A split damping vibration reduction milling cutter for valve body machining

Abstract

The invention discloses a split damping vibration reduction milling cutter for valve body processing, comprising a cutter head, a cutter bar, a damping gasket, and a connecting piece; the cutter head is provided with a cutter head cavity, and a cutter head connecting tooth is provided at the tail; the cutter bar head is provided with a cutter bar connecting tooth, and a threaded inner hole is provided at the axial position; the cutter head tail is plugged and matched with the cutter bar head; after plugging, there is a gap between the adjacent cutter head connecting tooth and the cutter bar connecting tooth side to place the damping gasket; the connecting piece is composed of a self-locking screw and a washer, the self-locking screw passes through the washer and the cutter head cavity, and is connected and locked with the cutter bar threaded inner hole of the cutter bar head with a certain size of axial preload force. By setting the size of the axial preload force, when the split damping vibration reduction milling cutter exceeds a specific torque during the valve body milling process, the cutter head and the cutter bar produce relative rotation, compress the damping gasket, suppress the impact vibration of the tool, reduce the risk of blade chipping, and at the same time disrupt the frequency of the milling force, suppress the occurrence of cutting chatter, and improve the processing quality.

Description

Technical Field

[0001] The invention belongs to the technical field of milling cutters, and in particular relates to a split damping and vibration-reducing milling cutter for valve body machining. Background Art

[0002] Valve body parts usually involve milling of structural features such as holes, grooves, and cavities. During the milling process, the milling cutter is subjected to alternating loads in the cutter head part, and the alternating loads force the milling cutter to vibrate. Due to the large overhang depth of the milling cutter, the static stiffness of the cutter body itself is low, and the amplitude of the cutter head increases, causing the machined surface to fail to meet the surface roughness requirements of the part. In addition, when the frequency of the alternating load is close to the natural frequency of the milling cutter itself, cutting chatter will also occur, which will greatly increase the vibration amplitude of the milling cutter, affect the processing accuracy, and reduce the service life of the machine tool and the tool. At the same time, the alternating load of the cutter head part causes a large impact on the blade, causing sudden damage such as chipping and breakage of the blade, resulting in downtime for blade replacement and even damage to the workpiece surface. Therefore, how to reduce the vibration of the milling cutter processing process is a key and difficult problem in ensuring the processing quality during metal milling.

[0003] The existing technology measures for reducing vibration during the milling cutter machining process and their limitations are as follows:

[0004] 1. Inlay carbide material

[0005] Vibration reduction measures: embed high-rigidity and high-strength carbide materials in parallel on both sides of the tool bar to improve static stiffness.

[0006] Limitations: Due to the influence of the stiffness and thickness of the two reinforcement materials and the degree of their bonding with the cutter body, the aspect ratio of this type of tool bar will also be subject to certain restrictions. It is generally suitable for processing occasions with relatively small milling forces.

[0007] 2. Reduce the weight of the cutter head

[0008] Vibration reduction measures: Reduce the weight of the cutter head with very little impact on static stiffness.

[0009] Limitations: The head resection method itself has great limitations, and its aspect ratio cannot be very large.

[0010] 3. Optimize the geometry of the cutting edge

[0011] Vibration reduction measures: The cutting edge of the cutter head adopts special geometric shapes such as variable helix angle and variable tooth angle to disrupt the frequency of milling force and suppress the occurrence of cutting chatter.

[0012] Limitations: The grinding method of cutting edges with special geometric shapes such as variable helix angle and variable tooth angle is complicated, the cutting edge accuracy detection is very difficult, and it is very difficult to regrind the tool after wear, resulting in high tool costs.

[0013] 4. Install a vibration damping block inside the tool bar

[0014] Vibration reduction measures: remove part of the material at the front end of the tool rod to obtain a cavity, and install an elastomer and a mass block in it to form an impact vibration reduction device.

[0015] Limitations: The size of the damping block is limited by the size of the tool bar, and the tool life is also severely limited by the life of the damper.

[0016] 5. Add vibration-damping particles inside the tool bar

[0017] Vibration reduction measures: remove a part of the front end of the tool rod to obtain a cavity, add granular material inside it, and use the collision and friction between the particles to consume the vibration energy.

