Forging forming method for thin-wall semi-circular hoop type structural component

Abstract

The invention belongs to the field of hot forging technology forming, and relates to a forging forming method for a thin-wall semi-circular hoop type structural part. According to the invention, the thin-wall semicircular hoop type structural member with guaranteed internal and external quality is forged and produced in a forming mode of bar (or plate)-blank-blank-blank-die forging, wherein the blank is realized in a mode of bending the blank by using a special moulding bed.

Description

Technical Field

[0001] The invention belongs to the field of hot forging technology and relates to a forging method for a thin-walled semicircular ring clamp-type structural part. Background Art

[0002] Clamps are commonly used in various aircraft, primarily to connect various internal components. Aviation forgings typically require high performance to ensure flight safety and longevity. In the aviation forging field, excellent performance requires a sound internal structure, which in turn requires a reliable forging method, especially for complex structural parts and metal materials with high forging requirements.

[0003] The main body of a clamp-type structural component is typically a thin-walled semicircular or annular ring, with relatively thick bosses at each end serving as connections to other parts. Semicircular clamp-type structural forgings are characterized by a semicircular core, an outer radius to wall thickness ratio of at least 4, and a horizontal length exceeding twice its width. These forgings have a roughly semicircular parting surface and a relatively deep cavity. For some materials with relatively high forging temperatures and good plasticity, such as ordinary structural steels such as 1Cr13Ni3MoVN, 300M, 30CrMnSiNi2A, suitable-sized plates or long strips can be directly used for press forming when producing such forgings. However, for some materials with relatively low forging temperatures and relatively high deformation resistance, such as high-strength structural steels and titanium alloys such as A-100, AF1410, and PH13-8Mo, the degree of change from "rectangular" to "semicircular" is too large. During the die forging process, the metal surface is prone to surface quality defects such as pinching, folding, and cracks, as well as forging risks such as pressing deviation and dislocation. There are even certain safety hazards. Even if it can be fully formed in the end, it will take a lot of firings, and a lot of grinding work is required between each firing. This is not only time-consuming and labor-intensive, but for those materials with high deformation requirements, such as A-100, TC18 and other metal materials, more firings of molding usually cannot guarantee their deformation requirements, nor can they ultimately have a better organization and higher performance.

[0004] When the parting surface is semicircular, the rough shape must be roughly a semicircular curve to ensure that the rough shape is well positioned within the mold cavity, thereby ensuring the smooth execution of the die forging process. For metal materials with high deformation resistance, the free forging operation of "bending" is also inconvenient to perform directly. This not only affects the shape consistency after pressing, but also poses certain safety risks. In order to avoid various surface quality and safety issues during the forging process of thin-walled semicircular ring clamp structural parts made of various materials, and to ensure their required structure and performance, it is necessary to develop a reasonable, feasible, stable and efficient forging method. Summary of the Invention

[0005] Purpose of the invention: To provide a forging method for thin-walled semicircular ring clamp-like structural parts, reduce the difficulty of making nearly semicircular rough shapes, and improve the stability of the die forging production process of thin-walled semicircular ring clamp-like structural parts.

