Small-size inner hole and special groove processing equipment and using method thereof

Abstract

The application discloses a small-size inner hole special-shaped groove machining device and a use method thereof, and is mainly used for machining a special-shaped groove (such as an oil groove in an inner hole of a dynamic or static pressure bearing bushing) of a workpiece inner hole surface. The device comprises a bottom plate, a front support, a rear support, a sliding workbench, a rotary workbench, a chuck, a tool holder component, a main motor, a feeding motor and a transmission assembly. A cutting tool is installed in a hollow gear shaft of the tool holder component, and main cutting movement is realized through synchronous belt driving; the workpiece is clamped on the chuck, the chuck rotates with the rotary workbench to realize circumferential feeding, the rotary workbench moves with the sliding workbench to realize axial feeding, and the special-shaped groove machining is completed through combination of the two feeding movements. The device solves the machining problem of the small-size inner hole special-shaped groove, replaces a traditional bench worker mode, improves machining efficiency and precision, and reduces cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of machining equipment, in particular to a small-size inner hole special-shaped groove machining equipment and a using method thereof. BACKGROUND

[0002] In mechanical manufacturing, the inner hole machining is difficult, so the inner hole of the part is mostly smooth surface or simple annular groove. However, the inner hole of the bearing shell (mostly copper alloy, low hardness) of the dynamic and static pressure bearing needs to be provided with a complex special-shaped groove (such as a "sun" type oil groove) to pass hydraulic oil, and the machining of such a groove becomes a difficult problem.

[0003] The traditional machining is only suitable for annular or straight-line axial through grooves, and cannot process complex structures such as non-through grooves and arc grooves. For this, the prior art mostly adopts hand tooling manual spudding, which is not only extremely low in efficiency and high in cost, but also poor in machining precision, and is difficult to meet the requirements. For large-size workpieces, an angle head can be installed on a boring and milling machine, but the size of the angle head is large, and a certain installation space is needed, so it cannot be adapted to the inner hole machining of small-size workpieces. Therefore, the efficient and high-precision machining of small-size inner hole special-shaped grooves has become a problem to be solved in the industry. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art, and provides a small-size inner hole special-shaped groove machining equipment and a using method thereof.

[0005] The technical solution adopted by the present application is as follows:

[0006] A small-size inner hole special-shaped groove machining equipment comprises a base plate, a front support, a rear support, a sliding workbench, a linear guide rail, a rotary workbench, a chuck, a tool holder component, a main motor, a driving wheel, a driven wheel, a synchronous belt, an axial feed motor, a rotary workbench feed motor and a ball screw pair. The front support and the rear support are fixed on the base plate, the linear guide rail is installed on the base plate, and the sliding workbench is slidably connected with the linear guide rail through a guide rail sliding block. The rotary workbench is installed on the sliding workbench, and the chuck is installed on the rotary workbench for clamping a workpiece. The tool holder component is installed on the front support, a hollow gear shaft is arranged in the tool holder component, and a milling cutter is installed on the hollow gear shaft. The main motor is installed on the front support, the driving wheel is connected with the output end of the main motor, the driven wheel is installed on the rear support through a driven wheel mounting seat, the synchronous belt is sleeved on the driving wheel and the driven wheel and is engaged with the hollow gear shaft. The axial feed motor is connected with the ball screw pair for driving the sliding workbench to move axially along the linear guide rail. The rotary workbench feed motor is used for driving the rotary workbench to rotate the workpiece circumferentially. The main motor drives the hollow gear shaft to drive the milling cutter to make a cutting main motion through the synchronous belt, and the axial movement of the sliding workbench and the circumferential rotation of the rotary workbench realize the feed motion of the workpiece.

[0007] Further, the tool holder component comprises a tool holder front half, a tool holder rear half, a guide column, a bearing and a round nut; the tool holder front half and the tool holder rear half are connected and fixed through the guide column, the hollow gear shaft is installed between the tool holder front half and the tool holder rear half through the bearing, and the round nut is used for axially positioning the bearing.

[0008] Further, the milling cutter is installed in the hollow gear shaft, the lower end of the hollow gear shaft is provided with a locking cap for axially locking the milling cutter, the upper end of the hollow gear shaft is provided with a screw hole, and the tail part of the milling cutter is provided with a platform, so that the milling cutter is circumferentially locked through the cooperation of the screw and the platform.

[0009] Further, the synchronous belt is a detachable connection synchronous belt.

[0010] Further, the ball screw pair comprises a ball screw, a screw nut, a screw fixed support seat and a screw floating support seat; one end of the ball screw is installed on the rear support seat through the screw fixed support seat, the other end is installed on the front support seat through the screw floating support seat, the screw nut is connected with the sliding workbench, the axial feeding motor is connected with the ball screw through the motor adapter, and the axial feeding motor is used to drive the ball screw to rotate to drive the sliding workbench to move.

