A multi-directional extrusion forming method for Ω-shaped rib plate components

Abstract

A multi-directional extrusion forming method for Ω-shaped ribbed plate components belongs to the field of forging. The method solves the problems of difficulty in plastic forming and high production cost of existing aluminum alloy Ω-shaped ribbed plate components. The method includes: 1. forging design; 2. die design; 3. semi-free die forging blank; 4. multi-directional extrusion forming. The method is used for multi-directional extrusion forming of Ω-shaped ribbed plate components.

Description

Technical Field

[0001] The invention belongs to the field of forging. Background Art

[0002] The rapid development of aerospace, weaponry, and other fields requires aircraft to possess faster speeds, longer ranges, and more agile maneuverability. To meet these demands, lightweighting aerospace structural components has become a key development direction. Structural lightweighting is a key aspect of lightweighting research. Designs such as complex contours, thin-walled, high-ribbed components, and integral structures are used to increase the load-bearing capacity per unit weight of material. Omega-shaped ribbed plate components are key load-bearing components in spacecraft fuel tanks. They feature a U-shaped web, flanges on either side of the web, and high-ribbed components distributed along the web and flanges, resulting in a complex structure. Casting is typically used to form these components, but defects such as porosity, component segregation, and coarse grains can hinder component strength and toughness. Machining using large forgings can improve strength and toughness compared to casting, but this method achieves a material utilization rate of less than 5%, resulting in significant material waste, significantly increasing machining time, and significantly increasing production costs. Precision shaping volume forming technology can improve the strength and toughness of components compared to castings while reducing production costs compared to machining. However, due to the high complexity of the shapes of Ω-shaped ribbed plate components, the forming of their flanges and curved ribs is extremely difficult using general unidirectional loading methods. The curved ribs also make it difficult to demold the forgings, and multiple sets of molds are often required for multi-step forming, which reduces production efficiency and increases production costs. Summary of the Invention

[0003] The present invention aims to solve the problems of difficulty in plastic forming and high production cost of existing aluminum alloy Ω-shaped rib plate components, and further provides a multi-directional extrusion forming method for Ω-shaped rib plate components.

[0004] A multi-directional extrusion forming method for an Ω-shaped ribbed plate component is carried out according to the following steps:

[0005] 1. Forging design:

[0006] Design Ω-shaped ribbed plate component forgings based on Ω-shaped ribbed plate component parts;

[0007] The Ω-shaped rib plate component is composed of a U-shaped web, a V-shaped flange and an Ω-shaped bending rib. V-shaped flanges are set on both sides of the U-shaped opening of the U-shaped web, and multiple Ω-shaped bending ribs are evenly distributed along the U-shaped web and the V-shaped flange. Let the maximum height of the part along the length direction of the U-shaped opening be H1, let the maximum width of the part along the width direction of the U-shaped opening be B1, H1:B1=(0.5~3):1, let the maximum width of the U-shaped opening on the U-shaped web be B 1U , B1:B 1U=(1~2.5):1, let the height of the U-shaped part of the Ω-shaped bending rib be H 13 , the width of the Ω-shaped bending rib is B 13 , H 13 :B 13 ≤7:1;

[0008] The Ω-shaped rib plate component forging consists of a U-shaped web, a flange, a bent rib, and a platform. The U-shaped web is obtained by setting machining allowances on both sides of the U-shaped web in the part. The flange is obtained by filling the V-shaped area along the highest point of the flange and setting a draft angle on the filled flange surface. The bent rib is obtained by setting machining allowances on both sides of the width and height of the Ω-shaped bent rib in the part, and rounding the rib root and top. The platform is obtained by setting a rectangular protrusion on the arc top of the U-shaped web in the part.

[0009] Assume that the thickness of the U-shaped web of the forging is T 21 , assuming the height of the bending rib of the forging is H 23 , T 21 :H 23 ≥0.5:1; Assume that the width of the forging ejection platform along the width direction of the U-shaped opening is B 24 , assuming that the maximum width of the U-shaped opening on the U-shaped web of the forging is B 2U , B 24 :B 2U =(0.4~0.8):1;

[0010] 2. Mold design:

[0011] The mold is a multi-directional forming mold, specifically composed of an upper mold, a lower mold and a pair of side molds;

[0012] The upper die is in the form of a punch, and the rib cavity of the forging's curved rib is located on the lower die and a pair of lateral dies. The lower die is a closed structure at both end faces in the length direction of the forging, and a lower top block is provided at the bottom of the lower die. The lower die and the pair of lateral dies are parted at the side walls of the U-shaped web of the forging, and both the lower die and the lateral dies are provided with rounded corners at the parting surfaces. The upper die is provided with an inwardly concave V-shaped resistance groove at the top of the U-shaped arc segment, and a vertical flash groove is provided between the upper die and the lateral dies.

