A method for establishing boring processing benchmarks for welding components

Abstract

The present application relates to the technical field of numerical control machining, and discloses a method for establishing a boring machining benchmark for a welding assembly. First, before machining, any boring hole of a part is selected, and a machining initial benchmark is established at the center of the hole. Then, based on the machining initial benchmark, the coordinates of the holes to be bored on the part are measured, and then the hole spacing deviation is calculated. The initial benchmark direct machining condition judgment is performed based on the hole spacing deviation. Finally, the final machining benchmark is established, and the boring hole is machined. The welding assembly machining benchmark establishment method proposed in the present application can effectively solve the problems of low machining efficiency and low product machining quality qualification rate caused by the current trial and error method.

Description

Technical Field

[0001] The present application relates to the technical field of numerical control machining, and in particular to a method for establishing a boring machining benchmark for a welding assembly. Background Art

[0002] In the aerospace field, some complex structural parts cannot be formed through overall processing, so welding is often used to splice multiple parts to form components. However, due to the manufacturing errors of parts and the large deformation of components formed by welding, the overall correction cannot meet the design tolerance requirements. Therefore, in order to meet the requirements of assembly and connection, secondary CNC boring processing is required for the assembly connection holes.

[0003] Since the welding assembly does not have a reference hole or reference surface for establishing a machining coordinate system, the traditional machining scheme cannot accurately establish a machining reference. At present, the trial and error method is used to solve the machining problem of assembly holes of welding assemblies at home and abroad. That is, one of the assembly holes is bored first, and then an initial reference is established at the center of the hole, and the remaining holes are bored based on the initial reference. After the machining is completed, the machining reference is adjusted by measuring the hole position and hole diameter data, and a second boring is performed. Repeat the previous steps, and then a third boring is performed... until the boring hole position, hole diameter and wall thickness tolerance meet the design requirements.

[0004] The traditional trial-and-error processing method needs to rely on the operator's experience to conduct trial processing. The processing efficiency and qualified rate of the product are greatly dependent on the operator's operating level. Summary of the invention

[0005] In order to solve the problems and shortcomings existing in the above-mentioned prior art, the present application proposes a method for establishing a boring processing benchmark for welding components. The method is based on the initial hole position measurement data under the initial benchmark, takes the minimum wall thickness as the boundary condition, and combines the design tolerance limit to give the judgment conditions for whether the benchmark is offset. When the boring hole spacing deviation exceeds the boundary condition of the benchmark offset, a method for calculating the machining benchmark coordinate offset value is proposed, and finally the establishment of the machining benchmark is realized.

[0006] In order to achieve the above-mentioned invention object, the technical solution of this application is as follows:

[0007] A method for establishing a boring processing benchmark for a welding assembly comprises the following steps:

[0008] Step S1. Before processing, select any boring hole of the part and establish the initial processing reference at the center of the hole;

[0009] Step S2. Based on the initial machining datum, measuring the coordinates of the holes to be bored on the part;

[0010] Step S3. Calculate the hole spacing deviation;

[0011] Step S4. Based on the hole spacing deviation, the initial reference direct processing condition is judged;

[0012] Step S5: Establish the final processing reference and process the boring hole.

[0013] Furthermore, in step S2, the coordinates of holes to be bored on the part are measured by a three-dimensional coordinate measuring machine.

[0014] Furthermore, the hole position coordinates refer to the coordinates of the center of the boring hole.

[0015] Furthermore, in step S3, calculating the hole spacing deviation means first calculating the actual hole spacing between the two bored holes based on the hole position coordinates measured in step S2, and then calculating the hole spacing deviation value δ between the actual hole spacing and the theoretical hole spacing according to the theoretical hole spacing between the two holes.

[0016] Furthermore, when calculating the actual hole spacing between two boring holes, the two boring holes are located in the same assembly plane.

[0017] Furthermore, in step S4, it is first determined whether the hole spacing deviation value δ satisfies the initial datum direct processing condition. If so, the initial processing datum is used as the final processing datum to directly perform the part boring process. If not, it is further determined whether the offset initial datum condition is met. If the offset initial datum condition is met, the initial processing datum is offset according to the offset value, and then the offset processing datum is used as the final processing datum to perform the part boring process. If the offset initial datum condition is not met, the part needs to be calibrated, and then the process returns to step S1.

[0018] Furthermore, the initial reference direct processing conditions are as follows:

[0019] -Δ11-λ

[0020] <δ1<Δ12+λ;

[0021] -Δ21-λ<δ2<Δ22+λ;

[0022] Among them, -Δ11 is the lower tolerance of the hole spacing in the X direction that needs to be met by the part boring; Δ12 is the upper tolerance of the hole spacing in the X direction that needs to be met by the part boring; -Δ21 is the lower tolerance of the hole spacing in the Z direction that needs to be met by the part boring; Δ22 is the upper tolerance of the hole spacing in the Z direction that needs to be met by the part boring; λ is the difference between the wall thickness of the part boring blank and the minimum allowable wall thickness of the part boring; δ1 is the hole spacing deviation in the X direction; δ2 is the hole spacing deviation in the Z direction.

