An adaptive compensation drilling and milling system for a steering gear housing bore system

Abstract

The present application relates to the technical field of drilling and milling, and discloses a self-adaptive compensation drilling and milling system for a steering gear housing hole system, which comprises a drilling and milling workbench and a drilling and milling mechanism; the drilling and milling mechanism is installed on the drilling and milling area of the drilling and milling workbench through a moving guide rail group; the drilling and milling area of the drilling and milling workbench is also provided with a clamping tool; the drilling and milling mechanism comprises a control shell, a rotating main shaft and a tool shank seat; the rotating main shaft is rotationally connected to the inside of the control shell and is in transmission connection with a driving motor installed on the control shell. The vertical compensation module relies on the piezoelectric jacking to drive the whole micro-lifting of the control shell, independently offsets the axial thermal elongation generated by the high-speed rotation of the main shaft, avoids the overcut of the hole depth, the radial compensation module is formed by the piezoelectric actuating units uniformly distributed in the circumference of the tool shank, the micron-level position of the tool in the X / Y direction can be independently adjusted, the hole diameter deviation caused by the tool wear and the tool setting of the thin-wall workpiece cutting can be compensated in real time, and the waste product rate of the steering gear housing hole processing is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of drilling and milling technology, and more specifically to an adaptive compensation drilling and milling system for a steering gear housing bore system. Background Technology

[0002] The automotive steering gear housing contains numerous positioning holes and stepped mounting holes. Two types of core dimensional errors exist during machining, severely restricting batch processing accuracy and finished product yield. Firstly, the high-speed rotation of the spindle generates continuous heat, causing axial thermal expansion, directly leading to overcutting of the machined hole depth and exceeding depth tolerances. Existing machine tools rely solely on unified Z-axis compensation, resulting in a large compensation stroke and lag response, failing to achieve micron-level independent micro-correction and insufficient compensation accuracy. Secondly, thin-walled housings are prone to elastic tool deflection during drilling and milling, and continuous tool machining causes progressive wear. Both factors contribute to undersized holes and hole position misalignment. Conventional standard tool holders lack radial fine-tuning capabilities, making it difficult to compensate for radial dimensional deviations in real time.

[0003] In existing technologies, adding a separate radial piezoelectric adjustment tool holder presents challenges in maintaining stable power supply during rotation. External slip rings are susceptible to corrosion from cutting fluid and aluminum dust, and the sliding friction structure wears quickly, easily leading to signal interruption during vibration. Traditional axial compensation mechanisms lack backlash elimination and self-locking protection structures, making them prone to compensation position drift due to cutting impacts, and the piezoelectric elements are susceptible to fatigue damage under prolonged continuous pressure. Currently, there is a lack of an integrated drilling and milling system that can simultaneously achieve adaptive compensation for axial thermal deformation and radial tool wear, making it impossible to simultaneously meet the high-precision machining requirements for both hole depth and diameter. Summary of the Invention

[0004] To address the aforementioned shortcomings of existing technologies, this invention provides an adaptive compensation drilling and milling system for steering gear housing bore systems. This system effectively solves the problems of excessive hole depth caused by spindle heating and axial elongation, as well as the dual machining errors of hole diameter and hole position dimensions caused by tool wear and workpiece deflection.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The present invention provides an adaptive compensation drilling and milling system for a steering gear housing bore system, including a drilling and milling table and a drilling and milling mechanism; the drilling and milling mechanism is mounted on the drilling and milling area of ​​the drilling and milling table via a movable guide rail assembly; the drilling and milling area of ​​the drilling and milling table is also provided with a clamping fixture, and the drilling and milling mechanism includes a control housing, a rotary spindle and a tool holder.

[0007] The rotating spindle is rotatably connected inside the control housing and is driven by a drive motor mounted on the control housing. The bottom end of the rotating spindle extends to the outside of the control housing and is fixedly connected to the tool holder. The tool holder contains a clamping seat for holding the tool and a radial compensation module. The radial compensation module adopts a circumferentially distributed piezoelectric actuation structure to adjust the clamping seat's independent radial micron-level displacement in the X / Y plane, compensating in real time for radial tool deflection errors caused by tool wear and cutting load. The radial compensation module is electrically connected to the electronic control board inside the control housing through a conductive module.

[0008] The control housing is mounted on the vertically moving Z-axis slide in the moving guide rail assembly. The Z-axis slide is equipped with an independent vertical compensation module. The vertical compensation module drives the control housing to move slightly up and down in the vertical direction by piezoelectric lifting drive, which drives the rotating spindle and the tool to move axially synchronously, thus offsetting the thermal elongation overcutting error caused by the high-speed rotation of the spindle.

[0009] Furthermore, the cylindrical mounting portion integrally formed at the top of the clamping seat extends into the interior of the clamping seat through a through-hole opened at the bottom of the tool holder seat.

