Methods to ensure the dimensional and positional accuracy of multiple cavities in complex welded box structures

Abstract

This invention discloses a method for ensuring the dimensional and positional accuracy of multiple cavities in a complex welded box assembly. The steps include: Step 1, determining two reference surfaces and point O for the upper and lower panels; Step 2, disassembling the paired upper and lower panels and machining positioning grooves and arc-shaped bosses respectively; Step 3, machining positioning bosses and cavity surfaces at the upper and lower ends of each vertical plate; Step 4, assembling the upper and lower panels with the six vertical plates, fitting and installing positioning pins to obtain the assembled complex welded box assembly; Step 5, completing the welding of all contact surfaces between the vertical plates and the upper and lower panels to obtain the finished complex welded box assembly. This method allows the multiple cavities of a complex welded box assembly to maintain their dimensional and positional requirements without post-weld machining, significantly reducing manufacturing costs and processing difficulty, and has wide applicability.

Description

Technical Field

[0001] This invention belongs to the field of mechanical manufacturing technology and relates to a method for ensuring the shape and position accuracy of multiple cavities in a complex welded box. Background Technology

[0002] With the increasing automation of oil drilling and production equipment, the number of automated tubing handling systems is growing. These products often require accurate positioning and uniform force in their transmission mechanisms. Therefore, complex welded box-type parts with multiple cavities and high requirements for the relative positions of the cavities are widely used. The shortcomings of existing technologies in processing such complex welded box-type parts are that, while ensuring the dimensions and relative positions of each cavity (in the work object of this invention, the center surfaces of multiple cavities must converge on the same straight line of the vertical panel), the relative positions of each cavity with other features of the box (arc-shaped bosses) must also be guaranteed.

[0003] To address this, existing technologies typically employ two methods: Method 1) Optimizing the welding process, eliminating post-weld machining. This involves measures such as adding temporary process supports within the cavity, ensuring adequate preheating, selecting areas with high rigidity as welding start points, designing specialized tooling, and using welding back plates to increase panel rigidity, thereby reducing welding deformation or ensuring the dimensional and positional tolerances of each cavity. However, these methods suffer from drawbacks in practice, including high processing costs, long pre-weld preparation time, high precision requirements for cavity assembly before welding, the impact of root welds on cavity surface dimensional and positional accuracy, high skill requirements for operators, and long production cycles. Method 2) Employing machining methods. This involves leaving the upper panel unwelded to allow for smooth tool entry and machining of the cavity inner wall, then welding the upper panel, and finally machining other features on the housing. This type of method results in an unclosed open structure for the box body during cavity processing, which is not rigid enough. During processing, problems such as deformation of the inner wall of the cavity and secondary deformation during the subsequent welding of the upper panel often occur. Furthermore, when processing other features after welding, it is impossible to accurately guarantee the shape and position requirements of each cavity and other features.

[0004] Due to the complex structure of these welded box-type parts, involving many welds, and the large amount of post-weld deformation and high processing difficulty, the manufacturing requirements are very high, making it difficult to achieve high-quality mass production. Therefore, it is urgent to develop new processing methods to effectively solve the technical problems existing in the above-mentioned processing. Summary of the Invention

[0005] The purpose of this invention is to provide a method for ensuring the form and position accuracy of multiple cavities in a complex welded box, which solves the problem in the prior art that neither the form and position tolerances between cavities nor the form and position tolerances between cavities and other features can be guaranteed.

[0006] The technical solution adopted in this invention is a method for ensuring the dimensional and positional accuracy of multiple cavities in a complex welded box, which is implemented according to the following steps:

[0007] Step 1: Determine the two reference planes and point O for the upper and lower panels;

[0008] Step 2: Disassemble the paired upper and lower panels and machine the positioning grooves and arc-shaped bosses respectively;

[0009] Step 3: Machining the positioning bosses and cavity surfaces on the upper and lower ends of each upright plate;

[0010] Step 4: Combine the top panel, bottom panel and six uprights, drill anti-deformation holes and install positioning pins to obtain the assembled complex welded box.

