A metal-graphite composite bipolar plate forming device

Abstract

The present invention provides a metal-graphite composite bipolar plate forming device, which solves the technical problem that the stamping forming of the existing bipolar plate forming device easily causes local cracks in graphite, flexible graphite paper and other materials with low plasticity; the forming device is provided with multiple punch assemblies; the punch assembly is provided with a segmented punch, the segmented punch is provided with a micro-protrusion and a first blind hole, the first blind hole is provided with a hole edge, and the first blind hole is installed with a first spring; the upper template is provided with multiple longitudinal through holes spaced from left to right, and each longitudinal through hole is installed with a punch assembly; the segmented punch is slidably connected in the longitudinal through hole; the pad covers the longitudinal through hole, the top end of the pressure rod is provided with a first stop, the pressure rod rod body passes through the second spring and the pad and enters the longitudinal through hole, the bottom end of the pressure rod is provided with a second stop, the second stop is connected to the first spring, and the second stop is stuck in the hole edge; the rod lengths of the multiple pressure rods exposed from the pad are distributed in a stepped manner from left to right; the device can be widely used in the field of precision manufacturing technology of fuel cell bipolar plates.

Description

Technical Field

[0001] The present application relates to the technical field of precision manufacturing of fuel cell bipolar plates, and in particular to a metal-graphite composite bipolar plate forming device. Background Art

[0002] Metal bipolar plates are one of the core components of fuel cells, with their primary functions being to conduct current, distribute gas, and support the cell stack structure. Due to the excellent electrical and thermal conductivity and high mechanical strength of metal materials, metal bipolar plates are increasingly used in fuel cells. However, their manufacturing process is relatively difficult, as complex flow channel structures must be machined onto their surfaces to meet gas distribution and water management requirements. Furthermore, due to the acidic electrolytes and high temperatures found in the fuel cell operating environment, metal bipolar plates are susceptible to corrosion and passivation, impacting their performance and service life. Therefore, improving the molding process and structural design of metal bipolar plates is particularly important.

[0003] The stamping process is the most commonly used method in the manufacture of metal bipolar plates. Its principle is to use a stamping die and a press to apply pressure to the metal sheet to cause it to undergo plastic deformation and form the required flow channel structure and geometric shape. The stamping process has become one of the preferred processes for bipolar plate processing due to its high production efficiency, low cost, and suitability for mass production. However, in the stamping process, multiple microchannels are formed at the same time. The formation of the microchannels requires the workpiece itself to undergo plastic deformation. Strain concentration usually occurs in the lower fillet, resulting in severe thickness thinning, which requires the material to have good plasticity. However, materials such as graphite and flexible graphite paper have almost no plasticity themselves, which can easily lead to local rupture during the stamping process. Summary of the Invention

[0004] The purpose of the present invention is to solve the shortcomings of the above-mentioned technology and provide a metal-graphite composite bipolar plate forming device to ensure that materials such as graphite and flexible graphite paper are intact during the preparation of the metal-graphite composite bipolar plate.

[0005] To this end, the present invention provides a metal-graphite composite bipolar plate forming device, which is provided with an upper mold mechanism and a lower mold mechanism. The upper mold mechanism is provided with an upper mold base plate and an upper mold plate, and micro-protrusions are provided below the lower surface of the upper mold plate; the lower mold mechanism is provided with a lower mold base plate and a lower mold plate, and micro-grooves are provided on the upper surface of the lower base plate. The upper mold plate and the lower mold plate are arranged opposite to each other up and down, and after the mold is closed, the micro-protrusions and micro-grooves match to form a microchannel.

[0006] The forming device is also provided with a stepped punch mechanism, which is provided with a pad and multiple punch assemblies; each punch assembly is provided with a segmented punch, a pressure rod, a first spring, and a second spring; the lower part of the segmented punch is provided with a micro-protrusion, and the upper part of the segmented punch is provided with a first blind hole with an opening facing upward; the opening of the first blind hole is provided with a hole edge extending inward, and a first spring is installed in the first blind hole.

[0007] The upper template is provided with a plurality of longitudinal through holes spaced apart from left to right, and each longitudinal through hole is correspondingly provided with a punch assembly; the segmented punch is arranged in the longitudinal through hole, and the two are slidably connected; the pad covers the longitudinal through hole, and the top end of the pressure rod is provided with a first stop, and the rod body of the pressure rod passes downward through the second spring and the pad and then enters the longitudinal through hole, and the bottom end of the pressure rod is provided with a second stop, and the second stop is connected to the first spring. Under the action of the elastic force of the first spring, the second stop is movably engaged in the edge of the hole.

[0008] The length of the rod body of each pressure rod located between the first stop portion and the pad is distributed in a stepped manner from left to right.

[0009] Preferably, the first spring is a force transmission spring.

