Cold punching die capable of improving flatness of cross section and using method of cold punching die

Abstract

The invention discloses a cold punching die capable of improving the flatness of a cross section and a using method thereof.The die comprises an upper die plate, a lower die plate, a pier extrusion male die, a pier extrusion female die, a fine punching male die and a fine punching female die, the pier extrusion male die and the fine punching male die are arranged on the upper die plate side by side, and the pier extrusion female die and the fine punching female die are arranged on the lower die plate; the upsetting extrusion female die is correspondingly arranged below the upsetting extrusion male die, the fine blanking female die is correspondingly arranged below the fine blanking male die, a limiting column is arranged in the upsetting extrusion female die, a cushion block is arranged below the upsetting extrusion female die, an ejector rod connected with the cushion block in a sliding mode is arranged at the lower end of the limiting column, a spring is arranged at the lower end of the ejector rod, and the spring is used for abutting against the ejector rod. And the fine blanking allowance of the upsetting extrusion is 8-9% of the single-side selected material thickness. The upsetting extrusion technology and the fine blanking technology are combined, and the flatness of the cross section of a product is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of stamping dies, and in particular to a cold stamping die capable of improving the flatness of a truncated surface and a use method thereof. Background Art

[0002] In the early days, the rotating parts were mainly processed by turning technology. Now, in order to reduce the processing cost of the products, most of them are formed by stamping dies. The traditional cold stamping die mainly adopts the structure of punching and extruding. First, two-thirds of the material thickness is extruded, and then the remaining one-third of the material is blanked. Because the size of the punching die is usually 0.02-0.003mm larger than the size of the extruded part in order to smoothly fit the part that has been extruded, the shape is as shown in the figure below. Figure 1 The pier squeeze foot a1 shown in the figure will form a side wall step difference d1 between the pier squeeze foot a1 and the blanking cutting position a2, which will cause the finished product to have poor assembly. Due to the large material thickness, it is difficult to achieve a small collapse angle and sufficient bright band, resulting in a low cross-sectional flatness of the product. If fine blanking equipment is used for production, the value of the fine equipment is more than tens of millions, and the cost is high.

[0003] In view of this, the applicant conducted in-depth research on the above issues, which led to the present case. Summary of the invention

[0004] The main purpose of the present invention is to provide a cold punching die and a method of using the same which can improve the flatness of the cross-section surface, and to combine the upsetting technology with the fine punching technology to effectively improve the flatness of the cross-section surface of the product.

[0005] In order to achieve the above object, the solution of the present invention is:

[0006] A cold stamping die capable of improving the flatness of a truncated surface comprises an upper template, a lower template, an ram extrusion punch, an ram extrusion die, a fine stamping punch and a fine stamping die. The ram extrusion punch and the fine stamping punch are arranged side by side on the upper template, the ram extrusion die and the fine stamping die are arranged on the lower template, the ram extrusion die is correspondingly arranged below the ram extrusion punch, and the fine stamping die is correspondingly arranged below the fine stamping punch. A limiting column is arranged in the ram extrusion die, a cushion block is arranged below the ram extrusion die, a push rod slidably connected to the cushion block is arranged at the lower end of the limiting column, a spring is arranged at the lower end of the push rod, and the spring is used to resist the push rod. The fine stamping reserve for ram extrusion is selected from 8% to 9% of the material thickness on one side.

[0007] Furthermore, a rounded corner R1 is provided at the cutting edge of the fine blanking die.

[0008] Furthermore, the size of the rounded corner R1 is 0.2 mm.

[0009] Furthermore, the fine blanking die selects a fine blanking clearance of 0.012 mm on one side.

[0010] A method for using the cold punching die comprises the following steps:

[0011] Step 1: convey the material to the lower template so that the material is placed between the extrusion convex die and the extrusion concave die;

[0012] Step 2: The upper template and the lower template are brought close to each other, and the material is extruded into shape under the cooperation of the extrusion convex die and the extrusion concave die;

[0013] Step 3: The upper mold plate is separated from the lower mold plate, and then the material is continuously conveyed between the fine blanking punch and the fine blanking die;

[0014] Step 4: The upper template is close to the lower template, and the material is blanked with the cooperation of the fine blanking punch and the fine blanking die. During the downward movement of the fine blanking punch, the fine blanking reserve is further squeezed, accounting for about 12% of the material thickness;

[0015] Step 5: Separate the lower template from the upper template and take away the punched material.

