A processing method for multi-aperture thin-walled cylindrical parts

Abstract

The present invention provides a method for processing multi-aperture thin-walled cylindrical parts, comprising the steps of grinding a blank, rough turning the outer shape, inner hole machining, and fine turning the outer shape; wherein the blank is subjected to the rough turning step to obtain a workpiece, the workpiece being composed of a coaxially arranged cylindrical large end and a cylindrical small end, the large end having a larger diameter than the small end; the inner hole machining comprising the steps of drilling the small end, drilling the large end, reaming the large end, boring the large end, primary boring the small end, fine boring the large end, secondary boring the small end, machining the small end, and fine turning the inner hole of the small end. The present invention adjusts the machining surface and the clamping position multiple times, and uses a specific clamping tool to position and clamp the workpiece before machining the inner hole. The machining process has good stability and high accuracy, can effectively reduce deformation of the part during machining, avoid part vibration, and effectively control the concentricity of the inner hole within a specified range, thereby reducing the amount of scrapped parts, improving the yield rate, and thus avoiding an increase in manufacturing costs.

Description

Technical Field

[0001] The invention belongs to the technical field of thin-walled parts processing, and in particular relates to a processing method for multi-aperture thin-walled cylindrical parts. Background Art

[0002] like Figure 1 A multi-aperture thin-walled cylindrical part shown is mainly composed of two coaxial cylinders with different outer diameters (named as the big end and the small end respectively), and four coaxial inner holes of different calibers and interconnected inside the two cylinders (one inner hole inside the big end, three inner holes inside the small end, and one inner hole at the transition connection between the two). When actually producing and processing the inner holes of the part, the concentricity of the inner holes needs to be controlled within ±0.02 mm. However, since the part has many inner holes and is a thin-walled part, it brings great difficulty to processing. In particular, when the existing processing method is used to process the four inner holes, the concentricity of each inner hole is difficult to control well, because the thin-walled part needs to be clamped and corrected when processing the inner hole, and improper clamping during clamping can easily cause the thin-walled part to deform and vibrate, resulting in poor surface finish and unstable size of each inner hole after processing, and difficult to meet the concentricity standards, resulting in scrapped parts and low yield rate. Therefore, there is an urgent need to improve the existing processing methods to ensure that the concentricity of all inner holes in each finished product is within the specified range to improve the yield. Summary of the Invention

[0003] In order to solve the above problems, the purpose of the present invention is to provide a processing method for multi-aperture thin-walled cylindrical parts, which can effectively reduce the deformation of parts during processing, avoid part vibration, and thus reduce the amount of scrapped parts and improve the yield rate.

[0004] The technical solutions for achieving the above-mentioned purpose of the present invention are as follows:

[0005] A method for machining a multi-aperture thin-walled cylindrical part comprises grinding a blank, rough turning the outer shape, inner hole machining, and fine turning the outer shape; wherein the blank is subjected to the rough turning step to obtain a workpiece, the workpiece comprising a coaxially arranged cylindrical large end and a cylindrical small end, the large end having a larger diameter than the small end; the inner hole machining comprises the following steps:

[0006] Step S1. Drilling the small end: With the small end of the workpiece facing upward, the large end is used as the support surface, and the outer wall of the large end is positioned and clamped, a hole is drilled downward from the center of the small end to form a first center hole. The depth of the first center hole is greater than the length of the small end.

[0007] Step S2. Drilling the big end: With the big end of the workpiece facing upward, use the small end as the support surface, and position and clamp the outer wall of the big end, drill downward from the center of the big end to form a second center hole connected to the first center hole. The second center hole has the same diameter as the first center hole and is coaxial.

[0008] Step S3. Expanding the large end: Keeping the workpiece in the placement and positioning clamping state of step S2, continue expanding the second center hole inside the large end to enlarge the aperture of the second center hole.

