Deep-cavity variable-wall-thickness conical component progressive extrusion forming method and device

Abstract

The invention belongs to the technical field of metal plate forming, and discloses an extrusion forming method and device for a deep-cavity variable-wall-thickness conical component. The method controls material flow through a step-by-step extrusion process, and comprises the following steps: processing a plunger matched with a plate; a plate is placed on the annular base, and upper and lower extrusion male dies are sequentially installed; the plunger is pressed downwards to be tightly attached to the plate, the male die is extruded upwards in a staged ascending mode, and the side wall variable-wall-thickness conical structure is formed step by step. The device comprises a lower extrusion male die, an annular base, a plunger, an inner ring upper extrusion male die and an outer ring upper extrusion male die, wherein the annular base, the outer ring upward extrusion male die, the inner ring upward extrusion male die and the plunger are sequentially sleeved from outside to inside; and the annular base is used for supporting the plate. The method solves the problems of difficult wall thickness control, low material utilization rate, overlarge extrusion force and the like in the traditional process, has the advantages of high forming quality, uniform stress distribution and suitability for batch production, and can be widely applied to the fields of aerospace, automobile manufacturing and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of metal sheet forming, and in particular relates to a progressive extrusion forming method and device for a deep cavity variable wall thickness tapered component. Background Art

[0002] With the increasingly urgent demand for lightweight, high-performance metal components in the aerospace, automobile manufacturing and energy equipment fields, deep-cavity variable-wall-thickness conical components have become an important form of key load-bearing components because of their advantages of both structural strength and material efficiency.

[0003] In traditional manufacturing processes, such components are often formed by welding after segmented casting or by subtractive machining. The segmented casting followed by welding method offers flexibility and reliable connections, but the mechanical properties of the parent material on both sides of the weld interface differ significantly, making crack initiation more likely under service loads. Fluctuations in the local temperature field can also induce non-uniform thermal deformation and residual stress concentration, ultimately leading to a systematic reduction in the structural load-bearing capacity. Subtractive machining methods offer stable production and high component precision, but their material utilization is low, making them unsuitable for mass production. Existing patents employ a method of strong shearing and extrusion, where an upsetting punch upward extrudes material from a storage area to a preset position, forcing the material in the storage area to plastically flow through the material extrusion channel, resulting in a tapered component. However, the extrusion force required for this extrusion is excessive, potentially leading to localized plastic deformation or even cracking of the mold, particularly in the variable cross-section transition zone. Furthermore, excessive frictional heat can cause localized temperature increases in the blank, leading to uneven material structure.

[0004] In short, the above-mentioned technical defects seriously restrict the large-scale application of deep-cavity variable-wall thickness components in key areas such as aircraft engine nozzles and launch vehicle fuel tanks, and there is an urgent need to develop new extrusion forming methods and supporting equipment. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a method and device for progressive extrusion forming of deep-cavity variable-wall-thickness conical components, which solves the problem that existing processing methods all lead to various defects in the final formed components.

[0006] The present invention is achieved through the following technical solutions: The present invention discloses a method for progressive extrusion forming of a deep cavity variable wall thickness tapered component, comprising the following steps: S1. Process the plunger according to the shape and size of the plate; S2, placing the plate on the ring base; Place the outer ring upward extrusion punch and the inner ring upward extrusion punch between the annular base and the plunger in sequence, wherein the outer ring of the outer ring upward extrusion punch is in close contact with the inner cavity of the annular base, the inner cavity of the upward extrusion punch is in close contact with the outer ring of the plunger, and the inner cavity of the outer ring upward extrusion punch is in close contact with the outer ring of the upward extrusion punch; S3. Lower the downward extrusion punch to a preset position so that the plunger fits tightly against the sheet; S4, moving the upward extrusion punch upward to a preset position; S5. Move the outer ring upward extrusion punch upward to a preset position; S6. Lift the downward extrusion punch and take out the extruded component to obtain a deep cavity variable wall thickness conical component.

[0007] Furthermore, when the room temperature plasticity of the plate material is poor, the material to be extruded in the side wall area is locally heated to a preset temperature before extrusion and then extrusion deformation is performed.

[0008] Furthermore, the plate is made of aluminum alloy, magnesium alloy, titanium alloy, carbon steel or stainless steel.

