A tool holder assembly with interchangeable tool holders and a control method

Abstract

The application discloses a shaft hole cutter bar assembly with replaceable tool holders and a control method, relates to the technical field of hole machining cutters, and comprises a cutter bar body, a quick-release locking mechanism, a bridge type boring tool holder and an intelligent control system. The quick-release locking mechanism is detachably positioned and locked at one end of the cutter bar body, and the bridge type boring tool holder is detachably installed at one end of the quick-release locking mechanism, so that the combined machining function of rough boring and fine boring is realized, and an operator can quickly switch cutters as required. The cutter bar body is arranged as a solid structure, so that the mass distribution of the cutter bar body is concentrated to one side of the boring bar mounting seat, the problem of gravity center offset of the existing hollow lengthened boring cutter bar is solved, the radial runout amount during high-speed rotation is significantly reduced, the problems of diameter size out-of-tolerance and rework of the shaft hole are avoided, and the deterioration of the surface roughness of the inner wall of the shaft hole caused by cutting vibration is reduced.

Description

Technical Field

[0001] This invention relates to the field of hole machining tool technology, and in particular to a shaft hole tool holder assembly with a replaceable tool holder and a control method thereof. Background Technology

[0002] In the machining process of the idler wheel shaft hole of the crossbeam, the idler wheel shaft hole has a stepped hole structure with a larger inner diameter and a smaller outer diameter. The outer diameter of the shaft hole is smaller than the outer diameter of the conventional boring bar. The machining of the large inner hole requires the use of an extended boring bar for feed cutting. Existing machining solutions generally use a hollow structure extended boring bar. This hollow boring bar adopts a hollow rod forming structure, which can be adapted to the boring conditions of long overhanging inner holes. It can extend into the workpiece to complete the boring and forming of the deep inner hole of the idler wheel shaft. It is a commonly used tooling structure for machining such irregular inner holes.

[0003] The existing hollow extended boring bar has a forward overall mass distribution and an off-center center of gravity. After assembling the boring tool, the overall dynamic balance is poor. During high-speed boring, the tool bar is prone to generating large radial runout. This structural defect cannot be eliminated by adjusting cutting parameters or clamping methods. It is very easy to cause the diameter of the bored shaft hole to be out of tolerance, resulting in a high rework rate in mass production. At the same time, the cutting vibration caused by the runout will also worsen the surface roughness of the inner wall of the shaft hole. This seriously restricts the ability to ensure dimensional consistency and batch processing efficiency in the boring of long overhanging deep holes, becoming a bottleneck for improving the quality and efficiency of this process. Summary of the Invention

[0004] The technical objective of this invention is to provide a shaft hole tool holder assembly and control method with a replaceable tool holder to address the shortcomings of the prior art, thereby solving the problems of large runout and poor machining accuracy of existing hollow boring tool holders and idler wheel shaft holes.

[0005] The technical solution adopted by this invention to solve its technical problem is: a shaft hole tool holder assembly with a replaceable tool holder, comprising a tool holder body, a quick-release locking mechanism, and a bridge-type boring bar holder. The tool holder body includes a tapered rod body, a straight rod body, and a boring bar mounting base. The tapered rod body, the straight rod body, and the boring bar mounting base are an integral structure. The quick-release locking mechanism is detachably positioned and locked to one end of the tool holder body. The quick-release locking mechanism includes a locking seat, a clamping arm support, a first clamping swing arm, a second clamping swing arm, and an eccentric... The quick-release frame and intermediate positioning pin are provided. The clamping arm support is located at the middle of one end of the locking seat. The first clamping swing arm and the second clamping swing arm are respectively hinged to both sides of the clamping arm support. The eccentric quick-release frame is hinged to the second clamping swing arm. The intermediate positioning pin is slidably installed inside the clamping arm support. The bridge-type boring tool holder is clamped and engaged with the first clamping swing arm and the second clamping swing arm through its clamping groove. The bridge-type boring tool holder is detachably installed at one end of the quick-release locking mechanism. The bridge-type boring tool holder is provided with a counterweight.

[0006] Furthermore, the quick-release locking mechanism also includes a fastening screw, two short locating pins, and two swing arm hinge pins. The fastening screw is threaded onto one side of the outer wall of the first clamping swing arm, the two short locating pins are respectively installed in the middle of the outer walls of the first clamping swing arm and the second clamping swing arm, and the two swing arm hinge pins are respectively hinged onto the other side of the outer walls of the first clamping swing arm and the second clamping swing arm. The clamping arm support includes a support base, two movable grooves, a positioning protrusion, two positioning holes, a clearance pin hole, and a pin assembly hole. The two movable grooves are respectively opened at the top and bottom ends of the support base. The positioning protrusion is located at the end of the support base away from the locking seat. The two positioning holes are both opened at the other end of the positioning protrusion. The clearance pin hole and the pin assembly hole are both opened inside the support base.

[0007] Furthermore, the locking seat includes a positioning base, a limiting groove, two stopping grooves and two storage slots. The limiting groove is located at the middle of one end of the positioning base, the two stopping grooves are located on both sides of one end of the positioning base, and the two storage slots are located at the top and bottom ends of the positioning base, respectively.

[0008] Furthermore, the bridge-type boring tool holder includes a tool holder base, two clamping slots, a positioning slot, and two positioning posts. The two clamping slots are respectively opened at the top and bottom of the tool holder base, the positioning slot is opened at the middle of one end of the tool holder base, and the two positioning posts are fixedly installed on the groove wall of the positioning slot. Multiple mounting screw holes are respectively opened on the upper and lower sides of one end of the tool holder base, and the two mounting slots are respectively opened on the front and rear sides of one end of the tool holder base.