[0011] Further, the outer diameter of the tool holder component is smaller than the inner hole diameter of the workpiece to be machined.

[0012] Further, it also comprises a driven wheel adjusting mechanism, the driven wheel adjusting mechanism comprises a connecting block and an adjusting screw, the adjusting screw is installed on the connecting block, and the end thereof abuts against the driven wheel mounting seat, so as to adjust the position of the driven wheel to tension the synchronous belt.

[0013] Further, the tool holder component further comprises a guide column, the two ends of the guide column are fixedly connected with the tool holder front half and the tool holder rear half respectively, and the guide column is used for guiding and positioning the connection between the tool holder front half and the tool holder rear half.

[0014] Further, the chuck is a three-jaw chuck, which comprises a chuck body and three clamping jaws, the three clamping jaws are uniformly distributed along the circumference of the chuck body, and are used for clamping and fixing the workpiece.

[0015] Further, a use method of a small-size inner hole special-shaped groove machining equipment, characterized in that the use method comprises the following steps:

[0016] S1: pretreating the workpiece to be machined, machining a pilot hole on the inner hole surface of the workpiece, and the pilot hole is used for guiding the milling cutter to cut radially along the workpiece to a preset groove depth in the initial stage of cutting;

[0017] S2: clamping and fixing the pretreated workpiece on the chuck, the chuck is installed on the rotary workbench, and the rotary workbench is installed on the sliding workbench;

[0018] S3: installing the milling cutter in the hollow gear shaft of the tool holder component and locking the milling cutter;

[0019] S4: Start the main motor, the main motor drives the driven wheel and the hollow gear shaft meshed with the synchronous belt to rotate through the driving wheel and the synchronous belt, to drive the milling cutter to rotate to realize the main cutting movement;

[0020] S5: Control the axial feed motor to drive the ball screw pair to operate, so that the sliding workbench moves axially along the linear guide rail, and at the same time, control the rotary workbench feed motor to drive the rotary workbench to make the workpiece rotate circumferentially, so as to realize the feeding of the workpiece through the combined movement of axial movement and circumferential rotation; wherein, after the milling cutter is radially fed to the preset groove depth along the lead-in hole in step S1, no radial feeding is performed during the entire machining process, until the machining of the special-shaped groove on the inner hole surface of the workpiece is completed.

[0021] As described above, due to the adoption of the above technical solutions, the beneficial effects of the present application are:

[0022] Breakthrough size limit: the outer circle diameter of the tool holder part is smaller than the inner hole of the workpiece, avoiding interference with the workpiece during machining, adapting to small size workpieces, and solving the problem that large size machine tool accessories cannot be applied.

[0023] Replace manual machining: through the mechanical transmission and feeding system, replace the traditional bench work shovel, improve the machining efficiency, reduce the labor cost, and avoid the precision fluctuation caused by manual operation.

[0024] Ensure machining precision: the main motor drives the hollow gear shaft through the synchronous belt, cooperates with the tension adjusting mechanism of the live connection synchronous belt, ensures the stable rotation of the tool, the ball screw pair drives the sliding workbench, cooperates with the circumferential feeding of the rotary workbench, realizes the accurate combination of axial and circumferential movement, the trajectory reproduction precision is high, far exceeding the manual machining precision.

[0025] Stable and reliable structure: the tool holder part is positioned and connected by the guide column, to ensure the coaxiality of the hollow gear shaft; the three-jaw chuck is automatically centered and clamped, to avoid the deformation of the low-hardness bearing shell workpiece; the lead-in hole design solves the problem of radial feeding of the closed inner hole, and the tool has no radial feeding during the machining process, further ensuring the consistency of the groove size.

[0026] In summary, the present device realizes the efficient and high-precision machining of small size inner hole special-shaped groove, adapts to the production needs of dynamic and static pressure bearing shell and other parts, and has strong practicality and economy. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a structural schematic diagram of the present application;

[0028] Figure 2 is a structural schematic diagram of the hidden part of the present application;

[0029] Figure 3Structure diagram of the invention's live adapter synchronous belt and tool holder component (radial section);

[0030] Figure 4 Structure diagram of the invention's front view;

[0031] Figure 5 Structure diagram of the invention's live adapter synchronous belt and tool holder component (axial 1 / 4 section);

[0032] Figure 6 Structure diagram of the invention's tool holder component (1 / 4 section);

[0033] Figure 7 Structure diagram of the invention's tool holder component before installation;

[0034] Figure 8 Structure diagram of the invention's hollow gear shaft;

[0035] Figure 9 Structure diagram of the invention's workpiece with special-shaped grooves on the inner surface;

[0036] Figure 10 Structure diagram of the invention's live adapter synchronous belt;

[0037] Markings in the figure:

