A hollow shaft machining process and production line

Abstract

This application discloses a hollow shaft machining process and production line, relating to the technical field of shaft machining. The process includes the following steps: performing a second stamping operation on the shaft workpiece; firstly, stamping a positioning hole on the axial end face of the shaft workpiece; secondly, narrowing the outer peripheral wall of the shaft workpiece away from the positioning hole to form a first connecting part; stamping the positioning hole to form a hollow hole; stamping the outer peripheral wall of the hollow hole to thin it and form a shaft body; and stamping the outer periphery of the hollow hole opening to narrow it and form a second connecting part. By performing these four stamping processes, the shaft workpiece is machined to produce the first connecting part, the second connecting part, the hollow hole, and the shaft body, replacing a radial forging machine and significantly reducing the production cost of hollow shafts.

Description

Technical Field

[0001] This application relates to the technical field of shaft machining, and more specifically, it relates to a hollow shaft machining process and machining production line. Background Technology

[0002] To meet lightweight standards, many new energy motors now use hollow shafts to reduce weight. (Refer to...) Figure 1 The hollow shaft includes a shaft body, a hollow hole coaxially opened in the shaft body, a first connecting part and a second connecting part located at the two ends of the shaft body in the axial direction.

[0003] Currently, the processing of hollow shafts relies heavily on imported radial forging machines, which are extremely expensive and significantly increase production costs. Therefore, there is an urgent need to develop a process and related equipment to replace radial forging machines for hollow shaft processing, thereby reducing production costs. Summary of the Invention

[0004] To reduce the production cost of hollow shafts, this application provides a hollow shaft processing technology and processing line.

[0005] This application provides a hollow shaft machining process, which adopts the following technical solution:

[0006] A hollow shaft machining process includes the following steps:

[0007] S100, the shaft workpiece is subjected to secondary stamping. The first stamping is used to stamp a positioning hole on the axial end face of the shaft workpiece. The second stamping narrows the outer peripheral wall of the shaft workpiece away from the positioning hole to form the first connecting part.

[0008] S200, punching the positioning holes of shaft workpieces to punch out hollow holes in the positioning holes;

[0009] S300, the outer peripheral wall of the hollow hole is stamped to thin the outer peripheral wall of the hollow hole in order to form a shaft body;

[0010] S400, the outer periphery of the hollow hole is punched to narrow the opening of the hollow hole, thereby forming the second connecting part.

[0011] The above technical solution involves processing shaft-type workpieces through four stamping processes. The first process processes positioning holes and a first connecting part on the shaft-type workpiece. The second process processes a hollow hole based on the positioning hole. The third process thins the outer peripheral wall of the hollow hole to process the shaft body. The fourth process narrows the opening of the hollow hole to form the second connecting part. This can replace the radial forging machine for processing shaft-type workpieces, greatly reducing the production cost of hollow shafts.

[0012] This application provides a hollow shaft processing production line, including a first stamping die, a second stamping die, a third stamping die, and a fourth stamping die arranged in sequence;

[0013] The first stamping die is used for secondary stamping of shaft-type workpieces;

[0014] The second stamping die is used to stamp the positioning holes of shaft-type workpieces;

[0015] The third stamping die is used to stamp the outer peripheral wall of the hollow hole;

[0016] The fourth stamping die is used to stamp the outer periphery of the hollow hole opening.

[0017] The above technical solutions have greatly reduced the production cost of hollow shafts.

[0018] Optionally, the first stamping die includes a first upper die and a first lower die;

[0019] The lower end of the first upper die is connected to a first punch assembly. The first punch assembly includes a first punch sleeve and a first punch core. The first punch sleeve is coaxially sleeved on the outer ring of the first punch core, and the first punch core protrudes from the lower end of the first punch sleeve.

[0020] The upper end of the first lower die is provided with a first concave die, the first concave die is provided with a first cavity for placing shaft-type workpieces, the first punch core is used to punch a positioning hole on the axial end face of the shaft-type workpiece, the bottom of the first cavity is provided with a first forming cavity, the first punch sleeve is used to press the end of the shaft-type workpiece away from the positioning hole into the first forming cavity, and the first forming cavity is used to narrow the end of the shaft-type workpiece away from the positioning hole to form a first connecting part.

[0021] The above technical solution involves setting up a first punch assembly, a first cavity, and a first forming cavity. The first punch core punches the end of the shaft-like workpiece to create a positioning hole. Then, the first punch sleeve presses the shaft-like workpiece axially into the first forming cavity. The side wall of the first forming cavity squeezes the circumferential outer wall of the shaft-like workpiece, narrowing the outer circumferential wall of the end of the shaft-like workpiece away from the positioning hole, thus forming the first connecting part. This method quickly forms the positioning hole and the first connecting part, improving processing efficiency.

