Numerical control milling cutter based on bidirectional positioning structure

Abstract

The invention relates to the technical field of milling cutters of milling machines, and discloses a numerical control milling cutter based on a bidirectional positioning structure, which comprises a cutter handle, the inner wall of the cutter handle is composed of a circular cavity and a trumpet-shaped cavity, the upper end of the cutter handle is in threaded connection with a blind rivet, and the lower end of the cutter handle is in threaded connection with a nut. A milling cutter body is rotationally arranged in the collet, and a mounting sleeve plate fixedly sleeves the lower side of the outer wall of the cutter handle. The numerical control milling cutter based on the two-way positioning structure can effectively solve the problems that in the prior art, a milling cutter positioning mode mainly adopts a one-way positioning or simple guiding structure, and the cutter easily generates microscopic slippage on the conical surface of the cutter handle under high-speed rotating centrifugal force and intermittent cutting impact; machining vibration and machining size fluctuation are caused by radial run-out; and the control on the axial position of the cutter also depends on single end surface contact, and the deep hole machining or stepped surface milling precision is seriously influenced due to axial movement easily caused by thermal deformation or mechanical stress.

Description

Technical Field

[0001] This invention relates to the field of milling cutter technology, and more specifically to a CNC milling cutter based on a bidirectional positioning structure. Background Technology

[0002] As a core tool in the field of metal cutting, the performance of CNC milling cutters directly determines the workpiece machining accuracy, surface quality, and production efficiency. They are widely used in high-precision machining fields such as aerospace, automotive manufacturing, and precision mold making. In scenarios such as high-speed milling, carbide machining, and micro-contour cutting, the bidirectional positioning accuracy of the tool at the spindle interface directly affects the workpiece surface quality, dimensional tolerances, and tool life. Therefore, in tool assembly and cutting operations, it is necessary to achieve multi-dimensional precise positioning, stable force transmission, and reliable connection and fixation.

[0003] To address this issue, this application designs a CNC milling cutter based on a bidirectional positioning structure. Existing CNC milling cutter positioning methods mainly employ unidirectional positioning or simple guide structures. In high-precision cutting scenarios where positioning consistency is critical, the tool is prone to micro-slippage on the tool holder tapered surface under high-speed rotational centrifugal force and intermittent cutting impact, leading to increased radial runout deviation and causing machining vibration and dimensional fluctuations. Controlling the axial position of the tool also relies on a single end face contact. Due to thermal deformation or mechanical stress, axial movement can easily occur, severely affecting the accuracy of deep hole machining or stepped surface milling. Summary of the Invention

[0004] To address the aforementioned shortcomings of existing technologies, this invention provides a CNC milling cutter based on a bidirectional positioning structure. This effectively solves the problems in existing technologies where milling cutter positioning methods primarily employ unidirectional positioning or simple guide structures. Under high-speed rotational centrifugal force and intermittent cutting impact, the cutter is prone to microscopic slippage on the tapered surface of the tool holder, leading to increased radial runout deviation, causing machining vibration and dimensional fluctuations. Furthermore, the control of the cutter's axial position also relies on a single end face contact, which is prone to axial movement due to thermal deformation or mechanical stress, severely affecting the accuracy of deep hole machining or stepped surface milling.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides a CNC milling cutter based on a bidirectional positioning structure, comprising:

[0007] The tool holder has an inner wall composed of a circular cavity and a trumpet-shaped cavity. The upper end of the tool holder is connected to a pull stud by a thread, and the lower end of the tool holder is connected to a nut by a thread. A collet is engaged inside the nut, and the milling cutter body is rotatably mounted inside the collet. A mounting plate is fixedly sleeved on the lower side of the outer wall of the tool holder. A support plate is installed in the middle of the inner wall of the tool holder. Both the tool holder and the collet are provided with a bidirectional positioning part. The tool holder, the nut, and the mounting plate are all provided with a chip-blocking part.

[0008] The bidirectional positioning part includes a hollow shaft that slides inside the tool holder, a docking plate is installed on the upper end of the hollow shaft, an auxiliary sleeve is fixedly sleeved on the lower side of the outer wall of the hollow shaft, and a bidirectional positioning group is provided on both the hollow shaft and the collet.