[0016] Furthermore, in step 2, the degree of saturation of the extrusion is 84%.

[0017] Furthermore, in step 4, a lubricant containing WS2 nanoparticles is sprayed on the material 0.5 seconds before fine blanking to reduce the friction coefficient to below 0.05.

[0018] Furthermore, in step 4, during fine blanking, the punching speed of the fine blanking punch is 4-6 mm / s.

[0019] Compared with the prior art, the beneficial effects are:

[0020] 1. The present invention first adopts the pier extrusion process to pier the material thickness of 8%-9% of the fine blanking single-side reserve, and sets a fine fine blanking gap. Under the action of the fine blanking reserve, the material is squeezed and flows in the thickness direction, and the pier extrusion collapse angle of the product is compensated, so that the pier extrusion collapse angle is much smaller than 0.03, and the pier extrusion collapse angle of the product is almost a sharp angle.

[0021] Second, since the collapse angle of the extrusion is compensated during the fine punching process, in order to reduce the burden of the first step of the extrusion process, the extrusion saturation of the present invention is 84% ​​when the material is extruded, which can effectively improve the service life of the extrusion punch and the extrusion die.

[0022] 3. As the fine blanking punch continues to move downward, the fine blanking reserve is further squeezed, accounting for about 12% of the total material thickness. At the final cutting position, the waste material gradually hardens, making the fracture more thorough and forming a fracture layer lower than the side wall of the pier.

[0023] Fourth, the present invention reasonably integrates the processes of two different molds, which not only reduces the stress on the mold, but also makes the outer contour bright band of the cross-section greater than 85% of the material thickness, effectively improving the flatness of the cross-section and greatly improving the matching performance of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the structure of the product obtained by traditional stamping process.

[0025] Figure 2 It is a structural sectional view of the mold of the present invention.

[0026] Figure 3 for Figure 2 A partial enlarged view of area A.

[0027] Figure 4 This is a schematic structural diagram of a product obtained by the stamping process of the present invention.

[0028] In the figure: an upper template 1, a lower template 2, an piercing punch 31, an piercing die 32, a limiting column 33, a cushion block 34, a push rod 35, a spring 36, a fine blanking punch 41, and a fine blanking die 42. DETAILED DESCRIPTION

[0029] In order to further explain the technical solution of the present invention, the present invention is described in detail below through specific embodiments.

[0030] like Figure 2-4As shown, a cold stamping die capable of improving the flatness of a truncated surface comprises an upper die plate 1, a lower die plate 2, an irritating punch 31, an irritating die 32, a fine stamping punch 41 and a fine stamping die 42. The upper die plate 1 and the lower die plate 2 are fixedly mounted on a punching machine. The irritating punch 31 and the fine stamping punch 41 are arranged side by side on the upper die plate 1. The irritating die 32 and the fine stamping die 42 are arranged on the lower die plate 2. The irritating die 32 is correspondingly arranged below the irritating punch 31. The fine stamping The die 42 is correspondingly arranged below the fine blanking punch 41. A limiting column 33 is arranged inside the extrusion die 32. A cushion block 34 is arranged below the extrusion die 32. A push rod 35 slidably connected to the cushion block 34 is arranged at the lower end of the limiting column 33. A spring 36 is arranged at the lower end of the push rod 35. The spring 36 is used to push against the push rod 35. The limiting column 33 and the push rod 35 can slide in the lower mold plate 2. The limiting column 33 is reset by the spring 36. During the extrusion process, the extrusion die 32 acts on the cushion block 34 and can be replaced at any time according to actual needs, thereby ensuring the stability of the parts. The present invention is obtained after repeated experiments. First, a fine blanking single-side reserve D1 of 8%-9% of the material thickness is made by the pier extrusion process, and a fine blanking gap of 0.012mm is accurately set. Under the action of the fine blanking reserve, the material is extruded and flows in the thickness direction, and the pier extrusion collapse angle A3 of the product is compensated, so that the pier extrusion collapse angle A3 is much smaller than 0.03, the pier extrusion collapse angle A3 of the product is almost a sharp angle, and has a larger cross-sectional bright band A2.

[0031] In this embodiment, a rounded corner R1 is provided at the blade edge of the fine blanking die 42, and the size of the rounded corner R1 is 0.2 mm. During the downward movement of the fine blanking punch 41, the fine blanking reserve is uniformly transitioned through R1 to obtain a uniform bright side wall.

