Roll for rotary machining method, embossing and cutting tool, rotary machining method, half plate and bipolar plate

Abstract

The invention relates to a roller (10, 11) for a rotary machining method, said roller (10, 11) having at least one embossing element (1) and at least one cutting element (3, 4, 5, 9). The invention further relates to an embossing and cutting tool (100), to a rotary machining method, to a half-plate produced according to said machining method, and to a bipolar plate comprising two half-plates.

Description

[0001] The present invention relates to a roller for rotary processing, an embossing and cutting tool, a rotary processing method, and a half-plate and a bipolar plate comprising two half-plates manufactured according to the processing method.

[0002] Rotary machining methods are used to introduce structures into flat or mesh workpieces to achieve desired workpiece geometries, particularly desired workpiece surface geometries. These rotary machining methods can include, for example, calendering, embossing, and / or stamping. Especially for mesh workpieces, the final step is to separate the mesh material, i.e., to cut it. For example, bipolar plates or bipolar plate halves can be produced by a roll-to-roll method. For this, the desired plate geometry is pressed into the starting material, and medium channels are punched out of the material. The material is then separated to obtain individual plates. Examples of embossing rollers can be found in CN216659110U or CN210333760U.

[0003] In these prior art methods, embossing and cutting are performed in separate devices called cassettes, each containing at least one set of rollers, and thus are done in steps. The starting material can be provided as a mesh material by an uncoiler. The first cassette shapes the mesh material. The mesh material then passes through a second cassette, for example, to stamp out corresponding media channels. Stamping can also involve cutting sheets from the mesh material. For example, an apparatus for a similar method is described in CN106393802A.

[0004] The separate process of embossing on one hand and cutting or stamping on the other means that the two cartridges must operate synchronously or must use alignment control. Both of these require considerable technical investment. In fields where the tolerance requirements between embossing and cutting edges are very high, such as bipolar plate manufacturing, existing methods have reached their limits, or require extremely high effort to meet the requirements.

[0005] In view of this, the object of the present invention is to further develop a roller for a rotary processing method that enables the combination of embossing and cutting.

[0006] The object of the present invention is achieved using a roller having the features of claim 1, an embossing and cutting tool according to claim 15, a rotary processing method according to claim 22, a half-plate according to claim 23, and a bipolar plate according to claim 25. Advantageous embodiments are as described in the respective appended claims.

[0007] The roller of the present invention for a rotary processing method has at least one embossing element and at least one cutting element.

[0008] Because the roller has at least one embossing element and at least one cutting element, the present invention allows embossing and cutting to be performed in combination, thereby completing the embossing and cutting steps, which are separate in the prior art, in one method. This reduces technical input by avoiding or at least simplifying the synchronization and / or alignment control of the separate steps.

[0009] Here, the difference between embossing and cutting is that embossing primarily involves reshaping a workpiece, such as deforming the surface of the workpiece by creating reliefs that form medium channels or similar features. In contrast, cutting is mainly a separation method, including punching and drilling, as it removes material from the workpiece. Cutting can also include cutting through the workpiece, especially separating sheet metal from workpieces that are mesh materials.

[0010] At least one cutting element can be engraved on the surface of the roller. The roller and the cutting element are designed as a single component, which means that greater stability can be achieved.

[0011] Additionally, at least one cutting element can be designed as a separate component and detachably attached to the roller surface. This allows the roller to be customized. For example, when at least one cutting element wears out, it can be readjusted or replaced. However, for engraved cutting elements, wear necessitates replacing the roller or re-engraving, both of which are more complex and costly.

[0012] In an embodiment with a detachably fixed cutting element, the roller body may have a threaded hole, and at least one cutting element has a matching through hole. The cutting element is detachably fixed in the threaded hole by means of a screw connection. To further secure at least one cutting element, thread-locking adhesive may be used, for example, which can prevent or at least make unintended loosening more difficult, but still allows for loosening again.

[0013] At least one cutting element may be configured in the axial direction of the roller next to at least one embossing element. This configuration is suitable for, for example, stamping an outer opening and / or cutting or severing at least a portion of the side of a workpiece.

[0014] Additionally, at least one cutting element may be positioned in front of or behind at least one embossing element in the direction of roller rotation. This configuration is suitable, for example, for punching and / or separating workpieces in front of and / or behind at least one embossing element in the direction of workpiece travel.

