Edge chamfered part precision stamping method and stamping die

Abstract

This invention relates to a precision stamping method and stamping die for chamfered parts, comprising the following steps: determining the size of a chamfering punch, the chamfering punch including two symmetrically arranged punches and a material receiving groove located between the two punches; chamfering, installing the chamfering punch of the determined size on the stamping die, the stamping die chamfering the opposite sides of adjacent parts; blanking, the stamping die blanking the chamfered strip to obtain the part. The above technical solution balances the flow of the strip on both sides through the symmetrically arranged two punches. Furthermore, the dedicated material receiving groove between the two punches provides a pre-set, sufficient flow space and a place to accommodate the extruded material. This allows most of the excess material that would otherwise cause the strip to elongate to be guided into the material receiving groove, thereby greatly eliminating the extrusion of the strip and ensuring the accuracy of feeding.

Description

Technical Field

[0001] This invention relates to the field of edge chamfering stamping technology, and particularly to a precision stamping method and stamping die for edge chamfering parts. Background Technology

[0002] Existing edge chamfering methods include direct pressing, pre-cutting groove method, and semi-punching method. The direct pressing method involves pressing the punch directly into the strip to form the chamfer. The semi-punching method uses a semi-punching process to first press the chamfer, then horizontally shifts the protruding strip at the bottom of the sheet metal to make room for the blanking punch, and finally blanks the material. The pre-cutting groove method involves pre-cutting grooves on the strip before pressing the chamfer, allowing excess material to be transferred into the grooves as much as possible.

[0003] However, the direct pressing method, the pre-cut trough method, and the semi-punching method have all failed to effectively solve the problem of the material strip occupied by the punch shifting to the surrounding areas during the chamfering pressing process, resulting in a longer material strip and affecting the feeding accuracy. Summary of the Invention

[0004] Therefore, a precision stamping method and stamping die for chamfered parts are needed. This method addresses the technical problem that direct pressing, pre-cutting of the material groove, and semi-punching methods have failed to effectively solve the problem of material strip shifting from the punch to the surrounding areas during chamfering, leading to strip elongation and affecting feeding accuracy.

[0005] To achieve the above objectives, the present invention provides a precision stamping method for chamfered parts, comprising the following steps:

[0006] S1: Determine the dimensions of the chamfering punch, which includes two punches arranged symmetrically and a material receiving groove located between the two punches;

[0007] S11: Based on the chamfer angle of the part, obtain the part side angle and the reverse side angle of the chamfering punch.

[0008] S12: Determine the length of the chamfering punch based on the thickness of the strip and the required chamfer length of the part, and obtain the height of the chamfering punch.

[0009] S13: Calculate the width of the material container based on the spacing between the samples;

[0010] S14: The product coefficient can also be determined based on the thickness of the material strip, and the depth of the material trough can be obtained in the end;

[0011] S2: Chamfering, the chamfering punch of a predetermined size is installed on the stamping die, and the stamping die chamfers the opposite sides of adjacent parts;

[0012] S3: Blanking. The stamping die blanks the chamfered strip to obtain the part.

[0013] Unlike existing technologies, the above-mentioned solution balances the flow of the material strip on both sides using two symmetrically arranged punches. A dedicated material receiving groove between the two punches provides a pre-set, ample flow space and a place to hold the extruded material. This ensures that most of the excess material that would otherwise cause the strip to elongate is guided into the receiving groove, thus greatly eliminating the extrusion of the strip and ensuring feeding accuracy. Furthermore, the chamfering punch can simultaneously chamfer opposite sides of adjacent parts, chamfering the edges of two parts in one go, improving chamfering efficiency.

[0014] As one embodiment of the present invention, the formula for calculating the depth of the material container is:

[0015] ;

[0016] in, The product coefficient, The length of the chamfering punch is to be determined by the chamfering pressure. To reduce the height of the chamfered punch, This refers to the width of the material container.