[0010] Preferably, the second spring is a compression spring.

[0011] Preferably, the forming device is further provided with a first guide column, both ends of which are respectively connected to the upper mold base plate and the lower mold base plate, and the first guide column is respectively slidably connected through the upper mold base plate, the upper mold plate and the lower mold plate.

[0012] Preferably, the longitudinal through hole of the upper template is a square hole.

[0013] Preferably, the forming device is also provided with a limiting support device, the support device is provided with a limiting support rod, a second blind hole opening downward is provided on the lower surface of the upper template, a third spring is installed in the second blind hole, the bottom end of the limiting support rod is installed on the lower template, and the top end of the limiting support rod is connected to the third spring.

[0014] Preferably, a third stopper is provided at the top end of the position-limiting support rod, the third stopper is connected to the third spring, and the third stopper is slidably connected to the inner wall of the second blind hole.

[0015] Preferably, the third spring is a limit spring.

[0016] The beneficial effects of the present invention are as follows: the present invention provides a metal-graphite composite bipolar plate forming device, which is provided with a stepped punch mechanism, the stepped punch mechanism is provided with a pad and a plurality of punch assemblies, each punch assembly is provided with a pressure rod, and the lengths of the rod bodies of the plurality of pressure rods exposed from the pad are distributed in a stepped manner from left to right. During the mold closing process of the hydraulic press, the plurality of punch assemblies successively descend in the longitudinal through-hole to form the microchannels of the plate workpiece in a sequence from left to right. Throughout the entire process, the formation of the microchannels of the metal-graphite composite bipolar plate relies on the flow of materials such as graphite and flexible graphite paper from the right to the left, rather than the overall stamping deformation of the prior art, which effectively avoids the breakage of materials such as graphite and flexible graphite paper, ensuring that materials such as graphite and flexible graphite paper are intact. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. 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.

[0018] Figure 1 It is a structural schematic diagram of a partial cross-sectional view of the present invention in a mold-opening state;

[0019] Figure 2 for Figure 1 A schematic structural diagram of the enlarged view of part A shown;

[0020] Figure 3 for Figure 1 A schematic structural diagram of an enlarged view of part B shown;

[0021] Figure 4 It is a structural schematic diagram of a partial cross-sectional view of action 1 during the mold closing process of the present invention;

[0022] Figure 5 It is a structural schematic diagram of a partial cross-sectional view of action 2 during the mold closing process of the present invention;

[0023] Figure 6 It is a structural schematic diagram of a partial cross-sectional view of the present invention in a mold closing state.

[0024] Markings in the figure: 1. Upper die base plate, 2. Upper template, 3. Micro protrusion, 4. Lower die base plate, 5. Lower template, 6. Micro groove, 7. Pad, 8. Punch assembly, 9. Segmented punch, 10. Pressure rod, 11. First spring, 12. Second spring, 13. First blind hole, 14. Hole edge, 15. Longitudinal through hole, 16. First stop, 17. Second stop, 18. First guide column, 19. Limit support device, 20. Limit support rod, 21. Second blind hole, 22. Third spring, 23. Third stop, 24. Sheet workpiece. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining this application and are not intended to limit this application. The methods used in this invention are conventional methods unless otherwise specified; the raw materials and devices used are conventional commercially available products unless otherwise specified.

[0026] Depend on Figure 1 、 Figure 2 As shown, the present invention provides a metal-graphite composite bipolar plate forming device, which is provided with an upper mold mechanism and a lower mold mechanism. The upper mold mechanism is provided with an upper mold base plate 1 and an upper mold plate 2, and a micro-protrusion 3 is provided below the lower surface of the upper mold plate 2; the lower mold mechanism is provided with a lower mold base plate 4 and a lower mold plate 5, and a micro-groove 6 is provided on the upper surface of the lower base plate. The upper mold plate 2 and the lower mold plate 5 are arranged opposite to each other up and down. After the mold is closed, the micro-protrusion 3 and the micro-groove 6 are matched to form a microchannel.

[0027] The forming device is also provided with a stepped punch mechanism, which is provided with a pad 7 and multiple punch assemblies 8; each punch assembly 8 is provided with a segmented punch 9, a pressure rod 10, a first spring 11, and a second spring 12. The lower part of the segmented punch 9 is provided with a micro-protrusion 3, and the upper part of the segmented punch 9 is provided with a first blind hole 13 with an opening facing upward. The opening of the first blind hole 13 is provided with a hole edge 14 extending inward, and a first spring 11 is installed in the first blind hole 13.