[0015] The roller may also include at least two cutting elements, wherein the at least two cutting elements are disposed on different sides of at least one embossed element in the axial direction of the roller, or the at least two cutting elements are disposed on different sides of at least one embossed element in the rotational direction of the roller. In this way, cutting can be performed on both sides of at least one embossed element.

[0016] The roller may also include at least three cutting elements, wherein at least one cutting element is disposed next to the embossing element in the axial direction of the roller, and at least one cutting element is disposed in front of or behind the at least one embossing element in the rotational direction of the roller. A preferred configuration of the cutting elements is that at least one cutting element is disposed next to the at least one embossing element in the axial direction, while at least one cutting element is disposed in front of or behind the at least one embossing element in the rotational direction. This combines the advantages and possibilities of different configurations. More preferably, more than one embossing element may be provided, wherein each embossing element may incorporate several cutting elements.

[0017] In particular, if at least one cutting element is designed as a separate component, additional mounting options, such as threaded holes, can be provided on the roller to allow at least one removably mounted cutting element to be detachably mounted at different locations on the roller, depending on application requirements. This means the roller can be used to stamp, for example, different surface textures, without requiring the replacement of the entire roller.

[0018] At least one cutting element may have a cutting profile with at least one continuous cutting edge. A continuous cutting edge means that the cutting edge has no grooves or notches, and is therefore particularly suitable for cutting or stamping to separate material from a workpiece, at least in certain areas.

[0019] Additionally, at least one cutting element may have a cutting profile with a cutting edge featuring at least one perforation. A perforation refers, in particular, to a notch or slit, for drilling into the workpiece. Within the scope of this invention, at least one cutting element of other shapes and profiles is also feasible. Specific designs depend on the particular application.

[0020] Preferably, at least one embossed element and at least one cut element are arranged on the roller at a distance. The distance is greater than 0 mm, preferably greater than 1 mm, and particularly preferably greater than 10 mm.

[0021] The rollers can be made primarily of metal or ceramic materials. These materials have the advantage of being able to withstand the mechanical stresses of embossing or cutting.

[0022] Alternatively, the rollers can be made primarily of synthetic materials. Synthetic materials are lighter than metals or ceramics, making the rollers easier to replace but reducing the durability of the bearings. Synthetic materials can be reinforced with carbon fiber to improve the roller's rigidity.

[0023] Preferably, the roller has an abrasion-resistant protective layer. This is especially suitable when the roller material contains synthetic materials. This protects the roller material from wear and improves its durability.

[0024] Another aspect of the present invention relates to an embossing and cutting tool, comprising a first roller and a second roller of the present invention. The second roller has at least one embossing element that mates with at least one embossing element of the first roller and at least one cutting element that mates with at least one cutting element of the first roller.

[0025] The embossing and cutting tool referred to herein, such as a so-called cassette, typically comprises two rollers. In the prior art, such cassettes are used as embossing or cutting tools. Since the embossing and cutting tool of the present invention comprises two rollers of the present invention, each having matching embossing and cutting elements, the present invention makes it possible to combine embossing and cutting in a single method step.

[0026] Preferably, at least one matching cutter of the second roller can be designed as a planar corresponding element. Alternatively, at least one matching cutter of the second roller can have a cutting profile. Depending on the application and workpiece material, one or other embodiments may be selected.

[0027] The distance between at least one cutting element of the first roller and at least one embossing element of the first roller, and the distance between at least one matching cutting element of the second roller and at least one matching embossing element of the second roller, can be designed such that the axis of at least one cutting element of the first roller is aligned with the axis of at least one matching cutting element of the second roller. This ensures that the matching cutting elements interlock in a favorable manner, enabling cutting to meet high tolerance requirements.

[0028] Preferably, the first and second rollers each have two spacer rings. The spacer rings can be manufactured to a predetermined diameter and act as spacers between the rollers to prevent damage to the cutting element. This means that when the rollers approach each other, the spacer rings prevent the gap between the rollers from becoming so small that the cutting edge of the cutting element impacts the mating cutting element, causing damage. The spacer rings also allow for pre-tensioning of the rollers. The spacer rings are typically mounted on the outside of the rollers, i.e., on the so-called roller flange. The spacer rings can also be designed as support rings.