[0017] Thus, after obtaining the specific values ​​of the product coefficient, the length of the chamfering punch, the height of the chamfering punch, and the width of the material groove, the depth of the material groove can be calculated, thereby accurately determining the width and height of the material groove. This provides a preset and sufficient flow space and a place to accommodate the material being extruded, improving the shearing surface quality, dimensional accuracy, and flatness of the chamfered parts.

[0018] As one embodiment of the present invention The calculation formula is , where α1 is the side angle of the chamfering punch.

[0019] Thus, it can be calculated using a specific formula. ,make The values ​​are more accurate.

[0020] As one embodiment of the present invention, the calculation formula for α1 is: α1 = α × (100%~105%); the calculation formula for α2 is α2 = α1 × (90%~60%), and α2 ≥ 30°; where α is the chamfer angle of the part, and α2 is the reverse angle of the chamfering punch.

[0021] Thus, α1 acts on the part, and α1 is calculated using a formula based on α to account for the springback of the strip. α2 is the reverse angle of the punch, and α2 acts on the scrap part. α2 is steeper than α1, which can reduce the overall volume of the pressing and chamfering punch, thereby reducing material flow.

[0022] As one embodiment of the present invention The value is:

[0023] When t < 6 mm =1.1-1.2; when t≥6mm, =1.05-1.1; where t is the thickness of the strip.

[0024] In this way, different product coefficients can be determined according to the different thicknesses of the strip, making the values ​​more reasonable.

[0025] As one embodiment of the present invention , ;in, The required length of the chamfer on the part, The required chamfer height for the part.

[0026] Thus, by setting > as well as > This avoids tearing at the chamfer inflection point from affecting the part itself, and the defects generated by stamping will remain on the scrap material with the blank, ensuring the quality of the chamfer edge of the part.

[0027] As one embodiment of the present invention, the specific steps in step S3 are as follows:

[0028] S31: The strip is located on the lower die, and the lower die is located below the punch and die;

[0029] S32: Closed stamping die, the blank holder and the counter pressure plate clamp the material respectively;

[0030] S33: The punch and die apply a punching force to the strip and maintain the pressure ring and the counter-pressure plate pressing the strip together;

[0031] S34: The blanking process is completed, and the part and the material are separated from the conveyor belt;

[0032] S35: Open the stamping die. At this time, the part and the blank are stored in the lower die and the punch and die respectively. The blank is lifted up as the pressure ring rises.

[0033] S35: The counter-pressure plate pushes out the parts, the upper push rod pushes out the material beans, blows away the parts and material beans, blows away the parts and material beans, and feeds the material belt forward once.

[0034] In this way, the material separation and waste disposal are integrated into a single process step, simplifying the process flow and reducing the number of molds and equipment usage. Furthermore, after completing one step, the material strip can be advanced one feeding distance to continue production, significantly improving production efficiency.

[0035] In one embodiment of the present invention, the rounding radius R1 at the cutting edge of the punch and die is (1%~3%)t, and the rounding radius R2 at the cutting edge of the lower die is (1%~3%)t, where t is the thickness of the strip.

[0036] In this way, by processing the cutting edge into rounded corners with specific radii (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 punching section, protects the mold, increases its service life, and optimizes the chamfering effect.

[0037] In one embodiment of the present invention, in step S31, the blanking gap C1 between the punch and die and the lower die at the non-chamfered position is ≤1%t. If a chamfer protection element is provided on the counter-pressure plate, the blanking gap C2 between the punch and die and the lower die at the chamfered position is ≤0.5%t. If no chamfer protection element is provided on the counter-pressure plate, the blanking gap C3 between the punch and die and the lower die at the chamfered position is ≤1%t. Wherein, t is the thickness of the strip.

[0038] In this way, by using a very small blanking gap (C≤1%t or 0.5%t) in conjunction with the rounded corner design of the cutting edge (R1, R2), high-quality pure shear separation is achieved, with a high degree of surface smoothness and very small burrs.

