A machining method of a transfer gear wheel and a transfer

Abstract

The application discloses a processing method of a gear carrier of a transfer case, and comprises the following steps: first clamping; turning a right side inner hole, an end face and an outer circle of a workpiece; second clamping; turning a left side end face outer circle, drilling and milling a groove; hobbing, chamfering and deburring; carburizing and quenching heat treatment; third clamping; hard turning and hard reaming the inner hole; fourth clamping; hard turning and hard milling; fifth clamping; gear grinding; sixth clamping; hard milling; seventh clamping; and wire cutting profiling. The application improves the processing efficiency and precision of the gear carrier of the transfer case, reduces the production cost, and provides a manufacturing process scheme for a high-precision incomplete gear with a relatively complex structure.

Description

Technical Field

[0001] This invention belongs to the field of vehicle transmission system transfer case processing technology, specifically relating to a method for processing the transfer case gear sector and a transfer case. Background Technology

[0002] Four-wheel drive transfer cases are important transmission components widely used in mid-to-high-end vehicles. As one of its key transmission components, the gear sector has special structural features and high precision requirements. The workpiece integrates structures such as end face protrusions, holes, end face grooves, and incomplete gears. The manufacturing process is complex and difficult to process. According to traditional processes, multiple special equipment, special tools, and tooling fixtures are required, resulting in high costs and low efficiency.

[0003] In existing processing technologies, the general manufacturing process for gear sectors is as follows:

[0004] (1) Casting or powder metallurgy can adapt to the special structure of the gear sector, but the strength and precision of the workpiece cannot meet the requirements of the drawings, the mold cost is high, and the mold manufacturing cycle is long.

[0005] (2) The strength can meet the requirements of the drawings when it is manufactured by machining, but the accuracy is not easy to guarantee. The process flow needs to be planned reasonably. Due to the special structure of the workpiece, there is currently no mature machining process to deal with it. Summary of the Invention

[0006] To address the aforementioned problems in the existing technology, this invention provides a processing method for a transfer case gear sector suitable for small-batch trial production, which improves the processing efficiency and accuracy of the transfer case gear sector, reduces production costs, and provides a manufacturing process solution for high-precision incomplete gears with complex structures.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A method for machining the gear sector of a transfer case includes the following steps:

[0009] S1. First clamping: Clamp the gear sector blank on the three-jaw chuck of the milling and turning center.

[0010] S2. Turning the inner hole, end face, and outer circle on the right side of the workpiece: Start the turning function of the turning-milling machining center, and perform rough turning and finish turning on the outer circle of the right end face of the workpiece in sequence; start the milling function of the turning-milling machining center to machine the middle inner hole;

[0011] S3. Second clamping: After turning the workpiece around, reinstall it on the three-jaw chuck jaws;

[0012] S4. Turning the outer circle of the left end face, drilling holes, and milling grooves: Start the turning function of the turning-milling machining center, and perform rough turning and finish turning on the outer circle of the left end face of the workpiece in sequence; start the milling function of the turning-milling machining center, mill the long groove on the end face and machine two positioning holes.

[0013] S5. Gear hobbing, chamfering, and deburring: Maintain the milling function of the milling-turning machining center, perform gear hobbing on the workpiece, and chamfer the gear tooth profile;

[0014] S6. Perform carburizing and quenching heat treatment on the workpiece;

[0015] S7. Third clamping: Clamp the heat-treated workpiece onto the three-jaw chuck of the milling and turning machining center;

[0016] S8. Hard turning and hard reaming of inner hole after heating: Start the turning function of the milling-turning machining center to perform hard turning on the right end face and outer circle of the workpiece; start the milling function of the milling-turning machining center to perform hard reaming on the middle inner hole.

[0017] S9. Fourth clamping: After the workpiece is turned around, it is re-clamped on the three-jaw chuck;

[0018] S10. Hard turning and hard milling: Start the turning function of the turning-milling machining center to perform hard turning on the left end face and outer circle of the workpiece; start the milling function of the turning-milling machining center to mill the trapezoidal groove on the end face.

