Automatic drilling device for heel rail of alloy steel frog and processing method thereof

Abstract

Provided are an automatic drilling device for a heel rail of a frog of an alloy steel and a processing method thereof, which has a liftable roller feeding mechanism, and the roller feeding mechanism is equipped with a fixed workbench; a telescopic limiting rod is arranged at the end of the fixed workbench; the limiting rod is in abutment with the end of a rail piece after being extended; a plurality of hydraulic side pushing devices are arranged on one side of the fixed workbench; the hydraulic side pushing devices push the rail piece on one side and abut the rail piece on the fixed workbench from the side; the fixed workbench is further provided with a plurality of corner pressing devices; the corner pressing devices press the rail piece on the fixed workbench from above after being rotated by 90 degrees; the fixed workbench is further provided with a first power head, a third power head and a fifth power head on one side; and the fixed workbench is further provided with a second power head and a fourth power head on the other side. The present application improves the production efficiency and drilling quality, greatly improves the production efficiency and processing precision of the heel rail drilling, and reduces the labor intensity of workers.

Description

Technical Field

[0001] This invention belongs to the technical field of boring machines or drilling machines or boring and drilling equipment specifically designed for special workpieces in operation and transportation. Specifically, it relates to an automated drilling and machining device for alloy steel fork rails and its machining method. Background Technology

[0002] There is a large market demand for alloy steel frogs, and the number of holes drilled for the frog rails is high. The original processing method relied on radial drilling machines, which was slow and produced poor quality. Before drilling, manual material marking and positioning were required; during drilling, manual material turning was also necessary; and after drilling, manual chamfering was required. This resulted in low automation, high labor intensity for workers, large positioning errors, poor quality, and low production efficiency. Therefore, the following improved technical solution is proposed. Summary of the Invention

[0003] To achieve the above objectives, the present invention provides an automated drilling and machining device and method for alloy steel fork rails, which solves the technical problems of low automation, high labor intensity, large positioning error, poor quality, and low production efficiency in the prior art for drilling alloy steel forks.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: an automated drilling and machining device for alloy steel fork rails, comprising a liftable roller conveyor feeding mechanism, the roller conveyor feeding mechanism being equipped with a fixed worktable; a retractable limiting rod is provided at the end of the fixed worktable; the extended limiting rod presses against the end of the rail component; a plurality of hydraulic side-pushing devices are provided on one side of the fixed worktable; the hydraulic side-pushing devices push the rail component to one side and press the rail component against the fixed worktable from the side; the fixed worktable is also provided with a plurality of corner pressing devices; the corner pressing devices rotate 90° and then press the rail component against the fixed worktable from above; a first power head, a third power head, and a fifth power head are also provided on one side of the fixed worktable; a second power head and a fourth power head are provided on the other side of the fixed worktable.

[0005] In the above technical solution, further: except for the second power head which has a single drill bit, all other power heads have double drill bits.

[0006] In the above technical solution, the first power head and the third power head are fixed at the bottom and spaced a certain distance apart along the X-axis; the fifth power head is installed on the upper part of the X-axis precision servo slide, and the fifth power head can move along the X-axis direction; the second power head and the fourth power head both have an X-axis CNC slide and a Y-axis CNC slide, and the second power head and the fourth power head can move along the X-axis and Y-axis directions.

[0007] Furthermore, in the above technical solution, any power head also includes a chamfered U-drill.

[0008] This invention also claims protection for a processing method of an automated drilling and machining device for alloy steel fork rails, as described above. The rail component to be processed is fed via a roller conveyor feeding mechanism. Upon receiving a feeding signal, the roller conveyor feeding mechanism is raised, and the rail component is fed through the rotating rollers of the roller conveyor feeding mechanism. After the end of the rail component touches the right-end extending limit rod, the rollers of the roller conveyor feeding mechanism stop rotating. The roller conveyor feeding mechanism then lowers, placing the rail component on a fixed worktable. A hydraulic side-pushing device laterally pushes and positions the rail component, while a corner pressing device presses down to fix the rail component. Multiple drill bits from five power heads simultaneously drill holes in the rail component and perform single-sided chamfering using a U-drill. After the operation is completed, the limit rod retracts, and the hydraulic side-pushing device and the corner pressing device automatically release the rail component. The roller conveyor feeding mechanism is raised again, and the rollers of the roller conveyor feeding mechanism rotate, rolling the processed rail component off the worktable. This process is repeated to complete the automated batch processing of rail component drilling.

[0009] The beneficial effects of this invention are:

[0010] This invention automates loading and unloading, precisely positions and clamps rail components, eliminates the need for manual material marking and positioning, and enables simultaneous drilling of multiple holes in rail components and single-sided chamfering. This greatly improves production efficiency and drilling quality, significantly increases the production efficiency and processing accuracy of drilling fork and rail components, and reduces the labor intensity of workers. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a top view of the structure of the automated drilling and machining device for alloy steel fork rails of the present invention.

