Continuous stamping process for engine lock catch handle

Abstract

The invention relates to a continuous stamping process for an engine lock catch handle. The continuous stamping process comprises the steps of punching, outer edge cutting, bending, primary raising, secondary raising, twisting, tertiary raising, shaping and blanking. From the process to the twisting step, most of the first bent part and the third bent part are of a planar structure. When the die is designed, the die surface is easily in full contact with the first bending part and the third bending part, and the two surfaces of the second bending part are free, so that the shape change is easy to control. After the first groove section and the second groove section improve the precision of the two independent areas of the material respectively, the third groove section enables the precision of the transition area between the two independent areas to be improved, and therefore the structural precision of the whole product is controlled in the technology, and control over the product precision through the grooves is better achieved. The folding angle of the first folding edge and the second folding edge does not need to be in place in one step, only a small corner needs to be formed, and bending and shaping are in place after subsequent steps are left.

Description

Technical Field

[0001] The invention relates to the technical field of stamping processing, and in particular to a continuous stamping process for an engine lock handle. Background Art

[0002] Metal stamping is a common process for processing many metal products. As customer needs diversify, mold design must also meet various product requirements.

[0003] Figure 1 The engine lock handle 1 is shown. The main body of the engine lock handle 1 includes a base surface 11, a first folded edge 12a, a first bent portion 13a, a second folded edge 12b, a second bent portion 13b, a third folded edge 12c and a third bent portion 13c, which are connected in sequence. The third folded edge 12c and the second folded edge 1b are in a three-dimensional spatial intersection relationship. The angle between the base surface 11 and the first bent portion 13a is nearly 90°, and the angle between the base surface 11 and the third bent portion 13c is also nearly 90°, but the second bent portion 13b is a curved surface structure. The difficulty in molding this structure is that the second bent portion 13b is particularly easy to distort, even if there is a groove 14 in its length direction to improve the structural strength. This engine lock handle 1 requires surface rubber coating, so the most important dimension is the relative position of the base surface 11 and the third bent portion 13c. However, according to the usual method of bending the three folded edges one by one, if the base surface 11 is used as the reference plane, the angle between the first bending portion 13a and the punching direction is 0, and the angle between the third bending portion 13c and the punching direction is also 0. The deformation is insufficient, the material rebounds severely, and the relative position relationship between the base surface 11 and the third bending portion 13c is difficult to meet the standard.

[0004] Chinese patent CN116967355A discloses a continuous stamping process for preventing the oil cup bracket from breaking. The oil cup bracket manufactured by the process is also a multi-bend strip, and has a strip convex hull in the middle to help fix the angles of each corner. However, the planes through which the strip convex hull (similar to the groove 14) pass mostly have a large plane area, so the strip convex hull is formed as a whole in the front, and the bending angle control is relatively simple. However, the second bending portion 13b in the above product is a flexure surface structure, and it is impossible for the mold to be tightly attached to both sides during molding. The groove 14 occupies a large area between the first bending portion 13a and the second bending portion 13b. If the groove 14 is formed in advance, the groove 14 will spread the deformation to various parts of the first bending portion 13a, resulting in an unsatisfactory structure, which in turn affects the relative position of the base surface portion 11 and the third bending portion 13c.

[0005] Therefore, it is necessary to design a new molding method to solve the above problems. Summary of the invention

[0006] The main object of the present invention is to provide a continuous stamping process for an engine latch handle, which can continuously form the engine latch handle and ensure the relative position accuracy between the base surface portion and the third bending portion.