[0018] Limitations: The vibration reduction effect of damping is related to factors such as cavity size, filling ratio, and particle type. However, there is no perfect theoretical model for particle damping characteristics; the contact force of particles during movement cannot be measured, and only approximate values ​​can be obtained indirectly through simulation, which cannot accurately obtain a good vibration reduction effect.

[0019] In addition, when processing the structural features of the valve body, a number of blades circumferentially arranged at the tail of the cutter head cut in and out of the workpiece as the cutter head rotates to remove material. During the process, the workpiece applies a periodic milling force to the blade, that is, for any blade, the milling cutter rotates one circle, the blade cuts in and out of the workpiece once, and is subjected to a cycle of milling force impact. During the high-speed rotation of the milling cutter, the blade is subjected to periodic impacts, among which the impact load in the tangential direction, that is, the tangential milling force, is the main cause of tool breakage and chipping. None of the above milling cutter vibration reduction methods in the prior art can accurately and actively reduce the impact load in tool processing, and there are certain limitations on the protection of the tool. Summary of the invention

[0020] The purpose of the present invention is to provide a split damping vibration reduction milling cutter for valve body machining in view of the above-mentioned deficiencies in the prior art, so as to solve or improve the above-mentioned problems.

[0021] In order to achieve the above object, the technical solution adopted by the present invention is:

[0022] A split damping and vibration-reducing milling cutter for valve body machining, characterized in that it comprises: a cutter head, a cutter bar, a blade, and a connecting piece; the cutter head and the cutter bar are both cylindrical structures, the cross sections of the cutter head and the cutter bar are both circular cross sections, and the cutter head and the cutter bar are coaxially arranged; the tail of the cutter head is connected to the head of the cutter bar, and a plurality of blades are circumferentially arranged at the head of the cutter head;

[0023] The cutter head is provided with a cutter head cavity, which is arranged in the cutter head along the cutter head axis direction, and the cutter head tail is provided with a cutter head connecting tooth, and a plurality of cutter head connecting teeth are distributed at intervals along the circumferential direction of the circular cross section of the cutter head tail, and the adjacent two sides of any cutter head connecting tooth are cutter head connecting grooves;

[0024] A tool rod threaded inner hole is provided at the tool rod axis position, the tool rod threaded inner hole extends from the tool rod head along the tool rod axis to the tool rod tail, the tool rod threaded inner hole is a blind hole, the tool rod head is provided with tool rod connecting teeth, a plurality of tool rod connecting teeth are distributed at intervals along the circumferential direction of the circular cross section of the tool rod head, and the adjacent two sides of any tool rod connecting tooth are tool rod connecting grooves;

[0025] The tail of the cutter head is plugged into the head of the cutter bar, the cutter head connecting teeth are plugged into the cutter bar connecting groove, and the cutter bar connecting teeth are plugged into the cutter head connecting groove; after plugging, the two sides of any cutter head connecting teeth are cutter bar connecting teeth, and the two sides of any cutter bar connecting teeth are cutter head connecting teeth; after plugging, there is a gap between the side surfaces of the adjacent cutter head connecting teeth and the cutter bar connecting teeth, and a damping gasket is placed in the gap; a number of axial end faces at the connection and matching place between the cutter head connecting teeth and the cutter bar connecting groove, and a number of axial end faces at the connection and matching place between the cutter head connecting groove and the cutter bar connecting teeth, together constitute a circular axial end face;

[0026] The connecting piece includes a self-locking screw and a washer, wherein the self-locking screw passes through the washer and the cutter head cavity and the cutter rod threaded inner hole of the cutter rod head;

[0027] Apply axial preload to the self-locking screw, and the annular axial end surface at the connection between the cutter head and the cutter rod generates static friction under the action of the axial preload. The axial preload of the self-locking screw is determined according to the tangential milling force in the machining process, so that when the torque generated by the tangential milling force exceeds the friction torque generated by the axial preload, the cutter head and the cutter rod generate relative rotation, and the adjacent cutter head connecting teeth and the cutter rod connecting teeth squeeze the damping gasket in the gap.

[0028] In order to ensure that the damping gasket performs compression damping near the peak value of the tangential milling force and reduce the peak value of the tangential milling force, the method for determining the axial preload force F is as follows. The axial end surface of the connection between the cutter head connecting teeth and the cutter bar connecting teeth generates static friction under the action of the axial preload force, and the maximum torque M that can be generated by the static friction is controlled. f The maximum torque M generated by the tangential milling force during milling is reached F_max When the cutter head connecting teeth and the cutter bar connecting teeth rotate relative to each other, the damping gasket is compressed for damping, that is, M f and M F_max The equation must be satisfied: M f =0.8M F_max .