[0009] Step S4. Boring the big end: Keep the workpiece in the placement and positioning clamping state of step S2, continue boring the second center hole inside the big end, expand the inner diameter of the second center hole, and increase the length of the second center hole in the direction of the first inner hole center hole, thereby forming the first inner hole inside the big end, and at the same time turning the big end end face to control the length of the first inner hole. After this step

[0010] Step S5. Boring the small end once: With the end face of the small end of the workpiece facing upward, the end face of the large end is used as the support surface, and the outer wall of the large end is positioned and clamped, the first center hole inside the small end is bored to expand the inner diameter of the first center hole, and then a second inner hole is formed at the transition connection between the small end and the large end, and a third inner hole is formed inside the small end.

[0011] Step S6. Big end precision boring: With the big end face of the workpiece facing upward and the small end face as the support surface, the lower part of the big end outer wall (near the small end) is positioned and clamped using a clamping fixture to bore the first inner hole, and the diameter and length of the first inner hole are continuously expanded until the diameter and length reach the specified numerical range.

[0012] Step S7. Secondary boring of the small end: The small end of the workpiece faces upward, with the large end as the support surface, and the expansion fixture is used to position and expand the inner wall of the large end, and the third inner hole is bored, and the diameter and length of the third inner hole are further expanded, while the outer wall of the small end is turned.

[0013] Step S8. Turning a hole at the small end: With the small end of the workpiece facing upward, use the large end as the support surface, and position and clamp the outer wall of the large end, continue turning the second inner hole and the third inner hole, expand the apertures of the second and third inner holes, and at the same time, turn the upper end of the third inner hole to form a fourth inner hole with a larger aperture than the third inner hole.

[0014] Step S9. Finish turning of the small end inner hole: With the small end face of the workpiece facing upwards, the large end end face is used as the support surface, and the expansion fixture is used to position and tighten the inner wall of the large end, and the second inner hole, the third inner hole, and the fourth inner hole are finish turned until the hole diameter and length reach the specified numerical range.

[0015] Furthermore, the length of the large end is greater than the length of the small end.

[0016] Furthermore, after completing step S4, the workpiece is first deburred and the appearance and size of the workpiece are checked, and then the workpiece is heat treated to remove the processing stress before proceeding to step S5.

[0017] Furthermore, the tooling used for positioning and clamping in steps S1-S5 and step S8 is a soft three-jaw chuck.

[0018] Furthermore, in step S1 , the depth of the first center hole is one-half to three-fifths of the total length of the workpiece.

[0019] Furthermore, the clamping tooling in step S6 includes a base, a mounting ring, a positioning column, and a clamping cover; the mounting ring is fixed to the top of the base; the positioning column is vertically fixed to the base and located in the center of the mounting ring, and the positioning column is tightly fitted with the third inner hole in step S5; the clamping cover is an inverted bowl-shaped body, the bottom of which is detachably connected to the mounting ring, and the top of the clamping cover is provided with a clamping hole concentric with the positioning column, and the clamping hole is tightly fitted with the lower part of the outer wall of the large end in step S6.

[0020] Furthermore, the bottom of the clamping cover is detachably connected to the mounting ring by a threaded connection, pressing the workpiece onto the base.

[0021] Furthermore, the clamping tool also includes a clamping ring, which is integrally fixed to the top of the clamping cover and concentric with the positioning column. The inner diameter of the clamping ring is equal to the inner diameter of the clamping hole, and the clamping ring is tightly fitted with the lower part of the outer wall of the large end in step S6.