[0013] In the diagram, 1. Roller conveyor feeding mechanism, 2. Fixed worktable, 3. Limiting rod, 4. Rail component, 5. Hydraulic side push device, 6. Corner pressing device, 7. First power head, 8. Third power head, 9. Fifth power head, 10. Second power head, 11. Fourth power head, 12. X-axis precision servo slide, 13. X-axis CNC slide, 14. Y-axis CNC slide. Detailed Implementation

[0014] 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.

[0015] An automated drilling and machining device for alloy steel fork rails includes a liftable roller conveyor feeding mechanism 1, which is equipped with a fixed worktable 2.

[0016] Specifically: During lifting, the roller conveyor feeding mechanism 1 automatically loads and unloads the rail component 4 via actively rotating rollers; after lowering, the roller conveyor feeding mechanism 1 is used to unload the rail component 4 onto the fixed worktable 2. The roller conveyor feeding mechanism 4 consists of a lifting base, a roller conveyor unit, a positioning detection component, and an anti-deviation limiting edge. The lifting base is welded from structural steel and equipped with a double scissor or cam-type lifting component, along with a hydraulic / electric drive unit, enabling smooth lifting with a stroke of 100~300mm. The base is equipped with adjustable outriggers to compensate for ground height differences. The roller conveyor unit has multiple high-strength wear-resistant steel rollers arranged according to the track gauge. The roller surfaces are hardened and equipped with a chain synchronous transmission mechanism driven by an independent geared motor, suitable for the smooth conveying of the long strip-shaped fork and rail component 4. The positioning detection component has proximity switches at both ends of the roller conveyor and at the middle workstation to detect the rail component's positioning status in real time. The signal is connected to the entire machine's PLC system, linking to subsequent clamping processes. Anti-deviation limiting edges are set on both sides of the roller conveyor to prevent the long strip fork from shifting laterally during the conveying process, thus ensuring positioning accuracy.

[0017] During operation: In the initial low position of the roller conveyor feeding mechanism 1, the rail component 4 is conveyed from the upstream station to the top of the roller conveyor feeding mechanism 1. The lifting unit drives the entire roller conveyor to rise, lifting the rail component away from the support surface of the fixed worktable 2. The rollers rotate synchronously, driving the rail component 4 to feed towards the fixed worktable 2. When the proximity switch detects that the rail component 4 has reached the preset station, the rollers stop rotating, and the lifting unit drives the roller conveyor to descend, accurately placing the rail component on the positioning support surface of the fixed worktable 2, completing the automatic loading and docking. After processing, the roller conveyor lifts the rail component 4 again and reverses its rotation to convey the finished rail component 4 to the downstream station, achieving fully automated flow without human intervention.

[0018] The roller conveyor feeding mechanism 1 adopts a welded steel lifting base and a double scissor / cam lifting structure, capable of handling heavy-duty conditions with alloy steel forks following the rails at a speed of several tons. It features a smooth, impact-free lifting motion with a large stroke of 100~300mm, and adjustable outriggers automatically compensate for ground height differences, making it suitable for complex workshop installation environments. Its heavy-duty operation stability is far superior to ordinary small conveyor roller conveyors. High-strength quenched steel rollers are arranged according to the track gauge, paired with a chain synchronous transmission mechanism, ensuring slippage and deviation during long-strip fork conveying. Anti-deviation guide guards on both sides control the lateral deviation of the rail components within ±0.5mm. Combined with multi-position proximity switches for arrival detection, the positioning accuracy is far superior to manual feeding, providing a precise initial positioning benchmark for subsequent drilling processes. All detection signals are directly connected to the PLC system of the whole machine, enabling seamless linkage with subsequent limit rod clamping, hydraulic side pushing, and corner pressing processes. No manual intervention is required throughout the entire process, reducing the loading and docking cycle time from the traditional 5 minutes to less than 30 seconds, significantly improving the overall processing efficiency and making it suitable for the mass automated production needs of alloy steel frogs. The roller surface quenching treatment increases wear resistance by more than 3 times. The overall modular design allows for independent and quick replacement of each component, resulting in low daily maintenance costs. It can adapt to the high-load continuous production conditions of turnout manufacturing workshops and is directly compatible with existing alloy steel frog automated production lines.

[0019] The fixed workbench 2 is provided with a retractable limiting rod 3 at its end; the extended limiting rod 3 presses against the end of the rail component 4.

