A high-precision milling cutter head for milling rails
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- MEIGELI (ZHEJIANG) TECH CO LTD
- Filing Date
- 2025-12-15
- Publication Date
- 2026-06-19
Smart Images
Figure CN121373528B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of milling cutter head technology, and in particular to a high-precision milling cutter head for milling railway tracks. Background Technology
[0002] As a core load-bearing component of rail transit, the surface flatness and contour accuracy of railway tracks directly affect the safety, stability, and comfort of train operation. After long-term service, railway tracks are prone to wear, peeling, cracks, and other defects, requiring repair or refurbishment through milling to restore their designed contours and performance. This process places stringent requirements on the precision, cutting stability, chip removal efficiency, and service life of the milling cutter: on the one hand, it is necessary to ensure that the dimensional tolerances and surface finish of the milled rails meet the standards of the rail transit industry, especially the radial runout of the milling cutter must be controlled within a very small range to avoid cutting deviations; on the other hand, it is necessary to address the characteristics of the railway material (high-carbon steel, alloy steel) with high hardness and high cutting resistance, reducing problems such as vibration, chip accumulation, and edge wear during the cutting process to ensure continuous and efficient machining.
[0003] However, existing milling cutters for rail milling still have many technical shortcomings in practical applications, which restrict the improvement of machining accuracy and work efficiency:
[0004] Insufficient cutting mechanics balance: Traditional milling cutter heads often use inserts with equal height and aligned layout, resulting in excessive load on the inserts in the middle area of the rail where cutting is concentrated, while the load on the inserts at both ends is insufficient, easily causing elastic deformation of the inserts and vibration of the cutter head. At the same time, some milling cutter heads use positive rake angle inserts, which have insufficient cutting edge rigidity and are prone to bending and deflection under large cutting forces, causing the cutting trajectory to deviate from the preset contour, resulting in dimensional deviations and excessive surface roughness. The single type of insert cannot be specifically adapted to the cutting needs of different parts of the rail, such as the top surface, sides, and corners, easily leading to localized incomplete cutting or over-cutting.
[0005] Poor chip removal and chip breaking performance: Existing chip grooves mostly adopt a single curvature or straight line structure, which is poorly adapted to the complex contours of railway tracks. After chips are generated, they are prone to jamming and accumulating in the groove. This not only squeezes the cutting edge, causing uneven force on the cutting edge, but also scratches the machined surface. At the same time, the accumulated chips change the actual cutting angle, further reducing the machining accuracy. Some milling cutter heads have not optimized the groove width and lead angle for the chip characteristics of railway track milling, resulting in unsmooth chip removal and a lack of effective chip breaking structure. Long chips are prone to entangle the cutting edge, causing cutting interruption or equipment failure.
[0006] Insufficient positioning accuracy and stability: The connection between the tool holder and the disc body often uses a single-direction positioning screw or a simple groove fit, lacking multiple constraint mechanisms. During high-speed milling, it is easily affected by radial centrifugal force and axial cutting force, resulting in problems such as tool holder displacement and circumferential runout, which leads to the offset of the cutting position of the insert. The positioning datum design is unreasonable, and some structures have stress concentration. Micro-deformation caused by heat and force during machining or cutting will further amplify the positioning error, making it difficult to meet the stringent requirements of high-precision milling for radial runout. The thickness of the tool pad lacks precise control, resulting in inconsistent insert installation datum and uneven cutting depth.
[0007] Limited cutting stability and lifespan of cutting inserts: An unreasonable insert layout concentrates the cutting load on a portion of the cutting edge, leading to excessive wear, dulling, or even breakage in certain areas. This not only shortens the effective cutting cycle of the inserts but also causes problems such as "biting" and vibration due to changes in the cutting edge shape, resulting in a continuous decline in subsequent machining accuracy. Some milling cutter heads have not optimized the insert structure for different cutting scenarios, and the contact method between the cutting edge and the rail is unreasonable, further aggravating the wear of the cutting edge and increasing the frequency of tool changes and operating costs. Summary of the Invention
[0008] This invention addresses the problems of cutting imbalance, poor chip removal, unstable positioning, short insert life, and substandard precision in existing rail milling cutter discs. It provides a high-precision milling cutter disc with multiple insert layouts, composite grooves, multiple positioning, and precise tool pad adjustment, which can meet the requirements of radial runout ≤0.01mm when milling rails.
[0009] This invention provides the following technical solution: a high-precision milling cutter disc for milling railway tracks, comprising a disc body, a tool holder, and inserts. Multiple sets of tool holders are evenly distributed and fixed around the disc body. Inserts are mounted on the tool holders, and the inserts are arranged in two rows on each set of tool holders. Chip grooves for chip removal are provided between each row of inserts on the tool holder. The chip grooves adopt a double-curvature spiral groove structure. The groove width of the chip groove is 17-27mm, and the lead angle of the chip groove is 25°. Each row of inserts is distributed at non-uniform heights along the length of the tool holder. The installation height of the inserts gradually increases from the middle area of the tool holder to both ends. The inserts adopt a negative rake angle structure design. The negative rake angle is the negative angle formed by the cutting edge of the insert relative to the base surface on the rear side.
[0010] In some embodiments, the blade includes a first rectangular blade, a second square blade, and a third angular blade. The four sides of the first rectangular blade are all straight and have no cutting edge angle design. The second square blade has an annular protrusion structure around the center hole. The third angular blade has a 45° chamfered cutting edge, forming a rhomboid cutting structure. The first row of blades has four second square blades and one third angular blade arranged sequentially from left to right. The second row of blades has four second square blades, one third angular blade, and one first rectangular blade arranged sequentially from left to right. The two rows of blades are staggered.
[0011] In some embodiments, the chip groove includes a first chip groove and a second chip groove with different curvatures. The curvature of the first chip groove is k1=1 / ρ1, and the curvature of the second chip groove is k2=1 / ρ2, where ρ is the radius of the arc of the corresponding profile of the rail.
