CN219520228U - Stamping die - Google Patents

Abstract

The utility model relates to a stamping die, which comprises a first die and a second die. The first die comprises a first body, a first concave part, a first convex part and a second convex part, wherein the first concave part and the first convex part are arranged on one side of the first body in a staggered manner, and the second convex part is opposite to the convex of the bottom wall of the first concave part. The second die comprises a second body, a second concave part and a third convex part, and the second concave part and the third convex part are arranged on one side of the second body in a staggered way. The first protruding portion is used for being abutted with the coating on the first side face of the substrate so that at least part of the second side face of the substrate is abutted with the inner surface of the second concave portion, and the third protruding portion is used for being abutted with the second side face of the substrate so that at least part of the coating on the first side face of the substrate is abutted with one end, away from the first body, of the second protruding portion. The stamping die is not easy to cause the problem of stretching and tearing the coating in the process of stamping the deformed coated substrate.

Description

Stamping die

Technical Field

The utility model relates to the technical field of fuel cell bipolar plate processing, in particular to a stamping die.

Background

Bipolar plates are an important component of fuel cells where they serve the functions of collecting current, gas distribution, and water and thermal management. Wherein the types of bipolar plates include metallic bipolar plates, the surfaces of which are typically coated with a protective coating.

It is common in the art to press-deform at least a portion of the coated substrate using a stamping die to form a bipolar plate having a flow channel structure. In the preparation process, as the deformation degree of the bending part is larger, the extensibility of the substrate material is larger than that of the coating material, namely, the substrate has higher toughness and is easy to generate necking phenomenon (local section reduction), the coating has lower toughness, the coating is easy to generate stretching tearing phenomenon, the protection effect of the coating on the substrate is easy to lose efficacy, the manufactured bipolar plate is easy to corrode in the actual use process, the attenuation degree of the service life of the manufactured fuel cell is larger, and the use experience of a user is poorer.

Disclosure of Invention

The utility model provides a stamping die, which is not easy to cause the problem of stretching and tearing of a coating in the process of stamping a substrate with the coating.

The utility model provides a stamping die which is used for stamping a substrate with a coating. The stamping die comprises a first die and a second die. The first die comprises a first body, a first concave part, a first convex part and a second convex part, wherein the first concave part and the first convex part are arranged on one side of the first body in a staggered manner, and the second convex part is opposite to the convex of the bottom wall of the first concave part. The second die comprises a second body, a second concave part and a third convex part, and the second concave part and the third convex part are arranged on one side of the second body in a staggered way. The first protruding portion is used for being abutted with the coating so that at least part of the second side face is abutted with the inner surface of the second concave portion, and the third protruding portion is used for being abutted with the second side face so that at least part of the coating is abutted with one end, away from the first body, of the second protruding portion.

The user first places the first mold and the second mold in a separated state and then places the coated substrate between the first mold and the second mold. Either one of the first mold and the second mold may be relatively fixed, and the other mold may be movable relative to the fixed mold. The description is given herein taking the example that the first mold is movable and the second mold is fixed. When the first mold approaches the second mold, the first protruding portion of the first mold can abut against the substrate with the coating layer, and the first protruding portion can apply a force to at least part of the substrate, in detail, at least part of the substrate can be extruded, bent and deformed by the first protruding portion, so that at least part of the substrate and at least part of the second side face approach the bottom wall of the second recessed portion of the second mold, at least part of the second side face of the extruded substrate can abut against the inner surface of the second recessed portion, and at this time, the inner surface of the second recessed portion can also apply a force to at least part of the substrate located in the second recessed portion, so that at least part of the substrate located in the second recessed portion is extruded by the first protruding portion and the second recessed portion simultaneously. Simultaneously, the third protruding part of the second mould is abutted with the second side face of the substrate, the other at least part of the substrate is extruded and bent by the third protruding part to deform, so that the other at least part of the substrate, the at least part of the first side face and the at least part of the coating positioned on the first side face are close to the bottom wall of the first concave part of the first mould, the at least part of the coating positioned on the first side face is extruded to a position abutted with one end of the second protruding part, which is away from the first body, at the moment, one end of the second protruding part, which is away from the first body, can also apply a force to the at least part of the substrate, which is positioned in the first concave part, so that the at least part of the substrate, which is positioned in the first concave part, is extruded and molded by the third protruding part and the second protruding part. Because the second protruding portion protrudes relative to the bottom wall of the first recessed portion, the coating layer located on the first side surface of the substrate can be abutted with one end, away from the first body, of the second protruding portion, and the coating layer located on the first side surface of the substrate is not easy to be abutted with a position with an included angle in the inner surface of the first recessed portion. In detail, the position with the included angle in the inner surface of the first concave part is not easy to apply more acting force to the first bending part of the substrate with the coating, and the deformation extension of the first bending part is smaller, namely the necking amount of the first bending part is smaller. Meanwhile, as the second protruding part protrudes relative to the bottom wall of the first concave part, in the last section of the secondary stamping process, one side of the first connecting part bears the extrusion of the third protruding part of the second die, and the other side of the first connecting part bears the extrusion of the second protruding part at the same time, so that the material of the first connecting part extends and flows to the first bending part when being extruded and deformed, and the process can slow down the extending and flowing of the material of the first bending part to the first connecting part and the second connecting part, namely further slow down the necking amount of the first bending part. Because the necking amount of the first bending part is smaller, the stretching deformation amount of the coating on the surface of the bullnose of the first bending part is also smaller, and the coating on the surface of the bullnose of the first bending part is not easy to stretch and tear. Therefore, compared with the stamping die in the prior art, the stamping die disclosed by the utility model is not easy to cause damage to the coating when the substrate with the coating is subjected to secondary stamping deformation, namely, the protection effect of the coating on the substrate is not easy to fail, the manufactured bipolar plate is not easy to corrode in the actual use process, correspondingly, the attenuation degree of the service life of the manufactured fuel cell is also less, and the use experience of a user is higher.

