A stepwise shearing forming method for T-rib cylindrical parts

Abstract

A step-by-step shearing forming method for a T-rib cylindrical part is based on the cylindrical part spinning forming process and the multi-directional coordinated loading of a rotary wheel. First, the shear rotary wheel loads the cylindrical part blank axially, and the material flows from the axial direction to the radial direction to form an I-rib cylindrical part; secondly, the flow rotary wheel loads twice in the positive and reverse directions along the axial direction to thin the other side of the cylindrical part blank and make the I-rib fuller; thirdly, the fractal rotary wheel loads radially along the top of the I-rib, and the material flows from the radial direction to the axial direction to form a Y-rib cylindrical part; finally, the flat rotary wheel loads radially along the top of the Y-rib, and the material continues to flow from the radial direction to the axial direction until a T-rib cylindrical part is formed. The step-by-step shearing forming method for a T-rib cylindrical part of the present invention realizes the overall plastic forming of the T-rib cylindrical part at room temperature, thereby improving the forming efficiency and reducing the production cost, that is, solving the technical problem that the traditional technology cannot effectively form the T-rib cylindrical part.

Description

Technical Field

[0001] The invention relates to the technical field of plastic processing of thin-walled parts, and in particular to a stepwise shearing forming method of a T-rib cylindrical part. Background Art

[0002] With the rapid development of high-end equipment such as rockets, missiles and artificial satellites in the aerospace field, especially the increasing requirements for large capacity, low consumption and long life of new-generation fighters and large launch vehicles, their key components are constantly developing in the direction of high performance, lightweight and high precision. In order to meet the above requirements, high-end equipment such as aerospace vehicles use a large number of complex thin-walled T-rib cylindrical parts made of lightweight and high-strength materials. This type of component not only uses difficult-to-deform materials such as high-strength aluminum alloys, but also has the difficult-to-form characteristics of a large-diameter cylinder (>1m) combined with a local complex rib structure (T-rib structure, <20mm), making its high-performance overall plastic forming very difficult. At present, the main manufacturing methods used are mechanical processing or block forming and then riveting / welding assembly.

[0003] However, mechanical processing has low material utilization, long cycle, and will cut off metal flow lines, generate complex residual stress, and lead to shape distortion and microcrack initiation; moreover, the process of forming by blocks and then riveting / welding assembly has many steps, long process, and rivets / welds will cause weight gain. Therefore, these two methods cannot achieve high-performance integral forming of T-rib cylindrical parts, and new integral plastic forming methods need to be developed.

[0004] The spinning process has the advantages of small forming load, high flexibility, high forming accuracy, etc., and has extremely high flexibility in the direction and form of the roller loading. Based on the spinning process and the multi-directional coordinated loading of the roller, by designing the roller shape, loading direction and roller intervention time, it is a potential method to achieve the overall plastic forming of T-ribbed cylindrical parts. After searching the existing technology, the main methods for spinning forming of ribbed cylindrical parts are shear forming and heat-assisted flow spinning.

[0005] In the Chinese patent application document with application number CN 114192647 A, a shearing forming method for cylindrical parts with an annular outer rib is disclosed. The method is based on the spinning forming process of cylindrical parts, uses an annular back pressure die to impose radial constraints on the cylindrical blank, and selects a shearing wheel and changes the working angle of the shearing wheel at the same time, so that the shearing working surface of the shearing wheel and the cylindrical blank are in contact in the form of an assembly surface, and the cylindrical blank is sheared and spun until an annular outer rib is formed. This method is mainly aimed at the forming of cylindrical parts with annular outer ribs, that is, only I-shaped ribs are formed, and T-shaped ribs cannot be formed.

[0006] In the Chinese patent application document with application number CN 110586730 A, a forming method of a cylindrical part with inner wall longitudinal ribs is disclosed. In this method, a preheated cylindrical blank is put on a spinning core mold, and the tail of the cylindrical blank is fixed with a tail top. While the spinning machine main shaft drives the spinning core mold and the cylindrical blank to rotate, a flame heating gun is ignited to uniformly heat the cylindrical blank, and the spinning wheel is processed according to the preset spinning process trajectory until the inner wall longitudinal ribs are formed. This method combines the advantages of flow spinning and hot processing to achieve the overall forming of a cylindrical part with inner wall longitudinal ribs, but the requirements for the spinning core mold are high, and it is difficult to extend to T-rib cylindrical parts. In addition, hot processing has problems such as high energy consumption and easy pollution.

