A continuous stamping process for an engine lock handle

Abstract

The present invention relates to a continuous stamping process for an engine lock handle, the steps comprising: punching, cutting the outer edge, bending, primary embossing, secondary embossing, twisting, tertiary embossing, shaping and blanking. When the process reaches the twisting step, the first bending portion and the third bending portion are both mostly planar structures. When designing the mold, the mold surface can easily make full contact with the first bending portion and the third bending portion, and the two sides of the second bending portion are free, which can make the deformation easier to control. After the first groove section and the second groove section improve the accuracy of the two independent areas of the material, the third groove section improves the accuracy of the transition area between the two independent areas, thereby controlling the structural accuracy of the entire product in the process, thereby better realizing the control of the groove on the accuracy of the product. 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 smaller turning angle is required, and it is left to bend and shape in place in the subsequent steps.

Description

Technical Field

[0001] The present 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 become more diverse, mold design must also meet various product requirements.

[0003] Figure 1 The figure shows an engine lock handle 1. The main body of this engine lock handle 1 includes a base portion 11, a first folded edge 12a, a first bend 13a, a second folded edge 12b, a second bend 13b, a third folded edge 12c, and a third bend 13c, which are connected in sequence. The third folded edge 12c and the second folded edge 1b are in a three-dimensional intersecting relationship. The angle between the base portion 11 and the first bend 13a is approximately 90°, and the angle between the base portion 11 and the third bend 13c is also approximately 90°. However, the second bend 13b has a curved surface structure. The difficulty in molding this structure lies in the fact that the second bend 13b is particularly prone to distortion, even though it has a groove 14 along its length to enhance structural strength. This engine lock handle 1 requires surface encapsulation, so the most important dimension is the relative position of the base portion 11 and the third bend 13c. However, according to the usual method of bending the three folding edges one by one, if the base surface portion 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 portion 11 and the third bending portion 13c is difficult to meet the standard.

[0004] Chinese patent CN116967355A discloses a continuous stamping process for preventing oil cup brackets from breaking. The resulting oil cup bracket is also a multi-bend strip, with a central strip convex bulge to help maintain the angles of each corner. However, the plane through which the strip convex bulge (similar to groove 14) passes often has a large flat area, so the strip convex bulge is formed first, making it easier to control the bend angles. However, in the above product, the second bend 13b is a curved surface structure, making it impossible for the mold to tightly adhere to both sides during molding. Groove 14 occupies a large area between the first bend 13a and the second bend 13b. If groove 14 is formed prematurely, the deformation will spread throughout the first bend 13a, resulting in an unsatisfactory structure and, in turn, affecting the relative position of the base surface 11 and the third bend 13c.

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

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

[0007] The present invention achieves the above-mentioned object through the following technical solution: a continuous stamping process for an engine lock handle, used to form the engine lock handle, the engine lock handle comprising a base surface, a first folded edge, a first bent portion, a second folded edge, a second bent portion, a third folded edge, and a third bent portion connected in sequence, the engine lock handle further comprising a groove extending from the base surface to the third bent portion, the second bent portion having a curved surface structure, the process steps comprising:

[0008] S1. Punching: The processing unit range of the material strip includes the positioning and connecting area on one side of the material strip and the forming area of ​​the remaining part. Based on the two sides of the material strip, a number of first positioning holes are punched in the positioning and connecting area, and a number of second positioning holes are punched in the forming area;

[0009] S2, cutting the outer edge: using the first positioning hole and the second positioning hole as a reference, cutting out the blank within the range of the forming area, with one end of the blank connected to the positioning and connecting area, and the second positioning hole being located outside the range of the blank;

[0010] S3. Bending: With the first positioning hole as a reference, forming a first folded edge and a second folded edge on the blank, wherein the side of the first folded edge close to the positioning connection area is the base surface portion, the area between the first folded edge and the second folded edge is the first bending portion, and the side of the second folded edge away from the first folded edge is the terminal flat portion, and the folding angles of the first folded edge and the second folded edge are each greater than their design angles, so that the angle between the terminal flat portion and the stamping direction is 60-90°;

[0011] S4, one-time embossing: with the first positioning hole as a reference, forming the second bending portion, the third folding edge, the third bending portion and the first groove segment on the terminal flat portion, wherein the first groove segment extends from the second bending portion to the third bending portion;

[0012] S5, secondary embossing: forming a second groove segment on the base surface portion with the first positioning hole as a reference;