[0038] 1-bottom plate, 2-front support, 3-driving wheel, 4-tool holder fixing block, 5-sliding workbench, 6-rotary workbench, 7-chuck body, 8-chuck claw, 9-tool holder component, 10-following wheel, 11-following wheel mounting seat, 12-adjusting screw, 13-connection block, 14-axial feeding motor, 15-rear support, 16-screw nut, 17-workpiece, 18-guide rail sliding block, 19-rotary workbench feeding motor, 20-linear guide rail, 21-main motor, 22-floating support seat of screw rod, 23-rolling ball screw rod, 24-live adapter synchronous belt, 25-screw rod fixed support seat, 26-motor adapter, 91-tool holder rear half, 92-tool holder front half, 93-guide column, 94-circular nut, 95-bearing, 96-hollow gear shaft, 97-milling cutter, 98-locking cap, 99-screw. DETAILED DESCRIPTION

[0039] The invention will be described in detail below with reference to the accompanying drawings.

[0040] In order to make the purpose, technical scheme and advantages of the invention clearer and more understandable, the invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are only used to explain the invention and do not limit the invention.

[0041] Example One

[0042] In this embodiment, asFigures 1-10 As shown in the drawings, a small size inner hole special-shaped groove processing equipment, including the base plate 1, front support 2, rear support 15, sliding workbench 5, linear guide rail 20, rotary workbench 6, chuck, tool holder component 9, main motor 21, driving wheel 3, driven wheel 10, synchronous belt, axial feed motor 14, rotary workbench 6 feed motor and ball screw 23 pair; front support 2 and rear support 15 are fixed on the base plate 1, linear guide rail 20 is installed on the base plate 1, sliding workbench 5 is slidably connected with linear guide rail 20 through guide rail slider 18; rotary workbench 6 is installed on sliding workbench 5, chuck is installed on rotary workbench 6, for clamping workpiece 17; tool holder component 9 is installed on front support 2, hollow gear shaft 96 is arranged in tool holder component 9, milling cutter 97 is installed on hollow gear shaft 96; main motor 21 is installed on front support 2, driving wheel 3 is connected with the output end of main motor 21, driven wheel 10 is installed on rear support 15 through driven wheel 10 mounting seat, synchronous belt is sleeved on driving wheel 3 and driven wheel 10 and is engaged with hollow gear shaft 96; axial feed motor 14 is connected with ball screw 23 pair, for driving sliding workbench 5 to move axially along linear guide rail 20; rotary workbench 6 feed motor is used for driving rotary workbench 6 to drive workpiece 17 to rotate circumferentially; main motor 21 drives hollow gear shaft 96 to drive milling cutter 97 to make cutting main movement through synchronous belt, and the feed movement of workpiece 17 is realized through the axial movement of sliding workbench 5 and the circumferential rotation of rotary workbench 6.

[0043] The base plate 1 provides basic support for the equipment, the front support 2 and the rear support 15 are fixed on the base plate 1 by bolts, forming a stable frame structure; the linear guide rail 20 is installed on the base plate 1 by screws 99, the guide rail slider 18 at the bottom of the sliding workbench 5 is slidably connected with the linear guide rail 20, so that the sliding workbench 5 can move smoothly along the linear guide rail 20; the rotary workbench 6 is fixed on the sliding workbench 5 by bolts, the chuck (such as a three-jaw chuck) is installed on the output end of the rotary workbench 6, used for clamping the workpiece 17 to be processed; the tool holder component 9 is installed on the front support 2 through the tool holder fixing block 4, the hollow gear shaft 96 in the tool holder component 9 is rotatably arranged through the bearing 95, and the milling cutter 97 is installed in the hollow gear shaft 96; the main motor 21 is fixed on the front support 2, the output shaft of which is connected with the driving wheel 3, the driven wheel 10 is installed on the rear support 15 through the driven wheel 10 mounting seat, the synchronous belt is sleeved on the driving wheel 3 and the driven wheel 10 and is engaged with the gear part of the hollow gear shaft 96, forming a transmission chain; the axial feed motor 14 is connected with the ball screw 23 pair through the motor adapter 26, the ball screw 23 is supported by the screw fixed support seat 25 (rear support 15 side) and the screw floating support seat 22 (front support 2 side) at both ends respectively, and the screw nut 16 is connected with the bottom of the sliding workbench 5; the rotary workbench 6 feed motor is connected with the rotary workbench 6, driving it to rotate.

