A precision stamping method and die for thick, narrow-rimmed ring-shaped parts

Abstract

This invention relates to a precision blanking method and mold for thick, narrow-rimmed ring-shaped parts. The method includes the following steps: S1, a punching inner hole step, including: S11, pre-punching inner hole: performing n pre-punching operations on the blank plate with the center point of the part as the center; S12, forming inner hole: performing a forming punching operation on the initial inner hole after the nth pre-punching operation to obtain a formed inner hole; S2, a blanking outer ring step: punching the outer side of the formed inner hole obtained in the punching inner hole step S1. The outer ring, whose shape and size are the design shape and size of the outer ring of the ring-shaped part, and the part of the blank plate located between the outer ring and the forming inner hole is the part blank; including the following steps: S21, outer ring pre-punching: perform m half-shear punchings in sequence, the punching thickness of each half-shear punching is 0.25t~0.85t, and reserve the final blanking thickness of 0.15t~0.25t; S22, final blanking punching: punch the part blank from the blank plate to obtain the formed ring-shaped part.

Description

Technical Field

[0001] This invention relates to the field of stamping forming technology for ring-shaped parts, and more specifically, to a precision stamping method and mold for thick, narrow-edge ring-shaped parts. Background Technology

[0002] Locking rings or retaining washers are a class of extremely important transmission components, widely used in aerospace, automotive, and machinery industries. They are core components of shaft transmission / braking systems such as engines, motors, and rotor assemblies. (See appendix) Figure 1 As shown, these types of parts have the following characteristics: 1) Due to the need for use at high temperatures, they are generally made of high-strength heat-resistant materials, such as GH4169, FGH4169, heat-resistant stainless steel, etc., which have high strength; 2) They have the characteristics of thick material and narrow edge, with the thickness t of the part being larger than the radial width a of the ring, and the t / a ratio being greater than 1 or even reaching 2; 3) The width a of the ring is smaller than its inner diameter R, and the R / a ratio is greater than 19; 4) In order to meet the locking function requirements, the assembly clearance of its mating parts is required to be small, and the dimensional accuracy of the parts is required to be high; 5) Some ring-type parts have an outer boss on the outer ring and an inner boss on the inner ring. Due to the above characteristics, the stamping of these ring-shaped parts is difficult, and the following difficulties exist: 1) The blanking force is large, and the overall rigidity of the mold is required to be high; 2) During blanking, the stability in the thickness direction is poor, and the inner ring is prone to concavity, resulting in uneven ring surface and uneven ring diameter; 3) Due to the small width of the ring, the blanking blanking amount is small, and the difference in blanking amount between the area without the boss and the area with the boss causes the ring diameter to deviate, resulting in elliptical deformation; 4) The thickness of the parts is relatively large, and defects such as burrs are prone to occur.

[0003] Traditional stamping processes typically involve punching and blanking, such as... Figure 2As shown. The first step is to form the inner hole by punching, and the second step is to form the outer ring by blanking. The mold is generally designed as a progressive die compound mold. When forming the above-mentioned thick material narrow-edge ring parts using traditional stamping process and mold, the following quality problems often occur: (1) The inner diameter is smaller than the reference size required by the drawing and does not meet the tolerance requirements; (2) The flatness of the parts is poor. The parts with bosses are relatively flat, while the parts without bosses are warped; (3) There are burrs and flange defects on the inner ring edge, outer ring edge and the area around the bosses; (4) The whole ring is partially elliptical, and the inner / outer diameter is smaller in the areas without bosses. The reasons for this are: (1) Due to the large thickness of the sheet metal and the small width of the ring, the sheet metal becomes unstable in the thickness direction during punching, resulting in excessively large punching angles for the inner and outer rings and an inner diameter smaller than the nominal size; (2) Due to the instability of the parts during punching, the circumferential rigidity is poor, resulting in low overall flatness, elliptical inner ring, and low inner hole roundness, leading to a smaller local inner hole size; (3) In areas with bosses, the outer ring is pressed more during blanking, resulting in better clamping during blanking; however, in other areas without bosses, there is radial extrusion and flow of material, thus the inner ring becomes smaller, causing concavity or warping. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the technical problem to be solved by the present invention is to provide a precision stamping method and mold for thick material narrow-edge ring-shaped parts, which effectively solves the problems of deformation, inaccurate dimensions, burrs and other defects in the stamping process of such parts.

[0005] To achieve the above objectives, the present invention provides a precision blanking method for thick, narrow-edge ring-shaped parts, used to blank ring-shaped parts from a blank plate. The design dimensions of the ring-shaped parts include the inner ring hole radius R, the radial width a, and the thickness t. The precision blanking method includes the following steps:

[0006] S1. The internal punching process includes the following steps:

[0007] S11. Pre-punching inner hole: Select the center point of the part on the blank plate as the center point of the ring-shaped part to be punched. Using the center point of the part as the center, perform n pre-punching inner holes in sequence, where 3≥n≥1. After each pre-punching, an initial inner hole is obtained on the blank plate, and the radius of the initial inner hole obtained after n pre-punching is denoted as R1 to R2. n When n≥2, the punching width A of the (i+1)th punching is i+1 =R i+1 -R i A i+1 The value is taken as 0.1R to 0.3R, n-1≥i≥1, and when the inner ring hole of the ring-shaped part has an inner boss, the presence of a boss structure on the initial inner hole is determined based on the radial thickness of the inner boss and the radius of the initial inner hole obtained after each pre-punching; after the nth pre-punching of the inner hole, the radius R of the initial inner hole is determined. nThe difference RR between the inner ring hole radius R and the inner ring hole radius R n It is 0.2R to 0.3R;

[0008] S12, Forming inner hole: Based on the initial inner hole after the nth pre-punching inner hole, a forming punch is performed again to obtain the formed inner hole. The shape and size of the formed inner hole are the design shape and size of the inner ring hole of the ring-type part.

