Forming structure and method for preventing eccentricity of orifice chamfer of liquid injection hole

Abstract

The forming structure comprises an upper die base, a lower die base and a material strap, the upper die base comprises an upper die plate, a stripper plate and a male die set, the lower die base comprises a lower die plate, a female die fixing plate and a female die block, the upper end face of the lower die plate abuts against the lower end face of the female die fixing plate, and the lower end face of the lower die plate abuts against the lower end face of the female die fixing plate. The lower end face of the material belt abuts against the upper end face of the female die fixing plate, the female die block is arranged in the female die fixing plate, during stamping, the upper die plate moves downwards to drive the male die block to move downwards, the male die block stamps the liquid injection hole pre-forming position of the material belt, and a liquid injection hole is formed in the material belt; the liquid injection hole forming method comprises the specific steps that 1, an inner hole is formed; step 2, pre-punching a chamfer of the formed liquid injection hole; 3, a liquid injection hole is formed; step 4, fine blanking; step 5, chamfering the back; when the liquid injection hole is formed, the procedure of forming and pre-punching chamfering is conducted on the inner hole before the liquid injection hole is formed, and the enclasping force of fine punching chamfering on a fine punching knife edge can be reduced.

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 structure for preventing the chamfering of the injection hole opening from being eccentric includes an upper mold base, a lower mold base, and a strip. The upper mold base includes an upper template, a stripper plate, and a punch assembly. The lower mold 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 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 on the strip, forming the injection hole on the strip.

[0005] Furthermore, the punch assembly includes a punching punch, a first chamfering punch, a pre-forming punch, a forming punch, and a fine blanking punch arranged sequentially. The punching punch punches an inner hole on the strip. 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. The forming punch punches an injection hole on the strip. A first protrusion is provided at the lower end of the pre-forming punch. A second protrusion is provided at the lower end of the forming punch. The height of the first protrusion is greater than that of the second protrusion.

[0006] Furthermore, a second chamfering punch is provided on the lower template. The second chamfering punch punches the side of the injection hole near the lower mold base, and a back chamfer is formed on the injection hole.

[0007] Furthermore, a molding method for preventing the chamfer of the injection hole opening from becoming eccentric includes the following specific steps in the molding of the injection hole during the molding of the top cover plate: 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. 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. Step 3, Forming injection hole: During the material strip stepping process, the upper die holder drives the pre-forming punch to punch at the inner hole of the material strip to form a pre-formed injection hole. After that, the forming punch punches at the pre-formed injection hole of the material strip to form a complete injection hole. Step 4, 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. The chamfer angle is R4. Step 5, 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.

[0008] 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.

[0009] Furthermore, in step 3, the specific steps for forming the injection hole are as follows: Step 31, 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 the 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. Step 32, Injection Hole Forming: Continue stamping at the pre-formed injection hole on the strip. The forming punch on the upper die base moves down to stamp the injection hole forming area of ​​the strip, thus forming 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] Furthermore, the chamfer angle R1 during pre-punching, the chamfer angle R2 during pre-forming injection hole, the chamfer angle R3 during forming, and the chamfer angle R4 during fine punching decrease sequentially.

[0011] Through the above improvements, this forming method can reduce the amount of material that the fine blanking punch needs to squeeze during chamfering, so that the excess material left in the fine blanking and forming of the R-angle is minimized, thereby reducing the clamping force of the fine blanking punch, thus extending the life of the parts and reducing the probability of aluminum powder generation.

[0012] 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.

[0013] 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

[0014] Figure 1 This is a flowchart of the process method for this application; 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. Figure 3 This is a magnified view of a portion of the structure at point A in the application; Figure 4 This is a magnified view of a portion of the structure at point B in the application; Figure 5 This is a magnified view of a portion of the structure at point C in this application; Figure 6 This is a schematic diagram of the stamping structure of the application; Figure 7 This is a magnified view of a portion of the structure at point D in the application; Figure 8 This is a magnified view of the structure at point E in the application.

[0015] 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

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0017] 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.

[0018] 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.

[0019] like Figures 1 to 8 As shown, a forming structure for preventing the chamfer 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 inside the die fixing plate 2.2. During stamping, the upper template 1.1 moves down, causing the punch assembly 1.3 to move down. The punch assembly 1.3 stamps the pre-forming part of the injection hole 3.4 on the strip 3, forming the injection hole 3.4 on the strip 3.

[0020] The punch assembly 1.3 includes a punching punch 1.31, a first chamfering punch 1.32, a pre-forming punch 1.33, a forming punch 1.34, and a fine blanking punch 1.35 arranged sequentially. 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. 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.

[0021] The lower template 2.1 is provided with a second chamfering punch 2.4, which punches the injection hole 3.4 on the side near the lower mold base 2, and forms a back chamfer 3.5 on the injection hole 3.4.

[0022] A molding method for preventing the chamfer of the injection hole 3.4 from being eccentric, wherein the specific steps for molding the injection hole 3.4 during the molding of the top cover plate are as follows: 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.

