A positioning processing method for cylindrical workpiece

Abstract

The present invention provides a method for positioning and processing a cylindrical workpiece, comprising the following steps: S1, determining the position of the rotation centerline of a turntable in a machine tool coordinate system; S2, placing the cylindrical workpiece on the turntable so that the centerline of the cylindrical workpiece coincides with the rotation centerline of the turntable; S3, determining the position of the bottom surface of the cylindrical workpiece in the machine tool coordinate system; and S4, establishing a workpiece coordinate system with the intersection of the bottom surface of the cylindrical workpiece and the rotation centerline as the zero point. According to the present invention, in the drawings of the cylindrical workpiece, since the holes, grooves, and planes distributed on the outer wall of the cylinder are designed with the centerline of the cylindrical workpiece as the reference axis and the bottom surface of the cylindrical workpiece as the reference surface, the centerline of the cylindrical workpiece is coincident with the rotation centerline of the turntable, and the workpiece coordinate system is established with the intersection of the bottom surface of the cylindrical workpiece and the rotation centerline as the zero point, so that the machine tool uses the centerline and bottom surface of the cylindrical workpiece as the processing reference, thereby ensuring that the processing dimensions and position accuracy of the holes, grooves, and planes meet the design requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of machining, in particular to a positioning machining method for a cylindrical workpiece. Background Art

[0002] Positioning cylindrical workpieces is a common problem in mechanical parts machining. For example, the main cylinders of steam turbines and large components in the 196 and 195 ultra-supercritical units all feature cylindrical cylinder structures, with various surface areas, holes, and slots distributed on the outer walls. During machining, there is a lack of direct measurement methods for the position of these holes, slots, and surfaces, making it impossible to determine whether the machined dimensions meet design requirements. This is especially true for inclined surfaces and inclined holes, where the positional accuracy cannot be measured. Summary of the Invention

[0003] In view of the above-mentioned shortcomings of the prior art, a technical problem to be solved by the present invention is to provide a positioning processing method for a cylindrical workpiece, which can ensure that the processing size and position of holes, grooves and planes meet the design requirements.

[0004] In order to solve the above technical problems, the present invention provides a cylindrical workpiece positioning processing method, comprising the steps of:

[0005] S1, determine the position of the rotation center line of the turntable in the machine tool coordinate system;

[0006] S2, placing the cylindrical workpiece on the turntable, and rotating the workpiece so that the center line of the cylindrical workpiece coincides with the rotation center line of the turntable;

[0007] S3, determining the position of the bottom surface of the cylindrical workpiece in the machine tool coordinate system;

[0008] S4, establish the workpiece coordinate system with the intersection of the bottom surface of the cylindrical workpiece and the rotation center line as the zero point;

[0009] S5, according to the drawing requirements of the cylindrical workpiece, setting the machining starting point of the cylindrical workpiece in the workpiece coordinate system;

[0010] S6, compile a processing program on the machine tool according to the drawing dimensions of the cylindrical workpiece and process the cylindrical workpiece.

[0011] Preferably, the S1 specifically includes:

[0012] S11, placing a first trial cut block and a second trial cut block on a turntable, wherein the first trial cut block and the second trial cut block are located on both sides of a rotation center line of the turntable;

[0013] S12: The machine tool spindle moves to the set position and maintains the Z-axis position unchanged. The tool is driven to machine the first reference surface on the first test block. The turntable is rotated 180° and the tool is driven to machine the second reference surface on the second test block.

[0014] S13, measuring the distance between the first reference plane and the second reference plane, dividing the obtained value by two and adding it to the value of the machine tool spindle in the Z-axis direction, thereby obtaining the position of the rotation center line of the turntable in the Z-axis direction of the machine tool coordinate system.

[0015] Furthermore, the S1 specifically includes:

[0016] S14, rotate the turntable 90° again, measure the symmetry plane between the first reference plane and the second reference plane, and move the machine tool spindle to the symmetry plane. At this time, the X-axial position of the machine tool spindle is the X-axial position of the rotation center line of the turntable in the machine tool coordinate system.

[0017] Preferably, the S2 specifically includes:

[0018] S21, placing the cylindrical workpiece upright on a turntable, and then bringing the probe of the dial indicator into contact with the inner circle or outer circle of the cylindrical workpiece;

[0019] S22, rotate the turntable and record the runout value of the dial indicator;

[0020] S23, adjust the position of the cylindrical workpiece on the turntable until the runout value measured by the dial indicator is close to zero.

