Forming method for preventing liquid injection hole orifice chamfer eccentricity

Abstract

The application provides a forming structure and method for preventing the eccentricity of the chamfer of the orifice of a liquid injection hole, comprising an upper die holder, a lower die holder and a material belt, the upper die holder comprises an upper die plate, a material removal plate and a male die set, the lower die holder comprises a lower die plate, a female die fixing plate and a female die set, the upper end surface of the lower die plate is in abutment with the lower end surface of the female die fixing plate, the lower end surface of the material belt is in abutment with the upper end surface of the female die fixing plate, the female die set is arranged in the female die fixing plate, the upper die plate is lowered to drive the male die set to be lowered during stamping, the male die set is used for stamping the pre-formed part of the liquid injection hole of the material belt to form the liquid injection hole on the material belt; the specific steps of the liquid injection hole forming are as follows: step 1, forming an inner hole; step 2, forming a pre-stamping chamfer of the liquid injection hole; step 3, forming the liquid injection hole; step 4, fine stamping; and step 5, back chamfering; the application can reduce the holding force of the fine stamping chamfer on the fine stamping knife edge by the process of forming a pre-stamping chamfer of the inner hole before the liquid injection hole forming.

Description

Technical Field

[0001] This invention relates to the technical field of lithium battery top cover sheets, and more particularly to a molding structure and method for preventing the chamfer of the injection hole opening from being eccentric. Background Technology

[0002] On conventional top cover products, the injection hole has a 0.3 R0 chamfer at the opening of the inner hole on the front side. In the past, the chamfering was done after fine blanking, which caused the following problems when forming the injection hole of the lithium battery top cover: 1. Fine blanking before chamfering will result in poor consistency of the front R angle and unqualified appearance; 2. The inner hole is affected by the forming extrusion, resulting in more material on one side and less material on the other side, causing eccentricity; 3. Fine blanking and chamfering in one step to form the R angle will cause powder accumulation at the opening of the injection hole. Summary of the Invention

[0003] To address the shortcomings and defects of existing technologies, this invention provides a molding structure and method for preventing the chamfer of the injection hole opening from becoming eccentric. To achieve the purpose of producing the top cover sheet, this invention provides the following technical solution.

[0004] A forming method for preventing the chamfering of an injection hole from being eccentric includes an upper die base, a lower die base, and a strip material. The upper die base includes an upper template, a stripper plate, and a punch assembly. The lower die base includes a lower template, a die fixing plate, and a die module. The upper end face of the lower template abuts against the lower end face of the die fixing plate, and the lower end face of the strip material abuts against the upper end face of the die fixing plate. The die module is disposed within the die fixing plate. During stamping, the upper template moves downward, causing the punch assembly to move downward. The punch assembly stamps the pre-forming area of ​​the injection hole in the strip material, forming the injection hole on the strip material. The punch assembly includes a punching punch, a first chamfering punch, and a die assembly arranged sequentially. The device comprises a pre-forming punch, a forming punch, and a fine-blanking punch. The punching punch punches an inner hole on the strip material. The first chamfering punch forms a pre-punched chamfer on the inner hole. The pre-forming punch punches a pre-forming injection hole on the strip material. The forming punch punches an injection hole on the strip material. The lower end of the pre-forming punch is provided with a first protrusion, and the lower end of the forming punch is provided with a second protrusion. The height of the first protrusion is greater than that of the second protrusion. A back chamfer is formed on the injection hole, and the angles R1 of the pre-punched chamfer, R2 of the pre-forming injection hole chamfer, R3 of the injection hole chamfer during forming, and R4 of the back chamfer after fine blanking decrease sequentially.

[0005] The specific steps for forming the injection hole during the top cover sheet forming process are as follows:

[0006] Step 1, forming the inner hole: The strip is fed into the stamping equipment and continuously fed forward on the stamping equipment. During the stepping process of the strip, the inner hole is punched out in the pre-forming area of ​​the liquid injection hole on the strip.

[0007] Step 2, Pre-punching chamfer of injection hole: During the material strip stepping process, the upper die base is pressed down, which drives the first chamfering punch to form a pre-punched chamfer on the side of the inner hole close to the upper die base. The angle of the pre-punched chamfer is R1.

[0008] Step 3, Pre-forming of injection hole: During the material strip stepping process, the pre-forming punch on the upper die holder punches the material strip to perform the pre-forming operation of injection hole, forming the first groove on the material strip, and chamfering the inner hole during pre-forming. The chamfer angle of the pre-formed injection hole is R2. During pre-forming, the side of the material strip near the lower die holder is pressed to form a convex part.

