Auxiliary tool and method for correcting wall thickness of cylindrical pressure vessel part

Abstract

The invention discloses an auxiliary tool and method for correcting the wall thickness of a cylindrical pressure vessel part, aims to solve the technical problems that an inner cavity cannot be machined, the wall thickness is difficult to adjust and the wall thickness cannot be ensured due to the fact that two end openings of a cylindrical pressure vessel are small, and relates to wall thickness correction of a forged cylindrical pressure vessel rib part which is strict in wall thickness requirement and cannot be machined in the inner cavity. Belongs to the technical field of machining. The auxiliary tool for correcting the wall thickness of the cylindrical pressure vessel type part comprises a lantern ring and a stud, a threaded hole is formed in the circumferential face of the lantern ring and assembled with one end of the stud, a dial is arranged on the periphery of the threaded hole, and the numerical value of a circle of the dial is the same as the thread pitch of the stud. Meanwhile, the invention discloses a cylindrical pressure vessel part wall thickness correction method, and the problem that local thin points of different degrees still exist in inner cavities of individual cylindrical pressure vessels after an axis adjustment method is adopted is solved through an extrusion correction method of the correction assistive device.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing, and relates to wall thickness correction of cylindrical pressure vessel parts, in particular to a wall thickness correction aid and method for cylindrical pressure vessel parts. Background Art

[0002] A cylindrical pressure vessel of a product has a structure such as Figure 1 As shown, the total length is relatively long, generally greater than 350mm; the inner holes at both ends of the workpiece are small, there are several annular ribs in the middle inner hole, the inner hole cannot be processed, and the wall thickness is , which is a critical dimension, the monthly production batch is particularly large.

[0003] The processing process is: rough machining of inner and outer circles---fine machining of inner and outer circles---forging and closing---straightening---fine machining of outer circle----check wall thickness----inspection.

[0004] Problem: After rough and fine machining of the inner and outer circles of the product blank, it will become a tube with uniform wall thickness. After hot forging, the inner cavity will be closed due to plastic deformation, and uneven deformation will occur at both ends and in the middle. After the outer circle is corrected (the inner hole is corrected based on the outer circle), the final wall thickness value tends to be uniform. However, there are still local thin spots in the inner cavity of the workpiece to varying degrees, such as Figure 2 This defect cannot be corrected after finishing the outer diameter, resulting in a scrap rate of up to 85% for the product, which seriously restricts the production progress and cannot guarantee the completion of the production task. Summary of the invention

[0005] In order to overcome the above-mentioned defects of the prior art, the purpose of the present invention is to provide a wall thickness correction aid and method for cylindrical pressure vessel parts, which is used to solve the technical problems that the two ends of the cylindrical pressure vessel are small, the inner cavity cannot be processed, the wall thickness adjustment is difficult, and the wall thickness cannot be guaranteed. It involves the wall thickness correction of forged cylindrical pressure vessel parts with strict wall thickness requirements and whose inner cavity cannot be processed.

[0006] The present invention is achieved by adopting the following technical solutions: The wall thickness correction aid for cylindrical pressure vessel parts comprises a collar and a stud. The collar circumferential surface is provided with a threaded hole, the threaded hole is assembled with one end of the stud, a dial is provided on the outer circumference of the threaded hole, and the value of one circle of the dial is the same as the pitch of the stud.

[0007] When used, the angle of rotation of the stud and the height of the stud's descent are related. The present invention indicates the corresponding relationship between the two through a dial. By observing the angle of rotation of the stud on the dial, the height of the stud can be known at a glance, as long as the stud's descent height is the same as the wall thickness difference of the cylindrical pressure vessel.

[0008] More preferably, it further comprises a handle, the non-threaded portion of the stud is provided with a through hole perpendicular to the axis, and the handle passes through the through hole.

[0009] Further preferably, the diameter of the non-threaded portion of the stud is larger than the threaded portion.

[0010] Further preferably, the collar is processed with a plane on one side of the threaded hole, and the scale plate is directly engraved on the plane.

[0011] Further preferably, the collar is provided with a slot for locating the threaded hole in a direction parallel to the axis.

[0012] Further preferably, the slot width is equal to the diameter of the threaded hole.

[0013] The present invention also provides a method for correcting the wall thickness of cylindrical pressure vessel parts, comprising the following steps: The first step is rough machining of inner and outer circles; The second step is finishing the inner and outer circles; The third step is forging and closing; The fourth step is straightening; The fifth step is axis adjustment and correction; The sixth step is auxiliary tool extrusion correction; S61, find the thin spot area of ​​the cylindrical pressure vessel; S62, calculating the difference between the thin spot area and the uniform wall thickness according to the wall thickness measurement; S63, place the cylindrical pressure vessel into the collar with the thin spot area placed under the studs; S64, rotate the studs tightening the cylindrical pressure vessel to the corresponding position on the dial according to the wall thickness difference.

