Machining method of stepped deep hole

Abstract

The invention discloses a stepped deep hole machining method and belongs to the field of numerical control machining. When a stepped deep hole is machined, a small hole drill bit is bent under stress, torsion combined torque is large, the coaxiality of a drilled large hole and a drilled small hole is poor, and the roughness of the inner wall face of a drilled hole is large. According to the deep hole machining method, the deep hole is machined in a segmented mode on the front face and the back face, namely, a large-diameter hole in one side of a workpiece is machined firstly, the workpiece is turned over and aligned, and then a small-diameter hole in the other side of the workpiece is machined, so that on one hand, the length of the deep hole machining tool can be reduced, and the problem that in the deep hole machining process, the machining precision is poor due to the fact that the machining tool is too long is solved; meanwhile, the coaxiality of the two deep holes can be ensured; and on the other hand, when the large-diameter hole is machined firstly and then the small-diameter hole is machined, flowing of cooling liquid is facilitated, and therefore sufficient cooling and chip removal of the workpiece are achieved. The method is mainly used for stepped deep hole machining.

Description

Technical Field

[0001] The invention belongs to the field of numerical control machining, and in particular relates to a method for machining a stepped deep hole. Background Art

[0002] Drilling of workpieces is generally completed by a drill bit. For deep holes with steps, a large-diameter hole is usually drilled first by a large-hole drill bit, and then the small-hole drill bit is inserted into the large hole and drilled out a small hole. This requires lengthening the length of the small-hole drill bit. Generally, the length-to-diameter ratio of the large-hole drill bit is 7.5, while the length-to-diameter ratio of the small-hole drill bit is 18.67. When the small-hole drill bit is drilling, the small-hole drill bit is bent by force, and the torsional combined torque is large, resulting in poor coaxiality between the drilled large hole and the small hole, large roughness of the inner wall of the drilled hole, insufficient cooling, difficulty in chip removal, and poor overall drilling accuracy. Summary of the invention

[0003] In view of this, the present invention provides a method for processing a stepped deep hole, which can ensure the coaxiality and small roughness of the inner wall surface of the stepped deep hole and improve the processing accuracy of the stepped deep hole.

[0004] The technical solution adopted by the present invention to solve the above technical problems is:

[0005] A method for processing a stepped deep hole, wherein the stepped deep hole of a workpiece includes at least two sequentially connected and coaxial deep holes, and the processing of the stepped deep hole is realized by using a CNC five-axis linkage machine tool, wherein the CNC five-axis linkage machine tool is provided with a working plate for clamping the workpiece, and the specific processing process is as follows:

[0006] S1, use 3D modeling software to model and program the workpiece, and import the compiled program into the CNC five-axis linkage machine tool;

[0007] S2, clamping the workpiece on the worktable and leveling it;

[0008] S3, workpiece alignment;

[0009] S4, using a deep hole processing tool to process the first section of the deep hole on the upper plane of the workpiece, and setting it as deep hole one;

[0010] S5, when the first deep hole 1 is processed, the working disk is rotated and step 4 is repeated to process the next deep hole 1 until all deep holes 1 are processed;

[0011] S6, machining two symmetrically arranged standard holes at the center plane of the workpiece to serve as alignment holes after the workpiece is turned over;

[0012] S7, flip the workpiece, clamp the workpiece on the workpiece plate again and level it;

[0013] S8, align the workpiece using two aligning holes;

[0014] S9, using a deep hole processing tool to process the first deep hole of the flip surface, and setting it as deep hole 2;

[0015] S10, when the first deep hole 2 is processed, the work disk is rotated and step 9 is repeated to process the next deep hole 2 until all deep holes 2 are processed.

[0016] Preferably, the CNC five-axis linkage machine tool further includes a machine tool probe, and the S3 includes the following steps:

[0017] S31, draw an alignment center line on the upper plane of the workpiece along the diameter direction, and rotate the work disk until the alignment center line on the workpiece is aligned with the x-axis of the workpiece coordinate system on the vertical plane, and the C-axis alignment is completed at this time;

[0018] S32, measuring at least three coordinate values ​​of the outer cylindrical surface of the workpiece by using a machine tool probe, and determining the center of the workpiece based on the at least three coordinate values;

[0019] S33, using the machine tool probe to contact the upper plane of the workpiece, determine the position of the contact point in the workpiece coordinate system, and thus determine the position of the upper plane of the workpiece in the workpiece coordinate system.

[0020] Preferably, in S4, when the deep hole 1 is a straight hole, the deep hole processing tool includes drill bit 1, drill bit 2 and reamer 1, assuming that the target hole diameter of the deep hole 1 is d, the diameter of the drill bit 1 is d2, the diameter of the drill bit 2 is d3, and the diameter of the reamer 1 is d4, wherein d2=d3<d4=d; S4 includes the following steps:

[0021] S41, drilling a hole with a drill bit aligned with the upper plane of the workpiece to be processed to obtain a guide hole 1;

[0022] S42, the drill bit 2 is inserted into the guide hole 1 and drills to a target depth to obtain the drill hole 1;

[0023] S43, reamer one is inserted into drill hole one and the hole is expanded to a target inner diameter to obtain a target deep hole one.