[0022] Optionally, the second stamping die includes a second upper die and a second lower die;

[0023] The lower end of the second upper die is connected to a second punch core;

[0024] The upper end of the second lower die is provided with a second concave die, and the upper end of the second concave die is provided with a second cavity. The second cavity is used to place shaft-type workpieces. The second punch core cooperates with the second cavity to punch a hollow hole in the positioning hole.

[0025] The above technical solution involves setting a second punch core and a second cavity. The second punch core presses down on the positioning hole and cooperates with the second cavity, causing the shaft workpiece to be elongated as a whole. A hollow hole is quickly formed based on the positioning hole, improving processing efficiency.

[0026] Optionally, the bottom of the second cavity is coaxially provided with a second clamping cavity, and the inner wall of the second clamping cavity is used to coaxially abut against the circumferential outer wall of the first connecting part.

[0027] Through the above technical solution, a second clamping cavity is set up. The inner wall of the second clamping cavity is used to coaxially abut against the circumferential outer wall of the first connecting part. In this way, the second clamping cavity can restrict the radial displacement of the first connecting part, thereby reducing the overall displacement of the shaft workpiece during the pressing down of the second punch core, reducing the error generated by processing, and improving the coaxiality between the hollow hole and the outer periphery of the shaft workpiece.

[0028] Optionally, a centering member is coaxially provided at the lower end of the second punch core, and the lower end of the centering member is used to abut against the bottom of the positioning hole to limit the radial offset between the second punch core and the positioning hole.

[0029] By using the above technical solution, a centering component is set up. When the centering component abuts against the bottom of the positioning hole, the radial offset between the second punch core and the positioning hole can be reduced, thereby reducing the relative offset between the second punch core and the positioning hole when it punches downward, and improving the concentricity between the formed hollow hole and the shaft workpiece.

[0030] Optionally, the third stamping die includes a third upper die and a third lower die;

[0031] The lower end of the third upper die is connected to a third upper punch, and the lower end of the third upper punch is provided with a third clamping cavity, which is used to clamp the first connecting part.

[0032] The upper end of the third lower die is provided with a third concave die, and the upper end of the third concave die is provided with a third forming cavity. The third upper punch is used to coaxially press one end of the shaft workpiece with a hollow hole into the third forming cavity. The third forming cavity is coaxially provided with a third lower punch, which is used to extend into the hollow hole to limit the deformation of the hollow hole. The third lower punch cooperates with the third forming cavity to thin the outer peripheral wall of the hollow hole to form a shaft body.

[0033] The above technical solution involves setting up a third upper punch, a third forming cavity, and a third lower punch. The clamping cavity of the third upper punch clamps the first connecting part, and the third upper punch drives the shaft workpiece to press down as a whole. The third lower punch extends into the hollow hole to restrict the deformation of the hollow hole. As a result, during the overall pressing down of the shaft workpiece, the inner wall of the third forming cavity and the third lower punch cooperate with each other to thin the outer peripheral wall of the hollow hole, so as to quickly form the shaft and improve processing efficiency.

[0034] Optionally, the fourth stamping die includes a fourth upper die and a fourth lower die;

[0035] The lower end of the fourth upper die is provided with a fourth upper punch, the fourth upper punch is provided with a fourth clamping cavity, the fourth clamping cavity is used to clamp the first connecting part, and the fourth upper punch is used to drive the first connecting part to press down.

[0036] The upper end of the fourth lower die is provided with a fourth lower concave die, and the upper end of the fourth lower concave die is provided with a fourth forming cavity. The inner wall of the fourth forming cavity is used to extrude the outer periphery at the opening of the hollow hole.

[0037] The above technical solution includes a fourth upper punch, a fourth clamping cavity, a fourth lower die, and a fourth forming cavity. The fourth upper punch drives the shaft-like workpiece to move downward as a whole. After the outer peripheral wall at the opening of the hollow hole contacts the inner wall of the fourth forming cavity, as the shaft-like workpiece is continuously pressed down, the fourth forming cavity continuously narrows the outer periphery at the opening of the hollow hole to quickly form the second connecting part and improve processing efficiency.

[0038] Optionally, the upper end of the fourth lower die is slidably connected to a fourth upper die, the fourth upper die slides relative to the fourth lower die in the vertical direction, and a return spring is provided between the fourth upper die and the fourth lower die, the return spring being used to lift the fourth upper die upward;

[0039] The fourth upper die has a connecting cavity for the shaft to pass through. The axis of the connecting cavity coincides with the axis of the fourth forming cavity. The inner wall of the connecting cavity is used to coaxially abut against the outer peripheral wall of the shaft.

