Welded shell wall thickness control method

Abstract

The embodiment of the invention discloses a method for controlling the wall thickness of a welded shell. The method comprises the steps that S1, a thin-wall surrounding shell, a hole seat and a reinforcing rib are welded into the welded shell; s2, supporting rings are placed in the inner circles of the two ends of the welding shell correspondingly, and clamping pieces are adopted for supporting the supporting rings; s3, primary turning is conducted on a lathe; s4, a plurality of generatrixes are delimited on the outer circle of the welding shell; s5, marking a plurality of measuring points on each bus, and performing wall thickness measurement on each measuring point to obtain a current wall thickness value corresponding to each measuring point; s6, the wall thickness difference between the current wall thickness value and the standard wall thickness value is calculated, and when the wall thickness difference is larger than or equal to a standard wall thickness difference threshold value, an out-of-tolerance area of the corresponding measuring point is marked; and S7, the out-of-tolerance area is knocked, the preset wall thickness is turned off, whether the wall thickness difference at the moment is smaller than the standard wall thickness difference threshold value or not is compared, and if not, the steps S4-S7 are repeated till the wall thickness difference is smaller than the standard wall thickness difference threshold value. The workpiece forming quality is improved.

Description

Technical Field

[0001] The present invention relates to the field of mechanical processing, and in particular to a method for controlling the wall thickness of a welding shell. Background Art

[0002] A welded shell is constructed from a thin-walled enclosure, stiffeners, and a housing. Stringent requirements for the outer diameter tolerance and surface quality are imposed on the welded shell. After welding, the shell must be turned to ensure the outer diameter is accurate. Therefore, a 2mm machining allowance is typically left on the outer surface of the thin-walled enclosure for turning. The conventional turning process involves aligning the centerline of the welded shell on a lathe and then gradually turning the outer diameter to the required dimensions as specified in the drawing.

[0003] Due to heat deformation during welding, the welded parts shrink, resulting in an uneven, wavy surface. This problem causes the wall thickness to become thinner after turning, making it difficult to maintain the 0.3mm tolerance. This leads to a high scrap rate for welded shells due to substandard wall thickness.

[0004] There is currently no effective solution to the problem of poor quality of shells after welding deformation in the prior art. Summary of the Invention

[0005] To solve the above problems, the present invention provides a method for controlling the wall thickness of a welded shell. In the process from thick to thin, the excess is removed in multiple times. Before removal, multiple busbars are marked, and the wall thickness value is measured on the busbar to find the area where the wall thickness value is greater than the standard value, and then knocked, thereby reducing the amount of cutting each time, so as to solve the problem of local wall thickness thinning and high scrap rate after turning in the prior art.

[0006] To achieve the above-mentioned object, the present invention provides a method for controlling the wall thickness of a welded shell, comprising: S1, welding a thin-walled shell, a hole seat, and a reinforcing rib to form a welded shell; S2, placing support rings in the inner circles of both ends of the welded shell, and supporting the support rings with a clamp; S3, aligning the outer circle of the welded shell on a lathe and performing initial turning;

[0007] S4. Evenly mark a preset number of busbars on the outer circle of the welded shell; S5. Mark multiple measuring points on each busbar, measure the wall thickness of each measuring point, and obtain the current wall thickness value corresponding to each measuring point; S6. Calculate the wall thickness difference between the current wall thickness value and the standard wall thickness value, compare the wall thickness difference with the standard wall thickness difference threshold, and when the wall thickness difference is greater than or equal to the standard wall thickness difference threshold, mark the out-of-tolerance area of ​​the corresponding measuring point; S7. Tap the out-of-tolerance area and turn off the wall thickness of a predetermined thickness, compare whether the wall thickness difference at this time is less than the standard wall thickness difference threshold, and if not, repeat steps S4-S7 until the wall thickness difference is less than the standard wall thickness difference threshold.

[0008] Further optionally, the preset number is 8.

[0009] Further optionally, marking a plurality of measurement points on each busbar includes: pre-demarcating a first area where the reinforcing ribs are located and a second area where the hole seats are located; and marking the measurement points while avoiding the first area and the second area.

[0010] Further optionally, the distance between adjacent measuring points is 100-150 mm.