[0007] The present invention realizes the above object through the following technical solutions: A continuous stamping process for an engine latch handle, used to form the engine latch handle. The engine latch handle includes a base surface portion, a first flanging, a first bending portion, a second flanging, a second bending portion, a third flanging, and a third bending portion connected in sequence. A groove extending from the base surface portion to the third bending portion is further provided on the engine latch handle. The second bending portion has a flexural surface structure. The process steps include: S1. Punching: The processing unit range of the strip includes a positioning connection area on one side of the strip and a forming area for the rest. Based on both sides of the strip, a number of first positioning holes are punched within the range of the positioning connection area, and a number of second positioning holes are punched within the range of the forming area. S2. Cutting the outer edge: Based on the first positioning holes and the second positioning holes, a blank is cut out within the range of the forming area. One end of the blank is connected to the positioning connection area, and the second positioning holes are located outside the range of the blank. S3. Bending: Based on the first positioning holes, a first flanging and a second flanging are formed on the blank. The side of the first flanging close to the positioning connection area is the base surface portion. The first bending portion is between the first flanging and the second flanging. The side of the second flanging away from the first flanging is the end plane portion. The folding angles of the first flanging and the second flanging are each greater than their designed angles, so that the included angle between the end plane portion and the stamping direction is 60 - 90°. S4. First convex punching: Based on the first positioning holes, the second bending portion, the third flanging, the third bending portion, and a first groove section are formed on the end plane portion. The first groove section extends from the second bending portion to the third bending portion. S5. Second convex punching: Based on the first positioning holes, a second groove section is formed on the base surface portion. S6. Twisting: Based on the first positioning holes, by stamping the first bending portion and the third bending portion, the second bending portion is twisted into the designed shape. S7. Third convex punching: Based on the first positioning holes, a third groove section is formed on the first bending portion. The two ends of the third groove section are respectively connected to the first groove section and the second groove section to form the groove. S8. Shaping: Based on the first positioning holes, the first flanging is bent to its designed angle, so that the blank is completely deformed into the engine latch handle. S9. Blanking: With the first positioning hole as the reference, cut off the positioning connection area to make the engine latch handle fall off.

[0008] Specifically, the punching step further includes forming an anti-deviation portion. The specific operation is to cut out two notches on the same side of the positioning connection area, and then fold down the material between the two notches by 90° to obtain the anti-deviation portion, and the anti-deviation portion is located between two adjacent first positioning holes.

[0009] Specifically, there are two hook portions on the same side of the base surface portion. The outer blank contour including the hook portion contour is cut out by the way of segmented edge cutting in the outer edge cutting step, and the two hook portions are folded down by 90° step by step between the first convexing step and the third convexing step.

[0010] Further, a convex hull is formed on the base surface portion during the second convexing at the same time. The second groove section is opposite to the position of one hook portion, and the convex hull is opposite to the position of the other hook portion.

[0011] Further, before the bending step, chamfering processing is performed on the outer contour of the blank.

[0012] Further, the first convexing step and the second convexing step are completed in the same working step.

[0013] Specifically, the punching step and / or the outer edge cutting step include the operation of cutting a first inner hole. The first inner hole is located within the range of the blank and outside the range of the base surface portion; there is also an operation of cutting a second inner hole between the shaping step and the blanking step, and the second inner hole is located within the range of the base surface portion.

[0014] Specifically, the operation of the shaping step includes shaping the relative position between the base surface portion and the third bending portion.

[0015] The beneficial effects of the technical solution of the present invention are as follows: 1. When the process reaches the torsion step, both the first bending portion and the third bending portion are mostly in a planar structure. When designing the mold, the mold surface can easily come into full contact with the first bending portion and the third bending portion, while the two sides of the second bending portion are free. In this case, the main deformation range is concentrated in the second bending portion, and the second bending portion is easier to obtain the complex shape in the design. Before and after the torsion step, the first bending portion and the third bending portion will maintain the initial planar structure and are not prone to deformation, so the deformation can be more easily controlled.

[0016] 2. After improving the accuracy of two independent regions of the material in the first groove section and the second groove section respectively, the third groove section improves the accuracy of the transition region between the two independent regions, thereby controlling the structural accuracy of the entire product in the process, and better realizing the control of the product accuracy by the groove.

