both the length and width of the welding fixture, ensuring that each subsequent first weld 31 and each second weld 32 can be connected end-to-end along the circumference of the welding fixture to form an annular closed weld, which helps reduce the difficulty of processing the annular closed welds in batches. Furthermore, by arranging the overlapping ends of adjacent projected portions, the two ends of the second weld 32 can be accurately overlapped with the ends of the adjacent first weld 31, which helps improve the forming efficiency of the annular closed weld and the processing efficiency of the assembly to be welded.

[0095] At the same time, the upper tooling 1 is configured as the first pressing plate 11 and the second pressing plate 12 , so that the structure of each pressing plate is relatively simplified, which is beneficial to reducing the overall processing difficulty of the upper tooling 1 and the subsequent maintenance cost.

[0096] Therefore, in this embodiment, the first pressing plate 11 and the second pressing plate 12 are matched with the bottom plate 21 in sequence, so that the welding equipment 7 can use segmented laser welding processing on the assembly to be welded, so that the first weld 31 and the second weld 32 formed on the assembly to be welded are both short welds, so that a long weld can be formed by connecting multiple short welds, so as to effectively disperse the heat input during laser welding and significantly suppress adverse effects such as uneven thermal deformation during laser welding. Furthermore, while ensuring that each first weld 31 and each second weld 32 are connected to form an annular closed weld, the welding quality and controllability of the annular closed weld can be improved, so that it has good sealing reliability, which is conducive to improving the production yield of the bipolar plate 3.

[0097] In a specific embodiment, Figure 2 、 Figure 3 、 Figure 6 and Figure 8 As shown, the first pressure plate 11 is also provided with a plurality of third through holes 114, and the plurality of third through holes 114 and the plurality of first through holes 111 are alternately arranged and spaced apart along the circumference of the welding tooling, and along the height direction of the welding tooling, the projections of the third through holes 114 on the bottom plate 21 and the projections of the second through holes 121 on the bottom plate 21 are distributed along the length direction and width direction of the welding tooling, and the ends of adjacent projections overlap.

[0098] When the first pressure plate 11 is matched with the base plate 21, the third through hole 114 guides the welding equipment 7 to form a third weld 33 on the component to be welded, and along the length and width directions of the welding tooling, the two ends of the second weld 32 are overlapped with the two ends of the adjacent third weld 33 respectively to form an annular closed weld for sealing the cavity area of ​​the component to be welded.

[0099] In the embodiment of the present application, the first pressing plate 11 is further provided with a plurality of third through holes 114 spaced apart along the circumference of the welding tool. During the laser welding process of the welding device 7 on the assembly to be welded, the third through holes 114 can guide the welding device 7 to form a plurality of third welds 33 on the assembly to be welded, and enable the plurality of third welds 33 to be spaced apart along the rearward direction of the welding tool.

[0100] This design approach allows the shape and size of the third weld 33 to be constrained by the shape and size of the third through-hole 114, facilitating improved control over the shape, structure, and length of the third weld 33. This reduces the likelihood of large shape errors in the third weld 33, preventing it from joining with the second weld 32 and the first weld 31 to form a closed annular weld for sealing the orifice of the bipolar plate 3. It also reduces the likelihood of the third weld 33 being too long, resulting in a long weld. Furthermore, by alternating and spacing the third welds 33 with the first through-holes 111 along the circumference of the welding tool, the risk of adjacent third welds 33 and first welds 31 prematurely joining in the molten state to form a long weld is avoided. This further reduces the likelihood of warping of the third weld 33 during laser welding, improving the weld quality and controllability of the third weld 33, and thereby increasing the pass rate of the third weld 33. This allows the third weld 33 to form a high-quality closed annular weld in the subsequent laser welding process, together with the second weld 32 and the first weld 31, ensuring the sealing reliability of the orifice of the bipolar plate 3 and increasing the production yield of the bipolar plate 3.

[0101] Meanwhile, along the height direction of the welding tool, the projection of the third through hole 114 on the bottom plate 21 and the projection of the second through hole 121 on the bottom plate 21 are distributed along the length direction and width direction of the welding tool, and the ends of adjacent projections overlap.

[0102] This design allows the projections of the third through-holes 114 and the second through-holes 121 on the base plate 21 to be distributed both along the length and width of the welding fixture. Furthermore, the projections of the third through-holes 114 and the first through-holes 111 on the base plate 21 are spaced apart circumferentially along the welding fixture, ensuring that the second weld 32 can subsequently connect the two adjacent first welds 31 and the third weld 33 simultaneously, thereby forming an annular closed weld for sealing the orifice area of ​​the bipolar plate 3. This helps reduce the difficulty of processing this annular closed weld during batch processing. Furthermore, by arranging for the ends of adjacent projected portions to overlap, the ends of the second weld 32 can accurately overlap both the ends of the two adjacent first welds 31 and the ends of the adjacent third weld 33, improving the efficiency of forming the annular closed weld and the processing efficiency of the welded assembly.

[0103] In a possible embodiment, along the height direction of the welding tool, the first through hole 111 and the second through hole 121 are projected onto the assembly to be welded in a straight line shape, and the third through hole 114 is projected onto the assembly to be welded in a trapezoidal, rectangular or C-shaped shape.

[0104] In a possible embodiment, the length of the first weld 31 is L1, and L1 satisfies 5cm≤L1≤10cm, and can be specifically 5cm, 5.2cm, 5.4cm, 5.6cm, 5.8cm, 6cm, 6.2cm, 6.4cm, 6.6cm, 6.8cm, 7cm, 7.2cm, 7.4cm, 7.6cm, 7.8cm, 8cm, 8.2cm, 8.4cm, 8.6cm, 8.8cm, 9cm, 9.2cm, 9.4cm, 9.6cm, 9.8cm, 10cm, etc.

