Precise stamping method and stamping die for part with chamfered edge

Abstract

The invention relates to a precise stamping method and stamping die for an edge chamfering part, and the method comprises the following steps: the size of a chamfering pressing punch is determined, and the chamfering pressing punch comprises two punch bodies which are symmetrically arranged and a material containing groove located between the two punch bodies; chamfering is conducted, specifically, a chamfering pressing punch with the determined size is installed on a stamping die, and the stamping die conducts chamfering on the opposite sides of the adjacent parts; and blanking is conducted, specifically, the chamfered material belt is blanked through a stamping die, and the part is obtained. According to the technical scheme, flowing of the material belts on the two sides is balanced through the two symmetrically-arranged punches. And a special material containing groove is formed between the two punches, so that a preset and sufficient flowing space and a containing place are provided for extruded materials. Most of redundant materials which will cause the extension of the material belt are guided into the material containing groove, so that the extrusion to the material belt is greatly eliminated, and the feeding accuracy is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of edge chamfering stamping, and in particular to a precision stamping method for edge chamfered parts and a stamping die. Background Art

[0002] Current methods for edge chamfering include direct pressing, pre-cutting, and semi-punching. The direct pressing method presses the punch directly into the material strip to form the chamfer. The semi-punching method uses a semi-punching process to first press the chamfer, then horizontally shifts the protruding material strip below the sheet to clear the punch for blanking, and finally blanks the material. The pre-cutting method pre-cuts a groove in the material strip, then presses the chamfer to minimize excess material into the groove.

[0003] However, the direct pressing method, the pre-cut material slot method and the semi-punching method have failed to effectively solve the problem that the material strip occupied by the punch is transferred to the surrounding areas during the chamfering pressing process, causing the material strip to become longer and affecting the feeding accuracy. Summary of the Invention

[0004] Therefore, a method and die for precision stamping of edge chamfered parts are needed to solve the technical problem that the direct pressing method, the pre-cut material slot method, and the semi-punching method are unable to effectively solve the problem that the material strip occupied by the punch is transferred to the surrounding areas during the chamfering pressing process, causing the material strip to stretch and affecting the feeding accuracy.

[0005] To achieve the above object, the present invention provides a method for precision stamping of edge chamfered parts, comprising the following steps: S1: Determine the size of the chamfering pressing punch, which includes two symmetrically arranged punches and a material receiving groove located between the two punches; S11: according to the chamfer angle of the part, obtaining the part side angle of the chamfer pressing punch and the back side angle of the chamfer pressing punch; S12: Determine the length of the chamfering punch according to the thickness of the material strip and the length of the chamfer required for the part, and obtain the height of the chamfering punch; S13: Obtaining the width of the material trough according to the sample spacing; S14: The product coefficient can also be determined according to the thickness of the material strip, and the depth of the material trough is finally obtained; S2: Chamfering, a chamfering punch with a determined size is installed on the stamping die, and the stamping die chamfers the opposite sides of adjacent parts; S3: Blanking: The stamping die blanks the chamfered strip to obtain parts.

[0006] Unlike existing technologies, this solution balances the flow of the material strip on both sides through two symmetrically positioned punches. A dedicated trough is then positioned between the two punches, providing a pre-set, ample flow space and a holding area for the extruded material. This allows the vast majority of excess material that would otherwise cause the strip to stretch to be diverted into the trough, significantly reducing compression and ensuring accurate feeding. Furthermore, the chamfering punch can simultaneously chamfer opposite sides of adjacent parts, chamfering both part edges simultaneously, improving chamfering efficiency.

[0007] As an embodiment of the present invention, the depth of the trough is calculated as follows: ; in, is the product coefficient, The length of the chamfering punch, The height of the chamfering punch, The width of the trough.

[0008] In this way, after obtaining the specific values ​​of the product coefficient, the length of the chamfering pressing punch, the height of the chamfering pressing punch and the width of the material groove, the depth of the material groove can be calculated, thereby accurately obtaining the width and height of the material groove, providing a preset, sufficient flow space and accommodation place for the extruded material, and improving the shear surface quality, dimensional accuracy and flatness of the edge chamfered parts.

[0009] As an embodiment of the present invention, The calculation formula is , where α1 is the part side angle of the chamfering pressing punch.

[0010] In this way, it can be calculated by the specific formula ,make The values ​​are more accurate.

[0011] As an embodiment of the present invention, the calculation formula of α1 is: α1=α×(100%~105%); the calculation formula of α2 is α2=α1×(90%~60%), and α2≥30°; wherein α is the chamfer angle of the part, and α2 is the reverse angle of the chamfer pressing punch.

