Drilling and counter sinking composite drill bit for high manganese steel combined frog

Abstract

The utility model provides a high manganese steel combined frog drilling and counter sinking composite drill bit which is provided with a cutter body, and the cutter body is provided with a U-shaped drill rod which is matched with a workpiece to be machined in depth and is of a T-shaped structure. The bottom end of the vertical rod body of the U-shaped drill rod is provided with a U-shaped drill hole drilling blade; a bolt hole chamfering cutter grain is arranged at the turning part of the T-shaped structure of the U-shaped drill rod; the horizontal part of the T-shaped structure of the U-shaped drill rod is provided with a counter sinking drill tool grain; a counter bore chamfering cutter grain is arranged above the counter boring drill cutter grain; the drilling end face of the U-shaped drill and the drilling end face of the spot facing drill are provided with cooling nozzles correspondingly. A spiral chip groove is formed in the U-shaped drill rod body; and the positions and the sizes of all the cutter grains on the cutter body are matched with the shape and the size of a to-be-machined hole of a to-be-machined workpiece. The chamfering device is efficient in machining, high in coaxiality, reliable in precision, low in manufacturing cost, smooth in hole wall, uniform in chamfering and suitable for popularization.

Description

Technical Field

[0001] The utility model belongs to the technical field of drilling bits for operating and transporting machine tools, and in particular relates to a high-manganese steel combined frog drilling and countersinking composite drill bit. Background Art

[0002] High-manganese steel monolithic frogs suffer from defects such as loose internal structure, air pores, shrinkage cavities, and sand inclusions, resulting in a short service life and hindering turnout maintenance and operation. Combination frogs overcome these shortcomings, meet railway transportation requirements, and avoid the phenomenon of local damage leading to overall failure. While ensuring frog performance and extending service life, they also offer ease of installation, maintenance, and repair. Components such as the fork core and wing rails are interchangeable online to reduce replacement and repair costs. As the production of combination frogs increases annually and captures a significant market share, there is an urgent need to improve the efficiency and precision of their components, reduce operator workload, and lower manufacturing costs.

[0003] In the existing technology, during the machining of the inlaid blocks, the main components of the inlaid wing rail type high manganese steel combination switch, it is necessary to drill bolt holes at the rail waist and countersinks for matching with the spacer irons when the entire group is assembled. The existing processing method is to first use a welding drill bit with a smaller diameter than the bolt hole to drill, and then replace it with a larger drill bit with a standard aperture to expand the hole. After all the bolt holes are processed, the corn milling cutter is replaced, the tool is re-aligned and positioned, and the countersinks are milled. After completion, the chamfering cutter is replaced to chamfer the holes. The three processes are lengthy and messy, and the cutting tools need to be replaced frequently. The machine tool operation path is repeated, and the coaxiality of the bolt hole and the countersink is not easy to ensure. The chamfer size is uneven, and the production efficiency is low. In this regard, the following technical solution is proposed. Utility Model Content

[0004] The utility model solves the technical problem of providing a composite drill bit for drilling and countersinking of high manganese steel combined frogs, solving the technical problems of low coaxiality, low efficiency and uneven chamfering in drilling and countersinking of high manganese steel combined frogs.

[0005] The technical solution adopted by the utility model is as follows: a high-manganese steel combined frog drilling and countersinking composite drill bit, which comprises a cutter body, wherein the cutter body has a U-drill drill rod with a T-shaped structure adapted to the depth of a workpiece to be processed; a U-drill drilling blade is provided at the bottom end of the vertical rod body of the U-drill drill rod; a bolt hole chamfering blade is provided at the turning point of the T-shaped structure of the U-drill drill rod; a countersinking drill blade is provided at the horizontal part of the T-shaped structure of the U-drill drill rod; a countersinking chamfering blade is provided above the countersinking drill blade; cooling nozzles are respectively provided on the U-drill drilling end face and the countersinking drill end face; the U-drill drill rod is provided with a spiral chip removal groove; the positions and sizes of all the blades on the cutter body are adapted to the shape and size of the hole to be processed of the workpiece to be processed.

