Cold extrusion forming device for intermediate shaft of transmission of new energy automobile

Abstract

The utility model discloses a new energy automobile transmission intermediate shaft cold extrusion forming device which comprises a first extrusion die and a second extrusion die, the first extrusion die is used for forming spiral teeth of intermediate shaft materials, and the second extrusion die is used for forming external splines of the intermediate shaft materials. Each of the first extrusion die and the second extrusion die comprises an upper die part and a lower die part, the upper die part comprises an outer punch and a core rod, the lower die part comprises a first lower die assembly, the first lower die assembly is provided with a forming cavity, forming teeth are arranged on the cavity wall of the forming cavity, the outer punch, the core rod and the forming cavity are coaxially arranged, the outer punch is of a cylindrical structure, and the core rod is of a cylindrical structure. The outer punch is arranged outside the core rod in a sleeving manner; a common oil press is utilized to extrude and form a spiral tooth through the first extrusion die and extrude and form an external spline through the second extrusion die, the production efficiency is high, the equipment cost is low, very small machining allowance is reserved on the tooth surface of the spiral tooth, cutting-off of a tooth cutting process metal flow line is avoided, and the strength of a tooth part is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of vehicle forming technology, specifically to a cold extrusion forming device for the intermediate shaft of a new energy vehicle transmission. Background Technology

[0002] The intermediate shaft inside the transmission of existing new energy vehicles is generally a hollow gear shaft. The existing processing method is usually to first use hot forging to form a blank and then use gear hobbing to process the helical teeth and external splines of the gear shaft.

[0003] When using this processing method, the gear hobbing equipment is expensive, resulting in high overall processing costs. In addition, gear hobbing is a cutting process, and the gears produced by gear hobbing will have poor overall strength of the gear shaft, which will ultimately affect the service life and safety of the automotive transmission.

[0004] In view of the above-mentioned defects, the creator of this utility model has finally obtained this utility model after a long period of research and practice. Utility Model Content

[0005] To address the aforementioned technical deficiencies, the present invention provides a cold extrusion forming device for intermediate shafts of new energy vehicle transmissions, used for processing and forming center shaft material. The center shaft material has a center hole along its axis and includes a first connecting section, a helical tooth section, an external spline section, and a second connecting section arranged sequentially along the axis. The outer surface of the helical tooth section is formed into helical teeth by a first extrusion die, and the outer surface of the external spline section is formed into an external spline by a second extrusion die.

[0006] The cold extrusion forming device for the intermediate shaft of the new energy vehicle transmission includes a first extrusion die and a second extrusion die; both the first extrusion die and the second extrusion die include an upper die part and a lower die part, the upper die part includes an outer punch and a mandrel, the lower die part includes a first lower die assembly, the first lower die assembly is provided with a forming cavity, the cavity wall of the forming cavity is provided with forming teeth, the outer punch, the mandrel and the forming cavity are all coaxially arranged, the outer punch is provided with a cylindrical structure, and the outer punch is sleeved outside the mandrel.

[0007] Preferably, the upper die part further includes an upper template and a punch pad, the upper template, the punch pad and the outer punch are arranged sequentially from top to bottom, the upper end of the outer punch is fixedly disposed on the bottom surface of the punch pad, and the upper template is connected to the press slide block.

[0008] Preferably, a mounting hole is provided on the axis of the outer punch, and an adjustment section and a guide section are provided in the mounting hole from top to bottom. The cross-sectional diameter of the adjustment section is larger than the cross-sectional diameter of the guide section, and the cross-sectional diameter of the guide section corresponds to the cross-sectional diameter of the mandrel. An adjustment block is fixedly provided at the upper end of the mandrel. The adjustment block is disposed in the adjustment section, and the cross-sectional diameter of the adjustment block is larger than the cross-sectional diameter of the guide section.

[0009] Preferably, the punch transition sleeve is fixed inside the upper die barrel by the upper die locking nut, the upper die barrel is fixedly set on the upper template, the punch pad is set inside the punch transition sleeve, and the outer punch is fixedly connected to the punch pad through the punch transition sleeve. The bilateral clearance between the outer punch and the punch transition sleeve is 0.03mm to 0.05mm, the bilateral clearance between the mandrel and the outer punch is 0.04mm to 0.08mm, and the axial floating amount of the mandrel inside the outer punch is 10mm to 15mm.