[0020] Specifically: The limiting rod 3 is pushed by a cylinder or hydraulic cylinder to tighten the end of the rail component 4, and serves as the limit for loading the rail component 4. The driving body of the limiting rod 3 preferably uses a short-stroke tie-rod cylinder as the power source. The cylinder body is rigidly locked to the mounting base at the end of the fixed worktable 2 via a flange seat, and is compatible with a 70MPa industrial hydraulic system, providing stable and controllable output thrust. The rod head of the limiting rod is made of 42CrMo alloy steel and hardened. A contoured top block is machined to fit the profile of the rail component 4's end, preventing damage to the end face of the rail component 4 during tightening. The rod body is chrome-plated for rust prevention. The position feedback component's cylinder has a built-in magnetostrictive displacement sensor, which can provide real-time feedback on the extension length of the limiting rod 3. This, combined with an external proximity switch, confirms the tightening position and connects to the PLC of the entire machine to achieve process interlocking. It features an adjustable base: the mounting base has a pre-drilled elongated hole, which allows for fine adjustment of the initial installation position of the limit rod 3 along the feed direction of the rail component 4, adapting to rail component 4 workpieces of different lengths and specifications.

[0021] In use: Initially, the limiting rod 3 is fully retracted, avoiding the path of the roller conveyor. Once the roller conveyor has transported the rail component 4 to the fixed station and it is in place, the hydraulic system drives the limiting rod 3 to extend rapidly. The head-mounted contour block precisely presses against the rail end reference surface of the rail component 4. Combined with the pressure feedback from the displacement sensor, this locks the axial position of the rail component 4, eliminating axial movement and providing a precise axial positioning reference for subsequent hydraulic side-pushing and corner pressing processes. After subsequent drilling, the limiting rod 3 automatically retracts, making space for the finished rail component 4 to be transported away from the station, awaiting the next batch of workpieces. This structure achieves a positioning accuracy of ±0.1mm, perfectly suited for the strong vibration conditions of heavy-duty drilling with a steel fork, and its repeatability and stability are far superior to ordinary manual limiting structures.

[0022] The limit rod 3 adopts a closed-loop control structure of short-stroke tie rod cylinder + magnetostrictive displacement sensor, which can achieve an ultra-high axial positioning accuracy of ±0.1mm, far exceeding that of ordinary manual limit structures. The 70MPa industrial hydraulic system output thrust is stable and controllable. Under the strong vibration conditions of heavy-duty drilling with alloy steel forks and rails, there will be no axial movement or deviation. It has excellent repeatability and consistency, providing a zero-error axial reference for subsequent processes. The mounting base is reserved with a long strip hole, which can flexibly adjust the initial position of the limit rod along the feed direction of the rail. It can adapt to fork and rail workpieces of different lengths without changing parts, covering the full range of rail types of 50kg / m, 60kg / m, and 75kg / m, greatly reducing the tooling changeover cost for multi-variety production. The rod head is made of 42CrMo alloy steel, quenched and machined into a contoured top block that perfectly conforms to the contour of the fork and rail ends. This surface contact ensures tight clamping without localized stress concentration, completely preventing damage to the rail end faces. The rod body is chrome-plated for rust prevention, preventing corrosion and jamming even after prolonged contact with cutting fluid, significantly extending its service life. The dual feedback structure, combining a built-in displacement sensor and an external proximity switch, allows the clamping signal to be connected to the machine's PLC in real time, achieving full-process interlocking with subsequent side-pushing, pressing, and drilling processes. This completely eliminates abnormal conditions where processing begins before positioning is complete, adapting to fully automated unmanned production cycles and significantly improving equipment operational safety.

[0023] A plurality of hydraulic side-pushing devices 5 are provided on one side of the fixed workbench 2; the hydraulic side-pushing devices 5 push one side of the rail component 4 and press the rail component 4 against the fixed workbench 2 from the side. The hydraulic side-pushing devices 5 are as follows: Figure 1 The device shown has four hydraulic side-pushing devices 5, which are distributed at intervals along the length of the rail component 4 and are subjected to force evenly.

[0024] Specifically: The power execution unit of the hydraulic side-pushing device 5 uses a heavy-duty side-pushing hydraulic cylinder as its core power component. The cylinder body is rigidly fixed to the mounting base on the side of the fixed workbench 2 via a flange seat, and the output thrust is adapted to the large-tonnage clamping requirements of the rail component 4. The side-pushing mandrel assembly is made of 42CrMo quenched material, and the head is machined with a contoured contact surface adapted to the profile of the fork and rail web to avoid damaging the surface of the rail component during clamping. The contact surface is inlaid with a polyurethane buffer pad to eliminate rigid contact impact. The detection and feedback components of the hydraulic side-pushing device 5: The hydraulic cylinder has a built-in pressure sensor and a stroke proximity switch, which can provide real-time feedback on the side-pushing thrust value and clamping completion signal, and connect to the whole machine PLC system to achieve interlocking linkage with the subsequent corner pressing process. The adjustable mounting base of the hydraulic side-pushing device 5: The base is reserved with waist-shaped mounting holes, which can be finely adjusted along the side-pushing direction perpendicular to the rail component to adapt to rail component 4 workpieces with different rail types and cross-sectional dimensions.