[0029] The maximum torque M generated by the tangential milling force during milling F_max The calculation formula is: F_max=F t_max R, where F t_max is the maximum value of the tangential milling force in the milling process, and R is the outer radius of the cutter head circular section.

[0030] The several axial end faces where the cutter head connecting teeth and the cutter bar connecting grooves are connected and matched, and the several axial end faces where the cutter head connecting grooves and the cutter bar connecting teeth are connected and matched, together constitute an annular axial end face. The annular axial end face generates static friction under the action of the axial preload force. The inner diameter of the annular axial end face is the outer circle radius R' of the cutter head annular cross section, and the outer diameter of the annular axial end face is the outer circle radius R of the cutter head annular cross section. The maximum torque M that can be generated by the static friction force is f The calculation formula is: , where R' is the inner radius of the cutter head ring section, dM is the friction torque of the torus surface microelement with an inner radius of r and a width of dr in the annular axial end face, where dr approaches infinitesimal; the friction torque formula of the torus surface microelement is: dM=rμdF, where μ is the friction coefficient, and dF is the positive pressure of the torus surface microelement; the positive pressure formula of the torus surface microelement is: dF=PdS, where P is the pressure of the torus surface, and dS is the microelement area; the microelement area formula is: dS=π(r+dr) 2 -πr 2 =2πrdr+π(dr) 2 =2πrdr; the pressure formula on the torus is: P=F / π(R 2 −R' 2 ), where F is the axial preload, R is the outer radius of the cutter head ring section, and R' is the inner radius of the cutter head ring section; it can be calculated , the obtained M f Substitute the above M f and M F_max The equation must be satisfied: M f =0.8M F_max =0.8F t_max R, the value of the axial preload F is: F=1.2F t_max R(R 2 −R' 2 ) / μ(R 3 −R' 3 ).

[0031] Preferably, the maximum value of the tangential milling force in the milling process is calculated by cutting force theory.

[0032] Preferably, the maximum value of the tangential milling force in the milling process is obtained from historical milling force monitoring data in previous processes.

[0033] Preferably, the tool head height is as small as possible without interfering with the cutting process to increase tool rigidity.

[0034] Preferably, the diameter of the cutter head cavity is 1 mm to 2 mm larger than the diameter of the self-locking screw.

[0035] Preferably, the damping gasket material is damping alloy or rubber.

[0036] Preferably, the cutter head and the cutter bar are made of tool steel or hard alloy, and the self-locking screw and the washer are made of carbon steel or stainless steel.

[0037] The present invention provides a split type damping vibration reduction milling cutter for valve body machining, which has the following beneficial effects:

[0038] 1. Set the preload force of the cutter head and the tool bar connector according to the tangential milling force, so that the damping gasket between the split damping and vibration-reducing milling cutter head and the tool bar is compressed and damped near the peak value of the tangential milling force, so as to accurately and reliably reduce the peak value of the tangential milling force and reduce the impact load of the blade during the tool processing process, so as to ensure the processing quality and improve the tool life.

[0039] 2. The present invention accurately calculates the preload force according to the size of the cutting force, so that the damping gasket is only compressed when the torque exceeds the limit. While ensuring the vibration reduction effect of the tool, the service life of the damping gasket is increased, the tool installation accuracy error caused by frequent disassembly and replacement of the gasket is reduced, the processing efficiency is improved, and the cost is saved.

[0040] 3. Since the relative rotation between the cutter head and the cutter bar compresses the damping gasket, the dynamic process of the blade cutting in and out of the workpiece is changed, thus disrupting the frequency of the milling force and suppressing the occurrence of cutting chatter.

[0041] 4. The toothed cutter head and cutter rod connection method improves the torsion and shear resistance of the connection and has high connection stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic diagram of the structure of a split-type damping and vibration-reducing milling cutter for valve body machining provided by the present invention.

[0043] Figure 2 It is a schematic diagram of the cutter head circular ring cross section and circular ring infinitesimal element.

[0044] Figure 3 Schematic diagram of the change of tangential milling force with tool rotation angle in milling processing using a non-vibration-damping milling cutter.

[0045] Figure 4 Schematic diagram of the change of tangential milling force with the tool rotation angle in milling processing using a split damping vibration reduction milling cutter.

