阅读说明：本技术 一种喷油嘴安装孔用金刚石复合铣刀 (Diamond composite milling cutter for oil nozzle mounting hole ) 是由 李晓 赵乐 于乔 邹建东 于 2019-10-28 设计创作，主要内容包括：一种喷油嘴安装孔用金刚石复合铣刀,涉及刀具包括刀体和刀柄,刀体由一级、二级和三级切削段组成,刀体和刀柄内设有冷却流道,一级切削段上的排屑槽内设有出水方向向前、与轴向呈10°-60°夹角的一级冲水孔,二级切削段上的排屑槽内设有出水方向向后、与轴向呈10°-45°夹角的二级冲水孔,三级切削段上的排屑槽内设有出水方向与轴向垂直的三级冲水孔；动平衡设计方法：在三维绘图软件中绘制刀具模型；确定刀具的重心坐标；设定重心坐标相区内排屑槽长度为变量；通过变量来调节重心坐标,选取使重心坐标靠近中心坐标最近的变量的数值为设计值。本发明冷却性能和排屑性能高、使用寿命长,动平衡精度高。(A kind of oil spray nozzle mounting hole uses the compound milling cutter of diamond, involve the cutter body and shank, the cutter body is made up of first, second grade and tertiary cutting section, there are cooling flow channels in cutter body and shank, there are first class flushing holes that the water outlet direction is forward, form 10-60 degrees of included angles with the axial in the chip groove on the first grade cutting section, there are second class flushing holes that the water outlet direction is backward, form 10-45 degrees of included angles with the axial in the chip groove on the second grade cutting section, there are tertiary flushing holes that the water outlet direction is perpendicular to axial in the chip groove on the tertiary cutting section; the dynamic balance design method comprises the following steps: drawing a tool model in three-dimensional drawing software; determining the barycentric coordinates of the cutter; setting the length of a chip groove in a barycentric coordinate phase region as a variable; and adjusting the barycentric coordinates through the variables, and selecting the numerical value of the variable which enables the barycentric coordinates to be close to the nearest to the barycentric coordinates as a design value. The invention has high cooling performance and chip removal performance, long service life and high dynamic balance precision.)

1. The utility model provides a compound milling cutter of diamond for fuel sprayer mounting hole, includes cutter body and handle of a knife, the cutter body comprises one-level cutting section, second grade cutting section and the tertiary cutting section that increases gradually from the past to back diameter, and one-level cutting section, second grade cutting section and tertiary cutting section are coaxial continuous, are equipped with four cutting teeth on the one-level cutting section, are equipped with two cutting teeth on the second grade cutting section, are equipped with two cutting teeth on the tertiary cutting section, are equipped with the PCD blade on the cutting tooth, and PCD blade one side is equipped with chip groove, its characterized in that: the chip groove on the first-stage cutting section is processed backwards from the front end of the first-stage cutting section, and the length of the chip groove is 30-80% of the axial length of the first-stage cutting section; the chip groove on the secondary cutting section is processed backwards from the front end of the secondary cutting section, and the chip groove (axial direction) on the secondary cutting section penetrates through the secondary cutting section and extends to the rear part of the tertiary cutting section; the chip groove on the third-stage cutting section is machined backwards from the front end of the third-stage cutting section, and the chip groove on the third-stage cutting section extends to the rear part of the third-stage cutting section; a cooling flow channel with the rear end connected with a water inlet at the rear end of the cutter handle is arranged in the cutter body and the cutter handle, at least one primary flushing hole which is forward in water outlet direction, forms an included angle of 10-60 degrees with the axial direction of the primary cutting section and is communicated with the cooling flow channel is arranged in each chip groove on the primary cutting section, at least one secondary flushing hole which is backward in water outlet direction, forms an included angle of 10-45 degrees with the axial direction of the secondary cutting section and is communicated with the cooling flow channel is arranged in each chip groove on the secondary cutting section, and at least one tertiary flushing hole which is vertical to the axial direction of the tertiary cutting section in water outlet direction and is communicated with the cooling flow channel is arranged in each chip groove;

the dynamic balance design method of the high-speed diamond composite milling cutter comprises the following steps:

the method comprises the following steps: drawing a cutter model of the high-speed diamond composite milling cutter in three-dimensional drawing software;

step two: determining the barycentric coordinates of the cutter;

step three: setting the length of a chip removal groove on the secondary cutting section and the length of a chip removal groove on the tertiary cutting section in the barycentric coordinate phase region as variables, wherein the change ranges of the length of the chip removal groove on the secondary cutting section and the length of the chip removal groove on the tertiary cutting section are within 20mm, and the step length is 0.05-0.2 mm, preferably 0.1 mm; and adjusting the barycentric coordinates by adjusting the numerical values of the variables, performing limited calculation, and selecting the numerical value of the variable which enables the barycentric coordinates to be close to the central coordinates and is closest to the central coordinates as a design value.