[0013] Assume that the height from the parting surface to the bottom of the mold cavity is H 45 , assuming the height of the U-shaped arc section of the U-shaped web of the forging is H 2U , H 45 :H 2U =(0.7~1.25):1;

[0014] Assume that the width of the concave V-shaped resistance groove is B 31 , B31 :B 2U =(0.2~0.4):1; Assume that the slope of both sides of the concave V-shaped resistance groove is θ 31 , and θ 31 =5°~10°;

[0015] 3. Semi-free die forging:

[0016] The billet is heated, the lower die and a pair of lateral dies are heated to the same temperature as the billet, the upper die is heated to a temperature 10°C to 50°C lower than the temperature of the lower die, the billet and the die are lubricated, the lateral die is opened, the lubricated billet is placed in the lower die, and the upper die is fully pressed down to form the billet. During the forming process, the lateral die and the billet have no contact, the forging billet at the lower end of the parting surface is the same as the cavity of the lower mold, and the forging billet at the upper end of the parting surface is free to deform, thereby obtaining a semi-free die forging billet;

[0017] The blank is an aluminum alloy round bar, and the blank length is L. b , the length of the Ω-shaped rib plate forging is L2, (L2-10mm) <L b ≤L2; let the blank volume be V b , the volume of Ω-shaped rib plate forgings is V2, V b =(1.05~1.25)V2;

[0018] 4. Multi-directional extrusion forming:

[0019] The lateral dies are closed, and the upper free deformation portion of the semi-free die forging billet is extruded and formed according to the lateral die cavity, thus completing the multi-directional extrusion forming method of Ω-shaped rib plate components.

[0020] The beneficial effects of the present invention are:

[0021] In response to the problems of great difficulty in plastic forming and demolding of Ω-shaped ribbed plate components and high production costs of existing methods, the present invention designs multi-directional extrusion forgings, dies, blanks and forming methods. Since the width and thickness of the forging flange are both large, a large amount of metal is required and filling is the most difficult, so pre-forming is required to achieve the aggregation of metal at the flange. The present invention uses the upper and lower dies in the multi-directional extrusion die, and takes advantage of the fact that the space above the parting surface of the upper and lower dies is not restricted by the die cavity. Through the semi-free die forging method, the metal extruded from the parting surface is firstly thicker due to the smaller deformation. After the upper die is fully pressed down, a trumpet-shaped preform with a thick upper end and a thin lower end is obtained, thereby achieving the aggregation of metal at the flange without the need to process additional pre-forming dies. Furthermore, due to the split mold structure between the lower and lateral molds, the ribs of the U-shaped arc segments of the forging are positioned in the lower mold, while the ribs of the U-shaped straight segments are positioned in the lateral molds. This allows the ribs of the arc segments to be demolded vertically, while the ribs of the straight segments are demolded horizontally, significantly reducing the difficulty of demolding the U-shaped ribs. The present invention utilizes a multi-directional extrusion method, employing simple round bar stock, to form Ω-shaped ribbed plate components using only one set of molds and one heat treatment cycle. Compared to direct machining using rectangular forgings, this method increases material utilization by more than three times, significantly reducing machining hours, and, compared to unidirectional loading forming methods, reduces the number of molds and heat treatment cycles, resulting in significant economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 1 is a part model of an Ω-shaped rib plate component in Example 1, Comparative Example 1, and Comparative Example 2. (a) is a visual diagram, (b) is a main view, 11 is a U-shaped web, 12 is a V-shaped flange, and 13 is an Ω-shaped bending rib;

[0023] Figure 2 2 is a forging model of an Ω-shaped rib plate component in Example 1, Comparative Example 1, and Comparative Example 2. (a) is a visual diagram, (b) is a main view, and (c) is an AA cross-sectional view in (b). 21 is a U-shaped web of the forging, 22 is a flange of the forging, 23 is a bending rib of the forging, and 24 is an ejection platform of the forging.