[0022] Furthermore, the expansion fixture described in step S7 and step S9 includes a bottom plate, a base, an adjusting bolt, a center shaft, a lower sleeve, an upper sleeve, and an extrusion ball; the base is fixed on the bottom plate, and a mounting hole is formed in the center of the top of the base; a threaded hole connected to the mounting hole is provided on the side wall of the base; the adjusting bolt is threadedly connected in the threaded hole; the center shaft is vertically fixed in the mounting hole and extends upward from the mounting hole, and the diameter of the center shaft is smaller than the diameter of the mounting hole; the lower sleeve is fixed in the center of the top of the base and is sleeved outside the center shaft, the inner wall of the lower sleeve is aligned with the inner wall of the mounting hole, and an annular cavity connected to the mounting hole is formed between the inner wall of the lower sleeve and the outer wall of the center shaft; an expansion sleeve made of elastic material is integrally fixed in the middle of the lower sleeve, and the outer wall of the expansion sleeve protrudes outward from the outer wall of the lower sleeve; the upper sleeve is detachably sleeved on the center shaft, and its bottom is sealed at the top of the annular cavity; the extrusion ball is a plurality of spherical or ellipsoidal particles filled in the mounting hole, threaded hole, and annular cavity.

[0023] Furthermore, the expansion sleeve is made of carbon spring steel, thinner than the lower sleeve. Carbon spring steel typically has a carbon content (mass fraction) between 0.62% and 0.90%. Based on its manganese content, carbon spring steel is categorized into two types: standard manganese content (mass fraction) (0.50% to 0.80%), such as 65, 70, and 85, and higher manganese content (mass fraction) (0.90% to 1.20%), such as 65Mn. Under a certain load, the steel undergoes elastic deformation. Within a specified range, this elastic deformation allows it to withstand a certain load without permanent deformation after the load is removed.

[0024] Furthermore, the extrusion ball is a rubber ball, which can be squeezed and transmit pressure under the squeezing of the adjusting bolt, and finally expand the expansion sleeve.

[0025] The present invention adjusts the processing surface and the clamping position multiple times, and adopts a specific clamping tool to position and clamp the workpiece before processing the inner hole. The processing has good stability and high accuracy, can effectively reduce the deformation of parts during processing, avoid part vibration, and effectively control the concentricity of the inner hole within the specified range, thereby reducing the amount of scrapped parts, improving the yield rate, and avoiding an increase in manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 2 This is a schematic structural diagram of the clamping fixture of the present invention;

[0027] Figure 3 for Figure 2 sectional view of

[0028] Figure 4 This is a schematic structural diagram of the expansion tooling of the present invention;

[0029] Figure 5 for Figure 4 sectional view of

[0030] Figure 6 for Figure 5 Schematic diagram of the structure when the squeeze ball is not installed;

[0031] As shown in the figure: 1-base, 2-mounting ring, 3-positioning column, 4-clamping cover, 5-clamping hole, 6-clamping ring, 7-bottom plate, 8-base, 9-mounting hole, 10-threaded hole, 11-adjusting bolt, 12-center axis, 13-lower sleeve, 14-annular cavity, 15-expansion sleeve, 16-upper sleeve, 17-extrusion ball, 18-first inner hole, 19-second inner hole, 20-third inner hole, 21-fourth inner hole. DETAILED DESCRIPTION

[0032] The following specific embodiments illustrate the embodiments of the present invention. Those skilled in the art can easily understand the other advantages and effects of the present invention from the contents disclosed in this specification. The described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] It should be noted that the structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions for the implementation of the present invention. Therefore, they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose of the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", etc. quoted in this specification are only for the convenience of description and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0034] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances. Example 1

[0035] This embodiment provides a method for processing multi-aperture thin-walled cylindrical parts, including blank grinding (grinding the blank obtained by forging), rough turning (turning the shape of the part), inner hole processing, and fine turning (making the part's external dimensions reach a specified numerical range), wherein the blank is subjected to the rough turning step to obtain a workpiece, the workpiece consisting of a large end and a small end coaxially arranged, the large end having a larger diameter than the small end, and the large end having a larger length than the small end.

