A reinforcing bar threading machine apparatus for engineering and a method of using the same

Abstract

The application relates to the technical field of metal thread cutting processing, and discloses a reinforcing steel bar threading machine equipment for engineering and a use method thereof, which comprises a bed body, a spindle box moving along the guide rail of the bed body, a servo mechanism for driving the axial feeding of the spindle box, and a clamping mechanism for clamping reinforcing steel bars; a high-speed electric spindle is arranged in the spindle box; an inner cyclone cutter head is arranged at the front end of the high-speed electric spindle; the inner cyclone cutter head is provided with an inner hole; the diameter of the inner hole is larger than the diameter of the reinforcing steel bar to be machined; and a plurality of groups of profile thread milling cutter pieces are arranged in the circumferential direction of the inner hole of the inner cyclone cutter head. The eccentric arrangement of the inner cyclone cutter head and the reinforcing steel bar axis and the intermittent cutting scheme of the plurality of groups of profile milling cutters make the cutting chips naturally broken into short and broken shapes when the cutting chips are formed and separated from the workpiece under the action of centrifugal force, and overcome the defects that long spiral cutting chips are necessarily generated due to the through connection of the cutting chip tracks at the beginning and end in the continuous cutting of the traditional comb cutter, and the reinforcing steel bars are further wound and the tooth surface is scratched.

Description

Technical Field

[0001] This invention relates to the field of metal thread cutting technology, specifically to an engineering rebar threading machine and its usage method. Background Technology

[0002] In construction engineering, high-strength steel bars of HRB500 and above are prone to tooth tip tearing when threaded by rolling due to their high surface hardness and limited ductility. Therefore, cutting and forming become the necessary choice. Currently, the commonly used cutting-type steel bar threading machines on construction sites use round or flat comb cutters as cutting tools. The cutting tools rotate and feed axially to cut out threads. This process has inherent defects derived from its cutting principle.

[0003] When a comb cutter cuts threads, multiple teeth simultaneously engage with the reinforcing bar to continuously remove metal. The cutting paths of each tooth are seamlessly connected, and the chips flow continuously along the front face, inevitably forming a spiral chip several meters long. Within the narrow annular space between the tool and the reinforcing bar, the long chips are compressed and curled. Once they become entangled on the machined thread surface and are dragged and crushed, they plow scratches onto the thread surface, compromising the fit accuracy. Operators must stop the machine to clean the chips after processing only a few reinforcing bars.

[0004] The mean diameter drift caused by tool wear is more insidious. The continuous friction between the comb cutter's cutting edge and the hard phase in the rebar causes the tool tip to slowly retract, directly reflected in the shrinkage of the deviation direction under the mean radial tolerance. The wear rate is non-linear, influenced by factors such as batch hardness fluctuations in the rebar, making it impossible to predict based on the number of parts processed. Existing equipment lacks online measurement methods and the function of closed-loop correction of the tool tip position; relying solely on post-processing sampling inspections means that by the time out-of-tolerance issues are discovered, a batch of scrap has already been generated.

[0005] Furthermore, the steel bars on construction sites are mostly 9 or 12 meters long, with only one end processed, leaving the vast majority of the length freely cantilevered outside the clamps. The self-weight of the cantilevered section generates bending moments, which, combined with the cutting force, induce low-frequency vibrations. Existing equipment only has two clamping points at the front and rear of the spindle box, and lacks effective vibration suppression measures at the cantilevered ends. The vibrations are directly reflected in errors in thread taper and ellipticity. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an engineering rebar threading machine and its usage method, which solves the problems of long chip entanglement and tool wear-induced mean diameter drift caused by the inherent characteristics of continuous cutting process in existing comb-type rebar threading machines, and the inability to correct these issues online in a closed-loop manner.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a rebar threading machine for engineering applications, comprising a bed, a spindle box that moves along the bed guide rail, a servo mechanism for driving the spindle box axially, and a clamping mechanism for clamping rebars.

