Machining method of eccentric tailstock sleeve

Abstract

A machining method of an eccentric tailstock sleeve comprises the steps that firstly, blanking is conducted, allowance is reserved, and secondly, a sleeve blank is obtained through rough turning; (3) carrying out high-temperature aging treatment on the sleeve blank; (4) milling the right end as an eccentric outer circle phi A1 as a process chuck and polishing a stepped hole phi B at the right end; fifthly, rough turning is conducted on the eccentric outer circle phi A1 and the stepped circular truncated cone phi D, and the allowance is reserved; sixthly, roughly boring the left end stepped circular truncated cone phi D, and reserving allowance to obtain a semi-finished sleeve product; seventhly, the semi-finished sleeve is subjected to heat treatment; eighthly, the eccentric outer circle phi A1 is subjected to rough grinding, and the allowance is reserved; ninth, the left end inner hole phi C, the stepped hole phi B and the length L are subjected to rough boring, and the allowance is reserved; tenthly, the eccentric outer circle phi A1 and the outer circle and the end face of the stepped circular truncated cone phi D are subjected to semi-accurate grinding; eleventhly, carrying out low-temperature aging treatment; twelfthly, accurately grinding an eccentric outer circle phi A1 to a design size range, and grinding an outer circle phi D and an end face of a stepped circular truncated cone to meet design requirements; and thirteenthly, the stepped hole phi B and the inner hole phi C are finely bored to the designed size, and a finished eccentric tailstock sleeve is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing, and in particular relates to a processing method of an eccentric tailstock sleeve. Background Art

[0002] The inner and outer circles of the tailstock sleeve of existing CNC machine tools are concentric. The production and manufacturing process, the tailstock component adjustment and the coaxial technology of the spindle end are mature. However, with the development of five-axis machine tools, the principle of tailstock component adjustment has changed, and the tailstock sleeve is designed with an eccentric structure of the inner and outer circles. The outer circle roundness of the sleeve is required to be less than or equal to 0.003mm, the cylindricality is less than or equal to 0.004mm, the inner hole roundness is less than or equal to 0.005mm, and the cylindricality is less than or equal to 0.01mm. The existing processing technology can no longer meet the processing requirements of the eccentric tailstock sleeve. Summary of the invention

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

[0004] The technical solution adopted by the present invention is: a method for processing an eccentric tailstock sleeve,

[0005] The first step is cutting: leave a 15-20mm allowance for the rod diameter and a 3-5mm allowance for the length L, and punch a center hole on the right end;

[0006] The second step is rough turning: three-claw clamps the left end of the bar, the tailstock holds the center hole of the right end, and the outer circle φA is turned with a margin of 10mm. The three-claw clamps the right end, the center frame holds the outer circle φA of the left end, and the stepped table φD of the left end is turned with a margin of 10mm. The three-claw clamps the left end of the bar, the center frame holds the right end of the outer circle φA, and the step hole φB of the right end is turned to be concentric with the outer circle φA, and the step hole φB is left with a margin of 2mm; the sleeve blank is obtained;

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

[0008] The fourth step is CNC milling: fix the sleeve blank after high temperature aging treatment through a V-shaped bracket, align it with the outer circle φA as the reference, and offset it with the center of the step hole φB as the reference h. Mill the right end to the eccentric outer circle φA1 as the process chuck with a 2mm margin; bore the right end step hole φB to remove the oxide scale in the light, rotate the worktable 180°, and drill the center hole concentric with the eccentric outer circle φA1 on the left end face;

[0009] Step 5, rough turning: the three-jaw chuck holds the process 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 margin of 2mm;

[0010] Step 6, rough boring: fix it with a V-shaped bracket, align it with the eccentric outer circle φA1 as the reference, bore the left end to form an inner hole φC concentric with the eccentric outer circle φA1, and leave a 2mm margin; drill the bottom hole of the threaded hole on the left end face and tap it, rotate the worktable 180°, bore the right end face length L with a 0.5mm margin, drill the bottom hole of the threaded hole on the right end face and tap it; get the semi-finished sleeve;

