Right-handed rotation right cutting-left-handed rotation right cutting composite milling cutter and production process

Abstract

The invention relates to the technical field of milling cutters, and particularly discloses a right-handed right cutting-left-handed right cutting composite milling cutter and a production process, the milling cutter comprises a cutter handle and a cutter head, a plurality of right-handed right cutting edges are arranged at one end, away from the cutter handle, of the cutter head, a plurality of left-handed right cutting edges are arranged at one end, close to the cutter handle, of the cutter head, and the right-handed right cutting edges and the left-handed right cutting edges are arranged in a staggered mode. Each left-handed right cutting edge extends into the space between the two adjacent right-handed right cutting edges; a main chip groove is reserved between every two adjacent left-handed right cutting edges, a right-handed auxiliary groove is reserved in the side, away from the edge portion of the right-handed right cutting edge, of the right-handed right cutting edge, a left-handed auxiliary groove is reserved in the side, away from the edge portion of the left-handed right cutting edge, of the left-handed right cutting edge, and a right-handed chip groove is reserved between every two adjacent right-handed right cutting edges. A communicating groove is reserved between the edge portion of the right-handed rotation right cutting edge and the end, away from the cutter handle, of the left-handed rotation right cutting edge. The chip removal device has the effects of increasing the number of chip removal paths, increasing the chip containing space and reducing the blockage phenomenon caused by chips.

Description

Technical Field

[0001] This application relates to the technical field of milling cutters, and in particular to a right-handed right-cut - left-handed right-cut composite milling cutter and its production process. Background Art

[0002] A milling cutter is a rotating tool with one or more cutting teeth used for milling. Milling cutters are mainly used for machining planes, steps, grooves, formed surfaces, and cutting workpieces on a milling machine, etc.

[0003] There are many types of milling cutters. When milling horizontal through slots on high-gloss boards, rubber wood boards, aluminum alloy thin plates, double-sided veneer boards and other plates, conventional single-spiral milling cutters or double-spiral edge milling cutters are often used for processing. Single-spiral milling cutters are relatively low in price and fast in processing speed, but they are likely to cause phenomena such as debris adhesion, fuzzing, and low surface finish on the slot walls of the plate through slots; when a double-spiral edge milling cutter is used to process thin plates, especially double-sided veneer boards, the surface of the through slot is relatively smooth, with fewer burrs and is not easily torn, and the quality of the processed products is relatively high. However, the double-spiral edge milling cutter has a high cost and a relatively low chip removal efficiency.

[0004] In the related technology, the Chinese patent with the application number 2014201152806 proposed a positive and negative spiral groove milling cutter, which includes two parts: a cutting edge part and a shank part. The cutting edge part includes a left spiral cutting edge and a right spiral cutting edge, and the two spiral cutting edges are arranged crosswise. The left spiral cutting edge is only composed of circumferential tooth profiles, and the right spiral cutting edge is composed of both end face tooth profiles and circumferential tooth profiles.

[0005] In view of the above-mentioned related technology, the inventor believes that there are the following defects: Since the chip removal grooves between the left cutting edges and the chip removal grooves between the right cutting edges have opposite helix directions, and the milling cutter is usually right-handed when milling a groove, at this time, the debris in the chip removal grooves of adjacent right cutting edges moves towards the direction of the tool shank, and the debris in the chip removal grooves of adjacent left cutting edges moves away from the direction of the tool shank. The debris in two opposite directions squeeze and collide with each other, which is likely to cause unsmooth chip removal and low chip removal efficiency during the operation of the milling cutter. Summary of the Invention

[0006] In order to improve the problems of unsmooth chip removal and low chip removal efficiency during the processing of double-helix milling cutters, this application provides a right-handed right-cut - left-handed right-cut composite milling cutter and its production process.

[0007] The right-handed right-cut - left-handed right-cut composite milling cutter and its production process provided by this application adopt the following technical solutions: A right-handed right-cut - left-handed right-cut composite milling cutter and production process, including a tool shank and a tool head. At one end of the tool head away from the tool shank, a plurality of right-handed right-cut edges are provided. At one end of the tool head close to the tool shank, a plurality of left-handed right-cut edges are provided. The right-handed right-cut edges and the left-handed right-cut edges are arranged alternately, and each left-handed right-cut edge extends into the space between two adjacent right-handed right-cut edges; A main chip evacuation groove is left between two adjacent left-handed right-cut edges. A right-handed auxiliary groove is left on the side of the right-handed right-cut edge away from its cutting edge. A left-handed auxiliary groove is left on the side of the left-handed right-cut edge away from its cutting edge. A right-handed chip evacuation groove is left between two adjacent right-handed right-cut edges. A communication groove is left between the cutting edge of the right-handed right-cut edge and the end of the left-handed right-cut edge away from the tool shank. The bottom walls of the main chip evacuation groove, the right-handed chip evacuation groove and the communication groove are smoothly connected.