[0008] A high-speed electric spindle is installed inside the spindle box. An internal cyclone milling cutter disc is installed at the front end of the high-speed electric spindle. The internal cyclone milling cutter disc has an inner hole with a diameter larger than that of the steel bar to be processed. Multiple sets of forming thread milling cutters are installed circumferentially in the inner hole of the internal cyclone milling cutter disc. The rotation axis of the internal cyclone milling cutter disc has a fixed eccentricity with the axis of the steel bar.

[0009] The clamping mechanism includes a front centering clamp on the feed side of the spindle box and a rear centering clamp on the discharge side, as well as a follow-up vibration damping bracket at the cantilever end of the reinforcing bar. The follow-up vibration damping bracket includes a support roller and a hydraulic damper that provides controllable damping force.

[0010] Preferably, the forming thread milling insert is an indexable carbide insert, and the forming thread milling insert has a full profile cutting edge that matches the target thread profile, and the number of inserts is 3 to 5 sets.

[0011] Preferably, the eccentricity Based on the inner diameter of the internal cyclone milling cutter disc Minor diameter of rebar thread and preset cut-in gap ,according to Sure.

[0012] Preferably, both the front centering clamp and the rear centering clamp are hydraulically driven self-centering V-shaped clamps, which are internally linked by a gear and rack mechanism to ensure centering; the support height of the follow-up vibration damping bracket is adjustable.

[0013] Preferably, it also includes an online non-contact measurement unit, which includes a line laser profile scanning sensor installed on the discharge side of the spindle box, used to perform axial scanning of the processed threaded section to obtain profile point cloud data, and to calculate the thread pitch diameter in real time according to the virtual three-needle method.

[0014] Preferably, the line laser profile scanning sensor is connected to the intelligent control unit via an EtherCAT bus, and transmits the measured thread pitch diameter value to the intelligent control unit in real time. The total scanning and calculation time of the line laser profile scanning sensor is less than 1.5 seconds, and the pitch diameter measurement uncertainty is less than ±3 micrometers.

[0015] Preferably, the internal cyclone milling cutter disc also integrates a tool radial micro-compensation execution unit. The tool radial micro-compensation execution unit includes a micro actuator and a transmission mechanism. The transmission mechanism is a two-stage amplification mechanism combining differential thread and wedge block, which converts the rotational motion of the actuator into the radial linear motion of the cutting tool and has a self-locking characteristic. It is used to adjust the radial extension of at least one forming thread milling cutting tool according to the control command.

[0016] Preferably, the tool radial micro-compensation execution unit supplies power and transmits compensation commands via non-contact inductive coupling, and includes a transmitting module fixed to the spindle box side and a receiving module integrated in the inner cyclone milling cutter head. The tool radial micro-compensation execution unit is configured to perform compensation actions only when a valid command is received and the inner cyclone milling cutter head is in a non-cutting state.

[0017] Preferably, it also includes an intelligent control unit, which receives the measured value of the thread pitch diameter output by the online non-contact measurement unit. When the measured pitch diameter deviates from the preset target value and exceeds the preset compensation trigger limit, it automatically calculates the radial compensation amount and sends a compensation command to the tool radial micro-compensation execution unit. At the same time, it accumulates the compensation amount to monitor the service life of the forming thread milling cutter. When the accumulated compensation amount reaches the preset limit, it triggers a replacement warning.

[0018] In addition, the present invention also provides a method for using a rebar threading machine for engineering applications, comprising the following steps:

[0019] The steel bar to be processed is inserted into the front centering clamp, the rear centering clamp and the spindle hole and supported on the follower vibration damping bracket. The clamping program is started so that the front centering clamp and the rear centering clamp clamp the steel bar by centering and clamping it, and the follower vibration damping bracket is controlled to apply damping.

[0020] The high-speed electric spindle is started to drive the internal cyclone milling cutter to rotate. The spindle box is fed axially according to the preset pitch. The internal cyclone milling cutter surrounds the steel bar and mills a complete thread in one go. The chips are directly discharged.

