Opposite wheel spinning and reducing spinning composite forming process for aluminum alloy inner container of vehicle-mounted hydrogen storage cylinder

Abstract

A vehicle-mounted hydrogen storage cylinder aluminum alloy inner container pair roller spinning and reducing spinning composite forming technology comprises the steps that a thick-wall tubular blank is clamped through an inner annular clamp and an outer annular clamp, the inner annular clamp and the outer annular clamp drive the blank to rotate, an inner spinning roller and an outer spinning roller move along the track of the first pass of pair roller spinning, and then multi-pass pair roller spinning is completed in the same mode; after a thin-wall formed part is obtained, the inner and outer annular clamps drive the thin-wall part to rotate, the diameter-reducing spinning roller moves along the track of the first pass of diameter-reducing spinning, the first pass of diameter-reducing spinning is completed, and then multi-pass diameter-reducing spinning is completed according to the same mode, so that a sealed formed part is obtained; the prepared hydrogen cylinder inner container has the advantages of being good in inner and outer surface quality, high in size precision, good in mechanical performance, high in efficiency, low in cost and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of spinning, and in particular relates to a composite forming process of wheel spinning and diameter reduction spinning of an aluminum alloy liner of a vehicle-mounted hydrogen storage cylinder. Background Art

[0002] High-pressure gaseous hydrogen storage technology uses gas cylinders as storage containers to store gaseous hydrogen through high-pressure compression. The current development direction of on-board hydrogen storage technology is to increase internal pressure, reduce tank mass, and increase hydrogen storage capacity. High-pressure hydrogen storage cylinders are mainly divided into pure steel metal cylinders (Type I), steel liner fiber-wound bottles (Type II), aluminum liner fiber-wound bottles (Type III) and plastic liner fiber-wound bottles (Type IV). Due to the low mass hydrogen storage density and serious hydrogen embrittlement problems of Type I and Type II hydrogen storage cylinders, it is difficult to meet the requirements of vehicle-mounted mass hydrogen storage density. Therefore, most on-board hydrogen storage cylinders use more advanced Type III and Type IV hydrogen storage cylinders. Type III and Type IV bottles are composed of liner, carbon fiber reinforced resin layer and glass fiber reinforced resin layer, which significantly reduces the mass of the cylinder and improves the unit mass hydrogen storage density. Type III hydrogen storage cylinders are usually 35MPa, and Type IV hydrogen storage cylinders are usually 70MPa. At present, most domestic hydrogen fuel cell vehicles use Type III hydrogen storage cylinders.

[0003] With the development of spinning technology, modern spinning technology has been widely used in the field of metal precision processing technology, including pipe manufacturing, aerospace, metal forming, etc. Spinning technology is to rotate the plate and the mold to make the plate produce plastic deformation in the mold to achieve the desired shape. Through spinning technology, high-efficiency, high-precision, seamless, lightweight, low-cost, high-quality parts manufacturing can be achieved to meet the needs of various industrial fields. In view of the great advantages of spinning technology in pipe forming, the product can have excellent mechanical properties, thereby improving the overall performance and safety of the gas cylinder, and to a certain extent, it can solve the defects brought by the traditional stamping process to the hydrogen storage cylinder. Therefore, the current forming process of the inner liner of the aluminum alloy hydrogen storage cylinder mainly adopts the spinning process.

[0004] A patent application entitled "A method for manufacturing an aluminum liner of a composite gas cylinder for a vehicle" (publication number: CN101885137 A) discloses an aluminum liner for making a composite gas cylinder for a vehicle, wherein the aluminum liner is composed of a thin-walled aluminum liner body, a gradually thickened portion of a head, and a mouth. A thick-walled aluminum tube is subjected to one-time spinning by a strong spinning thinning machine to reduce the tube wall thickness by more than 60%, and then a spinning and closing machine is used to form the head and the mouth. However, the strong spinning method requires the use of a core mold, and different core molds are required for cylinder liners with different inner diameters, which is costly and not suitable for production with diversified specifications. In addition, the inner surface of the cylinder liner cannot be strengthened, and the forming quality is poor.

[0005] The patent application entitled "A Method for Processing Metal Gas Cylinder Liners" (publication number: CN 108161372A) discloses that after the cylindrical wall portion of the cylindrical part is thinned by forced spinning on a forced spinning machine, the bottom of the simple part is cut off by a cutting machine to form a tubular part, and finally the two ends of the tubular part are spun, heat treated, and processed to form a double-mouth liner; however, the process of cutting off the bottom of the simple part by a cutting machine usually results in a certain amount of material loss, which will lead to a decrease in material utilization and an increase in cost, and in the process of cutting and forming, problems such as uneven cut section may occur, resulting in poor forming quality.