[0011] Step 5: Complete the welding of all the contact surfaces between the uprights and the top and bottom panels to obtain the finished complex welded box body.

[0012] The beneficial effects of this invention include the following aspects:

[0013] 1) The top panel, bottom panel, and upright plate are positioned using a double positioning method with positioning grooves and positioning pins, forming a stable "over-positioning" structure. On the one hand, this allows the panels and upright plates to support each other during welding, forming a closed and robust stable structure, increasing the product's rigidity. On the other hand, the cooperation of anti-deformation holes and positioning pins further increases the bending resistance of the top panel, bottom panel, and upright plate, effectively controlling deformation problems during welding while ensuring the assembly accuracy before welding. This avoids the complex processes of adding process supports, designing tooling, or implementing special welding processes required by existing technologies. It requires less technical skill from welding workers, is easy to implement, and has high applicability.

[0014] 2) It achieves the effect of meeting the shape and position requirements of each cavity without post-weld processing. This avoids the complex process of existing technologies that require processing the inner wall of the cavity first, then welding the top panel, and finally processing other feature parts. It eliminates the need for secondary welding and also solves the problem of not being able to guarantee the relative positional relationship between other feature parts and the cavities when processing them after welding. This reduces processing costs, improves product quality, and lowers the limiting requirements on processing equipment and personnel skill levels.

[0015] 3) Compared with the prior art, the method of the present invention separates the positioning surface and the welding surface on the upright plate, thereby avoiding welding on the positioning surface and reducing the impact of the weld on the positioning surface. At the same time, since the weld is not on the positioning surface, the process of grinding the weld after welding is eliminated.

[0016] 4) The method of the present invention first pairs the two panels and processes the horizontal and vertical reference surfaces, thereby determining the unified reference for subsequent processing from the source, thus ensuring the shape and position accuracy between each cavity and each cavity relative to other feature parts.

[0017] 5) The method of the present invention reduces the shape and position requirements of machining anti-deformation holes on the upright plate by drilling anti-deformation holes; on the other hand, it directly installs positioning pins after machining anti-deformation holes, which reduces the difficulty of assembly and strengthens the tightness of the fit, thereby improving the ability of the box to resist welding deformation.

[0018] 6) The method of the present invention assembles the box body by using the matching relationship between the positioning groove and the positioning boss on the panel and the upright plate. Then, anti-deformation holes are drilled, and the box body is fixed again by using the positioning holes and positioning pins with transition fit. This greatly increases the firmness of the box body, reduces subsequent welding deformation, and reduces the difficulty of assembly. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the complex welded box assembly of the object to be worked by the method of the present invention;

[0020] Figure 2 This is a bottom view of the lower surface of the upper panel in the working object of the method of the present invention;

[0021] Figure 3 This is a top view of the upper surface of the upper panel in the working object of the method of the present invention;

[0022] Figure 4 This is a schematic diagram of the structure of the vertical plate in the working object of the method of the present invention;

[0023] Figure 5 yes Figure 4 Schematic diagram of section AA in the diagram;

[0024] Figure 6 yes Figure 3 The structure view in direction D;

[0025] Figure 7 This is a schematic diagram of the positioning pin in the working object of the method of the present invention.

[0026] In the figure, 1. Top panel, 11. Positioning groove, 12. Anti-deformation hole one, 13. Horizontal reference surface, 14. Longitudinal reference surface, 15. Arc-shaped boss, 2. Vertical plate, 21. Anti-deformation hole two, 22. Positioning boss, 23. Cavity surface, 3. Positioning pin, 4. Bottom panel. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0028] Reference Figure 1 , Figure 6 The present invention provides a method for ensuring the shape and position accuracy of multiple cavities in a complex welded box. The components of the complex welded box involved in the processing are: one upper panel 1 and one lower panel 4. The upper panel 1 and the lower panel 4 are symmetrical in structure. Multiple vertical plates 2 are used to form different cavities (a total of 6 vertical plates 2 in Example 1). Multiple positioning pins 3 are used to connect the upper panel 1 and the lower panel 4 to the vertical plates 2 respectively (a total of 36 positioning pins 3 in Example 1).