[0036] The inner hole processing specifically includes the following steps:

[0037] Step S1. Drilling the Small End: Place the workpiece with the small end facing upward, using the large end as the support surface (placed on the operating table), and using a soft three-jaw chuck to position and clamp the outer wall of the large end. Drill a hole from the center of the small end downward to form a first center hole. The depth of the first center hole is greater than the length of the small end, and the depth of the first center hole is approximately one-half of the total length of the workpiece. Before drilling the small end, first place the workpiece with the large end facing upward, using the small end as the support surface (placed on the operating table), and drill a positioning hole in the large end of the workpiece. When drilling the small end, align the positioning hole on the large end with a pre-set positioning column on the operating table for center positioning. Using center positioning and edge positioning can effectively ensure the concentricity of the first center hole is within the specified range.

[0038] Step S2. Drilling the big end: The big end of the workpiece faces upward, with the small end face as the support surface (placed on the operating table), and the soft three-jaw chuck is used to position and clamp the outer wall of the big end, and drilling is performed downward from the center of the big end face (the center of the positioning hole) (enlarging the depth and diameter of the positioning hole) to form a second center hole connected to the first center hole. The second center hole has the same diameter as the first center hole and is coaxial. The second center hole is smoothly aligned with the wall of the first center hole, and the diameter of the second center hole is about one-third of the outer diameter of the big end.

[0039] Step S3. Expanding the hole at the big end: Keep the workpiece in the placement and positioning clamping state of step S2, and continue to expand the second center hole inside the big end to expand the aperture of the second center hole by about twice.

[0040] Step S4. Boring the big end: Keep the workpiece in the placement and positioning clamping state of step S2, and continue boring the second center hole inside the big end, enlarging the inner diameter of the second center hole (slightly enlarging the second center hole diameter), and increasing the length of the second center hole in the direction of the first inner hole center hole (the second center hole extends in the direction of the first inner hole center hole), thereby forming the following inside the big end: Figure 1 The first inner hole 18 shown is formed by expanding, boring and lengthening the second center hole, and the end face of the big end is turned at the same time to control the length of the first inner hole 18. The first inner hole 18 is entirely located inside the big end.

[0041] After completing step S4, the workpiece is first deburred and the appearance and size of the workpiece are inspected. The workpiece is then heat treated to remove the machining stress before proceeding to step S5.

[0042] Step S5. Boring the small end once: the small end of the workpiece faces upward, with the large end end as the support surface (placed on the operating table), and the soft three-jaw chuck is used to locate and clamp the outer wall of the large end, and the first center hole inside the small end is bored to expand the inner diameter of the first center hole. The expansion is specifically divided into two steps. The first step of expansion is to expand the inner diameter of the first center hole, and the second step of expansion is to expand the aperture of the first center hole located in the internal area of ​​the small end, thereby forming a second inner hole at the transition connection between the small end and the large end (the diameter of the second inner hole is smaller than the first inner hole), and forming a third inner hole inside the small end, and the diameter of the third inner hole is larger than the second inner hole.

[0043] Step S6. Precision boring of the big end: With the big end of the workpiece facing upwards, use the small end as the support surface (placed on the operating table), and use the clamping fixture to locate and clamp the lower part of the big end outer wall (near the small end), bore the first inner hole, and continue to expand the diameter and length of the first inner hole until its diameter and length reach the specified numerical range, completing the processing of the inner hole inside the big end.

[0044] Step S7. Secondary boring of the small end: The small end of the workpiece faces upward, with the large end as the support surface (placed on the operating table), and the inner wall of the large end is positioned and tightened using the expansion fixture, and the third inner hole is bored, and the diameter and length of the third inner hole are further expanded, while the outer wall of the small end is turned.

[0045] Step S8. Turning a hole at the small end: With the small end of the workpiece facing upward, use the large end as the support surface (placed on the operating table), and use a soft three-jaw chuck to position and clamp the outer wall of the large end, continue turning the second inner hole 19 and the third inner hole 20, expand the apertures of the second inner hole 19 and the third inner hole 20, and at the same time, turn the upper end of the third inner hole 20 to form a fourth inner hole 21 with a larger aperture than the third inner hole 20.