[0011] Further optionally, tapping the out-of-tolerance area includes: comparing the wall thickness difference corresponding to the out-of-tolerance area with a first wall thickness difference threshold, and when the wall thickness difference is less than the first wall thickness difference threshold, tapping the out-of-tolerance area with a first force; when the wall thickness difference is greater than or equal to the first wall thickness difference threshold, comparing the wall thickness difference corresponding to the out-of-tolerance area with a second wall thickness difference threshold, and if the wall thickness difference is less than the second wall thickness difference threshold, tapping the out-of-tolerance area with a second force; if the wall thickness difference is greater than or equal to the second wall thickness difference threshold, tapping the out-of-tolerance area with a third force; wherein, the first wall thickness difference threshold is greater than the standard wall thickness difference threshold, and the second wall thickness difference threshold is greater than the first wall thickness difference threshold; the force values ​​of the first force, the second force and the third force increase successively.

[0012] Further optionally, the preset thickness is 0.3-0.8 mm.

[0013] Further optionally, the clamping member is a four-jaw chuck.

[0014] The above technical solution has the following beneficial effects: the wall thickness of the welded shell is made uniform by identifying the wall thickness layer by layer and gradually reducing the excess wall thickness value; the wall thickness value is adjusted by repeatedly tapping the outer wall, so that the welding stress is released and the deformation of the welded shell is effectively reduced; this process method is simple and applicable, and can accurately identify and correct the parts with excess wall thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] 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 only 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 work.

[0016] Figure 1 is a structural schematic diagram of a welded housing provided by an embodiment of the present invention;

[0017] Figure 2 is a flow chart of a method for controlling the wall thickness of a welded shell provided by an embodiment of the present invention;

[0018] Figure 3 2 is a schematic structural diagram of a welded shell after marking measurement points according to an embodiment of the present invention;

[0019] Figure 4 is a flow chart of a measurement point marking method provided by an embodiment of the present invention;

[0020] Figure 5 It is a flowchart of a method for striking an out-of-tolerance area provided by an embodiment of the present invention.

[0021] Figure numerals: 1-support ring; 2-hole seat; 3-reinforcement rib; 4-thin-wall shell; 5-measuring point; 6-tolerance area; 7-busbar. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] In order to solve the problem in the prior art that welding deformation causes the shell surface to be uneven and wavy, resulting in loss of straightness of the busbar, and further causing the local wall thickness to be too thin when machining the outer diameter, an embodiment of the present invention provides a method for controlling the wall thickness of a welded shell. Figure 2 Flowchart of the method for controlling the wall thickness of a welded shell provided by an embodiment of the present invention. Figure 2 As shown, the method includes:

[0024] S1. Welding the thin-walled enclosure, hole seat, and reinforcement ribs into a welded shell;

[0025] like Figure 1 As shown, a certain type of shell is welded together by a thin-walled shell 4, a hole seat 2, and a reinforcing rib 3. The thin-walled shell is relatively thin and is generally cylindrical. The hole seat and reinforcing rib are fixedly welded inside the thin-walled shell.

[0026] Before turning, the thin-walled shell, hole seat and reinforcement ribs need to be welded into a whole to obtain a welded shell.

[0027] S2. Place support rings in the inner circles of both ends of the welded shell and use clamps to support the support rings;

[0028] Two support rings 1 are designed. The structure of the support rings must be able to be inserted into both ends of the welded shell and clamped to the welded shell to ensure the effective connection between the support rings and the welded shell. For example, the portion of the support ring inserted into the welded shell can have an interference fit with the welded shell, and the portion of the support ring inserted into the welded shell can be threaded.

[0029] The portion of the support ring located outside the welding shell is used for clamping with the clamping piece to ensure that the clamping piece can fix the welding shell.

[0030] The center line of the welded shell is aligned by two clamping parts to serve as the basis for subsequent turning.

[0031] S3. Align the outer circle of the welding shell on a lathe and perform initial turning;

[0032] Locate the outer circle of the welded shell on the lathe, and use the lathe to perform initial turning, that is, turn the outer circle once first to ensure that the surface is shiny.

[0033] S4. Evenly draw a preset number of busbars on the outer circle of the welded shell;

[0034] A predetermined number of busbars are evenly delineated on the outer circumference of the welded shell so that the busbars can be evenly distributed on the circumference.

[0035] S5. Mark multiple measuring points on each busbar, measure the wall thickness of each measuring point, and obtain the current wall thickness value corresponding to each measuring point;

[0036] like Figure 3 As shown, each busbar 7 is marked with measuring points 5. The measuring points can be marked evenly, that is, calibrated according to a predetermined interval; or unevenly, for example, more densely marked near the welding point and more loosely marked in other parts.

[0037] The wall thickness of each marked measuring point is measured to obtain the current wall thickness value corresponding to each measuring point. This measurement step can be performed using a wall thickness gauge, and the measured value can also be marked near the corresponding measuring point on the outer wall of the shell.