[0046] Markings in the figure: 1-cutter head, 2-cutter rod, 3-damping gasket, 4-connecting piece, 5-cutter head cavity, 6-cutter head connecting teeth, 7-cutter rod connecting teeth, 8-threaded inner hole of the cutter rod, 9-self-locking screw, 10-washer, 11-blade, 12-annular axial end face. DETAILED DESCRIPTION

[0047] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0048] A split damping vibration reduction milling cutter for valve body machining, such as Figure 1 As shown, it includes: a cutter head 1, a cutter bar 2, blades 11, and a connecting piece 4. The cutter head 1 and the cutter bar 2 are both cylindrical structures, and the cross sections of the cutter head 1 and the cutter bar 2 are both circular cross sections. The cutter head 1 and the cutter bar 2 are coaxially arranged. The tail of the cutter head 1 is connected to the head of the cutter bar, and a plurality of blades 11 are circumferentially arranged at the head of the cutter head.

[0049] The cutter head 1 is provided with a cutter head cavity 5, which is arranged in the cutter head 1 along the cutter head axis direction. The tail of the cutter head 1 is provided with a cutter head connecting tooth 6, and a plurality of cutter head connecting teeth 6 are distributed at intervals along the circumferential direction of the circular cross-section of the tail of the cutter head 1. The adjacent two sides of any cutter head connecting tooth 6 are cutter head connecting grooves.

[0050] A shank threaded inner hole 8 is provided at the axial position of the shank 2, and the shank threaded inner hole 8 extends from the head of the shank 2 along the shank axis to the tail of the shank. The shank threaded inner hole 8 is a blind hole. A shank connecting tooth 7 is provided at the head of the shank 2. A plurality of shank connecting teeth 7 are circumferentially spaced along the circular cross-section of the head of the shank 2, and the adjacent two sides of any shank connecting tooth 7 are shank connecting grooves.

[0051] The tail of the cutter head 1 is plugged into the head of the cutter bar 2, the cutter head connecting teeth 6 are plugged into the cutter bar connecting groove, and the cutter bar connecting teeth are plugged into the cutter head connecting groove. After plugging, the two sides of any cutter head connecting teeth 6 are cutter bar connecting teeth 7, and the two sides of any cutter bar connecting teeth 7 are cutter head connecting teeth 6. After plugging, there is a gap between the sides of the adjacent cutter head connecting teeth 6 and cutter bar connecting teeth 7, and the damping gasket 3 is placed in the gap. Several axial end faces at the connection and matching of the cutter head connecting teeth and the cutter bar connecting groove, and several axial end faces at the connection and matching of the cutter head connecting groove and the cutter bar connecting teeth, together constitute a circular axial end face 12.

[0052] The connecting member 4 includes a self-locking screw 9 and a washer 10. The self-locking screw 9 passes through the washer 10 and the cutter head cavity 5 and is connected to the cutter bar threaded inner hole 8 at the head of the cutter bar. An axial preload is applied to the self-locking screw 9, and the annular axial end face 12 at the connection point between the cutter head and the cutter bar generates a static friction force under the action of the axial preload. The axial preload of the self-locking screw is determined according to the tangential milling force during the machining process, so that when the torque generated by the tangential milling force exceeds the maximum static friction torque generated by the axial preload, the cutter head 1 and the cutter bar 2 generate relative rotation, and the adjacent cutter head connecting teeth 6 and the cutter bar connecting teeth 7 squeeze the damping gasket 3 in the gap, thereby suppressing the impact vibration of the milling cutter and reducing the risk of chipping of the blade 11. At the same time, the frequency of the milling force is disrupted to avoid the occurrence of cutting chatter.

[0053] Working principle: When the milling cutter rotates for milling, the blade 11 on the circumference of the head of the cutter head 1 cuts into the workpiece and is subjected to the milling force applied by the workpiece. The tangential milling force generates torque, which causes a tendency for relative rotation between the cutter head 1 and the tool bar 2. The axial preload provided by the self-locking screw 9 causes the annular axial end surface at the connection between the cutter head 1 and the tool bar 2 to generate a static friction torque that prevents relative rotation. When the torque generated by the tangential milling force increases normally and exceeds the maximum static friction torque, the cutter head 1 and the tool bar 2 generate a momentary slight relative rotation, and the tool bar connecting teeth and the cutter head connecting groove generate a momentary slight relative rotation. The adjacent cutter head connecting teeth 6 and tool bar connecting teeth 7 squeeze the damping gasket 3 in the gap to damp and reduce the impact force.

