Forging forming method for three-fork-shaped long rod type structural part

Abstract

The invention belongs to the field of hot forging technology forming, and relates to a forging forming method for a three-fork-shaped long rod type structural part. The three-fork-shaped long rod type structural part with the guaranteed internal quality and the guaranteed external quality is forged and produced in the forming mode of round rod blanking, blank making, rough forging and die forging, a rough blank obtained after blank making is subjected to upsetting and shaping through a special forming die, and the shape and the size required by the large head part of the rough blank are roughly pressed out; and then a special open plate is used for carrying out separate forging and pressing on the transition position of the trapezoidal part and the trifurcate part in the blank type large head, the shape of three branches is further trimmed, finally, the rod part is drawn out, and the large head is trimmed.

Description

Technical Field

[0001] The invention belongs to the field of hot forging technology forming, and relates to a forging forming method of a trident-shaped long rod-type structural part. Background Art

[0002] Trident-shaped long rod structural parts are often used as outer tube 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 ground taxiing, and usually requires excellent performance. Therefore, the manufacturing and quality assurance of this type of forgings are particularly important.

[0003] The three-pronged long rod structural parts are mainly composed of a "big head" and a long rod. The "big head" is composed of a "trapezoidal" structure and three "branches" distributed on one side of the wide side of the "trapezoidal" shape. These three "branches" make the forging look like a "fork" as a whole. In addition, because the structural parts of the landing gear are relatively complex, the shapes of the three branches are usually different. The shape characteristics of the three-pronged long rod structural parts are: 1) The three "branches" at the end of the big head of the forging are of different lengths and relatively narrow widths, so that there is a large gap area between the two adjacent branches. The long "branch" structure and the large number of gap areas usually greatly reduce the material utilization rate of this type of forgings, and there is also a certain problem of die forging swing. 2) The length of the upper and lower sides of the "trapezoid" differs greatly (usually more than 3.5 times), and there are many thin and narrow rib structures distributed on the oblique sides of the "trapezoid"; 3) The cross-section difference between the rod and the big head is large, and the length is relatively long; 4) There is a single or multiple high platform structure at the transition between the big head and the rod, and the cross-section height of the high platform part is greatly different from that of the rod. The superposition of shape characteristics such as large cross-section changes, narrow ribs, and large bosses has brought great difficulties to the forging production of this type of forgings, and the "branch" structure with different shapes makes it even more difficult.

[0004] For some projects with a relatively large overall projection area (0.2m 2 Forgings of metal materials with relatively low forging temperature and high metal deformation resistance (such as TC32, TC4, etc.), if a reasonable and feasible forging forming method is not formulated in advance, the production and manufacturing of such forgings will be almost impossible to achieve, or a large amount of raw materials will be consumed. However, greater material loss is often accompanied by more forging times, which not only further increases the production cost, but also increases certain quality risks for materials that are more sensitive to deformation. Summary of the invention

[0005] Purpose of the invention: To provide a forging method for a trident-shaped long rod-like structural member, so that the hot working part of the trident-shaped long rod-like forging can be manufactured and produced with higher production efficiency and material utilization rate.

[0006] Technical solution:

[0007] A forging method for a trident-shaped long rod-like structural member, wherein the trident-shaped long rod-like structural member comprises a large head and a long rod, wherein the large head is composed of a trapezoidal structure and three branches distributed on one side of the wide side of the trapezoid, and a single or multiple high platform structures exist at the transition between the large head and the rod.

[0008] The method comprises:

[0009] Step 1: Determine the rough shape and size according to the size of the forging; the rough shape is in line with the shape of the forging and includes a regular rod, a trapezoidal structure, and a regular trident part. The horizontal cross-sectional area of ​​the rough rod corresponding to the high platform structure is large;

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

[0011] The horizontal plane area of ​​the middle and long branches of the rough type is more than 80% of the horizontal plane area of ​​the middle and long branches of the corresponding forgings, and the ratio of the cross-sectional area of ​​the middle and long branches of the rough type to the cross-sectional area of ​​the middle and long branches of the corresponding forgings is between 1.2 and 1.4;

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

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

[0014] The gap between two adjacent branches of the wild trident part is connected and transitioned by a semicircle less than 1 / 2.