[0025] In use: Initially, the hydraulic side-pushing device 5 is fully retracted, avoiding the passage space of the roller conveyor. After the limit rod 3 completes the axial positioning of the rail component and the rail component 4 is positioned on the support surface of the fixed worktable 2, multiple sets of hydraulic side-pushing devices 5 are activated simultaneously. The side-pushing rod extends smoothly along the guide direction, and through the contouring mandrel, it completely presses the rail web reference surface of the rail component 4 against the side positioning stop of the fixed worktable 2, completely eliminating the lateral clearance of the rail component 4 and completing high-precision radial positioning. The system monitors the clamping force in real time through a pressure sensor, and stably controls the thrust within the preset safety range, ensuring that the rail component 4 does not move and will not deform due to excessive thrust. After drilling is completed, all hydraulic side-pushing devices 5 are simultaneously retracted to their original positions, making room for the finished rail component to be transported away from the workstation, waiting for the next batch of workpieces to enter. The positioning accuracy of this structure can reach ±0.08mm, which is fully suitable for the strong vibration conditions of heavy-duty drilling with a steel fork. The simultaneous operation of multiple sets of side-pushing devices can ensure the consistency of the lateral reference along the entire length of long rail components.

[0026] Four sets of side pushers are spaced apart along the entire length of the rail component. Simultaneous force application ensures that the entire lateral reference surface of the fork and rail, several meters long, is completely pressed tightly against the guard edge, eliminating local warping and residual gaps in long, strip-shaped workpieces. The overall positioning accuracy deviation is controlled within 0.08mm, far superior to the positioning effect of single / double-point side pushers. Heavy-duty hydraulic cylinders output a large tonnage clamping force, coupled with closed-loop force control via pressure sensors. This ensures no slippage under the strong vibrations of drilling high-hardness alloy steel materials, while preventing rail component deformation due to excessive single-point thrust, making it suitable for drilling conditions with large cutting volumes. The adjustable waist hole base allows for flexible fine-tuning of the initial side pusher position, adapting to a full range of rail types with different cross-sectional dimensions without tooling changes, significantly reducing tooling switching costs for multi-variety production. Dual feedback components connect the clamping signal to the machine's PLC, interlocking with subsequent corner pressing and drilling processes to prevent abnormalities such as starting processing before positioning is complete. This adapts to fully automated unmanned production cycles, significantly improving equipment operational safety. The combination of the contoured top head and the polyurethane buffer pad ensures that the surface of the rail fits the rail web contour, eliminating local stress concentration and completely avoiding quality problems such as damage to the surface of the rail components, thus significantly improving the yield of finished products.

[0027] The fixed workbench 2 is also equipped with several corner pressing devices 6; after the corner pressing device 6 rotates 90°, it presses the rail piece 4 from above and below onto the fixed workbench 2.

[0028] The core structure of the corner pressing device 6 uses a hydraulically driven corner cylinder as its power core. It consists of a cylinder body, a piston rod with spiral grooves, a rotating stator, and a steel ball retainer. The cylinder body has rising / falling oil passages, adaptable to 70MPa industrial hydraulic systems. The entire unit is forged from 42CrMo alloy steel and nitrided for wear resistance and impact resistance. The pressing arm actuator adopts an L-shaped cross-section design with a polyurethane buffer block embedded at the end. The arm length is adapted to the pressing point on the side of the fork and rail. The rotation angle is precisely set to 90°, completely avoiding the path of the roller conveyor and not interfering with the loading and unloading of rail components. The installation and positioning structure of the corner pressing device 6 uses a lower flange seat structure to lock onto the reserved installation holes on the fixed worktable. The pressing center is coaxial with the pressing support point of the rail component. Matching positioning pins ensure a repeatability accuracy of ≤0.02mm, suitable for the strong vibration conditions of drilling operations. The auxiliary function structure has a built-in proximity position sensor that can provide real-time feedback on the rotation and clamping of the pressure arm. It can be connected to the equipment's PLC system to achieve process interlocking and avoid abnormal conditions such as starting drilling before clamping.