[0021] After the spindle box retracts, the line laser profile scanning sensor scans the threaded section and calculates the measured mean diameter.

[0022] The intelligent control unit determines whether the measured mean diameter exceeds the preset compensation trigger limit. If it does, it calculates the radial compensation amount and sends it to the tool radial micro-compensation execution unit.

[0023] Release the front and rear centering clamps to remove the processed steel bar, and simultaneously execute the compensation command to adjust the radial position of the cutting tool, preparing for the next processing cycle.

[0024] This invention provides a rebar threading machine for engineering applications and its usage method. It has the following beneficial effects:

[0025] 1. This invention employs an internal vortex milling cutter disc eccentrically positioned with the steel bar axis and a multi-component milling cutter for intermittent cutting. This allows the chips to naturally break into short fragments upon formation and detach from the workpiece under centrifugal force. This cuts off the root cause of long chips from the cutting mechanism level, enabling continuous operation without stopping the machine for chip removal. It overcomes the defects of traditional comb-cut continuous cutting, which inevitably produces long spiral chips due to the continuous chip trajectory, which then entangle the steel bar and scratch the tooth surface.

[0026] 2. This invention integrates the line laser profile scanning sensor for measuring the thread pitch diameter piece by piece with the closed-loop linkage of the compensation mechanism built into the cutter head. Once tool wear is detected, causing the pitch diameter to deviate from the tolerance, the control system will wirelessly instruct the tool tip to complete the micron-level radial correction during the unloading gap. This ensures that the pitch diameter process capability index for batch processing is stably above 1.67, solving the shortcomings of existing equipment that lacks online measurement methods and relies on post-processing sampling inspection, which cannot prevent the generation of batch scrap.

[0027] 3. This invention integrates a two-stage amplification dynamometer mechanism consisting of a differential thread and a micro-wedge angle wedge connected in series into a rotating cutter head. It transmits electrical energy and compensation commands through non-contact inductive coupling, achieving radial adjustment of the cutter tip with a resolution of 1μm. The mechanism also has a friction self-locking characteristic, eliminating the contact friction pair required by traditional slip ring power supply, and improving the reliability of compensation execution of rotating components and the maintenance-free cycle. Attached Figure Description

[0028] Figure 1 This is a diagram illustrating the rebar threading machine for engineering applications in this invention.

[0029] Figure 2 This is a schematic diagram of the rebar threading machine for engineering applications in this invention;

[0030] Figure 3 This is a schematic diagram of the clamping mechanism of the rebar threading machine for engineering applications in this invention;

[0031] Figure 4 This is an exploded view of the spindle box of the rebar threading machine for engineering use in this invention;

[0032] Figure 5 For the present invention Figure 4 Enlarged view of point A in the image;

[0033] Figure 6 This is a diagram illustrating the spindle box in this invention;

[0034] Figure 7 This is a schematic diagram of the transmission mechanism in this invention;

[0035] Figure 8 This is a diagram showing the electrical signal connection architecture of the intelligent control unit in this invention.

[0036] The components include: 1. Bed; 2. Spindle box; 3. Servo mechanism; 4. Clamping mechanism; 5. Inner bore; 6. High-speed electric spindle; 7. Internal cyclone milling cutter head; 8. Forming thread milling cutter; 9. Front centering clamp; 10. Rear centering clamp; 11. Follow-up vibration damping bracket; 12. Line laser profile scanning sensor; 13. Miniature actuator; 14. Transmission mechanism; 15. Receiving module; 16. Support roller; 17. Hydraulic damper; 18. Intelligent control unit. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Please see the appendix Figure 1 -Appendix Figure 8 This invention provides a steel bar threading machine for engineering applications, used to cut straight threads on the ends of HRB400 or HRB500 grade steel bars at construction sites. The processed threads are connected to a standard straight thread sleeve to form a steel bar mechanical joint.