[0010] The radial compensation module includes several piezoelectric actuation units evenly distributed in a circle, used to radially drive the clamping seat inside the tool holder; one end of the piezoelectric actuation unit abuts against the inner wall of the tool holder, and the other end abuts against the clamping seat.

[0011] The diameter of the extension portion of the cylindrical mounting portion extending into the tool holder seat is larger than the diameter of the through opening, and the bottom of the extension portion contacts the bottom of the tool holder seat.

[0012] A disc spring assembly is connected between the inner top of the tool holder and the top of the cylindrical mounting part.

[0013] Furthermore, the vertical compensation module includes several piezoelectric actuators and a vertical guide rail pair; the control housing is slidably connected to the Z-axis slide table via the vertical guide rail pair, the several piezoelectric actuators are fixed to the bottom side of the Z-axis slide table in a straight line, and the side of the control housing is integrally formed with a pressure-bearing part, the actuating end of the several piezoelectric actuators contacts the bottom of the pressure-bearing part, and is used to drive the pressure-bearing part upward through the piezoelectric actuators, thereby causing the control housing and the spindle to move slightly upward vertically relative to the Z-axis slide table, thus compensating for the thermal elongation error of the spindle.

[0014] Furthermore, the vertical guide rail pair includes a guide rail frame and a guide rail block, the guide rail block slides vertically inside the guide rail frame, and the guide rail frame and the guide rail block are respectively fixed to the Z-axis slide table and the control housing; a self-locking unit is provided between the guide rail frame and the guide rail block;

[0015] At least two sets of second disc spring groups are connected between the control housing and the top of the Z-direction sliding table, and the second disc spring groups are configured to press down the control housing, so that the pressure-bearing portion is always in close contact with the actuating ends of the plurality of piezoelectric actuators.

[0016] Further, the self-locking unit includes an electromagnet, a metal plate, and a pressing portion; a connecting portion is horizontally and slidably connected inside the guide rail block, one end of the connecting portion is fixed to the pressing portion, and the other end extends into the control housing and is fixedly connected to the metal plate; the electromagnet is installed inside the control housing, and is configured to magnetically attract the metal plate when energized, so that the metal plate drives the connecting portion and the pressing portion to displace toward the inner wall of the guide rail frame, and the pressing portion abuts against the inner wall of the guide rail frame to form self-locking of the vertical guide pair.

[0017] Further, a strip-shaped tapered opening is formed on the inner wall of the guide rail frame, the strip-shaped tapered opening is formed along the length direction of the guide rail frame, and the abutting end of the pressing portion is tapered, which is configured to be inserted into the strip-shaped tapered opening to form self-locking of the vertical guide pair and centered positioning calibration after adjustment, so as to eliminate guide rail clearance;

[0018] A plurality of hidden grooves are formed on the tapered abutting end of the pressing portion along the length direction of the strip-shaped tapered opening, two symmetrically arranged balls and a first elastic member are disposed inside each hidden groove, and the first elastic member is configured to elastically press the two balls.

[0019] Further, the conductive module is located inside the control housing, and includes an insulating sleeve, a positive electrode contact block, a negative electrode contact block, and two conductive connecting portions; the insulating sleeve is fixed on the outer surface of the rotating main shaft, a line groove is formed inside the rotating main shaft, a circuit board is installed inside the line groove, and the circuit board is electrically connected to the piezoelectric actuating unit through a wire;

[0020] Two annular open grooves are formed on the outer surface of the insulating sleeve, the positive electrode contact block and the negative electrode contact block are respectively fixed in the two annular open grooves, and the conductive contact ends of the two contact blocks both extend into the line groove and are electrically connected to the circuit board;

[0021] The two conductive connecting portions are both electrically connected to the electric control board through wires, and the two conductive connecting portions are respectively in conductive connection with the positive electrode contact block and the negative electrode contact block.

[0022] Further, the conductive connecting portion includes an annular insulating mounting frame and a plurality of conductive portions; the insulating mounting frame is fixed inside the control housing, and the plurality of conductive portions are fixed on the insulating mounting frame in a circumferentially uniform distribution manner;

[0023] The cross sections of the positive electrode contact block and the negative electrode contact block are both C-shaped;

[0024] The conductive part includes a conductive frame and two conductive balls; the conductive frame is fixed on an insulating mounting frame and its end extends into the groove through the opening of an annular slot; the two conductive balls are disposed at the end of the conductive frame; a conductive elastic element is connected between the two conductive balls to elastically compress the two conductive balls, so that the two conductive balls elastically contact the top and bottom of the U-shaped contact block to form a conductive connection.

[0025] The insulating sleeve is equipped with two sets of lubrication units to reduce the coefficient of friction and heat between the conductive ball and the contact block.

[0026] Furthermore, the lubrication unit includes an annular grease reservoir filled with conductive grease. The grease reservoir is located inside the insulating sleeve and above the annular opening groove. A filling area is provided at the bottom of the end of the grease reservoir. Several circumferentially distributed filling ports are provided between the filling area and the interior of the annular opening groove.