[0010] Preferably, the lower mold portion further includes a lower template, a lower ejector rod, and a lower mold pad. The lower mold pad is disposed on the upper surface of the lower template. The first lower mold assembly is fixedly disposed above the lower mold pad. The lower mold pad has a blanking hole at its center. The blanking hole is coaxially disposed with the forming cavity. The lower ejector rod is vertically disposed in the blanking hole and is coaxially disposed with the mandrel.

[0011] Preferably, the lower template is connected to the press worktable, the template pad is installed in the lower template, the lower push rod is installed in the inner hole of the template pad, the lower mold pad is installed in the first lower mold barrel, and the first lower mold assembly is fixedly installed in the first lower mold barrel by the first lower mold cover.

[0012] Preferably, in the first extrusion die, the first lower die assembly includes a cavity die, a toothed die, and a forming pad, wherein the toothed die and the forming pad are disposed in the inner hole of the cavity die, and the toothed die is disposed above the forming pad, and the forming teeth are disposed on the toothed die.

[0013] Preferably, in the second extrusion die, the first lower die assembly includes a toothed die, the forming teeth being disposed on the toothed die, the toothed die being fixedly disposed within the first lower die barrel by the first lower die cap, and the toothed die being disposed above the lower die pad; the lower die part further includes a second lower die assembly, the second lower die assembly including a guide die, a first connecting bearing and a second connecting bearing, the guide die being disposed above the toothed die, the guide die having a guide cavity at its center, the guide cavity having guide teeth on its inner wall, the guide teeth being configured to cooperate with the helical teeth, and the guide cavity being coaxially disposed with the forming cavity; the second lower die assembly is disposed within a second lower die barrel, the lower end of the second lower die barrel being connected to the first lower die barrel, the upper end of the second lower die barrel being fixed in position within the second lower die barrel by the second lower die cap, the lower end of the guide die being connected to the upper surface of the toothed die by the first connecting bearing, the outer circular surface of the guide die being connected to the inner wall of the second lower die barrel by the second connecting bearing, and the guide die being able to rotate freely around the axis of the guide cavity.

[0014] Preferably, the lower surface of the guide mold and the upper surface of the tooth mold are provided with a gap of 1mm to 2mm through the first connecting bearing.

[0015] Preferably, the lower inner wall of the second lower mold barrel is provided with a first thread, and the upper outer wall of the first lower mold barrel is provided with a second thread. The first lower mold barrel and the second lower mold barrel are detachably connected by the first thread and the second thread.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: the spiral teeth are formed by extruding the first extrusion die set by this utility model through a conventional hydraulic press, and the external spline is formed by extruding the second extrusion die. The production efficiency is high and the equipment cost is low. The spiral teeth have a very small machining allowance, which avoids the cutting of the metal flow line in the tooth cutting process and greatly improves the strength of the teeth. At the same time, the external spline extruded by using the spiral teeth as a guide has good coaxiality with the spiral teeth. Attached Figure Description

[0017] Figure 1 This is a structural view of the central shaft material;

[0018] Figure 2 This is a schematic diagram of the billet changes in the cold extrusion forming method for the intermediate shaft of the new energy vehicle transmission.

[0019] Figure 3 This is a schematic diagram of the structure of the first processed blank;

[0020] Figure 4 This is a schematic diagram of the structure of the second processed blank;

[0021] Figure 5 This is a structural view of the first extrusion die;

[0022] Figure 6 This is a structural view of the second extrusion die.