[0019] S11. Fifth clamping: Install the workpiece on the expansion sleeve fixture of the gear grinding machine;

[0020] S12. Gear grinding;

[0021] S13. Sixth clamping: Mount the workpiece on the milling-turning machining center;

[0022] S14. Hard Milling: Activate the milling function of the milling-turn machining center to hard mill the semi-circular groove on the end face;

[0023] S15. Seventh clamping: Install the workpiece onto the wire cutting fixture;

[0024] S16. Wire cutting profile.

[0025] Further, step S2 includes: starting the turning function of the milling-turning machining center, using an external roughing tool to rough turn the outer diameter of the right end face of the workpiece, leaving a 0.4mm finishing allowance on one side; using an external finishing tool to finish turn the outer diameter of the right end face of the workpiece, leaving a 0.15mm hard turning allowance on one side of the right end face T2, and leaving a process chuck on the right end face D2; starting the milling function of the milling-turning machining center, using a drill bit to drill the middle inner hole, leaving a 0.1mm reaming allowance on one side; using a reamer to ream the middle inner hole, leaving a 0.02mm hard reaming allowance on one side.

[0026] Furthermore, in step S3, the hard jaws of the three-jaw chuck are replaced with soft jaws for a second clamping of the workpiece.

[0027] Further, step S4 includes: activating the turning function of the milling-turning machining center, using an external roughing tool to rough turn the outer diameter of the left end face of the workpiece, leaving a 0.4mm finishing allowance on one side; using an external finishing tool to finish turn the outer diameter of the left end face of the workpiece, leaving a 0.15mm hard turning allowance on one side of the left end face T3, and retaining the process chuck on the left end face D3; activating the milling function of the milling-turning machining center, using an end mill to mill the long groove on the end face; and using a drill bit to drill two positioning holes.

[0028] Further, step S5 includes: keeping the workpiece clamping state unchanged, keeping the milling function state of the milling-turning machining center unchanged, calling the gear hobbing function module, calling the hob, performing gear hobbing on the workpiece, and retaining a 0.1mm grinding allowance on the tooth surface; calling the chamfering cutter to chamfer the gear tooth profile.

[0029] Further, step S8 includes: starting the turning function of the turning-milling composite machining center, calling the superhard external turning tool, and hard turning the right end face and outer circle of the workpiece to ensure that the runout of the T4 end face is 0.01mm and the runout of the D4 outer circle is 0.01mm; starting the milling function of the turning-milling composite machining center, calling the hard reamer, and hard reaming the inner hole to the drawing size and accuracy requirements.

[0030] Further, step S10 includes: starting the turning function of the turning-milling composite machining center, calling the superhard external turning tool, performing hard turning on the left end face and outer circle of the workpiece, turning off the left process chuck, and ensuring that the axial dimension and end face geometric accuracy meet the drawing requirements; starting the milling function of the turning-milling composite machining center, calling the superhard end mill, and milling the trapezoidal groove on the end face.

[0031] Furthermore, the wire EDM fixture includes a base plate and a positioning pin. The positioning pin is connected to the middle inner hole of the gear sector. The base plate of the wire EDM fixture is provided with a first wire threading hole and a second wire threading hole.

[0032] Further, step S15 includes: installing the wire cutting fixture on the wire cutting machine and aligning it, aligning the middle inner hole on the workpiece with the positioning pin on the fixture, inserting the positioning pin into the middle inner hole of the workpiece, and pressing the workpiece with a pressure plate; step S16 includes: inserting the electrode wire through the first wire insertion hole 4, performing wire cutting along the outer contour of the workpiece, and exiting through the second wire insertion hole 5 after cutting, so that the workpiece is cut off as a whole.

[0033] The present invention also provides a transfer case gear sector, which is manufactured by the transfer case gear sector processing method described in the present invention.

[0034] The present invention has the following beneficial effects:

[0035] This invention utilizes milling and turning to perform pre-heat machining on the transfer case gear sector, enabling all pre-heat machining processes to be completed on a single machine, saving equipment resources, shortening the process flow, and improving production efficiency.

[0036] This invention uses hard reaming instead of hard turning or grinding to achieve post-heat finishing of small-diameter internal holes;

[0037] This invention improves the machining accuracy of teeth by retaining the process chuck and using full-tooth grinding.

[0038] This invention provides a simple fixture for wire cutting of incomplete gears.