[0044] After starting the main motor 21, the driving wheel 3 drives the driven wheel 10 and the hollow gear shaft 96 to rotate through the synchronous belt, and then drives the milling cutter 97 to rotate at high speed, realizing the main cutting movement; the axial feed motor 14 drives the ball screw 23 to rotate, and drives the sliding workbench 5 to move axially along the linear guide rail 20 (along the axis direction of the workpiece 17) through the screw nut 16; the rotary workbench 6 feed motor drives the rotary workbench 6 to drive the workpiece 17 to rotate circumferentially (rotate around the axis of the workpiece 17); through the combined movement of axial movement and circumferential rotation, the workpiece 17 forms a complex trajectory relative to the milling cutter 97, so as to process the inner hole special-shaped groove.

[0045] By integrating the base plate 1, the support, the workbench, the transmission mechanism and other components, an integrated machining equipment is formed. Due to the rigid connection (such as bolt fixing) and precise sliding / rotating cooperation (such as guide rail block 18, bearing 95) of each component, the stability of the whole equipment is ensured; the main motor 21 drives the milling cutter 97 through the synchronous belt transmission to realize high-efficiency cutting movement, and the combined movement of axial and circumferential feeding can flexibly adapt to the trajectory requirements of "day" type, arc and other special-shaped grooves. The problems of low efficiency and poor precision of traditional bench work, and the inadaptability of large-size machine tool accessories to small-size workpieces 17 are solved, the mechanized machining of small-size inner hole special-shaped grooves is realized, the machining efficiency and precision are improved, and the machining cost is reduced.

[0046] Further, the tool holder component 9 includes a tool holder front half 92, a tool holder rear half 91, a guide column 93, a bearing 95 and a round nut 94; the tool holder front half 92 and the tool holder rear half 91 are connected and fixed through the guide column 93, the hollow gear shaft 96 is installed between the tool holder front half 92 and the tool holder rear half 91 through the bearing 95, and the round nut 94 is used for axially positioning the bearing 95.

[0047] The tool holder component 9 is composed of the tool holder front half 92 and the tool holder rear half 91, and the two are positioned through the guide column 93 (the guide column 93 is matched with the positioning holes of the front half and the rear half at both ends) and are connected through bolt fastening; the hollow gear shaft 96 is installed in the bearing 95 holes of the tool holder front half 92 and the tool holder rear half 91 through two bearings 95 (such as deep groove ball bearings 95), the outer ring of the bearing 95 is interference-fitted with the tool holder body, and the inner ring is transition-fitted with the hollow gear shaft 96; the round nut 94 is connected with the end of the hollow gear shaft 96 through threads, and abuts against the inner ring of the bearing 95 to realize the axial positioning of the bearing 95.

[0048] When the main motor 21 drives the hollow gear shaft 96 to rotate through the synchronous belt, the bearing 95 converts the rotary motion of the hollow gear shaft 96 into low-friction rolling motion, the tool holder front half 92 and the rear half ensure coaxiality through the guide column 93, and the round nut 94 limits the axial movement of the bearing 95, so that the hollow gear shaft 96 does not have obvious radial or axial deviation during rotation.

[0049] The front half 92 and the rear half of the tool holder are positioned by the guide column 93, which ensures the coaxiality of the bearing 95 holes of the two halves, and avoids vibration of the hollow gear shaft 96 due to installation eccentricity; the setting of the bearing 95 reduces the friction resistance when the hollow gear shaft 96 rotates, and reduces energy loss; the axial positioning effect of the round nut 94 prevents the bearing 95 from loosening under the action of cutting force, and ensures the stability of the rotation of the hollow gear shaft 96. Finally, the cutting movement of the milling cutter 97 is more stable, and the machining precision (such as the consistency of the groove size) is improved, and the split tool holder structure facilitates the assembly and maintenance of the internal parts.

[0050] Further, the milling cutter 97 is installed in the hollow gear shaft 96, the lower end of the hollow gear shaft 96 is provided with a locking cap 98, and the locking cap 98 is used to axially lock the milling cutter 97; the upper end of the hollow gear shaft 96 is provided with a screw hole 99, and the tail part of the milling cutter 97 is provided with a platform, and the screw 99 passes through the screw hole 99 and cooperates with the platform to circumferentially lock the milling cutter 97.

[0051] The tail part of the milling cutter 97 is inserted into the inner hole of the hollow gear shaft 96, the locking cap 98 at the lower end of the hollow gear shaft 96 is connected with the hollow gear shaft 96 through threads, and after being tightened, the end face thereof abuts against the end face of the tail part of the milling cutter 97, thereby achieving axial locking of the milling cutter 97; the upper end of the hollow gear shaft 96 is provided with a radial screw hole 99, and the tail part of the milling cutter 97 is ground to have a flat surface (platform), and the screw 99 is tightly abutted against the platform of the tail part of the milling cutter 97 after passing through the screw hole 99, thereby achieving circumferential locking of the milling cutter 97.

