Machining method for straight line curved surface of inner cavity of workpiece

Abstract

The invention discloses a machining method for a straight line curved surface of an inner cavity of a workpiece, and belongs to the field of machining. The machining method for the straight line curved surface of the inner cavity of the workpiece comprises the steps that the inner cavity of the to-be-machined workpiece is divided into a plurality of machining sections in the circumferential direction of the inner cavity of the to-be-machined workpiece, and each machining section comprises a plurality of sub-machining sections which are sequentially connected in the circumferential direction of the inner cavity of the to-be-machined workpiece; a machining cutter is provided, the machining cutter comprises a cutter handle and a plurality of blades to be replaced, and the blades are matched with the cutter handle; and the machining sub-sections are sequentially machined through the machining tool, and after one machining sub-section is machined, the blade of the machining tool is replaced with one of the multiple blades to be replaced. According to the embodiment of the invention, the high-precision straight line curved surface can be machined in the inner cavity of the large-size workpiece.

Description

Technical Field

[0001] The present disclosure relates to the field of machining, and particularly to a method for machining a ruled surface in the inner cavity of a workpiece. Background Art

[0002] In the field of machining, milling is usually used to machine the inner cavity of a workpiece.

[0003] In the related art, there is a workpiece in which a ruled surface needs to be machined in its inner cavity. The cross-sectional shape of the inner cavity of this workpiece is irregular, and the size is large, with an axial depth reaching 400 mm and a cross-sectional perimeter reaching 2000 mm. Moreover, the machining accuracy requirements for the ruled surface are relatively high, with a surface roughness requirement of Ra1.6 and a dimensional tolerance of IT7 grade.

[0004] Due to the large size of the inner cavity of the workpiece and high machining accuracy requirements in the related art, the conventional machining methods cannot meet its machining requirements. Summary of the Invention

[0005] Embodiments of the present disclosure provide a method for machining a ruled surface in the inner cavity of a workpiece, which can machine a high-precision ruled surface in the inner cavity of a large-sized workpiece. The technical solution is as follows:

[0006] On the one hand, embodiments of the present disclosure provide a method for machining a ruled surface in the inner cavity of a workpiece, including:

[0007] Circumferentially along the inner cavity of the workpiece to be machined, divide the inner cavity of the workpiece to be machined into multiple machining segments, and each of the machining segments includes a plurality of sub-machining segments connected in sequence along the circumference of the inner cavity of the workpiece to be machined;

[0008] Provide a machining tool, the machining tool includes a tool holder and a plurality of replaceable blades, and each of the blades is matched with the tool holder;

[0009] Successively machine each of the sub-machining segments with the machining tool, and after machining one of the sub-machining segments, replace the blade of the machining tool with one of the plurality of replaceable blades.

[0010] In an implementation manner of the present disclosure, dividing the inner cavity of the workpiece to be machined into multiple machining segments includes:

[0011] According to the circumference of the inner cavity of the workpiece to be machined, evenly divide the inner cavity of the workpiece to be machined into multiple machining segments;

[0012] According to the designed shape of the ruled surface, divide each of the machining segments into a plurality of the sub-machining segments;

[0013] A plurality of the sub - processing segments of the same processing segment are respectively designed as a first curve segment, a first transition segment, a second curve segment, and a second transition segment.

[0014] In an implementation manner of the present disclosure, designing a plurality of the sub - processing segments of the same processing segment as a first curve segment, a first transition segment, a second curve segment, and a second transition segment respectively includes:

[0015] Making the first transition segment tangent to the first curve segment and making the first transition segment tangent to the second curve segment;

[0016] Making the second transition segment tangent to the second curve segment, and making the second transition segment tangent to the first curve segment of another adjacent processing segment.

[0017] In an implementation manner of the present disclosure, successively processing each of the sub - processing segments by the processing tool includes:

[0018] Adopting an arc - type approach for the approach tool path at the connection of each of the sub - processing segments, and adopting an arc - type retraction for the retraction tool path at the connection of each of the sub - processing segments.

