A manufacturing method for a conical thin-walled part

Abstract

The present invention discloses a manufacturing method for a conical thin-walled part, comprising the following steps: machining a plate-shaped blank, forming the cylindrical structure of the part by shovel spinning, forming the conical thin-walled structure of the part by shear spinning, and machining the margins at both ends. The present invention provides a manufacturing method for a conical thin-walled part with a short production cycle, high raw material utilization rate, and low manufacturing cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of plastic forming, and relates to a manufacturing method for a thin-walled conical barrel-shaped part, in particular to a manufacturing method for a thin-walled part with a cylindrical structure at the small end and a conical shape from the throat to the large end. Background Art

[0002] A typical part of the thin-walled conical barrel-shaped part is the inner liner of a rocket engine, and the material is mainly copper and copper alloy. On one side of the material is a cooling pipeline for loading liquid hydrogen and liquid oxygen, and on the other side is high-temperature gas, which has a wide application in the aerospace field.

[0003] In recent years, with the development of the aerospace industry, the production and delivery quantity of rocket engines has increased day by day, and the demand for the inner liners of thin-walled conical rocket engines has increased. At present, the thin-walled conical barrel-shaped parts are formed by turning a forging, and the following problems have gradually emerged in this production process:

[0004] (1) The forging is formed by hot die forging using a large hydraulic press, and the forging process flow is complex, the production cycle is long, and the delivery cycle is about one month;

[0005] (2) Adopting the forging scheme, the machining allowance is large, and the utilization rate of raw materials is only 10%, and the raw material cost is very high.

[0006] Therefore, there is an urgent need for a manufacturing method for thin-walled conical barrel-shaped parts to shorten the production cycle and reduce the manufacturing cost. Summary of the Invention

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a manufacturing method for thin-walled conical barrel-shaped parts.

[0008] To achieve the above purpose, the present invention adopts the following technical solutions:

[0009] A manufacturing method for thin-walled conical barrel-shaped parts includes the following steps:

[0010] A. Design of the plate blank for the thin-walled conical barrel-shaped part. Calculate the structural dimensions of the plate blank according to the dimensions of the thin-walled conical barrel-shaped part, and then process the plate into the required dimensions of the plate blank:

[0011] Thickness of the boss of the plate blank

[0012] The outer diameter d3 of the boss of the plate blank = (1.25 - 4)d1,

[0013] Thickness of the plate blank

[0014] The outer diameter d4 of the plate blank = d2 + (1.5 - 3)(t1 - t2),

[0015] The inner diameter D2 of the plate blank is (0.25 - 0.75)D1.

[0016] Among them, d1 is the outer diameter of the small-end cylindrical structure, D1 is the inner diameter of the small-end cylindrical structure, t0 is the wall thickness from the throat to the large-end conical thin-wall structure, θ is the cone angle, and d2 is the large-end outer diameter.

[0017] B. For the rotary swaging forming of the cylindrical structure of the conical thin-wall part, a rotary wheel with a fillet radius cuts into the plate surface along a direction forming an angle with the axis of the rotating plate blank and performs radial swaging, dividing the blank into two parts. One part is not affected by the swaging force and remains stationary; the other part is obliquely swaged by the rotary wheel and generates radial flow, and a cylindrical structure can be obtained.

[0018] C. For the shear spinning forming of the conical thin-wall structure of the conical thin-wall part, the plate blank is pressed by the tailstock plate against the end face of the mandrel and rotates together with the main shaft. The rotary wheel approaches the plate blank transversely and maintains a certain clearance value with the mandrel. At the same time, it moves at a uniform speed through the longitudinal feed movement of the rotary wheel. At this time, the rotary wheel applies pressure to the plate blank, causing the material to undergo point-by-point axial shear deformation and adhere tightly to the mandrel, and a conical thin-wall structure with a reduced wall thickness can be obtained.

[0019] D. Machining the allowances at both ends of the machined conical thin-wall part.

[0020] As a preferred method, in the step B, the rotary swaging forming process parameters are as follows: the forming fillet r1 of the rotary wheel is 0.5 - 3 mm; the angle α1 between the axis of rotation of the rotary wheel and the axis of the plate blank is 10 ≤ α1 ≤ 45°; the radial feed rate f1 of the rotary wheel, f1 ≤ 5 mm / r; the rotational speed n1 of the plate blank, n1 ≤ 50 r / min.