[0009] The chip-blocking part includes a receiving groove at the upper end of the nut, a matching groove at the lower end of the mounting plate, a side wall chip-blocking assembly on the tool holder, the nut and the mounting plate, and several mounting grooves evenly distributed in a circle at the bottom of the nut. A bottom chip-blocking assembly is provided on the nut and the several mounting grooves.

[0010] Furthermore, the bidirectional positioning assembly includes several receiving cavities located in the middle of the inner wall of the collet. These cavities are evenly distributed in a circular pattern, and alignment plates are slidably installed on the inner wall of each cavity via compression springs.

[0011] Furthermore, the bidirectional positioning assembly also includes a pressure plate installed at the lower end of the hollow shaft, with an alignment rod installed at the middle of the lower end of the pressure plate.

[0012] Furthermore, the sidewall chip-blocking assembly includes an annular sealing plate that is slidably installed on the inner wall of the mating groove. Several waist-shaped sliding holes that communicate with the trumpet-shaped cavity of the tool holder are opened on the inner wall of the mounting plate and the outer wall of the tool holder. The several waist-shaped sliding holes are evenly distributed around the circumference. A connecting rod is slidably installed on the inner wall of the waist-shaped sliding hole. The connecting rod has an L-shaped structure, and the vertical section of the annular sealing plate is fixedly connected to the annular sealing plate, while the horizontal section of the connecting rod is fixedly connected to the outer wall of the pressure plate.

[0013] Furthermore, the bottom chip-blocking assembly includes locking plates that are slidably mounted on the inner walls of several mounting grooves via compression springs. A magnetic sealing plate is magnetically connected to the bottom end of the nut. The outer wall of the magnetic sealing plate is simultaneously movably attached to the inner walls of several locking plates, and the inner wall of the locking plates is movably sleeved on the outer wall of the milling cutter body.

[0014] Furthermore, the outer wall of the milling cutter body is provided with alignment grooves corresponding to several receiving cavities, and the insertion ends of several alignment plates are movably attached to the inner wall of the corresponding alignment groove. A circular slot is provided in the middle of the upper end of the milling cutter body, and the outer wall of the pressure plate is movably attached to the inner wall of the circular slot.

[0015] Furthermore, a compression rod is installed at the lower end of the rivet. The lower end of the compression rod has a hemispherical structure and is movably attached to the mating plate.

[0016] Furthermore, symmetrical limit grooves are formed on the inner wall of the circular cavity of the tool holder, and symmetrical limit slides are installed on the outer wall of the hollow shaft. The limit slides on both sides are slidably connected to the inner wall of the corresponding limit groove, and the auxiliary sleeve is connected to the support plate by several compression springs.

[0017] The technical solution provided by this invention has the following advantages compared with the prior art:

[0018] This invention provides a CNC milling cutter based on a bidirectional positioning structure. After the collet and the milling cutter body are engaged, the operator continues to install a nut at the lower end of the tool holder via a threaded connection. As the nut is continuously screwed in, the collet is subjected to the squeezing force of the trumpet-shaped cavity of the tool holder and gradually locks itself closer to the outer wall of the milling cutter body until the collet completes the clamping of the milling cutter body. With the engagement effect of several alignment plates, a clamping and positioning fixture for the milling cutter body can be achieved, preventing it from moving axially. This avoids the problem in conventional assembly methods where the collet and the milling cutter body only have a single end face contact, which can easily cause axial movement due to thermal deformation or mechanical stress, seriously affecting the accuracy of deep hole machining or stepped surface milling.

[0019] During the rivet assembly stage, workers install the rivets on the upper end of the tool holder via threaded connections. As the rivets are continuously screwed in, the mating plate is subjected to the compressive force of the compression rod and gradually slides downward along the inner wall of the circular cavity of the tool holder. The pressure plate also drives the alignment rod to move downward synchronously, so that the alignment rod is inserted into the circular slot at the upper end of the milling cutter body. At the same time, the lower end face of the pressure plate will also fit tightly against the collet and the upper end of the milling cutter body. This achieves the effect of radially limiting the milling cutter body through the alignment rod and further axially limiting the milling cutter body through the pressure plate. This effectively prevents the milling cutter body from moving upward and avoids the conventional one-way positioning or simple guide structure positioning method for the milling cutter body. Under the centrifugal force of high-speed rotation and intermittent cutting impact, the tool is prone to micro-slippage on the tapered surface of the tool holder, resulting in increased radial runout deviation and causing problems such as machining vibration and machining dimensional fluctuations. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0021] Figure 1 This is a schematic diagram of the three-dimensional structure in an embodiment of the present invention;

