Sheet metal punch forming method

Abstract

The invention provides a sheet metal punch forming method which comprises the following steps: stretching to form a stretching part and a horizontal pressing edge positioned on the peripheral side of the stretching part on a sheet metal part; shaping, trimming and pre-stretching the closed clamping hook: shaping, trimming and pre-stretching the sheet metal part; extrusion molding: carrying out extrusion molding on the basis of the semicircular convex hull so as to form a closed clamping hook with a guide bevel edge; first-time circumferential bending is conducted, specifically, the edge part of the horizontal pressing edge is bent in the direction deviating from the stretching part till the edge part is perpendicular to a bottom plate of the stretching part, so that an inner hook bend is formed; and second-time circumferential bending is conducted, specifically, the horizontal pressing edge is bent in the direction deviating from the stretching part till the horizontal pressing edge is perpendicular to the bottom plate of the stretching part. The sheet metal punch forming method is suitable for forming a sheet metal part, wherein the edge of the sheet metal part is provided with a vertical bent edge, the edge of the vertical bent edge is provided with an inner hook bend, and the vertical bent edge is provided with a closed clamping hook with a guide bevel edge. When the closed clamping hook is formed, the semicircular convex hulls are pre-stretched firstly, then extrusion forming is carried out, and extrusion forming materials can be prevented from being broken by extrusion.

Description

Technical Field

[0001] The present invention belongs to the technical field of stamping dies, and specifically relates to a sheet metal stamping forming method. The sheet metal product formed by the stamping forming method has an inner hook bend on the edge of the bent edge and a closed hook and a guide bevel on the bent edge. Background Art

[0002] For some sheet metal products, such as TV back panels, Figures 1 to 4 As shown, to achieve a more stable and efficient assembly, prevent side light leakage, and realize more structural functions, the edges of the stretched portion (top, left, and right sides) must have a vertical bend with an inner hook formed on the edge of the vertical bend. At the same time, closed hooks with guiding bevels are formed at intervals along the length of the vertical bend (the hooks are not continuous). The height H of the closed hooks must be at least twice the material thickness t, and the shape must be a narrow, elongated strip (the length direction is the same as the vertical bend).

[0003] Currently, the back panel of a TV set generally adopts a vertical bending edge in the industry, and the hook on the vertical bending edge is a torn hook, that is, the hook is through. Correspondingly, the mold process is to form the hook first and then bend it. The corresponding mold structure is a conventional forming mold and bending mold, which cannot form stably. Figures 1 to 4 Sheet metal product shown.

[0004] The above information disclosed in this background technology is only used to increase the understanding of the background technology of this application. Therefore, it may contain information that does not constitute the prior art known to ordinary technicians in this field. Summary of the Invention

[0005] In response to the problems pointed out in the background technology, the present invention provides a sheet metal stamping forming method, which can form a sheet metal part with an inner hook bend on the edge of a vertical bending edge and a closed hook with a guiding bevel on the vertical bending edge.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: In some embodiments of the present application, a sheet metal stamping method is provided, comprising the following steps: Stretching to form a stretched portion and a horizontal pressing edge located around the stretched portion on the sheet metal part; Shaping, trimming and pre-stretching of the closed hook: shaping, trimming and pre-stretching the sheet metal part to form a semicircular bulge and through-cut grooves on the outer sides of the two ends of the semicircular bulge on the horizontal pressing edge. The pre-stretching direction is opposite to the stretching direction of the stretched part, and the length direction of the semicircular bulge is the same as the length direction of the horizontal pressing edge. Extrusion molding is performed on the basis of the semicircular convex hull to form a closed hook with a guiding bevel. The guiding bevel is located on the outside of the closed hook and is connected to the through-cut groove at both ends. The guiding bevel is inclined in the direction away from the stretching part. The first circumferential bending is to bend the edge of the horizontal pressing edge along the first pre-folding line located outside the closed hook in a direction away from the stretching portion until it is perpendicular to the bottom plate of the stretching portion to form an inner hook bend; The second circumferential bending is to bend the horizontal pressing edge along the second pre-folding line located on the inner side of the closed hook in a direction away from the stretching portion until it is perpendicular to the bottom plate of the stretching portion.

[0007] In some embodiments of the present application, the following step is further provided between the extrusion molding step and the first circumferential bending step: bending the horizontal pressing edge along the second pre-folding line located on the inner side of the closed hook toward the stretching portion at an acute angle.

[0008] In some embodiments of the present application, the extrusion molding die used in the extrusion molding step includes: The upper die comprises a punch fixing plate, an upper stripping plate and a hook punch; the upper stripping plate is located below the punch fixing plate and is floatingly connected to the punch fixing plate, and a first through-hole extending vertically is formed on the upper stripping plate; the hook punch is movably inserted in the first through-hole, the top end of which is fixedly connected to the punch fixing plate, and the bottom forming end extends through the bottom end of the first through-hole; a guiding bevel forming convex portion is formed on the bottom surface of the upper stripping plate, the guiding bevel forming convex portion is located on one side of the bottom end of the first through-hole, and the guiding bevel forming convex portion has a first forming inclined surface; The lower mold comprises a lower template and a hook inner top; a second through-hole extending vertically is formed on the lower template, and the top of the second through-hole is a hook forming groove that cooperates with the bottom forming end of the hook punch; the hook inner top is movably inserted in the second through-hole, and a limited fixing piece is formed at the bottom end of the second through-hole, and a first elastic piece is provided between the limited fixing piece and the hook inner top, for applying an upward reset elastic force to the hook inner top so that the top end of the hook inner top extends into the hook forming groove; a guide bevel forming recess is formed on the top surface of the lower template, and the guide bevel forming recess is located on one side of the top end of the second through-hole, and the guide bevel forming recess has a second forming inclined surface; When the inner top of the hook is pressed against the limit fixing part by the hook punch and the extruded lower bottom end of the sheet metal part, the hook punch and the inner top of the hook cooperate to form the closed hook, and the first forming bevel and the second forming bevel cooperate to form the guide bevel.