2. The diamond composite milling cutter for the oil nozzle mounting hole according to claim 1, wherein two of the four cutting teeth of the primary cutting section are symmetrical about the axis of the primary cutting section, and the other two cutting teeth are arranged in a staggered manner; two cutting teeth on the secondary cutting section are arranged on the secondary cutting section corresponding to two cutting teeth arranged in a staggered manner on the primary cutting section, and two cutting teeth on the tertiary cutting section are arranged on the tertiary cutting section corresponding to two cutting teeth symmetrically arranged on the primary cutting section.

3. The diamond composite milling cutter for the oil nozzle mounting hole according to claim 1, wherein the secondary cutting section is tapered such that a diameter thereof gradually increases from front to rear, and the cutting teeth thereof are secondary flutes cut in the secondary cutting section, and the secondary cutting teeth are provided on one side of the secondary flutes.

4. The diamond composite milling cutter for the oil nozzle mounting hole according to claim 1, wherein the three-dimensional drawing software is solidworks, UG, or the like.

5. The diamond composite milling cutter for the oil nozzle mounting hole according to claim 1, wherein the axial angle of a side surface of the PCD insert mounted on a chip removal groove of the secondary cutting section in the barycentric coordinate phase region is added in the third step is variable.

6. The diamond composite milling cutter for an oil jet mounting hole according to claim 5, wherein the axial angle of a side surface of the chip groove on which the PCD blade is mounted varies in a range of 2 to 5 °.

Technical Field

The invention relates to a cutter for machining and a dynamic balance design method thereof, in particular to a diamond composite milling cutter for an oil nozzle mounting hole, which has high cooling performance and chip removal performance, long service life and high dynamic balance precision.

Background

At present, high-precision holes of a plurality of engines and parts are processed by diamond multi-stage milling cutters. The multistage milling cutter has the advantages that the cutter body is designed according to different requirements of different depths and different diameters in the hole, so that the multistage milling cutter is formed by one-step machining, a time-consuming method for machining a plurality of milling cutters for many times is avoided, and the efficiency is improved. The oil nozzle mounting hole on the engine cylinder cover has the requirements of different diameters and shapes at different depths; the existing diamond composite milling cutter for the oil nozzle mounting hole is difficult to achieve the expected effect in the actual processing. The difference of different cutting diameters and the difference of step lengths of the multi-stage milling cutter often cause resonance in processing, although the resonance between the cutter, a machine tool and a workpiece can be effectively reduced by the design of the uneven-tooth cutter, unbalanced variables are introduced into the cutter, particularly the asymmetrical design of a cooling flow channel and a flushing hole, so that the unbalance and the uncertainty of the unbalance are further increased; during design, the vibration unbalance in machining and the vibration lines on the machined surface are generated due to the fact that accurate prediction calculation cannot be carried out. In the prior art, the dynamic balancing instrument is adopted to correct dynamic balance by drilling or turning partial materials, so that the appearance is influenced, the working efficiency is low, and the unbalance tolerance is achieved by repeatedly measuring and removing for many times. The cutting chips generated by the milling cutter during cutting are limited by the sizes of multiple step differences, are not easy to discharge smoothly, and seriously obstruct the heat dissipation of the cutter body, thereby causing the aggravation of the abrasion of the cutter, the reduction of the cutting capability and the shortening of the service life.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide the high-speed diamond compound milling cutter with high cooling performance, high chip removal performance, long service life and high dynamic balance precision and the dynamic balance design method thereof.