[0039] To achieve the above objectives, in a second aspect, the inventor provides a precision stamping die for chamfered parts, used to perform any of the precision stamping methods for chamfered parts provided by the inventor as described above, comprising:

[0040] The upper punch assembly includes an upper worktable, an upper pad plate, an upper fixed plate, a pressure ring seat, a pressure ring, a punch and die, an upper ejector rod, an upper punch, and a locking pin. The upper pad plate is installed below the upper worktable, and the upper fixed plate is installed below the upper pad plate. The pressure ring seat is connected to the upper worktable and is located below the upper fixed plate. The pressure ring is installed inside the pressure ring seat, and the punch and die are installed inside the pressure ring. The top of the punch and die is connected to the bottom of the upper pad plate. The upper ejector rod is located inside the upper worktable, and the output end of the upper ejector rod ejects the material through the upper punch. The locking pin is installed inside the pressure ring.

[0041] The lower punch assembly includes a lower worktable, a lower backing plate, a lower fixed plate, a lower die, a chamfering punch, a counter-pressure plate, and a lower ejector pin. The lower backing plate is installed above the lower worktable, and the lower fixed plate is installed above the lower backing plate. The lower die is installed on the lower fixed plate, and the chamfering punch and the counter-pressure plate are installed inside the lower die. The counter-pressure plate is used to cooperate with the punch and die to obtain the part. The lower ejector pin is located inside the lower worktable, and the output end of the lower ejector pin is connected to the bottom of the counter-pressure plate.

[0042] Unlike existing technologies, the precision stamping die for chamfered parts in this application, based on the determined size of the chamfering pressing punch, allows excess material to be guided into the material receiving groove of the chamfering pressing punch during the stamping process through the cooperation between the upper and lower punch components, greatly eliminating the squeezing of the material strip and ensuring the accuracy of feeding.

[0043] The above description of the invention is merely an overview of the technical solution of this application. In order to enable those skilled in the art to better understand the technical solution of this application and to implement it based on the description and drawings, and to make the above-mentioned objectives and other objectives, features and advantages of this application easier to understand, the following description is provided in conjunction with the specific embodiments and drawings of this application. Attached Figure Description

[0044] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, features, and effects of specific embodiments of this application and other related content, and should not be considered as limitations on this application.

[0045] In the accompanying drawings of the instruction manual:

[0046] Figure 1 This is a schematic diagram illustrating the engagement of a chamfering punch with a part and scrap according to an embodiment of this application;

[0047] Figure 2 This is a top view of a stamping die according to an embodiment of this application;

[0048] Figure 3 This is a schematic diagram of a material strip placed on a lower die according to an embodiment of this application;

[0049] Figure 4 This is a schematic diagram of the clamping ring and the counter-pressure plate clamping the material strip according to one embodiment of this application;

[0050] Figure 5 This is a schematic diagram of a chamfering punch and a die for cutting the strip according to an embodiment of this application;

[0051] Figure 6 This is a schematic diagram showing that, according to an embodiment of this application, the part and the material bead are respectively stored in the lower die and the punch and die;

[0052] Figure 7 This is a schematic diagram of the anti-pressure plate and the ejected material beans according to an embodiment of this application.

[0053] The reference numerals used in the above figures are explained as follows:

[0054] 100-Stamping die; 200-Strip material; 300-Material stub; 400-Part; 500-Scrap material; 1-Upper punch assembly; 11-Upper worktable; 12-Upper backing plate; 13-Upper fixing plate; 14-Blank ring seat; 15-Blank ring; 16-Punch and die; 17-Upper ejector pin; 18-Upper punch; 19-Locking pin; 2-Lower punch assembly; 21-Lower worktable; 22-Lower backing plate; 23-Lower fixing plate; 24-Lower die; 25-Chamfering pressing punch; 251-Punch; 252-Material trough; 26-Reverse pressure plate; 261-Ejector pin; 27-Lower ejector pin; 28-Guide pin; 3-Limiting post; 4-Guide post; 5-Balance plate. Detailed Implementation

[0055] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0056] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0057] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0058] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0059] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0060] Without further limitations, the use of terms such as “comprising,” “including,” “having,” or other similar open-ended expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0061] As understood in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0062] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for 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, they should not be construed as limitations on the embodiments of this application.