[0009] Furthermore, the bridge-type boring bar holder also includes a counterweight, a boring head, a tool head clamp, a reinforcing clamp, and multiple mounting bolts. The boring head is placed inside a mounting slot on one side, and the tool head clamp covers the outer side of the boring head. The multiple mounting bolts are respectively inserted through the counterweight, the tool head clamp, and the reinforcing clamp. The tool head clamp and the reinforcing clamp are both locked and fixed to the tool holder base by mounting bolts. The counterweight is locked and assembled inside a mounting slot on the other side by mounting bolts.

[0010] Furthermore, a limiting boss is provided at the middle of one end of the tool holder body, and a stop protrusion is provided at the top and bottom of the limiting boss. Locking screws are fixedly installed on both sides of one end of the tool holder body, and locking nuts are threaded on the outer walls of the two locking screws. The quick-release locking mechanism is fixedly connected to the tool holder body through the locking screws and locking nuts.

[0011] Furthermore, the short positioning pin is inserted into the clearance pin hole, the intermediate positioning pin shaft is slidably connected to the pin shaft assembly hole, the first clamping swing arm and the second clamping swing arm are both set as L-shaped structures, and the eccentric quick release frame is composed of a ball handle and an eccentric wheel.

[0012] Furthermore, the counterweight, the tool holder, and the reinforcing clamp are all provided with adjustment slots for the installation bolts to move. The tool holder is configured with an L-shaped structure, and the tool holder clamps and fixes the boring tool head in the installation slot by the installation bolts.

[0013] Furthermore, an intelligent control system is provided, which includes a sensing module, an execution module, and a controller. The sensing module includes a triaxial accelerometer, an eddy current displacement sensor, and a strain gauge force sensor. The triaxial accelerometer is installed on the front outer wall of the tool holder body, the eddy current displacement sensor is installed on the top front end of the tool holder body, and the strain gauge force sensor is installed on the upper outer wall of the front end of the bridge boring post. The execution module includes a servo screw assembly and an electromagnetic self-locking device. The servo screw assembly is installed in the mounting slot of the bridge boring post and is connected to the counterweight. The electromagnetic self-locking device is installed on one side of the quick-release locking mechanism. The controller is electrically connected to the sensing module and the execution module respectively.

[0014] A control method for a shaft hole tool holder assembly with a replaceable tool holder includes the following steps: After the operator completes the tool holder assembly and starts the intelligent control system, the system first synchronously collects three signals: acceleration, displacement, and cutting force. After zero-bias correction, bandpass filtering, and Hanning window preprocessing, the system extracts radial runout, root mean square value of vibration, mean and fluctuation of cutting force, and complex eccentricity vector in the frequency domain. When the amplitude of the eccentricity vector exceeds a preset threshold, the controller calculates the required radial displacement of the counterweight and drives the servo screw assembly to perform closed-loop adjustment of the counterweight position through an incremental PID algorithm until the residual imbalance converges to within 1μm. Based on the dynamic balance correction, the controller performs FFT on the acceleration signal to identify the vibration characteristic frequency. If resonance risk is detected and the cutting force fluctuation exceeds the limit, the feed rate is adaptively reduced according to the variable feed strategy. At the same time, the preload of the electromagnetic self-locking device is dynamically adjusted according to the measured cutting force. Throughout the machining process, the self-diagnostic module continuously monitors the sensor signals and actuator stroke, and immediately alarms and protects against abnormalities. The threshold baseline is automatically updated after each machining operation.

[0015] Compared with the prior art, the present invention has the following outstanding advantages: This invention solves the problem of center-of-gravity imbalance in existing hollow extended boring bar by setting the tool holder body as a solid structure and using a tapered rod body, a straight rod body and a boring bar mounting base integrally formed. This concentrates the mass distribution of the tool holder body towards the boring bar mounting base, significantly reduces the radial runout during high-speed rotation, avoids out-of-tolerance diameter of the shaft hole and rework problems, and reduces the deterioration of the surface roughness of the inner wall of the shaft hole caused by cutting vibration.

[0016] This invention achieves quick and easy installation and removal of the bridge-type boring tool holder by using the clamping slot of the bridge-type boring tool holder in conjunction with the clamping action of the first and second clamping arms. The dynamic balance adjustment of the counterweight ensures that the overall rotating system achieves a good dynamic balance. Welding tools or fine-tuning boring tools can be installed on the bridge-type boring tool holder, realizing the combined machining function of rough boring and fine boring. Operators can quickly switch tools as needed, greatly improving the flexibility and efficiency of on-site machining.

[0017] This invention achieves precise axial positioning and circumferential anti-rotation and anti-deviation of the quick-release locking mechanism on the tool holder body through the positioning and cooperation of the limiting boss and the limiting groove, the positioning and cooperation of the stop protrusion and the stop groove, and the locking and fixing of the locking screw and the locking nut. This ensures the consistency of the installation position of the quick-release locking mechanism and the straight section of the rod after repeated disassembly and assembly, and provides a stable assembly benchmark for the precise installation of the bridge boring tool holder.

[0018] The intelligent control method of this invention achieves millisecond-level response to the working state of the tool holder assembly, high-precision adaptive dynamic balancing, and intelligent vibration suppression, effectively ensuring the dimensional accuracy and surface quality of long overhang deep hole boring. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 for Figure 1 Enlarged view of a portion of the image; Figure 3 This is a schematic diagram of the tool holder body; Figure 4 for Figure 3 Enlarged view of a portion of the image; Figure 5 This is a structural diagram of the quick-release locking mechanism; Figure 6 Exploded view of the quick-release locking mechanism; Figure 7 This is a schematic diagram of the locking seat. Figure 8 This is a schematic diagram of the clamp arm support structure; Figure 9 This is one of the structural schematic diagrams of a bridge-type boring bar holder; Figure 10 This is the second structural schematic diagram of a bridge-type boring bar holder; Figure 11 This is a schematic diagram of the overall structure of an embodiment of an intelligent control system.

