Automobile component cold stamping die and stamping method thereof

Abstract

The application discloses a cold stamping die for automobile parts and a stamping method thereof, and relates to the technical field of stamping dies. The cold stamping die for automobile parts comprises an upper die plate and a lower die plate which are respectively installed on an upper mounting plate and a lower mounting plate, a sliding block is arranged in the upper die plate, a male die is installed on the bottom surface of the sliding block, and a female die groove corresponding to the male die is formed in the lower die plate; guide sleeves and guide columns are arranged on the upper mounting plate and the lower mounting plate; a punching pin for punching is installed on the upper die plate; the cold stamping die can realize the synchronous forming of a middle concave shape, four-hole punching, burr control and natural chamfering, the collaborative design of the pre-pressing inner concave ring groove area of the conical extrusion die and the precise punching of the punching pin can save the secondary processes of 'burr removal and manual chamfering' after traditional stamping, and the T-H-alpha-R parameter correlation logic is combined to ensure that the punching process requirements can be met by one-time stamping.

Description

Technical Field

[0001] This invention belongs to the field of stamping die technology, specifically, it relates to a cold stamping die for automotive parts and a stamping method thereof. Background Technology

[0002] The design of cold stamping dies for automotive parts is one of the key technologies in the automotive manufacturing industry, directly affecting the quality, production efficiency, and manufacturing cost of automotive parts. Stamping dies are special process equipment used in cold stamping to process metal or non-metal into parts or semi-finished products. They are commonly known as cold stamping dies. Working in conjunction with a press, they apply directional pressure to the material, forcing it to separate (e.g., punching, blanking) or undergo plastic deformation (e.g., bending, drawing), ultimately obtaining parts or semi-finished products that meet automotive assembly standards. Because sheet metal parts after stamping and punching require bolt assembly, sheet metal punching is the most frequently used stamping process, especially in automotive parts production.

[0003] In the production of automotive parts, cover plates are widely used. These types of parts often need to meet the process requirements of having a recessed center and perforations around the edges. However, due to the use of punching, the shearing deformation and tearing during the separation of the sheet metal leads to poor punching quality and bottom burrs, which can cause parts to fail to meet the process requirements after punching.

[0004] In existing technologies, burrs are usually removed by secondary processing after punching.

[0005] As disclosed in the prior art, patent CN217166053U discloses a precision punch for punching and stamping dies for removing burrs from metal parts. The punch includes a punch base and a punch core connected coaxially. The punch core has an insertion portion, on which a brush sleeve with bristles angled in the reverse punching direction is fitted. Thus, after the punch cuts a hole in the workpiece, it continues to press down, causing the brush sleeve to pass through the hole. Because the bristles of the brush sleeve are angled in the reverse punching direction, when the brush sleeve returns to its original position with the punch, the bristles effectively hook onto the burrs at the edge of the hole, effectively brushing them off. This technical solution not only effectively removes burrs from the hole edge during punching but also has a simple structure and is easy to implement.

[0006] The existing technology described above uses a brush sleeve, which hooks onto the burrs on the edge of the hole and removes them when the brush sleeve returns to its original position with the punch. However, the brush sleeve causes additional damage to the hole when it enters and exits the hole, resulting in low hole forming quality that does not meet process requirements. Furthermore, while the brush sleeve is effective at removing small burrs, it is not effective at removing larger burrs. Therefore, a cold stamping die for automotive parts and its stamping method are proposed. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a cold stamping die for automobile parts and a stamping method thereof that can overcome or at least partially solve the above problems.

[0008] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows: a cold stamping die for automotive parts, comprising: an upper template and a lower template respectively mounted on an upper mounting plate and a lower mounting plate; a slider is slidably disposed in the upper template, and a punch is mounted on the bottom surface of the slider; a die groove corresponding to the punch is opened on the lower template; a guide sleeve and a guide post are respectively disposed on the upper mounting plate and the lower mounting plate; a punch for punching is mounted on the upper template, and a pressure sleeve is slidably connected to the punch by a spring; a die hole is opened on the lower template, and a conical extrusion die for forming an inner concave annular groove area on the bottom surface of the sheet metal is installed in the die hole; a separation area is formed on the upper edge of the inner concave annular groove area; the conical extrusion die is used to increase the distance between the separation area of ​​the sheet metal and the bottom surface of the sheet metal; and a peeling rod is disposed on the slider.