[0012] In some embodiments, the tool holder is provided with receiving grooves for receiving the blade, each receiving groove forming an opening, the blade including a cutting edge facing the opening and a rake face facing the opening, and a blade pad is provided between the blade and the bottom surface of the receiving groove, the blade pad having a thickness of 3.97 to 4.13 mm.
[0013] In some embodiments, the disc body and the tool holder are connected by positioning screws. The positioning screws are set along a compound bias direction, which includes: a first angle of a° with the radial direction of the disc body; and a second angle of b° with the axial section of the disc body. The positioning screws extend obliquely along the compound bias direction, pass through the disc body, and are threadedly connected to the tool holder.
[0014] In some embodiments, the side wall of the disc body is provided with an annular groove arranged around its central axis, and the side wall of the disc body is provided with a plurality of positioning grooves; the plurality of positioning grooves are distributed around the central axis of the disc body, and a tool holder is installed in each positioning groove; the annular groove and the positioning groove are arranged perpendicular to each other, and the two are staggered to form a cross-shaped structure, with the annular groove passing through the middle of the positioning groove; the depth of the annular groove is greater than the depth of the positioning groove.
[0015] In some embodiments, a connecting block protrudes from the lower end face of the tool holder, the connecting block is accommodated in a positioning groove, the side wall of the positioning groove facing the front end of the milling cutter head in the rotation direction is a first inclined surface, the connecting block is provided with a plurality of wedges that cooperate with the first inclined surface, and the wedges include a second inclined surface that cooperates with the first inclined surface.
[0016] In some embodiments, there are two wedges, which are located on the left and right sides of the annular groove, respectively. The left wedge is located near the end of the annular groove, and the right wedge is located away from the end of the annular groove.
[0017] In some embodiments, a first slot is provided at the bottom of the positioning groove near the first inclined surface. The bottom of the first slot is inclined downward from the outside to the inside. A second slot and a third slot are provided on the front and rear sides of the connecting block, respectively. The bottom surface of the second slot is inclined downward from the end away from the connecting block to the end near the connecting block.
[0018] In some embodiments, a positioning block is provided between adjacent positioning slots, and when the tool holder is installed in the positioning slot, the left side wall of the tool holder abuts against the wall of the positioning block.
[0019] Compared with the prior art, the advantages of the present invention are as follows:
[0020] I. Optimization of cutting mechanics balance to lock in accuracy from the root.
[0021] Non-uniform height distribution principle: The cutting amount in the middle area of the rail is greater than that at both ends. The blade gradually rises from the middle of the tool holder to both ends, which can make the actual cutting depth of each blade more consistent and avoid elastic deformation of a single blade due to excessive load. Deformation will cause the cutting edge to deviate from the predetermined trajectory. Uniform load can reduce deformation from the source and ensure the accuracy of the cutting trajectory.
[0022] The principle of staggered layout: Two rows of coated milling cutters are arranged alternately and staggered, so that the cutting points of the two rows of cutting edges neither overlap nor concentrate. If the cutting cutters are aligned, the cutting impact will be concentrated at the same circumferential position, causing the cutter head to vibrate. The staggered layout can disperse the cutting impact, offset some of the vibration, and improve the surface finish and dimensional stability of the machined surface.
[0023] The principle of spiral cutting edge arrangement: The helical arrangement of the milling cutter and the cutting edge makes the cutting edge gradually contact the surface of the rail, cutting in and out step by step. Compared with the straight arrangement, the helical arrangement can avoid excessive instantaneous cutting force, disperse the cutting force while ensuring more sufficient force transmission, reduce vibration and impact, reduce instantaneous deviation of the cutting edge caused by impact, and ensure stable dimensional accuracy.
[0024] The principle of negative rake angle structure: The negative rake angle design significantly enhances the rigidity of the cutting edge and increases the thickness of the cutting edge. When milling rails, the cutting force is large, while the cutting edge with a positive rake angle is prone to bending and deformation. Deformation will directly cause the cutting depth and angle to deviate from the preset value. The high rigidity of the negative rake angle can avoid the deformation of the cutting edge and ensure that the cutting trajectory is highly consistent with the target contour.
[0025] The principle of differentiated blades and precision blade pads: Differentiated blades are specifically matched to the cutting needs of different parts of the rail, avoiding local cutting deviations caused by a single blade being adapted to multiple parts. The thickness of the blade pad is controlled between 3.97 and 4.13 mm to unify the blade installation reference. If the thickness deviation is large, it will cause some blades to cut too deeply and some to cut too shallowly. Precise thickness can ensure that the cutting edges of all blades are on the same reference plane, and with subsequent adjustments, the radial runout ≤0.01 mm accuracy requirement can be achieved.
[0026] II. Optimization of chip removal and chip breaking to eliminate factors interfering with accuracy.
[0027] The principle of double curvature spiral groove: The double curvature of the chip groove matches the arc radius of the corresponding contour of the rail, so that the chips can move along the arc of the groove wall after they are generated, avoiding jamming. The accumulated chips will squeeze the cutting edge, causing the cutting edge to deviate, and at the same time scrape the machined surface; the groove shape that fits the contour can allow the chips to be discharged smoothly, reducing interference with the cutting process and maintaining high precision continuity.
[0028] The principle of slot width and lead angle optimization: a slot width of 17-27mm is suitable for the amount of chips in rail milling, avoiding accumulation due to being too narrow and weakening the tool holder strength due to being too wide; a 25° lead angle gives the chips an axial discharge tendency, avoiding circumferential accumulation. Clogged chips will change the actual cutting angle of the cutting edge. Reasonable size design can ensure chip removal efficiency and avoid the decrease in accuracy caused by chips.