[0020] Figure 12 for Figure 11 Enlarged view of a portion of the image.

[0021] In the picture: 1. Tool holder body; 2. Quick-release locking mechanism; 3. Bridge-type boring bar holder; 4. Limiting boss; 5. Stopping protrusion; 6. Locking screw; 7. Locking nut; 11. Tapered rod body; 12. Straight rod body; 13. Boring bar mounting base; 14. Triaxial accelerometer; 15. Eddy current displacement sensor; 16. Strain gauge force sensor; 17. Servo screw assembly; 21. Locking seat; 22. Clamping arm support; 23. First clamping swing arm; 24. Second clamping swing arm; 25. Eccentric quick-release bracket; 26. Intermediate positioning pin; 27. Fastening screw; 28. 29. Short locating pin; 211. Swing arm hinge pin; 212. Locating base; 213. Limiting groove; 214. Stop groove; 215. Storage groove; 226. Support base; 227. Movable groove; 228. Locating protrusion; 229. Locating hole; 220. Clearance pin hole; 221. Pin assembly hole; 32. Tool holder base; 33. Clamping groove; 34. Locating groove; 35. Mounting screw hole; 36. Mounting groove; 37. Counterweight; 38. Boring head; 39. Tool holder; 310. Reinforcing holder; 311. Mounting bolt. Detailed Implementation

[0022] Refer to the instruction manual appendix Figure 1 To be continued Figure 12 The following is a detailed description of a shaft hole tool holder assembly with a replaceable tool holder and its control method according to the present invention.

[0023] Example 1 This invention discloses a shaft hole tool holder assembly with a replaceable tool holder, comprising a tool holder body 1. The tool holder body 1 includes a tapered rod 11, a straight rod 12, and a boring bar mounting seat 13. The tapered rod 11, the straight rod 12, and the boring bar mounting seat 13 are an integral structure with continuous metal distribution, avoiding the dispersion of the center of gravity in segmented structures. The diameter of the tapered rod 11 near the boring bar mounting seat 13 is larger than the diameter near the straight rod 12, and the large tapered section at the rear end is rich in metal, achieving a rearward shift of the overall center of gravity. The tool holder body 1 is designed as a solid structure, abandoning the traditional hollow design, significantly improving the rigidity of the rod and the base weight. A quick-release locking mechanism 2, through a limiting boss 4, a stop protrusion 5, a locking screw 6, and a locking nut 7, can be detachably positioned and locked to the end of the straight rod 12 away from the tapered rod 11. The concave-convex structure achieves axial and circumferential dual limiting, preventing mechanism deflection during high-speed rotation.

[0024] The quick-release locking mechanism 2 includes a locking seat 21, a clamping arm support 22, a first clamping swing arm 23, a second clamping swing arm 24, an eccentric quick-release frame 25, and a central positioning pin 26. The clamping arm support 22 is fixedly installed at the middle of the end of the locking seat 21 away from the straight section rod 12. The first clamping swing arm 23 and the second clamping swing arm 24 are respectively hinged to both sides of the clamping arm support 22. The eccentric quick-release frame 25 is hinged to the second clamping swing arm 24. The central positioning pin 26 is slidably installed inside the clamping arm support 22. The bridge-type boring tool holder 3 is clamped and engaged with the first clamping swing arm 23 and the second clamping swing arm 24 through its clamping groove 32. It can be detachably installed at the end of the quick-release locking mechanism 2 away from the straight section rod 12, so as to realize the overall quick replacement of the bridge-type boring tool holder 3. The tool holder does not need to be disassembled when switching between roughing and finishing boring conditions. The bridge-type boring tool holder 3 is equipped with a counterweight 37.

[0025] The quick-release locking mechanism 2 also includes a fastening screw 27, two short locating pins 28, and two swing arm hinge pins 29. The fastening screw 27 is threaded onto the outer wall of the first clamping swing arm 23 near the middle locating pin 26. The two short locating pins 28 are respectively installed in the middle of the outer wall of the first clamping swing arm 23 and the second clamping swing arm 24. The two swing arm hinge pins 29 are respectively hinged onto the other side of the outer wall of the first clamping swing arm 23 and the second clamping swing arm 24. The clamping arm support 22 includes a support base 221, two movable grooves 222, a locating protrusion 223, two locating holes 224, a clearance pin hole 225, and a pin assembly hole 226. The two movable grooves 222 are respectively opened at the top and bottom of the support base 221, and the locating protrusion 223 is provided at the support base. At the end of body 221 away from locking seat 21, two positioning holes 224 are opened at the other end of positioning protrusion 223. The clearance pin hole 225 and pin assembly hole 226 are both opened inside the support base 221. The short positioning pin 28 is inserted into the clearance pin hole 225. The intermittent insertion takes into account both convenient disassembly and assembly and limiting accuracy. The middle positioning pin 26 is slidably connected to the pin assembly hole 226. The hole wall is finely machined to reduce sliding friction. The swing arm moves smoothly in sync. The first clamping swing arm 23 and the second clamping swing arm 24 are both set as L-shaped structures. The bent shape forms a lever clamping structure, which amplifies the clamping force of the eccentric quick release frame 25. The eccentric quick release frame 25 is composed of a ball handle and an eccentric wheel. The ball handle is easy to hold, and the eccentric wheel generates a self-locking clamping force by relying on the difference in rotation radius.

