Method for machining an eccentric tailstock sleeve

Abstract

A processing method of eccentric tailstock sleeve, first step, blanking allowance, second step, rough turning to get sleeve blank; third step, high temperature aging treatment to sleeve blank, fourth step, milling right end as eccentric circle φA1 as process chuck and right end step hole φB visible light; fifth step, rough turning eccentric circle φA1 and step circle table φD allowance; sixth step, rough boring left end step circle table φD allowance, get sleeve semi-finished product; seventh step, sleeve semi-finished product heat treatment; eighth step, rough grinding eccentric circle φA1 allowance, ninth step, rough boring left end hole φC, step hole φB and length L allowance; tenth step, semi-fine grinding eccentric circle φA1 and step circle table φD outer circle, end face; eleventh step, low temperature aging treatment, twelfth step, fine grinding eccentric circle φA1 to design size range, grinding step circle table φD outer circle and end face to design requirement; thirteenth step, fine boring step hole φB, hole φC to design size, get eccentric tailstock sleeve finished product.

Description

Technical Field

[0001] This invention belongs to the field of machining technology, and particularly relates to a machining method for an eccentric tailstock sleeve. Background Technology

[0002] Currently, the inner and outer circles of the tailstock sleeve on CNC machine tools are concentric. The manufacturing process and the technology for assembling and adjusting the tailstock assembly to be coaxial with the spindle end are mature. However, with the development of five-axis machine tools, the assembly and adjustment principle of the tailstock assembly has changed. The tailstock sleeve is now designed with an eccentric structure of inner and outer circles, requiring the outer circle roundness to be less than or equal to 0.003 mm and the cylindricity to be less than or equal to 0.004 mm, and the inner hole roundness to be less than or equal to 0.005 mm and the cylindricity to be less than or equal to 0.01 mm. Existing machining processes can no longer meet the machining requirements of the eccentric tailstock sleeve. Summary of the Invention

[0003] This invention provides a method for processing an eccentric tailstock sleeve to overcome the shortcomings of the prior art.

[0004] The technical solution adopted in this invention is: a method for processing an eccentric tailstock sleeve.

[0005] Step 1, material preparation: Leave a 15-20 mm allowance for the diameter of the bar stock and a 3-5 mm allowance for the length L. Drill a center hole at the right end.

[0006] Step 2, rough turning: The three-jaw chuck holds the left end of the bar stock, and the tailstock supports the center hole at the right end. Turn the outer circle φA, leaving a 10 mm allowance. The three-jaw chuck holds the right end, and the center support lifts the outer circle φA at the left end. Turn the stepped frustum φD at the left end, leaving a 10 mm allowance. The three-jaw chuck holds the left end of the bar stock, and the center support lifts the right end of the outer circle φA. Turn the stepped hole φB at the right end, which is concentric with the outer circle φA, and leave a 2 mm allowance for the stepped hole φB; thus obtaining the sleeve blank.

[0007] The third step is to perform high-temperature aging treatment on the sleeve blank to remove the stress generated during processing;

[0008] Step 4, CNC milling: Fix the high-temperature aging treated sleeve blank with a V-shaped bracket, align it with the outer circle φA as the reference, offset by h with the center of the stepped hole φB as the reference, and mill the right end as the eccentric outer circle φA1 as the process chuck, leaving a 2mm allowance; bore the right end stepped hole φB to remove oxide scale, rotate the worktable 180°, and drill a center hole concentric with the eccentric outer circle φA1 on the left end face;

[0009] Step 5, rough turning: The process chuck is held by a three-jaw chuck, the tailstock holds the center hole, and the remaining part of the eccentric outer circle φA1 and the stepped frustum φD are turned with a allowance of 2mm.