[0009] S2, Outer Ring Blanking Process: An outer ring is punched outside the formed inner hole obtained in the inner hole punching process S1. The shape and dimensions of the outer ring are the designed shape and dimensions of the outer ring of the ring-type part. The portion of the blank plate located between the outer ring and the formed inner hole is the part blank. This includes the following steps:

[0010] S21. Outer ring pre-cutting: Perform m half-cutting operations sequentially, where 3 ≥ m ≥ 1, and the cutting thickness B of the i-th half-cutting operation. i The value ranges from 0.25t to 0.85t, and the total thickness B of m half-shear punching operations is... 总 The difference between the thickness t and the thickness t is 0.15t to 0.25t;

[0011] S22. Final blanking: The blank part is punched off from the blank plate to obtain the formed ring-shaped part.

[0012] Furthermore, in step S11, n = 1, and in step S21, m = 1.

[0013] Furthermore, in steps S21 and S22, an elastic support is provided on the lower side of the part blank.

[0014] Furthermore, the precision blanking method employs a precision blanking die, which includes an upper die mechanism and a lower die mechanism. The upper die mechanism includes an upper support plate, and the lower die mechanism includes a lower support plate. The upper die mechanism also includes an inner hole punch group and an outer ring punch group. The inner hole punch group includes n inner hole pre-punches and one inner hole forming punch, and the n inner hole pre-punches are respectively designated as inner hole pre-punches No. 1 to No. n. The outer ring punch group includes m outer ring pre-punches and one outer ring blanking punch, and the m outer ring pre-punches are respectively designated as outer ring pre-punches No. 1 to No. m. The lower die mechanism also includes a blank mounting assembly and an inner hole blanking mechanism, both mounted on the lower support plate. The blanking die includes blanking holes, semi-shearing blanking pads, and a final blanking hole. The blank plate mounting assembly is used to mount the blank plate, and there is a gap between the blank plate and the lower support plate when the blank plate is mounted. The blank plate mounting assembly can move downward when pressed and can elastically return to its original position and move upward when not pressed. There are n+1 inner hole blanking holes, which respectively cooperate with n inner hole pre-punches and inner hole forming punches. There are m semi-shearing blanking pads, which respectively cooperate with m outer ring pre-punches. The semi-shearing blanking pads can move downward when pressed and can elastically return to their original position and move upward when not pressed. When the precision blanking die is closed, the upper support plate presses tightly against the blank plate mounted on the blank plate mounting assembly, and presses the blank plate tightly against the lower stripper.

[0015] In step S11, the inner hole is pre-punched from the No. 1 inner hole pre-punch head to the No. n inner hole pre-punch head in sequence. Each time the inner hole is pre-punched, the blank plate of the ring-shaped part is positioned and installed on the blank plate mounting assembly, and the center point of the part is located directly below the center of the inner hole pre-punch head. Then the precision blanking die is closed, and an initial inner hole is punched out on the blank plate using the inner hole pre-punch head.

[0016] In step S12, the blank plate is positioned and installed on the blank plate mounting assembly, and the initial inner hole center is located directly below the center of the inner hole forming punch. Then, the precision blanking die is closed, and the inner hole forming punch is used to punch out the forming inner hole on the blank plate.

[0017] In step S21, the first to nth half-shearing punches are performed sequentially using the No. 1 outer ring pre-punch head to the No. m outer ring pre-punch head. Each half-shearing punch is performed as follows: the blank plate is positioned and installed on the blank plate mounting assembly, and the center of the forming inner hole is located directly below the center of the outer ring pre-punch head. Then the precision punching die is closed, and the outer ring pre-punch head is used to perform a half-shearing punch on the blank plate.

[0018] In step S22, the blank plate is positioned and installed on the blank plate mounting assembly, and the center of the forming inner hole is located directly below the center of the outer ring blanking punch. Then, the precision blanking die is closed, and the outer ring blanking punch is used to cut the part blank from the blank plate to obtain the formed ring-shaped part.

[0019] Further, the center points of the parts on the blank plate are multiple and located on a part positioning line along the left-right direction, and the distance between adjacent part center points is L. In the precision blanking die, the centers of the inner hole pre-punch, inner hole forming punch, outer ring pre-punch, and outer ring blanking punch are all located on a punch positioning line extending in the left-right direction. The inner hole pre-punch No. 1 to the nth inner hole pre-punch, the inner hole forming punch, the outer ring pre-punch No. 1 to the nth outer ring pre-punch, and the outer ring blanking punch are arranged sequentially from left to right, and the distance between adjacent punch center points is an integer multiple of L. The precision blanking method includes: blank The blank is installed on the blank mounting assembly of the precision blanking die. The part positioning line is located directly below the punch positioning line, and the rightmost part center point on the part positioning line is located directly below the No. 1 inner hole pre-punch. After each mold closing and mold opening of the precision blanking die, the blank plate moves a straight distance L to the left on the blank mounting assembly. The above mold closing, mold opening and blank plate moving operations are repeated until the rightmost part center point on the part positioning line completes one mold closing under the outer ring blanking punch. The inner hole punching process S1 and the outer ring blanking process S2 are completed sequentially at all part center points on the blank plate.