[0027] The filling port is equipped with a pressure valve plate, and the connecting area between the grease storage chamber and the filling area is provided with an arc-shaped guide surface.

[0028] Furthermore, the lubrication unit also includes an annular collecting groove, which is opened inside the insulating sleeve and located below the annular opening groove. The collecting groove is connected to the inside of the annular opening groove through an annular guide channel, which is located on the outer side of the annular opening groove. The receiving end of the annular guide channel is flared.

[0029] The technical solution provided by this invention has the following advantages compared with the prior art:

[0030] 1. This invention constructs a dual-layer independent adaptive compensation system for axial and radial directions, which can simultaneously solve the two core error problems in the machining of the steering gear housing holes. The vertical compensation module relies on piezoelectric lifting drive to control the overall micro-lifting of the housing, independently offsetting the axial thermal expansion generated by the high-speed rotation of the spindle and avoiding excessive hole depth cutting; the radial compensation module is composed of piezoelectric actuation units evenly distributed around the circumference inside the tool holder, which can independently adjust the micron-level position of the tool in the X / Y radial direction, and compensate for the hole diameter deviation caused by tool wear and tool deflection during cutting of thin-walled workpieces in real time, significantly reducing the scrap rate of steering gear housing hole machining.

[0031] 2. The self-locking unit of this invention uses an electromagnet to attract a conical clamping part that is embedded in the conical opening of the guide rail frame. The conical surface achieves centered positioning of the guide rail, completely eliminating assembly gaps. After compensation, the relative position is locked, relieving continuous pressure on the piezoelectric element and delaying fatigue wear. The clamping part incorporates ball bearings and an elastic element, converting dry friction into rolling friction during unlocking and sliding, preventing jamming and balancing locking rigidity with smooth, slight sliding. The overall structure can withstand compensation position drift caused by cutting impacts, balancing micron-level compensation accuracy and long-term operational stability.

[0032] 3. The present invention features a double conductive ball bearing and an elastic element that double-presses a U-shaped conductive ring, which maintains conductive contact under vibration conditions and prevents the compensation signal from being interrupted. The insulating sleeve integrates a grease storage cavity, a collection groove and a flow channel. The centrifugal force of the rotating spindle automatically delivers conductive grease to the friction pair, while simultaneously guiding and collecting waste grease mixed with metal shavings, thus realizing the integration of lubrication replenishment and shavings separation. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of the present invention;

[0035] Figure 2 This is a schematic diagram of the drilling and milling mechanism of the present invention;

[0036] Figure 3 This is a cross-sectional view of the control housing of the present invention;

[0037] Figure 4 This is a schematic diagram of the rotating spindle of the present invention;

[0038] Figure 5 This is a cross-sectional view of the tool holder of the present invention;

[0039] Figure 6 This is a cross-sectional view of the conductive module of the present invention;

[0040] Figure 7 This is a cross-sectional front view of the conductive module of the present invention;

[0041] Figure 8 This is a structural exploded view of the vertical compensation module of the present invention;

[0042] Figure 9 This is a top view of the combination of the vertical guide rail pair and the self-locking unit of the present invention;

[0043] Figure 10 This is a partial cross-sectional view of the clamping part of the present invention.

[0044] The labels in the diagram represent:

[0045] 10. Drilling and milling table; 11. Moving guide rail assembly; 12. Clamping fixture; 13. Drive motor; 14. Electrical control board;

[0046] 20. Drilling and milling mechanism; 21. Control housing; 22. Rotary spindle; 23. Tool holder; 231. Clamping seat; 232. Piezoelectric actuation unit; 233. Disc spring assembly 1;

[0047] 30. Conductive module; 31. Insulating sleeve; 32. Positive contact block; 33. Negative contact block; 34. Insulating mounting bracket; 35. Conductive frame; 36. Conductive ball; 37. Elastic element two;

[0048] 38. Lubrication unit; 381. Grease reservoir; 382. Collection tank; 383. Annular flow channel;

[0049] 40. Vertical compensation module; 41. Piezoelectric actuator; 42. Guide rail frame; 43. Guide rail block; 44. Disc spring assembly two;

[0050] 45. Self-locking unit; 451. Electromagnet; 452. Metal plate; 453. Clamping part; 454. Strip-shaped conical opening; 455. Ball bearing;

[0051] D. Knives. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0053] The present invention will be further described below with reference to embodiments.

[0054] Example 1:

[0055] Please see Figures 1 to 10 This invention provides a technical solution: an adaptive compensation drilling and milling system for steering gear housing holes. This system adopts an integrated CNC machining architecture of a drilling and milling worktable 10 (reference bed) and a Z-axis composite adaptive drilling and milling mechanism 20. It addresses three major machining error pain points for automotive steering gear housings: radial wear of the tool (D), high-speed thermal expansion of the rotary spindle 22, and guide rail misalignment after micro-compensation. It achieves real-time adaptive compensation of hole size, coaxiality, and position at the micrometer level. The entire machine is supported by the drilling and milling worktable 10, with a moving guide rail assembly 11 mounted on the table surface. The drilling and milling mechanism 20 is mounted on the Z-axis vertical slide of the moving guide rail assembly 11. The drilling and milling worktable 10 is equipped with a clamping fixture 12 at its drilling and milling station, allowing for quick clamping of multiple steering gear housings and ensuring a unified workpiece machining reference.