[0022] Figure 2This is a schematic diagram of the three-dimensional separation of the tool holder, pull stud, nut, collet, and milling cutter body in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of a partial three-dimensional cross-section in an embodiment of the present invention;

[0024] Figure 4 For the present invention Figure 3 Enlarged view of point X in the middle;

[0025] Figure 5 This is a schematic diagram of the three-dimensional separation of the bidirectional positioning part and the chip blocking part in an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of a partial three-dimensional cross-section of the tool holder, milling cutter body, and hollow shaft in an embodiment of the present invention;

[0027] Figure 7 This is a schematic diagram of a partial three-dimensional cross-section of the collet and the milling cutter body in an embodiment of the present invention;

[0028] Figure 8 This is a schematic diagram of the three-dimensional separation of the collet and the alignment plate in an embodiment of the present invention;

[0029] Figure 9 This is a schematic diagram of the three-dimensional chip-blocking working state transformation structure of the pull stud, annular sealing plate and magnetic sealing plate in an embodiment of the present invention.

[0030] The labels in the diagram represent: 1. Tool holder; 2. Pull stud; 21. Extrusion rod; 3. Nut; 4. Collet; 5. Milling cutter body; 6. Mounting sleeve; 7. Support plate; 8. Bidirectional positioning part; 81. Hollow shaft; 811. Limiting slide bar; 82. Butt plate; 83. Auxiliary sleeve; 84. Bidirectional positioning assembly; 841. Alignment insert plate; 842. Pressure plate; 843. Alignment insert rod; 9. Chip guard; 91. Side wall chip guard assembly; 911. Annular sealing plate; 912. Connecting rod; 92. Bottom chip guard assembly; 921. Locking plate; 922. Magnetic sealing plate. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0032] The present invention will be further described below with reference to embodiments.

[0033] Example:

[0034] Please see Figures 1-9 This invention provides a technical solution: a CNC milling cutter based on a bidirectional positioning structure, comprising:

[0035] The tool holder 1 has an inner wall composed of a circular cavity and a trumpet-shaped cavity. The upper end of the tool holder 1 is connected to a pull stud 2 by a thread, and the lower end of the tool holder 1 is connected to a nut 3 by a thread. A collet 4 is engaged inside the nut 3. The milling cutter body 5 is rotatably mounted inside the collet 4. A mounting plate 6 is fixedly sleeved on the lower side of the outer wall of the tool holder 1. A support plate 7 is installed in the middle of the inner wall of the tool holder 1. The support plate 7 has a ring structure. The tool holder 1 and the collet 4 are jointly provided with a bidirectional positioning part 8. The tool holder 1, the nut 3 and the mounting plate 6 are jointly provided with a chip-blocking part 9.

[0036] The bidirectional positioning part 8 includes a hollow shaft 81 that is slidably disposed inside the tool holder 1. A docking plate 82 is installed on the upper end of the hollow shaft 81. An auxiliary sleeve plate 83 is fixedly sleeved on the lower side of the outer wall of the hollow shaft 81. A bidirectional positioning group 84 is jointly provided on the hollow shaft 81 and the collet 4.

[0037] The chip-blocking part 9 includes a receiving groove at the upper end of the nut 3 and a mating groove at the lower end of the mounting sleeve 6. Both the receiving groove and the mating groove are annular designs. The tool holder 1, the nut 3 and the mounting sleeve 6 are jointly provided with a side wall chip-blocking assembly 91. The bottom end of the nut 3 is also provided with several mounting grooves that are evenly distributed in a circle. The nut 3 and several mounting grooves are jointly provided with a bottom chip-blocking assembly 92.

[0038] The bidirectional positioning group 84 includes several receiving cavities located in the middle of the inner wall of the collet 4. The several receiving cavities are evenly distributed in a circle. An alignment plate 841 is slidably installed on the inner wall of the receiving cavity by a compression spring. The lower end of the alignment plate 841 is wedge-shaped on the side near the milling cutter body 5, and the outer walls on both sides of the alignment plate 841 are rounded.