[0052] When the milling cutter 97 rotates at high speed for cutting, the axial cutting force attempts to make the milling cutter 97 move along the axial direction, the locking cap 98 offsets the axial force through the thread pre-tightening force, thereby preventing the milling cutter 97 from being axially loose; the circumferential cutting torque attempts to make the milling cutter 97 rotate relative to the hollow gear shaft 96, and the abutting force of the upper end screw 99 and the tail part platform of the milling cutter 97 generates a friction torque, which offsets the circumferential torque and prevents the milling cutter 97 from slipping circumferentially.

[0053] The double locking structure (axial + circumferential) forms a redundant constraint, which can resist the axial force and the circumferential torque in the cutting process at the same time. Compared with the single locking mode, the loosening of the milling cutter 97 due to vibration or excessive force is avoided, the relative position stability of the milling cutter 97 and the hollow gear shaft 96 is ensured, thereby ensuring the size precision of the depth and width of the groove, and the safety risk of the milling cutter 97 falling off is reduced.

[0054] Further, the synchronous belt is a live connection synchronous belt 24.

[0055] The synchronous belt adopts a live connection structure (such as a belt buckle type or a tooth-shaped butt joint type), the two ends of which can be detachably connected through a connection piece, and the synchronous belt is sleeved outside the gear part of the driving wheel 3, the driven wheel 10 and the hollow gear shaft 96, thereby forming a closed transmission belt.

[0056] When the main motor 21 drives the main wheel 3 to rotate, the synchronous belt drives the driven wheel 10 and the hollow gear shaft 96 to rotate synchronously through the toothed engagement, and the detachable adapter is designed with an anti-disengagement structure (such as toothed engagement or buckle locking), so that the detachable adapter will not be separated during transmission, thereby ensuring the continuity of transmission.

[0057] The conventional synchronous belt is a ring-shaped integrated structure, which needs to be sleeved from one end of the gear train during installation. For the compact gear train layout (small spacing between the main wheel 3, the driven wheel 10, and the hollow gear shaft 96) in the device, the installation difficulty is great. The detachable adapter synchronous belt 24 can be opened at both ends first, and then closed after surrounding the gear train, which greatly reduces the installation difficulty. At the same time, by adjusting the position of the driven wheel 10 (cooperating with the adjusting screw 12), the tension of the synchronous belt can be conveniently adjusted, so as to avoid slipping (affecting transmission accuracy) or accelerated wear (shortening the service life) caused by over-tightening, and ensure the transmission efficiency and stability.

[0058] Further, the ball screw 23 pair includes the ball screw 23, the screw nut 16, the screw fixed support seat 25, and the screw floating support seat 22; one end of the ball screw 23 is installed on the rear support 15 through the screw fixed support seat 25, the other end is installed on the front support 2 through the screw floating support seat 22, the screw nut 16 is connected with the sliding workbench 5, and the axial feed motor 14 is connected with the ball screw 23 through the motor adapter 26, for driving the ball screw 23 to rotate to drive the sliding workbench 5 to move.

[0059] The ball screw 23 pair is composed of the ball screw 23, the screw nut 16, the screw fixed support seat 25, and the screw floating support seat 22; the screw fixed support seat 25 is fixed on the rear support 15 through bolts, the bearing 95 (such as an angular contact ball bearing 95) in the screw fixed support seat 25 is rigidly connected with one end of the ball screw 23, and the axial and radial displacements of the end are limited; the screw floating support seat 22 is installed on the front support 2, the bearing 95 (such as a deep groove ball bearing 95) in the screw floating support seat 22 cooperates with the other end of the ball screw 23, and only limits the radial displacement, allowing a small amount of axial expansion and contraction (compensating for temperature changes or installation errors); the screw nut 16 is connected with the bottom of the sliding workbench 5 through bolts, and is engaged with the ball screw 23; the axial feed motor 14 is connected with the end of the ball screw 23 through the motor adapter 26, for driving the rotation of the ball screw 23.

[0060] When the axial feed motor 14 drives the ball screw 23 to rotate, the screw nut 16 cannot rotate because it is fixed with the sliding workbench 5, and then moves axially along the ball screw 23, driving the sliding workbench 5 to move synchronously along the linear guide rail 20 with the screw nut 16, thereby realizing the axial feeding of the workpiece 17.

[0061] The ball screw 23 is in rolling contact with the screw nut 16 through balls, and the friction coefficient is extremely low compared with a traditional sliding screw, reducing energy loss and heat generation in the feeding process and ensuring the stability of feeding; the combination design of the screw fixed support seat 25 and the floating support seat not only limits the radial swing of the screw (ensures the transmission accuracy), but also allows the axial micro expansion (avoids the deformation of the screw due to temperature changes or installation errors); the setting of the motor adapter 26 makes the connection of the axial feeding motor 14 and the ball screw 23 more adaptive, reducing assembly deviation.

[0062] Further, the outer diameter of the tool holder component 9 is smaller than the inner hole diameter of the workpiece 17 to be machined.