[0017] 3. Considering the processing difficulty of the end flat part, the folding angle between the first folding edge and the second folding edge does not need to reach the final state in one step. Only a small turning angle is required, and it is left to the subsequent steps to be bent and shaped into place. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a three-dimensional view of the engine latch handle; Figure 2 is a top view of the structural change of the strip; Figure 3 is a three-dimensional view of the structural change of the strip; Figure 4 is Figure 3 a partial enlarged view of position A in Figure 5 is Figure 3 a partial enlarged view of position B in

[0019] The marks in the figure are: 1 - engine latch handle, 11 - base part, 111 - second inner hole, 112 - convex hull, 12a - first folding edge, 12b - second folding edge, 12c - third folding edge, 13a - first bending part, 13b - second bending part, 13c - third bending part, 14 - groove, 15 - hook part, 16 - first inner hole; 2 - strip, 21 - positioning connection area, 211 - first positioning hole, 212 - notch, 213 - anti - deviation part, 22 - forming area, 221 - second positioning hole, 222 - blank, 2221 - end flat part, 2222 - first groove section, 2223 - second groove section, 2224 - third groove section. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The present invention will be further described in detail below in conjunction with specific embodiments.

[0021] Embodiment: As Figure 1As shown in the figure, the engine latch handle 1 includes a base portion 11, a first flanging 12a, a first bending portion 13a, a second flanging 12b, a second bending portion 13b, a third flanging 12c, and a third bending portion 13c that are connected in sequence. A groove 14 extending from the base portion 11 to the third bending portion 13c is further provided on the engine latch handle 1. Two hook portions 15 are provided on the same side of the base portion 11. A first inner hole 16 is provided on the third bending portion 13c, and a second inner hole 111 is provided on the base portion 11. The hook portions 15 are folded downward by 90° relative to the base portion 11. Both sides of the edge of the engine latch handle 1 have chamfers.

[0022] Both the first inner hole 16 and the second inner hole 111 are used to provide a cross-linking position for passing through the metal material when the engine latch handle 1 is rubber-coated. The position of the first inner hole 16 is not necessarily set on the third bending portion 13c, and it may also be at other positions outside the base portion 11, and the number is not necessarily one. The number of the second inner holes 111 is not necessarily one either.

[0023] As Figures 2 to 5 shown, a continuous stamping process for an engine latch handle is used to form the engine latch handle 1. The process steps include: S1. Punching: The processing unit range of the strip 2 includes a positioning connection area 21 on one side of the strip 2 and a forming area 22 for the rest. Based on both sides of the strip 2, a number of first positioning holes 211 are punched within the range of the positioning connection area 21, and a number of second positioning holes 221 are punched within the range of the forming area 22.

[0024] The first positioning holes 211 and the second positioning holes 221 are process holes used to determine the layout. The first positioning holes 211 provide positioning throughout the process section. The second positioning holes 221 provide positioning before the formed blank 222. Since the second positioning holes 221 are located within the forming area 22, more accurate positioning is provided for the cut outer edge of the blank 222.

[0025] The punching step further includes forming an anti-offset portion 213. The specific operation is to cut out two notches 212 on the same side of the positioning connection area 21, and then fold the material between the two notches 212 downward by 90° to obtain the anti-offset portion 213. The anti-offset portion 213 is located between two adjacent first positioning holes 211.

[0026] The anti-offset portion 213 is an L-shaped material directly connected to the edge of the positioning connection area 21. During material guiding, there will be an L-shaped groove on the die to match it, thereby guiding and correcting the overall moving position of the strip 2. Since this stamping process is a single suspension for the material, if there is no left-right direction limit for the material guiding direction, it is easy to cause the strip 2 to be sent offset, resulting in serious stamping inaccuracy problems. Therefore, it is necessary to add the anti-offset portion 213.

[0027] S2. Cut the outer edge: With the first positioning hole 211 and the second positioning hole 221 as the reference, cut out the blank 222 within the forming area 22. One end of the blank 222 is connected to the positioning connection area 21, and the second positioning hole 221 is outside the range of the blank 222.