[0023] The numbers in the diagram represent:

[0024] 1-Center shaft material; 2-First processed blank; 3-Second processed blank; 4-Upper die part; 5-Lower die part; 11-Center hole; 12-First connecting section; 13-Helical tooth section; 14-External spline section; 15-Second connecting section; 21-First roughing section; 22-Second roughing section; 23-Third roughing section; 31-First finishing section; 32-Second finishing section; 33-Third finishing section; 34-Fourth finishing section; 41-External punch; 42-Mandrel; 43-Upper template; 4 4-Punch pad; 45-Punch transition sleeve; 46-Upper die locking nut; 47-Upper die barrel; 51-Forming cavity; 52-Forming tooth; 53-Lower template; 54-Lower ejector rod; 55-Lower die pad; 56-Template pad; 57-First lower die barrel; 58-First lower die cap; 59-Die; 60-Tooth die; 61-Forming pad; 62-Guide die; 63-First connecting bearing; 64-Second connecting bearing; 65-Guide cavity; 66-Second lower die barrel; 67-Second lower die cap. Detailed Implementation

[0025] The above-mentioned and other technical features and advantages of this utility model will be described in more detail below with reference to the accompanying drawings.

[0026] Example 1

[0027] like Figure 1 and Figure 2 As shown, Figure 1 This is a structural view of the central shaft material; Figure 2 This is a schematic diagram of the billet changes in the cold extrusion forming method for the intermediate shaft of the new energy vehicle transmission.

[0028] The cold extrusion forming method for intermediate shafts of new energy vehicle transmissions is used to process and form a central shaft material 1. The central shaft material 1 has a central hole 11 along its axis. The central shaft material 1 includes a first connecting section 12, a helical tooth section 13, an external spline section 14, and a second connecting section 15 arranged sequentially along the axis. The outer surface of the helical tooth section 13 is formed into helical teeth by a first extrusion die, and the outer surface of the external spline section 14 is formed into an external spline by a second extrusion die. The cold extrusion forming device for intermediate shafts of new energy vehicle transmissions of this utility model includes a first extrusion die and a second extrusion die.

[0029] The cold extrusion forming method for the intermediate shaft of a new energy vehicle transmission includes the following steps:

[0030] S1, a hot forging billet is selected. The hot forging billet is a rotating body structure, and the outer circle and length dimensions of the hot forging billet are reserved for subsequent machining.

[0031] S2, the hot forged billet is subjected to spheroidizing annealing;

[0032] S3, drill a pre-rotation hole with the axis of the hot forged billet using a drill bit, the diameter of the pre-rotation hole being smaller than the designed diameter of the center hole 11;

[0033] S4, the hot forged billet is first machined to form a first machined billet 2. In the first machining, the pre-rotated hole is machined to the designed diameter of the center hole 11, such as... Figure 3 As shown, Figure 3 This is a schematic diagram of the structure of the first processed blank; the first processed blank 2 is provided with a first roughing section 21, a second roughing section 22 and a third roughing section 23. The first roughing section 21, the second roughing section 22 and the third roughing section 23 are all cylindrical structures. The first roughing section 21 corresponds to the first connecting section 12 and the helical tooth section 13, the second roughing section 22 corresponds to the external spline section 14, and the third roughing section 23 corresponds to the second connecting section 15. The length of the second roughing section 22 is the same as the designed length of the external spline section 14, and the designed length of the third roughing section 23 is the same as the designed length of the second connecting section 15.

[0034] S5, the first processed blank 2 is shot blasted;

[0035] S6, the surface of the first processed blank 2 is subjected to phosphating treatment;

[0036] S7, the first processed blank 2 is extruded through the first extrusion die to form a shaped blank; the first processed blank 2 is placed in the forming cavity of the first extrusion die, the mandrel of the first extrusion die passes through the central hole 11, and the outer punch of the first extrusion die extrudes the first roughing section 21 to form helical teeth;

[0037] S8, the forming blank is turned a second time to form a second processed blank 3, and in the second turning, the first roughing section 21 is processed to form the first connecting section 12 and the helical tooth section 13;

[0038] S9, the second processed blank 3 is shot blasted;

[0039] S10, the surface of the second processed blank 3 is subjected to phosphating treatment;

[0040] S11, the second processed blank 3 is extruded through the second extrusion die to form a center shaft material 1; the second processed blank 3 is placed in the forming cavity of the second extrusion die, the mandrel of the second extrusion die passes through the center hole 11, and the outer punch of the second extrusion die extrudes the second roughing section 22 to form an external spline.