[0015] The oblique sides of the wild trapezoidal structure cover more than half of the width of the ribs on both sides of the trapezoidal part of the large head of the forging;

[0016] The gap between the trapezoidal part of the rough type and the trapezoidal part of the forging 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-type rod to the forged rod is between 1.1 and 1.3;

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

[0020] Step 2: Determine the shape and size of the tire mold according to the rough shape and size;

[0021] The tire mold includes an upper tire mold and a lower tire mold. The upper tire mold is used for molding the wild-type big head three-pronged part. The upper tire mold cavity only molds the two outer branches of the wild-type big head three-pronged part. The lower tire mold cavity includes a trapezoidal part and a rectangular part.

[0022] The width of the lower tire mold cavity is consistent with the maximum width of the wild-type large-head trapezoidal part.

[0023] Step 3: Determine the structure and size of the special opening plate according to the rough shape and size; wherein the special opening plate is composed of a pressing block 6 and a hand-held rod 7, and is used to press out a semicircular shape between two adjacent branches of the rough-shaped large-head three-pronged part;

[0024] Step 4: Forge the round bar of appropriate size to obtain a square billet, the cross-sectional size of the square billet is 0.9-1.2 times the maximum cross-sectional size of the rough-shaped big head, and after forging, the material is divided to fully reserve the material required for the rough-shaped big head;

[0025] The part of the square blank corresponding to the rough-shaped rod part is completely stretched to obtain rough blank 1;

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

[0027] Step 5: Place the blank 1 into the cavity of the lower tire mold, use the upper hammer to upset the large head of the blank 1, then take the blank 1 out of the lower tire mold, and shape the large head of the blank; during the shaping, the bulges on both sides of the large head are tidied, and the thickness of the large head is flattened to obtain the blank 2;

[0028] Step 6: Place the blank 2 into the cavity of the lower tire mold, and use the upper hammer to upset the large head of the blank 2. During the upsetting, a small rectangular boss is left on the outside. The length of the small boss is greater than half the length of the long branch of the blank. After the small boss is pressed out, the blank 2 is taken out from the lower tire mold, and the blank 2 is reshaped to obtain the blank 3.

[0029] Step 7: Place the blank 3 into the cavity of the lower tire mold, then place the upper tire mold into the top of the three ends of the blank, and slowly press the upper tire mold down with the upper hammer until the mouths of the upper and lower tire molds overlap, and after closing the molds, withdraw the upper tire mold, take out the blank 3, and then shape it to obtain the blank 4;

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

[0031] Step nine: Lengthen the rod of rough blank six and trim the big end to obtain the rough shape.

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

[0033] Preferably, the widths of the three branches of the rough type are less than or equal to the maximum widths 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, among which BL, BM, BS are the maximum widths of the long "branch", medium-length "branch" and short "branch" of the forging respectively, and BL1, BM1, BS1 are the widths of the rough long "branch", medium-length "branch" and short "branch" respectively.

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

[0036] The depth of the semicircle is smaller than the radius of the semicircle and is as close as possible to the maximum depth of the gap between the two "branches" of the forging.

[0037] Preferably, the thickness dimensions of the three branches of the rough type are the same.

[0038] Preferably, the thickness of the upper tire mold cavity is larger than the thickness of the rough-type big head three-pronged part.

[0039] Preferably, the tire mold size satisfies:

[0040] 0.25Bmax<L6=(0.45~0.65)×L4, L7=(0.55~0.75)×L5, H2=(0.75~0.95)×H4, among which, Bmax: the maximum width dimension of the wild-type big head trapezoidal part and the width dimension of the tire mold mouth, L4: the length of the wild-type big head trapezoidal part, L5: the total length of the wild-type rod part, L6: the length of the trapezoidal part of the lower tire model cavity, L7: the length of the rectangular part of the lower tire model cavity, H2: the thickness dimension of the root of the lower tire model cavity, H4: the maximum thickness dimension of the wild-type rod part.

[0041] Preferably, the volume ratio of the lower tire mold cavity to the volume of the corresponding part of the rough mold is greater than 1.15.

[0042] Preferably, all height dimensions in the tire mold cavity should have a certain slope of 1.5° to 5°.

[0043] Beneficial effects:

[0044] 1. The present invention has a certain guiding role in the forging method of a trident-shaped long rod-like structural member from a bar or a plate with a certain thickness;

[0045] 2. Use appropriate auxiliary tooling to produce more complex shapes and reduce the difficulty of production.