[0009] Furthermore, the outer ring upward extrusion punch and the inner ring upward extrusion punch form a first inclined surface of the material extrusion flow channel, the fillet radius of the lower part of the first inclined surface is R1, the straight section length of the first inclined surface is L1, the inclined surface angle is θ1, 1mm≤R1≤3mm, 100mm≤L1≤150mm, 40°≤θ1≤50°; The outer side of the downward extrusion punch is pre-processed with a second inclined surface for forming a material extrusion flow channel. The radius of the lower part of the second inclined surface is R2, the straight section length of the second inclined surface is L2, and the inclined surface angle is θ2, 1mm≤R2≤5mm, 150mm≤L2≤180mm, θ2=θ1-2°.

[0010] Furthermore, in S6, the side walls of the obtained deep cavity variable wall thickness conical component decrease in thickness from bottom to top, the thickest wall thickness d1 at the lower end is 1 / 2 of the original plate wall thickness, and the thinnest wall thickness d2 at the end is 1 / 10 of the original plate wall thickness.

[0011] Furthermore, the downward speed of the downward extrusion punch is V1, the upward speed of the outer ring upward extrusion punch is V2, and the upward speed of the inner ring upward extrusion punch is also V2, 0.5mm / s≤V1≤1mm / s, 0.2mm / s≤V2≤0.5mm / s.

[0012] The present invention also discloses a device for realizing the method of progressive extrusion forming of a deep cavity variable wall thickness tapered component, comprising a descending extrusion punch, an annular base, an outer ring ascending extrusion punch, an inner ring ascending extrusion punch, and a plunger; the annular base, the outer ring ascending extrusion punch, the inner ring ascending extrusion punch, and the plunger are sequentially arranged from the outside to the inside; the annular base is used to support the plate; The forming surfaces of the downward extrusion punch, the outer ring upward extrusion punch and the inner ring upward extrusion punch are conical surfaces. In the initial state, the conical surfaces of the outer ring upward extrusion punch and the inner ring upward extrusion punch are coplanar. The downward extrusion punch, the outer ring upward extrusion punch and the inner ring upward extrusion punch are used to form and extrude the side wall of the plate, so that the side wall material to be extruded flows through the material extrusion flow channel to form a tapered component.

[0013] Furthermore, when the plate has a center hole, one end of the plunger is a flat plate structure, and the other end is prefabricated with a cylindrical protrusion. The diameter of the cylindrical protrusion is the same as the diameter of the center hole of the plate. The downward extrusion punch descends to a preset position, so that the plunger fits tightly with the center hole of the plate, limiting the flow direction of the material during side wall extrusion.

[0014] Furthermore, when the plate has no central hole, both ends of the plunger are flat plate structures.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: The method for progressive extrusion of a deep-cavity variable-wall-thickness component plate disclosed in the present invention effectively controls the progressive distribution of the overall wall thickness of a thin-walled component by extruding the side wall of the material and designing extrusion slopes of different angles to control the direction of material flow, thereby overcoming the problem of difficult control of the side wall thickness of parts in traditional forming bulging or drawing processes. Compared with milling, the method has high production efficiency, good process controllability, suitability for mass production, and good component configuration consistency. At the same time, the use of side wall extrusion deformation can reduce the extrusion force, make the material stress distribution uniform, improve the surface quality of the formed component, and enhance the strength of the thin-walled structure. Furthermore, when the material's room-temperature plasticity is poor, the sidewall area can be locally heated to an appropriate temperature before extrusion. This localized heating can enhance the material's plasticity, ensuring a sufficient processing range for plastic deformation. This ensures sufficient filling of the material during the extrusion process, facilitating smooth extrusion and resulting in a formed component with the desired large deformation capacity.

[0016] Furthermore, the plate is made of aluminum alloy, magnesium alloy, titanium alloy, carbon steel or stainless steel, and has good processing performance, high strength and a wide range of applications.

[0017] Furthermore, the upward extrusion punch forms a first inclined surface for the material extrusion channel. The lower portion of the first inclined surface has a fillet radius of R1, a straight line length of L1, and an angle of θ1, with a range of 1mm≤R1≤3mm, 100mm≤L1≤150mm, and 40°≤θ1≤50°. The outer side of the downward extrusion punch is pre-machined with a second inclined surface for forming the material extrusion channel. The lower portion of the second inclined surface has a fillet radius of R2, a straight line length of L2, and an angle of θ2, with a range of 1mm≤R2≤5mm, 150mm≤L2≤180mm, and θ2 = θ1-2°. Simulation results show that parameters within this range can produce a more precise and precise part configuration in the sidewall extrusion process.