[0041] This invention utilizes a conventional hydraulic press to extrude helical teeth and external splines, resulting in high production efficiency and low equipment cost. The helical teeth have a small machining allowance, avoiding the cutting of metal flow lines during the tooth cutting process and greatly improving the strength of the teeth. At the same time, the external splines extruded using the helical teeth as guides have good coaxiality with the helical teeth.

[0042] Example 2

[0043] In this embodiment, the cold extrusion forming method for the intermediate shaft of a new energy vehicle transmission specifically includes the following steps:

[0044] S1, Blank preparation: Prepare the hot forging blank, and leave allowances for subsequent machining in the outer circle and length dimensions of the hot forging blank.

[0045] S2, spheroidizing annealing: spheroidization grade 6, reduces billet hardness, refines grains, and gives the microstructure better plasticity and toughness.

[0046] S3, Drilling: Drill a hole according to the inner hole size of the turning drawing, with the size being smaller than the diameter of the turning inner hole.

[0047] S4, First turning: Turn the outer circle, inner hole, and length dimensions to the required dimensions according to the turning drawing.

[0048] Specifically, the outer circle of the first roughing section 21 The dimensions are the same as the major diameter of the helical gear, and the machining tolerance is controlled within 0 to 0.03 mm. The outer diameter of the second rough-machined section 22... The outer circle of the third roughing section 23 The length L1 of the third roughing section 23, the total length L2 of the third roughing section 23 and the second roughing section 22, and the overall length L3 of the first processed blank 2 are all reserved for subsequent machining allowances.

[0049] The diameter of the central hole 11 The dimensions are based on the minimum inner diameter of the finished center shaft, with allowance for subsequent machining. The tolerance is controlled within 0 to 0.02 mm to facilitate the subsequent machining of the center shaft material 1 into the finished center shaft.

[0050] Based on the weight of the central shaft material 1 and the determined outer diameter of the blank, Hole size The lengths L1 and L2 of each segment are calculated based on the weight of the central shaft material 1. The length L3 is calculated based on the weight of the central shaft material 1.

[0051] S5, shot blasting: the outer circle and inner hole of the first processed blank 2 are shot blasted to remove the oxides produced by spheroidizing annealing. This can form tiny uneven textures on the surface of the blank, increase the surface area of ​​the blank, and increase the surface treatment area.

[0052] S6, Surface treatment: The surface of the first processed blank 2 is treated with a phosphating saponification film to reduce friction when the metal flows, making it easier to form by extrusion.

[0053] S7, extruded spiral teeth.

[0054] S8, Second turning: The second turning is performed using the extruded helical teeth as the turning reference.

[0055] Specifically, such as Figure 4 As shown, Figure 4 This is a schematic diagram of the structure of the second processed blank; the second processed blank 3 includes a first finishing section 31, a second finishing section 32, a third finishing section 33 and a fourth finishing section 34. The first finishing section 31 corresponds to the first connecting section 12, the second finishing section 32 corresponds to the helical tooth section 13, the third finishing section 33 corresponds to the external spline section 14, and the fourth finishing section 34 corresponds to the second connecting section 15. The first finishing section 31 and the second finishing section 32 are formed by the first roughing section 21 through the second turning process.

[0056] The outer circle of the third finishing section 33 The outer circle of the fourth finishing section 34 The outer circle of the first finishing section 31 The length dimension L1' of the fourth finishing section 34, the total length dimension L2' of the third finishing section 33 and the fourth finishing section 34, the length dimension L3' of the second machining blank 3, and the length dimension L4' of the first finishing section 31 are all machined to the design dimensions by the second turning.

[0057] S9, shot blasting: The second processed blank 3 needs to be shot blasted again after the surface has been turned, so that the surface of the blank has a small texture, increasing the surface area of ​​the blank and increasing the surface treatment area.

[0058] S10, Surface treatment: The surface of the second processed blank 3 is treated with a phosphating saponification film to reduce friction when the metal flows, making it easier to form by extrusion.