[0020] Furthermore, the blank mounting assembly of the precision blanking die includes multiple mounting columns, and a support spring is provided below the mounting columns. The mounting columns are arranged in two parallel rows, and each row includes multiple mounting columns arranged in a straight line along the left and right direction. The mounting columns have snap-fit ​​grooves on their sides. When the blank plate is installed on the blank mounting assembly, its front and rear sides are embedded in the snap-fit ​​grooves of the two rows of mounting columns.

[0021] Furthermore, the precision blanking die is provided with the same positioning pins around the inner hole pre-punch, inner hole forming punch, outer ring pre-punch and outer ring blanking punch, and the blank plate is provided with the same positioning hole around the center point of each part, and the positioning pins extend into the positioning holes when the die is closed.

[0022] This invention also provides a precision blanking die for thick, narrow-edge ring-shaped parts, capable of performing the aforementioned precision blanking method. The precision blanking die includes an upper die mechanism and a lower die mechanism. The upper die mechanism includes an upper support plate, and the lower die mechanism includes a lower support plate. The upper die mechanism further includes an inner hole punch group and an outer ring punch group. The inner hole punch group includes n inner hole pre-punches and one inner hole forming punch, with the n inner hole pre-punches designated as inner hole pre-punches 1 to n. The outer ring punch group includes m outer ring pre-punches and one outer ring blanking punch, with the m outer ring pre-punches designated as outer ring pre-punches 1 to m. The lower die mechanism further includes a blank mounting assembly, an inner hole blanking hole, a half-shear blanking pad, and a final blanking hole, all mounted on the lower support plate. The blank mounting assembly is used to mount the blank plate, and when the blank plate is mounted, there is a gap between it and the lower support plate. The blank mounting assembly is subject to... The die can move downwards under pressure and elastically return to its original position when not under pressure. There are n+1 inner hole blanking holes, each corresponding to one of n inner hole pre-punches and inner hole forming punches. There are m semi-shearing blanking pads, each corresponding to one of m outer ring pre-punches. The semi-shearing blanking pads can move downwards under pressure and elastically return to their original position when not under pressure. When the precision blanking die is closed, the upper support plate presses tightly against the blank plate mounted on the blank plate mounting assembly. The blank plate is pressed tightly against the lower stripper. The first to nth inner hole pre-punches can respectively complete the first to nth pre-punching of the inner hole in step S11 of the precision punching method. The inner hole forming punch can complete the forming punching of the inner hole in step S12. The first to mth outer ring pre-punches can respectively complete the first to nth half-shearing in step S21. The outer ring blanking punch can complete the final blanking in step S22.

[0023] As described above, the precision blanking method and die of the present invention have the following beneficial effects:

[0024] 1. By employing a multi-stage punching method to obtain the inner ring hole of the ring-shaped part in stages, the punching force can be reduced, avoiding the concavity of the blank plate during inner hole punching. This results in a precise inner ring hole size and a flat blank, preparing for subsequent outer ring blanking. The outer ring of the part is blanked by applying a downward force from below the blank plate and simultaneously using a semi-shearing punching method in stages. This reduces the punching force of a single outer ring punching, effectively reducing or eliminating part deformation caused by a single blanking. The part and blank plate are subjected to bidirectional forces, thus maintaining a flat state. This invention can effectively solve the problems of deformation, inaccurate dimensions, burrs, and other defects in the stamping process of thick, narrow-edged ring-shaped parts. The produced parts have high precision and better stability.

[0025] 2. The use of precision blanking dies enables convenient and quick precision blanking, allowing for the simultaneous blanking of multiple ring-shaped parts, which greatly improves blanking efficiency and is easy to operate. Attached Figure Description

[0026] Figure 1 This is a simplified flowchart illustrating the precision punching method for holes according to the present invention.

[0027] Figure 2 This is a schematic diagram of the structure of the precision punching die for holes according to the present invention.

[0028] Figure 3 for Figure 2 Front view.

[0029] Figure 4 for Figure 3 EE section view.

[0030] Figure 5 for Figure 3 FF section view in the middle.

[0031] Figure 6 for Figure 2 Side view.

[0032] Figure 7 This is a partial structural schematic diagram of the precision punching die for holes in this invention.

[0033] Figure 8 This is a schematic diagram showing the installation and blanking of a blank sheet in a precision blanking die.

[0034] Figure 9 for Figure 8 A schematic diagram of the structure of the blank plate.

[0035] Figure 10 This is a structural diagram of a ring-shaped part.

[0036] Figure 11 This is a schematic diagram of the mounting column in this invention.