[0009] In some embodiments of the present application, the extrusion forming gap between the hook punch and the hook forming groove is 0.15mm-0.3mm.

[0010] In some embodiments of the present application, a convex rib is further formed on the top surface of the lower template and surrounds the periphery of the hook forming groove.

[0011] In some embodiments of the present application, the thickness of the rib is 1 / 4-1 / 3 of the thickness of the sheet metal part, and the width is 1 mm.

[0012] In some embodiments of the present application, the bending die used in the second circumferential bending step includes: An upper mold, comprising an upper mold base assembly, an upper stripping assembly, and an upper template assembly, wherein the upper stripping assembly is located below the upper template assembly and is floatingly connected to the upper mold base assembly, the upper template assembly is located below the upper mold base assembly and is fixedly connected to the upper mold base assembly, and the upper template assembly is located on the periphery of the upper stripping assembly; The lower mold comprises a lower template assembly and a lower mold base assembly, the lower template assembly is arranged above the lower mold base assembly, and the lower template assembly comprises a lower template and a swing block; a notch is formed on the top edge of the lower template, the swing block is arranged in the notch and is rotatably connected to the lower template; the position of the swing block corresponds to that of the upper template assembly, and the swing block can be rotated to a first position and a second position, and when in the first position, its inner side surface abuts against the side surface of the notch, and when in the second position, its bottom surface abuts against the bottom surface of the notch; an avoidance groove is provided on the outer side surface of the swing block, at least for avoiding the closed hook and the inner hook bending when it is in the second position; a second elastic member is provided between the notch and the swing block, for driving the swing block to rotate and return to the first position.

[0013] In some embodiments of the present application, a mounting hole is formed on the bottom surface of the notch portion, and a lifting pin is provided in the mounting hole. The top end of the lifting pin abuts against the bottom surface of the pendulum block to drive the pendulum block to rotate and return to the first position.

[0014] In some embodiments of the present application, the bottom surface of the notch portion is a horizontal plane, the side surface of the notch portion is an inclined plane, an obtuse angle is formed between the bottom surface of the notch portion and the side surface of the notch portion, and an arc-shaped groove is formed at the intersection of the bottom surface of the notch portion and the side surface of the notch portion; The bottom surface of the pendulum block is a plane, the inner side surface of the pendulum block is a plane, the angle between the bottom surface of the pendulum block and the inner side surface of the pendulum block is smaller than the obtuse angle, and an arc-shaped protrusion is formed at the junction of the bottom surface of the pendulum block and the inner side surface of the pendulum block, and the arc-shaped protrusion is rotatably engaged with the arc-shaped groove.

[0015] In some embodiments of the present application, the lower mold also includes an external release plate, which is used to move upward to push the material when the mold is opened; the external release plate is located above the lower mold base assembly and is located on the periphery of the lower template assembly. The external release plate is floatingly connected to the lower mold base assembly, and the external release plate is located below the upper template assembly.

[0016] Compared with the prior art, the advantages and positive effects of this application are: 1. The sheet metal stamping forming method of the present application is suitable for sheet metal parts having a vertical bend edge, an inner hook bend on the edge of the vertical bend edge, and a closed hook with a guiding bevel edge formed on the vertical bend edge; 2. When forming a closed hook on the horizontal flange of a sheet metal part, it is divided into two steps: first, pre-stretching a semicircular convex hull, and then extrusion molding. Pre-stretching can pre-pull a part of the material so that there is enough material for the next step of extrusion molding, avoiding the extrusion molding material from being squeezed and ensuring the smooth molding of the closed hook; 3. While the closed hook is pre-stretched, through grooves are cut on the outer sides of both ends of the semicircular convex bulge so that the closed hook with guiding bevel can be integrally formed during extrusion molding.