[0021] As a preferred method, in the step C, the shear spinning forming process parameters are as follows: the forming fillet r2 of the rotary wheel = (1 - 3)t0; the angle between the axis of rotation of the rotary wheel and the axis of the plate blank the feed rate f2 of the rotary wheel, 0.5 mm / r ≤ f2 ≤ 4 mm / r; the rotational speed n1 of the plate blank, n1 ≤ 100 r / min.

[0022] The present invention has the following advantages:

[0023] (1) After calculation, for the conical thin-wall part formed by the spinning forming process, compared with the forging forming process, the material utilization rate is increased from 10% of the raw material to 23%, saving the raw material cost of precious metals.

[0024] (2) The original forging process production cycle was about 1 month. Using the process method of the present invention, the processing time of the part can be shortened to 4 days, greatly improving the production efficiency. Brief Description of the Drawings

[0025] Figure 1 It is a schematic structural diagram of a conical thin-walled part;

[0026] Figure 2 It is a schematic structural diagram of a blank of a conical thin-walled part;

[0027] Figure 3 It is a schematic diagram of the shovel spinning forming of the cylindrical structure of a conical thin-walled part;

[0028] Figure 4 is Figure 3 a partial enlarged view;

[0029] Figure 5 It is a schematic structural diagram of the shear spinning forming of the conical thin-walled structure of a conical thin-walled part;

[0030] Figure 6 It is a schematic diagram of a conical thin-walled part in Embodiment 1;

[0031] Figure 7 It is a schematic diagram of a plate blank of a conical thin-walled part in Embodiment 1.

[0032] Among them, 1 - spinning wheel, 2 - tailstock, 3 - plate blank of conical thin-walled part, 4 - cylindrical structure, 5 - support plate, 6 - conical thin-walled structure, 7 - mandrel. Specific embodiments

[0033] The present invention will be described in detail below with reference to the accompanying drawings.

[0034] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] Embodiment 1:

[0036] In this embodiment, the material of the target part is copper T2, and the structural dimensions are as Figure 6 shown. The outer diameter of the small-end cylindrical structure is Φ228±0.2 mm, and the inner diameter is Φ220±0.2 mm; the wall thickness from the throat to the large-end conical thin-walled structure is 7±0.2 mm, the large-end outer diameter is Φ630±0.5 mm, and the cone angle is 60°.

[0037] The preparation method of this embodiment is as follows:

[0038] Machined plate blank → Shovel spinning forming of the cylindrical structure of the part → Shear spinning forming of the conical thin-walled structure of the part → Machining the allowances at both ends.

[0039] (1) Machine the plate into a plate blank, and calculate the structural dimensions of the plate blank according to the calculation formula in the invention content. The calculation results are as follows:

[0040] a. The thickness of the boss on the plate-shaped blank is 5 mm;

[0041] b. The outer diameter of the boss on the plate-shaped blank is 350 mm;

[0042] c. The thickness of the plate-shaped blank is 19 mm;

[0043] d. The outer diameter of the plate-shaped blank is 660 mm;

[0044] e. The inner diameter of the plate-shaped blank is 88 mm.

[0045] (2) As shown in Figure 3 Figure, the plate-shaped blank 3 of the part is spin-formed into a small-end cylindrical structure 4. The equipment used in this embodiment is a CZX800 / 3CNC numerically controlled power spinning machine, and a Siemens 840D control system is adopted. Before production, the support plate 5 needs to be installed on the main shaft of the equipment, and the main shaft rotation is realized through a servo motor; the spinning wheel 1 is installed on the spinning wheel seat of the equipment, and the spinning wheel seat is driven by a hydraulic cylinder to realize the radial and axial feed movements of the spinning wheel; the tailstock 2 is installed on the tailstock rod of the equipment to realize the axial movement of the tailstock 2.

[0046] The plate-shaped blank 3 is sleeved on the tailstock 2, and the plate-shaped blank 3 is tightened on the support plate 5 by the tailstock 2. The main shaft rotates together with the support plate, and the spinning wheel 1 realizes the radial and axial feed movements according to the preset program, completing the spin-forming of the small-end cylindrical structure 4 of the part. The main process parameters of the spin-forming are as follows:

[0047] a. The forming fillet of the spinning wheel is 2 mm;

[0048] b. The angle between the axis of rotation of the spinning wheel and the axis of the plate-shaped blank is 30°;

[0049] c. The radial feed rate of the spinning wheel is 2 mm / r:

[0050] d. The rotational speed of the plate-shaped blank is 30 r / min.

