A method for processing a U-shaped deep groove of a thin-walled cylinder segment shell

Abstract

The present application relates to a kind of thin-walled cylinder segment shell U type deep groove processing method, belong to large cylinder processing technical field, solve the problem of the deformation of large size thin-walled parts in the processing of prior art, uneven thickness of thin-walled deep groove.The method comprises: the outer end face of cylinder segment shell is preprocessed, adjust the coaxiality and straightness of the inner and outer circular end face of cylinder segment shell;Cylinder segment shell is aligned, determine the processing position of "U" type deep groove on cylinder segment shell;Based on the processing position of "U" type deep groove, the inner cavity of cylinder segment shell is pretreated;"U" type deep groove is processed on the outer end face of cylinder segment shell;Wherein, rough-half-precision-finishing machining mode is used to process "U" type groove;In the process of half-precision-finishing machining, the length of 20-40mm processing area section is single processing unit.High-precision processing of thin-walled cylinder segment shell U type deep groove is realized.

Description

Technical Field

[0001] This invention relates to the field of large cylindrical body processing technology, and in particular to a method for processing a U-shaped deep groove in a thin-walled cylindrical shell. Background Technology

[0002] A certain super-large cylinder is one of the important components of a spacecraft. It is equipped with supporting parts inside and has a "U"-shaped deep groove on its outside. The "U"-shaped deep groove needs to be distributed along the axis of the cylinder and the wall thickness needs to be uniform to ensure that the supporting parts located inside the cylinder can be opened by the "U"-shaped deep groove in the presence of fluid resistance, so that the supporting parts can enter and exit the cylinder smoothly without jamming.

[0003] Currently, the inner circle of the housing is generally clamped and supported by the machine tool's built-in three-jaw chuck for machining the inner and outer circles of the housing; when machining U-shaped deep grooves, layered machining is adopted, with each layer having a fixed feed rate.

[0004] However, due to the limited contact area between the three jaws and the parts, they cannot provide adequate support and fixation, making it difficult to guarantee the corresponding form and position tolerances during the machining of the inner and outer circles of thin-walled parts, which is not conducive to subsequent processes. Furthermore, the U-shaped deep groove has thin walls and a large span, and due to the lack of sufficient support, the parts are prone to deformation during cutting, ultimately resulting in extremely uneven wall thickness of the U-shaped deep groove, which seriously affects subsequent use. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a method for machining U-shaped deep grooves in thin-walled cylindrical shells, in order to solve the problems of easy deformation of large-sized thin-walled parts and uneven wall thickness of thin-walled deep grooves in the prior art.

[0006] On one hand, embodiments of the present invention provide a method for machining a U-shaped deep groove in a thin-walled cylindrical shell, comprising:

[0007] Step 1: Pre-machine the outer end face of the cylindrical shell section and adjust the coaxiality and straightness of the inner and outer circular end faces of the cylindrical shell section;

[0008] Step 2: Align the cylindrical shell section to determine the machining position of the "U" groove on the cylindrical shell section;

[0009] Step 3: Based on the machining position of the "U"-shaped deep groove, pre-process the inner cavity of the cylindrical shell section;

[0010] Step 4: Machin a U-shaped deep groove on the outer end face of the cylindrical shell section;

[0011] Among them, the "U" shaped groove is processed by roughing-semi-finishing-finishing.

[0012] During semi-finishing and finishing processes, a processing section of 20-40mm in length is used as a single processing unit.

[0013] Furthermore, step 1 includes:

[0014] S101: The cylindrical shell section is clamped by rounding both ends;

[0015] S102: Using the inner circular end face of one end of the cylindrical shell as the reference surface, adjust the straightness and centerline position of the outer end face of the cylindrical shell.

[0016] Furthermore, step S102 includes:

[0017] S1021: Determine the machining reference surface;

[0018] S1022: Rough machining of the outer end face of the cylindrical shell section, with a machining allowance of 2-3mm;

[0019] S1023: Perform finishing on the outer end face of the cylindrical shell section until a cylindrical shell section with a wall thickness of 7.8 mm is obtained.

[0020] Furthermore, step 2 includes:

[0021] S201: Determine the horizontal plane reference line and the symmetry plane reference line of the cylindrical shell section;

[0022] S202: Based on the determined horizontal plane reference line and symmetrical plane reference line, determine the machining position of the "U" shaped deep groove on the cylindrical shell.

[0023] Furthermore, in step 3, based on the determined machining position of the "U"-shaped deep groove on the cylindrical shell, the annular rib is milled at the corresponding position on the inner cavity of the cylindrical shell to obtain a cylindrical shell with notches in the internal annular rib.

[0024] Furthermore, step 4 includes:

[0025] S401: The cylindrical shell section is clamped by rounding both ends and then mounted on a horizontal lathe.

[0026] S402: Based on the location to be machined in the "U"-shaped deep groove, the recessed groove is machined on the cylindrical shell section using a roughing-semi-finishing-finishing method;

[0027] S403: Based on the determined location of the "U"-shaped deep groove to be processed, the "U"-shaped deep groove is processed in the recessed groove using a roughing-semi-finishing-finishing method.

[0028] Furthermore, step S402 includes:

[0029] S4021: Rough machining of the recessed groove using a one-pass cutting method;

[0030] S4022: Based on rough machining, the groove is semi-finished and the difference in rough machining is compensated.

[0031] S4023: Based on the semi-finishing process, the recessed groove is finished, and the difference compensation is performed on the semi-finishing process.

[0032] Furthermore, step S403 includes:

[0033] S4031: Determine the machining depth of the "U"-shaped deep groove;

[0034] S4032: Rough machining of "U" shaped deep grooves using a one-pass cutting method;

[0035] S4033: Based on rough machining, the "U" shaped deep groove is semi-finished, and the difference compensation is applied to the rough machining.

[0036] S4034: Based on the semi-finishing process, the "U"-shaped deep groove is finished, and the difference compensation is applied to the semi-finishing process.

[0037] Furthermore, during the semi-finishing process, a machining section of 20-40mm in length is used as a single machining unit. The cutting amount of the semi-finishing is adjusted based on the cutting deviation during roughing, and the difference compensation is performed for the roughing.

[0038] During the finishing process, a machining section of 20-40mm in length is used as a single machining unit. The cutting amount of finishing is adjusted based on the cutting deviation during semi-finishing, and the difference compensation is performed on the semi-finishing.

[0039] Furthermore, auxiliary tooling is used to clamp the cylindrical shell section;

[0040] The auxiliary tooling includes a chuck, a cover plate, and multiple tie rods. During clamping, the chuck and cover plate are placed at both ends of the cylindrical shell, and the two ends of the tie rods are connected to the chuck and cover plate respectively to fasten the chuck and cover plate to the openings at both ends of the cylindrical shell.

