A straightening device and method for boring bar machining

Abstract

The present application relates to the technical field of boring bar straightening, and particularly relates to a straightening device and method for boring bar machining, which comprises a workbench, a counter-topping assembly, a detection assembly, a straightening assembly and a linear driving part, the counter-topping assembly is arranged on the workbench and comprises a first top pin seat and a second top pin seat, the detection assembly is arranged on one side of the boring bar and comprises a support frame and a dial indicator, and is used for obtaining a radial run-out value when the boring bar rotates, the straightening assembly is located between the first top pin seat and the second top pin seat and comprises a bottom supporting roller and a top pressing roller which are arranged correspondingly in a vertical direction and clamp the boring bar, and the linear driving part is used for driving the bottom supporting roller and the top pressing roller to move synchronously along the boring bar in an axial direction according to the run-out value given by the detection assembly, so that continuous rolling straightening is realized in the curved section. Through axial continuous rolling, the segmented indentation is eliminated, and the elastic rebound is avoided, and the straightening efficiency is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of boring bar straightening technology, and in particular to a straightening device and method for boring bar machining. Background Technology

[0002] The boring bar is a key connecting component of a deep hole drilling and boring machine and its matching cutting tools (drill bit, boring head, roller burnishing head, and combined boring roller head). Its core function is to achieve precise control of cutting power transmission and axial feed motion. The straightness of the boring bar is particularly important, determining the roundness of the bored hole and increasing tool wear, directly affecting the service life of the matching tools. Therefore, during the manufacturing process of the boring bar, it is usually necessary to perform multiple straightening processes, and after each straightening, a corresponding stabilization process must be performed, following the operating principle of "adjust once, stabilize once." This method continuously optimizes and ultimately ensures that the boring bar meets the straightness standard required for machining.

[0003] In the existing technology, the straightening machine adopts point-to-point straightening with a fixed anvil and pressure head. Its working principle is that a dial indicator is used manually to detect the bending amount of the boring bar. After the detection is completed, the bending position is straightened by a hydraulic press. After straightening, it needs to be detected again. If it does not meet the qualified standard, the above straightening and detection steps need to be repeated until the boring bar is straightened to be qualified.

[0004] However, since the existing pressure head stroke is fixed, when the bending span is greater than the pressure head width, it is necessary to press in sections multiple times. After each shift, the gauge needs to be readjusted and pressure needs to be applied again. The auxiliary time accounts for more than 60% of the total working time. Moreover, both the pressure head and the anvil are rigid bodies (HRC55 and above). When straightening, the section pressing on the surface of the boring bar will produce micro-protrusion ridges that are higher than the base. These ridges can only be removed by subsequent turning and grinding processes, but cannot restore the homogeneous structure, which seriously affects the surface fatigue performance of the boring bar. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a straightening device and method for boring bar machining, which effectively solves the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a straightening device and method for boring bar machining, comprising:

[0007] Workbench;

[0008] The top assembly, set on the worktable, includes a first center seat and a second center seat that can slide relative to each other along the axial direction of the boring bar, for pressing against and rotating to support the boring bar at both ends;

[0009] The detection component, located on one side of the boring bar, includes a support frame and a dial indicator mounted on the support frame, for acquiring the radial runout value when the boring bar rotates;

[0010] A straightening assembly, located between the first center seat and the second center seat, includes a bottom support roller and a top pressure roller arranged vertically. The bottom support roller is located below the boring bar, and the top pressure roller is located above the boring bar. The bottom support roller and the top pressure roller clamp the boring bar.

[0011] A linear drive component is used to drive the bottom support roller and the top pressure roller to move synchronously along the boring bar axis based on the runout value given by the detection component, so as to achieve continuous rolling straightening in the bending section.

[0012] Furthermore, the support frame includes a mounting shaft, a drive shaft, and two support seats;

[0013] Both the mounting shaft and the drive shaft are arranged parallel to the boring bar, and the drive shaft is located between the mounting shaft and the boring bar. The two support seats are arranged at both ends of the mounting shaft and the drive shaft.

[0014] A rocker arm is provided on the mounting shaft, and the dial indicator is installed at the free end of the rocker arm;

[0015] A movable sleeve is provided on the drive shaft, and the swing arm rests on the upper part of the movable sleeve. An external force drives the drive shaft to rotate, causing the movable sleeve to drive the swing arm to move along the axial direction of the drive shaft.

[0016] Furthermore, the support base is provided with a vertical adjustment hole corresponding to the installation position of the mounting shaft.