[0029] The combined principle of corrugated cutting edge and double groove: The combination of corrugated cutting edge and double groove can force the chip to curl upward and sideways in both directions, reducing the curling radius of the fat chip. Uncontrolled long chips and fat chips will wrap around the cutting edge and squeeze the cutting edge, causing the cutting trajectory to deviate and scratching the machined surface. Forced chip breaking and curling can accelerate chip discharge, avoid chip interference with the cutting edge and the machined surface, and ensure cutting accuracy and surface quality.
[0030] III. Multiple positioning with zero deviation lays the foundation for high-precision benchmarks.
[0031] The principle of the compound bias positioning screw: The positioning screw is bidirectionally inclined and connected to form a bidirectional lock, which can simultaneously resist the radial centrifugal force and axial cutting force during high-speed milling, and avoid tool holder displacement. Tool holder displacement will cause the cutting position of the cutting tool to deviate from the preset contour. Zero displacement can ensure that the circumferential trajectory of the cutting edge is precisely matched with the target contour of the rail.
[0032] The cross-shaped structure, positioning blocks, and wedge blocks work together as follows: The annular groove and positioning groove of the disc intersect perpendicularly to form a cross-shaped structure. The positioning groove is responsible for bearing and positioning the tool holder connecting block, while the annular groove does not contact the connecting block, only optimizing the stress distribution of the structure and providing installation space. The positioning blocks between adjacent positioning grooves abut against the left side wall of the tool holder, forming a circumferential limit to prevent circumferential movement of the tool holder. The wedge blocks fit against the inclined surface of the positioning groove using a self-locking principle. Centrifugal force makes the fit tighter. The three work together to form multiple constraints of radial positioning, circumferential limiting, and inclined self-locking, which greatly reduces the positioning reference error and achieves zero installation deviation.
[0033] Tool pad adjustment principle: By adjusting the thickness of the tool pad within the range of 3.97 to 4.13 mm, the minute errors in the machining process are compensated, and the stringent precision requirement of radial runout of the milling cutter ≤ 0.01 mm is ultimately ensured.
[0034] The principle of slot design: Slots can reduce structural stress concentration and avoid micro-deformation caused by heat and force during machining or cutting. Micro-deformation can cause tool holder positioning offset. Slots can disperse stress, ensure positioning stability, and provide structural support for high-precision milling.
[0035] IV. The cutting blade exhibits strong cutting stability, maintaining high precision over a long period.
[0036] Differentiated cutting edges: Different cutting edges are specifically adapted to different cutting scenarios, reducing excessive local wear and ensuring the accuracy and stability of milling over a long period of time;
[0037] The negative rake angle combined with the multi-layout wear control principle: the negative rake angle improves the rigidity of the cutting edge and is not easy to break; the staggered, misaligned and spiral arrangement disperses the cutting load, reduces the peak force on a single edge, and avoids rapid dulling. A broken or dull cutting edge will cause "biting" and vibration, leading to a decrease in accuracy. The combination of the two designs can extend the effective cutting cycle of the insert, maintain the precise shape of the cutting edge during its service life, and maintain long-term high precision. Attached Figure Description
[0038] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0039] Figure 1 This is a schematic diagram of the structure of the present invention;
[0040] Figure 2 This is a schematic diagram of the disk body of the present invention;
[0041] Figure 3 For the present invention Figure 2 A magnified structural diagram at point A;
[0042] Figure 4 This is a structural schematic diagram of the disc body of the present invention from another angle;
[0043] Figure 5 For the present invention Figure 4 A magnified structural diagram at point B;
[0044] Figure 6 This is a schematic diagram of the tool holder structure of the present invention;
[0045] Figure 7 This is a schematic diagram of the tool holder of the present invention from another angle;
[0046] Figure 8 This is a schematic diagram of the angle structure of the blade mounted on the tool holder according to the present invention;
[0047] Figure 9 This is a schematic diagram of the milling cutter disc of the present invention for milling railway rails;
[0048] Figure 10 This is a schematic diagram of the first included angle of the radial angle of the positioning screw of the present invention;
[0049] Figure 11 This is a schematic diagram of the second included angle of the axial section of the positioning screw of the present invention.
[0050] In the diagram: 1. Disc body; 11. Annular groove; 12. Positioning groove; 121. First inclined surface; 122. First empty groove; 13. Positioning stop; 2. Tool holder; 21. First chip groove; 22. Second chip groove; 23. Receiving groove; 24. Connecting block; 25. Wedge block; 251. Second inclined surface; 26. Second empty groove; 27. Third empty groove; 3. Blade; 31. First rectangular blade; 32. Second square blade; 33. Third angular blade; 4. Tool pad; 5. Positioning screw. Detailed Implementation
[0051] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0052] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0053] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.
[0054] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.
[0055] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.
[0056] The technical solutions provided by the various embodiments of this application are described below with reference to the accompanying drawings.
[0057] Please see Figure 1-9 As shown in this embodiment: a high-precision milling cutter disc for milling railway tracks includes a disc body 1, a tool holder 2, and cutting inserts 3. Multiple sets of tool holders 2 are evenly distributed and fixed around the disc body 1. Cutting inserts 3 are mounted on the tool holders 2. The cutting inserts 3 are arranged in two rows on each set of tool holders 2. A chip groove for chip removal is provided between each row of cutting inserts 3 on the tool holder 2. The chip groove adopts a double curvature spiral groove structure. The groove width of the chip groove is 17-27mm, and the lead angle of the chip groove is 25°. Each row of cutting inserts 3 is distributed at non-uniform heights along the length of the tool holder 2. The installation height of the cutting inserts 3 gradually increases from the middle area of the tool holder 2 to both ends. The cutting inserts 3 adopt a negative rake angle structure design. The negative rake angle is the negative angle formed by the cutting edge of the cutting insert 3 relative to the base surface located on the rear side. The base surface is the reference plane after the cutting insert 3 is installed on the tool holder 2.
