A variable hole diameter machining device and method

Abstract

The application provides a variable-diameter hole machining device and method, which comprises a main tool bar, a top part of which is connected to a machine tool spindle through a tool holder, an upper part of which is drivenly connected with a planetary reduction structure, and a bottom part of which is provided with a first stepped hole diameter machining part; the first stepped hole diameter machining part is used for machining a first to-be-machined hole of a workpiece; the planetary reduction structure is engaged with a fixed gear cover and rotates inside the fixed gear cover under the driving of the main tool bar; the top part of the planetary reduction structure is rotatably connected to the main tool bar, and the bottom part is fixedly connected with a driven tool bar; the fixed gear cover is rotatably connected to the top part of the main tool bar and can be fixedly connected with a machine tool spindle housing; the driven tool bar is rotatably connected to the main tool bar, and the bottom part is provided with a second stepped hole diameter machining part; and the second stepped hole diameter machining part is used for machining a second to-be-machined hole of the workpiece. The application solves the problem of repeated positioning error accumulation in the tool changing process and has the advantages of high precision and low cost.

Description

Technical Field

[0001] This application relates to the field of machining technology, and more specifically, to a variable diameter hole machining apparatus and method. Background Technology

[0002] Currently, variable diameter hole parts are widely used in automotive and other industrial manufacturing fields. Some variable diameter hole parts have large and small hole diameters with significant dimensional differences. These parts require high positional accuracy and often involve multiple tool changes during machining, making them prone to coaxiality and positional inaccuracies. There are two main existing methods for machining variable diameter holes, as follows:

[0003] 1. Turning Method: This machining method has a limited processing range. For example, when turning holes with a length-to-diameter ratio greater than 4, the poor rigidity of the tool holder and the adverse factors such as vibration during cutting affect the cutting efficiency and the quality of the machined surface. This is especially true for deep holes with large diameters and variable diameter holes with steps, where the machining is even more difficult due to the rigidity of the tool holder and machine tool. In some cases, insufficient tool length may necessitate machining from both ends, which poses a greater challenge to ensuring the coaxial accuracy of the workpiece. When other machining elements (such as milling) are involved, secondary clamping is required, making it difficult to guarantee overall machining accuracy.

[0004] 2. Traditional milling method: This machining method involves many tool changes. During the repeated positioning of the tool, the machine tool clearance error accumulates, which greatly affects the machining accuracy. Due to the uncertainty of the accumulated machine tool clearance error, it is impossible to guarantee uniformity in dimensional control for the production of batch parts.

[0005] The machining tools and methods employed in this invention enable a single tool to complete six machining steps in one operation: roughing, semi-finishing, and finishing of large-diameter holes, and roughing, semi-finishing, and finishing of small-diameter holes. This allows for simultaneous machining of large and small holes at a fixed rotational speed, addressing the requirement of different tool rotation speeds. Furthermore, it solves the problem of accumulated positioning errors during tool changes. Summary of the Invention

[0006] The purpose of this application is to provide a variable diameter hole machining device and method, which can complete the roughing, semi-finishing, and finishing of the first and second holes to be machined in one operation using the same variable diameter hole machining device, thus solving the problem of accumulated positioning errors during tool changing; the specific solution is as follows:

[0007] A variable diameter hole machining apparatus, comprising:

[0008] The main tool holder is connected to the machine tool spindle at the top via a tool holder, has a planetary reduction gear connected to the upper drive, and has a first-step hole diameter machining section at the bottom.

[0009] The first stepped aperture machining part is used for machining a first to-be-machined hole of a workpiece.

[0010] The planetary reduction structure is rotatably connected to the top of the main tool bar and fixedly connected to the driven tool bar at the bottom.

[0011] The fixed gear cover is rotatably connected to the top of the main tool bar and fixedly connected to the machine tool spindle housing.

[0012] The driven tool bar is rotatably connected to the main tool bar and provided with a second stepped aperture machining part at the bottom.

[0013] The second stepped aperture machining part is used for machining a second to-be-machined hole of a workpiece.