[0037] Explanation of reference numerals in the attached figures

[0038] 1 Upper mold mechanism

[0039] 11 Upper support plate

[0040] 12 Upper mold base

[0041] 13. Inner hole pre-punch head

[0042] 14. Internal forming punch

[0043] 15 Outer ring pre-punch

[0044] 16 Outer ring blanking punch

[0045] 17 Positioning Posts

[0046] 2 Lower mold mechanism

[0047] 21 Lower support plate

[0048] 22 Lower mold base

[0049] 23. Blank plate mounting assembly

[0050] 231 Installation Column

[0051] 232 Support Spring

[0052] 233 Snap-fit ​​groove

[0053] 24 Inner hole blanking hole

[0054] 25 Half-shear punching pad

[0055] 26 Final discharge hole

[0056] 3. Billet Plate

[0057] 31 Positioning Holes

[0058] 4. Initial inner hole

[0059] 5. Forming the inner hole

[0060] 6. Part blank

[0061] 7. Ring-shaped parts Detailed Implementation

[0062] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0063] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0064] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0065] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0066] This invention provides a precision punching method for thick, narrow-edge ring-shaped parts, used to punch ring-shaped parts 7 from a blank plate 3, such as... Figure 9 and Figure 10 As shown, the design dimensions of the ring-shaped part 7 include the inner ring hole radius R, the radial width a, and the thickness t. The t / a ratio is relatively large, exceeding 1 or even reaching 2, and the R / a ratio can reach over 19. The outer ring of the ring-shaped part 7 has an outer boss, and the inner ring has an inner boss.

[0067] The precision punching method of the present invention includes the following steps:

[0068] S1. The internal punching process includes the following steps:

[0069] S11. Pre-punching the inner hole: Select the center point of the part on the blank plate 3 as the center point of the ring-shaped part 7 to be punched. Using the center point of the part as the center, perform n pre-punching operations in sequence, where 3 ≥ n ≥ 1. After each pre-punching operation, an initial inner hole 4 is obtained on the blank plate 3, that is, the center of the initial inner hole 4 is always at the center point of the part. The radii of the initial inner hole 4 obtained by n pre-punching operations are denoted as R1 to R2. n R1 to R n Gradually increase, when n≥2, R i+1 -R i =A i+1 Let A be the blanking width of the (i+1)th blanking pass, where n-1≥i≥1, and the blanking width A is... i+1The value is taken as 0.1R to 0.3R, meaning that starting from the second pre-punching of the inner hole, the punching width is taken as 0.1R to 0.3R for each punching. After the nth pre-punching of the inner hole, the radius R of the initial inner hole 4 is... n The difference RR between the inner ring hole radius R and the inner ring hole radius R n The width is 0.2R to 0.3R, meaning that after the last pre-punching of the inner hole is completed, the reserved blanking width for subsequent blanking is 0.2R to 0.3R.

[0070] If the inner hole of the ring-shaped part 7 does not have an inner boss, then the initial inner hole 4 obtained each time will be a complete circular hole. When the inner hole of the ring-shaped part 7 has an inner boss, then the presence or absence of a boss structure on the initial inner hole 4 is determined based on the radial width of the inner boss and the radius of the initial inner hole 4 obtained each time the inner hole is pre-punched. Figure 9 As shown, in this embodiment, the number of pre-punching inner holes is n=1. Since the radial width of the inner boss on the inner ring hole of the ring-shaped part 7 is relatively small, the initial inner hole 4 obtained by the first pre-punching is a complete circular hole without a boss structure. If the radial width of the inner boss is relatively large, then the initial inner hole 4 obtained at this time has a boss structure, and its shape and size are smaller than the design shape and size of the inner boss.

[0071] In this invention, the number of pre-punching inner holes n can be selected according to actual needs. When n≥2, the radius R1 of the initial inner hole 4 obtained by the first pre-punching inner hole is selected according to the number of pre-punching inner holes n and the inner ring hole radius R of the ring-shaped part 7.

[0072] S12, Forming and punching the inner hole: Based on the initial inner hole 4 after the nth pre-punching, a second forming and punching is performed to obtain the formed inner hole 5, as shown. Figure 10 As shown, the shape and dimensions of the formed inner hole 5 are the same as the design shape and dimensions of the inner ring hole of the ring-shaped part 7.

[0073] S2, Outer Ring Blanking Process: An outer ring is punched outside the formed inner hole 5 obtained in the inner hole punching process S1. The shape and dimensions of the outer ring are the designed shape and dimensions of the outer ring of the ring-shaped part 7. The portion of the blank plate 3 located between the outer ring and the formed inner hole 5 is referred to as the part blank 6. This includes the following steps:

[0074] S21. Outer ring pre-cutting: Perform m half-cutting operations sequentially, where 3 ≥ m ≥ 1, and the cutting thickness B of the i-th half-cutting operation. i The value ranges from 0.25t to 0.85t, and the total thickness B of m half-shear punching operations is... 总 The difference between the thickness and the blanking thickness t is 0.15t to 0.25t, meaning that after the last half-shear blanking is completed, the thickness reserved for the final blanking is 0.15t to 0.25t. Wherein the blanking thickness B... iThis refers to the distance between the blank portion 6 and the part before and after the semi-shearing blanking. As a preferred design, during the semi-shearing blanking, an elastic support is provided on the underside of the blank portion 6, and the blank portion 6 is always in contact with the elastic support, which does not affect the blanking and can improve the quality of the semi-shearing blanking.

[0075] S22. Final blanking: The part blank 6 is punched off from the blank plate 3 to obtain the formed ring-shaped part 7. Preferably, during the final blanking, an elastic support is provided on the underside of the blank plate 3 to improve the blanking quality of the semi-shearing.