[0009] Preferably, the upper template has a boss-type mounting cavity, the slider is slidably connected in the boss-type mounting cavity, a pad is mounted on the upper mounting plate, the upper template is mounted on the pad, and a spring is provided between the top surface of the slider and the pad.

[0010] Preferably, the second spring is fixedly connected to the pressure sleeve, and the end of the second spring away from the pressure sleeve is fixedly connected to the first cover, which is connected to the upper template by screws.

[0011] Preferably, the slider has symmetrically formed sliding cavities, one end of the peeling rod is slidably connected in the sliding cavity, a spring is provided between the peeling rod and the sliding cavity, and the peeling rod is connected to the slider through a cover.

[0012] Preferably, the lower template has a discharge cavity that is connected to the die hole for collecting waste material; a second pad is installed on the lower mounting plate, the lower template is installed on the second pad, the discharge cavity forms a closed chamber through the second pad, an air pipe connector connected to the discharge cavity is installed on one side of the lower template, one end of the discharge cavity penetrates the lower template, and a block is provided on the lower template at the penetration point.

[0013] Preferably, the conical extrusion die includes a cylindrical body, the top of which has a continuous upper plane and an inclined surface, and the cylindrical body has an inner hole with both ends penetrating through the cylindrical body.

[0014] Preferably, the punch has a straight cutting edge.

[0015] Preferably, the punch has a rounded edge.

[0016] Preferably, the sheet thickness is T, the inclined plane height is H, the radius of the circular arc edge is R, and the cone angle of the conical extrusion die is a, wherein H = (1 / 4~1 / 3)T, a = 30°~45°, and R = (0.15~0.25)H.

[0017] A stamping method for an automotive part includes the following steps:

[0018] S1. Place the sheet material to be processed on the lower template and limit its position using positioning blocks;

[0019] S2. The press drives the upper mounting plate to move downwards. The peeling rod first contacts the plate material to pre-press it, and then the punch contacts the plate material and cooperates with the die groove to press the central concave shape.

[0020] S3. The upper die continues to descend, and the pressure sleeve contacts both ends of the plate material, squeezing the plate material so that the bottom surface contacts the conical extrusion die, pressing out the inner concave annular groove area.

[0021] S4. When the pressure sleeve reaches its maximum stroke, the punch extends and penetrates the sheet metal, and the waste material is pushed into the discharge chamber, simultaneously forming a punch with no bottom burrs and a chamfer.

[0022] S5. The press drives the upper die to move upward, springs one, two, and three reset, and the peeling rod peels off the sheet metal, completing the stamping process.

[0023] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0024] 1. This automotive part cold stamping die enables simultaneous central concave forming, four-corner punching, burr control, and natural chamfering. Utilizing the synergistic design of the conical extrusion die's pre-pressed concave annular groove area and the precise punching of the punch, it eliminates the secondary processes of "deburring and manual chamfering" after traditional stamping. Compared to existing technologies, it can better "remove" burrs, thereby reducing the generation of burrs at the bottom edge of the punched holes. Furthermore, combined with TH-α-R parameter correlation logic, it ensures that the punching process requirements are met in a single stamping, effectively improving production efficiency.

[0025] 2. This automotive part cold stamping die features an upper die with a height difference design between the peeling rod, punch, and pressure sleeve. This design allows for the sequential connection of pre-clamping, concave forming, annular groove pre-clamping, and punching. The peeling rod pre-positions the sheet metal to prevent the ends from lifting during stamping. Springs one and two ensure continuous stamping by the punch and stable extrusion by the pressure sleeve. The lower die uses a tapered extrusion die with an annular groove pressed into the inclined surface to confine the separation zone within the sheet metal, preventing burrs from protruding from the bottom surface.

[0026] 3. In this cold stamping die for automotive parts, the discharge cavity of the lower die plate, in conjunction with a blocking block, enables centralized collection of waste material. The air pipe connector allows gas to be introduced to assist in material ejection and to cool the die.

[0027] 4. Compared with the existing technology where the absence of a pre-compression groove leads to numerous burrs on the bottom surface and requires secondary processing, this device uses an inner concave groove area to confine the burrs to the inner wall of the punch hole, and with the rounded edge, achieves a natural chamfer on the upper surface, resulting in a hole quality that is significantly better than that of traditional processes. Attached Figure Description

[0028] In the attached diagram:

[0029] Figure 1 This is a schematic diagram of the structure of a cold stamping die for automotive parts proposed in this invention;

[0030] Figure 2 This is a perspective view of a cold stamping die for automotive parts proposed in this invention;

[0031] Figure 3 This is a schematic diagram of the upper template, pad 1, lower template, and pad 2 of a cold stamping die for automotive parts proposed in this invention.