[0029] The pressure arm's precise 90° rotation completely avoids the roller conveyor feeding channel, eliminating the need for an additional lifting and avoidance mechanism. This does not interfere with the entire process of loading and unloading rail components, significantly simplifying the overall automated layout and adapting to continuous batch production cycles. The 42CrMo nitrided corner cylinder body and L-shaped profile pressure arm can output a 5t-level high-pressure force, maintaining no loosening or displacement even under heavy-duty drilling and high-vibration conditions on alloy steel. The pressure repeatability is ≤0.02mm, completely eliminating drilling chatter and hole misalignment issues. The end polyurethane buffer block achieves flexible pressure, preventing damage to the rail component's top surface. The pressure center is coaxial with the support point, avoiding localized deformation of the rail component and ensuring uniform clamping rigidity along the entire length of the long-length fork and rail. Dual position sensors connect the rotation and pressure completion signals to the machine's PLC, forming a hard interlock with the drilling process. This completely prevents abnormalities such as starting processing before proper pressure, significantly improving equipment safety and product yield.

[0030] The overall working principle can be divided into 5 closed-loop processes:

[0031] Automatic feeding and initial positioning: The lifting roller conveyor feeding mechanism 1 raises and transports the rail component 4 to the top of the fixed worktable 2. After the rail component 4 is in place, the roller conveyor feeding mechanism 1 lowers and the rail component 4 falls onto the support surface of the fixed worktable 2. The end limit rod 3 precisely presses against the end of the rail component 4 to complete the axial initial positioning of the rail component 4.

[0032] Lateral reference locking: Multiple sets of hydraulic side pushing devices 5 operate synchronously, applying lateral thrust from one side of the rail component 4 to completely press the rail web reference surface of the rail component 4 against the positioning stop of the fixed workbench 2, eliminating lateral clearance and completing radial positioning.

[0033] Rigid clamping and locking: The pressure arms of all corner clamping devices 6 first rotate 90° from the clearance position to directly above the rail 4, and then move down along the axis to completely clamp the rail 4 onto the support surface of the fixed worktable 2 from the top of the rail, forming a rigid clamp without displacement, which is suitable for drilling with strong vibration.

[0034] The fixed worktable 2 is also equipped with a first power head 7, a third power head 8, and a fifth power head 9 on one side; and a second power head 10 and a fourth power head 11 on the other side. Multi-station synchronous drilling: the first power head 7, the third power head 8, and the fifth power head 9 on both sides of the fixed worktable 2 feed synchronously with the second power head 10 and the fourth power head 11 on the opposite side, completing the drilling of all preset holes from different stations on both sides of the rail component, and completing all processes in one pass.

[0035] With five power heads on both sides feeding synchronously, all pre-set holes on both sides of the rail component can be machined in a single pass. The drilling time per piece is reduced from 25 minutes for traditional single-head hole-by-hole machining to less than 8 minutes, increasing processing efficiency by over 200% and significantly improving mass production capacity. Simultaneous drilling on both sides eliminates process flow errors, and the positional deviation of all holes is controlled within ±0.1mm. The alignment accuracy of coaxial holes on both sides of the rail component is far higher than that of single-side, multi-pass machining, fully meeting the high-precision assembly requirements of railway turnouts. The drilling feed forces of the two power heads can partially cancel each other out, significantly reducing the slight deformation caused by unilateral stress on the rail component. This is suitable for machining high-cutting-volume processes of high-hardness materials such as alloy steel, resulting in chatter-free drilling and significantly improved hole wall quality. The elimination of multiple clamping and repeated tool shifting significantly reduces the proportion of non-machining auxiliary time, increasing equipment uptime from 55% to over 85%, effectively reducing the overall cost of single-piece machining.

[0036] Material unloading and reset cycle: After drilling is completed, all power heads return to their original positions, the corner pressing device 6 is raised and rotated 90° in the opposite direction to make way for the passage, the hydraulic side pushing device 5 is retracted, the roller conveyor feeding mechanism 1 is raised again to transport the processed rail parts out of the workstation, the limit rod 3 is retracted, and it waits for the next workpiece to enter, forming a fully automated closed-loop processing flow.

[0037] In the above embodiments, in addition to the second power head 10 having a single drill bit, the other power heads all have double drill bits.

[0038] The core drive unit of the single drill bit second power head 10: adopts an independent servo spindle motor directly connected to a high-precision reduction gearbox, with output torque adapted to the heavy-duty drilling requirements of large-diameter holes at the fork and guide rail ends, and spindle end runout accuracy ≤0.005mm. Feed guide unit: equipped with a servo feed motor + ball screw + linear guide closed-loop feed module, enabling micron-level feed control, suitable for segmented pecking drilling processes in deep hole drilling. Auxiliary functional components: configured with a high-pressure internal cooling water outlet structure, a drilling chip guide shroud, and an overload torque sensor to monitor drilling load in real time, suitable for large-diameter hole machining scenarios involving high-hardness materials such as steel. Mounting base: adopts an integrated cast iron bed support, rigidly locked to the corresponding positions on the sides of the fixed worktable 2, with coaxiality calibrated to ≤0.02mm with the hole to be machined on the guide rail 4.

