Method for machining a hybrid input shaft gear hub

Abstract

The application discloses a kind of hybrid input shaft tooth hub's processing forming method, including the following steps: blanking, heating blanking;Blank stamping preforming, form the preformed blank with the preformed gear ring and preformed shaft body with two ends respectively have, the outer diameter of preformed gear ring and preformed shaft body All greater than the outer diameter of tooth hub set gear ring and shaft body;Final forging forming, make the sidewall of preformed gear ring inside and outside flat, and simultaneously forge out rib plate, and forge out a plurality of preformed hole forming groove with the width greater than the width of special-shaped hole set on rib plate;Cut off the flash excess material on the preformed gear ring outside of final forging forming blank, and punch out special-shaped hole preformed hole at the corresponding place of each preformed hole forming groove;Preformed gear ring inner spline is extruded by using cold extrusion process, while protrusions at the two orifices of special-shaped hole preformed hole are simultaneously extruded into special-shaped hole preformed hole by using piling extrusion process, and the chamfer of two ends orifice is simultaneously extruded, and the special-shaped hole with the size and shape consistent with set special-shaped hole is formed;Turning processing.

Description

Technical Field

[0001] This invention relates to the field of gear hub manufacturing, and more specifically to a method for machining and forming a hybrid input shaft gear hub. Background Technology

[0002] The input shaft gear hub is a key component in the transmission system, transmitting power between the engine, electric motor, and gearbox. The input shaft gear hub consists of a hub body with an internal spline at one end and a coaxial connecting shaft at the other. Multiple irregularly shaped holes are circumferentially arranged on a rib plate in the middle of the hub body. These holes have chamfered ends at both the upper and lower parts of the axial direction and are concave or oblong in shape. Currently, the manufacturing process for the input shaft gear hub involves blanking, upsetting, forging, punching, milling, chamfering the milled hole openings, and cold extrusion. This method cannot simultaneously process all the irregularly shaped holes, resulting in a long processing time, difficulty in controlling precision, and poor forming quality. Summary of the Invention

[0003] In view of the above-mentioned shortcomings of the existing technology, the purpose of the present invention is to provide a machining and forming method for a hybrid input shaft gear hub, which solves the problems of the existing methods for machining irregular holes on input shaft gear hubs, which mainly involve many steps, milling holes and milling chamfers at the hole openings, resulting in low machining accuracy and poor forming quality.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A method for machining a hybrid input shaft gear hub includes the following steps: S1, blanking, and then heating and upsetting the blanked bar; S2, pre-forming the upsetting blank by stamping to form a pre-formed blank with pre-formed gear rings and pre-formed shafts at both ends, wherein the outer diameters of the pre-formed gear rings and pre-formed shafts are both larger than the outer diameters of the gear hub's set gear rings and shafts; S3, performing final forging on the pre-formed blank to make the inner and outer sidewalls of the pre-formed gear rings flat, and simultaneously forging ribs, and forging multiple pre-hole forming grooves with a width greater than the set width of the irregular hole on the ribs, wherein the pre-hole forming grooves and the opposite sides of the pre-hole forming grooves protrude from the main body of the ribs, and the protrusion height and width are consistent; S4, using a trimming composite die to cut off the pre-formed blanks on the final forging blank. The flash material on the outer side of the preformed gear ring is removed, and irregular pre-holes are punched out at the corresponding positions of each pre-hole forming groove. The diameter of the irregular pre-hole is larger than the set diameter of the irregular hole, and the sum of the volumes of the protrusions at the two openings of the irregular pre-hole is greater than the difference between the volume of the irregular pre-hole and the volume of the irregular hole before chamfering. S5, the internal spline of the preformed gear ring is extruded by cold extrusion process, and the protrusions at the two openings of the irregular pre-hole are simultaneously extruded into the irregular pre-hole by upsetting process, and the chamfers at both ends of the openings are simultaneously extruded to form irregular holes with the same size and shape as the set irregular holes. S6, the preformed shaft and the outer side of the preformed gear ring of the cold-extruded blank are machined to make the gear ring reach the design thickness, and the shaft has the same design shape and size, thus completing the machining of the input shaft gear hub. Thus, the gear hub mainly undergoes processes such as blanking, upsetting, pre-forming by stamping, final forging, trimming and pre-forming by stamping, cold extrusion of internal splines and irregular holes, and blank turning. In the pre-forming process, the outer diameter of the pre-formed gear ring is larger than the set outer diameter. Therefore, during final forging, the corresponding positions of the ribs and pre-forming grooves are thicker and less prone to deformation. During forging, protrusions are formed on the outer side of the pre-forming groove and on the corresponding side. During cold extrusion, axial upsetting pressure is applied to press the volume of the two protrusions into the gap between the pre-forming hole and the extrusion punch, ensuring a close fit with the cold extrusion die and thus guaranteeing the dimensional accuracy and surface roughness of the irregular hole's side surface. Simultaneously, the chamfering at the end of the extrusion die during upsetting creates chamfers at both ends of the hole. Furthermore, while extruding the irregularly shaped holes, the internal splines are also extruded simultaneously on a single mold. This ensures the dimensional accuracy of both the internal splines and the irregularly shaped holes, as well as the positional relationship between the splines and the irregularly shaped holes. It eliminates the milling process previously used for irregularly shaped holes, which took 15 minutes per piece. Using punching + cold extrusion, extruding one piece takes only 10 seconds, significantly improving efficiency. The pre-formed gear ring has a diameter larger than the set diameter. During the cold extrusion of the internal splines, the gear ring thickness is greater than the set thickness, resulting in higher stress on the pre-formed gear ring. This prevents deformation due to excessive stress during the extrusion process.