[0017] Furthermore, both the first and second center seats include a sliding seat and a push rod rotatably disposed on the top of the sliding seat;

[0018] The two push rods within the first and second center seats are coaxially arranged.

[0019] Furthermore, the straightening assembly also includes a first driving member and a second driving member;

[0020] The first driving member is disposed below the bottom support roller, and its output end is connected to the bottom support roller for driving the bottom support roller to move upward in the vertical direction;

[0021] The second driving member is disposed above the top pressure roller, and its output end is connected to the top pressure roller for driving the top pressure roller to move downward in the vertical direction;

[0022] The first driving member and the second driving member can drive each other to bring the bottom support roller and the top pressure roller closer to each other, thereby clamping and pressurizing the boring bar;

[0023] The bottom support roller is provided with a first pressure sensor on its outer circumferential surface, and the top pressure roller is provided with a second pressure sensor on its outer circumferential surface, for detecting the pressure values ​​applied to the boring bar by the bottom support roller and the top pressure roller, respectively.

[0024] Furthermore, two sets of the straightening components are arranged along the axial direction of the boring bar, correspondingly arranged at the same end of the boring bar;

[0025] One set of the straightening components is fixedly mounted at one end of the boring bar;

[0026] Another set of the straightening components, driven by the linear drive, can move along the axis of the boring bar in a direction away from the fixed end.

[0027] Furthermore, two sets of the straightening assembly are arranged along the axial direction of the boring bar;

[0028] The two sets of straightening components are located in the middle of the boring bar and can move toward the two ends of the boring bar respectively by being driven by the linear drive.

[0029] Furthermore, the first center seat and the second center seat are slidably disposed on the worktable;

[0030] Hydraulic cylinders are provided on the sliding paths of the first and second center seats, and the two hydraulic cylinders are used to drive the first and second center seats to move closer to or further away from each other.

[0031] Furthermore, the bottom support roller includes a central roller and two side rollers symmetrically arranged on both sides of the central roller;

[0032] The top pressure roller is suspended directly above the intermediate roller, and the outer circumferential surfaces of both the top pressure roller and the intermediate roller have an inwardly concave arc-shaped structure.

[0033] The two side wheels are inclined and gradually spread outwards in a direction away from the middle wheel, forming a semi-support structure with the middle wheel at the bottom of the boring bar.

[0034] The present invention also provides a straightening method for boring bar machining, which uses the aforementioned straightening device for boring bar machining and includes the following steps:

[0035] Step 1: Hoist the boring bar to be straightened between the top-mounting components on the worktable, and control the first and second center seats to slide relative to each other along the axial direction of the boring bar, so that the push rods of the two center seats are precisely aligned with the center holes at both ends of the boring bar; drive the first and second center seats to continue to move closer, apply a preset preload to the two push rods until the push rods press against both ends of the boring bar, start the servo motor, and drive the boring bar to rotate at a low speed through the push rods;

[0036] Step 2: Adjust the position of the support frame of the detection component so that the dial indicator on the support frame is in contact with the outer cylindrical surface of the boring bar in the rotating state. Through the drive structure of the support frame, the dial indicator moves along the axis of the boring bar at preset intervals, and collects the radial runout value at each position in real time. The control unit receives the runout data of the dial indicator, generates the straightness deviation curve of the entire boring bar, and automatically identifies and marks the area with the maximum straightness deviation.

[0037] Step 3: Turn off the servo motor to stop the boring bar from rotating, start the linear drive to move the straightening assembly to the starting end of the key straightening area; start the drive structure of the straightening assembly to control the bottom support roller to move upward and the top pressure roller to move downward, so that the two gradually approach the boring bar until they contact the surface of the boring bar and form a stable clamping state;

[0038] Step 4: Start the linear drive to drive the support roller and pressure roller of the clamping boring bar to move synchronously along the axis of the boring bar. During the movement, through the coordinated control of the linear drive and the straightening component, a uniform straightening force is applied to the key straightening area, and 1-2 rounds of continuous rolling are performed until the straightness deviation area is corrected.

[0039] Step 5: After the rolling straightening is completed, turn off the linear drive, control the bottom support roller to move downward and the top pressure roller to move upward, moving away from each other to loosen the boring bar, and restart the servo motor to drive the boring bar to rotate. Repeat the testing process and retest the straightness of the entire boring bar section using a dial indicator. If the retest result meets the preset accuracy requirements, control the first center seat and the second center seat to slide in opposite directions, loosen the top support on the boring bar, and remove the straightened boring bar using a hoisting device. If the retest result does not meet the standard, repeat steps 3-5 until the straightness of the boring bar is qualified.