[0024] Figure 3 The mold model in step 2 of Example 1, (a) is a visual diagram, (b) is a side view of (a) in the BB direction, 3 is the upper mold, 4 is the lower mold, 5 is a pair of side molds, and 6 is the lower ejector block;

[0025] Figure 4 2 are cross-sectional views of the mold in step 2 of Example 1, (a) is a complete cross-sectional view, (b) is a partial enlarged view of the dotted box indicated by 31 in (a), 3 is the upper mold, 4 is the lower mold, 5 is a pair of lateral molds, 6 is the lower ejector block, 31 is the concave V-shaped resistance groove, and 32 is the flash groove;

[0026] Figure 5The blank model in step 3 of Example 1, Comparative Example 1 and Comparative Example 2;

[0027] Figure 6 This is the mold model in step 2 of comparative example 1, 3 is the upper mold, 4 is the lower mold, and 6 is the lower ejector block;

[0028] Figure 7 This is the mold model in step 2 of comparative example 2, 3 is the upper mold, 4 is the lower mold, 5 is a pair of side molds, and 6 is the lower ejector block;

[0029] Figure 8 The sectional views of the finite element simulation results of multi-directional extrusion forming in step 4 of Example 1 are shown, (a) before multi-directional extrusion forming, and (b) after multi-directional extrusion forming;

[0030] Figure 9 The finite element simulation results of the blank, semi-free die forging blank, and Ω-shaped rib plate component forging in Example 1 are intuitive diagrams. (a) is the blank described in step 3 of Example 1, (b) is the semi-free die forging blank prepared in step 3 of Example 1, and (c) is the Ω-shaped rib plate component forging prepared in step 4 of Example 1.

[0031] Figure 10 Cross-sectional views of the finite element simulation results of conventional open die forging in step three of comparative example 1, where (a) is when the metal just contacts the upper surface of the upper die flange cavity, and (b) is when the extrusion end is bent and folded;

[0032] Figure 11 This is a cross-sectional view of the finite element simulation results of multi-directional extrusion forming in step 4 of comparative example 2, (a) is before multi-directional extrusion forming, and (b) is after multi-directional extrusion forming. DETAILED DESCRIPTION

[0033] Specific embodiment 1: A multi-directional extrusion forming method of an Ω-shaped rib plate component in this embodiment is carried out in the following steps:

[0034] 1. Forging design:

[0035] Design Ω-shaped ribbed plate component forgings based on Ω-shaped ribbed plate component parts;

[0036] The Ω-shaped rib plate component is composed of a U-shaped web, a V-shaped flange and an Ω-shaped bending rib. V-shaped flanges are set on both sides of the U-shaped opening of the U-shaped web, and multiple Ω-shaped bending ribs are evenly distributed along the U-shaped web and the V-shaped flange. Let the maximum height of the part along the length direction of the U-shaped opening be H1, let the maximum width of the part along the width direction of the U-shaped opening be B1, H1:B1=(0.5~3):1, let the maximum width of the U-shaped opening on the U-shaped web be B 1U , B1:B 1U =(1~2.5):1, let the height of the U-shaped part of the Ω-shaped bending rib be H 13, the width of the Ω-shaped bending rib is B 13 , H 13 :B 13 ≤7:1;

[0037] The Ω-shaped rib plate component forging consists of a U-shaped web, a flange, a bent rib, and a platform. The U-shaped web is obtained by setting machining allowances on both sides of the U-shaped web in the part. The flange is obtained by filling the V-shaped area along the highest point of the flange and setting a draft angle on the filled flange surface. The bent rib is obtained by setting machining allowances on both sides of the width and height of the Ω-shaped bent rib in the part, and rounding the rib root and top. The platform is obtained by setting a rectangular protrusion on the arc top of the U-shaped web in the part.

[0038] Assume that the thickness of the U-shaped web of the forging is T 21 , assuming the height of the bending rib of the forging is H 23 , T 21 :H 23 ≥0.5:1; Assume that the width of the forging ejection platform along the width direction of the U-shaped opening is B 24 , assuming that the maximum width of the U-shaped opening on the U-shaped web of the forging is B 2U , B 24 :B 2U =(0.4~0.8):1;

[0039] 2. Mold design:

[0040] The mold is a multi-directional forming mold, specifically composed of an upper mold, a lower mold and a pair of side molds;

[0041] The upper die is in the form of a punch, and the rib cavity of the forging's curved rib is located on the lower die and a pair of lateral dies. The lower die is a closed structure at both end faces in the length direction of the forging, and a lower top block is provided at the bottom of the lower die. The lower die and the pair of lateral dies are parted at the side walls of the U-shaped web of the forging, and both the lower die and the lateral dies are provided with rounded corners at the parting surfaces. The upper die is provided with an inwardly concave V-shaped resistance groove at the top of the U-shaped arc segment, and a vertical flash groove is provided between the upper die and the lateral dies.