In one possible design, the second protrusion has a set height H1 and the first depression has a set depth D1, the ratio of the height H1 to the depth D1 being 0.15 to 0.20. And/or the second protruding part has a set width W1, the bottom wall of the first recessed part has a set width W2, and the ratio of the width W1 to the width W2 is 0.45-0.50.

In one possible design, both sides of the end of the second protrusion facing away from the first body include a first rounded corner.

In one possible design, the third protruding portion includes a first section and a second section, one end of the first section is connected with the second body, the other end of the first section is connected with the second section, one end of the second section facing away from the first section is used for abutting with the second side face, and the second section protrudes relative to the end face of the first section, so that first openings are formed on two sides of the second section.

In one possible design, the first section has a set height H2 and the second section has a set height H3, the ratio of height H3 to height H2 being 0.20 to 0.25. And/or one end of the first section, which is far away from the second body, is provided with a set width W3, the second section is provided with a set width W4, and the ratio of the width W4 to the width W3 is 0.50-0.55.

In one possible design, both sides of the end face of the first section that is connected to the second section include second rounded corners. And/or the two sides of the end surface of the second section facing away from the first section comprise third rounded corners.

In one possible design, the second mould further comprises a fourth protrusion, the fourth protrusion being raised with respect to the bottom wall of the second recess, the fourth protrusion being for abutment with the second side.

In one possible design, the fourth protrusion has a set height H4, the second recess has a set depth D2, and the ratio of the height H4 to the depth D2 is 0.10 to 0.15. And/or the fourth protruding part has a set width W5, the bottom wall of the second recessed part has a set width W6, and the ratio of the width W5 to the width W6 is 0.45-0.50.

In one possible design, the sides of the end of the fourth protrusion facing away from the second body include fourth rounded corners.

In one possible design, the stamping die further includes a flexible membrane disposed in the first die for facing a surface of the second die, the flexible membrane disposed in the second die for facing a surface of the first die.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the utility model as claimed.

Drawings

FIG. 1 is a schematic view of a structure of a coated substrate, wherein the coating on a first side of the substrate is not shown, and the coated substrate is in a state of not being deformed by stamping;

FIG. 2 is a schematic view of the coated substrate of FIG. 1 after being deformed by a single press;

FIG. 3 is a schematic view of the coated substrate of FIG. 2 after being deformed by secondary stamping;

fig. 4 is a schematic structural diagram of a stamping die according to a first embodiment of the present utility model;

FIG. 5 is a schematic diagram of the mating structure of the coated substrate of FIG. 3 and the stamping die of FIG. 4;

FIG. 6 is a schematic diagram of an exploded view of the stamping die of FIG. 4;

FIG. 7 is an enlarged view of a portion A of FIG. 6;

fig. 8 is a schematic structural diagram of a stamping die according to a second embodiment of the present utility model;

FIG. 9 is a schematic diagram of the mating structure of the coated substrate of FIG. 3 and the stamping die of FIG. 8;

FIG. 10 is a schematic view of an exploded view of the stamping die of FIG. 8;

FIG. 11 is an enlarged view of a portion B of FIG. 10;

FIG. 12 is an enlarged view of a portion C of FIG. 10;

fig. 13 is a schematic structural diagram of a stamping die according to a third embodiment of the present utility model;

fig. 14 is a schematic structural diagram of a stamping die according to a fourth embodiment of the present utility model.

Reference numerals:

10-stamping a die;

1-a first mold;

11-a first body;

12-a first recess;

13-a first boss;

14-a second boss;

141-a first rounded corner;

2-a second mold;

21-a second body;

22-a second recess;

23-a third boss;

231-first stage;

231 a-second rounded corners;

232-a second section;

232 a-third rounded corners;

233-first opening;

24-fourth bosses;

241-fourth rounded corners;

3-flexible film;

20-a substrate;

20 a-a first side;

20 b-a second side;

20 c-a first bend;

20 d-a first connection;

20 e-a second connection;

20 f-a third connection;

20 g-second bend.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the utility model and together with the description, serve to explain the principles of the utility model.

Detailed Description

For a better understanding of the technical solution of the present utility model, the following detailed description of the embodiments of the present utility model refers to the accompanying drawings.

