A forging method for a trident-shaped long rod-like structural component

Abstract

This invention belongs to the field of hot forging technology and relates to a forging method for a trident-shaped long rod-like structural component. The method involves forging a trident-shaped long rod-like structural component with guaranteed internal and external quality through a process of round bar blanking → billet preparation → rough forging → die forging. The rough forging process involves upsetting and shaping the billet obtained after blanking using a special die to roughly press out the required shape and size of the "big head" portion. Then, a special forging plate is used to separately forge and press down the transition between the trapezoidal portion and the trident portion in the big head of the rough forging, further refining the shape of the three "branches." Finally, the rod portion is lengthened, and the big head is finished.

Description

Technical Field

[0001] This invention belongs to the field of hot forging technology and relates to a forging method for a three-pronged long rod-like structural component. Background Technology

[0002] Trident-shaped long rod-like structural components are often used as outer cylinder forgings in the landing gear structures of various aircraft. The main function of the landing gear is to support the stability and safety of the aircraft during takeoff, landing, and taxiing, and it usually requires excellent performance. Therefore, the manufacturing and quality assurance of this type of forging are particularly important.

[0003] The main components of a trident-shaped long rod structure consist of a "large end" and a long rod. The "large end" is composed of a trapezoidal structure and three "branches" distributed along one side of the wide side of the trapezoid. These three "branches" make the forging resemble a "fork." Furthermore, because landing gear structures are relatively complex, the shapes of these three branches are usually different. The shape characteristics of trident-shaped long rod structures are: 1) The three "branches" at the large end of the forging are of varying lengths and relatively narrow widths, resulting in large gaps between adjacent branches. The long "branches" and numerous gaps typically significantly reduce the material utilization rate of this type of forging and also present certain problems with die forging material placement. 2) The lengths of the upper and lower sides of the "trapezoidal" shape differ significantly (usually more than 3.5 times), and there are many narrow rib structures distributed along the hypotenuses on both sides of the "trapezoidal" shape; 3) The cross-sectional area of ​​the shank and the large end differs greatly, and the lengths are relatively long; 4) There are one or more raised platform structures at the transition between the large end and the shank, and the cross-sectional height of the raised platform differs significantly from that of the shank. The superposition of large cross-sectional changes, narrow ribs, and large bosses has brought great difficulties to the forging production of this type of forging, and the "branch" structures with their varied shapes make it even more difficult.

[0004] For some projects with a relatively large overall projection area (0.2m) 2 For forgings of triangular long rods made of metal materials with relatively low forging temperatures and high resistance to metal deformation (such as TC32, TC4, etc.), it is almost impossible to manufacture such forgings without first developing a reasonable and feasible forging method, or it will consume a large amount of raw materials. However, large material losses are often accompanied by more forging cycles, which not only further increases the manufacturing cost, but also increases the quality risk for materials that are more sensitive to deformation. Summary of the Invention

[0005] Purpose of the invention: To provide a forging method for a triangular long rod-like structural component, enabling the hot-working portion of the triangular long rod-like forging to be manufactured with high production efficiency and material utilization.

[0006] Technical solution:

[0007] A forging method for a triangular long rod-like structural component, comprising a large end and a long rod, wherein the large end consists of a trapezoidal structure and three branches distributed on one side of the wide side of the trapezoid, and one or more raised platform structures exist at the transition between the large end and the rod.

[0008] The method includes:

[0009] Step 1: Determine the shape and dimensions of the rough die based on the dimensions of the forging; the shape of the rough die follows the shape of the forging and includes regular rods, trapezoidal structures, and regular triangular parts. The horizontal cross-sectional area of ​​the rods in the rough die corresponding to the high platform structure is large.

[0010] The horizontal surface area of ​​the long branch of the rough shape is more than 90% of the horizontal surface area of ​​the long branch of the corresponding forging, and the ratio of the cross-sectional area of ​​the long branch of the rough shape to the cross-sectional area of ​​the long branch of the corresponding forging is between 1.3 and 1.5.

[0011] The horizontal surface area of ​​the medium-length branch of the rough shape is more than 80% of the horizontal surface area of ​​the medium-length branch of the corresponding forging, and the ratio of the cross-sectional area of ​​the medium-length branch of the rough shape to the cross-sectional area of ​​the medium-length branch of the corresponding forging is between 1.2 and 1.4.

[0012] The horizontal surface area of ​​the short branch of the rough shape is more than 80% of the horizontal surface area of ​​the corresponding short branch of the forging, and the ratio of the cross-sectional area of ​​the short branch of the rough shape to the cross-sectional area of ​​the corresponding short branch of the forging is between 1.2 and 1.4.

[0013] The width of the three branches of the rough shape is less than or equal to the maximum width of the corresponding branches of the forging;

[0014] The gaps between adjacent branches of the rough-shaped three-pronged section are connected and transitioned using semicircles less than half their length.

