Finish machining method for internal spline input shaft

Abstract

A finish machining method for an internal spline input shaft is characterized by comprising the following steps: with central holes in two ends of the input shaft as a reference and the central axes of the central holes as a machining axis, firstly, performing finish turning on the central holes in the two ends of the input shaft, outer circles of bearings and positioning end surfaces by using a double-end numerical control lathe; and then the input shaft is sequentially subjected to internal spline broaching, gear hobbing, heat treatment, outer circle grinding at the two ends, inner hole finish turning at the two ends and gear grinding. The invention ensures the coaxiality of the reference of the center holes at the two ends of the input shaft, ensures that the excircle of the bearing is consistent with the reference of the center holes, effectively reduces the eccentric error of the center holes at the two ends and the excircle of the bearings at the two ends, reduces the error magnification of subsequent finish machining, improves the overall precision of the product, and improves the concentricity of the assembled bearings at the two ends of the input shaft. Transmission reliability of the input shaft is improved, transmission noise is reduced, finish machining takt of the input shaft is accelerated, finish machining efficiency is improved, and production benefits are improved.

Description

Technical Field

[0001] The invention relates to a finishing method for an internal spline input shaft, which is used for finishing the input shaft of a new energy reducer. Background Art

[0002] The input shaft of the new energy reducer has an inner cavity with internal splines and an outer wall with a gear structure. The input shaft blank needs to be fine-machined to form the finished input shaft. The current input shaft finishing process is: fine turning the outer circle inner hole at one end - fine turning the outer circle inner hole at the other end - drawing the inner spline - hobbing - heat treatment - grinding the outer circle end face at one end - grinding the outer circle end face at the other end - hot turning the inner hole at one end - hot turning the inner hole at the other end - grinding. The entire process takes a long time to process. Since the fine turning of one end and the fine turning of the other end are completed by two clampings, there are eccentric errors in the center holes at both ends and the outer circles of the bearings at both ends, which amplifies the errors in the subsequent processes such as drawing splines, hobbing, and grinding the outer circle after heat treatment. After the finished input shaft is assembled with bearings, the concentricity of the bearings is out of tolerance, causing the central axis of the input shaft to be deflected after being assembled to the reducer housing, affecting the transmission reliability and causing transmission noise. Summary of the invention

[0003] The finishing method of the internal spline input shaft provided by the present invention ensures the coaxiality of the center hole datums at both ends of the input shaft, and ensures that the outer circle of the bearing is consistent with the center hole datum, effectively reducing the eccentricity error of the center holes at both ends and the outer circles of the bearings at both ends; reduces the error amplification rate of subsequent finishing, improves the overall accuracy of the product, improves the concentricity of the assembled bearings at both ends of the input shaft, improves the transmission reliability of the input shaft, reduces transmission noise, accelerates the finishing rhythm of the input shaft, improves the finishing efficiency, and improves production benefits.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: The finishing method of the internal spline input shaft is characterized in that the center holes at both ends of the input shaft are taken as the reference and the central axis of the center hole is used as the processing axis. The center holes at both ends of the input shaft, the outer circle of the bearing and the positioning end face are first finished by a double-head CNC lathe, and then the input shaft is pulled with internal splines, hobbed, heat treated, ground at both ends of the outer circle, finished and ground at both ends of the inner hole.

[0005] Preferably, an outer cylindrical expansion sleeve is used on a double-head CNC lathe to clamp the middle outer circle of the input shaft, so that the center of the outer cylindrical expansion sleeve is aligned with the central axis of the center hole, and the center holes, bearing outer circles and positioning end faces at both ends of the input shaft are precision-machined synchronously in sequence.

[0006] Preferably, drawing an internal spline on the input shaft means: clamping the two ends of the broach with a main clamping tool body and a laying clamping tool body on a CNC broaching machine, respectively, clamping the input shaft on a CNC lathe so that the centers of the main clamping tool body and the laying clamping tool body are respectively aligned with the central axis of the center hole, and using the broaching tool to form an internal spline in the inner cavity of the input shaft.

[0007] Preferably, gear hobbing on the input shaft means: clamping the outer circle of the bearing at one end of the input shaft with a gear hobbing fixture on a CNC gear hobbing machine, and tightening the center hole at the other end with an upper center, so that the center of the gear hobbing fixture is aligned with the central axis of the center hole, and using a pre-grinding hob to perform gear hobbing on the input shaft gear.