[0063] The maximum outer diameter of the tool holder component 9 (including the tool holder front half 92, the rear half, and the external structure) is designed to be smaller than the inner hole diameter of the workpiece 17 to be machined (for example, when the inner hole diameter of the workpiece 17 is 50 mm, the outer diameter of the tool holder component 9 is set to 45 mm).

[0064] When the workpiece 17 rotates circumferentially under the drive of the rotary table 6 and moves axially under the drive of the sliding table 5, the inner hole wall of the workpiece 17 and the outer circle of the tool holder component 9 always maintain a gap (non-contact), and the iron filings generated by the milling cutter 97 can be discharged through the gap.

[0065] If the outer diameter of the tool holder component 9 is greater than or equal to the inner hole diameter of the workpiece 17, the workpiece 17 will collide (interfere) with the tool holder component 9 during feeding, causing damage to the workpiece 17 or the equipment; while the outer diameter of the tool holder component 9 is smaller than the inner hole diameter of the workpiece 17, the interference can be completely avoided, ensuring the safety of the machining process. At the same time, the existence of the gap provides a discharge channel for the iron filings, preventing the accumulation of iron filings in the cutting area (avoiding scratching the surface of the workpiece 17 or affecting the cutting of the milling cutter 97), and improving the machining quality.

[0066] Further, it also includes a driven wheel 10 adjusting mechanism, which includes a connecting block 13 and an adjusting screw 12, the adjusting screw 12 is installed on the connecting block 13, and the end thereof abuts against the driven wheel 10 mounting seat, for adjusting the position of the driven wheel 10 to tension the synchronous belt.

[0067] The driven wheel 10 adjusting mechanism includes a connecting block 13 and an adjusting screw 12; the connecting block 13 is fixed to the rear support 15, and a threaded hole is provided thereon, the adjusting screw 12 is in threaded cooperation with the threaded hole, and the end thereof abuts against the driven wheel 10 mounting seat; the driven wheel 10 mounting seat is connected with the rear support 15 through a long circular hole and a bolt (allowing micro displacement).

[0068] When the tension of the synchronous belt is insufficient (slip) or too tight (wear too fast), rotate the adjusting screw 12, the end of which pushes the driven wheel 10 mounting seat to move along the long circular hole direction (away from or close to the driving wheel 3), thereby changing the distance between the driving wheel 3 and the driven wheel 10, and achieving the adjustment of the tension of the synchronous belt; after the adjustment is completed, tighten the fixing bolt of the driven wheel 10 mounting seat to lock the position.

[0069] The tension of the synchronous belt directly affects the transmission accuracy (too loose is easy to slip, resulting in unstable speed of the hollow gear shaft 96; too tight will increase the load of the motor and the wear of the pulley). Through the thread cooperation of the adjusting screw 12 and the connecting block 13, the position of the driven wheel 10 can be adjusted in a small amount and accurately, and the tension of the synchronous belt can be conveniently adjusted to the best state, ensuring the stability of the main cutting motion (uniform speed of the milling cutter 97) and prolonging the service life of the synchronous belt and the pulley.

[0070] Further, the tool holder assembly 9 also includes a guide column 93, which is fixedly connected to the tool holder front half 92 and the tool holder rear half 91 at both ends, respectively, for guiding and positioning the connection of the tool holder front half 92 and the tool holder rear half 91.

[0071] The guide column 93 is a cylindrical structure, which is interference-fitted (or fixed by bolts) with the guide holes of the tool holder front half 92 and the tool holder rear half 91 at both ends, respectively, and is evenly distributed circumferentially (such as 2-4) along the tool holder assembly 9; after the tool holder front half 92 and the rear half are positioned by the guide column 93, they are tightly connected by circumferentially distributed screws 99.

[0072] When assembling the tool holder assembly 9, the guide column 93 is first inserted into the guide hole of the tool holder front half 92, and then cooperates with the guide hole of the tool holder rear half 91, ensuring that the bearing 95 holes (holes for installing the hollow gear shaft 96) of the two are completely coaxial; when tightening the screw 99, the guide column 93 limits the relative deviation of the front and rear halves, ensuring the overall accuracy after connection.

[0073] If the tool holder front half 92 and the rear half are only connected by the screw 99, the bearing 95 holes of the two may be decentered due to assembly deviation, which in turn causes radial runout when the hollow gear shaft 96 rotates (affecting the stability of the milling cutter 97); the guide column 93 rigidly positions the front and rear halves, forcing the bearing 95 holes of the two to remain coaxial, ensuring the rotational accuracy of the hollow gear shaft 96. At the same time, the guide column 93 shares part of the torque generated by the cutting force (avoiding excessive stress on the screw 99 alone), enhancing the overall rigidity of the tool holder assembly 9 and prolonging the service life.