[0039] The bidirectional positioning assembly 84 also includes a pressure plate 842 installed at the lower end of the hollow shaft 81, and an alignment rod 843 is installed at the middle of the lower end of the pressure plate 842.

[0040] The sidewall chip-blocking assembly 91 includes an annular sealing plate 911 slidably installed on the inner wall of the mating groove. Several waist-shaped sliding holes communicating with the trumpet-shaped cavity of the tool holder 1 are opened on the inner wall of the mounting sleeve 6 and the outer wall of the tool holder 1. The several waist-shaped sliding holes are evenly distributed around the circumference. A connecting rod 912 is slidably installed on the inner wall of the waist-shaped sliding holes. The connecting rod 912 has an L-shaped structure. The vertical section of the annular sealing plate 911 is fixedly connected to the annular sealing plate 911, and the horizontal section of the connecting rod 912 is fixedly connected to the outer wall of the pressure plate 842.

[0041] The bottom chip-blocking assembly 92 includes a locking plate 921 that is slidably mounted on the inner wall of several mounting grooves by compression springs. The bottom end of the nut 3 is magnetically connected to a magnetic sealing plate 922. The outer wall of the magnetic sealing plate 922 is simultaneously movably attached to the inner wall of several locking plates 921, and the inner wall of the locking plate 921 is movably sleeved on the outer wall of the milling cutter body 5.

[0042] The outer wall of the milling cutter body 5 is provided with alignment grooves corresponding to several receiving cavities. The insertion ends of several alignment plates 841 are respectively movably attached to the inner wall of the corresponding alignment groove. The upper end of the milling cutter body 5 is chamfered, and a circular slot is provided in the middle of the upper end of the milling cutter body 5. The outer wall of the pressure plate 842 is movably attached to the inner wall of the circular slot.

[0043] A compression rod 21 is installed at the lower end of the rivet 2. The lower end of the compression rod 21 is a hemispherical structure and is movably attached to the mating plate 82.

[0044] The inner wall of the circular cavity of the tool holder 1 is symmetrically provided with limiting grooves, and the outer wall of the hollow shaft 81 is symmetrically provided with limiting slide bars 811. The limiting slide bars 811 on both sides are slidably connected to the inner wall of the corresponding limiting grooves. The auxiliary sleeve 83 is connected to the support plate 7 by several compression springs.

[0045] In practice:

[0046] First, when the hollow shaft 81 and auxiliary sleeve 83 in this application are not assembled, the hollow shaft 81 is initially located on the upper side of the circular cavity of the tool holder 1 under the action of the compression spring. At this time, the upper end of the auxiliary sleeve 83 is tightly attached to the inner wall of the upper end of the trumpet-shaped cavity of the tool holder 1, and the upper end of the pressure plate 842 is tightly attached to the support plate 7.

[0047] During the assembly stage of the collet 4 and the milling cutter body 5, it should be noted that the snap-fit ​​connection between the collet 4 and the nut 3 is existing technology and will not be described in detail here. First, the worker snaps the collet 4 into the nut 3, and then the milling cutter body 5 is installed into the collet 4. It should be noted that, in order to ensure the stability, safety and machining quality of the milling process, when installing the milling cutter body 5 through the collet 4, the end of the milling cutter body 5 is usually not allowed to extend beyond the collet 4. If the end of the milling cutter body 5 extends beyond the collet 4, it means that the effective clamping length of the milling cutter body 5 in the collet 4 is shortened, which will lead to a decrease in clamping force and also a decrease in the rigidity of the milling cutter body 5 and an increase in vibration.