[0041] The tie rod abuts against the annular rib inside the cylindrical shell.

[0042] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0043] 1. This invention uses the inner circular end face of the cylindrical shell as a reference surface. By pre-processing the outer end face of the cylindrical shell, the coaxiality and straightness of the inner and outer circular end faces of the cylindrical shell are adjusted, thereby adjusting the uniformity of the wall thickness of the cylindrical shell. This ensures the uniformity of the wall thickness of the "U"-shaped deep groove in subsequent processing, thus avoiding the inability of the matching parts to smoothly punch open the protective sleeve due to uneven thickness of the "U"-shaped groove.

[0044] 2. The two ends of the cylindrical shell are respectively fitted onto the coaxial steps of the cover plate and the chuck, so that the ends of the cylindrical shell are rounded by the coaxial steps to prevent deformation. The tie rods abut against the annular ribs inside the cylindrical shell to support the annular ribs, thereby supporting the inner wall of the cylindrical shell and further reducing the risk of deformation of the cylindrical shell.

[0045] 3. The inner circle end face reference of the cylindrical shell is transferred to the cover plate, which overcomes the problem that the inner circle reference of the cylindrical shell is not easy to align. In addition, the inner circle end of the cylindrical shell is used for the push-in placement of matching parts. The inner circle end of the cylindrical shell is used as the alignment reference surface to avoid deviation caused by the inner circle end of the cylindrical shell, which would prevent the matching parts from being placed. This allows the matching parts to enter and exit the cylindrical shell without jamming.

[0046] 4. The sunken groove and "U" shaped groove are machined using a roughing-semi-finishing-finishing machining method. In the semi-finishing process, a machining section of 20-40mm in length is used as a single machining unit. Before machining a machining section, the wall thickness of the section is first measured using a wall thickness gauge to determine the cutting deviation during roughing. The cutting amount during semi-finishing is adjusted based on the cutting deviation during roughing to compensate for the difference in roughing. Similarly, in the finishing process, a machining section of 20-40mm in length is used as a single machining unit. Before machining a machining section, the wall thickness of the section is first measured using a wall thickness gauge to determine the cutting deviation during semi-finishing. The cutting amount during finishing is adjusted based on the cutting deviation during semi-finishing to compensate for the difference in semi-finishing. This method overcomes the problem of uneven cutting amount caused by deformation of the cylinder shell during roughing and semi-finishing.

[0047] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0048] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0049] Figure 1 This is a flowchart of the U-shaped deep groove machining method for thin-walled cylindrical shell in this invention;

[0050] Figure 2 This is a schematic diagram of the structure after the annular rib notch inside the shell of the cylindrical section of the present invention has been processed;

[0051] Figure 3 for Figure 2 Schematic diagram of the cross-section at point AA;

[0052] Figure 4 This is a schematic diagram of the structure of the auxiliary tooling used to clamp the cylindrical shell section in this invention;

[0053] Figure 5 This is a schematic diagram of the recessed groove and the "U"-shaped deep groove structure in this invention;

[0054] Figure 6 This is a schematic diagram of the chuck and cover plate structure in this invention.

[0055] Figure label:

[0056] 1-Cylinder section shell; 101-“U”-shaped deep groove; 102-Sunk groove; 103-Annular rib; 104-Annular rib notch; 2-Chuck; 3-Cover plate; 4-Tie rod; 5-Limiting plate; 8-Axial direction of cylinder section shell; 9-Horizontal plane reference line; 10-Symmetrical plane reference line; L-Cylinder section shell wall thickness; M-Sunk groove depth; E-“U”-shaped deep groove thickness. Detailed Implementation

[0057] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0058] A certain ultra-large cylindrical body is an important component of a spacecraft, with a length of 5-6 meters. The outer end face of the cylinder has axially distributed "U"-shaped deep grooves, which are the same length as the cylinder. The inner cavity of the cylinder must ensure that the supporting parts can enter and exit smoothly without jamming, while the outer "U"-shaped deep grooves must have uniform wall thickness to ensure that parts can be assembled and cut and separated in flight.

[0059] The inner and outer walls of the cylindrical blank are uneven in thickness, and multiple annular ribs are provided on the inner wall to improve the strength of the cylindrical body. Generally, each cylindrical shell section is processed separately, and then several cylindrical shell sections are assembled by welding to obtain the finished cylindrical body.

[0060] The cylinder body requires extremely high precision; otherwise, the supporting parts will be unable to break through the cylinder body and thus fail to perform their corresponding functions. For any single cylinder section shell, its shell wall is thin and its rigidity is weak. Moreover, the "U"-shaped deep groove has a large span (1172mm), a thin groove wall (0.75mm), and a large processing range. Currently, when processing the "U"-shaped deep groove, the cylinder section shell is prone to deformation, affecting the wall thickness accuracy of the "U"-shaped deep groove, which in turn affects the wall thickness accuracy of the "U"-shaped deep groove in the finished cylinder part. Consequently, it affects the smooth and unobstructed entry and exit of the supporting parts into and out of the cylinder body.

[0061] To address the above problems, this invention provides a method for machining a U-shaped deep groove in a thin-walled cylindrical shell, comprising:

[0062] Step 1: Pre-machine the outer end face of the cylindrical shell 1 and adjust the coaxiality and straightness of the inner and outer circular end faces of the cylindrical shell 1;

[0063] Step 2: Align the cylindrical shell section 1 to determine the machining position of the "U" groove on the cylindrical shell section 1;

[0064] Step 3: Based on the machining position of the "U"-shaped deep groove 101, pre-process the inner cavity of the cylindrical shell 1;

[0065] Step 4: Machining a U-shaped deep groove 101 on the outer end face of the cylindrical shell 1;

[0066] Among them, the "U" shaped groove 101 is processed by roughing-semi-finishing-finishing;

[0067] In the semi-finishing and finishing processes, a processing section of 20-40mm in length is used as a single processing unit.

[0068] All the processing units together form a complete "U"-shaped deep groove 101 processing area.

[0069] Compared with the prior art, the present invention uses the inner circular end face of the cylindrical shell as a reference surface and pre-processes the outer end face of the cylindrical shell to adjust the coaxiality and straightness of the inner and outer circular end faces of the cylindrical shell, thereby adjusting the uniformity of the wall thickness of the cylindrical shell. This ensures the uniformity of the wall thickness in the "U"-shaped deep groove that is subsequently machined. In this way, while ensuring the uniformity of the wall thickness, it can also ensure that the matching parts can enter and exit the cylindrical shell without obstruction. Furthermore, when machining the "U"-shaped groove, the wall thickness is measured every 20-40mm. Based on the wall thickness value obtained from the measurement, difference compensation is performed, and the number of feeds and the depth of feed are adjusted in a timely manner to ultimately ensure the uniformity of the wall thickness.