[0040] By using the above technical solution, a fourth upper die and a return spring are set up. Before pressing the lower end of the shaft workpiece into the fourth forming cavity, the shaft part is first pressed into the connecting cavity, and then the second connecting part is formed. The radial deformation of the shaft is restricted by the inner wall of the connecting cavity, so that the overall machined parts have higher precision.

[0041] Optionally, the upper wall of the communicating cavity is chamfered.

[0042] By using the above technical solution, a chamfer is set, and the chamfer guides the shaft to enter the connecting cavity more easily, thus improving the convenience of processing.

[0043] In summary, this application includes at least one of the following beneficial technical effects:

[0044] (1) The shaft workpiece is processed by the above four stamping processes to produce the first connecting part, the second connecting part, the hollow hole and the shaft body respectively, which replaces the radial forging machine and greatly reduces the production cost of the hollow shaft.

[0045] (2) By setting a centering component, the relative offset between the second punch core and the positioning hole is reduced when the second punch core is punched downward, thereby improving the concentricity between the formed hollow hole and the shaft workpiece.

[0046] (3) By setting a fourth upper die, a connecting cavity and a return spring, the radial deformation of the shaft is restricted by the inner wall of the connecting cavity, so that the precision of the machined parts is higher. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the hollow shaft.

[0048] Figure 2 This is a schematic diagram of the overall structure of this embodiment.

[0049] Figure 3 This is a schematic diagram of the structure of the first stamping die in this embodiment.

[0050] Figure 4 This is a schematic diagram of the structure of the second stamping die in this embodiment.

[0051] Figure 5 This is a schematic diagram of the structure of the third stamping die in this embodiment.

[0052] Figure 6 This is a schematic diagram of the structure of the fourth stamping die in this embodiment.

[0053] Figure label:

[0054] 1. Shaft body; 2. Positioning hole; 3. Hollow hole; 4. First connecting part; 5. Second connecting part;

[0055] 6. First stamping die; 601. First upper die; 602. First lower die; 603. First guide assembly; 6031. First guide sleeve; 6032. First guide post; 604. First pressure block; 605. First punch assembly; 6051. First punch sleeve; 6052. First punch core; 6053. First outer punch sleeve; 606. First die cavity; 6061. First upper die cavity; 6062. First lower die cavity; 607. First cavity; 608. First forming cavity; 6081. First cylindrical chamber; 6082. First frustum chamber; 6083. First shrinkage chamber; 609. First ejector;

[0056] 7. Second stamping die; 701. Second upper die; 702. Second lower die; 703. Second guide assembly; 7031. Second guide sleeve; 7032. Second guide post; 704. Second pressure block; 705. Second punch assembly; 7051. Second punch sleeve; 7052. Second punch core; 70521. Centering component; 706. Second die cavity; 7061. Second upper die cavity; 7062. Second lower die cavity; 707. Second cavity; 708. Second clamping cavity; 709. Second ejector;

[0057] 8. Third stamping die; 801. Third upper die; 802. Third lower die; 803. Third guide assembly; 8031. Third guide sleeve; 8032. Third guide post; 804. Third pressure block; 805. Third upper punch; 806. Third clamping cavity; 807. Third die cavity; 8071. Third upper die cavity; 8072. Third lower die cavity; 808. Third forming cavity; 809. Third lower punch;

[0058] 9. Fourth stamping die; 901. Fourth upper die; 902. Fourth lower die; 903. Fourth guide assembly; 9031. Fourth guide sleeve; 9032. Fourth guide post; 904. Fourth pressure block; 905. Fourth upper punch; 906. Fourth clamping cavity; 907. Fourth lower pad block; 908. Fourth lower die; 909. Fourth upper die; 910. Return spring; 911. Communicating cavity; 912. Fourth forming cavity; 913. Chamfer; 914. Fourth sliding cavity; 915. Fourth ejector. Detailed Implementation

[0059] The present application will be further described in detail below with reference to the accompanying drawings.

[0060] This application discloses a hollow shaft processing production line.

[0061] Reference Figure 2 It includes a first stamping die 6, a second stamping die 7, a third stamping die 8, and a fourth stamping die 9 arranged sequentially.