[0009] Step 4, Injection Hole Forming: Continue stamping at the pre-formed injection hole on the strip. The forming punch on the upper die holder moves down to stamp the injection hole forming area of ​​the strip to form the injection hole. During forming, the inner hole is chamfered. The chamfer angle on the injection hole during forming is R3, forming an annular recess around the convex part.

[0010] Step 5, Fine Blanking: During the material strip stepping process, the final formed injection hole is fine blanked, and the front of the injection hole is chamfered during fine blanking to shape the chamfer of the injection hole.

[0011] Step 6, Back chamfer: During the material strip stepping process, the second chamfering punch on the lower die base chamfers the side of the injection hole near the lower die base, forming a back chamfer at the lower end of the injection hole, with a chamfer angle of R4.

[0012] Compared with the prior art, the present invention reduces the clamping force of fine blanking on the fine blanking blade by performing a pre-punching and chamfering process on the inner hole before the injection hole is formed. Furthermore, when fine blanking with chamfering is performed, the R-angle on the front side is formed simultaneously after the fine blanking punch goes down. This ensures the consistency of the chamfer on the front opening and reduces the secondary impact of subsequent chamfering on fine blanking.

[0013] Furthermore, a second chamfering punch is provided on the lower template, and the second chamfering punch punches the side of the injection hole near the lower mold base.

[0014] Furthermore, step 1 also includes the forming of positioning holes. During the material strip stepping process, positioning holes for positioning are punched out on both sides of the material strip.

[0015] With the above improvements, the punched positioning holes can better fix the strip during the stamping process, preventing it from shifting during the strip's movement. Attached Figure Description

[0016] Figure 1 This is a flowchart of the process method for this application;

[0017] Figure 2 The diagram shows the strip state during the pre-forming of the injection hole, the forming of the injection hole, and the fine blanking process of the application.

[0018] Figure 3 This is a magnified view of a portion of the structure at point A in the application;

[0019] Figure 4 This is a magnified view of a portion of the structure at point B in the application.

[0020] Figure 5 This is a magnified view of the structure at point C in the application;

[0021] Figure 6 This is a schematic diagram of the stamping structure of the application;

[0022] Figure 7 This is a magnified view of a portion of the structure at point D in the application;

[0023] Figure 8 This is a magnified view of the structure at point E in the application.

[0024] Among them, 100 is the punching station for the inner hole; 101 is the pre-punching and chamfering station for forming; 102 is the pre-forming station for the injection hole; 103 is the forming station for the injection hole; 104 is the fine punching station; 105 is the back chamfering station; 1 is the upper die base; 1.1 is the upper template; 1.2 is the stripper plate; 1.3 is the punch assembly; 1.31 is the punching punch; 1.32 is the first chamfering punch; 1.33 is the pre-forming punch; 1.34 is the forming punch; 1 1.35. Fine blanking punch; 1.36. First punch; 1.37. Second punch; 2. Lower die base; 2.1. Lower template; 2.2. Die fixing plate; 2.3. Die module; 2.4. Second chamfering punch; 3. Strip material; 3.1. Inner hole; 3.2. Pre-punched chamfer; 3.3. Pre-formed injection hole; 3.4. Injection hole; 3.5. Back chamfer; 3.6. Protrusion; 3.7. Annular recess; 3.8. Positioning hole. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0026] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] like Figure 1 As shown, a molding method for preventing the chamfer of the injection hole 3.4 from being eccentric is described in the following process flow. Figure 1 As shown, in the direction of the forward feeding of the material belt 3, there are respectively provided a punching inner hole 3.1 station 100, a forming pre-punching and chamfering 3.2 station 101, a liquid injection hole 3.4 pre-forming station 102, a liquid injection hole 3.4 forming station 103, a fine punching station 104, and a back chamfering 3.5 station 105.

[0028] like Figures 1 to 8 As shown, a forming method for preventing the chamfering of the injection hole 3.4 from being eccentric includes an upper mold base 1, a lower mold base 2, and a strip 3. The upper mold base 1 includes an upper template 1.1, a stripper plate 1.2, and a punch assembly 1.3. The lower mold base 2 includes a lower template 2.1, a die fixing plate 2.2, and a die module 2.3. The upper end face of the lower template 2.1 abuts against the lower end face of the die fixing plate 2.2, and the lower end face of the strip 3 abuts against the upper end face of the die fixing plate 2.2. The die module 2.3 is disposed within the die fixing plate 2.2. During stamping, the upper template 1.1 moves downward, causing the punch assembly 1.3 to move downward. The punch assembly 1.3 stamps the pre-formed portion of the injection hole 3.4 on the strip 3, forming the injection hole 3.4 on the strip 3. The punch assembly 1.3 includes a punching punch 1.31, a first chamfering punch 1.32, and a pre-forming punch 1.33 arranged sequentially. The assembly includes a forming punch 1.33, a forming punch 1.34, and a fine blanking punch 1.35. The punching punch 1.31 punches an inner hole 3.1 on the strip 3. The first chamfering punch 1.32 forms a pre-punched chamfer 3.2 on the inner hole 3.3. The pre-forming punch 1.33 punches a pre-formed injection hole 3.3 on the strip 3. The forming punch 1.34 punches an injection hole 3.4 on the strip 3. The lower end of the pre-forming punch 1.33 is provided with a first protrusion 1.36, and the lower end of the forming punch 1.34 is provided with a second protrusion 1.37. The height of the first protrusion 1.36 is greater than that of the second protrusion 1.37. The lower die plate 2.1 is provided with a second chamfering punch 2.4, which punches the side of the injection hole 3.4 near the lower die base 2, and forms a back chamfer 3.5 on the injection hole 3.4.