[0070] Specifically, step 1 includes:

[0071] S101: The cylindrical shell 1 is clamped by rounding both ends;

[0072] Specifically, the cylindrical shell 1 is clamped using auxiliary tooling and then mounted on a horizontal lathe.

[0073] Among them, such as Figure 2-6 As shown, the auxiliary tooling includes a chuck 2, a cover plate 3, and multiple pull rods 4. During clamping, the chuck 2 and the cover plate 3 are placed at both ends of the cylindrical shell 1, and the two ends of the pull rods 4 are connected to the chuck 2 and the cover plate 3 respectively, so as to fasten the chuck 2 and the cover plate 3 to the openings at both ends of the cylindrical shell 1.

[0074] Specifically, one end face of the chuck 2 is the mounting surface, used for mounting on the machine tool, and the other end face is the clamping surface, which is pressed against the opening at one end of the cylindrical housing 1 under the tensioning action of the pull rod 4.

[0075] Furthermore, a coaxial step is provided on the clamping surface of the chuck 2. The outer diameter of the coaxial step is 0.1-0.2 mm smaller than the inner diameter of the opening at one end of the cylindrical shell 1. During clamping, the coaxial step provided on the clamping surface of the chuck 2 is inserted into the end opening of the cylindrical shell 1 to support the end opening of the cylindrical shell 1 and prevent deformation of the end of the cylindrical shell 1.

[0076] Specifically, one end face of the cover plate 3 is a pressing surface. During clamping, under the tensioning action of the pull rod 4, the pressing surface of the cover plate 3 is pressed against the opening at the other end of the cylindrical shell 1.

[0077] Furthermore, a coaxial step is provided on the pressing surface of the cover plate 3. The outer diameter of the coaxial step is 0.1-0.2 mm smaller than the inner diameter of the opening at the other end of the cylindrical shell 1. When clamping, the coaxial step provided on the pressing surface of the cover plate 3 is inserted into the end opening of the cylindrical shell 1 to support the end opening of the cylindrical shell 1 and prevent the end of the cylindrical shell 1 from deforming.

[0078] Furthermore, the outer diameters of the chuck 2 and the cover plate 3 are the same as the outer diameters at both ends of the cylindrical shell 1. Multiple limiting plates 5 are provided on the outer arc surfaces of the chuck 2 and the cover plate 3 to limit the cylindrical shell 1 in the diameter direction, ensuring that the cylindrical shell 1 will not slide, so as to avoid affecting the machining accuracy.

[0079] Specifically, multiple pull rods 4 are provided. One end of the pull rod 4 is screwed to the chuck 2, and the other end of the pull rod 4 passes freely through the cover plate 3. When clamping, a nut is provided at the end of the pull rod 4 located at the cover plate 3. The nut is screwed in, and the cover plate 3 is squeezed through the nut, thereby squeezing the cylindrical shell 1 through the cover plate 3, so as to clamp and fix the cylindrical shell 1 in the axial direction.

[0080] Furthermore, multiple sets of mounting holes are provided on the chuck 2 and the cover plate 3 respectively, so as to adjust the installation position of the pull rod 4 through the mounting holes; during installation, the two ends of the pull rod 4 are respectively inserted into a set of mounting holes, and the chuck 2 and the cover plate 3 are pressed against the two ends of the cylindrical shell 1 by the cooperation of the nut and the pull rod 4.

[0081] Furthermore, multiple tie rods 4 abut against the annular rib 103 to support the annular rib 103, thereby supporting the inner wall of the cylindrical shell 1 and reducing the risk of deformation of the cylindrical shell 1.

[0082] S102: Using the inner circular end face of one end of the cylindrical shell 1 as the reference surface, adjust the straightness and axis position of the outer end face of the cylindrical shell 1.

[0083] Specifically, including:

[0084] S1021: Determine the machining reference surface;

[0085] Specifically, the inner circular end face at one end of the cylindrical shell 1 is used as the machining reference surface, and a cover plate 3 is tightly fitted at this end. In this way, when multiple cylindrical shells 1 are assembled into a finished cylinder, the coaxiality of the multiple cylindrical shells 1 is ensured, and the matching parts are prevented from being unable to smoothly enter and exit the cylinder.

[0086] The coaxial step on the pressing surface of the cover plate 3 is inserted into the opening at one end of the cylindrical shell 1. The outer diameter of the cover plate 3 is the same as the outer diameter at the port of the cylindrical shell 1. Then, the reference surface of the inner circle end of the cylindrical shell 1 is transferred to the outer arc surface of the cover plate 3, so that the outer arc surface of the cover plate 3 is used as the machining reference surface.

[0087] S1022: Roughly machine the outer end face of the cylindrical shell 1, with a machining allowance of 2-3mm;

[0088] The wall thickness requirement for cylindrical shell 1 is 7.8mm, which means that the wall thickness of cylindrical shell 1 is 9.8-10.8mm. This ensures the rigidity of cylindrical shell 1 and reduces the risk of deformation.

[0089] S1023: Perform finishing on the outer end face of the cylindrical shell 1 until a cylindrical shell 1 with a wall thickness of 7.8 mm is obtained.

[0090] Specifically, the outer end face of the cylindrical shell 1 is precision machined by multiple passes, with each pass being less than or equal to 0.2 mm, until a cylindrical shell 1 with a wall thickness of 7.8 mm is obtained.

[0091] Specifically, step 2 includes:

[0092] S201: Determine the horizontal plane reference line and the symmetry plane reference line of the cylindrical shell 1;

[0093] Specifically, the cylindrical shell 1 is placed on a rotary table, the inner circle of the cylindrical shell 1 is aligned, and the horizontal plane reference line and the symmetrical plane reference line of the cylindrical shell 1 are drawn as the basis for alignment in subsequent CNC milling of the cylindrical shell 1.

[0094] S202: Based on the determined horizontal plane reference line and symmetrical plane reference line, determine the machining position of the "U" shaped deep groove 101 on the cylindrical shell 1.

[0095] Among them, two "U"-shaped deep grooves 101 are provided on the cylindrical shell 1, and the two "U"-shaped deep grooves 101 are symmetrically distributed.

[0096] Specifically, step 3 includes: removing the auxiliary tooling, transferring the cylindrical shell 1 to a milling machine, and milling the annular rib 103 at the corresponding position on the inner cavity of the cylindrical shell 1 based on the determined machining positions of the two "U"-shaped deep grooves 101 on the cylindrical shell 1, so as to obtain a cylindrical shell 1 with a notch in the inner annular rib 103, so as to avoid subsequent impact on the internal parts of the cylinder being ejected from the cylinder.

