Method for repairing lack of meat on outer wall of middle cylinder of hydraulic stand column

Abstract

The invention relates to the technical field of machining, in particular to a hydraulic stand column middle cylinder outer wall misrun repairing method, and mainly solves the technical problem that an existing middle cylinder outer wall misrun repairing method cannot be suitable for large-area misrun. According to the repairing method for the misrun of the outer wall of the middle cylinder of the hydraulic stand column, firstly, spot welding is conducted on the outer side of the outline of a misrun area to form an inner spot welding ring, then an area on the inner side of the inner spot welding ring is welded, and finally after a workpiece is completely cooled, spot welding is conducted on the outer side of the inner spot welding ring to form an outer spot welding ring. According to the method, the maximum outline of the meat missing area can be determined through the arrangement of the inner spot welding ring, welding missing is avoided, collapse and undercut can be avoided through the arrangement of the outer spot welding ring, and therefore the product rejection rate can be reduced, and labor, material and equipment cost can be greatly saved.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing, and in particular to a method for repairing a missing outer wall of a cylinder in a hydraulic column. Background Art

[0002] The rough material of the hydraulic column cylinder is usually made of pipe material or upsetting part. Due to defects in the material itself, bending caused by upsetting or misalignment during machining, large defects will appear on the outer wall of the cylinder after fine processing, and in most cases, there will be a lack of meat.

[0003] The existing method of repairing the missing area on the outer wall of the middle cylinder is generally to grind after welding. This method is suitable for smaller missing areas, but for larger missing areas, it is easy to cause problems such as collapse and undercut around the welding area, and because the missing area is usually irregular in shape, it is very easy to cause welding leakage. Summary of the invention

[0004] In order to overcome the technical defect that the existing method for repairing the missing flesh on the outer wall of the middle cylinder is not applicable to the missing flesh on a larger area, the present invention provides a method for repairing the missing flesh on the outer wall of the middle cylinder of a hydraulic column.

[0005] The method for repairing the outer wall of the hydraulic column cylinder provided by the present invention comprises the following steps in sequence: S1. Spot welding along the outer contour of the meat-deficient area to form an inner spot welding circle, leaving a gap between the inner spot welding circle and the contour of the meat-deficient area; S2. Welding the area within the inner spot welding circle; S3. Cooling; S4. Spot welding a circle in the outer area of ​​the inner spot welding circle to form an outer spot welding circle; S5. Fine-tune the outer circle and inner hole of the workpiece to meet the process size requirements.

[0006] Optionally, in step S1, the width of the gap is 3 mm to 5 mm.

[0007] Optionally, in step S2, welding is performed while cooling.

[0008] Optionally, in step S4, a small current of 200A to 250A is used for electric welding.

[0009] Optionally, step S5 is divided into the following sub-steps: S51. Grind the outer diameter of the workpiece to the process size requirements; S52. Honing the inner hole of the workpiece to the process size requirements.

[0010] Optionally, in step S51, the meat-less area is first ground and it is determined whether there are welding defects inside. If there are welding defects, rework is performed; if there are no welding defects, the outer circle of the workpiece is ground to the process size requirements.

[0011] Optionally, a grinding step is added between step S1 and step S2: The area within the inner spot welding ring is polished to remove the black skin on the surface of the workpiece.

[0012] The technical solution provided by the present invention has the following advantages compared with the prior art: The method for repairing the missing meat on the outer wall of the cylinder of the hydraulic column provided by the present invention first spot welds the outer side of the outline of the missing meat area to form an inner spot welding ring, then welds the area inside the inner spot welding ring, and finally spot welds the outer side of the inner spot welding ring to form an outer spot welding ring after the workpiece is completely cooled. The method can clarify the maximum outline of the missing meat area through the setting of the inner spot welding ring to avoid welding leakage, and can avoid collapse and undercutting through the setting of the outer spot welding ring, thereby reducing the product scrap rate and greatly saving labor, material and equipment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] 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.

[0014] 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.

[0015] Figure 1 A flowchart showing a repair method in an embodiment of the present invention; Figure 2 express Figure 1 A partial enlarged view of the middle A; Figure 3 express Figure 1 A partial enlarged view of point B in the middle.

[0016] In the figure: 1. Meat-missing area; 2. Inner spot welding ring; 3. Gap; 4. Outer spot welding ring. DETAILED DESCRIPTION

[0017] 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.

[0018] 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.

[0019] Combine the following Figures 1 to 3 The specific embodiments of the present invention are described in detail.

[0020] This embodiment provides a method for repairing a missing outer wall of a cylinder in a hydraulic column, comprising steps S1 to S5.