[0006] Technical solution: A forging method for a thin-walled semicircular ring-shaped clamp-like structural part, wherein the thin-walled semicircular ring-shaped clamp-like structural part comprises an annular portion and boss structures located at two ends. The method comprises: Step 1: Determine the rough shape and size according to the size of the forging; the rough shape is a V-shaped shape, where the curvature of the rough shape lower end surface and the lower mold cavity meets the following requirements: θ1min=(0.95~1.05)θmin, where θ is the angle between the tangent line on the inclined surface or curved surface near the die mouth of the lower mold cavity of the forging and the central axis; θ1min is the minimum angle between the inclined surface on the side where the rough shape lower end contacts the lower mold cavity of the forging and the central axis; the angle between the two inclined surfaces of the rough shape V-shaped transition radius; Step 2: Determine the shape and size of the tire mold according to the rough shape and size; The shape of the upper tire mold is a rectangular flat plate with a V-shaped punch. The root of the punch is a small plane, where H3 = (0.85-0.95) × H, where H is the maximum depth of the V-shaped upper end face of the rough mold, H3 is the height of the upper tire mold punch, B1 = (2.5-3.5) × B, L4 = (1-1.1) × L3, H4 = (0.5-0.7) × H3, where B1 is the width of the upper tire mold, L4 is the total length of the upper tire mold, H4 is the thickness of the root of the upper tire mold punch; B is the width of the rough mold. If the rough mold has multiple width sizes, the maximum width size is used; L3 is the total length of the rough mold. The lower tire mold has a V-shaped cavity; Lower tire mold cavity dimensions: B2 = (1.2~1.5) × B, H5 = (0.95~1.05) × H1, H6 = (0.95~1.05) × H2, where B2 is the width of the lower tire mold cavity, H1 is the maximum thickness of the ends of the rough mold, H5 is the height of both sides of the lower tire mold mouth, H6 is the maximum depth of the lower tire mold cavity, and H2 is the total height of the rough mold. Tire mold lower mold module dimensions: B3 = (3.5-5.5) × B2, L5 = (1.1-1.3) × L3, H7 = H6 + S, where B3 is the width of the lower mold module, L5 is the length of the lower mold module, H7 is the height of the lower mold module, S is the distance between the deepest part of the lower mold cavity and the bottom of the mold, and L3 is the total length of the mold. Step 3: Determine the shape and size of the blank according to the shape and size of the blank and the shape and size of the tire mold, wherein the blank is an elongated strip as a whole, and a trapezoidal shape is pressed out on one side of the middle part; Step 4: First, use the ordinary free forging method to forge the appropriate size bar into a square and draw it into a blank with a ladder shape on one side. Then, place the blank into the cavity of the lower die and adjust the length direction. Then, place the root of the upper die punch in the center of the trapezoidal side of the blank. Slowly press down to bend the blank. Stop when the two ends of the blank touch the root of the upper die punch. Finally, the desired blank shape is obtained. Step 5: Die forging the rough mold to obtain the forging.

[0007] Preferably, step one specifically includes: When the thickness in the middle of the forging is small and the thickness at both ends is large, θ1min>θ2min; when the thickness in the middle of the forging is large and the thickness at both ends is small, θ1min<θ2min, where θ1min is the minimum angle between the inclined surface on the side where the lower end of the rough mold contacts the lower mold cavity of the forging and the central axis, and θ2min is the minimum angle between the inclined surface on the side where the upper end of the rough mold contacts the upper mold cavity of the forging and the central axis.

[0008] Preferably, in step 1, the contact area between the lower end surface of the rough mold and the lower mold cavity is not less than 40%. Preferably, in step 1, the transition radius of the angle between the two inclined surfaces of the rough V-shaped shape satisfies: D3≤D1, D4≥D2, where D1: the size of the inner fillet of the center part of the thin-walled semi-circular clamp forging, D2: the size of the outer fillet of the center part of the thin-walled semi-circular clamp forging, D3: the size of the transition fillet at the angle between the two inclined surfaces of the upper end face of the rough type, D4: the size of the transition fillet at the angle between the two inclined surfaces of the lower end face of the rough type.

[0009] Preferably, in step 1, the width of the rough shape satisfies: 0.5Bmax<B<Bmin, where B is the width of the forging, Bmax is the maximum width of the forging, and Bmin is the minimum width of the forging; The length of the wild type meets the following requirements: L1=(0.8~1.0)×L2,L3=(0.9~1.2)×L2,wherein, L1: maximum contact length between the lower end surface of the rough type and both sides of the lower mold cavity of the forging, L2: total length of the thin-walled semicircular clamp forging, L3: total length of the rough type; Wild type highly satisfied: H<0.7×L,H2<0.55×L3,wherein, H is the maximum depth of the V-shaped upper end surface of the rough type, H2 is the total height of the rough type, L is the inner length of the V-shaped upper end surface of the rough type, and L3 is the total length of the rough type; The weight ratio of rough mold to die forging is between 1.2 and 1.4.