[0014] Optionally, the main tool bar comprises an upper bar body, a middle bar body and a lower bar body connected in sequence from top to bottom; the top of the upper bar body is fixedly connected to the tool holder, the middle part is rotatably connected to the fixed gear cover, and the lower part is provided with a first protruding part and a second protruding part in sequence from top to bottom; the first protruding part is rotatably connected to the planetary reduction structure; the second protruding part is detachably connected to the middle bar body; the outer surface of the middle bar body is provided with a driving gear, and the driving gear is drivingly connected to the planetary reduction structure; the middle bar body is detachably connected to the lower bar body; and the first stepped aperture machining part is arranged at the bottom of the lower bar body.

[0015] Optionally, the upper and lower ends of the middle bar body are threadedly connected to the upper bar body and the lower bar body; the top of the lower bar body is integrally connected with a bearing protection cover at a position where the lower bar body is in abutment with the driven tool bar, and correspondingly, a needle bearing is arranged at a corresponding position of the driven tool bar.

[0016] Optionally, the first stepped aperture machining part and the second stepped aperture machining part are structurally identical and each comprises at least three aperture cutting parts; the three aperture cutting parts are a first-level aperture cutting part, a second-level aperture cutting part and a third-level aperture cutting part arranged in a stepped manner from top to bottom, and the outer diameters of the aperture cutting parts decrease in sequence from top to bottom; the outer surfaces of the first-level aperture cutting part, the second-level aperture cutting part and the third-level aperture cutting part are symmetrically provided with tool grooves at the bottom near the two sides of the edge; and a blade is detachably fixed in each tool groove.

[0017] Optionally, each blade protrudes outward from the tool groove, the back of the blade is in abutment with the groove bottom of the tool groove, the side edge of the blade is in abutment with the side edge of the tool groove, and the lower edge of the blade is a cutting part of the blade.

[0018] Optionally, the top of the fixed gear cover is provided with at least one limiting column, and the limiting column is insert-fittingly fixed to the machine tool spindle housing.

[0019] Optionally, the planetary reduction structure comprises:

[0020] The planet carrier is fixedly installed with a transmission component at the top center hole, and the lower part is fixedly connected with a driven cutter bar;

[0021] The transmission component is internally fixed with a bearing, and the first convex part is rotationally connected with the bearing;

[0022] Three planet gears are rotationally connected with the planet carrier, and each planet gear is in meshing connection with a driving gear on one side and a fixed gear cover on the other side.

[0023] A variable hole machining method, comprising the following steps:

[0024] Step one: determining the hole diameter sizes of a first to-be-machined hole and a second to-be-machined hole of a machining workpiece;

[0025] Step two: matching a corresponding main cutter bar and a driven cutter bar according to the hole diameters and machining depths of the first to-be-machined hole and the second to-be-machined hole;

[0026] Step three: adjusting the cutting amount of a first stepped hole diameter machining part based on the material of the machining workpiece and the hole diameter of the first to-be-machined hole, and matching the cutting speed based on the cutting amount;

[0027] Step four: adjusting the cutting amount of a second stepped hole diameter machining part based on the material of the machining workpiece and the hole diameter of the second to-be-machined hole, and matching the cutting speed based on the cutting amount.

[0028] Optionally, the cutting amount of the first stepped hole diameter machining part in the step three specifically comprises: calculating the rotating speed of the first stepped hole diameter machining part according to the formula n1=v1 / πD1, wherein v1 is the first to-be-machined hole cutting speed, D1 is the main cutter bar diameter, and n1 is the required machining rotating speed of the first to-be-machined hole; correspondingly, the cutting amount of the second stepped hole diameter machining part in the step four comprises: calculating the rotating speed of the driven cutter bar according to the formula n2=v2 / πD2, wherein v2 is the second to-be-machined hole cutting speed, D2 is the driven cutter bar diameter, and n2 is the required machining rotating speed of the second to-be-machined hole.