[0006] Therefore, up to now, there is still a lack of a manufacturing method for the aluminum liner of the vehicle-mounted hydrogen storage cylinder with low production cost, good internal and external surface quality, and applicable to production with diversified specifications. Summary of the invention

[0007] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a composite forming process of wheel spinning and diameter reduction spinning for the aluminum alloy liner of a vehicle-mounted hydrogen storage cylinder, which can prepare aluminum alloy liner of a vehicle-mounted hydrogen storage cylinder adaptable to multiple sizes by wheel spinning and diameter reduction spinning. The aluminum alloy liner of the vehicle-mounted hydrogen storage cylinder has the advantages of high inner and outer surface quality, good mechanical properties, low cost and high efficiency.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] A composite forming process of wheel spinning and diameter reduction spinning for an aluminum alloy liner of a vehicle-mounted hydrogen storage cylinder comprises the following steps:

[0010] In the first step, the thick-walled tube blank 1 is clamped by an inner ring fixture 2 and an outer ring fixture 3, so that the inner and outer wheels 4 and 5 of the wheel spinning are located at the starting positions on both sides of the blank 1;

[0011] In the second step, the inner annular fixture 2 and the outer annular fixture 3 drive the blank 1 to rotate, and the inner and outer wheels 4 and 5 move along the trajectory of the first pass of thinning and spinning to complete the first pass of thinning and spinning to obtain the first pass thinning and forming part 6, and at the same time, the inner and outer wheels 4 and 5 return to the starting position;

[0012] In the third step, similar to the second step, the inner wheel 4 and the outer wheel 5 start to move from the starting position along the second pass trajectory of thinning and spinning, complete the second pass of thinning and spinning, and obtain the second pass thinning formed part, and at the same time, the inner wheel 4 and the outer wheel 5 return to the starting position;

[0013] Step 4: After the inner and outer wheels 4 and 5 have completed the subsequent thinning and spinning steps, the inner and outer ring fixtures 2 and 3 are removed to obtain a thin-walled formed part 7;

[0014] Step 5: Clamp the thin-walled formed part 7 by the inner annular fixture 2 and the outer annular fixture 3, so that the reducing wheel 8 for reducing the diameter and spinning is located outside the thin-walled formed part 7;

[0015] In the sixth step, the inner annular fixture 2 and the outer annular fixture 3 drive the thin-walled formed part 7 to rotate, and the diameter reduction wheel 8 moves along the trajectory of the first pass of the diameter reduction spinning; the first pass of the diameter reduction spinning is completed to obtain the first pass of the diameter reduction formed part 9, and the diameter reduction wheel 8 returns to the initial position;

[0016] In the seventh step, similar to the sixth step, the reducing wheel 8 starts to move from the initial position along the second-pass trajectory of the reducing spinning to complete the second-pass forming of the reducing spinning to obtain the second-pass reduced-diameter formed part. At the same time, after the reducing wheel 8 returns to the initial position, it completes the subsequent passes of the reducing spinning in sequence to obtain the sealing formed part 10, removes the inner ring clamp 2 and the outer ring clamp 3, and takes out the sealing formed part 10.

[0017] A real-time online temperature monitoring module is added during the shrinking spinning process to control the temperature during the shrinking spinning process in real time.

[0018] The inner annular fixture 2 and the outer annular fixture 3 drive the blank 1, each thinning process formed piece, the thin-walled formed piece 7, each diameter reduction process formed piece or the sealing formed piece 10 to rotate during the entire forming process, and the speed is controllable.

[0019] The rotational power of the inner ring clamp 2 and the outer ring clamp 3 is provided by a servo motor; the inner rotating wheel 4, the outer rotating wheel 5, and the reducing rotating wheel 8 are supported by a clamping mechanism, and after contacting with the blank 1, each thinning forming part, the thin-walled forming part 7, and each reducing forming part, the friction force drives the movement.

[0020] The movements of the inner wheel 4, the outer wheel 5 and the reduced diameter wheel 8 are respectively driven by a three-degree-of-freedom motion mechanism, which is realized by lateral motion, longitudinal motion and angular swing of the wheel head.

[0021] Compared with the prior art, the present invention provides the following advantages:

[0022] (1) Since the present invention adopts the method of wheel spinning, it has the advantage of strengthening the performance of both surfaces of the spun material compared with the method of spinning with a core mold. At the same time, the core mold is omitted, the processing cost is saved, the waste of the core mold material is reduced, and it is applicable to the production of cylinder liner forming with various diameters and wall thickness specifications.