[0039] The overall process method of this invention reduces the reference conversion during the processing and improves the processing accuracy; it also reduces the number of equipment transfers in traditional processes and reduces the investment in tooling and fixtures, thereby reducing costs. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the toothed sector blank structure according to an embodiment of the present invention;

[0042] Figure 2 This is a schematic diagram of the toothed fan product structure according to an embodiment of the present invention;

[0043] Figure 3 This is a flowchart of a processing method for a transfer case gear sector as described in Embodiment 1 of the present invention;

[0044] Figure 4 This is a schematic diagram of the gear fan pre-milling sequence in Embodiment 1 of the present invention;

[0045] Figure 5 This is a schematic diagram of the gear fan pre-milling sequence in Embodiment 1 of the present invention;

[0046] Figure 6 This is a schematic diagram of the gear fan after heat treatment milling sequence 1 in Embodiment 1 of the present invention;

[0047] Figure 7 This is a schematic diagram of the gear fan heating and milling sequence 2 in Embodiment 1 of the present invention;

[0048] Figure 8 This is a schematic diagram of the three-stage milling and turning process after heat dissipation in Embodiment 1 of the present invention;

[0049] Figure 9 This is a schematic diagram of the toothed sector wire cutting in Embodiment 1 of the present invention;

[0050] Figure 10 This is a schematic diagram of the toothed sector wire cutting fixture structure in Embodiment 1 of the present invention;

[0051] Figure 10 middle:

[0052] 1-Wire EDM fixture base plate; 2-Positioning pin; 3-Gear sector center inner hole; 4-Wire threading hole No. 1; 5-Wire threading hole No. 2; 6-Positioning hole No. 1; 7-Positioning hole No. 2. Detailed Implementation

[0053] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure of the invention, components and arrangements of specific examples are described below. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale.

[0054] Example 1

[0055] like Figure 3 As shown, a method for machining the sector gear of a transfer case includes the following steps:

[0056] S1. First clamping: Gear sector blank as shown in... Figure 1 As shown, the gear sector blank is clamped on the three-jaw chuck of the milling and turning center, and the outer circle of D1 is clamped with hard jaws to position the end face of T1.

[0057] S2. Turn the inner hole, end face, and outer circle on the right side of the workpiece, such as... Figure 4As shown: Start the turning function of the mill-turn machining center, use the external roughing tool to rough turn the outer diameter of the right end face of the workpiece, leaving a 0.4mm finishing allowance on one side. Use the external finishing tool to finish turn the outer diameter of the right end face of the workpiece, leaving a 0.15mm hard turning allowance on one side of the right end face T2, and leaving the process chuck on the right end face D2. Start the milling function of the mill-turn machining center, use the drill bit to drill the middle inner hole, leaving a 0.1mm reaming allowance on one side. Use the reamer to ream the middle inner hole, leaving a 0.02mm hard reaming allowance on one side.

[0058] S3. Second clamping: Loosen the chuck jaws, remove the workpiece, replace the hard jaws of the three-jaw chuck with soft jaws, turn the workpiece around and place it on the chuck jaws, clamp the outer circle of D2, and position the end face of T2.

[0059] S4. Turn the outer circle of the left end face, drill holes, and mill grooves, such as... Figure 5 As shown: Start the turning function of the milling-turning machining center, use the external roughing tool to rough turn the outer diameter of the left end face of the workpiece, leaving a 0.4mm finishing allowance on each side. Use the external finishing tool to finish turn the outer diameter of the left end face of the workpiece, leaving a 0.15mm hard turning allowance on each side of the left end face T3, and leaving the process chuck on the left end face D3. Start the milling function of the milling-turning machining center, use the end mill to mill the long groove on the end face. Use the drill bit to drill two positioning holes.

[0060] S5, hobbing, chamfering, deburring: Keep the workpiece clamping state unchanged, keep the milling function state of the milling-turning machining center unchanged, call the hobbing function module, call the hob, perform hobbing on the workpiece, and retain 0.1mm grinding allowance on the tooth surface; call the chamfering cutter to chamfer the gear tooth profile.

[0061] S6. Carburizing and quenching heat treatment: Loosen the chuck, remove the workpiece, and the pre-heat machining is completed; perform carburizing and quenching heat treatment on the workpiece.

[0062] S7. Third clamping: Clamp the heat-treated workpiece on the three-jaw chuck of the milling and turning center, position the T3 end face, and clamp the D3 outer circle.