[0058] It should be noted that when the milling cutter is milling the rail head profile of a 60N steel rail, the outer diameter of the milling cutter head is φ2700mm, the disc body 1 is equipped with a total of 60 tool holders 2, and the rail head profile of the 60N steel rail adopts a seven-segment arc design, with the radii of each segment being 8mm, 16mm, 60mm, 200mm, 60mm, 16mm and 8mm respectively.
[0059] In some embodiments, such as Figures 7-8As shown, the insert 3 includes a first rectangular insert 31, a second square insert 32, and a third angular insert 33. The four sides of the first rectangular insert 31 are all straight and have no cutting edge angle design. The second square insert 32 has an annular protrusion around its center hole. The third angular insert 33 has a 45° chamfered cutting edge, forming a rhombus cutting structure. The first row of inserts 3 has four second square inserts 32 and one third angular insert 33 arranged sequentially from left to right. The second row of inserts 3 has four second square inserts 32, one third angular insert 33, and one first rectangular insert 31 arranged sequentially from left to right. The two rows of inserts 3 are staggered. It should be noted that the annular protrusion around the center hole of the second square insert 32 can enhance the installation and positioning accuracy of the insert 3 and the tool holder 2, and avoid the insert 3 from shifting due to high-frequency vibration during milling, adapting to the heavy-duty cutting requirements of the core load-bearing area in the middle of the guide head. The 45° chamfered cutting edge of the third angular insert 33 forms a rhombus cutting structure. It can smoothly cut into the transition arc area on the side of the rail head, reducing cutting residue and surface burrs, and improving the machining finish of the transition area. The straight edge without cutting edge angle design of the first rectangular insert 31 can perform fine cutting on the rail head end face or flat area, making up for the machining blind spot of the arc cutting edge. At the same time, the two rows of inserts 3 adopt a combination mode of four second square inserts 32 and one third angular insert 33, and four second square inserts 32, one third angular insert 33 and one first rectangular insert 31, and are arranged in an alternating manner, which can make the cutting edge alternately bear the force, effectively disperse the single-edge cutting load, and avoid local overload. Combined with the φ2700mm outer diameter of the milling cutter head and the overall layout of 60 tool holders 2, it further improves the continuity and stability of the cutting process, reduces tool wear, extends the service life of inserts 3, and ensures that the machining accuracy of the 60N rail head profile is controlled within ±0.02mm, meeting the stringent requirements of rail milling and repair in high-speed rail, conventional rail and other scenarios.
[0060] It should be noted that the radial angle offsets of the four second square blades 32 and one third prism blade 33 of the front row blade 3 are 4°, 5°, 19°, 27° and 1° respectively, and the radial angle offsets of the four second square blades 32, one third prism blade 33 and one first rectangular blade 31 of the rear row blade 3 are 4°, 4°, 13°, 13°, 1° and 7° respectively.
[0061] Front row blades 3: Angle gradient adapts to the layered cutting of the core area of the rail head, enhancing heavy-load stability. The radial angle offsets of the four second-square blades 32 in the front row are designed to correspond one-to-one with "4°, 5°, 19°, 27°", and form a continuous angle gradient with the subsequent third-square blade 33 with a radial offset of 1°. This perfectly adapts to the profile curvature and stress distribution of the core load-bearing area in the middle of the 60N rail head: The first second-square blade 32 on the left has a radial offset of 4°, adapting to the radial cutting requirements of the left edge of the core area of the rail head, achieving smooth entry with a small offset angle and reducing initial cutting impact; the second second-square blade 32 has a radial offset of 5°, inheriting the cutting trajectory of the previous blade 3, optimizing the cutting force transmission through a small angle increment, and avoiding stress at the cutting junction of adjacent blades 3. The third and fourth second-square blades 32 are radially offset by 19° and 27° respectively, precisely matching the radial profile change of the rear part of the core area of the rail head. This makes the cutting edge fit the contact surface of the rail head more closely, maximizing the dispersion of radial pressure during heavy-load cutting. Combined with the installation and positioning advantages of its annular protrusion structure, it completely eliminates blade 3 offset and vibration during cutting in the core load-bearing area, ensuring the stability of heavy-load cutting. The third-square blade 33 in the front row is radially offset by 1°, forming a smooth transition with the angle gradient of the first four second-square blades 32. This allows the rhomboid cutting edge to cut into the transition arc area on the side of the rail head with almost no interference. The precise offset of 1° not only avoids edge collision during cutting in the transition area, but also ensures that cutting residue is minimized, further improving the surface finish of the transition area.
[0062] Rear row of blades 3: Complementary angles and functional adaptation, filling cutting blind spots and enhancing synergy. The four second-square blades 32 in the rear row are designed in a one-to-one correspondence of "4°, 4°, 13°, 13°", paired with a third-edge blade 33 with a 1° radial offset and a first-rectangular blade 31 with a 7° radial offset, forming an interlaced complementary angle system with the front row of blades 3: the first two second-square blades 32 in the rear row both adopt a 4° radial offset, forming an interlaced coverage with the cutting trajectories of the 4° and 5° blades 3 on the left side of the front row. The consistent angles ensure the repeatability of cutting accuracy in the core area of the guide head, while the interlaced layout allows the cutting edges to be alternately stressed, avoiding continuous load on the single-angle blades 3 in the front row; the third and fourth second-square blades 32 in the rear row have a 13° radial offset, forming an angle with the 19° and 27° blades 3 in the front row. The complementary design not only fills the cutting gap caused by the large angle offset of the front row, but also optimizes the chip removal path during the cutting of the rear row through a slightly smaller angle design, reducing the impact of chip accumulation on the machining accuracy of the core area. The rear row third edge insert 33 continues the 1° radial offset design, maintaining the same angle as the front row third edge insert 33, ensuring a uniform cutting standard in the transition arc area on both sides of the rail head and avoiding profile deviations between the front and rear rows. The rear row first rectangular insert 31 has a 7° radial offset, which is a dedicated functional adaptation design. This angle allows the straight edge cutting edge to fit the radial profile of the rail head end face or flat area in the optimal posture, avoiding cutting edge interference during finishing and reducing vibration during finishing through the 7° offset, ensuring the machining flatness of the flat area and perfectly filling the finishing blind spot of the curved cutting edge.