[0105] In a possible embodiment, the length of the second weld 32 is L2, and L2 satisfies 5cm≤L2≤10cm, and can be specifically 5cm, 5.1cm, 5.3cm, 5.5cm, 5.7cm, 5.9cm, 6.1cm, 6.3cm, 6.5cm, 6.7cm, 6.9cm, 7.1cm, 7.3cm, 7.5cm, 7.7cm, 7.9cm, 8.1cm, 8.3cm, 8.5cm, 8.7cm, 8.9cm, 9.1cm, 9.3cm, 9.5cm, 9.7cm, 9.9cm, 10cm, etc.

[0106] In a possible embodiment, the length of the third weld 33 is L3, and L3 satisfies 5cm≤L3≤10cm, and can be specifically 5cm, 5.1cm, 5.2cm, 5.3cm, 5.4cm, 5.5cm, 5.6cm, 5.7cm, 5.8cm, 5.9cm, 6cm, 6.1cm, 6.2cm, 6.3cm, 6.4cm, 6.5cm, 6.6cm, 6.7cm, 6.8cm, 6.9cm, 7cm, 7.1cm, 7.2cm, 7.3cm, 7.4cm, 7.5cm, 7.6cm, 7.7cm, 7.8cm, 7.9cm, 7.1cm, 7.1cm m, 7.2cm, 7.3cm, 7.4cm, 7.5cm, 7.6cm, 7.7cm, 7.8cm, 7.9cm, 8cm, 8.1cm, 8.2cm, 8.3cm, 8.4cm, 8.5cm, 8.6cm, 8.7cm, 8.8cm, 8.9cm, 9cm, 9.1cm, 9.2cm, 9.3cm, 9.4cm, 9.5cm, 9.6cm, 9.7cm, 9.8cm, 9.9cm, 10cm, etc.

[0107] In a specific embodiment, Figure 2As shown, the first pressing plate 11 includes a first pressing block 112 and multiple first protective devices 113. Along the circumference of the welding tool, multiple first protective devices 113 are spaced apart on the outside of the first pressing block 112, and a first through hole 111 is provided between the first pressing block 112 and the first protective devices 113.

[0108] In the embodiment of the present application, the first pressure block 112 is located at the center of the first pressure plate 11 along the length and width directions of the welding tool, and is used to clamp the component to be welded with the base plate 21 along the height direction of the welding tool, so that the welding tool can provide a uniform and stable clamping force to the component to be welded, ensuring that the component to be welded fits tightly with the welding tool, thereby reducing the possibility of displacement, cold welding and other adverse phenomena during the laser welding process, which is beneficial to improving the welding accuracy and welding quality of the first weld 31.

[0109] At the same time, along the length and width directions of the welding tooling, multiple first protection devices 113 are located on the side of the first pressure block 112 facing the edge of the first pressure plate 11 and are distributed at intervals along the circumference of the welding tooling, so that a first through hole 111 can be provided between each first protection device 113 and the first pressure block 112, so that each first protection device 113 can transport protective gas to the first through hole 111 adjacent to it during the laser welding process, so as to achieve a more precise and concentrated delivery effect of the protective gas, which is not only conducive to reducing the waste of protective gas and reducing production costs, but also conducive to shortening the time for the protective gas to flow into each first through hole 111, ensuring that the concentration of the protective gas in each first through hole 111 is sufficient, so as to better isolate the air and avoid the risk of defects such as oxidation and pores after the first weld 31 is formed, thereby improving the strength, density and aesthetics of the first weld 31.

[0110] In a specific embodiment, Figure 4 As shown, the second pressing plate 12 includes a second pressing block 122 and multiple second protective devices 123. Along the circumference of the welding tool, multiple second protective devices 123 are spaced apart on the outside of the second pressing block 122, and a second through hole 121 is provided between the second pressing block 122 and the second protective devices 123.

[0111] In the embodiment of the present application, the second pressure block 122 is located at the center of the second pressure plate 12 along the length and width directions of the welding tool, and is used to clamp the component to be welded with the base plate 21 along the height direction of the welding tool, so that the welding tool can provide a uniform and stable clamping force to the component to be welded, ensuring that the component to be welded fits tightly with the welding tool, thereby reducing the possibility of displacement, cold welding and other adverse phenomena during the laser welding process, which is beneficial to improving the welding accuracy and welding quality of the second weld 32.

[0112] At the same time, along the length and width directions of the welding tooling, multiple second protection devices 123 are located on the side of the second pressure block 122 facing the edge of the second pressure plate 12 and are distributed at intervals along the circumference of the welding tooling, so that a second through hole 121 can be provided between each second protection device 123 and the second pressure block 122, so that each second protection device 123 can transport protective gas to the second through hole 121 adjacent to it during the laser welding process, so as to achieve a more precise and concentrated delivery effect of the protective gas, which is not only conducive to reducing the waste of protective gas and reducing production costs, but also conducive to shortening the time for the protective gas to flow into each second through hole 121, ensuring that the concentration of the protective gas in each second through hole 121 is sufficient, so as to better isolate the air and avoid the risk of defects such as oxidation and the generation of pores after the second weld 32 is formed, thereby improving the strength, density and aesthetics of the second weld 32.

