Backward extrusion forming manufacturing tool for high shell part and using method of backward extrusion forming manufacturing tool

Abstract

The invention relates to the technical field of die forging, in particular to a backward extrusion forming manufacturing tool for a high shell part and a using method. Comprising an upper die base, an outer cylinder and a lower die base which are sequentially arranged from top to bottom, an upper punch is arranged on the upper die base, a lower punch is arranged on the lower die base, the upper punch and the lower punch both extend into the outer cylinder, the outer cylinder and the lower die base slide in a limited mode and are connected in a clamped mode, an upper backing ring is arranged between the upper die base and the outer cylinder, and a lower backing ring is arranged between the lower punch and the outer cylinder. According to the tool, after extrusion is completed, the upper punch moves upwards, so that the upper punch and the lower punch are demolded at the same time, the lower punch is prevented from being adhered to the shell, secondary pressing of the upper punch is not needed, the production efficiency of the shell is improved, the inner wall of the shell is prevented from being strained in the secondary pressing process, and the product percent of pass is increased.

Description

Technical Field

[0001] The invention relates to the technical field of die forging, and in particular to a reverse extrusion forming manufacturing tool for a relatively high shell part and a use method thereof. Background Art

[0002] The reverse extrusion process is a metal plastic processing method. Its basic principle is to apply pressure to make the metal material plastically deform in the mold, so as to obtain the desired shape and size of the product. The reverse extrusion forming technology is suitable for the preparation of cylinders with a large aspect ratio, because the high-diameter ratio parts can be formed by only one extrusion, which significantly improves the production efficiency and part accuracy.

[0003] At present, the cylinder pressing process is formed by the cooperation of the upper and lower punches and the outer cylinder. However, when the prepared shell height is greater than 400mm, the shell is easy to adhere to the outer cylinder and the lower punch under the action of high pressure. In this case, it is necessary to flip the integrated outer cylinder, shell and lower punch 180°, and then press the upper punch directly against the position of the lower punch, and take out the lower punch. In this process, the concentricity of the upper and lower punches is frequently inconsistent, resulting in steps on the inner wall of the shell. In addition, since the stamping action after the reversal needs to be performed at high temperature, the action needs to be fast and accurate, which places high demands on the staff, and the temperature of the forging will drop sharply during the flipping process, which reduces the production efficiency of the shell. In addition, part of the inner wall of the cylinder will be severely strained by the secondary high pressure, resulting in a low product qualification rate. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a reverse extrusion manufacturing tool for a relatively high shell part and a method for using the tool.

[0005] The technical solution of the present invention is: a reverse extrusion forming manufacturing tool for higher shell parts, including an upper die base, an outer cylinder and a lower die base arranged in sequence from top to bottom, the upper die base is provided with an upper punch, the lower die base is provided with a lower punch corresponding to the upper punch, the upper punch and the lower punch both extend into the interior of the outer cylinder, the outer cylinder and the lower die base are limited, slidable and clamped, an upper gasket is provided between the upper die base and the outer cylinder, the upper gasket includes a positioning gasket for positioning the outer cylinder, and a protective gasket for limiting the size of the part during extrusion, and a lower gasket is provided between the lower punch and the outer cylinder.

[0006] Note: After extrusion is completed, the above-mentioned tooling can be moved up by the upper punch, so that the upper punch and the lower punch can be demoulded at the same time to avoid the lower punch from sticking to the shell. Since there is no need for secondary pressing of the upper punch, the production efficiency of the shell is improved, and the inner wall of the shell is avoided from being damaged during the secondary pressing process, thereby improving the product qualification rate.

[0007] Furthermore, a clamping block is provided at the lower end of the outer cylinder, the inner wall of the lower die seat has an arc-shaped clamping groove for the clamping block to slide, and the upper top surface of the lower die seat has a docking groove for the clamping block to extend into the arc-shaped clamping groove.

