Intelligent manufacturing production line for hydrogen fuel cell metal plates

Abstract

The present invention discloses an intelligent manufacturing production line for hydrogen fuel cell metal plates, including a lower end surface of a male mold including a downwardly convex arc surface A and horizontal portions A at both ends of the arc length direction of the arc surface A; an upper end surface of a female mold including an upwardly convex arc surface B and horizontal portions B at both ends of the arc length direction of the arc surface B; when the mold is closed, under the action of the mold closing driving force, the arc surface A and the arc surface B gradually generate interaction forces from the center to both sides and form a relative plane matching the surface of the formed plate in the final state of the mold closing. The arc surface A and the arc surface B are centrally convex profile designs, which can realize gradual loading stamping and forming, reduce force loss when the plane contacts, have a higher utilization rate of the forming load, and have better consistency of the microstructure of the large-area metal plate.

Description

Technical Field

[0001] The present invention relates to the technical field of stamping and forming of hydrogen fuel cell metal plates, and in particular to an intelligent manufacturing production line for hydrogen fuel cell metal plates. Background Art

[0002] Metal plates are the "skeleton" and "blood vessels" of hydrogen fuel cells, playing multiple roles such as distributing fuel gas, collecting current, draining water, dissipating heat, and providing mechanical support, accounting for 24% of the cost, 60% of the volume, and 60-80% of the weight. In order to reduce the volume and weight of hydrogen fuel cells and improve the volume / mass power density, metal sheet stamping is used, and the wall thickness is reduced from 100μm to 75μm or even thinner; the characteristic size of the microchannel is less than 1.0mm, with an accuracy of 3-5μm; the metal plate area is large, and the outer contour size is greater than 500mm*220mm.

[0003] The above-mentioned structural characteristics of the metal plate bring great difficulties to the stamping and forming manufacturing of the metal plate, and the forming quality is not high, which has a significant impact on the performance of hydrogen fuel cells.

[0004] 1) Due to the bending deformation, friction, and edge pressure constraints of the punch and concave mold surfaces of the stamping die, the size of the microchannel is extremely uneven, low in the middle and high on both sides. In order to ensure reliable contact between the uneven microchannel and the proton exchange membrane group, additional preload force is required during the assembly of the fuel cell stack, which will affect the diffusion rate of the fuel gas in the proton exchange membrane group, thereby reducing the performance of the fuel cell.

[0005] 2) The microchannel dimensional accuracy is poor, such as the ridge top flatness is not high, the width error is large, which increases the contact resistance between the plate and the proton exchange membrane group, and also significantly reduces the performance of the fuel cell. Therefore, it is difficult to solve the above bottleneck problem by relying solely on traditional methods such as increasing the stamping forming force.

[0006] To this end, the present invention proposes an intelligent manufacturing production line for hydrogen fuel cell metal plates. Summary of the invention

[0007] The invention proposes a hydrogen fuel cell metal plate intelligent manufacturing production line. Based on the characteristics of the bending deformation of the thin plate stamping die surface, the commonly used flat surface design is changed to a curved surface design. The curved, center-high die surface gradually establishes contact with the thin plate. The force of local loading in the center area can ensure that the microchannel at the center of the plate is formed first, thereby improving the ridge width dimensional accuracy and dimensional consistency of the microchannel of the plate. Not only does it compensate for the influence of the bending deformation of the die surface on the forming accuracy of the metal plate, but also the local and gradual loading formed by the non-planar surface makes the formed microchannel higher in precision and better in dimensional consistency.

[0008] The technical solution disclosed in the present invention is as follows: A hydrogen fuel cell metal plate intelligent manufacturing production line, comprising:

[0009] A punch, wherein the lower end surface of the punch includes a downwardly convex arc surface A and horizontal portions A at both ends of the arc surface A in the arc length direction;

[0010] A concave die, wherein the upper end surface of the concave die includes an upward convex arc surface B and horizontal portions B at both ends of the arc surface B in the arc length direction;

[0011] Among them, when the mold is closed, under the action of the mold closing driving force, the arc surface A and the arc surface B gradually press against each other from the center to both sides and form a relative plane matching the surface of the formed sheet in the final state of the mold closing.