[0040] The beneficial effects of this invention are as follows: The top assembly can quickly slide and position the boring bar along the axial direction and support it; the detection assembly can directly detect the straightness of the boring bar; the straightening assembly automatically clamps the boring bar through the bottom support roller and the top pressure roller, and then the linear drive component drives the bottom support roller and the top pressure roller to move synchronously along the axial direction to complete the straightening. This eliminates the need for repeated manual operations, significantly shortens the single straightening cycle, and effectively improves the straightening efficiency. Furthermore, this invention uses a moving double-wheel continuous envelope loading to replace the traditional rigid single-point impact, enabling continuous straightening of the entire length with a single clamping. This avoids stress concentration at the joints of segmented pressing, eliminates the generation of micro-protrusion ridges from the root, and further ensures the integrity of the boring bar base. Attached Figure Description

[0041] 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 recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the isometric structure of the straightening device for boring bar machining in an embodiment of the present invention;

[0043] Figure 2 This is a top view of the straightening device for boring bar machining in an embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the detection component in an embodiment of the present invention;

[0045] Figure 4 This is a schematic diagram of the straightening component in an embodiment of the present invention;

[0046] Figure 5 This is a schematic diagram of the first working state of the two straightening components in an embodiment of the present invention;

[0047] Figure 6 This is a schematic diagram of the second working state of the two straightening components in an embodiment of the present invention;

[0048] Figure 7 This is a schematic diagram of the bottom support roller in an embodiment of the present invention.

[0049] Reference numerals: 1. Worktable; 2. Alignment assembly; 21. First center seat; 211. Sliding seat; 212. Push rod; 22. Second center seat; 3. Detection assembly; 31. Support frame; 311. Mounting shaft; 312. Drive shaft; 313. Support base; 313a. Vertical adjustment hole; 314. Swing rod; 315. Moving sleeve; 32. Dial indicator; 4. Straightening assembly; 41. Bottom support roller; 411. Intermediate roller; 412. Side roller; 42. Top pressure roller; 44. First drive component; 45. Second drive component; 5. Hydraulic cylinder. Detailed Implementation

[0050] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0052] like Figures 1 to 7 The straightening device for boring bar machining shown includes: a worktable 1, a top alignment assembly 2, a detection assembly 3, a straightening assembly 4, and a linear drive component;

[0053] The top assembly 2 is set on the worktable 1 and includes a first center seat 21 and a second center seat 22 that can slide relative to each other along the axial direction of the boring bar, for pressing against and rotating to support the boring bar at both ends;

[0054] The detection component 3 is located on one side of the boring bar, including a support frame 31 and a dial indicator 32 mounted on the support frame 31, for obtaining the radial runout value when the boring bar rotates;

[0055] The straightening assembly 4 is located between the first center seat 21 and the second center seat 22, and includes a bottom support roller 41 and a top pressure roller 42 arranged in the vertical direction. The bottom support roller 41 is located below the boring bar, and the top pressure roller 42 is located above the boring bar. The bottom support roller 41 and the top pressure roller 42 clamp the boring bar.

[0056] The linear drive (not shown in the figure) is used to drive the bottom support roller 41 and the top pressure roller 42 to move synchronously along the boring bar axis according to the runout value given by the detection component 3, so as to achieve continuous rolling straightening in the bending section.