[0006] In the above technical solution, as a further improvement of the present invention: the U-drill drilling blade particles are composed of U-drill inner edge blade particles and U-drill outer edge blade particles; the U-drill inner edge blade particles and the U-drill outer edge blade particles each have a group, and a group of U-drill inner edge blade particles and the U-drill outer edge blade particles are centrally symmetrically arranged.

[0007] In the above technical solution, as a further improvement of the present invention: the countersinking drill bit is composed of countersinking inner edge bit and countersinking outer edge bit; there are four groups of countersinking inner edge bit and countersinking outer edge bit; the four groups of countersinking inner edge bit and countersinking outer edge bit are centrally symmetrically arranged.

[0008] In the aforementioned combined technical solution, preferably: the main deflection angle of the inner blade of the U drill is 88°, the back angle is 7.5°, and the front angle is 0°.

[0009] In the aforementioned combined technical solution, preferably: the U-drill outer blade has a main deflection angle of 90°, a front angle of 0°, and a back angle of 7°.

[0010] On the basis of the main technical solution, it is preferred that: the main deflection angle of the bolt hole chamfering blade is 45°, the front angle is 0°, and the back angle is 11°.

[0011] On the basis of the above technical solution, preferably: the front angle of the inner blade of the countersinking is 0° and the back angle is 11°.

[0012] On the basis of the above technical solution, preferably: the front angle of the countersinking outer blade is 0° and the back angle is 11°.

[0013] On the basis of the main technical solution, it is preferred that: the main deflection angle of the countersink chamfering tool is 45°, the front angle is 0°, and the back angle is 11°.

[0014] The advantages of this utility model compared with the existing technology are:

[0015] 1. The utility model processes the bolt holes of the workpiece to be processed to a qualified standard in one go. Without moving the machine tool, the drilling is continued and the staggered end face cutters are used to continue cutting to countersink the feed side countersink. When the bottom of the countersink is reached, the two hole edges are chamfered synchronously. The composite drill bit of the utility model adopts an integrated structural design. After dynamic balancing simulation, it can prevent the diameter deviation caused by the sharp radial vibration of the drill rod during high-speed drilling.

[0016] 2. The utility model integrates three milling functions into one tool. The machine tool can complete the three processes of drilling, countersinking and chamfering in one feed cutting, improve the coaxiality of through holes and countersinks, reduce the number of machine tool positioning and tool change time, improve the processing efficiency of combined frog holes, and reduce manufacturing costs.

[0017] 3. The bolt hole and the countersink drilled by the utility model have good coaxiality, smooth hole walls, and uniform chamfers, which saves auxiliary tool setting time, improves production efficiency, and reduces manufacturing costs.

[0018] 4. During the entire cutting process of the utility model, compressed air or cutting fluid is introduced into the cooling nozzle, which can cool the tool and the workpiece and clean the inner wall of the hole, with reliable quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a three-dimensional diagram of the composite drill bit of the utility model;

[0020] Figure 2 This is a bottom view of the composite drill bit of the utility model;

[0021] Figure 3 This is a schematic structural diagram of the composite drill bit of the utility model in working state;

[0022] In the figure: 1- tool body, 2- countersink chamfering tool, 3- countersink inner edge tool, 4- U drill inner edge tool, 5- U drill outer edge tool, 6- bolt hole chamfering tool, 7- cooling nozzle, 8- countersink outer edge tool, 9- workpiece to be processed, 10- U drill rod, 11- countersink drill tool, 12- spiral chip groove. DETAILED DESCRIPTION

[0023] The following is a combination of the appended examples of the present invention Figure 1-3 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0024] (like Figure 1 、 Figure 3 A high manganese steel combined frog drilling and countersinking composite drill bit is shown, comprising a cutter body 1. The cutter body 1 is used for assembling with a spindle tool holder of a machine tool.

[0025] The cutter body 1 has a U-drill rod 10 with a T-shaped structure that matches the depth of the workpiece 9 to be processed. The T-shaped structure is adapted to the hole to be processed, ensuring the high efficiency and dimensional coaxial consistency of the bolt hole and the countersink in one processing, thereby improving processing efficiency.

[0026] (Combined with Figure 3 The bottom end of the vertical rod body of the U-drill drill rod 10 is provided with a U-drill drilling tool. The U-drill drilling tool is used for drilling the bolt hole in the first step.