[0013] S6. Twisting: Using the first positioning hole as a reference, twist the second bent portion into a designed shape by punching the first bent portion and the third bent portion;

[0014] S7, three-time embossing: with the first positioning hole as a reference, forming a third groove segment on the first bent portion, with both ends of the third groove segment respectively connected to the first groove segment and the second groove segment to form the groove;

[0015] S8, shaping: using the first positioning hole as a reference, bending the first folded edge to its designed angle, so that the blank is completely transformed into the engine lock handle;

[0016] S9, blanking: using the first positioning hole as a reference, cutting off the positioning connection area, so that the engine lock handle falls off.

[0017] Specifically, the punching step also includes forming a stop portion, and the specific operation is to cut two notches on the same side of the positioning connection area, and then fold the material between the two notches down 90° to obtain the stop portion, and the stop portion is located between two adjacent first positioning holes.

[0018] Specifically, two hook parts are provided on the same side of the base surface part, and the outer edge cutting step cuts out the outer contour of the blank including the contour of the hook part by means of segmented edge cutting, and the two hook parts are folded down 90° between the first embossing step and the third embossing step.

[0019] Furthermore, the secondary embossing simultaneously forms a bulge on the base surface portion, the second groove segment is opposite to one hook portion, and the bulge is opposite to the other hook portion.

[0020] Furthermore, before the bending step, the outer contour of the blank is chamfered.

[0021] Furthermore, the first embossing step and the second embossing step are completed in the same step.

[0022] Specifically, the punching step and / or the outer edge cutting step includes an operation of cutting a first inner hole, and the first inner hole is located within the range of the blank and outside the range of the base surface portion; between the shaping and blanking steps, there is also an operation of cutting a second inner hole, and the second inner hole is located within the range of the base surface portion.

[0023] Specifically, the operation of the shaping step includes shaping the relative position of the base surface portion and the third bending portion.

[0024] The beneficial effects of the technical solution of the present invention are:

[0025] 1. During the twisting step, the first and third bends are largely planar. The mold was designed so that the mold surface easily and fully contacts the first and third bends, while the two sides of the second bend are free. In this case, deformation primarily occurs in the second bend, making it easier to achieve the complex shape desired. Both the first and third bends maintain their initial planar structure before and after the twisting step, making deformation less susceptible to deformation and easier to control.

[0026] 2. After the first and second groove segments improve the precision of two independent areas of the material, the third groove segment improves the precision of the transition area between the two independent areas, thereby controlling the structural precision of the entire product during the process, thereby better realizing the control of the groove on the product precision.

[0027] 3. Considering the difficulty of processing the flat surface at the end, the folding angles of the first and second folding edges do not need to be completed in one step. Only a smaller turning angle is required, and the bending and shaping will be completed in the subsequent steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A perspective view of the engine lock handle;

[0029] Figure 2 A top view of the structural changes of the strip;

[0030] Figure 3 A three-dimensional diagram of the structural changes of the material strip;

[0031] Figure 4 for Figure 3 A partial enlarged view of position A in the middle;

[0032] Figure 5 for Figure 3 A partial enlarged view of position B in the middle.

[0033] The following are marked in the figure:

[0034] 1-engine lock handle, 11-base surface, 111-second inner hole, 112-convex hull, 12a-first folded edge, 12b-second folded edge, 12c-third folded edge, 13a-first bent portion, 13b-second bent portion, 13c-third bent portion, 14-groove, 15-hook portion, 16-first inner hole;

[0035] 2-material strip, 21-positioning connection area, 211-first positioning hole, 212-notch, 213-stop deflection portion, 22-forming area, 221-second positioning hole, 222-blank, 2221-end plane portion, 2222-first groove section, 2223-second groove section, 2224-third groove section. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below with reference to specific embodiments.

[0037] Example:

[0038] like Figure 1 As shown, 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 engine lock handle 1 also has a groove 14 extending from the base surface 11 to the third bent portion 13c. Two hook portions 15 are provided on the same side of the base surface 11. The third bent portion 13c has a first inner hole 16, and the base surface 11 has a second inner hole 111. The hook portions 15 are folded downward 90 degrees relative to the base surface 11. Both edges of the engine lock handle 1 are chamfered.