[0006] Furthermore, in S1, the heating temperature of the bar stock is controlled between 1100-1150℃. This set temperature ensures that the bar stock has good fluidity during subsequent forging, allowing it to be quickly deformed and shaped.

[0007] Furthermore, before S5 cold extrusion, the blanks after trimming and punching are normalized, shot blasted, and turned before phosphating and saponification. During normalizing, the temperature in the normalizing zone is 935±15℃, and the fan speed in the cooling zone is 50±5 to ensure that the product hardness is below 170HB. Shot blasting uses ordinary 0.6mm steel shot to tumble-blast the product for about 20-30 minutes to ensure that the oxide scale on the product surface is removed, avoiding oxide scale residue that could cause pits, scratches, and other problems on the product surface after extrusion. The coaxiality of the outer circle and the tooth profile is required to be within 0.05mm during blank turning to ensure that the tooth profile accuracy of the product meets the drawing requirements during extrusion. During phosphating and saponification, a suitable lubrication concentration is maintained to facilitate smooth extrusion and result in a better surface quality of the product after extrusion.

[0008] The above process offers the following advantages: 1. Improved precision: The extrusion process effectively corrects dimensional deviations after punching, improving hole precision. 2. Improved surface quality: The plastic deformation during extrusion significantly improves the surface roughness of irregularly shaped holes. 3. Enhanced mechanical properties: The extrusion process makes the material around the hole more compact, improving mechanical properties.

[0009] Furthermore, in S6, machining includes two roughing and two finishing machining operations. During roughing, the product's reference surface must be confirmed. The product's tooth profile and the special reference surface after cold extrusion should be used as the clamping reference. Special tooling should be made to ensure that the radial runout and end face runout of the tooling are ≤0.02mm, and the parallelism of the reference surface after roughing is ≤0.1mm. The clamping reference used during finishing machining is the same as that used during roughing. It is also required that the equipment be equipped with an airtightness sensitivity detection device during finishing machining, with a sensitivity setting of <0.1mm, to ensure that the product is clamped correctly during machining and that the product is not allowed to be clamped crookedly. Before the start of each shift, the end runout and radial runout of the tooling should be checked, and the end runout and radial runout should be <0.02mm. Attached Figure Description

[0010] Figure 1 This is a three-dimensional structural diagram of the hybrid input shaft gear hub in the embodiment;

[0011] Figure 2 This is a schematic cross-sectional view of the hybrid input shaft gear hub in the embodiment.

[0012] Figure 3 This is a diagram showing the molding and manufacturing process steps of the hybrid input shaft gear hub in the embodiment;

