Spheroidal graphite cast iron low-pressure inner cylinder split slope positioning verification method

Abstract

The invention relates to a nodular cast iron low-pressure inner cylinder upper half split slope positioning verification method. The method comprises the following steps that a nodular cast iron low-pressure inner cylinder upper half split is machined; the method comprises the following steps: marking a plurality of points on a to-be-processed slope position of an upper half split of a nodular cast iron low-pressure inner cylinder on the split in a fixed-point and fixed-length manner; the required inclination in the nodular cast iron low-pressure inner cylinder upper half drawing is converted into an angle, and a rotating workbench of the numerical control floor type boring machine is rotated by the angle; according to the rotated angle of the upper half of the nodular cast iron low-pressure inner cylinder, a dial indicator is used for detecting whether the height difference of the marked points drawn on the middle split face of the upper half of the nodular cast iron low-pressure inner cylinder meets the difference value required by a drawing or not.

Description

Technical Field

[0001] The present invention relates to the technical field of machining accuracy calculation, and in particular to a method for verifying the positioning of a dividing surface slope in a ductile iron low-pressure inner cylinder. Background Art

[0002] The domestic and international power generation markets are mainly dominated by wind power generation, thermal power generation, and hydropower generation. With the rapid development of science and technology, the thermal power generation market is optimizing and upgrading castings for internal components. The low-pressure inner cylinder of thermal power generation is undergoing casting transformation and upgrading, from the original steel castings to ductile iron castings, and the ductile iron low-pressure inner cylinder is optimized accordingly. The center dividing surface of the upper half of the ductile iron low-pressure inner cylinder is modified to an inclined surface, thereby increasing the tightness of the upper and lower halves of the ductile iron low-pressure inner cylinder.

[0003] The ductile iron low-pressure inner cylinder is divided into an upper low-pressure inner cylinder and a lower low-pressure inner cylinder. The upper low-pressure inner cylinder and the lower low-pressure inner cylinder rely on the middle surface contact for high-pressure sealing. The middle dividing surface of the upper low-pressure inner cylinder is inclined, and the lower low-pressure inner cylinder is flat. Bolt connection is used to connect and assemble the upper and lower halves of the ductile iron low-pressure inner cylinder together; the upper half of the ductile iron low-pressure inner cylinder adopts a 200 CNC floor boring machine to side-mount and fine-machine the middle dividing surface, and the lower half of the ductile iron low-pressure inner cylinder adopts a CNC gantry milling machine to flat-lay and fine-machine the middle dividing surface.

[0004] The 200 CNC floor-type boring machine fine-processes the inclination of the upper center dividing surface of the ductile iron low-pressure inner cylinder by the worktable rotation angle. However, since the inclination of the upper center dividing surface of the ductile iron low-pressure inner cylinder requires to be relatively precise, the accuracy of the rotation angle of the worktable of the 200 CNC floor-type boring machine is required to be relatively high, and it is impossible to confirm whether the rotation of the rotary worktable is accurate. Summary of the Invention

[0005] Based on the technical problems raised above, a method for verifying the inclination positioning of the dividing surface of the ductile iron low-pressure inner cylinder is provided. The present invention verifies whether the rotation angle of the worktable of the 200 CNC floor boring machine is accurate, and at the same time reduces the rotation accuracy requirements of the rotating worktable of the 200 CNC floor boring machine, thereby ensuring quality stability and avoiding the problem of unqualified gaps between the dividing surfaces of the upper and lower half cylinders of the ductile iron low-pressure inner cylinder, which leads to repeated repairs on the machine tool.

[0006] The technical means adopted in the present invention are as follows: A method for verifying the positioning of the inclination of the upper center dividing surface of a ductile iron low-pressure inner cylinder comprises the following steps: Machining the upper center surface of the ductile iron low-pressure inner cylinder; The upper half center surface of the ductile iron low-pressure inner cylinder needs to be machined to the slope position, and several points are marked on the center surface. The point selection method is to mark the fixed points and fixed lengths. Convert the required slope in the upper half drawing of the ductile iron low-pressure inner cylinder into an angle, and rotate the rotary table of the CNC floor-standing boring machine to the above angle; According to the rotation angle of the upper half of the ductile iron low-pressure inner cylinder, use a micrometer to check whether the height difference of the marked points drawn on the center dividing surface of the upper half of the ductile iron low-pressure inner cylinder meets the difference required by the drawing.