[0014] The seventh step is finishing the outer circle; The eighth step is verification.

[0015] Further preferably, S61 may adopt the following steps: S611, take several equally spaced sections along the axial direction of the outer circle of the cylindrical pressure vessel and perform wall thickness testing at 8 equal parts of the circumference of each section; S612, find the super-difference point, start intensive measurement in the super-difference point area, radiate from the super-difference point to the surrounding area, until reaching the qualified area; S613, mark the thin spot area and make a mark.

[0016] Further preferably, the fifth step includes the following steps: S51, take several equidistant sections along the axial direction of the outer circle of the cylindrical pressure vessel, and perform wall thickness inspection at 8 equal parts of the circumference of each section, and make digital records; S52, finding the out-of-tolerance point, and determining the offset direction and offset amount of the theoretical axis for adjusting the wall thickness of the cylindrical pressure vessel through numerical analysis; S53, using four-claw clamping to work, according to the calculated axis theoretical offset direction and offset, repair and bore the top holes at both ends of the cylindrical pressure vessel; S54, uses two tops to tighten the cylindrical pressure vessel and semi-finish turning the outer circle again to eliminate wall thickness deviation.

[0017] Further preferably, the fifth step further comprises the following steps: S55, repeat step S51, and check again whether the wall thickness exceeds the tolerance. If it does not meet the requirements, repeat steps S52 to S54 until the wall thickness difference meets the requirements.

[0018] Further preferably, the sixth step also includes the following steps: S65, according to the mark and the wall thickness measurement value, the thin spot area is corrected point by point and piece by piece using step S63 and step S64 in sequence; S66, semi-finishing the outer circle of a cylindrical pressure vessel by tightening it with two tops; S67, repeat step S61, and check again whether there are thin spots in the wall thickness. If there are, repeat steps S62 to S66 until the thin spots are completely eliminated.

[0019] The beneficial effects of the present invention compared with the existing technology are as follows: 1) By measuring the wall thickness and adjusting the axis position (axis adjustment method), the problem of uneven wall thickness caused by plastic deformation of the inner cavity after hot forging and uneven deformation at both ends and in the middle is solved.

[0020] 2) The problem of local thin spots to varying degrees still existing in the inner cavity of individual cylindrical pressure vessels after the axis adjustment method was solved by using the extrusion correction method with correction aids.

[0021] 3) The product qualification rate of cylindrical pressure vessels has been greatly improved from 15% in the past to over 95%.

[0022] 4) This processing scheme also provides a good reference processing scheme for the correction of other cylindrical pressure vessel parts with "small mouth and large cavity", whose inner cavity cannot be corrected and have strict requirements on wall thickness.

[0023] 5) It reduces the technical difficulty of workers during processing and greatly improves the processing efficiency of products. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 Schematic diagram showing the external structure of a cylindrical pressure vessel.

[0027] Figure 2 Schematic diagram showing local thin spots in a cylindrical pressure vessel.

[0028] Figure 3 Shows a front cross-sectional schematic diagram of the present invention.

[0029] Figure 4 A schematic top view of the present invention is shown.

[0030] Figure 5 Indicates the present invention Figure 4 Enlarged view of point I.

[0031] Figure 6 A schematic diagram showing the use of the auxiliary tool of the present invention is shown.

[0032] Figure 7 A flowchart of the present invention is shown.

[0033] In the figure: 1-ring, 2-stud, 3-dial, 4-handle, 5-flat surface, 6-slot, 7-thin spot area. DETAILED DESCRIPTION

[0034] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0035] In the description, it should be noted that the terms "first" and "second" are only used for descriptive purposes and should not be understood as indicating or implying relative importance. It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0036] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0037] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0038] The wall thickness correction aid for cylindrical pressure vessel parts includes a collar 1 and a stud 2. The collar 1 is provided with a threaded hole on its circumference, and the threaded hole is assembled with one end of the stud 2. A dial 3 is provided on the outer circumference of the threaded hole, and the value of one circle of the dial 3 is the same as the pitch of the stud 2. A handle 4 is also included. The unthreaded portion of the stud 2 is provided with a through hole perpendicular to the axis, and the diameter of the unthreaded portion of the stud 2 is larger than that of the threaded portion, and the handle 4 passes through the through hole. The unthreaded portion of the stud 2 has a larger diameter, and the diameter of the through hole can also be processed larger, so that the handle 4 with high strength can pass through, and the handle 4 can be helpful in rotating the stud 2.