[0024] Preferably, in S4, when the deep hole 1 is a deep inclined hole, the deep hole processing tools include drill bit 1, drill bit 2, milling cutter 1 and reamer 1, assuming that the target hole diameter of the deep inclined hole 1 is d, the diameter of the milling cutter 1 is d1, the diameter of the drill bit 1 is d2, the diameter of the drill bit 2 is d3, and the diameter of the reamer 1 is d4, wherein d1<d2=d3<d4=d; S4 includes the following steps:

[0025] S41, the milling cutter 1 is aligned with the position of the inclined hole to be machined on the workpiece, and a plane 1 for centering the inclined drilling is machined;

[0026] S42, a drill bit 1 extends into a plane 1 and drills a hole to obtain a guide hole 1;

[0027] S43, the drill bit 2 is inserted into the guide hole 1 and drills obliquely to a target depth to obtain the drill hole 1;

[0028] S44, a reamer is inserted into the drill hole and the hole is expanded to a target inner diameter to obtain a target deep inclined hole.

[0029] Preferably, when the deep hole is divided into three sections, after deep hole one is processed, the deep hole processing tool is sequentially inserted into deep hole one and processes the middle section deep hole until all the middle section deep holes are processed.

[0030] Preferably, the step S8 comprises the following steps:

[0031] S81, using a machine tool probe to measure at least three coordinate values ​​of the inner wall surfaces of the two alignment holes respectively, and determining the center point of each alignment hole based on the at least three coordinate values, determining the alignment center line based on the center points of the two alignment holes, and rotating the work disk so that the alignment center line is aligned with the x-axis in the workpiece coordinate system in the vertical plane, and at this time, there is no deviation in the C-axis direction before and after the workpiece is flipped;

[0032] S82, measuring at least three coordinate values ​​of the outer cylindrical surface of the workpiece by using a machine tool probe, and determining the center of the workpiece based on the at least three coordinate values, thereby determining the center of the workpiece coordinate system;

[0033] S83, taking the upper plane of the workpiece before flipping as a machining reference, and determining the position of the machining surface of the workpiece in the workpiece coordinate system.

[0034] Preferably, in S7, a three-jaw chuck is used to clamp and fix the workpiece, and in S83, a machine tool probe is used to contact the contact surface between the three-jaw chuck and the upper plane of the workpiece before flipping, to determine the position of the contact surface in the workpiece coordinate system, thereby determining the position of the machining surface of the workpiece in the workpiece coordinate system.

[0035] Preferably, in the above S83, the position of the machining surface after the workpiece is flipped in the workpiece coordinate system is determined based on the thickness of the workpiece and the coordinate value of the upper plane of the workpiece before flipping.

[0036] Preferably, in S9, when the deep hole is a straight hole, the deep hole processing tool includes a drill bit 3, a drill bit 4 and a reamer 2, and the target hole diameter of the deep hole 2 is d', the diameter of the drill bit 3 is d'2, the diameter of the drill bit 4 is d'3, and the diameter of the reamer 2 is d'4, wherein d'2=d'3<d'4=d'; S9 includes the following steps:

[0037] S91, the drill bit 3 is aligned with the flip surface of the workpiece to be processed to drill a hole to obtain the guide hole 2;

[0038] S92, the drill bit 4 is inserted into the guide hole 2 and drills to a target depth to obtain the drill hole 2;

[0039] S93, the second reamer is inserted into the second drill hole and the hole is expanded to the target inner diameter to obtain the target deep hole second.

[0040] Preferably, in S9, when the deep hole is a deep inclined hole, the deep hole processing tools include drill bit 3, drill bit 4, milling cutter 2 and reamer 2, assuming that the target hole diameter of the deep inclined hole 2 is d', the diameter of the milling cutter 2 is d'1, the diameter of the drill bit 3 is d'2, the diameter of the drill bit 4 is d'3, and the diameter of the reamer 2 is d'4, wherein d'1<d'2=d'3<d'4=d'; S9 includes the following steps:

[0041] S91, the second milling cutter is aligned with the position of the inclined hole to be machined on the workpiece, and a second plane for centering the inclined drilling is machined;

[0042] S92, the drill bit 3 extends into the plane 2 and drills a hole to obtain the guide hole 2;

[0043] S93, the drill bit 4 is inserted into the guide hole 2 and obliquely drills to a target depth to obtain the drill hole 2;

[0044] S94, the second reamer is inserted into the second drill hole and the hole is expanded to the target inner diameter to obtain the second target deep inclined hole.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] Since the entire hole depth of the stepped deep hole is relatively large, the deep hole is processed in sections and on both sides, that is, the large-diameter hole on one side of the workpiece is processed first, and the workpiece is turned over and aligned before processing the small-diameter hole on the other side of the workpiece. This processing method can, on the one hand, reduce the length of the deep hole processing tool and avoid the problem of poor processing accuracy caused by the excessive length of the processing tool during the deep hole processing, while ensuring the coaxiality of the two deep holes; on the other hand, when the large-diameter hole is processed first and the small-diameter hole is processed, the flow of coolant is conducive to the full cooling and chip removal of the workpiece. In addition, each deep hole processing is carried out in at least three steps, namely, drilling the guide hole, drilling the deep hole and reaming the hole with a reamer. This design can improve the processing accuracy of the deep hole, that is, ensure the shape, position and size requirements of the deep hole and reduce the roughness of the stepped deep hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings are incorporated as part of this application and are used to provide a further understanding of the present invention.