[0063] S8, hard turning after heat treatment, hard reaming of inner holes, such as Figure 6 As shown: Start the turning function of the mill-turn machining center, use the superhard external turning tool to hard turn the right end face and outer diameter of the workpiece, ensuring a runout of 0.01mm for the T4 end face and 0.01mm for the D4 outer diameter. Start the milling function of the mill-turn machining center, use the hard reamer to hard ream the inner hole to the dimensions and accuracy requirements of the drawing.

[0064] S9. Fourth clamping: Loosen the chuck, remove the workpiece, turn it around and clamp it on the three-jaw chuck, position the T4 end face, and clamp the D4 outer circle.

[0065] S10, hard turning, hard milling, such as Figure 7 As shown: Start the turning function of the mill-turn machining center, call the superhard external turning tool, and perform hard turning on the left end face and outer circle of the workpiece, and remove the left process chuck to ensure that the axial dimension and end face geometric accuracy meet the drawing requirements; Start the milling function of the mill-turn machining center, call the superhard end mill, and mill the trapezoidal groove on the end face.

[0066] S11. Fifth clamping: Loosen the chuck, remove the workpiece, install the workpiece on the expansion sleeve fixture of the gear grinding machine, expand the outer circle of D4, and position the end face of T4.

[0067] S12. Gear Grinding: Compile a gear grinding program, start the gear grinding machine, and perform gear grinding on the workpiece to ensure that the gear dimensions and accuracy meet the requirements of the drawing.

[0068] S13, Sixth clamping: Loosen the gear grinding machine fixture, remove the workpiece, install it on the milling and turning machining center, and press the two end faces T3 and T4 together.

[0069] S14, hard milling, such as Figure 8 As shown: Start the milling function of the milling-turning machining center, call the superhard end mill, and hard mill the semi-circular groove on the end face.

[0070] S15, Seventh clamping: Install the special wire EDM fixture on the wire EDM machine and align it. Align the locating pin hole on the workpiece with the locating pin on the fixture, ensuring that the bottom surface of the workpiece is close to the base plate of the fixture. Insert the locating pin into the inner hole in the middle of the workpiece and press the workpiece with the pressure plate.

[0071] S16, wire cutting profile, such as Figure 9 , Figure 10 As shown: The wire EDM fixture includes a base plate 1 and a positioning pin 2. The positioning pin 2 is connected to the middle inner hole 3 of the gear sector. The base plate 1 of the wire EDM fixture is provided with a first wire threading hole 4 and a second wire threading hole 5. The electrode wire is inserted through the first wire threading hole 4 and wire cuts along the outer contour of the workpiece. After the cutting is completed, it is pulled out through the second wire threading hole 5, which can ensure that the workpiece is cut off as a whole and the fixture is intact and can be reused.

[0072] Example 2

[0073] This embodiment is a transfer case gear sector, such as... Figure 2 As shown, it is processed using the method described in Example 1.