It should be understood that the described embodiments are merely some, but not all, embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The terminology used in the embodiments of the utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. As used in this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be understood that the term "and/or" as used herein is merely one relationship describing the association of the associated objects, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

It should be noted that, the terms "upper", "lower", "left", "right", and the like in the embodiments of the present utility model are described in terms of the angles shown in the drawings, and should not be construed as limiting the embodiments of the present utility model. In the context of this document, it will also be understood that when an element is referred to as being "on" or "under" another element, it can be directly on the other element or be indirectly on the other element through intervening elements.

The embodiment of the utility model provides a stamping die which can be applied to the technical field of fuel cell bipolar plate processing, in particular to stamping a coated substrate to form a bipolar plate with a flow passage structure. Referring to fig. 1-3, the substrate 20 includes a first side 20a and a second side 20b disposed opposite to each other, and a coating is disposed on a surface of the first side 20 a. In this case, the coating layer is thin with respect to the substrate 20, and thus the coating layer structure and the coating layer are not shown on the first side 20 a. Typically, the coated substrate 20 requires at least two stamping steps to deform to the desired bipolar plate, each stamping step producing less deformation, which reduces the likelihood of stretching the coating to tear. The following description will mainly take two-step stamping as an example, and as shown in fig. 1, the coated substrate 20 is in a state of not being deformed by stamping; as shown in fig. 2, the coated substrate 20 is in a state of being deformed by one press; as shown in fig. 3, the coated substrate 20 is in a state of being deformed by secondary stamping. As shown in fig. 3, the coated substrate 20 during and after the secondary stamping deformation includes a first bending portion 20c, a first connecting portion 20d, a second connecting portion 20e, a third connecting portion 20f, and a second bending portion 20g. In the same structure of the substrate 20, two ends of the first connecting portion 20d are connected with a first bending portion 20c, one end of the first bending portion 20c, which is away from the first connecting portion 20d, is connected with a second connecting portion 20e, one end of the second connecting portion 20e, which is away from the first bending portion 20c, is connected with a second bending portion 20g, and one end of the second bending portion 20g, which is away from the second connecting portion 20e, is connected with a third connecting portion 20 f. The portion of the coating that is located on the bullnose surface of the first bend 20c is more prone to stretch-tear problems during the secondary stamping deformation. In view of this technical problem, an embodiment of the present utility model provides a stamping die for secondary stamping deformation, and referring to fig. 4-5, the stamping die 10 of the embodiment of the present utility model can stamp and deform a coated substrate 20 shown in fig. 2 into a coated substrate 20 shown in fig. 3.

Referring to fig. 4-5, a stamping die 10 according to an embodiment of the present utility model includes a first die 1 and a second die 2. The first mold 1 includes a first body 11, a first concave portion 12, a first convex portion 13, and a second convex portion 14. The first concave portions 12 and the first convex portions 13 are alternately arranged at one side of the first body 11, and the second convex portions 14 are convex relative to the bottom wall of the first concave portion 12. The second mold 2 includes a second body 21, a second concave portion 22 and a third convex portion 23, and the second concave portion 22 and the third convex portion 23 are alternately disposed at one side of the second body 21. Wherein the first protrusion 13 is configured to abut against the coating layer (the coating layer located on the first side 20 a) such that at least a portion of the second side 20b abuts against an inner surface of the second recess 22, and the third protrusion 23 is configured to abut against the second side 20b such that at least a portion of the coating layer (the coating layer located on the first side 20 a) abuts against an end of the second protrusion 14 facing away from the first body 11.