[0059] S11, extruded spline.

[0060] Example 3

[0061] like Figure 5 and Figure 6 As shown, Figure 5 This is a structural view of the first extrusion die; Figure 6 This is a structural view of the second extrusion die.

[0062] Both the first extrusion die and the second extrusion die include an upper die part 4 and a lower die part 5. The upper die part 4 includes an outer punch 41 and a mandrel 42. The lower die part 5 includes a first lower die assembly. The first lower die assembly is provided with a forming cavity 51. The cavity wall of the forming cavity 51 is provided with forming teeth 52. The outer punch 41, the mandrel 42 and the forming cavity 51 are all coaxially arranged. The outer punch 41 is configured as a cylindrical structure and is sleeved outside the mandrel 42.

[0063] During the extrusion molding process, the first processed blank 2 or the second processed blank 3 is disposed in the forming cavity 51, and the mandrel 42 is disposed in the center hole 11 of the first processed blank 2 or the second processed blank 3. By moving the upper die part 4 downward, the outer punch 41 can contact the upper end of the first processed blank 2 or the second processed blank 3, and by further pressing the first processed blank 2 or the second processed blank 3, the spiral teeth or the external spline are formed by extrusion through the forming teeth 52.

[0064] Preferably, the upper mold part 4 further includes an upper template 43 and a punch pad 44. The upper template 43, the punch pad 44 and the outer punch 41 are arranged sequentially from top to bottom. The upper end of the outer punch 41 is fixedly disposed on the bottom surface of the punch pad 44. The upper template 43 is connected to the press slide block. The press slide block drives the punch pad 44 to move vertically, thereby realizing the pressing operation of the outer punch 41 and the mandrel 42.

[0065] Generally, the outer punch 41 has a mounting hole on its axis. The mounting hole has an adjustment section and a guide section arranged sequentially from top to bottom. The cross-sectional diameter of the adjustment section is larger than that of the guide section, and the cross-sectional diameter of the guide section corresponds to the cross-sectional diameter of the mandrel 42. An adjustment block is fixedly arranged at the upper end of the mandrel 42. The adjustment block is arranged in the adjustment section, and the cross-sectional diameter of the adjustment block is larger than that of the guide section, thereby enabling limited axial movement of the mandrel 42 within the outer punch 41.

[0066] Specifically, the punch transition sleeve 45 is fixed inside the upper die barrel 47 by the upper die locking nut 46. The upper die barrel 47 is fixedly set on the upper template 43. The punch pad 44 is set inside the punch transition sleeve 45, and the outer punch 41 is fixedly connected to the punch pad 44 through the punch transition sleeve 45. The bilateral clearance between the outer punch 41 and the punch transition sleeve 45 is 0.03mm to 0.05mm. The bilateral clearance between the mandrel 42 and the outer punch 41 is 0.04mm to 0.08mm. The axial floating amount of the mandrel 42 inside the outer punch 41 is 10mm to 15mm. The mandrel 42 can float up and down and can rotate freely in the circumferential direction, allowing the mandrel 42 to find its own center. When forming the helical teeth or the external spline, the mandrel 42 is not easy to break.

[0067] The spiral teeth are formed by extruding the first extrusion die of this invention using a conventional hydraulic press, and the external spline is formed by extruding the second extrusion die. This method has high production efficiency and low equipment cost. The spiral teeth have a small machining allowance, which avoids the cutting of metal flow lines in the tooth cutting process and greatly improves the strength of the teeth. At the same time, the external spline extruded by using the spiral teeth as a guide has good coaxiality with the spiral teeth.

[0068] Example 4

[0069] The lower mold part 5 also includes a lower template 53, a lower ejector rod 54, and a lower mold pad 55. The lower mold pad 55 is disposed on the upper surface of the lower template 53. The first lower mold assembly is fixedly disposed above the lower mold pad 55. The lower mold pad 55 has a blanking hole at its center. The blanking hole is coaxially disposed with the forming cavity 51. The lower ejector rod 54 is vertically disposed in the blanking hole and is coaxially disposed with the mandrel 42.

