Numerical control cutter for precision machining

Abstract

The invention relates to the technical field of numerical control tools, in particular to a numerical control tool for precision machining, which comprises a tool bar, a tool apron and a blade, an inclined mounting hole is formed in the front side of the tool bar, the axis of the inclined mounting hole and the axis of the tool bar form an angle of 45 degrees, and the inclined mounting hole penetrates through the left side and the right side of the tool bar and does not penetrate through the front end face of the tool bar. The tool apron is connected in the inclined mounting hole in a sliding manner; through the arrangement that the adjusting bolt penetrates through the positioning hole, even if an operator puts the boring cutter with the cutter holder and the unlocked cutter bar into use due to misoperation, the cutter holder slides towards the axial lead direction of the mounting hole and towards the outside of the inclined mounting hole under the action of centrifugal force until the inner side wall of the positioning hole is attached to the outer side wall of the adjusting bolt; the tool apron is limited by the adjusting bolt, so that the tool apron cannot continuously slide towards the outside of the inclined mounting hole; therefore, safety accidents caused by the fact that the tool apron is thrown out of the inclined mounting hole when the fastening assembly is not locked are avoided, and use safety of operators and the tool is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of numerical control tools, in particular to a numerical control tool for precision machining. Background Art

[0002] Precision machining includes diamond turning, diamond boring, honing, belt grinding and mirror grinding. The machining accuracy of precision machining is generally 10 to 0.1μm, the tolerance grade is above IT5, and the surface roughness is below Ra0.1μm. Among them, the diamond turning process adopts a machining method with a fixed tool and a rotating workpiece, while the diamond boring process adopts a machining method with a rotating tool and a fixed workpiece. Therefore, in the hole machining of complex cavities, irregular holes or non-rotating bodies, such as the inner hole machining of turbine blades in aircraft engines, the inner hole of automobile oil pumps or water pumps, and the cooling holes of injection molds, the diamond boring process has higher flexibility than the diamond turning process.

[0003] Since the minimum feed rate of the CNC boring machine is a fixed value after leaving the factory, when the processing accuracy requirement of the parts is less than the minimum feed rate of the CNC boring machine, the processing accuracy of the CNC boring machine cannot meet the part processing accuracy requirement. At the same time, after the tool wears out during the processing, it is necessary to increase the tool compensation to offset the tool wear, so as to ensure the processing accuracy. To address this problem, an independent fine-tuning boring tool has been derived. For example, the invention patent with authorization announcement number CN117532026B provides a boring tool compensation mechanism. The invention provides a first annular groove on the side wall of the tool holder body, and divides the tool holder body into a first adjustment part, a second adjustment part and a connecting part through the first annular groove. At the same time, a fine-tuning component is provided on the tool body to drive the second adjustment part to swing the tool assembly with the connecting part as the base point to perform size compensation of the tool assembly. Although this technical solution can perform tool compensation, the fine-tuning component in this technical solution adopts a piezoelectric actuator, and the piezoelectric crystal compensation method has a small adjustment amount, which is more suitable for tool wear compensation; when a larger adjustment amount is required, a mechanical adjustment structure is required. The more common compensation method is to use a thread for micro adjustment. For example, the utility model patent with the authorization announcement number CN213288710U provides a differential precision fine-tuning boring tool row, which is provided by arranging a sliding body that is matched with a dovetail groove at the bottom of the slide, a double-pitch threaded rod is provided on the slide, a second wedge is provided on the upper end of the double-pitch threaded rod, and a side wall of the sliding body is provided with a second wedge. The wedge block cooperates with the first wedge block, and a boring bar is set at the bottom of the slide; by rotating the double-pitch threaded rod, the second wedge block is pushed, and the second wedge block pushes the first wedge block, thereby completing the position adjustment of the slide and the boring bar and changing the processing diameter of the boring tool. The adjustment amount of this method is larger than that of the piezoelectric crystal type, but in this technical solution, since the slide and the slide are only locked by a set screw, it is easy for the operator to misoperate during use, resulting in a loose fastening between the slide and the slide, and the slide and the slide are eccentric structures. During precision boring, the slide is simultaneously subjected to the effects of centrifugal force and cutting force, which can easily cause the set screw to fail, thereby causing a safety accident. For example, the utility model patent with authorization announcement number CN219484234U provides a high-strength fine-tuning boring tool. The utility model provides a slide groove on the boring tool head, and the tool holder is slidably connected inside the slide groove. The side wall of the slide groove is provided with an adjustment bolt hole, and an adjustment screw is provided in the adjustment bolt hole to push the tool holder to extend the length, thereby achieving the adjustment of the boring tool processing diameter; this technical solution also adopts a locking method of a set screw to fix the tool holder, which is also prone to the problems of the above solution. Summary of the Invention