[0023] (2) Since the present invention adopts a circumferential clamping method instead of a central clamping method, it can form the aluminum liner parts of the hydrogen fuel cell vehicle cylinder, so it has the advantage of no forming defects in the center.

[0024] (3) The workpiece is fed from the outside of the circumference to the center, and the workpiece is gradually formed into the final shape through multiple spinning passes.

[0025] In summary, the present invention provides a composite forming process of wheel spinning and diameter reducing spinning for the aluminum alloy liner of a vehicle-mounted hydrogen storage cylinder, which can form aluminum liner parts of hydrogen fuel cell vehicle cylinders with high dimensional accuracy, good mechanical properties, high efficiency and low cost through wheel spinning and diameter reducing spinning. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 (a) is a schematic diagram of the inner and outer ring clamps clamping the blank and the positions of the inner and outer spinning wheels in an embodiment of the present invention; (b) is a schematic diagram of the first thinning and spinning forming process of the embodiment; (c) is a schematic diagram of the subsequent thinning and spinning multi-pass forming process.

[0027] Figure 2 (a) is a schematic diagram of the position of the reducing spinning wheel used in an embodiment of the present invention; (b) is a schematic diagram of the first forming process of reducing spinning; (c) is a schematic diagram of the completion of subsequent multiple forming steps of reducing spinning. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with embodiments and drawings.

[0029] A composite forming process of wheel spinning and diameter reduction spinning for an aluminum alloy liner of a vehicle-mounted hydrogen storage cylinder comprises the following steps:

[0030] The first step is to refer to Figure 1 In (a), the thick-walled tube blank 1 is clamped by an inner ring fixture 2 and an outer ring fixture 3, so that the inner and outer wheels 4 and 5 of the wheel spinning are located at the starting positions on both sides of the blank 1;

[0031] Step 2: Refer to Figure 1 In (b), the inner annular fixture 2 and the outer annular fixture 3 drive the blank 1 to rotate, and the inner and outer wheels 4 and 5 move along the trajectory of the first pass of thinning and spinning to complete the first pass of thinning and spinning, and obtain the first pass thinning and forming part 6, and at the same time, the inner and outer wheels 4 and 5 return to the starting position;

[0032] In the third step, similar to the second step, the inner wheel 4 and the outer wheel 5 start to move from the starting position along the second pass trajectory of thinning and spinning, complete the second pass of thinning and spinning, and obtain the second pass thinning formed part, and at the same time, the inner wheel 4 and the outer wheel 5 return to the starting position;

[0033] Step 4: Refer to Figure 1 In (c), after the inner and outer wheels 4 and 5 have completed the subsequent thinning and spinning steps, the inner annular fixture 2 and the outer annular fixture 3 are removed to obtain a thin-walled formed part 7;

[0034] Step 5: Refer to Figure 2 In (a), the thin-walled formed part 7 is clamped by the inner annular fixture 2 and the outer annular fixture 3, so that the reducing wheel 8 for reducing the diameter and spinning is located outside the thin-walled formed part 7;

[0035] Step 6: Refer to Figure 2 In (b), the inner annular fixture 2 and the outer annular fixture 3 drive the thin-walled formed part 7 to rotate, and the diameter reduction wheel 8 moves along the trajectory of the first pass of the diameter reduction spinning; the first pass of the diameter reduction spinning is completed to obtain the first pass of the diameter reduction formed part 9, and the diameter reduction wheel 8 returns to the initial position;

[0036] Step 7, refer to Figure 2 In (c), similar to the sixth step, the reducing wheel 8 starts to move from the initial position along the second-pass trajectory of the reducing spinning, completes the forming of the second-pass reducing spinning, and obtains the second-pass reduced-diameter formed part. At the same time, the reducing wheel 8 returns to the initial position and then completes the subsequent passes of the reducing spinning in sequence to obtain the sealing formed part 10. The inner ring clamp 2 and the outer ring clamp 3 are removed, and the sealing formed part 10 is taken out.

[0037] Since aluminum alloy materials are sensitive to temperature, a real-time online temperature monitoring module is added during the shrinking spinning process to control the temperature during the shrinking spinning process in real time.

[0038] The inner annular fixture 2 and the outer annular fixture 3 drive the blank 1, each thinning process formed piece, the thin-walled formed piece 7, each diameter reduction process formed piece or the sealing formed piece 10 to rotate during the entire forming process, and the speed is controllable.