[0056] The drilling and milling mechanism 20 is a multi-layer integrated error compensation assembly. The external protective carrier is the control housing 21, and the rotating spindle 22 is coaxially mounted inside the housing. The drive motor 13 is fixed to the upper end of the control housing 21 and fixed to the input end of the rotating spindle 22, providing rotational power for the drilling and milling cutting of the tool D. The lower end of the rotating spindle 22 is rigidly locked with the tool holder 23. The tool holder 23 is equipped with a clamping seat 231 and a circumferentially distributed radial compensation module. The radial compensation module uses a piezoelectric actuation unit 232 as the actuator and outputs micron-level radial displacement based on the piezoelectric inverse effect to compensate for the radial deflection size deviation caused by tool D wear and cutting load in real time.

[0057] The power supply link of the radial compensation module is built on the conductive module 30. The conductive module 30 is installed on the outer wall of the rotating spindle 22. The wires of the conductive module 30 and the electrical control board 14 inside the control housing 21 form a closed-loop signal circuit. The electrical control board 14 receives the compensation command from the machine tool CNC system and adjusts the voltage in real time to control the independent output of the compensation amount of each group of piezoelectric actuation units 232.

[0058] The control housing 21 is slidably mounted on the vertical guide rail pair of the Z-axis slide table, and is equipped with an independent vertical compensation module 40. The vertical compensation module 40 adopts a piezoelectric lifting drive structure, which can independently drive the control housing 21 and the rotary spindle 22 to lift vertically slightly, accurately offsetting the axial thermal elongation overcutting error generated by the continuous operation of the rotary spindle 22. The Z-axis slide table receives servo feed drive, which drives the entire drilling and milling mechanism 20 to lift and lower in a large stroke, completing the main cutting operation of drilling and milling the steering gear housing hole.

[0059] See attached document Figure 5 The upper end of the clamping seat 231 is integrally formed with a cylindrical mounting part, which extends upward through the bottom through hole of the tool holder seat 23 and into the inner cavity of the tool holder seat 23. The diameter of the outer circular disk at the upper end of the cylindrical mounting part is larger than the inner diameter of the through hole, forming an axial limiting step. The bottom surface of the disk is in full contact with the inner bottom surface of the tool holder seat 23, constraining the clamping seat 231 to only produce planar radial displacement and no axial movement.

[0060] The radial compensation module is evenly arranged with multiple piezoelectric actuation units 232 along the circumference of the clamping seat 231. One end of the piezoelectric actuation unit 232 abuts against the inner side wall of the tool holder seat 23, and the other end is pressed against the outer peripheral wall of the clamping seat 231. Each set of piezoelectric actuation units 232 can independently adjust the voltage output displacement to achieve arbitrary radial offset correction in both X and Y directions, and adapt to the error compensation requirements of round holes, eccentric mounting holes, and irregular stepped holes.

[0061] The disc spring assembly 233 is preloaded between the inner top surface of the tool holder 23 and the upper end of the cylindrical mounting part of the clamping seat 231. The disc spring assembly 233 continuously outputs a constant preload downward, pressing the bottom disc of the clamping seat 231 against the inner bottom of the tool holder 23, eliminating axial clearance during radial compensation, improving the overall rigidity of the tool D clamping, and suppressing the distortion of compensation values ​​caused by high-speed cutting vibration.

[0062] See attached document Figure 8 The vertical compensation module 40 is composed of a piezoelectric actuator 41 and a high-rigidity vertical guide rail pair coupled together. The vertical guide rail pair includes a guide rail frame 42 and a guide rail block 43. It adopts a square heavy-duty guide rail configuration, which has strong bending and torsional resistance and can withstand the axial cutting impact load of drilling and milling.

[0063] Multiple piezoelectric actuators 41 are linearly fixed at the bottom of the Z-axis sliding side. The control housing 21 has an integrally formed pressure-bearing part on its side wall. The actuating end of the piezoelectric actuator 41 continuously adheres to the bottom surface of the pressure-bearing part. After the piezoelectric actuator 41 is energized, it generates a micron-level axial lifting stroke, which directly lifts the control housing 21 and the rotating spindle 22 slightly upward, thus counteracting the axial overcut caused by the heating and elongation of the rotating spindle 22.

[0064] See attached document Figure 8 The vertical guide rail pair is composed of a guide rail frame 42 (fixed to the Z-axis slide table) and a guide rail block 43 (fixed to the control housing 21). The guide rail block 43 can only slide vertically along the guide rail frame 42, limiting the horizontal offset of the drilling and milling mechanism 20.