[0074] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for machining the gear sector of a transfer case, characterized in that, Includes the following steps: S1. First clamping: Clamp the gear sector blank on the three-jaw chuck of the milling and turning center. S2. Turning the inner hole, end face, and outer diameter of the workpiece on the right side: Start the turning function of the turning-milling composite machining center, and perform rough turning and finish turning on the outer diameter of the right end face of the workpiece in sequence; start the milling function of the turning-milling composite machining center to machine the middle inner hole; Step S2 includes: starting the turning function of the turning-milling composite machining center, calling the outer diameter rough turning tool to perform rough turning on the outer diameter of the right end face of the workpiece, leaving a 0.4mm finish turning allowance on one side; calling the outer diameter finish turning tool to perform finish turning on the outer diameter of the right end face of the workpiece, leaving a 0.15mm hard turning allowance on one side of the right end face T2, and leaving the process chuck on the right outer diameter D2; starting the milling function of the turning-milling composite machining center, calling the drill bit to drill the middle inner hole, leaving a 0.1mm reaming allowance on one side; calling the reamer to ream the middle inner hole, leaving a 0.02mm hard reaming allowance on one side; S3. Second clamping: After turning the workpiece around, reinstall it on the three-jaw chuck jaws; S4. Turning the outer diameter of the left end face, drilling, and milling the groove: Start the turning function of the turning-milling composite machining center, and perform rough turning and finish turning on the outer diameter of the left end face of the workpiece in sequence; start the milling function of the turning-milling composite machining center, mill the long groove on the end face, and machine two positioning holes; Step S4 includes: starting the turning function of the turning-milling composite machining center, using the outer diameter rough turning tool to perform rough turning on the outer diameter of the left end face of the workpiece, leaving a 0.4mm finish turning allowance on one side; using the outer diameter finish turning tool to perform finish turning on the outer diameter of the left end face of the workpiece, leaving a 0.15mm hard turning allowance on one side of the left end face T3, and retaining the process chuck on the left D3 outer diameter; starting the milling function of the turning-milling composite machining center, using the end mill, and milling the long groove on the end face; using the drill bit, and drilling two positioning holes; S5. Gear hobbing, chamfering, and deburring: Maintain the milling function of the milling-turning machining center, perform gear hobbing on the workpiece, and chamfer the gear tooth profile; S6. Perform carburizing and quenching heat treatment on the workpiece; S7. Third clamping: Clamp the heat-treated workpiece onto the three-jaw chuck of the milling and turning machining center; S8. Hard turning and hard reaming of the inner hole after heating: Start the turning function of the milling-turning center to hard turn the right end face and outer circle of the workpiece; start the milling function of the milling-turning center to hard ream the middle inner hole; Step S8 includes: starting the turning function of the milling-turning center, calling the superhard external turning tool, to hard turn the right end face and outer circle of the workpiece, ensuring that the runout of the T4 end face is 0.01mm and the runout of the D4 outer circle is 0.01mm; starting the milling function of the milling-turning center, calling the hard reamer, to hard ream the inner hole to the drawing dimensions and accuracy requirements; S9. Fourth clamping: After the workpiece is turned around, it is re-clamped on the three-jaw chuck; S10. Hard turning and hard milling: Start the turning function of the turning-milling composite machining center to perform hard turning on the left end face and outer circle of the workpiece; start the milling function of the turning-milling composite machining center to mill the trapezoidal groove on the end face; Step S10 includes: starting the turning function of the turning-milling composite machining center, calling the superhard external turning tool to perform hard turning on the left end face and outer circle of the workpiece, turning off the left process chuck to ensure that the axial dimension and end face geometric accuracy meet the drawing requirements; starting the milling function of the turning-milling composite machining center, calling the superhard end mill to mill the trapezoidal groove on the end face; S11. Fifth clamping: Install the workpiece on the expansion sleeve fixture of the gear grinding machine; S12. Gear grinding; S13. Sixth clamping: Mount the workpiece on the milling-turning machining center; S14. Hard Milling: Activate the milling function of the milling-turn machining center to hard mill the semi-circular groove on the end face; S15. Seventh clamping: Install the workpiece onto the wire cutting fixture; S16. Wire cutting profile.

2. The method for machining the transfer case sector as described in claim 1, characterized in that, In step S3, the hard jaws of the three-jaw chuck are replaced with soft jaws for the second clamping of the workpiece.

3. The method for machining the transfer case sector as described in claim 1, characterized in that, Step S5 includes: keeping the workpiece clamping state unchanged, keeping the milling function state of the milling-turning machining center unchanged, calling the gear hobbing function module, calling the hob, performing gear hobbing on the workpiece, leaving a 0.1mm grinding allowance on the tooth surface; calling the chamfering cutter to chamfer the gear tooth profile.

4. The method for machining the transfer case sector as described in claim 1, characterized in that, The wire EDM fixture includes a base plate and a positioning pin. The positioning pin is connected to the middle inner hole of the gear sector. The base plate of the wire EDM fixture is provided with a first wire threading hole and a second wire threading hole.

5. The method for machining the transfer case sector as described in claim 4, characterized in that, Step S15 includes: installing the wire cutting fixture on the wire cutting machine and aligning it, aligning the middle inner hole on the workpiece with the positioning pin on the fixture, inserting the positioning pin into the middle inner hole of the workpiece, and pressing the workpiece with a pressure plate; Step S16 includes: inserting the electrode wire through the first wire threading hole, performing wire cutting along the outer contour of the workpiece, and exiting through the second wire threading hole after cutting, so that the workpiece is cut off as a whole.

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