[0019] In an implementation manner of the present disclosure, successively processing each of the sub - processing segments by the processing tool includes:

[0020] Calculating the actual cutting diameter of the processing tool;

[0021] Processing the sub - processing segments based on the actual cutting diameter.

[0022] In an implementation manner of the present disclosure, calculating the actual cutting diameter of the processing tool includes:

[0023] Providing a trial - cut workpiece;

[0024] Determining the trial - cut dimension;

[0025] Using the processing tool, according to the trial - cut dimension, respectively machining a first trial - cut surface and a second trial - cut surface on the trial - cut workpiece, where the first trial - cut surface and the second trial - cut surface are two parallel and opposite planes;

[0026] Measuring the distance between the cut surfaces, where the distance between the cut surfaces is the distance between the first trial - cut surface and the second trial - cut surface;

[0027] Calculating the actual cutting diameter of the processing tool according to the following calculation formula:

[0028] Φd 实 =(H 理 +Φd 理 ) - H 实 ;

[0029] Among them, Φd 实 is the actual cutting diameter, and H 理 is the trial cutting size, Φd 理 is the theoretical cutting diameter of the machining tool, and H 实 is the section spacing.

[0030] In an implementation manner of the present disclosure, the material of the trial cutting piece is the same as that of the inner cavity of the workpiece to be machined.

[0031] In an implementation manner of the present disclosure, a machining tool is provided, including:

[0032] Check the outer circle runout of each of the blades to ensure that the outer circle runout of each blade does not exceed.mm.

[0033] In an implementation manner of the present disclosure, the machining tool further includes:

[0034] Use a shock-proof tool shank as the tool holder and a fine milling cutter as the blade.

[0035] In an implementation manner of the present disclosure, the machining tool further includes:

[0036] The overhang length of the machining tool is greater than the axial depth of the inner cavity of the workpiece to be machined by 6~mm.

[0037] The beneficial effects brought by the technical solution provided by the embodiments of the present disclosure at least include:

[0038] Through the machining method provided by the embodiments of the present disclosure, a straight-grooved surface can be machined in the inner cavity of the workpiece. During the machining process, first, the inner cavity of the workpiece to be machined is evenly divided into multiple machining segments along its circumferential direction, and further, each machining segment is divided into multiple sequentially connected sub-machining segments along the circumferential direction of the inner cavity of the workpiece to be machined, thereby providing an accurate machining range for subsequent segmented machining. Then, a machining tool is provided. The machining tool includes a tool holder and a plurality of replaceable blades, and each blade is matched with the tool holder, that is, each blade can be installed on the tool holder when needed to form a machining tool. Then, each sub-machining segment is machined in sequence by the machining tool. During the machining process, after each sub-machining segment is machined, the blade on the machining tool is replaced with one of the replaceable blades. In this way, it can be ensured that each sub-machining segment is machined with a new blade, effectively avoiding the reduction of machining accuracy caused by blade wear.

[0039] That is to say, in the processing method provided by the embodiments of the present disclosure, the inner cavity of the workpiece to be processed is divided into multiple sub-processing segments, and a new cutting tool is replaced before processing each sub-processing segment. In this way, even if the size of the inner cavity of the workpiece to be processed is large, the problem of reduced processing accuracy caused by the long-term wear of the cutting tool will not occur, so that a high-precision ruled surface can be processed in the inner cavity of the large-size workpiece. Description of the Drawings

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0041] Figure 1 is the front view of the workpiece provided by the embodiments of the present disclosure;

[0042] Figure 2 is the sectional view of the workpiece provided by the embodiments of the present disclosure in the A-A direction;

[0043] Figure 3 is the flowchart of a method for processing a ruled surface of the inner cavity of a workpiece provided by the embodiments of the present disclosure;

[0044] Figure 4 is the schematic diagram of the division of the processing segments provided by the embodiments of the present disclosure;

[0045] Figure 5 is the structural schematic diagram of the processing tool provided by the embodiments of the present disclosure;

[0046] Figure 6 is the flowchart of another method for processing a ruled surface of the inner cavity of a workpiece provided by the embodiments of the present disclosure;

[0047] Figure 7 is the schematic diagram of trial cutting provided by the embodiments of the present disclosure.