[0048] Figure 1 This is a schematic diagram of the structure of the center nozzle flange in Example 1 of the present invention.

[0049] Figure 2 This is a schematic diagram of the workpiece being mounted on the work plate via a three-jaw chuck.

[0050] Figure 3 A schematic diagram of a milling cutter machining a plane 1 for centering the inclined surface drilling when machining a deep inclined hole, wherein (a) is a schematic diagram of the machining process of the milling cutter 1, and (b) is a schematic diagram of the milling cutter 1 after the machining is completed and a plane 1 is formed on the workpiece surface.

[0051] Figure 4 Schematic diagram of drill one machining guide hole one when machining a deep inclined hole, wherein (a) is a schematic diagram of the machining process of drill one, and (b) is a schematic diagram of the guide hole one formed on the surface of the workpiece after the machining of drill one is completed.

[0052] Figure 5 Schematic diagram of drill bit two machining hole one when machining a deep inclined hole, wherein (a) is a schematic diagram of the machining process of drill bit two, and (b) is a schematic diagram of the drill bit two after machining is completed and hole one is formed in the workpiece.

[0053] Figure 6 A schematic diagram of a reamer machining a target deep inclined hole when machining a deep inclined hole, wherein (a) is a schematic diagram of the machining process of the reamer, and (b) is a schematic diagram of the reamer machining a target deep inclined hole after the machining is completed and the target deep inclined hole is formed in the workpiece.

[0054] Figure 7 Schematic diagram of two standard holes machined on the workpiece.

[0055] Figure 8 This is a schematic diagram of the workpiece being mounted on the work plate by the three-jaw chuck after being flipped.

[0056] Fig. 9 Schematic diagram of plane 2 processed by milling cutter 2 for centering inclined surface drilling when processing deep inclined holes, wherein (a) is a schematic diagram of the processing process of milling cutter 2, and (b) is a schematic diagram of plane 2 formed on the workpiece surface after milling cutter 2 is completed.

[0057] Fig.10 Schematic diagram of drill bit 3 machining guide hole 2 when machining a deep inclined hole, where (a) is a schematic diagram of the machining process of drill bit 3, and (b) is a schematic diagram of the guide hole 2 formed on the workpiece surface after drill bit 3 is completed.

[0058] Fig.11 Schematic diagram of drill bit 4 processing hole 2 when processing a deep inclined hole.

[0059] Fig.12 Schematic diagram of reamer two machining target deep inclined hole two when machining a deep inclined hole.

[0060] Explanation of the accompanying drawings: 1-working disk; 2-three-jaw chuck; 3-workpiece; 31-round table one; 32-round table two; 4-drill bit one; 5-drill bit two; 6-milling cutter one; 7-reamer one; 8-plane one; 9-guide hole one; 10-drill hole one; 11-target deep hole one; 12-standard hole; 13-drill bit three; 14-drill bit four; 15-milling cutter two; 16-reamer two; 17-plane two; 18-guide hole two; 20-target deep hole two. DETAILED DESCRIPTION

[0061] The present invention is described in detail below in conjunction with specific embodiments.

[0062] The present embodiment provides a method for processing a stepped deep hole. The stepped deep hole of the workpiece 3 includes at least two sections of sequentially connected and coaxial deep holes. The deep hole can be a deep straight hole or a deep inclined hole. The processing of the stepped deep hole is achieved by using a CNC five-axis linkage machine tool. The CNC five-axis linkage machine tool is provided with a working plate 1 and a three-jaw chuck 2 for clamping the workpiece 3, as well as a ruby ​​machine tool probe. Figures 1 to 12 , is the processing process of processing two deep holes, the specific processing process is as follows:

[0063] S1, using three-dimensional modeling software, such as CAD / CAM software, to model and program the workpiece, and import the compiled program into the CNC five-axis linkage machine tool;

[0064] S2, such as Figure 2 As shown, the three-jaw chuck 2 is fixed at the center of the working disk 1 of the CNC five-axis linkage machine tool, the upper plane of the three-jaw chuck 2 is leveled, and the error is controlled within 0.02mm. The three-jaw chuck 2 clamps and fixes the workpiece 3 to fix the workpiece 3 on the working disk 1, and the horizontality of the upper plane of the workpiece 3 is re-measured to control its error within 0.02mm, thereby realizing the leveling of the center nozzle flange;