[0029] The specific installation structure of all components of the object to be processed in this invention is as follows:

[0030] Reference Figure 2 , Figure 3 The structure of the upper panel 1 is as follows: a transverse reference surface 13 and a longitudinal reference surface 14 are respectively provided in the thickness direction of the upper panel 1; six elongated positioning grooves 11 are respectively opened on the inner surface (i.e., the lower surface) of the upper panel 1; two positioning grooves 11 form a group; three groups of positioning grooves 11 are distributed at 120° along the circumference; one group of positioning grooves 11 is perpendicular to the transverse reference surface 13; three through anti-deformation holes 12 are opened in each elongated positioning groove 11 in sequence; a total of 18 anti-deformation holes 12 are provided in the six positioning grooves 11; an arc-shaped boss 15 is provided on the outer surface (i.e., the upper surface) of the upper panel 1; the two anti-deformation holes 12 are directly opposite the inner side of the group of positioning grooves 11 that are perpendicular to the transverse reference surface 13 below the arc-shaped boss 15.

[0031] Reference Figure 4 , Figure 5 , Figure 6 Each upright plate 2 has the following structure: both its upper and lower surfaces are configured as positioning bosses 22, and each positioning boss 22 has three blind-hole-shaped anti-deformation holes 21; the inner surface of each upright plate 2 is also a boss shape, called a cavity surface 23; the length and width dimensions of the positioning bosses 22 are consistent with the positioning grooves 11 and they are interlocked; each anti-deformation hole 21 is coaxially aligned with an anti-deformation hole 12 and is fitted with a positioning pin 3; one embodiment of the positioning pin 3 is as follows: Figure 7 As shown;

[0032] The vertical plates 2 are paired to form a cavity. Six vertical plates 2 form three cavities respectively. The upper panel 1, lower panel 4, and the same set of vertical plates 2 together form the four faces of a cavity. The midpoints of the three cavities intersect at point O. The centers of the outer arc surfaces of the arc-shaped boss 15 on the upper panel 1 and the arc-shaped boss 15 on the lower panel 4 both coincide with point O. (See...) Figure 1 .

[0033] The positioning principle of the method of the present invention is as follows: First, the relative positions of all the upright plates 2 are determined by the positioning grooves 11 on the upper panel 1 and the lower panel 4 cooperating with the positioning bosses 22 on the upright plate 2; after the upper panel 1, the lower panel 4 and the upright plate 2 are combined, coaxial anti-deformation holes 12 and 21 are drilled; then, the upper panel 1, the lower panel 4 and the upright plate 2 are connected by the cooperation of the positioning pin 3 with the anti-deformation holes 12 and 21; finally, under the combined action of the positioning grooves 11 and the positioning pins 3, the relative positions of all the upright plates 2 are securely fixed, thereby controlling the deformation of the contact surfaces of the upright plates 2 during the welding process and fully ensuring the shape and position accuracy of the three cavities.

[0034] Reference Figure 6 and Figure 1 , ( Figure 6 (A schematic diagram of a cavity structure is shown). The product prepared by the method of the present invention must ensure the H and W dimensions of the three cavities, as well as the perpendicularity of adjacent surfaces and the parallelism of opposite surfaces of the three cavities; the vertical mid-surfaces of the three cavities must intersect on a straight line perpendicular to the upper panel 1 and the lower panel 4 and passing through point O; the outer arc surface center of the arc-shaped boss 15 on the outer surface of the upper panel 1 and the lower panel 4 must coincide with point O. To this end, the method of the present invention is implemented according to the following steps:

[0035] Step 1: Determine the two reference planes of the upper panel 1 and the lower panel 4, as well as point O.

[0036] The upper panel 1 and lower panel 4 are paired together by spot welding or mechanical clamping. The position of point O is marked, and the point is used as the origin of the coordinate system. In one installation, the mutually perpendicular transverse reference surface 13 and longitudinal reference surface 14 are machined, and the coordinates of the transverse reference surface 13 and longitudinal reference surface 14 relative to point O are recorded. The transverse reference surface 13 and longitudinal reference surface 14 on the upper panel 1 and lower panel 4 will serve as the unified reference surface for subsequent processing.