[0097] Specifically, step 4 includes:

[0098] S401: Use auxiliary tooling to clamp the cylindrical shell 1 and install the cylindrical shell 1 on a horizontal lathe;

[0099] Among them, the four tie rods 4 avoid the notch position of the annular rib 103 and abut against the annular rib 103 inside the cylindrical shell 1 respectively to support the annular rib 103, thereby supporting the inner wall of the cylindrical shell 1 and reducing the risk of deformation of the cylindrical shell 1.

[0100] S402: Based on the machining position of the "U"-shaped deep groove 101, the recessed groove 102 is machined on the cylindrical shell 1 using the roughing-semi-finishing-finishing method;

[0101] Specifically, including:

[0102] S4021: Rough machining of groove 102 is performed using a single pass to complete the cut;

[0103] Specifically, the cutting tool moves in multiple passes along the diameter of the cylindrical shell 1, with each pass reaching the target position along the axial direction of the cylindrical shell 1 in one pass, in order to improve machining efficiency.

[0104] S4022: Based on rough machining, the recessed groove 102 is semi-finished, and the difference compensation is performed on the rough machining.

[0105] In the axial direction of the cylindrical shell 1, a machining area segment with a length of 20-40mm is used as a single machining unit. The thickness is detected by a wall thickness gauge, and the difference is substituted to compensate for the difference in rough machining, so as to overcome the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during rough machining.

[0106] Specifically, before machining a section of the machining area, the wall thickness of the section is first measured using a wall thickness gauge to determine the cutting deviation during rough machining. Based on the cutting deviation during rough machining, the cutting amount of semi-finishing is adjusted to compensate for the difference in rough machining.

[0107] Specifically, based on the wall thickness of the cylindrical shell 1 and the total cutting amount of rough machining, the theoretical wall thickness of the groove 102 after rough machining is obtained. The actual wall thickness of the groove 102 in the machining area is compared with the theoretical wall thickness to obtain the cutting deviation after rough machining.

[0108] Furthermore, based on the cutting deviation after roughing of the machining area, the actual total cutting amount of semi-finishing is adjusted so that the actual total cutting amount of roughing-semi-finishing of the machining area is consistent with the theoretical total cutting amount.

[0109] In this way, differential compensation can be achieved for rough machining, overcoming the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during rough machining.

[0110] After all the processing areas are completed, a fully semi-finished recessed groove 102 is obtained.

[0111] S4023: Based on the semi-finishing, the recessed groove 102 is finished, and the difference compensation is performed on the semi-finishing.

[0112] In the axial direction of the cylindrical shell 1, a machining area segment with a length of 20-40mm is used as a single machining unit. The thickness is detected by a wall thickness gauge, and the difference is substituted to compensate for the difference in the semi-finishing process. This is to overcome the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during semi-finishing.

[0113] Specifically, before machining a section of the machining area, the wall thickness of the section is first measured using a wall thickness gauge to determine the cutting deviation during semi-finishing. Based on the cutting deviation during semi-finishing, the cutting amount of semi-finishing is adjusted to compensate for the difference in semi-finishing.

[0114] Specifically, based on the wall thickness of the cylindrical shell 1 and the total cutting amount of rough-semi-finishing, the theoretical wall thickness of the recessed groove 102 after semi-finishing is obtained. The actual wall thickness of the recessed groove 102 in the machining area is compared with the theoretical wall thickness to obtain the cutting deviation after semi-finishing.

[0115] Furthermore, based on the cutting deviation after semi-finishing of the machining area, the actual total cutting amount of finishing is adjusted so that the actual total cutting amount of roughing-semi-finishing-finishing of the machining area is consistent with the theoretical total cutting amount.

[0116] In this way, differential compensation can be achieved for semi-finishing, overcoming the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during semi-finishing.

[0117] After all the processing areas are completed, a fully finished recessed groove 102 is obtained.

[0118] For example, the depth of the recess 102 is 2.7 (0, +0.15) mm and the width is 40 arc length.

[0119] In the axial direction of the cylindrical shell 1, the two ends of the recessed groove 102 are respectively provided with a 15mm allowance between the two ends of the cylindrical shell 1 to facilitate the subsequent welding connection between multiple cylindrical shells 1.

[0120] S403: Based on the determined machining position of the "U"-shaped deep groove 101, the "U"-shaped deep groove 101 is machined in the recessed groove 102 using a roughing-semi-finishing-finishing method.

[0121] Specifically, including:

[0122] S4031: Determine the machining depth of the "U"-shaped deep groove 101;

[0123] The machining depth H of the "U"-shaped deep groove 101 satisfies:

[0124] H = LME

[0125] Where L is the wall thickness of section 1 of the cylindrical shell;

[0126] M is the depth of the groove 102;

[0127] E represents the wall thickness at point 101 of the "U"-shaped deep groove.

[0128] For example, L = 7.8 mm, M = 2.7 mm, E = 0.75 mm, then H = 7.8 - 2.7 - 0.75 = 4.35 mm.

[0129] S4032: Rough machining of "U" shaped deep groove 101 using a one-pass cutting method;

[0130] Specifically, the cutting tool moves in multiple passes along the diameter of the cylindrical shell 1, with each pass reaching the target position along the axial direction of the cylindrical shell 1 in one pass, in order to improve machining efficiency.

[0131] S4033: Based on rough machining, the "U" shaped deep groove 101 is semi-finished, and the difference compensation is applied to the rough machining.

[0132] Specifically, in the axial direction of the cylindrical shell 1, a machining section of 20-40mm in length is used as a single machining unit. The thickness is measured using a wall thickness gauge, and the difference is used to compensate for the difference in rough machining, so as to overcome the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during rough machining.

[0133] Before machining a certain section, the wall thickness of the section is first measured using a wall thickness gauge to determine the cutting deviation during rough machining. Based on the cutting deviation during rough machining, the cutting amount of semi-finishing is adjusted to compensate for the difference in rough machining.

[0134] Specifically, based on the wall thickness of the cylindrical shell 1, the total cutting amount of the groove 102 and the total cutting amount of the roughing process, the theoretical wall thickness of the "U"-shaped deep groove 101 after roughing is obtained. The actual wall thickness of the "U"-shaped deep groove 101 in the processing area is compared with the theoretical wall thickness to obtain the cutting deviation after roughing.

[0135] Furthermore, based on the cutting deviation after roughing of the machining area, the actual total cutting amount of semi-finishing is adjusted so that the sum of the actual total cutting amount of the groove 102 and the actual total cutting amount of the rough-semi-finishing of the "U"-shaped deep groove 101 in the machining area is consistent with the theoretical total cutting amount.

[0136] In this way, differential compensation can be achieved for rough machining, overcoming the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during rough machining.

[0137] After all the processing areas are completed, a complete semi-finished "U"-shaped deep groove 101 is obtained.