In this embodiment, referring to fig. 4-5, a user first places the first mold 1 and the second mold 2 in a separated state, and then places the coated substrate 20 shown in fig. 2 between the first mold 1 and the second mold 2. Either one of the first mold 1 and the second mold 2 may be relatively fixed, and the other mold may be moved relative to the fixed mold. The description is given here taking the example that the first mold 1 is movable and the second mold 2 is fixed. When the first mold 1 approaches the second mold 2, the first protrusion 13 of the first mold 1 can abut against the coated substrate 20, and the first protrusion 13 can apply a force to at least a portion of the substrate 20, in detail, at least a portion of the substrate 20 can be pressed, bent and deformed by the first protrusion 13, so that at least a portion of the substrate 20 and at least a portion of the second side 20b approach the bottom wall of the second recess 22 of the second mold 2, at least a portion of the second side 20b of the pressed substrate 20 can abut against the inner surface of the second recess 22, and at this time, the inner surface of the second recess 22 can also apply a force to at least a portion of the substrate 20 located in the second recess 22, so that at least a portion of the substrate 20 located in the second recess 22 is simultaneously pressed and molded by the first protrusion 13 and the second recess 22. At the same time, the third protruding portion 23 of the second mold 2 abuts against the second side face 20b of the substrate 20, and the other at least part of the substrate 20 is pressed, bent and deformed by the third protruding portion 23, so that the other at least part of the substrate 20, the at least part of the first side face 20a and the at least part of the coating layer located on the first side face 20a approach the bottom wall of the first recessed portion 12 of the first mold 1, the at least part of the coating layer located on the first side face 20a is pressed to a position abutting against one end of the second protruding portion 14, which is away from the first body 11, and at the same time, the one end of the second protruding portion 14, which is away from the first body 11, can apply a force to the at least part of the substrate 20 located in the first recessed portion 12, so that the at least part of the substrate 20 located in the first recessed portion 12 is simultaneously pressed and molded by the third protruding portion 23 and the second protruding portion 14. Since the second protruding portion 14 protrudes with respect to the bottom wall of the first recessed portion 12, the coating layer on the first side surface 20a of the substrate 20 can abut against one end of the second protruding portion 14 facing away from the first body 11, and the coating layer on the first side surface 20a of the substrate 20 cannot easily abut against a position having an included angle in the inner surface of the first recessed portion 12. In detail, the position with an included angle in the inner surface of the first concave portion 12 is not easy to apply more force to the first bending portion 20c of the coated substrate 20, and the deformation extension of the first bending portion 20c is smaller, i.e. the necking amount of the first bending portion 20c is smaller. Meanwhile, as the second protruding portion 14 protrudes relative to the bottom wall of the first concave portion 12, in the last stage of the secondary stamping process, one side of the first connecting portion 20d bears the extrusion of the third protruding portion 23 of the second die 2, and the other side of the first connecting portion 20d bears the extrusion of the second protruding portion 14 at the same time, so that the material of the first connecting portion 20d has a process of extending and flowing to the first bending portion 20c when being extruded and deformed, and the process can slow down the extending and flowing of the material of the first bending portion 20c to the first connecting portion 20d and the second connecting portion 20e, namely further slow down the necking amount of the first bending portion 20 c. Because the necking amount of the first bending portion 20c is smaller, the stretching deformation amount of the coating layer on the surface of the bullnose of the first bending portion 20c is smaller, and the coating layer on the surface of the bullnose of the first bending portion 20c is not easy to stretch and tear. Therefore, compared with the stamping die in the prior art, the stamping die 10 in the embodiment of the utility model is not easy to cause damage to the coating when the coated substrate 20 is subjected to secondary stamping deformation, namely, the protection effect of the coating on the substrate 20 is not easy to fail, the manufactured bipolar plate is not easy to corrode in the actual use process, correspondingly, the attenuation degree of the service life of the manufactured fuel cell is also less, and the use experience of a user is higher.

Further, since one side of the first connecting portion 20d is pressed by the third protruding portion 23 of the second die 2 during the last stage of the secondary stamping process, and the other side of the first connecting portion 20d is pressed by the second protruding portion 14 at the same time, the first connecting portion 20d can be flattened into a flat first connecting portion 20d as shown in fig. 3, and the first connecting portion 20d is not easy to rebound, so that the requirement of a user on the dimensional accuracy of the manufactured bipolar plate is met.

The first body 11 of the first mold 1 may be used for connection with other mechanisms, devices or apparatuses, for example, the first body 11 may be connected with a sliding device (not shown in the figure), and the sliding device may drive the first mold 1 to move toward the second mold 2 as a whole or away from the second mold 2. Accordingly, the second body 21 of the second mold 2 may be used in connection with other mechanisms, devices or apparatuses, for example, the second body 21 may be connected to a stage (not shown in the drawings) for fixedly supporting the second mold 2.

In addition, the number of the first concave portion 12, the first convex portion 13 and the second convex portion 14 of the first die 1 is not limited by the stamping die 10 according to the embodiment of the utility model, and the number of the second concave portion 22 and the third convex portion 23 of the second die 2 is not limited by the stamping die 10, so that a user can set a corresponding number of the first concave portion 12, the first convex portion 13, the second convex portion 14, the second concave portion 22 and the third convex portion 23 in the stamping die 10 according to the number of flow channels required by different types of bipolar plates.

Of course, in other embodiments, the stamping die 10 of the present utility model may also be used to perform a single stamping deformation operation on a substrate having a stretch-proof limit coating.

The following description will mainly take the secondary stamping deformation as an example to describe the stamping die 10 according to the embodiment of the present utility model.

Alternatively, as shown in fig. 6, the second protrusion 14 has a set height H1, the first recess 12 has a set depth D1, and the ratio of the height H1 to the depth D1 is 0.15-0.20. The ratio of the height H1 to the depth D1 may be 0.15, 0.16, 0.17, 0.18, 0.19, 0.20.