[0010] Preferably, in step 2, the distance S between the deepest part of the mold cavity under the tire mold and the bottom of the tire mold is not less than 100 mm.

[0011] Preferably, in step three, the size of the blank satisfies: L6=(1.01~1.05)×L3, H8=(1.01~1.05)×H1, H9=H2-H, θ2<θ3<70°, wherein, L6: total length of the blank, H8: thickness of both ends of the blank, H9: thickness of the middle part of the blank, θ3: angle between the middle inclined surface of the blank and the central axis, θ2 is the angle between the inclined surface on the side where the upper end of the blank contacts the mold cavity on the forging and the central axis.

[0012] Preferably, in step 4, the fetal membrane forging process is performed using a press.

[0013] Beneficial effects: 1. The present invention is forging from bar or plate to thin-walled semicircular ring clamp type special-shaped structural parts The model has a certain guiding role; 2. The use of appropriate auxiliary tooling can greatly reduce the difficulty of free forging production and improve its production safety. The present invention has a certain guiding role in the forging method of the semicircular V-shaped rough shape and the design of the corresponding special tire mold size; 3. The organization and performance are closely related, and the design of the degree of deformation determines the final form of the organization. The results provide a certain guidance for the deformation design of thin-walled semi-circular clamp-type special-shaped structural parts. 4. The present invention has a certain reference role in the forging production of thin-walled semi-circular casing structures (the ratio of the outer radius of the forging to the corresponding wall thickness is less than 4); 5. The present invention has a certain reference value for the forging production of thick-walled (the total length of the forging in the horizontal direction does not exceed 2 times the width) semi-circular structural parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the main forming methods of thin-walled semi-circular ring clamp structural parts; Figure 2 Schematic diagram of the appearance of thin-walled semi-circular ring clamp type structural parts; Figure 3 Schematic diagram of the rough shape of thin-walled semi-circular ring clamp structural parts; Figure 4 Schematic diagram of the placement of the rough form of thin-walled semi-circular ring clamp structural parts in the lower mold cavity; Figure 5 Schematic diagram of the upper die shape for forging thin-walled semicircular ring clamp structural parts; Figure 6 Schematic diagram of the lower die shape for forging thin-walled semicircular ring clamp structural parts; Figure 7 Schematic diagram of the rough shape of thin-walled semi-circular ring clamp structural parts; Figure 8 Schematic diagram of rough forming method of thin-walled semi-circular ring clamp structural parts; Figure 9 Schematic diagram of the rough shape of an A-100 clamp forging; Figure 10 Schematic diagram of the upper die shape used for forging a certain A-100 clamp forging; Figure 11 Schematic diagram of the lower die shape for forging a certain A-100 clamp forging; Figure 12 Schematic diagram of the rough shape of an A-100 clamp forging.