[0008] Preferably, grinding the outer circumference of both ends of the input shaft means: using the spire on the CNC external cylindrical grinder to clamp the input end so that the center of the spire is aligned with the central axis of the center hole, first grinding the end outer circumference and end face chamfer of one end of the input shaft, then turning the input shaft 180 degrees to swap the two ends of the input shaft, and then using the spire on the CNC external cylindrical grinder to clamp the input shaft so that the center of the spire is aligned with the central axis of the center hole, and grinding the end outer circumference and end face of the other end of the input shaft.

[0009] Preferably, finishing the inner holes at both ends of the input shaft means: using an outer cylindrical clamping sleeve to clamp the two ends of the input shaft on a double-head CNC lathe, aligning the center of the outer cylindrical clamping sleeve with the central axis of the center hole, and finishing the inner holes at both ends of the input shaft synchronously.

[0010] Preferably, grinding the input shaft means: clamping the input shaft with a gear grinding fixture on a CNC gear grinding machine to chamfer the front end of the outer circle of the bearing at one end, and tightening the center hole at the other end with an upper center, so that the center of the gear grinding fixture is aligned with the central axis of the center hole, and using a gear grinding wheel to grind and shape the input shaft gear.

[0011] The beneficial effects of the invention are: The finishing method of the internal spline input shaft of the present invention adopts a double-head CNC lathe to complete the finishing of the center holes at both ends of the input shaft, the outer circle of the bearing and the positioning end face through process optimization, so as to ensure the coaxiality of the center hole datum at both ends of the input shaft, and ensure that the outer circle of the bearing is consistent with the center hole datum, effectively reducing the eccentricity error of the center holes at both ends and the outer circle of the bearing at both ends; taking the center holes at both ends of the input shaft as the datum, using the center axis of the center hole as the machining axis to ensure the consistency of the datum of the subsequent finishing process, reducing the error amplification rate of the subsequent finishing, improving the overall accuracy of the product, improving the concentricity of the assembled bearings at both ends of the input shaft, improving the transmission reliability of the input shaft, and reducing the transmission noise; adopting a double-head CNC lathe to clamp the outer circle, completing the finishing of the center holes, the outer circle of the bearing and the positioning end face at both ends of the input shaft with one clamping, accelerating the finishing rhythm of the input shaft, improving the finishing efficiency, and improving the production benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the input shaft after the center holes at both ends of the input shaft and the outer circle of the bearing are finely machined in the fine machining method of the internal spline input shaft of the present invention.

[0013] Figure 2 This is a schematic diagram of the input shaft after the positioning end faces at both ends of the input shaft have been finely machined.

[0014] Figure 3 This is a schematic diagram of the input shaft after the input shaft is splined.

[0015] Figure 4 This is a schematic diagram of the input shaft after entering the gear hobbing process.

[0016] Figure 5 This is a schematic diagram of the input shaft after the outer circle of one end of the input shaft is ground and the end face is chamfered.

[0017] Figure 6 This is a schematic diagram of the input shaft after grinding the outer circle and end face of the other end of the input shaft.

[0018] Figure 7 This is a schematic diagram of the input shaft after the inner holes at both ends of the input shaft have been finely turned.

[0019] Figure 8 This is a schematic diagram of the input shaft after the input shaft is ground. DETAILED DESCRIPTION

[0020] Combine the following Figures 1 to 8 The embodiments of the present invention are described in detail.

[0021] The finishing method of the internal spline input shaft is characterized in that the center hole 1 at both ends of the input shaft is used as a reference, and the central axis 2 of the center hole 1 is used as the processing axis. The center hole 1 at both ends of the input shaft, the bearing outer circle 3 and the positioning end face 4 are first finished by a double-head CNC lathe, and then the input shaft is pulled into internal splines, hobbed, heat treated, ground at both ends of the outer circle, and finished and ground at both ends of the inner hole.