[0057] The straightening process of this boring bar is as follows: First, the boring bar is hoisted into the worktable 1. The first center seat 21 and the second center seat 22 slide relative to each other, synchronously tightening both ends of the boring bar and applying a certain preload. Then, a servo motor drives the boring bar to rotate at a low speed. The dial indicator 32 moves on the support frame 31, collecting radial runout data of the rotating boring bar every 50mm. The control unit generates a full-range runout curve based on the collected data, automatically marking the maximum bending segment and peak-to-peak value. When the boring bar stops rotating, the linear drive moves the bottom support roller 41 and the top pressure roller 42 simultaneously to the starting end of the maximum bending segment. The bottom support roller 41 and the top pressure roller 42 slowly approach each other, and the pressure sensor provides real-time feedback. When the contact force between the two rollers and the boring bar reaches 50N, the roller surface just touches the boring bar, eliminating the gap. At this point, the boring bar basically does not undergo plastic deformation, equivalent to zero. Position calibration; then, using the contact force as the reference zero point, continue moving the top pressure roller 42 and the bottom support roller 41 until both are pressurized to the set straightening force and locked. The control unit keeps the straightening force in constant force mode to achieve close-fitting rolling with the boring bar; the bottom support roller 41 and the top pressure roller 42 are driven to move synchronously along the axis of the boring bar through the linear drive component, and the entire bending section is rolled back and forth 1-2 times; finally, the bottom support roller 41 and the top pressure roller 42 return to their original positions, the boring bar rotates again, and the dial indicator 32 re-measures the entire process. If the runout throughout the process meets the processing requirements, and the surface roughness tester detects no visible ridges in the original bending area, then the straightness of the boring bar is qualified at this time; otherwise, straightening continues; after the straightening process is completed, the two center seats move away from each other, the overhead crane lifts the straightened boring bar, and puts it into the corresponding processing position to continue the next processing step. It should be noted that the driving force of the linear drive is parallel to the axis of the boring bar. One or two linear drives can be selected. When one linear drive is selected, it adopts a combination of motor and gear rack. The two gears are driven to rotate through the connecting rod, and the two racks are driven to move synchronously to achieve synchronous movement of the top pressure roller and the bottom support roller along the axis of the boring bar. When two linear drives are selected, the top pressure roller and the bottom support roller have independent drive structures, and the two drive structures are synchronously controlled by PLC.

[0058] In this invention, the top component 2 can quickly slide and position along the axial direction to support the boring bar, the detection component 3 can directly detect the straightness of the boring bar, and the straightening component 4 automatically clamps the boring bar through the bottom support roller 41 and the top pressure roller 42. Then, the linear drive component drives the bottom support roller 41 and the top pressure roller 42 to move synchronously along the axial direction to complete the straightening. This eliminates the need for repeated manual operations, significantly shortens the single straightening cycle, and effectively improves the straightening efficiency. Furthermore, this invention uses a moving double-wheel continuous envelope loading to replace the traditional rigid single-point impact, enabling continuous straightening of the entire length with a single clamping. This avoids stress concentration at the joints of segmented pressing and eliminates the generation of micro-protrusion ridges from the root, further ensuring the integrity of the boring bar base.

[0059] like Figure 3 and Figure 4 As shown, the support frame 31 includes a mounting shaft 311, a drive shaft 312, and two support seats 313; the mounting shaft 311 and the drive shaft 312 are both parallel to the boring bar, and the drive shaft 312 is located between the mounting shaft 311 and the boring bar, and the two support seats 313 are located at both ends of the mounting shaft 311 and the drive shaft 312.

[0060] A rocker arm 314 is provided on the mounting shaft 311, and a dial indicator 32 is installed on the free end of the rocker arm 314. A movable sleeve 315 is provided on the drive shaft 312, and the rocker arm 314 is attached above the movable sleeve 315. An external force drives the drive shaft 312 to rotate, so that the movable sleeve 315 drives the rocker arm 314 to move along the axial direction of the drive shaft 312.

[0061] The mounting shaft 311, drive shaft 312, and boring bar are arranged in parallel. The dial indicator 32 is mounted on the free end of the swing arm 314. One end of the swing arm 314 is fixed on the mounting shaft 311, and the other end is attached to the moving sleeve 315 of the drive shaft 312. This ensures that the swing arm 314 always maintains a stable posture with one end fixed and the other end supported. This allows the detection probe of the dial indicator 32 to continuously contact the surface of the boring bar without affecting the detection accuracy due to posture swaying during movement.

[0062] When it is necessary to move the dial indicator 32 along the boring bar axis to collect radial runout values ​​at different positions, an external force drives the drive shaft 312 to rotate. For example, the drive shaft 312 can be rotated by a motor or a manual drive structure. The moving sleeve 315 and the drive shaft 312 are connected by a threaded connection or a transmission fit structure. The rotational motion of the drive shaft 312 is converted into the linear motion of the moving sleeve 315 along the axis of the drive shaft 312. Since the rocker arm 314 is attached to the moving sleeve 315, it will move synchronously along the axis of the drive shaft 312 with the linear motion of the moving sleeve 315. Finally, the dial indicator 32 installed at the free end of the rocker arm 314 moves smoothly along the axis of the boring bar, so as to realize the continuous or intermittent collection of radial runout values ​​at different positions of the boring bar.

[0063] The support frame 31 achieves stable movement of the dial indicator 32 along the boring bar axis through a dual-axis support and linkage transmission structure. Compared with the traditional manual movement of the dial indicator 32, it not only reduces the intensity of manual operation, but also automates the detection process by linking with the control unit, ensuring the uniformity and consistency of the sampling position, avoiding the deviation of the sampling point caused by uneven force and speed during manual movement, and further ensuring the reliability of the detection data.