[0008] By adopting the above technical solution, during the milling groove operation, the chips milled by the right-handed right-cut edges are located in the right-handed chip evacuation groove and the communication groove and tend to enter the main chip evacuation groove. The chips milled by the left-handed right-cut edges are located in the main chip evacuation groove. When the chips in the communication groove collide with the chips in the main chip evacuation groove, they fly out at the junction where the communication groove merges into the main chip evacuation groove. There is also a small part of the chips in the communication groove after collision that enter the left-handed auxiliary groove and move and gradually fly out; a small part of the chips in the main chip evacuation groove collide with a small part of the chips milled by the next right-handed right-cut edge at the end of the main chip evacuation groove away from the tool shank, causing some chips to enter the right-handed auxiliary groove and continue to be discharged downward. The right-handed auxiliary groove and the left-handed auxiliary groove increase the volume for accommodating chips, and the right-handed auxiliary groove and the left-handed auxiliary groove further increase the chip discharge route, effectively reducing the phenomenon of chip blockage. During the milling groove operation of the double-sided veneer, the lower plate part of the double-sided veneer is subjected to an upward cutting component force by the right-handed right-cut edges, and the upper half part of the double-sided veneer is subjected to a downward cutting component force by the left-handed right-cut edges, so as to balance the overall force of the double-sided veneer, reduce machining vibration, improve cutting stability, and reduce the probability of separation at the junction of the double-sided veneer and chipping on the side wall of the double-sided veneer. At the same time, each left-handed right-cut edge extends into the space between two adjacent right-handed right-cut edges, that is, the left-handed right-cut edges and the right-handed right-cut edges form an axial overlap. The right-handed right-cut edges and the left-handed right-cut edges in the overlap area form a couple balance, reducing torque fluctuation. The overlap area also shifts the natural frequency of the tool to the common cutting excitation frequency band to suppress the vibration of the tool head.

[0009] Optionally, the bottom wall of the right-handed chip evacuation groove and the bottom wall of the communication groove are in a "V" shape. The distance from the bottom wall of the right-handed chip evacuation groove to the axis of the tool head is less than the distance from the bottom wall of the main chip evacuation groove to the axis of the tool head. The bottom wall of the end where the communication groove merges into the main chip evacuation groove protrudes from the bottom wall of the main chip evacuation groove.

[0010] By adopting the above technical solution, the right-handed chip removal groove and the communication groove are in a "human" shape, that is, the depth of the right-handed chip removal groove is greater at the end farther away from the tool shank, which is convenient for guiding the direction of waste chips when the tool tip drills holes. At the same time, the chip removal groove of the right-handed chip removal groove is deeper and has a larger volume, so that when the tool tip mills the groove, it is convenient to guide the direction of some downward chips in the main chip removal groove and some upward chips milled by the right-handed right cutting edge; the communication groove is higher than the main chip removal groove. When the communication groove and the main chip removal groove discharge chips, the chips in the main chip removal groove collide and squeeze with the chips in the communication groove. And most of the chips in the main chip removal groove are closer to the axis of the tool tip than the chips in the communication groove. Furthermore, the chips in the main chip removal groove squeeze most of the chips in the communication groove out of the main chip removal groove, and the remaining part enters the left-handed auxiliary groove, further reducing the phenomenon of chip blockage.

[0011] Optionally, the depth of the main chip removal groove is 1 mm, the width of the main chip removal groove is 2.2 mm, the width of the left-handed auxiliary groove is 1.3 mm, and the thickness of the tool tip is 4 mm.

[0012] By adopting the above technical solution, the large depth of the main chip removal groove and the large width of 3.5 mm of the main chip removal groove plus the left-handed auxiliary groove effectively ensure the temporary storage space for chips, reduce the phenomenon of chip blockage, and reduce the frequency of stopping the machine to clean chips. And the 1 mm depth of the main chip removal groove ensures that the tool tip has high strength at a high chip removal efficiency. If the depth of the main chip removal groove is 0.8 mm, the chip capacity is insufficient, and the frequency of stopping the machine to remove chips increases by 50%, resulting in a lower processing efficiency; if the depth of the main chip removal groove is 1.2 mm, that is, the thickness of the tool tip is reduced, although the chip removal efficiency is improved to some extent, the rigidity of the tool tip drops by 20%, affecting the machining accuracy of the workpiece and the service life of the tool tip.

[0013] Optionally, the helix angle of the right-handed right cutting edge is smaller than the helix angle of the left-handed right cutting edge.

[0014] By adopting the above technical solution, the small helix angle of the right-handed right cutting edge effectively enhances the axial cutting force, ensures that the lower substrate is stably pulled up, reduces cutting vibration, and is more suitable for the lower substrate with a higher density; the large helix angle of the left-handed right cutting edge can effectively improve the chip removal efficiency, and at the same time uses the downward pressure characteristic of the left-handed cutting edge to suppress the edge chipping of the upper layer, which is more suitable for the upper layer veneer.

[0015] Optionally, the land of the right-handed right cutting edge is 0.8 mm, and the land of the left-handed right cutting edge is 0.7 mm.

[0016] By adopting the above technical solution, since the right-handed right cutting edge not only performs milling groove operations but also drilling operations, and the right-handed right cutting edge usually acts on the lower substrate with a greater density. At the same time, the right-handed right cutting edge of the wide cutting edge band has a greater bending stiffness, stronger performance in suppressing cutting vibration of the lower layer, and higher load for dispersing impact. Thus, the risk of edge chipping is effectively reduced. However, the increase in the cutting edge band width will also cause an increase in the radius of chip curling, and the chips are more likely to enter the left-handed auxiliary groove in addition to entering the main chip discharge groove. That is, the design of the left-handed auxiliary groove is more convenient for discharging the chips generated by the right-handed right cutting edge, greatly reducing the blockage phenomenon caused by the increase in the cutting edge width; the left-handed right cutting edge of the narrow cutting edge band has a smaller frictional resistance and lower wear, thereby making the surface finish of the upper veneer higher, and the chip breaking efficiency is higher, which is more convenient for chip discharge.

[0017] Optionally, the first outer corner of the right-handed right cutting edge is 17° and the second outer corner is 35°.

[0018] By adopting the above technical solution, the smaller first outer corner of the right-handed right cutting edge improves the impact resistance of the edge and extends the tool life. At the same time, the small angle makes the flank more close to the workpiece to increase the contact area and disperse the pressure of the right-handed right cutting edge acting on the lower substrate of the workpiece, further avoiding the phenomenon of edge chipping on the lower substrate; the larger second outer corner reduces the friction area between the right-handed right cutting edge and the workpiece, thereby effectively reducing the cutting temperature. At the same time, it increases the space between the right-handed right cutting edge and the workpiece, which is equivalent to increasing the space of the right-handed auxiliary groove, further improving the chip discharge efficiency.