[0004] The purpose of the present invention is to provide a CNC tool for precision machining to solve the problem of fine adjustment of boring tools, and at the same time solve the problem that during the adjustment and machining process of fine-adjustment boring tools using a threaded fine-adjustment structure, operator errors or the influence of cutting forces are prone to occur, resulting in unstable fastening between the boring tool blade and the boring tool rod, thereby causing the boring tool blade to fall off and cause accidents.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A CNC tool for precision machining, comprising a tool bar, a tool holder and a blade, wherein an oblique mounting hole is provided on the front side of the tool bar, the axis of the oblique mounting hole is at 45 degrees to the axis of the tool bar, the oblique mounting hole passes through the left and right sides of the tool bar, and the oblique mounting hole does not pass through the front end surface of the tool bar, the tool holder is slidably connected in the oblique mounting hole, a mounting groove is provided on the upper end surface of the tool bar away from the tool bar, the blade is detachably mounted in the mounting groove, a countersunk vertical mounting hole is provided on the upper end of the tool bar, and a vertical mounting hole is provided on the bottom wall of the vertical mounting hole A threaded hole extending straight downwards, the threaded hole completely passes through the upper and lower sides of the tool rod, the adjusting bolt is coaxially arranged in the threaded hole, a positioning hole is provided on the tool holder, the positioning hole completely passes through the upper and lower sides of the tool holder, the adjusting bolt passes through the positioning hole, a transmission assembly is provided in the positioning hole, the transmission assembly is connected with the adjusting bolt and the positioning hole, and the adjusting bolt converts the rotation of the adjusting bolt into linear motion of the tool holder through the transmission assembly, a fastening assembly is provided on the tool rod, and the fastening assembly is used to limit or release the sliding between the tool holder and the oblique mounting hole.

[0007] By independently arranging the adjusting bolt and the fastening assembly, the centrifugal force, cutting force and vibration impact applied to the tool holder during the operation of the boring tool all act on the fastening assembly rather than on the positioning block or the adjusting bolt, thereby avoiding damage to the thread of the adjusting bolt due to the force applied during the operation of the boring tool, thereby ensuring the adjustment accuracy and service life of the adjusting bolt. Furthermore, by setting the adjusting bolt passing through the positioning hole, even if the operator fails to lock the fastening assembly due to error, the boring tool is put into use when the tool holder and the tool rod are not locked, and the centrifugal force applied to the tool holder is directed to the outside of the oblique mounting hole. Since the adjusting bolt is located in the positioning hole, after the tool holder is acted upon by the centrifugal force, the tool holder slides outward of the oblique mounting hole along the axial direction of the oblique mounting hole until the inner side wall of the positioning hole fits into the outer side wall of the adjusting bolt. At this time, the tool holder is limited by the adjusting bolt and cannot continue to slide outward of the oblique mounting hole. This avoids the situation where the tool holder is thrown out of the oblique mounting hole under the action of centrifugal force when the fastening assembly is not locked, thereby ensuring the safety of the operator and the tool.

[0008] Preferably, the transmission assembly includes a positioning block, the positioning hole is a waist-shaped hole, the inner side wall of the positioning hole is a slope, and the small end of the positioning hole is located at the bottom side, the inner side wall of the positioning hole is divided into a No. 1 positioning surface, a transition positioning surface and a No. 2 positioning surface along the axial direction of the oblique mounting hole, the distance between the No. 1 positioning surface and the blade is the shortest, and the large end diameter of the No. 1 positioning surface is larger than the large end diameter of the No. 2 positioning surface, the positioning block is a frustum with the small end at the bottom, the side wall of the positioning block is slidably connected to the inner wall of the positioning hole, the adjusting bolt is respectively a lower threaded section, a smooth section and an upper threaded section from bottom to top, the positioning block is interference fit with the smooth section, the upper end face of the positioning block abuts against the bottom of the upper threaded section, a scale dial is coaxially installed in the vertical mounting hole, and the scale dial is fixedly connected to the adjusting bolt.

[0009] The adjusting screw is rotated to the desired adjustment amount, and the tool holder is pulled until the inner wall of the positioning hole is in contact with the inner wall of the positioning block, and then the fastening assembly is locked to fix the tool holder and the tool rod, thus completing the adjustment of the boring tool, and the machining diameter of the boring tool is reduced after adjustment.

[0010] Furthermore, when the adjusting bolt is rotated to rotate it outward from the tool arbor, the positioning block rotates with the adjusting bolt and moves toward the large end of the positioning hole, thereby releasing the fixation of the fastening assembly on the tool holder. The adjusting bolt is rotated to move the positioning block toward the large end of the positioning hole, and the side wall of the positioning block is separated from the inner wall of the positioning hole. After the adjusting bolt is rotated to the required adjustment amount in conjunction with the dial, the tool holder is pulled until the inner wall of the positioning hole and the inner wall of the positioning block are in contact with each other, and then the fastening assembly is locked to fix the tool holder and the tool arbor, thereby completing the adjustment of the boring tool. The machining diameter of the boring tool is increased after adjustment.