[0054] In order to accurately and reliably reduce the peak value of the tangential milling force and ensure that the damping gasket can effectively perform compression damping near the peak value of the tangential milling force, the axial preload F is determined as follows: the maximum torque M that can be generated by the static friction between the cutter head 1 and the tool rod 2 under the action of the axial preload f The maximum torque M generated by the tangential milling force during milling is reached F_max When the connecting teeth of the cutter head and the connecting teeth of the cutter bar rotate relative to each other, that is, M f and M F_max Must satisfy formula 1: M f =0.8M F_max .

[0055] like Figure 2 As shown, the outer radius of the cutter head circular ring section is R, the inner radius of the cutter head circular ring section is R', the inner radius of the circular ring surface infinitesimal element of the cutter head circular ring section is r, and the width is dr.

[0056] The maximum torque M generated by the tangential milling force during milling F_max The calculation formula is as follows: F_max =F t_max R, where F t_maxis the maximum value of the tangential milling force in the milling process, and R is the outer radius of the cutter head circular section.

[0057] The maximum torque M that can be generated by the static friction between the cutter head and the cutter rod under the action of axial preload f The calculation formula is as follows: , where R' is the inner radius of the cutter head circular ring section, dM is the friction torque of the circular ring microelement with a radius of r and a width of dr in the cutter head circular ring section; the friction torque formula of the circular ring microelement is Formula 4: dM=rμdF, where μ is the friction coefficient, and dF is the positive pressure of the circular ring microelement; the positive pressure formula of the circular ring microelement is Formula 5: dF=PdS, where P is the pressure of the circular ring, and dS is the area of ​​the microelement; the microelement area formula is Formula 6: dS=2πrdr; the pressure formula of the circular ring is Formula 7: P=F / π(R 2 −R' 2 ), where F is the axial preload, R is the outer radius of the cutter head ring section, and R' is the inner radius of the cutter head ring section; Substituting equations 6 and 7 into equation 5, substituting equation 5 into equation 4, and substituting equation 4 into equation 3, we can calculate equation 8: M f =2μF(R 3 −R' 3 ) / 3(R 2 −R' 2 ). Substituting equation 2 and equation 8 into equation 1, we get M f =2μF(R 3 −R' 3 ) / 3(R 2 −R' 2 ) = 0.8M F_max =0.8 F t_max R, from which the calculation formula of the axial preload F can be obtained: F=1.2F t_max R(R 2 −R' 2 ) / μ(R 3 −R' 3 ). That is, in order to reduce the peak value of the tangential milling force and ensure that the damping gasket can effectively perform compression damping near the peak value of the tangential milling force, the axial preload F applied to the self-locking screw 9 is 1.2F. t_max R(R 2 −R' 2 ) / μ(R 3 −R' 3 ).

[0058] Preferably, the height of the cutter head 1 is as small as possible without interfering with the cutting process, so as to increase the rigidity of the tool.

[0059] Preferably, the diameter of the cutter head cavity 5 is 1 mm to 2 mm larger than the diameter of the self-locking screw 9 .

[0060] Preferably, the arbor threaded inner hole 8 and the self-locking screw 9 can cooperate with each other to produce a self-locking effect.

[0061] Preferably, the cutter head connecting teeth 6 and the cutter bar connecting teeth 7 are of the same size, have a fan-shaped cross-section, are evenly distributed along the circumference, are convex and concave teeth that can be inserted into each other, and have a connecting tooth height of 20 mm to 30 mm.

[0062] Preferably, the side clearance between the cutter head connecting teeth 6 and the cutter rod connecting teeth 7 after being inserted into each other is 1 mm to 2 mm, so as to accommodate the damping gasket 3.

[0063] Preferably, the damping gasket 3 is made of damping alloy or rubber.

[0064] Preferably, the cutter head 1 and the cutter bar 2 are made of tool steel or cemented carbide.

[0065] Preferably, the self-locking screw 9 and the washer 10 are made of carbon steel or stainless steel.

[0066] Preferably, the maximum value of the tangential milling force in the milling process is calculated by the milling force theory;

[0067] Preferably, the maximum value of the tangential milling force in the milling process is obtained from historical milling force monitoring data in previous processes.