[0062] Reference Figure 3The first stamping die 6 includes a first upper die 601 and a first lower die 602. The first upper die 601 is located directly above the first lower die 602. A first guide assembly 603 is provided between the first upper die 601 and the first lower die 602. The first guide assembly 603 includes a first guide sleeve 6031 and a first guide post 6032. The first guide post 6032 is vertically fixed to the upper end of the first lower die 602. The first guide sleeve 6031 is slidably connected to the first guide post 6032 in the vertical direction, and the upper end of the first guide sleeve 6031 is fixed to the lower end of the first upper die 601. The first upper die 601 and the first lower die 602 slide relative to each other in the vertical direction through the cooperation of the first guide sleeve 6031 and the first guide post 6032. In actual use, the first upper die 601 slides relative to the first lower die 602 in the vertical direction by being driven by a press.

[0063] Reference Figure 3 The lower end of the first upper die 601 is provided with a first pressure block 604 and a first punch assembly 605. The first pressure block 604 is fixed to the lower end of the first upper die 601. The first punch assembly 605 includes a first punch sleeve 6051, a first punch core 6052, and a first outer punch sleeve 6053. The upper ends of the first punch core 6052, the first punch sleeve 6051, and the first outer punch sleeve 6053 are respectively fixed to the lower end of the first pressure block 604. The axes of the first punch core 6052, the first punch sleeve 6051, and the first outer punch sleeve 6053 are all vertically arranged. The first punch sleeve 6051 is coaxially sleeved on the outer ring of the first punch core 6052, and the first outer punch sleeve 6053 is coaxially sleeved on the outer ring of the first punch sleeve 6051. The lower end of the first punch sleeve 6051 protrudes beyond the lower end of the first outer punch sleeve 6053, and the lower end of the first punch core 6052 protrudes beyond the lower end of the first punch sleeve 6051. In actual use, the first punch core 6052 is used to punch positioning holes 2 on shaft-like workpieces, and the first punch sleeve 6051 is used to abut against the axial end face of the shaft-like workpiece and press the shaft-like workpiece down as a whole.

[0064] Reference Figure 3The upper end of the first lower die 602 is provided with a first concave die 606, which includes a first upper concave die 6061 and a first lower concave die 6062. The first lower concave die 6062 is fixed to the upper end of the first lower die 602, and the first upper concave die 6061 is fixed to the upper end of the first lower concave die 6062. The upper end of the first upper concave die 6061 has a first cavity 607, and the first lower concave die 6062 has a first forming cavity 608. The first cavity 607 completely penetrates the upper and lower ends of the first upper concave die 6061 in the vertical direction, and the first forming cavity 608 completely penetrates the upper and lower ends of the first lower concave die 6062 in the vertical direction. The axis of the first cavity 607 and the axis of the first forming cavity 608 coincide with the axis of the first punch core 6052. The first cavity 607 is a cylindrical chamber, and the diameter of the first cavity 607 is slightly larger than the diameter of the shaft-like workpiece. The first cavity 607 is for inserting shaft-like workpieces.

[0065] Reference Figure 3 The first molding cavity 608 includes a first cylindrical cavity 6081, a first frustum cavity 6082, and a first contraction cavity 6083 arranged sequentially from top to bottom. The diameter of the first cylindrical cavity 6081 is equal to the diameter of the first concave cavity 607. The diameter of the first frustum cavity 6082 gradually decreases from top to bottom, and the diameter of the upper end of the first frustum cavity 6082 is the same as the diameter of the first cylindrical cavity 6081. The diameter of the first contraction cavity 6083 is equal to the diameter of the first connecting portion 4, and the first contraction cavity 6083 is used to mold the first connecting portion 4.

[0066] Reference Figure 3 The first lower die 602 is also provided with a first ejector 609. The first ejector 609 slides vertically relative to the first lower die 602. The upper end of the first pusher passes through the lower end of the first shrinkage chamber 6083 to eject the shaft workpiece that has been processed with the positioning hole 2 and the first connecting part 4.

[0067] Reference Figure 4 The second stamping die 7 includes a second upper die 701 and a second lower die 702. The second upper die 701 is located directly above the second lower die 702. A second guide assembly 703 is provided between the second upper die 701 and the second lower die 702. The second guide assembly 703 includes a second guide sleeve 7031 and a second guide post 7032. The upper end of the second lower die 702 is vertically fixed to the second guide post 7032, and the second guide sleeve 7031 is slidably connected to the second guide post 7032 in the vertical direction. The upper end of the second guide sleeve 7031 is fixed to the lower end of the second upper die 701. The second upper die 701 and the second lower die 702 slide relative to each other in the vertical direction through the cooperation of the second guide sleeve 7031 and the second guide post 7032. In actual use, the second upper die 701 slides relative to the second lower die 702 in the vertical direction driven by a press.