[0029] Optionally, the speed reduction ratio of the first to-be-machined hole required machining rotating speed n1 and the second to-be-machined hole required machining rotating speed n2 is obtained; and a corresponding planet speed reduction structure is matched according to the speed reduction ratio.

[0030] Compared with the prior art, the beneficial effects of the present application are:

[0031] The variable-diameter hole machining device can complete six processes of rough machining, semi-precision machining, precision machining of the second to-be-machined hole and rough machining, semi-precision machining and precision machining of the first to-be-machined hole at one time, can meet the inconsistent requirements of the machining tool rotating speed of the first to-be-machined hole and the second to-be-machined hole under the condition of fixed rotating speed, solves the problem of repeated positioning error accumulation in the tool changing process, and compared with the traditional machining method, saves the process, shortens the machining debugging time, improves the machining precision, improves the machining efficiency, saves the machining cost, and has more stability and accuracy compared with the traditional machining method. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of the variable-diameter hole machining device.

[0033] Figure 2 It is Figure 1 A-A sectional view.

[0034] Figure 3 It is Figure 2 the enlarged view of B in

[0035] Figure 4 It is another angle schematic diagram of the variable-diameter hole machining device.

[0036] Figure 5 It is a schematic diagram of the transmission structure of the planetary reduction structure and the main tool bar and the fixed gear cover.

[0037] Figure 6 It is a schematic diagram of the overall structure of the planetary reduction structure.

[0038] Figure 7 It is a schematic diagram of the structure of the workpiece.

[0039] In the figure:

[0040] 1, main tool bar;

[0041] 101, upper rod body;

[0042] 101A, first convex part;

[0043] 101B, second convex part;

[0044] 102, middle rod body;

[0045] 102A, driving gear;

[0046] 103, lower rod body;

[0047] 2, tool holder;

[0048] 3, planetary reduction structure;

[0049] 30, planetary support;

[0050] 31. transmission member;

[0051] 32. bearing;

[0052] 33. planetary gear;

[0053] 4A. first stepped bore machining portion;

[0054] 4B. second stepped bore machining portion;

[0055] 40. first bore cutting portion;

[0056] 41. second bore cutting portion;

[0057] 42. third bore cutting portion;

[0058] 43. tool groove;

[0059] 44. tool insert;

[0060] 5. first hole to be machined;

[0061] 6. second hole to be machined;

[0062] 7. fixed gear cover;

[0063] 8. driven tool bar;

[0064] 9. workpiece;

[0065] 10. bearing protection cover;

[0066] 11. limit post. DETAILED DESCRIPTION

[0067] In order to make the purposes, technical solutions and advantages of the present application clearer, the following will combine the accompanying drawings to further describe the present application in detail. Figures 1-7 It should be apparent that the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of the present application.

[0068] It should be understood that, although the terms first, second, third, etc. can be used in the embodiments of the present application to describe, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, without departing from the scope of the embodiments of the present application, the first can also be called the second, and similarly, the second can also be called the first.

[0069] Embodiment 1

[0070] The variable diameter hole machining device comprises a main tool bar 1, a first stepped hole machining part 4A, a planetary reduction structure 3, a fixed gear cover 7, a driven tool bar 8 and a second stepped hole machining part 4B; the main tool bar 1 is connected with the machine tool spindle through a tool holder 2 at the top, is drivenly connected with the planetary reduction structure 3 at the upper part, and is provided with the first stepped hole machining part 4A at the bottom; the first stepped hole machining part 4A is used for machining the first to-be-machined hole 5 of the workpiece 9; the planetary reduction structure 3 is engaged with the fixed gear cover 7 and rotates inside the fixed gear cover 7 under the driving of the main tool bar 1; the planetary reduction structure 3 is rotatably connected to the main tool bar 1 at the top and is fixedly connected with the driven tool bar 8 at the bottom; the fixed gear cover 7 is rotatably connected to the top of the main tool bar 1 and can be fixedly connected with the machine tool spindle shell, and the bottom of the fixed gear cover 7 is adjacent to the driven tool bar 8; the driven tool bar 8 is rotatably connected to the main tool bar 1 and is provided with the second stepped hole machining part 4B at the bottom, and the second stepped hole machining part 4B is used for machining the second to-be-machined hole 6 of the workpiece 9.

