A drawing die and drawing method for hardware appearance pieces with protective film

Abstract

The application provides a stretching die for hardware appearance pieces with protective films, which comprises a stretching die sleeve, an inner supporting plate and a stretching male punch. A through hole is arranged at the center of the stretching die sleeve, and a stamping surface is arranged on the inner wall of the through hole and abuts against the protective film of the hardware appearance piece. The stamping surface comprises a pre-pressing surface and a stamping surface arranged in sequence from top to bottom. The pre-pressing surface and the top surface of the inner supporting plate are arranged to be mutually inclined. The stretching die for hardware appearance pieces with protective films has a simple structure, and can complete the stamping and stretching operation by using one set of stretching die, thereby reducing the labor and stamping cost for stretching processing of the hardware appearance pieces with protective films. Meanwhile, the stamping and stretching bending effect of the hardware appearance pieces can be improved, the influence of the protective film on the stretching of the hardware appearance pieces can be reduced, and the problems of peripheral wrinkling and film breaking caused by stretching can be reduced. The application further provides a stretching method for hardware appearance pieces with protective films.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of stamping and drawing dies for hardware appearance parts, and particularly to a drawing die and drawing method for hardware appearance parts with protective films. BACKGROUND

[0002] With the continuous improvement of people's living standards, people's quality requirements for products are also getting higher and higher, and the requirements for electronic products are also getting higher and higher. 3C electronic products such as notebook computers, mobile phones, and tablets are also becoming more and more popular. The shells of such 3C electronic products are generally processed from hardware parts, and during the shell processing process, stamping and drawing are required to achieve the effect of side bending. When the hardware shell is stamped and drawn, a protective film with a thickness of about 0.05mm is attached to the surface of the hardware shell. Because the protective film is a soft material, its hardness is different from that of the hardware shell, so during the stamping and drawing process, quality defects such as wrinkling around the bending edge or film breaking may occur. The protective film attached to the surface of the hardware shell increases the difficulty of stamping and drawing of the product. SUMMARY

[0003] The present application aims to solve the problem that the surface of the hardware shell of the existing 3C electronic product is attached with a protective film before the drawing and stamping process, the hardness of the protective film is different from that of the hardware shell, and therefore quality defects such as wrinkling around the bending edge or film breaking may occur during the drawing and stamping process, and to provide a drawing die for hardware appearance parts with protective films.

[0004] The technical solution adopted by the present application to solve its technical problem is: a drawing die for hardware appearance parts with protective films, comprising a drawing die sleeve fixed on a stamping machine, an inner support plate arranged in the drawing die sleeve to support the hardware appearance part, and a drawing male punch fixed on a punch of the stamping machine; a through hole is arranged at the center of the drawing die sleeve for the inner support plate and the drawing male punch to pass through, a stamping surface is arranged on the inner wall of the through hole to abut against the protective film of the hardware appearance part, the stamping surface comprises a pre-pressing surface and a punch surface arranged in sequence from top to bottom, and the pre-pressing surface and the top surface of the inner support plate are arranged to be mutually inclined.

[0005] In one embodiment, an inclined angle is formed between the pre-pressing surface and the inner support plate, and the inclined angle is between 70°-80°.

[0006] In one embodiment, the inclined angle between the pre-pressing surface and the inner support plate is 72°.

[0007] In one embodiment, the height of the pre-pressing surface is greater than the height of the bending part of the hardware appearance part.

[0008] In one of the embodiments, a transition arc surface is further arranged between the pre-pressing surface and the top surface of the stretching die sleeve.

[0009] In one of the embodiments, the radius of the transition arc surface is greater than or equal to 4 mm.

[0010] In one of the embodiments, the radius of the transition arc surface is 4.5 mm.

[0011] The stretching die for the hardware appearance piece with the protective film has the beneficial effects that the stretching die is simple in structure and can be applied to most stamping machines, is specially used for stamping and stretching and bending of the hardware appearance piece with the protective film on the surface, can complete the stamping and stretching operation of the hardware appearance piece with the protective film by using one set of stretching die, reduces the labor and stamping cost for stretching processing of the hardware appearance piece with the protective film, improves the stamping and stretching and bending effect of the hardware appearance piece, reduces the influence of the protective film on the stretching of the hardware appearance piece, reduces the problems of peripheral wrinkling and film breaking caused by stretching, ensures the integrity of the protective film as much as possible, and reduces the risk of scratches and scratches of the hardware appearance piece in subsequent processing and transfer transportation.

[0012] The application further provides a stretching method for the hardware appearance piece with the protective film, which uses the above-mentioned stretching die for the hardware appearance piece with the protective film to stretch.