[0046] Step S9. Finish turning of the small end inner hole: With the small end of the workpiece facing upwards, use the large end as the support surface (placed on the operating table), and use the expansion fixture to position and tighten the inner wall of the large end, and finish turn the second inner hole 19, the third inner hole 20, and the fourth inner hole 21 until the hole diameter and length reach the specified value range (such as Figure 1 shown).

[0047] like Figure 2 and Figure 3As shown, the clamping fixture in step S6 includes a base 1, a mounting ring 2, a positioning column 3, a clamping cover 4, and a clamping ring 6; the base 1 is installed on the machine tool operating table; the mounting ring 2 is fixed to the top of the base 1 and is provided with an external thread on its outer wall; the positioning column 3 is vertically fixed to the base 1 and is located in the center of the mounting ring 2 (the center line of the positioning column 3 coincides with the center line of the mounting ring 2), and the positioning column 3 is tightly fitted with the third inner hole 20 in step S5; the clamping cover 4 is an inverted bowl-shaped body, and its bottom is detachably connected to the mounting ring 2 by a threaded connection to press the workpiece onto the base. The top of the clamping cover 4 is provided with a clamping hole 5 concentric with the positioning column 3, and the clamping hole 5 is tightly fitted with the lower part of the outer wall of the large end in step S6. The clamping ring 6 is integrally fixed to the top of the clamping cover 4 and is concentric with the positioning column 3. The inner diameter of the clamping ring 6 is equal to the inner diameter of the clamping hole 5, and the clamping ring 6 is tightly fitted with the lower part of the outer wall of the large end in step S6. When processing step S6, the workpiece is placed with the large end face upward and the small end face as the support surface in the clamping fixture installed on the operating table. When placing, the small end is aligned downward with the positioning column 3 in the mounting ring 2 and moved vertically downward so that the third inner hole 20 of the small end is sleeved outside the positioning column 3 until the small end face contacts the upper surface of the base 1. Then, the lower end of the clamping cover 4 is aligned downward with the large end of the workpiece and moved vertically downward so that the large end is sleeved in the clamping cover 4. The clamping cover 4 continues to move downward so that the large end extends upward from the clamping ring at the top of the clamping cover 4. The clamping cover 4 is continued to move downward and spirally rotated so that the lower end of the clamping cover 4 is threadedly connected to the mounting ring 2 until the clamping ring 4 clamps the lower part of the outer wall of the large end. Next, the machine tool can be started to bore the first inner hole 18 inside the large end, and the aperture and length of the first inner hole 18 are continuously expanded until the aperture and length reach the specified numerical range, thereby completing the processing of the inner hole inside the large end.