[0032] A method for using the cold punching die comprises the following steps:

[0033] Step 1: convey the material to the lower template 2 so that the material is placed between the extrusion convex die 31 and the extrusion concave die 32;

[0034] Step 2: The upper template 1 is brought close to the lower template 2, and the material is extruded and formed with the cooperation of the extrusion convex die 31 and the extrusion concave die 32, and the extrusion saturation is 84%. This can not only reduce the burden of the first step of the extrusion process, but also effectively improve the service life of the extrusion convex die 31 and the extrusion concave die 32.

[0035] Step 3: The upper mold plate 1 is separated from the lower mold plate 2, and then the material is continuously conveyed between the fine blanking punch 41 and the fine blanking die 42;

[0036] Step 4: The upper mold plate 1 and the lower mold plate 2 are brought close to each other, and the material is blanked with the cooperation of the fine blanking punch 41 and the fine blanking die. During the downward movement of the fine blanking punch 41, the fine blanking reserve is further squeezed, accounting for about 12% of the material thickness. Figure 4 As shown, at the final cutting position, the scrap material gradually hardens, making the fracture more thorough, forming a fracture layer A1 below the extrusion side wall.

[0037] Step 5: Separate the lower template 2 from the upper template 1 and take away the punched blank.

[0038] In this embodiment, in step 4, the material is sprayed with WS2 nanoparticle lubricant 0.5 seconds before fine blanking to reduce the friction coefficient to below 0.05, which can effectively reduce friction and improve material flow, thereby further improving the quality of the cut surface.

[0039] In this embodiment, during fine blanking in step 4, the punching speed of the fine blanking punch 41 is 4-6 mm / s, which can prolong the plastic deformation time and promote uniform separation of materials.

[0040] The present invention reasonably integrates the processes of two different molds, which not only reduces the stress on the mold, but also makes the outer contour bright band A2 of the cross-section greater than 85% of the material thickness, effectively improving the flatness of the cross-section and greatly improving the matching performance of the product.

[0041] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. A cold punching die capable of improving the flatness of a truncated surface, characterized in that: It includes an upper template, a lower template, an ram extrusion punch, an ram extrusion die, a fine blanking punch and a fine blanking die. The ram extrusion punch and the fine blanking punch are arranged side by side on the upper template, the ram extrusion die and the fine blanking die are arranged on the lower template, the ram extrusion die is correspondingly arranged below the ram extrusion punch, and the fine blanking die is correspondingly arranged below the fine blanking punch. A limiting column is arranged in the ram extrusion die, a cushion block is arranged below the ram extrusion die, a push rod slidably connected to the cushion block is arranged at the lower end of the limiting column, a spring is arranged at the lower end of the push rod, and the spring is used to push the push rod. The fine blanking reserve amount of ram extrusion is selected from 8%-9% of the material thickness on one side.

2. A cold punching die capable of improving the flatness of a truncated surface as claimed in claim 1, characterized in that: The cutting edge of the fine blanking die is provided with a rounded corner R1.

3. A cold punching die capable of improving the flatness of the truncated surface as claimed in claim 2, characterized in that: The size of the fillet R1 is 0.2 mm.

4. A cold punching die capable of improving the flatness of a truncated surface as claimed in claim 1, characterized in that: The fine blanking die has a single-sided fine blanking clearance of 0.012 mm.

5. A method for using the cold punching die according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: convey the material to the lower template so that the material is placed between the extrusion convex die and the extrusion concave die; Step 2: The upper template and the lower template are brought close to each other, and the material is extruded into shape under the cooperation of the extrusion convex die and the extrusion concave die; Step 3: The upper mold plate is separated from the lower mold plate, and then the material is continuously conveyed between the fine blanking punch and the fine blanking die; Step 4: The upper template is close to the lower template, and the material is blanked with the cooperation of the fine blanking punch and the fine blanking die. During the downward movement of the fine blanking punch, the fine blanking reserve is further squeezed, accounting for about 12% of the material thickness; Step 5: Separate the lower template from the upper template and take away the punched material.

6. A method of use according to claim 5, characterized in that: In step 2, the saturation of the squeeze is 84%.

7. A method of use according to claim 5, characterized in that: In step 4, the material is sprayed with a lubricant containing WS2 nanoparticles 0.5 seconds before fine blanking to reduce the friction coefficient to below 0.

05.

8. A method of use according to claim 5, characterized in that: In step 4, during fine blanking, the punching speed of the fine blanking punch is 4-6 mm / s.

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