[0027] In the above embodiment, as a further improved embodiment of the present invention: (such as Figure 2(As shown in the figure), the U-drill drilling insert consists of a U-drill inner blade insert 4, i.e., the center blade, and a U-drill outer blade insert 5, i.e., the peripheral blade. Each of the U-drill inner blade insert 4 and the U-drill outer blade insert 5 is provided in a set, and each set of the U-drill inner blade insert 4 and the U-drill outer blade insert 5 is centrally symmetrically arranged. The U-drill, through the combination of the inner and outer blades, can perform both drilling and boring operations simultaneously. This composite machining method significantly improves machining efficiency. The centrally symmetrical insert design makes the cutting force distribution more uniform, helping to reduce vibration and runout, thereby improving machining accuracy. Since the inner and outer blades operate simultaneously, the cutting force is dispersed across the two blades, reducing the load on a single blade and extending the tool life. The heat generated during the cutting process is also dispersed, less concentrated, due to the blades' dispersion, helping to reduce cutting temperatures and protect the tool from high-temperature damage. The centrally symmetrical insert design helps reduce vibration and noise during the cutting process, improving the safety of the machining environment. The uniform cutting force distribution and stable machining process help protect the workpiece from unnecessary damage and deformation. In summary, the U-drill drilling tool particles are composed of U-drill inner edge tool particles and U-drill outer edge tool particles, and the technical advantages of the central symmetrical arrangement of these two groups of tool particles are to improve processing efficiency and precision, enhance tool durability, adapt to various processing requirements, reduce processing costs and improve processing safety.

[0028] The T-shaped structure turning point of the U drill rod 10 is provided with a bolt hole chamfering cutter 6. The bolt hole chamfering cutter 6 is used for chamfering the bolt hole.

[0029] The horizontal portion of the T-shaped structure of the U-drill drill rod 10 is provided with a countersinking drill bit 11; the countersinking drill bit 11 is used for processing a countersink coaxial with the bolt hole.

[0030] In the above embodiment, as a further improved embodiment of the present invention: (such as Figure 2(As shown in the figure), the countersinking drill bit 11 consists of inner countersinking blade bits 3 and outer countersinking blade bits 8. These inner countersinking blade bits 3 and outer countersinking blade bits 8 are arranged in four groups, each symmetrically arranged. The four groups of centrally symmetrical blade bits ensure a more even distribution of cutting forces during the countersinking process, reducing vibration and deflection caused by uneven cutting forces, thereby improving machining accuracy. Multiple groups of blade bits operate simultaneously, making the cutting process smoother and helping to maintain the shape and dimensional accuracy of the orifice. The multiple blade bit design distributes the cutting load across multiple blades, reducing the wear rate of individual blades and thus extending the overall tool life. The evenly distributed cutting force also helps reduce the concentration of heat generated during cutting on a single blade, protecting the tool from high-temperature damage. Countersinking drill bit designs typically enable simultaneous completion of multiple machining tasks, such as countersinking and hole enlarging, reducing tool changes and machining steps, thereby improving machining efficiency. In summary, the four sets of center-symmetrically arranged inner countersinking blade particles 3 and outer countersinking blade particles 8 have significant technical advantages in countersinking processing, including improving processing accuracy and stability, enhancing tool durability and life, improving processing efficiency, adapting to various processing needs, and improving processing safety.

[0031] A countersinking chamfering blade 2 is provided above the countersinking drill blade 11. The countersinking chamfering blade 2 is used for chamfering the countersink.

[0032] Among them, cooling nozzles 7 are respectively provided on the drilling end faces of the U drill and the countersink drill; the cooling nozzles 7 are used to pass compressed air or cutting fluid to cool the tool body 1 and the workpiece 9 to be processed, and to clean the inner wall of the hole of the workpiece 9 to be processed, thereby ensuring the smoothness of the hole and improving the processing quality.

[0033] The U-drill drill rod 10 is provided with a spiral chip groove 12; the spiral chip groove 12 is used for synchronous chip removal during drilling. The design of the spiral chip groove enables the chips generated during the cutting process to be discharged smoothly along the groove, reducing the accumulation of chips in the drill rod and the hole, thereby avoiding processing interruptions and tool damage caused by chip blockage. Smooth chip removal ensures the continuity of processing, reduces the downtime and cleaning time required due to poor chip removal, and improves processing efficiency. The spiral chip groove not only removes chips, but also plays a role in heat dissipation. During the discharge process, the chips will take away part of the cutting heat, reduce the temperature of the drill rod and the workpiece, and help maintain the hardness and processing accuracy of the tool.