[0068] Reference Figure 4 The lower end of the second upper die 701 is provided with a second pressure block 704 and a second punch assembly 705. The second pressure block 704 is fixed to the lower end of the second upper die 701. The second punch assembly 705 includes a second punch sleeve 7051 and a second punch core 7052. The upper ends of the second punch core 7052 and the second punch sleeve 7051 are respectively fixed to the lower end of the second pressure block 704. The axes of the second punch core 7052 and the second punch sleeve 7051 are both vertically arranged, and the second punch sleeve 7051 is coaxially sleeved on the outer ring of the second punch core 7052. The lower end of the second punch core 7052 protrudes from the lower end of the second punch sleeve 7051. In actual use, the second punch core 7052 is used to punch a hollow hole 3 based on the positioning hole 2.

[0069] Reference Figure 4 The lower end of the second punch core 7052 is coaxially and integrally provided with a centering component 70521, which is a cross-shaped protrusion located at the lower end of the second punch core 7052. In actual use, the cross-shaped protrusion extends into the positioning hole 2. By aligning the center of the cross-shaped protrusion with the axis of the positioning hole 2, the circumferential sidewall of the cross-shaped protrusion abuts against the circumferential inner wall of the bottom of the positioning hole 2, thereby limiting the radial displacement between the second punch core 7052 and the positioning hole 2.

[0070] Alternatively, the positioning element can be a Phillips-shaped protrusion similar to that of a Torx screwdriver.

[0071] Reference Figure 4 The upper end of the second lower die 702 is provided with a second concave die 706, which includes a second upper concave die 7061 and a second lower concave die 7062. The second lower concave die 7062 is fixed to the upper end of the second lower die 702, and the second upper concave die 7061 is fixed to the upper end of the second lower concave die 7062. The upper end of the second upper concave die 7061 has a second cavity 707, and the second lower concave die 7062 has a second clamping cavity 708. The second cavity 707 completely penetrates the upper and lower ends of the second upper concave die 7061 in the vertical direction, and the second clamping cavity 708 completely penetrates the upper and lower ends of the second lower concave die 7062 in the vertical direction. The axis of the second cavity 707 and the axis of the second clamping cavity 708 coincide with the axis of the second punch core 7052. The second cavity 707 is a cylindrical chamber, which is used to accommodate shaft-type workpieces with pre-machined positioning holes 2 and first connecting parts 4. The second clamping cavity 708 is used for the first connecting part 4 to be embedded, and the circumferential inner wall of the second clamping cavity 708 is used to fit against the circumferential outer wall of the first connecting part 4 to limit the radial displacement of the first connecting part 4.

[0072] Reference Figure 4The second lower die 702 is also provided with a second ejector 709. The second ejector 709 slides vertically relative to the second lower die 702. The upper end of the second pusher enters from the lower end of the second shrinkage chamber to eject the shaft workpiece that has completed the hollow hole 3 machining.

[0073] Reference Figure 5 The third stamping die 8 includes a third upper die 801 and a third lower die 802. The third upper die 801 is located directly above the third lower die 802. A third guide assembly 803 is provided between the third upper die 801 and the third lower die 802. The third guide assembly 803 includes a third guide sleeve 8031 ​​and a third guide post 8032. The third guide post 8032 is vertically fixed to the upper end of the third lower die 802. The third guide sleeve 8031 ​​is slidably connected to the third guide post 8032 in the vertical direction, and the upper end of the third guide sleeve 8031 ​​is fixed to the lower end of the third upper die 801. The relative sliding in the vertical direction between the third upper die 801 and the third lower die 802 is achieved through the cooperation of the third guide sleeve 8031 ​​and the third guide post 8032. In actual use, the third upper die 801 is driven by a press to slide relative to the third lower die 802 in the vertical direction.

[0074] Reference Figure 5 The lower end of the third upper die 801 is provided with a third pressure block 804 and a third upper punch 805. The third pressure block 804 is fixed to the lower end of the third upper die 801, and the third upper punch 805 is fixed to the lower end of the third pressure block 804. The lower end of the third upper punch 805 is provided with a third clamping cavity 806, which is used to clamp the first connecting part 4.

[0075] Reference Figure 5 The upper end of the third lower die 802 is provided with a third concave die 807, which includes a third upper concave die 8071 and a third lower concave die 8072. The third lower concave die 8072 is fixed to the upper end of the third lower die 802, and the third upper concave die 8071 is fixed to the upper end of the third lower concave die 8072. The third upper concave die 8071 and the third lower concave die 8072 together form a third forming cavity 808, which extends vertically through the third upper concave die 8071 and the third lower concave die 8072. The upper end of the third lower die 802 is also fixed with a third lower punch 809, which is vertically positioned and extends into the third forming cavity 808 from the lower end of the third forming cavity 808. The axis of the third lower punch 809 coincides with the axis of the third forming cavity 808.