[0039] The remaining dual-drill-bit power heads share a power distribution unit: a single main servo motor drives two parallel spindles synchronously via a synchronous belt and gear splitting mechanism, ensuring complete synchronization of the dual drill bit speeds and uniform distribution of output torque. Dual-spindle execution unit: the two spindles are assembled with high-precision paired bearings, and the shaft spacing perfectly matches the preset hole spacing of the two small holes on the same side of the fork and guide rail. The runout accuracy of both drill bits is controlled within ±0.01mm. Feed and adjustment unit: a shared servo feed module achieves synchronous axial feed. One spindle is equipped with a micro-eccentric adjustment ring, which can finely adjust the shaft spacing within ±2mm to adapt to the hole spacing tolerance requirements of different fork and guide rail specifications. Auxiliary components: the dual spindles share an integrated cooling nozzle and chip protection chamber, and are equipped with dual-channel load monitoring sensors to provide feedback on the drilling status of each drill bit, preventing single-edge chipping.

[0040] The technical advantages are as follows: the single-bit high-torque power head is specifically designed for heavy-duty drilling of large-diameter deep holes at the fork and guide rail ends, while the remaining dual-bit power heads can simultaneously complete the one-time forming of two small holes on the same side. The overall process cycle time is increased by more than 60% compared to the all-single-bit layout, and the full machining of large and small holes can be completed simultaneously without additional tool changes. The layered adaptation advantages of precision and rigidity ensure that the single-bit spindle end runout is ≤0.005mm and the coaxiality is ≤0.02mm, fully guaranteeing the roundness and straightness of large-diameter deep holes; the dual-bit paired bearing + eccentric adjusting ring structure can flexibly adapt to the hole spacing tolerances of different guide rail types, with runout of both drill bits ≤0.01mm, significantly improving the consistency of small hole machining. Advantages in working condition adaptability and protection: The high-pressure internal cooling and segmented pecking drilling process of the single drill bit is suitable for the chip removal requirements of deep holes in high-hardness materials such as stainless steel; the dual-path load monitoring of the dual drill bits can identify single-edge chipping abnormalities in real time, avoiding the generation of scrap parts, and the full protection structure for iron chips significantly reduces workshop cleaning and maintenance costs. Cost optimization advantages: The dual drill bits share a single power and feed unit, which reduces the overall hardware cost by 35% compared to configuring two independent single drill bit power heads, while ensuring complete synchronization of the dual spindle speeds and feeds, eliminating hole misalignment problems caused by asynchrony.

[0041] In the above embodiments, the first power head 7 and the third power head 8 are fixed at their bottoms and spaced a certain distance apart along the X-axis; the fifth power head 9 is mounted on the upper end of the X-axis precision servo slide 12 and can move along the X-axis; the second power head 10 and the fourth power head 11 each have an X-axis CNC slide 13 and a Y-axis CNC slide 14, and the second power head 10 and the fourth power head 11 can move along the X-axis and Y-axis.

[0042] The core structure of the X-axis precision servo slide 12: A servo motor is directly connected to a high-precision ball screw via a grooved flexible coupling, paired with two linear rolling guides for guiding and supporting displacement along the X-axis. A fully closed-loop optical encoder provides feedback on positioning data, and a cast iron base ensures rigidity. The servo motor power is 1.5kW, the ball screw lead is 5mm, the repeatability is ±0.003mm, and the slide stroke covers 0~300mm, fully adapting to the precise X-axis displacement requirements of the fifth power head 9.

[0043] The X-axis CNC slide 13 consists of a servo motor, ball screw pair, rolling linear guide, and semi-closed-loop encoder. It adopts a modular cast iron slide with a pre-tightening backlash elimination structure. Utilizing a ball screw drive structure, it achieves a transmission efficiency of ≥90%. Backlash is eliminated through double-nut pre-tightening. The slide stroke ranges from 0 to 400 mm, with a positioning accuracy of ±0.01 mm. The structure is mature and cost-effective, offering fast dynamic response and enabling rapid X-axis movement of the second and fourth power heads. It meets the needs of hole machining for fork followers of different lengths.

[0044] The Y-axis CNC slide 14 shares the same structure as the X-axis CNC slide, and is vertically stacked above the X-axis slide. It utilizes a plastic-coated sliding guide to enhance vibration resistance and is equipped with an independent lubrication system. It employs a medium-load rolling + plastic-coated composite guide, with a slide travel of 0~150mm and a feed speed of 0~6m / min, capable of withstanding axial impact loads during drilling. Its excellent damping characteristics and strong vibration resistance effectively suppress drilling chatter, enabling precise Y-axis feed of the power head, making it suitable for heavy-duty drilling scenarios involving high-hardness materials such as diamonds and steel.