[0012] Thus, α1 acts on the part, and α1 is calculated based on α using a formula to account for the springback of the material strip. α2 is the reverse angle of the punch, which acts on the scrap part. α2 is steeper than α1, which can reduce the total volume of the punch pressed into the chamfer, thereby reducing material flow.

[0013] As an embodiment of the present invention, The value of is: When t<6mm, =1.1-1.2; when t≥6mm, =1.05-1.1; where t is the thickness of the strip.

[0014] In this way, different multiplication coefficients can be determined according to the thickness of the material strip, making the value more reasonable.

[0015] As an embodiment of the present invention, , ;in, The length of the chamfer required for the part, The height of the chamfer required for the part.

[0016] So, by setting > as well as > , thereby avoiding the tearing at the chamfer inflection point from affecting the part itself, and the defects caused by stamping will remain on the waste as the material is blanked, ensuring the quality of the chamfered edge of the part.

[0017] As an embodiment of the present invention, the specific steps in step S3 are: S31: the material strip is located on the lower concave die, and the lower concave die is located below the male and female dies; S32: The stamping die is closed, and the blank holder and the counter pressure plate respectively press the material; S33: The male and female dies apply a blanking force to the material strip, and keep the blank holder and the counter pressure plate pressing the material strip tightly; S34: Blanking is completed, and the parts and the material beans are separated from the material strip; S35: Open the stamping die. At this time, the part and the blank are stored in the lower die and the convex die respectively. The blank is lifted up as the blank holder rises. S35: The back pressure plate pushes the parts out, the upper ejector pushes the material beans out, blows away the parts and the material beans, and feeds the material belt forward once.

[0018] This integration of blank separation and waste handling into a single process simplifies the process flow, reduces the number of molds, and reduces equipment usage. Furthermore, after completing a process step, the material strip can be advanced a specific distance to continue production, significantly improving production efficiency.

[0019] As an embodiment of the present invention, the rounding R1 at the cutting edge of the male and female dies is (1%~3%)t, and the rounding R2 at the cutting edge of the lower die is (1%~3%)t, where t is the thickness of the material strip.

[0020] In this way, by processing the cutting edge into a fillet with a specific radius (R1, R2 = (1%~3%) t), the material separation principle is changed from "tearing" to "pure shearing" or "extrusion separation", which greatly improves the quality of the blanking section, protects the mold, increases its life, and optimizes the chamfering forming effect.

[0021] As an embodiment of the present invention, in step S31, the blanking gap C1 between the convex and concave dies and the lower die at the non-chamfered position is ≤1%t; if a chamfering protection piece is provided on the back pressure plate, the blanking gap C2 between the convex and concave dies and the lower die at the chamfered position is ≤0.5%t; if the chamfering protection piece is not provided on the back pressure plate, the blanking gap C3 between the convex and concave dies and the lower die at the chamfered position is ≤1%t; wherein t is the thickness of the material strip.

[0022] In this way, through the extremely small blanking gap (C≤1%t or 0.5%t) and the edge radius design (R1, R2), high-quality pure shear separation is achieved, with high cross-section smoothness and extremely small burrs.

[0023] To achieve the above objectives, in a second aspect, the inventors provide a precision stamping die for edge chamfered parts, which is used to perform any one of the precision stamping methods for edge chamfered parts provided by the inventors above, comprising: Upper punch assembly, the upper punch assembly includes an upper workbench, an upper pad, an upper fixed plate, a blank holder seat, a blank holder, a male and female die, an upper ejector rod, an upper punch and a locking pin. An upper pad is installed below the upper workbench, an upper fixed plate is installed below the upper pad, the blank holder seat is connected to the upper workbench and is located below the upper fixed plate, a blank holder is installed in the blank holder seat, a male and female die are installed in the blank holder, the top of the male and female die is connected to the bottom of the upper pad, an upper ejector rod is located in the upper workbench, the output end of the upper ejector rod ejects the bean through the upper punch, and the locking pin is installed in the blank holder ring; The lower punch assembly includes a lower workbench, a lower pad, a lower fixed plate, a lower die, a chamfering pressing punch, a back-pressure plate and a lower ejector rod. The lower pad is installed above the lower workbench, the lower fixed plate is installed above the lower pad, the lower die is installed on the lower fixed plate, the chamfering pressing punch and the back-pressure plate are installed in the lower die, the back-pressure plate is used to cooperate with the convex and concave dies to obtain parts, the lower ejector rod is located in the lower workbench, and the output end of the lower ejector rod is connected to the bottom of the back-pressure plate.