[0015] The trapezoidal structure of the rough shape has two inclined sides that cover more than half of the width of the ribs on both sides of the trapezoidal part of the large end of the forging;

[0016] The gap between the rough trapezoidal part and the forged trapezoidal part in the width direction is between 3 and 15 mm;

[0017] The gap between the rough rod and the forged rod in the width direction is between 6 and 20 mm;

[0018] The cross-sectional ratio of the rough-cut rod to the forged rod is between 1.1 and 1.3;

[0019] The ratio of the cross-sectional area of ​​the platform structure in the rough rod to the cross-sectional area of ​​the platform structure in the forging is between 1.25 and 1.45.

[0020] Step 2: Determine the shape and size of the mold based on the rough shape and dimensions;

[0021] The mold includes an upper mold and a lower mold. The upper mold is used to form the rough-cut large-head three-pronged part. The upper mold cavity only forms the two outer branches of the rough-cut large-head three-pronged part. The lower mold cavity includes a trapezoidal part and a rectangular part.

[0022] The width of the cavity opening of the lower tire model is consistent with the maximum width of the trapezoidal section of the rough-cut tire.

[0023] Step 3: Determine the structure and dimensions of the special cutting plate according to the shape and size of the rough mold; the special cutting plate consists of two parts: pressing block 6 and hand handle 7, which are used to press out the semi-circular shape between two adjacent branches in the three-pronged part of the rough mold.

[0024] Step 4: Forge a square billet from a round bar of appropriate size. The cross-sectional dimensions of the square billet are 0.9-1.2 times the maximum cross-sectional dimensions of the rough shape's large end. After forging, divide the material to fully reserve the material required for the rough shape's large end portion.

[0025] The corresponding rough rod part of the blank is drawn out completely, and after drawing out, a rough blank one is obtained.

[0026] The width and height of the first rod section of the blank are 5-10 mm smaller than the corresponding width and thickness of the rectangular part of the lower mold cavity; the length of the first rod section of the blank is 30-80 mm higher than the rectangular part of the lower mold.

[0027] Step 5: Place the blank 1 into the lower mold cavity, use the upper hammer to upset the large end of the blank 1, then remove the blank 1 from the lower mold and shape the large end of the blank 1; during shaping, smooth the bulges on both sides of the large end and flatten the thickness of the large end to obtain blank 2.

[0028] Step 6: Place the second blank into the lower mold cavity, and use the upper hammer to upset the large end of the second blank. When upsetting, leave a small rectangular boss on the outside. The length of the small boss is greater than half the length of the long branch of the blank. After pressing out the small boss, take the second blank out of the lower mold and shape the second blank to obtain the third blank.

[0029] Step 7: Place the blank 3 into the lower mold cavity, then place the upper mold into the top of the three ends of the blank 3, and slowly press down the upper mold with the upper hammer until the openings of the upper and lower molds overlap. After closing the mold, remove the upper mold and take out the blank 3. Then shape it to obtain the blank 4.

[0030] Step 8: Place blank 4 into the lower mold cavity, place the cutting plate on the corresponding position of the large end of the blank, and slowly press down to press out a semi-circular shape between the two branches to obtain blank 5; press out another semi-circular shape to obtain blank 6;

[0031] Step 9: Lengthen the rod part of the blank 6 and trim the big end to obtain the rough shape.

[0032] Step 10: Die forging the rough mold to obtain the forging.

[0033] Preferably, the width of the three branches of the rough shape is less than or equal to the maximum width of the corresponding branches of the forging, specifically:

[0034] BL1 = (0.95~1.0)×BL, BM = (0.85~0.95)×BM1, BS = (0.80~0.90)×BS1, where BL, BM, and BS are the maximum widths of the long "branch", medium-long "branch", and short "branch" of the forging, respectively, and BL1, BM1, and BS1 are the widths of the long "branch", medium-long "branch", and short "branch" of the roughing, respectively.

[0035] Preferably, the radius of the semicircle in the gap region between two adjacent branches of the roughing is greater than or equal to half the distance between two adjacent branches of the forging;

[0036] The depth of the semicircle should be as close as possible to the maximum depth of the gap between the two "branches" of the forging, while being less than the radius of the semicircle.

[0037] Preferably, the thickness of the three branches of the rough shape is the same.

[0038] Preferably, the thickness of the upper tire mold cavity is larger than the thickness of the rough-cut three-pronged section.

[0039] Preferably, the mold dimensions satisfy:

[0040] 0.25Bmax<L6=(0.45~0.65)×L4,L7=(0.55~0.75)×L5,H2=(0.75~0.95)×H4,where, Bmax: the maximum width of the large trapezoidal part of the rough mold and the width of the mold opening, L4: the length of the large trapezoidal part of the rough mold, L5: the total length of the rough mold rod, L6: the length of the trapezoidal part of the lower mold cavity, L7: the length of the rectangular part of the lower mold cavity, H2: the thickness of the root of the lower mold cavity, H4: the maximum thickness of the rough mold rod.

[0041] Preferably, the volume ratio of the lower tire model cavity to the corresponding part of the rough shape is 1.15 or higher.

[0042] Preferably, all vertical dimensions within the tire model cavity should have a certain slope: 1.5° to 5°.