[0063] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral arrangement; it can be a direct connection or an indirect connection through an intermediate medium; it can be a relationship of two components combined together, an interaction relationship between two components, or a connection within two structures. Those skilled in the art to which this application pertains can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0064] Existing methods such as direct pressing, pre-cut trough, and semi-punching have failed to effectively solve the problem of the material strip occupied by the punch shifting to all sides during the chamfering pressing process, resulting in a longer material strip and affecting feeding accuracy.

[0065] Therefore, this application provides a precision stamping method for chamfered parts, including the following steps:

[0066] S1: Determine the dimensions of the chamfering punch 25. The chamfering punch 25 includes two punches 251 arranged symmetrically and a material receiving groove 252 located between the two punches 251.

[0067] S11: Based on the chamfer angle of the part, obtain the part side angle and the reverse side angle of the chamfering punch.

[0068] S12: Determine the length of the chamfering punch based on the thickness of the strip and the required chamfer length of the part, and obtain the height of the chamfering punch.

[0069] S13: Calculate the width of the material container based on the spacing between the samples;

[0070] S14: The product coefficient can also be determined based on the thickness of the material strip, and the depth of the material trough can be obtained in the end;

[0071] S2: Chamfering, the chamfering punch 25 of the determined size is installed on the stamping die 100, and the stamping die 100 chamfers the opposite sides of the adjacent parts 400;

[0072] S3: Blanking. The stamping die 100 blanks the chamfered strip 200 to obtain part 400.

[0073] According to some embodiments of this application, please refer to Figures 1 to 7 This embodiment relates to a precision stamping method for chamfered parts, including the following steps:

[0074] S1: Determine the dimensions of the chamfering punch 25. The chamfering punch 25 includes two punches 251 arranged symmetrically and a material receiving groove 252 located between the two punches 251.

[0075] S11: Based on the chamfer angle of the part, obtain the part side angle and the reverse side angle of the chamfering punch.

[0076] S12: Determine the length of the chamfering punch based on the thickness of the strip and the required chamfer length of the part, and obtain the height of the chamfering punch.

[0077] S13: Calculate the width of the material container based on the spacing between the samples;

[0078] S14: The product coefficient can also be determined based on the thickness of the material strip, and the depth of the material trough can be obtained in the end;

[0079] S2: Chamfering, the chamfering punch 25 of the determined size is installed on the stamping die 100, and the stamping die 100 chamfers the opposite sides of the adjacent parts 400;

[0080] S3: Blanking. The stamping die 100 blanks the chamfered strip 200 to obtain part 400.

[0081] like Figure 1 As shown, the chamfering punch 25 includes two symmetrically arranged punches 251 and a material receiving groove 252 located between the two punches 251. Optionally, the punches 251 are claw-shaped. The required chamfer length, required chamfer height, chamfer angle, and strip thickness are known data. Based on this, the part side angle, the reverse side angle, the length of the chamfering punch, and the product coefficient can be obtained. The width of the material receiving groove is obtained according to the spacing, thus ultimately determining the depth of the material receiving groove.

[0082] In step S2, it is important to note that, as Figure 2 As 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 to the right). The black line represents the current stroke (including chamfering and blanking), and the blue line represents the stroke after the next feeding (the position of the blue line after the next forward feeding is from the position of the black line). The blue line shows that one feeding stroke punches four parts 400. These 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. Therefore, the stamping die 100 simultaneously chamfers the opposite sides of adjacent parts 400, improving chamfering efficiency.

[0083] In step S3, it is important to note that, as Figure 2 As shown, the blanked part 400 is a ratchet pawl, which is used in car door or tailgate locks.

[0084] Unlike existing technologies, the above-mentioned technical solution balances the flow of the material strip 200 on both sides through two symmetrically arranged punches 251. A dedicated material receiving groove 252 is provided between the two punches 251, offering a pre-defined and ample flow space and receiving area for the extruded material. This ensures that most of the excess material that would otherwise cause the material strip 200 to elongate is guided into the material receiving groove 252, thereby greatly eliminating the extrusion of the material strip 200 and ensuring feeding accuracy. Furthermore, the chamfering punch 25 can simultaneously chamfer opposite sides of adjacent parts 400, chamfering the edges of two parts 400 in one operation, improving chamfering efficiency.