[0065] A self-locking unit 45 is assembled between the guide rail frame 42 and the guide rail block 43. After a single axial thermal expansion micro-compensation is completed, the self-locking unit 45 locks the relative position of the guide rail pair, removes the piezoelectric actuator 41 from continuous pressure, extends the fatigue service life of the piezoelectric element, and avoids the drift of the compensation position caused by cutting impact.

[0066] At least two sets of disc springs 44 are symmetrically arranged between the top of the control housing 21 and the crossbeam on the Z-axis slide. The disc springs 44 provide a constant preload downwards, so that the pressure-bearing part of the control housing 21 is always in close contact with the actuation end of the piezoelectric actuator 41, eliminating the fit gap and ensuring that the piezoelectric lifting compensation has no backlash and no response lag.

[0067] See attached document Figures 8 to 10 The self-locking unit 45 is composed of an electromagnet 451, a metal plate 452, and a clamping part 453. A horizontal sliding through hole is opened inside the guide block 43, and a connecting part is slidably assembled in the through hole. The outer end is connected to the clamping part 453, and the inner end extends into the control housing 21 and is rigidly connected to the metal plate 452.

[0068] Electromagnet 451 is embedded in the inner cavity of control housing 21. After compensation, electromagnet 451 is energized to generate magnetic attraction force, which attracts metal plate 452 inward. Simultaneously, it drives the connecting part and the pressing part 453 to press against the inner wall of guide rail frame 42. The relative position of guide rail block 43 and guide rail frame 42 is locked by the interference friction of the conical surface.

[0069] See attached document Figure 3 , Figure 4 , Figure 6 and Figure 7The conductive module 30 is arranged inside the control housing 21 and in the middle of the rotating spindle 22. The insulating support base is the insulating sleeve 31, which is interference-fitted onto the outer surface of the rotating spindle 22 to achieve metal insulation isolation of the spindle. A through-line groove is opened in the center of the rotating spindle 22, and a miniature power supply circuit board is installed in the groove. The circuit board leads are connected upward to all piezoelectric actuation units 232 to complete the power supply transmission of the rotating end compensation element.

[0070] Two annular openings are formed on the outer wall of the insulating sleeve 31, and positive contact block 32 and negative contact block 33 are fixed in the slots respectively. The conductive pins on the inner side of positive contact block 32 and negative contact block 33 extend through the slot wall into the circuit slot and are electrically connected to the positive and negative solder pads of the circuit board to form a rotating side conductive ring base.

[0071] Two sets of conductive connection parts are assembled on the static side of the control housing 21. The two sets of conductive connection parts are respectively connected to the positive and negative output terminals of the control board 14 through wires. The conductive connection parts continuously slide in contact with the positive contact block 32 and the negative contact block 33, and continuously transmit compensation control electrical signals to the piezoelectric actuation unit 232 during the high-speed drilling and milling operation of the rotating spindle 22.

[0072] See attached document Figure 6 and Figure 7 The conductive connection part is fixed with an annular insulating mounting bracket 34 as the base. The insulating mounting bracket 34 is locked to the inner wall of the control housing 21. Multiple sets of independent conductive parts are evenly distributed along the circumference. Each set of conductive parts includes a conductive frame 35, a pair of conductive balls 36, and a conductive elastic element 37.

[0073] The conductive frame 35 extends cantilevered into the annular opening groove, and the end of the frame clamps two conductive balls 36. The conductive elastic element 37 is stretched laterally between the two conductive balls 36. The elastic element 37 continuously pre-tightens the two conductive balls 36, so that the balls are elastically attached to the upper and lower inner walls of the U-shaped positive electrode contact block 32 and negative electrode contact block 33 on both sides, forming a constant voltage conductive contact pair.

[0074] During drilling and milling, the rotating spindle 22 continuously vibrates at high frequency. When the conductive ball 36 on one side contracts due to impact, the conductive elastic element 37 quickly transfers the preload to the conductive ball 36 on the other side, ensuring that at least one ball is in close contact with the contact block, thus preventing power outages and loss of compensation signals under vibration conditions. The insulating sleeve 31 is equipped with two sets of lubrication units 38, which continuously supply conductive grease to the friction interface between the conductive ball 36 and the contact block, reducing the coefficient of friction, suppressing frictional heat generation, and extending the overall service life of the conductive module 30.

[0075] This invention integrates a miniature capacitive radial displacement sensor inside the tool holder 23. The sensor is fixed between the tool holder base and the clamping seat 231, and can collect the radial offset of the tool D relative to the tool holder reference in real time, realizing high-precision closed-loop detection. At the same time, a temperature sensor and an axial displacement sensor are arranged on the control housing 21 to monitor the spindle operating temperature rise and the amount of thermal expansion deformation of the spindle in real time.