[0022] The finishing method of the internal spline input shaft described above uses a double-head CNC lathe to complete the finishing of the center hole 1, the outer circle 3 of the bearing and the positioning end face 4 at both ends of the input shaft through process optimization, which ensures the coaxiality of the center hole datum at both ends of the input shaft, and ensures that the outer circle of the bearing is consistent with the center hole datum, effectively reducing the eccentricity error of the center hole at both ends and the outer circle of the bearing at both ends; taking the center hole 1 at both ends of the input shaft as the datum, and using the center axis 2 of the center hole 1 as the machining axis to ensure the consistency of the datum of the subsequent finishing process, reducing the error magnification rate of the subsequent finishing, improving the overall accuracy of the product, improving the concentricity of the assembled bearings at both ends of the input shaft, improving the transmission reliability of the input shaft, and reducing transmission noise; using a double-head CNC lathe to clamp the outer circle, and completing the finishing of the center hole 1, the outer circle 3 of the bearing and the positioning end face 4 at both ends of the input shaft with one clamping, accelerating the finishing beat of the input shaft, improving the finishing efficiency, and improving production benefits.

[0023] Among them, an outer cylindrical expansion sleeve is used to clamp the middle outer circle of the input shaft on the double-head CNC lathe, so that the center of the outer cylindrical expansion sleeve is aligned with the central axis 3 of the center hole 1, and the center hole 1, the outer circle 3 of the bearing, and the positioning end face 4 at both ends of the input shaft are synchronously fine-turned in sequence. The input shaft is clamped on the double-head CNC lathe, the center of the outer cylindrical expansion sleeve is aligned with the central axis 2 of the center hole 1, and then the two ends of the input shaft are synchronously fine-turned, first the center hole 1 is fine-turned, then the outer circle 3 of the bearing is fine-turned, and then the positioning end face 4 is fine-turned. The synchronous fine turning of the center hole 1, the outer circle 3 of the bearing and the positioning end face 4 at both ends of the input shaft is achieved in one clamping, which not only ensures the coaxiality of the center hole and the outer circle at both ends of the input shaft, but also shortens the processing time and improves the processing efficiency.

[0024] Among them, drawing the internal spline of the input shaft means: using the main clamping tool body and the laying clamping tool body to clamp the two ends of the broaching tool on the CNC broaching machine, respectively, clamping the input shaft on the CNC lathe so that the centers of the main clamping tool body and the laying clamping tool body are aligned with the central axis 2 of the center hole 1, and using the broaching tool to form the internal spline 5 in the inner cavity of the input shaft. The central axis 2 of the center hole 1 is used as the processing axis of the spline, and the processing datum is consistent, so as to improve the coaxiality of the internal spline 5 and the center hole 1.

[0025] Among them, gear hobbing for the input shaft means: using a gear hobbing fixture to clamp the outer circle of the bearing at one end of the input shaft on a CNC gear hobbing machine, and using a top center to press the center hole at the other end, so that the center of the gear hobbing fixture is aligned with the center axis 2 of the center hole, and using a pre-grinding hob to perform gear hobbing on the input shaft gear 6. The center axis 2 of the center hole 1 is used as the machining axis of the gear hobbing, and the machining datum is consistent, so as to improve the coaxiality of the input shaft gear 6 and the center hole 1.

[0026] Among them, grinding the outer circle of both ends of the input shaft means: using the tip on the CNC cylindrical grinder to clamp the input end, aligning the center of the tip with the central axis 2 of the center hole 1, first grinding the end outer circle 7 and end face chamfer 8 of one end of the input shaft, then turning the input shaft 180 degrees to swap the two ends of the input shaft, and then using the tip on the CNC cylindrical grinder to clamp the input shaft, aligning the center of the tip with the central axis of the center hole, and grinding the end outer circle 7 and end face 9 of the other end of the input shaft. Using the central axis 2 of the center hole 1 as the machining axis of the end outer circle, the machining datum is consistent, and the coaxiality of the end outer circle of the input shaft and the center hole 1 is improved.