[0038] S6. Calculate the wall thickness difference between the current wall thickness value and the standard wall thickness value, compare the wall thickness difference with the standard wall thickness difference threshold, and mark the out-of-tolerance area of ​​the corresponding measurement point when the wall thickness difference is greater than or equal to the standard wall thickness difference threshold;

[0039] like Figure 3As shown, the current wall thickness value is compared with the standard wall thickness value, and the wall thickness difference between the current wall thickness value and the standard wall thickness value is calculated. It is determined whether the wall thickness difference is greater than the standard wall thickness difference threshold. The absolute value is used for comparison. If the difference is greater than or equal to the standard wall thickness difference threshold, the measurement point is marked, and the out-of-tolerance area 6 is obtained.

[0040] For example, the standard wall thickness value is 8mm, the current wall thickness value is 8.5mm, and the standard wall thickness difference threshold is 0.3mm. Then the difference between the standard wall thickness value and the current wall thickness value is 0.5mm, and its absolute value is greater than the standard wall thickness difference threshold of 0.3mm. In this case, the measurement point needs to be marked.

[0041] As an optional implementation, the out-of-tolerance measurement point is formed into a circle, and the out-of-tolerance area is defined according to a predetermined radius.

[0042] As an optional implementation, Figure 3 As shown in FIG, when the measurement points near a certain out-of-tolerance measurement point also exceed the tolerance, the corresponding areas of the nearby measurement points can be circled into an out-of-tolerance area.

[0043] S7. Tapping the out-of-tolerance area and turning off the wall thickness of the predetermined thickness, comparing whether the wall thickness difference at this time is less than the standard wall thickness difference threshold. If not, repeating steps S4-S7 until the wall thickness difference is less than the standard wall thickness difference threshold.

[0044] The out-of-tolerance area is knocked to move it toward the center line of the welded shell to release the welding stress so that when the allowance is removed later, the cutting amount in the area with large wall thickness is reduced, thereby achieving the purpose of gradually making the wall thickness uniform.

[0045] After the tapping is completed, the wall thickness allowance of the predetermined thickness is turned off. At this time, the wall thickness difference is compared to see if it is less than the standard wall thickness difference threshold. If it is less than the standard wall thickness difference threshold, the next turning is stopped, otherwise the turning is continued until the wall thickness difference of all measuring points is less than the standard wall thickness difference threshold.

[0046] After the wall thickness is uniform, the surface finishing process is completed.

[0047] As an optional implementation, the preset number is 8.

[0048] In order to improve the uniformity of turning, in this embodiment, 8 generatrixes are evenly delineated on the outer circumference of the welded shell. On one circumference, the angle between every two of the 8 generatrixes is 45 degrees.

[0049] As an optional implementation, Figure 4 is a flow chart of a measurement point marking method provided by an embodiment of the present invention, such as Figure 4 As shown, multiple measurement points are marked on each busbar, including:

[0050] S501, pre-demarcating a first area where the reinforcing ribs are located and a second area where the hole seats are located;

[0051] S502: Mark the measurement point while avoiding the first area and the second area.

[0052] After welding the ribs and the hole seat, the locations of the ribs and the hole seat are demarcated to obtain the first and second areas. The wall thickness of these parts cannot be measured, so they need to be avoided when marking the measurement points.

[0053] As an optional implementation, the distance between adjacent measuring points is 100-150 mm.

[0054] The distance between adjacent measurement points can be a fixed value, for example, 120mm between two adjacent points. It can also be a variable value, for example, the distance between the current measurement point and the previous measurement point can be 110mm, and the distance between the current measurement point and the next measurement point can be 130mm. The distance can be set based on actual conditions.

[0055] As an optional implementation, Figure 5 Flowchart of the method for striking the out-of-tolerance area provided by an embodiment of the present invention. Figure 5 As shown, knock on the out-of-tolerance areas, including:

[0056] S701, comparing the wall thickness difference corresponding to the out-of-tolerance area with a first wall thickness difference threshold, and when the wall thickness difference is less than the first wall thickness difference threshold, tapping the out-of-tolerance area with a first force;

[0057] S702. When the wall thickness difference is greater than or equal to the first wall thickness difference threshold, compare the wall thickness difference corresponding to the out-of-tolerance area with the second wall thickness difference threshold. If the wall thickness difference is less than the second wall thickness difference threshold, tap the out-of-tolerance area with the second force; if the wall thickness difference is greater than or equal to the second wall thickness difference threshold, tap the out-of-tolerance area with the third force; wherein the first wall thickness difference threshold is greater than the standard wall thickness difference threshold, and the second wall thickness difference threshold is greater than the first wall thickness difference threshold; the force values ​​of the first force, the second force and the third force increase successively.

