Planet carrier fine boring positioning and clamping device

Abstract

The invention discloses a positioning and clamping device for fine boring of a planet carrier. The positioning and clamping device is characterized by comprising a base, equal-height blocks, an inner hole tensioning device, a pressing device and a positioning bolt, the base is installed on a boring equipment working platform, and the inner hole tensioning device is installed on the base and used for tensioning an inner hole in the lower end of a workpiece through a steel ball. The equal-height blocks are evenly distributed on the upper plane of the base in a circumferential mode and used for supporting workpieces. The lower end of the positioning bolt is mounted on the left upper side of the base, and the upper end is inserted into a process positioning hole in a workpiece; the two pressing devices are symmetrically arranged on the left side and the right side of the base and used for pressing the workpiece. The multiple steel balls which are arranged in the same horizontal plane and evenly distributed in the circumferential direction are adopted to tension / loosen the inner hole in the lower end of the workpiece along with vertical movement of the abrasion-resistant taper sleeve, operation is easy and fast, the tensioning positioning precision is high, the steel balls make point contact with the inner hole of the workpiece, the contact area is greatly reduced, and the inner hole of the workpiece cannot be damaged.

Description

Technical Field

[0001] The invention relates to the technical field of drive axle processing, and in particular to a planet carrier fine boring positioning clamping device used in a planet carrier fine boring process of a drive axle. Background Art

[0002] The planetary carrier is one of the main components of the planetary gear transmission. The planetary shaft or bearing is installed on the planetary carrier. When the planetary gear is used as a basic component, it is the part that bears the largest external torque in the mechanism. The structural design and manufacturing of the planetary gear has a great influence on the load distribution between the planetary gears and even the load-bearing capacity, noise and vibration of the transmission.

[0003] In order to ensure the boring accuracy of multiple circumferentially evenly distributed planetary gear shaft mounting holes on the drive axle planetary frame, the use of CNC machining center for precision boring is undoubtedly the primary equipment to ensure the boring accuracy and position of the drive axle planetary frame. After the CNC machining center has precision bored one hole, the remaining holes can be controlled and completed by the program compiled by the CNC machining center control system. However, it is critical to accurately and quickly position the workpiece before the first hole is processed. At present, most of them use three-claw tensioning to tighten the inner hole at the lower end of the workpiece for positioning, but the contact area between the three-claw and the inner hole of the workpiece is large, which is easy to cause indentation on the inner hole and damage the workpiece. In addition, when using three-claw positioning, the first hole processing position needs to be marked first and then manually corrected. The steps are relatively cumbersome, and the positioning accuracy is difficult to guarantee. In addition, every time the workpiece is replaced, it needs to be re-calibrated, the repeatability accuracy is poor, and the production efficiency is low.

[0004] Chinese patent CN203343768U discloses a planetary frame fixture, including a workbench, an internal centering mechanism arranged in the center of the workbench, and an external clamping mechanism arranged at the edge of the workbench; the internal centering mechanism includes a screw arranged in the middle, a clamping block connected by a hinge mechanism and the screw, and the hinge mechanism and the clamping block are provided with three sets, and rotating the vertically arranged screw can drive the clamping block to move back and forth in the horizontal direction; the external clamping mechanism includes a nut, a bolt, and a clamping head, and the nut is arranged on the clamping head, and the bolt passes through the clamping head. When the nut is tightened, the workpiece can be fixed on the workbench through the clamping head. After adopting the above structure, the parts can be positioned quickly and accurately. However, the processing accuracy and position of the three sets of hinge mechanisms and clamping blocks in the patent technical solution are difficult to reach consistency. Although they can be positioned quickly, the positioning accuracy is not high. Similarly, the device is the same as the three-claw tensioning principle. The first hole processing position needs to be manually corrected. Every time the workpiece is replaced, it needs to be re-calibrated, the repetition accuracy is poor, and the production efficiency is low.

[0005] Therefore, there is an urgent need to develop a drive axle planetary carrier positioning clamping device that can quickly and accurately position the first hole processing position by simply calibrating the clamping device and has high repeatability accuracy. Summary of the invention

[0006] In order to solve the problems that during the above-mentioned existing three-jaw tensioning and positioning, the three jaws have a large contact area with the inner hole of the workpiece, which is easy to cause indentations on the surface of the inner hole and damage the inner hole of the workpiece, and the first hole processing position needs to be manually corrected, the steps are relatively cumbersome, and the positioning accuracy is difficult to ensure, the present invention provides a planetary rack precision boring positioning clamping device, which uses a plurality of circumferentially evenly distributed steel balls arranged in the same horizontal plane to tighten / loosen the inner hole at the lower end of the workpiece as the wear-resistant taper sleeve moves up and down. The operation is simple and fast, and the tensioning and positioning accuracy is high. The steel balls are in point contact with the inner hole of the workpiece, and the contact area is greatly reduced, and the inner hole of the workpiece will not be damaged. By arranging all planes on the front side of the base to be parallel to the side walls of the horizontal T-slots of the equipment working platform, the positioning clamping device of the patent can be quickly corrected, and by arranging positioning pins on the base, the position of the first hole to be processed of the workpiece can be quickly located without further correction, thereby saving a lot of correction time and greatly improving production efficiency.