The technical scheme adopted by the invention for solving the defects of the prior art is as follows:

the utility model provides a compound milling cutter of diamond for fuel sprayer mounting hole, includes cutter body and handle of a knife, the cutter body comprises one-level cutting section, second grade cutting section and the tertiary cutting section that increases gradually from the past to back diameter, and one-level cutting section, second grade cutting section and tertiary cutting section are coaxial continuous, are equipped with four cutting teeth on the one-level cutting section, are equipped with two cutting teeth on the second grade cutting section, are equipped with two cutting teeth on the tertiary cutting section, are equipped with the PCD blade on the cutting tooth, and PCD blade one side is equipped with chip groove, its characterized in that: the chip groove on the first-stage cutting section is processed backwards from the front end of the first-stage cutting section, and the length of the chip groove is 30-80% of the axial length of the first-stage cutting section; the chip groove on the secondary cutting section is processed backwards from the front end of the secondary cutting section, and the chip groove (axial direction) on the secondary cutting section penetrates through the secondary cutting section and extends to the rear part of the tertiary cutting section; the chip groove on the third-stage cutting section is machined backwards from the front end of the third-stage cutting section, and the chip groove on the third-stage cutting section extends to the rear part of the third-stage cutting section; a cooling flow channel with the rear end connected with a water inlet at the rear end of the cutter handle is arranged in the cutter body and the cutter handle, at least one primary flushing hole which is forward in water outlet direction, forms an included angle of 10-60 degrees with the axial direction of the primary cutting section and is communicated with the cooling flow channel is arranged in each chip groove on the primary cutting section, at least one secondary flushing hole which is backward in water outlet direction, forms an included angle of 10-45 degrees with the axial direction of the secondary cutting section and is communicated with the cooling flow channel is arranged in each chip groove on the secondary cutting section, and at least one tertiary flushing hole which is vertical to the axial direction of the tertiary cutting section in water outlet direction and is communicated with the cooling flow channel is arranged in each chip groove;

the dynamic balance design method of the diamond composite milling cutter for the oil nozzle mounting hole comprises the following steps of:

the method comprises the following steps: drawing a cutter model of the high-speed diamond composite milling cutter in three-dimensional drawing software;

step two: determining the barycentric coordinates of the cutter;

step three: setting the length of a chip removal groove on the secondary cutting section and the length of a chip removal groove on the tertiary cutting section in the barycentric coordinate phase region as variables, wherein the change ranges of the length of the chip removal groove on the secondary cutting section and the length of the chip removal groove on the tertiary cutting section are within 20mm, and the step length is 0.05-0.2 mm, preferably 0.1 mm; and adjusting the barycentric coordinates by adjusting the numerical values of the variables, performing limited calculation, and selecting the numerical value of the variable which enables the barycentric coordinates to be close to the central coordinates and is closest to the central coordinates as a design value.

In the four cutting teeth on the primary cutting section, two cutting teeth are symmetrical with the axis of the primary cutting section, and the other two cutting teeth are arranged in a staggered manner; two cutting teeth on the secondary cutting section are arranged on the secondary cutting section corresponding to two cutting teeth arranged in a staggered mode (the positions are the same or close in the circumferential direction) on the primary cutting section, and two cutting teeth on the tertiary cutting section are arranged on the tertiary cutting section corresponding to two cutting teeth symmetrically arranged on the primary cutting section (the positions are the same or close in the circumferential direction).

The secondary cutting section is in a conical shape with the diameter gradually increased from front to back, the cutting teeth on the secondary cutting section are secondary chip grooves cut on the secondary cutting section, and the secondary cutting teeth are arranged on one side (the secondary cutting section) of each secondary chip groove. The axial angle of one side surface of the PCD blade mounted on the chip groove on the secondary cutting section is 2-8 degrees, a blade mounting groove is arranged on the cutting tooth, and the PCD blade is fixed in the blade mounting groove. The cutting edge of the PCD insert on the secondary cutting section (each point of contact with the workpiece and the portion machined thereon) is equidistant from the side of the secondary cutting section.

The three-dimensional drawing software can be solidworks, UG and the like.