[0070] After the outer punch 41 presses the first processed blank 2 or the second processed blank 3 downward to form the spiral teeth or the external spline, the bottom of the first processed blank 2 or the second processed blank 3 is pushed upward by the lower push rod 54, thereby realizing the ejection of the formed blank or the central shaft material 1.

[0071] Specifically, the lower template 53 is connected to the press worktable, the template pad 56 is installed in the lower template 53, the lower push rod 54 is installed in the inner hole of the template pad 56, the lower mold pad 55 is installed in the first lower mold barrel 57, and the first lower mold assembly is fixedly installed in the first lower mold barrel 57 by the first lower mold cover 58.

[0072] In the first extrusion die, the first lower die assembly includes a concave die 59, a toothed die 60, and a forming pad 61. The toothed die 60 and the forming pad 61 are disposed in the inner hole of the concave die 59, and the toothed die 60 is disposed above the forming pad 61. The forming teeth 52 are disposed on the toothed die 60. The outer walls of the toothed die 60 and the forming pad 61 are assembled with the inner wall of the concave die 59 with a gap of 0.01mm to 0.03mm. The toothed die 60 and the forming pad 61 can be fixed as a whole in the concave die 59. Therefore, after the first lower die assembly is assembled as a whole on the outside, it can be placed into the first lower die barrel 57, and it can be removed as a whole when disassembling the die, which is very convenient.

[0073] In the second extrusion die, the first lower die assembly includes a toothed die 60, with forming teeth 52 disposed on the toothed die 60. The toothed die 60 is fixedly disposed within the first lower die barrel 57 by the first lower die cover 58, and is disposed above the lower die pad 55. The lower die part 5 also includes a second lower die assembly, which includes a guide die 62, a first connecting bearing 63, and a second connecting bearing 64. The guide die 62 is disposed above the toothed die 60, and a guide cavity 65 is disposed at the center of the guide die 62. Guide teeth are disposed on the inner wall of the guide cavity 65, and the guide teeth are matched with the helical teeth. The guide cavity 65 and the forming cavity 51 are coaxially arranged; the second lower mold assembly is disposed in the second lower mold barrel 66, the lower end of the second lower mold barrel 66 is connected to the first lower mold barrel 57, the upper end of the second lower mold barrel 66 is fixed in position within the second lower mold barrel 66 by the second lower mold cover 67, the lower end of the guide mold 62 is connected to the upper surface of the tooth mold 60 by the first connecting bearing 63, and the outer circular surface of the guide mold 62 is connected to the inner wall of the second lower mold barrel 66 by the second connecting bearing 64, thereby enabling the guide mold 62 to rotate freely around the axis of the guide cavity 65.

[0074] Generally, the lower surface of the guide mold 62 and the upper surface of the tooth mold 60 are provided with a gap of 1mm to 2mm through the first connecting bearing 63 to ensure that the guide mold 62 can rotate smoothly around the axis.

[0075] The lower inner wall of the second lower mold barrel 66 is provided with a first thread, and the upper outer wall of the first lower mold barrel 57 is provided with a second thread. The first lower mold barrel 57 and the second lower mold barrel 66 are detachably connected by the first thread and the second thread, thereby fixing the first lower mold barrel 57 and the second lower mold barrel 66.

[0076] When the second processing blank 3 is placed in the forming cavity 51, the spiral teeth on the second processing blank 3 and the guide teeth in the guide cavity 65 are engaged and connected. When the outer punch 41 presses down on the second processing blank 3, in order to ensure the vertical and stable movement of the second processing blank 3 and the guiding effect of the guide teeth on the second processing blank 3, the guide mold 62 rotates freely around the axis of the guide cavity 65.

[0077] Example 5

[0078] In step S7, when the spiral teeth are extruded by the first extrusion die using a conventional hydraulic press, the first processed blank 2 is placed into the forming cavity 51. The press slide moves the outer punch 41 and the mandrel 42 downward together. The mandrel 42 first passes through the central hole 11, and the outer punch 41 enters the forming cavity 51 until the outer punch 41 contacts the upper end face of the first processed blank 2. At this time, the lower end face of the mandrel 42 extends downward beyond the forming teeth 52 by a certain distance, so that the first processed blank 2 flows downward along the mandrel 42 and the forming teeth 52 when it is extruded and deformed.