[0048] like Figure 4-6As shown, the expansion fixture described in step S7 and step S9 includes a bottom plate 7 , a base 8 , an adjusting bolt 11 , a central shaft 12 , a lower sleeve 13 , an upper sleeve 16 , and a squeezing ball 17 . The bottom plate 7 is installed on the machine tool operating table; the base 8 is fixed on the bottom plate 7, and a mounting hole 9 is formed in the center of the top of the base 8; a threaded hole 10 connected to the mounting hole 9 is provided on the side wall of the base 8; the threaded hole 10 is arranged horizontally, and its two ends respectively pass through the outer wall of the base 8 and the mounting 9 hole; the adjusting bolt 11 is threadedly connected in the threaded hole 10 to adjust the expansion tightness; the center shaft 12 (lower end) is vertically fixed in the mounting hole 9, and its upper end extends upward from the mounting hole 9. The diameter of the center shaft 12 is smaller than the diameter of the mounting hole 9. There is an annular space between the center shaft 12 and the mounting hole 9 for the extrusion ball 17 to move; the lower sleeve 13 is fixed in the center of the top of the base 8 and is sleeved outside the center shaft 12. The inner wall of the lower sleeve 13 is aligned with the inner wall of the mounting hole 9 (smoothly aligned), and the inner wall of the lower sleeve 13 is aligned with the inner wall of the mounting hole 9. An annular cavity 14 connected to the mounting hole 9 is formed between the outer walls of the shaft 12; an expansion sleeve 15 made of elastic material is fixed integrally in the middle of the lower sleeve 13, and the outer wall of the expansion sleeve 15 protrudes outward from the outer wall of the lower sleeve 13. The expansion sleeve 15 is made of carbon spring steel with a sleeve wall thickness less than the wall thickness of the lower sleeve 13, and can undergo elastic deformation under a certain load; the upper sleeve 16 is detachably mounted on the central shaft 12 (threadedly connected to the outer side of the upper end of the central shaft 12, or locked to the outer side of the upper end of the central shaft 12 by bolts), and the bottom of the upper sleeve 16 is sealed at the top of the annular cavity 14; the squeezing balls 17 are multiple spherical or ellipsoidal rubber balls filled in the mounting hole 9, threaded hole 10, and annular cavity 14. The squeezing balls 17 can move and transmit pressure under the squeezing of the adjusting bolt 11, and finally expand the expansion sleeve. Figure 6 As shown, when the squeeze ball is installed, the threaded hole 10 is first filled with the squeeze ball 17, and then the end of the adjusting bolt 11 is screwed into the threaded hole 10; then from the top of the lower sleeve 13 to the annular cavity 14 and the mounting hole 9, fill the squeeze ball 17 until it is full. It is best to install the upper sleeve 16 on the upper end of the central axis 12 and extend the lower end of the upper sleeve 16 into the annular cavity 14, and seal the top of the annular cavity 14 (while compressing the squeeze ball 17).

[0049] During steps S7 and S9, the workpiece's large end face is placed downwardly over upper sleeve 13 and lower sleeve 16 until the large end face contacts the top of base 8. Adjusting bolt 11 is then screwed further into threaded hole 10, compressing squeezing ball 17. Squeezing ball 17 rotates within mounting hole 9 and transmits compressive force upward. Squeezing ball 17, located above mounting hole 9, is pressed into annular cavity 14, compressing squeezing ball 17 inside expansion sleeve 15. Squeezing ball 17 inside annular cavity 14 moves outward under pressure and compresses the inside of expansion sleeve 15, causing expansion sleeve 15 to expand and tighten the workpiece. Steps S7 and S9 can then be performed. Once processing is complete, adjusting bolt 11 is reversed, causing expansion sleeve 15 to rebound and return to its original position, allowing the workpiece to be removed. Example 2

[0050] The difference between this embodiment and embodiment 1 is that:

[0051] To more tightly pack the annular cavity with the extrusion balls 17, improving force transmission efficiency and speed, the extrusion balls 17 are composed of two rubber balls of different diameters, with the smaller ball having a diameter 0.414 times that of the larger ball. This allows the gaps between extrusion balls 17 of the same diameter to be filled with smaller balls 17. When a force is applied to one of the extrusion balls 17, the force is quickly transferred to the adjacent extrusion balls 17, rapidly expanding the expansion sleeve 15 and tightening the workpiece. Example 3

[0052] The difference between this embodiment and embodiment 1 or 2 is that:

[0053] In order to enable the squeezing ball 17 to transfer the pressure from the mounting hole 9 upward to the squeezing ball 17 inside the expansion sleeve more smoothly, a spiral groove is fixed in the mounting hole 9, the lower end of the spiral groove is connected to the threaded hole 10, and the upper end is connected to the annular cavity 14. At the same time, the center line of the threaded hole 10 is staggered with the mounting hole 9 (not in the same plane), and preferably the center line of the threaded hole 10 is tangent to the outer side surface of the central axis 12 (lower end).