[0074] Further, the chuck is a three-jaw chuck, including a chuck body 7 and three chuck jaws 8, which are evenly distributed circumferentially along the chuck body 7, for clamping and fixing the workpiece 17.

[0075] The chuck is a three-jaw chuck, which comprises a chuck body 7 and three chuck jaws 8. The three chuck jaws 8 are evenly distributed along the circumference of the chuck body 7 (with an included angle of 120°) and are connected through a threaded transmission mechanism in the chuck body 7 (rotating the chuck wrench can drive the three chuck jaws 8 to move radially synchronously). The chuck body 7 is fixed to the output end of the rotary worktable 6 by bolts, and the center of rotation thereof coincides with the center of rotation of the rotary worktable 6.

[0076] When clamping the workpiece 17, the workpiece 17 is placed between the three chuck jaws 8, and the wrench is rotated to move the three chuck jaws 8 synchronously towards the center to clamp the outer circle of the workpiece 17 evenly from three directions. During the machining process, the rotary worktable 6 drives the chuck and the workpiece 17 to rotate synchronously. Since the three chuck jaws 8 are evenly distributed, the center of rotation of the workpiece 17 coincides with the center of the chuck (i.e., coincides with the center of the feed motion of the equipment).

[0077] The synchronous movement of the three chuck jaws 8 of the three-jaw chuck can automatically center, which solves the problem that it is difficult to ensure concentricity by manual clamping. The evenly distributed clamping force can avoid deformation of the workpiece 17 due to uneven force (especially suitable for bearing shells made of copper alloy and other low-hardness materials), thereby ensuring the stability of the workpiece 17 during machining. At the same time, the quick clamping / loosening function of the chuck jaws 8 (compared with bolt fixation) can shorten the clamping time of the workpiece 17 and improve the machining efficiency.

[0078] Embodiment Two

[0079] A method for using a small-size inner hole special-shaped groove machining equipment, characterized in that it comprises the following steps:

[0080] S1: Preprocessing the workpiece 17 to be machined to process a pilot hole on the inner hole surface of the workpiece 17, the pilot hole being used for guiding the milling cutter 97 to cut radially along the workpiece 17 to a preset groove depth during the initial stage of cutting;

[0081] S2: Clamping the preprocessed workpiece 17 between the chuck jaws 8 of the chuck, and fixing the workpiece 17 by tightening the chuck jaws 8. The chuck is installed on the rotary worktable 6, and the rotary worktable 6 is installed on the sliding worktable 5;

[0082] S3: Installing the milling cutter 97 in the hollow gear shaft 96 of the tool holder component 9, axially locking the milling cutter 97 through the locking cap 98 at the lower end of the hollow gear shaft 96, and circumferentially locking the milling cutter 97 by cooperating the platform at the tail of the milling cutter 97 with the screw 99 at the upper end of the hollow gear shaft 96;

[0083] S4: Starting the main motor 21, and rotating the milling cutter 97 to realize the main cutting motion by driving the driven wheel 10 and the hollow gear shaft 96 engaged with the synchronous belt through the driving wheel 3 and the synchronous belt;

[0084] S5: control the axial feed motor 14 to drive the ball screw 23 pair of operation, so that the sliding workbench 5 moves along the linear guide rail 20 in the axial direction, and control the rotary workbench 6 feed motor to drive the rotary workbench 6 to rotate the workpiece 17 in the circumferential direction, so that the combination of axial movement and circumferential rotation realizes the feed of the workpiece 17; wherein the milling cutter 97 is radially fed to the preset groove depth along the step S1 lead hole, and no radial feed is performed in the whole machining process until the machining of the special-shaped groove on the inner hole surface of the workpiece 17 is completed.

[0085] The setting of the lead hole solves the problem that the milling cutter 97 is difficult to be radially fed in the closed inner hole (avoiding the direct collision between the milling cutter 97 and the inner hole wall of the workpiece 17 when initially cutting); the rigid fixing of the clamping of the workpiece 17 and the installation of the milling cutter 97 ensures the stability of the relative position of the two in the machining process; the main motor 21 provides continuous cutting motion, and the combination of axial and circumferential feed can accurately reproduce the trajectory of the special-shaped groove (such as "day" type, arc). The whole process standardizes the machining steps, avoids the randomness of manual operation (such as benching), improves the machining precision and efficiency, and is especially suitable for batch machining of small-size inner hole special-shaped grooves.