[0013] S1: loading, the stretching male punch is separated from the stretching die sleeve, so that the top surface of the inner supporting plate is flush with the top surface of the stretching die sleeve, and then one side of the hardware appearance piece to be processed with the protective film is attached to the top surface of the inner supporting plate;

[0014] S2: fixing the product, the stretching male punch is pressed down, the bottom surface of the stretching male punch is attached to the other side of the hardware appearance piece, so that the inner supporting plate and the stretching male punch clamp the upper and lower end surfaces of the hardware appearance piece;

[0015] S3: pre-stretching, the stretching male punch is continuously pressed down, the hardware appearance piece is pressed down to the bottom end of the pre-pressing surface, and the part of the hardware appearance piece in contact with the pre-pressing surface forms a pre-bending part;

[0016] S4: fine stretching, the stretching male punch is continuously pressed down, the hardware appearance piece is pressed down to the bottom end of the die surface, and the part of the hardware appearance piece in contact with the die surface forms a bending part;

[0017] S5: blanking, the male stretch punch moves upward and separates from the hardware appearance piece, the inner supporting plate supports the hardware appearance piece to move upward in the through hole of the stretch die sleeve to above the stretch die sleeve, and the finished hardware appearance piece is taken off from the inner supporting plate.

[0018] The stretch method for the hardware appearance piece with the protective film provided by the application has the beneficial effects that the stretch die for the hardware appearance piece with the protective film is adopted, the stretch die is used in cooperation with the stamping machine to realize the stamping and stretching of the hardware appearance piece with the protective film, the stretching operation of the hardware appearance piece is completed through the two steps of pre-stretching and fine-stretching, and thus the problems of wrinkling and film breaking of the protective film at the bending part can be effectively relieved in the stamping process. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a perspective exploded structure schematic view of the stretch die for the hardware appearance piece with the protective film provided by the application;

[0020] Figure 2 is a partial enlarged view of the stretch die sleeve with the stamping surface in the stretch die for the hardware appearance piece with the protective film provided by the application;

[0021] Figure 3 is a flow chart of the stretch method for the hardware appearance piece with the protective film provided by the application;

[0022] Figure 4 is a sectional view of step one in the stretch method for the hardware appearance piece with the protective film provided by the application;

[0023] Figure 5 is a sectional view of step two in the stretch method for the hardware appearance piece with the protective film provided by the application;

[0024] Figure 6 is a sectional view of step three in the stretch method for the hardware appearance piece with the protective film provided by the application;

[0025] Figure 7 is a sectional view of step four in the stretch method for the hardware appearance piece with the protective film provided by the application;

[0026] Figure 8 is a sectional view of step five in the stretch method for the hardware appearance piece with the protective film provided by the application.

[0027] BRIEF DESCRIPTION OF DRAWINGS

[0028] 100 - stretch die for the hardware appearance piece with the protective film,

[0029] 10 - stretch die sleeve, 11 - through hole, 12 - stamping surface, 121 - pre-pressing surface, 122 - stamping surface, 123 - transition arc surface, a - inclination angle, H2 - height of pre-pressing surface;

[0030] 20 - inner support plate, 21 - top surface of inner support plate;

[0031] 30 - stretch male punch;

[0032] 40 - hardware appearance piece, 41 - bending part, H1 - height of bending part. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0034] Reference Figures 1-2 The present application provides a stretch die for hardware appearance piece with protective film 100. The stretch die 100 provided by the present application can be used on various stamping machines, and is specially used for stamping and stretching of hardware appearance piece with protective film. The stretch of hardware appearance piece can be completed by one set of stretch die, which not only solves the problem of cost increase and complicated process caused by two sets of die and two times of operation for one workpiece, but also avoids the problems of wrinkling and film breaking of the protective film of hardware appearance piece as much as possible on the basis of one set of stretch die, and ensures the quality of the stretched hardware appearance piece.

[0035] As Figure 1 shown, it is a perspective exploded structure diagram of the stretch die 100 provided by the present application. The stretch die 100 for hardware appearance piece with protective film provided by the present application comprises a stretch die sleeve 10 fixed on a stamping machine, an inner support plate 20 arranged in the stretch die sleeve 10 to support the hardware appearance piece 40, and a stretch male punch 30 fixed on a punch of the stamping machine. The stretch die sleeve 10 in the stretch die 100 is fixed on the workbench of the stamping machine, the stretch male punch 30 is fixed on the punch of the stamping machine, can vertically ascend and descend relative to the stretch die sleeve 10 along with the punch of the stamping machine, and passes through the stretch die sleeve 10. The inner support plate 20 is arranged inside the stretch die sleeve 10, and can ascend and descend in the stretch die sleeve 10 under the drive of the stamping machine. During the stretching operation, the inner support plate 20 and the stretch male punch 30 clamp the hardware appearance piece 40 from the upper and lower end surfaces of the hardware appearance piece 40, and drive the hardware appearance piece 40 to vertically move in the stretch die sleeve 10.