[0019] Optionally, a convex block is integrally formed on the outer cylindrical surface of the right-handed right cutting edge near the end of the tool shank. The edge of the convex block is collinear with the edge of the right-handed right cutting edge, and the outer fillet of the convex block is smaller than the first outer corner of the right-handed right cutting edge.

[0020] By adopting the above technical solution, since there are multiple helix directions at the intersection of the right-handed right cutting edge and the left-handed right cutting edge, it is easy to cause additional vibration at this place. The contact area between the convex block with a smaller outer fillet and the workpiece is larger, which forms local support for the right-handed right cutting edge to suppress cutting vibration. The edge of the convex block is collinear with the edge of the right-handed right cutting edge, which is convenient for the right-handed right cutting edge to divide the long chips into two sections during cutting or drilling, reducing the risk of long chip entanglement. And when cutting the double-sided veneer, the hardness of the hardened adhesive layer part of the double-sided veneer is higher than that of the double-sided veneer plate (such as soft metal plates like wood, plastic, thin aluminum plate, etc.). The convex block with a small flank angle has higher strength and is more suitable for high-hardness materials.

[0021] Optionally, the groove walls of the right-handed chip evacuation grooves, the cutting surfaces of the right-handed right cutting edges, and the cutting surfaces of the left-handed right cutting edges are all coated with a bottom layer and a surface layer, where the bottom layer is a TiAlN layer with a thickness of 2 μm and the surface layer is a TiSiN layer with a thickness of 0.5 μm; the groove walls of the main chip evacuation groove, the right-handed auxiliary groove, the left-handed auxiliary groove, and the communication groove are all coated with a transition layer and a functional layer, the transition layer is pure Ti with a thickness of 0.2 μm, and the functional layer is ta-C type DLC with a thickness of 1.5 μm.

[0022] By adopting the above technical solutions, the TiAlN bottom layer resists abrasive wear of the hard substrate, extends the edge life, the TiSiN surface layer refines the friction interface, reduces the friction coefficient with the workpiece, reduces the adhesion of chips, and thus extends the service life of the tool; the functional layer enables the chips to move smoothly within the groove wall due to its ultra-low friction coefficient, improving the chip evacuation efficiency, and the transition layer facilitates the coating of the functional layer, while relieving the residual stress of the functional layer and preventing the functional layer from cracking.

[0023] The present application also provides a production process for a right-handed right cutting-left-handed right cutting composite milling cutter, including the following steps: S1. Forming of the tool head and the tool shank: The high-strength alloy steel tool shank is subjected to a tempering treatment to make the tensile strength of the tool shank ≥ 1000 MPa, and then the powder metallurgy high-speed steel tool head and the tool shank are welded. S2. Machining and forming of the tool head: A five-axis CNC grinding machine is used to machine the right-handed right cutting edge, the left-handed right cutting edge, the main chip evacuation groove, the communication groove, and the right-handed chip evacuation groove, and the reinforcement plate is formed synchronously when grinding the right-handed right cutting edge and the left-handed right cutting edge. S3. Coating application: The groove walls of the right-handed chip evacuation grooves, the cutting surfaces of the right-handed right cutting edges, and the cutting surfaces of the left-handed right cutting edges are all first deposited with a 2-μm-thick TiAlN layer by magnetron sputtering, and it is ensured that the bias voltage is -50 V and the temperature is 450 °C during this process, and then a 0.5-μm-thick TiSiN layer is sprayed by high-velocity oxygen fuel spraying; the groove walls of the main chip evacuation groove, the right-handed auxiliary groove, the left-handed auxiliary groove, and the communication groove are all first plated with a pure Ti layer by ion plating, and then a DLC layer is coated by the PECVD process. S4. Precision inspection: The land width and helix angle of the right-handed right cutting edge and the left-handed right cutting edge are verified by laser scanning, and the groove depths of the main chip evacuation groove, the right-handed auxiliary groove, the left-handed auxiliary groove, and the communication groove are detected by a coordinate measuring machine. S5. Dynamic balance test: G2.5-level dynamic balance calibration is carried out at 15000 rpm.