[0113] In a specific embodiment, Figure 2 and Figure 3 As shown, the first pressure plate 11 also includes a plurality of first protection devices 113 and a plurality of third protection devices 115. Along the circumference of the welding tooling, the plurality of third protection devices 115 are alternately arranged with the plurality of first protection devices 113 and are spaced apart on the outside of the first pressure block 112. There is a third through hole 114 between the first pressure block 112 and the third protection device 115.

[0114] In the embodiment of the present application, along the length and width directions of the welding tooling, multiple third protection devices 115 are located on the side of the first pressure block 112 facing the edge of the first pressure plate 11 and are distributed at intervals along the circumference of the welding tooling, so that a third through hole 114 can be provided between each third protection device 115 and the first pressure block 112, so that each third protection device 115 can transport protective gas to the third through hole 114 adjacent to it during the laser welding process, so as to achieve a more precise and concentrated delivery effect of the protective gas, which is not only conducive to reducing the waste of protective gas and reducing production costs, but also conducive to shortening the time for the protective gas to flow into each third through hole 114, ensuring that the concentration of the protective gas in each third through hole 114 is sufficient, so as to better isolate the air and avoid the risk of defects such as oxidation and the generation of pores after the third weld 33 is formed, thereby improving the strength, density and aesthetics of the third weld 33.

[0115] In one possible embodiment, the first protective device 113 is detachably connected to the first pressure plate 11, the second protective device 123 is detachably connected to the second pressure plate 12, and the third protective device 115 is detachably connected to the first pressure plate 11. Through such a design approach, a modular design between the protective devices and the pressure plates can be achieved, so as to further simplify the structure of each pressure plate, which is conducive to reducing the overall processing difficulty and manufacturing cost of the upper tooling 1. Moreover, when the protective device is damaged due to long-term use or welding spatter, the protective device can be replaced separately, thereby eliminating the need to replace the entire pressure plate, which is conducive to reducing maintenance costs and shortening the downtime of the welding tooling, thereby helping to improve overall production efficiency and better meet actual production needs.

[0116] In one possible implementation, Figure 6 As shown, each pressing block has a side wall facing each protective device provided with an exhaust surface 41, which is inclined relative to the top surface of the pressing block. There is a first angle α between the exhaust surface 41 and the top surface of the pressing block, and α satisfies 30°≤α<60°.

[0117] In the embodiment of the present application, along the length direction and width direction of the welding tooling, the side wall of the first pressure block 112 facing the first protective device 113 is provided with an exhaust surface 41, and the exhaust surface 41 is inclined relative to the top surface of the first pressure block 112, and has a first angle α with the top surface of the first pressure block 112; the side wall of the second pressure block 122 facing the second protective device 123 is provided with an exhaust surface 41, and the exhaust surface 41 is inclined relative to the top surface of the second pressure block 122, and has a first angle α with the top surface of the second pressure block 122; the side wall of the first pressure block 112 facing the third protective device 115 is provided with an exhaust surface 41, and the exhaust surface 41 is inclined relative to the top surface of the first pressure block 112, and has a first angle α with the top surface of the first pressure block 112.

[0118] Among them, by setting an inclined exhaust surface 41, the metal vapor and welding smoke generated during the laser welding process can be effectively and smoothly discharged out of the through hole, so as to avoid the risk of metal vapor and welding smoke being retained inside the through hole and causing interference with the laser energy transmission, thereby ensuring the quality of the weld and reducing the possibility of contamination, thereby improving the processing quality of the components to be welded and improving the production yield of the bipolar plate 3.

[0119] At the same time, the first angle between the exhaust surface 41 and the top surface of the pressing block can be 30°, 32°, 34°, 36°, 38°, 40°, 42°, 44°, 46°, 48°, 50°, 52°, 54°, 56°, 58°, etc.

[0120] When the first angle between the exhaust surface 41 and the top surface of the pressing block is too small (for example, α is less than 30°), the flow direction of the metal vapor and welding smoke is close to the vertical direction, so that the two stay in the through hole for too long, which makes the energy transmission of the laser easily affected.

[0121] When the first angle between the exhaust surface 41 and the top surface of the pressing block is too large (for example, α is greater than 60°), the flow direction of the metal vapor and welding smoke is close to the horizontal direction, making it easy for the two to contaminate the weld, resulting in the protection effect of the shielding gas on the weld being affected.

[0122] Therefore, when the first angle between the exhaust surface 41 and the top surface of the pressing block satisfies 30°≤α<60°, the flow direction of the metal vapor and welding smoke is inclined relative to the horizontal direction and the vertical direction, so that the two can be pushed by the protective gas. They can not only quickly flow out of the through hole to reduce the obstruction of the laser, but also be separated from the weld to reduce the contamination of the weld, which is beneficial to improve the reliability of laser welding and ensure the processing quality of the weld.

[0123] In a specific embodiment, Figure 6 As shown, the side wall of the pressing block facing the protection device is further provided with a stepped surface 42 , and the exhaust surface 41 is connected to the top surface of the pressing block via the stepped surface 42 .

[0124] In the embodiment of the present application, along the length and width directions of the welding tooling, the side wall of the first pressure block 112 facing the first protective device 113 is further provided with a stepped surface 42, and its exhaust surface 41 is connected to the top surface of the first pressure block 112 through the stepped surface 42; the side wall of the second pressure block 122 facing the second protective device 123 is further provided with a stepped surface 42, and its exhaust surface 41 is connected to the top surface of the second pressure block 122 through the stepped surface 42; the side wall of the first pressure block 112 facing the third protective device 115 is further provided with a stepped surface 42, and its exhaust surface 41 is connected to the top surface of the first pressure block 112 through the stepped surface 42.