[0024] Different from the existing technology, the precision stamping die for edge chamfered parts of the technical solution of this application, on the basis of determining the size of the chamfering pressing punch, can guide the excess material in the stamping process into the material receiving groove of the chamfering pressing punch through the cooperation between the upper punch component and the lower punch component, thereby greatly eliminating the extrusion of the material strip and ensuring the accuracy of feeding.

[0025] The above-mentioned records related to the content of the invention are only an overview of the technical solution of this application. In order to enable ordinary technicians in this field to understand the technical solution of this application more clearly, and then implement it according to the text of the specification and the contents recorded in the drawings, and to make the above-mentioned purposes and other purposes, features and advantages of this application easier to understand, the following is an explanation in combination with the specific implementation methods and drawings of this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, characteristics and effects of the specific embodiments of this application and other related contents, and are not to be considered as limiting this application.

[0027] In the drawings of the specification: Figure 1 A schematic diagram of the chamfering pressing punch in accordance with an embodiment of the present application in cooperation with a part and waste material; Figure 2 A top view of a stamping die according to an embodiment of the present application; Figure 3 This is a schematic diagram of placing a material strip on a lower die according to one embodiment of the present application; Figure 4 This is a schematic diagram of the blank holder and the back pressure plate cooperating to press the material strip according to one embodiment of the present application; Figure 5 A schematic diagram of a chamfering pressing punch and a male and female die blanking a material strip according to an embodiment of the present application; Figure 6 This is a schematic diagram of a part and a material bean stored in a lower concave die and a male concave die, respectively, according to an embodiment of the present application; Figure 7 This is a schematic diagram of the back pressure plate and the ejection of beans according to one embodiment of the present application.

[0028] The reference numerals in the above drawings are described as follows: 100-stamping die; 200-material strip; 300-material bean; 400-parts; 500-waste; 1-upper punch assembly; 11-upper workbench; 12-upper pad; 13-upper fixed plate; 14-blank holder seat; 15-blank holder; 16-punch and concave die; 17-upper ejector pin; 18-upper punch; 19-locking pin; 2-lower punch assembly; 21-lower workbench; 22-lower pad; 23-lower fixed plate; 24-lower concave die; 25-chamfering pressing punch; 251-punch; 252-material trough; 26-back pressure plate; 261-elastic ejector pin; 27-lower ejector pin; 28-guide pin; 3-limiting column; 4-guide column; 5-balance plate. DETAILED DESCRIPTION

[0029] In order to explain in detail the possible application scenarios, technical principles, specific solutions that can be implemented, and the purpose and effects of this application, the following is a detailed description of the specific embodiments listed in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of this application and are therefore only examples and are not intended to limit the scope of protection of this application.

[0030] References to "embodiments" herein mean that the specific features, structures, or characteristics described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the word "embodiment" in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the various technical features mentioned in the embodiments can be combined in any manner to form a corresponding implementable technical solution.

[0031] Unless otherwise defined, the technical terms used herein have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms herein is only for describing specific embodiments and is not intended to limit this application.

[0032] In the description of this application, the term "and / or" is used to describe a logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and both A and B exist. In addition, the character " / " in this document generally indicates that the objects before and after are in a logical "or" relationship.

[0033] In this application, terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantity, priority or sequence relationship between these entities or operations.

[0034] Without further limitations, in this application, the words "include", "comprise", "have" or other similar open-ended expressions used in sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product that includes the elements, so that the process, method or product that includes a series of elements may include not only those defined elements, but also other elements that are not explicitly listed, or also include elements inherent to such process, method or product.

[0035] Consistent with the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceed" are understood to exclude the number itself; expressions such as "above," "below," and "within" are understood to include the number itself. Furthermore, in the description of the embodiments of this application, "multiple" means two or more (including two), and similar expressions related to "multiple," such as "multiple groups" and "multiple times," are also understood in this manner, unless otherwise specifically defined.

[0036] In the description of the embodiments of the present application, the space-related expressions used, such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or position relationship based on the orientation or position relationship shown in the specific embodiments or drawings, and are only for the convenience of describing the specific embodiments of the present application or facilitating the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, it should not be understood as a limitation on the embodiments of the present application.