[0024] In summary, the present application includes at least one of the following beneficial technical effects: 1. The chips milled by the right-handed right cutting edge are located in the right-handed chip evacuation groove and the connecting groove, and tend to enter the main chip evacuation groove. The chips milled by the left-handed right cutting edge are located in the main chip evacuation groove. When the chips in the connecting groove collide with the chips in the main chip evacuation groove, they fly out at the junction where the connecting groove merges into the main chip evacuation groove. There is also a small part of the chips in the connecting groove after collision that enter the left-handed auxiliary groove and move and gradually fly out. A small part of the chips in the main chip evacuation groove collide with a small part of the chips milled by the next right-handed right cutting edge at the end of the main chip evacuation groove far from the tool shank, causing some chips to enter the right-handed auxiliary groove and continue to be discharged downward. The right-handed auxiliary groove and the left-handed auxiliary groove increase the volume for accommodating chips, and the right-handed auxiliary groove and the left-handed auxiliary groove further increase the chip discharge route, effectively reducing the phenomenon of chip jamming; 2. The connecting groove is higher than the main chip evacuation groove. When the main chip evacuation groove and the connecting groove discharge chips, the chips in the main chip evacuation groove collide and squeeze with the chips in the connecting groove. Most of the chips in the main chip evacuation groove are closer to the axis of the tool tip than the chips in the connecting groove. Therefore, the chips in the main chip evacuation groove squeeze most of the chips in the connecting groove out of the main chip evacuation groove, and the remaining part enters the left-handed auxiliary groove. The groove depth of the right-handed chip evacuation groove is greater than that of the main chip evacuation groove, which also causes the chips milled by the right-handed right cutting edge to squeeze a part of the chips in the main chip evacuation groove, causing a part of the chips in the main chip evacuation groove to fly out directly and another part to enter the right-handed auxiliary groove and be discharged, further reducing the phenomenon of chip jamming; 3. The large groove depth of the main chip evacuation groove and the large groove width of 3.5 mm in total for the main chip evacuation groove plus the left-handed auxiliary groove effectively ensure the temporary storage space for chips, reduce the phenomenon of chip jamming, and reduce the frequency of stopping the machine to clean chips. The groove depth of 1 mm in the main chip evacuation groove ensures that at a high chip evacuation efficiency, the tool tip also has high strength, and only when the tool tip thickness is 4 mm, the groove depth of the main chip evacuation groove is 1 mm, and the sum of the groove widths of the main chip evacuation groove and the left-handed auxiliary groove is 3.5 mm, the synergistic effect reaches the optimum; 4. There are various helix directions at the intersection of the right-handed right cutting edge and the left-handed right cutting edge, which easily causes additional vibration at this place. The contact area between the convex block with a smaller outer fillet and the workpiece is larger, which forms a local support for the right-handed right cutting edge and suppresses cutting vibration. The edge of the convex block is collinear with the edge of the right-handed right cutting edge, which is convenient for the right-handed right cutting edge to divide the long chips into two sections during cutting or drilling, reducing the risk of long chip entanglement. And when cutting the double-sided veneer, the hardness of the hardened glue layer part of the double-sided veneer is higher than that of the plate of the double-sided veneer. The convex block with a small back angle has higher strength and is more suitable for high-hardness materials; 5. The TiAlN bottom layer resists abrasive wear of the hard substrate, extends the edge life. The TiSiN surface layer refines the friction interface, reduces the friction coefficient with the workpiece, and reduces chip adhesion, thereby extending the service life of the tool; The functional layer enables the chips to move smoothly within the groove wall due to its ultra-low friction coefficient, improving the chip evacuation efficiency. The transition layer facilitates the coating of the functional layer, and at the same time relieves the residual stress of the functional layer and prevents the functional layer from cracking. Description of the Drawings

[0025] Figure 1 is the overall structural schematic diagram of the embodiment of the present application; Figure 2 is the partial front view structural schematic diagram of the present application; Figure 3 is the structural schematic diagram mainly used to show the right-handed right cutting edge, bump, main chip evacuation groove, right-handed auxiliary groove and communication groove of the present application; Figure 4 is the left view structural schematic diagram of the present application; Figure 5 is the structural diagram of the present application.

[0026] Reference numerals: 11, tool shank; 12, tool tip; 21, right-handed right cutting edge; 211, bump; 22, left-handed right cutting edge; 31, main chip evacuation groove; 32, right-handed auxiliary groove; 33, left-handed auxiliary groove; 34, right-handed chip evacuation groove; 35, communication groove. Detailed implementation manners

[0027] The following will further describe the present application in detail Figures 1-5 in conjunction with the attached drawings.

[0028] Embodiment 1

[0029] The embodiment of the present application discloses a right-handed right cutting - left-handed right cutting composite milling cutter. Referring to Figure 1 , the right-handed right cutting - left-handed right cutting composite milling cutter includes a tool shank 11 and a tool tip 12 welded to the tool shank 11. At one end of the tool tip 12 far from the tool shank 11, a plurality of right-handed right cutting edges 21 are integrally formed. At one end of the tool tip 12 close to the tool shank 11, a plurality of left-handed right cutting edges 22 are integrally formed. In the present application, both the right-handed right cutting edges 21 and the left-handed right cutting edges 22 are three. The right-handed right cutting edges 21 and the left-handed right cutting edges 22 are arranged alternately. Each left-handed right cutting edge 22 extends into the space between two adjacent right-handed right cutting edges 21; a main chip evacuation groove 31 is left between two adjacent left-handed right cutting edges 22. The peripheral wall of the tool tip 12 is the bottom wall of the main chip evacuation groove 31. A right-handed auxiliary groove 32 is left on the side of the right-handed right cutting edge 21 far from its cutting edge. A left-handed auxiliary groove 33 is left on the side of the left-handed right cutting edge 22 far from its cutting edge. The right-handed right cutting edge 21 and the left-handed right cutting edge 22 are both stepped at the right-handed auxiliary groove 32 and the left-handed auxiliary groove 33 respectively. A right-handed chip evacuation groove 34 is left between two adjacent right-handed right cutting edges 21. A communication groove 35 is left between the cutting edge of the right-handed right cutting edge 21 and the end of the left-handed right cutting edge 22 far from the tool shank 11. The bottom walls of the main chip evacuation groove 31, the right-handed chip evacuation groove 34 and the communication groove 35 are smoothly connected.

[0030] During the milling slot operation, the chips milled by the right-handed right cutting edge 21 are located in the right-handed chip discharge groove 34 and the communication groove 35, and tend to enter the main chip discharge groove 31. The chips milled by the left-handed right cutting edge 22 are located in the main chip discharge groove 31. When the chips in the communication groove 35 collide with the chips in the main chip discharge groove 31, they fly out at the junction where the communication groove 35 joins the main chip discharge groove 31. There is also a small part of the chips in the communication groove 35 after collision that enter the left-handed auxiliary groove 33 and move and gradually fly out. A small part of the chips in the main chip discharge groove 31 collide with a small part of the chips milled by the next right-handed right cutting edge 21 at the end of the main chip discharge groove 31 away from the tool shank 11, causing some chips to enter the right-handed auxiliary groove 32 and continue to be discharged downward. The right-handed auxiliary groove 32 and the left-handed auxiliary groove 33 increase the volume that can accommodate chips, and the right-handed auxiliary groove 32 and the left-handed auxiliary groove 33 further increase the chip discharge route, effectively reducing the phenomenon of chip blockage.