[0071] The hole diameter of the second to-be-machined hole 6 is greater than that of the first to-be-machined hole 5, the centers of the two holes coincide, and the ratio of the two is greater than four, so that the machining rotation speeds required by the two to-be-machined holes and the tool bars are different; in the actual machining process, the machining precision difference and the high machining cost of the two to-be-machined holes are faced, and the variable diameter hole machining device capable of machining the two to-be-machined holes at the same time is designed, six processes such as rough machining, semi-precision machining, precision machining of the second to-be-machined hole 6 and rough machining, semi-precision machining and precision machining of the first to-be-machined hole 5 are completed at one time through the same variable diameter hole machining device, the machining precision of the workpiece 9 is improved as a whole, the machining cost is reduced, especially in the mass production process, the machining time is greatly reduced, and the consistency of the machined workpiece 9 can be ensured.

[0072] The main cutter bar 1 comprises an upper bar body 101, a middle bar body 102 and a lower bar body 103 connected in sequence from top to bottom; the top of the upper bar body 101 is fixedly connected to the cutter holder 2, the middle part is rotatably connected to the fixed gear cover 7, and the lower part is sequentially provided with a first protrusion 101A and a second protrusion 101B from top to bottom; wherein the upper bar body 101 is rotatably connected to the fixed gear cover 7 through a ball bearing, and the upper and lower end faces of the inner ring and the outer ring of the ball bearing are provided with C-shaped clamping springs; the first protrusion 101A is rotatably connected with the planetary reduction structure 3 through a ball bearing; the second protrusion 101B is detachably connected with the middle bar body 102; the outer surface of the middle bar body is provided with a driving gear 102A, and the driving gear is drivingly connected with the planetary reduction structure 3; the middle bar body 102 is detachably connected with the lower bar body 103; the first stepped hole diameter machining part 4A is arranged at the bottom of the lower bar body 103; the advantages of the design are that the main cutter bar 1 is arranged to be detachable upper bar body 101, middle bar body 102 and lower bar body 103, which facilitates the assembly of the variable diameter hole machining device, and further brings the advantages that the main cutter bar 1 and the driven cutter bar 8 with matched length and outer diameter can be selected and replaced according to the different hole diameters and hole depths of the first hole to be machined 5 and the second hole to be machined 6.

[0073] It should be noted that the top of the main cutter bar 1 and the cutter holder 2 can be assembled together by screwing, clamping or interference, and in the embodiment, the main cutter bar 1 and the cutter holder 2 are fixed by interference, and the advantages of the design are that different cutter holders 2 can be matched with different types of cutter shanks according to different machining equipment, which is convenient for workers to select in the later period.

[0074] Further, the upper and lower ends of the middle bar body 102 are threadedly connected to the upper bar body 101 and the lower bar body 103; the advantages of the design are that the main cutter bar 1 is easy to install and replace through threaded connection; the top of the lower bar body 103 is integrally connected with a bearing protection cover 10 at the abutting part with the driven cutter bar 8, and correspondingly, a needle bearing is arranged at the corresponding position of the driven cutter bar 8; the advantages of the design are that the needle bearing is arranged to prevent friction between the driven cutter bar 8 and the lower bar body 103, which affects the service life of the bearing, and the bearing protection cover 10 is designed to prevent iron filings from entering the inside of the needle bearing and affecting the service life of the bearing.