[0021] S1. Spot welding is performed along the outer side of the contour of the meat-missing area 1 to form an inner spot welding circle 2, and a gap 3 is left between the inner spot welding circle 2 and the contour of the meat-missing area 1.

[0022] It is easy to understand that the inner spot welding circle 2 confirms the maximum contour of the missing meat area, thereby preventing the repair defects caused by uneven welding boundaries.

[0023] It should be noted that if the gap 3 is too large, the main welding area will be too large, which may easily cause welding deformation; if the gap 3 is too small, it may cause unclean cleaning of the edge of the missing meat; therefore, in actual design, the gap 3 should be appropriate. The design of the gap 3 for different workpieces is different. This can be determined by technical personnel in this field through a limited number of tests. It is generally designed to be 3mm to 5mm.

[0024] S2. Weld the area within the inner spot welding circle 2.

[0025] Specifically, the welding is performed in a welding and cooling manner to prevent the inner hole of the cylinder from being deformed due to excessive welding heat.

[0026] S3. Cooling.

[0027] It is easy to understand that since the area within the inner spot welding ring 2 serves as the main welding area and the welding amount is large, the outer area around the welding range, i.e., adjacent to the spot welding ring 2, will shrink and collapse, so it needs to be fully cooled so that it no longer undergoes stress deformation to ensure the effect of the subsequent spot welding step S4.

[0028] S4. Perform spot welding on the outer area of ​​the inner spot welding circle 2 to form an outer spot welding circle 4.

[0029] Specifically, a small current of 200A to 250A is used for electric welding.

[0030] It should be noted that this step is mainly used to fill the peripheral collapse caused by the main welding area, and the small current spot welding method is used to prevent the occurrence of new collapse, undercut and other defects.

[0031] S5. Fine-tune the outer circle and inner hole of the workpiece to meet the process size requirements.

[0032] Specifically, this step is divided into the following sub-steps: S51. Grinding the outer circle of the workpiece to the process size requirement; S52. Honing the inner hole of the workpiece to the process size requirement.

[0033] More specifically, in step S51, the meat-less area 1 is first ground and it is determined whether there are welding defects inside. If there are welding defects, rework is performed; if there are no welding defects, the outer circle of the workpiece is ground to the process size requirements.

[0034] In addition, in this embodiment, a grinding step is added between step S1 and step S2: the area within the inner spot welding ring 2 is ground to remove the black skin on the surface of the workpiece, thereby preventing defects such as welding pores from being generated in subsequent welding.

[0035] It should be noted that the inner spot welding ring 2 has another function, namely, it can confirm the grinding area, thereby ensuring that the black skin in the meat-less area can be completely cleaned.

[0036] It should be noted that this method is not only applicable to the repair of the hydraulic column cylinder, but also to the hydraulic piston, piston rod, outer cylinder, etc.

[0037] 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. A method for repairing the outer wall of the hydraulic column cylinder that is missing meat. It is characterized in that The steps are as follows: S1. Spot welding is performed along the outer side of the contour of the meat-deficient area (1) to form an inner spot welding ring (2), wherein a gap (3) is left between the inner spot welding ring (2) and the contour of the meat-deficient area (1); S2. Welding the area within the inner spot welding ring (2); S3. Cooling; S4. Spot welding is performed on the outer area of ​​the inner spot welding ring (2) to form an outer spot welding ring (4); S5. Fine-tune the outer circle and inner hole of the workpiece to meet the process size requirements.

2. The method for repairing the outer wall of the hydraulic column cylinder missing according to claim 1, It is characterized in that In step S1, the width of the gap is 3 mm to 5 mm.

3. The method for repairing the outer wall of the hydraulic column cylinder missing according to claim 1, It is characterized in that In step S2, welding is performed by cooling while welding.

4. The method for repairing the outer wall of the hydraulic column cylinder missing according to claim 1, It is characterized in that In step S4, electric welding is performed using a small current of 200A to 250A.

5. The method for repairing the outer wall of the hydraulic column cylinder missing according to claim 1, It is characterized in that The step S5 is divided into the following sub-steps: S51. Grind the outer diameter of the workpiece to the process size requirements; S52. Honing the inner hole of the workpiece to the process size requirements.

6. The method for repairing the outer wall of the hydraulic column cylinder missing according to claim 5, It is characterized in that In step S51, the lack-of-meat area (1) is first ground and it is determined whether there are welding defects inside. If there are welding defects, rework is performed. If there are no welding defects, the outer circle of the workpiece is ground to the process size requirements.

7. The method for repairing the outer wall defect of the cylinder of a hydraulic column according to any one of claims 1 to 6, It is characterized in that A grinding step is added between step S1 and step S2: The area inside the inner spot welding ring (2) is polished to remove black skin on the surface of the workpiece.

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