[0026] Working principle: In use, the operator first aligns the boring bar mounting seat 13 of the integrated solid tool holder body 1 with the taper hole of the machine tool spindle and locks it with the tensioning mechanism, so that the tool holder body 1 forms a rigid connection with the spindle and rotates synchronously with the spindle. The large diameter end of the tapered rod 11 faces the boring bar mounting seat 13, causing the overall center of gravity of the assembly to shift backward, reducing the rotational eccentricity from the source. Then, the quick-release locking mechanism 2 is removed, and the locking seat 21 is fitted into the straight section of the rod 12 away from the machine tool spindle. At one end of the tapered rod 11, the locking screw 6 passes through the locking seat 21, and the locking nut 7 is tightened to apply axial locking force, pressing and fixing the quick-release locking mechanism 2 to the end of the straight rod 12; the clamping arm support 22 is hinged to the first clamping swing arm 23 and the second clamping swing arm 24 respectively through the swing arm hinge pin 29. When assembling the bridge-type boring tool holder 3, the clamping groove 32 is inserted into the first clamping swing arm 23 and the second clamping swing arm 24, and the eccentric quick-release frame 25 is moved, and the eccentric wheel The first L-shaped clamping arms 23 and the second clamping arms 24 on both sides are driven to clamp each other. The intermediate positioning pin 26 slides inside the pin mounting hole 226 of the clamping arm support 22, ensuring that the first clamping arms 23 and the second clamping arms 24 are synchronously aligned and clamped. The short positioning pin 28 is inserted into the clearance pin hole 225 of the clamping arm support 22 to achieve assembly limit. Then, the intermediate positioning pin 26 is locked by the fastening screw 27 to prevent the intermediate positioning pin 26 from being locked during operation. During machining, the machine tool drives the entire assembly to rotate synchronously. The solid tool holder body 1, together with the counterweight 37 on the bridge boring tool holder 3, optimizes the overall dynamic balance and reduces rotational eccentricity. The boring head 38 completes the deep hole boring operation of the crossbeam idler wheel with the feed of the assembly. When it is necessary to disassemble and replace the tool holder, the eccentric quick release bracket 25 is reversed to release the first clamping swing arm 23 and the second clamping swing arm 24, and the bridge boring tool holder 3 can be directly removed to achieve quick tool holder replacement.

[0027] Example 2: This embodiment is basically the same as the previous embodiment, except that the locking seat 21 includes a positioning base 211, a limiting groove 212, two stop grooves 213 and two storage slots 214. The limiting groove 212 is opened in the middle of one end of the positioning base 211, the two stop grooves 213 are opened on both sides of one end of the positioning base 211, and the two storage slots 214 are respectively opened at the top and bottom of the positioning base 211. The locking screw 6 can be inserted into the storage slot 214 to achieve recessed assembly. The locking screw 6 and the locking nut 7 are stored in the slot as a whole, which will not interfere with the opening and closing adjustment action of the clamping swing arm.

[0028] A limiting boss 4 is provided at the middle of one end of the straight rod 12, and the limiting boss 4 is positioned and engaged with the limiting groove 212. The top and bottom ends of the limiting boss 4 are provided with stop protrusions 5, and the stop protrusions 5 are positioned and engaged with the stop groove 213. Locking screws 6 are fixedly installed on both sides of one end of the straight rod 12, and locking nuts 7 are threaded on the outer walls of the two locking screws 6. The limiting boss 4 and the limiting groove 212 are both designed as trapezoidal structures. The trapezoidal inclined surface has a self-centering effect, and the assembly automatically finds the center. The stop protrusions 5 and the stop groove 213 are both designed as arc structures. The arc surface is adapted to rotational force and avoids the defects of stress concentration and easy wear caused by sharp corners. The limiting boss 4, the stop protrusions 5, and the straight rod 12 are integrated structures, formed by integral milling. The positioning reference is unified and there is no assembly misalignment. The locking nut 7 is a nylon anti-loosening nut. The built-in nylon ring fills the thread gap to suppress vibration and loosening, and no additional anti-loosening washer is required.

[0029] Working principle: During use, the operator assembles the quick-release locking mechanism 2 onto the end of the straight rod 12, so that the trapezoidal limiting boss 4 at the end of the straight rod 12 is embedded into the trapezoidal limiting groove 212 in the middle of the locking seat 21 to form an axial stop fit. At the same time, the arc-shaped stop protrusion 5 slides into the arc-shaped stop grooves 213 on both sides of the locking seat 21 to form a circumferential anti-rotation fit. Then, the locking screw 6 is passed through the receiving groove 214 of the locking seat 21, and the outer nylon anti-loosening locking nut 7 is tightened to apply axial locking force, pressing and fixing the quick-release locking mechanism 2 onto the end face of the limiting boss 4. The clamping arm support 22 is fixed to the front end of the locking seat 21 through the support base 221. The movable groove 222 on the support base 221 provides space for the swing arm to swing. The positioning hole 224 on the positioning protrusion 223 is used for precise alignment of the bridge boring tool holder 3. The short positioning pin 28 The avoidance pin hole 225 of the inserted support base 221 restricts the swing arm offset, and the intermediate positioning pin 26 slides in the pin assembly hole 226 to ensure that the two swing arms are clamped synchronously. Then, the clamping groove 32 of the bridge boring tool holder 3 is aligned with the clamping ends of the first clamping swing arm 23 and the second clamping swing arm 24 and pushed into place. The ball handle of the eccentric quick release bracket 25 is held and rotated downwards. The eccentric wheel rotates synchronously and pushes the second clamping swing arm 24 to swing around the swing arm hinge pin 29. The intermediate positioning pin 26 transmits power to drive the first clamping swing arm 23 to synchronously close and press the clamping groove 32. When the equipment is disassembled for maintenance, the locking nut 7 is loosened and the entire quick release locking mechanism 2 can be removed from the straight section rod 12 for easy cleaning and maintenance. The trapezoidal limit boss 4 and the arc-shaped stop protrusion 5 can resist cutting vibration for a long time. The assembly reference does not shift after repeated disassembly and assembly.