[0064] Preferably, the support base 313 is provided with a vertical adjustment hole 313a corresponding to the mounting position of the mounting shaft 311. The height of the mounting shaft 311 is adjusted up and down in the adjustment hole by means of bolts or other connecting parts, thereby driving the swing arm 314 and the dial indicator 32 to rise and fall synchronously. This can flexibly adapt to boring bars of different diameters and accurately adjust the dial indicator 32 to the optimal detection position close to the surface of the boring bar.

[0065] like Figure 2 As shown, both the first center seat 21 and the second center seat 22 include a sliding seat 211 and a push rod 212 rotatably mounted on top of the sliding seat 211; the two push rods 212 in the first center seat 21 and the second center seat 22 are coaxially arranged. After the push rod 212 presses against the boring bar, the boring bar can rotate synchronously with the push rod 212, and there will be no friction or jamming during the rotation due to the fixed push rod 212, ensuring the smooth rotation of the boring bar.

[0066] like Figure 4 As shown, preferably, the straightening assembly 4 further includes a first driving member 44 and a second driving member 45; the first driving member 44 is disposed below the bottom support roller 41, and its output end is connected to the bottom support roller 41, for driving the bottom support roller 41 to move upward in the vertical direction; the second driving member 45 is disposed above the top pressure roller 42, and its output end is connected to the top pressure roller 42, for driving the top pressure roller 42 to move downward in the vertical direction; the first driving member 44 and the second driving member 45 can drive each other to bring the bottom support roller 41 and the top pressure roller 42 closer to each other, thereby clamping and pressurizing the boring bar;

[0067] The bottom support roller 41 is provided with a first pressure sensor on its outer circumferential surface, and the top pressure roller 42 is provided with a second pressure sensor on its outer circumferential surface, for detecting the pressure values ​​applied to the boring bar by the bottom support roller 41 and the top pressure roller 42, respectively.

[0068] Selecting a position with good straightness as the initial rolling position allows the bottom support roller 41 and the top pressure roller 42 to naturally achieve simultaneous contact on both sides, achieving pressure balance without additional fine adjustments and avoiding pressure deviation caused by bending at the initial position. As the roller slides from the position with good straightness towards the curved section, the radial runout value gradually increases. The actual pressure values ​​of the bottom support roller 41 and the top pressure roller 42 are collected in real time by the first and second pressure sensors and fed back to the control unit. The control unit can predict changes in the degree of bending in advance based on the runout curve of the entire section pre-stored in the detection component 3, and gradually adjust the pressure to ensure that the pressure is always maintained within the range of effective straightening without damaging the boring bar, thereby improving the stability and accuracy of the entire straightening process.

[0069] like Figure 5As shown, two sets of straightening components 4 are arranged along the axial direction of the boring bar, corresponding to the same end of the boring bar; one set of straightening components 4 is fixedly arranged at one end of the boring bar; the other set of straightening components 4 can move away from the fixed end along the axis of the boring bar by being driven by a linear drive.

[0070] When the boring bar is bent in the middle, the initial rolling position is taken as the end with better straightness. The bottom support roller 41 and the top pressure roller 42 of the fixed group form a stable clamp on the area with better straightness at the end, which is equivalent to providing an axial fixed anchor point for the boring bar and preventing the tension generated by the straightening component 4 during rolling from causing the boring bar to move as a whole. Under the drive of the linear drive component, the bottom support roller 41 and the top pressure roller 42 of the moving group move precisely from the initial position at the end to the middle bent section, directly performing 1-2 round-trip continuous rolling on the middle bent area. At the same time, the clamping limit of the fixed group at the end allows the moving group to concentrate the straightening force on the middle bent section. Combined with the precise pressure control of the dual pressure sensing plates, it can more efficiently offset the bending stress in the middle and avoid wasting the straightening force.

[0071] like Figure 6 As shown, two sets of straightening components 4 are arranged along the axial direction of the boring bar; the two sets of straightening components 4 are located in the middle of the boring bar and can move toward the two ends of the boring bar respectively through the drive of the linear drive component.