[0042] Assume that the height from the parting surface to the bottom of the mold cavity is H 45 , assuming the height of the U-shaped arc section of the U-shaped web of the forging is H 2U , H 45 :H 2U =(0.7~1.25):1;

[0043] Assume that the width of the concave V-shaped resistance groove is B 31 , B 31 :B 2U=(0.2~0.4):1; Assume that the slope of both sides of the concave V-shaped resistance groove is θ 31 , and θ 31 =5°~10°;

[0044] 3. Semi-free die forging:

[0045] The billet is heated, the lower die and a pair of lateral dies are heated to the same temperature as the billet, the upper die is heated to a temperature 10°C to 50°C lower than the temperature of the lower die, the billet and the die are lubricated, the lateral die is opened, the lubricated billet is placed in the lower die, and the upper die is fully pressed down to form the billet. During the forming process, the lateral die and the billet have no contact, the forging billet at the lower end of the parting surface is the same as the cavity of the lower mold, and the forging billet at the upper end of the parting surface is free to deform, thereby obtaining a semi-free die forging billet;

[0046] The blank is an aluminum alloy round bar, and the blank length is L. b , the length of the Ω-shaped rib plate forging is L2, (L2-10mm) <L b ≤L2; let the blank volume be V b , the volume of Ω-shaped rib plate forgings is V2, V b =(1.05~1.25)V2;

[0047] 4. Multi-directional extrusion forming:

[0048] The lateral dies are closed, and the upper free deformation portion of the semi-free die forging billet is extruded and formed according to the lateral die cavity, thus completing the multi-directional extrusion forming method of Ω-shaped rib plate components.

[0049] In step three of this specific embodiment, the lateral die is retracted to a distance far enough from the mold closing position to ensure that there is no contact between the lateral die and the blank during the forming process in step three.

[0050] In step three of this specific embodiment, the upper die is pressed down to form the blank. The blank deforms under the pressure and cavity constraints of the upper and lower dies until metal is squeezed out of the parting surface of the lower and lateral dies. After this, the squeezed portion is no longer subject to pressure or the mold cavity constraints, and is free to warp and move rigidly only under the push of the unextruded portion. When the upper die is fully pressed down, a semi-free die forging blank is obtained, with the lower end of the parting surface aligned with the mold cavity and the upper end free to deform.

[0051] The beneficial effects of this specific embodiment are:

[0052] In this embodiment, in order to solve the problems of great difficulty in plastic forming and demolding of Ω-shaped ribbed plate components and high production costs of existing methods, multi-directional extrusion forgings, dies, blanks and forming methods are designed. Since the width and thickness of the flange of the forging are very large, a large amount of metal is required and filling is the most difficult, so pre-forming is required to achieve the aggregation of metal at the flange. This embodiment uses the upper and lower dies in the multi-directional extrusion die, and takes advantage of the fact that the space above the parting surface of the upper and lower dies is not restricted by the die cavity. Through the semi-free die forging method, the metal extruded from the parting surface is firstly thicker due to the smaller deformation. After the upper die is fully pressed down, a trumpet-shaped preform with a thick upper end and a thin lower end is obtained, which achieves the aggregation of metal at the flange without the need to process additional pre-forming dies. Furthermore, due to the split mold structure between the lower and lateral molds, the ribs of the U-shaped arc segments of the forging are positioned in the lower mold, while the ribs of the U-shaped straight segments are positioned in the lateral molds. This allows the ribs of the arc segments to be demolded vertically, while the ribs of the straight segments are demolded horizontally, significantly reducing the difficulty of demolding the U-shaped ribs. The present invention utilizes a multi-directional extrusion method, employing simple round bar stock, to form Ω-shaped ribbed plate components using only one set of molds and one heat treatment cycle. Compared to direct machining using rectangular forgings, this method increases material utilization by more than three times, significantly reducing machining hours, and, compared to unidirectional loading forming methods, reduces the number of molds and heat treatment cycles, resulting in significant economic benefits.

[0053] Specific embodiment 2: The difference between this embodiment and specific embodiment 1 is that in step 1, the distance between the top of the forging ejection platform and the top of the forging bending rib is set to H 24 , H 24 :B 1U =(0-1): 1. Other aspects are the same as those in the first embodiment.