[0030] Example 3: This embodiment is basically the same as the previous embodiment, except that the bridge-type boring tool holder 3 includes a tool holder base 31, two clamping grooves 32, a positioning groove 33, two positioning posts 34, multiple mounting screw holes 35, and two mounting grooves 36. The two clamping grooves 32 are respectively opened at the top and bottom of the tool holder base 31, the positioning groove 33 is opened at the middle of one end of the tool holder base 31, the two positioning posts 34 are fixedly installed on the groove wall of the positioning groove 33, the multiple mounting screw holes 35 are respectively opened on the upper and lower sides of one end of the tool holder base 31, and the two mounting grooves 36 are respectively opened on the front and rear sides of one end of the tool holder base 31.

[0031] The bridge-type boring bar holder 3 also includes a counterweight 37, a boring head 38, a tool head holder 39, a reinforcing clamp 310, and multiple mounting bolts 311. The boring head 38 is placed inside a mounting groove 36 on one side, and the tool head holder 39 covers the outside of the boring head 38. Multiple mounting bolts 311 are respectively inserted into the counterweight 37, the tool head holder 39, and the reinforcing clamp 310. The tool head holder 39 and the reinforcing clamp 310 are both locked and fixed to the tool holder base 31 by the mounting bolts 311. The counterweight 37 is locked and assembled to the other side mounting groove 36 by the mounting bolts 311. Inside the mounting groove 36, the counterweight 37, the tool holder 39, and the reinforcing clamp 310 are all provided with adjustment grooves for the mounting bolts 311 to move. The adjustment grooves can realize stepless position adjustment of the parts without the need for additional holes for adaptation. The tool holder 39 is set with an L-shaped structure, and the bent structure fits the surface of the boring head 38, which has a stronger clamping and wrapping effect. The tool holder 39 clamps and fixes the boring head 38 in the mounting groove 36 with the help of the mounting bolts 311. The boring head 38 can be radially fine-tuned by loosening the mounting bolts 311 to adapt to the boring needs of different hole diameters.

[0032] Working principle: After the quick-release locking mechanism 2 is assembled, the positioning groove 33 and the two positioning posts 34 of the bridge boring tool holder 3 are aligned with the positioning protrusion 223 and the two positioning holes 224 of the clamping arm support 22 to achieve precise alignment. This allows the clamping grooves 32 on the upper and lower sides of the tool holder base 31 to engage between the first clamping swing arm 23 and the second clamping swing arm 24. The eccentric quick-release bracket 25 is then moved to complete the overall clamping and fixing of the bridge boring tool holder 3. The tool holder base 31 is provided with mounting grooves 36 on the front and rear sides, in which... A boring head 38 is housed in a mounting slot 36 on one side. An L-shaped tool holder 39 and a reinforcing holder 310 cover the outside of the boring head 38. A mounting bolt 311 passes through the adjustment groove on the holder and is locked to the mounting screw hole 35 on the tool holder base 31. The extension length of the boring head 38 can be finely adjusted by adjusting the groove. A counterweight 37 is mounted in the mounting slot 36 on the other side using mounting bolt 311. The operator can adjust the mounting position of the counterweight 37 along the mounting slot 36 and then tighten the mounting bolt 311 to compensate for the boring. The eccentric load brought by the tool head 38; in the rough boring process, the bridge boring tool holder 3 equipped with the welded boring tool head 38 is used to quickly remove excess material from the inner hole of the workpiece. When switching to the fine boring process, the eccentric quick release frame 25 is rotated in the reverse direction, the eccentric wheel disengages from the second clamping arm 24, the first clamping arm 23 and the second clamping arm 24 automatically open, the current bridge boring tool holder 3 is directly removed, and a bridge boring tool holder 3 equipped with a fine-adjusting boring tool head 38 is installed and re-eccentrically locked. The tool tip extension is precisely controlled by the fine-adjusting boring tool. It achieves micron-level precision machining of shaft holes. After a single batch of machining is completed, the bridge-type boring tool holder 3 can be quickly disassembled and assembled, and the roughing and finishing boring tool holders can be seamlessly switched within seconds. In addition, the operator can also loosen the mounting bolt 311 to remove the boring tool head 38 from the mounting slot 36 according to the machining wear or tool specification adjustment requirements. After replacing it with a new boring tool head 38, the mounting bolt 311 is tightened again to complete the individual replacement of the boring tool head 38 without having to remove the entire bridge-type boring tool holder 3 from the quick-release locking mechanism 2.

[0033] Example 4: This embodiment adds an intelligent control system to the shaft hole tool holder assembly of any of the above embodiments to realize real-time monitoring of the working status of the tool holder assembly, adaptive dynamic balance adjustment and cutting vibration suppression. Relying on the system, the working condition signal of the tool holder assembly is collected in real time, and the dynamic balance counterweight adjustment and cutting vibration suppression are adaptively completed, thereby improving the boring machining accuracy and the automation level of the equipment.