[0039] Referring to the attached diagram, the equipment adopts a horizontal overall layout. The bed 1 is made of HT300 gray cast iron. After sufficient aging treatment to eliminate residual stress, the upper surface is precision ground to obtain the guide rail mounting base. Two linear rolling guide rail pairs are laid parallel on this base. The spindle box 2 sits above the guide rails via two sets of front and rear sliders. Its reciprocating motion along the axial direction of the reinforcing bars is driven by a servo mechanism 3. This servo mechanism 3 includes an AC servo motor and a set of precision ball screw pairs. The lead of the ball screw is selected as 10mm. The encoder feedback signal of the servo motor and the CNC system form a position closed loop, and the axial repeatability positioning accuracy is within ±0.01mm.

[0040] The spindle housing 2 houses a high-speed electric spindle 6 with a rated power of 7.5kW. This spindle can continuously output a cutting torque of no less than 40N·m within its typical operating range of 800 to 1500 r / min. Its front flange is fixedly connected to the internal cyclone end mill 7 via precision stoppers and evenly distributed bolts. The body of the internal cyclone end mill 7 is machined from 42CrMo alloy structural steel after quenching and tempering. It is annular in shape with a central inner hole 5. The diameter of this inner hole 5 is 80mm, significantly larger than the maximum outer diameter of the reinforcing bar to be machined, allowing the bar to pass freely through. Four insert mounting slots are formed at 90° intervals on the circumferential wall of the inner hole 5. Each slot houses a shaped thread end mill insert 8 secured by a central locking screw. All four forming thread milling inserts are indexable carbide inserts. The base material is PVD-coated KC725M or equivalent grade. The rake angle of the insert is 8° and the clearance angle is 6°. The profile of the cutting edge is completely consistent with the standard tooth profile of M25×3 thread. A single pass can envelop and cut a complete trapezoidal thread profile.

[0041] Unlike the conventional design of threading machines where the cutting tool and workpiece are arranged coaxially, this equipment intentionally keeps the rotation axis of the internal cyclone milling cutter 7 parallel to, but not coincident with, the axis of the reinforcing bar in space, with a strictly calculated eccentricity between the two axes. The eccentricity The calculation is based on the diameter of the inner hole 5 of the internal cyclone milling cutter disc 7. Theoretical minor diameter of the thread to be machined and a preset safety gap for cutting in. The relationship between the three: equal minus Divide the difference by 2 and then subtract Taking the machining of M25×3 threads in this embodiment as an example, its minor diameter... Approximately 21.752 mm, It is 80mm. Taking 0.8mm, the eccentricity was calculated. The diameter is approximately 28.3 mm. Due to the eccentric setting, the four forming thread milling inserts 8 do not continuously contact the surface of the reinforcing bar during the high-speed rotation of the cutter head. Instead, they only cut into the workpiece material within a certain arc of the rotation cycle. The central angle corresponding to this contact arc is between 30° and 60°. During the remaining arc segments, the inserts completely detach from the workpiece, constituting a typical intermittent cutting mechanism. In each cutting cycle, the chips are naturally divided into short C-shaped chips with a length of approximately 3 to 8 mm, thus avoiding the long spiral chips inherent in continuous cutting.

[0042] During machining, the high-speed electric spindle 6 drives the internal cyclone milling cutter head 7 to rotate at a speed of 1200 r / min. The spindle box 2, driven by the servo mechanism 3, advances along the axial direction of the reinforcing bar at a feed rate of 384 mm / min. This feed rate is derived by multiplying the single-tooth feed amount of 0.08 mm, the number of cutting inserts of 4, and the cutter head speed of 1200 r / min. For each revolution of the cutter head, the spindle box 2 is axially displaced by exactly one pitch, or 3 mm. The trajectory of the cutting edge of the tool in space precisely corresponds to the helical surface of the M25×3 thread. The 40 mm effective thread length is cut in approximately 6.2 seconds, which is 3 to 4 times more efficient than a traditional die-type threading machine of the same specifications.