[0007] To achieve the above-mentioned purpose, the present invention provides a planet carrier precision boring positioning clamping device, which is characterized by comprising a base, a height-equalizing block, an inner hole tensioning device, a clamping device and a positioning pin; The base is detachably and fixedly connected to the working platform of the boring equipment, a first through hole is provided in the middle of the base, and a first layer of holes is provided at the lower end of the first through hole; The inner hole tightening device is used to tighten the inner hole at the lower end of the workpiece through a steel ball, and includes a mandrel, a wear-resistant cone sleeve, a steel ball sleeve, a steel ball, a cover plate, a compression spring, and a locking screw; The core shaft comprises a first cylindrical portion, a second cylindrical portion, a third cylindrical portion, a fourth cylindrical portion and a mounting flange which are connected in sequence from top to bottom, are coaxial and have outer diameters increasing in sequence; the mounting flange is sleeved in the first layer of holes, the upper end surface is fitted with the inner bottom surface of the first layer of holes, and is detachably fixedly connected to the base through a plurality of bolts; the fourth cylindrical portion is sleeved in the first through hole; a spring mounting hole is provided in the middle of the upper end of the core shaft; a coaxial first threaded hole is provided at the bottom of the spring mounting hole; a coaxial second layer of holes with increasing apertures are provided at the lower end of the first threaded hole; The wear-resistant tapered sleeve is interference-fitted on the outer surface of the second cylindrical portion of the core shaft, and the taper of the outer conical surface of the wear-resistant tapered sleeve is set to 11±1°; The steel ball sleeve is sleeved on the outer side of the core shaft, with openings at both ends, and a first inner hole, a second inner hole, a third inner hole and a fourth inner hole are sequentially connected and coaxially arranged in the middle from top to bottom, the first inner hole has a larger aperture than the second inner hole, the third inner hole has a larger aperture than the second inner hole and the fourth inner hole, the second inner hole is sleeved on the outer side of the first cylindrical portion of the core shaft, the fourth inner hole is sleeved on the outer side of the third cylindrical portion of the core shaft, a plurality of radial through holes are uniformly distributed circumferentially relative to the axis of the core shaft on the outer side wall of the middle part of the third inner hole, each of the radial through holes is sleeved with a steel ball, and the inner side surface of the steel ball is supported on the outer side surface of the wear-resistant cone sleeve; The cover plate is detachably fixedly connected to the upper plane of the steel ball sleeve, a second through hole is provided in the middle, and a third layer of holes is provided at the lower end of the second through hole; The compression spring is installed in the spring installation hole and the third layer hole; When in working state, the locking screw passes through the second through hole, the third layer hole, the inner hole of the compression spring and the spring installation hole from top to bottom in sequence, and the lower end is threadedly connected with the first threaded hole, so that the steel ball sleeve and the mandrel are detachably fixedly connected. At this time, a plurality of steel balls move downward from top to bottom along the outer conical surface of the wear-resistant cone sleeve, and a plurality of steel balls are pushed outward at the same time, so that the steel balls tighten the inner hole of the lower disc of the workpiece; The contour blocks are provided with a plurality of pieces, which are evenly distributed in a circle and can be detachably fixedly connected to the upper plane of the base, and are arranged on the periphery of the mandrel. The upper planes of the plurality of contour blocks are in the same horizontal plane and are parallel to the upper plane of the base, so as to support the workpiece and realize the axial positioning of the workpiece; The lower end of the positioning pin is fixedly connected to the upper left side of the base by interference fit, and the upper end is inserted into the process positioning hole on the workpiece, and the fitting clearance between the outer cylindrical surface of the upper end and the process positioning hole is set to 0.1±0.05mm; when the positioning pin is inserted into the process positioning hole, one of the three holes to be processed of the workpiece must be located on the longitudinal center line of the upper end of the disc of the base, and the hole to be processed is set as the first processing hole. The CNC machining center starts programming from this first processing hole position, and automatically controls the fine boring processing of the next two holes to be processed through the program.

[0008] The clamping device is provided with two pieces, which are symmetrically arranged on the left and right sides of the base. The clamping device comprises a pressing plate, which is used to press the workpiece onto the equal-height block.

[0009] As a further improvement of the present technology, the base is set to be a disc with a piece cut off on the front side, and the cutting plane on the front side of the disc is set parallel to the rear side of the transverse T-slot on the working platform. The cutting plane runout is set to 0.02-0.03mm. When the positioning pin is inserted into the process positioning hole, the first processing hole of the workpiece can be positioned.

[0010] The setting of the cutting plane is used for the installation position correction of the device. It cooperates with the positioning pin to quickly position the workpiece. When working, the workpiece can be directly fine-bored when it is installed on the device, and there is no need to correct the position of the first processing hole, which greatly saves the first hole correction time and labor costs and improves production efficiency.

[0011] As a further improvement of the present technology, the coaxiality of the first cylindrical portion, the second cylindrical portion, the third cylindrical portion, and the fourth cylindrical portion of the mandrel is set to 0.012-0.015 mm, and the radial runout of the step surface between the fourth cylindrical portion and the mounting flange relative to the axis of the mandrel is set to 0.025-0.03 mm; The coaxiality of the second inner hole and the fourth inner hole of the steel ball sleeve is set to 0.02±0.005mm; The radial runout of the upper end surface, the lower end surface and the inner bottom surface of the first layer hole of the base relative to the axis of the first through hole is set to 0.015±0.005mm.

[0012] The above-mentioned coaxiality and radial runout settings can ensure the coaxiality and position accuracy of the mandrel, the steel ball sleeve and the base during assembly, thereby ensuring the precision boring accuracy of the workpiece.

[0013] As a further improvement of the present technology, a clearance fit is set between the second inner hole and the first cylindrical portion, and the fitting clearance is set to 0.03-0.04 mm; a clearance fit is set between the fourth inner hole and the third cylindrical portion, and the fitting clearance is set to 0.03-0.04 mm; and a fitting clearance between the fourth cylindrical portion and the first through hole is set to 0-0.01 mm.

[0014] This device ensures the above-mentioned matching clearance by grinding the second inner hole and the first cylindrical part, the fourth inner hole and the third cylindrical part, and the fourth cylindrical part and the first through hole, thereby ensuring the assembly accuracy of the core shaft and the steel ball sleeve, and the core shaft and the base, and also ensuring the coaxiality of the steel ball sleeve when it moves up and down on the outer cylindrical surface of the core shaft, achieving the precision requirement of tightening the inner hole of the workpiece with multiple steel balls at the same time.