[0012] On the basis of the above scheme, preferably, the upper end surface of the punch is fixedly connected to the upper die base through the punch support, and the upper die base is fixedly connected to the driving unit, and the driving unit is a common hydraulic press, a mechanical press or a servo press.

[0013] On the basis of the above scheme, as a preference, it further includes a fixing device surrounding the male mold for strongly restraining and fixing the plate on the horizontal portion B.

[0014] On the basis of the above scheme, as a preference, the fixing device includes a guide hole, a guide member, a pressure ring, and an elastic member arranged on the upper die base, one end of the guide member is fixed on the pressure ring surrounding the punch, and the other end extends into the guide hole, the pressure ring and the punch are gap-matched, each of the guide members corresponds to an elastic member, one end of the elastic member is fixedly connected to the punch, and the other end is fixedly connected to the upper die base.

[0015] On the basis of the above solution, preferably, the guide member is a guide bolt, the elastic member is a spring, and the spring is sleeved on the guide bolt.

[0016] On the basis of the above solution, as a preference, the lower end surface of the die is fixedly connected to the lower die base via a groove support, and the lower die base is fixedly connected to the work surface.

[0017] On the basis of the above solution, preferably, the die support and the lower die base are fixedly connected by fixing bolts.

[0018] On the basis of the above scheme, as a preference, a guide post is fixedly mounted on the lower end surface of the upper die base, and a guide hole A is provided on the lower die base, into which the guide post is inserted.

[0019] On the basis of the above scheme, preferably, the arc surface A is provided with a plurality of upper protrusions and an upper concave portion located between two adjacent upper protrusions, and the arc surface B is provided with a plurality of lower protrusions and a lower concave portion located between two adjacent lower protrusions, the upper protrusions cooperate with the lower concave portions, and the lower protrusions cooperate with the upper concave portions.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The lower surface of the punch and the upper surface of the die are designed as convex structures, which can compensate for the stamping forming error of the metal plate caused by the elastic deformation of the punch and die surfaces;

[0022] 2. The arc surface A and arc surface B are designed with a central convex surface, which can realize gradual loading and stamping forming, reduce the force loss during plane contact, have a higher utilization rate of the forming load, and have better consistency in the microstructure of large-area metal plates. Specifically, the forming starts from the center first to form a local load to improve the forming accuracy of the ultra-thin plate microstructure, and then, under the action of elastic deformation, the forming is gradually loaded from the center. The microstructure reduces the force loss during plane contact and can better ensure the consistency of the geometric dimensions of the metal plate microstructure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present invention;

[0024] Figure 2 It is a state diagram after mold closing of the present invention;

[0025] Figure 3 It is the state diagram when the punch and die are in contact;

[0026] Figure 4 This is a diagram of the state after the punch and die are closed. DETAILED DESCRIPTION

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0028] like Figure 1-4 As shown, the intelligent manufacturing production line of hydrogen fuel cell metal plates includes a punch 1, the lower end surface of the punch includes a downward convex arc surface A2 and horizontal portions A3 at both ends of the arc length direction of the arc surface A; a die 4, the upper end surface of the die includes an upward convex arc surface B5 and horizontal portions B6 at both ends of the arc length direction of the arc surface B; wherein, when the mold is closed, under the action of the mold closing driving force, the arc surface A and the arc surface B gradually press against each other from the center to the sides and form a relative plane matching the surface of the formed plate in the final state of the mold closing.

[0029] The upper end surface of the punch is fixedly connected to an upper die base 8 through a punch support 7, and the upper die base is fixedly connected to a driving unit, which is a common hydraulic press, a mechanical press or a servo press.

[0030] It also includes a fixing device surrounding the punch for strongly restraining and fixing the plate on the horizontal portion B. The fixing device includes a guide hole 9, a guide member 10, a blank holder 11, and an elastic member 12 arranged on the upper die seat. One end of the guide member is fixed to the blank holder surrounding the punch, and the other end extends into the guide hole. The blank holder is in clearance with the punch. Each of the guide members corresponds to an elastic member. One end of the elastic member is fixedly connected to the punch, and the other end is fixedly connected to the upper die seat.