[0011] Since the distance between the No. 1 positioning surface and the blade is closer than that between the No. 2 positioning surface and the large end of the No. 1 positioning surface is larger than that between the No. 2 positioning surface and the large end of the No. 1 positioning surface, even if the operator fails to lock the fastening assembly due to an operation error, the boring tool is put into use when the tool holder and the tool rod are not locked, and the centrifugal force applied to the tool holder is directed to the outside of the oblique mounting hole. Since the positioning block and the adjusting bolt are both located in the positioning hole, after the tool holder is acted upon by the centrifugal force, the tool holder slides outwards of the oblique mounting hole along the axial direction of the oblique mounting hole until the inner side wall of the positioning hole fits into the outer side wall of the positioning block. At this time, the tool holder is limited by the adjusting bolt and the positioning block and cannot continue to slide outwards of the oblique mounting hole. This avoids the situation where the tool holder is locked due to the centrifugal force. The tool holder is prevented from being thrown out of the oblique mounting hole due to the action of the tool holder, thereby preventing accidents caused by the tool holder, and ensuring the safety of the operator and the tool. Furthermore, since the tool holder is limited by the adjusting bolt and the positioning block, the maximum processing diameter of the blade is limited, thereby preventing the maximum processing diameter of the boring tool from becoming larger when the fastening assembly is not locked, thereby preventing the inner hole diameter of the workpiece from increasing, and thus preventing the workpiece from being scrapped. Furthermore, when the fastening assembly is not locked, the adjusting bolt is acted upon by the centrifugal force of the tool holder, and the adjusting bolt is acted upon by the shear force, and the axial direction of the adjusting bolt is not affected by the force of the tool holder, thereby preventing the thread of the adjusting bolt from being damaged by the external force during the operation of the boring tool, thereby ensuring the adjustment accuracy and service life of the adjusting bolt.

[0012] Preferably, the taper of the positioning block is 1:1.7678, the slopes of the No. 1 positioning surface, the transition positioning surface and the No. 2 positioning surface are all 1:3.5355, the pitch of the upper thread segment and the lower thread segment are both 0.25 mm, and the scale of the dial is 50 equal divisions.

[0013] When the adjusting bolt is rotated downward, the distance the positioning block moves downward for each rotation is h=0.25*1 / 50mm, the relative displacement between the tool holder and the oblique mounting hole is s=h*1 / 3.5355mm, and the radial feed amount of the tool holder is f=s*cos45°, that is, when the adjusting bolt is rotated downward by 1 scale, the radial feed amount of the tool holder is f=0.25*cos45° / (50*3.5355)=0.001mm=1μm; through the cooperation of the adjusting bolt, the positioning block and the positioning hole, the minimum feed amount of the tool holder can reach 1μm, which improves the application range of the boring tool.

[0014] Preferably, a spring mounting hole is provided on the side wall of the knife seat at one end away from the blade, the axis of the spring mounting hole is at 45° to the axis of the knife rod, and the spring mounting hole completely passes through the positioning hole and does not completely pass through the knife seat, a pressure spring is provided in the spring mounting hole, and one end of the pressure spring is connected to the end of the spring mounting hole close to the blade, and the other end is connected to an adjusting block, and the side of the adjusting block away from the pressure spring is slidably connected to the side wall of the positioning block.

[0015] The adjusting block is kept in contact with the side wall of the positioning block under the spring force of the pressure spring; when increasing the processing diameter of the boring tool, the locking of the tool holder on the fastening assembly is not released first, and the adjusting bolt is rotated to make it screwed outward from the tool rod. The positioning block rotates with the adjusting bolt and moves toward the large end of the positioning hole, and the side wall of the positioning block is separated from the inner wall of the positioning hole. The adjusting block is kept in contact with the side wall of the positioning block under the spring force of the pressure spring. After the adjusting bolt is rotated to the required adjustment amount in combination with the dial, the locking of the tool holder by the fastening assembly is released. The tool holder slides outward from the oblique mounting hole in the direction of the axial center line of the oblique mounting hole under the action of the spring force of the pressure spring until the inner side wall of the positioning hole is in contact with the outer side wall of the positioning block. The fastening assembly is then locked to lock the tool holder and the tool rod, thereby completing the adjustment of the boring tool, and the processing diameter of the boring tool is increased after adjustment.