[0010] Sixth step, rough boring: fixed by V-shaped support, eccentric outer circle φA1 as a reference to find the right, left end of the formation with eccentric outer circle φA1 concentric inner hole φC, 2mm allowance; drill left end face screw hole bottom hole and tapping, rotating worktable 180°, left end face length L allowance 0.5mm, drill right end face screw hole bottom hole and tapping; get sleeve semi-finished product;

[0011] Seventh step, sleeve semi-finished product heat treatment: improve the hardness and wear resistance;

[0012] Eighth step, rough grinding: in the sleeve semi-finished product after heat treatment left and right two end hole respectively install fixed adapter plug, and two end plug center hole with eccentric outer circle φA1 concentric; grinding machine two center respectively top two end plug center hole, eccentric outer circle φA1 and step round table φD, allowance 0.7mm-0.8mm;

[0013] Ninth step, rough boring: remove two end plug, through V-shaped support will sleeve semi-finished product fixed and eccentric outer circle φA1 as a reference to find the right, left end hole φC allowance 0.7-0.8 mm, rotating worktable rotating 180°, right end step hole φB and right end face, step hole φB allowance 0.7-0.8 mm, length L allowance 0.25 mm;

[0014] Tenth step, semi-fine grinding: install fixed two end plug again, grinding machine two center respectively top two end plug center hole, eccentric outer circle φA1 and step round table φD outer circle, end face, allowance 0.15mm-0.2mm;

[0015] Eleventh step, the sleeve semi-finished product after semi-fine grinding together with two end plug for low temperature aging treatment, remove the stress generated by processing;

[0016] Twelfth step, fine grinding: grinding machine two center respectively top two plug center hole, eccentric outer circle φA1 to design size range, grinding step round table φD outer circle and end face to design requirements;

[0017] Thirteenth step, fine boring: remove two end plug, through V-shaped support will sleeve semi-finished product fixed in horizontal machining center worktable, eccentric outer circle φA1 as a reference to find the right, and sleeve semi-finished product right end set support plate, ensure that the sleeve semi-finished product fixed after not deformation; eccentric outer circle φA1 as a reference to find the right end face and step hole φB to design size, rotating worktable 180°, eccentric outer circle φA1 as a reference to find the right end face ensure total length L design size, boring left end hole φC to design size; get eccentric tailstock sleeve finished product.

[0018] The left end plug is concentric plug, the right end plug is eccentric plug, the positioning boss of the right end of the concentric plug is coincident with the center of the left end center hole; the positioning boss of the inner end of the eccentric plug is concentric with the step hole φB.

[0019] The upper part of the support plate has a stepped through hole with a left large and right small step, and the eccentric outer circle φA1 of the right end of the sleeve semi-finished product is fixed in the left end of the stepped through hole, the lower end surface of the support plate is seated on the base of the V-shaped support, and the stepped through hole is concentric with the eccentric outer circle φA1.

[0020] The positioning boss at the inner end of the concentric plug and the positioning boss at the inner hole φC and the positioning boss at the inner end of the eccentric plug and the stepped hole φB are all gap fitted, and the gap is 0.01-0.03mm.

[0021] The stepped through hole left end and the eccentric outer circle φA1 of the sleeve semi-finished product right end are gap fitted, and the gap is 0.03-0.05mm.

[0022] Compared with the prior art, the present application has the beneficial effects of:

[0023] The present application solves the problem of machining the eccentric structure tail seat sleeve through a reasonable machining process. The eccentric outer circle grinding machining of the stepped hole and the outer circle is solved by installing plugs at both ends of the tail seat sleeve during grinding machining. The deformation of the sleeve stepped hole during boring machining is effectively solved by fixing the sleeve through the support plate during fine boring of the stepped hole, thereby ensuring the roundness and cylindricity of the stepped hole. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a tail seat sleeve structure schematic diagram of the present application;

[0025] Figures 2-6 is a process flow diagram of the present application. DETAILED DESCRIPTION

[0026] The present application will be described in detail below in combination with the accompanying drawings and specific embodiments. Figures 1-6

[0027] A machining method of an eccentric tail seat sleeve, the steps are as follows,

[0028] The tail seat sleeve is taken as an example of 20Cr2Ni4 bar stock, and the finished product outer circle diameter φA is 260mm, the length L is 800mm, the stepped hole and the outer circle φA eccentricity h is 4mm, and the tail seat sleeve is described, (see Figure 1 )