[0032] Figure 4 This is a schematic diagram of the structure of the punch of a cold stamping die for automotive parts proposed in this invention;

[0033] Figure 5 This is a schematic diagram of the punch and stripping rod of a cold stamping die for automotive parts proposed in this invention;

[0034] Figure 6 This is a schematic diagram of the boss-type mounting cavity and spring of a cold stamping die for automotive parts proposed in this invention.

[0035] Figure 7 This is a schematic diagram of the slider, punch, and stripping rod of a cold stamping die for automotive parts proposed in this invention.

[0036] Figure 8 This is a partial view of the punch, upper template, slider, and stripping rod of a cold stamping die for automotive parts proposed in this invention.

[0037] Figure 9 This is a schematic diagram of the air pipe connector of a cold stamping die for automotive parts proposed in this invention;

[0038] Figure 10 This is a schematic diagram of the positioning block of a cold stamping die for automotive parts proposed in this invention;

[0039] Figure 11 This is a schematic diagram of the material discharge cavity and blocking block of a cold stamping die for automotive parts proposed in this invention;

[0040] Figure 12This is a schematic diagram of the straight cutting edge of a cold stamping die for automotive parts proposed in this invention;

[0041] Figure 13 This is a schematic diagram of the arc-shaped cutting edge of a cold stamping die for automotive parts proposed in this invention;

[0042] Figure 14 This is a schematic diagram of the collapsed corner area, the concave annular groove area, and the separation area of ​​a cold stamping die for automotive parts proposed in this invention.

[0043] Figure 15 This is a schematic diagram of the upper plane, inclined plane, cylindrical body, and inner hole of a cold stamping die for automotive parts proposed in this invention;

[0044] Figure 16 Schematic diagram of stamped finished product Figure 1 ;

[0045] Figure 17 Schematic diagram of stamped finished product Figure 2 ;

[0046] Figure 18 This is a schematic diagram of the existing punching process.

[0047] In the diagram: 1. Upper mounting plate; 11. Pad 1; 12. Upper template; 121. Boss-type mounting cavity; 13. Guide sleeve; 14. Slider; 140. Punch; 141. Spring 1; 142. Slide cavity; 15. Punch; 1501. Straight cutting edge; 1502. Rounded cutting edge; 151. Pressure sleeve; 152. Spring 2; 153. Cover 1; 16. Peeling rod; 161. Spring 3; 162. Cover 2;

[0048] 2. Lower mounting plate; 21. Second pad; 22. Lower template; 220. Die cavity; 221. Positioning block; 23. Guide post; 24. Conical extrusion die; 241. Inner hole; 242. Upper plane; 243. Inclined surface; 245. Column; 25. Discharge cavity; 251. Air pipe connector; 252. Block; 26. Die cavity;

[0049] 3. Sheet metal; 30. Punching; 31. Collapsed corner area; 32. Inner concave annular groove area; 33. Separation area. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0051] Reference Figures 1-18The cold stamping die for automotive parts disclosed in this embodiment is mainly used for cold stamping of sheet metal 3 to achieve integrated processing of "central concave forming, four-corner punching, burr control, and natural chamfering". The thickness of sheet metal 3 is T, where T = 3~6mm, and in this embodiment, T = 3mm.

[0052] The overall structure of the stamping die includes:

[0053] The upper mold section includes an upper mounting plate 1, a pad 11, an upper template 12, a guide sleeve 13, a slider 14, a punch 140, a spring 141, a punch 15, a pressure sleeve 151, a spring 2 152, a cover 153, a peeling rod 16, a spring 3 161, and a cover 2 162. The upper template 12 is fixed to the upper mounting plate 1 via the pad 11. The upper template 12 has a boss-type mounting cavity 121 inside, and the slider 14 is slidably connected within the boss-type mounting cavity 121 (the structure of the boss-type mounting cavity 121 and the slider 14 is described in detail). Figure 7 A spring 141 is provided between the top surface of the slider 14 and the pad 11 (providing the slider 14 with a reset force and elastic pressure on the sheet 3). A punch 140 is installed on the bottom surface of the slider 14 (for concave forming of the middle of the sheet 3). Two sets of sliding cavities 142 (two cavities 142 in each set) are symmetrically opened on both sides of the slider 14. One end of the peeling rod 16 is slidably connected in the sliding cavity 142, and a spring 161 is provided between the peeling rod 16 and the sliding cavity 142 (to drive the peeling rod 16 to reset and prevent the formed sheet 3 from moving upward with the slider 14). The other end of the peeling rod 16 is limited by a cover 162 (the cover 162 also facilitates the installation and removal of the peeling rod 16).