[0034] like Figure 11 , Figure 12As shown, the intelligent control system includes a sensing module, an execution module, and a controller. The sensing module includes a triaxial accelerometer 14, an eddy current displacement sensor 15, and a strain gauge force sensor 16. The triaxial accelerometer 14 is installed on the outer right side of the front end of the straight section rod 12 to collect the radial vibration signal of the tool holder. The eddy current displacement sensor 15 is installed on the outer right side of the top end of the straight section rod 12 to detect the radial runout during the rotation of the tool holder. The two sensors are arranged orthogonally at 90° along the circumference of the straight section rod 12 to achieve synchronous acquisition of working condition data in two mutually perpendicular directions. A variable force sensor 16 is installed on the upper outer wall of the front end of the bridge boring bar 3 to collect the cutting force component during the cutting process in real time. The execution module includes a servo screw assembly 17 and an electromagnetic self-locking device. The servo screw assembly 17 is installed in the mounting groove 36 and is connected to the counterweight 37. The servo screw assembly 17 drives the counterweight 37 to move radially in the mounting groove 36 to achieve stepless fine adjustment of the counterweight position. The electromagnetic self-locking device is installed next to the locking nut 7 of the quick-release locking mechanism 2 and can receive commands from the controller to dynamically adjust the locking preload applied by the locking nut 7.

[0035] The controller is an embedded motion controller with an ARM Cortex-M7 core. The controller integrates a data acquisition card, signal conditioning circuit and power drive module, and is equipped with a real-time operating system. The controller is electrically connected to the sensing module and the execution module respectively. It receives vibration, displacement and cutting force data returned by the sensing module, and outputs drive signals to control the action of the execution module according to the preset control logic, so as to complete the dynamic balance correction of the tool holder and intelligent control of the locking force.

[0036] Working Principle: During operation, the operator first assembles the tool holder assembly according to any of the aforementioned embodiments and installs it on the machine tool spindle, then starts the intelligent control system. During machining, the three-axis accelerometer 14 collects the radial vibration signal of the tool holder in real time, and the eddy current displacement sensor 15 simultaneously detects the radial runout during the tool holder's rotation. Because they are arranged at 90° orthogonal angles, they can respectively acquire dynamic displacement data of the tool holder in two mutually perpendicular directions. Simultaneously, the strain gauge force sensor 16 monitors the cutting force component during the cutting process in real time. The above sensor signals are transmitted to the controller via shielded cables, where the data acquisition card and signal conditioning circuit inside the controller perform analog-to-digital conversion and filtering preprocessing. The real-time operating system on the controller performs comprehensive calculations on the received vibration, displacement, and cutting force data according to preset control logic. When the dynamic balance of the tool holder deviates from the set threshold, the controller outputs a drive signal to the servo screw assembly 17 through the power drive module. The servo screw assembly 17 drives the counterweight block 37 to move radially within the mounting groove 36, finely adjusting the counterweight position to restore the tool holder assembly to the target dynamic balance state. When the locking preload is detected to be lower than the preset value due to vibration relaxation, the controller sends an adjustment command to the electromagnetic self-locking device. The electromagnetic self-locking device dynamically adjusts the axial locking force of the locking nut 7 to ensure that the connection rigidity between the quick-release locking mechanism 2 and the tool holder body 1 always meets the processing requirements. The above monitoring, judgment and adjustment process is continuously cycled throughout the entire processing, so that the tool holder assembly always maintains excellent dynamic characteristics, effectively suppresses cutting vibration, and thus ensures the dimensional accuracy and surface quality of the shaft hole boring process.

[0037] Example 5: Based on Embodiment 4 above, this embodiment further provides a closed-loop control method and algorithm implementation for an intelligent control system, including the following steps: (I) Signal Acquisition and Preprocessing The sensing module uses a sampling frequency Three channels of signals were acquired simultaneously and denoted as follows: Acceleration signal: (These correspond to the two radial orthogonal directions of the triaxial accelerometer 14, respectively). Displacement signal: (These correspond to the two radial orthogonal directions of the eddy current displacement sensor 15, respectively). Cutting force signal: (Corresponding strain gauge force sensor 16); After the internal data acquisition card of the controller completes the analog-to-digital conversion, the signal conditioning circuit sequentially performs the following preprocessing steps: ① Zero bias correction:

[0038] in The original sampled signal, The number of sampling points is usually taken as... =1024; ② Bandpass filtering A second-order Butterworth bandpass filter is used, with the following transfer function:

[0039] Filter passband lower cutoff frequency (Filtering out low-frequency vibration interference from machine tools), upper passband cutoff frequency (Retaining the effective cutting frequency band of the tool), the coefficients are based on the sampling frequency. Pre-calculated and embedded in the controller using the bilinear transformation method; ③ Adding windows: To suppress spectral leakage, the Hanning window function is used to weight the sampled sequence:

[0040] The signal after windowing is:

[0041] (II) State Feature Extraction The controller extracts time-domain and frequency-domain features from the preprocessed signal to construct a real-time state feature vector for the tool holder assembly. ① Real-time value of radial runout: For displacement signal conduct Point FFT transform yields the spectrum. Extract spindle frequency ( The amplitude corresponding to the spindle speed (in r / min) is taken as the radial runout:

[0042] Where multiplied by 2 is the one-sided spectral restitution coefficient; ② Root mean square value of vibration:

[0043] ③ Mean and fluctuation of cutting force:

[0044] ④ Unbalanced eccentric vector Extract the phase of the rotational frequency components of the displacement signals in the two orthogonal directions respectively, and construct the complex eccentric vector:

[0045] in , These represent the amplitude of the jump in two orthogonal directions. , For the corresponding phase; (III) Dynamic Equilibrium Adaptive Control The controller is based on the real-time eccentric vector With preset threshold The comparison results determine whether to trigger a counterweight adjustment: Judgment logic: If Then, the counterweight position closed-loop adjustment is executed; ① Calculation of counterweight adjustment amount: Let the mass of counterweight 37 be... Its current radial position is (Obtained from encoder feedback of servo screw assembly 17), the adjustment range of counterweight 37 in mounting slot 36 is... Based on the principle of rotor dynamic balancing, the relationship between the correction vector generated by counterweight 37 and the eccentricity vector is as follows:

[0046] in The equivalent rotating mass of the tool holder assembly. The circumferential azimuth angle (fixed value) of the mounting groove 36 where the counterweight 37 is located. Let be the required radial displacement of counterweight 37. The solution is:

[0047] And limit its amplitude to no more than / 2, to prevent single adjustments from exceeding the limit; ② Servo control law The controller will target position The data is sent to the servo screw assembly 17 and driven using an incremental PID algorithm.