[0029] The spacer ring is preferably beveled at an angle. In this way, the invention makes it possible to vary the gap distance between the rollers. A 0-degree angle indicates that one running surface of the spacer ring is parallel and aligned with the crimped surface. This corresponds to a fixed gap distance, meaning it cannot be varied. The angle is particularly preferably in the range of 0 to 10 degrees.

[0030] Another aspect of the invention relates to a rotary machining method in which a workpiece is embossed and cut by the embossing and cutting tools of the invention in one process step. In this manner, compared to methods where the embossing and cutting steps are performed separately, the invention allows for the manufacture of the workpiece with less technical investment. Furthermore, higher precision can be achieved because the simultaneous operation of separate steps is no longer required, for example, through alignment control, or at least this is simplified. This is particularly advantageous in production processes with high tolerance requirements, such as bipolar plates or bipolar plate halves.

[0031] Another aspect of the invention relates to a half-plate manufactured according to the processing method of the invention. Preferably, the half-plate is made of a graphite-based material.

[0032] The present invention also relates to a bipolar plate comprising two halves of the present invention. Because embossing and cutting are performed in a single step during the production of the halves, high tolerance requirements for the surface structure and dielectric channels of the bipolar plate can be met. Simultaneously, time and costs are saved by reducing the technical complexity of production.

[0033] Exemplary embodiments of the present invention will be described with reference to the following accompanying drawings. Wherein: Figure 1 It is a rotary processing method that involves embossing and cutting using a separate cassette with existing technology; Figure 2 The embossing and cutting tool of the present invention includes two rollers having embossing and cutting components; Figure 3 This is an enlarged view of the embossed and cut parts of the embossing and cutting tool of the present invention; Figure 4 This is an embodiment of the embossing and cutting parts of the embossing and cutting tool of the present invention; Figure 5 This is an embodiment of the embossing and cutting tool of the present invention, having a spacer ring with parallel running surfaces; and Figure 6 This is another embodiment of the embossing and cutting tool of the present invention, which has a spacer ring with an inclined running surface.

[0034] Figure 1 Existing rotary processing methods are illustrated for producing planar components (such as plates) having, for example, specific, particularly fine surface geometries and / or dielectric channels. Typical applications include half-plates of bipolar plates or the bipolar plates themselves, especially for fuel cells.

[0035] like Figure 1As shown, embossing and cutting are performed using separate embossing and cutting tools, known as cassettes, each containing two rollers. Initial material 200 is supplied as a mesh by an uncoiler 300. A first cassette 400 embosses the mesh, for example, to form the desired surface structure. The mesh then passes through a second cassette 500, which punches out corresponding media channels and / or separates the entire sheet 600 from the mesh 200. Excess material 700 is discharged accordingly.

[0036] However, separating the embossing and cutting operations requires that the two cassettes 500 and 600 operate synchronously, or that alignment control be used. Both of these involve considerable technical investment. Especially in the field of bipolar plate production, the tolerances between the embossing and cutting edges are so small that they are impossible to achieve with current technology, or can only be achieved through extremely painstaking effort.

[0037] Therefore, it is necessary to achieve the simplest production of high-precision planar components. Figure 2 An embossing and cutting tool 100 is shown, including a first roller 10 and a second roller 11. The first roller 10 has an embossing element 1, a first cutting element 3, and a second cutting element 4. The second roller 11 has an embossing element 1 that matches the embossing element 1 of the first roller 10, a third cutting element 9 that matches the first cutting element 3, and a fourth cutting element 5 that matches the second cutting element 4.

[0038] The first roller 10 and the second roller 11 simultaneously include cutting elements 3, 4, 5, and 9 and embossing element 1. This means that the embossing and cutting tool 100 can reduce technical input by completing embossing and cutting in one cassette. On the one hand, this saves a process step; on the other hand, it eliminates the need for synchronous operation or alignment control required for separate embossing and cutting, or at least simplifies the process.

[0039] Figure 3 An enlarged view of the embossed part 1 and the cut parts 3, 4, 5, and 9 is shown. It can be seen that the first cut part 3 and its matching third cut part 9 are embossed on the roller surface. On the other hand, the second cut part 4 and its matching fourth cut part 5 are designed as detachable separate elements and attached to the roller surface. This detachable mounting allows for the replacement or readjustment of the cut parts 4 and 5, for example, by using different cutting profiles for different workpieces 2. Conversely, the fixedly embossed cut parts 3 and 9 are generally more robust and less prone to errors, such as misalignment.