[0015] Description of reference numerals: θ: The angle between the tangent line on the inclined surface or arc surface of the lower mold cavity of the forging near the die mouth and the central axis; θ1min: the minimum angle between the inclined surface on one side of the lower end of the rough mold (the side in contact with the lower mold cavity of the forging) and the central axis; θ2min is the minimum angle between the inclined surface on one side of the upper end of the rough mold (the side in contact with the mold cavity on the forging) and the central axis; θ3: The angle between the middle inclined surface of the rough type and the central axis; D1: The size of the inner fillet of the center part of the thin-walled semi-circular clamp forging; D2: The size of the outer fillet of the center part of the thin-walled semi-circular clamp forging; D3: The size of the transition radius at the angle between the two inclined surfaces of the upper end face of the rough type; D4: The size of the transition radius at the angle between the two inclined surfaces of the lower end face of the rough type; B: rough width, Bmax: maximum width of forging, Bmin: minimum width of forging; B1: upper tire mold width, B2: lower tire mold cavity width, B3: lower tire mold module width; L: The inner length of the V-shaped upper end surface of the rough type; L1: Maximum contact length between the lower end face of the rough mold and both sides of the lower mold cavity of the forging; L2: total length of thin-walled semicircular clamp forgings, L3: total length of rough type, L4: total length of upper mold; L5: Length of lower tire mold module, L6: Total length of blank; H: the maximum depth of the V-shaped upper end of the rough type, H1: the maximum thickness of the two ends of the rough type; H2: Overall height of the rough mold, H3: Height of the upper tire mold punch, H4: Thickness of the upper tire mold punch root; H5: height of both sides of the lower tire mold opening; H6: maximum depth of the lower tire mold cavity; H7: Height of the lower mold module, H8: Thickness of both ends of the rough mold, H9: Thickness of the middle part of the rough mold; S: The distance between the deepest part of the mold cavity under the tire mold and the bottom of the tire mold; 1: Thin-walled semicircular ring clamp structural parts blank; 2: Thin-walled semicircular ring clamp type structural parts; 3: Thin-walled semicircular ring clamp type structural parts; 4: Lower die for thin-walled semicircular ring clamp structural parts; 5: The upper die is used for forging thin-walled semicircular ring clamp structural parts; 6: Lower die for forging thin-walled semicircular ring clamp structural parts; 7: The root shape of the upper die punch for forging thin-walled semi-circular ring clamp structural parts. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the implementation of this application will be described in more detail below in conjunction with the drawings in the implementation of this application. In the drawings, the same or similar numbers throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and should not be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in conjunction with the drawings.

[0017] In the description of the present invention, it should be understood that the terms "center", "axial", "vertical", "up", "down", "upper end", "bottom end", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present invention.

[0018] The technical solution of the present invention is to form the forging by means of bar (or plate) → blank → blank → die forging (such as Figure 1 ) forging to produce a thin-walled semi-circular clamp-type structural part with guaranteed internal and external quality (such as Figure 2 ), where the rough shape is achieved by bending the rough blank using a special mold.

[0019] The design ideas for rough-type, special curved tire molds and rough blanks are as follows: 1. Wild design: In order to fit the shape of the forging, the overall shape of the rough type is also close to a semicircular shape. Considering that the mold can be smoothly ejected during forging, the shape of the rough type is designed to be a semicircular V-shaped shape (such as Figure 3 ), when the thickness in the middle of the forging is small and the thickness at the ends is large, θ1min>θ2min; otherwise, θ1min<θ2min. θ1min is the minimum angle between the inclined surface at the lower end of the rough shape (the side that contacts the lower mold cavity of the forging) and the central axis, and θ2min is the minimum angle between the inclined surface at the upper end of the rough shape (the side that contacts the upper mold cavity of the forging) and the central axis.

[0020] In addition, the size of the rough forging needs to take into account the actual shape structure and specific size distribution of the forging, and the following principles should be grasped: 1) Design of the slope of the two inclined surfaces of the rough-type V-shaped part: The curvature of the lower end face of the rough-type part and the lower mold cavity must be basically consistent, that is: θ1min=(0.95~1.05)θmin. Note: θ: The angle between the tangent line on the inclined surface or curved surface near the mold mouth of the lower mold cavity of the forging and the central axis. In addition, it is necessary to ensure that the contact area between the lower end face of the rough-type part and the lower mold cavity is not less than 40%, so as to ensure that the rough-type part can be smoothly placed in the lower mold cavity during die forging production. In theory, the upper end face of the rough-type part should also be designed according to the outer curvature of the upper mold of the forging part, but it does not have strict fitting requirements like the lower mold. Instead, it is rationally formulated according to the thickness size distribution of the forging part. For materials with special requirements for deformation, in addition to meeting the corresponding forming requirements, it is also necessary to meet the minimum deformation requirements and appropriately increase the thickness size.