[0048] During the insertion of the milling cutter body 5 into the collet 4, the operator can manually seal the end of the collet 4 to prevent the end of the milling cutter body 5 from exceeding the end of the collet 4, thus performing initial positioning. Under the action of the compression spring, several alignment plates 841 will initially extend out of their corresponding receiving cavities. As the milling cutter body 5 passes the alignment plates 841, the chamfered structure at the upper end of the milling cutter body 5 will simultaneously press against the alignment plates 841, causing them to retract into their respective receiving cavities for clearance. Once the end of the milling cutter body 5 is flush with the end of the collet 4, the operator can manually rotate the milling cutter body 5 to a suitable angle until the receiving cavities align with the alignment slots on the milling cutter body 5. At this point, under the action of the compression spring, the alignment plates 841 will... The collet 4 extends out of the corresponding receiving cavity and is inserted into the corresponding alignment slot. It should be noted that at this time, the length of the wedge-shaped structure at the bottom of the alignment plate 841 is shorter than the length of the alignment slot, thereby realizing the quick engagement of the collet 4 and the milling cutter body 5. This avoids the serious safety hazards caused by unstable clamping, such as shaking, slippage, or even flying out when the milling cutter body 5 is rotating at high speed. At the same time, during the milling process, the milling cutter body 5 will generate a large downward pull, avoiding the risk of the collet 4 being pulled out due to insufficient clamping force, which could lead to overcutting of the workpiece, resulting in poor machining or even scrap. In addition, the compression springs on several alignment plates 841 can also buffer the vibration generated by the milling cutter body 5 during the milling process, making the cutting process smoother and further reducing the positional fluctuation between the milling cutter and the workpiece.

[0049] After the collet 4 and the cutter body 5 have completed the clamping operation, the operator continues to install the nut 3 at the lower end of the tool holder 1 via a threaded connection. At this time, the nut 3 will drive the collet 4 to slide into the tool holder 1 along the inner wall of the trumpet-shaped cavity. As the nut 3 continues to screw in, the collet 4 will be subjected to the squeezing force of the trumpet-shaped cavity of the tool holder 1 and gradually lock towards the outer wall of the cutter body 5 until the collet 4 completes the clamping operation of the cutter body 5. At this time, the cutter body 5 cannot rotate. With the clamping effect of several alignment plates 841, the clamping and positioning fixture of the cutter body 5 can be realized, and it can prevent the axial movement of the cutter body 5. This avoids the problem that in the conventional assembly method, the collet 4 and the cutter body 5 only have a single end face contact, which can easily cause axial movement due to thermal deformation or mechanical stress, seriously affecting the accuracy of deep hole machining or stepped surface milling.

[0050] During the assembly stage of the pull stud 2, the worker installs the pull stud 2 on the upper end of the tool holder 1 via a threaded connection. At this time, the pull stud 2 will drive the pressing rod 21 to slide into the tool holder 1 along the inner wall of the circular cavity. As the pull stud 2 continues to screw in, the mating plate 82 will be subjected to the pressing force of the pressing rod 21 and gradually slide downward along the inner wall of the circular cavity of the tool holder 1. At this time, the mating plate 82 will simultaneously drive the hollow shaft 81, the limiting slide strips 811 on both sides, the auxiliary sleeve plate 83, and the pressure plate 842 to move downward synchronously. During this period, the limiting slide strips 811 on both sides will slide along the corresponding limiting slide grooves until the pull stud 2 is installed and tightly fitted to the upper end of the tool holder 1. At this time, the several compression springs between the auxiliary sleeve plate 83 and the support plate 7 will be compressed. In this state, the pressure plate 842 will also drive the alignment rod 843 to move downwards synchronously, so that the alignment rod 843 is inserted into the circular slot at the upper end of the milling cutter body 5. At the same time, the lower end face of the pressure plate 842 will also be tightly attached to the collet 4 and the upper end of the milling cutter body 5. This achieves the effect of radially limiting the milling cutter body 5 through the alignment rod 843 and further axially limiting the milling cutter body 5 through the pressure plate 842. This effectively prevents the milling cutter body 5 from moving upwards and avoids the conventional one-way positioning or simple guide structure positioning method of the milling cutter body 5. Under the high-speed rotation centrifugal force and intermittent cutting impact, the tool is prone to micro-slippage on the conical surface of the tool holder 1, resulting in increased radial runout deviation and causing machining vibration and machining dimension fluctuation problems.

[0051] It should be noted that before the pull stud 2 is installed, the upper end of the pressure plate 842 is initially tightly attached to the support plate 7. At this time, the annular sealing plate 911 retracts into the matching groove on the mounting sleeve plate 6. During the installation of the pull stud 2, the pressure plate 842 will drive several connecting rods 912 to move downward synchronously. The several connecting rods 912 will jointly drive the annular sealing plate 911 to move downward synchronously with the pressure plate 842. During this period, the several connecting rods 912 will slide along the inner wall of the corresponding waist-shaped sliding hole until the lower end of the annular sealing plate 911 is inserted into the receiving groove on the nut 3. This achieves the effect of chip protection at the threaded connection between the tool holder 1 and the nut 3 through the annular sealing plate 911, preventing the chips generated during the machining process from entering the nut 3 through the threaded connection, causing thread damage and nut 3 jamming. It should also be noted that the receiving groove on the nut 3 is deep enough to accommodate the height difference caused by different screwing depths of the nut 3, avoiding the phenomenon of the annular sealing plate 911 being blocked during insertion.