[0125] Through such a design, metal vapor and welding smoke can flow into the stepped surface 42 under the guidance of the exhaust surface 41, so as to reduce the possibility of backflow of metal vapor and welding smoke, ensure the reliability of laser welding, and reduce the overall weight of the pressing block, thereby achieving the purpose of lightweighting the upper tooling 1, which is conducive to reducing the overall production cost of the upper tooling 1.

[0126] In a specific embodiment, Figure 6As shown, each protective device is provided with an air intake channel 51 and a first exhaust channel 52. The first exhaust channel 52 is connected to the air intake channel 51, and the first exhaust channel 52 is inclined relative to the surface of the component to be welded. There is a second angle β between the first exhaust channel 52 and the surface of the component to be welded, and β satisfies 30°≤β<60°.

[0127] In the embodiment of the present application, the first protection device 113, the second protection device 123 and the third protection device 115 are all provided with an interconnected air intake channel 51 and a first exhaust channel 52, so that the protective gas can flow into the interior of the protection device through the air intake channel 51 and flow to the weld through the first exhaust channel 52, so as to blow the spatter, metal vapor and welding smoke generated during the laser welding process away from the surface of the molten pool, thereby reducing the damage caused by the spatter to the surface of the component to be welded, and reducing the possibility of metal vapor and welding smoke contaminating the molten pool and causing defects such as pores after the weld is formed. It can also avoid the risk of poor weld quality due to the laser being blocked, which is beneficial to improving the processing quality of the weld.

[0128] Among them, by setting the first exhaust channel 52 to be inclined relative to the surface of the component to be welded, the shielding gas can be blown toward the molten pool at a preset angle to form a directional flow air curtain, so that the shielding gas can be delivered to the surface of the molten pool more accurately and more concentratedly, so as to effectively blow away the spatter, metal vapor and welding smoke, thereby ensuring that the surface is flat after the weld is formed, and avoiding the risk of accumulation of metal vapor and welding smoke inside the through hole, which is beneficial to improving the stability of the weld formation, optimizing the forming shape of the weld, and ensuring that the annular closed weld has good sealing reliability.

[0129] The second angle between the first exhaust channel 52 and the surface of the component to be welded can be 30°, 31°, 33°, 35°, 37°, 39°, 41°, 43°, 45°, 47°, 49°, 51°, 53°, 55°, 57°, 59°, etc.

[0130] When the second angle between the first exhaust channel 52 and the surface of the component to be welded is too small (for example, β is less than 30°), the flow direction of the shielding gas is close to the horizontal direction, so that the shielding gas cannot effectively disperse the metal vapor and welding smoke diffusing toward the welding equipment 7, causing the metal vapor and welding smoke to easily accumulate inside the through hole to block the laser, thereby affecting the stability and reliability of laser welding, and further resulting in poor processing quality of the weld.

[0131] When the second angle between the first exhaust channel 52 and the surface of the component to be welded is too large (for example, β is greater than 60°), the flow direction of the shielding gas is close to the vertical direction, so that the shielding gas will impact the surface of the molten pool at a higher flow rate, which is not only likely to cause defects such as dents on the surface after the weld is formed, but also likely to generate a large amount of spatter, resulting in an increased loss rate.

[0132] Therefore, when the second angle between the first exhaust channel 52 and the surface of the component to be welded satisfies 30°≤β<60°, the flow direction of the shielding gas is inclined relative to both the horizontal and vertical directions, so that the shielding gas can cover the molten pool to provide effective protection while also dispersing metal vapor and welding smoke from the inside of the through hole to ensure the stability and reliability of laser welding. The angle at which the shielding gas flows to the molten pool is relatively gentle and is not prone to large impacts, thereby reducing losses caused by spattering and thereby reducing overall production costs.

[0133] In a specific embodiment, Figure 6 As shown, the protective device is also provided with a second exhaust channel 53, which is connected to the air inlet channel 51. Along the height direction of the welding tooling, the second exhaust channel 53 is located on the side of the first exhaust channel 52 away from the component to be welded, and the second exhaust channel 53 is arranged parallel to the surface of the component to be welded.

[0134] In the embodiment of the present application, the first protection device 113, the second protection device 123 and the third protection device 115 are all provided with a second exhaust channel 53 connected to the air inlet channel 51 and arranged in parallel with the first exhaust channel 52, so that after the protective gas flows into the interior of the protection device through the air inlet channel 51, a part of it flows to the weld through the first exhaust channel 52, which is used to provide protection for the molten pool and avoid the adverse effects of spatter, metal vapor and welding smoke on it, and the other part flows to the exhaust surface 41 through the second exhaust channel 53, which is used to blow spatter, metal vapor and welding smoke onto the exhaust surface 41, so that the spatter can drip on the exhaust surface 41, and the metal vapor and welding smoke can flow out of the through hole along the extension direction of the exhaust surface 41, so as to further reduce the damage caused by spatter to the surface of the component to be welded, and further improve the diffusion efficiency of metal vapor and welding smoke, thereby improving the safety and reliability of the laser welding process, which is conducive to improving the processing quality of the weld.

[0135] Among them, by setting the second exhaust channel 53 parallel to the surface of the component to be welded, the protective gas can flow into the through hole in a horizontal direction, so that the sputtering splashes and the upwardly diffused metal vapor and welding smoke can be blown onto the exhaust surface 41 at a higher flow rate, so as to cooperate with the first exhaust channel 52 to form double protection for the weld, which is conducive to further improving the safety and stability of the molten pool during the laser welding process, and thus can ensure that the weld has good processing quality after formation, which is more in line with actual production needs.