[0015] As a further improvement of the present technology, the interference between the second cylindrical portion and the inner hole of the wear-resistant cone sleeve is set to 0.03-0.05 mm; The wear-resistant tapered sleeve adopts the inner ring of the tapered roller bearing, and after interference fitting with the second cylindrical part, the outer tapered surface is ground together with the core shaft to a taper of 11±1°, and the finish of the outer tapered surface reaches above grade 7.

[0016] This device grinds the core shaft and the wear-resistant tapered sleeve to ensure the interference between the second cylindrical part and the inner hole of the wear-resistant tapered sleeve, and grinds the stop face of the wear-resistant tapered sleeve (the step face between the second cylindrical part and the third cylindrical part), then sets the wear-resistant tapered sleeve on the outer side surface of the second cylindrical part with the interference fit, and fits the end face with the stop face, and finally grinds the outer taper of the core shaft and the wear-resistant tapered sleeve together, thereby ensuring the coaxiality of the core shaft axis and the outer conical surface of the wear-resistant tapered sleeve, and ensuring the consistency of the radial movement accuracy of multiple steel balls when they move up and down with the outer conical surface of the wear-resistant tapered sleeve, thereby ensuring the positioning accuracy of the workpiece.

[0017] As a further improvement of the present technology, the outer surface of the core shaft is quenched and the hardness is set to HRC40-50, the surface finish of the first cylindrical portion, the second cylindrical portion, the third cylindrical portion and the fourth cylindrical portion is set to above level 6, the step surface finish between the second cylindrical portion and the third cylindrical portion is set to above level 6, and the step surface finish between the fourth cylindrical portion and the mounting flange is set to above level 6.

[0018] As a further improvement of the present technology, the steel ball sleeve is subjected to quenching and tempering treatment, the quenching and tempering hardness is set to HRC24-28, and the inner surface finish of the second inner hole and the fourth inner hole is set to be above grade 6; The cover plate is subjected to quenching and tempering treatment, the quenching and tempering hardness is set to HRC24-28, and the upper end surface finish is set to be above grade 6; The positioning pin is subjected to tempering treatment, and the tempering hardness is set to HRC24-28.

[0019] The device adopts the above-mentioned heat treatment and finish requirements, which can improve the strength of the core shaft, the steel ball sleeve, the cover plate and the positioning pin, reduce the contact friction, and greatly increase the service life of the device.

[0020] As a further improvement of the present technology, a clearance fit is set between the outer spherical surface of the steel ball and the inner surface of the radial through hole, and the fitting clearance is set to 0.02-0.03 mm; the position accuracy of the plurality of radial through holes relative to the axis of the core shaft is set to φ0.02-0.03 mm.

[0021] The above-mentioned setting of matching clearance and position accuracy further improves the positioning accuracy of the steel ball tightening the inner hole of the workpiece, thereby improving the boring accuracy of the workpiece.

[0022] As a further improvement of the present technology, the upper end surface of the first cylindrical portion is provided with a first chamfer of 5×15°, the upper end surface of the second cylindrical portion smoothly transitions with the outer cylindrical surface of the first cylindrical portion through a second chamfer of 15°, and the upper end surface of the fourth cylindrical portion smoothly transitions with the outer cylindrical surface of the third cylindrical portion through a third chamfer of 15°; The lengths of the second inner hole and the fourth inner hole are ≤10 mm, and the lower openings of the second inner hole and the fourth inner hole are respectively provided with a matching fourth chamfer and fifth chamfer of 3×15°.

[0023] The 15° chamfers on the end faces of the cylindrical parts on the above mandrel and on the inner holes of the steel ball sleeve make the steel ball sleeve move up and down with the mandrel faster and smoother, and limit the inner hole length of the steel ball sleeve in contact with the mandrel to within 10mm, which can reduce the friction between the steel ball sleeve and the mandrel and increase the service life.

[0024] As a further improvement of the present technology, four first bolt mounting holes are provided on the outer side of the base, and the positions correspond to the T-slots on the working platform of the precision boring equipment. A first hexagon socket bolt is provided in the first bolt mounting hole, and the lower end of the first hexagon socket bolt is threadedly connected to the T-nut in the T-slot of the working platform, so that the base and the working platform are detachably fixedly connected; The contour block is provided with three pieces, which are evenly distributed around the circumference. The contour block is arranged in a sector shape, and two second bolt mounting holes are arranged on the upper plane of the contour block. Corresponding second threaded holes are arranged at positions corresponding to the second bolt mounting holes on the base. A second hexagon socket bolt is arranged in the second bolt mounting hole, and the lower end of the second hexagon socket bolt is threadedly connected to the second threaded hole, so that the contour block is detachably fixedly connected to the base; The mounting flange is provided with a plurality of third bolt mounting holes evenly distributed in a circle, and third threaded holes are provided on the inner bottom surface of the first layer of holes at positions corresponding to the third bolt mounting holes, and third hexagon socket bolts are provided in the third bolt mounting holes, and the upper ends of the third hexagon socket bolts are threadedly connected with the third threaded holes to detachably and fixedly connect the mandrel to the base; The clamping device also includes a support block and a double-headed screw. The pressure plate is a rectangular plate with chamfers on the front and rear sides of the inner end. A waist-shaped groove matching the double-headed screw is provided on the upper plane on the inner side of the pressure plate. The transverse center line of the pressure plate is colinear with the transverse center line of the base. The lower end of the support block is fixedly connected to the outer edge of the base, and the upper end surface is supported on the lower plane of the outer end of the pressure plate. The lower end of the double-headed screw is threadedly connected to the base, and the upper end passes through the waist-shaped groove. The pressure plate is pressed against the plane of the bottom plate of the workpiece by a flat washer and a locking nut.