[0021] Preferably, the turntable is provided with equal-height blocks, and the cylindrical workpiece is placed on the equal-height blocks, and S3 specifically includes:

[0022] The position of the bottom surface of the cylindrical workpiece in the Y-axis direction of the machine tool coordinate system is determined by the position of the turntable table and the height value of the contour pad.

[0023] Preferably, the step S5 specifically includes: setting a machining starting point of the cylindrical workpiece along the circumferential direction in the workpiece coordinate system according to the drawing requirements of the cylindrical workpiece.

[0024] Preferably, the S6 specifically includes:

[0025] S61, when machining vertical surface features, use the coordinate translation command to translate the workpiece coordinate system to the required machining plane according to the drawing dimensions of the cylindrical workpiece, and perform tool compensation;

[0026] S62, when machining angled features, use coordinate translation and rotation coordinate system instructions to move and rotate the workpiece coordinate system to the required machining plane according to the drawing dimensions of the cylindrical workpiece, and perform universal head compensation and tool compensation.

[0027] Furthermore, the S6 specifically includes:

[0028] S60, measure the compensation data of the universal head.

[0029] As described above, the cylindrical workpiece positioning processing method of the present invention has the following beneficial effects:

[0030] According to the cylindrical workpiece positioning processing method of the present invention, in the drawing of the cylindrical workpiece, since the holes, grooves and planes distributed on the outer wall of the cylinder body are designed with the center line of the cylindrical workpiece as the reference axis and the bottom surface of the cylindrical workpiece as the reference surface, the center line of the cylindrical workpiece is coincided with the rotation center line of the turntable, and the workpiece coordinate system is established with the intersection of the bottom surface of the cylindrical workpiece and the rotation center line as the zero point, so that the machine tool uses the center line and bottom surface of the cylindrical workpiece as the processing reference, and combines the drawing requirements and drawing dimensions of the cylindrical workpiece to set the processing starting point and program the processing, thereby ensuring that the processing dimensions and position accuracy of the holes, grooves and planes meet the design requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Shown is a schematic diagram of a top view of a turntable and a machine tool spindle in S12 in one embodiment of the present invention;

[0032] Figure 2 Shown is a schematic diagram of a top view of a turntable and a machine tool spindle in S14 in one embodiment of the present invention;

[0033] Figure 3 It is a structural schematic diagram showing the processing state of a cylindrical workpiece in one embodiment of the present invention.

[0034] Explanation of Figure Numbers

[0035] 1 Turntable

[0036] 101 Rotation Centerline

[0037] 102 Symmetry plane

[0038] 2 Cylindrical workpiece

[0039] 201 Centerline

[0040] 202 Bottom

[0041] 203 vertical plane

[0042] 204 inclined hole

[0043] 3. First trial cut

[0044] 301 First datum plane

[0045] 4 Second trial cut

[0046] 401 Second reference plane

[0047] 5. Machine tool spindle

[0048] 510 Knife

[0049] 6 Equal height blocks

[0050] 7 Universal Head DETAILED DESCRIPTION

[0051] The following describes the implementation of the present invention through specific embodiments. People skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0052] Please refer to the accompanying drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are intended solely to facilitate understanding and reading by those skilled in the art, and are not intended to limit the conditions under which the present invention may be implemented. Therefore, they have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in size, provided they do not affect the efficacy and objectives of the present invention, shall remain within the scope of the technical content disclosed by the present invention.

[0053] This invention provides a method for positioning and machining cylindrical workpieces, suitable for use on large-scale horizontal boring and milling machines equipped with CNC rotary tables. This process scheme addresses the machining of cylindrical workpieces. For example, the machining of a steam turbine cylinder is a practical application. The cylinder is cylindrical and has surfaces, holes, and slots of varying types and angles distributed around its periphery. The position of each surface, hole, and slot relative to the cylindrical workpiece datum must be controlled to fully meet design requirements.

[0054] like Figure 1-3 As shown, the positioning processing method of the turbine cylinder includes the following steps:

[0055] S1, determining the position of the rotation center line 101 of the turntable 1 in the machine tool coordinate system;

[0056] S2, placing the cylindrical workpiece 2 on the turntable 1, and rotating the workpiece 2 so that the center line 201 of the cylindrical workpiece 2 coincides with the rotation center line 101 of the turntable 1;

[0057] S3, determining the position of the bottom surface 202 of the cylindrical workpiece 2 in the machine tool coordinate system;

[0058] S4, establishing a workpiece coordinate system with the intersection of the bottom surface 202 of the cylindrical workpiece 2 and the rotation center line 101 as the zero point;

[0059] S5, setting a machining starting point of the cylindrical workpiece 2 in the workpiece coordinate system according to the drawing requirements of the cylindrical workpiece 2;

[0060] S6, compiling a machining program on a machine tool according to the drawing dimensions of the cylindrical workpiece 2, and machining the cylindrical workpiece 2.