[0011] Step 7: Heat treatment of semi-finished sleeve: improve hardness and wear resistance;

[0012] Step 8, rough grinding: Install fixed and adapted plugs in the inner holes at the left and right ends of the heat-treated sleeve semi-finished product, and the center holes of the plugs at both ends are concentric with the eccentric outer circle φA1; the two tops of the grinder respectively hold the center holes of the plugs at both ends, grind the eccentric outer circle φA1 and the stepped frustum φD, and leave a margin of 0.7mm-0.8mm;

[0013] Step 9, rough boring: remove the plugs at both ends, fix the semi-finished sleeve by a V-shaped bracket and align it with the eccentric outer circle φA1 as the reference, bore the inner hole φC at the left end with a margin of 0.7-0.8mm, rotate the rotary table 180°, bore the step hole φB at the right end and the right end face, leave a margin of 0.7-0.8mm for the step hole φB, and leave a margin of 0.25mm for the length L;

[0014] Step 10, semi-fine grinding: install and fix the plugs at both ends again, the two centers of the grinder respectively hold the center holes of the plugs at both ends, grind the eccentric outer circle φA1 and the outer circle and end surface of the stepped frustum φD, leaving a margin of 0.15mm-0.2mm;

[0015] In the eleventh step, the semi-finished sleeve and the plugs at both ends are subjected to low-temperature aging treatment to remove the stress caused by processing;

[0016] Step 12: Fine grinding: The two centers of the grinding machine hold the center holes of the two plugs respectively, grind the eccentric outer circle φA1 to the designed size range, and grind the outer circle and end face of the stepped frustum φD to the designed requirements;

[0017] The thirteenth step, precision boring: remove the plugs at both ends, fix the semi-finished sleeve on the workbench of the horizontal machining center through a V-shaped bracket, align it with the eccentric outer circle φA1 as the reference, and install a support plate on the right end of the semi-finished sleeve to ensure that the semi-finished sleeve does not deform after being fixed; bore the right end face and the step hole φB to the designed size with the eccentric outer circle φA1 as the reference, rotate the workbench 180, bore the left end face with the eccentric outer circle φA1 as the reference to ensure the designed size of the total length L, and bore the left end inner hole φC to the designed size; obtain the finished eccentric tailstock sleeve.

[0018] The plug at the left end is a concentric plug, and the plug at the right end is an eccentric plug. The positioning boss at the right end of the concentric plug coincides with the center of 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.

[0019] The upper part of the support plate has a stepped through hole which is larger on the left and smaller on the right. The eccentric outer circle φA1 of the right end of the sleeve semi-finished product is fixed on 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 bracket, 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 inner hole φC, and the positioning boss at the inner end of the eccentric plug and the step hole φB are both clearance-matched, and the clearance is 0.01-0.03mm.

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

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention solves the problem of processing an eccentric tailstock sleeve through a reasonable processing technology. During the grinding process, plugs are respectively installed at both ends of the tailstock sleeve to solve the problem of grinding an outer circle in which the step hole is not concentric with the outer circle. During the precision boring of the step hole, the sleeve is fixed by a support plate to effectively solve the deformation of the sleeve step hole during the boring process, thereby ensuring the roundness and cylindricity of the step hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the tailstock sleeve structure of the present invention;

[0025] Figure 2-6 It is a process diagram of the present invention. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1-6 The present invention is described in detail with specific embodiments.

[0027] A processing method for an eccentric tailstock sleeve, the steps are as follows:

[0028] The tailstock sleeve is taken as an example of 20Cr2Ni4 bar material, and the finished product outer diameter φA is 260mm, the length L is 800mm, and the eccentricity h between the step hole and the outer circle φA is 4mm. (See Figure 1 )

[0029] The first step is cutting: the diameter of φA is 280mm, the length L is 800mm, leave a margin of 3-5mm, and punch a center hole on the right end.

