Forging Die and Forging Method for Rapid and Batch Preparation of Dumbbell-shaped Step Shaft Blanks

Abstract

The present invention provides a forging die and a forging method for quickly and batch-producing dumbbell-shaped stepped shaft blanks, including an upper die, an outer lower die frame, and a lower die arranged in sequence from top to bottom; a positioning hole is arranged in the outer lower die frame, the side wall of the positioning hole is inclined, and a plurality of axially extending anti-detachment sliding grooves are arranged on the side wall of the positioning hole. A core die that is slidably matched with the side wall of the positioning hole is arranged in the positioning hole. The core die has a central positioning through hole, and the core die is composed of a plurality of core die blocks spliced together. An anti-detachment sliding block is arranged on the outer wall of each core die block, and each anti-detachment sliding block is slidably matched with an anti-detachment sliding groove. During the demoulding process, it is only necessary to drive the dumbbell-shaped stepped shaft blank to move upward, and it is not necessary to disassemble the respective core die blocks of the core die. The demoulding is very convenient and fast. After demoulding, the core die blocks automatically slide downward under the action of gravity and re-form the core die. It is not necessary to install the core die again during the next forging, which can effectively reduce the operation amount and improve the forging efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of dumbbell-shaped stepped shaft blanks, and in particular to a forging die and a forging method for quickly and batch-producing dumbbell-shaped stepped shaft blanks. Background Art

[0002] Dumbbell-shaped parts are those with a small middle and large ends, similar to a dumbbell in shape. In the prior art, directly forging the parts from round bar stock will surely cause great material waste; while forging with a dumbbell-shaped stepped shaft blank with large diameters at both ends and a small diameter in the middle is undoubtedly an excellent way to achieve the precision forming of such forgings.

[0003] The dumbbell-shaped stepped shaft has a special structure. As Figure 1 shown, it is difficult to form using the conventional upsetting process. Generally, one end of the bar stock is upset first, and then the second end is upset. For details, reference can be made to the invention patent with the application number 201610454552.9.

[0004] When upsetting the second end of the blank, a special die is required. The die generally includes an upper die and a lower die. In order to prevent deformation of the second end and ensure that the middle shaft and the first end do not deform during upsetting, a middle shaft protective sleeve structure needs to be set on the upper die or the lower die. Since the forgings after forging are thick at both ends and thin in the middle, in order to take out the forgings from the die, the middle shaft protective sleeve structure is generally composed of multiple parts that can be detachably spliced. After forging, the middle shaft protective sleeve structure is disassembled so that the large end of the forging can pass through. The invention patent with the application number 201610454552.9 uses a core die to protect and position the middle shaft and the pre-forged large end, and the core die is separated after forging to take out the part.

[0005] The core die can adopt various detachable combination methods, but all need to be manually disassembled when taking out the part in order to take out the end with a larger diameter of the forging, resulting in low part-taking efficiency. When forging next time, the core die needs to be installed again, which consumes a certain amount of time and is not conducive to realizing rapid batch forging. The invention patent with the application number 202110448161.7 discloses a necking die for automotive chassis parts, which can only be used to prepare thin-walled chassis parts, and when in use, the forming core needs to be jacked up first and then the part is placed, and the operation is still not convenient enough. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a forging die and a forging method for quickly and batch-producing dumbbell-shaped stepped shaft blanks, which do not require manual installation of a core die before forging and can quickly take out the forgings after forging, so as to ensure the forging efficiency.

[0007] The technical solution adopted by the present invention to solve its technical problems is: a forging die for quickly and batch preparing dumbbell-shaped stepped shaft blanks, including an upper die, a lower die outer frame and a lower die arranged in sequence from top to bottom;

[0008] A positioning hole is arranged in the lower die outer frame. The side wall of the positioning hole is inclined, and the upper hole opening of the positioning hole is larger than the lower hole opening. A plurality of axially extending anti-detachment sliding grooves are arranged on the side wall of the positioning hole. A core die that slidably cooperates with the side wall of the positioning hole is arranged in the positioning hole. The core die has a central positioning through hole. The core die is composed of a plurality of core die blocks spliced together. An anti-detachment sliding block is arranged on the outer wall of each core die block. Each anti-detachment sliding block is located in an anti-detachment sliding groove and slidably cooperates with the anti-detachment sliding groove;

[0009] A head cavity is arranged between the upper die and the lower die outer frame. The lower die outer frame is liftably installed on the lower die. A lower die cavity is arranged on the lower die below the central positioning through hole.