[0043] Beneficial effects:

[0044] 1. This invention provides guidance for the forging process of three-pronged long rod-like structural parts, from bar stock or plates of a certain thickness.

[0045] 2. Using appropriate auxiliary tooling can produce rough shapes with relatively complex shapes and reduce the difficulty of their production.

[0046] This invention provides guidance for the forging and forming methods of forked long rods and the design of corresponding special molds and plates.

[0047] 3. This invention has certain reference value for the forging and forming production of triangular structural parts;

[0048] 4. This invention has certain reference value for the forging and forming production of multi-forked long rod forgings with more than three "branches". Attached Figure Description

[0049] Figure 1 Schematic diagram of the main forming methods for triangular long rod structural components;

[0050] Figure 2 Schematic diagram of the three-dimensional shape of a special die for forging a triangular long rod-type structural component;

[0051] Figure 3 Schematic diagram of the special forging plate for triangular long rod structural parts;

[0052] Figure 4 Schematic diagram of the rough shape of a trident-shaped long rod-like structural component;

[0053] Figure 5 Schematic diagram of the special die for forging of triangular long rod structural parts;

[0054] Figure 6 Schematic diagram of the rough forming process of a trident-shaped long rod structural component;

[0055] Figure 7 A diagram showing the placement of three blanks of a trident-shaped long rod-type structural component in the upper and lower molds;

[0056] Figure 8 Schematic diagram of the outer cylinder forging;

[0057] Figure 9 Schematic diagram of the rough shape of an outer cylinder forging;

[0058] Figure 10 A schematic diagram comparing the shape of a certain outer cylinder forging with the rough die;

[0059] Figure 11 A schematic diagram of the shape of a special die for forging a certain outer cylinder forging.

[0060] Explanation of reference numerals in the attached figures:

[0061] 1: Raw billet one; 2: Raw mold; 3: Forging; 4: Upper mold; 5: Lower mold; 6: Special pressing block for plate cutting; 7: Special hand handle for plate cutting; 8: Raw billet two; 9: Raw billet three; 10: Raw billet four; 11: Raw billet five; 12: Raw billet six

[0062] BL, BM, and BS represent the maximum widths of the long "branch", medium-long "branch", and short "branch" of the forging, respectively.

[0063] BL1, BM1, and BS1 represent the widths of the long, medium-length, and short branches of the wild type, respectively.

[0064] R1, R2: The radii of the semicircles connecting two adjacent "branches" in the wild shape.

[0065] B1, B2: The distance between two adjacent "branches" in the wasteland.

[0066] d1, d2: The depth of the semicircle connecting two adjacent "branches" in the rough shape; d3: The total depth of the pressing block in the special cutting plate.

[0067] L1, L2: The depth of the center position of the gap area between two adjacent branches of the forging.

[0068] H1: Thickness dimension of the upper tire mold root; H2: Thickness dimension of the lower tire mold cavity root.

[0069] H3: Thickness of the three branches of the rough-cut large-head three-pronged section; H4: Maximum thickness of the rough-cut rod section.

[0070] H5: Total thickness of the pressing blocks in the special cutting plate; H6: Thickness of the large end part of the rough shape.

[0071] Bmax: The maximum width of the large trapezoidal section of the rough mold and the width of the mold opening.

[0072] L3: The distance between the medium-length "branch" and the tip of the shortest branch in a wild-type big-head trident.

[0073] L4: Length of the large trapezoidal section of the rough shape; L5: Total length of the rough shape rod; L6: Length of the trapezoidal section of the lower tire model cavity.

[0074] L7: Length of the rectangular portion of the lower tire model cavity.

[0075] LJ1, LJ2, LJ3, LJ4: The four corners at the bottom of the rectangular section of the lower tire model cavity. Detailed Implementation

[0076] Using the method of this invention, trident-shaped long rod-like rough shapes can be produced, enabling the hot-working portion of trident-shaped long rod forgings to be manufactured with high production efficiency and material utilization. This invention is applicable to the forging production of trident-shaped long rod-like structural parts made of various materials, ensuring high stability in each forging process and ultimately ensuring that the internal and external quality of the forgings meets the required requirements. This invention is particularly beneficial for the forging production of trident-shaped long rod-like structural parts with high material deformation resistance, large projected area, and large cross-sectional changes.

[0077] The technical solution of this invention is a forming method that involves round bar blanking → billet preparation → forging → die forging (e.g.) Figure 1 Forging produces a trident-shaped long rod-like structural component with guaranteed internal and external quality (such as...). Figure 1 3), of which the barren type (such as Figure 1 (2) is achieved by using a special mold (such as...) Figure 2 (4 and 5) After blanking, the blank is upset and shaped to roughly press out the required shape and size of the "big head" part of the blank, and then a special cutting board (such as...) is used. Figure 3 The transition between the trapezoidal and triangular parts in the rough-shaped head is forged and pressed separately to further refine the shape of the three "branches". Finally, the rod is lengthened and the head is finished.