[0052] Because the gap in the collet 4 is small and its location is concealed, it is one of the key paths for chip intrusion, and the chips that enter are often difficult to clean. The operator places a magnetically attached sealing plate 922 of the appropriate size onto the end mill body 5 and presses it against the lower end of the nut 3 until the magnetically attached sealing plate 922 is magnetically connected to the lower end of the nut 3. During this process, the magnetically attached sealing plate 922 will simultaneously compress several locking plates 921, causing them to slide along their corresponding mounting grooves to avoid interference. After the magnetically attached sealing plate 922 is magnetically connected to the lower end of the nut 3, the locking plates 921 will, under the action of the compression springs, slide along their respective mounting grooves. The inner sliding returns to its original position and together clamps and limits the outer wall of the magnetic sealing plate 922, further preventing the magnetic sealing plate 922 from falling off. At this time, the magnetic sealing plate 922 can achieve the effect of chip protection for the lower end of the collet 4, preventing the chips generated during the processing from entering the inside of the collet 4 through the gaps, and preventing the long-term accumulation of chips from causing a decrease in the clamping accuracy of the collet 4. In addition, the annular sealing plate 911 and the magnetic sealing plate 922 respectively protect the collet 4 and the nut 3 from chips, avoiding the problem of spending a lot of time manually disassembling to clean the chips and impurities inside the nut 3 and the collet 4.

[0053] During the disassembly phase, the workers first manually disassemble the pull stud 2 and nut 3 through the threaded connection. At this time, the collet 4 will follow and exit into the tool holder 1, releasing the clamping and limiting effect on the milling cutter body 5. Since the outer walls on both sides of the alignment plate 841 are rounded, the workers then manually rotate the milling cutter body 5 to a suitable angle. The milling cutter body 5 will press against the two side walls of the alignment plate 841, causing it to retract into the corresponding receiving cavity to avoid obstruction. The milling cutter body 5 can then be removed. After the pull stud 2 is disassembled, under the action of the compression spring, the hollow shaft 81 will drive the docking plate 82 to slide upward synchronously to the upper side of the circular cavity of the tool holder 1 to return to its original position. At this time, the upper end of the auxiliary sleeve plate 83 will also tightly fit against the inner wall of the upper end of the trumpet-shaped cavity of the tool holder 1 to return to its original position. The upper end of the pressure plate 842 will tightly fit against the support plate 7 to return to its original position. With the left and right support of several connecting rods 912, the annular sealing plate 911 will also retract into the matching groove on the mounting sleeve plate 6 to return to its original position.

[0054] In summary, this application has the following advantages:

[0055] Advantage 1: During the assembly stage of the collet 4 and the milling cutter body 5, when the milling cutter body 5 passes through several alignment plates 841, the chamfered structure at the upper end of the milling cutter body 5 will simultaneously press against the alignment plates 841, causing them to retract into their corresponding receiving cavities for clearance. Once the end of the milling cutter body 5 is flush with the end of the collet 4, the operator manually rotates the milling cutter body 5 to a suitable angle until the receiving cavities align with the alignment slots on the milling cutter body 5. The alignment plates 841 will then extend out of their corresponding receiving cavities and insert into their respective alignment slots, thus achieving collet alignment. The quick-connection mechanism between the collet 4 and the milling cutter body 5 prevents the milling cutter body 5 from shaking, slipping, or even flying out due to unstable clamping during high-speed milling, which could pose serious safety hazards. At the same time, during the milling process, the milling cutter body 5 generates a large downward pull, preventing the collet 4 from being pulled out due to insufficient clamping force, which could lead to overcutting of the workpiece, resulting in poor machining or even scrap. In addition, the compression springs on several alignment plates 841 can also buffer the vibration generated by the milling cutter body 5 during milling, making the cutting process smoother and further reducing the positional fluctuation between the milling cutter and the workpiece.