[0008] Note: The above-mentioned clamping method enables relative movement between the outer cylinder and the lower die base, ensuring that the shell and the lower punch can be separated when the upper punch moves upward.

[0009] Furthermore, the inner wall of the outer cylinder is provided with a plurality of groups of radially arranged coating components for applying lubricant to the outer cylinder, each group of coating components includes a plurality of laterally arranged sliding holes, and a liquid supply pipe arranged on the side wall of the outer cylinder and connected one-to-one with the sliding holes, the sliding seal in the sliding hole is provided with a piston and a sliding column, one end of the piston is fixedly connected to the sliding column through a connecting rod, the inner wall of the sliding hole is provided with a storage groove for slidingly cooperating with the sliding column to release the lubricant, the storage groove is connected to the sliding hole through the sliding column, the connecting rod and the liquid channel connected in sequence in the piston, the outer cylinder is vertically limited and slidably connected with a movable rod corresponding one-to-one to the coating component, and the lower end of the movable rod is connected to the outer cylinder through a spring, the connecting rod is provided with a V-shaped block, and the movable rod is provided with a pressure column for cooperating one-to-one with the V-shaped block to push the connecting rod to slide left and right.

[0010] Description: The liquid supply pipe can provide lubricant to the sliding hole. When the upper die seat moves downward, the upper die seat can press down the movable rod to make the movable rod slide downward. The pressure column on the movable rod can press down the V-block and cooperate with the hydraulic pressure provided by the liquid supply pipe to make the connecting rod drive the sliding column to retract and contract once. When the sliding column contracts inward, the lubricant in the storage tank can be released to the front end of the sliding column. When the sliding column is reset, the lubricant will be pushed out and applied to the inner wall of the outer cylinder. When the upper die seat moves upward, the movable rod can be reset under the action of the spring, so that the sliding column contracts again to apply the lubricant, thereby avoiding adhesion between the shell and the outer cylinder and ensuring that the shell can be separated from the outer cylinder.

[0011] Furthermore, the pressure column is slidably connected to a blind hole provided on the movable rod, and the pressure column and the blind hole are connected by a spring, the pressure column is sleeved with a second airbag which utilizes inflation and deflation to control the contraction or extension of the pressure column, the upper end of the movable rod is fixedly sleeved with a first airbag connected to the second airbag, and the upper mold base is provided with a docking hole corresponding to the movable rod, and the connecting rod is provided with a clamping hole for clamping with the pressure column by utilizing the extension of the pressure column.

[0012] Note: When the upper die seat is not docked with the movable rod, the pressure column is engaged with the clamping hole. At this time, the sliding column cannot slide freely, so as to prevent the sliding column from shrinking during the extrusion process and causing defects on the shell surface. When the docking hole is docked with the movable rod, the upper die seat will first squeeze the first airbag, and the gas in the first airbag will enter the second airbag, causing the pressure column to shrink and separate from the clamping hole. At this time, the connecting rod can drive the sliding column to slide.

[0013] Furthermore, a plurality of clamping columns connected to the docking hole through springs are arranged in the side wall of the docking hole, and a clamping groove cooperating with the clamping column for clamping is arranged at the upper end of the movable rod.

[0014] Note: After the docking hole and the movable rod are docked, the clamping column can be clamped with the clamping groove, and the movable rod can be driven to move upward when the upper die seat moves upward to avoid insufficient spring elasticity, which causes the movable rod to be unable to reset. After the movable rod moves to the top, the upper die seat continues to move upward, and the clamping column will shrink, separating the clamping column from the movable rod.