[0043] The clamping mechanism 4 consists of three parts: a front centering clamp 9, a rear centering clamp 10, and a follow-up vibration damping bracket 11. The front centering clamp 9 is located on the feed side of the spindle box 2, adjacent to the front end face of the inner cyclone milling cutter disc 7; the rear centering clamp 10 is located on the discharge side of the spindle box 2. Both clamps have the same structure and are hydraulically driven self-centering V-type clamps. The jaw body is made of Cr12MoV cold work die steel hardened to HRC58 to 62, with a V-angle of 90°. The opening and closing of the left and right jaws are forced to be synchronized by a precision gear and rack mechanism. Regardless of the diameter of the steel bar being clamped, the axis of the steel bar is automatically aligned to the geometric center of the clamp, with a centering accuracy better than 0.05mm. The clamping force is adjusted by the hydraulic station via a proportional relief valve and can be set as needed within the range of 10kN to 50kN.

[0044] The follow-up vibration damping bracket 11 is positioned approximately 600mm outside the front centering clamp 9, in the direction of the cantilevered end of the rebar. Its core structure consists of two horizontally arranged support rollers 16, their surfaces coated with a polyurethane layer with a Shore A hardness of 85, which lift the rebar from below to form a V-shaped support. The roller bracket is mounted via a linear guide pair and can float freely within ±10mm along the rebar's axial direction to accommodate minor axial movement during processing. The floating motion of the bracket is controlled by a parallel hydraulic damper 17, the damping force of which is continuously adjusted by an independent proportional relief valve, with an adjustment range of 200N to 2000N. This hydraulic damper 17 converts the vibration energy generated by the cutting excitation of the rebar's cantilever section into dissipated hydraulic heat. Actual measurements show that after installing the follow-up vibration damping bracket 11, the amplitude of the rebar processing section decreases from 0.15mm to below 0.03mm, and the thread cylindricity error is correspondingly improved from above 0.1mm to better than 0.03mm.

[0045] The front centering clamp 9 and the rear centering clamp 10 establish rigid constraints from both ends of the reinforcing bar, determining the machining geometric datum; the follow-up vibration damping bracket 11 provides a flexible auxiliary support with adjustable damping at the cantilever end, responsible for absorbing and dissipating vibration energy. The separation of rigid positioning and flexible vibration damping functions is the essential feature that distinguishes this clamping scheme from existing single-point or double-point clamping.

[0046] The equipment also includes an online non-contact measurement unit. The core component of this unit is a linear laser profile scanning sensor 12, fixed to a precision adjustable bracket on the discharge side of the spindle box 2. This sensor uses a 405nm wavelength blue semiconductor laser and operates based on the laser triangulation principle. Each profile contains 800 measurement points, with a Z-axis repeatability of 0.5μm. It establishes a data link with the intelligent control unit 18 via an EtherCAT industrial Ethernet bus, with a maximum sampling frequency of 64kHz. After each rebar is milled and the spindle box 2 returns to its original position, the sensor automatically performs a scan along the thread axis, covering at least three thread pitches (9mm), to acquire the thread axial section point cloud data.

[0047] The point cloud data processing flow is as follows: Gaussian filtering is used to remove burr noise; the region of interest is segmented to extract the thread profile, and interference points in the end chamfer and transition arc areas are removed; finally, the virtual three-wire method, well-known in the field, is used to calculate the thread pitch diameter. The virtual three-wire method, based on the ISO 68-1 thread standard, searches for a virtual circle tangent to both sides between the left and right tooth surfaces of the thread profile. The diameter of this virtual circle is taken as the theoretical three-wire diameter, which is 1.732 mm for an M25×3 thread. The distance from the center of the virtual circle to the thread axis is the pitch radius, and twice that distance is the measured pitch diameter. The entire acquisition, filtering, segmentation, and calculation process is completed within 1.5 seconds, and the measurement uncertainty is rated as ±3 μm when the coverage factor k=2.