[0048] Reference Numerals in the Drawings:

[0049] 10. Processing Segment;

[0050] 20. Sub-Processing Segment;

[0051] 210. First Curve Segment; 220. First Transition Segment; 230. Second Curve Segment; 240. Second Transition Segment;

[0052] 30. Processing Tool;

[0053] 310. Tool Shank; 320. Cutting Tool;

[0054] 40. Test cutting piece; 410. First test cutting surface; 420. Second test cutting surface;

[0055] 100. Inner cavity of the workpiece. Specific implementation manner

[0056] To make the purpose, technical solution and advantages of the present disclosure clearer, the following will further describe the embodiments of the present disclosure in detail with reference to the accompanying drawings.

[0057] The embodiment of the present disclosure provides a method for machining a ruled surface of the inner cavity of a workpiece. This machining method is used to machine and obtain Figure 1 and Figure 2 the workpieces shown. Among them, Figure 1 is the front view of the workpiece, Figure 2 is the sectional view of the workpiece in the A-A direction.

[0058] Combined with Figure 1 and Figure 2 , the middle part of the workpiece has an inner cavity 100 of the workpiece. The inner contour of the inner cavity of the workpiece is approximately cylindrical. The axial depth of the inner cavity of the workpiece is 400 mm, and the ruled surface machining is on the cavity wall of the inner cavity of the workpiece.

[0059] Figure 3 is the flowchart of a method for machining a ruled surface of the inner cavity of a workpiece provided by the embodiment of the present disclosure. Combined with Figure 3 , in this embodiment, this machining method includes:

[0060] Step 301: Divide the inner cavity of the workpiece to be machined into multiple machining segments 10 along the circumferential direction of the inner cavity of the workpiece to be machined. Each machining segment 10 includes multiple sub-machining segments 20 connected in sequence along the circumferential direction of the inner cavity of the workpiece to be machined (see Figure 4 , in order to clearly show each sub-machining segment 20, Figure 4 only shows the outer edge contour of the side of the inner cavity of the workpiece).

[0061] Step 302: Provide a machining tool 30 (see Figure 5 ). The machining tool 30 includes a tool shank 310 and multiple replaceable cutting blades 320. Each cutting blade 320 is matched with the tool shank 310.

[0062] Step 303: Machine each sub-machining segment 20 in sequence through the machining tool 30.

[0063] Moreover, after machining one sub-machining segment 20, replace the cutting blade 320 of the machining tool 30 with one of the multiple replaceable cutting blades 320.

[0064] Through the processing method provided by the embodiments of the present disclosure, a ruled surface can be machined in the inner cavity of a workpiece. During the machining process, first, the inner cavity of the workpiece to be machined is evenly divided into a plurality of machining segments 10 along its circumferential direction, and further, each machining segment 10 is divided into a plurality of sequentially connected sub-machining segments 20 along the circumferential direction of the inner cavity of the workpiece to be machined, thereby providing an accurate machining range for subsequent segmented machining. Then, a machining tool 30 is provided. The machining tool 30 includes a tool shank 310 and a plurality of replaceable inserts 320. Each insert 320 is matched with the tool shank 310, that is, each insert 320 can be mounted on the tool shank 310 when needed to form the machining tool 30. Then, each sub-machining segment 20 is machined in sequence by the machining tool 30. During the machining process, after each sub-machining segment 20 is machined, the insert 320 on the machining tool 30 is replaced with one of the replaceable inserts 320. In this way, it can be ensured that each sub-machining segment 20 is machined with a new insert 320, effectively avoiding the reduction of machining accuracy caused by the wear of the insert 320.