[0021] 2) Design of transition radius between the two inclined surfaces of V-shaped D3≤D1, D4≥D2.

[0022] Note: D1: The inner fillet size of the center part of the thin-walled semi-circular clamp forgings; D2: The outer fillet size of the center part of the thin-walled semi-circular clamp forgings; D3: The transition fillet size at the angle between the two inclined surfaces of the upper end face of the rough type; D4: The transition fillet size at the angle between the two inclined surfaces of the lower end face of the rough type.

[0023] 3) Wild width design: 0.5Bmax<B<Bmin, so as to ensure that the rough shape can be completely placed in the mold cavity in the width direction, and to ensure the corresponding forming and deformation requirements.

[0024] Note: B: width dimension of rough type, Bmax: maximum width of forging, Bmin: minimum width of forging.

[0025] 4) Wild length design: L1=(0.8~1.0)×L2,L3=(0.9~1.2)×L2. In this way, the blank can be placed firmly on the lower die (such as Figure 4 4) in the cavity, and avoid unnecessary material loss.

[0026] Note: L1: Maximum contact length between the lower end face of the rough type and both sides of the lower mold cavity of the forging; L2: Total length of the thin-walled semicircular clamp forging; L3: Total length of the rough type.

[0027] 5) Wild height design: H<0.7×L, H2<0.55×L3.

[0028] H: Maximum depth of the V-shaped top surface of the rough type, H2: Total height of the rough type, L: Inner length of the V-shaped top surface of the rough type, L3: Total length of the rough type.

[0029] 6) Ensure that the weight ratio of rough mold to die forging is between 1.2 and 1.4 to meet the final forming requirements and high material utilization requirements.

[0030] 7) Because the outer contour of the rough shape is mainly guaranteed by the shape of the tire mold, usually the maximum fit between the two can reach 90%, so the rough shape should be designed to be as regular as possible, which can also reduce the difficulty of making the corresponding rough shape.

[0031] 2. Design of special die for forging: Design the special die for forging according to the shape and size of the die. The die consists of 2 pieces. The shape of the upper die is shown in the figure. Figure 5 5 in the figure, the shape of the lower mold is shown in Figure 66. The outer curvature of the tire mold is basically designed according to the shape of the rough shape, that is, the angle of the inclined surface of the tire mold cavity and the transition radius between the inclined surfaces are consistent with the rough shape design. However, the following principles must be grasped in detail: 2.1. Upper tire mold design: 1) The shape of the upper mold is a rectangular flat plate with a semicircular V-shaped punch. The root of the punch (such as Figure 5 7) should be designed as a small flat surface. This allows the upper die to rest securely on the upper end of the blank during bending. After bending, the contact surface between the blank and the base of the upper die punch will automatically form an arc. To ensure this arc best meets the blank design requirements, ensure H3 = (0.85-0.95) × H. Note: H3 is the height of the upper die punch.

[0032] 2) B1 = (2.5~3.5) × B (if the rough type has multiple width sizes, take the largest width size), L4 = (1~1.1) × L3, H4 = (0.5~0.7) × H3.

[0033] Note: B1: width of upper tire mold, L4: total length of upper tire mold, H4: thickness of the root of upper tire mold punch.

[0034] 2.2. Lower tire mold design: 1) Lower tire mold cavity size: B2=(1.2~1.5)×B, H5=(0.95~1.05)×H1, H6=(0.95~1.05)×H2, Note: B2: Width of the lower tire mold cavity, H1: Maximum thickness of both ends of the rough type, H5: Height of both sides of the lower tire mold mouth, H6: Maximum depth of the lower tire mold cavity.

[0035] 2) Tire mold lower mold module size: B3=(3.5~5.5)×B2, L5=(1.1~1.3)×L3, H7=H6+S Note: B3: Width of lower mold module, L5: Length of lower mold module, H7: Height of lower mold module, S: Distance between the deepest part of the mold cavity under the mold and the bottom of the mold. The specific distance should be appropriately selected according to the weight of the forging and the tonnage of the selected equipment. The minimum distance should be no less than 100mm to meet the corresponding mold strength requirements.