[0048] The internal cyclone milling cutter head 7 also integrates a tool radial micro-compensation actuator. This actuator's drive train employs a two-stage amplification scheme combining differential threads and wedges. The first stage is a differential thread mechanism, consisting of two precision threads with different pitches connected coaxially in series—the driving section with a 0.5mm pitch connects to the output shaft of the micro-actuator 13, and the driven section with a 0.45mm pitch connects to the push rod. For every revolution of the micro-actuator 13, the push rod only axially displaces 0.05mm. The second stage is a wedge block with a 1:100 wedge angle. The axial feed of the push rod pushes the wedge to slide, converting the axial motion into a radial motion perpendicular to it. A 0.05mm feed of the push rod corresponds to a 0.5μm radial lift of the insert holder. The micro-actuator 13 uses a stepper motor with 256 microstep subdivision drive, achieving a tool tip radial displacement resolution on the order of 1μm for the entire drive train. The wedge angle of the wedge is much smaller than the self-locking angle of steel friction, preventing reverse slippage of the insert holder under cutting loads, and the mechanism's rigidity is equivalent to that of the fixed tool holder.

[0049] The power supply and command transmission of this execution unit abandon the contact scheme of conductive slip rings and instead adopt a non-contact inductive coupling method. A transmitting coil and control circuit are fixed on both sides of the spindle housing. A receiving module 15, consisting of a receiving coil and a microcontroller circuit board, is installed at the corresponding position on the rear end face of the inner cyclone end mill 7, with an air gap of 1.5mm between them. Power transmission adopts the Qi wireless charging extended protocol, with a carrier frequency of 105 to 205kHz, stably providing 5W DC power. Command and feedback signals are bidirectionally FSK modulated via a 13.56MHz carrier, with a communication rate of 115.2kbps. The microcontroller inside the inner cyclone end mill 7 continuously monitors the speed signal fed back by the spindle encoder, and only executes the received compensation command when it confirms that the end mill is completely stationary or the cutting insert is in a non-cutting phase.

[0050] The intelligent control unit 18 operates a closed-loop compensation control strategy. It pre-stores target pitch diameter and tolerance zone information in the process database: the target pitch diameter of the M25×3 thread is 23.051 mm, the tolerance zone is 0.10 mm, and the acceptable range is 23.001 mm to 23.101 mm. Based on this, a preset compensation trigger limit is defined, taking the target pitch diameter ±T / 3, i.e., 23.018 mm to 23.084 mm.

[0051] The intelligent control unit 18 is directly connected to the line laser profile scanning sensor 12 via an EtherCAT industrial Ethernet bus. The line laser profile scanning sensor 12 uploads the thread profile point cloud data acquired by scanning to the intelligent control unit 18 in real time via the bus to complete the mean diameter calculation. It is directly connected to the corresponding proportional relief valve in the hydraulic station via independent control cables to the front centering clamp 9 and the rear centering clamp 10. The intelligent control unit 18 sends clamping force setting commands to each valve and receives valve core position feedback signals to confirm the clamping status, forming a bidirectional control loop. It is directly connected to the independent proportional relief valve corresponding to the hydraulic damper 17 via a control cable, and sends damping force setting commands to it in one direction to adjust the internal oil flow resistance of the hydraulic damper 17 to dissipate vibration energy.