[0015] On the other hand, the method for using the reverse extrusion manufacturing tooling design of the higher shell part comprises the following steps:

[0016] S1, clamp the outer cylinder onto the lower die seat, control the upper die seat to descend and adjust the position of the lower die seat during the descent of the upper die seat, so that the positioning gasket ring can enter the outer cylinder, and then fix the position of the lower die seat. At this time, the upper punch, the lower punch and the outer cylinder are concentric;

[0017] S2, control the upper die seat to rise so that the upper punch completely exits the outer cylinder, and remove the positioning gasket and replace it with a protective gasket;

[0018] S3, preheating the blank, then placing the blank into the outer cylinder, controlling the upper die seat to descend, and causing the upper punch and the lower punch to extrude the blank to obtain a shell;

[0019] S4. After extrusion is completed, the upper die seat is controlled to rise. Since the shell is adhered to the upper punch, the lower punch and the outer cylinder, the upper punch will drive the outer cylinder to move upward during the rising process, so that the shell and the lower punch are separated, until the outer cylinder is limited by the lower die seat and cannot move further upward. As the upper die seat continues to rise, the upper punch is separated from the shell, and then the outer cylinder is removed from the lower die seat, and the shell is taken out of the outer cylinder.

[0020] Description: The above method uses the upper punch and the lower punch to demould at the same time, which avoids the adhesion of the lower punch and the shell, improves production efficiency, avoids defects on the inner wall of the shell during secondary pressing, and improves the product qualification rate.

[0021] Furthermore, in step S3, the blank is cylindrical, and both ends of the blank are chamfered before being kept warm, and the chamfer radius is R7 to R9.

[0022] Note: The cylindrical blank has a better forming effect. Chamfering can reduce the stress concentration at the edge of the blank during the stamping process and improve the surface quality of the shell.

[0023] Furthermore, the preheating method is: keeping the blank at 750-850°C for 140-160 minutes.

[0024] Note: Insulation can improve the plasticity of the blank, reduce the difficulty of extrusion, and avoid defects inside the shell.

[0025] The beneficial effects of the present invention are:

[0026] (1) After extrusion is completed, the tooling of the present invention can move up the upper punch so that the upper punch and the lower punch can be demolded at the same time, thereby avoiding adhesion of the lower punch to the shell. Since there is no need for secondary pressing with the upper punch, the production efficiency of the shell is improved, and the inner wall of the shell is avoided from being damaged during the secondary pressing process, thereby improving the product qualification rate.

[0027] (2) When the upper mold base of the present invention moves downward, the upper mold base can press down the movable rod, causing the slide column to retract and extend once to apply lubricant to the inner wall of the outer cylinder. When the upper mold base moves upward, the movable rod can be reset under the action of the spring, causing the slide column to retract once again to apply lubricant to the inner wall of the outer cylinder, thereby avoiding adhesion between the shell and the outer cylinder and ensuring that the shell can be separated from the outer cylinder.

[0028] (3) The method of the present invention simultaneously demolds the upper punch and the lower punch, thereby avoiding adhesion between the lower punch and the shell, improving production efficiency, and avoiding defects on the inner wall of the shell during secondary pressing, thereby improving product qualification rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a longitudinal sectional view of embodiment 1 of the present invention;

[0030] Figure 2 This is a schematic diagram of the protective gasket ring installation structure of Example 1 of the present invention;

[0031] Figure 3 is a longitudinal sectional view of Embodiment 2 of the present invention;

[0032] Figure 4 yes Figure 3 A magnified image of point A;

[0033] Figure 5 is a schematic diagram of the structure of the movable rod of Embodiment 2 of the present invention;

[0034] Figure 6 is a schematic diagram of the connecting rod structure of Example 2 of the present invention;

[0035] Figure 7 This is a schematic diagram of the outer cylinder structure of Example 3 of the present invention;

[0036] Figure 8 yes Figure 7 A magnified view of point B;

[0037] Fig. 9 yes Figure 7 Enlarged view of point C;

[0038] Fig.10 is a schematic diagram of the connecting rod structure of Example 3 of the present invention;

[0039] Among them, 1-upper die base, 11-docking hole, 12-clamping column, 2-protective gasket, 3-positioning gasket, 4-upper punch, 5-outer cylinder, 51-sliding hole, 511-storage tank, 52-liquid supply pipe, 53-piston, 54-sliding column, 55-connecting rod, 551-clamping hole, 56-clamping block, 57-movable rod, 571-first air bag, 58-V-block, 59-pressure column, 591-second air bag, 6-lower punch, 8-lower die base. DETAILED DESCRIPTION

[0040] In order to further illustrate the method adopted by the present invention and the effect achieved, the technical solution of the present invention will be clearly and completely described in combination with experiments below.