[0063] Differentiated angle design, such as the complementary 19° angle in the front row and 13° angle in the rear row, and the distinction between the core area (4° / 5°) and the transition area (1° / 7°), not only ensures the targeted cutting function of each area, but also achieves the continuity of the overall cutting process, improving the efficiency and quality of rail milling repair, and reducing tool maintenance and replacement costs.
[0064] In some embodiments, such as Figures 6-9 As shown, the chip groove includes a first chip groove 21 and a second chip groove 22 with different curvatures. The curvature of the first chip groove 21 is k1=1 / ρ1, and the curvature of the second chip groove 22 is k2=1 / ρ2, where ρ is the radius of the arc of the corresponding profile of the rail.
[0065] When the milling cutter mills the rail head profile of a 60N steel rail, the curvature of the first chip groove 21 and the second chip groove 22 of the chip removal groove is determined based on the rail head profile of the 60N steel rail: the rail head profile of the 60N steel rail contains seven arc segments. The radius of the middle arc of the first chip groove 21 is ρ1=200mm, and the curvature is k1=1 / ρ1=0.005mm-1; the radius of the transition arc on the side of the second chip groove 22 is ρ2=60mm, and the curvature is k2=1 / ρ2≈0.0167mm-1. By precisely matching the rail profile, the chip removal effect is further optimized.
[0066] It should be noted that the curvatures of the first chip groove 21 and the middle arc ρ1=200mm of the rail head, and the second chip groove 22 and the transition arc ρ2=60mm of the side of the rail head, correspond one-to-one. This ensures that the inner wall of the chip groove forms a smooth and fitting guide channel with the cutting trajectory, allowing chips to flow naturally along the curvature of the groove. This avoids the chip jamming and accumulation problems caused by traditional single-curvature grooves, thus improving chip removal efficiency. The double-curvature structure, along with the 17-27mm groove width and 25° lead angle of the chip groove, works synergistically to ensure sufficient chip space and guide the chips to be quickly discharged in a spiral direction through curvature guidance. This reduces the residence time of chips in the cutting area, lowers cutting resistance and the vibration amplitude of the milling cutter head, and indirectly improves the efficiency of the rail head. The head profile machining accuracy ensures that the error is controlled within ±0.02mm; the curvature design that adapts to the profile avoids severe friction between chips and the groove wall and the cutting edge of the insert 3, reduces chip scraping on the machined surface, improves the surface finish of the rail head, and reduces the wear rate of the cutting edge of the insert 3. Combined with the evenly distributed layout of 60 tool holders 2, the overall tool life is extended; for the complex profile of the seven-segment arc of the 60N rail head, the double curvature chip groove can accurately cover the chip removal requirements of the core cutting area, eliminating the need for additional auxiliary chip removal structures and simplifying the design complexity of the tool holder 2. At the same time, it adapts to the outer diameter of the milling cutter head of φ2700mm, ensuring the compactness of the overall structure and cutting stability.
[0067] In some embodiments, such as Figures 6-9As shown, the tool holder 2 is provided with receiving grooves 23 for accommodating the cutting inserts 3. Each receiving groove 23 forms an opening. The cutting insert 3 includes a cutting edge facing the opening and a rake face facing the opening. A tool pad 4 is provided between the cutting insert 3 and the bottom surface of the receiving groove 23. The thickness of the tool pad 4 is 3.97 to 4.13 mm. It should be noted that the thickness of the tool pad 4 covers an adjustable range of 3.97 to 4.13 mm, which can be precisely fine-tuned for the non-uniform height installation requirements of each group of cutting inserts 3. This ensures that the rising trajectory of each row of cutting inserts 3 along the length of the tool holder 2 is completely fitted with the profile of the 60N steel rail head, so that the cutting edges of each cutting insert 3 form a continuous and adapted cutting trajectory, further ensuring that the machining accuracy is stable within ±0.02 mm. The tool pad 4 forms a buffer isolation layer between the cutting insert 3 and the bottom surface of the receiving groove 23, which can absorb... The high-frequency vibration generated during milling avoids cutting edge deviation or breakage caused by direct rigid contact between the insert 3 and the receiving groove 23, which is especially suitable for heavy-duty cutting scenarios of high-strength materials such as rails, and improves cutting stability. The tool pad 4 can avoid direct friction and wear between the insert 3 and the bottom surface of the receiving groove 23 during installation. At the same time, by uniformly transmitting the cutting load, it reduces local stress concentration on the insert 3. Combined with the staggered layout of the insert 3, it further extends the service life of the insert 3 and reduces the frequency of consumable replacement. The standardized thickness range of 3.97 to 4.13 mm facilitates mass production and on-site maintenance. When the insert 3 wears or needs to be finely adjusted to adapt to different rail profiles, it can be quickly achieved by replacing the tool pad 4 with one of different thicknesses without modifying the tool holder 2 or the receiving groove 23, thus improving equipment operation and maintenance efficiency.