[0056] Secondly, after the collet 4 and the milling cutter body 5 have completed the clamping operation, the operator continues to install the nut 3 at the lower end of the tool holder 1 via a threaded connection. As the nut 3 is continuously screwed in, the collet 4 will be subjected to the squeezing force of the trumpet-shaped cavity of the tool holder 1 and gradually lock towards the outer wall of the milling cutter body 5 until the collet 4 completes the clamping operation of the milling cutter body 5. With the clamping effect of several alignment plates 841, the clamping and positioning fixture of the milling cutter body 5 can be realized, and it can prevent the milling cutter body 5 from moving axially. This avoids the problem in conventional assembly methods where the collet 4 and the milling cutter body 5 only have a single end face contact, which can easily cause axial movement due to thermal deformation or mechanical stress, seriously affecting the accuracy of deep hole machining or stepped surface milling.

[0057] Thirdly, during the assembly stage of the pull stud 2, the worker installs the pull stud 2 on the upper end of the tool holder 1 through a threaded connection. As the pull stud 2 is continuously screwed in, the mating plate 82 will be subjected to the extrusion force of the extrusion rod 21 and gradually slide downward along the inner wall of the circular cavity of the tool holder 1. The pressure plate 842 will also drive the alignment rod 843 to move downward synchronously, so that the alignment rod 843 is inserted into the circular slot at the upper end of the milling cutter body 5. At the same time, the lower end face of the pressure plate 842 will also be tightly attached to the collet 4 and the upper end of the milling cutter body 5. This achieves the effect of radially limiting the milling cutter body 5 through the alignment rod 843 and further axially limiting the milling cutter body 5 through the pressure plate 842. This effectively prevents the milling cutter body 5 from moving upward and avoids the conventional one-way positioning or simple guide structure positioning method for the milling cutter body 5. Under the high-speed rotation centrifugal force and intermittent cutting impact, the tool is prone to micro-slippage on the conical surface of the tool holder 1, resulting in increased radial runout deviation and causing problems such as machining vibration and machining dimensional fluctuation.

[0058] Fourthly, during the installation of the pull stud 2, the pressure plate 842 will drive several connecting rods 912 to move downwards synchronously. The several connecting rods 912 will jointly drive the annular sealing plate 911 to move downwards synchronously with the pressure plate 842 until the lower end of the annular sealing plate 911 is inserted into the receiving groove on the nut 3. This achieves the effect of chip protection at the threaded connection between the tool holder 1 and the nut 3 through the annular sealing plate 911, preventing chips generated during processing from entering the nut 3 through the threaded connection, causing thread damage and nut 3 jamming. The receiving groove on the nut 3 is deep enough to accommodate the height difference caused by different screwing depths of the nut 3, avoiding the phenomenon of the annular sealing plate 911 being blocked during insertion.

[0059] Fifthly, the operator places the appropriately sized magnetic sealing plate 922 onto the milling cutter body 5 and presses it down onto the lower end of the nut 3 until the magnetic sealing plate 922 is magnetically connected to the lower end of the nut 3. During this process, the magnetic sealing plate 922 will simultaneously press against several locking plates 921 to prevent them from falling off. After the magnetic sealing plate 922 is magnetically connected to the lower end of the nut 3, the locking plates 921 will work together to clamp and limit the outer wall of the magnetic sealing plate 922, further preventing the magnetic sealing plate 922 from falling off. The magnetic sealing plate 922 can effectively protect the lower end of the collet 4 from chips, preventing chips generated during processing from entering the collet 4 through the gaps and avoiding the problem that long-term accumulation of chips may lead to a decrease in the clamping accuracy of the collet 4. In addition, the annular sealing plate 911 and the magnetic sealing plate 922 respectively protect the collet 4 and the nut 3 from chips, avoiding the problem of spending a lot of time manually disassembling and cleaning chips and impurities from the inside of the nut 3 and the collet 4.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A CNC milling cutter based on a bidirectional positioning structure, characterized in that, include: The tool holder (1) has an inner wall consisting of a circular cavity and a trumpet-shaped cavity. The upper end of the tool holder (1) is connected to a pull stud (2) by a thread. The lower end of the tool holder (1) is connected to a nut (3) by a thread. A collet (4) is engaged in the nut (3). The milling cutter body (5) is rotatably installed inside the collet (4). A mounting plate (6) is fixedly sleeved on the lower side of the outer wall of the tool holder (1). A support plate (7) is installed in the middle of the inner wall of the tool holder (1). A bidirectional positioning part (8) is provided on both the tool holder (1) and the collet (4). A chip-blocking part (9) is provided on both the tool holder (1), the nut (3) and the mounting plate (6). The bidirectional positioning part (8) includes a hollow shaft (81) that is slidably disposed inside the tool holder (1). A docking plate (82) is installed on the upper end of the hollow shaft (81). An auxiliary sleeve plate (83) is fixedly sleeved on the lower side of the outer wall of the hollow shaft (81). A bidirectional positioning group (84) is provided on both the hollow shaft (81) and the collet (4). The chip-blocking part (9) includes a receiving groove at the upper end of the nut (3), a matching groove at the lower end of the mounting plate (6), a side wall chip-blocking assembly (91) on the tool holder (1), the nut (3) and the mounting plate (6), and a number of mounting grooves evenly distributed in a circle at the bottom end of the nut (3), and a bottom chip-blocking assembly (92) on the nut (3) and the number of mounting grooves.