[0085] like Figure 1 As shown, the formula for calculating the depth of the material container is:

[0086] ;

[0087] in, The product coefficient, The length of the chamfering punch is to be determined by the chamfering pressure. To reduce the height of the chamfered punch, This refers to the width of the material container.

[0088] Thus, after obtaining the specific values ​​of the product coefficient, the length of the chamfering punch, the height of the chamfering punch, and the width of the material channel, the depth of the material channel can be calculated, thereby accurately determining the width and height of the material channel 252. This provides a preset and sufficient flow space and a place to accommodate the extruded material, improving the shear surface quality, dimensional accuracy, and flatness of the edge chamfering part 400.

[0089] like Figure 1 As shown, The calculation formula is , where α1 is the side angle of the chamfering punch.

[0090] The length of the chamfering punch can be determined based on the thickness of the strip. Specific proportional coefficients are shown in the table below:

[0091]

[0092] When the strip thickness t is 0-2mm, the length of the chamfering punch is... +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... .

[0093] Thus, it can be calculated using a specific formula. ,make The values ​​are more accurate.

[0094] like Figure 1 As shown, the formula for calculating α1 is: α1 = α × (100%~105%); the formula for calculating α2 is α2 = α1 × (90%~60%), and α2 ≥ 30°; where α is the chamfer angle of the part, and α2 is the reverse angle of the chamfering punch.

[0095] The asymmetrical angle setting of the chamfered pressing punch 25 is conducive to the flow of material into the material tank 252.

[0096] Thus, α1 acts on part 400. Based on α, α1 is calculated using a formula to account for the springback of strip 200. α2 is the reverse angle of the punch. α2 acts on the scrap 500. α2 is steeper than α1, which can reduce the overall volume of the pressing and chamfering punch 25, thereby reducing material flow.

[0097] According to some embodiments of this application, optionally, The value is:

[0098] When t < 6 mm =1.1-1.2; when t≥6mm, =1.05-1.1; where t is the thickness of the strip.

[0099] In this way, different product coefficients can be determined according to the different thicknesses of the strip, making the values ​​more reasonable.

[0100] like Figure 1 As shown, , ;in, The required chamfer length for the part. The required chamfer height for the part.

[0101] Optionally, the dimensions of the chamfering punch 25 are set ( and ) and the required chamfer dimensions for part 400 ( and If the difference is greater than 0.2t, avoid potential tearing at the chamfered edge.

[0102] Thus, by setting > as well as > This avoids tearing at the chamfer inflection point from affecting part 400 itself. Defects caused by stamping will remain on scrap 500 with the blanking material, ensuring the quality of the chamfered edge of part 400.

[0103] like Figures 3 to 7 As shown, the specific steps in step S3 are as follows:

[0104] S31: The strip 200 is located on the lower die 24, and the lower die 24 is located below the punch and die 16;

[0105] S32: Close the stamping die 100, and the pressure ring 15 and the counter pressure plate 26 respectively press the material;

[0106] S33: The punch and die 16 apply a punching force to the strip 200 and maintain the pressure ring 15 and the counter-pressure plate 26 pressing the strip 200 against it;

[0107] S34: The blanking process is completed, and part 400 and material 300 are separated from the strip 200;

[0108] S35: Open the stamping die 100. At this time, the part 400 and the material bean 300 are stored in the lower die 24 and the punch and die 16 respectively. The material bean 300 is lifted up as the pressure ring 15 rises.

[0109] S35: The counter-pressure plate 26 pushes out the part 400, the upper push rod 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.

[0110] Optionally, after step S35, step S36 is also included: repeating steps S32 to S35 until the material strip 200 is unloaded.

[0111] In this way, the material separation and waste material 500 are integrated into one step through the above steps, simplifying the process and reducing the number of molds and equipment usage. On the other hand, after completing one step, the material strip 200 can be advanced one feeding distance to continue production, which significantly improves production efficiency.