[0025] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention uses a plurality of steel balls evenly distributed in a circle arranged in the same horizontal plane to tighten / loosen the inner hole at the lower end of the workpiece as the wear-resistant cone sleeve moves up and down. The operation is simple and fast, the tightening and positioning accuracy is high, and the steel balls are in point contact with the inner hole of the workpiece, the contact area is greatly reduced, and the inner hole of the workpiece will not be damaged; 2. The present invention can quickly calibrate the patented positioning and clamping device by arranging a plane on the front side of the base that is parallel to the side wall of the transverse T-slot of the equipment working platform. By arranging a positioning pin on the base, the position of the first hole to be processed of the workpiece can be quickly located. When clamping the workpiece, there is no need to calibrate the position of the first hole, which saves a lot of calibration time, greatly improves production efficiency, and has high repeatability accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 This is a schematic diagram of the installation structure of the working platform of the embodiment of the present invention and the CNC machining center; Figure 3 It is a schematic diagram of a cross-sectional structure of an embodiment of the present invention; Figure 4 This is a schematic diagram of a cross-sectional structure of a mandrel according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the cross-sectional structure of a steel ball sleeve according to an embodiment of the present invention; Figure 6Schematic diagram of the structure of the inner ring of a tapered roller bearing and a schematic diagram of the structure of a wear-resistant tapered sleeve after grinding according to an embodiment of the present invention; Figure 7 This is a schematic diagram of a cross-sectional structure of a cover plate according to an embodiment of the present invention; Figure 8 Schematic diagram of the workpiece structure of an embodiment of the present invention.

[0027] In the figure: 1, working platform, 101, T-slot, 2, base, 201, first through hole, 202, first layer hole, 203, cutting plane, 3, inner hole tensioning device, 31, mandrel, 3101, first cylindrical part, 3102, second cylindrical part, 3103, third cylindrical part, 3104, fourth cylindrical part, 3105, mounting flange, 3106, spring mounting hole, 3107, first threaded hole, 3108, second layer hole, 3109, first chamfer, 3110, second chamfer, 3111, third chamfer, 32, steel ball sleeve, 3201, first inner hole, 3202, second inner hole, 3203, third inner hole, 3204, fourth inner hole, 3205, upper cylindrical part, 3 206. conical part, 3207. lower cylindrical part, 3208. fourth chamfer, 3209. fifth chamfer, 33. wear-resistant taper sleeve, 3301. inner hole of wear-resistant taper sleeve, 34. steel ball, 35. cover plate, 3501. second through hole, 3502. third layer hole, 36. compression spring, 37. locking screw, 4. positioning pin, 5. clamping device, 51. support block, 52. pressure plate, 5201. waist-shaped groove, 53. double-headed screw, 54. washer, 55. locking nut, 6. equal height block, 7. workpiece, 701. lower disc, 702. upper disc, 703. support column, 704. hole to be processed, 705. process positioning hole, 8. first hexagon socket bolt, 9. second hexagon socket bolt. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention. like Figure 8The figure shows the structure schematic diagram of the drive axle planet carrier J6.3A-4, which is a workpiece 7 for clamping and positioning in the embodiment of the present invention, including a lower disc 701, an upper disc 702, and three evenly distributed support columns 703 connecting the upper disc 702 and the lower disc 701. The upper disc 702 and the lower disc 701 are provided with three corresponding coaxial planetary shaft holes ( ), staggered with the three support columns 703, the three planetary shaft holes are the holes to be processed 704 that need to be finely bored on the workpiece 7, the coaxiality requirement between the three planetary shaft hole pitch circle and the stop is 0.04mm, the verticality requirement with the end face is 0.025mm, and the hole spacing between the three holes to be processed 704 is 119.512±0.03mm. In this embodiment, the three holes to be processed 704 are finely bored by a CNC machining center, and each corresponding coaxial hole to be processed 704 on the upper disc 702 and the lower disc 701 needs to be bored out at the same time, and the coaxiality requirement is 0.004mm.

[0030] like Figures 1 to 8 As shown, the embodiment of the present invention includes a base 2, a height equalizing block 6, an inner hole tensioning device 3, a clamping device 5 and a positioning pin 4; The base 2 is detachably fixedly connected to the working platform 1 of the boring equipment (a CNC machining center is used in this embodiment), a first through hole 201 is provided in the middle of the base 2, and a first layer of holes 202 is provided at the lower end of the first through hole 201; Four first bolt mounting holes are provided on the outer side of the base 2, and their positions correspond to the T-slot 101 on the working platform 1. A first hexagon socket bolt 8 is provided in the first bolt mounting hole. The lower end of the first hexagon socket bolt 8 is threadedly connected to the T-nut in the T-slot 101 of the working platform 1, so that the base 2 and the working platform 1 are detachably fixedly connected.

[0031] The inner hole tightening device 3 is used to tighten the inner hole at the lower end of the workpiece through a steel ball, and includes a mandrel 31, a wear-resistant cone sleeve 33, a steel ball sleeve 32, a steel ball 34, a cover plate 35, a compression spring 36, and a locking screw 37; The mandrel 31 comprises a first cylindrical portion 3101, a second cylindrical portion 3102, a third cylindrical portion 3103, a fourth cylindrical portion 3104 and a mounting flange 3105 which are connected in sequence from top to bottom, are coaxial and have outer diameters increasing in sequence. The mounting flange 3105 is sleeved in the first layer hole 202, and the upper end surface is in contact with the inner bottom surface of the first layer hole 202, and is detachably fixedly connected to the base 2 by a plurality of bolts. The fourth cylindrical portion 3104 is sleeved in the first through hole 201. A spring mounting hole 3106 is provided in the middle of the upper end of the mandrel 31. A coaxial first threaded hole 3107 is provided at the bottom of the spring mounting hole 3106. A coaxial second layer hole 3108 with an increasing aperture is provided at the lower end of the first threaded hole 3107. The mounting flange 3105 is provided with three third bolt mounting holes evenly distributed in a circle, and the inner bottom surface of the first layer hole 202 is provided with third threaded holes at positions corresponding to the third bolt mounting holes. The third bolt mounting holes are provided with third hexagon socket bolts, and the upper ends of the third hexagon socket bolts are threadedly connected to the third threaded holes to detachably and fixedly connect the core shaft 31 and the base 2.

