The present disclosure claims the priority of the Chinese Patent Application No. 201911024770.9, filed to the SIPO on Oct. 25, 2019, titled “Rotary extrusion forming method for cabin section workpiece” which is incorporated herein by reference in its entirety.
The present disclosure belongs to the technical field of extrusion forming dies, and more particularly relates to a rotary extrusion forming method for a cabin section workpiece.
As a thin-walled load-bearing structure, irregularly-shaped thin-walled cabin section workpieces are widely used in aerospace, civil engineering, chemical industry, shipbuilding and other fields. In the existing plastic forming technology, it is impossible to form a main body of the irregularly-shaped thin-walled cabin section workpiece with different wall thickness through forward extrusion and reverse extrusion, and a generally adopted forming method includes the steps of first extruding a conical barrel-shaped workpiece with equal wall thickness, and then turning portions requiring thin wall thickness. However, this forming method has the disadvantages as follows.
First, the barrel body must have the maximum wall thickness required for forming, which is material wasting.
Second, the streamline is completely cut off, resulting in a reduction in the bearing capacity of the thin-walled portions.
Third, the production process takes too long.
No relevant solutions are available for the technical problems existing in the machining and forming process of the above irregularly-shaped thin-walled cabin section workpieces. Therefore, it is urgent to find an effective solution to solve the above problems.
An objective of the present disclosure is to provide a rotary extrusion forming method for a cabin section workpiece to address the deficiencies in the above technology, so as to solve the problem of wasting materials in the machining and forming process of the existing irregularly-shaped thin-walled cabin section workpieces.
The present disclosure provides a rotary extrusion forming method for a cabin section workpiece, including a male die, a female die, an upper die assembly, a lower die base and a rotation driving device. The male die is arranged on the upper die assembly which can drive the male die to move in the vertical and horizontal directions. The female die is arranged on the lower die base in such a manner that it can rotate about a vertical axis, and the rotation driving device is in drive connection with the female die and can drive the female die to rotate about the vertical axis. The method further includes the following steps of:
S1: preparing a hollow truncated cone-shaped blank;
S2: heating the prepared blank to a molding temperature and holding, and preheating the female die and the male die to above the molding temperature and holding;
S3: assembling the upper die assembly on a press;
S4: applying lubricant on the female die and the male die, and placing and fixing the blank into a die cavity of the female die;
S5: starting up the rotation driving device to drive the female die to rotate on the lower die base, so that the female die drives the blank to rotate; starting up the press to move the male die down to a machining position of the blank in the die cavity through the upper die assembly, and machining inner side walls of the blank; and
S6: after the blank is formed by machining, making the male die move up by the press to a preset position through the upper die assembly.
In some embodiments, after the male die moves out of the die cavity to the preset position, the method further includes a step of:
S7: jacking an ejector plate at the bottom of the die cavity up by an ejector bar, so as to strip the formed workpiece.
In some embodiments, in S2, the molding temperature to which the blank is heated is a recrystallization temperature of the blank material, and the blank is heated to the molding temperature and held at the temperature for 4 to 6 hours.
In some embodiments, the male die includes a left half male die and a right half male die, the upper die assembly includes a push-pull device, an upper die base and a press connector, and the left half male die and the right half male die are movably arranged on the upper die base along the horizontal direction. A wedge, arranged between the left half male die and the right half male die, is connected to the press connector. The upper die base and the press connector are respectively in drive connection with the press, and the push-pull device is arranged on the upper die base for driving the left half male die and the right half male die to move left and right along the horizontal direction. In S5 to S6, machining the inner side walls of the blank by the male die specifically includes steps as follows:
when the upper die base drives the left half male die and the right half male die to move down to the machining position of the blank in the die cavity, the press connector drives the wedge to move down, and the push-pull device drives the left half male die and the right half male die to feed separately to extrude the inner side walls of the blank; and
after the left half male die and the right half male die extrude the inner side walls of the blank to a first forming position, the wedge remains motionless; after the upper die base drives the left half male die and the right half male die to move up to a second forming position, the press connector drives the wedge to move up; and after the push-pull device drives the left half male die and the right half male die to close and to move to a designated position, the upper die base drives the left half male die and the right half male die to move up to the preset position.
In some embodiments, an inclined surface is formed on both sides of the wedge, respectively, and inclined surfaces, on which the wedge is arranged in a sliding manner, are formed between the left half male die and the right half male die; the inclined surface on the left side of the wedge matches with the inclined surface of the left half male die and the inclined surface on the right side of the wedge matches with the inclined surface of the right half male die; the wedge slides up and down on the inclined surfaces between the left half male die and the right half male die to drive the left half male die and the right half male die to open or close.