[0072] When the boring bar exhibits a shape with bends at both ends and good straightness in the middle, the two sets of straightening components 4 are centrally positioned, forming a bidirectional synchronous straightening mode. The two sets of straightening components 4 do not require reciprocating motion and can simultaneously start from the central reference position via linear drives. One set moves towards the left end of the boring bar to continuously roll and straighten the bend at the left end, while the other set moves towards the right end to synchronously straighten the bend at the right end, completely eliminating reciprocating backlash and halving the straightening time at each end, significantly shortening the overall straightening cycle. Furthermore, during the straightening process, the pressure sensors of both sets provide real-time feedback of their respective pressure values. The control unit adjusts the output of the corresponding drives to ensure that the left end uses appropriate pressure to eliminate slight bends, while the right end uses greater pressure to counteract severe bends. This avoids overpressure damage and ensures thorough straightening at both ends, achieving independent pressure control for the two sets of straightening components 4.

[0073] When the boring bar is bent, stress concentration occurs inside the metal. During the straightening process, rolling is used to rearrange the metal grains. After the originally bent boring bar returns to a straight shape, its actual length will increase slightly due to the straightening of the bent section. Therefore, as a preferred structure, the first center seat 21 and the second center seat 22 are slidably arranged on the worktable 1, and hydraulic cylinders 5 are provided on the sliding paths of the first center seat 21 and the second center seat 22. The two hydraulic cylinders 5 are used to drive the first center seat 21 and the second center seat 22 to move closer to each other or further away from each other.

[0074] During initial clamping, the initial distance between the first center seat 21 and the second center seat 22 is adjusted according to the length of the boring bar. The initial distance is greater than the length of the boring bar. After determining the position of the first center seat 21 and the second center seat 22, the hydraulic cylinder 5 is fixedly installed on the outer side of the sliding path of the two center seats. The cylinder body of the hydraulic cylinder 5 is fixed to the worktable 1, and the piston rods of the two are set opposite to each other. The piston rods are connected to the center seats, and the boring bar is placed between the first center seat 21 and the second center seat 22. The hydraulic cylinders 5 on both sides extend synchronously, driving the two center seats to move closer to each other and axially positioning and tightening the boring bar. At this time, the rod-side oil chamber and the rodless oil chamber of the hydraulic cylinders 5 on both sides are in a closed state, and the preload on the boring bar is maintained by the pressure inside the cylinder.

[0075] Before straightening, the control system opens the series throttle valve between the rod-side oil chamber and the rodless oil chamber of the hydraulic cylinder 5 to balance the pressure in the two chambers. The piston rod can freely extend and retract with the center seat and is in a floating state. At the same time, the throttle valve provides damping force to ensure that the preload is stable within the set range.

[0076] When the boring bar is straightened and lengthened, it generates axial thrust, which pushes the center seat to move the piston rod outward. The hydraulic oil flows between the two chambers through the throttle valve, achieving unobstructed floating. After the straightening assembly 4 completes the full straightening action, the connecting valve is closed to lock the position and continues to maintain the preload on the boring bar.

[0077] like Figure 4 As shown, the top pressure roller 42 is suspended directly above the intermediate roller 411, as... Figure 7 As shown, the bottom support roller 41 includes an intermediate roller 411 and two side rollers 412 symmetrically arranged on both sides of the intermediate roller 411; and the outer circumferential surfaces of the top pressure roller 42 and the intermediate roller 411 are both concave arc-shaped structures; the two side rollers 412 are inclined and gradually spread outward in the direction away from the intermediate roller 411, and form a semi-support structure with the intermediate roller 411 at the bottom of the boring bar.

[0078] The concave arc-shaped structure's curvature matches the outer circle curvature of the boring bar, allowing the wheel surface and the boring bar surface to form a surface contact. This evenly distributes the straightening force over a larger contact area, preventing local pressure from exceeding the yield strength of the boring bar material. This eliminates surface indentations at the source, ensuring the surface roughness of the boring bar and reducing the risk of surface fatigue damage. In addition, the upper and lower arc surfaces can also provide radial restraint for the boring bar, preventing lateral deviation and keeping it always on the preset rolling path. This ensures that the straightening force is precisely applied to the curved section, further guaranteeing the consistency of straightness.

[0079] The two side wheels 412 are symmetrically inclined, and the inclination angle is usually adjusted according to the diameter of the boring bar. The two side wheels 412 and the middle wheel 411 form a triangular support area at the bottom of the boring bar. The middle wheel 411 bears the main vertical downward gravity of the boring bar, and the two side wheels 412 bear the lateral component forces on both sides respectively. Through the stability principle of the triangular structure, the boring bar is prevented from tipping over to either side.