[0046] The present invention has a certain guiding role in the forging forming method of the forked long rod type and the design of the corresponding special tire mold and the opening plate;

[0047] 3. The present invention has a certain reference effect on the forging production of trident-shaped structural parts;

[0048] 4. The present invention has a certain reference role in the forging and molding production of multi-forked long rod forgings with more than three "branches". BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Schematic diagram of the main forming methods of trident-shaped long rod structural parts;

[0050] Figure 2 Schematic diagram of the three-dimensional shape of the special die for forging trident-shaped long rod structural parts;

[0051] Figure 3 Schematic diagram of the special open plate shape for forging of trident-shaped long rod structural parts;

[0052] Figure 4 Schematic diagram of the rough appearance of a trident-shaped long rod-type structural part;

[0053] Figure 5 Schematic diagram of the appearance of the special die for forging trident-shaped long rod structural parts;

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

[0055] Figure 7 Schematic diagram of the placement of the blank three of the trident-shaped long rod structural part in the upper and lower molds;

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

[0057] Fig. 9 Schematic diagram of the rough shape of a certain outer cylinder forging;

[0058] Fig.10 A comparison of the appearance of a certain outer cylinder forging and the rough type;

[0059] Fig.11 Schematic diagram of the appearance of a special die used for forging an outer cylinder forging.

[0060] Description of reference numerals:

[0061] 1: Blank 1, 2: Blank type, 3: Forging, 4: Upper mold, 5: Lower mold, 6: Special plate opening block, 7: Special plate opening hand lever, 8: Blank 2, 9: Blank 3, 10: Blank 4, 11: Blank 5, 12: Blank 6

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

[0063] BL1, BM1, and BS1 are the widths of the wild long "branch", medium long "branch", and short "branch" respectively.

[0064] R1, R2: The radius of the semicircle connecting two adjacent "branches" of the wild type.

[0065] B1, B2: The distance between two adjacent "branches" of the wild type.

[0066] d1, d2: the depth of the connecting semicircle between two adjacent "branches" of the rough type, d3: the total depth of the pressing block in the special opening plate.

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

[0068] H1: The thickness of the upper tire mold root, H2: The thickness of the lower tire mold cavity root.

[0069] H3: The thickness of the three branches of the wild-type big-head three-pronged part; H4: The maximum thickness of the wild-type rod.

[0070] H5: Total thickness of the pressed block in the special opening plate, H6: Thickness of the rough-type large head part.

[0071] Bmax: The maximum width of the wild-type large-head trapezoidal part and the width of the tire mold mouth.

[0072] L3: The distance from the middle-length "branch" in the wild-type big-head trident to the top of the shortest branch.

[0073] L4: the length of the rough-type big head trapezoidal part, L5: the total length of the rough-type rod part, L6: the length of the trapezoidal part of the lower tire model cavity.

[0074] L7: The length of the rectangular part of the lower tire mold cavity.

[0075] LJ1, LJ2, LJ3, LJ4: The four corners at the bottom of the rectangular part of the lower tire model cavity. DETAILED DESCRIPTION

[0076] By using the method of the present invention, a three-pronged long rod type rough mold can be produced, so that the three-pronged long rod type forgings can complete the manufacturing and production of the hot processing part under high production efficiency and material utilization rate. The present invention can be applied to the forging production of three-pronged long rod type structural parts under various materials, ensuring that each forging process has high stability, and ultimately ensuring that the internal and external quality of the forgings meets the required requirements. The present invention is particularly beneficial to the forging production of three-pronged long rod type structural parts with large material deformation resistance, large projection area, and large cross-sectional changes.

[0077] The technical solution of the present invention is to form the round bar by blanking → blanking → forging → die forging (such as Figure 1 ) Forging produces a three-pronged long rod-like structural part with guaranteed internal and external quality (such as Figure 1 3), among which the absurd type (such as Figure 1 2) is by using a special tire mold (such as Figure 2 4 and 5) to upset and shape the rough blank obtained after blank making, roughly press out the shape and size required for the "big head" part of the rough shape, and then use a special opening plate (such as Figure 3 ) The transition between the trapezoidal part and the three-pronged part of the wild-type big head is forged and pressed down separately, and the shapes of the three "branches" are further trimmed. Finally, the rod is lengthened and the big head is trimmed.