[0065] S3, workpiece 3 alignment, the specific steps are as follows:

[0066] S31, draw an alignment center line on the upper plane of the workpiece 3 and along the diameter direction, rotate the work disk 1 until the alignment center line on the workpiece 3 is aligned with the X axis in the workpiece coordinate system on the vertical plane, and the C axis alignment is completed at this time;

[0067] S32, using a ruby ​​machine tool probe of a CNC five-axis linkage machine tool to measure four coordinate values ​​of the outer cylindrical surface of the workpiece 3, and determining the center of the workpiece 3 based on the four coordinate values, thereby determining the center of the workpiece coordinate system;

[0068] S33, using the ruby ​​machine tool probe of the CNC five-axis linkage machine tool to contact the upper plane of the workpiece 3, determine the position of the contact point in the workpiece coordinate system, and thus determine the position of the upper plane of the workpiece 3 in the workpiece coordinate system;

[0069] S4, use the deep hole processing tool to process the first deep hole on the upper plane of the workpiece, and set it as deep hole 1. Since the processing methods of straight holes and inclined holes are slightly different, they are explained separately:

[0070] When the deep hole 1 is a straight hole, the deep hole processing tool includes a drill bit 1, a drill bit 2 and a reamer 1. Assuming that the target hole diameter of the deep hole 1 is d, the diameter of the drill bit 1 is d2, the diameter of the drill bit 2 is d3, and the diameter of the reamer 1 is d4, wherein d2=d3<d4=d; S4 includes the following steps:

[0071] S41, drilling a hole with a drill bit aligned with the upper plane of the workpiece to be processed to obtain a guide hole 1;

[0072] S42, the drill bit 2 is inserted into the guide hole 1 and drills to a target depth to obtain the drill hole 1;

[0073] S43, reamer one is inserted into drill hole one and the hole is expanded to a target inner diameter to obtain a target deep hole one.

[0074] When the deep hole 1 is a deep inclined hole, Figures 3 to 6 As shown, a deep hole processing tool is used to process the first section of a deep inclined hole on a plane of a workpiece 3, and it is set as a deep inclined hole 1. The deep hole processing tool includes a drill 1 4, a drill 2 5, a milling cutter 1 6 and a reamer 1 7. Assuming that the target hole diameter of the deep inclined hole 1 is d, the diameter of the milling cutter 1 6 is d1, the diameter of the drill 1 4 is d2, the diameter of the drill 2 5 is d3, and the diameter of the reamer 1 7 is d4, wherein d1<d2=d3<d4=d, the specific processing process is as follows:

[0075] S41, the milling cutter 6 is aligned with the position of the inclined hole to be machined on the workpiece 3, and a plane 8 for centering the inclined drilling is machined;

[0076] S42, the drill bit 4 is inserted into the plane and drilled to obtain a guide hole 9 with a depth of 5 mm;

[0077] S43, a drill bit 5 made of cemented carbide is inserted into the guide hole 9 and drilled obliquely to a target depth to obtain a drill hole 10;

[0078] S44, the reamer 7 is inserted into the drill hole 10 and the hole is expanded to a target inner diameter to obtain a target deep hole 11;

[0079] S5, when the first deep hole 1 is processed, the work disk 1 is rotated, and step 4 is repeated to process the next deep hole 1 until all deep holes 1 are processed;

[0080] S6, such as Figure 7As shown, two symmetrically arranged standard holes 12 are machined at the center plane of the workpiece 3 to serve as alignment holes after the workpiece 3 is flipped, so as to ensure that there is no deviation in the C-axis direction of the workpiece 3 before and after flipping;

[0081] S7, such as Figure 8 As shown, the three-jaw chuck 2 is turned over and fixed at the center of the work plate 1 of the CNC five-axis linkage machine tool, the contact surface between the three-jaw chuck 2 and the workpiece 3 is leveled, and the error is controlled within 0.02mm, the workpiece 3 is turned over, and clamped and fixed by the three-jaw chuck 2, and the horizontality of the upper plane of the workpiece 3 before turning over is re-measured, so that the error is controlled within 0.02mm;

[0082] S8, using two alignment holes to align the workpiece 3, the specific process is as follows:

[0083] S81, using the ruby ​​probe of the CNC five-axis linkage machine tool to measure at least three coordinate values ​​of the inner wall surfaces of the two alignment holes respectively, and determining the center point of each alignment hole based on the at least three coordinate values, determining the alignment center line based on the center points of the two alignment holes, and rotating the work disk 1 so that the alignment center line is aligned with the x-axis in the workpiece coordinate system in the vertical plane, and at this time, there is no deviation in the C-axis direction before and after the workpiece 3 is flipped;

[0084] S82, measuring at least three coordinate values ​​of the outer cylindrical surface of the workpiece 3 by using a machine tool probe, and determining the center of the workpiece 3 based on the at least three coordinate values, thereby determining the center of the workpiece coordinate system;