In some embodiments, the inclined surfaces on the both sides of the wedge are consistent with the gradient of outer side walls of the blank, and/or are consistent with the gradient of the inclined surfaces of the left half male die and the right half male die.
In some embodiments, the die cavity, having an inner wall consistent with the gradient of the outer side walls of the blank, is provided in the female die.
In some embodiments, a circular cavity, having a floating device arranged at the bottom thereof, is provided on the lower die base, and the female die is rotatably arranged in the circular cavity and floats up and down in the circular cavity through the floating device; a stopper, having a groove arranged on an inner side face thereof, is provided on an upper end face of the lower die base; and an annular stiffener is provided on the outer side wall of the female die, and the female die is clamped in the groove through the annular stiffener and can float up and down in the groove.
In some embodiments, it further includes thrust bearing plates having an upper thrust bearing plate arranged at the bottom of the female die and a lower thrust bearing plate arranged at the bottom of the circular cavity. When the female die moves down to a lower limit position of the groove, the upper thrust bearing plate and the lower thrust bearing plate are interlocked to limit the movement of the female die.
In some embodiments, the blank is magnesium alloy, aluminum alloy or titanium alloy.
The rotary extrusion forming method for a cabin section workpiece provided by the present disclosure can avoid machining by cutting, improve material utilization rate, and reduce consumption in subsequent machining stages, thereby reducing the production cost and improving the production efficiency. On the other hand, it can also improve the mechanical performance of the main body and avoid the decline in the load-bearing capacity caused by cutting-off streamline. Furthermore, by employing the solution provided by the present disclosure, the workpiece adopts an isothermal forming mode in its forming process, i.e., the blank is always closed in the female die in the forming process, thereby avoiding the temperature reduction of the blank, eliminating the uneven deformation caused by the heat exchange between the blank and the air, further improving the deformation uniformity and reducing the wall thickness difference.
The present disclosure will be further described in detail as below with reference to the accompanying drawings by the specific embodiments.
The present disclosure will be further described with reference to the accompanying drawings:
in which:
10: press connector; 11: upper die base; 12: wedge; 121: inclined surface; 122: inclined surface; 13: left half male die; 131: inclined surface; 14: right half male die; 141: inclined surface; 15: left half male die retainer; 16: right half male die retainer; 17: left retainer hydraulic cylinder; 18: right retainer hydraulic cylinder; 19: female die; 191: outer side wall; 192: annular stiffener; 193: die cavity; 195: short stiffener; 20: rotation driving device; 201: first gear; 202: first pulley; 203: second gear; 204: second pulley; 205: clutch; 206: motor; 21: stopper; 210: annular oil gallery; 22: lower die base; 221: circular cavity; 222: annular oil gallery; 23: thrust bearing plate; 24: steel ball bearing bracket; 241: receiving cavity; 25: steel ball; 251: annular groove; 26: spring; 27: ejector bar; 28: through hole; 29: ejector plate; 291: first notch; 292: second notch; 3: blank; 31: inner side wall; 32: outer side wall; and 33: bulge.
It should be noted that the embodiments and characteristics therein of the present disclosure may be combined with each other without conflict. The present disclosure will be described in detail as below with reference to the accompanying drawings by the embodiments.
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The rotary extrusion forming die for a cabin section workpiece provided by the present disclosure can avoid machining by cutting, improve material utilization rate, and reduce consumption in subsequent machining stages, thereby reducing the production cost and improving the production efficiency. On the other hand, it can also improve the mechanical performance of the main body of the workpiece and avoid the decline in the load-bearing capacity caused by cutting-off streamline. Furthermore, by employing the solution provided by the present disclosure, the workpiece adopts an isothermal forming mode in the forming process, i.e., the blank is always closed in the female die in the forming process, thereby avoiding the temperature reduction of the blank, eliminating the uneven deformation caused by the heat exchange between the blank and the air, further improving the deformation uniformity and reducing the wall thickness difference.
Accordingly, in combination with the above solution, as shown in
S1: Blanking is performed to prepare a hollow truncated cone-shaped blank. Specifically, the blank is preferably made of light alloy, which is aluminum alloy, titanium alloy or magnesium alloy, and so on.
S2: Preparation for forming is performed, namely the prepared blank is heated to a molding temperature and held at this temperature, the molding temperature to which the blank is heated is a recrystallization temperature of the blank material, after the blank is heated to the molding temperature (i.e., the recrystallization temperature), the holding time is preferably 4-6 hours, preferably 4 hours, and the female die and the male die are preheated to above the molding temperature and held.