The invention further improves the method, in the third step, the axial angle of one side surface (cutting tooth) of the chip groove installation PCD blade on the secondary cutting section in the barycentric coordinate phase region is added as a variable (namely the included angle between the one side surface (cutting tooth) of the chip groove installation PCD blade and the axis, and in the conventional state, the one side surface (cutting tooth) of the chip groove installation PCD blade is parallel to the axis or the axis is positioned on the plane of the side surface). The axial angle of the side (cutting tooth) of the chip groove where the PCD insert is mounted varies in the range of 2-8 °. The step size is 0.01 to 0.1, preferably 0.03 to 0.06. Because the axial angle of one side surface of the PCD blade arranged on the chip removal groove on the secondary cutting section is changed, the axial angle of the PCD blade on the secondary cutting section parallel to the chip removal groove is changed, the PCD blade needs to be processed after being arranged on the secondary cutting section, and the distance between the cutting edge of the PCD blade and the side surface of the secondary cutting section is equal. Through setting for a side axial angle of chip groove installation PCD blade as parameter variable, when optimizing dynamic balance, can strengthen cutter arbor intensity, because the cutting edge of the PCD blade on the second grade cutting segment is long and thin, the diameter size combines cooling hole and wash water hole to make this regional sectional area very little, stress arouses the cutter arbor fracture greatly easily, the axial angle of the PCD blade on the second grade cutting segment can guarantee that the cutting is steady, reduce the cutting force, should reduce the chip removal groove degree of depth under the prerequisite of guaranteeing the chip removal goes on smoothly simultaneously, with reinforcing cutter arbor intensity.

The structure of the cooling flow channel and the direction of the flushing hole ensures that cooling liquid flows through the cooling flow channel and the flushing hole to cool the cutter body and then is flushed and discharged from the flushing hole; the impact angle when the cooling liquid flows out can make the chip-breaking in the chip groove flow out from front to back along with the impact direction (water outlet direction) respectively, so that the defects that the chip-breaking of the first-stage cutting section flows out backwards and is blocked by the end face of the second-stage cutting section are avoided, the chip removal process is ensured to be smooth, and the cooling effect is good. The dynamic balance optimization of the cutter structure is assisted by design examples such as solidworks and UG, and the dynamic balance precision of the cutter during high-speed operation is guaranteed. The unbalance caused by uneven teeth, asymmetrical flushing holes in different directions and asymmetrical flushing holes is compensated, the balance of the cutter can be ensured in the design process, repeated dynamic balance measurement and unbalance removal of the finished cutter are avoided, and the cutter body is attractive in appearance.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 is a schematic front view of the present invention.

Fig. 3 is a top view of fig. 2.

Fig. 4 is an enlarged right view of fig. 2.

Fig. 5 is a schematic perspective view of the present invention.

Fig. 6 is a partially enlarged view of fig. 1 at a.