[0041] Example 1: Figure 1 , Figure 2 As shown, a reverse extrusion forming manufacturing tool for a higher shell part includes an upper die base 1, an outer cylinder 5 and a lower die base 8 arranged in sequence from top to bottom, an upper punch 4 is arranged on the upper die base 1, and the upper punch 4 is threadedly connected to the upper die base 1, and a lower punch 6 corresponding to the upper punch 4 is arranged on the lower die base 8, and the lower punch 6 is threadedly connected to the lower die base 8, and the upper punch 4 and the lower punch 6 are extended to the inside of the outer cylinder 5, and the outer cylinder 5 and the lower die base 8 are limited, slidable and clamped, and the upper die base 1 and the outer cylinder 5 are connected. An upper gasket is arranged between the upper and lower punches 6 and the outer cylinder 5, and the upper gasket includes a positioning gasket 3 for positioning the outer cylinder 5 and a protective gasket 2 for limiting the size of the parts during extrusion. The positioning gasket 3 and the protective gasket 2 are connected to the upper die seat 1 by bolts, and a lower gasket 7 is arranged between the lower punch 6 and the outer cylinder 5; a clamping block 56 is arranged at the lower end of the outer cylinder 5, and the inner wall of the lower die seat 8 has an arc-shaped clamping groove for the clamping block 56 to slide, and the upper top surface of the lower die seat 8 has a docking groove for the clamping block 56 to extend into the arc-shaped clamping groove;

[0042] The method for using the above-mentioned reverse extrusion forming manufacturing tooling design for the higher shell part includes the following steps:

[0043] S1, clamp the outer cylinder 5 onto the lower die base 8, control the upper die base 1 to descend and adjust the position of the lower die base 8 during the descent of the upper die base 1, so that the positioning gasket 3 can enter the outer cylinder 5, and then fix the position of the lower die base 8. At this time, the upper punch 4, the lower punch 6 and the outer cylinder 5 are concentric;

[0044] S2, control the upper die base 1 to rise so that the upper punch 4 is completely out of the outer tube 5, and remove the positioning gasket 3 and replace it with the protection gasket 2;

[0045] S3, preheating the blank, then putting the blank into the outer cylinder 5, controlling the upper die seat 1 to descend, so that the upper punch 4 and the lower punch 6 extrude the blank to obtain a shell; the blank is cylindrical, and both ends of the blank are chamfered before being kept warm, and the chamfer radius is R8; the preheating method is: keeping the blank at 800°C for 150 minutes;

[0046] S4. After extrusion is completed, the upper die base 1 is controlled to rise. Since the shell is adhered to the upper punch 4, the lower punch 6 and the outer cylinder 5, the upper punch 4 will drive the outer cylinder 5 to move upward during the rising process, so that the shell and the lower punch 6 are separated, until the outer cylinder 5 is limited by the lower die base 8 and cannot move further upward. As the upper die base 1 continues to rise, the upper punch 4 is separated from the shell, and then the outer cylinder 5 is removed from the lower die base 8, and the shell is taken out of the outer cylinder 5.