[0068] According to one embodiment of the present application, referring to Figure 1-Figure 2 , the above steps will be described in detail below.

[0069] The workpiece material is TC4 titanium alloy, the axial cutting depth is 0.5mm, the radial cutting depth is 15mm, the feed speed is 1500mm / min, the spindle speed is 1200r / min, the cutter head and the tool bar are made of tool steel, the friction coefficient between the tool steels under lubrication is 0.1, the outer diameter of the annular axial end face is 19mm, the inner diameter of the annular axial end face is 7mm, the cutter head connecting teeth and the tool bar connecting teeth are both 5 teeth of the same size, the diameter of the self-locking screw is 6mm, and the relationship between the tightening torque T of the self-locking screw and the axial preload F is measured by the strain method using a resistance strain gauge. F and T are approximately in direct proportion. The data fitting shows that the size relationship between F and T is: F=600T. The tangential milling force of the non-vibration-damping milling cutter changes with the tool rotation angle as shown in the figure. Figure 3 As shown, F t_max =608N, and the phase between the peaks of the tangential milling force is 90°, which can easily cause cutting chatter.

[0070] Substituting the above specific values ​​into equation 9, we can solve for the axial preload F=6639N, and the torque T=11N·m required to tighten the self-locking screw. Using a torque wrench to tighten the self-locking screw with a torque of 11N·m, we can obtain the change of the tangential milling force of the split damping milling cutter with the tool rotation angle as shown in the figure. Figure 4 As shown in the figure, the maximum tangential milling force in the milling process is 566N, and because the split damping and vibration-reducing milling cutter exceeds the specified torque during the milling process, the cutter head and the cutter rod produce relative displacement to compress the damping gasket, causing the tangential milling force to have multiple peaks when a single blade cuts in and out of the workpiece, disrupting the standard 90° phase between the peaks of the tangential milling force, that is, disrupting the frequency of the tangential milling force, thereby suppressing the occurrence of cutting chatter.

[0071] The above results indicate that the split damping and vibration-damping milling cutter designed by the present invention for valve body processing can reasonably set the size of the preload force so that when the split damping and vibration-damping milling cutter exceeds a specific torque during the milling process, the cutter head and the cutter rod produce relative displacement to compress the damping gasket, thereby suppressing the impact vibration of the tool and reducing the risk of blade chipping; at the same time, the frequency of the milling force can be disrupted, and the occurrence of cutting chatter can be suppressed, thereby improving the processing quality. In addition, damping for specific impacts prolongs the service life of the damping gasket while ensuring the vibration reduction effect.

[0072] Although the specific implementation of the invention is described in detail in conjunction with the drawings, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A split damping vibration reduction milling cutter for valve body machining, characterized in that: include: Cutting head, cutting rod, cutting blade, connecting parts; The cutter head and the cutter bar are both cylindrical structures, the cross sections of the cutter head and the cutter bar are both circular cross sections, the cutter head and the cutter bar are coaxially arranged, the tail of the cutter head is connected to the head of the cutter bar, and a plurality of blades are circumferentially arranged at the head of the cutter head; The cutter head is provided with a cutter head cavity, which is arranged in the cutter head along the cutter head axis direction, and the cutter head tail is provided with a cutter head connecting tooth, and a plurality of cutter head connecting teeth are distributed at intervals along the circumferential direction of the circular cross section of the cutter head tail, and the adjacent two sides of any cutter head connecting tooth are cutter head connecting grooves; A tool rod threaded inner hole is provided at the tool rod axis position, the tool rod threaded inner hole extends from the tool rod head along the tool rod axis to the tool rod tail, the tool rod threaded inner hole is a blind hole, the tool rod head is provided with tool rod connecting teeth, a plurality of tool rod connecting teeth are distributed at intervals along the circumferential direction of the circular cross section of the tool rod head, and the adjacent two sides of any tool rod connecting tooth are tool rod connecting grooves; The tail of the cutter head is plugged into the head of the cutter bar, the cutter head connecting teeth are plugged into the cutter bar connecting groove, and the cutter bar connecting teeth are plugged into the cutter head connecting groove; after plugging, the two sides of any cutter head connecting teeth are cutter bar connecting teeth, and the two sides of any cutter bar connecting teeth are cutter head connecting teeth; after plugging, there is a gap between the side surfaces of the adjacent cutter head connecting teeth and the cutter bar connecting teeth, and a damping gasket is placed in the gap; a number of axial end faces at the connection and matching place between the cutter head connecting teeth and the cutter bar connecting groove, and a number of axial end faces at the connection and matching place between the cutter head connecting groove and the cutter bar connecting teeth, together constitute a circular axial end face; The connecting parts include a self-locking screw and a washer. The self-locking screw passes through the washer, the cavity of the cutter head and the threaded inner hole of the cutter bar at the head of the cutter bar. An axial preload is applied to the self-locking screw, and the annular axial end surface at the connection between the cutter head and the cutter bar generates a static friction force under the action of the axial preload. The axial preload of the self-locking screw is determined according to the tangential milling force during the processing, so that when the torque generated by the tangential milling force exceeds the maximum static friction torque generated by the axial preload, the cutter head and the cutter bar generate relative rotation, and the adjacent cutter head connecting teeth and the cutter bar connecting teeth squeeze the damping gasket in the gap. In order to ensure that the damping gasket is compressed and damped near the peak moment of the tangential milling force and accurately reduce the peak value of the tangential milling force, the magnitude of the axial preload F is 1.2F. t_max R(R 2 −R' 2 ) / μ(R 3 −R' 3 ), where F t_max is the maximum tangential milling force in milling, R is the outer radius of the cutter head circular ring section, R' is the inner radius of the cutter head circular ring section, and μ is the friction coefficient.