[0054] Twist the adjusting bolt 11 to further screw it into the threaded hole 10, and compress the squeezing ball 17 tangentially into the mounting hole 9. The squeezing ball 17 moves upward along the spiral groove in the mounting hole 9 and transmits the compressive force upward. The squeezing ball 17 located at the upper part of the mounting hole 9 is pressed into the annular cavity 14, squeezing the squeezing ball 17 on the inner side of the expansion sleeve. The squeezing ball 17 in the annular cavity 14 moves outward under the pressure and squeezes the inner side of the expansion sleeve 15, causing the expansion sleeve 15 to expand outward and tighten the workpiece. Then, step S7 and step S9 can be processed. After the processing is completed, screw the adjusting bolt 11 in the opposite direction, the expansion sleeve 15 rebounds and resets, and the workpiece can be removed. The setting of the spiral groove can make the movement of the squeezing ball 17 smoother and the transmission of the compressive force more timely and stable.

[0055] Other aspects of the present invention that are not described in detail are all conventional techniques known to those skilled in the art.

[0056] It should be noted that the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements that are inherent to such process, method, article, or apparatus.

[0057] The protection scope of the present invention is not limited to the technical solutions disclosed in the specific implementation methods. Any modifications, equivalent replacements, improvements, etc. made to the above embodiments based on the technical essence of the present invention fall within the protection scope of the present invention.

Claims

1. A method for machining a multi-aperture, thin-walled cylindrical part, comprising: grinding a blank, rough turning the outer shape, inner hole machining, and fine turning the outer shape; wherein the blank is subjected to the rough turning step to obtain a workpiece, wherein the workpiece comprises a large end and a small end coaxially arranged, wherein the diameter of the large end is larger than the diameter of the small end; and wherein: The inner hole processing comprises the following steps: Step S1. Drilling the small end: With the small end of the workpiece facing upward and the large end as the support surface, the outer wall of the large end is positioned and clamped, and a hole is drilled downward from the center of the small end to form a first center hole. The depth of the first center hole is greater than the length of the small end. Step S2. Drilling the Large End: With the large end of the workpiece facing upward and the small end serving as the support surface, the outer wall of the large end is positioned and clamped. Drill downward from the center of the large end to form a second center hole that is connected to the first center hole. The second center hole has the same diameter as the first center hole and is coaxial. Step S3. Expanding the large end: Keeping the workpiece in the placement and positioning clamping state of step S2, continue expanding the second center hole inside the large end to increase the aperture of the second center hole; Step S4. Boring the Big End: With the workpiece maintained in the placement and positioning clamping state of Step S2, continue boring the second center hole inside the big end, enlarging the inner diameter of the second center hole and increasing the length of the second center hole toward the center of the first inner hole, thereby forming the first inner hole inside the big end. Simultaneously, the end face of the big end is turned to control the length of the first inner hole. Step S5. Boring the small end once: With the small end of the workpiece facing upward and the large end as the support surface, the outer wall of the large end is positioned and clamped. The first center hole inside the small end is bored to enlarge the inner diameter of the first center hole. A second inner hole is formed at the transition point between the small end and the large end, and a third inner hole is formed inside the small end. Step S6. Big End Fine Boring: With the big end of the workpiece facing upward and the small end serving as the support surface, the first inner hole is bored using a clamping fixture to position and clamp the lower portion of the big end outer wall. The diameter and length of the first inner hole are continuously expanded until the diameter and length reach the specified range. Step S7. Secondary boring of the small end: With the small end of the workpiece facing upward and the large end as the support surface, the third inner hole is bored using an expansion fixture to position and expand the inner wall of the large end. The diameter and length of the third inner hole are further expanded, while the outer wall of the small end is turned. Step S8. Turning a hole at the small end: With the small end of the workpiece facing upward and the large end as the support surface, position and clamp the outer wall of the large end. Continue turning the second and third inner holes, enlarging the diameters of the second and third inner holes. Simultaneously, turn the upper end of the third inner hole to form a fourth inner hole with a larger diameter than the third inner hole. Step S9. Finish turning of the small end inner hole: With the small end face of the workpiece facing upwards, the large end end face is used as the support surface, and the expansion fixture is used to position and tighten the inner wall of the large end, and the second inner hole, the third inner hole, and the fourth inner hole are finish turned until the hole diameter and length reach the specified numerical range.