[0080] The present invention also provides a method for straightening boring bars, employing a straightening device for boring bars, comprising the following steps:

[0081] Step 1: Hoist the boring bar to be straightened between the first center seat 21 and the second center seat 22. Control the first center seat 21 and the second center seat 22 to slide relative to each other along the axial direction of the boring bar, so that the push rods 212 of the two center seats are precisely aligned with the center holes at both ends of the boring bar. Drive the first center seat 21 and the second center seat 22 to continue to move closer, apply a preset preload to the two push rods 212 until the push rods 212 press against both ends of the boring bar. Start the servo motor, and drive the boring bar to rotate at a low speed through the push rods 212. Ensure that the boring bar has no axial displacement or radial wobble, avoid detection and straightening errors caused by clamping deviations, and reduce rework rate.

[0082] Step 2: Adjust the position of the support frame 31 of the detection component 3 so that the detection end of the dial indicator 32 on the support frame 31 is in contact with the outer cylindrical surface of the boring bar in the rotating state. Through the driving structure of the support frame 31, the dial indicator 32 moves along the axis of the boring bar at preset intervals (such as every 50mm) to collect the radial runout value at each position in real time. The control unit receives the runout data of the dial indicator 32, generates the straightness deviation curve of the entire boring bar, and automatically identifies and marks the area with the maximum straightness deviation. No manual judgment is required, the detection efficiency is improved by more than 30%, and the accurate positioning makes the subsequent straightening more targeted.

[0083] Step 3: Turn off the servo motor to stop the boring bar from rotating, start the linear drive to move the straightening assembly 4 to the starting end of the key straightening area; start the drive structure of the straightening assembly 4 to control the bottom support roller 41 to move upward and the top pressure roller 42 to move downward, so that the two gradually approach the boring bar until they contact the surface of the boring bar and form a stable clamping state.

[0084] Step 4: Activate the linear drive to drive the support roller and pressure roller clamping the boring bar to move synchronously along the boring bar axis. During the movement, through the coordinated control of the linear drive and the straightening component 4, a uniform straightening force is applied to the key straightening area, and 1-2 rounds of continuous rolling are performed until the straightness deviation area is corrected. Continuous rolling replaces the traditional single-point impact, which not only eliminates segmented indentations and reduces elastic rebound, but also avoids damage to the boring bar surface, ensuring surface roughness and fatigue performance. The straightness consistency can reach within 0.02mm / m.

[0085] Step 5: After the rolling straightening is completed, turn off the linear drive, control the bottom support roller 41 to move downward and the top pressure roller 42 to move away from each other to loosen the boring bar, restart the servo motor to drive the boring bar to rotate, repeat the detection process, and re-measure the straightness of the entire boring bar section using dial indicator 32; if the re-measurement result meets the preset accuracy requirements, control the first center seat 21 and the second center seat 22 to slide in opposite directions, loosen the top support of the boring bar, and remove the straightened boring bar using the hoisting equipment; if the re-measurement result does not meet the standard, repeat steps 3-5 until the straightness of the boring bar is qualified.

[0086] After each straightening, the product is retested using a dial indicator 32 to prevent defective products from being rejected due to insufficient straightening force or improper parameters. The repeated straightening mechanism for defective products allows for parameter adjustment without re-clamping, reducing material waste and labor time, and improving the product qualification rate.

[0087] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A straightening device for boring bar machining, characterized in that, include: Workbench; The top assembly, set on the worktable, includes a first center seat and a second center seat that can slide relative to each other along the axial direction of the boring bar, for pressing against and rotating to support the boring bar at both ends; The detection component, located on one side of the boring bar, includes a support frame and a dial indicator mounted on the support frame, for acquiring the radial runout value when the boring bar rotates; A straightening assembly, located between the first center seat and the second center seat, includes a bottom support roller and a top pressure roller arranged vertically. The bottom support roller is located below the boring bar, and the top pressure roller is located above the boring bar. The bottom support roller and the top pressure roller clamp the boring bar. A linear drive component is used to drive the bottom support roller and the top pressure roller to move synchronously along the boring bar axis according to the runout value given by the detection component, so as to achieve continuous rolling straightening in the bending section; Two sets of straightening components are arranged along the axial direction of the boring bar. The two sets of straightening components are located in the middle of the boring bar and can move toward the two ends of the boring bar respectively by the drive of the linear drive. The bottom support roller includes a middle roller and two side rollers symmetrically arranged on both sides of the middle roller; the top pressure roller is suspended directly above the middle roller, and the outer circumferential surfaces of the top pressure roller and the middle roller are both concave arc-shaped structures; The two side wheels are inclined and gradually spread outwards in a direction away from the middle wheel, forming a semi-support structure with the middle wheel at the bottom of the boring bar, keeping the boring bar always on the preset rolling path, and ensuring that the straightening force is accurately applied to the bending section.