[0047] Example 2: Figure 3 As shown, this embodiment is basically the same as the embodiment 1, except that five groups of liquid coating components are radially arranged on the inner wall of the outer cylinder 5 and are used to apply lubricant to the inner wall of the outer cylinder 5, each group of liquid coating components includes five sliding holes 51 arranged transversely and connected to the liquid supply pipe 52, and liquid supply pipes 52 arranged on the side wall of the outer cylinder 5 and connected to the sliding holes one by one; a piston plate is slidably sealed in the liquid supply pipe 52, and the left end of the piston plate is connected to the liquid supply pipe 52 through a spring;

[0048] like Figure 4 As shown, a piston 53 and a sliding column 54 are provided in a sliding seal in the sliding hole 51, and the right end of the piston 53 is fixedly connected to the sliding column 54 through a connecting rod 55. A storage groove 511 is provided on the inner wall of the sliding hole 51 for slidingly cooperating with the sliding column 54 to release lubricant. The storage groove 511 is connected to the sliding hole 51 through a liquid channel that is sequentially connected to the sliding column 54, the connecting rod 55 and the piston 53. The length of the storage groove 511 is 1.5 cm smaller than the sliding distance of the sliding column 54, and the connection point between the liquid channel and the storage groove 511 is located at the left end of the storage groove 511 to ensure that the liquid channel and the storage groove 511 are not connected when the sliding column 54 slides to the left. A movable rod 57 corresponding to the coating liquid assembly is vertically limited and slidably connected in the outer cylinder 5. The outer cylinder 5 is slidably connected to the movable rod 57 through a circular hole provided therein, and a limiting ring for limiting its sliding range is provided on the side wall of the movable rod 57, as shown in FIG. Figure 5 , Figure 6 As shown, the lower end of the movable rod 57 is connected to the outer cylinder 5 through a spring, a V-shaped block 58 is provided on the connecting rod 55, and a pressure column 59 is provided on the movable rod 57 for cooperating with the V-shaped block 58 to push the connecting rod 55 to slide left and right.

[0049] The working principle of the outer cylinder 5 is as follows: the liquid supply pipe 52 will push the lubricant into the sliding hole 51 under the action of the piston plate, and enter the storage tank 511 through the liquid channel. When the upper die seat 1 descends, the blank will be squeezed and deformed until the upper die seat 1 contacts the movable rod 57. At this time, the first stage of extrusion has been completed and the main body of the shell has been formed. As the upper die seat 1 continues to descend, the second stage of extrusion begins. Then the upper die seat 1 presses the movable rod 57 to make the movable rod 57 slide downward. At this time, the pressure column 59 squeezes the V-shaped block 58, so that the connecting rod 55 drives the sliding block 58 to slide downward. The column 54 slides to the left and shrinks to the left end of the storage groove 511. At this time, the liquid channel is closed by the inner wall of the sliding hole, and the liquid channel and the storage groove 511 are no longer connected. At this time, the lubricant in the storage groove 511 is released to the right end of the sliding column 54 under the action of gravity. When the pressure column 59 passes the apex of the V-shaped block 58, under the hydraulic pressure provided by the liquid supply pipe 52, the connecting rod 55 drives the sliding column 54 to start sliding to the right. When the liquid channel and the storage groove 511 are connected again, the storage groove 511 is closed by the sliding column 54, and the sliding column 54 continues to slide to the right to push the lubricant into the outer cylinder 5.

[0050] When the upper die seat 1 rises, the movable rod 57 will be reset under the action of the spring, so that the pressure column 59 squeezes the V-shaped block 58 again, and the slide column 54 slides back and forth to push the lubricant into the outer tube 5.