[0017] Other features and advantages of the present invention will become more apparent after reading the detailed description of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] Figure 1 is a schematic diagram of the three-dimensional structure of a television back panel according to an embodiment; Figure 2 for Figure 1 A magnified view of part A; Figure 3 is a schematic cross-sectional structural diagram of a television back panel according to an embodiment; Figure 4 for Figure 3 A magnified view of part B; Figure 5 is a schematic diagram of a partial structure of a television back panel after completing a stretching process according to an embodiment; Figure 6 This is a schematic diagram of the partial structure of the television back panel after completing the shaping, edge trimming and closed hook pre-stretching processes according to the embodiment; Figure 7This is a schematic diagram of the partial structure of the back panel of a television set after the extrusion molding process is completed according to the embodiment; Figure 8 is a schematic diagram of the partial structure of the television back panel after completing the first circumferential bending process according to the embodiment; Figure 9 is a schematic diagram of the partial structure of the television back panel after completing the second circumferential bending process according to the embodiment; Figure 10 is a schematic diagram of the three-dimensional structure of an extrusion molding die according to an embodiment; Figure 11 for Figure 10 A top view of Figure 12 for Figure 11 CC cross-sectional view; Figure 13 for Figure 12 Magnified view of the D part; Figure 14 Schematic diagram of the assembly structure of the upper die block, hook punch, lower die block, hook inner top and spacer of the extrusion forming die according to the embodiment; Figure 15 for Figure 14 Schematic diagram of the cross-sectional structure; Figure 16 for Figure 15 A magnified view of part E; Figure 17 Schematic diagram of the structure of the upper die block of the extrusion molding die from the bottom perspective according to the embodiment; Figure 18 Schematic diagram of the lower die block structure of the extrusion molding die according to the embodiment; Figure 19 Schematic diagram of the three-dimensional structure of the bending die used in the second circumferential bending step according to the embodiment; Figure 20 Schematic diagram of the cross-sectional structure of a bending die used in the second circumferential bending step according to the embodiment; Figure 21 for Figure 20 Magnified view of part F; Figure 22 Schematic diagram of the relative positional relationship between the lower template, the swing block and the back panel of the TV set of the bending mold used in the second circumferential bending step according to the embodiment.

[0020] Figures 1 to 9 Reference numerals: 10. TV back panel; 11. Stretching part; 12. Horizontal pressing edge; 13. Vertical bending edge; 14. Inner hook bending; 15. Closing hook; 16. Aligning bevel edge; 17. Semicircular convex hull; 18. Through-cut groove; Figures 10 to 18Reference numerals: 1000, extrusion molding die; 1100, upper die; 1110, upper code template; 1120, punch fixing plate; 1130, upper stripper plate; 1131, first through-hole portion; 1132, guiding bevel molding convex portion; 1133, first molding bevel; 1134, upper stripper plate body; 1135, upper die insert; 1140, hook punch; 1150, connecting insert; 1160, upper die base; 1200, lower die; 1210, lower template; 1211, second through-portion; 1212, hook forming groove; 1213, guiding bevel forming recess; 1214, second forming bevel; 1215, lower template body; 1216, lower mold insert; 1217, rib; 1220, hook inner top; 1230, position limiting fixture; 1240, lower pad; 1250, lower mold base; 1260, lower pad; 1270, lower code template; Figures 19 to 22 Reference numerals: 2000, bending die; 2100, upper die; 2110, upper die base assembly; 2111, upper code template; 2112, upper pad; 2113, upper die base; 2114, upper clamp; 2120, upper stripper assembly; 2121, upper stopper; 2122, upper stripper body; 2123, contour sleeve; 2130, upper template assembly; 2131, bending support block; 2132, punching pad; 2133, upper template; 2200, lower die; 2210, lower template assembly ; 2211, lower template; 2212, pendulum block; 2213, notch; 2214, inner side of the pendulum block; 2215, side of the notch; 2216, bottom surface of the pendulum block; 2217, bottom surface of the notch; 2218, avoidance groove; 2219, lifting pin; 22100, arc groove; 22110, arc protrusion; 2220, lower die base assembly; 2221, lower splint; 2222, lower die base; 2223, lower pad; 2224, lower code template; 2230, outer release plate. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0023] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0024] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0025] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0026] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0027] In some embodiments of the present application, a sheet metal stamping forming method is proposed for forming a sheet metal part having an inner hook bend 14 on the edge of a vertical bend edge 13 and a closed hook 15 with a guide bevel 16 formed on the vertical bend edge 13, such as Figures 1 to 4 The back panel 10 of the television is shown.

[0028] In some embodiments of the present application, a sheet metal stamping method is provided, comprising the following steps: Stretching to form a stretched portion 11 and a horizontal pressing edge 12 located around the stretched portion 11 on the sheet metal part (thin metal plate), such as Figure 5 As shown; Shaping, trimming and pre-stretching of the closed hook, shaping, trimming and pre-stretching the sheet metal to form the required shape on the stretching part 11, etc., and cutting off the edge waste at different circumferential positions of the horizontal pressing edge 12 at intervals (such as Figure 6 The left side of the dotted line shown in FIG is the cut waste) is pre-stretched on the horizontal pressing edge 12 to form a semicircular convex hull 17, as shown in FIG. Figure 6 As shown, through grooves 18 are cut out on the outer sides of both ends of the semicircular convex hull 17. The pre-stretching direction is opposite to the stretching direction of the stretching portion 11. The length direction of the semicircular convex hull 17 is the same as the length direction of the horizontal pressing edge 12. Figure 6 As shown, combined with Figure 2 As shown; Trimming and punching, i.e., cutting off the edge waste remaining in the circumferential direction of the horizontal pressing edge 12 after the steps of "shaping, trimming and pre-stretching of the closed hook", and punching holes on the stretching portion 11 and the horizontal pressing edge 12, including process holes and functional holes; After extrusion molding, trimming and punching are completed, extrusion molding is performed on the basis of the semicircular convex hull 17 to form a closed hook 15 with a guiding bevel 16. The guiding bevel 16 is located on the outside of the closed hook 15, and the two ends are connected with the through-cut groove 18. The guiding bevel 16 is inclined in the direction away from the stretching portion 11, as shown in FIG. Figure 7 As shown, combined with Figure 2 As shown; The first circumferential bending is to bend the edge of the horizontal pressing edge 12 along the first pre-folding line located outside the closing hook 15 in a direction away from the stretching portion 11 until it is perpendicular to the bottom plate of the stretching portion 11 to form an inner hook bend 14; The second circumferential bending is to bend the horizontal pressing edge 12 along the second pre-folding line located inside the closing hook 15 in a direction away from the stretching portion 11 until it is perpendicular to the bottom plate of the stretching portion 11 .