[0078] 1) The design ideas of the wild type are as follows:

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

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

[0081] 1.1.1) Usually, the cross-section of each "branch" of the trident part is relatively small compared with the rod part, the platform and the big head, so the heat dissipation is relatively fast during the forging process, and the metal here is also difficult to flow, especially the long "branch" in the trident, because it is farthest from the rough-shaped big head, and the material of the big head part cannot "replenish" it, making it even more difficult to fill and form. Therefore, the horizontal plane area of ​​the long branch is more than 90% of the horizontal plane area of ​​the corresponding long branch of the forging, especially in the width direction, and the cross-sectional ratio between the rough-shaped and the forging should be between 1.3 and 1.5, so as to ensure that the forging has enough material in this place and fully ensure that it can be filled and formed. For the other two "branches" closer to the big head, the horizontal plane area corresponding to the forging body is covered to more than 80% depending on the specific situation, and the cross-sectional ratio between the two is 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 are the maximum widths of the long “branch”, medium-long “branch” and short “branch” of the forging respectively.

[0084] BL1, BM1, and BS1 are the widths of the wild long "branch", medium long "branch", and short "branch" respectively.

[0085] 1.1.2) The gap area between the two "branches" of the rough-type three-pronged part is connected and transitioned with a semicircle less than 1 / 2. This can better avoid obvious clamping defects between the two "branches" during the die forging process, and can also ensure the smooth pressing and removal of the special pressing plate during forging.

[0086] The radius of the semicircle must be greater than or equal to half the distance between two adjacent "branches" of the forging, and 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. Finally, in order to facilitate forging and pressing, the thickness dimensions of the three "branches" are 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 radius of the semicircle connecting two adjacent "branches" of the wild type;

[0089] B1, B2: the distance between two adjacent “branches” of the wild type;

[0090] d1, d2: the depth of the connecting semicircle between two adjacent “branches” of the wild type;

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

[0092] 1.2) According to the principle of minimum resistance of metal, it is most difficult for metal to flow in the vertical direction, followed by the width direction and the length direction. For forgings with thin and narrow ribs, if the rough width covers too little of the rib width, not only will it be difficult to fill the top of the rib, but it will also form a serious "rib penetration" phenomenon at its root, that is, a pinch defect. Therefore, this should cover more than 1 / 2 of the rib width.

[0093] 1.2.1) The trapezoidal part of the rough-type big head is a "trapezoidal" shape similar to the big head of the forging. The oblique sides of the "trapezoidal" must cover more than half of the width of the ribs on both sides of the trapezoidal part of the big head of the forging;

[0094] 1.2.2) Because the trapezoidal part in the big head has a large projection area, it is relatively difficult to "move the material" as a whole. Therefore, the gap between the rough-type trapezoidal part and the forging trapezoidal part in the width direction is set between 3 and 15 mm. The deformation of the rod part is relatively large. The gap between the rough-type rod part and the forging rod part in the width direction can be slightly larger, between 6 and 20 mm, but the materials of the rough-type rod part can be "supplied" to each other. The cross-sectional ratio of the rough-type rod part to the forging rod part can be between 1.1 and 1.3;

[0095] 1.2.3) Although the high platform of the forging rod can be reverse extruded by the billet on its front and rear sides, that is, the front and rear directions can provide it with a certain amount of material "supply", but the metal there is extremely difficult to flow upward. Therefore, the height dimension of the corresponding high platform structure in the rough-type rod must still be close to or greater than the overall height of the high platform part of the forging. The ratio of the cross-sectional area of ​​the corresponding high platform structure in the rough-type rod to the cross-sectional area of ​​the high platform structure of the forging is between 1.25 and 1.45.

[0096] 1.2.4) More than 90% of the horizontal area of ​​the rough part can be placed in the mold cavity, which can not only ensure the subsequent die forging effect, but also have a higher material utilization rate.

[0097] 2) The design ideas of special tire mold are as follows:

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

[0099] 2.1.) All width and length dimensions in the upper tire mold cavity are consistent with the relevant dimensions of the three-pronged part of the rough-type big head; the thickness dimension of the upper tire mold cavity should be larger than the thickness dimension of the three-pronged part of the rough-type big head, so that the upper tire mold can be placed in the rough blank three-pronged part with a relatively large head thickness (such as Figure 6 9) above.

[0100] H1=(1.2~1.35)×H3

[0101] Note: H1: thickness of the root of the upper tire mold; H3: thickness of the three branches of the wild-type big-head three-pronged part.