[0016] By setting the pressure spring and the adjusting block, when the machining diameter of the boring tool is increased, after adjusting the adjustment amount of the adjusting bolt, the operator does not need to pull the tool holder until the inner wall of the positioning hole is in contact with the inner wall of the positioning block. Under the spring force of the pressure spring, the adjusting block remains in contact with the side wall of the positioning block, and after the locking of the fastening assembly on the tool holder is released, the spring force of the pressure spring acts on the tool holder and pushes the tool holder until the inner wall of the positioning hole is in contact with the outer wall of the positioning block. This avoids the situation where the operator forgets to pull the tool holder or fails to pull the tool holder to the specified position when increasing the machining diameter of the boring tool, causing the actual machining diameter of the boring tool to be inconsistent with the theoretical diameter. This improves the convenience and stability of the boring tool adjustment and ensures the adjustment accuracy of the boring tool.

[0017] Preferably, the fastening assembly includes a fastening block and a fastening bolt, and positioning grooves are provided on both side walls of the knife seat parallel to the oblique mounting hole, a positioning boss is provided on one side wall of the oblique mounting hole close to the tail end of the knife rod, and two threaded through holes are provided on one side wall of the oblique mounting hole close to the front end of the knife rod, and fastening bolts are provided in both threaded through holes, and the fastening block is arranged in the oblique mounting hole, and one end of the fastening bolt extending into the oblique mounting hole is rotatably connected to the fastening block, and both side walls of the positioning groove are inclined surface structures with the same inclination, and the positioning boss and the fastening block are both slidingly fitted in the positioning groove, the depth of the positioning groove is H1, and the height of the positioning boss and the fastening block is H2, wherein H1>H2.

[0018] When the fastening bolt is rotated to rotate it outward from the tool arbor, the locking block is disengaged from the inner side wall of the positioning groove on that side, thereby releasing the locking of the locking block on the tool holder, and the constraint of the tool holder in the axial direction of the oblique mounting hole is released; when the fastening bolt is rotated to rotate it into the tool arbor, the locking block is fitted with the inner side wall of the positioning groove on that side, and the positioning boss is fitted with the inner side wall of the positioning groove on that side, thereby completing the locking of the locking block and the tool holder, and the tool holder is constrained in the axial direction of the oblique mounting hole; By setting the matching surfaces of the positioning groove, the positioning protrusion and the fastening block as inclined surfaces, the parallelism of the center line of the tool holder and the axial center line of the inclined mounting hole is ensured when the locking block locks the tool holder, thereby ensuring the accuracy of the machining diameter of the boring tool; further, the setting of the inclined surface increases the contact area between the fastening block, the positioning protrusion and the positioning groove, improves the friction between the fastening block, the positioning protrusion and the positioning groove, ensures the fastening between the tool holder and the tool rod, and thus ensures the stability of the machining diameter of the boring tool.

[0019] Preferably, both front and rear ends of the fastening block are provided with deformable flexible sheets, and both side walls of the flexible sheet are flush with both side walls of the fastening block respectively. The height of the flexible sheet is H3, wherein H1<H3. By arranging flexible sheets at the front and rear ends of the fastening block, and the height H3 of the flexible sheets is greater than the depth of the groove, when the fastening bolt is rotated to rotate it outward from the tool arbor, the tool holder is acted upon by the elastic force of the flexible sheet, and the positioning boss remains in contact with the positioning groove, thereby avoiding the angular offset between the center line of the tool holder and the axial line of the oblique mounting hole, which causes jamming between the tool holder and the oblique mounting hole, ensuring the smoothness of sliding between the tool holder and the oblique mounting hole, thereby ensuring the smoothness of adjustment of the boring tool; at the same time, the fastening block avoids chips from entering the gap between the fastening block and the positioning groove on this side, thereby ensuring the smoothness of sliding between the tool holder and the oblique mounting hole, and at the same time avoiding the gap between the fastening block and the positioning groove on this side, causing the fit between the fastening block and the positioning groove on this side, thereby ensuring the locking effect of the fastening block on the tool holder, and ensuring the fastening stability between the tool holder and the tool arbor.

[0020] Preferably, the tool arbor and tool holder are both made of carbide steel with a blackened surface treatment, and the adjustment bolt is made of stainless steel. By using carbide steel to make the tool arbor and tool holder, the strength of the tool arbor and tool holder is ensured, preventing damage to the boring tool during machining. The blackened surface treatment also improves the rust resistance of the tool arbor and tool holder, preventing oxidation and rust on the surface of the tool holder and the inner wall of the positioning groove, which could affect the sliding between the tool holder and the oblique mounting hole, and the fit between the locking block and the positioning groove. This ensures smooth adjustment of the boring tool and the stability of the fastening between the tool holder and tool arbor. By using stainless steel to make the adjustment bolt, the thread strength of the adjusting bolt is increased, while the shear resistance of the adjusting bolt is enhanced, preventing damage to the adjusting bolt thread from external forces during boring tool operation, thereby ensuring the adjustment accuracy and service life of the adjusting bolt.