[0023] 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.

[0024] While step 1 is being performed, pole holes are punched out in the pre-forming area of ​​pole holes on the material strip 3.

[0025] 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.

[0026] 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.

[0027] Meanwhile, while step 2 is being performed, a back groove is being formed on the pole hole of the material strip 3.

[0028] Step 3, forming injection hole 3.4: During the stepping process of strip 3, the upper die holder 1 drives the pre-forming punch 1.33 to punch at the inner hole 3.1 on strip 3 to form the pre-formed injection hole 3.4. Then, the forming punch 1.34 punches at the pre-formed injection hole 3.4 on strip 3 to form the complete injection hole 3.4.

[0029] In step 3, the specific steps for forming the injection hole 3.4 are as follows: Step 31, 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 strip 3 is pressed on the side near the lower die holder 2 to form a protrusion 3.6.

[0030] Step 32, Forming of injection hole 3.4: Continue stamping at the pre-formed part of injection hole 3.4 on the material 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 the material 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.

[0031] Step 4, fine blanking: During the 3-step process 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. The chamfer angle is R4.

[0032] During step 4, the fine blanking includes chamfering. After the fine blanking punch punches down at 1.35 degrees, 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.

[0033] Step 5, 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.

[0034] The chamfer angle R1 of pre-punching chamfer 3.2, the chamfer angle R2 of pre-forming injection hole 3.3, the chamfer angle R3 of injection hole 3.4 during forming, and the chamfer angle R4 during fine punching decrease sequentially.

[0035] This forming method can reduce the amount of material that the fine blanking punch needs to squeeze during chamfering, so that the excess material left in the fine blanking and forming of the R-angle is minimized, thereby reducing the clamping force of the fine blanking punch, thus extending the life of the parts and reducing the probability of aluminum powder generation.

[0036] 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 structure for preventing the chamfer of the injection hole opening from becoming eccentric, characterized in that: The assembly includes an upper die base (1), a lower die base (2), and a strip (3). The upper die base (1) includes an upper template (1.1), a stripper plate (1.2), and a punch assembly (1.3). The lower die 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 inside the die fixing plate (2.2). During stamping, the upper template (1.1) moves down, causing the punch assembly (1.3) to move down. The punch assembly (1.3) stamps the pre-forming part of the injection hole (3.4) of the strip (3), forming the injection hole (3.4) on the strip (3).

2. The molding structure for preventing eccentricity of the chamfer at the injection hole opening according to claim 1, characterized in that: 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), 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 (3.1). The pre-forming punch... (1.33) A pre-formed injection hole (3.3) is punched on the strip (3), and a forming punch (1.34) is punched on the strip (3). A first protrusion (1.36) is provided at the lower end of the pre-formed punch (1.33), and a second protrusion (1.37) is provided at the lower end of the forming punch (1.34). The height of the first protrusion (1.36) is greater than that of the second protrusion (1.37).

3. The molding structure for preventing the chamfer of the injection hole opening from becoming eccentric according to claim 2, characterized in that: The lower template (2.1) is provided with a second chamfering punch (2.4), which punches the side of the injection hole (3.4) near the lower mold base (2) to form a back chamfer (3.5) on the injection hole (3.4).

4. A molding structure for preventing eccentricity of the chamfer at the injection hole opening according to any one of claims 1-3, and a molding method for preventing eccentricity of the chamfer at the injection hole opening, characterized in that: During the molding process of the top cover sheet, 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 the pre-punched chamfer of the injection hole (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 the pre-punched chamfer (3.2) on the side of the inner hole (3.1) close to the upper die holder (1). The angle of the pre-punched chamfer (3.2) is R1. Step 3, forming injection hole (3.4): During the stepping process of the strip (3), the upper die holder (1) drives the pre-forming punch (1.34)(1.33) to punch at the inner hole (3.1) on the strip (3) to form the pre-formed injection hole (3.4). Then, the forming punch (1.34) punches at the pre-formed injection hole (3.4) on the strip (3) to form the complete injection hole (3.4). Step 4, 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 and the chamfer angle is R4. Step 5, 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).

5. A molding method for preventing eccentric chamfering of the injection hole opening according to claim 4, characterized in that: In step 3, the specific steps for forming the injection hole (3.4) are as follows: Step 31, 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 32, Forming of injection hole (3.4): Continue to stamp 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 stamps 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, and an annular recess (3.7) is formed around the convex part (3.6).

6. A molding method for preventing eccentric chamfering of the injection hole opening according to claim 5, characterized in that: The angles R1 of the pre-punching chamfer (3.2), R2 of the chamfer of the pre-forming injection hole (3.3), R3 of the chamfer of the injection hole (3.4) during forming, and R4 of the back chamfer (3.5) during fine punching decrease sequentially.

7. A molding method for preventing eccentric chamfering of the injection hole opening according to claim 4, 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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