[0040] To enable the detachable installation of the cutting components 4 and 5, the main bodies of the first roller 10 and the second roller 11 each have threaded holes 7. The cutting components 4 and 5 have corresponding, matching through holes 6, allowing them to be detachably fixed in the threaded holes 7 by means of screw fasteners (not shown).

[0041] In embodiments not shown, the first roller 10 and / or the second roller 11 may have more than one threaded hole 7. Depending on application requirements, the cutters 4 and 5 may be positioned at different locations on the first roller 10 or the second roller 11. Additional cutters can also be used in this way. Furthermore, in alternative embodiments, all cutters 3, 4, 5, and 9 may be engraved or detachably attached. For example, a configuration using only engraved cutters is more stable and less prone to errors, while using only detachably attached cutters 3, 4, 5, and 9 provides greater flexibility. Conventional use as cutting tools in separate embossing and cutting equipment, or use as embossing tools after removing the cutters 3, 4, 5, and 9, are also feasible options.

[0042] Cutting elements 3, 4, 5, and 9 are arranged adjacent to at least one embossing element 1 in the axial direction x of the first roller 10 and the second roller 11. In an alternative embodiment (not shown), cutting elements 3, 4, 5, and 9 may also be arranged in the rotational direction r of the rollers 10 and 11, either in front of or behind the at least one embossing element 1. These two arrangements of cutting elements 3, 4, 5, and 9 can also be combined, such that cutting elements 3, 4, 5, and 9 are arranged beside, in front of, or behind the embossing element 1 in both the axial direction x of the first roller 10 and the rotational direction r. Different arrangements provide options for different sheet metal cutting sizes and for drilling holes at different locations on the workpiece. For example, cutting elements 3, 4, 5, and 9 arranged in the axial direction x next to the embossing element 1 can be used to create media channels, while cutting elements 3, 4, 5, and 9 arranged in the rotational direction r can be used to cut or pierce the workpiece 2.

[0043] In embodiments not shown, the first roller 10 and / or the second roller 11 may include more than one embossing element 1. Cutting elements 3, 4, 5, and 9 may also be disposed between the embossing elements 1.

[0044] like Figure 3In the illustrated embodiment, on rollers 10 and 11, the embossing element 1 of the first roller 10 is spaced apart from the cutting elements 3 and 4 by a distance b, and the matching embossing element 1 of the second roller 11 is spaced apart from the matching cutting elements 5 and 9 by a distance a. Both distances a and b are greater than 0 mm. In particular, distances a and b are designed to align the corresponding axes y of the cutting elements 3 and 4 of the first roller 10 with the corresponding axes z of the matching cutting elements 5 and 9 of the second roller 11. Here, distance b is greater than distance a because the matching cutting elements 5 and 9 are wider than the cutting elements 3 and 4 on the first roller 10. By aligning axes y and z, a favorable fit can be achieved between the cutting elements 3 and 4 and the matching cutting elements 5 and 9.

[0045] Here, cutting elements 3 and 4 each have a cutting profile, wherein the cutting profile has a continuous cutting edge. Therefore, cutting elements 3 and 4 are combined with matching cutting elements 5 and 9, each element being designed as a planar corresponding element, which can punch holes in different areas of the workpiece 2. For example, the cutting profiles of cutting elements 3 and 4 can be square, circular, or elliptical, so as to punch corresponding shapes from the workpiece 2. However, more complex shapes, or cutting elements 3 and 4 extending along the entire radius of the first roller 10, are also feasible, for example, to cut off the edges of the workpiece.

[0046] Alternatively, the cutting profiles of cut pieces 3, 4, 5, and 9 can have at least one perforation on the cutting edge. This indicates that the cutting profiles are not continuous, for example, to achieve drilling of workpiece 2. This is advantageous, for example, if it is only desired to cut and / or remove individual pieces of material in a later stage of the processing or during use.

[0047] Figure 4 Another embodiment of the embossing and cutting tool 100 is shown. Here, the matching cutting parts 5 and 9 of the second roller 11 also have cutting contours. In this way, the perforation effect can be improved or the cutting can be cleaner.

