Female die and self-piercing riveting equipment

Abstract

The utility model relates to the technical field of riveting equipment, and provides a female die and self-piercing riveting equipment, the provided female die is provided with a die cavity, a centering groove is formed in the bottom wall of the die cavity, the orientation of a groove opening of the centering groove and the orientation of an opening of the die cavity are the same, and the center line of the centering groove coincides with the center line of the die cavity. According to the scheme, the problem that in the prior art, a material subjected to self-piercing riveting is prone to cracks can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of riveting equipment, and in particular to a die and self-piercing riveting equipment. Background Art

[0002] Self-pierce riveting (SPR) has the advantages of high efficiency, low requirements on the dimensional accuracy of parts and components, simple operation, and good economic benefits. It is widely used in vehicle processing technology, such as body connection technology. Figure 1 As shown in the flat die, when the self-pierce riveting equipment uses the flat die for riveting, cracks are likely to appear on the surface of some materials being self-pierce riveted, such as aluminum alloy materials. Utility Model Content

[0003] In view of this, the present application provides a die and a self-piercing riveting device to solve the problem in the prior art that cracks easily occur in the material after self-piercing riveting.

[0004] In order to achieve the above objectives, this application provides the following technical solutions:

[0005] A concave mold has a mold cavity, the bottom wall of the mold cavity is provided with a centering groove, the notch of the centering groove and the opening of the mold cavity are oriented in the same direction, and the center line of the centering groove coincides with the center line of the mold cavity.

[0006] Optionally, the cross-section of the centering groove is circular, and the diameter of the centering groove gradually increases along the direction from the bottom wall to the opening.

[0007] Optionally, the bottom wall of the mold cavity includes a raised portion protruding toward the opening, and the centering groove is provided in the raised portion; and / or,

[0008] Optionally, the distance between the bottom of the centering groove and the opening is less than the maximum depth of the mold cavity in the centerline direction.

[0009] Optionally, the protrusion is a truncated cone-shaped structure, and the diameter of the truncated cone-shaped structure gradually increases along the direction from the opening to the bottom wall.

[0010] Optionally, the side wall of the mold cavity is a circumferential side wall, and the bottom wall further includes a curved surface, and the circumferential side wall is smoothly connected to the outer edge of the bottom surface of the truncated cone structure away from the opening through the curved surface.

[0011] Optionally, the diameter of the circumferential side wall gradually increases along the direction from the bottom wall to the opening.

[0012] Optionally, the female mold has a first surface for contacting the material to be riveted, the first surface is arranged around the opening, and the angle between the generatrix of the truncated cone structure and the first surface is 12-18°.

[0013] Optionally, the cross-section of the centering groove is circular, the maximum diameter of the centering groove is 2-5 mm, and the maximum depth of the centering groove along the center line direction is 0.3-0.8 mm.

[0014] Optionally, the maximum diameter of the mold cavity is 10-12 mm, and the maximum depth of the mold cavity along the center line direction is 1.2-1.8 mm.

[0015] A self-piercing riveting device comprises the die described in any one of the above items.

[0016] In the embodiment of the present application, a centering groove is provided on the bottom wall of the mold cavity. When the die is used in a self-piercing riveting device, the material being riveted partially flows into the centering groove during the self-piercing riveting process. The centering groove can center the riveted material, reducing the shaking of the riveted material, thereby alleviating the problem of cracking of the riveted material. Therefore, the embodiment of the present application can solve the problem of cracking in the material after self-piercing riveting in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0018] Figure 1 It is a structural diagram of a flat mold in the prior art;

[0019] Figure 2 A schematic structural diagram of a concave mold provided in an embodiment of the present application;

[0020] Figure 3 A cross-sectional view of a concave mold provided in an embodiment of the present application;

[0021] Figure 4 A dimensioned diagram of the concave mold provided in an embodiment of the present application;

[0022] Figure 5When the self-piercing riveting equipment uses the flat die of the prior art to self-pierce rivet the upper steel plate and the lower aluminum alloy plate, the surface structure diagram of the material obtained (the schematic diagram in the upper left corner of the figure) and the cross-sectional diagram of the material that cooperates with the die (the schematic diagram in the lower left corner of the figure); and when the self-piercing riveting equipment uses the die in this application to self-pierce rivet the upper steel plate and the lower aluminum alloy plate, the surface structure diagram of the material obtained (the schematic diagram in the upper right corner of the figure) and the cross-sectional diagram of the material that cooperates with the die (the schematic diagram in the lower right corner of the figure).