[0054] Specific embodiment 3: The difference between this embodiment and either specific embodiment 1 or 2 is that: in step 1, the draft angle of the flange surface after filling is set to θ 2f ,θ 2f =5°~20°. Other aspects are the same as those in the first or second embodiment.

[0055] Specific embodiment 4: The difference between this embodiment and the specific embodiments 1 to 3 is that in step 1, the fillet radius of the rib root of the forging bending rib is set to R 23 , R 23 :H 23 =(0.8-1.5): 1. Other aspects are the same as those in the first to third embodiments.

[0056] Specific embodiment 5: This embodiment differs from any one of the specific embodiments 1 to 4 in that: in step 1, the radius of the fillet at the top of the forging bending rib is set to r 23 , the width of the bending rib of the forging is B 23 , r23 :B 23 =(0.2-0.8): 1. Other aspects are the same as those of the first to fourth embodiments.

[0057] Specific embodiment 6: This embodiment differs from any one of the specific embodiments 1 to 5 in that the upper die, lower die and a pair of side dies described in step 2 are provided with draft angles at both end faces in the length direction of the forging, and the draft angle is θ d ,θ d =3°~10°. Other aspects are the same as those in the first to fifth embodiments.

[0058] Specific embodiment 7: This embodiment differs from specific embodiments 1 to 6 in that the parting surface in step 2 is a horizontal surface. Other aspects are the same as specific embodiments 1 to 6.

[0059] Specific embodiment eight: The difference between this embodiment and the specific embodiments one to seven is that in step two, the fillet of the lower mold at the parting surface is set to R4, R4 = (0.1 ~ 0.4) H 45 The rest is the same as the specific embodiments 1 to 7.

[0060] Specific embodiment 9: This embodiment differs from the specific embodiments 1 to 8 in that: in step 2, the rounded corner of the lateral mold at the parting surface is set to R5, R5 = (0.1 ~ 0.4) H 45 The rest is the same as the specific embodiments 1 to 8.

[0061] Specific embodiment 10: This embodiment differs from specific embodiments 1 to 9 in that in step 3, the blank is heated to a temperature of 420° C. to 480° C. The rest is the same as specific embodiments 1 to 9.

[0062] The following examples are used to verify the beneficial effects of the present invention:

[0063] Example 1, combined with Figures 1 to 5 :

[0064] A multi-directional extrusion forming method for an Ω-shaped ribbed plate component is carried out according to the following steps:

[0065] 1. Forging design:

[0066] Design Ω-shaped ribbed plate component forgings based on Ω-shaped ribbed plate component parts;

[0067] The Ω-shaped rib plate component is composed of a U-shaped web, a V-shaped flange and an Ω-shaped bending rib. V-shaped flanges are provided on both sides of the U-shaped opening of the U-shaped web, and multiple Ω-shaped bending ribs are evenly distributed along the U-shaped web and the V-shaped flange. Assuming that the maximum height of the part along the length direction of the U-shaped opening is H1, and H1=400mm, and the maximum width of the part along the width direction of the U-shaped opening is B1, and B1=526mm, H1:B1=0.76:1, and the maximum width of the U-shaped opening on the U-shaped web is B 1U , and B 1U =296mm, B1:B 1U =1.78:1, let the height of the U-shaped part of the Ω-shaped bending rib be H 13 , and H 13 =30mm, the width of the Ω-shaped bending rib is B 13 , and B 13 =7mm, H 13 :B 13 =4.29:1;

[0068] The Ω-shaped rib plate component forging consists of a U-shaped web, a flange, a bent rib, and a platform. The U-shaped web is obtained by setting machining allowances on both sides of the U-shaped web in the part. The flange is obtained by filling the V-shaped area along the highest point of the flange and setting a draft angle on the filled flange surface. The bent rib is obtained by setting machining allowances on both sides of the width and height of the Ω-shaped bent rib in the part, and rounding the rib root and top. The platform is obtained by setting a rectangular protrusion on the arc top of the U-shaped web in the part.