[0068] In some embodiments, such as Figures 10-11As shown, the disc body 1 and the tool holder 2 are connected by positioning screws 5. The positioning screws 5 are set along a compound bias direction, which includes: a first angle of a° with the radial direction of the disc body 1; and a second angle of b° with the axial section of the disc body 1. The positioning screws 5 extend obliquely along the compound bias direction, passing through the disc body 1 and threadedly connecting with the tool holder 2. It should be noted that: a° = 18° ± 2°, b° = 20° ± 2°. It should be noted that the compound bias layout with double angles is precisely adapted to the force characteristics of the milling cutter disc with an outer diameter of φ2700mm when rotating. The 18° ± 2° radial angle can offset the circumferential cutting force borne by the tool holder 2, and the 20° ± 2° axial section angle can resist the axial impact force during the milling process. The double force offset improves the anti-loosening ability of the positioning screws 5 and avoids the displacement of the tool holder 2 caused by high-speed rotation and heavy-load cutting. The oblique extension connection method is more advanced than the traditional method. The direct insertion design provides positioning and limiting in both radial and axial directions, resulting in higher fitting accuracy between the tool holder 2 and the disc 1. Combined with the cooperation of the positioning groove 12 and the wedge block 25, it further reduces the circumferential positioning error of the tool holder 2, providing structural assurance for overall machining accuracy. The tolerance range of ±2° for the composite bias angle balances machining feasibility and assembly error tolerance, facilitating the batch installation and debugging of 60 tool holders 2. At the same time, the oblique insertion structure makes the screw force more even, avoiding screw breakage or disc 1 thread damage caused by local stress concentration, and extending the service life of the connection structure. This connection method works in conjunction with the cross-shaped structure of the disc 1's annular groove 11 and positioning groove 12. The oblique insertion path of the screw avoids the chip removal channel, does not affect chip discharge, and enhances the overall rigidity of the tool holder 2 through multi-dimensional fastening, reducing the impact of cutting vibration on the machined surface and further improving the machining surface finish of the 60N steel rail head profile.
[0069] In some embodiments, such as Figures 2-5As shown, the side wall of the disc body 1 is provided with an annular groove 11 arranged around its central axis, and the side wall of the disc body 1 is provided with multiple positioning grooves 12; the multiple positioning grooves 12 are distributed around the central axis of the disc body 1, and a tool holder 2 is installed in each positioning groove 12; the annular groove 11 and the positioning groove 12 are arranged perpendicular to each other, and the two intersect to form a cross-shaped structure, with the annular groove 11 passing through the middle of the positioning groove 12; the depth of the annular groove 11 is greater than the depth of the positioning groove 12. It should be noted that: the cross-shaped intersecting structure of the annular groove 11 and the depth design of the positioning groove 12 ensures that the annular groove 11 does not contact the tool holder 2, and the bottom of the positioning groove 12 contacts the tool holder 2. The precise division of labor ensures accurate coordination between the tool holder 2 installation and positioning, chip removal efficiency, and overall structural stability: the bottom of the positioning groove 12 directly contacts the tool holder 2, providing a stable load-bearing support surface for the 60 tool holders 2. Combined with the layout of the tool holders 2 distributed around the central axis of the disk body 1, it ensures that the circumferential spacing uniformity error of the tool holders 2 is ≤0.01mm. Simultaneously, it directly transfers the cutting load to the disk body 1, avoiding stress deformation caused by the tool holders 2 being suspended, laying a structural foundation for the continuity of the cutting trajectory of the inserts 3, and guaranteeing the requirement of ±0.02mm machining accuracy for the 60N steel rail head profile. Meanwhile, the annular groove 11 does not contact the tool holder 2, forming a ring around the disk body 1. The gap, together with the positioning groove 12 and the chip groove of the tool holder 2, forms a through-type chip removal path of the chip groove, positioning groove 12, and annular groove 11. After falling into the positioning groove 12 through the gap of the tool holder 2, the chips can be quickly discharged through the gap of the annular groove 11. Compared with the traditional closed structure, the chip removal efficiency is improved, and the accumulation of chips in the mating area between the tool holder 2 and the disc 1 is completely avoided, reducing the wear on the side wall of the tool holder 2 and the positioning screw 5. The design of the annular groove 11 being deeper than the positioning groove 12 not only achieves precise positioning of the tool holder 2 through the bottom contact of the positioning groove 12, but also provides sufficient space for chip removal through the deep avoidance of the annular groove 11. At the same time, the cross-shaped staggered structure can enhance the chip removal efficiency. The deformation resistance of the sidewall of the disc body 1 disperses the radial stress generated by the 60 tool holders 2 during heavy-duty cutting, adapts to the high-speed rotation requirements of the milling cutter disc with an outer diameter of φ2700mm, avoids structural failure of the disc body 1 due to concentrated stress, and the design of the annular groove 11 not contacting the tool holder 2 can effectively avoid the installation path of the tool holder 2, avoid assembly interference, and reduce the difficulty of batch installation. The contact fit at the bottom of the positioning groove 12 can limit the axial movement of the tool holder 2. Combined with the composite bias fixation of the positioning screw 5, it forms a dual positioning of bottom support and multi-directional fastening, further improving the stability of the tool holder 2 during the cutting process and reducing the impact of vibration on the surface finish of the machined surface.
[0070] In some embodiments, such as Figures 6-7As shown, a connecting block 24 protrudes from the lower end face of the tool holder 2. The connecting block 24 is housed in the positioning groove 12. The side wall of the positioning groove 12 facing the front end of the milling cutter head in the rotation direction is a first inclined surface 121. The connecting block 24 is provided with several wedges 25 that cooperate with the first inclined surface 121. The wedges 25 include a second inclined surface 251 that cooperates with the first inclined surface 121. It should be noted that the close cooperation between the first inclined surface 121 and the second inclined surface 251 can realize the automatic centering and positioning of the tool holder 2 during installation. With the contact support at the bottom of the positioning groove 12, the installation positioning error of the tool holder 2 is controlled, ensuring the uniformity of the circumferential spacing of the 60 tool holders 2. This provides a precise guarantee for the cutting trajectory of the insert 3 to adapt to the profile of the 60N steel rail head, further consolidating the machining accuracy requirement of ±0.02mm. The milling cutter head rotates at high speed. When subjected to heavy-duty cutting, the inclined surface structure can decompose the circumferential cutting force and axial impact force on the tool holder 2 into normal pressure along the inclined surface, dispersing the localized force concentration. At the same time, the self-locking property of the inclined surface, combined with the compound bias fastening of the positioning screw 5, significantly improves the tool holder 2's resistance to loosening and movement, preventing the tool holder 2 from shifting during cutting. The inclined surface provides a guide for the connecting block 24 to be installed into the positioning groove 12, reducing the difficulty of batch assembly of 60 tool holders 2. Moreover, the close fit of the inclined surface can increase the contact area between the tool holder 2 and the positioning groove 12, so that the cutting load is more evenly transmitted to the disc body 1, reducing the structural deformation caused by local stress. Combined with the cross-shaped layout of the annular groove 11 and the positioning groove 12, the overall operational stability of the milling disc body 1 is further enhanced, and the service life of the equipment is extended.