[0037] Unless otherwise expressly specified or limited, in the description of the embodiments of the present application, the terms "installed", "connected", "connected", "fixed", "set", etc. used should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integrated setting; it can be a direct connection, or an indirect connection through an intermediate medium; it can be a relationship in which two components are combined together, or an interaction relationship between two components, or a communication between two structures. For those skilled in the art of the present application, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0038] The existing direct pressing method, pre-cut material trough method and semi-punching method have failed to effectively solve the problem of the material strip occupied by the punch being transferred to the surrounding areas during the chamfering pressing process, causing the material strip to become longer and affecting the feeding accuracy.

[0039] In view of this, an embodiment of the present application provides a method for precision stamping of edge chamfered parts, comprising the following steps: S1: Determine the size of the chamfering pressing punch 25 , which includes two symmetrically arranged punches 251 and a material receiving groove 252 located between the two punches 251 ; S11: according to the chamfer angle of the part, obtaining the part side angle of the chamfer pressing punch and the back side angle of the chamfer pressing punch; S12: Determine the length of the chamfering punch according to the thickness of the material strip and the length of the chamfer required for the part, and obtain the height of the chamfering punch; S13: Obtaining the width of the material trough according to the sample spacing; S14: The product coefficient can also be determined according to the thickness of the material strip, and the depth of the material trough is finally obtained; S2: Chamfering: a chamfering punch 25 of a determined size is mounted on the stamping die 100 , and the stamping die 100 chamfers opposite sides of adjacent parts 400 ; S3: Blanking: the stamping die 100 blanks the chamfered strip 200 to obtain a part 400.

[0040] According to some embodiments of this application, please refer to Figures 1 to 7 This embodiment relates to a precision stamping method for edge chamfered parts, comprising the following steps: S1: Determine the size of the chamfering pressing punch 25 , which includes two symmetrically arranged punches 251 and a material receiving groove 252 located between the two punches 251 ; S11: according to the chamfer angle of the part, obtaining the part side angle of the chamfer pressing punch and the back side angle of the chamfer pressing punch; S12: Determine the length of the chamfering punch according to the thickness of the material strip and the length of the chamfer required for the part, and obtain the height of the chamfering punch; S13: Obtaining the width of the material trough according to the sample spacing; S14: The product coefficient can also be determined according to the thickness of the material strip, and the depth of the material trough is finally obtained; S2: Chamfering: a chamfering punch 25 of a determined size is mounted on the stamping die 100 , and the stamping die 100 chamfers opposite sides of adjacent parts 400 ; S3: Blanking: the stamping die 100 blanks the chamfered strip 200 to obtain a part 400.

[0041] like Figure 1 As shown, the chamfering punch 25 includes two symmetrically arranged punches 251 and a material storage groove 252 located between the two punches 251. Optionally, the punch 251 is claw-shaped. The required chamfer length, required chamfer height, chamfer angle, and material strip thickness are known. Based on this, the part side angle of the chamfering punch, the back angle of the chamfering punch, the length of the chamfering punch, and the product coefficient can be obtained. The width of the material storage groove is then determined based on the spacing between the rows, and ultimately the depth of the material storage groove is determined.

[0042] What needs to be emphasized in step S2 is that Figure 2As shown, the distance between the blue line and the black line part 400 is the feeding distance (the feeding direction shown in the figure is feeding to the right), the black line is the current punch (including chamfering and blanking), and the blue line is the punch after the next feed (from the blue line position to the black line position after the next forward feed). The blue lines show that four parts 400 are punched in one feed. Four parts 400 correspond to two chamfering punches 25, and one chamfering punch 25 corresponds to two parts 400, that is, one punch 251 of the chamfering punch 25 corresponds to one part 400. As a result, the stamping die 100 simultaneously chamfers the opposite sides of adjacent parts 400, improving chamfering efficiency.

[0043] What needs to be emphasized in step S3 is that Figure 2 As shown, the blanked part 400 is a ratchet, which is used on a car door or a trunk door lock.

[0044] Unlike existing technologies, this technical solution balances the flow of the material strip 200 on both sides through two symmetrically arranged punches 251. Furthermore, a dedicated material trough 252 is provided between the two punches 251, providing a pre-set, ample flow space and a place to accommodate the extruded material. This allows the vast majority of excess material that would otherwise cause the material strip 200 to stretch to be diverted into the trough 252, significantly eliminating the compression of the material strip 200 and ensuring accurate feeding. Furthermore, the chamfering punch 25 can simultaneously chamfer the opposite sides of adjacent parts 400, chamfering the edges of two parts 400 at once, improving chamfering efficiency.