[0069] Assume that the thickness of the U-shaped web of the forging is T 21 , and T 21 =25mm, assuming the height of the bending rib of the forging is H 23 , and H 23 =29mm, T 21 :H 23 =0.86:1; Assume that the width of the forging ejection platform along the width direction of the U-shaped opening is B 24 , and B 24 =172mm, assuming the maximum width of the U-shaped opening on the U-shaped web of the forging is B 2U , and B 2U =284mm, B 24 :B 2U =0.61:1; Assume that the maximum height of the forging along the length direction of the U-shaped opening is H2, and H2 = 412 mm;

[0070] 2. Mold design:

[0071] The mold is a multi-directional forming mold, specifically composed of an upper mold, a lower mold and a pair of side molds;

[0072] The upper die is in the form of a punch, and the rib cavity of the forging's curved rib is located on the lower die and a pair of lateral dies. The lower die is a closed structure at both end faces in the length direction of the forging, and a lower top block is provided at the bottom of the lower die. The lower die and the pair of lateral dies are parted at the side walls of the U-shaped web of the forging, and both the lower die and the lateral dies are provided with rounded corners at the parting surfaces. The upper die is provided with an inwardly concave V-shaped resistance groove at the top of the U-shaped arc segment, and a vertical flash groove is provided between the upper die and the lateral dies.

[0073] Assume that the height from the parting surface to the bottom of the mold cavity is H 45 , and H 45 =125mm, assuming the height of the U-shaped arc section of the U-shaped web of the forging is H 2U , and H 2U =113mm, H 45 :H 2U =1.11:1;

[0074] Assume that the width of the concave V-shaped resistance groove is B 31 , and B 31 =70mm, B 31 :B 2U =0.25:1; Assume the slope of both sides of the concave V-shaped resistance groove is θ 31 , and θ 31 =7°;

[0075] 3. Semi-free die forging:

[0076] The billet is heated to 440°C, the lower die and a pair of lateral dies are heated to the same temperature as the billet, the upper die is heated to a temperature 20°C lower than the lower die temperature, the billet and the die are lubricated, the lateral die is opened, the lubricated billet is placed in the lower die, and the upper die is fully pressed down to form the billet. During the forming process, the lateral die and the billet have no contact, the forging billet at the lower end of the parting surface is the same as the cavity of the lower mold, and the forging billet at the upper end of the parting surface is free to deform, thereby obtaining a semi-free die forging billet;

[0077] The blank is 2A12 aluminum alloy round bar, and the blank length is L b , and L b =659mm, assuming the billet diameter is φ b ,φ b =265mm, the length of the Ω-shaped rib plate forging is L2, and L2 = 659mm, L2 = L b ; Assume the blank volume is V b , the volume of Ω-shaped rib plate forgings is V2, V b =1.20V2;

[0078] 4. Multi-directional extrusion forming:

[0079] The lateral dies are closed, and the upper free deformation part of the semi-free die forging billet is extruded and formed according to the lateral die cavity to obtain an Ω-shaped rib plate component forging, thus completing the Ω-shaped rib plate component multi-directional extrusion forming method.

[0080] In step 1, the unilateral allowance of the bending rib of the forging in the width direction is 5mm, and the unilateral allowance in the height direction is 9mm; the unilateral allowance on the inner and outer sides of the U-shaped web is 10mm.

[0081] In step 1, the distance between the top of the forging ejection platform and the top of the forging bending rib is H 24 , H 24 :B 1U =0.82:1.

[0082] In step 1, the draft angle of the flange surface after filling is θ 2f ,θ 2f =15°.

[0083] In step 1, the fillet radius of the rib root of the forging bending rib is R 23 , and R 23 =35mm, R 23 :H 23 =1.21:1.

[0084] In step 1, the fillet radius of the top of the forging bending rib is r 23 , and r 23 =12mm, the width of the bending rib of the forging is B 23 , and B 23 =17mm, r 23 :B 23 =0.71:1.

[0085] The upper die, lower die and a pair of side dies described in step 2 are provided with draft angles at both end faces in the length direction of the forging, and the draft angle is set as θ d ,θ d =7°.

[0086] The parting surface described in step 2 is a horizontal surface.

[0087] In step 2, the radius of the lower mold at the parting surface is set to R4, and R4 = 30mm, R4 = 0.24H 45 .

[0088] In step 2, set the radius R5 of the lateral mold at the parting surface, and R5 = 25mm, R5 = 0.2H 45 .

[0089] Figure 8This is a cross-sectional view of the finite element simulation results of multi-directional extrusion forming in step 4 of Example 1, (a) is before multi-directional extrusion forming, and (b) is after multi-directional extrusion forming. Figure 8 (a) The trumpet-shaped forging is thick at the top and thin at the bottom. Figure 8 As shown in the circled position in (a), the material is successfully gathered at the forging flange position. Figure 8 In the forging (b), the flange position is well filled and there is no defect of incomplete filling.