Detailed Description

The utility model provides a compound milling cutter of diamond for nozzle mounting hole, includes cutter body and handle of a knife 8, and cutter body and the coaxial fixed of handle of a knife 8 link to each other, and the cutter body comprises one-level cutting section 2, second grade cutting section 5 and the tertiary cutting section that increases gradually in diameter after to in the past, and one-level cutting section 2 is cylindricly with tertiary cutting section is whole, and second grade cutting section 5 is by preceding toper (circular cone post) to the grow gradually of back diameter. The primary cutting section 2, the secondary cutting section 5 and the tertiary cutting section are coaxially connected, the diameter of the front end of the secondary cutting section 2 is the same as that of the rear end of the primary cutting section, and the diameter of the rear end of the secondary cutting section is the same as that of the front end of the tertiary cutting section. Four cutting teeth are circumferentially distributed on the primary cutting section 2, two cutting teeth are circumferentially distributed on the secondary cutting section 5, two cutting teeth are circumferentially distributed on the tertiary cutting section, a PCD blade is arranged on each cutting tooth, and a chip removal groove is formed in one side of each PCD blade. As can be seen from the figure, the cutting teeth on the primary cutting section 2 are provided with a primary chip removal groove 13 which is machined backwards from the front end of the primary cutting section, and the length of the primary chip removal groove is 30-80% of the axial length of the primary cutting section, and is usually about 50%; the primary cutting section on one side of the primary chip groove 13 is a primary cutting tooth (the axial angle of one side surface of the primary cutting section, on which the PCD blade is arranged, is 0 degrees); the cutting teeth on the secondary cutting section 5 are provided with a secondary chip groove 15 from the front end of the secondary cutting section to the rear, and the secondary chip groove penetrates through the secondary cutting section and extends to the rear part of the tertiary cutting section, so that broken chips in the secondary chip groove can be discharged backwards; the secondary cutting section on the secondary chip groove 15 side is a secondary cutting tooth (a cutting tooth on the secondary cutting section). The cutting teeth on the third-stage cutting section are provided with third-stage chip grooves 17 which are machined backwards from the front end of the third-stage cutting section and extend to the rear part of the third-stage cutting section, so that broken chips in the third-stage chip grooves are conveniently discharged backwards. The third-stage cutting section on one side of the third-stage chip groove 17 is a third-stage cutting tooth (a cutting tooth on the third-stage cutting section). The cutting teeth are provided with blade mounting grooves, the PCD blades are fixed in the blade mounting grooves, the cutting teeth of the primary cutting section are provided with the primary PCD blades 1, the cutting teeth of the secondary cutting section are provided with the secondary PCD blades 4, and the cutting teeth of the tertiary cutting section are provided with the tertiary PCD blades 16. Two cutting teeth of the four cutting teeth 1 on the primary cutting section 2 are symmetrical about the axis of the primary cutting section, and the other two cutting teeth are arranged in a staggered manner; two cutting teeth 4 on the secondary cutting section are arranged on the secondary cutting section corresponding to two cutting teeth arranged in a staggered way on the primary cutting section (the positions are the same or close in the circumferential direction), and two cutting teeth on the tertiary cutting section are arranged on the tertiary cutting section corresponding to two cutting teeth which are symmetrical with the axis of the primary cutting section on the primary cutting section (the positions are the same or close in the circumferential direction). The specific structure is as shown in fig. 4, four primary cutting teeth on the primary cutting section are respectively T1, T2, T3 and T4, wherein T1 and T3 are symmetrically distributed on two sides of the axis of the primary cutting section, two cutting teeth T2 and T4 are arranged in a staggered manner, that is, different angles are formed in the circumferential direction of the primary cutting section with respect to T1 or T3, the included angle between T2 and T1 in the circumferential direction of the primary cutting section is 94 °, and the included angle between T4 and T1 in the circumferential direction of the primary cutting section is 97 °; two cutting teeth on the secondary cutting section and the primary cutting teeth T2 and T4 are correspondingly arranged, namely: the circumferential positions of the two cutting teeth on the secondary cutting section are the same as or similar to the circumferential positions of the primary cutting teeth T2 and T4 on the primary cutting section. The principle of the design is that the cutter teeth with unequal tooth distribution can change the cutting force waveform, so that the milling force waveforms of all the cutter teeth are not consistent any more. The amplitude spectral lines of the milling force in a frequency domain are distributed on various frequencies at close intervals, and because the energy generated when the cutter works is constant, after the milling force is dispersed on the close frequencies, the amplitude on each frequency is small, namely the excitation energy is dispersed, so that the vibration of a machine tool-cutter-workpiece system is not easy to excite. A water inlet is arranged in the center of the rear end of the cutter handle, and a cooling flow passage 7 with the rear end connected with the water inlet at the rear end of the cutter handle is arranged in the cutter body and the cutter handle; the cooling flow passage 7 is coaxial with the cutter body and the cutter handle, and the front end of the cooling flow passage is closed. A primary flushing hole 12 which is provided with a forward water outlet direction, forms an included angle of 30 degrees with the axial direction of the primary cutting section and is communicated with the cooling flow channel 7 is arranged in each chip groove 13 on the primary cutting section, cooling liquid sprayed in the primary flushing hole 12 is sprayed on a PCD cutter point on the primary cutting section or the vicinity of the PCD cutter point, and broken chips cut by the primary PCD cutter blade can be flushed out from the front end of the chip groove on the primary cutting section; each chip groove 15 on the secondary cutting section 5 is internally provided with a secondary flushing hole 3 which has a backward water outlet direction and forms an included angle of 20 degrees with the axial direction of the secondary cutting section and is communicated with a cooling flow channel, and cooling liquid sprayed in the secondary flushing hole 3 is sprayed in the middle of or near a PCD cutting edge on the secondary cutting section, can impact broken chips cut by the secondary PCD cutting blade and is discharged from the chip groove on the secondary cutting section to the rear part of the tertiary cutting section; a third-stage flushing hole which is vertical to the axial direction of the third-stage cutting section in the water outlet direction and communicated with the cooling flow channel is arranged in each chip groove on the third-stage cutting section, and broken chips cut by the three-stage PCD blade can be impacted and discharged from the rear part of the chip groove on the third-stage cutting section; it can be seen from the figure that the three-level cutting teeth in this embodiment are stepped cutting teeth, a first-level conical section 11 with a diameter gradually increasing from front to back is processed at the front end of the three-level cutting section, a second-level column section 14 is arranged at the rear side of the first-level conical section 11, a third-level main body section 6 is arranged at the rear side of the second-level column section 14, the diameter of the second-level column section 14 which is cylindrical is smaller than that of the third-level main body section 6 which is cylindrical, the three-level cutting section is formed by sequentially connecting the first-level conical section 11, the second-level column section 14 and the third-level main body section 6, a three-level chip groove is processed backwards from the front end of the first-level conical section, the three-level cutting teeth at one side of the three-level chip groove comprise three parts, namely a first-level conical section tooth, a. Two tertiary flushing holes 10 and 9 are arranged in each chip groove 17 on the tertiary cutting section, wherein a pcd cutter which sprays cooling liquid from one tertiary flushing hole 10 on the tertiary cutting section is positioned in the middle of or near the blade in the middle of the primary conical section, and a pcd cutter which sprays cooling liquid from the other tertiary flushing hole 9 on the tertiary cutting section is positioned at the cutter point between the secondary column section and the tertiary main body section or the pcd cutter is positioned at the pcd blade at the front end of the tertiary main body section.