[0028] The blank 222 is the raw material sheet area of the engine latch handle 1 before forming, and is formed by cutting the waste material outside the forming area 22. To ensure that the blank 222 can move step by step, before blanking, one end of it must always remain connected to the positioning connection area 21. Since most of the blank 222 has to be bent and cannot always be coplanar with the original plane of the strip 2, it can only be connected to the positioning connection area 21 with the base surface portion 11 as the reference surface, and the rest is semi-suspended, so that it can deform freely.

[0029] The step of cutting the outer edge cuts out the outer contour of the blank 222 including the contour of the hook portion 15 by means of segmented edge cutting.

[0030] According to the structure of the blank 222, the cut waste material will also have a relatively complex shape. To avoid the problem of tool jamming, the segmented edge cutting method is generally used to obtain the complete contour of the blank 222. For the hook portion 15, it has a J-shaped structure, so the segmented edge cutting method is to first punch out the middle round hole, then punch out the small L-shaped waste material inside from one side of the round hole, and then punch out the large L-shaped waste material outside.

[0031] Before the bending step, chamfering is performed on the outer contour of the blank 222.

[0032] When cutting metal materials, burrs usually remain on the contour. For overmolding, such burrs are not conducive to the wrapping of plastic and form an area where the plastic is prone to breakage. Therefore, chamfers need to be shaped when the blank 222 is still in a planar structure. Otherwise, after bending, the material will not be in a planar structure, and at this time, the chamfer cannot be processed completely. However, the chamfering process can also be completed in segments within a limited number of processing steps, which is beneficial to the rational use of the die space.

[0033] S3. Bending: With the first positioning hole 211 as the reference, form the first folded edge 12a and the second folded edge 12b on the blank 222. The side of the first folded edge 12a close to the positioning connection area 21 is the base surface portion 11. Between the first folded edge 12a and the second folded edge 12b is the first bending portion 13a. The side of the second folded edge 12b away from the first folded edge 12a is the end plane portion 2221. The folding angles of the first folded edge 12a and the second folded edge 12b are each greater than their designed angles, so that the included angle between the end plane portion 2221 and the stamping direction is 60 - 90°.

[0034] The end planar portion 2221 is the raw material sheet area of the second bending portion 13b, the third hemming 12c, and the third bending portion 13c. The purpose of the planar bending is to initially form the first hemming 12a and the second hemming 12b, thereby forming a spacer area between the base surface portion 11, the first bending portion 13a, and the end planar portion 2221. Since the processing difficulty of the end planar portion 2221 needs to be considered, the folding angle between the first hemming 12a and the second hemming 12b does not need to be in place in one step, and only a relatively small turning angle is required, and the folding and shaping will be completed in place in subsequent steps.

[0035] S4. First embossing and second embossing: With the first positioning hole 211 as the reference, the second bending portion 13b, the third hemming 12c, the third bending portion 13c, and the first groove section 2222 are formed on the end planar portion 2221, and at the same time, the second groove section 2223 is formed on the base surface portion 11. The first groove section 2222 extends from the second bending portion 13b to the third bending portion 13c.

[0036] The first groove section 2222 is a raised structure on the end planar portion 2221. Prior to forming this structure, the end planar portion 2221 will have a relatively small springback amount during subsequent bending, improving the folding angle accuracy at the third hemming 12c. The second groove section 2223 is a raised structure on the base surface portion 11, which can improve the structural rigidity of the base surface portion 11 and the accuracy of this structure of the base surface portion 11. The first embossing operation and the second embossing operation here can theoretically be completed in two steps, but combining them into one step saves more processing steps. Since the main deformation area for the first embossing is at the third hemming 12c and the main deformation area for the second embossing is at the base surface portion 11, and the two positions are at a certain distance, the deformations at the two places will not interfere with each other. In this step, there are no protrusions on the first bending portion 13a, and its initial planar structure can be maintained.

[0037] During the second embossing, a convex boss 112 is formed on the base surface portion 11 at the same time. The second groove section 2223 is opposite to one hook portion, and the convex boss 112 is opposite to the other hook portion.