[0065] That is to say, in the processing method provided by the embodiments of the present disclosure, the inner cavity of the workpiece to be machined is divided into a plurality of sub-machining segments 20, and a new insert 320 is replaced before machining each sub-machining segment 20. In this way, even if the size of the inner cavity of the workpiece to be machined is large, there will be no problem of reduced machining accuracy caused by the long-term machining wear of the insert 320, so that a high-precision ruled surface can be machined in the inner cavity of a large-size workpiece.

[0066] Figure 6 The flowchart of another method for machining a ruled surface in the inner cavity of a workpiece provided by the embodiments of the present disclosure is combined with Figure 6 , in this embodiment, the processing method includes:

[0067] Step 601: Along the circumferential direction of the inner cavity of the workpiece to be machined, the inner cavity of the workpiece to be machined is divided into a plurality of machining segments 10, and each machining segment 10 includes a plurality of sub-machining segments 20 that are sequentially connected along the circumferential direction of the inner cavity of the workpiece to be machined (see Figure 4 ).

[0068] In the above implementation, the division of the inner cavity of the workpiece to be processed is carried out in two stages. The first stage is to evenly divide the inner cavity of the workpiece to be processed into multiple processing segments 10. Since the processing segments 10 are evenly divided, it can ensure that the processing time of each processing segment 10 is almost the same, and the wear degree of the processing tool 30 is also the same, which is convenient for controlling the wear condition of the processing tool 30. The second stage is to divide each processing segment 10 into multiple sub-processing segments 20. In this way, the wear condition of the processing tool 30 can be controlled more precisely. During the process of dividing the sub-processing segments 20, it can be divided according to the shape of the ruled surface to ensure that the inner cavity of the processed workpiece can meet the design requirements.

[0069] In this embodiment, step 601 includes the following steps:

[0070] Step 6011: According to the perimeter of the inner cavity of the workpiece to be processed, evenly divide the inner cavity of the workpiece to be processed into multiple processing segments 10.

[0071] Step 6012: According to the designed shape of the ruled surface, divide each processing segment 10 into multiple sub-processing segments 20.

[0072] In the above implementation, the designed shape of the ruled surface refers to the shape of the ruled surface expected to be processed.

[0073] In this embodiment, multiple sub-processing segments 20 of the same processing segment 10 are respectively designed as a first curve segment 210, a first transition segment 220, a second curve segment 230, and a second transition segment 240 (see Figure 4 ). Among them, the first curve segment 210 is a surface with a smaller diameter, the diameter of the first curve segment 210 is 600 mm, the second curve segment 230 is a surface with a larger diameter, the diameter of the second curve segment 230 is 650 mm, and the first transition segment 220 and the second transition segment 240 are connected between the first curve segment 210 and the second curve segment 230 to achieve a smooth transition between the first curve segment 210 and the second curve segment 230.

[0074] In order to ensure that the first transition segment 220 and the second transition segment 240 can play a good role in smooth transition, exemplarily, during the process of dividing multiple sub-processing segments 20 of the same processing segment 10, for the first transition segment 220, the first transition segment 220 is tangent to the first curve segment 210 and tangent to the second curve segment 230. For the second transition segment 240, the second transition segment 240 is tangent to the second curve segment 230, and the second transition segment 240 is tangent to the first curve segment 210 of the adjacent another processing segment 10.

[0075] In the above implementation, both the first transition section 220 and the second transition section 240 include two sections of curves, which are smoothly connected between the two sections of curves. The first section of curve is tangent to and smoothly connected with the first curve section 210, and the second section of curve is tangent to and smoothly connected with the second curved surface. Through the first transition section 220 and the second transition section 240, the machining tool 30 can smoothly transition between the first curve section 210 and the second curve section 230, effectively ensuring the machining accuracy of the ruled surface.