[0052] After the line laser contour scanning sensor 12 outputs the measured mean diameter value, the intelligent control unit 18 compares it with the preset compensation trigger limit. If the measured value falls within the trigger limit, no compensation command is generated, and unloading is directly allowed. If the measured value falls between 23.001mm and 23.018mm, it indicates that the tool tip has experienced perceptible wear. Although the current workpiece is still acceptable, the trend shows that it is about to exceed the tolerance. The intelligent control unit 18 immediately calculates the radial compensation amount. The calculation formula is ΔR, which is equal to the proportional coefficient multiplied by the difference between the target mean diameter and the measured mean diameter, and then divided by 2. The proportional coefficient is between 0.8 and 1.0 to prevent oscillation caused by single overcompensation. This command is temporarily stored and then issued during the unloading interval. If the measured value has fallen below the lower tolerance limit of 23.001mm, the system determines that it is unacceptable, issues an audible and visual alarm, performs compensation, and requires the operator to re-inspect the next product. If two consecutive products are unacceptable, the equipment is forcibly locked and a tool replacement is prompted.

[0053] The operation procedure for using the equipment in this embodiment is as follows. The operator selects the processing recipe on the human-machine interface, and the system retrieves the corresponding parameters from the process database. A 9-meter or 12-meter long steel bar is inserted above the support roller 16 of the follow-up vibration damping bracket 11, the front centering clamp 9, the inner hole 5 of the inner cyclone milling cutter disc 7, and the rear centering clamp 10, with the front end of the steel bar extending approximately 50mm beyond the front end of the cutter disc. After starting the automatic cycle, the rear centering clamp 10 first clamps with a force of 30kN to establish an axial reference. After a delay of 0.5 seconds, the front centering clamp 9 clamps with the same pressure. Finally, the hydraulic damper 17 of the follow-up vibration damping bracket 11 cuts in with a preset damping force of 800N. The high-speed electric spindle 6 accelerates to 1200r / min via a 3-second ramp, the high-pressure cooling pump is turned on simultaneously, the spindle box 2 quickly approaches at 15m / min and then switches to a feed speed of 384mm / min. The inner cyclone milling cutter disc 7 mills a 40mm full thread length around the steel bar in one pass. The spindle box 2 retracts to trigger the measurement program, and the line laser profile scanning sensor 12 outputs the measured mean diameter within 1.5 seconds. If compensation is required, the system calculates the compensation amount and sends it to the receiving module 15 via a wireless channel during the unloading gap. The micro actuator 13 drives the transmission mechanism 14 to complete the radial adjustment of the tool tip. The intelligent control unit 18 continuously accumulates the compensation amount. When it reaches 0.25mm, a yellow warning is triggered to prompt tool preparation. When it reaches 0.35mm, a red alarm is triggered and the start button is locked, forcibly replacing the forming thread milling insert 8.

[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A rebar threading machine for engineering applications, comprising a bed (1), a spindle box (2) that moves along a bed guide rail, a servo mechanism (3) for driving the spindle box axially, and a clamping mechanism (4) for clamping rebar, characterized in that: The spindle box (2) is equipped with a high-speed electric spindle (6). The front end of the high-speed electric spindle (6) is equipped with an internal cyclone milling cutter disc (7). The internal cyclone milling cutter disc (7) has an inner hole (5). The diameter of the inner hole (5) is larger than the diameter of the steel bar to be processed. Multiple sets of forming thread milling cutters (8) are installed circumferentially in the inner hole (5) of the internal cyclone milling cutter disc (7). The rotation axis of the internal cyclone milling cutter disc (7) has a fixed eccentricity with the axis of the steel bar. The clamping mechanism (4) includes a front centering clamp (9) and a rear centering clamp (10) on the feed side of the spindle box (2) and a follow-up vibration damping bracket (11) on the cantilever end of the steel bar. The follow-up vibration damping bracket (11) includes a support roller (16) and a hydraulic damper (17) that provides controllable damping force.

2. The rebar threading machine for engineering applications according to claim 1, characterized in that, The forming thread milling cutter (8) is a mechanically indexable carbide insert. The forming thread milling cutter (8) has a full profile cutting edge that is consistent with the target thread profile. The number of cutters is 3 to 5 sets.

3. The rebar threading machine for engineering applications according to claim 1, characterized in that, The eccentricity According to the inner diameter (5) of the internal cyclone milling cutter disc (7) Minor diameter of rebar thread and preset cut-in gap ,according to Sure.