[0112] like Figure 3 As shown, the rounding radius R1 at the cutting edge of the punch and die 16 is (1%~3%)t, and the rounding radius R2 at the cutting edge of the lower die 24 is (1%~3%)t, where t is the thickness of the strip.

[0113] When the stamping die 100 is in the initial position, the cutting edges of the punch and die 16 are rounded with R1, and the cutting edges of the lower die 24 are rounded with R2.

[0114] In this way, by processing the cutting edge into rounded corners with specific radii (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 punching section, protects the mold, increases its service life, and optimizes the chamfering effect.

[0115] like Figure 3 As shown, in step S31, the blanking gap C1 between the punch and die 16 and the lower die 24 at the non-chamfered position is ≤1%t. If a chamfer protection element is provided on the counter-pressure plate 26, the blanking gap C2 between the punch and die 16 and the lower die 24 at the chamfered position is ≤0.5%t. If no chamfer protection element is provided on the counter-pressure plate 26, the blanking gap C3 between the punch and die 16 and the lower die 24 at the chamfered position is ≤1%t. Wherein, t is the thickness of the strip.

[0116] When the stamping die 100 is in the initial position, there is a blanking clearance C between the punch and die 16 and the lower die 24.

[0117] In this way, by using a very small blanking gap (C≤1%t or 0.5%t) in conjunction with the rounded corner design of the cutting edge (R1, R2), high-quality pure shear separation is achieved, with a high degree of surface smoothness and very small burrs.

[0118] 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 chamfered parts, used to perform a precision stamping method for chamfered parts. The die includes an upper punch assembly 1 and a lower punch assembly 2. The upper punch assembly 1 includes an upper worktable 11, an upper pad plate 12, an upper fixed plate 13, a blank holder 14, a blank holder 15, a punch and die 16, an upper ejector rod 17, an upper punch 18, and a locking pin 19. The upper pad plate 12 is installed below the upper worktable 11, and the upper fixed plate 13 is installed below the upper pad plate 12. The blank holder 14 is connected to the upper worktable 11 and located below the upper fixed plate 13. The blank holder 14 contains the blank holder 15, and the punch and die 16 are installed inside the blank holder 15. The top of the punch and die 16 is connected to the bottom of the upper pad plate 12. The upper ejector rod 17... 7 is located inside the upper worktable 11. The output end of the upper ejector rod 17 ejects the material bead 300 through the upper punch 18. The locking pin 19 is installed inside the pressure ring 15. The lower punch assembly 2 includes a lower worktable 21, a lower pad plate 22, a lower fixing plate 23, a lower die 24, a chamfering pressing punch 25, a counter-pressure plate 26, and a lower ejector rod 27. The lower pad plate 22 is installed above the lower worktable 21. The lower fixing plate 23 is installed above the lower pad plate 22. The lower die 24 is installed on the lower fixing plate 23. The chamfering pressing punch 25 and the counter-pressure plate 26 are installed inside the lower die 24. The counter-pressure plate 26 is used to cooperate with the punch and die 16 to obtain the part 400. The lower ejector rod 27 is located inside the lower worktable 21. The output end of the lower ejector rod 27 is connected to the bottom of the counter-pressure plate 26.

[0119] A limiting post 3 is installed at each of the two symmetrical feet of the upper worktable 11 and the lower worktable 21 (specifically, the limiting post 3 includes an upper limiting post 3 and a lower limiting post 3, the upper worktable 11 is connected to the pressure ring seat 14 through the upper limiting post 3, and the lower limiting post 3 is connected to the lower worktable 21). In addition, a guide post 4 is installed at each of the two symmetrical feet, and the guide post 4 plays a guiding role.

[0120] V-shaped pressure teeth can be set on the pressure ring 15 and the lower die 24 to create a strong and controllable triaxial compressive stress state outside the material separation zone, which can suppress the unfavorable flow of the strip 200 during the punching process, thereby achieving pure shear separation.