[0076] Step 602: Provide a machining tool 30 (see Figure 5 ), the machining tool 30 includes a tool shank 310 and a plurality of replaceable inserts 320, and each insert 320 is matched with the tool shank 310.

[0077] In the above implementation, each replaceable insert 320 is matched with the tool shank 310, that is, each replaceable insert 320 can be installed on the tool shank 310 to form the machining tool 30.

[0078] Exemplarily, in step 602, check the outer circle runout of each insert 320 to ensure that the outer circle runout of each insert 320 does not exceed 0.01 mm.

[0079] In this way, the accuracy during machining by the machining tool 30 can be effectively ensured.

[0080] Exemplarily, in step 602, use a shock-absorbing tool shank as the tool shank 310 and a fine milling cutter as the insert 320.

[0081] In the above implementation, using a shock-absorbing tool shank as the tool shank 310 can effectively reduce the vibration generated by the machining tool 30 during machining, which is beneficial to improving the machining accuracy. And using a fine milling cutter as the insert 320 is also beneficial to improving the machining accuracy.

[0082] Since the axial depth of the inner cavity of the workpiece to be machined is relatively large, it is necessary to ensure that the machining tool 30 can move sufficiently in the inner cavity of the workpiece to be machined during machining without interference and collision with the workpiece to be machined.

[0083] To this end, exemplarily, in step 602, the overhang length of the machining tool 30 is 60 - 100 mm greater than the axial depth of the inner cavity of the workpiece to be machined.

[0084] For example, if the axial depth of the inner cavity of the workpiece to be machined is 400 mm, then the overhang length of the machining tool 30 should be 460 - 500 mm.

[0085] In this embodiment, the overhang length of the machining tool 30 is 480 mm. Designing the overhang length of the machining tool 30 as the above value can, on the one hand, ensure that there is no interference collision between the machining tool 30 and the workpiece to be machined, and on the other hand, avoid the vibration of the machining tool 30 caused by the excessive overhang length of the machining tool 30.

[0086] It should be noted that the overhang length of the machining tool 30 refers to the distance between the tip of the cutting blade 320 and the part of the tool shank 310 clamped by the spindle socket after the cutting blade 320 and the tool shank 310 are combined.

[0087] Step 603: Machine the first curve segment 210 with the machining tool 30.

[0088] In this embodiment, step 603 includes:

[0089] Step 6031: Calculate the actual cutting diameter of the machining tool 30.

[0090] Exemplarily, step 6031 includes:

[0091] First, provide a trial cut workpiece 40.

[0092] It should be noted that in order to ensure the accuracy of the actual cutting diameter, the material of the trial cut workpiece 40 is the same as that of the inner cavity of the workpiece to be machined.

[0093] Next, determine the trial cut size.

[0094] In the above implementation, the trial cut size is the feed rate of the machining tool 30 when cutting the trial cut workpiece 40.

[0095] The trial cut size is a manually set value and can be manually set according to the size of the trial cut workpiece 40.

[0096] Then, with the machining tool 30, according to the trial cut size, machine the first trial cut surface 410 and the second trial cut surface 420 on the trial cut workpiece 40 respectively. The first trial cut surface 410 and the second trial cut surface 420 are two parallel and opposite planes (see Figure 7 ).

[0097] Then, measure the distance between the cut surfaces. The distance between the cut surfaces is the distance between the first trial cut surface 410 and the second trial cut surface 420.

[0098] Finally, according to the following calculation formula, calculate the actual cutting diameter of the machining tool 30:

[0099] Φd 实 =(H 理 +Φd 理 )-H 实 ; (1)

[0100] Among them, Φd 实 is the actual cutting diameter, and H 理 is the trial cutting size, Φd 理 is the theoretical cutting diameter of the machining tool 30, and H 实 is the section spacing.

[0101] Step 6032: Machine the first curve segment 210 of the sub-machining segment 20 based on the actual cutting diameter.