[0076] like Figures 1 to 11 As shown, the present invention also provides a precision blanking die for realizing the above-mentioned precision blanking method for the ring-shaped part 7. The precision blanking die includes an upper die mechanism 1 and a lower support plate 21. The upper die mechanism 1 includes an upper support plate 11, an upper die base 12, and other conventional structures. The upper support plate 11 is mounted on the upper die base 12 and moves up and down with the upper die base 12. The upper die mechanism 1 moves up and down to perform die closing and die opening operations. The lower die mechanism 2 includes a lower support plate 21, a lower die base 22, and other conventional structures. The lower support plate 21 is mounted on the upper die base 12.

[0077] In this invention, the upper die mechanism 1 further includes an inner hole punch group and an outer ring punch group. The inner hole punch group includes n inner hole pre-punches 13 and one inner hole forming punch 14, where 3 ≥ n ≥ 1, and the n inner hole pre-punches 13 are respectively designated as inner hole pre-punches 13 to n. The outer ring punch group includes m outer ring pre-punches 15 and one outer ring blanking punch 16, where 3 ≥ m ≥ 1, and the m outer ring pre-punches are respectively designated as outer ring pre-punches 15 to m. The lower die mechanism 2 further includes a blank mounting assembly 23, an inner hole blanking hole 24, a semi-shear blanking pad 25, and a final blanking hole 26, all disposed on the lower support plate 21. The mounting component 23 is used to mount the blank plate 3, and there is a gap between the blank plate 3 and the lower support plate 21 when the blank plate 3 is mounted. The blank plate mounting component 23 can move down when it is pressed and can elastically return to its original position and move up when it is not pressed. There are n+1 inner hole blanking holes 24, which are respectively matched with n inner hole pre-punches 13 and inner hole forming punches 14. The inner hole blanking holes 24 are located directly below the corresponding punches and can accommodate the punches to extend into them. There are m half-shear blanking pads 25, which are respectively matched with m outer ring pre-punches 15, that is, they are located directly below the corresponding outer ring pre-punches 15. The half-shear blanking pads 25 can move down when they are pressed and can elastically return to their original position and move up when they are not pressed.

[0078] When the precision blanking die is closed, the upper die mechanism 1 moves downward, and the upper support plate 11 presses against the blank plate 3 mounted on the blank plate mounting assembly 23. The blank plate mounting assembly 23 is pressed and retracts downward, pressing the blank plate 3 against the lower support plate 21. At this time, the blank plate 3 is held by the upper support plate 11 and the lower support plate 21. The first to nth internal hole pre-punches 13 can respectively complete the first to nth pre-punching of the internal hole in step S11 of the above precision blanking method, and can extend into the corresponding internal hole blanking hole 24. The internal hole forming punch 14 can complete the forming punching of the internal hole in step S12, and can extend into the corresponding internal hole blanking hole 24. Outer ring pre-punch heads 15 to m can respectively complete the first to nth half-shearing punches in step S21. In the design, the height difference between the punching working surface at the lower end of outer ring pre-punch head i and the lower end surface of the upper support plate 11 is equal to B1 to B. i The sum of m≥i≥1, thus enabling the predetermined half-shearing thickness to be achieved. The outer ring blanking punch 16 can complete the final blanking in step S22. In the design, the height difference between the blanking working surface at the lower end of the outer ring blanking punch 16 and the lower end surface of the upper support plate 11 is greater than the wall thickness t of the blank plate, so that the part blank 6 can be smoothly punched off the blank plate 3.

[0079] In step S11, the inner hole pre-punching head 13 to the nth inner hole pre-punching head 13 are used sequentially to perform the first to the nth pre-punching of the inner hole. Each pre-punching of the inner hole is as follows: the blank plate 3 of the ring-shaped part 7 is positioned and installed on the blank plate mounting assembly 23, and the center point of the part is located directly below the center of the inner hole pre-punching head 13. Then, the precision blanking die is closed, and the inner hole pre-punching head 13 is used to punch out the initial inner hole 4 on the blank plate 3. The blanking waste falls into the corresponding inner hole blanking blanking hole 24 below the inner hole pre-punching head 13. Preferably, the shape of the inner hole blanking blanking hole 24 is the same as the shape of the inner hole pre-punching head 13. When the inner hole pre-punching head 13 extends into the inner hole blanking blanking hole 24, the two are fitted with a clearance fit, thereby better ensuring the blanking quality.

[0080] In step S12, the blank plate 3 is positioned and installed on the blank plate mounting assembly 23. Initially, the center of the inner hole 4 (i.e., the center point of the part) is located directly below the center of the inner hole forming punch 14, that is, the two are coaxial. Then, the precision blanking die is closed, and the inner hole forming punch 14 is used to punch out the formed inner hole 5 on the blank plate 3. Preferably, the shape of the inner hole forming punch 14 is the same as the shape of its corresponding inner hole blanking hole 24. When the inner hole forming punch 14 extends into the inner hole blanking hole 24, the two are fitted with a clearance fit, thereby better ensuring the blanking quality.