[0054] A punch 15 is also fixed on the upper template 12 (used for punching holes at the four corners of the sheet 3 to form punch holes 30; the punch 15 is installed by setting mounting holes on the upper template 12, and the punch 15 is installed from the surface of the upper template 12 into the mounting holes, and is installed on the pad 11 by the upper template 12 to limit and fix the punch 15. It should be understood that the end of the punch 15 with a larger diameter protrudes slightly from the surface of the upper template 12 to prevent the punch 15 from moving up and down in the mounting hole after installation). A pressure sleeve 151 is sleeved on the end of the punch 15, and the pressure sleeve 151 can slide on the punch 15. A spring 152 is connected between the pressure sleeve 151 and the cover 153 (the spring 152 makes the pressure sleeve 151 press the sheet 3 tightly).

[0055] The lower mold section includes a lower mounting plate 2, a second pad 21, a lower template 22, a guide post 23, a conical extrusion die 24, and a blocking block 252. The lower template 22 is fixed to the lower mounting plate 2 by the second pad 21. The top surface of the lower template 22 has a die groove 220 corresponding to the punch 140 (to form the concave shape in the middle), and die holes 26 are opened at the four corners. The conical extrusion die 24 is installed in the die holes 26 by interference fit. The lower template 22 has a discharge cavity 25 inside and communicates with the die holes 26. One end of the discharge cavity 25 penetrates through the side of the lower template 22, and a blocking block 252 is set on the lower template 22 at the penetration position (on the one hand, to make the discharge cavity 25 a closed chamber; on the other hand, the blocking block 252 can be removed to facilitate the cleaning out of the waste material in the discharge cavity 25).

[0056] The conical extrusion die 24 includes a cylindrical body 245, with a continuous upper plane 242 and inclined plane 243 at the top, and a through inner hole 241 in the center (for the punch 15 to pass through).

[0057] In the initial state, the upper mounting plate 1 and the lower mounting plate 2 are separated, and springs 141, 152, and 161 are all in their natural extended state; plate 3 is placed on the top surface of the lower template 22, and is limited by the positioning block 221 (see reference). Figure 10 This improves placement speed and accuracy. In the initial state, the end of the peeling rod 16 protrudes from the punch 140, and the pressure sleeve 151 is shorter than the punch 140, creating a height difference between the peeling rod 16, the punch 140, and the pressure sleeve 151. The height difference from high to low is as follows: peeling rod 16 > punch 140 > pressure sleeve 151 > punch 15.

[0058] During mold closing, the press drives the upper mounting plate 1 downward, and the guide sleeve 13 slides along the guide post 23 to ensure mold closing accuracy. First, the peeling rod 16 will contact the surface of the sheet metal 3 to pre-press the sheet metal 3 and prevent misalignment. Then, during the continuous downward movement of the upper mounting plate 1, the peeling rod 16 slides into the slide cavity 142 and squeezes the spring 161. Subsequently, the punch 140 contacts the sheet metal 3 and presses it down. The punch 140 cooperates with the die groove 220 to press the middle of the sheet metal 3 into a concave shape. During the pressing process of the punch 140, the two ends of the sheet metal 3 will lift up. At this time, the peeling rod 16 will limit the lifting up to avoid excessive lifting and low forming quality. Secondly, the continuous downward movement of the upper mounting plate 1 will also cause the slider 14 to retract into the boss-type mounting cavity 121 and squeeze the spring 141, so that the punch 140 continues to press the sheet metal 3. During this process, the pressure sleeve 151 contacts the two ends of the sheet metal 3, and during the retraction of the punch 140, the pressure sleeve 151 continuously squeezes the sheet metal 3, so that the bottom surface of the sheet metal 3 makes hard contact with the conical extrusion die 24, pressing out the inner concave annular groove area 32. Among them, in order to improve the wear resistance of the pressure sleeve 151 and the conical extrusion die 24, high-speed steel, powder metallurgy high-speed steel or heat-treated metal materials can be used.