In this embodiment, as shown in fig. 6, when the ratio of the height H1 to the depth D1 is too small, for example, the ratio of the height H1 to the depth D1 is less than 0.15, the height H1 of the second protrusion 14 is too small. In the secondary stamping process, the first connecting portion 20d of the coated substrate 20 is difficult to be extruded in advance by the second protruding portion 14, or the time that the first connecting portion 20d is extruded by the second protruding portion 14 is too short, so that the material of the first bending portion 20c is not easy to slow down to extend and flow to the first connecting portion 20d, the necking amount of the first bending portion 20c is large, and the coating on the surface of the bullnose of the first bending portion 20c is easy to generate a stretching tearing problem. Moreover, the first connection portion 20d is not easily flattened and shaped by the second protrusion portion 14, and the first connection portion 20d is easily rebounded, so that the requirement of a user on the dimensional accuracy of the bipolar plate is not easily met. When the ratio of the height H1 to the depth D1 is too large, for example, when the ratio of the height H1 to the depth D1 is greater than 0.20, the height of the second protrusion 14 is too large, the first connection portion 20D is extruded and shaped by the second protrusion 14 prematurely, and when the first connection portion 20D is extruded and flattened by the second protrusion 14, the first bending portion 20c is still not sufficiently bent, i.e. the bending degree of the first bending portion 20c is smaller, so that it is difficult to meet the requirement of the user on the size of the bipolar plate, and the coated substrate 20 still needs to be further punched and bent, so that the punching process is complicated. Therefore, the ratio of the height H1 to the depth D1 is better in the range of 0.15-0.20, the problem that the coating is not easy to stretch and tear is solved, the requirement of a user on the size precision of the bipolar plate is met, and the required stamping process is simplified.

Alternatively, as shown in fig. 6, the second protrusion 14 has a set width W1, the bottom wall of the first recess 12 has a set width W2, and the ratio of the width W1 to the width W2 is 0.45-0.5. The ratio of the width W1 to the width W2 may be specifically 0.45, 0.46, 0.47, 0.48, 0.49, 0.5.

In this embodiment, as shown in fig. 6, when the ratio of the width W1 to the width W2 is too small, for example, the ratio is smaller than 0.45, the width of the second protrusion 14 is too small, the contact area between the second protrusion 14 and the first connection portion 20d in the coated substrate 20 is too small, the pressing pressure between the first connection portion 20d and the second protrusion 14 is too high during the secondary stamping process, and the first connection portion 20d and the connected coating portion are easily extruded by the second protrusion 14 to form surface quality defects such as pits and cracks. Meanwhile, the parts of the first connecting part 20d supported by the second protruding part 14 are fewer, and the parts of the first connecting part 20d not supported by the second protruding part 14 are easy to bend towards the first body 11 when being extruded by the third protruding part 23, namely, the first connecting part 20d is not easy to be extruded and flattened, and the requirement of users on the size precision of bipolar plates is difficult to be met. When the ratio of the width W1 to the width W2 is too large, for example, when the ratio is greater than 0.5, the second convex portion 14 is too wide, at least part of the first bending portion 20c is easily contacted with the second convex portion 14 during the secondary stamping, the first bending portion 20c and the coating on the bullnose surface of the first bending portion 20c bear more force of the second convex portion 14, the necking amount of the first bending portion 20c is larger, and the coating on the bullnose surface of the first bending portion 20c is easily subjected to tensile tearing. Therefore, the ratio of the width W1 to the width W2 is preferably 0.45 to 0.50, the first connecting portion 20d and the connected coating portion are less likely to be damaged by the extrusion of the second protruding portion 14, the requirement of the user on the dimensional accuracy of the bipolar plate is met, and the coating on the bullnose surface of the first bending portion 20c is not easy to stretch and tear.

Alternatively, as shown in fig. 7, both sides of the end of the second protrusion 14 facing away from the first body 11 include a first rounded portion 141. With this arrangement, both sides of the second protruding portion 14 facing away from the end of the first body 11 are not sharp, and when the second protruding portion 14 presses the first connecting portion 20d of the coated substrate 20, the first connecting portion 20d is not easily pressed by the second protruding portion 14 to form a surface quality defect such as a pit or a crack, and the coating on the surface of the first connecting portion 20d is not easily damaged.

Wherein the second protrusion 14 may be integrally formed with the bottom wall of the first recess 12. Alternatively, in other embodiments (not shown), the second protrusions 14 may be separate structures, and the second protrusions 14 may be threadably secured to the bottom wall of the first recess 12, in which arrangement the user may replace the second protrusions 14 having different widths and heights to meet the user's different size requirements and different dimensional accuracy requirements for the bipolar plate.

The following description will mainly take the case that the second protrusion 14 is integrally formed with the bottom wall of the first recess 12.

In addition, the second protrusion 14 may be located at a bottom wall center region of the first recess 12.

Alternatively, as shown in fig. 8-9, the third protruding portion 23 includes a first section 231 and a second section 232, one end of the first section 231 is connected to the second body 21, the other end of the first section 231 is connected to the second section 232, one end of the second section 232 facing away from the first section 231 is used for abutting against the second side 20b, and the second section 232 protrudes relative to the end face of the first section 231, so that a first opening 233 is formed on two sides of the second section 232.