[0102] In step 6032, the cutting-in tool path adopts circular arc feed, the cutting-out tool path adopts circular arc retraction, and the machining process is continuous.

[0103] Step 604: Replace the blade 320 of the machining tool 30 with one of the multiple blades 320 to be replaced.

[0104] Step 605: Machine the first transition segment 220 through the machining tool 30.

[0105] Exemplarily, the process of step 605 is similar to that of step 603, and will not be elaborated here.

[0106] It should be noted that since the actual cutting diameter will change after the blade 320 is replaced, it is necessary to recalculate the actual cutting diameter after the blade 320 is replaced before machining.

[0107] Step 606: Replace the blade 320 of the machining tool 30 with one of the multiple blades 320 to be replaced.

[0108] Step 607: Machine the second curve segment 230 through the machining tool 30.

[0109] Exemplarily, the process of step 607 is similar to that of step 603, and will not be elaborated here.

[0110] Step 608: Replace the blade 320 of the machining tool 30 with one of the multiple blades 320 to be replaced.

[0111] Step 609: Machine the second transition segment 240 through the machining tool 30.

[0112] Exemplarily, the process of step 609 is similar to that of step 603, and will not be elaborated here.

[0113] Through steps 603 to 609, the machining of one machining segment 10 can be completed. After that, repeat steps 603 to 609 to complete the machining of all other machining segments in sequence.

[0114] Through the processing method provided by the embodiments of the present disclosure, a ruled surface can be machined in the inner cavity of a workpiece. During the machining process, first, the inner cavity of the workpiece to be machined is evenly divided into multiple machining segments 10 along its circumferential direction, and further, each machining segment 10 is divided into multiple sequentially connected sub-machining segments 20 along the circumferential direction of the inner cavity of the workpiece to be machined, thereby providing an accurate machining range for subsequent segmented machining. Then, a machining tool 30 is provided. The machining tool 30 includes a tool shank 310 and multiple replaceable inserts 320. Each insert 320 is matched with the tool shank 310, that is, each insert 320 can be installed on the tool shank 310 when needed to form the machining tool 30. Then, each sub-machining segment 20 is machined in sequence by the machining tool 30. During the machining process, after each sub-machining segment 20 is machined, the insert 320 on the machining tool 30 is replaced with one of the replaceable inserts 320. In this way, it can be ensured that each sub-machining segment 20 is machined with a new insert 320, effectively avoiding the reduction of machining accuracy caused by the wear of the insert 320.

[0115] That is to say, in the processing method provided by the embodiments of the present disclosure, the inner cavity of the workpiece to be machined is divided into multiple sub-machining segments 20, and a new insert 320 is replaced before machining each sub-machining segment 20. In this way, even if the size of the inner cavity of the workpiece to be machined is large, there will be no problem of reduced machining accuracy caused by the wear of the insert 320 during long-term machining, so that a high-precision ruled surface can be machined in the inner cavity of a large-size workpiece.

[0116] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meaning as understood by those of ordinary skill in the field to which the present disclosure belongs. The words "first", "second", "third" and similar terms used in the specification and claims of the present patent application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "a" or "one" do not indicate a quantity limitation, but indicate the existence of at least one. The words "comprising" or "including" and similar terms mean that the elements or objects appearing before "comprising" or "including" cover the elements or objects listed after "comprising" or "including" and their equivalents, and do not exclude other elements or objects. The words "connected" or "coupled" and similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", "top", "bottom" etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

[0117] The above is not any form of limitation to the present disclosure. Although the present disclosure has been disclosed as above through embodiments, it is not intended to limit the present disclosure. Any person skilled in the art can make some changes or modifications to form equivalent embodiments by using the technical content disclosed above within the scope of the technical solution of the present disclosure. However, as long as it does not depart from the technical solution of the present disclosure, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present disclosure still fall within the scope of the technical solution of the present disclosure.