[0010] Further, both the positioning hole and the core die are frustum-shaped.

[0011] Further, the head cavity is arranged on the upper surface of the lower die outer frame. The depth of the head cavity is equal to the length of the blank head. The upper die is a horizontal plate. The horizontal plate is naturally placed on the upper surface of the lower die outer frame. The positioning hole is located at the bottom of the head cavity.

[0012] Further, a guiding hole is arranged on the lower surface of the lower die outer frame. A guiding column is arranged on the upper surface of the lower die. The upper end of the guiding column extends into the guiding hole and slidably cooperates with the guiding hole. A spring is arranged between the bottom of the guiding hole and the guiding column.

[0013] Further, both the upper hole opening and the lower hole opening of the positioning hole are rounded.

[0014] The forging method using the above forging die for quickly and batch preparing dumbbell-shaped stepped shaft blanks includes

[0015] Upsetting one end of the bar stock to obtain a T-shaped intermediate blank;

[0016] Let the small end of the T-shaped intermediate blank pass downward through the central positioning through hole and extend into the lower die cavity. Place the upper die on the top of the lower die outer frame so that the large end of the T-shaped intermediate blank is located in the head cavity. Then press down the upper die so that the lower die outer frame moves downward. At the same time, the small end of the T-shaped intermediate blank is upset in the lower die cavity to obtain a dumbbell-shaped stepped shaft blank;

[0017] After forging, remove the upper die, and pull the dumbbell-shaped stepped shaft blank upward. When the lower end of the dumbbell-shaped stepped shaft blank reaches the core die, push the core die to slide obliquely upward along the side wall of the positioning hole, and the diameter of the central positioning through hole increases. When the diameter of the central positioning through hole is greater than the outer diameter of the lower end of the dumbbell-shaped stepped shaft blank, the lower end of the dumbbell-shaped stepped shaft blank passes through the central positioning through hole to complete demoulding. After demoulding, the core die automatically slides downward under the action of gravity and resets.

[0018] Further, the forging process of the T-shaped intermediate blank is as follows: Prepare a cylinder lower die, and a positioning blind hole is provided on the upper surface of the cylinder lower die; Place one end of the bar stock into the positioning blind hole, and the upper end of the bar stock is located outside the positioning blind. Place the cylinder upper die on the upper end of the bar stock and apply a downward pressure to the cylinder upper die to upset the upper end of the bar stock to obtain the T-shaped intermediate blank.

[0019] Further, after forging, use a clamp to hold the upper end of the dumbbell-shaped stepped shaft blank and pull the dumbbell-shaped stepped shaft blank upward.

[0020] Further, when the lower die outer frame moves downward, the spring is compressed. After the dumbbell-shaped stepped shaft blank is formed, the spring extends to assist in pushing the dumbbell-shaped stepped shaft blank upward.

[0021] The beneficial effects of the present invention are as follows: By setting the hole wall of the positioning hole of the lower die outer frame as an inclined surface and providing an anti-detachment sliding groove on this inclined surface, and by providing an anti-detachment sliding block on the outer wall of each core die module, and the anti-detachment sliding block is in sliding fit with the anti-detachment sliding groove, the core die can slide obliquely upward or downward along the hole wall of the positioning hole. During the sliding process, the central positioning through hole of the core die becomes larger or smaller. When demoulding after forging, only need to drive the dumbbell-shaped stepped shaft blank upward. The lower end of the dumbbell-shaped stepped shaft blank pushes the core die upward to slide, making the central positioning through hole gradually increase until the lower end of the dumbbell-shaped stepped shaft blank passes through the central positioning through hole. During the demoulding process, only need to drive the dumbbell-shaped stepped shaft blank upward, without disassembling each core die module of the core die. The demoulding is very convenient and fast. After demoulding, the core die modules automatically slide downward under the action of gravity and re-form the core die. There is no need to install the core die again during the next forging, which can effectively reduce the operation amount, improve the forging efficiency, and realize the rapid batch processing of the dumbbell-shaped stepped shaft blank. Description of the Drawings

[0022] Figure 1 is a schematic diagram of the dumbbell-shaped stepped shaft blank;

[0023] Figure 2 is a forming schematic diagram of the T-shaped intermediate blank;

[0024] Figure 3 is a front view sectional schematic diagram of the forging die of the dumbbell-shaped stepped shaft blank;