[0076] The entire equipment consists of two independent detection and control logics: axial compensation and radial compensation. These logics are decoupled from each other and do not interfere with each other.

[0077] The spindle thermal deformation axial compensation process is as follows: During normal machine tool processing, the Z-axis slide completes a wide range of feed cutting actions; the temperature sensor collects spindle temperature rise data in real time, and the controller calculates the spindle thermal elongation in real time based on the temperature-deformation conversion model. When the spindle generates axial elongation due to high-speed rotation and causes a deviation in the feed depth of the tool D, the vertical compensation module 40 arranged between the slide and the control housing 21 performs a micro-axial adjustment of the control housing 21 through piezoelectric drive, which drives the spindle, tool holder, and tool D to synchronously move slightly, thereby offsetting the spindle thermal deformation error and ensuring the stability of the hole machining depth dimension.

[0078] The radial adaptive compensation process of the tool holder is as follows: During the drilling and milling of the steering gear housing, the thin-walled part of the workpiece experiences elastic yielding under the action of cutting force. At the same time, the cutting edge of the tool D undergoes slight progressive wear with the increase of machining cycles. Both of these factors lead to a decrease in the actual cutting radius of the tool D and a negative deviation in the machined hole diameter. This invention uses a capacitive radial displacement sensor built into the tool holder to collect high-frequency real-time radial offset data of the tool D, which can simultaneously identify instantaneous dynamic tool yielding offset and long-term cumulative tool D wear offset.

[0079] The weak signal collected by the sensor is transmitted to the controller through the closed annular conductive structure inside the control housing 21. The controller outputs a corresponding drive signal based on the real-time radial deviation, which then supplies power to the piezoelectric actuation unit 232 arranged circumferentially inside the tool holder through the same conductive circuit. By controlling the slight expansion and contraction of the piezoelectric ceramics in different orientations, the radial position of the clamping seat 231 and the tool D is independently adjusted, thus offsetting the instantaneous offset caused by cutting and gradually compensating for the dimensional deviation caused by slight wear of the tool D, so that the actual cutting radius of the tool D is always maintained within the qualified machining range.

[0080] This invention uses a built-in rolling contact conductive structure on the spindle to replace traditional wired wiring. The entire conductive contact area is enclosed inside the control housing 21, completely isolating external cutting fluid, metal dust and water mist, thus avoiding problems such as short circuits, poor contact and cable tangling from the root. At the same time, rolling friction is used instead of sliding friction, which greatly reduces contact wear under high-speed rotation conditions and improves long-term working stability.

[0081] The overall system forms a dual-layer collaborative adaptive compensation system of "macroscopic axial thermal deformation compensation of the spindle + microscopic radial wear and tool deflection compensation at the D end of the tool". Axial compensation ensures the accuracy of hole depth, and radial compensation ensures the accuracy of hole diameter and hole position. The motion degrees of freedom of the two compensation mechanisms are independent and there is no coupling interference. They can work synchronously, which greatly improves the dimensional consistency of batch processing of the steering gear housing hole system and reduces the scrap rate.

[0082] Example 2: The difference from Example 1 is that;

[0083] See attached document Figure 9 and Figure 10 The inner sidewall of the guide rail frame 42 has a strip-shaped tapered opening 454 along its vertical length, and the end of the mating part 453 is machined into a matching tapered boss. When the electromagnet 451 is engaged and locked, the tapered boss of the mating part 453 is completely embedded in the strip-shaped tapered opening 454. The tapered double-sided fit increases the friction contact area and improves the self-locking load-bearing capacity. On the other hand, the bidirectional tapered inclined surface automatically centers and calibrates the guide rail block 43, eliminating the coaxial deviation of the rotating spindle 22 caused by the guide rail assembly gap.

[0084] Multiple hidden grooves are opened along the length of the tapered end of the clamping part 453. The ball bearings 455 and the elastic element are symmetrically assembled in the grooves. When the electromagnet 451 is de-energized and unlocked, the elastic element pushes the ball bearings 455 on both sides outward. The ball bearings 455 protrude from the tapered surface and roll into contact with the two inclined surfaces of the strip-shaped tapered opening 454, converting dry friction into rolling friction. This reduces the slight sliding resistance of the guide block 43 and prevents the clamping part 453 from getting stuck inside the strip-shaped tapered opening 454, ensuring the smooth execution of the next round of spindle thermal expansion compensation action.

[0085] Example 3: The difference from Example 1 is that;

[0086] See attached document Figure 6 and Figure 7 The lubrication unit 38 includes an annular grease reservoir 381 filled with conductive grease. The grease reservoir 381 is located inside the insulating sleeve 31 and above the annular opening groove. The bottom of the end of the grease reservoir 381 has an interconnected filling area. Several circumferentially distributed filling ports are provided between the filling area and the inside of the annular opening groove. The filling ports are used to fill the inside of the annular opening groove with long-lasting conductive grease, which not only plays a lubricating role, but also captures a small amount of wear debris and improves the conductivity of the ball 36.