[0029] In some embodiments of the present application, the following step is further provided between the extrusion molding step and the first circumferential bending step: the horizontal pressing edge 12 is bent at an acute angle α toward the stretching portion 11 along a second pre-folding line located on the inner side of the closed hook 15 .

[0030] In some embodiments of the present application, the acute angle α has an angle value ranging from 5° to 10°, for example, 8°.

[0031] That is, the horizontal pressing edge 12 is first bent along the second pre-folding line located inside the closed hook 15 in the direction toward the stretching portion 11 at an acute angle α, and then the edge of the horizontal pressing edge 12 is bent along the first pre-folding line located outside the closed hook 15 in the direction away from the stretching portion 11 until it is perpendicular to the bottom plate of the stretching portion 11, and the inner hook bend 14 is formed as shown in FIG. Figure 8 As shown; on this basis, a second circumferential bending is performed to form a vertical bending edge 13 with a negative-angle inner hook bend 14, that is, the inner hook bend 14 is inclined to the side where the stretching portion 11 is located at a certain angle, and the angle value is equal to the angle value of the acute angle α. At the same time, a closed hook 15 with a guiding bevel 16 is formed on the vertical bending edge 13.

[0032] By using the sheet metal stamping forming method in some embodiments of the present application, it is possible to form a sheet metal part with a vertical bending edge 13, and the edge of the vertical bending edge 13 has an inner hook bend 14, and at the same time, a closed hook 15 with a guide bevel 16 is formed on the vertical bending edge 13, such as a TV back panel 10, thereby improving the assembly effect of the TV back panel 10 and realizing more structural functions, and the closed hook 15 can effectively prevent light leakage from the side of the TV back panel 10.

[0033] When forming the closed hook 15, it is divided into two steps. First, the semicircular convex hull 17 is pre-stretched, and then the extrusion molding is carried out. The pre-stretching can pre-stretch a part of the material so that there is enough material for the next extrusion molding to avoid the extrusion molding material being squeezed and broken, thereby ensuring the smooth molding of the closed hook 15.

[0034] While the closed hook 15 is pre-stretched, through grooves 18 are cut out on the outer sides of both ends of the semicircular convex bulge 17 so that the closed hook 15 with the guiding bevel 16 can be integrally formed during extrusion molding.

[0035] Reference Figures 10 to 18 As shown, in some embodiments of the present application, the extrusion molding die 1000 used in the extrusion molding step includes an upper mold 1100 and a lower mold 1200 .

[0036] In some embodiments of the present application, the upper die 1100 includes an upper code template 1110 , an upper die base 1160 , a punch fixing plate 1120 , an upper stripping plate 1130 and a hook punch 1140 .

[0037] The punch fixing plate 1120 is located below the upper code template 1110 and is fixedly connected to the upper code template 1110. The upper release plate 1130 is located below the punch fixing plate 1120 and is floatingly connected to the punch fixing plate 1120. The floating setting of the upper release plate 1130 is the same as the existing technology and will not be elaborated on.

[0038] A vertically extending first through-portion 1131 is formed on the upper stripping plate 1130, and the hook punch 1140 is movably inserted in the first through-portion 1131, that is, it and the upper stripping plate 1130 can move relative to each other in the up and down directions; the top end of the hook punch 1140 is fixedly connected to the punch fixing plate 1120, and the bottom end of the hook punch 1140 is its forming end, and the forming end of the hook punch 1140 extends downward through the bottom end of the first through-portion 1131; a guide bevel forming protrusion 1132 is formed on the bottom surface of the upper stripping plate 1130, and the guide bevel forming protrusion 1132 is located on one side of the bottom end of the first through-portion 1131 and protrudes downward, and the guide bevel forming protrusion 1132 has a first forming bevel 1133.

[0039] In some embodiments of the present application, the lower mold 1200 includes a lower mold plate 1210 and a hook inner top 1220 .

[0040] A vertically extending second through portion 1211 is formed on the lower template 1210, and the second through portion 1211 is opposite to the first through portion 1131. The top of the second through portion 1211 is provided with a hook forming groove 1212 that cooperates with the forming end of the hook punch 1140; the hook inner top 1220 is movably inserted in the second through portion 1211, that is, it and the lower template 1210 can move relative to each other in the up and down directions; a limiting fixing member 1230 is formed at the bottom end of the second through portion 1211, and a first elastic member is provided between the limiting fixing member 1230 and the hook inner top 1220, which is used to apply an upward reset elastic force to the hook inner top 1220 so that the top of the hook inner top 1220 extends into the hook forming groove 1212.