[0034] It should be emphasized that the positions and sizes of all the cutting particles on the cutter body 1 are adapted to the shape and size of the holes to be machined in the workpiece 9 to ensure high machining efficiency.

[0035] In the aforementioned combination embodiment, preferably: the U-drill inner blade has a main deflection angle of 88°, a clearance angle of 7.5°, and a rake angle of 0°. It should be noted that the technical advantages of the U-drill inner blade, especially under the settings of a main deflection angle of 88°, a clearance angle of 7.5°, and a rake angle of 0°, are mainly reflected in the following aspects: Main deflection angle of 88°: This angle design allows the U-drill to have larger cutting-in and cutting-out angles during cutting, which is conducive to maintaining a stable cutting force and stable cutting efficiency during the machining process. A larger main deflection angle can reduce the fluctuation of cutting force during the cutting process, reduce tool vibration, and thus improve machining stability and precision.

[0036] 7.5° clearance angle: The choice of clearance angle is crucial to tool durability. While maintaining cutting edge strength, the 7.5° clearance angle reduces friction and heat buildup between the tool and the workpiece during cutting, lowering tool wear and the risk of chipping. This design helps extend tool life, reduces the frequency of tool changes, and ultimately improves productivity.

[0037] 0° rake angle: The choice of rake angle directly affects the sharpness of the cutting edge and the amount of cutting force. While not the sharpest (compared to more negative rake angles), a 0° rake angle design provides greater cutting edge strength and stability, making it less susceptible to chipping during machining. This design is particularly important when machining hard or difficult-to-machine materials, as it ensures a smooth cutting process while maintaining high machining accuracy.

[0038] Comprehensive Advantages: With a design featuring an 88° lead angle, a 7.5° back angle, and a 0° rake angle, the U-drill demonstrates high cutting efficiency, stability, and durability. This comprehensive cutting performance allows the U-drill to maintain excellent performance in machining a wide range of materials, especially difficult-to-machine materials such as stainless steel and cast iron.

[0039] In summary, the U-drill inner edge blade can give full play to its technical advantages in cutting efficiency, stability, durability and comprehensive cutting performance when the main deflection angle is 88°, the back angle is 7.5° and the rake angle is 0°.

[0040] In the aforementioned combined embodiment, preferably, the U-drill outer blade has a 90° main rake angle, a 0° rake angle, and a 7° relief angle. Regarding this preferred embodiment, it should be noted that a 90° main rake angle means that the contact angle between the cutting edge and the workpiece surface is a right angle. This design helps maintain stable cutting forces during the cutting process, reduces vibration and deviation, and thus improves machining accuracy. A right rake angle also concentrates cutting forces, facilitating high-precision hole machining.

[0041] 7° clearance angle: This 7° clearance angle maintains cutting edge strength while minimizing friction and heat buildup during cutting. An appropriate clearance angle reduces the contact area between the tool and the workpiece, reducing cutting heat and frictional wear, thereby extending tool life. This is crucial for improving production efficiency and reducing costs.

[0042] 0° Rake Angle: Although a cutting edge with a 0° rake angle is not the sharpest (compared to a more negative rake angle), it can enhance the strength of the cutting edge while maintaining a certain degree of sharpness. This design makes the U drill less likely to chip during processing, especially when processing hard or difficult-to-machine materials, and can maintain stable cutting performance.

[0043] Comprehensive Design: The comprehensive design of the main deflection angle, rake angle, and clearance angle enables the U drill to remove material efficiently and stably during the cutting process. Especially when drilling large diameter and deep holes, this design can significantly improve cutting efficiency and shorten the processing cycle.

[0044] The U-drill's outer blade design also offers excellent adaptability, enabling it to accommodate a wide range of machining conditions and materials. By replacing different blade types, the U-drill can easily handle the machining needs of different materials, thereby increasing the flexibility and diversity of the production line.