[0013] Figure 4 This is a structural diagram of the blank after trimming and cold extrusion in the forming and manufacturing method S4 of the hybrid input shaft gear hub in the embodiment. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0015] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product is in use. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, the terms "horizontal," "vertical," etc., do not indicate that the component is required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0016] like Figures 1-4As shown, the processing and forming method of the hybrid input shaft gear hub provided in this embodiment includes the following steps: S1, cutting the material using a high-speed circular saw, and then heating and upsetting the cut bar; S2, pre-forming the upset blank by stamping to form a pre-formed blank with a pre-formed gear ring and a pre-formed shaft at both ends, wherein the outer diameter of the pre-formed gear ring and the pre-formed shaft are both larger than the outer diameter of the gear hub's set gear ring and shaft; S3, performing final forging on the pre-formed blank to make the inner and outer sidewalls of the pre-formed gear ring flat, and simultaneously forging ribs, and forging multiple pre-hole forming grooves with a width greater than the set width of the irregular hole on the ribs (the shape of the pre-hole forming groove is the same as the shape of the preset irregular hole, such as...). Figure 3 As shown), the pre-hole forming groove and the opposite sides of the pre-hole forming groove both protrude from the main body of the rib plate, and the protrusion height and width are consistent; S4, the flash material on the outside of the pre-formed gear ring on the final forging blank is cut off using a trimming composite mold, and irregular pre-holes are punched at the corresponding positions of each pre-hole forming groove. The diameter of the irregular pre-hole is larger than the set diameter of the irregular hole, and the sum of the volumes of the protrusions at the two openings of the irregular pre-hole is greater than the difference between the volume of the irregular pre-hole and the volume of the irregular hole in the un-chamfered state (i.e., attached). Figure 4In the diagram, V1+V2>V3, where V3 is the difference between the volume of the pre-formed irregular hole and the volume of the irregular hole before chamfering; the volume of V1 = the bottom area of ​​the circumferential raised step S1 × the step height H1, and the volume of V2 = the bottom area of ​​the circumferential bottom step S2 × the step height H2); S5, the internal spline of the pre-formed gear ring is extruded using a cold extrusion process, and the protrusions at the two openings of the pre-formed irregular hole are simultaneously extruded into the pre-formed irregular hole using an upsetting process, and the chamfers at both ends of the openings are simultaneously extruded to form an irregular hole with the same size and shape as the designed irregular hole; S6, the pre-formed shaft and the outer side of the pre-formed gear ring of the cold-extruded blank are machined to make the gear ring reach the designed thickness, and the shaft with the same design shape and size, thus completing the machining of the input shaft gear hub. Thus, the gear hub mainly undergoes processes such as blanking, upsetting, pre-forming by stamping, final forging, trimming and pre-forming by stamping, cold extrusion of internal splines and irregular holes, and blank turning. In the pre-forming process, the outer diameter of the pre-formed gear ring is larger than the set outer diameter. Therefore, during final forging, the corresponding positions of the ribs and pre-forming grooves are thicker and less prone to deformation. During forging, protrusions are formed on the outer side of the pre-forming groove and on the corresponding side. During cold extrusion, axial upsetting pressure is applied to press the volume of the two protrusions into the gap between the pre-forming hole and the extrusion punch, ensuring a close fit with the cold extrusion die and thus guaranteeing the dimensional accuracy and surface roughness of the irregular hole's side surface. Simultaneously, the chamfering at the end of the extrusion die during upsetting creates chamfers at both ends of the hole. Furthermore, while extruding the irregularly shaped holes, the internal splines were also extruded simultaneously on a single mold. This ensured the dimensional accuracy of both the internal splines and the irregularly shaped holes, as well as the positional relationship between the splines and the irregularly shaped holes. This eliminated the milling process previously used for irregularly shaped holes, which took 15 minutes per piece. Using punching + cold extrusion, extruding one piece takes only 10 seconds, significantly improving efficiency. The pre-formed gear ring diameter is larger than the set diameter. During the cold extrusion of the internal splines, the gear ring thickness is greater than the set thickness, resulting in greater stress on the pre-formed gear ring. This prevents deformation due to excessive stress during extrusion. To reduce punching deformation during trimming and punching the pre-holes, a spring was designed to apply axial pressure to the ribs. To ensure no tearing on the punched side, a rounded corner R was designed at the front end of the punch, utilizing the punching principle.

[0017] Furthermore, in S1, the heating temperature of the bar stock is controlled between 1100-1150℃. This set temperature ensures that the bar stock has good fluidity during subsequent forging, allowing it to be quickly deformed and shaped.

[0018] Furthermore, before S5 cold extrusion, the blanks after trimming and punching are normalized, shot blasted, and turned before phosphating and saponification. During normalizing, the temperature in the normalizing zone is 935±15℃, and the fan speed in the cooling zone is 50±5HZ to ensure that the product hardness is below 170HB. Shot blasting uses ordinary 0.6mm steel shot to tumble-blast the product for about 20-30 minutes to ensure that the oxide scale on the product surface is removed, avoiding oxide scale residue that could cause pits, scratches, and other problems on the product surface after extrusion. The coaxiality of the outer circle and the tooth profile is required to be within 0.05mm during blank turning to ensure that the tooth profile accuracy of the product meets the drawing requirements during extrusion. During phosphating and saponification, a suitable lubrication concentration is maintained to facilitate smooth extrusion and result in a better surface quality of the product after extrusion.