[0079] The outer punch 41 pushes the first processed blank 2 to continue moving downwards, and the first processed blank 2 forms the spiral teeth through the forming teeth 52 and the mandrel 42. After completion, the press slide retracts upwards, driving the outer punch 41 and the mandrel 42 to move upwards together, so that the mandrel 42 completely disengages from the center hole 11 and returns to the upper limit position of the press slide. The press push rod pushes the lower push rod 54 upwards to push the formed blank out of the forming cavity 51. The formed blank is then manually removed and placed into the material frame.

[0080] In step S11, when the external spline is extruded by the second extrusion die using a conventional hydraulic press, the second processed blank 3 is placed into the guide cavity 65. The helical teeth of the second processed blank 3 are provided with a gap of 0.01mm with the guide teeth in the guide cavity 65. The press slide drives the outer punch 41 and the mandrel 42 to move downward together. The mandrel 42 first passes through the center hole 11, and the outer punch 41 enters the guide cavity 65 until the outer punch 41 contacts the upper end face of the second processed blank 3. At this time, the lower end face of the mandrel 42 should extend downward beyond the forming teeth 52 by a certain distance, so that the second processed blank 3 flows downward along the mandrel 42 and the forming teeth 52 when it is extruded and deformed.

[0081] The outer punch 41 pushes the second processed blank 3 to continue moving downward. The second processed blank 3 forms the external spline through the forming teeth 52 and the mandrel 42. The coaxiality of the external spline and the spiral teeth can reach 0.025mm by using the guide teeth as the guide for the blank extrusion.

[0082] The press slide retracts upward, causing the outer punch 41 and the mandrel 42 to move upward together, so that the mandrel 42 completely disengages from the central hole 11 and returns to the upper limit position of the press slide. The press push rod pushes the lower push rod 54 upward, and the lower push rod 54 pushes the central shaft material 1 upward. At this time, because the guide tooth is a helical tooth shape that matches the helical tooth, the central shaft material 1 drives the guide mold 62 to rotate using the first connecting bearing 63 and the second connecting bearing 64, thereby realizing the ejection of the central shaft material 1. The central shaft material 1 is then manually removed and placed into the material frame.

[0083] The above description is merely a preferred embodiment of the present utility model and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present utility model, all of which will fall within the protection scope of the present utility model.

Claims

1. A cold extrusion forming apparatus for intermediate shafts of new energy vehicle transmissions, used for processing and forming center shaft material, wherein the center shaft material has a center hole along its axis, and the center shaft material includes a first connecting section, a helical tooth section, an external spline section, and a second connecting section arranged sequentially along the axis, characterized in that, The device includes a first extrusion die and a second extrusion die. The outer circular surface of the helical tooth segment is formed into helical teeth by the first extrusion die, and the outer circular surface of the external spline segment is formed into external splines by the second extrusion die. Both the first extrusion die and the second extrusion die include an upper die part and a lower die part. The upper die part includes an outer punch and a mandrel. The lower die part includes a first lower die assembly. The first lower die assembly is provided with a forming cavity. The cavity wall of the forming cavity is provided with forming teeth. The outer punch, the mandrel, and the forming cavity are all coaxially arranged. The outer punch is configured as a cylindrical structure and is sleeved outside the mandrel.

2. The cold extrusion forming apparatus for intermediate shafts of new energy vehicle transmissions as described in claim 1, characterized in that, The upper die part also includes an upper template and a punch pad. The upper template, the punch pad and the outer punch are arranged in order from top to bottom. The upper end of the outer punch is fixedly set on the bottom surface of the punch pad. The upper template is connected to the press slide.