[0021] Preferably, the first positioning surface, the transition positioning surface, and the second positioning surface are all surface hardened to HBC65-HBC68, and the side wall of the positioning block is nitrided, with the nitrided layer having a thickness of 0.1-0.2 mm and a surface hardness of HBC68-HBC72. The first positioning surface, the transition positioning surface, and the second positioning surface are surface hardened to improve the wear resistance and surface strength of the inner side wall of the positioning hole. The side wall of the positioning block is nitrided to improve the wear resistance, corrosion resistance, and fatigue strength of the side wall of the positioning block. At the same time, the hardness of the positioning block side wall is higher than that of the inner side wall of the positioning hole, thereby avoiding wear of the positioning block during adjustment and causing a change in the positioning block taper, thereby ensuring the service life of the positioning block. At the same time, the positioning block and the adjusting bolt are interference fit. When the adjusting bolt is rotated, the positioning block rotates with the adjusting bolt, avoiding unilateral wear of the positioning block and the positioning hole, which causes a decrease in the fit between the two, and ensuring the adjustment accuracy of the boring tool.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention allows the adjusting bolt to pass through the positioning hole. Even if the operator mistakenly puts the boring tool into use without locking the tool holder and the tool rod, the tool holder is acted upon by centrifugal force to slide toward the axis of the mounting hole and outward of the oblique mounting hole until the inner side wall of the positioning hole abuts against the outer side wall of the adjusting bolt. The tool holder is then limited by the adjusting bolt and cannot continue to slide outward of the oblique mounting hole. This avoids the possibility of the tool holder being thrown out of the oblique mounting hole when the fastening assembly is not locked, thereby ensuring the safety of the operator and the tool.

[0024] 2. The present invention arranges the adjusting bolt and the fastening assembly independently. When the boring tool is in operation, the centrifugal force, cutting force and vibration impact to which the tool holder is subjected all act on the fastening assembly rather than on the positioning block or the adjusting bolt, thereby avoiding damage to the thread of the adjusting bolt due to force applied during the operation of the boring tool, thereby ensuring the adjustment accuracy and service life of the adjusting bolt.

[0025] 3. The present invention sets the matching surfaces of the positioning groove, the positioning protrusion and the fastening block as inclined surfaces. When the locking block locks the tool holder, the parallelism of the center line of the tool holder and the axial center line of the oblique mounting hole is ensured, thereby ensuring the accuracy of the machining diameter of the boring tool; at the same time, the contact area between the fastening block, the positioning protrusion and the positioning groove is increased, and the friction between the fastening block, the positioning protrusion and the positioning groove is improved, thereby ensuring the fastening between the tool holder and the tool rod, thereby ensuring the stability of the machining diameter of the boring tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the overall structure of the CNC tool for precision machining of the present invention;

[0027] Figure 2 This is an exploded view of a CNC tool for precision machining according to the present invention;

[0028] Figure 3 A top view of a numerically controlled tool for precision machining according to the present invention;

[0029] Figure 4 for Figure 3 The sectional view at AA in FIG;

[0030] Figure 5 for Figure 3 Cross-sectional view at BB in the figure;

[0031] Figure 6 This is a schematic diagram of the tool holder structure of the CNC tool for precision machining of the present invention;

[0032] Figure 7 This is a state diagram of the CNC tool for precision machining of the present invention when it is retracted to the minimum diameter;

[0033] Figure 8 This is a state diagram of the CNC tool for precision machining of the present invention when it is extended to its maximum diameter.

[0034] In the figure: 1. Tool bar; 101. Oblique mounting hole; 102. Positioning boss; 103. Threaded hole; 104. Vertical mounting hole; 2. Tool holder; 201. Mounting slot; 202. Positioning hole; 2021. Positioning surface No. 1; 2022. Transition positioning surface; 2023. Positioning surface No. 2; 2024. Avoidance slot; 203. Positioning groove; 204. Spring mounting hole; 3. Blade; 4. Positioning block; 5. Fastening block; 6. Pressure spring; 7. Adjusting block; 8. Fastening bolt; 9. Adjusting bolt; 901. Upper threaded section; 902. Smooth section; 903. Lower threaded section; 10. Dial; 11. Flexible sheet; 12. Locking bolt. DETAILED DESCRIPTION

[0035] See also Figures 1 to 8 The present invention provides a CNC tool for precision machining, and the technical solution is as follows:

[0036] See also Figure 1 and Figure 2 A CNC tool for precision machining includes a tool rod 1, a tool holder 2 and a blade 3. An oblique mounting hole 101 is provided on the front side of the tool rod 1. The axis of the oblique mounting hole 101 is at 45 degrees to the axis of the tool rod 1. The oblique mounting hole 101 passes through the left and right sides of the tool rod 1, and the oblique mounting hole 101 does not pass through the front end surface of the tool rod 1. The tool holder 2 is slidably connected in the oblique mounting hole 101. A mounting groove 201 is provided on the upper end surface of the tool rod 1 away from the tool rod 1. The blade 3 is installed in the mounting groove 201. A locking bolt 12 is provided on the blade 3. The blade 3 is detachably connected to the tool holder 2 through the locking bolt 12.