[0051] (3) As shown in Figure 5 Figure, the plate-shaped blank of the part is shear-spun into a conical thin-wall structure 6. The equipment used in this embodiment is a CZX800 / 3CNC numerically controlled power spinning machine, and a Siemens 840D control system is adopted. Before production, the mandrel 7 needs to be installed on the main shaft of the equipment, and the main shaft rotation is realized through a servo motor; the spinning wheel 1 is installed on the spinning wheel seat of the equipment, and the spinning wheel seat is driven by a hydraulic cylinder to realize the radial and axial feed movements of the spinning wheel; the tailstock 2 is installed on the tailstock rod of the equipment, and the axial movement of the tailstock can be realized.

[0052] Three sets of plate blanks 3 are sleeved on the tailstock plate 2, and the tailstock plate 2 is used to tightly press the plate blank 3 against the end face of the core mold 7. The main shaft rotates together with the core mold, and the spinning wheel 1 moves radially and axially according to a preset program to complete the shear spinning forming of the tapered thin-walled structure 6 at the large end of the part. The main process parameters of the shear spinning forming are as follows:

[0053] a. The forming fillet of the spinning wheel is 14 mm;

[0054] b. The angle between the axis of rotation of the spinning wheel and the axis of the plate blank is 30°;

[0055] c. The feed rate of the spinning wheel is 3 mm / r;

[0056] d. The rotational speed of the plate blank is 50 r / min.

[0057] (4) Machine the allowances at both ends to obtain qualified products.

[0058] The present invention is not limited to the foregoing specific embodiments. The present invention extends to any new feature or any new combination disclosed in this specification, as well as any new method or process step or any new combination disclosed.

Claims

1. A manufacturing method for a conical thin-walled part, characterized in that, It includes the following steps: A. Design of the plate blank for the conical thin-walled part. Calculate the structural dimensions of the plate blank according to the dimensions of the conical thin-walled part, and then process the plate into the required dimensions of the plate blank: Thickness of the boss of the plate blank The outer diameter d3 of the boss of the plate blank = (1.25 - 4)d1, Thickness of the plate blank The outer diameter d4 of the plate blank = d2 + (1.5 - 3)(t1 - t2), The inner diameter D2 of the plate blank = (0.25 - 0.75)D1, where d1 is the outer diameter of the small-end cylindrical structure, D1 is the inner diameter of the small-end cylindrical structure, t0 is the wall thickness from the throat to the large-end conical thin-walled structure, θ is the cone angle, and d2 is the large-end outer diameter; B. Rotary swaging forming of the cylindrical structure of the conical thin-walled part. Use a roller with a fillet radius to cut into the plate surface along a direction at an angle to the axis of the rotating plate blank and perform radial swaging, so that the blank is divided into two parts. One part is not affected by the swaging force and remains in place; the other part is swaged obliquely by the roller and generates radial flow, and a cylindrical structure can be obtained; C. Shearing spinning forming of the conical thin-walled structure of the conical thin-walled part. The plate blank is pressed by the tailstock plate against the end face of the mandrel and rotates together with the main shaft. The roller approaches the plate blank transversely and maintains a certain clearance value with the mandrel. At the same time, it moves at a uniform speed through the longitudinal feeding movement of the roller. At this time, the roller applies pressure to the plate blank, causing the material to produce point-by-point axial shear deformation and cling to the mandrel, and a conical thin-walled structure with a reduced wall thickness can be obtained; D. Machine-process the allowances at both ends of the machined conical thin-walled part.

2. The manufacturing method of a conical thin-walled part according to claim 1, characterized in that: In the step B, the rotary swaging forming process parameters are as follows: the forming fillet r1 of the roller is 0.5 - 3 mm; the angle α1 between the axis of rotation of the roller and the axis of the plate blank, 10 ≤ α1 ≤ 45°; the radial feeding rate f1 of the roller, f1 ≤ 5 mm / r; the rotational speed n1 of the plate blank, n1 ≤ 50 r / min.

3. A manufacturing method of a conical thin-walled part according to claim 1, characterized in that: In the step C, the shear spinning process parameters are as follows: the forming fillet r2 of the roller is (1 - 3)t0; the angle between the rotation axis of the roller and the axis of the plate blank The feed rate f2 of the roller is 0.5 mm / r ≤ f2 ≤ 4 mm / r; the rotational speed n1 of the plate blank is n1 ≤ 100 r / min.

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