[0030] The second step is rough turning: three-claw clamps the left end of the bar, the tailstock holds the center hole of the right end, and the outer circle φA is turned with a diameter allowance of 10mm. The three-claw clamps the right end, the center frame holds the outer circle φA of the left end, and the left end face is turned to light. The left end stepped round table φD is turned to leave a allowance of 10mm. The three-claw clamps the left end of the bar, the center frame holds the right end of the bar, and the right end face is turned to light. The step hole φB at the right end is concentric with the outer circle φA, and the step hole φB leaves a allowance of 2mm; the sleeve blank is obtained;

[0031] The third step is to perform aging treatment on the sleeve blank; heating it to 450-550℃ to remove the stress generated by rough machining.

[0032] The fourth step is CNC milling: fix the aged sleeve blank through a V-shaped bracket, align it with the outer circle φA as the reference, take the center of the step hole φB as the reference, offset the center of the inner hole h by 4mm, mill the outer circle of the right end process chuck φA1×20mm, leave a margin of 2mm, mill the right end face to the light, and bore the right end step hole φB to the light to remove the oxide scale to ensure the subsequent heat treatment performance; rotate the worktable 180°, mill the left end face to the light, and drill the center hole concentric with the process chuck φA1×20; (see Figure 2 )

[0033] The fifth step is rough turning: the three-jaw chuck clamps the process chuck, the tailstock holds the center hole, and the remaining part of the outer circle φA1 and the stepped frustum φD are turned with a margin of 2mm;

[0034] Step 6, rough boring: fix it with a V-shaped bracket, align it with the eccentric outer circle φA1 as the reference, bore the left end face to see the light, bore the inner hole φC concentric with the eccentric outer circle φA1 at the left end, and leave a 2mm allowance; drill the bottom hole of the threaded hole on the left end face and tap it, rotate the worktable 180°, bore the right end face length L with a 0.5mm allowance, drill the bottom hole of the threaded hole on the right end face and tap it; get the semi-finished sleeve; (see Figure 3 )

[0035] Step 7: Heat treatment of semi-finished sleeve; carburizing: depth 2.5-2.6mm; quenching: hardness HRC58, improve hardness and wear resistance;

[0036] Step 8, rough grinding: Install the matching plugs 1 in the inner holes at the left and right ends of the heat-treated sleeve semi-finished product, and the center holes of the plugs 1 at both ends are concentric with the deflected outer circle φA1; the plugs 1 are fixedly connected to the corresponding ends by screws, and the two tops of the grinder respectively hold the center holes of the plugs 1 at both ends, grind the deflected outer circle φA1 and the stepped frustum φD, and leave a margin of 0.7mm-0.8mm; (see Figure 4 )

[0037] Step 9, rough boring: remove the plugs 1 at both ends, fix the semi-finished sleeve by a V-shaped bracket and align it with the eccentric outer circle φA1 as the reference, bore the inner hole φC with a margin of 0.7-0.8mm, rotate the rotary table 180° to bore the eccentric step hole and the right end face at the right end, leaving a margin of 0.7-0.8mm for the step hole and a margin of 0.25mm for the length L; (see Figure 5 )

[0038] Step 10, semi-finishing grinding: install the matching plugs 1 in the inner holes at the left and right ends of the sleeve again, and the center holes of the plugs 1 at both ends are concentric with the eccentric outer circle φA1. The two centers of the grinder respectively hold the center holes of the plugs 1 at both ends, grind the eccentric outer circle φA1 and the outer circle and end surface of the left end stepped frustum φD, and leave a margin of 0.15mm-0.2mm; (see Figure 4 )

[0039] Step 11: The semi-finished sleeve and the plugs at both ends are subjected to low-temperature aging treatment, that is, heated to 120-150°C and naturally cooled to room temperature to remove stress;

[0040] Step 12: Fine grinding: The two centers of the grinding machine hold the center holes of the two plugs 1 respectively, grind the eccentric outer circle φA1 to the designed size range, and grind the outer circle and end face of the stepped frustum φD to the designed requirements; (see Figure 4 )