[0051] Example 3: Figure 7 As shown, this embodiment is basically the same as embodiment 2, except that the pressure column 59 is slidably connected to the blind hole provided on the movable rod 57, the pressure column 59 is slidably connected to the blind hole through a slider provided at its right end, and the right end of the slider is connected to the blind hole through a spring, the pressure column 59 is sleeved with a second air bag 591 that controls the contraction or extension of the pressure column 59 by inflation and deflation, the second air bag 591 is arranged at the left end of the slider, the upper end of the movable rod 57 is fixedly sleeved with a first air bag 571 that is connected to the second air bag 591, the first air bag 571 is connected to the second air bag 591 through a gas channel provided in the movable rod 57, and the upper mold base 1 is provided with a docking hole 11 corresponding to the movable rod 57, as shown in FIG. Fig. 9 , Fig.10 As shown, the connecting rod 55 is provided with a clamping hole 551 for clamping with the pressure column 59 by extending it; Figure 8 As shown, two clamping columns 12 connected to the docking hole 11 through springs are arranged in the side wall thereof, and a clamping groove for engaging with the clamping columns 12 is arranged at the upper end of the movable rod 57 .

[0052] The working principle of the above-mentioned pressure column 59 is as follows: when the upper mold base 1 does not press the movable rod 57, the pressure column 59 extends outward and engages with the card hole. At this time, the slide column 54 cannot shrink, so as to avoid the shrinkage of the slide column 54 during the extrusion process. When the upper mold base 1 presses the movable rod 57, the docking hole 11 will first squeeze the first air bag 571, so that the gas in the first air bag 571 enters the second air bag 591. The inflation of the second air bag 591 pushes the pressure column 59 to slide to the right. At this time, the pressure column 59 is separated from the connecting rod 55. As the movable rod 57 continues to move downward, the pressure column 59 can press down the V-shaped block 58, and the slide column 54 can slide. After the movable rod 57 completely enters the docking hole 11, the card column 12 can be engaged with the card slot. When the upper mold base 1 moves upward, the upper mold base 1 can drive the movable rod 57 to move upward. When the movable rod 57 rises to the highest point, the card column 12 can shrink to separate the upper mold base 1 from the movable rod 57.

[0053] Example 4: This example is basically the same as Example 1, except that both ends of the blank are chamfered before being kept warm, and the chamfer radius is R7.

[0054] Example 5: This example is basically the same as Example 1, except that both ends of the blank are chamfered before being kept warm, and the chamfer radius is R9.

[0055] Example 6: This example is basically the same as Example 1, except that the preheating method is: keeping the blank at 750°C for 140 minutes.

[0056] Example 7: This example is basically the same as Example 1, except that the preheating method is: keeping the blank at 850°C for 160 minutes.

Claims

1. A reverse extrusion forming manufacturing tool for a relatively high shell part, characterized in that: The invention comprises an upper die base (1), an outer cylinder (5) and a lower die base (8) which are arranged in sequence from top to bottom, wherein an upper punch (4) is arranged on the upper die base (1), and a lower punch (6) corresponding to the upper punch (4) is arranged on the lower die base (8), wherein both the upper punch (4) and the lower punch (6) extend into the interior of the outer cylinder (5), and the outer cylinder (5) and the lower die base (8) are limitedly slidable and clamped, and an upper gasket is arranged between the upper die base (1) and the outer cylinder (5), and the upper gasket comprises a positioning gasket (3) for positioning the outer cylinder (5) and a protective gasket (2) for limiting the size of a part during extrusion, and a lower gasket (7) is arranged between the lower punch (6) and the outer cylinder (5).

2. The reverse extrusion forming manufacturing tool for a higher shell part according to claim 1, characterized in that: A clamping block (56) is provided at the lower end of the outer cylinder (5), the inner wall of the lower die seat (8) has an arc-shaped clamping groove for the clamping block (56) to slide, and the upper top surface of the lower die seat (8) has a docking groove for the clamping block (56) to extend into the arc-shaped clamping groove.