[0102] 2.2) The width of the lower mold cavity is consistent with the maximum width of the trapezoidal part of the rough type. The length of the trapezoidal part of the lower mold is rationally formulated by comparing the width of the mouth and the length of the corresponding part of the rough type. The rough type rod has a relatively small cross-section and dissipates heat relatively quickly during forging. Therefore, the length difference between the rectangular part in the lower mold cavity and the rough type rod should not be too large. The thickness of the root of the lower mold cavity cannot be much smaller than the maximum thickness of the rough type rod, otherwise, it will be difficult to forge it during subsequent forging. 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: the maximum width of the rough-type big head trapezoidal part and the width of the tire mold mouth, L4: the length of the rough-type big head trapezoidal part, L5: the total length of the rough-type rod, L6: the length of the trapezoidal part of the lower tire mold cavity, L7: the length of the rectangular part of the lower tire mold cavity, H2: the thickness of the root of the lower tire mold cavity, H4: the maximum thickness of the rough-type 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 greater than 1.15.

[0107] 2.4) All height dimensions in the mold cavity must have a certain slope (1.5°~5°) so that the stem of the blank can be taken out from the lower mold and the upper mold can be taken out from the big head of the blank after pressing. In order to more accurately control the material abundance of each part, the larger the height dimension, the smaller the slope.

[0108] 2.5) The four corners at the bottom of the rectangular part of the lower tire mold cavity (such as Figure 5 LJ1, LJ2, LJ3, and LJ4) in the mold cannot be chamfered, otherwise, the rough blank will be "stuck" in the lower tire mold cavity after pressing and cannot be taken out; other parts must be chamfered, and the transition between the big head and the stem should be smoothed with a large fillet greater than R50, and the rest of the parts can be transitioned with a fillet of R10 to 30 depending on the situation.

[0109] 3) The design ideas of special opening board are as follows:

[0110] Special opening plate is made of pressing block (such as Figure 3 6) and a hand-held rod (such as Figure 3 7) In the case of the two semicircles of the wild type with different sizes, the number is 2, and the sizes correspond to each other. Otherwise, only one is needed. The function of the special opening plate is to press out the semicircular shape between the two adjacent branches of the wild type big head trident part.

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

[0112] 3.2) When using the open plate to press the semicircular shape of the wild-type large head part, the materials on both sides of the semicircle will be squeezed in the height direction and thickness direction at the same time. Therefore, the total length and thickness of the open plate should be appropriately larger than the height of the middle and long "branch" in the wild-type trident and the thickness of the wild-type trident part, respectively, to ensure that the upper hammer head will not press on the top of any branch during pressing, and the open plate will not be embedded in the wild-type 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 opening plate, L3: distance from the middle and long "branch" to the top of the shortest branch in the wild type big head trident, H5: total thickness of the pressing block in the special opening plate, H6: thickness of the wild type big head part.

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

[0116] 4) The production of the rough form of the trident-shaped long rod structural parts is all carried out on a free forging hammer of appropriate tonnage. The forging process is as follows: Figure 6 The specific steps are as follows:

[0117] Step 1: Make a rough block (such as Figure 1 and Figure 6 1) in the above.

[0118] First, forge a round bar of appropriate size into a square, the cross-sectional size of which is 0.9-1.2 times the maximum cross-sectional size of the rough-shaped big head. After forging, divide the material, that is, leave enough material for the rough-shaped big head part, and stretch the rest. After stretching, the width and height of the rough-shaped rod part must be 5-10mm smaller than the corresponding width and thickness of the rectangular part of the lower tire mold cavity, and the length of the rough-shaped rod part must be 30-80mm higher than the rectangular part of the lower tire mold.

[0119] Step 2: Make a rough block 2 (such as Figure 6 8).

[0120] Put the blank into the cavity of the lower mold, and then use the upper hammer to upset the large head of the blank. Then take the blank out of the lower mold and shape the large head. When shaping, the bulges on both sides of the large head are tidied and the thickness of the large head is appropriately flattened.

[0121] Step 3: Make rough block 3 (such as Figure 6 9).

[0122] Put the second blank into the cavity of the lower tire mold, and use the upper hammer to upset the big head part. When upsetting, leave out the material for the long "branch" in the three-pronged part, that is, leave a small rectangular boss at the corresponding position on the top of the big head 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, take the blank out of the lower tire mold and shape it.

[0123] Step 4: Make the rough piece 4 (such as Figure 6 10).