[0039] The rotational power of the inner ring clamp 2 and the outer ring clamp 3 is provided by a servo motor; the inner rotating wheel 4, the outer rotating wheel 5, and the reducing rotating wheel 8 are supported by a clamping mechanism, and after contacting with the blank 1, each thinning forming part, the thin-walled forming part 7, and each reducing forming part, the friction force drives the movement.

[0040] The movements of the inner wheel 4, the outer wheel 5 and the reduced diameter wheel 8 are respectively driven by a three-degree-of-freedom motion mechanism, which is realized by lateral motion, longitudinal motion and angular swing of the wheel head.

[0041] The beneficial effects of this embodiment are: the performance of both surfaces of the spun material is enhanced, the processing cost is saved, and the waste of core mold materials is reduced. It is suitable for the production of cylinder liners with various diameters and wall thickness specifications. There is no forming defect in the center, the forming quality is high, it is simple and easy to operate, the production efficiency is high, and the influence of repeated clamping and positioning on the forming accuracy is avoided.

Claims

1. A composite forming process of wheel spinning and diameter reduction spinning for the aluminum alloy liner of a vehicle-mounted hydrogen storage cylinder, characterized in that: The following steps are involved: In the first step, a thick-walled tube blank (1) is clamped by an inner ring clamp (2) and an outer ring clamp (3), so that an inner rotating wheel (4) and an outer rotating wheel (5) for wheel spinning are located at the starting positions on both sides of the blank (1); In the second step, the inner annular fixture (2) and the outer annular fixture (3) drive the blank (1) to rotate, and the inner wheel (4) and the outer wheel (5) move along the trajectory of the first pass of thinning and spinning to complete the first pass of thinning and spinning to obtain the first pass thinning and forming part (6), and at the same time the inner wheel (4) and the outer wheel (5) return to the starting position; In the third step, similar to the second step, the inner wheel (4) and the outer wheel (5) start to move from the starting position along the trajectory of the second pass of thinning and spinning, complete the second pass of thinning and spinning, and obtain the second pass thinning and forming part, and at the same time, the inner wheel (4) and the outer wheel (5) return to the starting position; In the fourth step, after the inner wheel (4) and the outer wheel (5) have completed the subsequent thinning and spinning forming, the inner annular fixture (2) and the outer annular fixture (3) are removed to obtain a thin-walled formed part 7; The fifth step is to clamp the thin-walled formed part (7) through the inner annular clamp (2) and the outer annular clamp (3) so that the reducing wheel (8) for reducing the diameter and spinning is located outside the thin-walled formed part (7); In the sixth step, the inner annular fixture (2) and the outer annular fixture (3) drive the thin-walled formed part (7) to rotate, and the diameter reduction wheel (8) moves along the trajectory of the first pass of the diameter reduction spinning; the first pass of the diameter reduction spinning is completed to obtain the first pass of the diameter reduction formed part (9), and at the same time, the diameter reduction wheel (8) returns to the initial position; In the seventh step, similar to the sixth step, the reducing wheel (8) starts to move from the initial position along the trajectory of the second step of reducing spinning to complete the second step of forming and obtain the second step of reducing spinning. At the same time, after the reducing wheel (8) returns to the initial position, it completes the subsequent steps of forming in sequence to obtain the sealing formed part (10), removes the inner ring clamp (2) and the outer ring clamp (3), and takes out the sealing formed part (10).

2. The process according to claim 1, characterized in that: A real-time online temperature monitoring module is added during the shrinking spinning process to control the temperature during the shrinking spinning process in real time.

3. The process according to claim 1, characterized in that: The inner annular clamp (2) and the outer annular clamp (3) drive the blank (1), each thinning forming part, the thin-walled forming part (7), each shrinking forming part or the sealing forming part (10) to rotate during the entire forming process, and the speed is controllable.

4. The process according to claim 1, characterized in that: The rotational power of the inner ring clamp (2) and the outer ring clamp (3) is provided by a servo motor; the inner rotating wheel (4), the outer rotating wheel (5) and the reducing rotating wheel (8) are supported by a clamping mechanism, and after contacting with the blank (1), each thinning process, the thin-walled formed part (7) and each reducing process, the friction force drives the movement.

5. The process according to claim 1, characterized in that: The movements of the inner wheel (4), the outer wheel (5) and the reduced diameter wheel (8) are driven by three-degree-of-freedom motion mechanisms, which are respectively realized by lateral motion, longitudinal motion and angular swing of the wheel head.

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