Flexible spinning forming process for oversized-diameter end socket paired wheels

Abstract

A flexible spinning forming process for a super-large-diameter end socket pair wheel comprises the steps that a circular-plate-shaped blank is clamped through an inner annular clamp and an outer annular clamp, then the blank is driven by the inner annular clamp and the outer annular clamp to rotate, an inner spinning wheel moves according to the track of the current pass, and when the inner spinning wheel exceeds an outer spinning wheel by a certain angle, the inner spinning wheel rotates; the inner spinning roller and the outer spinning roller move together according to the track of the current pass until the inner spinning roller and the outer spinning roller move to the contact position of the blank on the other side and the inner annular clamp, the current pass is completed, a current-pass formed part is obtained, multi-pass forming is completed in the same mode subsequently, and after forming of the final pass is completed, the inner annular clamp and the outer annular clamp are detached, and a high-dimensional-precision and high-precision formed part is obtained. The sealing head part is high in mechanical performance; the problems that in the end socket forming process, the technological process is complex, the technological precision is low, and the machining efficiency is low are effectively solved, and the prepared ultra-large-diameter end socket has the advantages of being high in size precision, good in mechanical performance, high in efficiency, low in cost and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of wheel spinning, and in particular relates to a flexible spinning process for a wheel with an ultra-large diameter end cap. Background Art

[0002] The application fields of super-large diameter heads with a diameter of more than 5 meters mainly include fuel tanks, solid rocket engine shells and large pressure vessels in aerospace. The fuel tank in the rocket is composed of a cylindrical barrel and a spherical head. It is a thin-walled structure used to store two liquid fuels, hydrogen and oxygen. It is the main load-bearing component of the rocket structure and bears the weight of other instruments and equipment of the rocket. During the rocket launch process, the fuel tank will be subjected to severe dynamic and static loads, including pressure, tension and bending, etc. Its structural form, material properties and structural bearing capacity play a decisive role in the overall performance of large-scale launch vehicle equipment. As one of the main structural parts, the head of the fuel tank has high requirements for its manufacturing technology and manufacturing precision. With the rapid development of high-tech fields such as aviation, aerospace, petroleum, chemical industry, and nuclear industry, high-quality, large-size, thin-walled, and complex-shaped super-large diameter heads are in very high demand in many fields, and elliptical heads have been widely used due to their uniform surface stress.

[0003] The traditional forming processes of ultra-large diameter heads at present mainly include the following methods: the split-flap welding method, which is based on bending a flat blank into flaps and then welding them together to form a head. This method has uneven overall mechanical properties due to the presence of welds, and is prone to stress concentration and brittle fracture under dynamic load conditions; the two-step spinning method (Chen Wanzhong, Zhu Fengyu. Analysis of components of two-step head cold spinning technology [J]. Forging and Stamping, 2005 (10): 84-86.), which first presses the flat blank into a dome shape on a drum press and then performs flanging on a flanging spinning machine. This method requires large equipment investment, occupies a large area, consumes a lot of energy, and has low production efficiency; the one-step spinning method (Zhang Xingguo, Huang Shaodong. One-step spinning method) One-step dieless head spinning process research [J]. Forging Technology, 1992 (3): 38-40.), through the center clamping method, the drum pressing and flanging operations are completed on one machine at the same time. This method uses the center clamping method, and there is a defect in the center when forming the closed head; the die spinning method (Zhang Xingguo, Wang Tao. Optimization of the spindle parameters of the one-step die head spinning machine [J]. Metal Forming Technology, 1992, 010 (5): 231-234.), uses a mold with the same shape as the inner wall of the head, and the head blank is rolled on the mold to form. This method has a high core mold cost and the inner surface of the head cannot be strengthened; the multi-point progressive forming method has a complex equipment structure and high cost; the expansion method has a complex process flow and high cost. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a process for flexible spinning forming of ultra-large diameter heads on wheels, which can form ultra-large diameter heads by flexible spinning on wheels, and has the advantages of high dimensional accuracy, good mechanical properties, high efficiency and low cost.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A flexible spinning forming process for a super-large diameter head wheel includes the following steps:

[0007] In the first step, the circular plate-shaped blank 1 is clamped by the inner ring fixture 2 and the outer ring fixture 3, and the inner side of the outer ring fixture 3 is consistent with the outer generatrix shape of the current pass forming head; the starting position of the inner and outer wheels 4 and 5 for the wheel spinning is located at the intersection of the inner and outer ring fixtures 2, 3 and the edges of one side of the blank 1;

[0008] In the second step, the inner ring fixture 2 and the outer ring fixture 3 drive the blank 1 to rotate, and the inner wheel 4 moves along the trajectory of the first pass. When the inner wheel 4 moves beyond the outer wheel 5 by a certain angle, the inner wheel 4 and the outer wheel 5 keep a certain angle staggered and move together along the trajectory of the first pass until the blank 1 on the other side contacts the inner ring fixture 2 and the outer ring fixture 3, completing the first pass of spinning forming, and obtaining the first pass formed part 6, and at the same time, the inner wheel 4 and the outer wheel 5 return to the starting position;

[0009] 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 to complete the second pass of spinning forming to obtain the second pass formed part, and at the same time, the inner wheel 4 and the outer wheel 5 return to the starting position;

[0010] In the fourth step, after the inner and outer wheels 4 and 5 complete the subsequent forming steps in sequence, a head forming part 7 is finally obtained, and the inner annular clamp 2 and the outer annular clamp 3 are removed to take out the head forming part 7.

[0011] In the second step, the hypotrochoid 4 moves beyond the epitrochoid 5 by a certain angle of 35° to 60°.

[0012] The inner annular fixture 2 and the outer annular fixture 3 drive the circular plate-shaped blank 1 and each formed part to rotate during the entire forming process, and the rotation speed is controllable.

[0013] The rotational power of the inner ring clamp 2 and the outer ring clamp 3 is provided by a servo motor.

[0014] The inner and outer wheels 4 and 5 that form the wheel spinning are held by a clamping mechanism. After they come into contact with the blank 1 or the formed parts of each pass, the inner and outer wheels 4 and 5 are driven to move by friction.

[0015] The movements of the inner and outer wheels 4 and 5 are driven by three-degree-of-freedom motion mechanisms respectively, and the three-degree-of-freedom motion mechanism is realized by lateral movement, longitudinal movement and angular swing of the wheel head.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] (1) Since the present invention adopts the method of wheel spinning, compared with the die spinning method, the performance of both surfaces of the spun material can be enhanced, while the core mold is omitted, the processing cost is saved, and the waste of core mold material is also reduced.

[0018] (2) Since the present invention has few steps, it is simple and easy to operate, and has high production efficiency. The entire forming process can be formed at one time on the same device, avoiding the influence of repeated clamping and positioning on the forming accuracy.

[0019] (3) Since the present invention adopts a circumferential clamping method instead of a central clamping method, a head part without a hole in the center can be formed, so it has the advantage of no forming defects in the center.

[0020] (4) Since the present invention adopts a method of feeding from the outer side of the blank circumference to the center, the blank is gradually formed into the final shape through multi-pass planning, so it has the advantage of high forming quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the inner and outer annular fixtures used in the embodiment of the present invention to clamp the blank and the positions of the inner and outer rotating wheels.

[0022] Figure 2 It is a schematic diagram of the first forming process of an embodiment of the present invention.

[0023] Figure 3 It is a schematic diagram of the subsequent multi-pass forming process of an embodiment of the present invention.

[0024] Figure 4 Schematic diagram of the shape of the hypotrochoid or epitrochoid used in the embodiments of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with embodiments and drawings.

[0026] A flexible spinning forming process for a super-large diameter head wheel includes the following steps:

[0027] The first step is to refer to Figure 1, the circular plate-shaped blank 1 is clamped by the inner ring fixture 2 and the outer ring fixture 3, and the inner side of the outer ring fixture 3 is consistent with the outer generatrix shape of the current pass forming head; the starting position of the inner and outer wheels 4 and 5 for the wheel spinning is located at the intersection of the inner and outer ring fixtures 2, 3 and the edges of one side of the blank 1;