[0085] S83, taking the upper plane of the workpiece 3 before flipping as a processing reference, and determining the position of the processing surface of the workpiece 3 in the workpiece coordinate system; specifically, using a machine tool probe to contact the contact surface between the three-jaw chuck 2 and the upper plane of the workpiece 3 before flipping, determining the position of the contact surface in the workpiece coordinate system, thereby determining the position of the processing surface of the workpiece 3 in the workpiece coordinate system; or determining the position of the processing surface of the workpiece 3 after flipping in the workpiece coordinate system based on the thickness of the workpiece 3 and the coordinate value of the upper plane of the workpiece 3 before flipping;

[0086] S9, use the deep hole processing tool to process the first deep hole of the flip surface, and set it as deep hole 2. Since the processing methods of straight holes and inclined holes are slightly different, they are explained separately:

[0087] When the deep hole is a straight hole, the deep hole processing tool includes a drill bit 3, a drill bit 4 and a reamer 2. Assuming that the target hole diameter of the deep hole 2 is d′, the diameter of the drill bit 3 is d′2, the diameter of the drill bit 4 is d′3, and the diameter of the reamer 2 is d′4, wherein d′2=d′3<d′4=d′; S9 includes the following steps:

[0088] S91, the drill bit 3 is aligned with the flip surface of the workpiece to be processed to drill a hole to obtain the guide hole 2;

[0089] S92, the drill bit 4 is inserted into the guide hole 2 and drills to a target depth to obtain the drill hole 2;

[0090] S93, the second reamer is inserted into the second drill hole and the hole is expanded to the target inner diameter to obtain the target deep hole second.

[0091] like Figures 9 to 12 As shown, when the deep hole is a deep inclined hole, a deep hole processing tool is used to process the first section of the inclined hole of the flip surface. The deep hole processing tool includes a drill bit 3 13, a drill bit 4 14, a milling cutter 2 15 and a reamer 2 16. Assuming that the target hole diameter of the deep hole 2 is d', the diameter of the milling cutter 2 15 is d'1, the diameter of the drill bit 3 13 is d'2, the diameter of the drill bit 4 14 is d'3, and the diameter of the reamer 2 16 is d'4, wherein d'1<d'2=d'3<d'4=d'; the specific process is as follows:

[0092] S91, the second milling cutter 15 is aligned with the position of the inclined hole to be machined on the workpiece 3, and a second plane 17 for centering the inclined drilling is machined;

[0093] S92, the drill bit 13 extends into the plane 17 and drills a hole to obtain the guide hole 18;

[0094] S93, the carbide drill bit 14 is inserted into the guide hole 18 and drilled obliquely to the target depth to obtain the second drill hole;

[0095] S94, the reamer 16 is inserted into the drilled hole 2 and expanded to a target inner diameter to obtain a target deep inclined hole 20.

[0096] S10, when the first deep hole 2 is processed, the work disk 1 is rotated and step 9 is repeated to process the next deep hole 2 until all deep holes 2 are processed.

[0097] Since the entire hole depth of the stepped deep hole is relatively large, the deep hole of this embodiment is processed in sections and on both sides, that is, the large-diameter hole on one side of the workpiece 3 is processed first, and the small-diameter hole on the other side of the workpiece 3 is processed after the workpiece 3 is turned over and aligned. This processing method can, on the one hand, reduce the length of the deep hole processing tool, avoid the problem of poor processing accuracy caused by the excessive length of the processing tool during the deep hole processing, and at the same time ensure the coaxiality of the two deep holes; on the other hand, when the large-diameter hole is processed first and the small-diameter hole is processed, it is conducive to the flow of coolant to achieve sufficient cooling and chip removal of the workpiece 3. In addition, each deep straight hole processing is carried out in three steps, namely, drilling a guide hole, drilling a deep hole and reaming the hole, while the inclined hole processing is carried out in four steps, namely, milling out a plane for centering the inclined surface drilling, drilling a guide hole, drilling a deep hole and reaming the hole. Such a design can improve the processing accuracy of the deep straight hole or deep inclined hole, that is, ensure the shape, position and size requirements of the deep straight hole or deep inclined hole, and reduce the roughness of the stepped deep straight hole or deep inclined hole.

[0098] Embodiment 1:

[0099] The center nozzle flange in the re-ignition unit is pre-processed. The center nozzle flange includes a frustum 31, a frustum 32 and a frustum 3 which are sequentially arranged and integrally connected from top to bottom. Twelve groups of stepped inclined holes penetrating the upper and lower surfaces of the workpiece 3 need to be processed on the center nozzle flange. Each group of stepped inclined holes includes a coaxial and interconnected large-diameter hole (target inclined hole 11) and a small-diameter hole (target inclined hole 20). The diameter of the large-diameter hole is φ9.6±0.1 and the hole depth is 71.5 mm. The diameter of the small-diameter hole is φ6.6±0.1 and the hole depth is 40 mm. The roughness of the stepped inclined hole is 3.2. Figure 1 As shown. During the experimental processing, it was found that the currently provided tool could not guarantee the requirements of the aperture and roughness of the stepped inclined hole, so it was necessary to change the processing method to meet the requirements of the product illustration. This embodiment uses the DMG DMU125FD system Siemens 840D CNC five-axis linkage machine tool to realize the processing of stepped deep inclined holes. The CNC five-axis linkage machine tool is equipped with a work plate 1 and a three-jaw chuck 2 for clamping the workpiece 3, and a ruby ​​machine tool probe for measuring the center of the circle. The specific processing process is as follows:

[0100] S1, using three-dimensional modeling software, such as CAD / CAM software, to model and program the center nozzle flange, and import the compiled program into a CNC five-axis linkage machine tool;

[0101] S2, fix the three-jaw chuck 2 at the center of the working disk 1 of the CNC five-axis linkage machine tool, level the upper plane of the three-jaw chuck 2, and control the error within 0.02mm. The three-jaw chuck 2 clamps and fixes the truncated table 31 of the center nozzle flange to fix the center nozzle flange on the working disk 1, re-measure the horizontality of the upper plane of the center nozzle flange, and control its error within 0.02mm to achieve the leveling of the center nozzle flange;

[0102] S3, center nozzle flange alignment, the specific steps are as follows:

[0103] S31, draw an alignment center line on the upper plane of the center nozzle flange and along the diameter direction, rotate the work disk 1 until the alignment center line on the center nozzle flange is aligned with the X axis in the workpiece coordinate system on the vertical plane, and the C axis alignment is completed at this time;

[0104] S32, using the ruby ​​machine tool probe of the CNC five-axis linkage machine tool to measure four coordinate values ​​of the outer cylindrical surface of the frustum 31 of the center nozzle flange, and determining the center of the workpiece 3 based on the four coordinate values, thereby determining the center of the workpiece coordinate system;

[0105] S33, using the ruby ​​machine tool probe of the CNC five-axis linkage machine tool to contact the upper plane of the truncated table 31 of the central nozzle flange to determine the position of the contact point in the workpiece coordinate system, thereby determining the position of the upper plane of the central nozzle flange in the workpiece coordinate system;

[0106] S4, use a deep hole processing tool to process a large diameter hole on the flat side of the center nozzle flange, the deep hole processing tool includes a drill bit 4, a drill bit 5, a milling cutter 6 and a reamer 7, the target hole diameter of the large diameter hole is 9.6mm, the diameter d1 of the milling cutter 6 is 8mm, the diameter d2 of the drill bit 4 is 9mm, the diameter d3 of the drill bit 5 is 9mm, and the diameter d4 of the reamer 7 is 9.6mm (since there is no standard 9.6mm reamer on the market, it is modified from an end mill, that is, the bottom tip of the end mill is cut off to form a reamer with a bottom plane), the specific processing process is as follows:

[0107] S41, the milling cutter 6 is aligned with the position of the inclined hole to be machined on the upper plane of the center nozzle flange, and a plane 8 for centering the inclined surface drilling is machined;

[0108] S42, the drill bit 4 is inserted into the plane and drilled to obtain a guide hole 9 with a depth of 5 mm;

[0109] S44, a carbide drill bit 5 is inserted into the guide hole 9 and obliquely drilled to a target depth of 71.5 mm, while leaving a machining allowance of 0.3 mm to obtain a drill hole 10;

[0110] S44, a reamer 7 is inserted into a drill hole 10 and the hole is expanded to a target inner diameter of 9.6 mm to obtain a large-diameter hole;

[0111] S5, when the first large-diameter hole is processed, the working disk 1 is rotated according to the angle between two adjacent large-diameter holes, and step 4 is repeated to process the next large-diameter hole until all large-diameter holes are processed;

[0112] S6, machining two symmetrically arranged standard holes 12 at the center plane of the center nozzle flange to serve as alignment holes after the workpiece 3 is flipped, to ensure that there is no deviation in the C-axis direction of the workpiece 3 before and after flipping;

[0113] S7, flip the three-jaw chuck 2 and fix it at the center of the working disk 1 of the CNC five-axis linkage machine tool, level the contact surface between the three-jaw chuck 2 and the center nozzle flange, and control the error within 0.02mm; flip the workpiece 3, the three-jaw chuck 2 clamps and fixes the frustum 32 of the center nozzle flange to fix the center nozzle flange on the working disk 1 again, and re-measure the horizontality of the upper plane of the center nozzle flange before flipping, so that the error is controlled within 0.02mm;

[0114] S8, using two alignment holes to align the workpiece 3, the specific process is as follows:

[0115] S81, using the ruby ​​probe of the CNC five-axis linkage machine tool to measure at least three coordinate values ​​of the inner wall surfaces of the two alignment holes respectively, and determining the center point of each alignment hole based on the at least three coordinate values, determining the alignment center line based on the center points of the two alignment holes, and rotating the work disk 1 so that the alignment center line is aligned with the x-axis in the workpiece coordinate system in the vertical plane, and at this time, there is no deviation in the C-axis direction before and after the workpiece 3 is flipped;