[0041] The thirteenth step is fine boring: remove the plugs 1 at both ends, fix the semi-finished sleeve on the workbench of the horizontal machining center (DMG125H) through a V-shaped bracket, align it with the eccentric outer circle φA1 as the reference, fix the left and right ends on the workbench through the pressure plate 2, bore the right end face to the finished length, and then remove the right end pressure plate 2, install the support plate 3, and the lower end face of the support plate 3 is seated on the upper end face of the V-shaped bracket base, and the support plate 3 is fixed to the workbench through the pressure plate 2 to ensure that the semi-finished sleeve is not deformed after being fixed, and bore the right end deflected step hole φB to the designed size with the eccentric outer circle φA1 as the reference, rotate the workbench 180, bore the left end face with the eccentric outer circle φA1 as the reference to ensure the total length L, and bore the left end inner hole φC to the designed size; the finished product of the deflected tailstock sleeve is obtained.

[0042] ( Figure 6 )

[0043] In one embodiment, in the eighth step, the plug at the left end is a concentric plug, and the plug at the right end is an eccentric plug. The positioning boss at the right end of the concentric plug coincides with the center of 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; and the eccentricity of the positioning boss is 4mm. In order to reduce the difficulty of processing, the eccentric plug is composed of a positioning plug and an end cover. The outer end of the end cover has a concentric center hole and the inner end has an eccentric concave platform. The positioning plug is inserted into the eccentric concave platform and fixed together by screws. The positioning boss at the inner end of the concentric plug and the inner hole φC, and the positioning boss at the inner end of the eccentric plug and the step hole φB are all clearance-matched, and the clearance is 0.01-0.03mm.

[0044] In one embodiment, in the thirteenth step, the upper portion of the support plate 3 has a stepped through hole that is larger on the left and smaller on the right, the eccentric outer circle φA1 at the right end of the sleeve semi-finished product is fixed on the left end of the stepped through hole, the lower end face of the support plate is seated on the base of the V-shaped bracket, and the stepped through hole is concentric with the eccentric outer circle φA1.

[0045] When in use, the screw is threaded through the threaded hole of the support plate 3 and the right end of the sleeve to fix the support plate 3 and the sleeve together. After measuring the center height of the sleeve outer circle φA1, the lower end face of the support plate 3 is processed according to the measured value, and then the lower end face of the support plate 3 is seated on the base of the V-shaped bracket. The left end of the step through hole and the eccentric outer circle φA1 of the right end of the sleeve semi-finished product are clearance-matched, and the clearance is 0.03-0.05mm. The pressing plate does not directly press the eccentric outer circle φA1 of the sleeve semi-finished product, which reduces the deformation of the inner hole of the step of the sleeve semi-finished product during the fine boring process, thereby ensuring the roundness and cylindricity of the finished sleeve.