[0136] In a specific embodiment, Figure 6 As shown, the protective device is further provided with an air accommodating cavity 54 and an air delivery channel 55 that are connected to each other. The other end of the air accommodating cavity 54 is connected to the air inlet channel 51, and the other end of the air delivery channel 55 is connected to the first exhaust channel 52 and the second exhaust channel 53 respectively.

[0137] Among them, along the transmission direction of the protective gas, the flow cross-sectional area of ​​the gas containing cavity 54 is S1, the flow cross-sectional area of ​​the gas transmission channel 55 is S2, the flow cross-sectional area of ​​the first exhaust channel 52 is S3, and the flow cross-sectional area of ​​the second exhaust channel 53 is S4, and S1, S2, S3, and S4 satisfy at least one of the following conditions: S1>S2, S2>S3, S2>S4, S3≥S4.

[0138] In the embodiment of the present application, the first protection device 113, the second protection device 123 and the third protection device 115 are all provided with an air storage cavity 54 and an air delivery channel 55 that are interconnected, so that the protective gas first flows into the air storage cavity 54 through the air inlet channel 51, and then the protective gas is guided to the through hole through the air delivery channel 55, and the protective gas is diverted at the outlet of the air delivery channel 55, so that part of the protective gas flows to the weld through the first exhaust channel 52, and the other part of the protective gas flows to the exhaust surface 41 through the second exhaust channel 53.

[0139] Specifically, along the transmission direction of the shielding gas, the flow cross-sectional area of ​​the gas chamber 54 can be larger than the flow cross-sectional area of ​​the gas transmission channel 55, so as to increase the flow rate of the shielding gas and improve the transmission efficiency of the shielding gas in the protection device, so that it can flow out of the protection device in a shorter time, which is conducive to improving the response speed of the protection device and ensuring the safety and reliability during the laser welding process.

[0140] Specifically, along the transmission direction of the shielding gas, the flow cross-sectional area of ​​the gas delivery channel 55 can be larger than the flow cross-sectional area of ​​the first exhaust channel 52, so that after the shielding gas is diverted, the flow rate of the shielding gas flowing to the weld can be further improved, which is conducive to further improving the transmission efficiency of the shielding gas, so that the shielding gas can continuously flow to the molten pool and cover its surface to isolate the air and reduce the possibility of the weld being oxidized or producing surface defects such as pores. At the same time, the shielding gas can also continuously purge the metal vapor and welding smoke around the molten pool to avoid contamination of the molten pool and ensure the processing quality of the weld.

[0141] Specifically, along the transmission direction of the shielding gas, the flow cross-sectional area of ​​the gas delivery channel 55 can be larger than the flow cross-sectional area of ​​the second exhaust channel 53, so that after the shielding gas is diverted, the flow rate of the shielding gas flowing to the exhaust surface 41 can be further improved, which is conducive to further improving the transmission efficiency of the shielding gas, so that the shielding gas can be continuously blown toward the exhaust surface 41 to blow the splashes onto the exhaust surface 41, reducing the possibility of splashes dripping on the component to be welded and causing damage to its surface, and blowing the metal vapor and welding smoke that block the laser onto the exhaust surface 41, so that they can flow out of the through hole along the extension direction of the exhaust surface 41, thereby improving the diffusion efficiency of the metal vapor and welding smoke, thereby ensuring the safety and reliability of the laser welding process and improving the processing quality of the weld.

[0142] In a possible implementation, along the height direction of the welding tool, the gas supply channel 55 may be arranged in parallel with the second exhaust channel 53 .

[0143] Specifically, the flow cross-sectional area of ​​the first exhaust channel 52 can be larger than the flow cross-sectional area of ​​the second exhaust channel 53, so that most of the diverted shielding gas flows to the weld, so as to further improve the safety and reliability of the molten pool during the laser welding process. Alternatively, the flow cross-sectional area of ​​the first exhaust channel 52 can be equal to the flow cross-sectional area of ​​the second exhaust channel 53, so as to improve the uniformity of the shielding gas diversion, thereby ensuring that the molten pool solidifies smoothly to form a weld while reducing the shielding effect of spatter, metal vapor and welding smoke on the laser, thereby ensuring the safety and reliability of the weld during the processing process, so as to improve the forming quality of the weld.

[0144] In a specific embodiment, Figure 6 As shown, the protection device also includes a diverter block 56, which is installed at the outlet of the gas transmission channel 55. The diverter block 56 is provided with a sharp corner (not marked in the figure) on the side facing the gas chamber 54. The angle of the sharp corner is γ, and γ satisfies 30°≤γ<60°.

[0145] In an embodiment of the present application, a diverter block 56 is provided at the outlet of the gas delivery channel 55 of the first protection device 113, the second protection device 123 and the third protection device 115, which is used to divert the protective gas flowing to the through hole, so that part of the protective gas can flow to the weld through the first exhaust channel 52, and the other part of the protective gas can flow to the exhaust surface 41 through the second exhaust channel 53.

[0146] Among them, the diverter block 56 is provided with a sharp corner on the side facing the gas chamber 54, so that the incoming shielding gas can be separated along the side wall of the sharp corner, thereby reducing the possibility of turbulence of the shielding gas at the outlet of the gas transmission channel 55, and further improving the smoothness of the diversion when the shielding gas has a higher flow rate, so as to reduce the energy loss of the shielding gas during the transmission process, so that the shielding gas after diversion can be blown to the surface of the weld and the exhaust surface 41.