[0007] In summary, the existing method of spinning forming of ribbed cylindrical parts is suitable for the forming of I-ribbed cylindrical parts, but it cannot get rid of the dependence of the structural characteristics of the component on the mold, that is, it cannot meet the forming requirements of T-ribbed cylindrical parts. Summary of the invention

[0008] In order to solve the above-mentioned technical problems existing in the prior art, the present invention provides a step-by-step shear forming method for T-rib cylindrical parts. The forming method realizes the overall plastic forming of the T-rib cylindrical parts at room temperature, thereby improving the forming efficiency and reducing the production cost, that is, solving the technical problem that traditional technology cannot effectively form T-rib cylindrical parts.

[0009] To achieve the above object, the present invention provides a stepwise shearing forming method for a T-rib cylindrical member, which comprises the following steps:

[0010] S1. Clamp the cylindrical blank onto the core mold of the CNC spinning machine, and assemble the shearing wheel, the flow wheel, the fractal wheel, and the flat wheel onto the wheel frame of the CNC spinning machine;

[0011] S2, adjusting the shearing wheel so that its shearing working surface contacts the surface of the cylindrical blank, starting the CNC spinning machine, causing the cylindrical blank to rotate circumferentially under the drive of the core mold, and controlling the shearing wheel to feed along the axial direction of the cylindrical blank until the shearing wheel feed amount is reached, thereby preparing an incomplete I-rib cylindrical part with an incomplete I-rib structure;

[0012] S3, adjust the flow wheel so that its working surface is in vertical contact with the surface of the unsaturated I-shaped rib cylindrical part, continue the rotating state of the cylindrical part blank in step S2, and the flow wheel thins the unthinned side of the unsaturated I-shaped rib cylindrical part to make the wall thickness of both sides equal, and then the flow wheel axially extrudes and shapes the unsaturated I-shaped rib structure to obtain a full I-shaped rib cylindrical part with a full I-shaped rib structure, wherein the rib height of the full I-shaped rib structure is h s , width is w s ;

[0013] S4, adjusting the fractal wheel so that its fractal working surface contacts the top of the full I-shaped rib structure, continuing the rotation state of the cylindrical blank in step S2, and making the fractal wheel perform radial feeding motion until the fractal wheel feed amount is reached, thereby preparing a Y-shaped rib cylindrical part with Y-shaped ribs;

[0014] S5. Adjust the flat rotating wheel so that its working surface is in vertical contact with the surface of the Y-rib cylindrical part. Continuing the rotation state of the cylindrical part blank in step S2, the flat rotating wheel is radially loaded along the top of the Y-rib to reshape the Y-rib cylindrical part into a T-rib cylindrical part.

[0015] As a further preferred technical solution of the present invention, a positioning step is processed at the end of the cylindrical blank in step S1, and the height of the positioning step is equal to the shearing amount of the shearing wheel in step S2.

[0016] As a further preferred technical solution of the present invention, the shearing wheel comprises an upper shearing working surface and a lower shearing working surface with an angle of 90° between them. The upper and lower shearing working surfaces are connected by a transition fillet, and the radius of the wheel fillet is 0.5 to 3 mm.

[0017] As a further preferred technical solution of the present invention, the flow wheel is a double-cone angle wheel, the wheel forming angle is 0-30°, the radius of the wheel fillet is 0.5-3mm, and the thinning amount of the flow wheel is equal to the shearing amount of the shear wheel.

[0018] As a further preferred technical solution of the present invention, the fractal wheel is a double cone angle wheel, the wheel forming angle is 30-45°, and the radius of the wheel fillet is 0.5-3 mm.

[0019] As a further preferred technical solution of the present invention, the flat wheel has a forming angle of 0°, and the feed amount of the flat wheel is equal to the feed amount of the fractal wheel.