[0025] Figure 4 It is a top view schematic diagram of the cooperation between the core mold and the lower mold outer frame;

[0026] Figure 5 It is a forging schematic diagram of a dumbbell-shaped stepped shaft blank;

[0027] Reference numerals: 2—upper tube mold; 3—T-shaped intermediate blank; 4—lower tube mold; 5—upper mold; 6—lower mold outer frame; 61—end cavity; 63—positioning hole; 64—anti-disengagement chute; 65—guide hole; 7—lower mold; 71—lower mold cavity; 72—guide post; 8—spring; 9—core mold; 91—central positioning through hole; 92—anti-disengagement slider. Detailed implementation manners

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0029] As Figure 3 and Figure 4 shown, the forging die for quickly and batch-producing a dumbbell-shaped stepped shaft blank of the present invention includes an upper mold 5, a lower mold outer frame 6, and a lower mold 7 which are sequentially arranged from top to bottom.

[0030] A positioning hole 63 is provided in the lower mold outer frame 6. The side wall of the positioning hole 63 is inclined, and the upper end orifice of the positioning hole 63 is larger than the lower end orifice. A plurality of axially extending anti-disengagement chutes 64 are provided on the side wall of the positioning hole 63. A core mold 9 slidably engaged with the side wall of the positioning hole 63 is provided in the positioning hole 63. The core mold 9 has a central positioning through hole 91. The core mold 9 is composed of a plurality of core mold blocks spliced together. An anti-disengagement slider 92 is provided on the outer wall of each core mold block. Each anti-disengagement slider 92 is located in an anti-disengagement chute 64 and is slidably engaged with the anti-disengagement chute 64.

[0031] An end cavity 61 is provided between the upper mold 5 and the lower mold outer frame 6. The lower mold outer frame 6 is liftably installed on the lower mold 7. A lower mold cavity 71 is provided on the lower mold 7 below the central positioning through hole 91.

[0032] The lower mold 7 and the lower mold cavity 71 are used to form the lower end head of the dumbbell-shaped stepped shaft blank. The shape and size of the lower mold cavity 71 are consistent with the size of the lower end head of the dumbbell-shaped stepped shaft blank. The lower mold outer frame 6 and the upper mold 5 are used to position and protect the upper part of the intermediate shaft and the upper end head of the T-shaped intermediate blank 3, so that the T-shaped intermediate blank 3 remains stable during forging, and at the same time prevent the upper part of the intermediate shaft and the upper end head of the T-shaped intermediate blank 3 from deforming during subsequent forging. During the process of upsetting the lower end of the T-shaped intermediate blank 3, the height of the T-shaped intermediate blank 3 gradually decreases. In order to adapt to the change in height, the lower mold outer frame 6 is liftably installed on the lower mold 7.

[0033] Specifically, the upper part of the intermediate shaft of the T-shaped intermediate blank 3 is positioned and protected by the core mold 9. The shape and size of the central positioning through hole 91 are adapted to the upper part of the intermediate shaft of the T-shaped intermediate blank 3, ensuring that the small end of the T-shaped intermediate blank 3 can pass through the central positioning through hole 91, but there is not too large a gap between the upper part of the intermediate shaft and the hole wall of the central positioning through hole 91.

[0034] Since the diameter of the central positioning through hole 91 is smaller than the end diameter of the dumbbell-shaped stepped shaft blank, in order to achieve rapid demolding, the present invention sets a positioning hole 63 at the middle position of the lower die outer frame 6. The side wall of the positioning hole 63 is inclined, and the upper hole opening of the positioning hole 63 is larger than the lower hole opening. A plurality of axially extending anti-detachment sliding grooves 64 are provided on the side wall of the positioning hole 63. The core modules of the core mold 9 are slidably matched with the anti-detachment sliding grooves 64 through anti-detachment sliders 92, so that each core module is slidably matched with the side wall of the positioning hole 63. The anti-detachment sliding groove 64 can be a dovetail groove or a groove body with a trapezoidal cross-section, and the width of its groove opening is smaller than the width of other parts. The shape of the anti-detachment slider 92 is adapted to the shape of the anti-detachment sliding groove 64 to prevent the anti-detachment slider 92 from detaching from the groove opening of the anti-detachment sliding groove 64, thereby ensuring that the core module can stably slide up and down along the side wall of the positioning hole 63. The inclined side wall of the positioning hole 63 has the function of automatic positioning. During forging, the inclined side wall of the positioning hole 63 can stably support the core module and ensure the stability of the core mold 9. In addition, since the side wall of the positioning hole 63 is inclined and the opening area gradually increases from bottom to top, when the core module slides obliquely upward along the side wall of the positioning hole 63, the core modules will gradually separate, causing the diameter of the central positioning through hole 91 to gradually increase until the end of the dumbbell-shaped stepped shaft blank can pass through. By arranging the anti-detachment slider 92 at the lower part of the core module, the inclination degree of the side wall of the positioning hole 63 should meet the requirement that when the anti-detachment slider 92 moves to the upper part of the anti-detachment sliding groove 64 along with the core module, the diameter of the central positioning through hole 91 increases to be large enough for the end of the dumbbell-shaped stepped shaft blank to pass through. In order to prevent the anti-detachment slider 92 from detaching from the upper port of the anti-detachment sliding groove 64 and causing the core module to lose positioning, a stop block can be arranged in the upper port of the anti-detachment sliding groove 64 to ensure that the anti-detachment slider 92 is always located in the anti-detachment sliding groove 64.