[0078] 1) The design concept for the undeveloped area is as follows:

[0079] The shape of the rough die is basically designed according to the shape of the corresponding forging, such as Figure 4 As shown, it is a fork-shaped structure with relatively regular cross-sectional shapes in each part.

[0080] 1.1) Design of the three-pronged section:

[0081] 1.1.1) Typically, the cross-sections of each "branch" in a three-pronged fork are relatively small compared to the main shaft, the platform, and the large end. Therefore, they dissipate heat quickly during forging, and the metal in these areas is less fluid, especially the longer "branch" because it is furthest from the large end of the rough mold. The material in the large end cannot "replenish" it, making it even more difficult to fill the forging completely. Therefore, the horizontal surface area of ​​the longer branch should be at least 90% of the horizontal surface area of ​​the corresponding branch in the forging, especially in the width direction. Furthermore, the cross-sectional ratio between the rough mold and the forging should be between 1.3 and 1.5 to ensure sufficient material surplus in that area and to ensure complete filling. For the other two "branches" closer to the large end, the horizontal surface area corresponding to the forging body should cover at least 80% of the forging body, depending on the specific situation, and the cross-sectional ratio between the two should be between 1.2 and 1.4.

[0082] BL1=(0.95~1.0)×BL, BM=(0.85~0.95)×BM1, BS=(0.80~0.90)×BS1

[0083] Note: BL, BM, and BS represent the maximum widths of the long "branch", medium-long "branch", and short "branch" of the forging, respectively.

[0084] BL1, BM1, and BS1 represent the widths of the long, medium-length, and short branches of the wild type, respectively.

[0085] 1.1.2) The gap between the two "branches" of the rough three-pronged part is connected and transitioned by a semicircle less than 1 / 2. This can better avoid obvious pinching defects between the two "branches" during the die forging process, and also ensure that the special pressure plate can be pressed down and removed smoothly during the forging process.

[0086] The radius of the semicircle must be greater than or equal to half the distance between two adjacent "branches" of the forging. The depth of the semicircle, while being less than its radius, should be as close as possible to the maximum depth of the gap between the two "branches" of the forging. Finally, to facilitate forging pressing, the thickness of the three "branches" is generally designed to be the same. That is:

[0087] R1≥B1 / 2, R2≥B2 / 2, R1>d1=(0.5~1.1)×L1, R2>d2=(0.5~1.1)×L2

[0088] Note: R1, R2: the radii of the semicircles connecting two adjacent "branches" in the rough shape;

[0089] B1, B2: The distance between two adjacent "branches" in the wasteland;

[0090] d1, d2: The depth of the semicircle connecting two adjacent "branches" in the wasteland;

[0091] L1, L2: The depth of the center position of the gap area between two adjacent branches of the forging.

[0092] 1.2) According to the principle of least resistance in metal flow, the flow of metal is most difficult in the vertical direction, followed by the width direction and then the length direction. For forgings with narrow ribs, if the width of the rough die covers too little of the rib width, not only will the top of the rib be difficult to fill, but a serious "rib-penetrating" phenomenon, i.e., clamping defect, will also form at its root. Therefore, this part should cover more than 1 / 2 of the rib width.

[0093] 1.2.1) The trapezoidal part in the rough shape is a trapezoidal shape similar to that of the forging big end. The two sides of the trapezoidal part should cover more than half of the width of the ribs on both sides of the trapezoidal part of the forging big end.

[0094] 1.2.2) Because the projected area of ​​the trapezoidal part in the large head is large, the overall "material feeding" is relatively difficult. Therefore, the gap between the rough trapezoidal part and the forging trapezoidal part in the width direction is set to be between 3 and 15 mm. The deformation of the rod part is relatively large. The gap between the rough rod part and the forging rod part in the width direction can be slightly larger, between 6 and 20 mm. However, the material of the rough rod part can be "supplemented" by each other. The cross-sectional ratio of the rough rod part and the forging rod part can be between 1.1 and 1.3.

[0095] 1.2.3) Although the raised platform of the forging rod can be formed by reverse extrusion using the billets on its front and rear sides, meaning it can receive some material "supply" in the front-to-back direction, the metal at this point is extremely difficult to flow upwards. Therefore, the height dimension of the corresponding raised platform structure in the rough rod still needs to be close to or greater than the overall height of the raised platform portion of the forging. The ratio of the cross-sectional area of ​​the corresponding raised platform structure in the rough rod to the cross-sectional area of ​​the raised platform structure in the forging is between 1.25 and 1.45.

[0096] 1.2.4) More than 90% of the horizontal area of ​​the rough shape can be placed into the mold cavity, which can ensure the subsequent die forging effect and also make it have a high material utilization rate.

[0097] 2) The design concept of the special mold is as follows:

[0098] The mold is designed based on the shape and size of the rough shape, and is divided into upper mold (such as...). Figure 2 and Figure 5 4) and the lower mold (such as Figure 2 and Figure 6 (5) The upper mold is mainly used for forming the three-pronged part of the rough shape, the material volume of the trapezoidal part (within the L6 area) in the lower mold is mainly used for the material of the trapezoidal part of the rough shape, and the rectangular part (within the L7 area) in the lower mold cavity is used for the material of the rod part of the rough shape.