[0039] The collar 1 is processed with a plane 5 on one side of the threaded hole, and the dial 3 is directly engraved on the plane 5. The plane 5 provides a platform for processing the dial 3, and the dial 3 is used to observe the rotation angle of the stud 2. The collar 1 is provided with a slot 6 in a direction parallel to the axis, and the width of the slot 6 is equal to the diameter of the threaded hole. The slot 6 helps to quickly locate the position of the threaded hole on the collar 1.

[0040] In order to improve the qualified rate of cylindrical pressure vessels, we have optimized the correction method of cylindrical pressure vessels. The wall thickness correction method of cylindrical pressure vessel parts is realized by using the wall thickness correction auxiliary tool of cylindrical pressure vessel rib parts, such as Figure 7 As shown, the steps are as follows: The first step is rough machining of inner and outer circles; The second step is finishing the inner and outer circles; The third step is forging and closing; The fourth step is straightening; After the forged end of the cylindrical pressure vessel is straightened, the outer circle is semi-finished and the wall thickness is adjusted.

[0041] The fifth step is axis adjustment and correction; S51, take several equidistant sections along the axial direction of the outer circle of the cylindrical pressure vessel, and perform wall thickness inspection at 8 equal parts of the circumference of each section, and make digital records; In this embodiment, 15 cross sections are taken along the axial direction of the cylindrical pressure vessel, and each cross section is divided into 8 equal parts, for a total of 120 points for wall thickness detection.

[0042] S52, finding the out-of-tolerance point, and determining the offset direction and offset amount of the theoretical axis for adjusting the wall thickness of the cylindrical pressure vessel through numerical analysis; S53, using four-claw clamping to work, according to the calculated axis theoretical offset direction and offset, repair and bore the top holes at both ends of the cylindrical pressure vessel; S54, using two tops to hold the cylindrical pressure vessel tightly, semi-finish turning the outer circle again to eliminate the wall thickness deviation; S55, repeat step S51, and check again whether the wall thickness exceeds the tolerance. If it does not meet the requirements, repeat steps S52 to S54 until the wall thickness difference meets the requirements.

[0043] This embodiment needs to ensure that the wall thickness is .

[0044] After 2-3 times of the fifth step, the wall thickness of most cylindrical pressure vessels tends to be uniform. However, some cylindrical pressure vessels still have local thin spots in the inner cavity to varying degrees, which can no longer be corrected by the above method. Therefore, in order to make the wall thickness of the cylindrical pressure vessel uniform, the local thin spots are corrected again, that is, the cylindrical pressure vessel wall thickness correction auxiliary tool is used for extrusion correction.

[0045] The sixth step is auxiliary tool extrusion correction; S61, find out the thin spot area 7 of the cylindrical pressure vessel; S611, take several equally spaced sections along the axial direction of the outer circle of the cylindrical pressure vessel and perform wall thickness testing at 8 equal parts of the circumference of each section; In this embodiment, wall thickness detection is performed at 120 points in total along the axial direction of the cylindrical pressure vessel at 15 cross sections and at 8 equal parts of the circumference.

[0046] S612, find the super-difference point, start intensive measurement in the super-difference point area, radiate from the super-difference point to the surrounding area, until reaching the qualified area; S613, mark out the thin spot area 7 and mark it at the same time.

[0047] S62, calculating the difference between the thin spot area 7 and the uniform wall thickness according to the wall thickness measurement; S63, such as Figure 3 As shown, the cylindrical pressure vessel is placed in the collar 1, and the thin spot area 7 is placed under the stud 2; S64, according to the wall thickness difference, the stud 2 that presses against the cylindrical pressure vessel is rotated to the corresponding position on the dial 3. Under the downward pressure of the stud 2, the outer circle at the local thin point is concave and the inner hole is convex by a corresponding value. When the outer circle is finely processed later, the concave part will be removed, thereby eliminating the thin wall point.

[0048] S65, according to the mark and the wall thickness measurement value, the thin spot area 7 is corrected point by point and piece by piece using steps S63 and S64 in sequence; S66, semi-finishing the outer circle of a cylindrical pressure vessel by tightening it with two tops; S67, repeat step S61, and check again whether there is a thin spot area 7 in the wall thickness. If there is, repeat steps S62 to S66 until the thin spot area 7 is completely eliminated.

[0049] like Figure 3-5 As shown, in this embodiment, the thread pitch of the stud 2 is 1.5mm, and the dial 3 is divided into 15 large grids in one circle, that is, the scale value of one large grid is 0.1mm. When the stud 2 rotates along the dial 3 by one large grid, it means that the stud 2 presses down the thin point by 0.1mm, and rotates one circle, it means that the thin point is pressed down by 1.5mm, that is, the thin point is deformed by the same value, so that the thin point is deformed to bulge toward the inner cavity.

[0050] The seventh step is fine turning of the outer circle; the eighth step is calibration.

[0051] By adopting the above two correction methods, the local thin spots of the cylindrical pressure vessel are corrected to ensure the wall thickness requirements, thereby greatly improving the product qualification rate.