The dynamic balance design method of the high-speed diamond composite milling cutter comprises the following steps:

the method comprises the following steps: drawing a cutter model of the high-speed diamond compound milling cutter in three-dimensional drawing software solidworks;

step two: determining the quality attribute M and the barycentric coordinate of the cutter according to the material of the cutter, namely: inputting density data, and determining a mass attribute M and a gravity center coordinate by three-dimensional drawing software;

step three: setting the length of a chip removal groove on the secondary cutting section and the length of a chip removal groove on the tertiary cutting section in the barycentric coordinate phase region as parameter variables, wherein the variation ranges of the length of the chip removal groove on the secondary cutting section and the length of the chip removal groove on the tertiary cutting section are within 20mm, and the step length is 0.05-0.2 mm. The length of the chip removal groove on the secondary cutting section in the embodiment is 45mm, and the change range of the length is 17mm, namely the length of the chip removal groove on the secondary cutting section can be adjusted between 45mm and 62 mm, and the step length is set to be 0.1 mm; the length of the chip removal grooves on the three-stage cutting section is 36 mm, the change range of the length is 15mm, namely the length of the chip removal grooves on the three-stage cutting section can be adjusted between 36 mm and 51 mm, and the step length is set to be 0.1 mm. The gravity center coordinate is adjusted by adjusting the numerical value of the variable, limited calculation (the maximum is 25500 times) is carried out, and the optimal calculation result is selected, so that the gravity center coordinate of the cutter model of the high-speed diamond compound milling cutter is closest to the center coordinate (axis).

The invention is further improved, and the axial angle of one side surface (cutting tooth) of the PCD blade mounted on the chip groove on the secondary cutting section in the barycentric coordinate phase region is set as a parameter variable, namely the included angle between the one side surface (cutting tooth) of the PCD blade mounted on the chip groove and the axis is set as a variable. The axial angle of one side surface (cutting tooth) of the PCD blade arranged on the chip groove is adjusted within the range of 2-8 degrees; the step size is 0.01 to 0.1 °, preferably 0.03 to 0.06 °. Conventionally, the side (cutting tooth) of a flute mounting PCD insert is parallel to the axis or the axis lies in the plane of the side. Because the axial angle of one side surface of the PCD blade arranged on the chip removal groove on the secondary cutting section is changed, the axial angle of the PCD blade on the secondary cutting section parallel to the chip removal groove is changed, the PCD blade needs to be processed after being arranged on the secondary cutting section, and the distance between the cutting edge of the PCD blade and the side surface of the secondary cutting section is equal. Through setting for a side axial angle of chip groove installation PCD blade as parameter variable, when optimizing dynamic balance, can strengthen cutter arbor intensity, because the cutting edge of the PCD blade on the second grade cutting segment is long and thin, the diameter size combines cooling hole and wash water hole to make this regional sectional area very little, stress arouses the cutter arbor fracture greatly easily, the axial angle of the PCD blade on the second grade cutting segment can guarantee that the cutting is steady, reduce the cutting force, should reduce the chip removal groove degree of depth under the prerequisite of guaranteeing the chip removal goes on smoothly simultaneously, with reinforcing cutter arbor intensity. The axial angle of one side surface of the PCD blade installed on the chip removing groove, the length of the chip removing groove on the secondary cutting section and the length of the chip removing groove on the tertiary cutting section are set as variables, the parameter value of the appropriate step length regulating variable is selected in a specified range, and the parameter value which is close to (0, 0) as much as possible in a two-dimensional coordinate is extracted through multiple times of calculation and is the design value of the high-speed diamond composite milling cutter.