[0099] 2.1.) All width and length dimensions within the upper mold cavity should be consistent with the relevant dimensions of the three-pronged section in the large end of the rough die; the thickness of the upper mold cavity should have a larger margin compared to the thickness of the three-pronged section of the large end of the rough die, so that the upper mold can accommodate the relatively thick rough die (e.g., the three-pronged section of the large end). Figure 6 Above 9 in the middle.

[0100] H1 = (1.2 ~ 1.35) × H3

[0101] Note: H1: Thickness dimension of the upper mold base; H3: Thickness dimension of the three branches of the rough-cut large-head three-pronged section.

[0102] 2.2) The width of the lower mold cavity opening should match the maximum width of the trapezoidal section of the rough die. The length of the trapezoidal section of the lower mold should be rationally determined by comparing the width of the opening and the corresponding length of the rough die. Because the rough die rod has a relatively small cross-section, it dissipates heat relatively quickly during forging; therefore, the length difference between the rectangular section in the lower mold cavity and the rough die rod should not be too large. The thickness of the root of the lower mold cavity should not be much smaller than the maximum thickness of the rough die rod; otherwise, it will be difficult to forge during subsequent forging and drawing. That is:

[0103] 0.25Bmax<L6=(0.45~0.65)×L4, L7=(0.55~0.75)×L5,

[0104] H2 = (0.75 ~ 0.95) × H4

[0105] Note: Bmax: Maximum width of the large trapezoidal part of the rough mold and width of the mold opening; L4: Length of the large trapezoidal part of the rough mold; L5: Total length of the rough mold rod; L6: Length of the trapezoidal part of the lower mold cavity; L7: Length of the rectangular part of the lower mold cavity; H2: Thickness of the root of the lower mold cavity; H4: Maximum thickness of the rough mold rod.

[0106] 2.3) The ratio of the volume of the lower tire model cavity to the volume of the corresponding part of the rough mold is above 1.15.

[0107] 2.4) All vertical dimensions within the mold cavity must have a certain slope (1.5°~5°) so that the rod part of the pressed blank can be removed from the lower mold and the upper mold can be removed from the large end of the blank. To more accurately control the material surplus of each part, the slope should be relatively smaller when the height dimension is larger.

[0108] 2.5) The four corners at the bottom of the rectangular part of the lower tire model cavity (such as...) Figure 5 LJ1, LJ2, LJ3, and LJ4 in the blank should not be chamfered; otherwise, the blank will get stuck in the lower mold cavity after pressing and cannot be removed. All other parts should be chamfered. The transition between the big end and the rod should be smoothed with a large fillet greater than R50. For other parts, a fillet of R10 to R30 can be used as appropriate.

[0109] 3) The design concept for the dedicated cutting board is as follows:

[0110] Specialized opening plates are made of pressure blocks (such as...) Figure 3 6) and handheld sticks (such as Figure 3 It consists of two parts (7) in the rough shape. If the two semicircles of the rough shape are not the same size, there are 2 pieces, and the sizes correspond one-to-one. Otherwise, only 1 piece needs to be made. The purpose of the special cutting plate is to press out the semicircular shape between two adjacent branches in the three-pronged part of the rough shape.

[0111] 3.1) The diameter, width, and depth of the semicircle in the compaction block are consistent with the relevant dimensions of the semicircle in the rough three-pronged part.

[0112] 3.2) During the process of pressing the semi-circular shape of the large end portion of the rough die using a slab, the material on both sides of the semi-circle will be squeezed simultaneously in both the height and thickness directions. Therefore, the total length and thickness of the slab must be appropriately greater than the height of the middle long "branch" in the three-pronged rough die and the thickness of the three-pronged rough die, respectively, to ensure that the upper hammer does not press on the top of any branch during pressing, and that the slab does not embed itself into the rough die body. That is:

[0113] d3=L3+d1 / d2+(20~50)mm, H5=H6+(80~150)mm

[0114] Note: d3: Total depth of the pressing block in the special cutting plate; L3: Distance between the middle and long "branch" in the rough-shaped big head three-pronged section and the top of the shortest branch; H5: Total thickness of the pressing block in the special cutting plate; H6: Thickness of the rough-shaped big head section.

[0115] 3.3) The hand handle in the special opening plate is made of steel rod with a diameter of Φ5mm~15mm and welded to the middle area of ​​the pressure block. The length of the hand handle is 1.2 to 2 times the total thickness of the pressure block.

[0116] 4) The fabrication of the rough shape of the three-pronged long rod structural component is carried out entirely on a free forging hammer of appropriate tonnage, and the forging process is as follows: Figure 6 As shown, the specific operation steps are as follows:

[0117] Step 1: Create a rough blank (e.g., Figure 1 and Figure 6 1).