[0061] By adopting this positioning processing method, in the drawing of the cylindrical workpiece 2, since the holes, grooves and planes distributed on the outer wall of the cylinder body are designed with the center line 201 of the cylindrical workpiece 2 as the reference axis and the bottom surface 202 of the cylindrical workpiece 2 as the reference surface, the center line 201 of the cylindrical workpiece 2 is coincided with the rotation center line 101 of the turntable 1, and the workpiece coordinate system is established with the intersection of the bottom surface 202 of the cylindrical workpiece 2 and the rotation center line 101 as the zero point, so that the machine tool uses the center line 201 and the bottom surface 202 of the cylindrical workpiece 2 as the processing reference, and combines the drawing requirements and drawing dimensions of the cylindrical workpiece 2 to set the processing starting point and program the processing, thereby ensuring that the processing dimensions and position accuracy of the holes, grooves and planes meet the design requirements.

[0062] As a preferred implementation, S1 in this embodiment specifically includes:

[0063] S11, placing a first trial cut block 3 and a second trial cut block 4 on the turntable 1, wherein the first trial cut block 3 and the second trial cut block 4 are located on both sides of the rotation center line 101 of the turntable 1;

[0064] S12: The machine tool spindle 5 moves to the set position and maintains the Z-axis position unchanged, driving the tool 510 to machine the first reference surface 301 on the first trial cutting block 3. The turntable 1 is rotated 180°, and the tool 510 is driven to machine the second reference surface 401 on the second trial cutting block 4.

[0065] S13, measuring the distance between the first reference plane 301 and the second reference plane 401, dividing the obtained value by two, and adding it to the value of the machine tool spindle 5 in the Z-axis direction, thereby obtaining the Z-axis position of the rotation centerline 101 of the turntable 1 in the machine tool coordinate system;

[0066] S14, rotate the turntable 1 90° again, and measure the midpoint of the distance between the first reference plane 301 and the second reference plane 401 to measure the symmetry plane 102 of the first reference plane 301 and the second reference plane 401, and move the machine tool spindle 5 to the symmetry plane 102. At this time, the X-axial position of the machine tool spindle 5 is the X-axial position of the rotation center line 101 of the turntable 1 in the machine tool coordinate system.

[0067] Specific examples Figure 1 As shown, the Z-axial position of the rotation centerline 101 of the turntable 1 is on the symmetry plane 102 of the first datum plane 301 and the second datum plane 401, that is, the Z-axial distance a between the rotation centerline 101 and the first datum plane 301 = the Z-axial distance b between the rotation centerline 101 and the second datum plane 401. Therefore, by superimposing a or b on the value of the machine tool spindle 5 in the Z-axial direction at this time, the Z-axial position of the rotation centerline 101 of the turntable 1 in the machine tool coordinate system can be obtained.

[0068] like Figure 2As shown, at this time, the X-axial position of the rotation center line 101 of the turntable 1 is on the symmetry plane 102 of the first reference plane 301 and the second reference plane 401. Therefore, the machine tool spindle 5 is moved to the symmetry plane 102 in the X-axis direction, and the center line of the machine tool spindle 5 is aligned with the symmetry plane 102. At this time, the X-axial position of the machine tool spindle 5 is the X-axial position of the rotation center line 101 of the turntable 1 in the machine tool coordinate system.

[0069] The positions of the rotation center line 101 of the turntable 1 in the Z-axis and X-axis directions of the machine tool coordinate system are determined in the above manner, and the rotation center line 101 of the turntable 1 is parallel to the Y-axis direction of the machine tool coordinate system.

[0070] As a preferred implementation, S2 in this embodiment specifically includes:

[0071] S21, placing the cylindrical workpiece 2 upright on the turntable 1, and then bringing the probe of the dial indicator into contact with the inner circle or outer circle of the cylindrical workpiece 2;

[0072] S22, rotate the turntable 1 and record the runout value of the dial indicator;

[0073] S23, adjusting the position of the cylindrical workpiece 2 on the turntable 1 until the runout value measured by the dial indicator is close to zero.