[0031] Moreover, during the milling slot operation of the double-sided veneer, the right-handed right cutting edge 21 exerts an upward cutting component force on the lower plate part of the double-sided veneer, and the left-handed right cutting edge 22 exerts a downward cutting component force on the upper half of the double-sided veneer to balance the overall force of the double-sided veneer, reduce machining vibration, improve cutting stability, and reduce the probability of separation at the junction of the double-sided veneer and chipping on the side wall of the double-sided veneer. At the stepped part of the right-handed right cutting edge 21 and the left-handed right cutting edge 22, it is convenient to ensure the strength of the right-handed right cutting edge 21 and the left-handed right cutting edge 22 while maximizing the volume of the right-handed auxiliary groove 32 and the left-handed auxiliary groove 33, that is, the right-handed right cutting edge 21 and the left-handed right cutting edge 22 maximize the chip discharge efficiency within the qualified strength range. Each left-handed right cutting edge 22 extends into two adjacent right-handed right cutting edges 21, that is, the left-handed right cutting edge 22 forms an axial overlap with the right-handed right cutting edge 21. The right-handed right cutting edge 21 and the left-handed right cutting edge 22 in the overlapping area form a couple balance, reducing torque fluctuation. The overlapping area also shifts the natural frequency of the tool to the common cutting excitation frequency band to suppress the vibration of the tool tip 12.

[0032] Refer to Figure 1 , the bottom wall of the right-handed chip discharge groove 34 and the bottom wall of the communication groove 35 are in a "person" shape. The distance from the bottom wall of the right-handed chip discharge groove 34 to the axis of the tool tip 12 is less than the distance from the bottom wall of the main chip discharge groove 31 to the axis of the tool tip 12. The bottom wall of the end where the communication groove 35 joins the main chip discharge groove 31 protrudes from the bottom wall of the main chip discharge groove 31.

[0033] The right-handed chip evacuation groove 34 and the communication groove 35 are in a "herringbone" shape, that is, the depth of the right-handed chip evacuation groove 34 increases as it gets farther away from the end of the tool shank 11, which is convenient for guiding the direction of waste chips when the cutting head 12 drills holes. At the same time, the groove depth of the right-handed chip evacuation groove 34 is relatively deep and the volume is relatively large, so that when the cutting head 12 mills the groove, it is convenient to guide the direction of some downward chips in the main chip evacuation groove 31 and some upward chips milled by the right-handed right cutting edge 21; the communication groove 35 is higher than the main chip evacuation groove 31. When the communication groove 35 and the main chip evacuation groove 31 evacuate chips, the chips in the main chip evacuation groove 31 collide and squeeze with the chips in the communication groove 35. Most of the chips in the main chip evacuation groove 31 are closer to the axis of the cutting head 12 than the chips in the communication groove 35. Therefore, the chips in the main chip evacuation groove 31 squeeze most of the chips in the communication groove 35 out of the main chip evacuation groove 31, and the remaining part enters the left-handed auxiliary groove 33, further reducing the phenomenon of chip blockage.

[0034] Refer to Figures 2-5 , the groove depth of the main chip evacuation groove 31 is 1 mm, the groove width is 2.2 mm, the groove width of the left-handed auxiliary groove 33 is 1.3 mm, and the thickness of the cutting head 12 is 4 mm. The large groove depth of the main chip evacuation groove 31 and the total large groove width of 3.5 mm of the main chip evacuation groove 31 plus the left-handed auxiliary groove 33 effectively ensure the temporary storage space for chips, reduce the phenomenon of chip blockage, and reduce the frequency of stopping the machine to clean chips. Moreover, the 1 mm groove depth of the main chip evacuation groove 31 ensures that at a high chip evacuation efficiency, the cutting head 12 also has high strength. If the groove depth of the main chip evacuation groove 31 is 0.8 mm, the chip capacity is insufficient, and the frequency of stopping the machine to evacuate chips increases by 50%, resulting in a lower processing efficiency; if the groove depth of the main chip evacuation groove 31 is 1.2 mm, that is, the thickness of the cutting head 12 decreases, although the chip evacuation efficiency is improved to some extent, the rigidity of the cutting head 12 decreases by 20%, affecting the machining accuracy of the workpiece and the service life of the cutting head 12. The same is true for the 4 mm thickness of the cutting head 12, that is, if the thickness of the cutting head 12 is too thick, it will affect the depth of the main chip evacuation groove 31, and if it is too thin, it will affect the rigidity of the cutting head 12. The flexural rigidity EI ∝ h3. For example, the 4 mm thickness is increased to (4 / 3)3 ≈ 2.37 times compared with 3 mm.

[0035] Only when the thickness of the cutting head 12 is 4 mm, the groove depth of the main chip evacuation groove 31 is 1 mm, and the sum of the groove widths of the main chip evacuation groove 31 and the left-handed auxiliary groove 33 is 3.5 mm, the synergistic effect reaches the optimum, making the delamination rate of the upper layer veneer reach a relatively low 3%, the chipping rate of the lower layer substrate optimized to 5%, and the feed speed also increased from 800 mm / min of the conventional two-way spiral milling cutter to 1500 mm / min, that is, the chip evacuation efficiency, tool strength, and machining accuracy in the workpiece processing process are balanced. When one of the index data changes, the strength and chip evacuation performance of the tool change exponentially.