[0028] The upper template 2 is provided with a plurality of longitudinal through holes 15 spaced apart from left to right, and each longitudinal through hole 15 is correspondingly installed with a punch assembly 8; the segmented punch 9 is arranged in the longitudinal through hole 15, and the two are slidably connected; the pad 7 covers the longitudinal through hole 15, and the top end of the pressure rod 10 is provided with a first stop 16, and the rod body of the pressure rod 10 passes downward through the second spring 12 and the pad 7 and then enters the longitudinal through hole 15, and the bottom end of the pressure rod 10 is provided with a second stop 17, and the second stop 17 is connected to the first spring 11. Under the action of the elastic force of the first spring 11, the second stop 17 is movably engaged in the hole edge 14.

[0029] The lengths of the rods of the plurality of pressure rods 10 exposed from the pad 7 are distributed in a stepped manner from left to right.

[0030] When the present invention is used, the upper die base plate 1 and the lower die base plate 4 are fixed on the hydraulic press respectively, wherein the upper die base plate 1 is fixedly connected to the crossbeam of the hydraulic press, and the lower die base plate 4 is fixed on the base of the hydraulic press. The downward pressure of the upper die base plate 1 is controlled by controlling the displacement of the crossbeam of the hydraulic press; first, the plate workpiece 24 to be formed is placed in the forming area on the lower template 5, and the plate workpiece 24 is the existing metal-graphite composite plate to be formed.

[0031] The specific forming process is as follows: the hydraulic press is started, the upper die base plate 1 moves downward, first touching the first punch assembly 8 on the left, pushing the pressure rod 10 of the punch assembly 8 downward, so that the first spring 11 and the second spring 12 are compressed, driving the segment punch 9 to move downward, and the micro protrusion 3 at the bottom of the segment punch 9 matches the micro groove 6 located directly below it, forming the micro channel of the plate workpiece 24 on the far left, as shown in FIG. Figure 1 、 Figure 2 、 Figure 4 shown.

[0032] As the upper die base plate 1 continues to move downward, it touches the second punch assembly 8 on the left, compressing the second pressure rod 10 on the left to move downward, so that the first spring 11 and the second spring 12 are compressed, driving the segment punch 9 to move downward, causing the sheet workpiece 24 to flow to the left to form the second microchannel on the left, as shown in FIG. Figure 4 、 Figure 5 shown.

[0033] As the upper die plate 1 continues to move downward, the segmented punches 9 of the five punch assemblies 8 form the microchannels from left to right. Finally, the entire upper die plate 2 is driven downward to complete the final mold closing process and prepare the metal graphite composite bipolar plate. Figure 6 shown.

[0034] During the entire process, the formation of the microchannels of the metal-graphite composite bipolar plate relies on the flow of materials such as graphite and flexible graphite paper from the right to the left, rather than the overall stamping deformation of the existing technology, which effectively avoids the rupture of materials such as graphite and flexible graphite paper, ensuring that materials such as graphite and flexible graphite paper are intact.

[0035] In some embodiments, Figure 2 As shown, the first spring 11 is preferably a force transmission spring that maintains a constant elastic force within a corresponding stroke.

[0036] In some embodiments, Figure 2 As shown, the second spring 12 is preferably a compression spring for resisting compression force or storing energy.

[0037] In some embodiments, Figure 1 As shown, the forming device is preferably also provided with a first guide column 18 for guiding and positioning, and the two ends of the first guide column 18 are respectively connected to the upper mold base plate 1 and the lower mold base plate 4, and the first guide column 18 is respectively slidably connected through the upper mold base plate 1, the upper mold plate 2, and the lower mold plate 5.

[0038] In some embodiments, Figure 2 As shown, the longitudinal through hole 15 of the upper template 2 is preferably a square hole with good stability.

[0039] In some embodiments, Figure 1 、 Figure 3 As shown, the forming device is preferably further provided with a limit support device 19, which is provided with a limit support rod 20. A second blind hole 21 opening downward is provided on the lower surface of the upper template 2, and a third spring 22 is installed in the second blind hole 21. The bottom end of the limit support rod 20 is installed on the lower template 5, and the top end of the limit support rod 20 is connected to the third spring 22. When the forming device is closing the mold, the third spring 22 is compressed, and the top end of the limit support rod 20 gradually enters the second blind hole 21. The third spring 22 is continuously compressed, and the mold is finally closed. When the forming device is opening the mold, the elastic force of the third spring 22 is released, pushing the upper template 2 upward, so that the upper template 2 and the lower template 5 are completely separated.

[0040] In some embodiments, preferably, a third stop 23 is provided at the top of the limiting support rod 20, the third stop 23 is connected to the third spring 22, and the third stop 23 is slidingly connected to the inner wall of the second blind hole 21, so that the upper template 2 rises or falls more stably and reliably.

[0041] In some embodiments, the third spring 22 is preferably a limit spring, which uses the elasticity of the spring to limit the range of the moving part.