[0018] The device disclosed in the present invention for realizing the above-mentioned method of progressive extrusion forming of deep cavity variable wall thickness component plates includes a downward extrusion device and an upward extrusion device; the upward and downward extrusion processes are combined to complete the processing of conical components in a set of equipment; each component has a simple structure, is easy to process and manufacture, has a low manufacturing cost, is highly compatible with conventional presses, and is suitable for large-scale processing and production of the same type of deep cavity variable wall thickness conical components. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the plate before downward extrusion; Figure 2 This is a schematic diagram of the completion of downward extrusion of the plate; Figure 3 This is a schematic diagram of the completion of the first upward extrusion of the plate; Figure 4 This is a schematic diagram of the second upward extrusion of the plate; Figure 5 Schematic diagram of the sheet after forming; Figure 6 is a schematic diagram of the parameters of the two inclined planes; Figure 7 It is a simulation process diagram and a schematic diagram of the final formed component rotation; In the figure: 1. Downward extrusion punch; 2. Plate; 3. Ring base; 4. Outer ring upward extrusion punch; 5. Inner ring upward extrusion punch; 6. Plunger. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, which are intended to explain the present invention rather than to limit it.

[0021] like Figure 1 As shown, a set of specific devices is used to realize the progressive extrusion forming method of deep cavity variable wall thickness conical components of the present invention. This example is used to specifically explain the progressive extrusion forming method of deep cavity variable wall thickness conical components of the present invention, which does not constitute a limitation of the present invention. The method of the present invention can be realized by using any existing device that can realize its step-by-step function.

[0022] The material of the plate 2 to be formed is aluminum alloy, magnesium alloy, titanium alloy, carbon steel or stainless steel.

[0023] like Figure 1As shown, a device for realizing a progressive extrusion forming method of a deep-cavity variable-wall-thickness conical component comprises a descending extrusion punch 1, an annular base 3, an outer ring ascending extrusion punch 4, an inner ring ascending extrusion punch 5 and a plunger 6; the annular base 3, the outer ring ascending extrusion punch 4, the inner ring ascending extrusion punch 5 and the plunger 6 are sequentially arranged from the outside to the inside; the annular base 3 is used to support the plate 2; the descending extrusion punch 1, the outer ring ascending extrusion punch 4 and the inner ring ascending extrusion punch 5 are used to form and extrude the side wall of the plate 2, so that the material to be extruded on the side wall flows through the material extrusion flow channel to form a conical component; the forming surfaces of the descending extrusion punch 1, the outer ring ascending extrusion punch 4 and the inner ring ascending extrusion punch 5 are conical surfaces. In the initial state, the conical surfaces of the outer ring ascending extrusion punch 4 and the inner ring ascending extrusion punch 5 are coplanar. After the descending extrusion punch 1 descends, the plate 2 is pressed into the forming space.

[0024] One end of the plunger 6 is a flat plate structure, and the shape of the other end depends on whether the plate 2 has a central hole.

[0025] If the plate 2 has a center hole, one end of the plunger 6 is a flat plate structure, and the other end is prefabricated with a cylindrical protrusion. The diameter of the cylindrical protrusion is the same as the diameter of the center hole of the plate 2. The downward extrusion punch 1 descends to a preset position, so that the plunger 6 fits tightly with the center hole of the plate 2, limiting the flow direction of the material during side wall extrusion.

[0026] If the plate 2 has no central hole, both ends of the plunger 6 are flat plate structures.

[0027] Among them, the outer ring upward extrusion punch 4 and the inner ring upward extrusion punch 5 are placed between the annular base 3 and the plunger 6 in sequence, the outer ring of the outer ring upward extrusion punch 4 is close to the inner cavity of the annular base 3, the inner cavity of the inner ring upward extrusion punch 5 is close to the outer ring of the plunger 6, and the inner cavity of the outer ring upward extrusion punch 4 is close to the outer ring of the inner ring upward extrusion punch 5.

[0028] When the plate 2 has a central hole, the above-mentioned device is used to perform an extrusion forming method for a deep cavity variable wall thickness tapered component, including the following steps: Downward extrusion forming: Figure 1 As shown, the plunger 6 is machined according to the size and thickness of the center hole of the plate 2; one end of the plunger 6 is a flat plate structure, and the diameter of the other end is exactly the same as the diameter of the center hole of the plate 2 after it is pressed down to the predetermined position; the plate 2 is placed on the annular base 3; the outer ring upward extrusion punch 4 and the inner ring upward extrusion punch 5 are placed in sequence between the annular base 3 and the plunger 6; like Figure 2 As shown, the downward extrusion punch 1 is lowered to a preset position so that the plunger 6 fits tightly with the center hole of the plate 2; like Figure 3 As shown, the inner ring upward extrusion punch 5 is moved upward to a preset position; like Figure 4As shown, the outer ring upward extrusion punch 4 is moved upward to a preset position; Lift the downward extrusion punch 1 and take out the extruded component to obtain Figure 5 The deep cavity tapered component with variable wall thickness is shown.