[0045] like Figure 1 As shown in the figure, the calculation formula for the depth of the trough is: ;

[0046] in, is the product coefficient, The length of the chamfering punch, The height of the chamfering punch, The width of the trough.

[0047] In this way, after obtaining the specific values ​​of the multiplication coefficient, the length of the chamfering pressing punch, the height of the chamfering pressing punch and the width of the material groove, the depth of the material groove can be calculated, thereby accurately obtaining the width and height of the material groove 252, providing a preset, sufficient flow space and accommodation place for the extruded material, and improving the shear surface quality, dimensional accuracy and flatness of the edge chamfered part 400.

[0048] like Figure 1 As shown, The calculation formula is , where α1 is the part side angle of the chamfering pressing punch.

[0049] The length of the chamfering punch can be determined according to the thickness of the material strip. The specific proportional coefficients are shown in the following table:

[0050] When the strip thickness t is 0-2mm, the length of the chamfering punch +0.5mm, when the strip thickness t is 2-4mm, the length of the chamfering punch +0.8mm, when the strip thickness t is 4-8mm, the length of the chamfering punch +1mm, when the strip thickness t is greater than 8mm, the length of the chamfering punch +1.5mm; when the calculated value is greater than the strip thickness t, take .

[0051] In this way, it can be calculated by the specific formula ,make The values ​​are more accurate.

[0052] like Figure 1 As shown in the figure, the calculation formula of α1 is: α1=α×(100%~105%); the calculation formula of α2 is α2=α1×(90%~60%), and α2≥30°; among them, α is the chamfer angle of the part, and α2 is the reverse angle of the chamfer pressing punch.

[0053] The asymmetric angle setting of the chamfered pressing punch 25 is conducive to the flow of material into the material trough 252.

[0054] Thus, α1 acts on part 400. α1 is calculated based on α using a formula to account for the springback of strip 200. α2 is the punch's reverse angle, acting on the scrap 500. α2 is steeper than α1, reducing the total volume of the chamfered punch 25, thereby reducing material flow.

[0055] According to some embodiments of the present application, optionally, The value of is: When t<6mm, =1.1-1.2; when t≥6mm, =1.05-1.1; where t is the thickness of the strip.

[0056] In this way, different multiplication coefficients can be determined according to the thickness of the material strip, making the value more reasonable.

[0057] like Figure 1 As shown, , ;in, is the length of the chamfer required for the part, The height of the chamfer required for the part.

[0058] Optionally, the size of the chamfer pressing punch 25 is set ( and ) and the required chamfer size of part 400 ( and ) should differ by more than 0.2t to avoid possible tearing at the chamfered edge.

[0059] So, by setting > as well as > , thereby preventing the tearing at the chamfer inflection point from affecting the part 400 itself, and the defects caused by stamping will remain on the waste material 500 as the material is blanked, ensuring the quality of the chamfer edge of the part 400.

[0060] like Figures 3 to 7 As shown, the specific steps in step S3 are: S31: The material strip 200 is located on the lower concave die 24, and the lower concave die 24 is located below the male and female die 16; S32: The stamping die 100 is closed, and the blank holder 15 and the counter-pressure plate 26 respectively press the material; S33: The male and female dies 16 apply a blanking force to the material strip 200 and keep the blank holder 15 and the counter pressure plate 26 pressing the material strip 200 tightly; S34: Punching is completed, and the part 400 and the material bean 300 are separated from the material strip 200; S35: The stamping die 100 is opened. At this time, the part 400 and the bead 300 are respectively stored in the lower die 24 and the male and female die 16. The bead 300 is lifted up as the blank holder 15 rises. S35: The back pressure plate 26 pushes out the part 400, and the upper ejector 17 pushes out the material bean 300, blows away the part 400 and the material bean 300, blows away the part 400 and the material bean 300, and feeds the material belt 200 forward once.

[0061] Optionally, after step S35 , step S36 is further included: repeating steps S32 to S35 until the blanking of the material strip 200 is completed.

[0062] Thus, the above steps integrate the separation of blanks and the processing of waste material 500 into a single process, simplifying the process flow and reducing the number of mold sets and equipment usage. Furthermore, after completing a process step, the material strip 200 can be advanced a feeding distance to continue production, significantly improving production efficiency.

[0063] like Figure 3As shown, the rounding R1 of the cutting edge of the male and female dies 16 is (1%-3%)t, and the rounding R2 of the cutting edge of the lower die 24 is (1%-3%)t, where t is the thickness of the material strip.