[0081] In step S21, the first to nth half-shearing punches are performed sequentially using the outer ring pre-punch head 15 to the m outer ring pre-punch head 15. Each half-shearing punch is performed as follows: the blank plate 3 is positioned and installed on the blank plate mounting assembly 23, and the center of the forming inner hole 5 (i.e. the center point of the part) is located directly below the center of the outer ring pre-punch head 15, that is, the two are coaxial. Then the precision punching die is closed, and the outer ring pre-punch head 15 is used to perform a half-shearing punch on the blank plate 3, that is, the part blank 6 between the outer ring and the forming inner hole 5 is punched down a certain distance. At this time, the half-shearing punching pad 25 below the outer ring pre-punch head 15 is pressed down by the same distance. The half-shearing punching pad 25 always stays in contact with the lower side of the part blank 6 for support.

[0082] In step S22, the blank plate 3 is positioned and installed on the blank plate mounting assembly 23, and the center of the forming inner hole 5 (i.e. the center point of the part) is located directly below the center of the outer ring blanking punch 16, that is, the two are coaxial; then the precision blanking die is closed, and the outer ring blanking punch 16 is used to punch the part blank 6 from the blank plate 3 to obtain the formed ring-shaped part 7.

[0083] As a preferred design, such as Figure 7 and Figure 8 As shown, in this embodiment, there are multiple center points of the parts on the blank plate 3, located on a part positioning line along the left and right direction. That is, multiple ring-shaped parts 7 can be punched out from the blank plate 3. The distance between the center points of adjacent parts is L. In the precision punching die, the centers of the inner hole pre-punch 13, the inner hole forming punch 14, the outer ring pre-punch 15, and the outer ring blanking punch 16 are all located on a punch positioning line along the left and right direction. The inner hole pre-punch 13 to the nth inner hole pre-punch 13, the inner hole forming punch 14, the outer ring pre-punch 15 to the nth outer ring pre-punch 15, and the outer ring blanking punch 16 are arranged sequentially from left to right, and the distance between the center points of adjacent punches is an integer multiple of L. The precision punching method includes the following operations: Figure 2 and Figure 8As shown, the blank plate 3 is installed on the blank plate mounting assembly 23 of the precision blanking die. The part positioning line is located directly below the punch positioning line (that is, the projection of the part positioning line on the blank plate 3 coincides with the part positioning line), and the rightmost part center point on the part positioning line is located directly below the No. 1 inner hole pre-punch 13. After each mold closing and mold opening of the precision blanking die, the blank plate 3 moves a straight distance L to the left on the blank plate mounting assembly 23. These three operations are grouped together, and the above mold closing, mold opening and blank plate 3 moving operations are repeated until the leftmost part center point on the part positioning line completes one mold closing under the outer ring blanking punch 16. At this time, the inner hole punching process S1 and the outer ring blanking process S2 are completed sequentially at all the part center points on the blank plate 3. Therefore, by using the precision blanking die in this embodiment, different blanking operations of different ring-shaped parts 7 can be completed simultaneously in one die closing process, enabling the simultaneous blanking of multiple ring-shaped parts 7, thereby greatly improving the blanking efficiency and making the operation convenient.

[0084] As a preferred design, such as Figure 7 and Figure 8 As shown, in this embodiment, the blank mounting assembly 23 of the precision blanking die includes multiple mounting posts 231, and a support spring 232 is provided below each mounting post 231. The mounting posts 231 are arranged in two parallel rows, and each row includes multiple mounting posts 231 arranged in a straight line along the left and right direction. The sides of the mounting posts 231 are provided with snap-fit ​​grooves 233. When the blank plate 3 is installed on the blank mounting assembly 23, its front and rear sides are embedded in the snap-fit ​​grooves 233 of the two rows of mounting posts 231. With the above design, after the blank plate 3 is installed, it can move in a straight line along the left and right direction in the snap-fit ​​grooves 233 without reinstallation. When the mold is closed, the mounting posts 231 are compressed, the support spring 232 is compressed, and the mounting posts 231 can move down smoothly. When not compressed, they can smoothly return to their original position under the action of the support spring 232.

[0085] As a preferred design, such as Figure 7 and Figure 8 As shown, in this embodiment, the precision blanking die is provided with the same positioning pins 17 around the inner hole pre-punch 13, the inner hole forming punch 14, the outer ring pre-punch 15, and the outer ring blanking punch 16. The number of positioning pins 17 can be selected according to actual needs. The blank plate 3 is provided with the same positioning holes 31 around the center point of each part. When the die is closed, the positioning pins 17 around the inner hole pre-punch 13, the inner hole forming punch 14, the outer ring pre-punch 15, and the outer ring blanking punch 16 can extend into the positioning holes 31 around the center point of the part located directly below the punch on the blank plate 3, thereby realizing the positioning of the blank plate 3 during stamping and the positioning during left and right movement.

[0086] As can be seen from the above, the precision punching method and mold of the present invention have the following beneficial effects:

[0087] 1. By employing a multi-stage punching method to obtain the inner ring hole of the ring-shaped part 7 in steps, the punching force can be reduced, avoiding the concavity of the blank plate 3 during inner ring punching, thus obtaining a precise inner ring hole size and a flat blank, preparing for subsequent outer ring blanking. The outer ring of the part is blanked off in steps using a semi-shear punching method, which reduces the punching force of a single outer ring punching, effectively reducing or eliminating part deformation caused by single blanking. This invention can effectively solve the problems of deformation, inaccurate dimensions, burrs, and other defects in the stamping process of thick, narrow-edged ring-shaped parts 7, resulting in parts with high precision and superior stability.