[0019] Furthermore, in S6, machining includes two roughing and two finishing machining operations. During roughing, the product's reference surface must be confirmed. The product's tooth profile and the special reference surface after cold extrusion should be used as the clamping reference. Special tooling should be made to ensure that the radial runout and end face runout of the tooling are ≤0.02mm, and the parallelism of the reference surface after roughing is ≤0.1mm. The clamping reference used during finishing machining is the same as that used during roughing. It is also required that the equipment be equipped with an airtightness sensitivity detection device during finishing machining, with a sensitivity setting of <0.1mm, to ensure that the product is clamped correctly during machining and that the product is not allowed to be clamped crookedly. Before the start of each shift, the end runout and radial runout of the tooling should be checked, and the end runout and radial runout should be <0.02mm.

[0020] Specifically, in this application, a first rough machining is performed, followed by two finish machining operations, and then a second rough machining is carried out. After the above operations are completed, sorting, final inspection, cleaning and rust removal, and packing and warehousing are carried out.

[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A method for machining and forming a hybrid input shaft gear hub, characterized in that, The process includes the following steps: S1, blanking and heating the blanked bar before upsetting; S2, preforming the upset blank by stamping to form a preformed blank with a preformed gear ring and a preformed shaft at both ends, wherein the outer diameter of the preformed gear ring and the preformed shaft are both larger than the outer diameter of the gear ring and the shaft set by the gear hub; S3, performing final forging on the preformed blank to make the inner and outer sidewalls of the preformed gear ring flat, and simultaneously forging ribs, and forging multiple pre-hole forming grooves with a width greater than the set width of the irregular hole on the ribs, wherein the pre-hole forming grooves and the opposite sides of the pre-hole forming grooves protrude from the main body of the ribs, and the protrusion height of the protruding part of the pre-hole forming groove is the same as the protrusion height of the protruding part on the opposite side of the pre-hole forming groove, and the protrusion width of the protruding part of the pre-hole forming groove is the same as the protrusion width of the protruding part on the opposite side of the pre-hole forming groove; S4. Using a trimming composite die, the flash material on the outer side of the pre-formed gear ring on the final forged blank is removed, and irregular pre-holes are punched at the corresponding positions of each pre-hole forming groove. The diameter of the irregular pre-hole is larger than the set diameter of the irregular hole, and the sum of the volumes of the protrusions at the two openings of the irregular pre-hole is greater than the difference between the volume of the irregular pre-hole and the volume of the irregular hole before chamfering. S5. The internal spline of the pre-formed gear ring is extruded using a cold extrusion process, and the protrusions at the two openings of the irregular pre-hole are simultaneously extruded into the irregular pre-hole using an upsetting process, and the chamfers at both ends of the openings are simultaneously extruded to form irregular holes with the same size and shape as the set irregular holes. S6. The pre-formed shaft and the outer side of the pre-formed gear ring of the cold-extruded blank are machined to make the gear ring reach the designed thickness and the shaft consistent with the designed shape and size, thus completing the machining of the input shaft gear hub.

2. The method for machining and forming the hybrid input shaft gear hub according to claim 1, characterized in that, In S1, the heating temperature of the bar is controlled between 1100-1150℃.

3. The method for machining and forming the hybrid input shaft gear hub according to claim 1 or 2, characterized in that, Before S5 cold extrusion, the blanks after trimming and punching are normalized, shot blasted, and turned before phosphating and saponification. During normalizing, the temperature in the normalizing zone is between 910-935℃, and the fan speed in the cooling zone is 45-55HZ to ensure that the product hardness is below 170HB. Shot blasting uses ordinary 0.6mm steel shot to tumble and polish the product for 20-30 minutes. The coaxiality of the outer circle and tooth shape is required to be within 0.05mm during blank turning to ensure that the tooth shape accuracy of the product meets the drawing requirements during extrusion. A suitable lubrication concentration is ensured during phosphating and saponification.

4. The method for machining and forming the hybrid input shaft gear hub according to claim 3, characterized in that, In S6, machining includes two roughing turns and two finishing turns. During roughing, the datum surface of the product must be confirmed. The tooth profile of the product and the datum surface after cold extrusion are used as the clamping datum. The pre-formed gear ring is machined using a tooling. During machining, the radial runout and end face runout of the tooling should be ≤0.02mm, and the parallelism of the datum surface after roughing should be ≤0.1mm. During finishing, the clamping datum used is the same as that used during roughing. It is required that the equipment be equipped with an airtightness sensitivity detection device during finishing. The tooling sensitivity is set to <0.1mm, and the end runout and radial runout of the tooling should be <0.02mm.

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