[0007] Furthermore, the processing of the upper center surface of the ductile iron low-pressure inner cylinder is specifically as follows: rough processing and finally replacing the finishing cutter head with a cutting depth of 0.02mm to complete the finishing of the center surface, ensuring that there is no height difference in the center surface and the surface roughness is above Ra1.6.

[0008] Furthermore, the upper center dividing surface of the ductile iron low-pressure inner cylinder is inclined, and the lower center dividing surface is flat. After the inspection is completed, the upper and lower parts of the ductile iron low-pressure inner cylinder are connected with bolts to perform center dividing surface sealing inspection.

[0009] Furthermore, the sealing test is specifically to use a 0.03mm feeler gauge to check the gap of the center dividing surface. If the 0.03mm feeler gauge cannot be inserted, it proves that the sealing of the center dividing surface of the ductile iron low-pressure inner cylinder meets the requirements.

[0010] Furthermore, the process of taking a number of points and marking them on the mid-plane includes: taking the center of the workpiece as the zero point, that is, taking the center of the workpiece as the origin of the coordinate system, Draw a horizontal line on the midline at 150±5mm in the Y direction. Mark point 1 on the horizontal line at the position of 20±2mm in the positive X direction of the minimum inner radius. Mark points 2, 3, and 4 in order of spacing A, B, and C outward. Mark point 9 on the horizontal line at the position of the minimum inner radius in the negative X direction corresponding to the positive X dimension. Mark points 10, 11, and 12 in order of spacing A, B, and C outward. Draw a horizontal line on the midline at 150±5mm downward from the Y direction, and mark point 5 on the horizontal line at a position 20±2mm from the minimum inner radial direction in the positive X direction. Mark points 6, 7, and 8 outwards in sequence, with spacings A, B, and C. Mark point 13 on the horizontal line at a position corresponding to the positive X dimension in the negative X direction of the minimum inner radial direction, and mark points 14, 15, and 16 outwards in sequence, with spacings A, B, and C.

[0011] Furthermore, the angle of the upper half of the ductile iron low-pressure inner cylinder is verified, and the verification trajectory is as follows: starting from the zero point, the trajectories of several points in each quadrant are verified in turn, namely, the X positive and Y positive areas, the X positive and Y negative areas, the X negative and Y positive areas, and the X negative and Y negative areas.

[0012] The verification method disclosed in the present invention verifies the accuracy of the rotation angle of the rotary table of a 200 CNC floor-standing boring machine by drawing positioning marking points, angle rotation, and fixed-point height measurement, thereby solving the problem that the rotation angle of the rotary table cannot be confirmed after the inclination of the center dividing surface of a ductile iron low-pressure inner cylinder is processed on a 200 CNC floor-standing boring machine.

[0013] Compared with the prior art, the present invention has the following advantages: 1. The method for verifying the inclination positioning of the dividing surface of the ductile iron low-pressure inner cylinder avoids the problem of inaccurate precision of the rotary table of the 200 CNC floor boring machine. It can directly verify the stability of the 200 CNC floor boring machine, and there is no need to require too high precision for the rotary table of the 200 CNC floor boring machine, which would waste costs.

[0014] 2. The method for verifying the inclination positioning of the center dividing surface of the ductile iron low-pressure inner cylinder is to complete the fine processing of the center dividing surface of the ductile iron low-pressure inner cylinder, and the upper and lower halves of the ductile iron low-pressure inner cylinder meet the gap requirements of the drawing.

[0015] 3. This method for verifying the inclination of the split surface of the ductile iron low-pressure inner cylinder prevents the gap between the upper and lower halves of the ductile iron low-pressure inner cylinder from not meeting the drawing requirements, which would lead to repeated machine repairs of the upper half of the ductile iron low-pressure inner cylinder, which is time-consuming, labor-intensive, and delays the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0017] Figure 1 This is a schematic diagram of the upper center section of a ductile iron low-pressure inner cylinder.

[0018] Figure 2 This is a schematic diagram of the upper center section of a ductile iron low-pressure inner cylinder. Figure 1 Right view of .

[0019] Figure 3 This is a schematic diagram of the upper half rotation angle of a ductile iron low-pressure inner cylinder.

[0020] Figure 4 This is a schematic diagram for verifying the upper slope of a ductile iron low-pressure inner cylinder.

[0021] Figure 5 This is a schematic diagram of the verification trajectory of the upper half of a ductile iron low-pressure inner cylinder.