[0037] See also Figures 3 to 6, a positioning hole 202 is provided on the knife seat 2, and the positioning hole 202 completely passes through the upper and lower sides of the knife seat 2. The positioning hole 202 is a waist-shaped hole, and the inner side wall of the positioning hole 202 is a slope, and the small end of the positioning hole 202 is located at the lower side. The inner side wall of the positioning hole 202 is divided into a first positioning surface 2021, a transition positioning surface 2022 and a second positioning surface 2023 along the axial direction of the oblique mounting hole 101. The distance between the first positioning surface 2021 and the blade 3 is the shortest, and the large end diameter of the first positioning surface 2021 is larger than the large end diameter of the second positioning surface 2023. The inner wall of the positioning hole 202 is slidably connected with a positioning block 4, and the positioning Block 4 is in the shape of a cone with the small end at the bottom. A countersunk vertical mounting hole 104 is provided at the upper end of the tool rod 1. A vertical downward threaded hole 103 is provided on the bottom wall of the vertical mounting hole 104. The threaded hole 103 completely passes through the upper and lower sides of the tool rod 1. An adjusting bolt 9 is coaxially arranged in the threaded hole 103. The adjusting bolt 9 is respectively a lower threaded section 903, a smooth section 902 and an upper threaded section 901 from bottom to top. The positioning block 4 is interference fit with the smooth section 902. The upper end face of the positioning block 4 abuts against the bottom of the upper threaded section 901. A dial 10 is coaxially arranged in the vertical mounting hole 104, and the dial 10 is fixedly connected to the adjusting bolt 9.

[0038] See also Figure 2 、 Figure 3 and Figure 5 , positioning grooves 203 are provided on both side walls of the tool holder 2 parallel to the oblique mounting hole 101, a positioning boss 102 is provided on one side wall of the oblique mounting hole 101 near the tail end of the tool rod 1, and two threaded through holes are provided on one side wall of the oblique mounting hole 101 near the front end of the tool rod 1, and fastening bolts 8 are provided in both threaded through holes. A fastening block 5 is provided in the oblique mounting hole 101, and one end of the fastening bolt 8 extending into the oblique mounting hole 101 is rotatably connected to the fastening block 5. The two side walls of the positioning groove 203 are inclined structures with the same slope, and the positioning boss 102 and the fastening block 5 are both slidably matched with the positioning groove 203. The depth of the positioning groove 203 is 1.45mm, and the height of the positioning boss 102 and the fastening block 5 is 1.2mm. A deformable flexible sheet 11 is provided at the front and rear ends of the fastening block 5, and the two side walls of the flexible sheet 11 are flush with the two side walls of the fastening block 5 respectively, and the height of the flexible sheet 11 is 1.5mm.

[0039] See also Figure 3 、 Figure 4 and Figure 6A spring mounting hole is provided on the side wall of the knife seat 2 away from the blade 3, and the axis of the spring mounting hole 204 is 45 degrees to the axis of the knife rod 1, and the spring mounting hole 204 completely passes through the positioning hole 202 and does not completely pass through the knife seat 2. A pressure spring 6 is provided in the spring mounting hole 204, and one end of the pressure spring 6 is connected to the end of the spring mounting hole 204 close to the blade 3, and the other end is connected to an adjusting block 7. The side of the adjusting block 7 away from the pressure spring 6 is slidably connected to the side wall of the positioning block 4, and an avoidance groove 2024 is provided on the side wall of the No. 1 positioning surface 2021. When the side wall of the positioning block 4 is in contact with the No. 1 positioning surface 2021, the adjusting block 7 is completely pressed into the avoidance groove 2024.

[0040] It should be noted that the taper of the positioning block 4 is 1:1.7678, the slopes of the No. 1 positioning surface 2021, the transition positioning surface 2022 and the No. 2 positioning surface 2023 are all 1:3.5355, and the pitch of the upper thread section 901 and the lower thread section 903 are both 0.25mm; the tool rod 1 and the tool seat 2 are both made of carbide steel, and the surface is blackened, and the adjusting bolt 9 is made of stainless steel; the No. 1 positioning surface 2021, the transition positioning surface 2022 and the No. 2 positioning surface 2023 are all surface hardened to HBC65~HBC68, and the side wall of the positioning block 4 is nitrided, the nitriding layer is 0.1~0.2mm thick, and the surface hardness is HBC68~HBC72.