[0138] S4034: Based on the semi-finishing process, the "U"-shaped deep groove 101 is finished, and the difference compensation for the semi-finishing process is performed.

[0139] Specifically, in the axial direction of the cylindrical shell 1, a machining area segment with a length of 20-40mm is used as a single machining unit. The thickness is measured using a wall thickness gauge, and the difference is substituted to compensate for the difference in the semi-finishing process. This is to overcome the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during semi-finishing.

[0140] Before machining a certain section, the wall thickness of the section is first measured using a wall thickness gauge to determine the cutting deviation during semi-finishing. Based on the cutting deviation during semi-finishing, the cutting amount during finishing is adjusted to compensate for the difference in semi-finishing.

[0141] Among them, based on the wall thickness of the cylindrical shell 1, the total cutting amount of the groove 102 and the total cutting amount of rough-semi-finishing, the theoretical wall thickness of the "U"-shaped deep groove 101 after semi-finishing is obtained. The actual wall thickness of the "U"-shaped deep groove 101 in the machining area is compared with the theoretical wall thickness to obtain the cutting deviation after semi-finishing.

[0142] Furthermore, based on the cutting deviation after semi-finishing of the machining area, the actual total cutting amount of finishing is adjusted so that the sum of the actual total cutting amount of the groove 102 in the machining area and the actual total cutting amount of the rough-semi-finishing-finishing of the "U"-shaped deep groove 101 is consistent with the theoretical total cutting amount.

[0143] In this way, differential compensation can be achieved for semi-finishing, overcoming the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during semi-finishing.

[0144] After all processing areas are completed, a fully finished "U"-shaped deep groove 101 is obtained.

[0145] In the axial direction of the cylindrical shell 1, the two ends of the "U"-shaped deep groove 101 are respectively provided with a 15mm allowance between the two ends of the cylindrical shell 1 to facilitate the subsequent welding connection between multiple cylindrical shells 1.

[0146] For example, the "U"-shaped deep groove 101 has a depth of 4.35 mm and a width of 8 arc lengths.

[0147] The "U"-shaped deep groove 101 is located in the middle of the sunken groove 102, and the "U"-shaped deep groove 101 and the sunken groove 102 are of equal length.

[0148] In this way, by combining high feed rate for roughing and low feed rate for finishing, machining efficiency can be improved while avoiding deformation of the cylinder shell due to excessive feed rate.

[0149] Compared with the prior art, the present invention uses the inner circular end face of the cylindrical shell 1 as a reference surface, and pre-processes the outer end face of the cylindrical shell 1 to adjust the coaxiality and straightness of the inner and outer circular end faces of the cylindrical shell 1, thereby adjusting the uniformity of the wall thickness of the cylindrical shell 1. This ensures the uniformity of the wall thickness at the "U"-shaped deep groove 101 in subsequent processing, thus avoiding the inability of the matching parts to smoothly punch open the protective sleeve due to the uneven thickness of the "U"-shaped groove 101.

[0150] Using the inner circular end face of the cylindrical shell 1 as the reference surface, the cylindrical shell 1 is clamped by supporting the two ends to reduce the risk of deformation of the cylindrical shell 1 during processing.

[0151] The two ends of the cylindrical shell 1 are respectively fitted onto the coaxial steps of the cover plate 3 and the chuck 2, so as to round the ends of the cylindrical shell 1 through the coaxial steps to avoid its deformation. The tie rod 4 abuts against the annular rib 103 inside the cylindrical shell 1 to support the annular rib 103, thereby supporting the inner wall of the cylindrical shell 1 and further reducing the risk of deformation of the cylindrical shell 1.

[0152] The inner circle end face reference of the cylindrical shell 1 is transferred to the cover plate 3, which overcomes the problem that the inner circle reference of the cylindrical shell 1 is not easy to align. In addition, the inner circle end of the cylindrical shell 1 is used for the push-type placement of matching parts. The inner circle end of the cylindrical shell 1 is used as the alignment reference surface to avoid deviation caused by the inner circle end of the cylindrical shell 1, which would prevent the matching parts from being placed. This allows the matching parts to enter and exit the cylindrical shell 1 without jamming.

[0153] The recessed groove 102 and the "U"-shaped groove 101 are machined using a rough-semi-finish-finish machining process. In the semi-finish machining process, a 20-40mm long machining section is used as a single machining unit. Before machining a section, a wall thickness gauge is used to measure the wall thickness of that section to determine the cutting deviation during rough machining. Based on this deviation, the cutting amount in the semi-finish machining is adjusted to compensate for the difference in rough machining. Similarly, in the finish machining process, a 20-40mm long machining section is used as a single machining unit. Before machining a section, a wall thickness gauge is used to measure the wall thickness of that section to determine the cutting deviation during semi-finish machining. Based on this deviation, the cutting amount in the finish machining is adjusted to compensate for the difference in semi-finish machining. This process overcomes the problem of uneven cutting amounts caused by deformation of the cylindrical shell 1 during rough and semi-finish machining.

[0154] Example 1

[0155] A method for machining a U-shaped deep groove in a thin-walled cylindrical shell includes:

[0156] Step 1: Pre-machine the outer end face of the cylindrical shell 1 and adjust the coaxiality and straightness of the inner and outer circular end faces of the cylindrical shell 1;

[0157] Specifically, including:

[0158] S101: The cylindrical shell 1 is clamped by rounding both ends;

[0159] Specifically, including:

[0160] S1011: Install the chuck 2 on the milling and turning machining center, and screw one end of each of the four tie rods 4 into the mounting holes on the chuck 2;

[0161] The center line of chuck 2 is located on a horizontal plane, meaning chuck 2 is installed vertically.

[0162] S1012: Fit one end of the cylindrical shell 1 onto the coaxial step of the chuck 2;

[0163] Specifically, in the horizontal direction, the cylindrical shell 1 is passed through the four tie rods 4 until one end of the cylindrical shell 1 is fitted onto the coaxial step of the chuck 2. During this process, the annular rib 103 inside the cylindrical shell 2 abuts against the tie rods 4 to support the cylindrical shell 1, which facilitates the subsequent installation of the cover plate 3.

[0164] The outer diameter of the coaxial step on the chuck 2 is 0.2 mm smaller than the inner diameter of the opening at one end of the cylindrical shell 1.

[0165] S1013: Insert the coaxial step of the cover plate 3 into the other end of the cylindrical shell 1. At this time, the other end of the cylindrical shell 1 fits snugly onto the coaxial step of the cover plate 3.

[0166] The other ends of the four tie rods 4 pass through the corresponding mounting holes on the cover plate 3 and protrude outside the cover plate 3 to reserve the position for nut installation.

[0167] The outer diameter of the coaxial step on the cover plate 3 is 0.2 mm smaller than the inner diameter of the opening at the other end of the cylindrical shell 1.