[0064] When the stamping die 100 is in the initial position, the cutting edges of the male and female dies 16 are rounded R1, and the cutting edges of the lower female die 24 are rounded R2.

[0065] In this way, by processing the cutting edge into a fillet with a specific radius (R1, R2 = (1%~3%) t), the material separation principle is changed from "tearing" to "pure shearing" or "extrusion separation", which greatly improves the quality of the blanking section, protects the mold, increases its life, and optimizes the chamfering forming effect.

[0066] like Figure 3 As shown, in step S31, the blanking gap C1 between the convex-concave die 16 and the lower die 24 at the non-chamfered position is ≤1%t, if a chamfering protection piece is provided on the back pressure plate 26, then the blanking gap C2 between the convex-concave die 16 and the lower die 24 at the chamfered position is ≤0.5%t, if the chamfering protection piece is not provided on the back pressure plate 26, then the blanking gap C3 between the convex-concave die 16 and the lower die 24 at the chamfered position is ≤1%t; wherein, t is the thickness of the material strip.

[0067] When the punching die 100 is in the initial position, a blanking gap C is provided between the male and female dies 16 and the lower female dies 24 .

[0068] In this way, through the extremely small blanking gap (C≤1%t or 0.5%t) and the edge radius design (R1, R2), high-quality pure shear separation is achieved, with high cross-section smoothness and extremely small burrs.

[0069] According to some embodiments of this application, please refer to Figures 3 to 7, this embodiment also relates to a precision stamping die 100 for edge chamfered parts, which is used to perform a precision stamping method for edge chamfered parts, an upper punch assembly 1 and a lower punch assembly 2, the upper punch assembly 1 includes an upper workbench 11, an upper pad 12, an upper fixed plate 13, a blank holder 14, a blank holder 15, a punch and die 16, an upper ejector 17, an upper punch 18 and a locking pin 19, an upper pad 12 is installed below the upper workbench 11, an upper fixed plate 13 is installed below the upper pad 12, the blank holder 14 is connected to the upper workbench 11 and is located below the upper fixed plate 13, a blank holder 15 is installed in the blank holder 14, a punch and die 16 is installed in the blank holder 15, the top of the punch and die 16 is connected to the bottom of the upper pad 12, and the upper ejector 17 is connected to the upper punch 18 and a locking pin 19. 7 is located in the upper workbench 11, the output end of the upper ejector 17 ejects the bean 300 through the upper punch 18, and the locking pin 19 is installed in the pressure ring 15; the lower punch assembly 2 includes a lower workbench 21, a lower pad 22, a lower fixed plate 23, a lower die 24, a chamfering pressing punch 25, a back-pressure plate 26 and a lower ejector 27, a lower pad 22 is installed above the lower workbench 21, a lower fixed plate 23 is installed above the lower pad 22, a lower die 24 is installed on the lower fixed plate 23, a chamfering pressing punch 25 and a back-pressure plate 26 are installed in the lower die 24, the back-pressure plate 26 is used to cooperate with the punch and die 16 to obtain the part 400, the lower ejector 27 is located in the lower workbench 21, and the output end of the lower ejector 27 is connected to the bottom of the back-pressure plate 26.

[0070] A limit column 3 is installed at each of the two symmetrical feet of the upper workbench 11 and the lower workbench 21 (specifically, the limit column 3 includes an upper limit column 3 and a lower limit column 3, the upper workbench 11 is connected to the pressure ring seat 14 through the upper limit column 3, and the lower limit column 3 is connected to the lower workbench 21), and a guide column 4 is installed at each of the other two symmetrical feet, and the guide column 4 plays a guiding role.

[0071] V-shaped pressure rings can be set on the pressure ring 15 and the lower die 24 to create a strong and controllable three-dimensional compressive stress state outside the material separation area, which can suppress the adverse flow of the material strip 200 during the blanking process, thereby achieving pure shear separation.

[0072] The lower punch assembly 2 is provided with a locking groove at a position corresponding to the locking pin 19. The locking groove cooperates with the locking pin 19 to fix the material strip 200. The locking pin limits the matching accuracy of the blank holder 15 and the lower die 24. At the same time, the lower punch assembly 2 is provided with a lower punch at a position corresponding to the upper punch 18, so that the upper punch 18 and the lower punch cooperate to punch out the material beans 300. In some embodiments, the upper punch assembly 1 is also provided with a punch assembly for punching out the material beans 300 at other locations of the material strip 200, which is mainly used to eject the material beans 300 through the lower punch assembly 2. In other embodiments, the upper punch assembly 1 also includes a guide pin 28, and the lower punch assembly 2 is provided with a guide hole at a position corresponding to the guide pin 28. The guide pin 28 can accurately position the material strip 200, eliminate feeding errors, and ensure the accuracy of the stamping position. In particular, during the continuous die production process, the material strip 200 needs to be fed forward intermittently according to a certain feeding distance. The precise fit between the cylindrical surface of the guide pin 28 and the inner wall of the guide hole will forcibly pull back or push the material strip 200 to a precise position.