2. The method for processing multi-aperture thin-walled cylindrical parts according to claim 1, characterized in that: The length of the large end is greater than the length of the small end.

3. The method for processing multi-aperture thin-walled cylindrical parts according to claim 1, characterized in that: After completing step S4, the workpiece is first deburred and the appearance and size of the workpiece are inspected. The workpiece is then heat treated to remove the machining stress before proceeding to step S5.

4. The method for processing multi-aperture thin-walled cylindrical parts according to claim 1, characterized in that: In step S1 , the depth of the first center hole is one-half to three-fifths of the total length of the workpiece.

5. The method for processing multi-aperture thin-walled cylindrical parts according to claim 1, characterized in that: The clamping tooling in step S6 includes a base, a mounting ring, a positioning column, and a clamping cover; the mounting ring is fixed to the top of the base; the positioning column is vertically fixed to the base and located in the center of the mounting ring, and the positioning column is tightly fitted with the third inner hole in step S5; the clamping cover is an inverted bowl-shaped body, the bottom of which is detachably connected to the mounting ring, and the top of the clamping cover is provided with a clamping hole concentric with the positioning column, and the clamping hole is tightly fitted with the lower part of the outer wall of the large end in step S6.

6. The method for processing a multi-aperture thin-walled cylindrical part according to claim 5, characterized in that: The bottom of the clamping cover is detachably connected to the mounting ring in a threaded connection manner.

7. The method for processing a multi-aperture thin-walled cylindrical part according to claim 5, characterized in that: The clamping fixture also includes a clamping ring, which is integrally fixed to the top of the clamping cover and concentric with the positioning column. The inner diameter of the clamping ring is equal to the inner diameter of the clamping hole, and the clamping ring is tightly fitted with the lower part of the outer wall of the large end in step S6.

8. The method for processing a multi-aperture thin-walled cylindrical part according to any one of claims 1 to 7, characterized in that: The expansion fixture described in step S7 and step S9 includes a bottom plate, a base, an adjusting bolt, a center shaft, a lower sleeve, an upper sleeve, and a squeezing ball; The base is fixed on the bottom plate, and a mounting hole is formed in the center of the top of the base; a threaded hole connected to the mounting hole is provided on the side wall of the base; The adjusting bolt is threadedly connected in the threaded hole; The central shaft is vertically fixed in the mounting hole and extends upwardly out of the mounting hole, and the diameter of the central shaft is smaller than the diameter of the mounting hole; The lower sleeve is fixed at the center of the top of the base and is sleeved outside the central axis. The inner wall of the lower sleeve is aligned with the inner wall of the mounting hole. An annular cavity connected to the mounting hole is formed between the inner wall of the lower sleeve and the outer wall of the central axis. An expansion sleeve made of elastic material is fixed integrally in the middle of the lower sleeve. The outer wall of the expansion sleeve protrudes outward from the outer wall of the lower sleeve. The upper sleeve is detachably mounted on the central shaft, and its bottom is sealed on the top of the annular cavity; The extruded balls are multiple spherical or ellipsoidal particles filled in the mounting holes, threaded holes and annular cavities.

9. The method for processing multi-aperture thin-walled cylindrical parts according to claim 8, characterized in that: The expansion sleeve is made of carbon spring steel with a thickness smaller than that of the lower sleeve.

10. The method for processing multi-aperture thin-walled cylindrical parts according to claim 8, characterized in that: The extrusion ball is a rubber ball.

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