[0041] See also Figures 1 to 7 When the machining diameter of the boring tool is reduced, the fastening bolt 8 is rotated to make it rotate outward from the tool arbor 1, and the locking block is disengaged from the inner wall of the positioning groove 203 on this side, thereby releasing the locking block from the tool holder 2, and the constraint of the tool holder 2 in the axial direction of the oblique mounting hole 101 is released; the adjusting bolt 9 is rotated to make it screw into the tool arbor 1, and the positioning block 4 rotates with the adjusting bolt 9 and moves toward the small end of the positioning hole 202; since the positioning block 4 is in a frustum shape, and the side wall of the positioning block 4 is slidably connected with the inner wall of the positioning hole 202, and since the large end diameter of the No. 1 positioning surface 2021 is smaller than the large end diameter of the No. 2 positioning surface 2023, the positioning block 4 moves toward the small end of the positioning hole 202 When moving, the side wall of the positioning block 4 and the inner wall of the positioning hole 202 slide relative to each other, and the tool holder 2 moves into the oblique mounting hole 101. During the process, the pressure spring 6 is compressed, and the spring potential energy of the pressure spring 6 gradually increases. After rotating the adjusting bolt 9 to the required adjustment amount in conjunction with the dial 10, rotate the fastening bolt 8 to screw it into the tool rod 1, and the locking block fits with the inner wall of the positioning groove 203 on this side, and the positioning boss 102 fits with the inner wall of the positioning groove 203 on this side, thereby completing the locking of the locking block and the tool holder 2, and the tool holder 2 is constrained in the axial direction of the oblique mounting hole 101; that is, the adjustment of the boring tool is completed, and the machining diameter of the boring tool after adjustment is reduced.

[0042] See also Figures 1 to 6 and Figure 8 When the machining diameter of the boring tool is increased, the adjusting bolt 9 is rotated to make it rotate outward from the tool arbor 1, and the positioning block 4 rotates along with the adjusting bolt 9 and moves toward the large end of the positioning hole 202. The adjusting bolt 9 is rotated to make the positioning block 4 move toward the large end of the positioning hole 202, and the side wall of the positioning block 4 is separated from the inner wall of the positioning hole 202. After the adjusting bolt 9 is rotated to the required adjustment amount in conjunction with the scale plate 10, the fastening bolt 8 is rotated to make it rotate outward from the tool arbor 1, and the locking block is separated from the inner wall of the positioning groove 203 on this side, thereby releasing the locking block from the tool holder 2, and the tool holder 2 is fixed in the oblique mounting hole. The constraint on the axial direction of 101 is released; the spring force of the pressure spring 6 acts on the tool holder 2 and pushes the tool holder 2 until the inner wall of the positioning hole 202 is in contact with the outer wall of the positioning block 4, and the fastening bolt 8 is rotated to screw it into the tool rod 1. The locking block is in contact with the inner wall of the positioning groove 203 on this side, and the positioning boss 102 is in contact with the inner wall of the positioning groove 203 on this side, thereby completing the locking of the locking block and the tool holder 2, and the tool holder 2 is constrained in the axial direction of the oblique mounting hole 101; that is, the adjustment of the boring tool is completed, and the processing diameter of the boring tool after adjustment is increased.

[0043] A specific embodiment of the present invention has been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the embodiment described above. For those skilled in the art, various changes, modifications, substitutions, and variations to these embodiments without departing from the principles and ideas of the present invention should still fall within the scope of protection of the present invention.

Claims

1. A CNC tool for precision machining, comprising a tool bar (1), a tool holder (2) and a blade (3), characterized in that: The front side of the knife rod (1) is provided with an oblique mounting hole (101), the axis of the oblique mounting hole (101) is at a 45° angle with the axis of the knife rod (1), the oblique mounting hole (101) passes through the left and right sides of the knife rod (1), and the oblique mounting hole (101) does not pass through the front end surface of the knife rod (1), the knife seat (2) is slidably connected in the oblique mounting hole (101), the upper end surface of the knife rod (1) away from the knife rod (1) is provided with a mounting groove (201), the blade (3) can be detachably installed in the mounting groove (201), the upper end of the knife rod (1) is provided with a countersunk vertical mounting hole (104), the bottom wall of the vertical mounting hole (104) is provided with a vertical downward threaded hole (103), the The threaded hole (103) completely penetrates the upper and lower sides of the knife rod (1); the adjusting bolt (9) is coaxially arranged in the threaded hole (103); a positioning hole (202) is provided on the knife seat (2); the positioning hole (202) completely penetrates the upper and lower sides of the knife seat (2); the adjusting bolt (9) penetrates the positioning hole (202); a transmission component is provided in the positioning hole (202); the transmission component is connected with the adjusting bolt (9) and the positioning hole (202); and the adjusting bolt (9) converts the rotation of the adjusting bolt (9) into the linear motion of the knife seat (2) through the transmission component; a fastening component is provided on the knife rod (1); the fastening component is used to limit or release the sliding between the knife seat (2) and the oblique mounting hole (101).