[0118] First, forge a round bar of appropriate size into a square block. The cross-sectional dimensions of the square block are 0.9-1.2 times the maximum cross-sectional dimensions of the large end of the rough mold. After forging, divide the material, that is: leave enough material for the large end of the rough mold, and draw the rest of the material. After drawing, the width and height of the rough billet rod should be 5-10 mm less than the corresponding width and thickness of the rectangular part of the lower mold cavity, and the length of the rough billet rod should be 30-80 mm higher than the rectangular part of the lower mold.

[0119] Step Two: Create the second rough blank (e.g.) Figure 6 (8)

[0120] The blank is placed into the lower mold cavity, and then the larger end of the blank is upset using the upper hammer. Afterward, the blank is removed from the lower mold, and the larger end is shaped. During shaping, the bulges on both sides of the larger end are smoothed, and the thickness of the larger end is appropriately flattened.

[0121] Step 3: Create the rough blank (e.g., ...) Figure 6 (9 in the middle).

[0122] Place the blank into the lower mold cavity and use the upper hammer to upset the larger end. During upsetting, leave material for the long "branch" of the three-pronged section; that is, leave a small rectangular boss at the corresponding position at the top of the larger end of the blank. The length of this small boss must be greater than half the length of the long branch of the blank. After pressing out the small boss, remove the blank from the lower mold and shape it.

[0123] Step 4: Create the rough blank (e.g., ...) Figure 6 10 in the middle).

[0124] Place the blank three into the lower mold cavity, then place the upper mold near the top of the large end of the blank, and then adjust its position in all directions to make it as centered as possible. Figure 7 As shown. Use the hammer to slowly press down the upper mold until the openings of the upper and lower molds overlap. After closing the mold, remove the upper mold and take out the blank, then shape it.

[0125] Step 5: Produce blank five and blank six (e.g.) Figure 6 (11, 12).

[0126] Place blank four into the lower mold cavity, place one of the cutting plates on the corresponding position of the large end of the blank, start the equipment, slowly press down, and press out the required semi-circular shape to obtain blank five. Use another cutting plate to press out the semi-circular shape on the other side, thereby pressing out the shape and size of the three "branches" to obtain blank six.

[0127] Step Six: Create the final rough form.

[0128] The rod section of the blank 6 is lengthened, and its large end size is adjusted to meet the design requirements.

[0129] If a large bulge appears on the side of the large end of the blank during upsetting using a die, and this bulge extends beyond the die cavity, the pressing should be stopped immediately, the blank should be removed from the die cavity, the bulge should be adjusted with a hammer and anvil, and upsetting should continue. That is, the upsetting part using the die can be repeated.

[0130] Implementation Cases

[0131] An outer cylinder forging, material grade: TC32, forging weight: 142 kg, forging projected area: 0.31 m². The forging's shape is a typical three-pronged long rod forging, with main external dimensions as follows: Figure 8 As shown, the three-pronged section of the forging's large end consists of three differently shaped "branches." The width of each branch is relatively small, while their lengths differ significantly. The longer branch also has a small raised platform. The area of ​​the gap between two adjacent "branches" is approximately 0.011 mm.2 The two width dimensions of the trapezoidal section at the larger end of the forging differ by a factor of 4.2, and there are narrow ribs with a width of only 30mm around the inner and outer perimeter of the trapezoid. The rod section of the forging is relatively long, with a smaller cross-section compared to the larger end. There are two raised platforms on the rod section, with cross-sectional areas of 0.029m² each. 2 0.0245m 2 .

[0132] The roughing shape and dimensions designed based on the forging dimensions are as follows: Figure 9 As shown, the rough shape follows the shape of the forging, with each branch of the three-pronged fork transitioning with a half-circle of the same size; the matching between the rough shape and the forging is as follows. Figure 10 As shown, the rough mold covers approximately 95% of the horizontal plane of the long "branch" in the three-pronged fork of the forging's large end, and approximately 90% of the other two branches. Approximately 95% of the rough mold's overall area can fit into the mold cavity. The "trapezoidal" portion of the rough mold's large end covers more than half the width of the narrow ribs on both sides of the forging. The gap between the rough mold and the forging in the width direction is 13mm for the large end and 18mm for the shank.

[0133] The mold dimensions designed based on the rough shape are as follows: Figure 11 As shown.

[0134] A dedicated cutting plate was designed. The semi-circular dimensions of the pressure block in the dedicated cutting plate are the same as those in the roughing. The total length of the pressure block is 150mm, and the total thickness of the pressure block is 180mm. The handle of the pressure plate is made of Φ10mm steel rod, and the handle is 250mm long.

[0135] The forging process of a certain outer cylinder forging is as follows:

[0136] Step 1: Cut the material using a saw. The material size is Φ300×570mm.

[0137] Step 2: Use a 2500t high-speed forging machine to produce billet 1.

[0138] After heating the bar stock as required, forge it into a square billet with a cross-sectional dimension of 350×190. Then, divide the stock into sections and draw out the longer rods. The cross-sectional dimension of the drawn rods is 200×190.

[0139] Step 3: Use a 2500t high-speed forging machine to forge the rough shape and create the rough shape.