[0074] In the above manner, the center line 201 of the cylindrical workpiece 2 is made to coincide with the rotation center line 101 of the turntable 1, and the smaller the runout value measured by the dial indicator, the higher the degree of coincidence between the center line 201 of the cylindrical workpiece 2 and the rotation center line 101 of the turntable 1, thereby also determining the position of the center line 201 of the cylindrical workpiece 2 in the machine tool coordinate system, which is convenient for subsequent programming and processing.

[0075] like Figure 3 As shown, as a preferred embodiment, the turntable 1 in this embodiment is provided with a spacer 6 of equal height, and the cylindrical workpiece 2 is placed on the spacer 6 of equal height. S3 specifically includes:

[0076] The position of the bottom surface 202 of the cylindrical workpiece 2 along the Y-axis of the machine tool coordinate system is determined by the position of the tabletop of the turntable 1 and the height of the contour block 6. Since the height of the contour block 6 remains constant, the position of the bottom surface 202 of the cylindrical workpiece 2 along the Y-axis of the machine tool coordinate system is the same for different cylindrical workpieces 2. Therefore, only one S3 operation is required, and this operation can be omitted for subsequent processing of other cylindrical workpieces 2, thereby greatly improving processing efficiency.

[0077] As a preferred embodiment, S5 in this embodiment specifically includes: setting a circumferential machining starting point for the cylindrical workpiece 2 in the workpiece coordinate system according to the drawing requirements of the cylindrical workpiece 2. Because the cylindrical workpiece 2 is cylindrical, it cannot be guaranteed that the circumferential position of the cylindrical workpiece 2 will be the same each time it is placed on the turntable 1. Therefore, during the machining process, it is necessary to set a circumferential machining starting point for the cylindrical workpiece 2 in the workpiece coordinate system according to the drawing requirements of the cylindrical workpiece 2 to ensure that the circumferential position of the holes, slots, and planes in the cylindrical workpiece 2 meets the design requirements.

[0078] After completing steps S1-S5, CNC programming and machining dimensional control become relatively simple. Because the references marked on the design drawings of the cylindrical workpiece 2 are its centerline 201 and bottom surface 202, coordinate translation and tool compensation in the Z-axis direction can accurately control the characteristic dimensions of the vertical surface 203 during programming. Furthermore, by combining compensation with the various accessory heads (particularly the universal head 7), coordinate system rotation, and tool compensation, the positions of the various inclined surfaces and inclined holes 204 can be precisely controlled. If equipped with an automatic tool changing system, fully automated machining is possible.

[0079] Therefore, as a preferred implementation, S6 in this embodiment specifically includes:

[0080] S61, when processing the vertical surface 203 feature, use the coordinate translation command to translate the workpiece coordinate system to the required processing plane according to the drawing size of the cylindrical workpiece 2, and perform tool compensation;

[0081] S62, when processing angled features, use coordinate translation and rotation coordinate system instructions to move and rotate the workpiece coordinate system to the required processing plane according to the drawing dimensions of the cylindrical workpiece 2, and perform universal head compensation and tool compensation.

[0082] Through coordinate translation instructions, coordinate system rotation instructions, universal head compensation and tool compensation, the complexity of dimensional relationship setting during programming can be greatly reduced, the probability of programming errors can be reduced, and the processing size and position accuracy can be guaranteed.

[0083] Specifically, S6 in this embodiment further includes:

[0084] S60 , measuring compensation data of the universal head 7 .

[0085] like Figure 3 As shown, A represents the length of the universal head A1 axis, B represents the length of the universal head C1 axis, C represents the distance between the inclined hole 204 and the centerline 201 of the cylindrical workpiece 2, F represents the distance between the inclined hole 204 and the bottom surface 202 of the cylindrical workpiece 2, and E represents the distance between the rotation centerline 101 of the turntable 1 and the machine tool spindle 5. These data are measured for the purpose of compiling a machining program.

[0086] In the prior art, according to the conventional zero position setting method, the operation is very cumbersome. Every time a hole type (or groove type) is changed, the tool needs to be re-set to zero, which seriously affects the processing efficiency and the CNC programming is very cumbersome.

[0087] The primary purpose of applying the technology of this invention is to overcome the limitations of conventional zero-position setting methods, facilitating the rapid positioning and zero-position setting of a cylindrical workpiece 2 on a turntable 1. This solves the challenges of zero-position setting and CNC programming for inclined surfaces and inclined holes 204 in spatial structures. The same cylindrical workpiece 2 only needs to be zero-positioned once to complete drilling and milling operations on all its structures.