3. The reverse extrusion manufacturing tool for a relatively high shell part according to claim 1, characterized in that: The inner wall of the outer cylinder (5) is provided with a plurality of groups of radially arranged liquid coating components for applying lubricant into the outer cylinder (5), each group of liquid coating components comprises a plurality of transversely arranged sliding holes (51), and a liquid supply pipe (52) arranged on the side wall of the outer cylinder (5) and connected to the sliding holes in a one-to-one correspondence, a piston (53) and a sliding column (54) are provided in a sliding seal in the sliding hole (51), one end of the piston (53) is fixedly connected to the sliding column (54) through a connecting rod (55), and a storage member (53) is provided on the inner wall of the sliding hole (51) for slidingly cooperating with the sliding column (54) to release the lubricant. The storage tank (511) is connected to the slide hole (51) through a slide column (54), a connecting rod (55) and a liquid channel connected in sequence in the piston (53); a movable rod (57) corresponding to the coating liquid component is vertically limited and slidably connected in the outer cylinder (5), and the lower end of the movable rod (57) is connected to the outer cylinder (5) through a spring; a V-shaped block (58) is provided on the connecting rod (55); and a pressure column (59) is provided on the movable rod (57) for cooperating with the V-shaped block (58) in a one-to-one correspondence to push the connecting rod (55) to slide left and right.

4. The reverse extrusion manufacturing tool for a relatively high shell part according to claim 3, characterized in that: The pressure column (59) is slidably connected to a blind hole provided on the movable rod (57), and the pressure column (59) and the blind hole are connected by a spring. The pressure column (59) is sleeved with a second air bag (591) which is controlled by inflation or deflation to shrink or extend the pressure column (59). The upper end of the movable rod (57) is fixedly sleeved with a first air bag (571) which is connected to the second air bag (591). The upper mold base (1) is provided with a docking hole (11) corresponding to the movable rod (57). The connecting rod (55) is provided with a clamping hole (551) for clamping with the pressure column (59) by extending it.

5. The reverse extrusion manufacturing tool for a higher shell part according to claim 4, characterized in that: A plurality of clamping columns (12) connected to the docking hole (11) via springs are arranged in the side wall of the docking hole (11), and a clamping groove for clamping with the clamping column (12) is arranged at the upper end of the movable rod (57).

6. The method for using the reverse extrusion manufacturing tooling for a higher shell part according to claim 1, based on the reverse extrusion manufacturing tooling for a higher shell part according to any one of claims 1 to 5, is characterized in that: The following steps are involved: S1, clamping the outer cylinder (5) onto the lower die base (8), controlling the upper die base (1) to descend and adjusting the position of the lower die base (8) during the descent of the upper die base (1) so that the positioning gasket (3) can enter the outer cylinder (5), and then fixing the position of the lower die base (8), at which time the upper punch (4), the lower punch (6) and the outer cylinder (5) are concentric; S2, controlling the upper die seat (1) to rise so that the upper punch (4) is completely withdrawn from the outer cylinder (5), and the positioning gasket (3) is removed and replaced with a protective gasket (2); S3, preheating the blank, then placing the blank into the outer cylinder (5), controlling the upper die seat (1) to descend, and causing the upper punch (4) and the lower punch (6) to extrude the blank to obtain a shell; S4. After extrusion is completed, the upper die seat (1) is controlled to rise. Since the shell is adhered to the upper punch (4), the lower punch (6) and the outer cylinder (5), the upper punch (4) will drive the outer cylinder (5) to move upward during the rising process, so that the shell and the lower punch (6) are separated, until the outer cylinder (5) is limited by the lower die seat (8) and cannot move further upward. As the upper die seat (1) continues to rise, the upper punch (4) is separated from the shell, and then the outer cylinder (5) is removed from the lower die seat (8), and the shell is taken out of the outer cylinder (5).

7. The method for using the reverse extrusion manufacturing tool for a relatively high shell part according to claim 6, characterized in that: In step S3, the blank is cylindrical, and both ends of the blank are chamfered before being kept warm, and the chamfer radius is R7-R9.

8. The method for using the reverse extrusion manufacturing tool for a relatively high shell part according to claim 6, characterized in that: The preheating method is: keeping the blank at 750-850° C. for 140-160 minutes.

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