[0059] It is important to understand that both spring 141 and spring 152 are special mold springs, which have high stiffness characteristics and their elastic coefficient (spring constant) is significantly higher than that of ordinary springs. Effective compression stroke will only occur when the external force reaches its design working load threshold. This characteristic ensures that the spring maintains the stability of the pressure sleeve 151 during the pre-contact stage of the mold (such as when the pressure sleeve 151 initially contacts the sheet 3), avoiding premature compression caused by slight external force, thereby ensuring molding accuracy.

[0060] When pressing the concave annular groove area 32, during the maximum upward stroke of the pressing sleeve 151, the end of the punch 15 extends out of the pressing sleeve 151, penetrates the sheet 3 and enters the inner hole 241 of the conical extrusion die 24, and pushes the punched waste into the discharge cavity 25, thus completing the punching operation on the sheet 3.

[0061] After punching is completed, the press drives the upper mounting plate 1 to move upward, and springs 141, 152, and 161 reset. Under the action of spring 161, the stripping rod 16 peels the sheet metal 3 from the punch 140, and the pressure sleeve 151 resets to prevent the sheet metal 3 from moving upward with the punch 15, thus completing one punching operation.

[0062] Before that, refer to Figure 18 , Figure 18 This refers to the punching state produced by stamping dies that do not employ the conical extrusion die 24, which is currently the only type of stamping technology available. Figure 18The fracture zone indicated in the middle is the tear zone caused by the separation of the sheet metal during punching. Its inner wall is mostly characterized by fractures and many burrs. Below the fracture zone is the burr area, with burrs protruding from the bottom surface of the sheet metal.

[0063] Reference Figure 12 In this device, during the punching operation, the punch 15 uses a straight cutting edge 1501. During the process of the punch 15 penetrating the sheet metal 3, because the bottom surface of the sheet metal 3 is pre-pressed with an inner concave annular groove area 32, the separation area 33 changes to the inside of the sheet metal 3, that is, the inner wall of the punch hole 30. Therefore, when the punch 15 applies pre-extrusion to the upper surface of the sheet metal 3, the punching operation is completed when the punch 15 reaches the separation area 33 (the upper edge of the inner concave annular groove area 32, which is the separation point between the waste and the sheet metal 3), and the punch hole 30 is formed. This design can reduce... Figure 8 The thickness of the fracture zone effectively prevents burrs from forming on the bottom surface of sheet metal 3 at the punch hole 30. Secondly, the tapered extrusion die 24 has an inclined surface 243 (see reference...) Figure 15 Therefore, when the conical extrusion die 24 extrudes the bottom surface of the sheet metal 3, it will present a "beveled" shape at the edge of the punch 30 on the bottom surface of the sheet metal 3. The "beveled" position is smoother than the existing fracture zone, thus forming a punch 30 of better quality.

[0064] In some embodiments, refer to Figure 13 The punch 15 uses a rounded cutting edge 1502. Compared with a straight cutting edge 1501, the rounded cutting edge 1502 can increase the curvature of the corner area 31 in the punch 30 (making the edge of the punch 30 on the surface of the sheet 3 rounded, avoiding sharp edges or burrs in the corner area), and can also make the corner area 31 more rounded than the punch 30 in the prior art. Figure 18 The edges of the collapsed corners are smoother, further improving the forming quality of the punched hole 30, thereby meeting the process requirements;

[0065] Among them, the collapsed corner area 31 is naturally generated when the punch 15 makes a hole and comes into contact with the sheet 3, and the sheet 3 at the contact position separates.

[0066] In some embodiments, refer to Figure 14 , Figure 15 Let the thickness of sheet metal 3 be T, the height of inclined plane 243 be H, the radius of the circular arc edge 1502 be R, and the cone angle of the conical extrusion die 24 be a, where H = (1 / 4~1 / 3)T, a = 30°~45°, and R = (0.15~0.25)H;

[0067] The height H of the inclined plane 243 directly determines the depth of the concave annular groove area 32. When H is 1 / 4 to 1 / 3 of the thickness T of the sheet 3, the separation area 33 is located in the "middle layer plastic deformation zone" of the sheet 3 (rather than the rigid zone near the bottom). At this time, the burrs generated by the separation of the sheet 3 will be concentrated on the inner wall of the punch 30, avoiding the appearance of burrs on the bottom surface (assembly contact surface) of the sheet 3, so no secondary grinding is required.