[0048] Figure 5 An embodiment of the embossing and cutting tool 100 is shown, wherein a first roller 10 and a second roller 11 each have two spacer rings 8. The spacer rings 8 are located at both ends of the rollers 10 and 11, i.e., so-called crimping. The spacer rings 8 are designed so that their running surfaces are parallel to and aligned with the roller surfaces. The spacer rings 8 are sized so that when the rollers 10 and 11 approach each other, the gap between them does not become so narrow that the cutting profiles of the cutters 3 and 4 of the first roller and the matching cutters 5 and 9 of the second roller collide and damage each other. The spacer rings 8 also allow for pre-tensioning of the rollers 10 and 11.

[0049] like Figure 6In the illustrated embodiment, the spacer ring 8 is beveled at an angle α, causing the running surface of the spacer ring 8 to be inclined. This invention allows the gap between rollers 10 and 11 to be set by adjusting at least one roller 10 or 11 in the axial direction x. According to embodiments of the embossing and / or cutting elements 1, 3, 4, 5, and 9, the gap between the rollers can be adjusted to avoid damaging the embossing and / or cutting elements 1, 3, 4, 5, and 9, while still achieving the desired surface structure of the tool.

[0050] Rollers 10 and 11 substantially comprise synthetic materials, such as elastomers containing carbon fibers for added strength. In other embodiments not shown, the synthetic material may alternatively or additionally comprise co-elastomers, polymers, or copolymers, or may be substantially made of metallic or ceramic materials.

[0051] To improve the durability of the rollers 10 and 11, each roller 10 and 11 has a wear-resistant protective layer. The wear-resistant protective layer comprises amorphous carbon, especially diamond-like carbon. Due to the superior hardness properties of diamond-like carbon, a wear-resistant protective layer with a thickness of less than 0.5 mm is sufficient to provide adequate wear protection. In other embodiments not shown, the wear-resistant protective layer may additionally or alternatively contain metals and / or silicon.

[0052] In the rotary machining method (not shown), the workpiece 2 is embossed and cut by the embossing and cutting tool 100 in a single process step. In this way, one process step can be eliminated, and the simultaneous operation of separate embossing and cutting steps is no longer required. This rotary machining method thus achieves high precision while saving time and cost.

[0053] The rotary processing method is therefore suitable for producing, for example, half-plates for bipolar plates. Such a bipolar plate comprises two half-plates. The half-plates and their bipolar plates typically comprise graphite-based materials. For this purpose, in the rotary processing method, a graphite-based mesh material can be provided to the embossing and cutting tool 100 using an uncoiler. In this case, the graphite-based mesh material can be exfoliated graphite, but it can also be an alternative pure graphite or other graphite composite material. Furthermore, the graphite-based mesh material can contain thermosetting or thermoplastic resins as a matrix material, and / or contain carbon black, graphene, carbon fibers, or expanded graphite as fillers.

[0054] In an alternative embodiment, the half-plate produced using the rotary processing method may include a metal-based material, thereby providing a metal-based bipolar plate. In the rotary processing method, the metal-based material can be fed to the embossing and cutting tool 100 as a metal-based mesh material using an uncoiler. The metal-based mesh material may include stainless steel, titanium, and / or aluminum. Furthermore, the metal-based half-plate or bipolar plate may have a coating comprising a noble metal (such as gold), carbon, ceramic, and / or metal nitride, and may be a single layer or multiple layers. Partial or selective coatings may also be used.

[0055] The features disclosed in the foregoing description, drawings and claims can be used individually or in any combination to implement the present invention.

[0056] List of component symbols:

Claims

1. A roller (10, 11) for rotary processing, wherein the roller (10, 11) comprises at least one embossing element (1) and at least one cutting element (3, 4, 5, 9).

2. The roller (10, 11) as claimed in claim 1, wherein at least one cutting element (3, 4, 5, 9) is etched on the surface of the roller.

3. The rollers (10, 11) as claimed in claim 1, wherein the at least one cutting element (3, 4, 5, 9) is designed as a separating element and is detachably fixed to the surface of the roller.

4. The roller (10, 11) as claimed in claim 3, wherein the main body of the roller has a threaded hole (7), the at least one cutting element (4, 5) has a matching through hole (6), and the cutting element (4, 5) is detachably fixed to the threaded hole (7) by means of a screw connection.