[0032] The wear-resistant cone sleeve 33 is interference-fittedly sleeved on the outer surface of the second cylindrical portion 3102 of the core shaft 31, and the taper of the outer cone surface of the wear-resistant cone sleeve 33 is set to 11±1°; The steel ball sleeve 32 is sleeved on the outer side of the core shaft 31, with both ends open, and the middle is provided with a first inner hole 3201, a second inner hole 3202, a third inner hole 3203 and a fourth inner hole 3204 which are connected and coaxial in sequence from top to bottom. The aperture of the first inner hole 3201 is larger than that of the second inner hole 3202, and the aperture of the third inner hole 3203 is larger than that of the second inner hole 3202 and the fourth inner hole 3204. The second inner hole 3202 is sleeved on the outer side of the first cylindrical portion 3101 of the core shaft 31, and the fourth inner hole 3204 is sleeved on the outer side of the third cylindrical portion 3103 of the core shaft 31. Six radial through holes 3208 are uniformly distributed circumferentially relative to the axis of the core shaft 31 on the outer side wall of the middle part of the third inner hole 3203, and each radial through hole 3208 is sleeved with a steel ball 34, and the inner side surface of the steel ball 34 is supported on the outer side surface of the wear-resistant cone sleeve 33. The cover plate 35 is detachably fixedly connected to the upper plane of the steel ball sleeve 32, and a second through hole 3501 is provided in the middle, and a third layer of holes 3502 are provided at the lower end of the second through hole 3501; The compression spring 36 is installed in the spring installation hole 3106 and the third layer hole 3502; In the working state, the locking screw 37 passes through the second through hole 3501, the third layer hole 3502, the inner hole of the compression spring 36 and the spring mounting hole 3106 from top to bottom in sequence, and the lower end is threadedly connected with the first threaded hole 3107, so that the steel ball sleeve 32 and the core shaft 31 are detachably fixedly connected. At this time, the six steel balls 34 move downward from top to bottom along the outer conical surface of the wear-resistant cone sleeve 33, and several steel balls 34 are pushed outward at the same time, so that the steel balls 34 tighten the inner hole of the lower disc 701 of the workpiece 7; There are three equal height blocks 6, which are evenly distributed in a circle and can be detachably fixedly connected to the upper plane of the base 2, and are arranged on the periphery of the mandrel 31. The upper planes of the three equal height blocks 6 are in the same horizontal plane and are parallel to the upper plane of the base 2, so as to support the workpiece 7 and realize the axial positioning of the workpiece 7; The height-contact block 6 is configured as a sector, and two second bolt mounting holes are provided on the upper plane of the height-contact block 6. The base 2 is provided with corresponding second threaded holes at positions corresponding to the second bolt mounting holes. A second hexagon socket bolt 9 is provided in the second bolt mounting hole, and the lower end of the second hexagon socket bolt 9 is threadedly connected with the second threaded hole, so that the height-contact block 6 and the base 2 are detachably fixedly connected; The lower end of the positioning pin 4 is fixedly connected to the upper left side of the base 2 by interference fit, and the upper end is inserted into the process positioning hole 705 on the workpiece 7, and the fitting clearance between the outer cylindrical surface of the upper end and the process positioning hole 705 is set to 0.1±0.05mm; when the positioning pin 4 is inserted into the process positioning hole 705, one of the three holes 704 to be processed of the workpiece 7 must be located on the longitudinal center line of the upper end of the disk of the base 2, and the hole 704 to be processed is set as the first processing hole.

[0033] By plugging the positioning pin 4 into the process positioning hole 705, the first processing hole of the workpiece 7 can be quickly positioned without the need to calibrate the first processing hole. The CNC machining center can then perform precision boring of the first processing hole. After the first processing hole is completed, the next two holes to be processed 704 are completed by the program control of the CNC machining center. After the three holes to be processed 704 are completed, the boring tool of the CNC machining center is reset to directly above the first processing hole, waiting for the processing of the next workpiece.

[0034] The clamping device 5 is provided with two pieces, which are symmetrically arranged on the left and right sides of the base 2 . The clamping device 5 includes a pressing plate 52 for pressing the workpiece 7 onto the equal height block 6 .

[0035] The base 2 is set to be a disc with a piece cut off on the front side. The cutting plane 203 on the front side of the disc is set parallel to the rear side of the transverse T-slot 101 on the working platform 1. The runout of the cutting plane is set to 0.02-0.03 mm. The setting of the cutting plane 203 is used for the installation position correction of the device, and cooperates with the positioning pin 4 to quickly position the workpiece 7. During operation, when the workpiece 7 is installed on the device, it can be directly fine-bored without the need to correct the position of the first processing hole, which greatly saves the first hole correction time and labor costs and improves production efficiency.

[0036] Preferably, the coaxiality of the first cylindrical portion 3101, the second cylindrical portion 3102, the third cylindrical portion 3103, and the fourth cylindrical portion 3104 of the mandrel 31 is set to 0.012-0.015 mm, and the radial runout of the step surface between the fourth cylindrical portion 3104 and the mounting flange 3105 relative to the axis of the mandrel 31 is set to 0.025-0.03 mm; The coaxiality of the second inner hole 3202 and the fourth inner hole 3204 of the steel ball sleeve 32 is set to 0.02±0.005mm; The radial runout of the upper end surface, the lower end surface and the inner bottom surface of the first layer hole 202 relative to the axis of the first through hole 201 is set to 0.015±0.005 mm.