[0087] A pressure valve plate is provided inside the filling port, and an arc-shaped guide surface is provided in the connecting area between the grease storage chamber 381 and the filling area. When the insulating sleeve 31 rotates with the rotating spindle 22, the conductive lubricating grease in the grease storage chamber 381 is pressurized to the filling area by centrifugal force, and then pressurized to the annular opening groove through the filling port to form a feeding operation. The pressure valve plate adopts the existing pressure type valve plate. Under normal conditions, the valve plate is in the closed state, and it automatically opens when encountering pressure. The opening range of the valve plate is controlled according to the pressure.

[0088] The lubrication unit 38 also includes an annular collection groove 382, ​​which is located inside the insulating sleeve 31 and below the annular opening groove. The collection groove 382 is connected to the inside of the annular opening groove through an annular guide channel 383. The annular guide channel 383 is located on the outer side of the annular opening groove. When the insulating sleeve 31 rotates with the rotating spindle 22, the grease containing wear debris in the annular opening groove is pressurized by centrifugal force into the annular guide channel 383 and the collection groove 382 to form a waste collection operation. The receiving end of the annular guide channel 383 is flared to increase the receiving range and the guiding intensity of the grease inside the annular guide channel 383, so as to realize automatic grease replenishment and automatic separation of wear debris, without the need for frequent disassembly and maintenance of the slip ring structure of the conductive module 30.

[0089] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive compensation drilling and milling system for a steering gear housing bore system, comprising a drilling and milling table (10) and a drilling and milling mechanism (20); the drilling and milling mechanism (20) is mounted on the drilling and milling area of ​​the drilling and milling table (10) via a moving guide rail assembly (11); the drilling and milling area of ​​the drilling and milling table (10) is further provided with a clamping fixture (12), characterized in that: The drilling and milling mechanism (20) includes a control housing (21), a rotary spindle (22), and a tool holder (23); The rotating spindle (22) is rotatably connected to the inside of the control housing (21) and is connected to the drive motor (13) installed on the control housing (21). The bottom end of the rotating spindle (22) extends to the outside of the control housing (21) and is fixedly connected to the tool holder (23). The tool holder (23) is provided with a clamping seat (231) for clamping the tool (D) and a radial compensation module. The radial compensation module adopts a circumferentially distributed piezoelectric actuation structure for adjusting the clamping seat (231) in the X / Y plane with independent radial micron-level displacement, and real-time compensation for radial tool deflection size error caused by tool (D) wear and cutting load. The radial compensation module is electrically connected to the electrical control board (14) inside the control housing (21) through a conductive module (30). The control housing (21) is installed on the vertical Z-axis slide in the moving guide rail group (11). The Z-axis slide is equipped with an independent vertical compensation module (40). The vertical compensation module (40) drives the control housing (21) to move slightly up and down in the vertical direction by piezoelectric lifting drive, which drives the rotating spindle (22) and the tool (D) to move axially synchronously, thus offsetting the thermal elongation overcutting error caused by the high-speed rotation of the spindle.

2. The adaptive compensation drilling and milling system for a steering gear housing bore system according to claim 1, characterized in that: The cylindrical mounting part integrally formed on the top of the clamping seat (231) extends into the interior of the clamping seat (231) through the through opening at the bottom of the tool holder seat (23); The radial compensation module includes several piezoelectric actuation units (232) evenly distributed in a circle, used to radially drive the clamping seat (231) inside the tool holder (23); one end of the piezoelectric actuation unit (232) abuts against the inner wall of the tool holder (23), and the other end abuts against the clamping seat (231). The diameter of the extension portion of the cylindrical mounting portion extending into the inside of the tool holder (23) is larger than the diameter of the through opening, and the bottom of the extension portion contacts the bottom of the inside of the tool holder (23); A disc spring assembly (233) is connected between the inner top of the tool holder (23) and the top of the cylindrical mounting part.

3. The adaptive compensation drilling and milling system for a steering gear housing bore system according to claim 1, characterized in that: The vertical compensation module (40) includes several piezoelectric actuators (41) and a vertical guide rail pair; the control housing (21) is slidably connected to the Z-axis slide through the vertical guide rail pair, several piezoelectric actuators (41) are fixed in a line arrangement at the bottom of the side of the Z-axis slide, and the side of the control housing (21) is integrally formed with a pressure bearing part, and the actuating end of several piezoelectric actuators (41) contacts the bottom of the pressure bearing part, which is used to drive the pressure bearing part to rise upward through the piezoelectric actuators (41), thereby causing the control housing (21) and the main shaft to move slightly upward vertically relative to the Z-axis slide, thus compensating for the thermal elongation error of the main shaft.