[0038] The convex boss 112 and the second groove section 2223 can resist the deformation problem of the base surface portion 11 caused by the bending of the two hook portions 15, ensuring a full folding angle.

[0039] S5. Twisting: With the first positioning hole 211 as the reference, by stamping the first bending portion 13a and the third bending portion 13c, the second bending portion 13b is twisted into the designed shape.

[0040] When the process reaches the torsion step, both the first bending portion 13a and the third bending portion 13c mostly present a planar structure. When designing the mold, the mold surface can easily come into full contact with the first bending portion 13a and the third bending portion 13c, while both sides of the second bending portion 13b are free. In this case, the main range of deformation is concentrated in the second bending portion 13b, and the second bending portion 13b is more likely to obtain the complex shape in the design. Before and after the torsion step, the first bending portion 13a and the third bending portion 13c will maintain the initial planar structure and are not easily deformed, so the deformation can be more easily controlled.

[0041] S6. Third convex punching: Taking the first positioning hole 211 as the reference, a third groove section 2224 is formed on the first bending portion 13a. The two ends of the third groove section 2224 are respectively connected to the first groove section 2222 and the second groove section 2223 to form the groove 14.

[0042] The role of the third groove section 2224 here is to connect the first groove section 2222 and the second groove section 2223, so that the overall springback amount of the blank 222 along the length direction is small. That is to say, after the first groove section 2222 and the second groove section 2223 improve the accuracy of two independent regions of the material respectively, the third groove section 2224 is to improve the accuracy of the transition region between the two independent regions, so as to control the structural accuracy of the whole product in the process, and thus better realize the control of the product accuracy by the groove 14. The reduction of the angle in the bending step can also make the first bending portion 13a in an angle that is easier to form the third groove section 2224.

[0043] Between the first convex punching step and the third convex punching step, the two hook portions 15 are folded down step by step by 90°.

[0044] Bending 90° at one time is likely to break the hook portion 15, so generally it is necessary to bend 45° first and then bend to 90°.

[0045] S7. Shaping: Taking the first positioning hole 211 as the reference, the first folded edge 12a is bent to its designed angle, so that the blank 222 is completely deformed into the engine lock handle 1. The operation of the shaping step includes shaping the relative positions of the base surface portion 11 and the third bending portion 13c.

[0046] In order to facilitate the processing of the end planar portion 2221, the bending deformation amount has been reduced in the bending step. To obtain the target product structure, the first folded edge 12a needs to be bent again, which is actually the shaping of a specific area. On the basis that the groove 14 has been formed in advance, the material also has a small springback amount during this bending. For the structure of the engine lock handle 1 itself, the relative positions of the base surface portion 11 and the third bending portion 13c are the most important, so generally it will also be shaped to the dimensions specified in the drawing at one time at this stage.

[0047] S8. Blanking: Taking the first positioning hole 211 as a reference, cut off the positioning connection area 21 to make the engine latch handle 1 fall off.

[0048] At this time, the engine latch handle 1 has completed the processing of all structures and no longer requires material guiding, so the positioning connection area 21 needs to be cut off.

[0049] The punching step and / or the outer edge cutting step include the operation of cutting the first inner hole 16, and the first inner hole 16 is within the range of the blank 222 and outside the range of the base surface portion 11; between the shaping step and the blanking step, there is also the operation of cutting the second inner hole 111, and the second inner hole 111 is within the range of the base surface portion 11.

[0050] Because before the bending step, the material where the first inner hole 16 is located is still in a horizontal position and is the easiest to stamp, it should be processed first, otherwise the positional accuracy of the hole cannot be guaranteed. And the material where the second inner hole 111 is located is always in a horizontal position. At this time, the influence of the material pulling of operations such as edge cutting, bossing, and shaping on the positional accuracy of the hole should be considered first. Therefore, the punching of the second inner hole 111 should be appropriately postponed, that is, when the material pulling no longer exists approximately, the punching position can be more accurate.