[0086] The above only describes the preferred embodiments of the application and is not used to limit the application, and any modification, equivalent replacement and improvement made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A small-size inner hole special-shaped groove processing equipment, characterized in that: It includes a base plate, a front support, a rear support, a sliding worktable, a linear guide, a rotary worktable, a chuck, a tool holder component, a main motor, a driving wheel, a driven wheel, a synchronous belt, an axial feed motor, a rotary worktable feed motor and a ball screw pair; the front support and the rear support are fixed to the base plate, the linear guide is installed on the base plate, and the sliding worktable is slidably connected to the linear guide through a guide slider; the rotary worktable is installed on the sliding worktable, and the chuck is installed on the rotary worktable for clamping the workpiece; the tool holder component is installed on the front support, and a hollow gear shaft is provided in the tool holder component, and a hollow gear shaft is installed on the hollow gear shaft A milling cutter is installed; the main motor is installed on the front support, the driving wheel is connected to the output end of the main motor, the driven wheel is installed on the rear support through the driven wheel mounting seat, and the synchronous belt is sleeved on the driving wheel and the driven wheel and meshes with the hollow gear shaft; the axial feed motor is connected to the ball screw pair, used to drive the sliding worktable to move axially along the linear guide rail; the rotary table feed motor is used to drive the rotary table to drive the workpiece to rotate circumferentially; the main motor drives the hollow gear shaft through the synchronous belt to drive the milling cutter to perform the main cutting motion, and the feed motion of the workpiece is realized by the axial movement of the sliding worktable and the circumferential rotation of the rotary table; The tool holder component includes a front half of the tool holder, a rear half of the tool holder, a guide column, a bearing and a round nut; the front half of the tool holder and the rear half of the tool holder are connected and fixed by the guide column, the hollow gear shaft is installed between the front half of the tool holder and the rear half of the tool holder through the bearing, and the round nut is used to axially position the bearing; A milling cutter is installed in the hollow gear shaft, and a locking cap is provided at the lower end of the hollow gear shaft, and the locking cap is used to lock the milling cutter axially; a screw hole is provided at the upper end of the hollow gear shaft, and a platform is provided at the tail of the milling cutter, and a screw is passed through the screw hole and cooperates with the platform to lock the milling cutter circumferentially; The outer diameter of the tool holder component is smaller than the inner diameter of the workpiece to be processed.

2. The small-size inner hole special-shaped groove processing equipment according to claim 1 is characterized in that: The synchronous belt is a live-jointed synchronous belt.

3. The small-size inner hole special-shaped groove processing equipment according to claim 1 is characterized in that: The ball screw pair includes a ball screw, a screw nut, a screw fixed support seat and a screw floating support seat; one end of the ball screw is installed on the rear support seat through the screw fixed support seat, and the other end is installed on the front support seat through the screw floating support seat. The screw nut is connected to the sliding workbench, and the axial feed motor is connected to the ball screw through a motor adapter, which is used to drive the ball screw to rotate to drive the sliding workbench to move.

4. The small-size inner hole special-shaped groove processing equipment according to claim 1 is characterized in that: It also includes a driven wheel adjustment mechanism, which includes a connecting block and an adjusting screw. The adjusting screw is installed on the connecting block, and its end abuts against the driven wheel mounting seat, and is used to adjust the position of the driven wheel to tighten the synchronous belt.

5. The small-size inner hole special-shaped groove processing equipment according to claim 1 is characterized in that: The tool holder component also includes a guide column, the two ends of which are fixedly connected to the front half of the tool holder and the rear half of the tool holder respectively, and are used to guide and position the connection between the front half of the tool holder and the rear half of the tool holder.

6. The small-sized inner hole special-shaped groove processing equipment according to claim 1 is characterized in that: The chuck is a three-jaw chuck, comprising a chuck body and three jaws. The three jaws are evenly distributed along the circumference of the chuck body and are used to clamp and fix a workpiece.

7. A method for using a small-sized inner hole special-shaped groove processing device, applied to a small-sized inner hole special-shaped groove processing device according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: Pre-processing the workpiece to be machined, machining a guide hole on the inner surface of the workpiece, wherein the guide hole is used for the milling cutter to feed radially along the workpiece to a preset groove depth in the initial stage of cutting; S2: Clamping and fixing the pre-treated workpiece on a chuck, wherein the chuck is mounted on a rotary table, and the rotary table is mounted on a sliding table; S3: Install the milling cutter into the hollow gear shaft of the cutter holder component and lock the milling cutter; S4: Start the main motor, which drives the driven wheel and the hollow gear shaft meshing with the synchronous belt through the driving wheel and the synchronous belt, thereby driving the milling cutter to rotate to achieve the main cutting motion; S5: Control the axial feed motor to drive the ball screw pair to operate, so that the sliding worktable moves axially along the linear guide rail, and at the same time control the rotary table feed motor to drive the rotary table to drive the workpiece to rotate circumferentially, and realize the feeding of the workpiece through the combined movement of axial movement and circumferential rotation; wherein, after the milling cutter radially feeds along the guide hole described in step S1 to the preset groove depth, no radial feeding is performed during the entire processing process until the processing of the special-shaped groove on the inner hole surface of the workpiece is completed.

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