[0121] The lower punch assembly 2 has a locking groove at the corresponding position of the locking pin 19. The locking groove cooperates with the locking pin 19 to fix the strip 200, and the locking pin limits the fitting accuracy between the pressure ring 15 and the lower die 24. Simultaneously, the lower punch assembly 2 has a lower punch at the corresponding position of the upper punch 18, so that the upper punch 18 and the lower punch cooperate to punch the material bead 300. In some embodiments, the upper punch assembly 1 also has a punch assembly for punching other material bead 300s of the strip 200, which mainly ejects the material bead 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 has a guide hole at the corresponding position of the guide pin 28. The guide pin 28 can accurately position the strip 200, eliminate feeding errors, and ensure stamping position accuracy. Especially in the continuous die production process, the 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 the strip 200 back or push it to the precise position.

[0122] Optionally, the lower punch assembly 2 also includes a spring-loaded ejector pin 261, which is installed inside the counter-pressure plate 26. After the strip 200 undergoes processes such as chamfering and stamping, it may partially sag, resulting in an uneven overall surface. An uneven strip 200 can hinder the smooth movement of the feeding mechanism and even cause feeding errors. Therefore, by installing the spring-loaded ejector pin 261 inside the counter-pressure plate 26, the spring force is used to lift the strip 200 upwards, restoring it to a flat horizontal surface, thus achieving stable and accurate feeding.

[0123] like Figures 3 to 7 As shown, the workflow of the precision stamping die 100 for chamfered parts is as follows: First, the chamfering punch 25 chamfers the strip 200 for the first time, that is, chamfers the opposite sides of adjacent parts 400. Second, the strip 200 is fed forward once, and the chamfering punch 25 chamfers the fed strip 200. At the same time, the chamfered portion of the strip 200 is discarded to obtain the first chamfered part 400. The portion exceeding the required chamfer size of part 400 is left on the strip 200 from which the first part 400 is removed as scrap 500. Third, the strip 200 is fed forward once more, and the chamfering punch 25 chamfers the fed strip 200 again. At the same time, the chamfered portion of the strip 200 is discarded to obtain the second chamfered part 400. Finally, the above steps are repeated until the strip 200 is stamped. It should be noted that during the second stamping, the precision stamping die 100 for chamfering the edge-cornering parts simultaneously blanks the first part 400 and chamfers the second part 400 during the third stamping.

[0124] Thus, based on the chamfering punch 25, the upper punch assembly 1 and the lower punch assembly 2 work together to guide excess material during the stamping process into the material receiving groove 252 of the chamfering punch 25, which greatly eliminates the squeezing of the material strip 200 and ensures the accuracy of feeding.

[0125] like Figure 3 As shown, the stamping die 100 also includes a balance plate 5, which is mounted on the pressure ring 15.

[0126] The core function of the balance plate 5 is to act as a rigid stop when the mold closes, precisely limiting the final downward movement of the pressure ring 15. This indirectly and precisely controls the final pressure exerted on the compressed material.

[0127] Unlike existing technologies, the precision stamping die for chamfered parts in this application, based on the determined size of the chamfering pressing punch, allows excess material to be guided into the material receiving groove of the chamfering pressing punch during the stamping process through the cooperation between the upper and lower punch components, greatly eliminating the squeezing of the material strip and ensuring the accuracy of feeding.

[0128] According to some embodiments of this application, optionally, the lower punch assembly 2 also includes a chamfer protection member, which is installed on the counter-pressure plate 26, and the chamfer protection member has a protrusion at the corresponding position of the chamfer of the strip 200.

[0129] In this way, by setting up chamfer protection components, the material in the chamfer area is prevented from being crushed or pre-deformed during the blanking stage, ensuring the accuracy and consistency of the final chamfer geometry.

[0130] 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, any changes and modifications made to the embodiments described herein based on the innovative concept of the present invention, or equivalent structural or procedural transformations made using the content of the present invention's specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields, are all included within the scope of patent protection of the present invention.