[0073] Optionally, the lower punch assembly 2 further includes a spring-loaded ejector pin 261, which is installed in the back pressure plate 26. After the material strip 200 undergoes processes such as chamfering and stamping, it may partially sink, causing the entire material strip 200 to be uneven. The uneven material strip 200 will hinder the smooth movement of the feeding mechanism and even cause feeding errors. Therefore, a spring-loaded ejector pin 261 is installed in the back pressure plate 26, and the spring force is used to lift the material strip 200 upward, restoring it to a flat horizontal surface, thereby achieving stable and accurate feeding.

[0074] like Figures 3 to 7 As shown, the working process of the precision stamping die 100 for edge chamfered parts is as follows: first, the chamfering pressing punch 25 is used to chamfer the material strip 200 for the first time, that is, the opposite sides of the adjacent parts 400 are chamfered. Secondly, the material strip 200 is fed forward once, and the chamfering pressing punch 25 chamfers the fed material strip 200. At the same time, the chamfered part of the material strip 200 is blanked to obtain the first part 400 with chamfers, and the part that exceeds the size of the chamfer required for the part 400 will remain on the material strip 200 after the first part 400 is removed as waste 500. Once again, the material strip 200 is fed forward once more, and the chamfering pressing punch 25 still chamfers the fed material strip 200. At the same time, the chamfered part of the material strip 200 is blanked to obtain the second part 400 with chamfers. Finally, the above steps are repeated until the stamping of the material strip 200 is completed. What needs to be explained in this process is that during the second stamping, the precision stamping die 100 for edge chamfered parts blanks the first part 400 while chamfering the second part 400. During the third stamping, the precision stamping die 100 for edge chamfered parts blanks the second part 400 while chamfering the third part 400.

[0075] In this way, on the basis of determining the chamfering pressing punch 25, the upper punch assembly 1 and the lower punch assembly 2 can cooperate to enable the excess material during the stamping process to be introduced into the material receiving groove 252 of the chamfering pressing punch 25, thereby greatly eliminating the extrusion of the material strip 200 and ensuring the accuracy of feeding.

[0076] like Figure 3 As shown, the stamping die 100 further includes a balancing plate 5 , which is mounted on the blank holder 15 .

[0077] The core function of the balance plate 5 is to act as a rigid stop when the mold is closed, accurately limiting the final position of the downward movement of the blank holder 15. It indirectly and accurately controls the final pressure on the compressed material.

[0078] Different from the existing technology, the precision stamping die for edge chamfered parts of the technical solution of this application, on the basis of determining the size of the chamfering pressing punch, can guide the excess material in the stamping process into the material receiving groove of the chamfering pressing punch through the cooperation between the upper punch component and the lower punch component, thereby greatly eliminating the extrusion of the material strip and ensuring the accuracy of feeding.

[0079] According to some embodiments of the present application, optionally, the lower punch assembly 2 further includes a chamfer protection member, which is mounted on the back pressure plate 26 , and the chamfer protection member is provided with a protrusion at a corresponding position of the chamfer of the material strip 200 .

[0080] In this way, by providing the chamfer protection piece, the material in the chamfered area is prevented from being crushed or pre-deformed during the blanking stage, thereby ensuring the accuracy and consistency of the final chamfered geometry.

[0081] It should be noted that although the above embodiments have been described herein, this does not limit the scope of patent protection of the present invention. Therefore, based on the innovative concept of the present invention, changes and modifications to the embodiments described herein, or equivalent structural or equivalent process transformations made using the contents of the present invention's specification and drawings, and direct or indirect application of the above technical solutions to other related technical fields, are all included in the scope of patent protection of the present invention.