[0036] Refer to Figure 2 and Figure 5, the helix angle of the right-handed right cutting edge 21 is smaller than that of the left-handed right cutting edge 22. The helix angle of the right-handed right cutting edge 21 is 20°, and the helix angle of the left-handed right cutting edge 22 is 30°. The small helix angle of the right-handed right cutting edge 21 effectively enhances the axial cutting force, ensures that the lower substrate is stably pulled up, reduces cutting vibration. For every 5° reduction in the helix angle, the axial force increases by about 15%, making it more suitable for the denser lower substrate; the large helix angle of the left-handed right cutting edge 22 has a higher proportion of axial cutting force and less vibration, and the large helix angle can effectively improve the chip evacuation efficiency, reduce scratches on the workpiece surface, and at the same time suppress the upper layer chipping by using the downward pressure characteristic of the left-handed cutting edge, making it more suitable for the upper layer veneer.

[0037] Refer to Figure 1 and Figure 5 , the land width of the right-handed right cutting edge 21 is 0.8 mm, and the land width of the left-handed right cutting edge 22 is 0.7 mm. Since the right-handed right cutting edge 21 is also used for drilling in addition to milling the groove, and the right-handed right cutting edge 21 usually acts on the denser lower substrate. At the same time, the right-handed right cutting edge 21 with a wide land width has a greater bending stiffness, stronger performance in suppressing the cutting vibration of the lower layer, and a higher load for dispersing the impact, thus effectively reducing the risk of edge chipping. However, the increase in the land width will also cause the radius of the chip curl to increase, and the chips are more likely to enter the left-handed auxiliary groove 33 in addition to entering the main chip evacuation groove 31. That is, the design of the left-handed auxiliary groove 33 is more convenient for the evacuation of the chips generated by the right-handed right cutting edge 21, greatly reducing the blockage phenomenon caused by the increase in the edge width; the left-handed right cutting edge 22 with a narrow land width has a smaller frictional resistance and lower wear, thus making the surface finish of the upper layer veneer higher, and the chip fracture efficiency is higher, making it more convenient for chip evacuation.

[0038] Refer to Figure 4 , the first outer corner of the right-handed right cutting edge 21 is 17° and the second outer corner is 35°. The smaller first outer corner of the right-handed right cutting edge 21 improves the impact resistance of the edge and extends the tool life. At the same time, the small angle makes the flank closer to the workpiece to increase the contact area and disperse the pressure of the right-handed right cutting edge 21 acting on the lower substrate of the workpiece, further avoiding the phenomenon of chipping on the lower substrate; the larger second outer corner reduces the friction area between the right-handed right cutting edge 21 and the workpiece, thus effectively reducing the cutting temperature. At the same time, it increases the space between the right-handed right cutting edge 21 and the workpiece, which is equivalent to increasing the space of the right-handed auxiliary groove 32, further improving the chip evacuation efficiency.

[0039] Refer to Figure 3, on the outer cylindrical surface of the right-handed right cutting edge 21 near one end of the tool shank 11, a convex block 211 is integrally formed. The cutting edge of the convex block 211 is collinear with the cutting edge of the right-handed right cutting edge, and the outer fillet angle of the convex block 211 is smaller than the first outer clearance angle of the outer circle of the right-handed right cutting edge. The outer fillet angle of the convex block 211 is 3° - 15°, which is determined according to the workpiece material during actual use. Since there are multiple helix directions at the intersection of the right-handed right cutting edge 21 and the left-handed right cutting edge 22, it is easy to cause additional vibration at this place. The convex block 211 with a smaller outer fillet angle has a larger contact area with the workpiece, forming local support for the right-handed right cutting edge and suppressing cutting vibration. The cutting edge of the convex block 211 is collinear with the cutting edge of the right-handed right cutting edge 21, which is convenient for the right-handed right cutting edge 21 to divide the long chip into two sections during cutting or drilling, reducing the risk of long chip entanglement. And when cutting the double-sided veneer, the hardness of the hardened glue layer part of the double-sided veneer is higher than that of the plate of the double-sided veneer (such as soft metal plates like wood, plastic, thin aluminum plate, etc.). The convex block 211 with a small clearance angle has higher strength and is more suitable for high-hardness materials.

[0040] Referring to Figure 1, the groove walls of the right-handed chip flutes 34, the cutting surfaces of the right-handed right cutting edge 21, and the cutting surfaces of the left-handed right cutting edge 22 are all coated with a bottom layer and a surface layer. Among them, the bottom layer is a TiAlN layer with a thickness of 2μm, and the surface layer is a TiSiN layer with a thickness of 0.5μm; the groove walls of the main chip flutes 31, the right-handed secondary flutes 32, the left-handed secondary flutes 33, and the connecting flutes 35 are all coated with a transition layer and a functional layer. The transition layer is pure Ti with a thickness of 0.2μm, and the functional layer is ta-C type DLC with a thickness of 1.5μm.

[0041] The TiAlN bottom layer resists abrasive wear of the hard substrate, provides substrate hardness, resists substrate impact, extends the cutting edge life, and the temperature resistance of the bottom layer > 800°C. The TiSiN surface layer refines the friction interface, reduces the friction coefficient with the workpiece, reduces chip adhesion, and thus extends the tool life. Moreover, the surface layer further increases the hardness to HV3800 - 4000. When the thickness of the TiAlN layer < 1.5μm, the hardness is insufficient; when > 3μm, the brittleness increases; the functional layer enables the chip to move smoothly within the groove wall due to its ultra-low friction coefficient, improves the chip evacuation efficiency, makes the friction coefficient between the functional layer and the chips of most workpieces ≤ 0.1, reduces the adhesion force of built-up edge by 90% compared with the uncoated tool, and significantly reduces the cutting fluid requirement. The transition layer facilitates the coating of the functional layer, simultaneously relieves the residual stress of the functional layer, and prevents the functional layer from cracking. Among them, the thickness of the functional layer being 1.5μm is the optimal solution for balancing wear resistance and bonding strength. When the thickness of the functional layer is 1.0μm, the tool life is only 400 linear meters. When the thickness of the functional layer is 2.0μm, the coating is prone to peeling.