[0020] As a further preferred technical solution of the present invention, the shearing wheel, the flow wheel, the fractal wheel and the flat wheel are all provided in two numbers, and are symmetrically distributed and installed on the wheel frame of the CNC spinning machine.

[0021] As a further preferred technical solution of the present invention, the core mold rotation speed is 30-180rpm, the shear wheel feed speed is 0.5-2mm / s, the flow wheel feed speed is 0.3-3mm / s, the fractal wheel feed speed is 0.5-2.5mm / s, and the flat wheel feed speed is 0.5-2.5mm / s.

[0022] As a further preferred technical solution of the present invention, in step S3, the rib height of the full I-shaped rib structure is h s , width is w s , where the tendon height h sThe outer diameter D0 of the cylindrical blank, the shearing amount s of the shearing wheel, and the feed amount f of the shearing wheel s Satisfies the following relationship:

[0023] Where: D1 = D0-2s;

[0024] Width w of full I-type rib structure s ≈s.

[0025] As a further preferred technical solution of the present invention, the height H, width W, web thickness t1, flange thickness t2, shearing amount s, feed amount f of the T-rib cylindrical part are s And, the feed rate of the fractal wheel is f p , satisfying the following relationship:

[0026] H≈h s -f p ; t1≈s; t2≈0.5s.

[0027] The step-by-step shearing forming method of the T-rib cylindrical part of the present invention is based on the spinning forming process of the cylindrical part and the multi-directional coordinated loading of the rotary wheel, combined with various local shearing deformation methods such as shearing forming, flow spinning and fractal spinning, and sequentially forms the I-rib structure and the T-rib structure through the axial and radial loading of the rotary wheel, realizing the step-by-step shearing deformation of the cylindrical part blank, and finally realizing the integrated and step-by-step shearing forming of the T-rib cylindrical part. Due to the adoption of the above technical scheme, the present invention has the following beneficial effects compared with the prior art:

[0028] 1. The overall plastic forming of the T-rib cylindrical parts is achieved through shear forming, flow spinning, fractal spinning and other local shear deformations, avoiding the introduction of rivets / welds, and effectively improving the forming accuracy and service reliability of the T-rib cylindrical parts;

[0029] 2. The parameters of the T-rib structure (web height, wing height, web thickness, wing thickness) are controlled by the shearing wheel shearing amount, shearing wheel feed amount, fractal wheel feed amount and flat wheel feed amount, and are not limited by the geometric factors of the mold and the barrel blank. Therefore, the present invention is conducive to forming a small-sized T-rib structure (mm level) on a large-diameter cylinder (m level), thereby improving the forming limit of the T-rib cylindrical part. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0031] Figure 1 It is a schematic diagram of the structure of a cylindrical blank;

[0032] Figure 2It is a schematic diagram of the structure of an unfull I-shaped rib cylindrical part;

[0033] Figure 3 It is a schematic diagram of the structure of a full I-shaped rib cylindrical part;

[0034] Figure 4 It is a schematic diagram of the structure of a Y-shaped ribbed cylindrical part;

[0035] Figure 5 It is a schematic diagram of the structure of a T-rib cylindrical part;

[0036] Figure 6 is a schematic diagram of the structure of the shear wheel, in which the dotted line is its center line, and 90° is the angle between the upper shear working surface and the lower shear working surface;

[0037] Figure 7 Schematic diagram of the structure of the flow wheel, the dotted line in the figure is its center line, and 0 to 30° is the wheel forming angle;

[0038] Figure 8 Schematic diagram of the structure of the fractal wheel, the dotted line in the figure is its center line, and 30-45° is the forming angle of the wheel;

[0039] Fig. 9 It is a schematic diagram of the structure of the flat-rotating wheel, and the dotted line in the figure is its center line;

[0040] Fig.10 It is a schematic diagram of the process of stepwise shearing and forming of T-rib cylindrical parts;

[0041] Fig.11 It is a schematic diagram of the key dimensions in the step-by-step shearing of T-rib cylindrical parts.