[0124] Place the blank into the lower mold cavity, then place the upper mold close to the top of the blank, and then adjust the front, back, left, and right positions to make it as centered as possible. Figure 7 As shown. Use the upper hammer to slowly press down the upper mold until the mouths of the upper and lower molds overlap. After closing the molds, remove the upper mold, take out the blank, and then shape it.

[0125] Step 5: Make rough blocks 5 and 6 (such as Figure 6 11, 12).

[0126] Place blank No. 4 into the cavity of the lower tire mold, place one of the open plates on the corresponding position of the large end of the blank, start the equipment, slowly press down to press out the required semicircular shape to obtain blank No. 5, use another open plate to press out the semicircular shape on the other side, thereby pressing out the shapes and sizes of three "branches" to obtain blank No. 6.

[0127] Step 6: Create the final shape.

[0128] The rod of rough blank No. 6 is lengthened and its big end size is trimmed to the design requirements.

[0129] During the upsetting process using the tire mold, if a large bulge appears on the side of the big end of the blank, and the bulge has exceeded the outside of the tire mold cavity, the downward pressure should be stopped immediately, and the blank should be taken out of the tire mold cavity, and the bulge should be adjusted with a hammer and anvil before continuing the upsetting. That is, the upsetting part of the tire mold can be repeated.

[0130] Implementation Cases

[0131] A certain outer cylinder forging, material grade: TC32, forging weight: 142Kg, forging projection area: 0.31m2. The shape structure of this forging belongs to the typical three-pronged long rod forging, and the main shape dimensions are as follows Figure 8 As shown. The trident part of the forging head is composed of three "branches" of different shapes, and the width of the three branches is relatively small, the length size is quite different, and there is a raised platform on the long branch. The gap area between two adjacent "branches" is about: 0.011mm2 The two widths of the "trapezoidal" part of the forging head differ by 4.2 times, and there are thin and narrow ribs with a width of only 30mm around the inner and outer periphery of the "trapezoidal" part. The forging rod is relatively long, and the cross section is relatively small compared to the big head. There are two raised platforms on the rod, and the cross-sectional areas of the two high platforms are 0.029m 2 、0.0245m 2 .

[0132] The rough shape and size designed according to the forging size are as follows Fig. 9 As shown in the figure, the rough shape follows the shape of the forging, and the branches of the big head three-pronged fork are transitioned by 1 / 2 semicircles of the same size; the matching of the rough shape and the forging is shown in the figure. Fig.10 As shown, it can be seen that the rough type covers about 95% of the horizontal surface of the long "branch" in the forged big head trident, and the other two branches cover about 90%. About 95% of the rough type as a whole can be placed in the mold cavity; the "trapezoidal" part of the rough type big head covers more than 1 / 2 of the width of the thin and narrow ribs on both sides of the forging. The gap between the rough type and the forging in the width direction is 13mm for the big head and 18mm for the stem.

[0133] The tire mold size designed according to the rough size is as follows Fig.11 shown.

[0134] A special opening plate is designed. The semicircle size of the pressing block in the special opening plate is the same as that in the rough type. The total length of the pressing block is 150mm and the total thickness of the pressing block is 180mm. The holding rod of the pressing plate is made of a Φ10mm steel rod and the length of the holding rod is 250mm.

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

[0136] Step 1: Use a saw to cut the material, the cutting size is: Φ300×570mm.

[0137] Step 2: Use a 2500t fast forging machine to make blank one.

[0138] After the bar is heated as required, it is forged into a square billet with a cross-sectional size of 350×190, and then the material is divided and the rod is drawn. The cross-sectional size of the rod after drawing is: 200×190

[0139] Step 3: Use a 2500t fast forging machine to forge the rough piece to produce the rough shape.

[0140] 1) Forging the first fire: Heat the blank 1 as required and put it into the lower mold, upset the big head part of the blank, then take it out from the lower mold, trim the bulges on both sides of the big head, and flatten the thickness of the big head part to 135mm to obtain blank 2. Put the blank 2 into the cavity of the lower mold, upset the big head part, leave a rectangular boss with a length of about 60mm at the corresponding position of the top of the big head of the blank, then take the blank out of the lower mold for shaping, and after shaping, put the blank into the cavity of the lower mold, press the length of the rectangular boss part to 100mm, then take the blank out of the lower mold for shaping to this point, and obtain blank 3.