[0042] The implementation principle of a right-handed right-cut - left-handed right-cut composite milling cutter and its production process in an embodiment of this application is as follows: The chips milled by the right-handed right-cut edge 21 are located in the right-handed chip evacuation groove 34 and the communication groove 35, and tend to enter the main chip evacuation groove 31. The chips milled by the left-handed right-cut edge 22 are located in the main chip evacuation groove 31. The communication groove 35 is higher than the main chip evacuation groove 31. When the chips in the communication groove 35 collide with the chips in the main chip evacuation groove 31, the chips in the main chip evacuation groove 31 collide and squeeze with the chips in the communication groove 35. And most of the chips in the main chip evacuation groove 31 are closer to the axis of the tool head 12 than the chips in the communication groove 35. Thus, the chips in the main chip evacuation groove 31 squeeze most of the chips in the communication groove 35 out of the main chip evacuation groove 31, and the remaining part enters the left-handed auxiliary groove 33 and gradually flies out. At the same time, some of the chips generated by the left-handed right-cut edge 22 also enter the left-handed auxiliary groove 33, and then gradually fly out or fly out after colliding with the chips entering the left-handed auxiliary groove 33 from the communication groove 35. The right-handed auxiliary groove 32 and the left-handed auxiliary groove 33 increase the volume for accommodating chips, and the right-handed auxiliary groove 32 and the left-handed auxiliary groove 33 further increase the chip evacuation route, effectively reducing the phenomenon of chip jamming; During this process, the right-handed right-cut edge 21 makes the lower plate part of the double-sided veneer panel receive an upward cutting component force, and the left-handed right-cut edge 22 makes the upper half part of the double-sided veneer panel receive a downward cutting component force, so as to balance the overall force of the double-sided veneer panel, reduce machining vibration, improve cutting stability, and reduce the probability of separation at the junction of the double-sided veneer panel and chipping at the side wall of the double-sided veneer panel; During drilling operations, the right-handed right-cut edge 21 usually acts on the lower substrate with a greater density. At the same time, the right-handed right-cut edge 21 with a wide edge band has a greater flexural rigidity, stronger performance in suppressing cutting vibration of the lower layer, and higher load for dispersing impact, thus effectively reducing the risk of edge chipping; And during the entire operation process, the TiAlN bottom layer resists abrasive wear of the hard substrate, provides substrate hardness, resists substrate impact, and prolongs the edge life. The TiSiN surface layer further increases hardness, refines the friction interface, reduces the friction coefficient with the workpiece, reduces chip adhesion, and thus prolongs the service life of the tool. The functional layer enables the chips to move smoothly within the groove wall due to its ultra-low friction coefficient, improves chip evacuation efficiency. The transition layer facilitates the coating of the functional layer, and at the same time relieves the residual stress of the functional layer and prevents the functional layer from cracking.

[0043] Embodiment Two

[0044] The embodiment of this application discloses a production process of a right-handed right-cut - left-handed right-cut composite milling cutter. Referring to the figure, the production process of the right-handed right-cut - left-handed right-cut composite milling cutter includes the following steps: S1. Forming of the tool head 12 and the tool handle 11: The high-strength alloy steel tool handle 11 is subjected to tempering treatment to make the tensile strength of the tool handle 11 ≥ 1000 MPa. Then, the powder metallurgy high-speed steel tool head 12 and the tool handle 11 are welded by high-frequency induction brazing, and after welding, slow cooling is carried out to eliminate residual stress; S2. Machining and forming of the tool head 12: A five-axis CNC grinding machine is used to machine the right-handed right cutting edge 21, the left-handed right cutting edge 22, the main chip flute 31, the connecting groove 35, and the right-handed chip flute 34. When grinding the right-handed right cutting edge 21 and the left-handed right cutting edge 22, the reinforcing plate is formed synchronously; S3. Coating application: The groove wall of the right-handed chip flute 34, the cutting surface of the right-handed right cutting edge 21, and the cutting surface of the left-handed right cutting edge 22 are all first deposited with a 2μm TiAlN layer by magnetron sputtering, and it is ensured that the bias voltage is -50V and the temperature is 450°C during this process. Then, a 0.5μm thick TiSiN layer is sprayed by high-velocity oxygen fuel spraying; The groove walls of the main chip flute 31, the right-handed secondary chip flute 32, the left-handed secondary chip flute 33, and the connecting groove 35 are all first coated with a pure Ti layer by ion plating, and then a DLC layer is coated by the PECVD process; S4. Precision detection: The land width and helix angle of the right-handed right cutting edge 21 and the left-handed right cutting edge 22 are verified by laser scanning, and the groove depths of the main chip flute 31, the right-handed secondary chip flute 32, the left-handed secondary chip flute 33, and the connecting groove 35 are detected by a coordinate measuring machine; S5. Dynamic balance test: G2.5 level dynamic balance calibration is carried out at 15000 rpm, and the residual unbalance amount < 0.5 g·mm / kg.