[0041] A guiding bevel molding recess 1213 is formed on the top surface of the lower template 1210 , and the guiding bevel molding recess 1213 is located on one side of the top end of the second through portion 1211 , and the guiding bevel molding recess 1213 has a second molding bevel 1214 .

[0042] When the closed hook 15 is extruded and formed, the TV back panel 10 is positioned on the lower template 1210, and the semicircular convex bulge 17 on the horizontal pressing edge 12 is opposite to the hook forming groove 1212; the upper mold 1100 is driven downward by the press to close the mold, and the upper stripper 1130 and the lower template 1210 press the material of the TV back panel 10, and the first forming inclined surface 1133 and the second forming inclined surface 1214 cooperate to form the guide inclined edge 16; the mold is continued to be closed, and the hook punch 1140 continues to move downward and enters the hook forming groove 1212, pressing the material downward into the hook forming groove 1212, and the material around the hook is squeezed thin and high to keep it closed. The inner top 1220 of the hook is pressed down until it rests on the limiting fixing piece 1230, and the forming height of the closed hook 15 is limited. The hook punch 1140 and the inner top 1220 of the hook cooperate to complete the forming of the closed hook 15.

[0043] When the mold is opened, the upper mold 1100 moves upward, and the inner top 1220 of the hook is driven upward and reset by the first elastic member provided below, pushing the closed hook 15 that has completed extrusion molding out of the hook molding groove 1212, completing the material removal, and the TV back panel 10 can be easily taken out.

[0044] By using the extrusion molding die 1000 in some embodiments of the present application, a closed hook 15 with a guiding bevel 16 can be formed, which simplifies the mold structure and reduces the mold cost.

[0045] In some embodiments of the present application, Figures 13 to 15 As shown, a connecting insert 1150 can be welded to the top of the hook punch 1140. The connecting insert 1150 is embedded in the punch fixing plate 1120 in the form of an insert and fastened to the punch fixing plate 1120 by screws, thereby facilitating the disassembly, assembly and adjustment of the hook punch 1140.

[0046] In some embodiments of the present application, the upper stripping plate 1130 includes an upper stripping plate body 1134 and an upper die block 1135. The upper stripping plate body 1134 is floatingly connected to the punch fixing plate 1120. The upper die block 1135 is embedded in the upper stripping plate body 1134 in the form of an insert. The first through portion 1131, the guide bevel forming protrusion 1132 and the first forming bevel 1133 are formed on the upper die block 1135. The upper die block 1135 is fastened to the upper stripping plate body 1134 by screws, so that different upper die blocks 1135 can be easily disassembled and replaced, thereby facilitating the matching of different hook punches 1140.

[0047] In some embodiments of the present application, the lower template 1210 includes a lower template body 1215 and a lower mold block 1216. The lower mold block 1216 is embedded in the lower template body 1215 in the form of an insert. The second through portion 1211, the guide bevel forming recess 1213 and the second forming bevel 1214 are formed on the lower mold block 1216. The lower mold block 1216 is fastened to the lower template body 1215 by screws, so that different lower mold blocks 1216 can be easily disassembled and replaced, thereby facilitating the matching of different hook inner tops 1220.

[0048] In some embodiments of the present application, the lower mold 1200 further includes a lower pad 1240, a lower mold base 1250, a lower pad 1260, and a lower code template 1270, which are sequentially arranged from top to bottom. The lower pad 1240, the lower mold base 1250, the lower pad 1260, and the lower code template 1270 are fixedly connected as a whole. The lower template 1210 is fixed on the lower pad 1240, and the limiting fixing member 1230 is embedded in the lower pad 1240 in the form of an insert. Figure 13 shown.

[0049] In some embodiments of the present application, Figure 16 As shown, the extrusion molding gap L between the hook punch 1140 and the hook molding groove 1212 is 0.15mm-0.3mm. The extrusion molding gap L is limited to this range and is smaller than the thickness of the TV back panel 10 to ensure that the closed hook 15 will not be squeezed or torn during molding.

[0050] In some embodiments of the present application, Figures 16 to 18 As shown, the top surface of the lower template 1210 is further formed with a rib 1217 that wraps around the periphery of the hook forming groove 1212. The rib 1217 protrudes upward relative to the top surface of the lower template 1210. When the upper stripper plate 1130 and the lower template 1210 press the material of the television back panel 10, the rib 1217 is pressed and embedded into the television back panel material, thereby confining the back panel material within the forming area of ​​the enclosed hook 15 to the space enclosed by the rib 1217, effectively limiting the material flow and ensuring more complete extrusion molding.

[0051] The top surface of the rib 1217 is as flat as possible to reduce damage to the TV back panel 10 and reduce indentations. The thickness of the rib 1217 is preferably 1 / 4-1 / 3 of the thickness of the TV back panel 10, and the width is preferably 1 mm.

[0052] In some embodiments of the present application, reference is made to Figures 19 to 22 The bending mold 2000 used in the second circumferential bending step includes an upper mold 2100 and a lower mold 2200.

[0053] In some embodiments of the present application, the upper mold 2100 includes an upper mold base assembly 2110, an upper stripping assembly 2120 and an upper template assembly 2130. The upper stripping assembly 2120 is located below the upper template assembly 2130 and is floatingly connected to the upper mold base assembly 2110. The upper template assembly 2130 is located below the upper mold base assembly 2110 and is fixedly connected to the upper mold base assembly 2110. The upper template assembly 2130 is located on the periphery of the upper stripping assembly 2120.