[0022] In the figure: 1-upper half of ductile iron low-pressure inner cylinder, 2-rotating worktable, (point 1-point 16)-inclination verification points of the upper half of ductile iron low-pressure inner cylinder, (AF)-inclination verification distance of the upper half of ductile iron low-pressure inner cylinder, (H1-H6)-inclination verification height of the upper half of ductile iron low-pressure inner cylinder, (G)-rotation angle of the upper half of ductile iron low-pressure inner cylinder. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0026] Unless otherwise specified, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments can have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0027] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0028] For ease of description, spatially relative terms such as "above," "above," "on the upper surface of," and "above" may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "on top of" another device or structure would then be positioned as "below" or "below" the other device or structure. Thus, the exemplary term "above" may include both the orientations of "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used herein should be interpreted accordingly.

[0029] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0030] The embodiment of the present invention discloses a method for verifying the positioning of the inclination of the upper center dividing surface of a ductile iron low-pressure inner cylinder, comprising the following steps: like Figure 1 As shown, the center surface of the upper half of a ductile iron low-pressure inner cylinder is machined. The machining process specifically includes rough machining and, finally, replacing the finishing cutter head with a 0.02mm cut, finishing the center surface to ensure that the center surface has no height difference and a surface roughness of Ra1.6 or higher. The finished product of the center surface of the upper half of the ductile iron low-pressure inner cylinder is obtained.

[0031] The upper half of the center surface of the ductile iron low-pressure inner cylinder needs to be machined to the slope position, and several points are marked on the center surface. The point selection method is to mark the points at fixed points and fixed lengths. The point selection process of marking several points on the center surface includes: Figure 2As shown, the workpiece center is the zero point, that is, the coordinate system with it as the origin, the cylinder body geometric center is the origin O(0,0,0), the X axis is horizontal to the right, the Y axis is vertically upward, and the Z axis is along the cylinder body axis.

[0032] Draw a horizontal line on the midline at 150±5mm in the Y direction. Mark point 1 on the horizontal line at the position of 20±2mm in the positive X direction of the minimum inner radius. Mark points 2, 3, and 4 in order of spacing A, B, and C outward. Mark point 9 on the horizontal line at the position of the minimum inner radius in the negative X direction corresponding to the positive X dimension. Mark points 10, 11, and 12 in order of spacing A, B, and C outward. Points 2 and 3 are located close to the sides of the circular cavity in the center of the low-pressure inner cylinder, and point 4 is located at the outer end of the center dividing plane. In other words, A, B, and C are related to the cylinder size, and the same applies to other points.

[0033] Draw a horizontal line on the midline at 150±5mm downward from the Y direction, and mark point 5 on the horizontal line at a position 20±2mm from the minimum inner radial direction in the positive X direction. Mark points 6, 7, and 8 outwards in sequence, with spacings A, B, and C. Mark point 13 on the horizontal line at a position corresponding to the positive X dimension in the negative X direction of the minimum inner radial direction, and mark points 14, 15, and 16 outwards in sequence, with spacings A, B, and C.

[0034] Convert the required slope in the upper half drawing of the ductile iron low-pressure inner cylinder into an angle, and rotate the rotary table of the CNC floor boring machine to the above angle. When rotating the rotary table, it should be noted that the rotation angle needs to be rotated in one direction to avoid the angular rotation deviation caused by the reverse clearance of the rotary table. The rotation angle is G, such as Figure 3 shown.

[0035] According to the rotation angle of the upper half of the ductile iron low-pressure inner cylinder, use a micrometer to check whether the height difference of the marked points drawn on the center dividing surface of the upper half of the ductile iron low-pressure inner cylinder meets the requirements of the drawing. Among them, A corresponds to H1, B corresponds to H2, C corresponds to H3, D corresponds to H4, E corresponds to H5, and F corresponds to H6. Figure 4 The total length of points H1 to H6 must cover the width of the midpoint. H1 is the height at point 2, H2 is the height at point 3, and H3 is the height at point 4. These heights can be calculated from the distances from the corresponding points to the reference and the slope angle tanG. Furthermore, the angle of the upper half of the ductile iron low-pressure inner cylinder is verified. The verification trajectory is as follows: starting from the zero point, the trajectory of several points in each quadrant is verified in sequence, namely the X positive and Y positive areas, the X positive and Y negative areas, the X negative and Y positive areas, and the X negative and Y negative areas. That is, zero point → point 1 → point 2 → point 3 → point 4, zero point → point 5 → point 6 → point 7 → point 8, zero point → point 9 → point 10 → point 11 → point 12, zero point → point 13 → point 14 → point 15 → point 16, see for details. Figure 5 Since the machine tool has repeated positioning errors, the detection structure will have deviations. Therefore, verification is carried out in sequence, and each quadrant is independently established with a coordinate system and then re-measured to ensure the consistency of the overall slope. Specifically, the dial indicator is fixed on the spindle end face, the probe is perpendicular to the center plane, and the actual height H is measured point by point. 实 , judgment: H 实 -H i ≤ 0.01 mm, where H i It is the theoretical value of the drawing.