[0141] 2) Forging the second fire: Heat the blank No. 3 as required and put it into the lower mold, then put the upper mold into the top of the big end of the blank and adjust the position. Use the upper hammer to press down the upper mold at a speed of ~10mm / s until the gap between the mouth of the upper and lower molds is about 30mm. Remove the upper mold, take out the blank, and shape it. After shaping, continue to put the blank into the upper and lower molds, and press it down at a speed of ~15mm / s until the mouth of the upper and lower molds overlap. After closing the mold, take out the blank and shape it. After shaping, the thickness of the three-pronged part of the big end of the blank is 115mm. So far, blank No. 4 is obtained.

[0142] 3) Forging the third fire: Heat the blank 4 as required and put it into the lower mold. Put the special opening plate on the position of the big end of the blank to press out the required semicircular shape. Then take out the opening plate and put it on the other side to press out the shape of the other side. Then take away the opening plate. Take the blank out of the lower mold and shape it. At this point, blank 6 is obtained.

[0143] 4) Forging the rough shape: After heating the rough shape according to the requirements, the rod is stretched and the big end size is trimmed to the design requirements. At this point, the rough shape is completed.

[0144] Step 4: Use 630KJ to die forge the hammer.

[0145] After heating the rough mold as required, transfer it to the corresponding equipment and adjust the position of the rough mold in the mold cavity. When hammering, first lightly hit 2 to 3 hammers to position it, and then hit it hard a few times to form it. The die forging is completed in 3 fires.

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

[0147] Step six: heat treatment, heat treatment system: double annealing.

[0148] Step 7: Physical and chemical tests.

[0149] Finally, a certain outer cylinder was forged through three processes: blank making, forging, and die forging. Among them, the shape and size design of the special plate for the special tire mold machine are reasonable and feasible, which is time-saving and simple in actual operation. The final forged rough type has good physical consistency, and more than 88% fits the theoretical design. The shape and size design of the rough type are reasonable to meet the needs of forging forming. During die forging, the rough type is placed stably in the mold cavity. When hammering, the rough type has no obvious displacement phenomenon. After hammering, there is no "rib running" phenomenon at the root of the narrow rib of the big head of the forging. Finally, the die forging production was completed with fewer fires, and the forging filling effect was better. The three "branches" of the three-pronged part of the big head of the forging and the two raised platforms of the rod were all fully formed. According to calculations, the material utilization rate of the outer cylinder forging is 79%.

[0150] After physical and chemical testing, the results showed that the low-magnification structure of the forgings was the required fuzzy grains, with no clear grains visible to the naked eye, and the high-magnification structure was equiaxed, with an α content of 30%, meeting the specified requirements. In addition, the performance data of the forgings fully met the requirements of the standard.