[0029] Furthermore, the angles R1 of the pre-punching chamfer 3.2, R2 of the pre-forming injection hole chamfer 3.3, R3 of the injection hole 3.4 during forming, and R4 of the back chamfer 3.5 after fine punching decrease sequentially. This reduces the amount of material that the fine punch needs to squeeze during chamfering, minimizing the excess material left in the fine punching and forming of the R-angle, thereby reducing the clamping force of the fine punch, extending the life of the parts, and reducing the probability of aluminum powder generation.

[0030] During the molding process of the top cover sheet, the specific steps for molding the injection hole 3.4 are as follows:

[0031] Step 1, Forming the inner hole 3.1: Feed the strip 3 into the stamping equipment and feed the strip 3 forward continuously on the stamping equipment. During the stepping process of the strip 3, punch out the inner hole 3.1 in the pre-forming area of ​​the injection hole 3.4 on the strip 3.

[0032] Step 1 also includes the forming of positioning holes 3.8. During the stepping process of the material strip 3, positioning holes 3.8 for positioning are punched on both sides of the material strip 3. The punched positioning holes 3.8 can fix the material strip 3 well and prevent the material strip 3 from shifting during the stepping process.

[0033] While step 1 is being performed, pole holes are punched out in the pre-forming area of ​​pole holes on the material strip 3.

[0034] Step 2, Pre-punching chamfer 3.2 in injection hole 3.4: During the stepping process of strip 3, upper die holder 1 is pressed down, which drives the first chamfering punch 1.32 to form a pre-punched chamfer 3.2 on the side of inner hole 3.1 near upper die holder 1. The angle of the pre-punched chamfer 3.2 is R1.

[0035] Before the injection hole 3.4 is pre-formed, a pre-punching chamfer 3.2 is designed. On the one hand, it can be chamfered first, and on the other hand, it can play the role of material blocking and shaping, preventing excessive material from being squeezed out when other parts of the product are formed, which would cause the pre-punching inner hole 3.1 of the injection hole 3.4 to be squeezed out of center.

[0036] Meanwhile, while step 2 is being performed, a back groove is being formed on the pole hole of the material strip 3.

[0037] Step 3, Pre-forming of injection hole 3.4: During the stepping process of the strip 3, the pre-forming punch 1.33 on the upper die holder 1 punches the strip 3 to perform the pre-forming operation of injection hole 3.4, forming the first groove on the strip 3, and chamfering the inner hole 3.1 during pre-forming, wherein the chamfering angle of the pre-formed injection hole 3.3 is R2. During pre-forming, the side of the strip 3 near the lower die holder 2 is pressed to form a protrusion 3.6.

[0038] Step 4, Forming of injection hole 3.4: Continue stamping at the pre-formed part of injection hole 3.4 on strip 3. The forming punch 1.34 on the upper die holder 1 moves down to stamp the forming area of ​​injection hole 3.4 on strip 3, thereby forming injection hole 3.4. During forming, the inner hole 3.1 is chamfered. The chamfer angle on injection hole 3.4 during forming is R3, and an annular recess 3.7 is formed around the protrusion 3.6.

[0039] Step 5, fine blanking: During the 3-step advance of the material strip, the final formed injection hole 3.4 is fine blanked, and the front of the injection hole 3.4 is chamfered during fine blanking to shape the chamfer of the injection hole 3.4.

[0040] During step 5, the fine blanking includes chamfering. After the fine blanking punch punches down at 1.35, the R-angle on the front is formed simultaneously. This ensures the consistency of the chamfer on the front opening and reduces the secondary impact of subsequent chamfering on the fine blanking.

[0041] Step 6, back chamfer 3.5: During the stepping process of the strip 3, the second chamfering punch 2.4 on the lower die holder 2 chamfers the side of the injection hole 3.4 near the lower die holder 2, forming a back chamfer 3.5 at the lower end of the injection hole 3.4, with a chamfer angle of R4.