[0023] exist Figure 1-Figure 5 middle:

[0024] 100, mold cavity; 110, centering groove; 120, bottom wall; 121, raised portion; 122, curved surface; 130, circumferential side wall;

[0025] 200. First surface. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0027] The automotive industry is rapidly developing. To meet user needs, the iteration rate of vehicle models is accelerating, and the manufacturing cycle is rapidly shortening. This has driven the development of automotive parts towards high integration and lightweighting. At the same time, as new energy vehicles occupy an increasing market share, body integration and lightweighting have become key research directions. Body structural parts have successfully entered the historical stage. Body structural parts can usually be processed using the die-casting process.

[0028] The die-casting aluminum alloy process in the automotive industry has the advantages of high dimensional accuracy, good surface finish, high dimensional stability, the ability to form complex shapes, and high production efficiency. In addition, since the content of aluminum in the earth's crust is second only to oxygen and silicon, it ranks third and is the most abundant metal element in the earth's crust. Aluminum alloys are widely used in important industrial fields such as aviation, construction, automobiles, and electricity. Therefore, the die-casting aluminum alloy process is increasingly favored by the automotive industry.

[0029] With the development of body structure parts technology and process, the size of die-cast parts is getting larger and larger, and the integration is getting higher and higher. The weight of the front and rear wheel arches of ordinary passenger cars is 3-4kg, and the longitudinal beam is 7-8kg. In recent years, with the rise of one-piece die-casting technology, the size of the one-piece rear body has developed to about 1.5m×1.5m, and the weight has reached more than 56kg. Compared with the rear body made of steel of the same size, the rear body made of aluminum can reduce weight by 15%. Compared with the white body made of steel of the same size, the white body made of aluminum can reduce weight by 35%. Therefore, the use of die-casting aluminum alloy process is becoming more and more extensive.

[0030] At the same time, due to the increasing demand for emission reduction and consumption reduction in today's social development situation, the lightweight design of vehicle bodies has also received more and more attention. The riveting process can solve the problem of lightweight vehicle bodies in the following aspects: 1. It can realize the connection process problem between materials of different forms. Compared with other connection processes such as welding, riveting is the best choice for connecting non-ferrous metals, which makes it possible to apply lightweight materials for vehicle bodies; 2. It solves the connection strength and safety problems between materials of different forms. The riveting process fully meets the requirements of static strength and dynamic fatigue strength, and has impact energy absorption characteristics, overcomes the shortcomings of welding, and meets safety requirements; 3. It solves the noise and waterproof problems in the car, allowing different forms of materials to have glue coating to achieve the purpose of sound insulation and waterproofing; 4. The materials that can be connected include aluminum (cast aluminum, profiles, plates), deep drawn steel, high-strength steel, magnesium, copper and non-metallic materials. Therefore, the riveting process is widely used in vehicle production.

[0031] In the riveting process, self-pierce riveting (SPR) has the advantages of simple and reliable structure, high efficiency, low cost, low requirements for component product dimensional accuracy, simple operation, low failure rate, and good economic benefits. Therefore, it is widely used in vehicle processing technology, such as body connection technology. However, when using the self-pierce riveting process, due to the complexity of the influencing factors, cracks are common on the surface of aluminum alloy die-cast body structural parts (such as one-piece rear body) during actual riveting, which is not conducive to the structural strength and other performance of the aluminum alloy die-cast body structural parts.

[0032] For this reason, Figure 2-Figure 5 As shown, an embodiment of the present application provides a die that can be used in self-piercing riveting equipment. The die disclosed in the embodiment of the present application includes a die cavity 100, and a centering groove 110 is formed on the bottom wall 120 of the die cavity 100. The notch of the centering groove 110 and the opening of the die cavity 100 face the same direction, and the center line of the centering groove 110 coincides with the center line of the die cavity 100.

[0033] In the embodiment of the present application, the bottom wall 120 of the mold cavity 100 is provided with a centering groove 110. When the die is used in a self-piercing riveting device, during the self-piercing riveting process, the riveted material partially flows into the centering groove 110. The centering groove 110 can center the riveted material, reducing the shaking of the riveted material, thereby alleviating the problem of cracking of the riveted material. Therefore, the embodiment of the present application can solve the problem of cracking in the material after self-piercing riveting in the prior art.

[0034] Optionally, when the die in the embodiment of the present application is applied to a self-piercing riveting device, the upper layer material of the materials riveted by the self-piercing riveting device may be a steel plate, and the lower layer material may be an aluminum alloy plate. Of course, in other embodiments, the upper and lower layers may also be plates of other materials, and this is not limited herein.