[0045] The above are all the preferred embodiments of this application. The protection scope of this application is not limited by this. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A right-handed right-cutting-left-handed right-cutting composite milling cutter, comprising a tool handle (11) and a tool head (12), characterized in that: A plurality of right-handed right cutting edges (21) are arranged at one end of the cutter head (12) away from the cutter handle (11), and a plurality of left-handed right cutting edges (22) are arranged at one end of the cutter head (12) close to the cutter handle (11), the right-handed right cutting edges (21) and the left-handed right cutting edges (22) are arranged alternately, and each of the left-handed right cutting edges (22) extends between two adjacent right-handed right cutting edges (21); A main chip groove (31) is left between two adjacent left-handed right cutting edges (22); a right-handed secondary groove (32) is left on the side of the right-handed right cutting edge (21) away from its cutting edge; a left-handed secondary groove (33) is left on the side of the left-handed right cutting edge (22) away from its cutting edge; a right-handed chip groove (34) is left between two adjacent right-handed right cutting edges (21); a connecting groove (35) is left between the cutting edge of the right-handed right cutting edge (21) and the end of the left-handed right cutting edge (22) away from the tool handle (11); and the main chip groove (31), the right-handed chip groove (34) and the bottom wall of the connecting groove (35) are smoothly connected.

2. A right-handed and right-cutting / left-handed and right-cutting composite milling cutter according to claim 1, characterized in that: The groove bottom wall of the right-handed chip groove (34) and the groove bottom wall of the connecting groove (35) are in a "human" shape, the groove bottom wall of the right-handed chip groove (34) is at a smaller distance from the axis of the cutter head (12) than the groove bottom wall of the main chip groove (31) is at an axis of the cutter head (12), and the bottom wall of the connecting groove (35) at one end where it merges into the main chip groove (31) protrudes from the bottom wall of the main chip groove (31).

3. The right-handed and right-cutting / left-handed and right-cutting compound milling cutter according to claim 1, characterized in that: The main chip removal groove (31) has a groove depth of 1 mm and a groove width of 2.2 mm, the left-handed auxiliary groove (33) has a groove width of 1.3 mm, and the tool head (12) has a thickness of 4 mm.

4. The right-handed and right-cutting / left-handed and right-cutting compound milling cutter according to claim 1, characterized in that: The helix angle of the right-handed cutting edge (21) is smaller than the helix angle of the left-handed cutting edge (22).

5. The right-handed and right-cutting / left-handed and right-cutting composite milling cutter according to claim 4, characterized in that: The edge band of the right-handed cutting edge (21) is 0.8 mm, and the edge band of the left-handed cutting edge (22) is 0.7 mm.

6. The right-handed and right-cutting / left-handed and right-cutting compound milling cutter according to claim 4, characterized in that: The first clearance angle of the outer circle of the right-handed right cutting edge (21) is 17°, and the second clearance angle of the outer circle is 35°.

7. The right-handed and right-cutting / left-handed and right-cutting compound milling cutter according to claim 1, characterized in that: A protrusion (211) is integrally formed on the outer circumferential surface of the right-handed right cutting edge (21) close to one end of the knife handle (11); the cutting edge of the protrusion (211) is colinear with the cutting edge of the right-handed right cutting edge (21), and the outer round angle of the protrusion (211) is smaller than the first clearance angle of the outer circle of the right-handed right cutting edge (21).

8. The right-handed and right-cutting / left-handed and right-cutting compound milling cutter according to claim 1, characterized in that: The groove wall of the right-handed chip groove (34), the cut surface of the right-handed right cutting edge (21) and the cut surface of the left-handed right cutting edge (22) are all coated with a bottom layer and a surface layer, wherein the bottom layer is a TiAlN layer with a thickness of 2 μm and the surface layer is a TiSiN layer with a thickness of 0.5 μm; The groove walls of the main chip groove (31), the right-handed auxiliary groove (32), the left-handed auxiliary groove (33) and the connecting groove (35) are all coated with a transition layer and a functional layer, the transition layer is 0.2 μm thick pure Ti, and the functional layer is 1.5 μm thick ta-C type DLC.

9. A production process of a right-handed right-cutting-left-handed right-cutting compound milling cutter, based on a right-handed right-cutting-left-handed right-cutting compound milling cutter according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, forming the cutter head (12) and the cutter handle (11): the high-strength alloy steel cutter handle (11) is subjected to a modulation process so that the tensile strength of the cutter handle (11) is ≥1000 MPa, and then the powder metallurgy high-speed steel cutter head (12) and the cutter handle (11) are welded; S2, machining and forming of the cutter head (12): using a five-axis CNC grinder to machine a right-handed right cutting edge (21), a left-handed right cutting edge (22), a main chip groove (31), a connecting groove (35) and a right-handed chip groove (34), and simultaneously forming a reinforcing plate when grinding the right-handed right cutting edge (21) and the left-handed right cutting edge (22); S3, coating: the groove wall of the right-handed chip groove (34), the cut surface of the right-handed right cutting edge (21) and the cut surface of the left-handed right cutting edge (22) are first deposited with a 2 μm thick TiAlN layer by magnetron sputtering, and the bias voltage is ensured to be -50V and the temperature is 450°C, and then a 0.5 μm thick TiSiN layer is sprayed by high-speed oxygen fuel; the groove walls of the main chip groove (31), the right-handed auxiliary groove (32), the left-handed auxiliary groove (33) and the connecting groove (35) are first ion-plated with a pure Ti layer, and then a DLC layer is coated by a PECVD process; S4, precision detection: verifying the width and spiral angle of the right-handed right cutting edge (21) and the left-handed right cutting edge (22) by laser scanning, and detecting the groove depth of the main chip groove (31), the right-handed auxiliary groove (32), and the left-handed auxiliary groove (33) by a three-coordinate measuring machine; S5. Dynamic balance test: Perform G2.5 level dynamic balance calibration at 15000rpm.

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