Claims

1. A forging method for a trident-shaped long rod-like structural member, characterized in that: The trident-shaped long rod structural member comprises a large head and a long rod, wherein the large head is composed of a trapezoidal structure and three branches distributed on one side of the wide side of the trapezoid, and there is a single or multiple high platform structures at the transition between the large head and the rod, and the method comprises: Step 1: Determine the rough shape and size according to the size of the forging; the rough shape is in line with the shape of the forging and includes a regular rod, a trapezoidal structure, and a regular trident part. The horizontal cross-sectional area of ​​the rough rod corresponding to the high platform structure is large; The horizontal plane area of ​​the long branch of the rough type is more than 90% of the horizontal plane area of ​​the long branch of the corresponding forging, and the ratio of the cross-sectional area of ​​the long branch of the rough type to the cross-sectional area of ​​the long branch of the corresponding forging is between 1.3 and 1.5; The horizontal plane area of ​​the middle and long branches of the rough type is more than 80% of the horizontal plane area of ​​the middle and long branches of the corresponding forgings, and the ratio of the cross-sectional area of ​​the middle and long branches of the rough type to the cross-sectional area of ​​the middle and long branches of the corresponding forgings is between 1.2 and 1.4; The horizontal plane area of ​​the short branch of the rough type is more than 80% of the horizontal plane area of ​​the short branch of the corresponding forging, and the ratio of the cross-sectional area of ​​the short branch of the rough type to the cross-sectional area of ​​the short branch of the corresponding forging is between 1.2 and 1.4; The width of the three branches of the rough type is less than or equal to the maximum width of the corresponding branches of the forging; The gap between two adjacent branches of the wild trident part is connected and transitioned by a semicircle less than 1 / 2. The oblique sides of the wild trapezoidal structure cover more than half of the width of the ribs on both sides of the trapezoidal part of the large head of the forging; The gap between the trapezoidal part of the rough type and the trapezoidal part of the forging 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-type rod to the forged rod is between 1.1 and 1.3; The ratio of the cross-sectional area of ​​the corresponding high platform structure in the rough-shaped rod to the cross-sectional area of ​​the high platform structure of the forging is between 1.25 and 1.45; Step 2: Determine the shape and size of the tire mold according to the rough shape and size; The tire mold includes an upper tire mold and a lower tire mold. The upper tire mold is used for molding the wild-type big head three-pronged part. The upper tire mold cavity only molds the two outer branches of the wild-type big head three-pronged part. The lower tire mold cavity includes a trapezoidal part and a rectangular part. The width of the lower tire mold cavity is consistent with the maximum width of the wild-type large-head trapezoidal part. Step 3: Determine the structure and size of the special opening plate according to the rough shape and size; wherein the special opening plate is composed of a pressing block (6) and a hand-held rod (7), and is used to press out a semicircular shape between two adjacent branches of the rough-shaped large-head three-pronged part; Step 4: Forge the round bar of appropriate size to obtain a square billet, the cross-sectional size of the square billet is 0.9-1.2 times the maximum cross-sectional size of the rough-shaped big head, and after forging, the material is divided to fully reserve the material required for the rough-shaped big head; The part of the square blank corresponding to the rough-shaped rod part is completely stretched to obtain rough blank 1; The width and height of the first rod of the blank are both 5 to 10 mm smaller than the corresponding width and thickness of the rectangular part of the lower tire mold cavity; the length of the first rod of the blank is 30 to 80 mm higher than the rectangular part of the lower tire mold; Step 5: Place the blank 1 into the cavity of the lower tire mold, use the upper hammer to upset the large head of the blank 1, then take the blank 1 out of the lower tire mold, and shape the large head of the blank; during the shaping, the bulges on both sides of the large head are tidied, and the thickness of the large head is flattened to obtain the blank 2; Step 6: Place the blank 2 into the cavity of the lower tire mold, and use the upper hammer to upset the large head of the blank 2. During the upsetting, a small rectangular boss is left on the outside. The length of the small boss is greater than half the length of the long branch of the blank. After the small boss is pressed out, the blank 2 is taken out from the lower tire mold, and the blank 2 is reshaped to obtain the blank 3. Step 7: Place the blank 3 into the cavity of the lower tire mold, then place the upper tire mold into the top of the three ends of the blank, and slowly press the upper tire mold down with the upper hammer until the mouths of the upper and lower tire molds overlap, and after closing the molds, withdraw the upper tire mold, take out the blank 3, and then shape it to obtain the blank 4; Step 8: Place blank 4 into the cavity of the lower tire mold, place the open plate on the corresponding position of the blank's large end, and slowly press down to press out a semicircular shape between the two branches to obtain blank 5; press out another semicircular shape to obtain blank 6; Step 9: Lengthen the rod of the rough blank No. 6 and trim the big end to obtain the rough shape; Step 10: 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 type 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, among which BL, BM, BS are the maximum widths of the long "branch", medium-long "branch" and short "branch" of the forging respectively, and BL1, BM1, BS1 are the widths of the rough long "branch", medium-long "branch" and short "branch" respectively.

3. The method according to claim 2, characterized in that The radius of the semicircle of the gap area between two adjacent branches of the rough type is greater than or equal to half the distance between two adjacent branches of the forging; The depth of the semicircle is smaller than the radius of the semicircle and is as close as possible to the maximum depth of the gap between the two "branches" of the forging.

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

5. The method according to claim 1, characterized in that The thickness of the upper tire model cavity is larger than that of the wild-type big head three-pronged part.

6. The method according to claim 1, characterized in that Tire mold size meets: 0.25Bmax<L6=(0.45~0.65)×L4, L7=(0.55~0.75)×L5, H2=(0.75~0.95)×H4, among which, Bmax: the maximum width dimension of the wild-type big head trapezoidal part and the width dimension of the tire mold mouth, L4: the length of the wild-type big head trapezoidal part, L5: the total length of the wild-type rod part, L6: the length of the trapezoidal part of the lower tire model cavity, L7: the length of the rectangular part of the lower tire model cavity, H2: the thickness dimension of the root of the lower tire model cavity, H4: the maximum thickness dimension of the wild-type rod part.

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

15.

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

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