[0027] Among them, finishing the inner holes at both ends of the input shaft means: using an outer cylindrical clamping sleeve to clamp the two ends of the input shaft on a double-head CNC lathe, aligning the center of the outer cylindrical clamping sleeve with the central axis of the center hole, and finishing the inner holes 10 at both ends of the input shaft synchronously. Using the central axis 2 of the center hole 1 as the machining axis of the inner holes at both ends, the machining datum is consistent, and the coaxiality of the inner holes 10 at both ends of the input shaft and the center hole 1 is improved. The input shaft is clamped on a double-head CNC lathe, and the inner holes 10 at both ends of the input shaft are finished synchronously. Only one clamping is required to achieve the synchronous finishing of the inner holes at both ends of the input shaft, which not only ensures the coaxiality of the inner holes at both ends of the input shaft, but also shortens the processing time and improves the processing efficiency.

[0028] Among them, the input shaft is ground by using a gear grinding fixture to chamfer the front end of the bearing outer circle 3 at one end of the input shaft on a CNC gear grinding machine, and the other end is tightened against the center hole with an upper center, so that the center of the gear grinding fixture is aligned with the center axis 2 of the center hole, and the input shaft gear 6 is ground and reshaped with a gear grinding wheel. The tooth shape and tooth direction of the input shaft gear 6 are corrected so that the tooth shape and tooth direction of the input shaft gear 6 meet the tolerance requirements.

[0029] The above is a complete description of the technical solutions of the embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the described embodiments are only part of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

Claims

1. A finishing method for an internal spline input shaft, characterized in that: Taking the center holes at both ends of the input shaft as the reference and the center axis of the center hole as the machining axis, the center holes, bearing outer circles and positioning end faces at both ends of the input shaft are first precision-turned using a double-head CNC lathe. Then the input shaft is sequentially subjected to internal spline pulling, gear hobbing, heat treatment, outer circle grinding at both ends, precision turning and gear grinding of the inner holes at both ends.

2. The finishing method of the internal spline input shaft according to claim 1, characterized in that On the double-head CNC lathe, an outer cylindrical expansion sleeve is used to clamp the middle outer circle of the input shaft, so that the center of the outer cylindrical expansion sleeve is aligned with the central axis of the center hole, and the center holes, bearing outer circles and positioning end faces at both ends of the input shaft are precision-machined synchronously in sequence.

3. The finishing method of the internal spline input shaft according to claim 2, characterized in that: Drawing internal splines on the input shaft means: using the main clamping tool body and the laying clamping tool body to clamp the two ends of the broaching tool on the CNC broaching machine respectively, clamping the input shaft on the CNC lathe so that the centers of the main clamping tool body and the laying clamping tool body are aligned with the central axis of the center hole respectively, and using the broaching tool to form internal splines in the inner cavity of the input shaft.

4. The finishing method of the internal spline input shaft according to claim 2, characterized in that , gear hobbing for the input shaft means: using a gear hobbing fixture on a CNC gear hobbing machine to clamp the outer circle of the bearing at one end of the input shaft, and using an upper center to tighten the center hole at the other end, so that the center of the gear hobbing fixture is aligned with the central axis of the center hole, and a pre-grinding hob is used to perform gear hobbing on the input shaft gear.

5. The finishing method of an internal spline input shaft according to claim 2, characterized in that: Grinding the outer circle of both ends of the input shaft means: using the spire on the CNC external cylindrical grinder to clamp the input end, aligning the center of the spire with the central axis of the center hole, first grinding the end outer circle and end face chamfer of one end of the input shaft, then turning the input shaft 180 degrees to swap the two ends of the input shaft, and then clamping the input shaft with the spire on the CNC external cylindrical grinder, aligning the center of the spire with the central axis of the center hole, and grinding the end outer circle and end face of the other end of the input shaft.

6. The finishing method of an internal spline input shaft according to claim 2, characterized in that: Finish turning the inner holes at both ends of the input shaft means: using an outer cylindrical expansion sleeve to clamp the two ends of the input shaft on a double-head CNC lathe, aligning the center of the outer cylindrical expansion sleeve with the central axis of the center hole, and synchronously finish turning the inner holes at both ends of the input shaft.

7. The finishing method of an internal spline input shaft according to claim 2, characterized in that: Gear grinding of the input shaft means: using a gear grinding fixture to clamp the front end of the bearing outer circle of one end of the input shaft on a CNC gear grinding machine, chamfering the front end, and using an upper center to tighten the center hole at the other end, so that the center of the gear grinding fixture is aligned with the central axis of the center hole, and using a gear grinding wheel to grind and shape the input shaft gear.

Images