[0168] S1014: By using the cooperation of the nut and the pull rod 4, the chuck 2 and the cover plate 3 are pressed against both ends of the cylindrical shell 1 to clamp and fix the cylindrical shell 1.

[0169] Specifically, the mounting holes on the chuck 2 and the cover plate 3 correspond one-to-one, and the diameter of the pull rod 4 is slightly smaller than the diameter of the mounting hole on the cover plate 3, so that one end of the pull rod 4 can pass through the mounting hole on the cover plate 3.

[0170] One end of the pull rod 4 passes through the mounting hole of the cover plate 3 and is located outside the cover plate 3. This part is engaged with the nut. When the nut is screwed in, the nut is used to press the cover plate 3, so that the chuck 2 and the cover plate 3 are pressed at both ends of the cylindrical shell 1 to clamp and fix the cylindrical shell 1.

[0171] The nuts at the ends of the four tie rods are screwed in by the same distance.

[0172] The clamping force of the cover plate 3 and chuck 2 on the cylindrical shell 1 can be adjusted by controlling the distance the nut is screwed in. This clamping force can keep the cylindrical shell 1 stationary relative to the cover plate 3 and chuck 2 during the processing.

[0173] Among them, the four tie rods 4 respectively abut against the annular ribs 103 inside the cylindrical shell 1 to support the annular ribs 103, thereby supporting the inner wall of the cylindrical shell 1 and reducing the risk of deformation of the cylindrical shell 1.

[0174] When using auxiliary tooling to clamp the cylindrical shell 1, the center lines of the chuck 2 and the cover plate 3 coincide.

[0175] S1015: Four limiting plates 5 are installed on the outer arc surfaces of the chuck 2 and the cover plate 3 respectively to limit the cylindrical shell 1 in the diameter direction.

[0176] Specifically, four limiting plates 5 are evenly provided on the cover plate 3, and the limiting plates 5 are installed on the cover plate 3 by screws.

[0177] Four limiting plates 5 are evenly arranged on the chuck 2, and the limiting plates 5 are installed on the chuck 2 by screws.

[0178] Among them, the limiting plates 5 located on the cover plate 3 and the chuck 2 are staggered.

[0179] S102: Using the inner circular end face of one end of the cylindrical shell 1 as the reference surface, adjust the straightness and axis position of the outer end face of the cylindrical shell 1.

[0180] Specifically, including:

[0181] S1021: Determine the machining reference surface;

[0182] Specifically, the inner circular end face at one end of the cylindrical shell 1 is used as the machining reference surface, and a cover plate 3 is tightly fitted at this end. In this way, when multiple cylindrical shells 1 are assembled into a finished cylinder, the coaxiality of the multiple cylindrical shells 1 is ensured, and the matching parts are prevented from being unable to smoothly enter and exit the cylinder.

[0183] The coaxial step on the pressing surface of the cover plate 3 is inserted into the opening at one end of the cylindrical shell 1. The outer diameter of the cover plate 3 is the same as the outer diameter at the port of the cylindrical shell 1. Then, the reference surface of the inner circle end of the cylindrical shell 1 is transferred to the outer arc surface of the cover plate 3, so that the outer arc surface of the cover plate 3 is used as the machining reference surface.

[0184] S1022: Roughly machine the outer end face of the cylindrical shell 1, with a machining allowance of 2mm;

[0185] The wall thickness requirement for cylindrical shell 1 is 7.8mm, which means that the wall thickness of cylindrical shell 1 is 9.8mm at this time. This ensures the rigidity of cylindrical shell 1 and reduces the risk of deformation of cylindrical shell 1.

[0186] S1023: Perform finishing on the cylindrical shell 1 by multiple passes, with each pass being less than or equal to 0.2mm, until a cylindrical shell 1 with a wall thickness of 7.8mm is obtained.

[0187] Among them, the coaxiality of the inner and outer end faces of the finished cylindrical shell 1 is 0.05, and the straightness is 0.12.

[0188] Before the outer end face of the cylindrical shell 1 is processed, the inside of the cylindrical shell 1 is the shaped surface after processing, that is, the inside of the cylindrical shell 1 can accommodate the corresponding parts.

[0189] Step 2: Align the cylindrical shell 1 to determine the machining position of the "U" groove 101 on the cylindrical shell 1;

[0190] Specifically, including:

[0191] S201: Determine the horizontal plane reference line and the symmetry plane reference line of the cylindrical shell 1;

[0192] Specifically, the cylindrical shell 1 is placed on a rotary table, the inner circle of the cylindrical shell 1 is aligned, and the horizontal plane reference line and the symmetrical plane reference line of the cylindrical shell are drawn as the basis for alignment in subsequent CNC milling of the cylindrical shell 1.

[0193] S202: Based on the determined horizontal plane reference line and symmetrical plane reference line, determine the machining position of the "U" shaped deep groove 101 on the cylindrical shell 1.

[0194] Among them, two "U"-shaped deep grooves 101 are provided on the cylindrical shell 1, and the two "U"-shaped deep grooves 101 are symmetrically distributed.

[0195] Step 3: Based on the machining position of the "U"-shaped deep groove 101, pre-process the inner cavity of the cylindrical shell 1;

[0196] Specifically, this includes: removing the auxiliary tooling, transferring the cylindrical shell 1 to a milling machine, and milling the annular rib 103 at the corresponding position on the inner cavity of the cylindrical shell 1 based on the determined machining positions of the two "U"-shaped deep grooves 101 on the cylindrical shell 1, so as to obtain a cylindrical shell 1 with notches in the internal annular rib 103, so as to avoid affecting the internal parts of the cylinder from being ejected from the cylinder.

[0197] The width of the annular rib notch 104 is the same as the width of the "U"-shaped deep groove 101.

[0198] Among them, the annular ribs 103 inside the cylindrical shell 1 are punched open by milling.

[0199] Step 4: Machining a U-shaped deep groove 101 on the outer end face of the cylindrical shell 1;

[0200] Specifically, including:

[0201] S401: Use auxiliary tooling to clamp the cylindrical shell 1 and install the cylindrical shell 1 on a horizontal lathe;

[0202] Among them, the four tie rods 4 avoid the position of the annular rib notch 104 and abut against the annular rib 103 inside the cylindrical shell 1 respectively.

[0203] S402: Based on the processing position of the "U"-shaped deep groove 101, a recessed groove 102 is processed on the cylindrical shell 1;

[0204] Specifically, including:

[0205] S4021: Rough-machined groove;

[0206] The machining tool is a Φ12mm end mill; during roughing: the rotation speed is S3500r / min and the feed rate is F1500mm / min.