[0088] 2. The use of precision blanking dies enables convenient and quick precision blanking, allowing for the simultaneous blanking of multiple ring-shaped parts, greatly improving blanking efficiency and facilitating operation.

[0089] In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of precision blanking of a thick material narrow edge ring type part, for blanking a ring type part (7) from a blank plate (3), the ring type part (7) having a design size comprising an inner ring hole radius R, a radial width a and a thickness t, characterized in that: The precision blanking method comprises the following steps: S1, a punch inner hole process, comprising the following steps: S11, pre-punching inner hole: selecting a part center point on the blank plate (3) as the center point of the ring part (7) to be punched, taking the part center point as the center, sequentially performing n times of pre-punching inner hole, 3≥n≥1, after each pre-punching inner hole, an initial inner hole (4) is obtained on the blank plate (3), and the radius of the initial inner hole (4) obtained by n times of pre-punching inner hole is sequentially recorded as R1 to Rn n When n≥2, the i+1th punching width A i+1 =R i+1 -R i , A i+1 is 0.1R-0.3R, n-1≥i≥1, and when the inner ring hole of the ring part (7) has an inner boss, according to the thickness of the inner boss in the radial direction and the radius of the initial inner hole (4) obtained by each pre-punching inner hole, it is determined whether the initial inner hole (4) has a boss structure; after the n times of pre-punching inner hole is completed, the radius R n of the obtained initial inner hole (4) is 0.2R-0.3R larger than the inner ring hole radius R n . S12, a forming punch inner hole: on the basis of the initial inner hole (4) after the n times of pre-punching inner hole, a forming punch is further performed to obtain a forming inner hole (5), and the shape and size of the forming inner hole (5) are the design shape and size of the inner ring hole of the ring part (7); S2, a punch outer ring blanking process: an outer ring is punched outside the forming inner hole (5) obtained in the punch inner hole process S1, the shape and size of the outer ring are the design shape and size of the outer ring of the ring part (7), and the part blank (6) is located between the outer ring and the forming inner hole (5); comprising the following steps: S21, outer ring pre-punching: m times of half-shear punching is sequentially performed, 3≥m≥1, and the punching thickness B of the i-th half-shear punching is i 0.25t~0.85t, and the total thickness B of the m times of half-shear punching is 总 0.15t~0.25t; S22, a final blanking punch: the part blank (6) is punched from the blank plate (3) to obtain a formed ring part (7).

2. The fine blanking method according to claim 1, characterized in that: In the step S11, n = 1, and in the step S21, m = 1.

3. The fine blanking method according to claim 2, characterized in that: In the steps S21 and S22, an elastic support is arranged at the lower side of the part blank (6).

4. The fine blanking method according to claim 3, characterized in that: A precision blanking die is adopted, the precision blanking die comprises an upper die mechanism (1) and a lower die mechanism (2), the upper die mechanism (1) comprises an upper supporting plate (11), the lower die mechanism (2) comprises a lower supporting plate (21), the upper die mechanism (1) further comprises an inner hole punch group and an outer ring punch group, the inner hole punch group comprises n inner hole pre-punches (13) and an inner hole forming punch (14), and the n inner hole pre-punches (13) are respectively marked as No. 1 inner hole pre-punch (13) to No. n inner hole pre-punch (13), the outer ring punch group comprises m outer ring pre-punches (15) and an outer ring blanking punch (16), and the m outer ring pre-punches (15) are respectively marked as No. 1 outer ring pre-punch (15) to No. m outer ring pre-punch (15); the lower die mechanism (2) further comprises a blank plate mounting assembly (23), an inner hole blanking and punching hole (24), a half-shear punching pad (25) and a final blanking hole (26) which are all arranged on the lower supporting plate (21), the blank plate mounting assembly (23) is used for mounting the blank plate (3), and when the blank plate (3) is mounted, there is a spacing between the blank plate (3) and the lower supporting plate (21), the blank plate mounting assembly (23) can be moved downward when pressed and can be elastically reset to move upward when not pressed, the inner hole blanking and punching hole (24) is n+1, and is matched with the n inner hole pre-punches (13) and the inner hole forming punch (14) one by one, the half-shear punching pad (25) is m, and is matched with the m outer ring pre-punches (15), the half-shear punching pad (25) can be moved downward when pressed and can be elastically reset to move upward when not pressed; when the precision blanking die is closed, the upper supporting plate (11) is tightly attached to the blank plate (3) mounted on the blank plate mounting assembly (23), and the blank plate (3) is tightly attached to the lower supporting plate (21); In the step S11, the first to the n-th pre-punching holes are sequentially punched by using the first to the n-th inner hole pre-punching heads (13). Each pre-punching hole is as follows: after the blank plate (3) of the ring part (7) is positioned and installed on the blank plate installation assembly (23) and the part center point is located directly below the center of the inner hole pre-punching head (13), the fine blanking die is closed, and the inner hole pre-punching head (13) punches a preliminary inner hole (4) on the blank plate (3); In the step S12, the blank plate (3) is positioned and installed on the blank plate installation assembly (23), and the center of the preliminary inner hole (4) is located directly below the center of the inner hole forming punch (14), then the fine blanking die is closed, and the inner hole forming punch (14) punches a formed inner hole (5) on the blank plate (3); In the step S21, the first to the m-th half-shear punching is sequentially performed by using the first to the m-th outer ring pre-punching head (15). Each half-shear punching is as follows: after the blank plate (3) is positioned and installed on the blank plate installation assembly (23) and the center of the formed inner hole (5) is located directly below the center of the outer ring pre-punching head (15), the fine blanking die is closed, and the outer ring pre-punching head (15) performs a half-shear punching on the blank plate (3); In the step S22, the blank plate (3) is positioned and installed on the blank plate installation assembly (23), and the center of the formed inner hole (5) is located directly below the center of the outer ring blanking punch (16), then the fine blanking die is closed, and the outer ring blanking punch (16) punches the part blank (6) from the blank plate (3) to obtain a formed ring part (7).