[0042] In the figure: 1. Cylindrical blank; 2. Positioning step; 3. Incomplete I-rib cylindrical part; 4. Incomplete I-rib structure; 5. Full I-rib cylindrical part; 6. Full I-rib structure; 7. Y-rib cylindrical part; 8. Y-rib structure; 9. T-rib cylindrical part; 10. T-rib structure; 11. Core mold; 12. Shearing wheel; 13. Flow wheel; 14. Fractal wheel; 15. Flat wheel.

[0043] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0044] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. The terms such as "upper", "lower", "left", "right", "middle" and "one" cited in the preferred embodiments are only for the convenience of description, and are not used to limit the scope of the present invention. The change or adjustment of the relative relationship shall also be regarded as the scope of the present invention without substantially changing the technical content.

[0045] The step-by-step shearing forming method of a T-rib cylindrical part proposed in the present invention is based on the cylindrical part spinning forming process and the multi-directional coordinated loading of a rotary wheel. First, the shear rotary wheel loads the cylindrical part blank axially, and the material flows from the axial direction to the radial direction to form an I-rib cylindrical part; secondly, the flow rotary wheel loads twice in the positive and reverse directions along the axial direction to thin the other side of the cylindrical part blank and make the I-rib fuller; thirdly, the fractal rotary wheel loads radially along the top end of the I-rib, and the material flows from the radial direction to the axial direction to form a Y-rib cylindrical part; finally, the flat rotary wheel loads radially along the top end of the Y-rib, and the material continues to flow from the radial direction to the axial direction until a T-rib cylindrical part is formed.

[0046] Embodiment 1

[0047] See also Figure 1-11 The 6061 aluminum alloy T-shaped rib cylindrical member 9 (such as Figure 5 ), its geometric dimensions are: outer diameter D1 is 198mm, inner diameter d is 180mm, and the processed T-shaped rib (such as Fig.11 ) has a height H of 4 mm, a width W of 5 mm, a web thickness t1 of 1 mm, and a flange thickness t2 of 0.5 mm. Figure 5 ) geometric dimensions, it can be seen that the I-shaped rib cylindrical member 5 (such as Figure 3 )'s geometric dimensions are: I-type reinforcement (such as Fig.11 ) s 6mm, rib width w s 1mm; cylindrical blank 1 (such as Fig.11 ) has the following geometric dimensions: outer diameter D0 is 200 mm, inner diameter d is 180 mm, positioning step 2 (such as Figure 1 ) has a length C1 of 0.5 to 1.5 mm; the core mold 11 (such as Fig.10 ) has a diameter of 179mm.

[0048] like Fig.10 As shown, the stepwise shearing forming method of the T-rib cylindrical part specifically comprises the following steps:

[0049] Pre-design of step-by-step shearing forming process parameters:

[0050] The T-rib cylindrical part 9 is the target workpiece. According to the key geometric dimensions of the T-rib cylindrical part 9 (height H, width W, web thickness t1, wing thickness t2), the following key process parameters are designed: the shearing amount s of the shearing wheel is 1 mm, the feed amount f s The thinning amount of the flow wheel is 1mm, the feed amount is 10mm, the feed speed is 1mm / s, and the intervention time is 6.1s; the feed amount of the fractal wheel is f pThe feed amount of the flat wheel is 2mm and the feed speed is 1.5mm / s; the feed amount of the flat wheel is 2mm and the feed speed is 1mm / s; the spindle speed is 90rpm.

[0051] Among them, the shearing amount s of the shearing wheel and the feed amount f of the shearing wheel are s , the feed rate of the fractal wheel f p The relationship between the geometric dimensions of the T-rib cylindrical member 9 satisfies the following relationship:

[0052] H≈h s -f p ; t1≈s; t2≈0.5s;

[0053] in, Where: D1 = D0-2s; width w of I-type reinforcement s ≈s.

[0054] The above formula is used to design key process parameters such as the shearing amount of the shear wheel, which reduces the cost and time of process parameter design and helps to improve production efficiency.

[0055] In the following processing, in order to facilitate the distinction of the fullness of the I-type ribs, the incomplete I-type ribs are called incomplete I-type rib structures, and the full I-type ribs are called full I-type rib structures.