[0039] Both the first inner hole 16 and the second inner hole 111 serve to provide cross-linking points through the metal material when the engine lock handle 1 is rubber-coated. The first inner hole 16 is not necessarily located on the third bent portion 13c; it may also be located elsewhere outside the base surface portion 11. The number of the first inner hole 16 is not necessarily one. The number of the second inner hole 111 is also not necessarily one.

[0040] like Figures 2 to 5 As shown, a continuous stamping process for an engine lock handle is used to form an engine lock handle 1. The process steps include:

[0041] S1. Punching: The processing unit range of the material strip 2 includes the positioning and connecting area 21 located on one side of the material strip 2 and the forming area 22 of the remaining part. Based on the two sides of the material strip 2, a number of first positioning holes 211 are punched out within the range of the positioning and connecting area 21, and a number of second positioning holes 221 are punched out within the range of the forming area 22.

[0042] The first and second positioning holes 211 and 221 are process holes used to determine the layout. The first positioning hole 211 provides positioning throughout the entire process. The second positioning hole 221 provides positioning before forming the blank 222. Because the second positioning hole 221 is located within the forming area 22, it provides more precise positioning for trimming the outer edge of the blank 222.

[0043] The punching step also includes forming a stop portion 213. The specific operation is to cut two notches 212 on the same side of the positioning connection area 21, and then fold the material between the two notches 212 down 90° to obtain the stop portion 213. The stop portion 213 is located between the two adjacent first positioning holes 211.

[0044] The deflection stop 213 is an L-shaped material directly connected to the edge of the positioning connection area 21. During material feeding, an L-shaped groove in the die matches this groove, thereby guiding the overall movement of the material strip 2. Because the stamping process is a single-hanging process for the material, the lack of left and right limiters in the material feeding direction can easily cause the material strip 2 to deviate, resulting in serious stamping errors. Therefore, the deflection stop 213 is necessary.

[0045] S2. Cutting the outer edge: Based on the first positioning hole 211 and the second positioning hole 221 , cut out the blank 222 within the range of the forming area 22 . One end of the blank 222 is connected to the positioning and connecting area 21 , and the second positioning hole 221 is located outside the range of the blank 222 .

[0046] Blank 222 is the raw material sheet area of ​​the engine lock handle 1 before forming. It is formed by removing the waste material from the outer periphery of the forming area 22. To ensure that blank 222 can move stepwise, one end of it must remain connected to the positioning and connection area 21 before blanking. Because the majority of blank 222 is bent and cannot remain coplanar with the original plane of the material strip 2, it can only be connected to the positioning and connection area 21 using the base surface 11 as the reference surface. The remaining portion is semi-suspended, allowing for free deformation.

[0047] The outer edge trimming step is to cut out the outer contour of the blank 222 including the contour of the hook portion 15 by means of segmented trimming.

[0048] Due to the structure of the blank 222, the cut scrap may have a relatively complex shape. To avoid the problem of tool jamming, a segmented trimming method is generally used to obtain a complete outline of the blank 222. For the hook portion 15, it has a J-shaped structure. Therefore, the segmented trimming method is to first punch out the central circular hole, then punch out the inner small L-shaped scrap from one side of the circular hole, and then punch out the outer large L-shaped scrap.

[0049] Before the bending step, the outer contour of the blank 222 is chamfered.

[0050] When metal materials are cut, they often leave burrs on their contours. For plastic encapsulation, these burrs can hinder plastic wrapping and create areas of plastic that are susceptible to breakage. Therefore, the chamfers must be formed while the blank 222 is still flat. Otherwise, after bending, the material will no longer be flat, making it impossible to fully chamfer. However, chamfering can also be completed in stages within a limited number of steps, which helps to effectively utilize mold space.

[0051] S3. Bending: With the first positioning hole 211 as a reference, a first folded edge 12a and a second folded edge 12b are formed 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, the first folded edge 12a and the second folded edge 12b are between the first folded edge 12a and the second folded edge 12b, and the side of the second folded edge 12b away from the first folded edge 12a is the end plane portion 2221. The folding angle of the first folded edge 12a and the folding angle of the second folded edge 12b are respectively greater than their design angles, so that the angle between the end plane portion 2221 and the stamping direction is 60~90°.

[0052] The terminal flat surface 2221 forms the raw material area for the second bend 13b, the third fold 12c, and the third bend 13b. The purpose of this flat bending is to initially shape the first and second folds 12a, 12b, thereby forming a separation between the base surface 11, the first bend 13a, and the terminal flat surface 2221. Considering the difficulty of machining the terminal flat surface 2221, the angle between the first and second folds 12a, 12b need not be fully formed in one step; a smaller angle is sufficient, which will be bent and shaped in a subsequent step.