[0035] The rivets used in self-piercing riveting have a cavity. During the riveting process, the centering groove 110 is opposite to the cavity of the rivet (with the riveted material between the two). As the rivet moves toward the bottom wall 120, the riveted material flows in the centering groove 110, and the centering groove 110 enters the cavity of the rivet. Therefore, adding a centering groove 110 in the mold cavity 100 can also increase the flow of material in the rivet cavity, preventing the material capacity in the rivet cavity from being small, resulting in the nail foot not yielding and thus affecting the interlocking value. At the same time, the rivet tip does not yield and directly penetrates into the underlying material (such as aluminum alloy plate), resulting in the minimum wall thickness of the underlying material being too small, thereby causing cracks.

[0036] In a further technical solution, the cross-section of the centering groove 110 can be circular, and the diameter of the centering groove 110 can gradually increase along the direction from the bottom wall 120 to the opening. That is, the centering groove 110 is a gradually expanding structure along the direction from the bottom wall 120 to the opening. This structure facilitates the riveted material to separate from the die after the self-piercing riveting is completed.

[0037] The bottom wall 120 may have various structures. In an optional embodiment, the bottom wall 120 may be a planar structure having a groove that is recessed away from the opening to form the centering groove 110 .

[0038] The self-piercing riveting process involves punching, drawing and bending, and has high requirements for the elongation of the riveted material. For example, in order to prevent the aluminum alloy sheet from cracking due to riveting, the existing technology usually performs T7 heat treatment on the aluminum alloy sheet (such as the aluminum alloy sheet made of AlSi10MnMg) to ensure that the elongation of the aluminum alloy material reaches more than 10%.

[0039] In the embodiment of the present application, the bottom wall 120 of the mold cavity 100 may include a raised portion 121 that protrudes toward the opening, and the centering groove 110 may be formed in the raised portion 121. With this structure, during the self-pierce riveting process, the bending and tensile deformation of the material in the portion opposite the raised portion 121 can be reduced, thereby reducing the requirement for material elongation while ensuring that the material does not crack.

[0040] In an optional embodiment, the distance between the bottom of the centering groove 110 and the opening can be equal to the maximum depth of the mold cavity 100 along the centerline. In a preferred embodiment, the distance between the bottom of the centering groove 110 and the opening can be less than the maximum depth of the mold cavity 100 along the centerline. In this structure, the requirement for material elongation can be further reduced while ensuring that the material does not crack.

[0041] In an optional embodiment, the protrusion 121 may be a cylindrical structure.

[0042] In another optional embodiment, the raised portion 121 can be a truncated cone-shaped structure, and the diameter of the truncated cone-shaped structure can gradually increase along the direction from the opening to the bottom wall 120. The raised portion 121 of this structure has a guiding effect on the opening of the rivet, which can assist in the opening of the rivet and prevent the rivet from piercing the riveted underlying material due to failure to yield, while increasing the interlocking value.

[0043] The sidewall of the mold cavity 100 may be a circumferential sidewall 130, and the bottom wall 120 may further include a curved surface 122. The circumferential sidewall 130 may be smoothly connected to the outer edge of the bottom surface of the truncated cone structure away from the opening via the curved surface 122. In this case, it is possible to avoid the formation of relatively sharp protrusions on the riveted material.

[0044] In a further technical solution, the diameter of the circumferential side wall 130 may gradually increase along the direction from the bottom wall 120 to the opening. This structure facilitates the separation of the riveted material from the die after the riveting is completed.

[0045] The die has a first surface 200 for contacting the material to be riveted. The first surface 200 is arranged around the opening. The angle A between the generatrix of the truncated cone structure and the first surface 200 can be 12-18°, for example, 12°, 15°, or 18°. Controlling the angle A within this angle range helps to increase the material in the rivet cavity during the self-piercing riveting process, thereby improving the interlocking value.

[0046] The cross-section of the centering groove 110 can be circular, and the maximum diameter D2 of the centering groove 110 can be 2-5 mm, for example, 2 mm, 3 mm, 4 mm, or 5 mm. The maximum depth H2 of the centering groove 110 along the centerline can be 0.3-0.8 mm, for example, 0.3 mm, 0.5 mm, or 0.8 mm. Within this size range, the amount of stretching of the riveted material is minimized, which helps reduce the shaking of the riveted material during self-piercing and reduces the risk of material cracking.

[0047] The maximum diameter D1 of the mold cavity 100 can be 10-12 mm, for example, 10 mm, 11 mm, 12 mm, and the maximum depth H1 of the mold cavity 100 along the center line direction can be 1.2-1.8 mm, for example, 1.2 mm, 1.5 mm, 1.8 mm. Within this size range, the fluidity of the riveted material (for example, aluminum alloy material) is optimal, which helps prevent the riveted material from cracking and helps ensure that the interlocking value meets the requirements.