[0037] The above-mentioned coaxiality and radial runout settings can ensure the coaxiality and position accuracy of the mandrel 31, the steel ball sleeve 32, and the base 2 during assembly, thereby ensuring the precision boring accuracy of the workpiece.

[0038] Preferably, a clearance fit is set between the second inner hole 3202 and the first cylindrical portion 3101, and the clearance is set to 0.03-0.04 mm; a clearance fit is set between the fourth inner hole 3204 and the third cylindrical portion 3103, and the clearance is set to 0.03-0.04 mm; and a clearance fit is set between the fourth cylindrical portion 3104 and the first through hole 201, and the clearance is set to 0-0.01 mm.

[0039] This device ensures the above-mentioned fitting clearance by grinding the second inner hole 3202 and the first cylindrical portion 3101, the fourth inner hole 3204 and the third cylindrical portion 3103, and the fourth cylindrical portion 3104 and the first through hole 201, thereby ensuring the assembly accuracy of the core shaft 31 and the steel ball sleeve 32, and the core shaft 31 and the base 2, and also ensuring the coaxiality of the steel ball sleeve 32 when it moves up and down on the outer cylindrical surface of the core shaft 31, thereby achieving the accuracy requirement of tightening the inner hole at the lower end of the workpiece 7 with multiple steel balls 34 at the same time.

[0040] Preferably, the interference between the second cylindrical portion 3102 and the inner hole 3301 of the wear-resistant cone sleeve is set to 0.03-0.05 mm; The wear-resistant tapered sleeve 33 adopts the inner ring of the tapered roller bearing. After interference fit with the second cylindrical part 3102, the outer conical surface is ground together with the core shaft 31 to a taper of 11±1°, and the finish of the outer conical surface reaches above grade 7.

[0041] This device grinds the core shaft 31 and the wear-resistant tapered sleeve 33 to ensure the interference between the second cylindrical portion 3102 and the inner hole 3301 of the wear-resistant tapered sleeve, and grinds the stop end surface of the wear-resistant tapered sleeve 33 (i.e., the step surface between the second cylindrical portion 3102 and the third cylindrical portion 3103), and then the wear-resistant tapered sleeve 33 is interference-fittedly sleeved on the outer surface of the second cylindrical portion 3102, with the end face fitted with the stop end surface, and finally the core shaft 31 and the wear-resistant tapered sleeve 33 are ground together to ensure the coaxiality of the axis of the core shaft 31 and the outer conical surface of the wear-resistant tapered sleeve 33, so as to ensure the consistency of the radial movement accuracy of the 6 steel balls 34 as they move up and down with the outer conical surface of the wear-resistant tapered sleeve 33, thereby ensuring the positioning accuracy of the workpiece 7.

[0042] Preferably, the outer surface of the core shaft 31 is quenched and the hardness is set to HRC40-50, the surface finish of the first cylindrical portion 3101, the second cylindrical portion 3102, the third cylindrical portion 3103 and the fourth cylindrical portion 3104 is set to level 6 or above, the step surface finish between the second cylindrical portion 3102 and the third cylindrical portion 3103 is set to level 6 or above, and the step surface finish between the fourth cylindrical portion 3104 and the mounting flange 3105 is set to level 6 or above.

[0043] Preferably, the steel ball sleeve 32 is subjected to quenching and tempering treatment, and the quenching and tempering hardness is set to HRC24-28, and the inner surface finish of the second inner hole 3202 and the fourth inner hole 3204 is set to be above grade 6; The cover plate 35 is subjected to quenching and tempering treatment, the quenching and tempering hardness is set to HRC24-28, and the upper end surface finish is set to be above grade 6; The positioning pin 4 is subjected to quenching and tempering treatment, and the quenching and tempering hardness is set to HRC24-28.

[0044] The device adopts the above-mentioned heat treatment and finish requirements, which can improve the strength of the core shaft 31, the steel ball sleeve 32, the cover plate 35 and the positioning pin 4, reduce the contact friction, and greatly increase the service life of the device.

[0045] Preferably, a clearance fit is set between the outer spherical surface of the steel ball 34 and the inner surface of the radial through hole 3208, and the fitting clearance is set to 0.02-0.03 mm; the position accuracy of the six radial through holes 3208 relative to the axis of the core shaft 31 is set to φ0.02-0.03 mm.

[0046] The above-mentioned setting of the matching clearance and the position accuracy further improves the positioning accuracy of the steel ball 34 tightening the inner hole of the workpiece 7, thereby improving the boring accuracy of the workpiece 7.

[0047] Preferably, the upper end surface of the first cylindrical portion 3102 is provided with a first chamfer 3109 of 5×15°, the upper end surface of the second cylindrical portion 3102 smoothly transitions with the outer circumferential surface of the first cylindrical portion 3101 through a second chamfer 3110 of 15°, and the upper end surface of the fourth cylindrical portion 3104 smoothly transitions with the outer circumferential surface of the third cylindrical portion 3103 through a third chamfer 3111 of 15°; The length of the second inner hole 3202 and the fourth inner hole 3204 is ≤10 mm, and the lower openings of the second inner hole 3202 and the fourth inner hole 3204 are respectively provided with a matching fourth chamfer 3209 and a fifth chamfer 3210 of 3×15°.

[0048] The 15° chamfers on the end faces of the cylindrical portions on the core shaft 31 and on the inner holes of the steel ball sleeve 32 enable the steel ball sleeve 32 to move up and down with the core shaft 31 more quickly and smoothly, and limit the inner hole length of the steel ball sleeve 32 in contact with the core shaft 31 to within 10 mm, thereby reducing the friction between the steel ball sleeve 32 and the core shaft 31 and increasing the service life.

[0049] Preferably, the outer side surface of the steel ball sleeve 32 includes an upper cylindrical portion 3205 , a conical portion 3206 and a lower cylindrical portion 3207 which are sequentially connected from top to bottom, and six radial through holes 3208 are provided in the middle of the lower cylindrical portion 3207 .