[0052] The invention is a processing method which is easy to operate, economical, safe, efficient and reliable, and is particularly suitable for mass production and processing of cylindrical pressure vessel parts.

[0053] The above is only a specific implementation of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments, and they should all be covered by the protection scope of the claims.

Claims

1. Wall thickness correction tool for cylindrical pressure vessel parts, characterized by: It comprises a collar (1) and a stud (2); a threaded hole is arranged on the circumferential surface of the collar (1); the threaded hole is assembled with one end of the stud (2); a dial (3) is arranged on the outer circumference of the threaded hole; the value of one circle of the dial (3) is the same as the pitch of the stud (2).

2. The wall thickness correction tool for cylindrical pressure vessel parts according to claim 1 is characterized in that: It also comprises a handle (4), the portion of the stud (2) without threads being provided with a through hole perpendicular to the axis, and the handle (4) passes through the through hole.

3. The wall thickness correction tool for cylindrical pressure vessel parts according to claim 2 is characterized in that: The diameter of the non-threaded portion of the stud (2) is larger than the threaded portion.

4. The wall thickness correction tool for cylindrical pressure vessel parts according to claim 1 is characterized in that: The collar (1) is machined with a flat surface (5) on one side of the threaded hole, and the scale plate (3) is directly engraved on the flat surface (5).

5. The wall thickness correction tool for cylindrical pressure vessel parts according to claim 1 is characterized in that: The collar (1) is provided with a slot (6) for positioning the threaded hole in a direction parallel to the axis.

6. The wall thickness correction tool for cylindrical pressure vessel parts according to claim 5 is characterized in that: The width of the slot (6) is equal to the diameter of the threaded hole.

7. Wall thickness correction method for cylindrical pressure vessel parts, characterized by: The method is implemented by using the wall thickness correction tool for cylindrical pressure vessel parts as described in any one of claims 1 to 6; Here are the steps: The first step is rough machining of inner and outer circles; the second step is fine machining of inner and outer circles; the third step is forging and closing; the fourth step is straightening; The fifth step is axis adjustment and correction; The sixth step is auxiliary tool extrusion correction; S61, find the thin spot area of ​​the cylindrical pressure vessel (7); S62, calculating the difference between the thin spot area (7) and the uniform wall thickness according to the wall thickness measurement; S63, placing the cylindrical pressure vessel into the collar (1) and placing the thin spot area (7) below the stud (2); S64, rotating the stud (2) for tightening the cylindrical pressure vessel to a corresponding position on the dial (3) according to the wall thickness difference; The seventh step is fine turning of the outer circle; the eighth step is calibration.

8. The wall thickness correction method for cylindrical pressure vessel parts according to claim 7 is characterized in that: S61 can adopt the following steps: S611, take several equally spaced sections along the axial direction of the outer circle of the cylindrical pressure vessel and perform wall thickness testing at 8 equal parts of the circumference of each section; S612, find the super-difference point, start intensive measurement in the super-difference point area, radiate from the super-difference point to the surrounding area, until reaching the qualified area; S613, mark the thin spot area (7) and make a mark at the same time.

9. The wall thickness correction method for cylindrical pressure vessel parts according to claim 8, characterized in that: The sixth step also includes the following steps: S65, according to the mark and the wall thickness measurement value, the thin spot area (7) is corrected point by point and piece by piece using step S63 and step S64; S66, semi-finishing the outer circle of a cylindrical pressure vessel by tightening it with two tops; S67, repeat step S61, and check again whether there is a thin spot area (7) in the wall thickness. If there is, repeat steps S62 to S66 until the thin spot area (7) is completely eliminated.

10. The wall thickness correction method of cylindrical pressure vessel parts according to any one of claims 7 to 9, characterized in that: The fifth step includes the following steps: S51, take several equidistant sections along the axial direction of the outer circle of the cylindrical pressure vessel, and perform wall thickness inspection at 8 equal parts of the circumference of each section, and make digital records; S52, finding the out-of-tolerance point, and determining the offset direction and offset amount of the theoretical axis for adjusting the wall thickness of the cylindrical pressure vessel through numerical analysis; S53, using four-claw clamping to work, according to the calculated axis theoretical offset direction and offset, repair and bore the top holes at both ends of the cylindrical pressure vessel; S54, uses two tops to tighten the cylindrical pressure vessel and semi-finish turning the outer circle again to eliminate wall thickness deviation.

11. The wall thickness correction method of cylindrical pressure vessel parts according to claim 10, characterized in that: The fifth step also includes the following steps: S55, repeat step S51, and check again whether the wall thickness exceeds the tolerance. If it does not meet the requirements, repeat steps S52 to S54 until the wall thickness difference meets the requirements.

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