4. The adaptive compensation drilling and milling system for a steering gear housing bore system according to claim 3, characterized in that: The vertical guide rail pair includes a guide rail frame (42) and a guide rail block (43). The guide rail block (43) slides vertically inside the guide rail frame (42), and the guide rail frame (42) and the guide rail block (43) are respectively fixed to the Z-axis slide table and the control housing (21). A self-locking unit (45) is provided between the guide rail frame (42) and the guide rail block (43). At least two sets of disc spring groups (44) are connected between the top of the control housing (21) and the Z-axis slide. The disc spring groups (44) are used to press down on the control housing (21) so that the pressure-bearing part is always in close contact with the actuating end of several piezoelectric actuators (41).

5. An adaptive compensation drilling and milling system for a steering gear housing bore system according to claim 4, characterized in that: The self-locking unit (45) includes an electromagnet (451), a metal plate (452), and a clamping part (453). The guide block (43) has a connecting part that slides horizontally inside. One end of the connecting part is fixed to the clamping part (453), and the other end extends into the control housing (21) and is fixedly connected to the metal plate (452). The electromagnet (451) is installed inside the control housing (21) and is used to magnetically attract the metal plate (452) when energized, so that the metal plate (452) drives the connecting part and the clamping part (453) to move in the direction of the inner wall of the guide frame (42). The clamping part (453) clamps against the inner wall of the guide frame (42) to form a self-locking vertical guide pair.

6. An adaptive compensation drilling and milling system for a steering gear housing bore system according to claim 5, characterized in that: The inner wall of the guide frame (42) is provided with a strip-shaped conical opening (454), which is opened along the length of the guide frame (42). The abutting end of the clamping part (453) is conical and is used to insert into the strip-shaped conical opening (454) to form a self-locking vertical guide pair and a centered positioning calibration after adjustment, thereby eliminating the gap between the guide rails. The tapered end of the clamping part (453) has several hidden grooves along the length of the strip-shaped tapered opening (454). Each hidden groove is provided with two symmetrically arranged balls (455) and an elastic element. The elastic element is used to elastically compress the two balls (455).

7. The adaptive compensation drilling and milling system for a steering gear housing bore system according to claim 1, characterized in that: The conductive module (30) is located inside the control housing (21) and includes an insulating sleeve (31), a positive electrode contact block (32), a negative electrode contact block (33), and two conductive connection parts. The insulating sleeve (31) is fixed to the outer surface of the rotating spindle (22), and a circuit groove is opened inside the rotating spindle (22). A circuit board is installed inside the circuit groove, and the circuit board is electrically connected to the piezoelectric actuation unit (232) through wires. The outer surface of the insulating sleeve (31) has two annular opening slots. The positive electrode contact block (32) and the negative electrode contact block (33) are respectively fixed in the two annular opening slots, and the conductive contact ends of the two contact blocks extend into the circuit slots and are electrically connected to the circuit board. Both conductive connection parts are electrically connected to the control board (14) via wires, and the two conductive connection parts are electrically connected to the positive contact block (32) and the negative contact block (33) respectively.

8. An adaptive compensation drilling and milling system for a steering gear housing bore system according to claim 7, characterized in that: The conductive connection includes an annular insulating mounting bracket (34) and multiple conductive parts; the insulating mounting bracket (34) is fixed inside the control housing (21), and the multiple conductive parts are fixed on the insulating mounting bracket (34) in a circumferentially evenly distributed manner; The cross-sections of the positive electrode contact block (32) and the negative electrode contact block (33) are both U-shaped; The conductive part includes a conductive frame (35) and two conductive balls (36); the conductive frame (35) is fixed on an insulating mounting frame (34), and its end extends into the groove through the opening of an annular opening groove. The two conductive balls (36) are disposed at the end of the conductive frame (35), and a conductive elastic element (37) is connected between the two conductive balls (36) for elastically squeezing the two conductive balls (36) so that the two conductive balls (36) elastically contact the top and bottom of the U-shaped contact block to form a conductive connection. The insulating sleeve (31) is provided with two sets of lubrication units (38) to reduce the coefficient of friction and heat between the conductive ball (36) and the contact block.

9. An adaptive compensation drilling and milling system for a steering gear housing bore system according to claim 8, characterized in that: The lubrication unit (38) includes an annular grease reservoir (381) filled with conductive grease. The grease reservoir (381) is located inside the insulating sleeve (31) and above the annular opening groove. A filling area is provided at the bottom of the end of the grease reservoir (381) and is connected to each other. A number of circumferentially distributed filling ports are provided between the filling area and the interior of the annular opening groove. The filling port is equipped with a pressure valve plate, and the connecting area between the grease storage chamber (381) and the filling area is provided with an arc-shaped guide surface.

10. An adaptive compensation drilling and milling system for a steering gear housing bore system according to claim 9, characterized in that: The lubrication unit (38) further includes an annular collection groove (382), which is opened inside the insulating sleeve (31) and located below the annular opening groove. The collection groove (382) is connected to the inside of the annular opening groove through an annular guide channel (383). The annular guide channel (383) is located on the outer side of the annular opening groove, and the receiving end of the annular guide channel (383) is flared.

Images