[0076] Reference Figure 6The fourth stamping die 9 includes a fourth upper die 901 and a fourth lower die 902. The fourth upper die 901 is located directly above the fourth lower die 902. A fourth guide assembly 903 is provided between the fourth upper die 901 and the fourth lower die 902. The fourth guide assembly 903 includes a fourth guide sleeve 9031 and a fourth guide post 9032. The upper end of the fourth lower die 902 is vertically fixed to the fourth guide post 9032, and the fourth guide sleeve 9031 is slidably connected to the fourth guide post 9032 in the vertical direction. The upper end of the fourth guide sleeve 9031 is fixed to the lower end of the fourth upper die 901. The fourth upper die 901 and the fourth lower die 902 slide relative to each other in the vertical direction through the cooperation of the fourth guide sleeve 9031 and the fourth guide post 9032. In actual use, the fourth upper die 901 slides relative to the fourth lower die 902 in the vertical direction by being driven by a press.

[0077] Reference Figure 6 , refer to Figure 6 The lower end of the fourth upper die 901 is provided with a fourth pressure block 904 and a fourth upper punch 905. The fourth pressure block 904 is fixed to the lower end of the fourth upper die 901, and the fourth lower punch is fixed to the lower end of the fourth pressure block 904. The lower end of the fourth lower punch is provided with a fourth clamping cavity 906, which is used to clamp the first connecting part 4.

[0078] Reference Figure 6 The upper end of the fourth lower mold 902 is provided with a fourth lower pad 907, a fourth lower die 908, and a fourth upper die 909. The fourth lower pad 907 is fixed to the upper end of the fourth lower mold 902, the fourth lower die 908 is fixed to the upper end of the fourth lower pad 907, and the fourth upper die 909 is slidably connected to the upper end of the fourth lower die 908, sliding vertically relative to the fourth lower die 908. A return spring 910 is installed between the fourth upper die 909 and the fourth lower die 908, the return spring 910 is vertically positioned, and the return spring 910 is used to lift the fourth upper die 909 upward.

[0079] Reference Figure 6 The fourth upper die 909 has a connecting cavity 911 through which the shaft 1 passes. The axis of the connecting cavity 911 is set in the vertical direction, and the connecting cavity 911 passes through the upper and lower ends of the fourth upper die 909 along the axial direction. The inner wall of the connecting cavity 911 is used to coaxially abut against the outer peripheral wall of the shaft 1.

[0080] Reference Figure 6The fourth lower die 908 has a fourth forming cavity 912, the axis of which coincides with the axis of the connecting cavity 911. The fourth forming cavity 912 extends vertically through both ends of the fourth lower die 908. The inner wall of the fourth forming cavity 912 is used to press the outer periphery of the hollow hole 3 opening. The upper end of the fourth forming cavity 912 is also provided with a chamfer 913. In actual processing, the chamfer 913 makes it easier for the shaft 1 to be pressed into the fourth forming cavity 912.

[0081] Reference Figure 6 The upper end of the fourth lower pad 907 is provided with a fourth sliding cavity 914. The axis of the fourth sliding cavity 914 coincides with the axis of the fourth forming cavity 912. The fourth sliding cavity 914 passes through the upper and lower ends of the fourth lower pad 907 along the axial direction. The fourth lower die 902 is provided with a fourth ejector 915. The fourth ejector is slidably connected to the fourth lower die 902. The fourth ejector 915 slides vertically relative to the fourth lower die 902. The upper end of the fourth ejector 915 is used to extend into the fourth sliding cavity 914 and the fourth forming cavity 912 to eject the processed workpiece.

[0082] This application also discloses a hollow shaft machining process.

[0083] The specific steps are as follows:

[0084] S100, the shaft workpiece is stamped twice. The first stamping is used to stamp out the positioning hole 2 on the axial end face of the shaft workpiece. The second stamping narrows the outer peripheral wall of the shaft workpiece away from the positioning hole 2 to form the first connecting part 4.

[0085] Reference Figure 1 The actual operation of this step is as follows: The shaft workpiece is coaxially installed into the first cavity 607. The press drives the first upper die 601 to press down, and the first upper die 601 drives the first punch core 6052 to press down, so that the first punch core 6052 is aligned with the axial center position of the end of the shaft workpiece to punch out the positioning hole 2. Then the press continues to drive the first punch sleeve 6051 to press down, so that the lower end of the first punch sleeve 6051 abuts against the upper end of the shaft workpiece and presses down the entire shaft workpiece. After the entire shaft workpiece is pressed down, the lower end of the shaft workpiece will be squeezed by the inner wall of the first forming cavity 608 and form the first connecting part 4.