[0053] S4, one-time embossing and two-time embossing: taking the first positioning hole 211 as a reference, a second bending portion 13b, a third folding edge 12c, a third bending portion 13c and a first groove segment 2222 are formed on the end plane portion 2221, and at the same time, a second groove segment 2223 is formed on the base surface portion 11, and the first groove segment 2222 extends from the second bending portion 13b to the third bending portion 13c.

[0054] The first groove section 2222 is a raised structure on the terminal plane portion 2221. Prioritizing the formation of this structure can make the terminal plane portion 2221 have a smaller rebound amount in the subsequent bending, thereby improving the accuracy of the folding angle at the third folding edge 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 improve the accuracy of the structure of the base surface portion 11. The single embossing operation and the secondary embossing operation here can theoretically be completed in two steps, but combining them into one step saves more work steps. Because the main deformation area of ​​the single embossing is at the third folding edge 12c, and the main deformation area of ​​the secondary embossing is at the base surface portion 11, the two positions are at a certain distance, and the deformations at the two locations will not interfere with each other. In this step, there is no protrusion on the first bending portion 13a, and it can maintain its original planar structure.

[0055] The secondary embossing simultaneously forms a convex bump 112 on the base surface portion 11 , the second groove section 2223 is opposite to one hook portion, and the convex bump 112 is opposite to the other hook portion.

[0056] The convex bulge 112 and the second groove section 2223 can resist the deformation of the base surface portion 11 caused by the bending of the two hook portions 15, thereby ensuring that the folded corner is full.

[0057] S5. Twisting: With the first positioning hole 211 as a reference, the second bent portion 13b is twisted into a designed shape by punching the first bent portion 13a and the third bent portion 13c.

[0058] When the process reaches the twisting step, the first and third bends 13a, 13c are both largely planar. When designing the mold, the mold surface easily and fully contacts the first and third bends 13a, 13c, while the two sides of the second bend 13b are free. In this case, deformation primarily occurs in the second bend 13b, making it easier for the second bend 13b to achieve the complex shape desired. Before and after the twisting step, the first and third bends 13a, 13c maintain their initial planar structure and are less susceptible to deformation, making deformation easier to control.

[0059] S6. Three-time embossing: Based on the first positioning hole 211 , a third groove segment 2224 is formed on the first bending portion 13 a . Both ends of the third groove segment 2224 are respectively connected to the first groove segment 2222 and the second groove segment 2223 to form a groove 14 .

[0060] The function of the third groove segment 2224 is to connect the first groove segment 2222 and the second groove segment 2223, thereby reducing the overall springback of the blank 222 along its length. In other words, after the first groove segment 2222 and the second groove segment 2223 have improved the precision of two independent areas of the material, the third groove segment 2224 improves the precision of the transition area between the two independent areas, thereby controlling the structural precision of the entire product during the process and better controlling the product precision of the groove 14. The reduced angle of the bending step also places the first bend 13a at an angle that is more conducive to forming the third groove segment 2224.

[0061] Between the first embossing step and the third embossing step, the two hook portions 15 are folded down 90 degrees in steps.

[0062] Bending 90° at one time will easily break the hook portion 15 , so it is generally necessary to bend it 45° first and then bend it to 90°.

[0063] S7, shaping: With the first positioning hole 211 as a reference, bend the first folded edge 12a to its designed angle, so that the blank 222 is completely transformed into the engine lock handle 1. The shaping step includes shaping the relative position of the base surface portion 11 and the third bent portion 13c.

[0064] To facilitate processing of the flat end portion 2221, the bending step has already minimized deformation. However, to achieve the desired product structure, the first folded edge 12a requires further bending, effectively reshaping a specific area. Given that the groove 14 has already been preformed, this bending also minimizes material springback. Regarding the structure of the engine lock handle 1 itself, the relative position of the base portion 11 and the third folded portion 13c is of paramount importance, so shaping to the dimensions specified in the drawings is typically performed at this stage.

[0065] S8, blanking: using the first positioning hole 211 as a reference, cut off the positioning connection area 21 to make the engine lock handle 1 fall off.

[0066] At this point, the engine lock handle 1 has completed all structural processing and no longer requires lead-in, so the positioning connection area 21 needs to be cut off.