[0036] The upper center plane of the ductile iron low-pressure inner cylinder is inclined, while the lower center plane is flat. After the test meets the requirements, use a thinner to wipe the center plane to remove iron filings and oil stains. Use connecting bolts to pre-tighten the upper and lower halves of the ductile iron low-pressure inner cylinder and perform a center plane sealing test.

[0037] The above sealing test is specifically to use a 0.03mm feeler gauge to check the gap of the center dividing surface. If the 0.03mm feeler gauge cannot be inserted, it proves that the sealing of the center dividing surface of the ductile iron low-pressure inner cylinder meets the requirements.

[0038] This invention replaces post-assembly testing with pre-verification, verifying the inclination by marking points on the machine tool, allowing early detection of angular deviations and avoiding rework due to unsatisfactory assembly. This invention intercepts problems during the machining process, reduces the number of assembly tests, and effectively shortens the construction period.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for verifying the slope positioning of the upper center plane of a ductile iron low-pressure inner cylinder, characterized in that: The steps include: Machining the upper center surface of the ductile iron low-pressure inner cylinder; The upper half center surface of the ductile iron low-pressure inner cylinder needs to be machined to the slope position, and several points are marked on the center surface. The point selection method is to mark the fixed points and fixed lengths. Convert the required slope in the upper half drawing of the ductile iron low-pressure inner cylinder into an angle, and rotate the rotary table of the CNC floor-standing boring machine to the above angle; According to the rotation angle of the upper half of the ductile iron low-pressure inner cylinder, use a micrometer to check whether the height difference of the marked points drawn on the center dividing surface of the upper half of the ductile iron low-pressure inner cylinder meets the difference required by the drawing.

2. The method according to claim 1, characterized in that The processing of the upper center surface of the ductile iron low-pressure inner cylinder is specifically as follows: rough processing and finally replacing the finishing cutter head to cut 0.02mm, finishing the center surface, ensuring that there is no height difference in the center surface and the surface roughness is above Ra1.

6.

3. The method according to claim 1, characterized in that The upper center dividing surface of the ductile iron low-pressure inner cylinder is inclined, and the lower center dividing surface is flat. After the inspection is completed, the upper and lower parts of the ductile iron low-pressure inner cylinder are connected with bolts to conduct center dividing surface sealing inspection.

4. The method according to claim 1, wherein The sealing test is specifically to use a 0.03mm feeler gauge to check the gap of the center dividing surface. If the 0.03mm feeler gauge cannot be inserted, it proves that the sealing of the center dividing surface of the ductile iron low-pressure inner cylinder meets the requirements.

5. The method according to claim 1, characterized in that The process of taking several points and marking them on the mid-plane includes: taking the center of the workpiece as the zero point, that is, taking the center of the workpiece as the origin of the coordinate system, Draw a horizontal line on the midline at 150±5mm in the Y direction. Mark point 1 on the horizontal line at the position of 20±2mm in the positive X direction of the minimum inner radius. Mark points 2, 3, and 4 in order of spacing A, B, and C outward. Mark point 9 on the horizontal line at the position of the minimum inner radius in the negative X direction corresponding to the positive X dimension. Mark points 10, 11, and 12 in order of spacing A, B, and C outward. Draw a horizontal line on the midline at 150±5mm downward from the Y direction, and mark point 5 on the horizontal line at a position 20±2mm from the minimum inner radial direction in the positive X direction. Mark points 6, 7, and 8 outwards in sequence, with spacings A, B, and C. Mark point 13 on the horizontal line at a position corresponding to the positive X dimension in the negative X direction of the minimum inner radial direction, and mark points 14, 15, and 16 outwards in sequence, with spacings A, B, and C.

6. The method according to claim 5, characterized in that The angle verification of the upper half of the ductile iron low-pressure inner cylinder is carried out, and the verification trajectory is as follows: starting from the zero point, the trajectories of several points in each quadrant are verified in turn, namely, the X positive and Y positive areas, the X positive and Y negative areas, the X negative and Y positive areas, and the X negative and Y negative areas.

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