[0037] In particular, for panels with certain complex shapes that do not have mutually perpendicular horizontal reference surfaces 13 and vertical reference surfaces 14, allowances can be left for machining the reference surfaces when cutting the panel, or two reference plates can be temporarily welded onto the panel to form mutually perpendicular horizontal and vertical reference surfaces by machining the temporary reference plates.

[0038] Step 2: Disassemble the paired upper panel 1 and lower panel 4, and machine the positioning groove 11 and the arc-shaped boss 15 respectively.

[0039] Align the transverse reference surface 13 and longitudinal reference surface 14 processed in step 1. Determine point O as the origin of the workpiece coordinates based on the recorded coordinates. Process six positioning grooves 11 on the inner surfaces of the upper panel 1 and the lower panel 4. The width and length dimensions of each positioning groove 11 are of H7 grade accuracy, and the depth of each positioning groove 11 is 1 / 3 to 1 / 2 of the thickness of the panel. The intersection of the mid-faces of the two pairs of positioning grooves 11 processed at this time is point O.

[0040] After flipping the panel once, the coordinate zero point (i.e., point O) is still determined by the transverse reference plane 13 and the longitudinal reference plane 14. The arc-shaped bosses 15 on the outer surfaces of the upper panel 1 and the lower panel 4 are machined. Since the machining references of the positioning grooves 11 and the arc-shaped bosses 15 are the same, the relative positional relationship between each positioning groove 11 and the arc-shaped bosses 15 can be guaranteed.

[0041] Step 3: Machining the positioning bosses 22 and cavity surfaces 23 at the upper and lower ends of each vertical plate 2.

[0042] The relative position of the positioning boss 22 on each upright plate 2 and the cavity surface 23 will determine the width of the assembled cavity (the two cavity surfaces 23 will form two surfaces on the width of a cavity). Therefore, the left end face of the positioning boss 22 is used as the machining reference (see...). Figure 5 (Left end face) In the same installation, the right end face of the positioning boss 22 (the left and right end faces of the positioning boss 22 together form the width dimension of the positioning boss 22) and the cavity surface 23 are machined to ensure the form and position relationship between the cavity surface 23 and the positioning boss 22. The width dimension of the positioning boss 22 is g6 precision, which forms an H7 / g6 fit relationship with the positioning groove 11 on the upper panel 1 and the lower panel 4 to ensure the form and position accuracy of the cavity formed after assembly.

[0043] Step 4: Assemble the top panel 1, bottom panel 4, and six uprights 2, and install the positioning pins 3.

[0044] 4.1) Apply pressure accurately to the position directly above each vertical plate 2 with the pressure plate of the pressure equipment. Shims should be placed at other pressing positions to ensure the rigidity during clamping, so as to obtain the preliminary assembly of the upper panel 1, the lower panel 4 and the six vertical plates 2; align the transverse reference surface 13 and the longitudinal reference surface 14 processed in step 1 to determine the coordinate zero point as point O; this method can ensure the uniformity of the processing reference, thereby ensuring the relative position accuracy of the processing features.

[0045] 4.2) Drill anti-deformation holes on one side of the preliminary assembly. The fit between each anti-deformation hole and the positioning pin 3 is a transition fit H7 / k6. The number of anti-deformation holes can be increased or decreased according to the amount of welding deformation and the requirements of cavity shape and position tolerance. The more holes, the better the effect. However, the total number of anti-deformation holes 21 on the upper and lower end faces of each vertical plate 2 should not be less than 4 (i.e., at least two on each end face, and three on each end face in this embodiment). The inner diameter of the anti-deformation hole and the diameter of the positioning pin 3 should be 1 / 3 to 1 / 2 of the width of the positioning boss 22. The larger the proportion, the better the effect. At the same time, the depth of the positioning pin 3 should be greater than 2-3 times the thickness of the upper panel 1 (or lower panel 4) to ensure firm positioning. The inner end of the positioning pin 3 is machined into a 15° conical surface for easy assembly.