2. The straightening device for boring bar machining according to claim 1, characterized in that, The support frame includes a mounting shaft, a drive shaft, and two support bases; Both the mounting shaft and the drive shaft are arranged parallel to the boring bar, and the drive shaft is located between the mounting shaft and the boring bar. The two support seats are arranged at both ends of the mounting shaft and the drive shaft. A rocker arm is provided on the mounting shaft, and the dial indicator is installed at the free end of the rocker arm; A movable sleeve is provided on the drive shaft, and the swing arm rests on the upper part of the movable sleeve. An external force drives the drive shaft to rotate, causing the movable sleeve to drive the swing arm to move along the axial direction of the drive shaft.

3. The straightening device for boring bar machining according to claim 2, characterized in that, The support base is provided with a vertical adjustment hole corresponding to the installation position of the mounting shaft.

4. The straightening device for boring bar machining according to claim 1, characterized in that, Both the first and second center seats include a sliding seat and a top rod rotatably disposed on the top of the sliding seat; The two push rods within the first and second center seats are coaxially arranged.

5. The straightening device for boring bar machining according to claim 1, characterized in that, The straightening assembly further includes a first driving element and a second driving element; The first driving member is disposed below the bottom support roller, and its output end is connected to the bottom support roller for driving the bottom support roller to move upward in the vertical direction; The second driving member is disposed above the top pressure roller, and its output end is connected to the top pressure roller for driving the top pressure roller to move downward in the vertical direction; The first driving member and the second driving member can drive each other to bring the bottom support roller and the top pressure roller closer to each other, thereby clamping and pressurizing the boring bar; The bottom support roller is provided with a first pressure sensor on its outer circumferential surface, and the top pressure roller is provided with a second pressure sensor on its outer circumferential surface, for detecting the pressure values ​​applied to the boring bar by the bottom support roller and the top pressure roller, respectively.

6. The straightening device for boring bar machining according to claim 1, characterized in that, The first center seat and the second center seat are slidably mounted on the worktable; Hydraulic cylinders are provided on the sliding paths of the first and second center seats, and the two hydraulic cylinders are used to drive the first and second center seats to move closer to or further away from each other.

7. A straightening method for boring bar machining, characterized in that, The straightening device for boring bar machining as described in any one of claims 1-6 includes the following steps: Step 1: Hoist the boring bar to be straightened between the top-mounting components on the worktable, and control the first and second center seats to slide relative to each other along the axial direction of the boring bar, so that the push rods of the two center seats are precisely aligned with the center holes at both ends of the boring bar; drive the first and second center seats to continue to move closer, apply a preset preload to the two push rods until the push rods press against both ends of the boring bar, start the servo motor, and drive the boring bar to rotate at a low speed through the push rods; Step 2: Adjust the position of the support frame of the detection component so that the dial indicator on the support frame is in contact with the outer cylindrical surface of the boring bar in the rotating state. Through the drive structure of the support frame, the dial indicator moves along the axis of the boring bar at preset intervals, and collects the radial runout value at each position in real time. The control unit receives the runout data of the dial indicator, generates the straightness deviation curve of the entire boring bar, and automatically identifies and marks the area with the maximum straightness deviation. Step 3: Turn off the servo motor to stop the boring bar from rotating, start the linear drive to move the straightening assembly to the starting end of the key straightening area; start the drive structure of the straightening assembly to control the bottom support roller to move upward and the top pressure roller to move downward, so that the two gradually approach the boring bar until they contact the surface of the boring bar and form a stable clamping state; Step 4: Start the linear drive to drive the support roller and pressure roller of the clamping boring bar to move synchronously along the axis of the boring bar. During the movement, through the coordinated control of the linear drive and the straightening component, a uniform straightening force is applied to the key straightening area, and 1-2 rounds of continuous rolling are performed until the straightness deviation area is corrected. Step 5: After the rolling straightening is completed, turn off the linear drive, control the bottom support roller to move downward and the top pressure roller to move upward, moving away from each other to loosen the boring bar, and restart the servo motor to drive the boring bar to rotate. Repeat the testing process and retest the straightness of the entire boring bar section using a dial indicator. If the retest result meets the preset accuracy requirements, control the first center seat and the second center seat to slide in opposite directions, loosen the top support on the boring bar, and remove the straightened boring bar using a hoisting device. If the retest result does not meet the standard, repeat steps 3-5 until the straightness of the boring bar is qualified.

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