[0088] The technical solution of the present invention achieves a breakthrough in the rapid positioning and standardized programming of various spatial structures in the cylindrical workpiece 2. By using the contour pads 6, the position of the cylindrical workpiece 2 on the turntable 1 can be calibrated, and the work of setting the CNC zero point can be reduced (only the processing starting position of the cylindrical workpiece 2 along the circumferential direction needs to be set). It has the advantages of high accuracy in processing positioning and CNC program compilation, and is particularly suitable for the positioning processing of cylindrical workpieces such as the main cylinder of the gas turbine and the cylinders in the 196 and 195 ultra-supercritical units, and has a popularizable and far-reaching application significance.

[0089] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for positioning and processing a cylindrical workpiece, characterized in that: Including steps: S1, determining the position of the rotation center line (101) of the turntable (1) in the machine tool coordinate system; S2, placing the cylindrical workpiece (2) on the turntable (1), and rotating the workpiece (2) so that the center line (201) of the cylindrical workpiece (2) coincides with the rotation center line (101) of the turntable (1); S3, determining the position of the bottom surface (202) of the cylindrical workpiece (2) in the machine tool coordinate system; S4, establishing a workpiece coordinate system with the intersection of the bottom surface (202) of the cylindrical workpiece (2) and the rotation center line (101) as the zero point; S5, according to the drawing requirements of the cylindrical workpiece (2), setting the machining starting point of the cylindrical workpiece (2) in the workpiece coordinate system; S6, compiling a machining program on a machine tool according to the drawing dimensions of the cylindrical workpiece (2), and machining the cylindrical workpiece (2); Said S1 specifically includes: S11, placing a first trial cut block (3) and a second trial cut block (4) on the turntable (1), wherein the first trial cut block (3) and the second trial cut block (4) are located on both sides of the rotation center line (101) of the turntable (1); S12, the machine tool spindle (5) moves to a set position and keeps the Z-axis position unchanged, drives the tool (510) to machine a first reference surface (301) on the first trial cutting block (3), rotates the turntable (1) 180 degrees, and drives the tool (510) to machine a second reference surface (401) on the second trial cutting block (4); S13, measuring the distance between the first reference plane (301) and the second reference plane (401), dividing the obtained value by two and adding it to the value of the machine tool spindle (5) in the Z-axis direction, thereby obtaining the position of the rotation center line (101) of the turntable (1) in the Z-axis direction of the machine tool coordinate system; Said S1 specifically also includes: S14, rotating the turntable (1) by 90 degrees, measuring the symmetry plane (102) between the first reference plane (301) and the second reference plane (401), and moving the machine tool spindle (5) to the symmetry plane (102). At this time, the X-axis position of the machine tool spindle (5) is the X-axis position of the rotation center line (101) of the turntable (1) in the machine tool coordinate system; The S2 specifically includes: S21, placing the cylindrical workpiece (2) upright on the turntable (1), and then bringing the probe of the dial indicator into contact with the inner circle or outer circle of the cylindrical workpiece (2); S22, rotating the turntable (1) and recording the runout value of the dial indicator; S23, adjusting the position of the cylindrical workpiece (2) on the turntable (1) until the runout value measured by the dial indicator is close to zero; The turntable (1) is provided with a contour pad (6), and the cylindrical workpiece (2) is placed on the contour pad (6). S3 specifically includes: determining the position of the bottom surface (202) of the cylindrical workpiece (2) in the Y-axis direction of the machine tool coordinate system through the position of the table surface of the turntable (1) and the height value of the contour pad (6).

2. The cylindrical workpiece positioning processing method according to claim 1, characterized in that: The S5 specifically includes: setting a machining starting point of the cylindrical workpiece (2) along the circumferential direction in the workpiece coordinate system according to the drawing requirements of the cylindrical workpiece (2).

3. The cylindrical workpiece positioning processing method according to claim 1, characterized in that: The S6 specifically includes: S61, when machining the vertical surface (203) feature, use the coordinate translation command to translate the workpiece coordinate system to the plane to be machined according to the drawing size of the cylindrical workpiece (2), and perform tool compensation; S62, when machining features with angles, uses coordinate translation and rotation coordinate system instructions to move and rotate the workpiece coordinate system to the plane to be machined according to the drawing dimensions of the cylindrical workpiece (2), and performs universal head compensation and tool compensation.

4. The method for positioning and processing a cylindrical workpiece according to claim 3, wherein: The S6 specifically further includes: S60, measure the compensation data of the universal head (7).

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