2. A CNC tool for precision machining according to claim 1, characterized in that: The transmission assembly comprises a positioning block (4), the positioning hole (202) is a waist-shaped hole, the inner side wall of the positioning hole (202) is an inclined surface, and the small end of the positioning hole (202) is located at the bottom, and the inner side wall of the positioning hole (202) is divided into a first positioning surface (2021), a transition positioning surface (2022) and a second positioning surface (2023) in sequence along the axial direction of the oblique mounting hole (101), the first positioning surface (2021) is the shortest distance from the blade (3), and the large end diameter of the first positioning surface (2021) is larger than the large end diameter of the second positioning surface (2023). The positioning block (4) is in the shape of a cone with a small end at the bottom, the side wall of the positioning block (4) is slidably connected to the inner wall of the positioning hole (202), the adjusting bolt (9) comprises, from bottom to top, a lower threaded section (903), a smooth section (902) and an upper threaded section (901), the positioning block (4) and the smooth section (902) are interference fit, the upper end surface of the positioning block (4) is in contact with the bottom of the upper threaded section (901), a dial (10) is coaxially mounted in the vertical mounting hole (104), and the dial (10) is fixedly connected to the adjusting bolt (9).

3. A CNC tool for precision machining according to claim 2, characterized in that: The taper of the positioning block (4) is 1:1.7678, the slopes of the No. 1 positioning surface (2021), the transition positioning surface (2022) and the No. 2 positioning surface (2023) are all 1:3.5355, the pitches of the upper thread segment (901) and the lower thread segment (903) are both 0.25 mm, and the scale of the dial (10) is 50 equally divided scales.

4. A CNC tool for precision machining according to claim 2, characterized in that: A spring mounting opening is provided on the side wall of the end of the knife seat (2) away from the blade (3); the axis of the spring mounting hole (204) is at 45 degrees to the axis of the knife rod (1); the spring mounting hole (204) completely passes through the positioning hole (202) but does not completely pass through the knife seat (2); a pressure spring (6) is provided in the spring mounting hole (204); one end of the pressure spring (6) is connected to the end of the spring mounting hole (204) close to the blade (3), and the other end is connected to an adjustment block (7); the side of the adjustment block (7) away from the pressure spring (6) is slidably connected to the side wall of the positioning block (4).

5. A CNC tool for precision machining according to claim 2, characterized in that: The fastening assembly comprises a fastening block (5) and a fastening bolt (8); positioning grooves (203) are provided on both side walls of the knife seat (2) parallel to the oblique mounting hole (101); a positioning boss (102) is provided on one side wall of the oblique mounting hole (101) close to the rear end of the knife rod (1); two threaded through holes are provided on one side wall of the oblique mounting hole (101) close to the front end of the knife rod (1); fastening bolts (8) are provided in both the threaded through holes; the fastening block (5) ) is arranged in the oblique mounting hole (101), one end of the fastening bolt (8) extending into the oblique mounting hole (101) is rotatably connected to the fastening block (5), the two side walls of the positioning groove (203) are inclined surface structures with the same inclination, the positioning boss (102) and the fastening block (5) are both slidably matched with the positioning groove (203), the depth of the positioning groove (203) is H1, and the height of the positioning boss (102) and the fastening block (5) is H2, wherein H1>H2.

6. A CNC tool for precision machining according to claim 5, characterized in that: The front and rear ends of the fastening block (5) are both provided with a deformable flexible sheet (11), the two side walls of the flexible sheet (11) are respectively flush with the two side walls of the fastening block (5), and the height of the flexible sheet (11) is H3, wherein H1<H3.

7. A CNC tool for precision machining according to claim 1, characterized in that: The knife rod (1) and the knife seat (2) are both made of hard alloy steel, and the surface is blackened, and the adjusting bolt (9) is made of stainless steel.

8. A CNC tool for precision machining according to claim 2, characterized in that: The first positioning surface (2021), the transition positioning surface (2022) and the second positioning surface (2023) are all surface hardened to HBC65-HBC68, and the side wall of the positioning block (4) is nitrided, the nitrided layer is 0.1-0.2 mm thick, and the surface hardness is HBC68-HBC72.

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