[0031] The guide piece is a guide bolt, and the elastic piece is a spring, and the spring is sleeved on the guide bolt.

[0032] The lower end surface of the concave die is fixedly connected to the lower die base 14 through the groove support 13, and the lower die base is fixedly connected to the work table.

[0033] The die support and the lower die base are fixedly connected by fixing bolts 15.

[0034] A guide post 16 is fixedly mounted on the lower end surface of the upper die base, and a guide hole A17 is provided on the lower die base, into which the guide post is inserted.

[0035] The arc surface A has a plurality of upper protrusions and an upper concave portion between two adjacent upper protrusions, and the arc surface B has a plurality of lower protrusions and a lower concave portion between two adjacent lower protrusions. The upper protrusions cooperate with the lower concave portions, and the lower protrusions cooperate with the upper concave portions.

[0036] More specifically, the intelligent manufacturing production line for hydrogen fuel cell metal plates is mainly composed of an upper die base, a punch support, a pressure ring, a spring, a guide bolt, a guide column, a die, a die support, a lower die base and fixing bolts.

[0037] The lower surface of the punch is distributed with microstructures 18, and the upper surface of the die is also provided with microstructures, which cooperate with the microstructures on the lower surface of the punch to stamp and form the metal plate.

[0038] The upper surface of the punch is fixed to the upper die seat through the punch support, forming the upper half die, which is usually fixed on the moving slide of the equipment. The lower surface of the die is fixed to the lower die seat through the die support and fixing bolts, forming the lower half die, which is usually fixed on the working table of the equipment.

[0039] A blank holder is provided on the periphery of the punch. The blank holder force is provided by a spring. The spring can also be replaced by other elastic elements. The blank holder is connected to the upper die seat through a guide bolt, which can ensure that the blank holder moves up and down within a certain displacement range and is guided by the guide bolt. Ultra-thin plates such as stainless steel and titanium are placed between the die, the punch and the blank holder. The blank holder provides a clamping force to strongly constrain its movement, so that the ultra-thin plate is fixed on the die; under the action of the microstructure on the lower surface of the punch and the microstructure on the upper surface of the die, the ultra-thin plate undergoes plastic deformation, and a metal plate consistent with the shape of the microstructure is formed by stamping.

[0040] A guide column is installed near the edge of the upper die base, and cooperates with the guide sleeve installed on the lower die base to provide guidance for the up and down movement of the upper half die to ensure the precise matching of the punch microstructure and the die microstructure.

[0041] In order to improve the stamping quality of the metal plate microstructure, the lower surface of the punch is designed to be a convex shape, and the upper surface of the die is designed to be a convex shape. As the upper die moves downward, the microstructure at the center of the punch first contacts the microstructure at the center of the die, and then gradually stamps the ultra-thin plate microstructure. When the upper die continues to move downward, under the action of external force, the punch and die undergo elastic deformation, and the microstructure contact at the center gradually evolves into the microstructure of the entire surface contacting, and finally forms the entire metal plate with a microstructure.

[0042] Working process:

[0043] The gradual loading stamping of the bending compensation profile of the hydrogen fuel cell metal plate can be carried out on ordinary hydraulic presses, mechanical presses, servo presses and other equipment. In order to ensure the quality of metal plate forming, the self-developed servo press with a tonnage of 15t is selected, which can provide 3-5μm high-precision displacement control. The forming device is placed on the work surface of the servo press and fixed by bolts, pressure blocks, etc.; the servo press slider is controlled to move downward, and when it is close to the upper surface of the upper die seat of the forming device, the upper die seat and the press slider are fixed with bolts, pressure blocks, etc., and the press slider drives the upper half die to move up and down through the upper die seat.