4. The rebar threading machine for engineering applications according to claim 1, characterized in that, The front centering clamp (9) and the rear centering clamp (10) are both hydraulically driven self-centering V-shaped clamps, and their internal gear rack mechanism ensures centering; the support height of the follow-up vibration damping bracket (11) is adjustable.

5. The rebar threading machine for engineering applications according to claim 1, characterized in that, It also includes an online non-contact measurement unit, which includes a line laser contour scanning sensor (12) installed on the discharge side of the spindle box (2) for axial scanning of the processed threaded section to obtain contour point cloud data, and for real-time calculation of the thread pitch diameter based on the virtual three-needle method.

6. The rebar threading machine for engineering applications according to claim 5, characterized in that, The line laser profile scanning sensor (12) is connected to the intelligent control unit (18) via the EtherCAT bus, and transmits the measured thread pitch diameter value to the intelligent control unit (18) in real time. The total scanning and calculation time of the line laser profile scanning sensor (12) is less than 1.5 seconds, and the pitch diameter measurement uncertainty is less than ±3 micrometers.

7. The rebar threading machine for engineering applications according to claim 5, characterized in that, The internal cyclone milling cutter disc (7) also integrates a tool radial micro-compensation execution unit. The tool radial micro-compensation execution unit includes a micro actuator (13) and a transmission mechanism (14). The transmission mechanism (14) is a two-stage amplification mechanism combining differential thread and wedge. It converts the rotational motion of the actuator into the radial linear motion of the cutting tool and has a self-locking characteristic. It is used to adjust the radial extension of at least one forming thread milling cutter (8) according to the control command.

8. The rebar threading machine for engineering applications according to claim 7, characterized in that, The tool radial micro-compensation execution unit supplies power and transmits compensation commands through non-contact inductive coupling. It includes a transmitter module fixed on the side of the spindle box (2) and a receiver module (15) integrated in the inner cyclone milling cutter (7). The tool radial micro-compensation execution unit is configured to perform compensation actions only when a valid command is received and the inner cyclone milling cutter (7) is in a non-cutting state.

9. The rebar threading machine for engineering applications according to claim 7, characterized in that, It also includes an intelligent control unit (18), which receives the measured value of the thread pitch diameter output by the online non-contact measurement unit. When the measured pitch diameter deviates from the preset target value and exceeds the preset compensation trigger limit, it automatically calculates the radial compensation amount and sends a compensation command to the tool radial micro-compensation execution unit. At the same time, it accumulates the compensation amount to monitor the service life of the forming thread milling cutter (8). When the accumulated compensation amount reaches the preset limit, it triggers a replacement warning.

10. A method of using a rebar threading machine for engineering applications, characterized in that, The application of the rebar threading machine equipment for engineering use as described in claims 1-9 includes the following steps: Insert the steel bar to be processed into the front centering clamp (9), the rear centering clamp (10) and the spindle hole and support it on the follower vibration damping bracket (11). Start the clamping program so that the front centering clamp (9) and the rear centering clamp (10) clamp the steel bar by centering and control the follower vibration damping bracket (11) to apply damping. Start the high-speed electric spindle (6) to drive the inner cyclone milling cutter disc (7) to rotate, the spindle box (2) feeds axially according to the preset pitch, the inner cyclone milling cutter disc (7) mills a complete thread around the steel bar in one go, and the chips are directly discharged; After the spindle box (2) retracts, the line laser profile scanning sensor (12) scans the threaded section and calculates the measured mean diameter; The intelligent control unit (18) determines whether the measured mean diameter exceeds the preset compensation trigger limit. If it does, it calculates the radial compensation amount and sends it to the tool radial micro-compensation execution unit. Release the front centering clamp (9) and the rear centering clamp (10), take out the processed steel bar, and at the same time execute the compensation command to adjust the radial position of the blade to prepare for the next processing cycle.

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