5. The roller (10, 11) as described in any of the preceding claims, wherein the at least one cutting element (3, 4, 5, 9) is disposed next to the at least one embossing element (1) in the axial direction (x) of the roller (10, 11).

6. The roller (10, 11) as described in any of the preceding claims, wherein the at least one cutting element (3, 4, 5, 9) is disposed in front of or behind the at least one embossing element (1) in the rotational direction (r) of the roller (10, 11).

7. The roller (10, 11) as claimed in any of the preceding claims, comprising at least two cutting elements (3, 4, 5, 9), wherein the at least two cutting elements (3, 4, 5, 9) are disposed on different sides of the at least one embossing element (1) in the axial direction (x) of the roller (10, 11), or the at least two cutting elements (3, 4, 5, 9) are disposed on different sides of the at least one embossing element (1) in the rotational direction (r) of the roller (10, 11).

8. The roller (10, 11) as described in any of the preceding claims, comprising at least three cutting elements (3, 4, 5, 9), wherein at least one cutting element (3, 4, 5, 9) is disposed next to the embossing element (1) in the axial direction (x) of the roller (10, 11), and at least one cutting element (3, 4, 5, 9) is disposed in front of or behind the at least one embossing element (1) in the rotational direction (r) of the roller (10, 11).

9. The roller (10, 11) as described in any of the preceding claims, wherein the cutting element (3, 4, 5, 9) has a cutting profile with at least one continuous cutting edge.

10. The roller (10, 11) as described in any of the preceding claims, wherein the cutting element (3, 4, 5, 9) has a cutting profile with a cutting edge having at least one perforation.

11. The roller (10, 11) as described in any of the preceding claims, wherein the at least one embossing element (1) and the at least one cutting element (3, 4, 5, 9) are disposed on the roller (10, 11) at a distance (a, b) greater than 0 mm, preferably greater than 1 mm, and specifically preferably greater than 10 mm.

12. The roller (10, 11) as described in any of the preceding claims, wherein the material of the roller comprises a metal or ceramic material.

13. The roller (10, 11) as described in any of the preceding claims, wherein the material of the roller comprises a synthetic material.

14. The roller (10, 11) as described in any of the preceding claims, wherein the roller (10, 11) comprises an abrasion-resistant protective layer.

15. An embossing and cutting tool (100) comprising a first roller (10) as claimed in claims 1 to 15 and a second roller (11) as claimed in claims 1 to 15, wherein the second roller (11) has at least one embossing element (1) corresponding to at least one embossing element of the first roller (11), and at least one cutting element (5, 9) corresponding to at least one cutting element (3, 4) of the first roller (11).

16. The embossing and cutting tool (100) as claimed in claim 15, wherein at least one matching cutting element (5, 9) of the second roller (11) is designed as a planar corresponding element.

17. The embossing and cutting tool (100) as claimed in claim 15, wherein at least one matching cutter (5, 9) of the second roller (11) has a cutting profile.

18. The embossing and cutting tool (100) according to any one of claims 15 to 17, wherein the distance (b) between at least one cutting element (3, 4) of the first roller (10) and at least one embossing element (1) of the first roller (10) and the distance (a) between at least one matching cutting element (5, 9) of the second roller (11) and the at least one matching embossing element (1) are designed such that the axis (y) of at least one cutting element (3, 4) of the first roller (10) is aligned with the axis (z) of at least one matching cutting element (5, 9) of the second roller (11).

19. The embossing and cutting tool (100) according to any one of claims 15 to 18, wherein the first roller (10) and the second roller (11) each comprise two spacer rings (8).

20. The embossing and cutting tool (100) as claimed in claim 19, wherein the spacer ring (8) is beveled at an angle (α).

21. The embossing and cutting tool (100) as claimed in claim 20, wherein the angle (α) is between 0 degrees and 10 degrees.

22. A rotary machining method, wherein a workpiece (2) is embossed and cut by an embossing and cutting tool as described in any one of claims 1 to 21 during the method steps.

23. A half-plate manufactured by the rotary machining method as described in claim 22.

24. The half-plate of claim 23, comprising a graphite-based material.

25. The half-plate of claim 23, comprising a metal-based material.

26. A bipolar plate comprising two half-plates as claimed in any one of claims 23 to 25.

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