2. A split damping and vibration reducing milling cutter for valve body machining according to claim 1, characterized in that: Maximum value of tangential milling force F in milling t_max It is obtained by cutting force theory calculation or from historical milling force monitoring data in previous processing.

3. A split damping and vibration reducing milling cutter for valve body machining according to claim 2, characterized in that: The axial preload force F is determined as follows: Controls the maximum torque M that can be generated by the static friction between the cutter head and the cutter bar under the action of the axial preload F f The maximum torque M generated by the tangential milling force during milling is reached F_max When the cutting force is 0.8 times of the original value, the connecting teeth of the cutter head and the connecting teeth of the cutter bar rotate relative to each other, reducing the peak value of the tangential milling force, that is, M f and M F_max Need to meet: M f =0.8M F_max ; The maximum torque M generated by the tangential milling force during milling F_max The calculation formula is: F_max =F t_max R, where F t_max is the maximum value of the tangential milling force in the milling process, and R is the outer radius of the cutter head circular ring section; The maximum torque M that can be generated by the static friction between the cutter head and the cutter bar under the action of axial preload f The calculation formula is: , where R' is the inner radius of the cutter head circular ring section, dM is the friction torque of the circular ring microelement with a radius of r and a width of dr in the cutter head circular ring section; The formula of friction torque on the torus microelement is: dM=rμdF, where μ is the friction coefficient and dF is the normal pressure on the torus microelement; The formula for the normal pressure on the infinitesimal element of a torus is: dF=PdS, where P is the pressure on the torus and dS is the area of ​​the infinitesimal element; The formula for the area of ​​a microelement is: dS=2πrdr; The formula for the pressure on the torus is: P = F / π (R 2 −R' 2 ), where F is the axial preload, R is the outer radius of the cutter head circular ring section, and R' is the inner radius of the cutter head circular ring section; Then we can calculate: M f =2μF(R 3 −R' 3 ) / 3(R 2 −R' 2 ) = 0.8M F_max =0.8 F t_max R; The calculation formula for the axial preload force F can be obtained: F=1.2F t_max R(R 2 −R' 2 ) / μ(R 3 −R' 3 ).

4. A split damping and vibration reducing milling cutter for valve body machining according to claim 3, characterized in that: The tool head height is as small as possible without interfering with the cutting process to increase tool rigidity.

5. A split damping and vibration reducing milling cutter for valve body machining according to claim 4, characterized in that: The diameter of the cutter head cavity is 1mm~2mm larger than the diameter of the self-locking screw.

6. A split damping and vibration reducing milling cutter for valve body machining according to claim 5, characterized in that: The damping gasket material is made of damping alloy or rubber.

7. According to the split damping vibration reduction milling cutter for valve body machining as described in claim 6, the cutter head and the cutter bar are made of tool steel or cemented carbide, and the self-locking screws and washers are made of carbon steel or stainless steel.

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