[0116] S82, using a machine tool probe to measure at least three coordinate values ​​of the outer cylindrical surface of the center nozzle flange, and determining the center of the workpiece 3 based on the at least three coordinate values, thereby determining the center of the workpiece coordinate system;

[0117] S83, taking the upper plane of the center nozzle flange before flipping as the processing reference, and determining the position of the processing surface of the center nozzle flange in the workpiece coordinate system; specifically, using the machine tool probe to contact the contact surface between the three-jaw chuck 2 and the upper plane of the center nozzle flange before flipping, determining the position of the contact surface in the workpiece coordinate system, thereby determining the position of the processing surface of the center nozzle flange (the lower surface of the center nozzle flange) in the workpiece coordinate system; or determining the position of the processing surface of the center nozzle flange after flipping in the workpiece coordinate system based on the thickness of the center nozzle flange and the coordinate value of the upper plane of the center nozzle flange before flipping;

[0118] S9, using a deep hole processing tool to process a small diameter hole of the center nozzle flange, the deep hole processing tool includes a drill bit 3 13, a drill bit 4 14, a milling cutter 2 15 and a reamer 2 16, the target hole diameter of the small diameter hole is 6.6 mm, the diameter of the milling cutter 2 15 is 5 mm, the diameter of the drill bit 3 13 is 6 mm, the diameter of the drill bit 4 14 is 6 mm, and the diameter of the reamer 2 16 is 6.6 mm; the specific process is as follows:

[0119] S91, the second milling cutter 15 is aligned with the position of the inclined hole to be machined on the workpiece 3, and a second plane 17 for centering the inclined drilling is machined;

[0120] S92, the drill bit 13 is inserted into the plane 17 and drilled to obtain a guide hole 18 with a depth of 5 mm;

[0121] S93, the carbide drill bit 14 is inserted into the guide hole 18 and drilled obliquely to the target depth, leaving a processing allowance of 0.1 mm to obtain the second drill hole;

[0122] S94, the second reamer 16 is inserted into the second drill hole and expanded to the target inner diameter to obtain a small diameter hole.

[0123] S10, when the first small-diameter hole is processed, the working disk 1 is rotated according to the angle between two adjacent small-diameter holes, step 9 is repeated, and the next small-diameter hole is processed until all small-diameter holes are processed.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for processing a stepped deep hole, characterized in that: The stepped deep hole of the workpiece includes at least two sections of sequentially connected and coaxial deep holes. The processing of the stepped deep hole is realized by using a CNC five-axis linkage machine tool. The CNC five-axis linkage machine tool is provided with a working plate for clamping the workpiece. The specific processing process is as follows: S1, use 3D modeling software to model and program the workpiece, and import the compiled program into the CNC five-axis linkage machine tool; S2, clamping the workpiece on the worktable and leveling it; S3, workpiece alignment; S4, using a deep hole processing tool to process the first section of the deep hole on the upper plane of the workpiece, and setting it as deep hole one; S5, when the first deep hole 1 is processed, the working disk is rotated and step 4 is repeated to process the next deep hole 1 until all deep holes 1 are processed; S6, machining two symmetrically arranged standard holes at the center plane of the workpiece to serve as alignment holes after the workpiece is turned over; S7, flip the workpiece, clamp the workpiece on the workpiece plate again and level it; S8, align the workpiece using two aligning holes; S9, using a deep hole processing tool to process the first deep hole of the flip surface, and setting it as deep hole 2; S10, when the first deep hole 2 is processed, the work disk is rotated and step 9 is repeated to process the next deep hole 2 until all deep holes 2 are processed.

2. A method for processing a stepped deep hole according to claim 1, characterized in that: The CNC five-axis linkage machine tool further includes a machine tool probe, and the S3 includes the following steps: S31, draw an alignment center line on the upper plane of the workpiece along the diameter direction, and rotate the work disk until the alignment center line on the workpiece is aligned with the x-axis of the workpiece coordinate system on the vertical plane, and the C-axis alignment is completed at this time; S32, measuring at least three coordinate values ​​of the outer cylindrical surface of the workpiece by using a machine tool probe, and determining the center of the workpiece based on the at least three coordinate values; S33, using the machine tool probe to contact the upper plane of the workpiece, determine the position of the contact point in the workpiece coordinate system, and thus determine the position of the upper plane of the workpiece in the workpiece coordinate system.

3. A method for processing a stepped deep hole according to claim 1, characterized in that: In the above S4, when the deep hole 1 is a straight hole, the deep hole processing tool includes a drill bit 1, a drill bit 2 and a reamer 1. Assuming that the target hole diameter of the deep hole 1 is d, the diameter of the drill bit 1 is d2, the diameter of the drill bit 2 is d3, and the diameter of the reamer 1 is d4, wherein d2=d3<d4=d; S4 includes the following steps: S41, drilling a hole with a drill bit aligned with the upper plane of the workpiece to be processed to obtain a guide hole 1; S42, the drill bit 2 is inserted into the guide hole 1 and drills to a target depth to obtain the drill hole 1; S43, reamer one is inserted into drill hole one and the hole is expanded to a target inner diameter to obtain a target deep hole one.