Claims

1. A method for precision stamping of an edge chamfered part, characterized by, Comprising the following steps: S1: determining the size of the chamfer pressing punch, the chamfer pressing punch comprising two punches arranged symmetrically and a material containing groove located between the two punches; S11: obtaining the part side angle of the chamfer pressing punch and the reverse side angle of the chamfer pressing punch according to the chamfer angle of the part; S12: determining the length of the chamfer pressing punch according to the thickness of the material belt and the length of the chamfer required by the part, and obtaining the height of the chamfer pressing punch; S13: obtaining the width of the material containing groove according to the layout spacing; S14: the product coefficient can also be determined according to the thickness of the material belt, and finally the depth of the material containing groove is obtained; S2: chamfering, installing the chamfer pressing punch with the determined size on the stamping die, and the stamping die chamfers the opposite sides of adjacent parts; S3: blanking, the stamping die blanks the material belt with chamfer, and obtains the part; The calculation formula of the depth of the material containing groove is: wherein, is a product coefficient, is a length of the chamfer press punch, is a height of the chamfer press punch, is a width of the material container groove; The calculation formula is wherein, α1 is the part side angle of the chamfer pressing punch; 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 side angle of the chamfer pressing punch; The values of the numerical values are: when t < 6 mm, = 1.1 - 1.2; when t > 6 mm, = 1.05 - 1.1; where t is the thickness of the strip; , ; wherein, the length of the chamfer required for the part, the height of the chamfer required for the part.

2. The method of precision stamping of edge chamfered parts according to claim 1, characterized in that, The specific steps in step S3 are: S31: the material belt is located on the lower die, and the lower die is located below the convex-concave die; S32: close the stamping die, and the blank holder and the counter pressure plate press the material tightly respectively; S33: the convex-concave die applies a blanking force to the material belt, and the blank holder and the counter pressure plate keep pressing the material belt tightly; S34: the blanking is completed, and the part and the material bean are separated from the material belt; S35: open the stamping die, at this time, the part and the material bean are stored in the lower die and the convex-concave die respectively, and the material bean is lifted up with the blank holder; S36: the counter pressure plate ejects the part, the ejector rod ejects the material bean, blows away the part and the material bean, and feeds the material belt forward once.

3. The method of claim 2, wherein, The blade edge of the convex-concave die is rounded R1=(1%~3%)t, and the blade edge of the lower die is rounded R2=(1%~3%)t, wherein t is the thickness of the material belt.

4. The method of claim 3, wherein, In step S31, the blanking gap C1 between the convex-concave die and the lower die at the non-chamfered part is ≤1%t, if the chamfer protection piece is arranged on the counter pressure plate, the blanking gap C2 between the convex-concave die and the lower die at the chamfered part is ≤0.5%t, if the chamfer protection piece is not arranged on the counter pressure plate, the blanking gap C3 between the convex-concave die and the lower die at the chamfered part is ≤1%t; Wherein, t is the thickness of the material belt.

5. A precision stamping die for an edge chamfered part, characterized by, The edge chamfering part precision stamping method for performing the edge chamfering part precision stamping method according to any one of claims 1-4, comprising: The upper punch assembly comprises an upper workbench, an upper base plate, an upper fixed plate, a blank holder seat, a blank holder, a punch-die, an upper ejector pin, an upper punch and a locking pin, the upper workbench is provided below the upper base plate, the upper base plate is provided below the upper fixed plate, the blank holder seat is connected with the upper workbench and is provided below the upper fixed plate, the blank holder seat is provided with the blank holder, the blank holder is provided with the punch-die, the top of the punch-die is connected with the bottom of the upper base plate, the upper ejector pin is located in the upper workbench, the output end of the upper ejector pin is provided with the upper punch to eject the material bean, and the locking pin is installed in the blank holder; The lower punch assembly comprises a lower workbench, a lower base plate, a lower fixed plate, a lower die, a chamfer pressing punch, a counter-pressure plate and a lower ejector pin, the lower workbench is provided above the lower base plate, the lower base plate is provided above the lower fixed plate, the lower fixed plate is provided with the lower die, the lower die is provided with the chamfer pressing punch and the counter-pressure plate, the counter-pressure plate is used to cooperate with the punch-die to obtain the part, and the lower ejector pin is located in the lower workbench and the output end of the lower ejector pin is connected with the bottom of the counter-pressure plate.

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