[0045] While the specific relationship between chip evacuation performance and the lead angle, rake angle, and clearance angle is not directly mentioned, U-drills generally have excellent chip evacuation performance. Their unique cutter body structure and internal coolant system (if equipped) effectively remove chips generated during the cutting process, reducing the risk of cutting blockage and tool damage, which is also an important part of the U-drill's technical advantages.

[0046] Based on the main technical solution embodiment, the bolt hole chamfering blade preferably has a 45° main rake angle, a 0° front angle, and an 11° back angle. This preferred embodiment should be noted that this angle design allows the cutting edge to form a relatively smooth transition when entering the bolt hole, helping to reduce sudden changes in cutting force and thus improving cutting stability. Furthermore, the 45° main rake angle also helps to create a better chip flow path during cutting, reducing chip accumulation and cutting heat accumulation, thereby improving processing efficiency and quality.

[0047] 11° clearance angle: A relatively large clearance angle (such as 11°) helps reduce friction and heat accumulation between the tool and the workpiece, lowering the risk of tool wear. Furthermore, a larger clearance angle enhances heat dissipation, further extending tool life. This is crucial for improving production efficiency and reducing costs.

[0048] 0° Rake Angle: Although a 0° cutting edge is not the sharpest (compared to a more negative rake angle), it can enhance the cutting edge strength while maintaining a certain degree of sharpness. This design makes the bolt hole chamfering tool less likely to chip during machining, especially when machining harder materials, and can maintain stable cutting performance.

[0049] This bolt hole chamfering tool design also offers excellent machining adaptability. Due to the optimal selection of the lead angle, rake angle, and relief angle, the tool can be used to chamfer bolt holes of various specifications and materials. This design also helps improve machining accuracy and surface quality, meeting various machining requirements.

[0050] In practice, the bolt hole chamfering tool design also helps improve operational simplicity. Due to its stable cutting force, excellent tool durability, and strong processing adaptability, operators can more easily master tool usage skills, improving processing efficiency and quality.

[0051] Based on the aforementioned technical solution embodiment, preferably: the inner countersinking blade 3 has a rake angle of 0° and a clearance angle of 11°. The outer countersinking blade 8 has a rake angle of 0° and a clearance angle of 11°. It should be noted that the 0° rake angle design means that the cutting edge is relatively straight when it contacts the workpiece, without excessive tilt, which helps to enhance the cutting edge's strength. During countersinking, the cutting edge must withstand significant cutting forces and impacts. Therefore, a stronger cutting edge can reduce the risk of chipping and breakage, thereby improving the tool's durability.

[0052] A relatively large clearance angle helps reduce friction and heat buildup between the tool's flank face and the machined workpiece surface. This design not only reduces tool wear but also extends tool life. Furthermore, the large clearance angle enhances heat dissipation, further protecting the cutting edge from high temperatures.

[0053] The proper combination of rake and clearance angles helps maintain cutting stability. A 0° rake angle ensures the cutting edge maintains good centering when engaging the workpiece, reducing fluctuations in cutting forces. An 11° clearance angle, on the other hand, creates a stable cutting environment, minimizing vibration and noise during cutting.

[0054] Although a 0° rake angle may not be the most favorable angle for chip formation, in some countersinking applications, this design can ensure more stable contact between the cutting edge and the workpiece, thereby helping to achieve better machining quality and surface roughness. Of course, this also needs to be determined based on the specific processing materials and process requirements.

[0055] The design of the rake and clearance angles enables the countersinking inner edge cutter grain 3 to be suitable for a variety of materials and processing conditions. Whether processing hard materials or carrying out mass production, the tool can maintain good cutting performance and durability.

[0056] Based on the main technical solution embodiment, the countersink chamfering tool preferably has a 45° main rake angle, a 0° rake angle, and an 11° relief angle. Notes on this preferred embodiment include: This 45° main rake angle allows the cutting edge to form a smoother transition when entering the countersink, helping to reduce vibration and sudden changes in cutting force during the cutting process, thereby improving cutting stability and efficiency. The 45° main rake angle also allows the cutting edge to better adapt to the shape of the countersink, achieving uniform cutting.

[0057] The 0° rake angle ensures that the cutting edge maintains high strength and rigidity during machining, making it less susceptible to damage due to excessive cutting forces. This design is particularly suitable for machining hard materials and can extend the tool's service life.