[0050] Preferably, the clamping device 5 also includes a support block 51 and a double-headed screw 53. The pressure plate 52 is a rectangular plate with chamfered front and rear sides of the inner end. A waist-shaped groove 5201 matching the double-headed screw 53 is provided on the inner upper plane of the pressure plate 52. The transverse center line of the pressure plate 52 is colinear with the transverse center line of the base 2. The lower end of the support block 51 is fixedly connected to the outer edge of the base 2, and the upper end surface is supported on the lower plane of the outer end of the pressure plate 52. The lower end of the double-headed screw 53 is threadedly connected to the base 2, and the upper end passes through the waist-shaped groove 5201. The pressure plate 52 is pressed against the upper plane of the bottom plate of the workpiece 7 by a flat washer 54 and a locking nut 55.

[0051] Processing performance test of this embodiment: Take 5 planetary carrier J6.3A-4 products from the same batch and position and clamp them through this embodiment, and then test them after precision boring to test the apertures of the three planetary shaft holes 704. mm, hole spacing 119.512±0.03mm, coaxiality between the planetary shaft hole pitch circle and the stop φ0.04mm and perpendicularity between the planetary shaft hole and the end face 0.015mm. The test data are shown in Table 1 below.

[0052] Table 1

[0053] From the test data in Table 1, it can be seen that after the planet carrier J6.3A-4 is positioned and clamped by this embodiment, the diameters of the three planet shaft holes evenly distributed on the circumference are , the hole spacing of 119.512±0.03mm can meet the product technical requirements, the coaxiality of the planetary shaft hole pitch circle and the stop φ0.04mm and the perpendicularity of the planetary shaft hole and the end face 0.015mm can also meet the product technical requirements, ensuring product quality.

[0054] After adopting this embodiment, the time for correcting the first hole of each product is saved, 8 products can be processed in 1 hour, and the production efficiency is increased by 2 to 3 times.

[0055] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A planet carrier precision boring positioning clamping device, characterized in that: It includes a base, a height equalizing block, an inner hole tensioning device, a clamping device and a positioning pin; The base is detachably and fixedly connected to the working platform of the boring equipment, a first through hole is provided in the middle of the base, and a first layer of holes is provided at the lower end of the first through hole; The inner hole tightening device is used to tighten the inner hole at the lower end of the workpiece through a steel ball, and includes a mandrel, a wear-resistant cone sleeve, a steel ball sleeve, a steel ball, a cover plate, a compression spring, and a locking screw; The core shaft comprises a first cylindrical portion, a second cylindrical portion, a third cylindrical portion, a fourth cylindrical portion and a mounting flange which are connected in sequence from top to bottom, are coaxial and have outer diameters increasing in sequence; the mounting flange is sleeved in the first layer of holes, the upper end surface is fitted with the inner bottom surface of the first layer of holes, and is detachably fixedly connected to the base through a plurality of bolts; the fourth cylindrical portion is sleeved in the first through hole; a spring mounting hole is provided in the middle of the upper end of the core shaft; a coaxial first threaded hole is provided at the bottom of the spring mounting hole; a coaxial second layer of holes with increasing apertures are provided at the lower end of the first threaded hole; The wear-resistant tapered sleeve is interference-fitted on the outer surface of the second cylindrical portion of the core shaft, and the taper of the outer conical surface of the wear-resistant tapered sleeve is set to 11±1°; The steel ball sleeve is sleeved on the outer side of the core shaft, with openings at both ends, and a first inner hole, a second inner hole, a third inner hole and a fourth inner hole are sequentially connected and coaxially arranged in the middle from top to bottom, the first inner hole has a larger aperture than the second inner hole, the third inner hole has a larger aperture than the second inner hole and the fourth inner hole, the second inner hole is sleeved on the outer side of the first cylindrical portion of the core shaft, the fourth inner hole is sleeved on the outer side of the third cylindrical portion of the core shaft, a plurality of radial through holes are uniformly distributed circumferentially relative to the axis of the core shaft on the outer side wall of the middle part of the third inner hole, each of the radial through holes is sleeved with a steel ball, and the inner side surface of the steel ball is supported on the outer side surface of the wear-resistant cone sleeve; The cover plate is detachably fixedly connected to the upper plane of the steel ball sleeve, a second through hole is provided in the middle, and a third layer of holes is provided at the lower end of the second through hole; The compression spring is installed in the spring installation hole and the third layer hole; When in working state, the locking screw passes through the second through hole, the third layer hole, the inner hole of the compression spring and the spring installation hole from top to bottom in sequence, and the lower end is threadedly connected with the first threaded hole, so that the steel ball sleeve and the mandrel are detachably fixedly connected. At this time, a plurality of steel balls move downward from top to bottom along the outer conical surface of the wear-resistant cone sleeve, and a plurality of steel balls are pushed outward at the same time, so that the steel balls tighten the inner hole of the lower disc of the workpiece; The contour blocks are provided with a plurality of pieces, which are evenly distributed in a circle and can be detachably fixedly connected to the upper plane of the base, and are arranged on the periphery of the mandrel. The upper planes of the plurality of contour blocks are in the same horizontal plane and are parallel to the upper plane of the base, so as to support the workpiece and realize the axial positioning of the workpiece; The lower end of the positioning pin is fixedly connected to the upper left side of the base by interference fit, and the upper end is inserted into the process positioning hole on the workpiece, and the fitting clearance between the outer cylindrical surface of the upper end and the process positioning hole is set to 0.1±0.05mm; when the positioning pin is inserted into the process positioning hole, one of the three holes to be processed of the workpiece must be located on the longitudinal center line of the upper end of the disc of the base, and the hole to be processed is set as the first processing hole.

2. The clamping device is provided with two pieces, which are symmetrically arranged on the left and right sides of the base. The clamping device includes a pressing plate, which is used to press the workpiece onto the equal height block.