[0028] Step 2: Refer to Figure 2 , the inner ring fixture 2 and the outer ring fixture 3 drive the blank 1 to rotate, and the inner wheel 4 moves along the trajectory of the first pass. When the inner wheel 4 moves beyond the outer wheel 5 by a certain angle (35° to 60°), the inner wheel 4 and the outer wheel 5 keep a certain staggered angle and move together along the trajectory of the first pass until the blank 1 on the other side contacts the inner ring fixture 2 and the outer ring fixture 3, completing the first pass of spinning forming, and obtaining the first pass formed part 6, and at the same time, the inner wheel 4 and the outer wheel 5 return to the starting position;

[0029] 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 to complete the second pass of spinning forming to obtain the second pass formed part, and at the same time, the inner wheel 4 and the outer wheel 5 return to the starting position;

[0030] Step 4: Refer to Figure 3 After the inner and outer wheels 4 and 5 complete the subsequent forming steps in sequence, a head forming part 7 is finally obtained, and the inner annular clamp 2 and the outer annular clamp 3 are removed to take out the head forming part 7.

[0031] The inner annular fixture 2 and the outer annular fixture 3 drive the circular plate-shaped blank 1 and each formed part to rotate during the entire forming process, and the rotation speed is controllable.

[0032] The rotational power of the inner ring clamp 2 and the outer ring clamp 3 is provided by a servo motor.

[0033] like Figure 4 As shown, D is the diameter of the inner wheel 4 and the outer wheel 5, B is the width of the inner wheel 4 and the outer wheel 5, r r is the fillet radius of the inner and outer wheels 4 and 5. The inner and outer wheels 4 and 5 that form the wheel spinning are held by a clamping mechanism, and after contacting with the blank 1 or each formed part, the inner and outer wheels 4 and 5 are driven to move by friction.

[0034] The movements of the inner and outer wheels 4 and 5 are driven by three-degree-of-freedom motion mechanisms respectively, and the three-degree-of-freedom motion mechanism is realized by lateral movement, longitudinal movement and angular swing of the wheel head.

[0035] 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. The center has no forming defects, 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 flexible spinning forming process for a super-large diameter head wheel, characterized in that: The following steps are involved: In the first step, a circular plate-shaped blank (1) is clamped by an inner ring fixture (2) and an outer ring fixture (3), and the inner side of the outer ring fixture (3) is consistent with the outer generatrix shape of the current forming head; the starting positions of the inner and outer wheels (4) and (5) for forming the wheel spinning are located at the edge intersection of the inner and outer ring fixtures (2), (3) and one side of the blank (1); In the second step, the inner ring clamp (2) and the outer ring clamp (3) drive the blank (1) to rotate, and the inner wheel (4) moves along the trajectory of the first pass. When the inner wheel (4) moves beyond the outer wheel (5) by a certain angle, the inner wheel (4) and the outer wheel (5) keep the staggered angle and move together along the trajectory of the first pass until the blank (1) on the other side contacts the inner ring clamp (2) and the outer ring clamp (3), completing the first pass of spinning forming, and obtaining the first pass formed 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 second pass trajectory to complete the second pass of spinning forming to obtain a second pass formed 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 and outer wheels (4) and (5) complete the subsequent forming steps in sequence, a head forming part (7) is finally obtained, and the inner annular clamp (2) and the outer annular clamp (3) are removed to take out the head forming part (7).

2. The process according to claim 1, characterized in that: In the second step, the hypotrochoid (4) moves beyond the epitrochoid (5) by a certain angle of 35° to 60°.

3. The process according to claim 1, characterized in that: The inner annular clamp (2) and the outer annular clamp (3) drive the circular plate-shaped blank (1) and each formed part to rotate during the entire forming process, and the rotation speed is controllable.

4. The process according to claim 1, characterized in that: The rotational power of the inner annular clamp (2) and the outer annular clamp (3) is provided by a servo motor.

5. The process according to claim 1, characterized in that: The inner and outer wheels (4) and (5) for forming the wheel spinning are held by a clamping mechanism. After contacting the blank (1) or each formed part, the inner and outer wheels (4) and (5) are driven to move by friction.

6. The process according to claim 1, characterized in that: The movements of the inner wheel (4) and the outer wheel (5) are driven by a three-degree-of-freedom motion mechanism respectively, and the three-degree-of-freedom motion mechanism is realized by lateral movement, longitudinal movement and angular swing of the wheel head.

Images