[0029] First step, blanking: φA diameter is 280mm, length L is 800mm, and the remaining amount is 3-5mm, the right end is punched with a center hole,

[0030] ​Second step, rough turning: three jaw clamping bar left end, tailstock top holding right end center hole, turning outer circle φA diameter leaving 10mm margin, three jaw clamping right end, center frame lifting left end outer circle φA, turning left end face light, turning left end step circle table φD leaving 10mm margin, three jaw clamping bar left end, center frame lifting bar right end, turning right end face light, turning right end step hole φB concentric with outer circle φA, and step hole φB leaving 2mm margin; obtaining sleeve blank;

[0031] Third step, aging treatment for sleeve blank; heating to 450-550℃, removing stress generated by rough machining.

[0032] Fourth step, numerical control milling: fixing the sleeve blank after aging treatment by V-shaped support, aligning with outer circle φA as reference, taking step hole φB hole center as reference, milling right end outer circle process chuck φA1x20mm leaving 2mm margin, milling right end face light, boring right end step hole φB light to remove oxidation skin, to ensure subsequent heat treatment performance; rotating worktable 180°, milling left end face light, drilling concentric center hole with process chuck φA1x20; (see Figure 2 )

[0033] Fifth step, rough turning; three jaw chuck clamping the process chuck, tailstock top holding the center hole, turning the remaining part of outer circle φA1 and step circle table φD leaving 2mm margin;

[0034] Sixth step, rough boring: fixing by V-shaped support, aligning with eccentric outer circle φA1 as reference, boring left end face light, boring inner hole φC concentric with eccentric outer circle φA1 at left end leaving 2mm margin; drilling left end face thread hole bottom hole and tapping, rotating worktable 180°, boring right end face length L leaving 0.5mm margin, drilling right end face thread hole bottom hole and tapping; obtaining sleeve semi-finished product; (see Figure 3 )

[0035] Seventh step, heat treatment for sleeve semi-finished product; carburizing: depth 2.5-2.6mm; quenching: hardness HRC58, improving hardness and wear resistance;

[0036] Eighth step, rough grinding: installing adaptive plug 1 in left and right end inner holes of sleeve semi-finished product after heat treatment respectively, and the center hole of plug 1 at both ends is concentric with eccentric outer circle φA1; plug 1 and corresponding end are fixedly connected through screw, grinding eccentric outer circle φA1 and step circle table φD leaving 0.7mm-0.8mm margin; (see Figure 4 )

[0037] Step 9, rough boring: remove the two end plugs 1, fix the sleeve semi-finished product through the V-shaped support and align with the eccentric outer circle φA1 as the reference, bore the inner hole φC with a remaining amount of 0.7-0.8 mm, rotate the workbench by 180° to bore the right end eccentric step hole and the right end face, the step hole has a remaining amount of 0.7-0.8 mm, and the length L has a remaining amount of 0.25 mm; (see Figure 5 )

[0038] Step 10, semi-fine grinding: install the appropriate plugs 1 in the left and right end inner holes of the sleeve again, and the center hole of the two end plugs 1 is concentric with the eccentric outer circle φA1, the grinding machine two tips respectively hold the center hole of the two end plugs 1, grind the eccentric outer circle φA1 and the left end step circular table φD outer circle, end face, with a remaining amount of 0.15-0.2 mm; (see Figure 4 )

[0039] Step 11, after the semi-fine grinding of the sleeve semi-finished product, the two end plugs are subjected to low temperature aging treatment, that is, heated to 120-150℃, and naturally cooled to room temperature; stress relief;

[0040] Step 12, fine grinding: the grinding machine two tips respectively hold the center hole of the two plugs 1, grind the eccentric outer circle φA1 to the design size range, and grind the step circular table φD outer circle and end face to the design requirement; (see Figure 4 )