[0036] As Figure 1As shown in the drawings, the stretch die 100 provided by the present application is provided with a through hole 11 in the center of the stretch die sleeve 10, through which the inner support plate 20 and the stretch male punch 30 can pass, and a stamping surface 12 is arranged on the inner wall of the through hole 11, which abuts against the protective film of the hardware appearance part 40. The shape of the through hole 11 is related to the profile of the product to be processed. In the embodiment, as shown in the drawings, the hardware appearance part 40 is a product with a rectangular profile, and correspondingly, the through hole 11 arranged in the center of the stretch die sleeve 10 is a rectangular through hole. The number of the stamping surfaces 12 arranged on the inner wall of the through hole 11 is also determined by the parts of the hardware appearance part 40 that need to be stretched. In the embodiment, as shown in the drawings, three sides of the rectangular profile of the hardware appearance part 40 need to be stretched and bent, so three stamping surfaces 12 are arranged on the inner wall of the through hole 11 of the stretch die sleeve 10, and each stamping surface 12 is continuous and identical in structure. Figure 1 Figure 1 As shown in the drawings, the stretch die sleeve 10 is provided with three stamping surfaces 12 on the inner wall of the through hole 11, and each stamping surface 12 is continuous and identical in structure.

[0037] As shown in the drawings, the stretch die sleeve 10 is provided with three stamping surfaces 12 on the inner wall of the through hole 11, and each stamping surface 12 is continuous and identical in structure. Figure 2 As shown in the drawings, the stretch die sleeve 10 is provided with three stamping surfaces 12 on the inner wall of the through hole 11, and each stamping surface 12 is continuous and identical in structure.

[0038] As shown in the drawings, the stretch die sleeve 10 is provided with three stamping surfaces 12 on the inner wall of the through hole 11, and each stamping surface 12 is continuous and identical in structure. Figure 2 As shown in the drawings, the stretch die sleeve 10 is provided with three stamping surfaces 12 on the inner wall of the through hole 11, and each stamping surface 12 is continuous and identical in structure.

[0039] ​The pre-pressing surface 121 in the stretching die sleeve 10 forms an inclined angle a with the inner support plate 20, and the inclined angle a is between 70° and 80°. If the inclined angle a of the pre-pressing surface 121 is less than 70°, the pre-pressing effect on the hardware appearance part 40 cannot be achieved, and the protective film attached to the hardware appearance part 40 cannot be tightened. If the inclined angle a of the pre-pressing surface 121 is greater than 80°, the protective film will be damaged, wrinkles or broken film will occur when the protective film is pre-pressed, and the purpose of synchronously stretching the protective film and the hardware appearance part 40 cannot be achieved. In the embodiment, the inclined angle a between the pre-pressing surface 121 in the stretching die sleeve 10 and the inner support plate 20 is 72°. When the pre-pressing surface 121 is designed at 72°, the yield rate of the product after the hardware appearance part 40 and the protective film are punched and stretched is the highest, the wrinkling condition around the bending part 41 is the least, and there is no broken film of the protective film after stretching.

[0040] As shown in Figure 2 , the height of the pre-pressing surface 121 in the punching surface 12 in the stretching die sleeve 10 is H2. As shown in Figure 8 , the height of the bending part 41 in the hardware appearance part 40 is H1. In order to ensure that the pre-pressing surface 121 can fully achieve the pre-pressing effect on the bending part 41, the height H2 of the pre-pressing surface 121 is greater than the height H1 of the bending part 41 of the hardware appearance part 40. If the height H2 of the pre-pressing surface 121 is too large, the stretching stroke required by the stretching punch 30 each time is larger, but if the height H2 of the pre-pressing surface 121 is less than the height H1 of the bending part 41 of the hardware appearance part 40, the pre-stretching effect of the stretching die sleeve 10 on the hardware appearance part 40 is poor, and it cannot be ensured that the protective film attached to the hardware appearance part 40 can achieve the pre-pressing effect of being tightened when the hardware appearance part 40 enters the punching surface 122.