[0056] S1. Install the mold and blank:

[0057] The cylindrical blank 1 is clamped with the core mold 11 of the CNC spinning machine by bolts; the shearing wheel 12, the flow wheel 13, the fractal wheel 14, and the flat wheel 15 are assembled on the wheel frame of the CNC spinning machine, as shown in FIG. Fig.10 All the above process parameters are input into the spinning machine operating system to generate the motion trajectory of the spinning wheel.

[0058] In this embodiment, it should be noted that on the CNC spinning machine, the number of the shearing wheel 12, the flow wheel 13, the fractal wheel 14 and the flat wheel 15 are all 2, which are symmetrically installed on the wheel frame of the CNC spinning machine; the radius of the shearing wheel 12, the flow wheel 13 and the fractal wheel 14 are all 0.5mm.

[0059] S2, Shearing Forming:

[0060] Adjust the shearing wheel 12 so that its shearing working surface contacts the surface of the cylindrical blank 1, start the CNC spinning machine, and make the cylindrical blank 1 rotate circumferentially driven by the core mold 11, with a rotation speed of 90rpm. At the same time, control the shearing wheel 12 to feed 6.2mm axially along the cylindrical blank 1, and the axial feed speed is 1mm / s to prepare an incomplete I-rib cylindrical part 3 with an incomplete I-rib structure 4.

[0061] S3, Flow Spinning:

[0062] The flow wheel 13 is adjusted so that its working surface is in vertical contact with the surface of the unfull I-rib cylindrical part 3, and the rotation state of the cylindrical part blank 1 in step S2 is continued. At 6.1s, the flow wheel 13 first presses down 1mm along the unthinned side of the unfull I-rib cylindrical part 3, and then feeds 10mm in the axial positive direction to make the wall thickness on both sides equal, and then feeds 10.3mm in the axial reverse direction. The unfull I-rib structure 4 is extruded and shaped under the action of the axial extrusion pressure to obtain a full I-rib cylindrical part 5 with a full I-rib structure 6. During this process, the feeding speed of the flow wheel 13 is 1mm / s. After flow spinning, the rib height of the full I-rib cylindrical part 5 is 6mm and the rib width is 1mm.

[0063] S4, fractal spinning:

[0064] The fractal rotating wheel 14 is adjusted so that its fractal working surface contacts the top of the full I-shaped rib structure 6, and the rotation state of the cylindrical blank 1 in step S2 is continued. The fractal rotating wheel 14 is radially fed 1 mm along the cylindrical blank 1, and the radial feed speed is 1.5 mm / s to prepare a Y-shaped rib cylindrical part 7 with a Y-shaped rib structure 8.

[0065] S5, shaping and spinning:

[0066] Adjust the flat rotating wheel 15 so that its working surface is in vertical contact with the surface of the Y-rib cylindrical part 7, continue the rotation state of the cylindrical part blank 1 in step S2, and feed the flat rotating wheel 15 radially along the top of the Y-rib structure 8 by 2mm, and the radial feeding speed is 1mm / s, so as to shape the Y-rib cylindrical part 7 into a T-rib cylindrical part 9 with a T-rib structure 10. At this time, the T-rib structure 10 has a height of 4mm, a width of 5mm, a web thickness of 1mm, and a wing plate thickness of 0.5mm.

[0067] S6. Unloading operation:

[0068] The flat rotary wheel 15 is withdrawn radially, and after the rotary wheel unloading operation is performed, the mold is removed, and the T-rib cylindrical part 9 is unloaded from the core mold, and finally the desired target workpiece is obtained, and its geometric dimensions are: the outer diameter D1 is 198mm, the inner diameter d is 180mm, and the T-rib (such as Fig.11 ) has a height H of 4 mm, a width W of 5 mm, a web thickness t1 of 1 mm, and a wing plate thickness t2 of 0.5 mm.

[0069] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples and that various changes or modifications may be made to the embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is limited only by the appended claims.