[0048] in: For the first Position deviation per control cycle; To control the cycle; These are the tuned PID parameters; ③ Convergence judgment: After the counterweight adjustment is completed, the controller reads the eccentricity vector again. ,like ( To allow for residual unbalance (usually taken as 1 μm), the dynamic balancing correction is considered complete; otherwise, the above steps are repeated to form a closed-loop iterative convergence. (iv) Active suppression of cutting vibration Based on dynamic balancing correction, the controller further utilizes force and vibration signals to adaptively fine-tune cutting parameters in order to suppress residual cutting vibration. ① Identification of vibration characteristic frequencies: For acceleration signals FFT analysis was performed to identify the peak frequency. ,like Approaching the natural frequency of the tool holder If the value is within ±10% (as obtained in advance by modal testing), it is considered a resonance risk state; ② Suppression of cutting force fluctuations (variable feed strategy): When resonance risk is detected and ( When the force fluctuation threshold (taken as 15% of the rated cutting force) is reached, the controller issues a speed reduction command, reducing the feed rate from the current value. Adjusted to:

[0049] in This is the attenuation coefficient (default is 0.3), while also limiting... To ensure processing efficiency; ③ Self-adaptive adjustment of locking preload: 16 Strain gauge force sensor monitors the average cutting force in real time The controller dynamically adjusts the preload of the electromagnetic self-locking device based on the magnitude of the cutting force. :

[0050] in This is the initial preload (obtained from static calibration). =0.15 is the coupling coefficient. When When the fluctuation increases, the locking preload increases simultaneously to ensure that the quick-release locking mechanism 2 does not slip under high load; (v) System self-diagnosis and security protection The controller has a built-in self-diagnostic module that performs real-time health monitoring of sensor signals and actuator status. ① Sensor fault detection: Calculate the mean value of each sensor signal. with standard deviation If M consecutive sampling points satisfy:

[0051] If the sensor signal is determined to be abnormal, the controller will immediately report a fault code and suspend processing to avoid erroneous control due to sensor failure. ② Actuator travel over-limit protection: Servo screw assembly 17 has a built-in position feedback encoder, when the counterweight is 37 positions Approaching mechanical hard limit ( or , When the distance is less than 0.5mm, the controller automatically stops driving in that direction and triggers an audible and visual alarm. ③ Self-learning threshold update: The controller records vibration, runout, and cutting force data throughout each machining process. After machining, it automatically updates the statistical baseline of each threshold, achieving adaptive drift compensation of the thresholds to adapt to tool wear and slow changes in working conditions. As can be seen from the above, after the operator completes the assembly of the tool holder assembly and starts the intelligent control system, the controller will execute the above five stages in a cycle: first at 20 The system synchronously acquires three signals: acceleration, displacement, and cutting force at a kHz sampling rate. After zero-bias correction, bandpass filtering, and Hanning window preprocessing, it extracts radial runout, root mean square vibration value, mean and fluctuation of cutting force, and complex eccentricity vector in the frequency domain. When the amplitude of the eccentricity vector exceeds a preset threshold, the controller calculates the required radial displacement of the counterweight and drives the servo screw assembly to perform closed-loop adjustment of the counterweight position through an incremental PID algorithm until the residual imbalance converges to within 1μm. Based on dynamic balance correction, the controller performs FFT on the acceleration signal to identify the vibration characteristic frequency. If resonance risk is detected and the cutting force fluctuation exceeds the limit, the feed rate is adaptively reduced according to the variable feed strategy. At the same time, the preload of the electromagnetic self-locking device is dynamically adjusted according to the measured cutting force. Throughout the machining process, the self-diagnostic module continuously monitors the sensor signals and actuator stroke, and immediately alarms and protects against abnormalities. After each machining operation, the threshold baseline is automatically updated, thereby achieving millisecond-level response to the working status of the tool holder assembly, high-precision adaptive dynamic balancing, and intelligent vibration suppression, effectively ensuring the dimensional accuracy and surface quality of long overhanging deep hole boring.

[0052] The embodiments listed above are for understanding the present invention only and are not intended to limit the technical solutions described in the present invention. Those skilled in the art can make various changes or modifications based on the technical solutions described in the claims, and all equivalent changes or modifications should be covered within the scope of protection of the claims of the present invention. Any aspects not detailed in the present invention are well-known techniques to those skilled in the art.

Claims

1. A shaft hole tool holder assembly with a replaceable tool holder, comprising a tool holder body, characterized in that, It also includes a quick-release locking mechanism, a bridge-type boring bar holder, and an intelligent control system. The quick-release locking mechanism is detachably positioned and locked to one end of the tool holder body. The quick-release locking mechanism includes a locking seat, a clamping arm support, a first clamping swing arm, a second clamping swing arm, an eccentric quick-release frame, and a central positioning pin. The clamping arm support is located at the middle of one end of the locking seat. The first and second clamping swing arms are respectively hinged to both sides of the clamping arm support. The eccentric quick-release frame is hinged to the second clamping swing arm. The central positioning pin is slidably installed inside the clamping arm support. The bridge-type boring bar holder is clamped and engaged with the first and second clamping swing arms through its clamping groove. The bridge-type boring bar holder is detachably installed at one end of the quick-release locking mechanism. The bridge-type boring bar holder is equipped with a counterweight.