[0041] As shown in Figure 2 , the punching surface 12 in the stretching die sleeve 10 further comprises a transition arc surface 123, and the pre-pressing surface 121 of the punching surface 12 and the top surface 13 of the stretching die sleeve 10 are further provided with the transition arc surface 123. The provision of the transition arc surface 123 can effectively reduce the contact between the edge of the hardware appearance part 40 and the top surface 13 of the stretching die sleeve 10 during the punching process, and avoid unnecessary contact between the top surface 13 of the stretching die sleeve 10 and the side surface of the hardware appearance part 40. Therefore, the radius of the transition arc surface 123 in the stretching die sleeve 10 is greater than or equal to 4 mm. In the embodiment, the radius of the transition arc surface 123 is 4.5 mm.

[0042] The stretch die 100 of the hardware appearance piece 40 with a protective film provided by the application is simple in structure and can be applied to most punch machines, and is specially used for punching, stretching and bending of the hardware appearance piece 40 with a protective film. The punching, stretching and bending operation of the hardware appearance piece 40 with a protective film can be completed by using a set of stretch dies 100, the labor and punching cost for stretching the hardware appearance piece 40 with a protective film are reduced, the effect of punching, stretching and bending of the hardware appearance piece 40 is improved, the influence of the protective film on the stretching of the hardware appearance piece 40 is reduced, the problems of peripheral wrinkling and film breaking caused by stretching are reduced, the integrity of the protective film is ensured as much as possible, and the risk of scratch and scratch of the hardware appearance piece 40 in the subsequent processing and transfer transportation process is reduced.

[0043] As shown in Figures 3-8 The application further provides a stretching method of the hardware appearance piece 40 with a protective film, which uses the above-mentioned stretching die 100 of the hardware appearance piece 40 with a protective film to stretch. As shown in Figure 3 The flow chart of the stretching method provided by the application, the stretching method of the hardware appearance piece 40 with a protective film provided by the application includes the following steps:

[0044] As shown in Figure 4 The state diagram of step 1 in the stretching method provided by the application. S1 in the stretching method: feeding, the stretch male punch 30 is fixed on the punch head of the punch machine, the stretch die sleeve 10 is fixed on the workbench of the punch machine, the stretch male punch 30 and the stretch die sleeve 10 in the stretch die 100 are separated by operating the punch machine, the inner supporting plate 20 and the workbench of the punch machine can be automatically reset to the top surface of the inner supporting plate 20 and the top surface of the stretch die sleeve 10 by setting elastic members or other reset components, and then the hardware appearance piece 40 to be processed with a protective film is attached to the top surface of the inner supporting plate 20. In step S1, the hardware appearance piece 40 to be processed can be placed above the stretch die sleeve 10 by a mechanical arm, and the side with the protective film is placed downward, so that the protective film can be attached to the top surface 21 of the inner supporting plate 20. The placing step of the hardware appearance piece 40 can be completed by a mechanical arm or manually, and the hardware appearance piece 40 to be processed can be placed in the stretch die 100.

[0045] As shown in Figure 5The diagram shown is a state diagram of step 2 in the stretching method provided by the present invention. In step S2 of this stretching method: the product is fixed, and the punch in the stamping machine is moved downward, causing the stretching punch 30 fixed on the punch to press down, so that the bottom surface of the stretching punch 30 is attached to the other side of the hardware appearance part 40. The side of the hardware appearance part 40 that is attached to the bottom surface of the stretching punch 30 is not provided with a protective film. When the stretching punch 30 is attached to the hardware appearance part 40, the inner support plate 20 in the stretching die 100 and the stretching punch 30 clamp the upper and lower end faces of the hardware appearance part 40.

[0046] like Figure 6 The diagram shown is a state diagram of step 3 in the stretching method provided by the present invention. In this stretching method, S3 is pre-stretching. As the punch in the stamping press continues to press down, the stretching punch 30 continues to press down, pressing the side of the metal exterior part 40 with the protective film to the bottom of the pre-pressing surface 121 of the stamping surface 12. At this time, the side of the metal exterior part 40 with the protective film is always in contact with the stamping surface 12 of the stretching die sleeve 10, and bends along with the pre-pressing surface 121 of the stamping surface 12. The portion of the metal exterior part 40 in contact with the pre-pressing surface 121 forms a pre-bent portion. The bending angle generated by this pre-bent portion is approximately equal to the inclination angle α generated by the inclination on the pre-pressing surface 121. The bending angle of this pre-bent portion does not reach the designed angle of the bending portion 41 of the metal exterior part 40.