[0147] At the same time, the angle of the pointed corner can be 30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, 55°, 56°, 57°, 58°, 59°, etc.

[0148] In a possible implementation, along the height direction of the welding tool, the cross-sectional shape of the diverter block 56 may be a right triangle or a right trapezoid.

[0149] In a specific embodiment, Figure 5 and Figure 6 As shown, the bottom plate 21 is provided with a groove 212 , and along the height direction of the welding tool, the projections of the first through hole 111 , the second through hole 121 and the third through hole 114 are located within the projection range of the groove 212 .

[0150] In the embodiment of the present application, during the laser welding of the assembly to be welded by the welding equipment 7, the first weld 31, the second weld 32 and the third weld 33 will be formed in the first through hole 111, the second through hole 121 and the third through hole 114 respectively, so that the projections of the first weld 31, the second weld 32 and the third weld 33 along the height direction of the welding tool are located within the projection range of the groove 212. Therefore, by setting the groove 212 on the bottom plate 21, a gap can be provided between the weld and the bottom plate 21 along the height direction of the welding tool, which is used to provide an accommodating space for the molten pool to deform downward, so as to avoid the risk of the molten pool and the bottom plate 21 adhering to each other, resulting in a fixed connection between the assembly to be welded and the bottom plate 21, thereby reducing the possibility of damage to the bottom plate 21, which is beneficial to reducing the maintenance cost of the lower tooling 2 and extending the service life of the welding tool.

[0151] In a specific embodiment, Figure 5 and Figure 7 As shown, the base plate 21 is provided with a welding area 211 for placing the components to be welded. The base plate 21 is also provided with a slide groove 213. Along the circumference of the welding tool, multiple slide grooves 213 are spaced apart on the outside of the welding area 211. The welding tool also includes a slider 6, which slides along the extension direction of the slide groove 213 to limit the movement of the components to be welded along the length and width directions of the welding tool.

[0152] In the embodiment of the present application, the slider 6 is slidably connected to the base plate 21 through the sliding groove 213 to improve the stability and smoothness of the slider 6 during the sliding process and reduce the difficulty of operation.

[0153] Among them, the slide grooves 213 distributed at intervals along the length direction of the welding tooling all extend along the width direction of the welding tooling, and the slide grooves 213 distributed at intervals along the width direction of the welding tooling all extend along the length direction of the welding tooling, so that each slide groove 213 points to the welding area 211, so that the slider 6 can move toward the direction close to the welding area 211 under the guidance of the slide groove 213 so as to abut against the outer edge of the component to be welded, and can also move toward the direction away from the welding area 211 under the guidance of the slide groove 213 so as to separate from the outer edge of the component to be welded, and then the slider 6 and the slide groove 213 can limit the horizontal movement of the component to be welded, so as to shorten the positioning time of the component to be welded during the placement process and improve the assembly accuracy and assembly efficiency.

[0154] At the same time, in the subsequent process of cooperation between the upper tooling 1 and the lower tooling 2, it can be ensured that the projections of the first through hole 111, the second through hole 121 and the third through hole 114 along the height direction of the welding tooling are all within the projection range of the groove 212, so as to improve the welding accuracy of the welding equipment 7 and improve the overall work efficiency.

[0155] In a possible embodiment, the plurality of slide grooves 213 are symmetrically distributed along the length and width directions of the welding tool relative to the welding area 211 to improve the uniformity of the force applied to the assembly to be welded.

[0156] An embodiment of the present application further provides a bipolar plate welding method, wherein the welding tool as described in any one of the above items is used to weld the assembly to be welded to form a bipolar plate 3, and the welding method includes:

[0157] Stack the components to be welded on the base plate 21; match the first pressing plate 11 with the base plate 21; weld the components to be welded through the first through hole 111 to form a first weld 31; match the second pressing plate 12 with the base plate 21; weld the components to be welded through the second through hole 121 to form a second weld 32.

[0158] Wherein, along the circumference of the welding tool, both ends of the second weld 32 are respectively overlapped with the ends of at least two adjacent first welds 31 to form an annular closed weld for sealing the outer edge of the assembly to be welded.

[0159] In the embodiment of the present application, after the components to be welded are stacked and placed on the base plate 21, the first pressing plate 11 and the base plate 21 are controlled to clamp the components to be welded along the height direction of the welding tooling, so that the welding equipment 7 processes the first weld 31 on the components to be welded through the first pressing plate 11. After the processing of multiple first welds 31 is completed, the first pressing plate 11 and the base plate 21 are separated, and the second pressing plate 12 and the base plate 21 are controlled to clamp the components to be welded along the height direction of the welding tooling, so that the welding equipment 7 processes the second weld 32 on the components to be welded through the second pressing plate 12. In the process of laser welding the components to be welded by the welding equipment 7 through the second pressing plate 12, the two ends of the second weld 32 can be respectively overlapped with the ends of two adjacent first welds 31, so that the first welds 31 and the second welds 32 alternately arranged along the circumference of the welding tooling are connected to form an annular closed weld for sealing the outer edge of the bipolar plate 3.

[0160] Through such a design, the welding equipment 7 can use a segmented processing method to perform laser welding on the assembly to be welded. Not only can the time for replacing the tooling 1 (i.e., the time for the first pressure plate 11 and the second pressure plate 12 to replace each other) be used to dissipate the heat of the previously formed weld to reduce the possibility of overall heat input accumulation, but the first through holes 111 and the second through holes 121 distributed at intervals can also be used to shorten the processing time of the welding equipment 7 for each first weld 31 and each second weld 32, so as to avoid heat input accumulation in each weld while ensuring that the length of each weld is short, thereby reducing the possibility of long welds in the process of laser welding the assembly to be welded, avoiding the risk of uneven thermal deformation of the assembly to be welded due to heat input accumulation, and reducing the possibility of warping of the assembly to be welded during laser welding, which is beneficial to improving the welding quality of the first weld 31 and the second weld 32, so as to ensure the sealing reliability of the annular closed weld, improve the production yield of the bipolar plate 3, and better meet actual production needs.