[0036] 3. Rough design: Figure 7 shown The overall shape of the blank is a long strip, with a trapezoidal shape pressed out on one side of the middle part. This provides a preliminary shape for subsequent tire mold bending and avoids surface quality defects such as folding caused by severe deformation. The blank size is mainly designed based on the blank size. The width of the blank is consistent with the blank size. The other design principles are as follows: L6=(1.01~1.05)×L3, H8=(1.01~1.05)×H1, H9=H2-H, θ2<θ3<70°.

[0037] L6: total length of the blank, H8: thickness of both ends of the blank, H9: thickness of the middle part of the blank, θ3: angle between the middle inclined part of the blank and the central axis.

[0038] The forging process of thin-walled semi-circular ring clamps and other special-shaped structural parts is as follows: Figure 8 As shown, the specific operation is: first, use ordinary free forging to forge a bar of appropriate size into a square and stretch it into a blank with a ladder shape on one side, then place the blank into the cavity of the lower die and adjust the length direction. After that, place the root of the upper die punch in the center on the trapezoidal side of the blank. Start the equipment, press down slowly, bend the blank, and stop when the two ends of the blank touch the root of the upper die punch, and finally obtain the required blank shape. In order to avoid the upper die shaking left and right or the blank sliding back and forth during the pressing process, it is recommended to use equipment with a slower pressing speed, such as a press. During this process, almost no plastic deformation occurs inside the blank. For materials that are more sensitive to deformation, such as A-100, the heating temperature needs to be appropriately reduced during this process to ensure the corresponding internal quality.

[0039] Implementation Cases An A-100 clamp forging weighs 23 kg and has a semicircular parting surface. The outer radius is 126 mm, the thickness at this point is 25 mm, and the front-to-back ratio is 5.04. The forging has a total horizontal length of 575 mm, a maximum width of 108 mm, and a front-to-back ratio of 5.32, making it a typical thin-walled, semicircular clamp-like special-shaped structural component. Furthermore, the inner radius is 101 mm, the minimum width is 77 mm, and the thickness is thinner in the middle and thicker at the ends, with a maximum thickness of 76 mm. The angle of the inclined surface near the die opening of the lower mold cavity is 52°.

[0040] The overall forging process is as follows: Step 1: Use a saw to cut the material, the cutting size is: Ф150×235mm.

[0041] Step 3: Use a 3t free forging hammer to make the blank.

[0042] After the bar is heated as required, the bar is transferred to the lower anvil of the corresponding forging hammer by a trackless manipulator, and then the equipment is started. The bar is first forged to: 130 (length) × 65 (width) × 130 (height), and then it is stretched to Figure 9 The blank size shown is 31.5 kg. After pressing, the blank is transferred to a dry flat surface and air-cooled to room temperature.

[0043] Step 3: Use 2500t fast forging machine to make tire mold (see the upper mold size Figure 10 , see the size of the lower tire mold Figure 11 ) bending.

[0044] Heat the blank as required. About 10 minutes before the blank is removed from the oven, place the lower mold on the lower hammer anvil. Once the blank is heated to the required temperature, use a trackless robot to transfer the blank to the lower mold cavity and quickly adjust the position with a crowbar. Then place the upper mold on the upper end of the blank and move it to the center. Then start the machine and slowly press down at a speed of ~15mm / s. After the pressing is completed, remove the upper mold first and then remove the blank (such as Figure 12 After the pressing is completed, the blanks are transferred to a dry flat ground and air-cooled to room temperature.

[0045] Step 4: Use 630KJ to die forge the hammer.