[0035] The positioning hole 63 and the core mold 9 can be frustum-shaped, and their cross-sections are both square. The core mold 9 is composed of 2 or 4 core modules. As a preferred embodiment, the positioning hole 63 and the core mold 9 are both frustum-shaped, that is, the cross-section is circular, and the core mold 9 is composed of 2, 3 or 4 core modules.

[0036] The method for preparing a dumbbell-shaped stepped shaft blank using the above-mentioned mold is as follows:

[0037] Upsetting one end of the bar stock to obtain a T-shaped intermediate blank 3. This step can adopt the existing technology. Preferably, a cylinder lower die 4 is prepared. A positioning blind hole is provided on the upper surface of the cylinder lower die 4. During forging, one end of the bar stock is placed into the positioning blind hole. The diameter of the bar stock is adapted to the diameter of the positioning blind hole. The upper end of the bar stock is located outside the positioning blind hole. The cylinder upper die 2 is placed on the upper end of the bar stock. The cylinder upper die 2 can be a horizontal plate. In order to ensure the forming quality of the end head, a end head forming cavity can be provided on the upper surface of the cylinder upper die 2 or the upper surface of the cylinder lower die 4. Applying a downward pressure to the cylinder upper die 2 to upset the upper end of the bar stock to obtain the T-shaped intermediate blank 3, as Figure 2 shown. There is no connection relationship between the cylinder upper die 2 and the cylinder lower die 4. After the upper part end head is formed, the cylinder upper die 2 can be directly removed, which is very convenient.

[0038] Forming of the dumbbell-shaped stepped shaft: As Figure 5 shown, the small end of the T-shaped intermediate blank 3 is downwardly passed through the central positioning through hole 91 and extends into the lower die cavity 71. The upper die 5 is placed on the top of the lower die outer frame 6, such that the large end of the T-shaped intermediate blank 3 is located in the end head cavity 61. At this time, the upper surface of the upper part end head of the T-shaped intermediate blank 3 contacts the upper die 5, the lower stepped surface of the upper part end head of the T-shaped intermediate blank 3 contacts the upper surface of the core die 9, and the upper surface of the lower die outer frame 6 contacts the upper die 5. This can prevent the pressing force from being transmitted to the upper part end head of the already formed T-shaped intermediate blank 3 when the upper die 5 is pressed downward, resulting in the upper part end head being upset again, and ensure that the pressing force is transmitted to the small end of the T-shaped intermediate blank 3, such that the small end of the T-shaped intermediate blank 3 is upset and formed into the lower part end head.

[0039] Then press down the upper die 5, such that the lower die outer frame 6 moves downward. At the same time, the small end of the T-shaped intermediate blank 3 is upset and formed into the lower part end head in the lower die cavity 71 to obtain a dumbbell-shaped stepped shaft blank.

[0040] Demoulding: After forging, remove the upper die 5 and pull the dumbbell-shaped stepped shaft blank upward. Specifically, a clamp can be used to clamp the upper end head of the dumbbell-shaped stepped shaft blank and pull the dumbbell-shaped stepped shaft blank upward, or a ejector rod can be provided in the lower die 7, and the ejector rod is used to push the dumbbell-shaped stepped shaft blank to demould and move upward. When the lower part end head of the dumbbell-shaped stepped shaft blank reaches the core die 9, push the core die 9 to slide obliquely upward along the side wall of the positioning hole 63, and the diameter of the central positioning through hole 91 increases. When the diameter of the central positioning through hole 91 is greater than the outer diameter of the lower part end head of the dumbbell-shaped stepped shaft blank, the lower part end head of the dumbbell-shaped stepped shaft blank passes through the central positioning through hole 91 to complete demoulding. After demoulding, the core die 9 automatically slides downward and resets under the action of gravity.