[0047] like Figure 7 The diagram shown is a state diagram of step 4 in the stretching method provided by the present invention. In this stretching method, S4 is fine stretching. As the punch in the stamping press continues to press down, the stretching punch 30 continues to press down, pressing the side of the metal exterior part 40 with the protective film down to the bottom of the stamping surface 122. At this time, the portion of the metal exterior part 40 that contacts the stamping surface 122 forms a bent portion 41. The angle between the stamping surface 122 and the horizontal plane is the designed angle of the bent portion 41, so that the bent portion 41 meets the design requirements.

[0048] like Figure 8 The diagram shown is a state diagram of step 5 in the stretching method provided by the present invention. In step S5 of the stretching method: unloading, the punch of the stamping machine is reset upward, driving the stretching punch 30 to move upward and separate from the metal appearance part 40. At this time, the reset component set at the bottom of the inner support plate 20 will drive the inner support plate 20 to move upward, so that the inner support plate 20 supports the metal appearance part 40 and moves upward within the through hole 11 of the stretching die sleeve 10 to above the stretching die sleeve 10, and the stamped metal appearance part 40 is removed from the inner support plate 20.

[0049] The present application provides a stretching method of the hardware appearance piece 40 with the protective film, adopts the stretching die 100 of the hardware appearance piece 40 with the protective film, realizes the stamping stretching of the hardware appearance piece 40 with the protective film by the stretching die 100 cooperating with the stamping machine table, and completes the stretching operation of the hardware appearance piece 40 through the two steps of pre-stretching and fine stretching, so that the wrinkling and film breaking problems of the protective film at the bending part can be effectively relieved in the stamping process.

[0050] The above only is the preferred embodiment of the present application, and does not limit the present application, and any modification, equivalent replacement and improvement within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method of stretching a hardware-appearing piece with a protective film, characterized by, The stretching method of the hardware appearance piece with protective film uses a stretching die for hardware appearance piece with protective film, which comprises a stretching die sleeve fixed on a punch machine, an inner support plate arranged in the stretching die sleeve to support the hardware appearance piece, and a stretching male punch fixed on a punch head of the punch machine; A through hole is arranged at the center of the stretching die sleeve, through which the inner support plate and the stretching male punch pass, and a stamping surface abutting against the protective film of the hardware appearance piece is arranged on the inner wall of the through hole, which comprises a pre-stamping surface and a stamping surface arranged in sequence from top to bottom, and the pre-stamping surface and the top surface of the inner support plate are arranged to be mutually inclined; The stretching method of the hardware appearance piece with protective film comprises the following steps: S1: feeding, the stretching male punch is separated from the stretching die sleeve, so that the top surface of the inner support plate is flush with the top surface of the stretching die sleeve, and then the hardware appearance piece to be processed with the protective film is attached to the top surface of the inner support plate; S2: fixing the product, the stretching male punch is pressed down, the bottom surface of the stretching male punch is attached to the other side surface of the hardware appearance piece, so that the inner support plate and the stretching male punch clamp the upper and lower end surfaces of the hardware appearance piece; S3: pre-stretching, the stretching male punch is continuously pressed down, the hardware appearance piece is pressed down to the bottom end of the pre-stamping surface, and the part of the hardware appearance piece in contact with the pre-stamping surface forms a pre-bent part; S4: fine stretching, the stretching male punch is continuously pressed down, the hardware appearance piece is pressed down to the bottom end of the stamping surface, and the part of the hardware appearance piece in contact with the stamping surface forms a bent part; S5: discharging, the stretching male punch moves upward and separates from the hardware appearance piece, the inner support plate supports the hardware appearance piece to move upward above the stretching die sleeve in the through hole of the stretching die sleeve, and the hardware appearance piece after stamping is taken off from the inner support plate.

2. The method of claim 1, wherein the metal appearance piece is a metal appearance piece with a protective film. The inclined angle between the pre-stamping surface of the stretching die sleeve and the inner support plate is 70°-80°.

3. The method of claim 2, wherein the metal appearance piece is a metal appearance piece with a protective film. The inclined angle between the pre-stamping surface and the inner support plate is 72°.

4. The stretch method of a hardware appearance piece with a protective film according to claim 1, wherein The height of the pre-stamping surface is greater than the height of the bent part of the hardware appearance piece.

5. The stretch method of a hardware appearance piece with a protective film according to claim 1, wherein A transition arc surface is further arranged between the pre-stamping surface and the top surface of the stretching die sleeve.

6. The method of claim 5, wherein the metal appearance piece is a metal appearance piece with a protective film. The radius of the transition arc surface is greater than or equal to 4mm.

7. The method of claim 6, wherein the metal appearance piece is a metal appearance piece with a protective film. The radius of the transition arc surface is 4.5mm.

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