[0071] In some embodiments, such as Figures 6-7 As shown, there are two wedges 25, located on the left and right sides of the annular groove 11, respectively. The left wedge 25 is positioned closer to the annular groove 11, and the right wedge 25 is positioned further away from the annular groove 11. It should be noted that the double wedges 25 form a symmetrical fit with the first inclined surface 121 from both sides of the annular groove 11. Compared to a single wedge 25, this achieves bidirectional positioning and limiting, controlling the installation and positioning error of the tool holder 2, ensuring the uniformity of the circumferential spacing of the 60 tool holders 2, and providing double assurance for the precise adaptation of the cutting trajectory of the blade 3 to the profile of the 60N steel rail head. The left wedge 25 is closer to the annular groove 11, and the right wedge 25 is further away from the annular groove 11. The distribution ensures that the stress support points of the tool holder 2 connecting block 24 are evenly distributed along the length of the positioning groove 12, which can effectively disperse the radial and circumferential stress during heavy-duty cutting, avoid deformation of the connecting block 24 caused by stress concentration on one side, adapt to the high-speed rotation requirements of the milling cutter head with an outer diameter of φ2700mm, and improve the structural rigidity of the tool holder 2. The left wedge block 25 is set close to the annular groove 11, which can avoid the through chip removal path of the chip groove, positioning groove 12, and annular groove 11, without obstructing the chip flow. The right wedge block 25 strengthens the positioning support at the far end of the tool holder 2, balances the force offset caused by the avoidance space on the side of the annular groove 11, and achieves a balance between positioning accuracy and chip removal efficiency.
[0072] In some embodiments, such as Figures 2-5 As shown, the bottom of the positioning groove 12 is provided with a first empty groove 122 near the first inclined surface 121. The bottom of the first empty groove 122 is inclined downward from the outside to the inside. The front and rear sides of the connecting block 24 are respectively provided with a second empty groove 26 and a third empty groove 27. The bottom surface of the second empty groove 26 is inclined downward from the end away from the connecting block 24 to the end near the connecting block 24. It should be noted that the inclined design of the first empty groove 122 can guide the residual chips in the positioning groove 12 to fall into the annular groove 11 along the inclined surface, and the inclined structure of the second empty groove 26 assists in this process. The chips falling from the chip groove of the tool holder 2 quickly enter the positioning groove 12. These chips, along with the main chip removal path of the chip groove, positioning groove 12, and annular groove 11, complement each other, completely eliminating dead angles in the fit between the positioning groove 12 and the connecting block 24. This prevents chip jamming and positioning deviation of the tool holder 2, further improving chip removal efficiency. Simultaneously, it reduces scratching and wear on the mating surfaces of the first inclined surface 121 and the second inclined surface 251 caused by chips. The hollow groove structure, through reasonable avoidance, reduces the contact area between the positioning groove 12 and the connecting block 24, thus preventing chip jamming during assembly. To address interference issues, space is reserved for thermal expansion and contraction during the high-speed rotation and cutting heat of the milling cutter head, preventing structural jamming or loosening due to temperature deformation and ensuring the long-term stability of the 60 tool holders 2. The first slot 122 is close to the first inclined surface 121 without damaging the core support area at the bottom of the positioning slot 12. The second and third slots of the connecting block 24 avoid the critical contact points between the wedge block 25 and the positioning slot. While optimizing chip removal and avoiding air gaps, the load-bearing rigidity of the tool holder 2 is not weakened, and the overall weight of the tool holder 2 and the disc body 1 is moderately reduced. The inertial load during low-speed rotation, combined with the fastening of the double wedge block 25 and the positioning screw 5, ensures the positioning accuracy of the tool holder 2 and consolidates the machining accuracy of the 60N rail head profile of ±0.02mm. In addition, the clearance space formed by the slot makes it easier to align the connecting block 24 with the guide when it is installed into the positioning slot 12, reducing the difficulty of batch assembly and debugging time of 60 tool holders 2. At the same time, the inclined design of the slot can reduce the impact and disturbance of chips on the tool holder 2, indirectly improving the stability of the cutting process and further optimizing the surface finish of the rail head.
[0073] In some embodiments, such as Figures 2-5As shown, each adjacent positioning slot 12 is provided with a positioning block 13. When the tool holder 2 is installed in the positioning slot 12, the left side wall of the tool holder 2 abuts against the wall of the positioning block 13. It should be noted that the abutment between the positioning block 13 between adjacent positioning slots 12 and the left side wall of the tool holder 2, together with the positioning slot 12, the inclined surface of the double wedge block 25, and the composite biased fastening of the positioning screw 5, forms a three-sided positioning structure with bottom support, inclined surface self-locking, and block limiting. This completely restricts the circumferential movement of the tool holder 2, controls the uniformity error of the circumferential spacing of the 60 tool holders 2, and provides the final guarantee for the precise fit of the cutting trajectory of the blade 3 with the profile of the 60N steel rail head. It consolidates the machining accuracy requirement of ±0.02mm and can directly share the circumferential cutting force when the milling cutter head rotates at high speed and under heavy load during the φ2700mm outer diameter, avoiding wear or deformation of the connection structure caused by local stress overload and improving the long-term stability of the connection. At the same time, the positioning block 13 forms a clear assembly datum, which greatly reduces the difficulty and time of batch installation and debugging of 60 tool holders 2 and improves production efficiency. Moreover, the multiple blocks are evenly distributed along the circumference of the disc body 1, which can enhance the rigidity of the side wall of the disc body 1, disperse the circumferential stress and avoid radial deformation of the disc body 1. Its layout can also avoid the through chip removal path, so as to achieve a balance between positioning accuracy, structural strength, chip removal efficiency and assembly convenience.