[0041] Step 13, fine boring: remove the two end plugs 1, fix the sleeve semi-finished product on the workbench of the horizontal machining center (DMG125H) through the V-shaped support, align with the eccentric outer circle φA1 as the reference, fix the left and right ends on the workbench through the pressing plate 2, bore the right end face to the finished product length, then remove the right end pressing plate 2, sleeve support plate 3, and the lower end surface of the support plate 3 is seated on the upper end surface of the V-shaped support base, the support plate 3 is fixed with the workbench through the pressing plate 2, ensure that the sleeve semi-finished product is not deformed after being fixed, bore the right end eccentric step hole φB to the design size with the eccentric outer circle φA1 as the reference, rotate the workbench by 180°, bore the left end face to ensure the total length L with the eccentric outer circle φA1 as the reference, and bore the left end inner hole φC to the design size; get the eccentric tailstock sleeve finished product. (. Figure 6 )

[0042] In one embodiment, in the eighth step, the plug at the left end is a concentric plug, the plug at the right end is an eccentric plug, the positioning boss at the right end of the concentric plug is coaxial with the center hole at the left end, the positioning boss at the inner end of the eccentric plug is coaxial with the stepped hole φB, and the eccentricity of the positioning boss is 4 mm. In order to reduce the processing difficulty, the eccentric plug is composed of a positioning plug and an end cover, the end cover has a concentric center hole at the outer end and an eccentric recess at the inner end, the positioning plug is inserted into the eccentric recess and fixed together by screws. The positioning boss at the inner end of the concentric plug is in clearance fit with the inner hole φC, and the positioning boss at the inner end of the eccentric plug is in clearance fit with the stepped hole φB, and the clearance is 0.01-0.03 mm.

[0043] In one embodiment, in the thirteenth step, the upper part of the support plate 3 has a stepped through hole with a larger left end and a smaller right end, the sleeve semi-finished product is fixed at the right end of the stepped through hole, the lower end surface of the support plate is seated on the base of the V-shaped support, and the stepped through hole is coaxial with the eccentric outer circle φA1.

[0044] In use, the screw is screwed into the threaded hole at the right end of the support plate 3 and the sleeve to fix the support plate 3 and the sleeve together, after measuring the center height of the outer circle φA1 of the sleeve, the lower end surface of the support plate 3 is processed according to the measured value, and then the lower end surface of the support plate 3 is seated on the base of the V-shaped support. The left end of the stepped through hole is in clearance fit with the eccentric outer circle φA1 at the right end of the sleeve semi-finished product, and the clearance is 0.03-0.05 mm. The pressing plate does not directly press the eccentric outer circle φA1 of the sleeve semi-finished product, which reduces the deformation of the stepped inner hole of the sleeve semi-finished product during fine boring processing, thereby ensuring the roundness and cylindricity of the finished sleeve.

[0045] The above embodiments are only preferred embodiments of the present application and are not intended to limit the scope of the application. Any equivalent changes made according to the content of the claims of the present application shall be included within the scope of the claims of the present application.