[0140] 1) First forging stage: After heating the billet as required, place it in the lower mold and upset the larger end of the billet. Then remove the billet from the lower mold, smooth out the bulges on both sides of the larger end, and flatten the thickness of the larger end to 135mm to obtain billet two. Place billet two into the lower mold cavity and upset the larger end, leaving a rectangular boss of about 60mm in length at the corresponding position at the top of the larger end of the billet. Then remove the billet from the lower mold for shaping. After shaping, put the billet back into the lower mold cavity and press the length of the rectangular boss to 100mm. Then remove the billet from the lower mold for shaping. This process yields billet three.

[0141] 2) Second Forging Stage: After heating the billet three as required, place it in the lower mold, then place the upper mold at the top of the larger end of the billet and adjust its position. Use the upper hammer to press down the upper mold at a speed of ~10mm / s until the gap between the upper and lower mold openings is approximately 30mm. Remove the upper mold and take out the billet for shaping. After shaping, continue to place the billet into the upper and lower molds and press down at a speed of ~15mm / s until the openings of the upper and lower molds overlap. After closing the molds, take out the billet and shape it. After shaping, the thickness of the three-pronged portion at the larger end of the billet is 115mm. This yields the fourth billet.

[0142] 3) Third forging step: After heating the blank four as required, place it in the lower mold. Place the special cutting plate on one side of the larger end of the blank and press out the required semi-circular shape. Then remove this cutting plate and place it on the other side to press out the shape of the other side. Finally, remove the cutting plate. Remove the blank from the lower mold and shape it. At this point, blank six is ​​obtained.

[0143] 4) Fourth forging stage: After heating the blank as required, elongate its rod section and trim its large end to meet design requirements. This completes the production of the blank.

[0144] Step 4: Forge the hammer with 630KJ.

[0145] After heating the rough mold as required, transfer it to the appropriate equipment and adjust its position within the mold cavity. During hammering, first strike lightly 2-3 times to position it, then strike heavily a few more times to shape it. The die forging process is completed in 3 heats.

[0146] Step 5: Use flame cutting to remove most of the burrs on the outer contour of the forging.

[0147] Step 6: Heat treatment, heat treatment regime: double annealing.

[0148] Step 7: Physical and chemical tests.

[0149] Ultimately, the outer cylinder component was forged through three processes: blank preparation, rough forging, and die forging. The design of the dedicated die-cutting machine with its specific shape and dimensions was reasonable and feasible, saving time and simplifying operation. The resulting rough mold exhibited good consistency, with over 88% conforming to the theoretical design. The shape and dimensions of the rough mold were well-designed, meeting the requirements for forging. During die forging, the rough mold remained stable within the die cavity, exhibiting no significant displacement during hammering. After hammering, there was no "rib slippage" at the root of the narrow rib at the large end of the forging. Finally, die forging was completed with fewer passes, and the forging achieved good filling, fully filling the three branches of the three-pronged section at the large end and the two raised platforms of the rod. The material utilization rate of the outer cylinder forging was calculated to be 79%.

[0150] After conducting physicochemical tests, the results showed that the low-magnification microstructure of the forging consisted entirely of the required indistinct grains, with no clearly visible grains. The high-magnification microstructure was equiaxed, with an α content of 30%, meeting the specified requirements. Furthermore, the performance data of the forging fully met the requirements of the standard.

Claims

1. A forging method for a three-pronged long rod-like structural component, characterized in that, The triangular long rod-like structural member includes a large end and a long rod. The large end consists of a trapezoidal structure and three branches distributed on one side of the trapezoidal wide side. There is one or more elevated structures at the transition between the large end and the rod. The method includes: Step 1: Determine the shape and dimensions of the rough die based on the dimensions of the forging; the shape of the rough die follows the shape of the forging and includes regular rods, trapezoidal structures, and regular triangular parts. The horizontal cross-sectional area of ​​the rods in the rough die corresponding to the high platform structure is large. The horizontal surface area of ​​the long branch of the rough shape is more than 90% of the horizontal surface area of ​​the long branch of the corresponding forging, and the ratio of the cross-sectional area of ​​the long branch of the rough shape to the cross-sectional area of ​​the long branch of the corresponding forging is between 1.3 and 1.

5. The horizontal surface area of ​​the medium-length branch of the rough shape is more than 80% of the horizontal surface area of ​​the medium-length branch of the corresponding forging, and the ratio of the cross-sectional area of ​​the medium-length branch of the rough shape to the cross-sectional area of ​​the medium-length branch of the corresponding forging is between 1.2 and 1.

4. The horizontal surface area of ​​the short branch of the rough shape is more than 80% of the horizontal surface area of ​​the corresponding short branch of the forging, and the ratio of the cross-sectional area of ​​the short branch of the rough shape to the cross-sectional area of ​​the corresponding short branch of the forging is between 1.2 and 1.