2. A CNC milling cutter based on a bidirectional positioning structure according to claim 1, characterized in that: The bidirectional positioning group (84) includes several receiving cavities located in the middle of the inner wall of the collet (4). The several receiving cavities are evenly distributed in a circle, and the inner wall of the receiving cavity is slidably installed with a positioning plate (841) by a compression spring.

3. A CNC milling cutter based on a bidirectional positioning structure according to claim 2, characterized in that: The bidirectional positioning group (84) also includes a pressure plate (842) installed at the lower end of the hollow shaft (81), and an alignment rod (843) is installed at the middle of the lower end of the pressure plate (842).

4. A CNC milling cutter based on a bidirectional positioning structure according to claim 1, characterized in that: The sidewall chip-blocking assembly (91) includes an annular sealing plate (911) that is slidably installed on the inner wall of the sliding groove. Several waist-shaped sliding holes that communicate with the trumpet-shaped cavity of the tool handle (1) are opened on the inner wall of the mounting sleeve (6) and the outer wall of the tool handle (1). The several waist-shaped sliding holes are evenly distributed in a circle. A connecting rod (912) is slidably installed on the inner wall of the waist-shaped sliding hole. The connecting rod (912) has an L-shaped structure. The vertical section of the annular sealing plate (911) is fixedly connected to the annular sealing plate (911), and the horizontal section of the connecting rod (912) is fixedly connected to the outer wall of the pressure plate (842).

5. A CNC milling cutter based on a bidirectional positioning structure according to claim 1, characterized in that: The bottom chip-blocking assembly (92) includes a locking plate (921) that is slidably installed on the inner wall of several mounting grooves by compression springs. The bottom end of the nut (3) is magnetically connected to a magnetic sealing plate (922). The outer wall of the magnetic sealing plate (922) is simultaneously movably attached to the inner wall of several locking plates (921), and the inner wall of the locking plate (921) is movably sleeved on the outer wall of the milling cutter body (5).

6. A CNC milling cutter based on a bidirectional positioning structure according to claim 1, characterized in that: The milling cutter body (5) has several accommodating cavities on its outer wall, and the insertion ends of several alignment plates (841) are movably attached to the inner wall of the corresponding alignment groove. A circular slot is provided in the middle of the upper end of the milling cutter body (5), and the outer wall of the pressure plate (842) is movably attached to the inner wall of the circular slot.

7. A CNC milling cutter based on a bidirectional positioning structure according to claim 1, characterized in that: The lower end of the rivet (2) is equipped with a compression rod (21), the lower end of the compression rod (21) is a hemispherical structure and is movably attached to the mating plate (82).

8. A CNC milling cutter based on a bidirectional positioning structure according to claim 4, characterized in that: The tool holder (1) has symmetrically opened limit grooves on the inner wall of the circular cavity, and the hollow shaft (81) has symmetrically installed limit strips (811) on the outer wall. The limit strips (811) on both sides are slidably connected to the inner wall of the corresponding limit groove. The auxiliary sleeve (83) is connected to the support plate (7) by several compression springs.

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