[0054] In some embodiments of the present application, the lower mold 2200 includes a lower mold plate assembly 2210 and a lower mold base assembly 2220 .

[0055] The lower template assembly 2210 is arranged above the lower mold base assembly 2220 , and the lower template assembly 2210 includes a fixed lower template 2211 and a swing block 2212 .

[0056] A notch 2213 is formed on the top edge of the lower template 2211, and the pendulum block 2212 is arranged in the notch 2213 and is rotatably connected to the lower template 2211. The cross-sectional area of ​​the notch 2213 is larger than the cross-sectional area of ​​the pendulum block 2212, so that the notch 2213 leaves rotation space for the pendulum block 2212. The pendulum block 2212 is arranged in the notch 2213 and can rotate and swing relative to the lower template 2211.

[0057] The position of the pendulum block 2212 corresponds to that of the upper template assembly 2130. The pendulum block 2212 can be rotated to a first position and a second position. When in the first position, the inner side surface 2214 of the pendulum block abuts against the side surface 2215 of the notch portion. When in the second position, the bottom surface 2216 of the pendulum block abuts against the bottom surface 2217 of the notch portion.

[0058] An avoidance groove 2218 is formed on the outer surface of the pendulum block 2212, and the avoidance groove 2218 is at least used to avoid the closed hook 15 and the inner hook bend 14 of the TV back panel 10 when the pendulum block 2212 is in the second position; a second elastic member is provided between the notch 2213 and the pendulum block 2212, and the elastic force of the second elastic member is used to drive the pendulum block 2212 to rotate and return to the first position.

[0059] During molding, the TV back panel 10 that has completed the first circumferential bending is positioned on the lower template assembly 2210. At this time, the pendulum block 2212 is in the first position under the action of the second elastic member, and the pendulum block 2212 supports the horizontal pressure edge 12 of the TV back panel 10. During the closing process of the upper mold 2100 and the lower mold 2200, the upper stripping assembly 2120 first contacts the TV back panel 10, and during the pressing process, the pendulum block 2212 is driven to rotate and reaches the second position, i.e., the molding position. Figure 21 and Figure 22As shown, the second elastic member is compressed, and at the same time the back panel 10 of the TV is in a tightened state. The upper mold 2100 continues to move downward to close the mold, so that the upper template assembly 2130 continues to move downward, and the horizontal pressing edge 12 completes the downward bending action around to form a vertical bending edge 13 with an inner hook bend 14 and a closed hook 15 with a guide bevel 16. The closed hook 15 and the inner hook bend 14 are avoided in the avoidance groove 2218 of the swing block 2212.

[0060] When the mold is opened, the upper template assembly 2130 and the upper stripping assembly 2120 leave the lower mold 2200 and the TV back panel 10, and the pendulum block 2212 rotates and resets to the first position under the action of the second elastic member, rotating to avoid the closed hook 15 and the inner hook folding edge, making it convenient to remove the TV back panel 10 product.

[0061] In some embodiments of the present application, Figure 20 and Figure 21 As shown, the lower mold 2200 also includes an outer release plate 2230, which is used to move upward when the mold is opened to realize ejection of the material, that is, to eject the TV back panel 10 product upward, further facilitating the removal of the material.

[0062] The outer release plate 2230 is located above the lower mold base assembly 2220 and outside the lower mold plate assembly 2210. The outer release plate 2230 is floatingly connected to the lower mold base assembly 2220 and is located below the upper mold plate assembly 2130. During mold closing, the outer release plate 2230 is pressed downward by the upper mold plate assembly 2130 and is located below the circumference of the TV back panel 10. During mold opening, the outer release plate 2230 floats up and resets, pressing against the intersection of the vertical bend edge 13 and the inner hook bend 14 of the TV back panel 10, driving the TV back panel 10 to separate from the lower mold plate assembly 2210 and float out of the mold surface, after which the back panel product can be more easily removed.

[0063] In some embodiments of the present application, a plurality of rectangular springs are arranged between the outer release plate 2230 and the lower template assembly 2210 to achieve a floating setting of the outer release plate 2230.

[0064] In some embodiments of the present application, the upper die base assembly 2110 includes, from top to bottom, an upper die plate 2111, an upper pad 2112, an upper die base 2113, and an upper clamping plate 2114. The upper die plate 2111, upper pad 2112, upper die base 2113, and upper clamping plate 2114 are screwed together. The upper die plate 2111 is used to connect to the punch press, thereby connecting the entire upper die 2100 to the punch press. The pad serves to adjust the height of the upper die 2100. The pad is removable, allowing the height of the upper die 2100 to be adjusted according to the specific size of the punch press or the sheet metal part to be formed.