Claims

1. A precision stamping method for edge chamfered parts, characterized in that: The following steps are involved: S1: Determine the size of the chamfering pressing punch, which includes two symmetrically arranged punches and a material receiving groove located between the two punches; S11: according to the chamfer angle of the part, obtaining the part side angle of the chamfer pressing punch and the back side angle of the chamfer pressing punch; S12: Determine the length of the chamfering punch according to the thickness of the material strip and the length of the chamfer required for the part, and obtain the height of the chamfering punch; S13: Obtaining the width of the material trough according to the sample spacing; S14: The product coefficient can also be determined according to the thickness of the material strip, and the depth of the material trough is finally obtained; S2: Chamfering, a chamfering punch with a determined size is installed on the stamping die, and the stamping die chamfers the opposite sides of adjacent parts; S3: Blanking: The stamping die blanks the chamfered strip to obtain parts.

2. The precision stamping method for edge chamfered parts according to claim 1, characterized in that: The calculation formula for the depth of the trough is: ； in, is the product coefficient, The length of the chamfering punch, The height of the chamfering punch, The width of the trough.

3. The precision stamping method for edge chamfered parts according to claim 2, characterized in that: The calculation formula is , where α1 is the part side angle of the chamfering pressing punch.

4. The method for precision stamping of edge chamfered parts according to claim 3, characterized in that: The calculation formula of α1 is: α1=α×(100%~105%); the calculation formula of α2 is α2=α1×(90%~60%), and α2≥30°; among them, α is the chamfer angle of the part, and α2 is the reverse angle of the chamfer pressing punch.

5. The precision stamping method for edge chamfered parts according to claim 2, characterized in that: The value of is: When t<6mm, =1.1-1.2; when t≥6mm, =1.05-1.1; where t is the thickness of the strip.

6. The precision stamping method for edge chamfered parts according to claim 2, characterized in that: , ;in, is the length of the chamfer required for the part, The height of the chamfer required for the part.

7. The precision stamping method for edge chamfered parts according to claim 1, characterized in that: The specific steps in step S3 are: S31: the material strip is located on the lower concave die, and the lower concave die is located below the male and female dies; S32: The stamping die is closed, and the blank holder and the counter pressure plate respectively press the material; S33: The male and female dies apply a blanking force to the material strip, and keep the blank holder and the counter pressure plate pressing the material strip tightly; S34: Blanking is completed, and the parts and the material beans are separated from the material strip; S35: Open the stamping die. At this time, the part and the blank are stored in the lower die and the convex die respectively. The blank is lifted up as the blank holder rises. S35: The back pressure plate pushes the parts out, the upper ejector pushes the beans out, blows away the parts and the beans, and feeds the material belt forward once.

8. The method for precision stamping of edge chamfered parts according to claim 7, characterized in that: The rounding of the cutting edge of the male and female dies is R1 = (1% ~ 3%) t, and the rounding of the cutting edge of the lower die is R2 = (1% ~ 3%) t, where t is the thickness of the material strip.

9. The method for precision stamping of edge chamfered parts according to claim 8, characterized in that: In step S31, the blanking gap C1 between the convex and concave dies and the lower die at the non-chamfered position is ≤1%t; if a chamfering protection piece is provided on the counter pressure plate, the blanking gap C2 between the convex and concave dies and the lower die at the chamfered position is ≤0.5%t; if the chamfering protection piece is not provided on the counter pressure plate, the blanking gap C3 between the convex and concave dies and the lower die at the chamfered position is ≤1%t; wherein t is the thickness of the material strip.

10. A precision stamping die for edge chamfered parts, characterized in that: A method for precision stamping an edge chamfered part according to any one of claims 1 to 9, comprising: An upper punch assembly comprises an upper working table, an upper pad, an upper fixed plate, a blank holder, a blank holder, a male and female die, an upper ejector rod, an upper punch and a locking pin. The upper pad is installed below the upper working table, the upper fixed plate is installed below the upper pad, the blank holder rod is connected to the upper working table and is located below the upper fixed plate, the blank holder rod is installed in the blank holder rod seat, the male and female die are installed in the blank holder rod, the top of the male and female die is connected to the bottom of the upper pad, the upper ejector rod is located in the upper working table, the output end of the upper ejector rod ejects the beans through the upper punch, and the locking pin is installed in the blank holder rod; The lower punch assembly includes a lower workbench, a lower pad, a lower fixed plate, a lower die, a chamfering pressing punch, a back-pressure plate and a lower push rod. The lower pad is installed above the lower workbench, the lower fixed plate is installed above the lower pad, the lower die is installed on the lower fixed plate, the chamfering pressing punch and the back-pressure plate are installed in the lower die, the back-pressure plate is used to cooperate with the male and female dies to obtain parts, the lower push rod is located in the lower workbench, and the output end of the lower push rod is connected to the bottom of the back-pressure plate.

Images