[0074] The same or similar parts between the various embodiments in this specification can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments.
[0075] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A high-precision milling cutter disc for milling railway tracks, comprising a disc body (1), a tool holder (2), and cutting blades (3), wherein multiple sets of the tool holders (2) are evenly distributed and fixed around the disc body (1) in a circumferential direction, and the cutting blades (3) are mounted on the tool holders (2), wherein the cutting blades (3) are arranged in two rows on each set of the tool holders (2), characterized in that: The tool holder (2) is provided with chip grooves for chip removal between each row of blades (3). The chip grooves adopt a double curvature spiral groove structure. The groove width of the chip groove is 17-27mm and the lead angle of the chip groove is 25°. Each row of blades (3) is distributed at non-equal heights along the length of the tool holder (2). The installation height of the blades (3) gradually increases from the middle area of the tool holder (2) to both ends. The blades (3) adopt a negative rake angle structure design. The negative rake angle is the negative angle formed by the cutting edge of the blade (3) relative to the base surface on the rear side. The chip groove includes a first chip groove (21) and a second chip groove (22) with different curvatures. The curvature of the first chip groove (21) is k1=1 / ρ1, and the curvature of the second chip groove (22) is k2=1 / ρ2, where ρ is the radius of the arc of the corresponding profile of the rail. The blade (3) includes a first rectangular blade (31), a second square blade (32), and a third angular blade (33). The first row of blades (3) has four second square blades (32) and one third angular blade (33) arranged from left to right. The second row of blades (3) has four second square blades (32), one third angular blade (33), and one first rectangular blade (31) arranged from left to right. The two rows of blades (3) are staggered. The radial angle offsets of the four second square blades (32) and one third angular blade (33) in the front row of blades (3) are 4°, 5°, 19°, 27°, and 1°, respectively. The radial angle offsets of the four second square blades (32), one third angular blade (33), and one first rectangular blade (31) in the rear row of blades (3) are 4°, 4°, 13°, 13°, 1°, and 7°, respectively. The side wall of the disc (1) is provided with an annular groove (11) arranged around its central axis, and the side wall of the disc (1) is provided with a plurality of positioning grooves (12); the plurality of positioning grooves (12) are distributed around the central axis of the disc (1), and a tool holder (2) is installed in each positioning groove (12); the annular groove (11) and the positioning groove (12) are arranged perpendicular to each other, and the two intersect to form a cross-shaped structure, the annular groove (11) passes through the middle of the positioning groove (12); the depth of the annular groove (11) is greater than the depth of the positioning groove (12); The lower end face of the tool holder (2) has a protruding connecting block (24), which is housed in the positioning groove (12). The side wall of the positioning groove (12) facing the front end of the milling cutter head rotation direction is a first inclined surface (121). The connecting block (24) is provided with a plurality of wedges (25) that cooperate with the first inclined surface (121). The wedges (25) include a second inclined surface (251) that cooperates with the first inclined surface (121). The bottom of the positioning groove (12) is provided with a first empty groove (122) near the first inclined surface (121). The bottom of the first empty groove (122) is inclined downward from the outside to the inside. The front and rear sides of the connecting block (24) are provided with a second empty groove (26) and a third empty groove (27), respectively. The bottom surface of the second empty groove (26) is inclined downward from the end away from the connecting block (24) to the end near the connecting block (24).
2. The high-precision milling cutter disc for milling railway tracks according to claim 1, characterized in that: The first rectangular blade (31) has four straight edges and no cutting edge angle design. The second square blade (32) has an annular protrusion structure around the center hole. The third prismatic blade (33) has a 45° chamfered cutting edge, forming a rhomboid cutting structure.
3. A high-precision milling cutter head for milling railway tracks according to claim 1, characterized in that: The tool holder (2) is provided with a receiving groove (23) for accommodating the blade (3), each receiving groove (23) forming an opening, the blade (3) including a cutting edge facing the opening and a rake face facing the opening, and a blade pad (4) is provided between the blade (3) and the bottom surface of the receiving groove (23), the blade pad (4) having a thickness of 3.97 to 4.13 mm.
4. A high-precision milling cutter head for milling railway tracks according to claim 1, characterized in that: The disc body (1) and the tool holder (2) are connected by a positioning screw (5). The positioning screw (5) is set along a compound bias direction, which includes: a first angle of a° with the radial direction of the disc body (1); and a second angle of b° with the axial section of the disc body (1). The positioning screw (5) extends obliquely along the compound bias direction, passes through the disc body (1), and is threadedly connected to the tool holder (2).
5. A high-precision milling cutter head for milling railway tracks according to claim 1, characterized in that: There are two wedges (25), which are located on the left and right sides of the annular groove (11), respectively. The left wedge (25) is located near the annular groove (11), and the right wedge (25) is located away from the annular groove (11).
6. A high-precision milling cutter head for milling railway tracks according to claim 1, characterized in that: A positioning block (13) is provided between each adjacent positioning groove (12). When the tool holder (2) is installed in the positioning groove (12), the left side wall of the tool holder (2) abuts against the wall of the positioning block (13).