[0041] It can be seen that after adopting the present invention, the forming steps of the lower end of the dumbbell-shaped stepped shaft blank include: placing the T-shaped intermediate blank 3 → installing the upper die 5 → forging → removing the upper die 5 → directly taking out the dumbbell-shaped stepped shaft blank. While the forming steps of the traditional forging method include: installing the core die → placing the T-shaped intermediate blank 3 → installing the upper die 5 → forging → removing the upper die 5 → disassembling the core die → taking out the dumbbell-shaped stepped shaft blank. It can be seen that the present invention omits the manual installation and disassembly processes of the core die 9, simplifies the production process, and is conducive to realizing the rapid and batch preparation of dumbbell-shaped stepped shaft blanks.

[0042] The end cavity 61 can be arranged on the lower surface of the upper die 5. Preferably, the end cavity 61 is arranged on the upper surface of the lower die outer frame 6. The depth of the end cavity 61 is equal to the length of the upper end of the T-shaped intermediate blank 3. The upper die 5 is a horizontal plate, and the horizontal plate is naturally placed on the upper surface of the lower die outer frame 6. The positioning hole 63 is located at the bottom of the end cavity 61. After arranging the end cavity 61 on the lower die outer frame 6, the upper die 5 can adopt a horizontal plate with a certain thickness, reducing the weight and volume of the upper die 5, which is conducive to the rapid installation and removal of the upper die 5. And since the upper die 5 can be naturally placed on the upper surface of the lower die outer frame 6 during forging, the operation is very convenient and fast, which can further improve the installation and removal efficiency of the upper die 5. The depth of the end cavity 61 is equal to the length of the upper end of the T-shaped intermediate blank 3, which can ensure that the upper end of the T-shaped intermediate blank 3 and the upper surface of the lower die outer frame 6 are in contact with the upper die 5 simultaneously during forging, and the lower surface of the upper end of the T-shaped intermediate blank 3 is in contact with the upper surface of the core die 9 to protect the upper end and prevent the already formed upper end from being subjected to forging force again.

[0043] The lower die outer frame 6 can be lifted and lowered by various existing lifting mechanisms. Preferably, a guiding hole 65 is arranged on the lower surface of the lower die outer frame 6, and a guiding post 72 is arranged on the upper surface of the lower die 7. The upper end of the guiding post 72 extends into the guiding hole 65 and is in sliding fit with the guiding hole 65, and a spring 8 is arranged between the bottom of the guiding hole 65 and the guiding post 72. During the forging process, when the lower die outer frame 6 moves downward, the spring 8 is compressed and has a large elastic force. After the dumbbell-shaped stepped shaft blank is formed, the spring 8 elongates to assist in pushing the dumbbell-shaped stepped shaft blank upward, thereby reducing the force required for demolding.

[0044] Both the upper and lower orifices of the positioning hole 63 are rounded, which is adapted to the shape of the upset end.