[0046] After heating the blank as required, a trackless robot transfers the bar stock to the corresponding lower mold cavity. A crowbar quickly adjusts the blank's position. After adjustment, the horizontal length of the blank's contact points with both sides of the lower mold cavity is 565mm. The maximum contact length between the blank's lower end face and both sides of the forging's lower mold cavity is 565mm, and the blank's lower end face has approximately 60% contact with the lower mold cavity. When hammering, first use two to three light strikes to position the blank, followed by several heavy strikes to form the blank, ensuring maximum alignment. At the end of forging, the blank is transferred to a dry, flat surface and air-cooled to room temperature.

[0047] Step 5: Use flame cutting to cut off most of the burrs on the outer contour of the forging.

[0048] Step 6: Heat treatment. Heat treatment system: normalizing + high temperature tempering Step 7: Perform physical and chemical tests on relevant testing equipment.

[0049] Finally, a certain A-100 clamp forging was produced through three forging processes: blank forging, die bending, and die forging. Among them, the shape and size of the die are reasonably designed and feasible, which is time-saving and simple in actual operation, and the overall safety risks are extremely small. The final forged blank has good physical consistency, and more than 90% fits the theoretical design. The shape and size of the blank are reasonably designed. During die forging, the blank is placed stably in the mold cavity, and there is no skew when hammering. After die forging, the surface quality of the forging is good, without obvious surface defects such as pinching and folding. The above three forging processes are all completed within one fire. Except for the bending of the die, the average deformation of the forgings in the other fires is more than 30%.

[0050] After conducting physical and chemical tests on a certain clamp forging, the results showed that the overall low-magnification microstructure of the forging was relatively uniform, the high-magnification microstructure met the requirements of grade 8 grain size, the tensile strength was above 1970MPa, and the elongation was above 15%. The entire physical and chemical results fully met the standard requirements.

[0051] This method significantly reduces the difficulty of producing nearly semicircular shapes and improves the stability of the die forging process for thin-walled semicircular ring-shaped clamps. This method is applicable to the production of such forgings using a variety of materials, ensuring that each forging step meets the corresponding deformation requirements, thereby ensuring that the internal and external quality of the final forging meets design requirements. This method is particularly beneficial for the forging of thin-walled semicircular clamps, such as those made from materials with high deformation resistance and large projected areas.

[0052] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A forging method for a thin-walled semicircular ring clamp type structural member, characterized in that: The thin-walled semicircular ring clamp structure includes a ring portion and a boss structure at both ends. The method comprises: Step 1: Determine the rough shape and size according to the size of the forging; the rough shape is a V-shaped shape, where the curvature of the rough shape lower end surface and the lower mold cavity meets the following requirements: θ1min=(0.95~1.05)θmin, where θ is the angle between the tangent line on the inclined surface or curved surface near the die mouth of the lower mold cavity of the forging and the central axis; θ1min is the minimum angle between the inclined surface on the side where the rough shape lower end contacts the lower mold cavity of the forging and the central axis; the angle between the two inclined surfaces of the rough shape V-shaped transition radius; Step 2: Determine the shape and size of the tire mold according to the rough shape and size; The shape of the upper tire mold is a rectangular flat plate with a V-shaped punch. The root of the punch is a small plane, where H3 = (0.85-0.95) × H, where H is the maximum depth of the V-shaped upper end face of the rough mold, H3 is the height of the upper tire mold punch, B1 = (2.5-3.5) × B, L4 = (1-1.1) × L3, H4 = (0.5-0.7) × H3, where B1 is the width of the upper tire mold, L4 is the total length of the upper tire mold, H4 is the thickness of the root of the upper tire mold punch; B is the width of the rough mold. If the rough mold has multiple width sizes, the maximum width size is used; L3 is the total length of the rough mold. The lower tire mold has a V-shaped cavity; Lower tire mold cavity dimensions: B2 = (1.2~1.5) × B, H5 = (0.95~1.05) × H1, H6 = (0.95~1.05) × H2, where B2 is the width of the lower tire mold cavity, H1 is the maximum thickness of the ends of the rough mold, H5 is the height of both sides of the lower tire mold mouth, H6 is the maximum depth of the lower tire mold cavity, and H2 is the total height of the rough mold. Tire mold lower mold module dimensions: B3 = (3.5-5.5) × B2, L5 = (1.1-1.3) × L3, H7 = H6 + S, where B3 is the width of the lower mold module, L5 is the length of the lower mold module, H7 is the height of the lower mold module, S is the distance between the deepest part of the lower mold cavity and the bottom of the mold, and L3 is the total length of the mold. Step 3: Determine the shape and size of the blank according to the shape and size of the blank and the shape and size of the tire mold, wherein the blank is an elongated strip as a whole, and a trapezoidal shape is pressed out on one side of the middle part; Step 4: First, use the ordinary free forging method to forge the appropriate size bar into a square and draw it into a blank with a ladder shape on one side. Then, place the blank into the cavity of the lower die and adjust the length direction. Then, place the root of the upper die punch in the center of the trapezoidal side of the blank. Slowly press down to bend the blank. Stop when the two ends of the blank touch the root of the upper die punch. Finally, the desired blank shape is obtained. Step 5: Die forging the rough mold to obtain the forging.