[0058] A relatively large back angle design helps reduce friction and heat accumulation between the tool back face and the machined surface of the workpiece, reducing tool wear. At the same time, a large back angle can also enhance the tool's heat dissipation capacity, further protecting the cutting edge from high temperatures, thereby improving its durability.

[0059] Due to the good stability and durability of the cutting edge, the tool can maintain low cutting forces and vibration levels during machining, thereby reducing the roughness and waviness of the machined surface. This helps to improve the smoothness and aesthetics of the machined surface and meet higher machining quality requirements.

[0060] This design of countersink chamfering tool can adapt to the processing requirements of countersinks of various sizes and shapes. Whether it is a small diameter precision hole or a large diameter through hole, efficient chamfering can be achieved by adjusting the cutting parameters and tool path. This wide applicability enables the tool to perform excellently in a variety of processing situations.

[0061] It should be noted that for the U-drill inner edge blade 4 and the U-drill outer edge blade 5, the rake angle affects the sharpness of the cutting edge and the magnitude of the cutting force; the back angle affects the strength of the turning tool and the wear of the back tool surface; and the edge inclination angle affects the flow direction of the chips and the strength of the tool tip.

[0062] The front angle of the bolt hole chamfering tool 6 is selected according to the specific processing requirements. The selection of the back angle also takes into account the strength and durability of the tool.

[0063] The rake angle of the inner countersinking tool 3 and the outer countersinking tool 8 is also selected according to the processing material and cutting conditions. The selection of the back angle takes into account the friction and heat during the cutting process, as well as the rigidity of the tool.

[0064] The rake angle of the countersink chamfering tool 2 is also selected according to the processing requirements and workpiece material. The choice of the back angle will balance the strength and durability of the cutting edge.

[0065] A method for drilling and countersinking a high manganese steel composite frog related to the present invention comprises the following steps:

[0066] Step S1, assembling the tool body 1 and the machine tool spindle tool holder.

[0067] The precise assembly of the cutter body 1 and the machine tool spindle toolholder ensures the stability and accuracy of the tool during machining, thereby improving machining accuracy. The stable connection reduces vibration and deviation during cutting, ensuring that the size and shape of the machined part meet the design requirements.

[0068] Step S2: calibrate the tool and set the safety distance.

[0069] Tool setting is a critical step in ensuring the correct relative position between the tool and the workpiece. Through precise tool setting, the contact point between the tool and the workpiece during the cutting process can be ensured to be accurate, so that parts that meet the requirements can be processed. Setting a safety distance can prevent the tool from colliding with the workpiece or overcutting during the machining process, protecting the workpiece and tool from damage. In addition, setting a reasonable safety distance can reduce downtime caused by misoperation or machine tool failure. Setting a safety distance can prevent the tool from being damaged by overcutting or collision during the machining process, protecting the integrity of the machine tool and tool. At the same time, setting a safety distance also helps to reduce vibration and impact during the cutting process, further protecting the machine tool and tool. Through precise tool setting and setting a reasonable safety distance, the risk to the operator during the machining process can be reduced and personal safety can be ensured.

[0070] Step S3: The U-drill drill bit contacts the workpiece 9 to be processed to perform bolt hole drilling. In step S3, the machine tool feed rate and spindle speed are set according to the cutting parameters of the U-drill bolt hole to process the bolt hole.

[0071] It's important to note that by precisely setting the machine tool's feed rate and spindle speed, you can ensure stable cutting speeds and forces during the U-drill drilling process, thereby reducing vibration and deviation during cutting and improving machining accuracy. The selection of cutting parameters has a significant impact on tool life. Excessively high cutting speeds and feed rates can lead to increased tool wear, while excessively low cutting parameters can cause instability in the cutting process, also damaging the tool. By properly setting cutting parameters, you can balance cutting efficiency and tool life, ensuring that the tool maintains optimal cutting performance for a longer period of time. Proper cutting parameters can reduce cutting forces and heat during cutting, thereby reducing surface roughness and improving surface finish. Generally speaking, harder materials require lower speeds, and larger U-drill diameters require lower speeds. The feed rate should be selected based on the effects of cutting forces and heat. A lower feed rate reduces cutting forces but decreases cutting efficiency, while a higher feed rate increases cutting efficiency but may increase cutting forces and heat. Therefore, it's important to find a balance that ensures both stable and efficient cutting.