[0045] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A forging die for rapidly and batch-producing dumbbell-shaped stepped shaft blanks, characterized in that, It includes an upper die (5), a lower die outer frame (6), and a lower die (7) which are arranged in sequence from top to bottom; A positioning hole (63) is arranged inside the lower die outer frame (6). The side wall of the positioning hole (63) is inclined, and the upper orifice of the positioning hole (63) is larger than the lower orifice. A plurality of axially extending anti - detachment sliding grooves (64) are arranged on the side wall of the positioning hole (63). A core die (9) which is slidably matched with the side wall of the positioning hole (63) is arranged inside the positioning hole (63). The core die (9) has a central positioning through - hole (91). The core die (9) is composed of a plurality of core die blocks spliced together. An anti - detachment sliding block (92) is arranged on the outer wall of each core die block. Each anti - detachment sliding block (92) is located in an anti - detachment sliding groove (64) and is slidably matched with the anti - detachment sliding groove (64); A head cavity (61) is arranged between the upper die (5) and the lower die outer frame (6). The lower die outer frame (6) is installed on the lower die (7) in a liftable manner. A lower die cavity (71) is arranged on the lower die (7) below the central positioning through - hole (91); The head cavity (61) is arranged on the upper surface of the lower die outer frame (6). The depth of the head cavity (61) is equal to the length of the blank head. The upper die (5) is a horizontal plate. The horizontal plate is naturally placed on the upper surface of the lower die outer frame (6). The positioning hole (63) is located at the bottom of the head cavity (61); A guiding hole (65) is arranged on the lower surface of the lower die outer frame (6). A guiding post (72) is arranged on the upper surface of the lower die (7). The upper end of the guiding post (72) extends into the guiding hole (65) and is slidably matched with the guiding hole (65). A spring (8) is arranged between the bottom of the guiding hole (65) and the guiding post (72); The small end of the T - shaped intermediate blank (3) passes downward through the central positioning through - hole (91) and extends into the lower die cavity (71). The upper die (5) is placed on the top of the lower die outer frame (6). The large end of the T - shaped intermediate blank (3) is located inside the head cavity (61). The upper surface of the upper end of the T - shaped intermediate blank (3) abuts against the lower surface of the upper die (5). The lower stepped surface of the upper end of the T - shaped intermediate blank (3) abuts against the upper surface of the core die (9). The upper surface of the lower die outer frame (6) abuts against the lower surface of the upper die (5).

2. The forging die for quickly and batch preparing dumbbell-shaped stepped shaft blanks according to claim 1, wherein, Both the positioning hole (63) and the core die (9) are frustum - shaped.

3. The forging die for rapidly and batch preparing dumbbell-shaped stepped shaft blanks according to claim 1, wherein, Both the upper orifice and the lower orifice of the positioning hole (63) are rounded.

4. A forging method for rapidly and batch-producing dumbbell-shaped stepped shaft blanks, using the forging die for rapidly and batch-producing dumbbell-shaped stepped shaft blanks described in any one of claims 1 to 3, characterized in that, It includes Upsetting one end of a bar stock to obtain a T - shaped intermediate blank (3); The small end of the T - shaped intermediate blank (3) passes downward through the central positioning through - hole (91) and extends into the lower die cavity (71). The upper die (5) is placed on the top of the lower die outer frame (6) so that the large end of the T - shaped intermediate blank (3) is located in the head cavity (61). Then the upper die (5) is pressed down, so that the lower die outer frame (6) moves downward. At the same time, the small end of the T - shaped intermediate blank (3) is upset in the lower die cavity (71) to obtain a dumbbell - shaped stepped shaft blank; After forging, remove the upper die (5). Pull the dumbbell-shaped stepped shaft blank upward. When the lower end of the dumbbell-shaped stepped shaft blank reaches the core die (9), push the core die (9) to slide obliquely upward along the side wall of the positioning hole (63), and the diameter of the central positioning through hole (91) increases. When the diameter of the central positioning through hole (91) is greater than the outer diameter of the lower end of the dumbbell-shaped stepped shaft blank, the lower end of the dumbbell-shaped stepped shaft blank passes through the central positioning through hole (91) to complete demoulding. After demoulding, the core die (9) automatically slides downward and resets under the action of gravity.

5. The forging method for rapidly and batch producing dumbbell-shaped stepped shaft blanks as claimed in claim 4, characterized in that, The forging process of the T-shaped intermediate blank (3) is as follows: Prepare the barrel lower die (4), and a positioning blind hole is provided on the upper surface of the barrel lower die (4); Place one end of the bar stock into the positioning blind hole, with the upper end of the bar stock outside the positioning blind hole. Place the barrel upper die (2) on the upper end of the bar stock and apply a downward pressure to the barrel upper die (2) to upset the upper end of the bar stock to obtain the T-shaped intermediate blank (3).

6. The forging method for rapidly and batch preparing dumbbell-shaped stepped shaft blanks as claimed in claim 4, characterized in that, After forging, use a clamp to hold the upper end of the dumbbell-shaped stepped shaft blank and pull the dumbbell-shaped stepped shaft blank upward.

7. The forging method for quickly and batch producing dumbbell-shaped stepped shaft blanks according to claim 4, characterized in that, When the lower die outer frame (6) moves downward, the spring (8) is compressed. After the dumbbell-shaped stepped shaft blank is formed, the spring (8) elongates to assist in pushing the dumbbell-shaped stepped shaft blank upward.

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