[0075] Further, the first stepped aperture machining part 4A and the second stepped aperture machining part 4B are structurally identical and each comprises at least three aperture cutting parts; wherein the three aperture cutting parts are a first-level aperture cutting part 40, a second-level aperture cutting part 41 and a third-level aperture cutting part 42 arranged in a step-down manner, and the outer diameters of the aperture cutting parts decrease from top to bottom; the bottom of the outer surface of the first-level aperture cutting part 40, the second-level aperture cutting part 41 and the third-level aperture cutting part 42 is symmetrically provided with a tool groove 43 on both sides close to the edge, and a blade 44 is detachably fixed in each tool groove 43. In this application, the first stepped aperture machining part 4A and the second stepped aperture machining part 4B can be used to machine two holes to be machined of the workpiece 9, and the first-level aperture cutting part 40, the second-level aperture cutting part 41 and the third-level aperture cutting part 42 can be used for rough machining, semi-finish machining and finish machining of the corresponding holes to be machined. Of course, the workpiece 9 with higher precision requirements can also be provided with four aperture cutting parts, which can be selected according to actual conditions, and details are not described here.

[0076] Compared with the traditional machining method, the present application can complete the finish machining program of the workpiece 9 in one machining process, avoids the operations of secondary clamping, replacing the tool head during clamping process and repeated positioning of the tool, solves the problem of accumulated positioning error during tool replacement, shortens the machining debugging time, improves the machining precision, enhances the machining efficiency, saves the machining cost, and has more stability and accuracy compared with the traditional machining method.

[0077] Further, each blade 44 protrudes outwardly from the tool groove 43, the back of the blade 44 is attached to the groove bottom of the tool groove 43, the side edge of the blade 44 is attached to the side edge of the tool groove 43, and the lower edge of the blade 44 is the cutting part of the blade 44; wherein the blade 44 is fixed in the tool groove 43 by screws; the advantages of this design are that the blades 44 symmetrically arranged on both sides of the aperture cutting part are designed, and the installation position of the blade 44 is designed, so that the variable-diameter hole machining device of the present application rotates more stably during operation and has better cutting effect; secondly, the blade 44 is designed in a detachable manner, which is convenient for replacing the worn blade 44.

[0078] The top of the fixed gear cover 7 is provided with at least one limiting column 11, which can be inserted and fixed with the machine tool spindle housing; in this application, the top of the fixed gear cover 7 is provided with two limiting columns 11; the advantages of this design are that during use, the two limiting columns 11 are aligned with the insertion holes on the machine tool spindle housing; and the fixed gear cover 7 is prevented from rotating when the machine tool spindle rotates. It should be noted that the variable-diameter hole machining device of the present application needs to remain stationary during use.

[0079] The planetary reduction structure 3 comprises a planetary support 30, a transmission component 31 and three planetary gears 33; the planetary support 30 is coaxial with the main tool bar 1, and the transmission component 31 is fixedly installed at the top center hole; the lower part of the planetary support 30 is fixedly connected with the driven tool bar 8 in an interference manner; the transmission component 31 is internally fixed with a bearing 32, and the first protruding part 101A is rotationally connected through the bearing 32, wherein the bearing 32 is a ball bearing; the three planetary gears 33 are all rotationally connected on the planetary support 30 through two needle bearings, and the angle formed by the center of the planetary gears 33 and the virtual connection line of the shaft of the planetary support between any two of the planetary gears 33 is 120 degrees; the planetary support 30 is provided with a limit snap spring for limiting the downward sliding of the planetary gears 33; each planetary gear 33 is meshed with the driving gear 102A on one side and the fixed gear cover 7 on the other side.

[0080] The planetary reduction structure 3 can be driven by the main shaft of the machine tool, so that the main tool bar 1 and the driven tool bar 8 of the variable-diameter hole machining device have two different rotating speeds at the same time, thereby machining holes with different diameters. During use, workers can complete the finishing process of the two kinds of holes according to the designed machining path, greatly shorten the machining time, improve the machining precision and reduce the machining time cost.