[0068] If H < 1 / 4T, the separation zone 33 is close to the bottom surface of the sheet 3, and burrs may still be generated on the bottom surface. If H > 1 / 3T, the concave annular groove zone 32 is too deep, which will cause the remaining thickness of the hole wall of the punch 30 to be too thin (especially for thin sheet metal). After stamping, the hole wall is prone to deformation (such as collapse and wrinkles), which will affect the structural strength of the bolt assembly. Therefore, this range can take into account both "burr avoidance" and "hole wall strength".

[0069] The cone angle α controls the inclination angle of the side wall of the concave annular groove area 32. At this time, the extrusion force of the conical extrusion die 24 can be evenly transmitted to the concave annular groove area 32 along the inclined surface 243, pressing out an annular groove with a flat edge (without wrinkles caused by local overpressure).

[0070] If α < 30° (taper too steep), the sidewall of the concave annular groove 32 is steep, and the punch 15 will easily squeeze the sidewall to form a "lateral protrusion" during punching; if α > 45° (taper too gentle), the extrusion force is dispersed and a clear annular groove cannot be formed (only a slight indentation), thus losing the pre-pressure guiding effect. Therefore, this angle range can ensure that the punching force is consistent with the stress direction of the sidewall of the concave annular groove 32, avoiding the protrusion of the inner wall of the punched hole 30.

[0071] Among them, the radius R of the arc edge 1502 is related to the depth H of the annular groove, which makes the depth of the depression on the upper surface of the sheet 3 and the punching position of the bottom wall of the concave annular groove area 32 form a "gradual transition", naturally forming a smooth chamfer.

[0072] If R < 0.15H, the cutting edge is too sharp, and "tearing burrs" are easily generated during punching; if R > 0.25H, the cutting edge is too blunt, which will lead to "extrusion rather than separation", and "extrusion force residual protrusion" is likely to appear on the inner wall of the punched hole 30. Therefore, this ratio can balance "shearing sharpness" and "extrusion forming properties" to ensure the accuracy of the chamfer at the hole opening.

[0073] The diameter of the punched holes should ideally be controlled between 3mm and 18mm.

[0074] In summary, by using the THaR parameter association logic, the process of forming the central concave shape, punching the four corners, controlling the two-way burrs, and chamfering the upper surface can be completed simultaneously in one stamping operation, eliminating multiple subsequent processes (chamfering and deburring) in traditional processes and effectively improving production efficiency.

[0075] In some embodiments, refer to Figure 9An air pipe connector 251 is installed on one side of the lower template 22 (the air pipe connector 251 is connected to the air compressor equipment through an air pipe). When the block 252 is still in the discharge chamber 25, air is introduced into the discharge chamber 25 through the air pipe connector 251. The gas pushes the formed sheet 3 to separate from the lower template 22 through the die hole 26, thereby avoiding the difficulty in removing the formed sheet 3 and realizing the automatic material removal action. At the same time, the pumped gas can also cool the lower template 22.

[0076] Example: Refer to Figures 1-18 A stamping method for an automotive part includes the following steps:

[0077] S1. Place the sheet material 3 to be processed on the lower template 22 and limit its position by the positioning block 221;

[0078] S2. The press drives the upper mounting plate 1 to move downwards. The peeling rod 16 first contacts the plate 3 to pre-press it, and then the punch 140 contacts the plate and cooperates with the die groove 220 to press the central concave shape.

[0079] S3. The upper die continues to descend, and the pressure sleeve 151 contacts both ends of the plate material 3, squeezing the plate material so that the bottom surface contacts the conical extrusion die 24, pressing out the concave annular groove area 32.

[0080] S4, when the pressure sleeve 151 reaches its maximum stroke, the punch 15 extends through the plate 3, and the waste is pushed into the discharge chamber 25, simultaneously forming a punch 30 with no bottom burrs and a chamfer.

[0081] S5. The press drives the upper die to move upward, spring 141, spring 252, and spring 3161 reset, and the peeling rod 16 peels off the sheet 3, completing the stamping.