[0090] Figure 9 The figures are intuitive diagrams of the finite element simulation results of the blank, semi-free die forging blank and Ω-shaped rib plate type component forging in Example 1, (a) is the blank described in step 3 of Example 1, (b) is the semi-free die forging blank prepared in step 3 of Example 1, and (c) is the Ω-shaped rib plate type component forging prepared in step 4 of Example 1; it can be seen from the figures that the forgings are well filled at all positions along the length direction without any defects of incomplete filling.

[0091] Comparative Example 1: Combination Figure 1 、 2 , 5, and 6 specifically explain that this comparative example differs from Example 1 in that the forming die in step 2 is a one-way die, the bending rib cavities are all located within the lower die, and both the lower and upper dies are provided with horizontal flash grooves on the outer edges of the flanges; step 3 is conventional open die forging, where forming is completed by pressing the upper die into place, and step 4 is omitted. The remaining steps are the same as in Example 1.

[0092] Figure 10 This is a cross-sectional view of the finite element simulation results of conventional open die forging in step 3 of comparative example 1. (a) is when the metal just contacts the upper surface of the upper die flange cavity, and (b) is when the extrusion end is bent and folded; Figure 10 (a) It can be seen that since the thickness of the forging web is very small compared to the flange, when the metal contacts the upper surface of the upper die flange cavity, the forging in the flange cavity appears as a long and thin strip, such as Figure 10 As shown in the circle in (a), the metal in this shape has poor stability and becomes unstable during the forming process, resulting in folding, such as Figure 10 As shown in the circle in (b).

[0093] Comparative Example 2: Combination Figure 1 、 2 , 5 and 7 specifically illustrate that the difference between this comparative example and Example 1 is that: in step 2, H 45 =150mm, H 45 :H 2U =1.33:1. The remaining steps are the same as those in Example 1.

[0094] Figure 11This is a cross-sectional view of the finite element simulation results of multi-directional extrusion in step 4 of comparative example 2. (a) is before multi-directional extrusion, and (b) is after multi-directional extrusion. Because the height of the parting surface from the bottom of the mold cavity is too large, the height of the forging blank produced by semi-free die forging is also too large, resulting in a large amount of metal at the highest point of the extrusion end entering the flash groove between the upper die and the side die. Figure 11 As shown in the circle in (a); this part of the metal can only continue to fill the flash groove during the subsequent multi-directional extrusion forming, and cannot fill the mold cavity, such as Figure 11 As shown in the rectangular box in (b), this will cause serious material shortage at the flange, resulting in the flange not being fully filled, such as Figure 11 As shown in the circle in (b).

Claims

1. A multi-directional extrusion forming method for Ω-shaped rib plate components, characterized in that It is carried out in the following steps:

1. Forging design: Design Ω-shaped rib plate component forgings based on Ω-shaped rib plate component parts; The Ω-shaped rib plate component part is composed of a U-shaped web, a V-shaped flange and an Ω-shaped bending rib. V-shaped flanges are arranged on both sides of the U-shaped opening of the U-shaped web, and a plurality of Ω-shaped bending ribs are evenly arranged along the U-shaped web and the V-shaped flange. The maximum height of the part along the length direction of the U-shaped opening is H1, the maximum width of the part along the width direction of the U-shaped opening is B1, H1:B1=(0.5-3):1, the maximum width of the U-shaped opening on the U-shaped web is B 1U , B1:B 1U =(1~2.5):1, let the height of the U-shaped part of the Ω-shaped bending rib be H 13 , the width of the Ω-shaped bending rib is B 13 , H 13 :B 13 ≤7:1; The Ω-shaped rib plate type component forging is composed of a forged U-shaped web, a forged flange, a forged bending rib and a forged ejection platform; the forged U-shaped web is obtained by setting machining allowances on both sides of the U-shaped web in the part; the forged flange is obtained by filling the V-shaped area along the highest point of the flange in the part, and setting a draft angle on the filled flange surface; the forged bending rib is obtained by setting machining allowances on both sides of the width and height direction of the Ω-shaped bending rib in the part, and rounding the rib root and the rib top; the forged ejection platform is obtained by setting a rectangular protrusion on the arc top of the U-shaped web in the part; Assume the thickness of the U-shaped web of the forging is T 21 , assuming the height of the bending rib of the forging is H 23 , T 21 :H 23 ≥0.5:1; Assume that the width of the forging ejection platform along the width direction of the U-shaped opening is B 24 , assuming that the maximum width of the U-shaped opening on the U-shaped web of the forging is B 2U , B 24 :B 2U =(0.4~0.8):1; 2. Mould design: The mold is a multi-directional forming mold, specifically composed of an upper mold, a lower mold and a pair of side molds; The upper die is in the form of a punch, the rib cavity of the forging bending rib is located on the lower die and a pair of lateral dies, and the lower die is a closed structure at both end faces in the length direction of the forging, and a lower top block is arranged at the bottom of the lower die; the lower die and the pair of lateral dies are separated at the side wall of the U-shaped web of the forging, and the lower die and the lateral die are both provided with rounded corners at the separation surface; the upper die is provided with a concave V-shaped resistance groove at the top of the U-shaped arc segment, and a vertical flash groove is provided between the upper die and the lateral die; Assume that the height from the parting surface to the bottom of the mold cavity is H 45 , assuming that the height of the U-shaped arc section of the U-shaped web of the forging is H 2U , H 45 :H 2U =(0.7~1.25):1; Assume that the width of the concave V-shaped resistance groove is B 31 , B 31 :B 2U =(0.2~0.4):1; Assume the slope of both sides of the concave V-shaped resistance groove is θ 31 , and θ 31 =5°~10°; 3. Semi-free die forging: The billet is heated, the lower die and a pair of lateral dies are heated to the same temperature as the billet, the upper die is heated to a temperature 10°C to 50°C lower than the temperature of the lower die, the billet and the die are lubricated, and the lateral die is opened, the lubricated billet is placed in the lower die, and the upper die is fully pressed down to form the billet. During the forming process, the lateral die has no contact with the billet, the forging billet at the lower end of the parting surface is the same as the lower mold cavity, and the forging billet at the upper end of the parting surface is freely deformed to obtain a semi-free die forging billet; The blank is an aluminum alloy round bar, and the length of the blank is L. b , the length of the Ω-shaped rib plate forging is L2, (L2-10mm) <L b ≤L2; Assume the blank volume is V b , the volume of the Ω-shaped rib plate forging is V2, V b =(1.05~1.25)V2; 4. Multi-directional extrusion forming: The lateral dies are closed, and the upper free deformation part of the semi-free die forging billet is extruded and formed according to the lateral mold cavity, thus completing the multi-directional extrusion forming method of Ω-shaped rib plate components.

2. A multi-directional extrusion forming method for an Ω-shaped rib plate component according to claim 1, characterized in that In step 1, the distance between the top of the forging ejection platform and the top of the forging bending rib is H. 24 , H 24 :B 1U =(0~1):

1.

3. The multi-directional extrusion forming method of an Ω-shaped rib plate component according to claim 1, characterized in that In step 1, the draft angle of the flange surface after filling is θ 2f ,θ 2f =5°~20°.

4. The multi-directional extrusion forming method of an Ω-shaped rib plate component according to claim 1, characterized in that In step 1, the radius of the fillet at the root of the forging bending rib is R 23 , R 23 :H 23 =(0.8~1.5):

1.

5. The multi-directional extrusion forming method of an Ω-shaped rib plate component according to claim 1, characterized in that In step 1, the radius of the fillet at the top of the forging bending rib is r 23 , the width of the bending rib of the forging is B 23 , r 23 :B 23 =(0.2~0.8):

1.

6. The multi-directional extrusion forming method of an Ω-shaped rib plate component according to claim 1, characterized in that The upper die, lower die and a pair of side dies described in step 2 are provided with draft angles at both end faces in the length direction of the forging, and the draft angle is θ d ,θ d =3°~10°.

7. The multi-directional extrusion forming method of an Ω-shaped rib plate component according to claim 1, characterized in that The parting surface described in step 2 is a horizontal surface.

8. The multi-directional extrusion forming method of an Ω-shaped rib plate component according to claim 1, characterized in that In step 2, the fillet of the lower mold at the parting surface is set to R4, R4 = (0.1 ~ 0.4) H 45 .

9. The multi-directional extrusion forming method of an Ω-shaped rib plate component according to claim 1, characterized in that In step 2, the fillet of the lateral mold at the parting surface is set to R5, R5 = (0.1 ~ 0.4) H 45 .

10. The multi-directional extrusion forming method of an Ω-shaped rib plate component according to claim 1, characterized in that In step three, the blank is heated to a temperature of 420°C to 480°C.

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