4. A method for processing a stepped deep hole according to claim 1, characterized in that: In the above S4, when the deep hole 1 is a deep inclined hole, the deep hole processing tools include drill bit 1, drill bit 2, milling cutter 1 and reamer 1. Assuming that the target hole diameter of the deep inclined hole 1 is d, the diameter of the milling cutter 1 is d1, the diameter of the drill bit 1 is d2, the diameter of the drill bit 2 is d3, and the diameter of the reamer 1 is d4, wherein d1<d2=d3<d4=d; S4 includes the following steps: S41, the milling cutter 1 is aligned with the position of the inclined hole to be machined on the workpiece, and a plane 1 for centering the inclined drilling is machined; S42, a drill bit 1 is inserted into a plane 1 and drills a hole to obtain a guide hole 1; S43, the drill bit 2 is inserted into the guide hole 1 and drills obliquely to a target depth to obtain the drill hole 1; S44, reamer one is inserted into drill hole one and the hole is expanded to a target inner diameter to obtain a target deep inclined hole one.

5. The method for machining a stepped deep hole according to claim 1, characterized in that: When the deep hole is divided into three sections, after deep hole one is processed, the deep hole processing tool is inserted into deep hole one in sequence and processes the middle section deep hole until all the middle section deep holes are processed.

6. A method for processing a stepped deep hole according to claim 1, characterized in that: The S8 comprises the following steps: S81, using a machine tool probe to measure at least three coordinate values ​​of the inner wall surfaces of the two alignment holes respectively, and determining the center point of each alignment hole based on the at least three coordinate values, determining the alignment center line based on the center points of the two alignment holes, and rotating the work disk so that the alignment center line is aligned with the x-axis in the workpiece coordinate system in the vertical plane, and at this time, there is no deviation in the C-axis direction before and after the workpiece is flipped; S82, measuring at least three coordinate values ​​of the outer cylindrical surface of the workpiece by using a machine tool probe, and determining the center of the workpiece based on the at least three coordinate values, thereby determining the center of the workpiece coordinate system; S83, taking the upper plane of the workpiece before flipping as a machining reference, and determining the position of the machining surface of the workpiece in the workpiece coordinate system.

7. A method for processing a stepped deep hole according to claim 6, characterized in that: In the above S7, a three-jaw chuck is used to clamp and fix the workpiece. In the above S83, a machine tool probe is used to contact the contact surface between the three-jaw chuck and the upper plane of the workpiece before flipping to determine the position of the contact surface in the workpiece coordinate system, thereby determining the position of the machining surface of the workpiece in the workpiece coordinate system.

8. A method for processing a stepped deep hole according to claim 6, characterized in that: In the above-mentioned S83, the position of the machining surface after the workpiece is flipped in the workpiece coordinate system is determined based on the thickness of the workpiece and the coordinate value of the upper plane of the workpiece before flipping.

9. A method for machining a stepped deep hole according to claim 1, characterized in that: In S9, when the deep hole is a straight hole, the deep hole processing tools include drill bit 3, drill bit 4 and reamer 2, and the target hole diameter of deep hole 2 is d′, the diameter of drill bit 3 is d′2, the diameter of drill bit 4 is d′3, and the diameter of reamer 2 is d′4, wherein d′2=d′3<d′4=d′; S9 includes the following steps: S91, the drill bit 3 is aligned with the flip surface of the workpiece to be processed to drill a hole to obtain the guide hole 2; S92, the drill bit 4 is inserted into the guide hole 2 and drills to a target depth to obtain the drill hole 2; S93, the second reamer is inserted into the second drill hole and the hole is expanded to the target inner diameter to obtain the target deep hole second.

10. The method for machining a stepped deep hole according to claim 1, characterized in that: In the above S9, when the deep hole is a deep inclined hole, the deep hole processing tools include drill bit 3, drill bit 4, milling cutter 2 and reamer 2, and the target hole diameter of the deep inclined hole 2 is d', the diameter of the milling cutter 2 is d'1, the diameter of the drill bit 3 is d'2, the diameter of the drill bit 4 is d'3, and the diameter of the reamer 2 is d'4, wherein d'1<d'2=d'3<d'4=d'; S9 includes the following steps: S91, the second milling cutter is aligned with the position of the inclined hole to be machined on the workpiece, and a second plane for centering the inclined drilling is machined; S92, the drill bit 3 extends into the plane 2 and drills a hole to obtain the guide hole 2; S93, the drill bit 4 is inserted into the guide hole 2 and obliquely drills to a target depth to obtain the drill hole 2; S94, the second reamer is inserted into the second drill hole and the hole is expanded to the target inner diameter to obtain the second target deep inclined hole.

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