[0067] 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 located within the range of the blank 222 and outside the range of the base surface portion 11; between the shaping and blanking steps, the operation of cutting the second inner hole 111 is also included, and the second inner hole 111 is located within the range of the base surface portion 11.

[0068] Because the material where the first inner hole 16 is located is still horizontal before the bending step, punching is easiest, so it should be processed first, otherwise the hole position accuracy cannot be guaranteed. The material where the second inner hole 111 is located is always horizontal. At this time, the impact of the material pulling during trimming, embossing, and shaping operations on the hole position accuracy must be given priority consideration. Therefore, the punching of the second inner hole 111 should be appropriately postponed, that is, when the material is basically no longer pulled, so that the position can be more accurate.

[0069] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A continuous stamping process for an engine lock handle, for forming an engine lock handle, wherein the engine lock handle comprises a base surface, a first folded edge, a first bent portion, a second folded edge, a second bent portion, a third folded edge, and a third bent portion connected in sequence; the engine lock handle further comprises a groove extending from the base surface to the third bent portion; the second bent portion is a curved surface structure, characterized in that The process steps include: S1. Punching: The processing unit range of the material strip includes the positioning and connecting area on one side of the material strip and the forming area of ​​the remaining part. Based on the two sides of the material strip, a number of first positioning holes are punched in the positioning and connecting area, and a number of second positioning holes are punched in the forming area; S2, cutting the outer edge: using the first positioning hole and the second positioning hole as a reference, cutting out the blank within the range of the forming area, with one end of the blank connected to the positioning and connecting area, and the second positioning hole being located outside the range of the blank; S3. Bending: With the first positioning hole as a reference, forming a first folded edge and a second folded edge on the blank, wherein the side of the first folded edge close to the positioning connection area is the base surface portion, the area between the first folded edge and the second folded edge is the first bending portion, and the side of the second folded edge away from the first folded edge is the terminal flat portion, and the folding angles of the first folded edge and the second folded edge are each greater than their design angles, so that the angle between the terminal flat portion and the stamping direction is 60-90°; S4, one-time embossing: with the first positioning hole as a reference, forming the second bending portion, the third folding edge, the third bending portion and the first groove segment on the terminal flat portion, wherein the first groove segment extends from the second bending portion to the third bending portion; S5, secondary embossing: forming a second groove segment on the base surface portion with the first positioning hole as a reference; S6. Twisting: Using the first positioning hole as a reference, twist the second bent portion into a designed shape by punching the first bent portion and the third bent portion; S7, three-time embossing: with the first positioning hole as a reference, forming a third groove segment on the first bent portion, with both ends of the third groove segment respectively connected to the first groove segment and the second groove segment to form the groove; S8, shaping: using the first positioning hole as a reference, bending the first folded edge to its designed angle, so that the blank is completely transformed into the engine lock handle; S9, blanking: using the first positioning hole as a reference, cutting off the positioning connection area so that the engine lock handle falls off; The punching step also includes forming a stop part, which is specifically performed by cutting two notches on the same side of the positioning connection area, and then folding the material between the two notches down 90° to obtain the stop part, which is located between two adjacent first positioning holes.

2. The continuous stamping process for the engine lock handle according to claim 1, characterized in that: Two hook parts are provided on the same side of the base surface part, and the outer edge cutting step cuts out the outer contour of the blank including the contour of the hook part in a segmented edge cutting manner, and the two hook parts are folded down 90° between the first embossing step and the third embossing step.

3. The continuous stamping process for the engine lock handle according to claim 2, characterized in that: The secondary embossing simultaneously forms a bulge on the base surface portion, the second groove segment is opposite to one hook portion, and the bulge is opposite to the other hook portion.

4. The continuous stamping process for the engine lock handle according to claim 1 or 2, characterized in that: Before the bending step, the outer contour of the blank is chamfered.

5. The continuous stamping process for the engine lock handle according to claim 1 or 2, characterized in that: The first embossing step and the second embossing step are completed in the same working step.

6. The continuous stamping process for the engine lock handle according to claim 1, characterized in that: The punching step and / or the outer edge cutting step include a first inner hole cutting operation, which is located within the range of the blank and outside the range of the base surface portion; the shaping and blanking steps also include a second inner hole cutting operation, which is located within the range of the base surface portion.

7. The continuous stamping process for the engine lock 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 bent portion.

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