[0065] In some embodiments of the present application, Figure 20As shown, the upper stripping plate assembly 2120 includes an upper stop plate 2121 and an upper stripping plate body 2122. The upper stop plate 2121 is located above the upper stripping plate body 2122 and is connected to the upper stripping plate body 2122 as a whole. There is no relative movement between the two. A plurality of rectangular springs are clamped between the upper stop plate 2121 and the upper mold base 2113, and the rectangular springs pass through the upper clamping plate 2114; the upper stop plate 2121 is connected through a contour sleeve 2123, and the contour sleeve 2123 passes through the upper mold base 2113 and the upper clamping plate 2114 and is suspended on the upper clamping plate 2114. The upper stop plate 2121 is floatingly connected to the upper mold base 2113 through the rectangular spring and the contour sleeve 2123.

[0066] The upper stripping plate body 2122 is screwed to the upper stop plate 2121 , and its inner contour is adapted to the outer contour of the TV back plate 10 so as to reliably press the TV back plate 10 .

[0067] In some embodiments of the present application, the upper stripping plate body 2122 is a multi-piece assembly structure, so that any one or more pieces can be easily replaced, thereby improving the flexibility of mold use and reducing mold costs.

[0068] In some embodiments of the present application, Figure 19 and Figure 20 As shown, the upper template assembly 2130 is a multi-piece structure, including an outer bending support block 2131, an inner upper folding pad 2132, and an inner lower upper template 2133. The bending support block 2131, folding pad 2132, and upper template 2133 can be fastened together by screws. During closed mold bending, the upper template 2133 contacts the horizontal pressure edge 12 of the TV back panel 10 and presses downward to bend. The upper template assembly 2130 is specifically fixed to the upper clamping plate 2114 of the upper mold base assembly 2110.

[0069] By configuring the upper template assembly 2130 as a multi-piece splicing structure, it is convenient for each part to be disassembled, assembled, and adjusted, so that the bending gap can be adjusted according to specific working conditions.

[0070] In some embodiments of the present application, Figure 19 and Figure 20 As shown, the lower die base assembly 2220 includes, from top to bottom, a lower clamping plate 2221, a lower die base 2222, a lower pad 2223, and a lower locking plate 2224. The lower clamping plate 2221, lower die base 2222, lower pad 2223, and lower locking plate 2224 are connected together by screws. The lower pad 2223 adjusts the height of the upper die 2100. The outer release plate 2230 can be specifically mounted on the lower clamping plate 2221.

[0071] In some embodiments of the present application, Figure 21As shown, a plurality of mounting holes are formed on the bottom surface 2217 of the notch portion at intervals along its length direction, and a lifting pin 2219 is provided in each mounting hole, serving as the above-mentioned second elastic member; the top end of the lifting pin 2219 abuts against the bottom surface of the pendulum block 2212 to drive the pendulum block 2212 to rotate and reset to the first position; when the pendulum block 2212 is in the second position, the lifting pin 2219 is pressed into the inside of the mounting hole by the pendulum block 2212, so that the bottom surface 2216 of the pendulum block can fit and abut against the bottom surface 2217 of the notch portion.

[0072] In some embodiments of the present application, Figure 21 As shown, the bottom surface 2217 of the notch portion is a horizontal plane, and the side surface 2215 of the notch portion is an inclined plane. Correspondingly, the bottom surface 2216 of the pendulum block is a plane, and the inner side surface 2214 of the pendulum block is a plane. When the pendulum block 2212 is in the first position or the second position, it can contact and abut against the plane of the notch portion 2213, so that the pendulum block 2212 can be firmly maintained in the first position or the second position, which is beneficial to improving the bending forming effect.

[0073] An obtuse angle β is formed between the bottom surface 2217 of the notch and the side surface 2215 of the notch, and an angle between the bottom surface 2216 of the pendulum block and the inner side surface 2214 of the pendulum block is smaller than the obtuse angle β, so that the space of the notch 2213 is larger, which can accommodate the pendulum block 2212 and provide space for the rotation of the pendulum block 2212. For example, the angle between the bottom surface 2216 of the pendulum block and the inner side surface 2214 of the pendulum block can be a right angle.

[0074] An arc-shaped groove 22100 is formed at the junction of the bottom surface 2217 of the notch portion and the side surface 2215 of the notch portion, and the extension direction of the arc-shaped groove 22100 is the same as the extension direction of the notch portion 2213; an arc-shaped protrusion 22110 is formed at the junction of the bottom surface 2216 of the pendulum block and the inner side surface 2214 of the pendulum block, and the arc-shaped protrusion 22110 is embedded in the arc-shaped groove 22100, and the arc-shaped protrusion 22110 is rotatably matched with the arc-shaped groove 22100 to realize the rotational connection between the pendulum block 2212 and the lower template 2211.

[0075] During installation, one end of the arc-shaped protrusion 22110 can be aligned with one end of the arc-shaped groove 22100, and then the arc-shaped protrusion 22110 can be slid and inserted into the arc-shaped groove 22100 to achieve the installation of the pendulum block 2212.