[0081] The application also provides a variable-diameter hole machining method, which comprises the following steps:

[0082] Step one: determining the hole diameter sizes of the first to-be-machined hole 5 and the second to-be-machined hole 6 of the machining workpiece 9;

[0083] Step two: matching the corresponding main tool bar 1 and driven tool bar 8 according to the hole diameters and machining depths of the first to-be-machined hole 5 and the second to-be-machined hole 6;

[0084] Step three: adjusting the cutting amount of the first stepped hole diameter machining part 4A based on the material of the machining workpiece 9 and the hole diameter of the first to-be-machined hole 5, and matching the cutting speed based on the cutting amount;

[0085] Step four: adjusting the cutting amount of the second stepped hole diameter machining part 4B based on the material of the machining workpiece 9 and the hole diameter of the second to-be-machined hole 6, and matching the cutting speed based on the cutting amount.

[0086] The cutting amount of the first stepped hole machining part 4A in the step three specifically includes: calculating the rotating speed of the first stepped hole machining part 4A according to the formula n1=v1 / πD1, wherein v1 is the cutting speed of the first hole to be machined 5, D1 is the diameter of the main tool bar 1, and n1 is the required machining rotating speed of the first hole to be machined 5; correspondingly, the cutting amount of the second stepped hole machining part 4B in the step four includes: calculating the rotating speed of the driven tool bar 8 according to the formula: n2=v2 / πD2, wherein v2 is the cutting speed of the second hole to be machined 6, D2 is the diameter of the driven tool bar 8, and n2 is the required machining rotating speed of the second hole to be machined 6.

[0087] According to the required machining rotating speed n1 of the first hole to be machined 5 and the required machining rotating speed n2 of the second hole to be machined 6, the speed reduction ratio of the two is obtained; and according to the speed reduction ratio, the corresponding planetary speed reduction structure 3 is matched.

[0088] It should be noted that: the speed reduction ratio = input rotating speed / output rotating speed; in the present application, the main tool bar 1 is the input rotating speed, and the driven tool bar 8 is the output rotating speed; according to the speed reduction ratio, the number of teeth of the transmission gear can be calculated, the speed reduction ratio = the number of teeth of the planetary gear ÷ the number of teeth of the driving gear; the driving gear part in the main tool bar 1 is the fixed number of teeth of the driving gear, and the number of teeth of the planetary gear can be calculated by using this method.

[0089] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in various different forms, and should not be construed as being limited to only the embodiments set forth herein. It should be understood that the embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art, and in the drawings, the thickness of layers and regions can be exaggerated for clarity, and the same reference numerals are used throughout the drawings to designate the same elements, and thus a description thereof will be omitted.

Claims

1. A variable diameter hole machining device, characterized in that, include: The main tool holder (1) is connected to the machine tool spindle at the top via the tool holder (2), the upper drive is connected to the planetary reduction structure (3), and the bottom is provided with the first stepped hole diameter machining part (4A). The first stepped hole diameter machining section (4A) is used to machine the first hole (5) to be machined in the workpiece (9); The planetary reduction structure (3) has planetary gears that mesh with the fixed gear cover (7) and rotate inside the fixed gear cover (7) under the drive of the driving gear (102A) of the main cutter bar (1); the top of the planetary support of the planetary reduction structure (3) is rotatably connected to the main cutter bar (1), and the bottom is fixedly connected to the driven cutter bar (8). The fixed gear cover (7) is rotatably connected to the top of the main tool bar (1) and fixed to the machine tool spindle housing; The driven tool holder (8) is rotatably connected to the main tool holder (1), and a second stepped hole diameter machining part (4B) is provided at the bottom. The second-step bore diameter machining section (4B) is used to machine the second hole (6) of the workpiece (9).

2. The variable diameter hole processing device according to claim 1, characterized in that, The main cutter bar (1) includes an upper rod body (101), a middle rod body (102), and a lower rod body (103) connected sequentially from top to bottom. The top of the upper rod body (101) is fixedly connected to the tool holder (2), the middle part is rotatably connected to a fixed gear cover (7), and the lower part is provided with a first protrusion (101A) and a second protrusion (101B) sequentially from top to bottom. The first protrusion (101A) is rotatably connected to the planetary reduction structure (3). The second protrusion (101B) is detachably connected to the middle rod body (102). The outer surface of the middle rod body (102) is provided with a drive gear (102A), which is drivenly connected to the planetary reduction structure (3). The middle rod body (102) is detachably connected to the lower rod body (103). The first stepped hole diameter processing part (4A) is provided at the bottom of the lower rod body (103).