S3: Die assembly is performed, namely the upper die assembly is assembled on a press. Further, the die assembly includes an upper die base and a press connector which are in drive connection with the press respectively, and the press is a double-action press. The male die includes a left half male die and a right half male die which are movably arranged on the upper die base along the horizontal direction. A wedge connected to the press connector is arranged between the left half male die and the right half male die, and the upper die base and the press connector are in drive connection with the press respectively.
S4: Lubricant is applied evenly on the die cavity 193 of the female die 19, the left half male die 13 and the right half male die 14, and the heated blank is put and fixed into the die cavity 193 of the female die 19. The lubricant application is mainly used to facilitate die stripping. At the same time, the deformation between the blank and the die cavity 193 in the process of extruding the blank by the male die can be avoided, and the machining accuracy is improved.
S5: Forming is performed, namely the rotation driving device is started up to drive the female die to rotate on the lower die base, so that the female die drives the blank to rotate; the press is started up to move the male die down to a machining position of the blank in the die cavity through the upper die assembly, and the inner side walls of the blank are machined.
S6: After the blank is formed by machining, the press makes the male die up move to a preset position through the press connector.
S7: An ejector plate at the bottom of the die cavity is jacked up by an ejector bar, so as to strip the formed workpiece.
S8: Application of lubricating oil is continued, so as to proceed with the next process of rotary extrusion of a shaped thin-walled cabin section workpiece.
With the above solution, the deficiencies of the traditional turning technology are overcome, and the workpiece can be formed by one-time heating and one-time rotary extrusion of a main body thereof under the condition of mass production, which avoids machining by cutting, improves material utilization rate, and reduces consumption in subsequent machining stages, thereby reducing the production cost, improving the production efficiency and effectively shortening the production process.
Preferably, in the embodiment combined with the above solution, the workpiece machining process is as follows: the rotation driving device 20 is started up to drive the female die 19 to rotate on the lower die base 22, and the female die 19 drives the blank 3 to rotate, and the left half male die 13 and the right half male die 14 are closed on the upper die base 11 and fixed under the press connector 10. The upper die base 11 drives the left half male die 13 and the right half male die 14 to move down. When the left half male die 13 and the right half male die 14 move down to the machining position in the blank 3, the press connector 10 drives the wedge 12 to move down, and a push-pull device drives the left half male die 13 and the right half male die 14 to feed separately, so as to start to extrude the inner side wall 31 of the blank 3. After a first forming position is reached, the wedge 12 remains motionless, and the upper die base 11 drives the left half male die 13 and the right half male die 14 to move up. After a second forming position is reached, the press connector 10 drives the wedge 12 to move up, and a gap is left between the left half male die 13 and the right half male die 14, so that the push-pull device pushes the left half male die 13 and the right half male die 14 to move left and right. After a designated position is reached, the upper die base 11 drives the left half male die 13 and the right half male die 14 to move up, and the formed workpiece and an ejector plate 29 held in the female die 19 are jacked up by an ejector bar 27 to complete die stripping.
Preferably, in the embodiment combined with the above solution, an inclined surface is formed on both sides of the wedge, respectively, and inclined surfaces, on which the wedge is arranged in a sliding manner, are formed between the left half male die and the right half male die; the inclined surface on the left side of the wedge matches with the inclined surface of the left half male die and the inclined surface on the right side of the wedge matches with the inclined surface of the right half male die. The wedge slides up and down on the inclined surfaces between the left half male die and the right half male die to drive the left half male die and the right half male die to open or close.
Preferably, in the embodiment combined with the above solution, as shown in
Preferably, in the embodiment combined with the above solution, as shown in
Preferably, in the embodiment combined with the above solution, as shown in
With the above solution, the blanking can be performed by sawing the ready-made blank, the workpiece can be formed by one-time heating and one-time rotary extrusion of a main body thereof, which avoids machining by cutting, improves material utilization rate, and reduces consumption in subsequent machining stages, thereby reducing the production cost and improving the production efficiency
Those described above are merely preferred embodiments of the present disclosure, and are not intended to limit the present disclosure in any form. Without departing from the scope of the technical solution of the present disclosure, those of skill in the art may make many possible variations and modifications to the technical solution of the present disclosure or modify them into equivalent embodiments with equivalent variations using the above-described technical content. Therefore, any changes, equivalent variations and modifications made without departing from the scope of the technical solution of the present disclosure to the above embodiments according to the technology of the present disclosure shall fall within the protection scope of the technical solution.
Number | Date | Country | Kind |
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201911024770.9 | Oct 2019 | CN | national |