In this embodiment, as shown in fig. 8-9, during the secondary stamping process, one end of the second section 232 facing away from the first section 231 can abut against the second side 20b of the coated substrate 20 and can apply a force to the second side 20b, in detail, another at least part of the substrate 20 can be extruded and bent by the second section 232, so that the other at least part of the substrate 20, at least part of the first side 20a and at least part of the coating located on the first side 20a are close to the bottom wall of the first concave portion 12 of the first mold 1, at least part of the coating located on the first side 20a is extruded to a position abutting against one end of the second convex portion 14 facing away from the first body 11, and at this time, one end of the second convex portion 14 facing away from the first body 11 can also apply a force to at least part of the substrate 20 located in the first concave portion 12, so that at least part of the substrate 20 located in the first concave portion 12 is simultaneously extruded and molded by the second section 232 and the second convex portion 14. Since the second section 232 protrudes from the end surface of the first section 231 and the first notch 233 is formed on both sides of the second section 232, the second side surface 20b of the substrate 20 does not abut against the inner surface of the first notch 233. Specifically, the third protrusion 23 is less likely to apply a large force to the first bending portion 20c, and the deformation extension amount of the first bending portion 20c is smaller, that is, the necking amount of the first bending portion 20c is smaller. On the basis of the effect of the smaller necking amount of the first bent portion 20c brought about by the structural arrangement of the first die 1 described above, the structural arrangement of the third convex portion 23 according to the embodiment of the present utility model can cooperatively reduce the necking amount of the first bent portion 20 c. Meanwhile, due to the protrusion of the second section 232 opposite to the end of the first section 231 facing away from the second body 21, in the last section of the secondary stamping process, one side of the first connecting portion 20d is extruded by the second section 232, and the other side of the second connecting portion 20e is extruded by the second protrusion 14, so that the material of the first connecting portion 20d has a process of extending and flowing to the first bending portion 20c when being extruded and deformed, and the material of the first bending portion 20c extends and flows to the first connecting portion 20d, i.e. the necking amount of the first bending portion 20c is further slowed down. In view of the above, the amount of tensile deformation of the coating on the bullnose surface of the first bend 20c is also less, and the coating on the bullnose surface of the first bend 20c is less prone to cracking. Therefore, compared with the stamping die in the prior art, the stamping die 10 in the embodiment of the utility model is less likely to cause damage to the coating when the coated substrate 20 is subjected to secondary stamping deformation, namely, the protection effect of the coating on the substrate 20 is less likely to fail, the manufactured bipolar plate is less likely to be corroded in the actual use process, correspondingly, the attenuation degree of the service life of the manufactured fuel cell is less, and the use experience of a user is higher.

Wherein the first section 231 may be integrally formed with the second section 232. Alternatively, in other embodiments (not shown), the second section 232 is a separate structure, and the second section 232 may be threadably secured to the end of the first section 231 facing away from the second body 21, in which arrangement the user may replace the second section 232 with a different width and height to meet the user's different dimensional requirements and different dimensional accuracy requirements for the bipolar plate.

The following description will mainly take the case that the first section 231 and the second section 232 are integrally formed.

In addition, the second section 232 is located in a central region of the end of the first section 231 facing away from the second body 21.

Alternatively, as shown in fig. 10, the first section 231 has a set height H2, the second section 232 has a set height H3, and the ratio of the height H3 to the height H2 is 0.20-0.25. The ratio of the height H3 to the height H2 may be 0.20, 0.21, 0.22, 0.23, 0.24, 0.25.

In this embodiment, referring to fig. 10, when the ratio of the height H3 to the height H2 is too small, for example, the ratio is smaller than 0.20, the height of the second section 232 is too small, and the first section 231 is easy to contact the fillet surface of the first bending portion 20c during the secondary stamping process, i.e. the first section 231 is easy to apply more force to the fillet surface of the first bending portion 20c, the material of the first bending portion 20c is easy to flow toward the first connecting portion 20d, i.e. the necking amount of the first bending portion 20c is larger, and the stretching tearing problem of the coating of the fillet surface of the first bending portion 20c is easy to occur. When the ratio of the height H3 to the height H2 is too large, for example, when the ratio is greater than 0.25, the height of the second section 232 is too large, and accordingly, the height of the first notch 233 and the avoidance space are too large, it is difficult for the first section 231 to apply a relatively large force to the portion of the second connecting portion 20e near the first bending portion 20c, and it is difficult for the portion of the second connecting portion 20e near the first bending portion 20c to sufficiently abut against the side wall of the first recess portion 12, so that it is difficult to satisfy the requirement of the user on the dimensional accuracy of the bipolar plate. Therefore, the ratio of the height H3 to the height H2 is preferably within 0.20 to 0.25, and the coating on the surface of the bullnose of the first bending portion 20c is not easy to cause a stretching tearing problem, so that the size precision of the manufactured bipolar plate is high.

Alternatively, as shown in fig. 10, the end of the first section 231 facing away from the second body 21 has a set width W3, the second section 232 has a set width W4, and the ratio of the width W4 to the width W3 is 0.50-0.55. The ratio of the width W4 to the width W3 may be specifically 0.50, 0.51, 0.52, 0.53, 0.54, or 0.55.