Claims

1. A stepwise shearing forming method for a T-rib cylindrical part, characterized in that: The following steps are involved: S1. Clamp the cylindrical blank onto the core mold of the CNC spinning machine, and assemble the shearing wheel, the flow wheel, the fractal wheel, and the flat wheel onto the wheel frame of the CNC spinning machine; S2, adjusting the shearing wheel so that its shearing working surface contacts the surface of the cylindrical blank, starting the CNC spinning machine, causing the cylindrical blank to rotate circumferentially under the drive of the core mold, and controlling the shearing wheel to feed along the axial direction of the cylindrical blank until the shearing wheel feed amount is reached, thereby preparing an incomplete I-rib cylindrical part with an incomplete I-rib structure; S3, adjusting the flow roller so that its working surface is in vertical contact with the surface of the unsaturated I-rib cylindrical part, continuing the rotating state of the cylindrical part blank in step S2, the flow roller thins the unthinned side of the unsaturated I-rib cylindrical part to make the wall thicknesses on both sides equal, and then the flow roller axially extrudes and shapes the unsaturated I-rib structure to obtain a full I-rib cylindrical part with a full I-rib structure; S4, adjusting the fractal wheel so that its fractal working surface contacts the top of the full I-shaped rib structure, continuing the rotation state of the cylindrical blank in step S2, and making the fractal wheel perform radial feeding motion until the fractal wheel feed amount is reached, thereby preparing a Y-shaped rib cylindrical part with Y-shaped ribs; S5. Adjust the flat rotating wheel so that its working surface is in vertical contact with the surface of the Y-rib cylindrical part. Continuing the rotation state of the cylindrical part blank in step S2, the flat rotating wheel is radially loaded along the top of the Y-rib to reshape the Y-rib cylindrical part into a T-rib cylindrical part.

2. The stepwise shearing forming method of a T-rib cylindrical part according to claim 1, characterized in that: In step S1, a positioning step is processed at the end of the cylindrical blank, and the height of the positioning step is equal to the shearing amount of the shearing wheel in step S2.

3. The stepwise shearing forming method of a T-rib cylindrical part according to claim 1, characterized in that: The shearing wheel comprises an upper shearing working surface and a lower shearing working surface with an included angle of 90 degrees. The upper and lower shearing working surfaces are connected by a transition fillet, and the radius of the fillet of the wheel is 0.5-3 mm.

4. The stepwise shearing forming method of a T-rib cylindrical part according to claim 1, characterized in that: The flow wheel is a double cone angle wheel, the wheel forming angle is 0-30 degrees, the radius of the wheel fillet is 0.5-3mm, and the thinning amount of the flow wheel is equal to the shearing amount of the shear wheel.

5. The stepwise shearing forming method of a T-rib cylindrical part according to claim 1, characterized in that: The fractal wheel is a double cone-angle wheel, the wheel forming angle is 30-45 degrees, and the radius of the wheel fillet is 0.5-3 mm.

6. The stepwise shearing forming method of a T-rib cylindrical part according to claim 1, characterized in that: The flat wheel has a forming angle of 0°, and the feed amount of the flat wheel is equal to the feed amount of the fractal wheel.

7. The stepwise shearing forming method of a T-rib cylindrical member according to claim 1, characterized in that: The shearing wheel, the flow wheel, the fractal wheel and the flat wheel are all provided in two pieces, and are symmetrically distributed and installed on the wheel frame of the CNC spinning machine.

8. The stepwise shearing forming method of a T-rib cylindrical member according to claim 1, characterized in that: The core mold rotation speed is 30-180 rpm, the shearing wheel feed speed is 0.5-2 mm / s, the flow wheel feed speed is 0.3-3 mm / s, the fractal wheel feed speed is 0.5-2.5 mm / s, and the flat wheel feed speed is 0.5-2.5 mm / s.

9. The stepwise shearing forming method of a T-rib cylindrical member according to claim 1, characterized in that: The rib height of the full I-shaped rib structure is h s , width is w s , where the tendon height h s The outer diameter D0 of the cylindrical blank, the shearing amount s of the shearing wheel, and the feed amount f of the shearing wheel s Satisfies the following relationship: Where: D1 = D0-2s; Width w of full I-type rib structure s ≈s.

10. The stepwise shearing forming method of a T-rib cylindrical member according to claim 9, characterized in that: The height H, width W, web thickness t1, flange thickness t2 of the T-rib cylinder, the shearing amount s of the shearing wheel, and the feed amount f of the fractal wheel p , satisfying the following relationship: H≈h s -f p ; t1≈s;t2≈0.5s。

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