[0086] S200, punch the positioning hole 2 of the shaft workpiece to punch out the hollow hole 3 on the positioning hole 2;

[0087] Reference Figure 2The actual operation of this step is as follows: The shaft workpiece with the machined positioning hole 2 and the first connecting part 4 is placed into the second cavity 707, so that the first connecting part 4 is embedded in the second clamping cavity 708, and the circumferential outer wall of the first connecting part 4 abuts against the circumferential inner wall of the second clamping cavity 708, limiting the radial offset between the shaft workpiece and the second clamping cavity 708 and the second cavity 707. After the shaft workpiece is installed, the press drives the second upper die 701 to press down, so that the second punch core 7052 moves downward. During the descent of the second punch core, the centering part 70521 will first abut against the bottom of the positioning hole 2 concentrically. Then, during the downward punching process of the second punch core 7052, the circumferential outer wall of the shaft workpiece will extend upward evenly with the downward pressure of the second punch core 7052, thereby forming the hollow hole 3. The shaft workpiece will rarely be eccentric with the second punch core 7052, which can ensure the concentricity of the punched hollow hole 3 with the outer wall of the shaft workpiece.

[0088] S300, the outer peripheral wall of the hollow hole 3 is stamped to thin the outer peripheral wall of the hollow hole 3 in order to form the shaft body 1;

[0089] Reference Figure 3 The actual operation of this step is as follows: The first connecting part 4 is coaxially inserted into the third clamping cavity 806. The press drives the third upper die 801 to move downward, and the third upper die 801 drives the third upper punch 805 to move downward. The downward movement of the third upper punch 805 drives the shaft workpiece to move downward. As the shaft workpiece is pressed down, the third lower punch 809 will coaxially extend into the hollow hole 3 to ensure that the inner diameter of the hollow hole 3 does not change. Then the third upper punch 805 continuously presses down the shaft workpiece, and the third lower punch 809 cooperates with the third forming cavity 808 to continuously thin and stretch the circumferential outer wall of the hollow hole 3 to form the shaft body 1.

[0090] S400, the outer periphery of the opening of the hollow hole 3 is punched to narrow the opening of the hollow hole 3, thereby forming the second connecting part 5.

[0091] Reference Figure 4 The actual operation of this step is as follows: The first connecting part 4 is coaxially installed into the fourth clamping cavity 906. The press drives the fourth upper die 901 to move down. The fourth upper die 901 moves down and drives the shaft workpiece to move down. During the movement of the shaft workpiece, it will first coaxially pass into the connecting cavity 911. After the lower end of the fourth lower punch abuts against the upper end of the fourth upper die 909, the fourth lower punch will push the fourth upper die 909 down. Then, the outer periphery at the opening of the hollow hole 3 will be gradually pressed into the fourth forming cavity 912. The fourth forming cavity 912 will continuously narrow the outer periphery at the opening of the hollow hole 3 to form the second connecting part 5. During the forming process of the second connecting part 5, since the shaft body 1 of the shaft workpiece is located in the connecting cavity 911, the inner wall of the connecting cavity 911 can effectively limit the deformation of the shaft body 1 of the shaft workpiece, thereby improving the accuracy of the processed shaft workpiece.

[0092] The working principle of this embodiment is as follows: the positioning hole 2 and the first connecting part 4 are processed by the first stamping die 6, the hollow hole 3 is processed by the second stamping die 7, the shaft body 1 is processed by the third stamping die 8, and the second connecting part 5 is processed by the fourth stamping die 9, thereby replacing the radial forging machine and greatly reducing the production cost of the hollow shaft.