[0082] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A cold stamping die for automotive parts, comprising an upper mounting plate (1), a lower mounting plate (2), and sheet metal (3), characterized in that, Also includes: Upper template (12) and lower template (22) are respectively installed on the upper mounting plate (1) and lower mounting plate (2). A slider (14) is slidably arranged in the upper template (12). A punch (140) is installed on the bottom surface of the slider (14). A cavity groove (220) corresponding to the punch (140) is opened on the lower template (22). The upper mounting plate (1) and the lower mounting plate (2) are respectively provided with guide sleeves (13) and guide posts (23); A punch (15) for punching is installed on the upper template (12), and a pressure sleeve (151) is slidably connected to the punch (15) by a spring (152). The lower template (22) has a die hole (26) and a conical extrusion die (24) is installed in the die hole (26) to form an inner concave annular groove area (32) on the bottom surface of the sheet (3). A separation area (33) is formed on the upper edge of the inner concave annular groove area (32). The conical extrusion die (24) is used to increase the distance between the separation area (33) of the sheet (3) and the bottom surface of the sheet (3). A peeling bar (16) is provided on the slider (14). A height difference is formed between the peeling bar (16), the punch (140), and the pressure sleeve (151). The height difference from high to low is peeling bar (16) > punch (140) > pressure sleeve (151) > punch (15). The punch (15) has a rounded blade edge (1502); The conical extrusion die (24) includes a cylindrical body (245), the top of which has a continuous upper plane (242) and a slope (243). The cylindrical body (245) has an inner hole (241) through which both ends of the inner hole (241) penetrate the cylindrical body (245). The thickness of the sheet metal (3) is T, the height of the slope (243) is H, the radius of the arc edge (1502) is R, and the cone angle of the conical extrusion die (24) is a, where H = (1 / 4~1 / 3)T, a = 30°~45°, and R = (0.15~0.25)H. Among them, the radius R of the arc edge (1502) is related to the depth H of the annular groove, which increases the curvature of the collapsed corner area (31) in the punch (30) and makes the depth of the depression on the upper surface of the sheet (3) and the punching position of the bottom wall of the concave annular groove area (32) form a gradual transition, naturally forming a smooth chamfer. The upper template (12) has a boss-type mounting cavity (121), the slider (14) is slidably connected in the boss-type mounting cavity (121), a pad (11) is installed on the upper mounting plate (1), the upper template (12) is installed on the pad (11), and a spring (141) is provided between the top surface of the slider (14) and the pad (11). The second spring (152) is fixedly connected to the pressure sleeve (151), and the end of the second spring (152) away from the pressure sleeve (151) is fixedly connected to the first cover (153). The first cover (153) is connected to the upper template (12) by screws. The slider (14) has symmetrically opened sliding cavities (142), one end of the peeling rod (16) is slidably connected in the sliding cavity (142), and a spring three (161) is provided between the peeling rod (16) and the sliding cavity (142). The peeling rod (16) is connected to the slider (14) through the cover two (162).

2. The cold stamping die for automotive parts according to claim 1, characterized in that, The lower template (22) has a discharge cavity (25) which is connected to the die hole (26) to collect waste material; A pad two (21) is installed on the lower mounting plate (2), and the lower template (22) is installed on the pad two (21). The discharge chamber (25) forms a closed chamber through the pad two (21). A vent pipe connector (251) connected to the discharge chamber (25) is installed on one side of the lower template (22). One end of the discharge chamber (25) passes through the lower template (22), and a block (252) is provided on the lower template (22) at the passage.

3. A stamping method for automotive parts, based on the cold stamping die for automotive parts as described in claim 2, characterized in that, Includes the following steps: S1. Place the sheet material (3) to be processed on the lower template (22) and limit its position by the positioning block (221); S2, the press drives the upper mounting plate (1) to move downwards, the peeling rod (16) first contacts the plate material (3) to pre-press, and then the punch (140) contacts the plate material and cooperates with the die groove (220) to press the central concave shape; S3. The upper die continues to descend, and the pressure sleeve (151) contacts both ends of the plate (3), squeezing the plate so that the bottom surface contacts the conical extrusion die (24) to press out the concave annular groove area (32). S4. When the pressure sleeve (151) reaches its maximum stroke, the punch (15) extends through the plate (3) and the waste is pushed into the discharge chamber (25), simultaneously forming a punch (30) with no bottom burrs and a chamfer. S5. The press drives the upper die to move upward, spring 1 (141), spring 2 (152), and spring 3 (161) reset, and the peeling rod (16) peels off the sheet material (3) to complete the stamping.

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