[0207] In the diameter direction of the cylindrical shell 1, the total cutting amount of rough machining is 2mm, which is divided into 4 passes. Each pass is completed in one pass along the axial direction of the cylindrical shell 1 to improve machining efficiency.

[0208] S4022: Based on rough machining, the recessed groove 102 is semi-finished;

[0209] In the axial direction of the cylindrical shell 1, a 30mm long machining section is used as a single machining unit. The thickness is measured using a wall thickness gauge, and the difference is used to compensate for the difference in rough machining, so as to overcome the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during rough machining.

[0210] Specifically, before machining a section of the machining area, the wall thickness of the section is first measured using a wall thickness gauge to determine the cutting deviation during rough machining. Based on the cutting deviation during rough machining, the cutting amount of semi-finishing is adjusted to compensate for the difference in rough machining.

[0211] The total cutting amount of rough machining is 2mm. Theoretically, the remaining wall thickness at the recessed groove 102 is L-2=7.8-2=5.8mm, where L is the wall thickness of the cylindrical shell 1.

[0212] The theoretical total cutting amount during semi-finishing is 0.4 mm, and it is done in 7 passes.

[0213] Before processing, the wall thickness of the processing area is measured using a wall thickness gauge and compared with 5.8mm. The absolute value of the difference between the two values ​​is obtained. If the wall thickness of the processing area is less than 5.8mm, the actual total cutting amount of the processing area is: 0.4 - absolute value of the difference.

[0214] If the wall thickness of the machining area is greater than 5.8mm, then the actual total cutting amount of the machining area is: 0.4 + absolute value of the difference.

[0215] In this way, differential compensation can be achieved for rough machining, overcoming the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during rough machining.

[0216] After all the processing areas are completed, a fully semi-finished recessed groove 102 is obtained.

[0217] During semi-finishing: the rotational speed is S1500r / min, the feed rate is F500mm / min, and the cutting tool is a Φ12mm end mill.

[0218] S4023: Based on the semi-finishing process, the recessed groove 102 is finished.

[0219] In the axial direction of the cylindrical shell 1, a 30mm long machining section is used as a single machining unit. The thickness is measured using a wall thickness gauge, and the difference is used to compensate for the difference in the semi-finishing process. This is to overcome the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during semi-finishing.

[0220] Specifically, before machining a section of the machining area, the wall thickness of the section is first measured using a wall thickness gauge to determine the cutting deviation during semi-finishing. Based on the cutting deviation during semi-finishing, the cutting amount during finishing is adjusted to compensate for the difference in semi-finishing.

[0221] The total cutting amount of roughing and semi-finishing is 2 + 0.4 = 2.4 mm. Theoretically, the remaining wall thickness at the recessed groove 102 is L - 2.4 = 7.8 - 2.4 = 5.4 mm, where L is the wall thickness of the cylindrical shell 1.

[0222] The theoretical total cutting amount during finishing is 0.3mm, and it is done in 6 passes.

[0223] Before processing, the wall thickness of the processing area is measured using a wall thickness gauge and compared with 5.4mm. The absolute value of the difference between the two values ​​is obtained. If the wall thickness of the processing area is less than 5.4mm, the actual total cutting amount of the processing area is: 0.3 - absolute value of the difference.

[0224] If the wall thickness of the machining area is greater than 5.4mm, then the actual total cutting amount of the machining area is: 0.3 + absolute value of the difference.

[0225] In this way, differential compensation can be achieved for semi-finishing, overcoming the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during semi-finishing.

[0226] After all the processing areas are completed, a fully finished recessed groove 102 is obtained.

[0227] During finishing, the rotational speed is S1500r / min, the feed rate is F500mm / min, and the cutting tool is a Φ12mm end mill.

[0228] In the axial direction of the cylindrical shell 1, the two ends of the recessed groove 102 are respectively provided with a 15mm allowance between the two ends of the cylindrical shell 1 to facilitate the subsequent welding connection between multiple cylindrical shells 1.

[0229] At this point, the depth of the recessed groove 102 is 2.7 (0, +0.15) mm, and the width is 40 arc length.

[0230] S403: Based on the determined position of the "U"-shaped deep groove 101 to be processed, process the "U"-shaped deep groove 101 in the recessed groove 102.

[0231] Specifically, including:

[0232] S4031: Determine the machining depth of the "U"-shaped deep groove 101;

[0233] The machining depth H of the "U"-shaped deep groove 101 satisfies:

[0234] H = LME

[0235] Where L is the wall thickness of section 1 of the cylindrical shell;

[0236] M is the depth of the groove 102;

[0237] E represents the thickness of the "U"-shaped deep groove, which is 101.

[0238] Specifically, L = 7.8 mm, M = 2.7 mm, E = 0.75 mm, and H = 7.8 - 2.7 - 0.75 = 4.35 mm.

[0239] Among them, the width of the "U"-shaped deep groove 101 is 8 arc lengths.

[0240] S4032: Rough machining of "U" shaped deep groove 101;

[0241] The machining tool is a Φ8mm ball end mill. During roughing, the rotation speed is S2500r / min and the feed rate is F1200mm / min.

[0242] In the diameter direction of the cylindrical shell 1, the total cutting amount of rough machining is 2mm, which is divided into 4 passes. Each pass is completed in one pass along the axial direction of the cylindrical shell 1 to improve machining efficiency.

[0243] S4033: Based on rough machining, the "U" shaped deep groove 101 is semi-finished;

[0244] In the axial direction of the cylindrical shell 1, a 30mm long machining section is used as a single machining unit. The thickness is measured using a wall thickness gauge, and the difference is used to compensate for the difference in rough machining, so as to overcome the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during rough machining.

[0245] Specifically, before machining a section of the machining area, the wall thickness of the section is first measured using a wall thickness gauge to determine the cutting deviation during rough machining. Based on the cutting deviation during rough machining, the cutting amount of semi-finishing is adjusted to compensate for the difference in rough machining.

[0246] The total cutting amount of rough machining is 2mm. Theoretically, the remaining wall thickness at the "U"-shaped deep groove 101 is L-2.7-2=7.8-2.7-2=3.1mm, where L is the wall thickness of the cylindrical shell 1.

[0247] The theoretical total cutting amount during semi-finishing is 2.1 mm, which is achieved through 7 passes.

[0248] Before processing, the wall thickness of the processing area is measured using a wall thickness gauge and compared with 3.1 mm. The absolute value of the difference between the two values ​​is obtained. If the wall thickness of the processing area is less than 3.1 mm, the actual total cutting amount of the processing area is: 2.1 - absolute value of the difference.

[0249] If the wall thickness of the machining area is greater than 3.1 mm, then the actual total cutting amount of the machining area is: 2.1 + absolute value of the difference.

[0250] In this way, differential compensation can be achieved for rough machining, overcoming the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during rough machining.