5. The fine blanking method according to claim 4, characterized in that: The part center points on the blank plate (3) are multiple and located on a part positioning straight line in the left-right direction, the distance between adjacent part center points is L, and the centers of the inner hole pre-punching head (13), the inner hole forming punch (14), the outer ring pre-punching head (15), and the outer ring blanking punch (16) in the fine blanking die are located on a punch positioning straight line extending in the left-right direction, the first to the n-th inner hole pre-punching heads (13), the inner hole forming punch (14), the first to the m-th outer ring pre-punching heads (15), and the outer ring blanking punch (16) are sequentially arranged from left to right, and the distance between adjacent punch center points is an integer multiple of L; The fine blanking method comprises the following steps: the blank plate (3) is installed on the blank plate installation assembly (23) of the fine blanking die, the part positioning straight line is located directly below the punch positioning straight line, and the rightmost part center point on the part positioning straight line is located directly below the first inner hole pre-punching head (13); after the fine blanking die is closed and opened each time, the blank plate (3) moves linearly to the left on the blank plate installation assembly (23) by a distance L, and the above closing, opening, and blank plate (3) moving operations are repeated until the rightmost part center point on the part positioning straight line is located directly below the outer ring blanking punch (16) and completes a closing and opening operation, and the inner hole punching process S1 and the outer ring blanking process S2 are sequentially completed at all part center points on the blank plate (3).

6. The fine blanking method according to claim 5, characterized in that: The blank plate mounting assembly (23) of the precision blanking die comprises a plurality of mounting columns (231), and a supporting spring (232) is arranged below the mounting column (231), the mounting columns (231) are arranged in two rows parallel to each other, and each row comprises a plurality of mounting columns (231) arranged linearly in the left-right direction, the side surface of the mounting column (231) is provided with a clamping groove (233), and when the blank plate (3) is mounted on the blank plate mounting assembly (23), the front and rear two side edges of the blank plate (3) are embedded in the clamping grooves (233) of the two rows of mounting columns (231).

7. The fine blanking method according to claim 5, characterized in that: The precision blanking die is provided with the same positioning column (17) around the periphery of the inner hole pre-punch (13), the inner hole forming punch (14), the outer ring pre-punch (15) and the outer ring blanking punch (16), and the blank plate (3) is provided with the same positioning hole (31) around the periphery of the center point of each part, and the positioning column (17) extends into the positioning hole (31) when the die is closed.

8. A precision blanking die for thick material narrow edge ring type parts, capable of performing the precision blanking method as claimed in claim 1, comprising an upper die mechanism (1) comprising an upper material supporting plate (11) and a lower die mechanism (2) comprising a lower material supporting plate (21), characterized in that: The upper die mechanism (1) further comprises an inner hole punch group and an outer ring punch group, the inner hole punch group comprises n inner hole pre-punches (13) and an inner hole forming punch (14), and the n inner hole pre-punches (13) are respectively marked as No. 1 inner hole pre-punch (13) to No. n inner hole pre-punch (13), the outer ring punch group comprises m outer ring pre-punches (15) and an outer ring blanking punch (16), and the m outer ring pre-punches (15) are respectively marked as No. 1 outer ring pre-punch (15) to No. m outer ring pre-punch (15); the lower die mechanism (2) further comprises a blank plate mounting assembly (23), an inner hole blanking and blanking hole (24), a half-shear blanking pad (25) and a final blanking hole (26) which are all arranged on the lower supporting plate (21), the blank plate mounting assembly (23) is used for mounting the blank plate (3), and there is a spacing between the blank plate (3) and the lower supporting plate (21) when the blank plate (3) is mounted, the blank plate mounting assembly (23) can be lowered under pressure and can be elastically reset to be raised when not under pressure, the inner hole blanking and blanking hole (24) is n+1, and is matched with the n inner hole pre-punches (13) and the inner hole forming punch (14) one by one, the half-shear blanking pad (25) is m, and is matched with the m outer ring pre-punches (15), the half-shear blanking pad (25) can be lowered under pressure and can be elastically reset to be raised when not under pressure; when the precision blanking die is closed, the upper supporting plate (11) is pressed and tightly attached to the blank plate (3) mounted on the blank plate mounting assembly (23), and the blank plate (3) is pressed and tightly attached to the lower supporting plate (21), the No. 1 inner hole pre-punch (13) to the No. n inner hole pre-punch (13) can respectively complete the first to the n times of pre-punching inner holes in the step S11 in the precision blanking method, the inner hole forming punch (14) can complete the forming punch inner hole in the step S12, the No. 1 outer ring pre-punch (15) to the No. m outer ring pre-punch (15) can respectively complete the first to the n times of half-shear blanking in the step S21, and the outer ring blanking punch (16) can complete the final blanking and blanking in the step S22.

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