2. The shaft hole tool holder assembly with a replaceable tool holder according to claim 1, characterized in that, The quick-release locking mechanism also includes a fastening screw, two short positioning pins and two swing arm hinge pins. The fastening screw is threaded onto one side of the outer wall of the first clamping swing arm. The two short positioning pins are respectively installed in the middle of the outer walls of the first clamping swing arm and the second clamping swing arm. The two swing arm hinge pins are respectively hinged onto the other side of the outer walls of the first clamping swing arm and the second clamping swing arm. The clamping arm support includes a support base, two movable grooves, a positioning protrusion, two positioning holes, a clearance pin hole, and a pin assembly hole. The two movable grooves are respectively opened at the top and bottom ends of the support base. The positioning protrusion is located at the end of the support base away from the locking seat. The two positioning holes are both opened at the other end of the positioning protrusion. The clearance pin hole and the pin assembly hole are both opened inside the support base.

3. A shaft hole tool holder assembly with a replaceable tool holder according to claim 1, characterized in that, The locking seat includes a positioning base, a limiting groove, two stopping grooves and two storage slots. The limiting groove is located at the middle of one end of the positioning base, the two stopping grooves are located on both sides of one end of the positioning base, and the two storage slots are located at the top and bottom of the positioning base, respectively.

4. A shaft hole tool holder assembly with a replaceable tool holder according to claim 1, characterized in that, The bridge-type boring tool holder includes a tool holder base, two clamping slots, a positioning slot, and two positioning posts. The two clamping slots are respectively opened at the top and bottom of the tool holder base. The positioning slot is opened at the middle of one end of the tool holder base. The two positioning posts are fixedly installed on the groove wall of the positioning slot. Multiple mounting screw holes are respectively opened on the upper and lower sides of one end of the tool holder base. The two mounting slots are respectively opened on the front and rear sides of one end of the tool holder base.

5. A shaft hole tool holder assembly with a replaceable tool holder according to claim 4, characterized in that, The bridge-type boring bar holder also includes a counterweight, a boring head, a tool head clamp, a reinforcing clamp, and multiple mounting bolts. The boring head is placed inside a mounting slot on one side, and the tool head clamp covers the outer side of the boring head. The multiple mounting bolts are respectively inserted through the counterweight, the tool head clamp, and the reinforcing clamp. The tool head clamp and the reinforcing clamp are both locked and fixed to the tool holder base by mounting bolts. The counterweight is locked and assembled inside a mounting slot on the other side by mounting bolts.

6. A shaft hole tool holder assembly with a replaceable tool holder according to claim 1, characterized in that, A limiting boss is provided at the middle of one end of the tool holder body. The top and bottom ends of the limiting boss are provided with stop protrusions. Locking screws are fixedly installed on both sides of one end of the tool holder body. Locking nuts are threaded onto the outer walls of the two locking screws. The quick-release locking mechanism is fixedly connected to the tool holder body through the locking screws and locking nuts.

7. A shaft hole tool holder assembly with a replaceable tool holder according to claim 2, characterized in that, The short positioning pin is inserted into the clearance pin hole, the intermediate positioning pin is slidably connected to the pin assembly hole, the first clamping swing arm and the second clamping swing arm are both set as L-shaped structures, and the eccentric quick release frame is composed of a ball handle and an eccentric wheel.

8. A shaft hole tool holder assembly with a replaceable tool holder according to claim 5, characterized in that, The counterweight, the tool holder, and the reinforcing clamp are all provided with adjustment slots for the installation bolts to move. The tool holder is designed with an L-shaped structure, and the tool holder clamps and fixes the boring tool head in the installation slot by the installation bolts.

9. A shaft hole tool holder assembly with a replaceable tool holder according to claim 1, characterized in that, The intelligent control system includes a sensing module, an execution module, and a controller. The sensing module includes a triaxial accelerometer, an eddy current displacement sensor, and a strain gauge force sensor. The triaxial accelerometer is mounted on the front outer wall of the tool holder body, the eddy current displacement sensor is mounted on the top front end of the tool holder body, and the strain gauge force sensor is mounted on the upper outer wall of the front end of the bridge boring post. The execution module includes a servo screw assembly and an electromagnetic self-locking device. The servo screw assembly is mounted in the mounting slot of the bridge boring post and is connected to the counterweight. The electromagnetic self-locking device is mounted on one side of the quick-release locking mechanism. The controller is electrically connected to the sensing module and the execution module respectively.

10. A control method for a shaft hole tool holder assembly with a replaceable tool holder according to any one of claims 1 to 9, characterized in that, Includes the following steps: After the operator completes the assembly of the tool holder assembly and starts the intelligent control system, the system first synchronously collects three signals: acceleration, displacement, and cutting force. After zero-bias correction, bandpass filtering, and Hanning window preprocessing, the system extracts radial runout, root mean square value of vibration, mean and fluctuation of cutting force, and complex eccentricity vector in the frequency domain. When the amplitude of the eccentricity vector exceeds the preset threshold, the controller calculates the radial displacement required by the counterweight and drives the servo screw assembly to perform closed-loop adjustment of the counterweight position through an incremental PID algorithm until the residual imbalance converges to within 1μm. Based on the dynamic balance correction, the controller performs FFT on the acceleration signal to identify the vibration characteristic frequency. If a resonance risk is detected and the cutting force fluctuation exceeds the limit, the feed rate is adaptively reduced according to the variable feed strategy, and the preload of the electromagnetic self-locking device is dynamically adjusted according to the measured cutting force. Throughout the entire processing, the self-diagnostic module continuously monitors sensor signals and actuator stroke, immediately alarming and protecting against abnormalities, and automatically updating the threshold baseline after each processing cycle.

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