[0058] Different tapping forces are used for different deviation values. When the wall thickness difference is greater than the standard wall thickness difference threshold and less than the first wall thickness difference threshold, the first force is used to tap the deviation area. When the wall thickness difference is greater than or equal to the first wall thickness difference threshold and less than the second wall thickness difference threshold, the second force is used to tap. When the wall thickness difference is greater than or equal to the second wall thickness difference threshold, the third force is used to tap. The force values ​​of the first, second, and third forces increase successively.

[0059] As an optional implementation, a rubber hammer may be used for striking, and the force of the rubber hammer may be controlled by a transmission motor of different frequencies and powers.

[0060] As an optional implementation, the preset thickness is 0.3-0.8 mm.

[0061] After the tapping is completed, the wall thickness of 0.3-0.8 mm is turned off, and preferably 0.5 mm of the allowance is turned off each time.

[0062] As an optional embodiment, the clamping member is a four-jaw chuck.

[0063] The two support rings are fixed by two four-jaw chucks respectively, so that the center line of the welding shell can be aligned by adjusting the distance between the four jaws of the chuck.

[0064] The above technical solution has the following beneficial effects: the wall thickness of the welded shell is made uniform by identifying the wall thickness layer by layer and gradually reducing the excess wall thickness value; the wall thickness value is adjusted by repeatedly tapping the outer wall, so that the welding stress is released and the deformation of the welded shell is effectively reduced; this process method is simple and applicable, and can accurately identify and correct the parts with excess wall thickness.

[0065] The specific implementation methods of the above inventions further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above content is only the specific implementation methods of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for controlling the wall thickness of a welded shell, characterized in that: include: S1. Welding the thin-walled enclosure, hole seat, and reinforcement ribs into a welded shell; S2. Place support rings in the inner circles of both ends of the welded shell, and use clamps to support the support rings; S3. Aligning the outer circle of the welded shell on a lathe and performing initial turning; S4. Evenly delineating a preset number of busbars on the outer circle of the welded shell; S5. Mark multiple measuring points on each busbar, measure the wall thickness of each measuring point, and obtain the current wall thickness value corresponding to each measuring point; S6. Calculate the wall thickness difference between the current wall thickness value and the standard wall thickness value, compare the wall thickness difference with the standard wall thickness difference threshold, and mark the out-of-tolerance area of ​​the corresponding measurement point when the wall thickness difference is greater than or equal to the standard wall thickness difference threshold; S7, tapping the out-of-tolerance area and turning off the wall thickness of a predetermined thickness, comparing whether the wall thickness difference at this time is less than the standard wall thickness difference threshold, if not, repeating steps S4-S7 until the wall thickness difference is less than the standard wall thickness difference threshold.

2. The method for controlling the wall thickness of a welded shell according to claim 1, wherein: The preset number is 8.

3. The method for controlling the wall thickness of a welded shell according to claim 1, wherein: The multiple measurement points are marked on each busbar, including: Predefine a first area where the reinforcing rib is located and a second area where the hole seat is located; The measuring points are marked avoiding the first location area and the second location area.

4. The method for controlling the wall thickness of a welded shell according to claim 3, wherein: The distance between adjacent measuring points is 100-150 mm.

5. The method for controlling the wall thickness of a welded shell according to claim 1, wherein: The out-of-tolerance area is struck, including: comparing the wall thickness difference corresponding to the out-of-tolerance area with a first wall thickness difference threshold, and when the wall thickness difference is less than the first wall thickness difference threshold, tapping the out-of-tolerance area with a first force; When the wall thickness difference is greater than or equal to the first wall thickness difference threshold, compare the wall thickness difference corresponding to the out-of-tolerance area with the second wall thickness difference threshold. If the wall thickness difference is less than the second wall thickness difference threshold, use the second force to tap the out-of-tolerance area; if the wall thickness difference is greater than or equal to the second wall thickness difference threshold, use the third force to tap the out-of-tolerance area; wherein, the first wall thickness difference threshold is greater than the standard wall thickness difference threshold, and the second wall thickness difference threshold is greater than the first wall thickness difference threshold; the force values ​​of the first force, the second force and the third force increase successively.

6. The method for controlling the wall thickness of a welded shell according to claim 1, wherein: The preset thickness is 0.3-0.8 mm.

7. The method for controlling the wall thickness of a welded shell according to claim 1, wherein: The clamping part is a four-jaw chuck.

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