[0161] In other possible embodiments, after the components to be welded are stacked and placed on the base plate 21, the second pressing plate 12 and the base plate 21 are controlled to clamp the components to be welded along the height direction of the welding tooling, so that the welding equipment 7 processes the second weld 32 on the components to be welded through the second pressing plate 12. After the processing of multiple second welds 32 is completed, the second pressing plate 12 is separated from the base plate 21, and the first pressing plate 11 and the base plate 21 are controlled to clamp the components to be welded along the height direction of the welding tooling, so that the welding equipment 7 processes the first weld 31 on the components to be welded through the first pressing plate 11. In the process of laser welding the components to be welded by the welding equipment 7 through the first pressing plate 11, the two ends of the first weld 31 can be respectively overlapped with the ends of two adjacent second welds 32, so that the first welds 31 and the second welds 32 alternately arranged along the circumference of the welding tooling are connected to form an annular closed weld for sealing the outer edge of the bipolar plate 3.

[0162] In a specific embodiment, during the process of welding the assembly to be welded through the first through hole 111 to form the first weld 31, the welding method further includes:

[0163] The components to be welded are welded through the third through holes 114 to form a third weld 33 .

[0164] In which, along the length and width directions of the welding tool, the two ends of the second weld 32 overlap the two ends of the adjacent third weld 33 respectively to form an annular closed weld for sealing the cavity area of ​​the component to be welded.

[0165] In the embodiment of the present application, since the first pressure plate 11 is also provided with a plurality of third through holes 114 that are spaced apart along the circumference of the welding tool and alternately arranged with the first through holes 111, the welding equipment 7 can process the first weld 31 on the component to be welded through the first pressure plate 11, and can also process the third weld 33 on the component to be welded through the first pressure plate 11, so that the plurality of third welds 33 and the plurality of first welds 31 are alternately arranged and spaced apart along the circumference of the welding tool.

[0166] Through such a design, when the welding equipment 7 processes the second weld 32 on the assembly to be welded through the second pressing plate 12, the two ends of the second weld 32 can be respectively overlapped on the ends of the two adjacent first welds 31, and can also be respectively overlapped on the ends of the third weld 33 adjacent thereto, forming an annular closed weld for sealing the cavity area of ​​the bipolar plate 3, which is beneficial to improving the forming efficiency of the annular closed weld and improving the processing efficiency of the assembly to be welded.

[0167] In a specific embodiment, before the first pressing plate 11 is matched with the bottom plate 21, the welding method further includes:

[0168] The assembly to be welded is clamped by the slider 6 to limit the movement of the assembly to be welded along the length direction and the width direction of the welding tool.

[0169] In the embodiment of the present application, the slider 6 can be slidably connected to the base plate 21 via the slide groove 213, so that the slider 6 can move in a direction close to the welding area 211 under the guidance of the slide groove 213 so as to abut against the outer edge of the component to be welded, and can also move in a direction away from the welding area 211 under the guidance of the slide groove 213 so as to separate from the outer edge of the component to be welded, thereby enabling the slider 6 to limit the horizontal movement of the component to be welded, thereby shortening the positioning time of the component to be welded during the placement process and improving assembly accuracy and assembly efficiency. In addition, during the subsequent cooperation between the upper tooling 1 and the lower tooling 2, it can be ensured that the projections of the first through hole 111, the second through hole 121, and the third through hole 114 along the height direction of the welding tooling are all located within the projection range of the groove 212, thereby improving the welding accuracy of the welding equipment 7 and improving the overall work efficiency.

[0170] The above describes in detail the structure, features and effects of the present application based on the embodiments shown in the drawings. The above is only a preferred embodiment of the present application, but the present application does not limit the scope of implementation to what is shown in the drawings. Any changes made in accordance with the concept of the present application, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the description and drawings, should be within the scope of protection of the present application.

Claims

1. A welding tool for welding components to be welded, characterized in that: The welding tool comprises: An upper tooling, the upper tooling comprising a first pressing plate and a second pressing plate, the first pressing plate being provided with a plurality of first through holes, the second pressing plate being provided with a plurality of second through holes, the plurality of first through holes and the plurality of second through holes being spaced apart along the circumference of the welding tooling; A lower tooling, the lower tooling comprising a bottom plate, wherein along the height direction of the welding tooling, projections of the first through holes on the bottom plate and projections of the second through holes on the bottom plate are alternately arranged along the circumference of the welding tooling, and ends of adjacent projections overlap; Specifically, when the first pressure plate is matched with the base plate, the first through-hole guide welding equipment forms a first weld on the component to be welded; when the second pressure plate is matched with the base plate, the second through-hole guide welding equipment forms a second weld on the component to be welded, and along the circumference of the welding tooling, the two ends of the second weld are at least respectively overlapped with the ends of two adjacent first welds to form an annular closed weld for sealing the outer edge of the component to be welded.