The dynamic balance design method of the diamond composite milling cutter for the oil nozzle mounting hole in the embodiment specifically comprises the following operation steps: drawing or importing a cutter model of the high-speed diamond compound milling cutter in three-dimensional drawing software solidworks, wherein the main shaft direction of the cutter model is the z-axis direction, and the rotating shaft direction is irrelevant to the unbalance amount, so that the total mass of the cutter is calculated to be 331.42 g by only considering the radial coordinate of the cutter and setting the material of the cutter (the input quantity is density data of the material of the cutter), the initial barycentric coordinate (without considering the rotating shaft direction) is a two-dimensional coordinate (0.021 and 0.042), and the corresponding original unbalance amount is as follows: 15.56 g.mm; the balance grade G is 29.50 when the rotating speed is 6000r/min according to the national standard, which far exceeds the standard of dynamic balance, and the application of the cutter in practice is influenced.

Through setting for the parameter of chip removal groove length on a side axial angle and the second grade cutting section of chip groove installation PCD blade and the chip removal groove length on the tertiary cutting section as the variable, calculate in foretell parameter range and step length within range to progressively reduce parameter range and step length interval, calculate many times and draw, make two-dimensional coordinate press close to (0, 0) as far as possible, promptly: the sensor barycentric coordinates in the design software solidworks are the minimum value from the center coordinates (0, 0). And finally, the balance grade calculated at the rotating speed of 6000r/min is about 0.8, and is basically consistent with the measurement result of the finished product on a dynamic balance measuring instrument, so that the correction of the finished product is avoided. Because the axial angle of one side surface of the PCD blade mounted on the chip removal groove on the secondary cutting section is in relation with the cutter for stable cutting, the parameter range is set to be within 5 degrees, and the length of the chip removal groove is selected in a reasonable range in a changing way; and (5) performing limited calculation and selecting an optimal calculation result. Further, calculating the unbalance U and the balance grade index G of the cutter according to a formula.

The structure of the cooling flow channel and the direction of the flushing hole ensures that cooling liquid flows through the cooling flow channel and the flushing hole to cool the cutter body and then is flushed and discharged from the flushing hole; the impact angle when the cooling liquid flows out can make the chip-breaking in the chip groove flow out from front to back along with the impact direction (water outlet direction) respectively, so that the defects that the chip-breaking of the first-stage cutting section flows out backwards and is blocked by the end face of the second-stage cutting section are avoided, the chip removal process is ensured to be smooth, and the cooling effect is good. The dynamic balance optimization of the cutter structure is assisted by design examples such as solidworks and UG, and the dynamic balance precision of the cutter during high-speed operation is guaranteed. The unbalance caused by uneven teeth, asymmetrical flushing holes in different directions and asymmetrical flushing holes is compensated, the balance of the cutter can be ensured in the design process, repeated dynamic balance measurement and unbalance removal of the finished cutter are avoided, and the cutter body is attractive in appearance. Through setting for a side axial angle of chip groove installation PCD blade as the variable, when optimizing dynamic balance in reasonable parameter range, can strengthen cutter arbor intensity, because the cutting edge of the PCD blade on the second grade cutting section is long and thin, the diameter size combines cooling hole and wash port to make this regional sectional area very little, the cutter arbor fracture is aroused easily greatly to stress, the axial angle of the PCD blade on the second grade cutting section can guarantee that the cutting is steady, reduce the cutting force, should reduce the chip groove degree of depth under the prerequisite of guaranteeing that the chip removal goes on smoothly simultaneously, with reinforcing cutter arbor intensity.