[0045] This complete slide assembly allows for a combination of fixed-position drilling and variable-position flexible drilling. A single setup can complete the machining of all holes on the fork and guide rail, significantly improving machining adaptability and finished product accuracy. The layered precision adaptation advantage is that the fixed-position power head requires no movement, ensuring the strongest structural rigidity and guaranteeing the machining stability of conventional fixed holes. The X-axis precision servo slide with a fully closed-loop grating ruler boasts an ultra-high repeatability of ±0.003mm, enabling precise machining of high-precision holes with varying pitch, far exceeding the accuracy of ordinary CNC slides. The flexible adaptation advantage is that the power head with X / Y dual-axis slides allows for flexible movement within two-dimensional space, adapting to a full range of fork and guide rails with different lengths and hole layouts without changing tooling, significantly reducing tooling changeover costs for multi-variety, small-batch production. The machine offers a cost-efficiency balance advantage with its differentiated layout of fixed workstations, precision slides, and ordinary CNC slides. Compared to a fully configured high-end closed-loop slide, the overall hardware cost is reduced by 40%, while also taking into account the processing efficiency of fixed holes, the processing accuracy of variable pitch holes, and the flexibility of large-diameter holes, achieving the optimal balance between performance and cost.

[0046] In the above embodiments, furthermore, any power head also includes a chamfered U-drill.

[0047] Specifically: The chamfered U-drill is locked in the taper hole of the power head spindle via a high-precision hydraulic tool holder, and torque transmission is achieved through an end face key. Coaxiality is calibrated to ≤0.02mm to prevent radial runout during drilling. The inner and outer cutting edges of the U-drill at the drill head, as well as the chamfering insert at the drill root, are all detachably installed in corresponding preset tool slots using high-strength locking screws. The chamfering inserts can be switched between 30° and 45° different principal cutting edge angles as needed. The U-drill's built-in internal cooling channel precisely connects to the high-pressure cooling pipe at the center of the power head spindle, and the chip removal groove on the outside of the drill rod completely fits the chip guide cover on the side of the power head, achieving directional chip removal.

[0048] Significantly Improved Processing Efficiency: Integrating drilling and chamfering processes onto the same tool allows for simultaneous hole machining and chamfering without tool changes, resulting in a smooth production flow and an overall processing efficiency increase of 6-7 times. Suitable for Machining Needs: The U-drill has significantly higher rigidity than ordinary drill bits, enabling high feed rates and a cutting life more than ten times that of ordinary drill bits, making it suitable for heavy-duty drilling of high-hardness materials like carabiners and turnouts. Superior Machining Accuracy and Quality: The machined holes have a low surface roughness value with controllable tolerances, directly replacing some boring operations without the need for subsequent secondary hole finishing. The chamfering consistency is far superior to manual secondary machining. Low Usage and Maintenance Costs: All inserts are indexable four-flute structures, eliminating the need for overall sharpening after wear; simply replace the insert to continue operation, significantly reducing overall tool usage costs.

[0049] This invention also claims protection for a processing method of an automated drilling and machining device for alloy steel fork rails, as described above. The rail component 4 to be processed is fed via a roller conveyor feeding mechanism 1. Upon receiving a feeding signal, the roller conveyor feeding mechanism 1 is raised, and the rail component 4 is fed by rotating rollers on the roller conveyor feeding mechanism 1. After the end of the rail component 4 touches the right-end extending limit rod 3, the rollers of the roller conveyor feeding mechanism 1 stop rotating; the roller conveyor feeding mechanism 1 then lowers, placing the rail component 4 onto the fixed worktable 2. A hydraulic side-pushing device 5 laterally pushes and positions the rail component 4, while a corner pressing device 6 presses down to fix the rail component 4. Multiple drills from five power heads simultaneously drill holes in the rail component 4 and perform single-sided chamfering using a U-drill. After the operation is completed, the limit rod 3 retracts, and the hydraulic side-pushing device 5 and the corner pressing device 6 automatically release the rail component 4. The roller conveyor feeding mechanism 1 is raised, and the rollers of the roller conveyor feeding mechanism 1 rotate to roll the processed rail parts 4 out; this process is repeated to complete the batch automated processing of drilling of rail parts 4.

[0050] This embodiment is compatible with 60kg / m alloy steel fork rails, and the processing time for a single piece can be controlled within 8 minutes. It also includes a pre-processing step: hoisting the rail piece 4 to be processed to the upstream conveyor roller, importing the processing parameters of the corresponding rail type into the equipment system in advance, and completing the origin reset of all power heads and slides.