[0046] Install all positioning pins 3, and perform secondary assembly and positioning of the upper panel 1, lower panel 4 and vertical plate 2 to form "over-positioning", which further increases the firmness and positioning accuracy of the entire complex welded box body. This is called a secondary assembly.

[0047] 4.3) Flip the secondary assembly over and repeat step 4.2) to process the anti-deformation holes on the other side of the secondary assembly and install the corresponding positioning pins 3 to obtain the assembled complex welded box.

[0048] Step 4 utilizes a drill bit, which on the one hand reduces the machining accuracy required for drilling holes directly on the upright plate 2 and the panel 1; on the other hand, by directly installing the positioning pin 3 after machining the anti-deformation hole, the assembly difficulty can be reduced.

[0049] Step 5: Perform overall welding on the assembled complex welded box, that is, complete the welding of all contact surfaces of the upright plates 2 with the upper panel 1 and the lower panel 4 to obtain the finished complex welded box.

[0050] Example 1

[0051] The No. 1 complex welded box body was processed according to the above steps of the method of the present invention. The resulting finished product was inspected by magnetic detection, and the weld was good. The measured data of deformation at the three key parts of the cavity were +0.3mm, +0.4mm, and +0.35mm in width W (product size error requirement is ±0.5mm), and +0.2mm, +0.35mm, and +0.4mm in height H (product size error requirement is ±1mm). The parallelism was 0.2mm, 0.28mm, and 0.3mm respectively (product requirement is that the parallelism between the two cavity surfaces in the width direction is 0.5mm), and the perpendicularity was 0.28mm, 0.3mm, and 0.23mm respectively (product requirement is that the perpendicularity between the two cavity surfaces in the width direction and the lower panel is 0.5mm).

[0052] As can be seen, the overall deformation is within the allowable range and fully meets the product quality requirements when manufactured according to the method of the present invention.

[0053] Example 2

[0054] The No. 2 complex welded box body was processed according to the above steps of the method of the present invention. The resulting product was inspected by magnetic detection, and the weld was good. The measured data of deformation at the three key parts of the cavity were +0.25mm, +0.2mm, and +0.15mm in width W (product size error requirement is ±0.5mm), and +0.22mm, +0.25mm, and +0.3mm in height H (product size error requirement is ±1mm). The parallelism was 0.38mm, 0.2mm, and 0.2mm (product requirement is 0.5mm parallelism between the two cavity surfaces in the width direction), and the perpendicularity was 0.2mm, 0.36mm, and 0.2mm (product requirement is 0.5mm perpendicularity between the two cavity surfaces in the width direction and the lower panel).

[0055] As can be seen, the overall deformation is within the allowable range and fully meets the product quality requirements when manufactured according to the method of the present invention.

[0056] Example 3

[0057] The No. 3 complex welded box body was processed according to the above steps of the method of the present invention. The resulting product was inspected by magnetic detection, and the weld was good. The measured data of deformation at the three key parts of the cavity were +0.21mm, +0.22mm, and +0.18mm in width W (product size error requirement is ±0.5mm), and +0.27mm, +0.32mm, and +0.23mm in height H (product size error requirement is ±1mm). The parallelism was 0.18mm, 0.21mm, and 0.38mm (product requirement is 0.5mm parallelism between the two cavity surfaces in the width direction), and the perpendicularity was 0.31mm, 0.27mm, and 0.18mm (product requirement is 0.5mm perpendicularity between the two cavity surfaces in the width direction and the lower panel).

[0058] As can be seen, the overall deformation is within the allowable range and fully meets the product quality requirements when manufactured according to the method of the present invention.

[0059] Example 4

[0060] The No. 4 complex welded box body was processed according to the above steps of the method of the present invention. The resulting product was inspected by magnetic detection, and the weld was good. The measured data of deformation at the three key parts of the cavity were +0.3mm, +0.32mm, and +0.28mm in width W (product size error requirement is ±0.5mm), and +0.31mm, +0.38mm, and +0.33mm in height H (product size error requirement is ±1mm). The parallelism was 0.18mm, 0.21mm, and 0.25mm (product requirement is 0.5mm parallelism between the two cavity surfaces in the width direction), and the perpendicularity was 0.3mm, 0.22mm, and 0.33mm (product requirement is 0.5mm perpendicularity between the two cavity surfaces in the width direction and the lower panel).