[0044] When the metal plate is stamped, the upper die is lifted 10-50mm by the slider of the press, and then a flat, clean, 0.05-0.1mm thick 304 or 316 or titanium ultra-thin plate is placed on the upper surface of the die. Then the press is started and the slider moves downward. The blank holder first contacts the upper surface of the ultra-thin plate, and as the slider continues to move downward, the ultra-thin plate is pressed down by the spring to provide strong constraints; the slider continues to move downward, and the microstructures in the center of the punch and the die contact the upper and lower surfaces of the ultra-thin plate respectively, and then the microstructure is stamped; the slider continues to move downward, the punch and the die undergo elastic deformation, and the deformation gradually increases. During this process, the contact area gradually increases, forming a gradually loaded stamping, and finally the lower surface of the punch and the upper surface of the die are all in close contact to complete the stamping. After that, the slider of the servo press moves upward, lifts the upper die, and the stamped metal plate can be taken out of the mold device. At this point, the stamping process of the hydrogen fuel cell metal plate is completed.

[0045] Since the lower surface of the punch and the upper surface of the die are raised, not flat, the elastic deformation of the punch and die can be compensated; at the same time, the center contacts the microstructure first, and then expands continuously, and the forming is gradually expanded until it is completed. The protruding height of the lower surface of the punch or the upper surface of the die is determined according to the size of the plate. For example, when the plate length is 300-500mm and the width is 100-250mm, the protruding height is 0.1-0.5mm. The accurate value can be obtained by analyzing and calculating the specific mold material and forming force.

[0046] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. Intelligent manufacturing production line for hydrogen fuel cell metal plates, It is characterized in that include: A punch, wherein the lower end surface of the punch includes a downwardly convex arc surface A and horizontal portions A at both ends of the arc surface A in the arc length direction; A concave die, wherein the upper end surface of the concave die includes an upward convex arc surface B and horizontal portions B at both ends of the arc surface B in the arc length direction; Among them, the protruding height of the lower surface of the punch or the upper surface of the die is 0.1-0.5mm. When the mold is closed, under the action of the mold closing driving force, the arc surface A and the arc surface B gradually press each other from the center to both sides and form a relative plane matching the surface of the formed sheet in the final state of the mold closing. It also includes a fixing device for firmly restraining and fixing the plate on the horizontal part B.

2. The intelligent manufacturing production line for hydrogen fuel cell metal plates according to claim 1, It is characterized in that The upper end surface of the punch is fixedly connected to the upper die seat through the punch support, and the upper die seat is fixedly connected to the driving unit. The driving unit is a common hydraulic press, a mechanical press or a servo press.

3. The intelligent manufacturing production line for hydrogen fuel cell metal plates according to claim 1, It is characterized in that The fixing device includes a guide hole, a guide member, a pressure ring, and an elastic member arranged on the upper die base. One end of the guide member is fixed to the pressure ring surrounding the punch, and the other end extends into the guide hole. The pressure ring and the punch are clearance-matched. Each of the guide members corresponds to an elastic member. One end of the elastic member is fixedly connected to the punch, and the other end is fixedly connected to the upper die base.

4. The intelligent manufacturing production line for hydrogen fuel cell metal plates according to claim 3, It is characterized in that The guide piece is a guide bolt, and the elastic piece is a spring, and the spring is sleeved on the guide bolt.

5. The intelligent manufacturing production line for hydrogen fuel cell metal plates according to claim 2, It is characterized in that The lower end surface of the concave die is fixedly connected to the lower die seat through the groove support, and the lower die seat is fixedly connected to the work table.

6. The intelligent manufacturing production line for hydrogen fuel cell metal plates according to claim 5, It is characterized in that The die support and the lower die base are fixedly connected by fixing bolts.

7. The intelligent manufacturing production line for hydrogen fuel cell metal plates according to claim 5, It is characterized in that A guide post is fixedly mounted on the lower end surface of the upper die seat, and a guide hole A is provided on the lower die seat, into which the guide post is inserted.

8. The intelligent manufacturing production line for hydrogen fuel cell metal plates according to any one of claims 1 to 7, It is characterized in that The arc surface A has a plurality of upper protrusions and an upper concave portion between two adjacent upper protrusions, and the arc surface B has a plurality of lower protrusions and a lower concave portion between two adjacent lower protrusions. The upper protrusions cooperate with the lower concave portions, and the lower protrusions cooperate with the upper concave portions.

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