[0076] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0077] The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A sheet metal stamping method, characterized in that: The steps include: Stretching to form a stretched portion and a horizontal pressing edge located around the stretched portion on the sheet metal part; Shaping, trimming and pre-stretching of the closed hook: shaping, trimming and pre-stretching the sheet metal part to form a semicircular bulge and through-cut grooves on the outer sides of the two ends of the semicircular bulge on the horizontal pressing edge. The pre-stretching direction is opposite to the stretching direction of the stretched part, and the length direction of the semicircular bulge is the same as the length direction of the horizontal pressing edge. Extrusion molding is performed on the basis of the semicircular convex hull to form a closed hook with a guiding bevel. The guiding bevel is located on the outside of the closed hook and is connected to the through-cut groove at both ends. The guiding bevel is inclined in the direction away from the stretching part. The first circumferential bending is to bend the edge of the horizontal pressing edge along the first pre-folding line located outside the closed hook in a direction away from the stretching portion until it is perpendicular to the bottom plate of the stretching portion to form an inner hook bend; The second circumferential bending is to bend the horizontal pressing edge along the second pre-folding line located on the inner side of the closed hook in a direction away from the stretching portion until it is perpendicular to the bottom plate of the stretching portion.

2. The sheet metal stamping method according to claim 1, wherein: The following step is further provided between the extrusion molding step and the first circumferential bending step: bending the horizontal pressing edge along the second pre-folding line located on the inner side of the closed hook toward the stretching portion at an acute angle.

3. The sheet metal stamping method according to claim 2, wherein: The extrusion molding dies used in the extrusion molding step include: The upper die comprises a punch fixing plate, an upper stripping plate and a hook punch; the upper stripping plate is located below the punch fixing plate and is floatingly connected to the punch fixing plate, and a first through-hole extending vertically is formed on the upper stripping plate; the hook punch is movably inserted in the first through-hole, the top end of which is fixedly connected to the punch fixing plate, and the bottom forming end extends through the bottom end of the first through-hole; a guiding bevel forming convex portion is formed on the bottom surface of the upper stripping plate, the guiding bevel forming convex portion is located on one side of the bottom end of the first through-hole, and the guiding bevel forming convex portion has a first forming inclined surface; The lower die comprises a lower template and a hook inner top; a second through-portion extending vertically is formed on the lower template, the top end of the second through-portion is a hook forming groove that cooperates with the bottom forming end of the hook punch; the hook inner top is movably inserted in the second through-portion, a limited fixing piece is formed at the bottom end of the second through-portion, and a first elastic piece is provided between the limited fixing piece and the hook inner top; a guide bevel forming recess is formed on the top surface of the lower template, the guide bevel forming recess is located on one side of the top end of the second through-portion, and the guide bevel forming recess has a second forming inclined surface; When the bottom end of the hook inner top is pressed against the limit fixing piece by the hook punch, the hook punch and the hook inner top cooperate to form the closed hook, and the first forming bevel and the second forming bevel cooperate to form the guide bevel.

4. The sheet metal stamping method according to claim 3, wherein: The extrusion forming gap between the hook punch and the hook forming groove is 0.15mm-0.3mm.

5. The sheet metal stamping method according to claim 3, wherein: A convex rib is also formed on the top surface of the lower template and surrounds the periphery of the hook forming groove.

6. The sheet metal stamping method according to claim 5, characterized in that: The thickness of the convex rib is 1 / 4-1 / 3 of the thickness of the sheet metal part, and the width is 1 mm.

7. The sheet metal stamping method according to claim 1, wherein: The bending dies used in the second circumferential bending step include: An upper mold, comprising an upper mold base assembly, an upper stripping assembly, and an upper template assembly, wherein the upper stripping assembly is located below the upper template assembly and is floatingly connected to the upper mold base assembly, the upper template assembly is located below the upper mold base assembly and is fixedly connected to the upper mold base assembly, and the upper template assembly is located on the periphery of the upper stripping assembly; The lower mold comprises a lower template assembly and a lower mold base assembly, the lower template assembly is arranged above the lower mold base assembly, and the lower template assembly comprises a lower template and a swing block; a notch is formed on the top edge of the lower template, the swing block is arranged in the notch and is rotatably connected to the lower template; the position of the swing block corresponds to that of the upper template assembly, and the swing block can be rotated to a first position and a second position, when in the first position, its inner side surface abuts against the side surface of the notch, and when in the second position, its bottom surface abuts against the bottom surface of the notch; an avoidance groove is provided on the outer side surface of the swing block, at least for avoiding the closed hook and the inner hook bending when it is in the second position; a second elastic member is provided between the notch and the swing block, for driving the swing block to rotate and return to the first position.

8. The sheet metal stamping method according to claim 7, wherein: A mounting hole is formed on the bottom surface of the notch portion, and a lifting pin is provided in the mounting hole. The top end of the lifting pin abuts against the bottom surface of the pendulum block to drive the pendulum block to rotate and return to the first position.

9. The sheet metal stamping method according to claim 7, wherein: The bottom surface of the notch portion is a horizontal plane, the side surface of the notch portion is an inclined plane, an obtuse angle is formed between the bottom surface of the notch portion and the side surface of the notch portion, and an arc groove is formed at the intersection of the bottom surface of the notch portion and the side surface of the notch portion; The bottom surface of the pendulum block is a plane, the inner side surface of the pendulum block is a plane, the angle between the bottom surface of the pendulum block and the inner side surface of the pendulum block is smaller than the obtuse angle, and an arc-shaped protrusion is formed at the junction of the bottom surface of the pendulum block and the inner side surface of the pendulum block, and the arc-shaped protrusion is rotatably engaged with the arc-shaped groove.

10. The sheet metal stamping method according to claim 7, wherein: The lower mold also includes an outer stripping plate, which is used for moving upward to assist in ejecting materials when the mold is opened.

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