[0042] It should be noted that:

[0043] (1) During the process of opening or closing the mold of the hydraulic press, under the action of the spring force of the first spring 11 and the second spring 12, the punch assembly 8 rises or falls in the longitudinal through hole 15; intuitively, the pressure rod 10 drives the segment punch 9 to rise or fall.

[0044] (2) The mold opening process after the hydraulic press mold is closed, the working state of the present invention is as follows Figure 6 、 Figure 5 、 Figure 4 、 Figure 1 order.

[0045] (3) By Figure 1As shown, the lengths of the rods 10 exposed from the backing plate 7 are distributed in a stepped manner from left to right, preferably in an arithmetic progression, and the length difference between the rods of two adjacent rods 10 exposed from the backing plate 7 is equal to the height of the microfluidic channel. The operator can adjust the length of the rods 10 according to actual conditions.

[0046] In the description of the present invention, it should be understood that the terms "left", "right", "up", "down", "top", "bottom", "front", "back", "inside", "outside", "back", "middle", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention. It should be noted that in the above-mentioned embodiments, the "first", "second" and "third" mentioned do not represent an absolute distinction in structure and / or function, nor do they represent a sequence of execution, but are merely for the convenience of description.

[0047] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A metal-graphite composite bipolar plate forming device, the forming device is provided with an upper mold mechanism and a lower mold mechanism, the upper mold mechanism is provided with an upper mold base (1) and an upper mold plate (2), and a micro-protrusion (3) is provided below the lower surface of the upper mold plate (2); the lower mold mechanism is provided with a lower mold base (4) and a lower mold plate (5), and a micro-groove (6) is provided on the upper surface of the lower mold plate, the upper mold plate (2) and the lower mold plate (5) are arranged relative to each other in an upper and lower direction, and after the mold is closed, the micro-protrusion (3) and the micro-groove (6) are matched to form a micro-channel, characterized in that The forming device is further provided with a stepped punch mechanism, the stepped punch mechanism being provided with a pad (7) and a plurality of punch assemblies (8); each of the punch assemblies (8) being provided with a segmented punch (9), a pressure rod (10), a first spring (11), and a second spring (12); a micro protrusion (3) being provided at the lower portion of the segmented punch (9); a first blind hole (13) opening upwardly being provided at the upper portion of the segmented punch (9); a hole edge (14) extending inwardly being provided at the opening of the first blind hole (13); and a first spring (11) being installed in the first blind hole (13); The upper template (2) is provided with a plurality of longitudinal through holes (15) spaced from left to right, and each longitudinal through hole (15) is correspondingly provided with a punch assembly (8); the segmented punch (9) is arranged in the longitudinal through hole (15), and the two are slidably connected; the pad (7) covers the longitudinal through hole (15), and the top end of the pressure rod (10) is provided with a first stopper (16), and the rod body of the pressure rod (10) passes downward through the second spring (12) and the pad (7) and then enters the longitudinal through hole (15), and the bottom end of the pressure rod (10) is provided with a second stopper (17), and the second stopper (17) is connected to the first spring (11), and under the action of the elastic force of the first spring (11), the second stopper (17) is movably engaged in the hole edge (14); The lengths of the rod bodies of the plurality of pressure rods (10) exposed from the pad (7) are distributed in a step-wise descending manner from left to right.

2. The metal-graphite composite bipolar plate forming device according to claim 1, characterized in that: The first spring (11) is a force transmission spring.

3. The metal-graphite composite bipolar plate forming device according to claim 1, characterized in that: The second spring (12) is a compression spring.

4. The metal-graphite composite bipolar plate forming device according to claim 1, characterized in that: The forming device is further provided with a first guide column (18), the two ends of which are respectively connected to the upper mold base plate (1) and the lower mold base plate (4), and the first guide column (18) is respectively slidably connected and passes through the upper mold base plate (1), the upper mold plate (2), and the lower mold plate (5).

5. The metal-graphite composite bipolar plate forming device according to claim 1, characterized in that: The longitudinal through hole (15) of the upper template (2) is a square hole.

6. The metal-graphite composite bipolar plate forming device according to claim 1, characterized in that: The forming device is further provided with a limiting support device (19), the supporting device is provided with a limiting support rod (20), a second blind hole (21) opening downward is provided on the lower surface of the upper template (2), a third spring (22) is installed in the second blind hole (21), the bottom end of the limiting support rod (20) is installed on the lower template (5), and the top end of the limiting support rod (20) is connected to the third spring (22).

7. The metal-graphite composite bipolar plate forming device according to claim 6, characterized in that: A third stopper (23) is provided at the top end of the position-limiting support rod (20), the third stopper (23) is connected to the third spring (22), and the third stopper (23) is slidably connected to the inner wall of the second blind hole (21).

8. The metal-graphite composite bipolar plate forming device according to claim 6, characterized in that: The third spring (22) is a limit spring.

Images