Claims

1. A method for machining a ruled surface of a workpiece cavity, characterized in that: include: Dividing the inner cavity of the workpiece to be processed into a plurality of processing sections (10) along the circumference of the inner cavity of the workpiece to be processed, each of the processing sections (10) comprising a plurality of sub-processing sections (20) sequentially connected along the circumference of the inner cavity of the workpiece to be processed; A machining tool (30) is provided, wherein the machining tool (30) comprises a tool handle (310) and a plurality of blades (320) to be replaced, wherein each blade (320) matches the tool handle (310); Each of the sub-processing sections (20) is processed in sequence by the processing tool (30), and after processing a section of the sub-processing section (20), the blade (320) of the processing tool (30) is replaced with one of the multiple blades (320) to be replaced.

2. The processing method according to claim 1, characterized in that: The inner cavity of the workpiece to be processed is divided into a plurality of processing sections (10), including: According to the perimeter of the inner cavity of the workpiece to be processed, the inner cavity of the workpiece to be processed is evenly divided into a plurality of processing sections (10); According to the designed shape of the ruled curved surface, each processing section (10) is divided into a plurality of sub-processing sections (20); The plurality of sub-processing sections (20) of the same processing section (10) are respectively designed as a first curved section (210), a first transition section (220), a second curved section (230) and a second transition section (240).

3. The processing method according to claim 2, characterized in that: The plurality of sub-processing sections (20) of the same processing section (10) are respectively designed as a first curved section (210), a first transition section (220), a second curved section (230) and a second transition section (240), comprising: The first transition section (220) is tangent to the first curved section (210), and the first transition section (220) is tangent to the second curved section (230); The second transition section (240) is tangent to the second curved section (230), and the second transition section (240) is tangent to the first curved section (210) of another adjacent processing section (10).

4. The processing method according to claim 1, characterized in that: The processing sub-segments (20) are processed in sequence by the processing tool (30), comprising: The cutting-in tool path at the connection of each sub-processing section (20) adopts circular arc type cutting-in, and the cutting-out tool path at the connection of each sub-processing section (20) adopts circular arc type cutting-out.

5. The processing method according to claim 1, characterized in that: The processing sub-segments (20) are processed in sequence by the processing tool (30), comprising: Calculating and obtaining the actual cutting diameter of the machining tool (30); Based on the actual cutting diameter, the sub-processing section (20) is processed.

6. The processing method according to claim 5, characterized in that: Calculating the actual cutting diameter of the machining tool (30) comprises: Provide a trial cut piece; Determine the trial cutting size; Using the machining tool (30), a first test cutting surface and a second test cutting surface are respectively machined on the test cutting piece according to the test cutting size, wherein the first test cutting surface and the second test cutting surface are two parallel and opposite planes; The cut surface spacing is measured, where the cut surface spacing is the distance between the first test cut surface and the second test cut surface; The actual cutting diameter of the machining tool (30) is calculated according to the following formula: Φd 实 =(H 理 +Φd 理 )-H 实 ; Among them, Φd 实 is the actual cutting diameter, H 理 is the trial cutting size, Φd 理 is the theoretical cutting diameter of the machining tool (30), H 实 is the section spacing.

7. The processing method according to claim 6, characterized in that: The material of the trial-cut piece is the same as the material of the inner cavity of the workpiece to be processed.

8. The processing method according to claim 1, characterized in that: A machining tool (30) is provided, comprising: The outer circle runout of each blade (320) is checked to ensure that the outer circle runout of each blade (320) does not exceed 0.01 mm.

9. The processing method according to claim 1, characterized in that: A machining tool (30) is provided, further comprising: A vibration-proof tool rod is used as the tool handle (310), and a precision milling cutter is used as the blade (320).

10. The processing method according to claim 1, characterized in that: A machining tool (30) is provided, further comprising: The overhang length of the machining tool (30) is greater than the axial depth of the inner cavity of the workpiece to be machined by 60 to 100 mm.

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