[0051] The above are only some embodiments of the present invention. For those of ordinary skill in the art, without departing from the inventive concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A continuous stamping process for an engine latch handle, used to form an engine latch handle. The engine latch handle includes a base portion, a first flanging, a first bending portion, a second flanging, a second bending portion, a third flanging, and a third bending portion that are sequentially connected. A groove extending from the base portion to the third bending portion is further provided on the engine latch handle. The second bending portion has a flexible curved surface structure, and it is characterized in that The process steps include: S1. Punching: The processing unit range of the strip includes a positioning connection area on one side of the strip and a forming area for the rest. Based on the two sides of the strip, a number of first positioning holes are punched within the range of the positioning connection area, and a number of second positioning holes are punched within the range of the forming area; S2. Cutting the outer edge: Based on the first positioning holes and the second positioning holes, a blank is cut out within the range of the forming area. One end of the blank is connected to the positioning connection area, and the second positioning holes are outside the range of the blank; S3. Bending: Based on the first positioning holes, a first fold edge and a second fold edge are formed on the blank. The side of the first fold edge close to the positioning connection area is the base surface part. The part between the first fold edge and the second fold edge is the first bending part. The side of the second fold edge away from the first fold edge is the end plane part. The folding angles of the first fold edge and the second fold edge are each greater than their designed angles, so that the included angle between the end plane part and the stamping direction is 60 - 90°; S4. First convex punching: Based on the first positioning holes, a second bending part, a third fold edge, a third bending part, and a first groove section are formed on the end plane part. The first groove section extends from the second bending part to the third bending part; S5. Second convex punching: Based on the first positioning holes, a second groove section is formed on the base surface part; S6. Twisting: Based on the first positioning holes, by stamping the first bending part and the third bending part, the second bending part is twisted into the designed shape; S7. Third convex punching: Based on the first positioning holes, a third groove section is formed on the first bending part. The two ends of the third groove section are respectively connected to the first groove section and the second groove section to form the groove; S8. Shaping: Based on the first positioning holes, the first fold edge is bent to its designed angle, so that the blank is completely deformed into the engine lock handle; S9. Blanking: Based on the first positioning holes, the positioning connection area is cut off, so that the engine lock handle drops off.

2. The continuous stamping process of the engine latch handle according to claim 1, characterized in that: In the punching step, a deviation-preventing part is also formed. The specific operation is to cut out two notches on the same side of the positioning connection area, and then fold down the material between the two notches by 90° to obtain the deviation-preventing part. The deviation-preventing part is located between two adjacent first positioning holes.

3. The continuous stamping process of the engine latch handle according to claim 1, characterized in that: Two hook parts are provided on the same side of the base surface part. In the step of cutting the outer edge, the outer contour of the blank including the contour of the hook parts is cut out by means of segmented edge cutting. Between the first convex punching step and the third convex punching step, the two hook parts are folded down by 90° step by step.

4. The continuous stamping process of the engine latch handle according to claim 3, characterized in that: At the same time of the second convex punching, a convex boss is formed on the base surface part. The second groove section is opposite to one hook part, and the convex boss is opposite to the other hook part.

5. The continuous stamping process of the engine latch handle according to claim 1 or 3, characterized in that: Before the bending step, chamfering processing is performed on the outer contour of the blank.

6. The continuous stamping process of the engine latch handle according to claim 1 or 3, characterized in that: The first convex punching step and the second convex punching step are completed in the same working step.

7. The continuous stamping process of the engine latch handle according to claim 1, characterized in that: The punching step and / or the outer edge cutting step include an operation of cutting a first inner hole, the first inner hole being within the range of the blank and outside the range of the base surface portion; between the shaping step and the blanking step, there is also an operation of cutting a second inner hole, the second inner hole being within the range of the base surface portion.

8. The continuous stamping process of the engine latch handle according to claim 1, characterized in that: The operation of the shaping step includes shaping the relative positions of the base surface portion and the third bending portion.

Images