Claims

1. A machining method of eccentric tailstock sleeve, characterized in that: first step, blanking: the diameter of the bar stock is left with a margin of 15-20 mm, the length L is left with a margin of 3-5 mm, and a center hole is punched at the right end; second step, rough turning: the left end of the bar stock is clamped by three-jaw chuck, the right end center hole is held by tailstock, the outer circle φA is turned with a margin of 10 mm, the right end is clamped by three-jaw chuck, the outer circle φA is held by center rest, the left end stepped round table φD is turned with a margin of 10 mm, the left end of the bar stock is clamped by three-jaw chuck, the outer circle φA right end is held by center rest, the right end stepped hole φB is turned concentric with the outer circle φA with a margin of 2 mm, and a sleeve blank is obtained; third step, high-temperature aging treatment is performed on the sleeve blank to remove the stress generated during machining; fourth step, numerical control milling: the sleeve blank after high-temperature aging treatment is fixed by V-shaped support, the outer circle φA is used as the reference for alignment, the stepped hole φB hole center is used as the reference for offset h, the right end is milled as eccentric outer circle φA1 as the process chuck with a margin of 2 mm; the right end stepped hole φB is polished to remove the oxide skin, the rotary table is rotated by 180°, and the center hole concentric with the eccentric outer circle φA1 is drilled on the left end face; fifth step, rough turning: the process chuck is clamped by three-jaw chuck, the center hole is held by tailstock, the remaining part of the eccentric outer circle φA1 and the stepped round table φD are turned with a margin of 2 mm; sixth step, rough boring: the sleeve semi-finished product is fixed by V-shaped support, the eccentric outer circle φA1 is used as the reference for alignment, the left end is bored to form an inner hole φC concentric with the eccentric outer circle φA1 with a margin of 2 mm; the left end face threaded hole bottom hole is drilled and tapped, the rotary table is rotated by 180°, the right end face length L is bored with a margin of 0.5 mm, and the right end face threaded hole bottom hole is drilled and tapped; a sleeve semi-finished product is obtained; seventh step, heat treatment of the sleeve semi-finished product: improve the hardness and wear resistance; eighth step, rough grinding: the sleeve semi-finished product after heat treatment is fixed by installing and fixing the adapted plugs in the left and right end inner holes respectively, and the center holes of the plugs at both ends are concentric with the eccentric outer circle φA1; the two tips of the grinder respectively hold the center holes of the plugs at both ends, the eccentric outer circle φA1 and the stepped round table φD are ground with a margin of 0.7-0.8 mm; ninth step, rough boring: the plugs at both ends are removed, the sleeve semi-finished product is fixed by V-shaped support and aligned with the eccentric outer circle φA1, the left end inner hole φC is bored with a margin of 0.7-0.8 mm, the rotary table is rotated by 180°, the right end stepped hole φB and the right end face are bored, the stepped hole φB has a margin of 0.7-0.8 mm, and the length L has a margin of 0.25 mm; tenth step, semi-fine grinding: the plugs at both ends are installed and fixed again, the two tips of the grinder respectively hold the center holes of the plugs at both ends, the eccentric outer circle φA1 and the stepped round table φD outer circle and end face are ground with a margin of 0.15-0.2 mm; tenth step, semi-fine grinding: the sleeve semi-finished product after semi-fine grinding is subjected to low-temperature aging treatment together with the plugs at both ends to remove the stress generated during machining; twelfth step, fine grinding: the two tips of the grinder respectively hold the center holes of the two plugs, the eccentric outer circle φA1 is ground to the designed size range, and the stepped round table φD outer circle and end face are ground to the design requirement. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Thirteenth step, fine boring: remove the two end plugs, through the V-shaped support to fix the sleeve semi-finished product on the horizontal machining center workbench, to eccentric circle φA1 as the reference to find the right, and the sleeve semi-finished product right end sleeve support plate, ensure that the sleeve semi-finished product fixed after not deformed; eccentric circle φA1 as the reference to bore right end face and step hole φB to the design size, rotating workbench 180°, eccentric circle φA1 as the reference to bore left end face to ensure the total length L design size, bore left end hole φC to the design size; get eccentric tailstock sleeve finished product.

2. A method of machining an eccentric tailstock sleeve as defined in claim 1, characterized in that: The left end plug is a concentric plug, and the right end plug is an eccentric plug. The positioning boss at the right end of the concentric plug is coaxial with the center hole at the left end. The positioning boss at the inner end of the eccentric plug is concentric with the step hole φB.

3. The method of claim 1, wherein: The upper part of the support plate has a stepped through hole with a left large right small structure. The sleeve semi-finished product right end eccentric circle φA1 is sleeved and fixed at the left end of the stepped through hole. The lower end surface of the support plate is seated on the base of the V-shaped support, and the stepped through hole is concentric with the eccentric circle φA1.

4. The method of claim 2, wherein: The positioning boss at the inner end of the concentric plug is coaxial with the inner hole φC, and the positioning boss at the inner end of the eccentric plug is coaxial with the step hole φB. Both have a clearance fit, and the clearance is 0.01-0.03mm.

5. The method of claim 3, wherein: The left end of the stepped through hole and the right end eccentric circle φA1 of the sleeve semi-finished product have a clearance fit, and the clearance is 0.03-0.05mm.

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