4. The width of the three branches of the rough shape is less than or equal to the maximum width of the corresponding branches of the forging; The gaps between adjacent branches of the rough-shaped three-pronged section are connected and transitioned using semicircles less than half their length. The trapezoidal structure of the rough shape has two inclined sides that cover more than half of the width of the ribs on both sides of the trapezoidal part of the large end of the forging; The gap between the rough trapezoidal part and the forged trapezoidal part in the width direction is between 3 and 15 mm; The gap between the rough rod and the forged rod in the width direction is between 6 and 20 mm; The cross-sectional ratio of the rough-cut rod to the forged rod is between 1.1 and 1.3; The ratio of the cross-sectional area of ​​the platform structure in the rough rod to the cross-sectional area of ​​the platform structure in the forging is between 1.25 and 1.

45. Step 2: Determine the shape and size of the mold based on the rough shape and dimensions; The mold includes an upper mold and a lower mold. The upper mold is used to form the rough-cut large-head three-pronged part. The upper mold cavity only forms the two outer branches of the rough-cut large-head three-pronged part. The lower mold cavity includes a trapezoidal part and a rectangular part. The width of the cavity opening of the lower tire model is consistent with the maximum width of the trapezoidal section of the rough-cut tire. Step 3: Determine the structure and dimensions of the special cutting plate according to the shape and size of the rough shape; the special cutting plate consists of two parts: a pressing block (6) and a hand-held rod (7), which is used to press out the semi-circular shape between two adjacent branches in the three-pronged part of the rough shape; Step 4: Forge a square billet from a round bar of appropriate size. The cross-sectional dimensions of the square billet are 0.9-1.2 times the maximum cross-sectional dimensions of the rough shape's large end. After forging, divide the material to fully reserve the material required for the rough shape's large end portion. The corresponding rough rod part of the blank is drawn out completely, and after drawing out, a rough blank one is obtained. The width and height of the first rod section of the blank are 5-10 mm smaller than the corresponding width and thickness of the rectangular part of the lower mold cavity; the length of the first rod section of the blank is 30-80 mm higher than the rectangular part of the lower mold. Step 5: Place the blank 1 into the lower mold cavity, use the upper hammer to upset the large end of the blank 1, then remove the blank 1 from the lower mold and shape the large end of the blank 1; during shaping, smooth the bulges on both sides of the large end and flatten the thickness of the large end to obtain blank 2. Step 6: Place the second blank into the lower mold cavity, and use the upper hammer to upset the large end of the second blank. When upsetting, leave a small rectangular boss on the outside. The length of the small boss is greater than half the length of the long branch of the blank. After pressing out the small boss, take the second blank out of the lower mold and shape the second blank to obtain the third blank. Step 7: Place the blank 3 into the lower mold cavity, then place the upper mold into the top of the three ends of the blank 3, and slowly press down the upper mold with the upper hammer until the openings of the upper and lower molds overlap. After closing the mold, remove the upper mold and take out the blank 3. Then shape it to obtain the blank 4. Step 8: Place blank 4 into the lower mold cavity, place the cutting plate on the corresponding position of the large end of the blank, and slowly press down to press out a semi-circular shape between the two branches to obtain blank 5; press out another semi-circular shape to obtain blank 6; Step 9: Lengthen the rod part of the blank 6 and trim the big end to obtain the blank shape; Step 10: Die forging the rough mold to obtain the forging.

2. The method according to claim 1, characterized in that, The width of the three branches of the rough shape is less than or equal to the maximum width of the corresponding branches of the forging, specifically: BL1 = (0.95~1.0)×BL, BM = (0.85~0.95)×BM1, BS = (0.80~0.90)×BS1, where BL, BM, and BS are the maximum widths of the long "branch", medium long "branch", and short "branch" of the forging, respectively, and BL1, BM1, and BS1 are the widths of the long "branch", medium long "branch", and short "branch" of the roughing, respectively.

3. The method according to claim 2, characterized in that, The radius of the semicircle in the gap region between two adjacent branches of the rough shape is greater than or equal to half the distance between two adjacent branches of the forging; The depth of the semicircle should be as close as possible to the maximum depth of the gap between the two "branches" of the forging, while being less than the radius of the semicircle.

4. The method according to claim 1, characterized in that, The thickness of the three branches of the rough shape is the same.

5. The method according to claim 1, characterized in that, The thickness of the upper tire mold cavity is larger than the thickness of the rough-cut three-pronged section.

6. The method according to claim 1, characterized in that, The mold dimensions meet the following requirements: 0.25Bmax<L6=(0.45~0.65)×L4,L7=(0.55~0.75)×L5,H2=(0.75~0.95)×H4,where, Bmax: the maximum width of the large trapezoidal part of the rough mold and the width of the mold opening, L4: the length of the large trapezoidal part of the rough mold, L5: the total length of the rough mold rod, L6: the length of the trapezoidal part of the lower mold cavity, L7: the length of the rectangular part of the lower mold cavity, H2: the thickness of the root of the lower mold cavity, H4: the maximum thickness of the rough mold rod.

7. The method according to claim 1, characterized in that, The volume ratio of the lower tire model cavity to the corresponding part of the rough mold is greater than 1.

15.

8. The method according to claim 1, characterized in that, All vertical dimensions within the tire model cavity must have a certain slope: 1.5° to 5°.

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