[0046] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, all equivalent changes made to the contents described in the claims of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for processing an eccentric tailstock sleeve, characterized in that: The first step is cutting: leave a 15-20mm allowance for the rod diameter and a 3-5mm allowance for the length L, and punch a center hole on the right end; The second step is rough turning: three-claw clamps the left end of the bar, the tailstock holds the center hole of the right end, and the outer circle φA is turned with a margin of 10mm. The three-claw clamps the right end, the center frame holds the outer circle φA of the left end, and the stepped table φD of the left end is turned with a margin of 10mm. The three-claw clamps the left end of the bar, the center frame holds the right end of the outer circle φA, and the step hole φB of the right end is turned to be concentric with the outer circle φA, and the step hole φB is left with a margin of 2mm; the sleeve blank is obtained; The third step is to perform high temperature aging treatment on the sleeve blank to remove the stress generated by processing; The fourth step is CNC milling: fix the sleeve blank after high temperature aging treatment through a V-shaped bracket, align it with the outer circle φA as the reference, and offset it with the center of the step hole φB as the reference h. Mill the right end to the eccentric outer circle φA1 as the process chuck with a 2mm margin; bore the right end step hole φB to remove the oxide scale in the light, rotate the worktable 180°, and drill the center hole concentric with the eccentric outer circle φA1 on the left end face; Step 5, rough turning: the three-jaw chuck holds the process 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 margin of 2mm; Step 6, rough boring: fix it with a V-shaped bracket, align it with the eccentric outer circle φA1 as the reference, bore the left end to form an inner hole φC concentric with the eccentric outer circle φA1, and leave a 2mm margin; drill the bottom hole of the threaded hole on the left end face and tap it, rotate the worktable 180°, bore the right end face length L with a 0.5mm margin, drill the bottom hole of the threaded hole on the right end face and tap it; get the semi-finished sleeve; Step 7: Heat treatment of semi-finished sleeve: improve hardness and wear resistance; Step 8, rough grinding: Install fixed and adapted plugs in the inner holes at the left and right ends of the heat-treated sleeve semi-finished product, and the center holes of the plugs at both ends are concentric with the eccentric outer circle φA1; the two tops of the grinder respectively hold the center holes of the plugs at both ends, grind the eccentric outer circle φA1 and the stepped frustum φD, and leave a margin of 0.7mm-0.8mm; Step 9, rough boring: remove the plugs at both ends, fix the semi-finished sleeve by a V-shaped bracket and align it with the eccentric outer circle φA1 as the reference, bore the inner hole φC at the left end with a margin of 0.7-0.8mm, rotate the rotary table 180°, bore the step hole φB at the right end and the right end face, leave a margin of 0.7-0.8mm for the step hole φB, and leave a margin of 0.25mm for the length L; Step 10, semi-fine grinding: install and fix the plugs at both ends again, the two centers of the grinder respectively hold the center holes of the plugs at both ends, grind the eccentric outer circle φA1 and the outer circle and end surface of the stepped frustum φD, leaving a margin of 0.15mm-0.2mm; In the eleventh step, the semi-finished sleeve and the plugs at both ends are subjected to low-temperature aging treatment to remove the stress caused by processing; Step 12: Fine grinding: The two centers of the grinding machine hold the center holes of the two plugs respectively, grind the eccentric outer circle φA1 to the designed size range, and grind the outer circle and end face of the stepped frustum φD to the designed requirements; The thirteenth step, precision boring: remove the plugs at both ends, fix the semi-finished sleeve on the workbench of the horizontal machining center through a V-shaped bracket, align it with the eccentric outer circle φA1 as the reference, and install a support plate on the right end of the semi-finished sleeve to ensure that the semi-finished sleeve does not deform after being fixed; bore the right end face and the step hole φB to the designed size with the eccentric outer circle φA1 as the reference, rotate the workbench 180, bore the left end face with the eccentric outer circle φA1 as the reference to ensure the designed size of the total length L, and bore the left end inner hole φC to the designed size; obtain the finished eccentric tailstock sleeve.

2. The method for processing an eccentric tailstock sleeve according to claim 1, characterized in that: The plug at the left end is a concentric plug, and the plug at the right end is an eccentric plug. The positioning boss at the right end of the concentric plug coincides with the center of 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 for processing an eccentric tailstock sleeve according to claim 1, characterized in that: The upper part of the support plate has a stepped through hole which is larger on the left and smaller on the right. The eccentric outer circle φA1 of the right end of the sleeve semi-finished product is fixed on 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 bracket, and the stepped through hole is concentric with the eccentric outer circle φA1.

4. The method for processing an eccentric tailstock sleeve according to claim 2, characterized in that: The positioning boss at the inner end of the concentric plug and the inner hole φC, and the positioning boss at the inner end of the eccentric plug and the step hole φB are both clearance-matched, and the clearance is 0.01-0.03mm.

5. The method for processing an eccentric tailstock sleeve according to claim 3, characterized in that: The left end of the step through hole and the eccentric outer circle φA1 of the right end of the sleeve semi-finished product are clearance-matched, and the clearance is 0.03-0.05mm.

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