3. The variable diameter hole processing device according to claim 2, characterized in that, The upper and lower ends of the middle rod (102) are respectively connected to the upper rod (101) and the lower rod (103) by threads; the top of the lower rod (103) is integrally connected with the part that fits with the driven tool bar (8) and a bearing protection cover (10) is provided. Correspondingly, a needle roller bearing is provided at the corresponding position of the driven tool bar (8).

4. The variable diameter hole processing device according to claim 2, characterized in that, The first stepped aperture machining section (4A) and the second stepped aperture machining section (4B) have the same structure and both include at least three aperture cutting sections. The three aperture cutting sections are a first-level aperture cutting section (40), a second-level aperture cutting section (41), and a third-level aperture cutting section (42) distributed in upper and lower steps, and the outer diameter of the aperture cutting sections decreases from top to bottom. The bottom of the outer surface of the first-level aperture cutting section (40), the second-level aperture cutting section (41), and the third-level aperture cutting section (42) are symmetrically provided with tool grooves (43) near the edges, and each tool groove (43) is detachably fixed with a cutting blade (44).

5. The variable diameter hole processing device according to claim 4, characterized in that, Each blade (44) extends outward from the groove (43), and the back of the blade (44) is in contact with the bottom of the groove (43), the side of the blade (44) is in contact with the side of the groove (43), and the lower edge of the blade (44) is the cutting part of the blade (44).

6. The variable diameter hole machining device according to claim 1, characterized in that, The top of the fixed gear cover (7) is provided with at least one limiting post (11), which is inserted and fixed to the machine tool spindle housing.

7. The variable diameter hole processing device according to claim 2, characterized in that, The planetary deceleration structure (3) includes: The planetary support (30) has a transmission component (31) fixedly installed at the center hole at the top, and its lower part is fixedly connected to the driven tool bar (8); The transmission component (31) has a bearing (32) fixed inside and is rotatably connected to the first protrusion (101A) through the bearing (32). Three planetary gears (33) are rotatably connected to the planetary support (30). Each planetary gear (33) meshes with the driving gear on one side and with the fixed gear cover (7) on the other side.

8. A method for machining a variable diameter hole, characterized in that, The method applied to the variable diameter hole machining apparatus of claim 1 includes the following steps: Step 1: Determine the diameter of the first hole to be machined and the second hole to be machined (6) of the workpiece (9); Step 2: Match the corresponding master tool bar (1) and driven tool bar (8) according to the hole diameter and hole depth of the first and second holes to be machined (6). Step 3: Based on the material of the workpiece (9) and the diameter of the first hole to be processed, adjust the cutting amount of the first stepped hole diameter machining part, and match the cutting speed based on the cutting amount; Step 4: Adjust the cutting amount of the second-step hole diameter machining part (4B) based on the material of the workpiece (9) and the diameter of the second hole (6), and match the cutting speed based on the cutting amount.

9. The method for machining variable diameter holes according to claim 8, characterized in that, In step three, the rotational speed of the first stepped hole diameter machining section is calculated according to the formula n1=v1 / πD1, where v1 is the cutting speed of the first hole to be machined, D1 is the diameter of the main tool bar, and n1 is the required machining speed of the first hole to be machined; correspondingly, in step four, the rotational speed of the driven tool bar (8) can be calculated according to the formula n2=v2 / πD2, where v2 is the cutting speed of the second hole to be machined (6), D2 is the diameter of the driven tool bar (8), and n2 is the required machining speed of the second hole to be machined (6).

10. The method for machining a variable diameter hole according to claim 9, characterized in that, The reduction ratio is obtained based on the required machining speed n1 for the first hole to be machined and the required machining speed n2 for the second hole to be machined; the corresponding planetary reduction structure is matched according to the reduction ratio.

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