[0048] Using the above-mentioned die size for self-pierce riveting equipment makes the self-pierce riveting process have better process matching, high reliability, low failure rate and long service life.

[0049] The concave die in the embodiment of the present application is used for self-piercing riveting equipment to perform self-piercing riveting on the upper steel plate and the lower aluminum alloy plate (such as a one-piece rear body). There is no need to heat treat the aluminum alloy material, and the minimum elongation of the aluminum alloy material is controlled to be above 4%. Please refer to Figure 5 From the cross-sectional view of the material that matches the die in the lower right corner, it can be seen that after testing, the interlocking value a between the rivet and the underlying aluminum alloy sheet is 0.38 mm, the minimum wall thickness b of the aluminum alloy material in the die is 1.19 mm, and there is no crack.

[0050] For the test of the self-piercing riveting equipment using flat die in the prior art, please refer to Figure 5 From the cross-sectional view of the material that matches the die in the lower left corner, it can be seen that the lower aluminum alloy plate has a crack c (there are multiple cracks, and the shapes of the cracks in each location may be different). The test results show that the interlocking value e between the rivet and the lower aluminum alloy plate is 0.96 mm, and the minimum wall thickness d of the aluminum alloy material in the die from the crack c is 1.01 mm. This crack will extend and expand, leading to complete cracking, which has a very adverse effect on the strength of the riveted material and does not meet the quality requirements.

[0051] It should be noted that the die in the above size range is suitable for rivets of a certain size. When the size of the rivet changes, the size of the die can be adjusted.

[0052] Based on the above-mentioned die, the embodiment of the present application further provides a self-piercing riveting device, which includes the above-mentioned die. Since the self-piercing riveting device includes the above-mentioned die, the beneficial effects brought by the die are described above and will not be repeated here.

[0053] The basic principles of the present application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this application are merely illustrative and not restrictive, and it should not be assumed that these advantages, strengths, and effects are required of each embodiment of this application. In addition, the specific details disclosed above are merely illustrative and facilitating understanding, and are not restrictive. The above details do not limit this application to necessarily being implemented using the above specific details.

[0054] The block diagrams of the devices, devices, equipment, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "include," "comprise," "have," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0055] It should also be noted that in the apparatus, device, and method of the present application, each component or each step can be decomposed and / or recombined, and such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0056] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0057] It should be understood that the qualifiers "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only used to more clearly illustrate the technical solutions and cannot be used to limit the scope of protection of the present application.

[0058] The above description has been provided for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A die, characterized in that: The concave mold has a mold cavity (100), and a centering groove (110) is provided on the bottom wall (120) of the mold cavity (100). The notch of the centering groove (110) and the opening of the mold cavity (100) face the same direction, and the center line of the centering groove (110) coincides with the center line of the mold cavity (100).

2. The die according to claim 1, wherein: The cross section of the centering groove (110) is circular, and the diameter of the centering groove (110) gradually increases along the direction from the bottom wall (120) to the opening.

3. The die according to claim 1 or 2, characterized in that: The bottom wall (120) of the mold cavity (100) includes a protruding portion (121) protruding toward the opening, and the centering groove (110) is opened on the protruding portion (121); and / or, The distance between the bottom of the centering groove (110) and the opening is less than the maximum depth of the mold cavity (100) in the centerline direction.

4. The die according to claim 3, wherein: The protrusion (121) is a truncated cone-shaped structure, and the diameter of the truncated cone-shaped structure gradually increases along the direction from the opening to the bottom wall (120).

5. The die according to claim 4, characterized in that The side wall of the mold cavity (100) is a circumferential side wall (130), and the bottom wall (120) further includes a curved surface (122). The circumferential side wall (130) is smoothly connected to the outer edge of the bottom surface of the truncated cone structure away from the opening through the curved surface (122).

6. The die according to claim 5, characterized in that Along the direction from the bottom wall (120) to the opening, the diameter of the circumferential side wall (130) gradually increases.

7. The die according to claim 4, wherein: The concave mold has a first surface (200) for contacting the material to be riveted, the first surface (200) is arranged around the opening, and the angle between the generatrix of the truncated cone structure and the first surface (200) is 12-18 degrees.

8. The die according to claim 1, wherein: The cross section of the centering groove (110) is circular, the maximum diameter of the centering groove (110) is 2-5 mm, and the maximum depth of the centering groove (110) along the center line direction is 0.3-0.8 mm.

9. The die according to claim 1, wherein: The maximum diameter of the mold cavity (100) is 10-12 mm, and the maximum depth of the mold cavity (100) along the center line direction is 1.2-1.8 mm.

10. A self-piercing riveting device, characterized in that: Comprising the concave mold according to any one of claims 1 to 9.

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