[0072] Step S4: After the bolt hole is drilled through, the countersink drill bit 11 performs countersink milling. In step S4, before the countersink tool is involved, the program sets the spindle speed to be reduced to the countersink milling processing parameters to process the countersink.

[0073] It should be noted that countersinking is usually performed on the basis of a bolt hole that has been drilled through. At this time, the depth and diameter of the hole have been determined, so an excessively high spindle speed is not required to continue cutting the material. Lowering the spindle speed can reduce cutting force and cutting heat, thereby reducing tool wear and the risk of workpiece deformation; at the same time, a lower speed helps maintain the stability of the cutting process, reduces vibration and impact, and further protects the tool and workpiece. Countersinking often has high requirements for the dimensional accuracy and surface quality of the hole. Lowering the spindle speed can make the cutting process smoother, reduce cutting errors and dimensional deviations caused by vibration, and thus improve machining accuracy. In addition, a lower speed can also help to obtain better surface finish and meet the strict requirements for the surface quality of the countersink.

[0074] Step S5: After the countersink is drilled to the required depth, the bolt hole chamfering tool 6 and the countersink chamfering tool 2 are used to chamfer the bolt hole and the countersink. In step S5, after the countersink is drilled to the required depth, the machine tool spindle is paused and then chamfering is performed.

[0075] It should be noted that the machine tool spindle can pause for 1 second. Pausing allows the cutting system to reach a new stable state, reducing vibrations and deviations caused by continuous cutting, thereby improving machining accuracy. Pausing can ensure that the countersink has accurately reached the predetermined depth position, providing an accurate benchmark for subsequent chamfering. Pausing after the countersink reaches the predetermined depth and then performing chamfering can avoid unnecessary damage to the workpiece due to continuing to feed too deep. By pausing to clearly distinguish between the two processing stages of countersinking and chamfering, the entire cutting process can be made clearer and more orderly, reducing waste of processing time due to confusion or misoperation. In addition, during the pause, the operator can check and adjust the status of the machine tool and tool to ensure that the chamfering process can proceed smoothly, thereby reducing processing interruptions caused by improper adjustments.

[0076] During the entire machining process, compressed air or cutting fluid is introduced into the cooling nozzle 7 to cool the tool body 1 and the workpiece 9 to be machined, and to clean the inner wall of the hole of the workpiece 9 to be machined.

[0077] It should be noted that the introduction of compressed air or cutting fluid can effectively lower the temperature in the cutting zone, reducing workpiece deformation and tool wear caused by high temperatures, thereby maintaining tool sharpness and workpiece dimensional stability, and improving machining accuracy. Chips and impurities generated during the cutting process can affect the quality of the machined surface. The introduction of compressed air or cutting fluid can promptly remove these impurities, maintaining surface cleanliness and further improving machining accuracy. The introduction of compressed air or cutting fluid through cooling nozzles can significantly lower the temperature in the cutting zone, slowing tool wear and extending tool life. It also helps reduce thermal stress in the workpiece caused by high temperatures, extending workpiece life. Cutting fluid also provides a lubricating effect, reducing the friction coefficient between the tool and the workpiece, lowering cutting forces, and further minimizing tool wear and workpiece damage. The cooling and cleaning effects help maintain cutting stability, reduce cutting force fluctuations and vibrations caused by cutting heat and impurity accumulation, and thus improve machining efficiency. By extending tool life, the need for frequent tool changes due to tool wear can be reduced, further improving machining efficiency. Cutting fluid or compressed air can remove chips and impurities generated during machining, maintaining the cleanliness of the machined surface and preventing contamination and damage from impurities. Proper cooling and lubrication can help reduce scratches and burrs on the workpiece surface during cutting, improving the smoothness and flatness of the machined surface.

[0078] From the above description, it can be seen that the present invention completes the machining of bolt holes in a workpiece to a satisfactory standard in a single operation. Without the machine tool moving, drilling continues, using staggered end-face cutters to countersink the feed-side countersink. Upon reaching the bottom of the countersink, both hole edges are simultaneously chamfered. This composite drill bit utilizes an integrated structural design, and after dynamic balancing simulation, it prevents excessive hole diameter deviations caused by severe radial runout of the drill rod during high-speed drilling.