[0093] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A hollow shaft processing production line, characterized in that: It includes a first stamping die (6), a second stamping die (7), a third stamping die (8), and a fourth stamping die (9) arranged sequentially; The first stamping die (6) is used for secondary stamping of shaft-type workpieces; The second stamping die (7) is used to stamp the positioning hole (2) of the shaft workpiece and to stamp out the hollow hole (3) on the positioning hole; The third stamping die (8) is used to stamp the outer peripheral wall of the hollow hole (3); The fourth stamping die (9) is used to stamp the outer periphery of the opening of the hollow hole (3); The first stamping die (6) includes a first upper die (601) and a first lower die (602); The lower end of the first upper die (601) is connected to a first punch assembly (605). The first punch assembly (605) includes a first punch sleeve (6051) and a first punch core (6052). The first punch sleeve (6051) is coaxially sleeved on the outer ring of the first punch core (6052). The first punch core (6052) protrudes from the lower end of the first punch sleeve (6051). The upper end of the first lower die (602) is provided with a first concave die (606), the first concave die (606) is provided with a first cavity (607) for placing shaft-type workpieces, the first punch core (6052) is used to punch out a positioning hole (2) on the axial end face of the shaft-type workpiece, the bottom of the first cavity (607) is provided with a first forming cavity (608), the first punch sleeve (6051) is used to press the end of the shaft-type workpiece away from the positioning hole (2) into the first forming cavity (608), and the first forming cavity (608) is used to narrow the end of the shaft-type workpiece away from the positioning hole (2) to form a first connecting part (4); The fourth stamping die (9) includes a fourth upper die (901) and a fourth lower die (902); The lower end of the fourth upper die (901) is provided with a fourth upper punch (905), the fourth upper punch (905) is provided with a fourth clamping cavity (906), the fourth clamping cavity (906) is used to clamp the first connecting part (4), and the fourth upper punch (905) is used to drive the first connecting part (4) to press down. The upper end of the fourth lower die (902) is provided with a fourth lower concave die (908), and the upper end of the fourth lower concave die (908) is provided with a fourth forming cavity (912). The inner wall of the fourth forming cavity (912) is used to extrude the outer periphery at the opening of the hollow hole (3). The upper end of the fourth lower die (908) is slidably connected to the fourth upper die (909). The fourth upper die (909) slides relative to the fourth lower die (908) in the vertical direction. A return spring (910) is provided between the fourth upper die (909) and the fourth lower die (908). The return spring (910) is used to lift the fourth upper die (909) upward. The fourth upper die (909) is provided with a connecting cavity (911) for the shaft (1) to pass through. The axis of the connecting cavity (911) coincides with the axis of the fourth forming cavity (912). The inner wall of the connecting cavity (911) is used to coaxially abut against the outer peripheral wall of the shaft (1).

2. The hollow shaft processing production line according to claim 1, characterized in that: The second stamping die (7) includes a second upper die (701) and a second lower die (702); The lower end of the second upper die (701) is connected to the second punch core (7052); The upper end of the second lower die (702) is provided with a second die (706), and the upper end of the second die (706) is provided with a second cavity (707). The second cavity (707) is used for placing shaft-type workpieces. The second punch core (7052) cooperates with the second cavity (707) to punch out a hollow hole (3) on the positioning hole (2).

3. The hollow shaft processing production line according to claim 2, characterized in that: The bottom of the second cavity (707) is coaxially provided with a second clamping cavity (708), and the inner wall of the second clamping cavity (708) is used to coaxially abut against the outer circumferential wall of the first connecting part (4).

4. The hollow shaft processing production line according to claim 2, characterized in that: The lower end of the second punch core (7052) is coaxially provided with a centering member (70521), the lower end of which is used to abut against the bottom of the positioning hole (2) to limit the radial offset between the second punch core (7052) and the positioning hole (2).

5. The hollow shaft processing production line according to claim 1, characterized in that: The third stamping die (8) includes a third upper die (801) and a third lower die (802); The lower end of the third upper die (801) is connected to a third upper punch (805), and the lower end of the third upper punch (805) is provided with a third clamping cavity (806), which is used to clamp the first connecting part (4). The upper end of the third lower die (802) is provided with a third concave die (807), and the upper end of the third concave die (807) is provided with a third forming cavity (808). The third upper punch (805) is used to coaxially press one end of the shaft workpiece with a hollow hole (3) into the third forming cavity (808). The third forming cavity (808) is coaxially provided with a third lower punch (809). The third lower punch (809) is used to extend into the hollow hole (3) to limit the deformation of the hollow hole (3). The third lower punch (809) cooperates with the third forming cavity (808) to thin the outer peripheral wall of the hollow hole (3) to form a shaft body (1).

6. The hollow shaft processing line according to claim 1, characterized in that: The upper cavity wall of the connecting cavity (911) is provided with a chamfer (913).

7. A hollow shaft machining process, characterized in that: The hollow shaft processing line, including any one of claims 2-6, employs the following steps: S100, the shaft workpiece is stamped twice. The first stamping is used to stamp out the positioning hole (2) on the axial end face of the shaft workpiece. The second stamping narrows the outer peripheral wall of the shaft workpiece away from the positioning hole (2) to form the first connecting part (4). S200, the positioning hole (2) of the shaft workpiece is punched, and a hollow hole (3) is punched out on the positioning hole (2); S300, the outer peripheral wall of the hollow hole (3) is stamped to thin the outer peripheral wall of the hollow hole (3) to form the shaft (1); S400, the outer periphery of the opening of the hollow hole (3) is punched to narrow the opening of the hollow hole (3) to form the second connecting part (5).

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