3. The cold extrusion forming apparatus for intermediate shafts of new energy vehicle transmissions as described in claim 2, characterized in that, An mounting hole is provided on the axis of the outer punch. An adjustment section and a guide section are arranged sequentially from top to bottom in the mounting hole. The cross-sectional diameter of the adjustment section is larger than that of the guide section, and the cross-sectional diameter of the guide section corresponds to the cross-sectional diameter of the mandrel. An adjustment block is fixedly provided at the upper end of the mandrel. The adjustment block is located in the adjustment section, and the cross-sectional diameter of the adjustment block is larger than that of the guide section.

4. The cold extrusion forming apparatus for intermediate shafts of new energy vehicle transmissions as described in claim 3, characterized in that, The punch transition sleeve is fixed inside the upper die barrel by the upper die locking nut. The upper die barrel is fixedly set on the upper template. The punch pad is set inside the punch transition sleeve, and the outer punch is fixedly connected to the punch pad through the punch transition sleeve. The bilateral clearance between the outer punch and the punch transition sleeve is 0.03mm to 0.05mm. The bilateral clearance between the mandrel and the outer punch is 0.04mm to 0.08mm. The axial floating amount of the mandrel inside the outer punch is 10mm to 15mm.

5. The cold extrusion forming apparatus for intermediate shafts of new energy vehicle transmissions as described in claim 1, characterized in that, The lower mold part further includes a lower template, a lower ejector rod, and a lower mold pad. The lower mold pad is disposed on the upper surface of the lower template. The first lower mold assembly is fixedly disposed above the lower mold pad. The lower mold pad has a blanking hole at its center. The blanking hole is coaxially disposed with the forming cavity. The lower ejector rod is vertically disposed in the blanking hole and is coaxially disposed with the mandrel.

6. The cold extrusion forming apparatus for intermediate shafts of new energy vehicle transmissions as described in claim 5, characterized in that, The lower template is connected to the press workbench. The template pad is installed in the lower template, the lower push rod is installed in the inner hole of the template pad, the lower mold pad is installed in the first lower mold barrel, and the first lower mold assembly is fixedly installed in the first lower mold barrel by the first lower mold cover.

7. The cold extrusion forming apparatus for intermediate shafts of new energy vehicle transmissions as described in claim 6, characterized in that, In the first extrusion die, the first lower die assembly includes a cavity die, a toothed die, and a forming pad. The toothed die and the forming pad are disposed in the inner hole of the cavity die, and the toothed die is disposed above the forming pad, with the forming teeth disposed on the toothed die.

8. The cold extrusion forming apparatus for intermediate shafts of new energy vehicle transmissions as described in claim 6, characterized in that, In the second extrusion die, the first lower die assembly includes a toothed die, the forming teeth being disposed on the toothed die, the toothed die being fixedly disposed inside the first lower die barrel by the first lower die cap, and the toothed die being disposed above the lower die pad; the lower die part also includes a second lower die assembly, the second lower die assembly including a guide die, a first connecting bearing and a second connecting bearing, the guide die being disposed above the toothed die, the guide die having a guide cavity at its center, the guide cavity having guide teeth on its inner wall, the guide teeth being configured to cooperate with the helical teeth, and the guide cavity being coaxially disposed with the forming cavity; the second lower die assembly is disposed inside the second lower die barrel, the lower end of the second lower die barrel being connected to the first lower die barrel, the upper end of the second lower die barrel being fixed in position within the second lower die barrel by the second lower die cap, the lower end of the guide die being connected to the upper surface of the toothed die by the first connecting bearing, the outer circular surface of the guide die being connected to the inner wall of the second lower die barrel by the second connecting bearing, and the guide die being able to rotate freely around the axis of the guide cavity.

9. The cold extrusion forming apparatus for intermediate shafts of new energy vehicle transmissions as described in claim 8, characterized in that, The lower surface of the guide mold and the upper surface of the tooth mold are provided with a gap of 1mm to 2mm through the first connecting bearing.

10. The cold extrusion forming apparatus for intermediate shafts of new energy vehicle transmissions as described in claim 8, characterized in that, The lower inner wall of the second lower mold barrel is provided with a first thread, and the upper outer wall of the first lower mold barrel is provided with a second thread. The first lower mold barrel and the second lower mold barrel are detachably connected by the first thread and the second thread.

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