[0079] The utility model integrates three milling functions into one tool. The three processes of drilling, countersinking and chamfering can be completed in one feed cutting of the machine tool, thereby improving the coaxiality of the through hole and the countersink, reducing the number of machine tool positioning times and tool change time, improving the processing efficiency of the combined frog hole, and reducing manufacturing costs.

[0080] The bolt hole drilled by the utility model has good coaxiality with the countersink, smooth hole wall and uniform chamfer, thus saving auxiliary tool setting time, improving production efficiency and reducing manufacturing cost.

[0081] In summary, the utility model solves the technical problems of low coaxiality, low efficiency and uneven chamfering in drilling and countersinking of high manganese steel combined frogs. It has high processing efficiency, high coaxiality, reliable precision, low manufacturing cost, smooth hole wall and uniform chamfering, and is suitable for promotion.

[0082] It should be understood that although this specification is described according to one embodiment, this embodiment does not only include one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in this embodiment can also be appropriately arranged and combined to form other embodiments that can be understood by those skilled in the art.

[0083] The above preferred embodiments are not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes made to the contents described in the claims of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A high manganese steel composite frog drilling and countersinking composite drill bit, having a cutter body (1), characterized in that: The cutter body (1) has a U-drill drill rod (10) with a T-shaped structure adapted to the depth of the workpiece (9) to be processed; a U-drill drilling blade is provided at the bottom end of the vertical rod body of the U-drill drill rod (10); a bolt hole chamfering blade (6) is provided at the turning point of the T-shaped structure of the U-drill drill rod (10); a countersinking drill blade (11) is provided at the horizontal part of the T-shaped structure of the U-drill drill rod (10); a countersinking chamfering blade (2) is provided above the countersinking drill blade (11); wherein cooling nozzles (7) are respectively provided on the U-drill drilling end face and the countersinking drill drilling end face; the U-drill drill rod (10) rod body has a spiral chip removal groove (12); the positions and sizes of all the blades on the cutter body (1) are adapted to the shape and size of the hole to be processed of the workpiece (9) to be processed.

2. The high manganese steel combined frog drilling and countersinking composite drill bit according to claim 1, characterized in that: The U-drill drilling blade particles are composed of U-drill inner edge blade particles (4) and U-drill outer edge blade particles (5); each of the U-drill inner edge blade particles (4) and the U-drill outer edge blade particles (5) has a group, and the U-drill inner edge blade particles (4) and the U-drill outer edge blade particles (5) of a group are centrally symmetrically arranged.

3. The high manganese steel combined frog drilling and countersinking composite drill bit according to claim 1, characterized in that: The countersinking drill bit (11) is composed of a countersinking inner edge bit (3) and a countersinking outer edge bit (8); the countersinking inner edge bit (3) and the countersinking outer edge bit (8) are provided in four groups; the four groups of countersinking inner edge bit (3) and countersinking outer edge bit (8) are centrally symmetrically arranged.

4. The high manganese steel composite frog drilling and countersinking composite drill bit according to claim 2, characterized in that: The U-drill inner blade (4) has a main deflection angle of 88°, a back angle of 7.5°, and a front angle of 0°.

5. The high manganese steel combined frog drilling and countersinking composite drill bit according to claim 2, characterized in that: The U-drill outer blade (5) has a main deflection angle of 90°, a front angle of 0°, and a back angle of 7°.

6. The high manganese steel combined frog drilling and countersinking composite drill bit according to claim 1, characterized in that: The bolt hole chamfering blade (6) has a main deflection angle of 45°, a front angle of 0°, and a back angle of 11°.

7. The high manganese steel composite frog drilling and countersinking composite drill bit according to claim 3, characterized in that: The countersinking inner blade (3) has a front angle of 0° and a back angle of 11°.

8. The high manganese steel combined frog drilling and countersinking composite drill bit according to claim 3, characterized in that: The countersinking outer blade (8) has a front angle of 0° and a back angle of 11°.

9. The high manganese steel combined frog drilling and countersinking composite drill bit according to claim 1, characterized in that: The countersink chamfering blade (2) has a main deflection angle of 45°, a front angle of 0°, and a back angle of 11°.

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