In this embodiment, as shown in fig. 10, when the ratio of the width W4 to the width W3 is too small, for example, the ratio is smaller than 0.50, the width of the second section 232 is too small, the contact area between the second section 232 and the first connecting portion 20d is too small, and the extrusion pressure between the first connecting portion 20d and the second section 232 is too large during the secondary stamping process, so that the first connecting portion 20d is easily extruded by the second section 232 to form surface quality defects such as pits and cracks. When the ratio of the width W4 to the width W3 is too large, for example, the ratio is greater than 0.55, the width of the second segment 232 is too large, and the second segment 232 easily contacts the first bending portion 20c and easily applies more pressing force to the first bending portion 20c, so that the necking amount of the first bending portion 20c is larger, and the stretching tearing problem of the coating on the bullnose surface of the first bending portion 20c easily occurs. Therefore, the ratio of the width W4 to the width W3 is preferably in the range of 0.50 to 0.55, the surface quality of the first connecting portion 20d is high after being extruded and shaped, and the coating on the bullnose surface of the first bending portion 20c is not easy to cause a stretch-tear problem.

Alternatively, as shown in fig. 11, both sides of the end surface of the first section 231 connected to the second section 232 include second rounded portions 231a. With this arrangement, both sides of the end surface of the first segment 231 connected to the second segment 232 are not sharp, and when the second rounded corner 231a presses the second connection portion 20e, the second connection portion 20e is less likely to be pressed by the first segment 231 to have surface quality defects such as pits or cracks.

Optionally, as shown in fig. 11, both sides of the end surface of the second section 232 facing away from the first section 231 include third rounded corners 232a. In this arrangement, both sides of the end surface of the second section 232 facing away from the first section 231 are not sharp, and when the second section 232 presses the first connecting portion 20d, the first connecting portion 20d is not easily pressed by the second section 232 to have surface quality defects such as pits or cracks.

Optionally, referring to fig. 9 to 10, the second mold 2 further includes a fourth protrusion 24, where the fourth protrusion is protruding with respect to the bottom wall of the second recess 22, and the fourth protrusion 24 is configured to abut against the second side 20 b.

In this embodiment, as shown in fig. 9-10, when the first protrusion 13 of the first mold 1 applies a force to the coated substrate 20 so that at least a portion of the second side 20b of the substrate 20 approaches the bottom wall of the second recess 22, at least a portion of the second side 20b can be pressed to a position abutting against the fourth protrusion 24, at this time, one end of the fourth protrusion 24 facing away from the second body 21 can also apply a force to at least a portion of the substrate 20 located in the second recess 22, so that at least a portion of the substrate 20 located in the second recess 22 is simultaneously pressed by the first protrusion 13 and the fourth protrusion 24 to form a flat third connection portion 20f, and the third connection portion 20f is not easy to rebound, so as to meet the size precision requirement of the bipolar plate for the user.

Alternatively, as shown in fig. 10, the fourth protrusion 24 has a set height H4, the second recess 22 has a set depth D2, and the ratio of the height H4 to the depth D2 is 0.10-0.15. The ratio of the height H4 to the depth D2 may be 0.10, 0.11, 0.12, 0.13, 0.14, 0.15.

In this embodiment, as shown in fig. 10, when the ratio of the height H4 to the depth D2 is too small, for example, the ratio is smaller than 0.10, the height of the fourth protruding portion 24 is too small, and in the secondary stamping process, the third connecting portion 20f of the coated substrate 20 is not easily pressed by the fourth protruding portion 24 in advance, or the time that the third connecting portion 20f is pressed and flattened by the fourth protruding portion 24 is too short, the third connecting portion 20f is not easily flattened, the third connecting portion 20f is easily rebounded, and the requirement of the user on the dimensional accuracy of the bipolar plate is not easily met. When the ratio of the height H4 to the depth D2 is too large, for example, the ratio is greater than 0.15, the height of the fourth protruding portion 24 is too large, and in the secondary stamping process, the third connecting portion 20f is pressed and molded by the fourth protruding portion 24 too early, and when the third connecting portion 20f is pressed and leveled by the fourth protruding portion 24, the second bending portion 20g is still not sufficiently bent, that is, the bending degree of the second bending portion 20g is smaller, so that it is difficult to meet the requirement of the user on the size of the bipolar plate, and the coated substrate 20 still needs to be further stamped and bent, so that the stamping process is complicated. Therefore, the ratio of the height H4 to the depth D2 is preferably in the range of 0.10 to 0.15.

Alternatively, as shown in fig. 10, the fourth protrusion 24 has a predetermined width W5, the bottom wall of the second recess 22 has a predetermined width W6, and the ratio of the width W5 to the width W6 is 0.45-0.50. The ratio of the width W5 to the width W6 may be specifically 0.45, 0.46, 0.47, 0.48, 0.49, 0.50.

In this embodiment, as shown in fig. 10, when the ratio of the width W5 to the width W6 is too small, for example, the ratio is smaller than 0.45, the width of the fourth protrusion 24 is too small, the contact area between the fourth protrusion 24 and the third connection portion 20f in the coated substrate 20 is too small, and the pressing pressure between the fourth protrusion 24 and the third connection portion 20f is too large during the secondary stamping process, the third connection portion 20f is easily extruded by the fourth protrusion 24 to form surface quality defects such as pits and cracks. Meanwhile, the third connecting portion 20f has fewer portions supported by the fourth protruding portion 24, and the portion of the third connecting portion 20f not supported by the fourth protruding portion 24 is easy to bend toward the second body 21 when being pressed by the first protruding portion 13, i.e. the third connecting portion 20f is not easy to be pressed and flattened by the fourth protruding portion 24, and it is difficult to meet the requirement of users on the size precision of the bipolar plate. When the ratio of the width W5 to the width W6 is too large, for example, the ratio is greater than 0.50, the width of the fourth protrusion 24 is too large, and exceeds the effective contact area of the fourth protrusion 24 and the third connection portion 20f, the structure of the fourth protrusion 24 is redundant, and the fourth protrusion 24 is too close to the side wall of the second recess 22, so that it is inconvenient to finish the position with an included angle in the second recess 22 by using the processing device. Therefore, the ratio of the width W5 to the width W6 is preferably in the range of 0.45 to 0.50.