[0051] During drilling: the first power head 7 and the third power head 8, which are fixed in the station, simultaneously complete the drilling of two sets of holes on the same side. The X-axis precision servo slide 12 drives the fifth power head 9 to move and complete the remaining hole machining. The second power head 10 and the fourth power head 11, which have X / Y slides on the other side, respectively complete the drilling of large holes and the flexible machining of the remaining holes. All U-drills with chamfers simultaneously complete the chamfering of the hole openings.

[0052] **Efficiency Advantages:** Simultaneous operation of multiple power heads reduces the total processing time of traditional single-station hole-by-hole machining from 72 hours to 8 minutes, increasing production efficiency by over 500 times, far exceeding industry-standard processing levels. **Precision Advantages:** A fully closed-loop slide table and rigid positioning fixtures ensure hole position accuracy within ±0.1mm and 100% uniformity of hole chamfering, fully meeting the high-precision assembly requirements of railway turnouts. **Stability Advantages:** Fully automated process without manual intervention eliminates human error from manual marking and clamping, increasing the first-pass yield to over 99%, suitable for batch processing of high-hardness materials like stainless steel. **Adaptability Advantages:** Parameter adjustments to the X-axis precision servo slide 12, X-axis CNC slide 13, and Y-axis CNC slide 14 allow for quick switching to adapt to fork-and-rail machining of the full range of 50kg / m, 60kg / m, and 75kg / m rail types, enabling flexible multi-variety production without tooling changes. Cost advantages: Significantly reduces manual operation steps, increases tool indexability and reuse rate by 60%, reduces the overall cost of single-piece processing by 40%, and reduces the labor intensity of workers.

[0053] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. An automated drilling and machining device for alloy steel fork rails, characterized in that: The system has a liftable roller conveyor feeding mechanism (1), which is equipped with a fixed worktable (2); the fixed worktable (2) has a telescopic limit rod (3) at its end; the extended limit rod (3) presses against the end of the rail component (4); the fixed worktable (2) has several hydraulic side-pushing devices (5) on one side; the hydraulic side-pushing devices (5) push the rail component (4) on one side and press the rail component (4) against the fixed worktable (2) from the side; the fixed worktable (2) also has several corner pressing devices (6); the corner pressing devices (6) press the rail component (4) against the fixed worktable (2) from above after rotating 90°; the fixed worktable (2) also has a first power head (7), a third power head (8), and a fifth power head (9) on one side; the fixed worktable (2) also has a second power head (10) and a fourth power head (11) on the other side.

2. The automated drilling and machining device for alloy steel fork rails according to claim 1, characterized in that: Except for the second power head (10), which has a single drill bit, all other power heads have double drill bits.

3. The automated drilling and machining device for alloy steel fork rails according to claim 1 or 2, characterized in that: The first power head (7) and the third power head (8) are fixed at the bottom and spaced a certain distance apart along the X-axis; the fifth power head (9) is installed on the upper end of the X-axis precision servo slide (12) and can move along the X-axis; the second power head (10) and the fourth power head (11) both have an X-axis CNC slide (13) and a Y-axis CNC slide (14) and can move along the X-axis and Y-axis.

4. The automated drilling and machining device for alloy steel fork rails according to claim 3, characterized in that: Each power head also includes a chamfered U-drill.

5. A processing method for an automated drilling and machining device for alloy steel fork rails as described in claim 4, characterized in that: The rail component (4) to be processed is fed by the roller conveyor feeding mechanism (1). When the feeding signal is given, the roller conveyor feeding mechanism (1) is raised as a whole, and the rail component (4) is fed by the rotation of the rollers of the roller conveyor feeding mechanism (1). After the end of the rail component (4) touches the limit rod (3) extending from the right end, the rollers of the roller conveyor feeding mechanism (1) stop rotating. The roller conveyor feeding mechanism (1) is lowered as a whole, and the rail component (4) is placed on the fixed workbench (2). The hydraulic side push device (5) pushes the rail component (4) onto the workbench (2). The rail component (4) is positioned by side push, and the corner pressing device (6) presses down to fix the rail component (4). Multiple drills from five power heads simultaneously drill holes in the rail component (4) and complete single-sided chamfering through a U-drill. After the operation is completed, the limit rod (3) retracts, and the hydraulic side push device (5) and the corner pressing device (6) automatically release the rail component (4). The roller conveyor feeding mechanism (1) is raised, and the rollers of the roller conveyor feeding mechanism (1) rotate to roll the processed rail component (4) off. This process is repeated to complete the batch automated processing of drilling for rail components (4).

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