2. The welding tool according to claim 1, characterized in that: The first pressure plate includes a first pressure block and a plurality of first protective devices. Along the circumference of the welding tool, the plurality of first protective devices are distributed at intervals on the outside of the first pressure block, and the first through hole is provided between the first pressure block and the first protective device; the second pressure plate includes a second pressure block and a plurality of second protective devices. Along the circumference of the welding tool, the plurality of second protective devices are distributed at intervals on the outside of the second pressure block, and the second through hole is provided between the second pressure block and the second protective device.

3. The welding tool according to claim 2, characterized in that: The side wall of each pressing block facing each protective device is provided with an exhaust surface, which is inclined relative to the top surface of the pressing block. There is a first angle α between the exhaust surface and the top surface of the pressing block, and α satisfies 30°≤α<60°.

4. The welding tool according to claim 3, characterized in that: A side wall of the pressing block facing the protection device is further provided with a stepped surface, and the exhaust surface is connected to the top surface of the pressing block via the stepped surface.

5. The welding tool according to claim 2, characterized in that: Each protective device is provided with an air intake channel and a first exhaust channel, the first exhaust channel is connected to the air intake channel, and the first exhaust channel is inclined relative to the surface of the component to be welded, and there is a second angle β between the first exhaust channel and the surface of the component to be welded, and β satisfies 30°≤β<60°.

6. The welding tool according to claim 5, characterized in that: The protective device is also provided with a second exhaust channel, which is connected to the air inlet channel. Along the height direction of the welding tooling, the second exhaust channel is located on the side of the first exhaust channel away from the component to be welded, and the second exhaust channel is arranged parallel to the surface of the component to be welded.

7. The welding tool according to claim 6, characterized in that: The protective device is further provided with an air accommodating cavity and an air delivery channel which are communicated with each other, the other end of the air accommodating cavity is communicated with the air inlet channel, and the other end of the air delivery channel is communicated with the first exhaust channel and the second exhaust channel respectively; Among them, along the transmission direction of the protective gas, the flow cross-sectional area of ​​the gas containing cavity is S1, the flow cross-sectional area of ​​the gas transmission channel is S2, the flow cross-sectional area of ​​the first exhaust channel is S3, and the flow cross-sectional area of ​​the second exhaust channel is S4, and S1, S2, S3, and S4 satisfy at least one of the following conditions: S1>S2, S2>S3, S2>S4, S3≥S4.

8. The welding tool according to claim 7, characterized in that: The protection device also includes a diverter block, which is installed at the outlet of the gas transmission channel. The diverter block is provided with a sharp corner on the side facing the gas accommodating cavity. The angle of the sharp corner is γ, and γ satisfies 30°≤γ<60°.

9. The welding tool according to any one of claims 1 to 8, characterized in that: The first pressing plate is further provided with a plurality of third through holes, the plurality of third through holes and the plurality of first through holes being alternately arranged and spaced apart along the circumference of the welding jig, and along the height direction of the welding jig, the projections of the third through holes on the bottom plate and the projections of the second through holes on the bottom plate are distributed along the length direction and the width direction of the welding jig, and the ends of adjacent projections overlap; When the first pressure plate is matched with the base plate, the third through-hole guide welding equipment forms a third weld on the component to be welded, and along the length and width directions of the welding tooling, the two ends of the second weld are overlapped with the two ends of the adjacent third weld to form an annular closed weld for sealing the cavity area of ​​the component to be welded.

10. The welding tool according to claim 9, characterized in that: The first pressure plate also includes a first pressure block, multiple first protective devices and multiple third protective devices. Along the circumference of the welding tooling, the multiple third protective devices and the multiple first protective devices are alternately arranged and spaced apart on the outside of the first pressure block. The third through hole is provided between the first pressure block and the third protective device.

11. The welding tool according to claim 9, characterized in that: The bottom plate is provided with a groove, and along the height direction of the welding tool, the projections of the first through hole, the second through hole and the third through hole are located within the projection range of the groove.

12. The welding tool according to any one of claims 1 to 8, characterized in that: The base plate is provided with a welding area for placing the components to be welded. The base plate is also provided with a slide groove. Along the circumference of the welding tool, multiple slide grooves are spaced apart on the outside of the welding area. The welding tool also includes a slider, which slides along the extension direction of the slide groove to limit the movement of the components to be welded along the length and width directions of the welding tool.

13. A method for welding a bipolar plate, comprising welding the assembly to be welded using the welding tool according to any one of claims 1 to 12, wherein: The welding method comprises: Laying the components to be welded on the bottom plate in a stacked manner; mate the first pressing plate with the bottom plate; Welding the component to be welded through the first through hole to form a first weld; engaging the second pressing plate with the bottom plate; Welding the assembly to be welded through the second through hole to form a second weld; Wherein, along the circumference of the welding tool, both ends of the second weld are respectively overlapped with at least the ends of two adjacent first welds to form an annular closed weld for sealing the outer edge of the assembly to be welded.

14. The welding method according to claim 13, characterized in that: The first pressing plate is further provided with a third through hole. In the process of welding the assembly to be welded through the first through hole to form the first weld, the welding method further includes: Welding the assembly to be welded through the third through hole to form a third weld; Wherein, along the length direction and width direction of the welding tool, the two ends of the second weld are overlapped with the two ends of the adjacent third weld respectively to form an annular closed weld for sealing the cavity area of ​​the component to be welded.

15. The welding method according to claim 13, characterized in that: The bottom plate is further provided with a slide groove, and the welding tool further includes a slider, and the slider slides along the extension direction of the slide groove. Before the first pressing plate is matched with the bottom plate, the welding method further includes: The assembly to be welded is clamped by the slider to limit the movement of the assembly to be welded along the length direction and the width direction of the welding tool.

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