3. The planet carrier precision boring positioning clamping device according to claim 1, characterized in that: The base is set to be a disc with a piece cut off on the front side. The cutting plane on the front side of the disc is set parallel to the rear side of the horizontal T-slot on the working platform. The cutting plane runout is set to 0.02-0.03mm. When the positioning pin is inserted into the process positioning hole, the first processing hole of the workpiece can be positioned.

4. The planet carrier precision boring positioning clamping device according to claim 1, characterized in that: The coaxiality of the first cylindrical part, the second cylindrical part, the third cylindrical part and the fourth cylindrical part of the mandrel is set to 0.012-0.015 mm, and the radial runout of the step surface between the fourth cylindrical part and the mounting flange relative to the axis of the mandrel is set to 0.025-0.03 mm; The coaxiality of the second inner hole and the fourth inner hole of the steel ball sleeve is set to 0.02±0.005mm; The radial runout of the upper end surface, the lower end surface and the inner bottom surface of the first layer hole of the base relative to the axis of the first through hole is set to 0.015±0.005mm.

5. The planet carrier precision boring positioning clamping device according to claim 3, characterized in that: The second inner hole and the first cylindrical portion are set to have a clearance fit, and the clearance is set to 0.03-0.04 mm; the fourth inner hole and the third cylindrical portion are set to have a clearance fit, and the clearance is set to 0.03-0.04 mm; the clearance between the fourth cylindrical portion and the first through hole is set to 0-0.01 mm.

6. The planet carrier precision boring positioning clamping device according to claim 1, characterized in that: The interference between the second cylindrical portion and the inner hole of the wear-resistant cone sleeve is set to 0.03-0.05 mm; The wear-resistant tapered sleeve adopts the inner ring of the tapered roller bearing, and after interference fitting with the second cylindrical part, the outer tapered surface is ground together with the core shaft to a taper of 11±1°, and the finish of the outer tapered surface reaches above grade 7.

7. The planet carrier precision boring positioning clamping device according to claim 1, characterized in that: The outer surface of the core shaft is quenched and the hardness is set to HRC40-50. The surface finish of the first cylindrical part, the second cylindrical part, the third cylindrical part and the fourth cylindrical part is set to level 6 or above, the step surface finish between the second cylindrical part and the third cylindrical part is set to level 6 or above, and the step surface finish between the fourth cylindrical part and the mounting flange is set to level 6 or above.

8. The planet carrier precision boring positioning clamping device according to claim 1, characterized in that: The steel ball sleeve is subjected to quenching and tempering treatment, and the quenching and tempering hardness is set to HRC24-28, and the inner surface finish of the second inner hole and the fourth inner hole is set to be above grade 6; The cover plate is subjected to quenching and tempering treatment, the quenching and tempering hardness is set to HRC24-28, and the upper end surface finish is set to be above grade 6; The positioning pin is subjected to tempering treatment, and the tempering hardness is set to HRC24-28.

9. The planet carrier precision boring positioning clamping device according to claim 1, characterized in that: The outer spherical surface of the steel ball and the inner side surface of the radial through hole are set to a clearance fit, and the fitting clearance is set to 0.02-0.03 mm; the position accuracy of the plurality of radial through holes relative to the axis of the core shaft is set to φ0.02-0.03 mm.

10. The planet carrier precision boring positioning clamping device according to claim 1, characterized in that: The upper end surface of the first cylindrical portion is provided with a first chamfer of 5×15°, the upper end surface of the second cylindrical portion smoothly transitions with the outer circumferential surface of the first cylindrical portion through a second chamfer of 15°, and the upper end surface of the fourth cylindrical portion smoothly transitions with the outer circumferential surface of the third cylindrical portion through a third chamfer of 15°; The lengths of the second inner hole and the fourth inner hole are ≤10 mm, and the lower openings of the second inner hole and the fourth inner hole are respectively provided with a matching fourth chamfer and fifth chamfer of 3×15°.

11. The planet carrier precision boring positioning clamping device according to claim 1, characterized in that: Four first bolt mounting holes are provided on the outer side of the base, and the positions thereof correspond to the T-slots on the working platform of the precision boring equipment. First hexagon socket bolts are provided in the first bolt mounting holes, and the lower ends of the first hexagon socket bolts are threadedly connected with the T-nuts in the T-slots of the working platform, so as to detachably and fixedly connect the base to the working platform. The contour block is provided with three pieces, which are evenly distributed around the circumference. The contour block is arranged in a sector shape, and two second bolt mounting holes are arranged on the upper plane of the contour block. Corresponding second threaded holes are arranged at positions corresponding to the second bolt mounting holes on the base. A second hexagon socket bolt is arranged in the second bolt mounting hole, and the lower end of the second hexagon socket bolt is threadedly connected to the second threaded hole, so that the contour block is detachably fixedly connected to the base; The mounting flange is provided with a plurality of third bolt mounting holes evenly distributed in a circle, and third threaded holes are provided on the inner bottom surface of the first layer of holes at positions corresponding to the third bolt mounting holes, and third hexagon socket bolts are provided in the third bolt mounting holes, and the upper ends of the third hexagon socket bolts are threadedly connected with the third threaded holes to detachably and fixedly connect the mandrel to the base; The clamping device also includes a support block and a double-headed screw. The pressure plate is a rectangular plate with chamfers on the front and rear sides of the inner end. A waist-shaped groove matching the double-headed screw is provided on the upper plane on the inner side of the pressure plate. The transverse center line of the pressure plate is colinear with the transverse center line of the base. The lower end of the support block is fixedly connected to the outer edge of the base, and the upper end surface is supported on the lower plane of the outer end of the pressure plate. The lower end of the double-headed screw is threadedly connected to the base, and the upper end passes through the waist-shaped groove. The pressure plate is pressed against the plane of the bottom plate of the workpiece by a flat washer and a locking nut.

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