Alternatively, as shown in fig. 12, both sides of the end of the fourth protrusion 24 facing away from the second body 21 include fourth rounded corners 241. With this arrangement, both sides of the end of the fourth protrusion 24 facing away from the second body 21 are not sharp, and when the fourth protrusion 24 presses the third connection portion 20f of the coated substrate 20, the third connection portion 20f is less likely to be pressed by the fourth protrusion 24 to form surface quality defects such as pits or cracks.

Optionally, referring to fig. 13-14, the stamping die 10 of the embodiment of the present utility model further includes a flexible film 3, where the flexible film 3 is disposed on a surface of the first die 1 facing the second die 2, and the flexible film 3 is disposed on a surface of the second die 2 facing the first die 1. When the stamping die 10 of the embodiment of the utility model performs stamping deformation on the substrate with the coating, the flexible film 3 can perform lubrication between the first die 1 and the substrate 20 with the coating, the flexible film 3 can perform buffer lubrication between the second die 2 and the substrate 20 with the coating, the abrasion degree of the surfaces of the first die 1 and the second die 2 is reduced, the service lives of the first die 1 and the second die 2 are prolonged, the abrasion degree of the surface of the substrate 20 with the coating is also reduced, the surface quality precision of the substrate 20 with the coating is high, the coating is not easy to stretch and tear, and the yield of the manufactured bipolar plate is high.

The material of the flexible film 3 may be a polymer film, a lubricating grease or a resin film.

The above description is only of the preferred embodiments of the present utility model and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (10)

1. A stamping die for stamping a coated substrate, the substrate comprising oppositely disposed first and second sides, the coating disposed on the first side, the stamping die comprising:

the first die comprises a first body, a first concave part, a first convex part and a second convex part, wherein the first concave part and the first convex part are arranged on one side of the first body in a staggered manner, and the second convex part is raised relative to the bottom wall of the first concave part;

the second die comprises a second body, a second concave part and a third convex part, wherein the second concave part and the third convex part are arranged on one side of the second body in a staggered way;

the first protruding portion is used for being abutted with the coating so that at least part of the second side face is abutted with the inner surface of the second concave portion, and the third protruding portion is used for being abutted with the second side face so that at least part of the coating is abutted with one end, away from the first body, of the second protruding portion.

2. The stamping die of claim 1, wherein the second raised portion has a set height H1, the first recessed portion has a set depth D1, and a ratio of the height H1 to the depth D1 is 0.15 to 0.20;

and/or the second protruding portion has a set width W1, the bottom wall of the first recessed portion has a set width W2, and the ratio of the width W1 to the width W2 is 0.45-0.50.

3. The stamping die of claim 1, wherein both sides of the end of the second boss facing away from the first body include first rounded corners.

4. A stamping die as claimed in any one of claims 1 to 3, wherein the third boss comprises a first section and a second section, one end of the first section is connected to the second body, the other end of the first section is connected to the second section, one end of the second section facing away from the first section is adapted to abut the second side face, and the second section is raised relative to an end face of the first section to form a first gap on both sides of the second section.

5. The stamping die of claim 4, wherein the first section has a set height H2 and the second section has a set height H3, the ratio of the height H3 to the height H2 being 0.20-0.25;

and/or one end of the first section, which is away from the second body, is provided with a set width W3, the second section is provided with a set width W4, and the ratio of the width W4 to the width W3 is 0.50-0.55.

6. The press die of claim 4, wherein both sides of the end surface of the first segment that is connected to the second segment include second rounded corners;

and/or, two sides of the end surface of the second section facing away from the first section comprise third rounded corners.

7. A stamping die as in any one of claims 1-3, wherein the second die further comprises a fourth boss for abutment with the second side surface, the fourth boss being raised relative to the bottom wall of the second recess.

8. The stamping die of claim 7, wherein the fourth protrusion has a set height H4, the second depression has a set depth D2, and a ratio of the height H4 to the depth D2 is 0.10-0.15;

and/or the fourth protruding part has a set width W5, the bottom wall of the second concave part has a set width W6, and the ratio of the width W5 to the width W6 is 0.45-0.50.

9. The stamping die of claim 7, wherein two sides of the end of the fourth boss facing away from the second body include fourth rounded corners.

10. A stamping die as in any one of claims 1-3, further comprising a flexible film disposed in the first die for facing a surface of the second die, the flexible film disposed in the second die for facing a surface of the first die.