[0061] As can be seen, the overall deformation is within the allowable range and fully meets the product quality requirements when manufactured according to the method of the present invention.

Claims

1. A method for ensuring the shape and position accuracy of multiple cavities in a complex group-welded box, the complex group-welded box being composed of one upper panel (1) and one lower panel (4), the upper panel (1) and the lower panel (4) being structurally symmetrical and consistent, multiple vertical panels (2), and multiple positioning pins (3), characterized in that: the upper panel (1) is provided with a transverse reference surface (13) and a longitudinal reference surface (14) in the thickness direction of the upper panel (1), the inner surface of the upper panel (1) is provided with six long strip-shaped positioning grooves (11), every two positioning grooves (11) form a group, and three groups of positioning grooves (11) are distributed at an angle of 120° along the circumference, and one group of positioning grooves (11) is perpendicular to the transverse reference surface (13); each long strip-shaped positioning groove (11) is sequentially provided with three through anti-deformation holes (12); the outer surface of the upper panel (1) is provided with an arc-shaped boss (15) which is opposite to two anti-deformation holes (12) on the inner side of the group of positioning grooves (11) perpendicular to the transverse reference surface (13); the upper end surface and the lower end surface of each vertical panel (2) are provided with positioning bosses (22), each positioning boss (22) is provided with three blind anti-deformation holes (21); the inner vertical surface of each vertical panel (2) is also boss-shaped and is referred to as a cavity surface (23); the positioning boss (22) has the same length and width as the positioning groove (11) and is inserted and matched with the positioning groove (11), and each anti-deformation hole (21) is coaxially and correspondingly communicated with an anti-deformation hole (12) upward or downward, the method connects the upper panel (1) and the lower panel (4) with the vertical panel (2) by using the matching relationship between the positioning pin (3) and the anti-deformation hole (12) and the anti-deformation hole (21), ensures the fixed and firm relative position of all vertical panels (2), controls the deformation of the contact surface of the vertical panel (2) during the welding process, ensures the shape and position accuracy of the three cavities, and is implemented according to the following steps: step 1, determining two reference surfaces and an O point of the upper panel (1) and the lower panel (4); the specific process is: the upper panel (1) and the lower panel (4) are matched into one body by spot welding or mechanical pressing, the position of the O point is determined by marking, the transverse reference surface (13) and the longitudinal reference surface (14) are processed in one installation, and the coordinates of the transverse reference surface (13) and the longitudinal reference surface (14) relative to the O point are recorded; step 2, disassembling the matched upper panel (1) and lower panel (4) to process the positioning groove (11) and the arc-shaped boss (15), respectively, ​ ​ ​ ​ ​ ​ The specific process is: the horizontal reference surface (13) and the longitudinal reference surface (14) of the step 1 processing are found, the O point is determined as the workpiece coordinate origin according to the recorded coordinates, six positioning grooves (11) on the inner surfaces of the upper panel (1) and the lower panel (4) are processed, the width and length dimensions of each positioning groove (11) are H7 level precision, and the depth of each positioning groove (11) is 1 / 3-1 / 2 of the thickness of the panel; The arc-shaped boss (15) on the outer surfaces of the upper panel (1) and the lower panel (4) is processed by turning over once and still determining the O point by the horizontal reference surface (13) and the longitudinal reference surface (14); In step 3, the specific process is: The left end surface of the positioning boss (22) is taken as the processing reference, the right end surface of the positioning boss (22) and the cavity surface (23) are processed in the same installation, the width dimension of the positioning boss (22) is g6 precision, and the positioning boss (22) forms an H7 / g6 matching relationship with the positioning groove (11) on the upper panel (1) and the lower panel (4). ​ 2. The method of claim 1, wherein, ​ ​

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