[0029] In a preferred embodiment of the present invention, when the room temperature plasticity of the material is poor, before the next extrusion forming step, the material in the side wall area is locally heated to a preset temperature and then extrusion deformation is performed.

[0030] In a preferred embodiment of the present invention, Figure 6 As shown, the upward extrusion punch forms the first inclined surface of the material extrusion flow channel, the radius of the lower part of the first inclined surface is R1, the straight section length of the first inclined surface is L1, the inclined surface angle is θ1, 1mm≤R1≤3mm, 100mm≤L1≤150mm, 40°≤θ1≤50°.

[0031] The outer side of the downward extrusion punch 1 is prefabricated with a second inclined surface, which forms the material extrusion channel. The lower portion of the second inclined surface has a fillet radius of R2, a straight segment length of L2, and an angle of θ2. The range of 1mm≤R2≤5mm, 150mm≤L2≤180mm, and θ2=θ1-2°. Simulation results show that parameters within this range produce a more precise and precise part configuration during the sidewall extrusion process. When θ2 is 2° less than θ1, the wall thickness variation rate during simulation is better, more consistent with expectations.

[0032] In a preferred embodiment of the present invention, the downward speed of the downward extrusion punch 1 is V1, and the upward speed of the outer ring upward extrusion punch 4 and the inner ring upward extrusion punch 5 is V2, 0.5mm / s≤V1≤1mm / s, 0.2mm / s≤V2≤0.5mm / s.

[0033] like Figure 7 As shown in FIG, the forming method is simulated by Deform simulation software, and the results show that the forming process meets the expected effect, and the formed part is a deep cavity variable wall thickness tapered component.

[0034] The present invention will be further described below with a specific example: Prefabricated as Figure 5 The deep cavity tapered component with variable wall thickness shown has sidewalls that decrease in thickness from bottom to top. The parameters are: R1 = 1 mm, R2 = 1 mm, L1 = 125 mm, θ1 = 45°, L2 = 135 mm, θ2 = 43°, d = 5 mm, and the thickest wall at the bottom, d1, is 1 / 2 of d, while the thinnest wall at the end, d2, is 1 / 10 of d.

[0035] First, the downward extrusion process is performed. A plate 2 with a thickness of 5mm and made of 1100 aluminum alloy is placed on the annular base 3. The downward extrusion punch 1 descends to the preset position at a speed V1 of 0.5mm / s. Under the overall constraint formed by the outer ring upward extrusion punch 4 and the inner ring upward extrusion punch 5, the plate 2 is extruded. Figure 2 As shown, the material side wall extrusion area is obtained, and the parameters are R1 is 1 mm, R2 is 1 mm, L1 is 125 mm, θ1 is 45°, L2 is 135 mm, θ2 is 43°, and d is 5 mm.

[0036] Then, the progressive sidewall extrusion process is performed. The outer ring upward extrusion punch 4 and the downward extrusion punch 1 are fixed, and the inner ring upward extrusion punch 5 extrude the sidewall material upward at a speed V2 of 0.3mm / s to a preset position, forcing the material to flow plastically through the material extrusion flow channel. Then, the inner ring upward extrusion punch 5 is fixed, the downward extrusion punch 1 is still fixed, and the outer ring upward extrusion punch 4 also extrude the sidewall material upward at a speed V2 of 0.3mm / s to a preset position, and the following is obtained: Figure 5 In the tapered component shown, the original thickness distance d of the plate 2 is reduced to a maximum of 0.5 mm.

[0037] It should be noted that the present invention is not limited to the above-mentioned embodiments, and any obvious improvements or changes to the above-mentioned embodiments made by those skilled in the art will not exceed the concept of the present invention and the scope of protection of the appended claims.