[0251] After all the processing areas are completed, a complete semi-finished "U"-shaped deep groove 101 is obtained.

[0252] During semi-finishing: the rotational speed is S1500r / min, the feed rate is F300mm / min, and the cutting tool is a Φ8mm ball end mill.

[0253] S4034: Based on the semi-finishing process, the "U" shaped deep groove 101 is finished.

[0254] In the axial direction of the cylindrical shell 1, a 30mm long machining section is used as a single machining unit. The thickness is measured using a wall thickness gauge, and the difference is used to compensate for the difference in the semi-finishing process. This is to overcome the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during semi-finishing.

[0255] Specifically, before machining a section of the machining area, the wall thickness of the section is first measured using a wall thickness gauge to determine the cutting deviation during semi-finishing. Based on the cutting deviation during semi-finishing, the cutting amount during finishing is adjusted to compensate for the difference in semi-finishing.

[0256] The total cutting amount of roughing and semi-finishing is 2 + 2.1 = 4.1 mm. Theoretically, the remaining wall thickness at the "U"-shaped deep groove 101 is L - 2.7 - 4.1 = 7.8 - 2.7 - 4.1 = 1 mm, where L is the wall thickness of the cylindrical shell 1.

[0257] The theoretical total cutting amount during finishing is 0.25mm, and it is done in 6 passes.

[0258] Before processing, the wall thickness of the processing area is measured using a wall thickness gauge and compared with 1mm. The absolute value of the difference between the two is obtained. If the wall thickness of the processing area is less than 1mm, the actual total cutting amount of the processing area is: 0.25 - absolute value of the difference.

[0259] If the wall thickness of the machining area is greater than 1mm, then the actual total cutting amount of the machining area is: 0.25 + absolute value of the difference.

[0260] In this way, differential compensation can be achieved for semi-finishing, overcoming the problem of uneven cutting amount caused by deformation of the cylindrical shell 1 during semi-finishing.

[0261] After all processing areas are completed, a fully finished "U"-shaped deep groove 101 is obtained.

[0262] During finishing, the rotational speed is S1500r / min, the feed rate is F300mm / min, and the cutting tool is a Φ8mm ball end mill.

[0263] In the axial direction of the cylindrical shell 1, the two ends of the "U"-shaped deep groove 101 are respectively provided with a 15mm allowance between the two ends of the cylindrical shell 1 to facilitate the subsequent welding connection between multiple cylindrical shells 1.

[0264] At this time, the depth of the "U"-shaped deep groove 101 is 4.35 mm and the width is 8 arc lengths. The "U"-shaped deep groove 101 is located in the middle of the recessed groove 102.

[0265] Among them, the "U"-shaped deep groove 101 and the sunken groove 102 are of equal length.

[0266] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0267] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for machining a U-shaped deep groove in a thin-walled cylindrical shell, characterized in that, include: Step 1: Pre-machine the outer end face of the cylindrical shell section and adjust the coaxiality and straightness of the inner and outer circular end faces of the cylindrical shell section; Among them, the cylindrical shell is clamped by using an auxiliary tooling with rounded ends. The auxiliary tooling includes a chuck, a cover plate and multiple pull rods. During clamping, the chuck and cover plate are placed at both ends of the cylindrical shell, and the two ends of the pull rods are connected to the chuck and cover plate respectively to fasten the chuck and cover plate to the openings at both ends of the cylindrical shell. The clamping surfaces of the chuck and cover plate are provided with coaxial steps, the outer diameter of which is 0.1-0.2 mm smaller than the inner diameter of the opening at one end of the cylindrical shell. The tie rod abuts against the annular rib inside the cylindrical shell; Step 2: Align the cylindrical shell section to determine the machining position of the "U"-shaped deep groove on the cylindrical shell section; Step 3: Based on the machining position of the "U"-shaped deep groove, pre-process the inner cavity of the cylindrical shell section; At the corresponding position on the inner cavity of the cylindrical shell, the annular ribs are milled to obtain a cylindrical shell with notches in the internal annular ribs; Step 4: Machining a U-shaped deep groove on the outer end face of the cylindrical shell section; Step 4 includes: S401: The cylindrical shell section is clamped by rounding both ends and then mounted on a horizontal lathe. S402: Based on the location to be machined in the "U"-shaped deep groove, the recessed groove is machined on the cylindrical shell section using a roughing-semi-finishing-finishing method; S403: Based on the determined location of the "U"-shaped deep groove to be processed, the "U"-shaped groove is processed in the recessed groove using a roughing-semi-finishing-finishing process; In the semi-finishing process, a processing area segment with a length of 20-40mm is used as a single processing unit. Before processing a processing area segment, the wall thickness of the segment is first detected using a wall thickness gauge to determine the cutting deviation during roughing. Based on the cutting deviation during roughing, the cutting amount of semi-finishing is adjusted to compensate for the difference in roughing. During the finishing process, a 20-40mm long machining section is used as a single machining unit. Before machining a machining section, the wall thickness of the section is first measured using a wall thickness gauge to determine the cutting deviation during semi-finishing. Based on the cutting deviation during semi-finishing, the cutting amount during finishing is adjusted to compensate for the difference in semi-finishing.

2. The method according to claim 1, characterized in that, In step 1, the straightness and centerline position of the outer end face of the cylindrical shell are adjusted using the inner circular end face of one end of the cylindrical shell as the reference surface.

3. The method according to claim 2, characterized in that, Step 1 includes: S1021: Determine the machining reference surface; S1022: Rough machining of the outer end face of the cylindrical shell section, with a machining allowance of 2-3mm; S1023: Perform finishing on the outer end face of the cylindrical shell section until a cylindrical shell section with a wall thickness of 7.8 mm is obtained.

4. The method according to claim 1, characterized in that, Step 2 includes: S201: Determine the horizontal plane reference line and the symmetry plane reference line of the cylindrical shell section; S202: Based on the determined horizontal plane reference line and symmetrical plane reference line, determine the machining position of the "U" shaped deep groove on the cylindrical shell.

5. The method according to claim 1, characterized in that, Step S402 includes: S4021: Rough machining of the recessed groove using a one-pass cutting method; S4022: Based on rough machining, the groove is semi-finished and the difference in rough machining is compensated. S4023: Based on the semi-finishing process, the recessed groove is finished, and the difference compensation is performed on the semi-finishing process.

6. The method according to claim 1, characterized in that, Step S403 includes: S4031: Determine the machining depth of the "U"-shaped deep groove; S4032: Rough machining of "U" shaped deep grooves using a one-pass cutting method; S4033: Based on rough machining, the "U"-shaped deep groove is semi-finished, and the difference compensation is applied to the rough machining. S4034: Based on the semi-finishing process, the "U"-shaped deep groove is finished, and the difference compensation is applied to the semi-finishing process.

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