[0042] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A molding method for preventing the chamfer of the injection hole opening from being eccentric, characterized in that: The assembly includes an upper mold base (1), a lower mold base (2), and a strip (3). The upper mold base (1) includes an upper template (1.1), a stripper plate (1.2), and a punch assembly (1.3). The lower mold base (2) includes a lower template (2.1), a die fixing plate (2.2), and a die assembly (2.3). The upper end face of the lower template (2.1) abuts against the lower end face of the die fixing plate (2.2), and the lower end face of the strip (3) abuts against the upper end face of the die fixing plate (2.2). Module (2.3) is disposed within the die fixing plate (2.2). During stamping, the upper template (1.1) moves downward, causing the punch assembly (1.3) to move downward. The punch assembly (1.3) stamps the pre-forming portion of the injection hole (3.4) on the strip (3), forming the injection hole (3.4) on the strip (3). The punch assembly (1.3) includes, in sequence, a punching punch (1.31), a first chamfering punch (1.32), a pre-forming punch (1.33), and a forming punch (1.34). 4) and a fine blanking punch (1.35), wherein the punching punch (1.31) punches an inner hole (3.1) on the strip (3), the first chamfering punch (1.32) forms a pre-punched chamfer (3.2) on the inner hole (3.1), the pre-forming punch (1.33) punches a pre-formed injection hole (3.3) on the strip (3), and the forming punch (1.34) punches an injection hole (3.4) on the strip (3). The lower end of the pre-forming punch (1.33) is provided with The first protrusion (1.36) is provided with a second protrusion (1.37) at the lower end of the forming punch (1.34), and the height of the first protrusion (1.36) is greater than that of the second protrusion (1.37); a back chamfer (3.5) is formed on the injection hole (3.4), and the angles R1 of the pre-punched chamfer (3.2), R2 of the pre-formed injection hole (3.3) chamfer, R3 of the injection hole (3.4) during forming, and R4 of the back chamfer (3.5) after fine punching decrease sequentially; During the top cover sheet molding process, the specific steps for molding the injection hole (3.4) are as follows: Step 1, forming inner hole (3.1): feed the strip (3) into the stamping equipment, and feed the strip (3) forward continuously on the stamping equipment. During the stepping process of the strip (3), punch out the inner hole (3.1) in the pre-forming area of ​​the injection hole (3.4) on the strip (3). Step 2, forming injection hole (3.4) pre-punching chamfer (3.2): During the stepping process of the strip (3), the upper die holder (1) presses down, driving the first chamfering punch (1.32) to form a pre-punching chamfer (3.2) on the side of the inner hole (3.1) close to the upper die holder (1). The angle of the pre-punching chamfer (3.2) is R1. Step 3, Pre-forming of injection hole (3.4): During the stepping process of the strip (3), the pre-forming punch (1.33) on the upper die holder (1) punches the strip (3) to perform the pre-forming operation of injection hole (3.4), forming the first groove on the strip (3), and chamfering the inner hole (3.1) during pre-forming, wherein the chamfering angle of the pre-formed injection hole (3.3) is R2, and during pre-forming, the side of the strip (3) near the lower die holder (2) is pressed to form a protrusion (3.6); Step 4, Forming of injection hole (3.4): Continue to punch at the pre-forming part of injection hole (3.4) on the strip (3). The forming punch (1.34) on the upper die holder (1) moves down and punches the forming area of ​​injection hole (3.4) on the strip (3) to form injection hole (3.4). During forming, the inner hole (3.1) is chamfered. The chamfer angle on injection hole (3.4) during forming is R3. An annular recess (3.7) is formed around the convex part (3.6). Step 5, fine blanking: During the stepping process of the material strip (3), the final formed injection hole (3.4) is fine blanked, and the front of the injection hole (3.4) is chamfered during fine blanking so that the chamfer of the injection hole (3.4) is shaped. Step 6, back chamfer (3.5): During the stepping process of the strip (3), the second chamfering punch (2.4) on the lower die holder (2) chamfers the side of the injection hole (3.4) close to the lower die holder (2), and forms a back chamfer (3.5) at the lower end of the injection hole (3.4), with a chamfer angle of R4.

2. The molding method for preventing the chamfer of the injection hole opening from being eccentric according to claim 1, characterized in that: A second chamfering punch (2.4) is provided on the lower template (2.1), and the second chamfering punch (2.4) punches the side of the injection hole (3.4) near the lower mold base (2).

3. The molding method for preventing the chamfer of the injection hole opening from being eccentric according to claim 1, characterized in that: Step 1 also includes the forming of positioning holes (3.8). During the stepping process of the strip (3), positioning holes (3.8) for positioning are punched out on both sides of the strip (3).

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