Claims

1. A method for progressive extrusion forming of a deep cavity tapered component with variable wall thickness, characterized in that: The following steps are involved: S1, processing the plunger (6) according to the shape and size of the plate (2); S2, placing the plate (2) on the annular base (3); The outer ring upward extrusion punch (4) and the inner ring upward extrusion punch (5) are sequentially placed between the annular base (3) and the plunger (6), wherein the outer ring of the outer ring upward extrusion punch (4) is in close contact with the inner cavity of the annular base (3), the inner cavity of the upward extrusion punch (5) is in close contact with the outer ring of the plunger (6), and the inner cavity of the outer ring upward extrusion punch (4) is in close contact with the outer ring of the upward extrusion punch (5); S3, lowering the downward extrusion punch (1) to a preset position so that the plunger (6) and the plate (2) are in close contact; S4, moving the upward extrusion punch (5) upward to a preset position; S5, moving the outer ring upward extrusion punch (4) upward to a preset position; S6. Lift the downward extrusion punch (1) and take out the extruded component to obtain a deep cavity variable wall thickness conical component.

2. The progressive extrusion forming method of a deep cavity variable wall thickness tapered component according to claim 1, characterized in that: When the room temperature plasticity of the plate (2) material is poor, the material to be extruded in the side wall area is locally heated to a preset temperature before extrusion, and then extrusion deformation is performed.

3. The progressive extrusion forming method of a deep cavity variable wall thickness tapered component according to claim 1, characterized in that: The material of the plate (2) is aluminum alloy, magnesium alloy, titanium alloy, carbon steel or stainless steel.

4. The progressive extrusion forming method of a deep cavity variable wall thickness tapered component according to claim 1, characterized in that: The outer ring upward extrusion punch (4) and the inner ring upward extrusion punch (5) form a first inclined surface of the material extrusion flow channel, the fillet radius of the lower part of the first inclined surface is R1, the straight section length of the first inclined surface is L1, the inclined surface angle is θ1, 1mm≤R1≤3mm, 100mm≤L1≤150mm, 40°≤θ1≤50°; The outer side of the downward extrusion punch (1) is pre-processed with a second inclined surface for forming a material extrusion flow channel, the fillet radius of the lower part of the second inclined surface is R2, the straight section length of the second inclined surface is L2, the inclined surface angle is θ2, 1mm≤R2≤5mm, 150mm≤L2≤180mm, θ2=θ1-2°.

5. The progressive extrusion forming method of a deep cavity variable wall thickness tapered component according to claim 1, characterized in that: In S6, the side wall of the obtained deep cavity variable wall thickness conical component decreases in thickness from bottom to top, the thickest wall thickness d1 at the lower end is 1 / 2 of the wall thickness of the original plate (2), and the thinnest wall thickness d2 at the end is 1 / 10 of the wall thickness of the original plate (2).

6. The progressive extrusion forming method of a deep cavity variable wall thickness tapered component according to claim 1, characterized in that: The downward speed of the downward extrusion punch (1) is V1, the upward speed of the outer ring upward extrusion punch (4) is V2, and the upward speed of the inner ring upward extrusion punch (5) is also V2, 0.5mm / s≤V1≤1mm / s, 0.2mm / s≤V2≤0.5mm / s.

7. A device for implementing the progressive extrusion forming method of a deep cavity variable wall thickness tapered component according to any one of claims 1 to 6, characterized in that: It comprises a downward extrusion punch (1), an annular base (3), an outer ring upward extrusion punch (4), an inner ring upward extrusion punch (5) and a plunger (6); the annular base (3), the outer ring upward extrusion punch (4), the inner ring upward extrusion punch (5) and the plunger (6) are sequentially arranged from the outside to the inside; the annular base (3) is used to support the plate (2); The forming surfaces of the downward extrusion punch (1), the outer ring upward extrusion punch (4) and the inner ring upward extrusion punch (5) are conical surfaces, and in an initial state, the conical surfaces of the outer ring upward extrusion punch (4) and the inner ring upward extrusion punch (5) are coplanar; The downward extrusion punch (1), the outer ring upward extrusion punch (4) and the inner ring upward extrusion punch (5) are used to form and extrude the side wall of the plate, so that the material to be extruded on the side wall flows through the material extrusion flow channel to form a tapered component.

8. The device for the progressive extrusion forming method of a deep cavity variable wall thickness tapered component according to claim 7, characterized in that: When the plate (2) has a center hole, one end of the plunger (6) is a flat plate structure, and the other end is prefabricated with a cylindrical protrusion, the diameter of the cylindrical protrusion is the same as the diameter of the center hole of the plate (2), and the downward extrusion punch (1) descends to a preset position, so that the plunger (6) and the center hole of the plate (2) are tightly fitted, limiting the flow direction of the material when the side wall is extruded.

9. The device for the progressive extrusion forming method of a deep cavity variable wall thickness tapered component according to claim 7, characterized in that: When the plate (2) has no central hole, both ends of the plunger (6) are flat plate structures.

Images