2. The method according to claim 1, characterized in that Step 1 specifically includes: When the thickness in the middle of the forging is small and the thickness at both ends is large, θ1min>θ2min; when the thickness in the middle of the forging is large and the thickness at both ends is small, θ1min<θ2min, where θ1min is the minimum angle between the inclined surface on the side where the lower end of the rough mold contacts the lower mold cavity of the forging and the central axis, and θ2min is the minimum angle between the inclined surface on the side where the upper end of the rough mold contacts the upper mold cavity of the forging and the central axis.

3. The method according to claim 2, characterized in that In step 1, the contact area between the lower end surface of the rough mold and the cavity of the lower mold is no less than 40%.

4. The method according to claim 1, characterized in that In step 1, the transition radius of the angle between the two inclined surfaces of the V-shaped rough shape satisfies: D3≤D1, D4≥D2, where D1: the size of the inner fillet of the center part of the thin-walled semi-circular clamp forging, D2: the size of the outer fillet of the center part of the thin-walled semi-circular clamp forging, D3: the size of the transition fillet at the angle between the two inclined surfaces of the upper end face of the rough type, D4: the size of the transition fillet at the angle between the two inclined surfaces of the lower end face of the rough type.

5. The method according to claim 1, characterized in that In step 1, the width of the rough shape satisfies: 0.5Bmax<B<Bmin, where B is the width of the forging, Bmax is the maximum width of the forging, and Bmin is the minimum width of the forging; The length of the wild type meets the following requirements: L1=(0.8~1.0)×L2,L3=(0.9~1.2)×L2,wherein, L1: maximum contact length between the lower end surface of the rough type and both sides of the lower mold cavity of the forging, L2: total length of the thin-walled semicircular clamp forging, L3: total length of the rough type; Wild type highly satisfied: H<0.7×L,H2<0.55×L3,wherein, H is the maximum depth of the V-shaped upper end surface of the rough type, H2 is the total height of the rough type, L is the inner length of the V-shaped upper end surface of the rough type, and L3 is the total length of the rough type; The weight ratio of rough mold to die forging is between 1.2 and 1.

4.

6. The method according to claim 1, characterized in that In step 2, the distance S between the deepest part of the mold cavity under the tire mold and the bottom of the tire mold is not less than 100 mm.

7. The method according to claim 1, characterized in that In step three, the size of the blank satisfies: L6=(1.01~1.05)×L3, H8=(1.01~1.05)×H1, H9=H2-H, θ2<θ3<70°, among which, L6: total length of the blank, H8: thickness of both ends of the blank, H9: thickness of the middle part of the blank, θ3: angle between the middle inclined surface of the blank and the central axis, θ2 is the angle between the inclined surface on the side where the upper end of the blank contacts the mold cavity on the forging and the central axis.

8. The method according to claim 1, characterized in that In step 4, the membrane forging process is performed using a press.

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