[0023] Furthermore, the initial reference conditions of the offset are specifically as follows:

[0024] -Δ11-2λ<δ1<Δ12+2λ;

[0025] -Δ21-2λ<δ2<Δ22+2λ;

[0026] Among them, -Δ11 is the lower tolerance of the hole spacing in the X direction that needs to be met by the part boring; Δ12 is the upper tolerance of the hole spacing in the X direction that needs to be met by the part boring; -Δ21 is the lower tolerance of the hole spacing in the Z direction that needs to be met by the part boring; Δ22 is the upper tolerance of the hole spacing in the Z direction that needs to be met by the part boring; λ is the difference between the wall thickness of the part boring blank and the minimum allowable wall thickness of the part boring; δ1 is the hole spacing deviation in the X direction; δ2 is the hole spacing deviation in the Z direction.

[0027] Furthermore, the offset value is obtained by the following calculation expression:

[0028]

[0029]

[0030] Among them, ΔX is the value that the initial datum needs to be offset in the X direction; ΔZ is the value that the initial datum needs to be offset in the Z direction; -Δ11 is the lower tolerance of the hole spacing in the X direction that needs to be met by the part boring; Δ12 is the upper tolerance of the hole spacing in the X direction that needs to be met by the part boring; -Δ21 is the lower tolerance of the hole spacing in the Z direction that needs to be met by the part boring; Δ22 is the upper tolerance of the hole spacing in the Z direction that needs to be met by the part boring; λ is the difference between the wall thickness of the part boring blank and the minimum allowable wall thickness of the part boring; δ1 is the hole spacing deviation in the X direction; δ2 is the hole spacing deviation in the Z direction.

[0031] Beneficial effects of this application:

[0032] The method for establishing a welding part processing benchmark proposed in this application can effectively solve the problems of low processing efficiency and low product processing quality qualification rate caused by the current trial and error method. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The foregoing and following detailed description of the present application will become more apparent when read in conjunction with the following drawings, in which:

[0034] Figure 1 This is a flow chart of the application method;

[0035] Figure 2 This is a schematic diagram of the overall parts of the embodiment of the present application;

[0036] Figure 3 This is a side view of a part of an embodiment of the present application;

[0037] Figure 4 for Figure 3 Middle AA section view. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the technical solutions in this application, the following will further illustrate the technical solutions for achieving the invention purpose of this application through several specific embodiments. It should be noted that the technical solutions claimed for protection in this application include but are not limited to the following embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0039] In the aerospace field, some complex structural parts cannot be formed through overall processing, so welding is often used to splice multiple parts to form components. However, due to the manufacturing errors of parts and the large deformation of components formed by welding, the overall correction cannot meet the design tolerance requirements. Therefore, in order to meet the requirements of assembly and connection, secondary CNC boring processing is required for the assembly connection holes.

[0040] Since the welding assembly does not have a reference hole or reference surface for establishing a machining coordinate system, the traditional machining scheme cannot accurately establish a machining reference. At present, the trial and error method is used to solve the machining problem of assembly holes of welding assemblies at home and abroad. That is, one of the assembly holes is bored first, and then an initial reference is established at the center of the hole, and the remaining holes are bored based on the initial reference. After the machining is completed, the machining reference is adjusted by measuring the hole position and hole diameter data, and a second boring is performed. Repeat the previous steps, and then a third boring is performed... until the boring hole position, hole diameter and wall thickness tolerance meet the design requirements.

[0041] The above-mentioned trial-and-error processing method needs to rely on the experience of the operator to conduct trial processing, and the processing efficiency and qualified rate of the product greatly depend on the operating level of the operator.

[0042] Based on this, an embodiment of the present application proposes a method for establishing a boring processing benchmark for a welding assembly. This method is based on the initial hole position measurement data under the initial benchmark, takes the minimum wall thickness as the boundary condition, and combines the design tolerance limit to give the judgment conditions for whether the benchmark is offset. When the boring hole spacing deviation exceeds the boundary condition of the benchmark offset, a method for calculating the machining benchmark coordinate offset value is proposed, and finally the establishment of the machining benchmark is realized.

[0043] This embodiment discloses a method for establishing a boring processing benchmark for a welding assembly. Figure 1 , the method is specifically as follows.

[0044] Step S1. Before processing, select any boring hole of the part, take its hole center as the coordinate origin, and establish the initial processing datum at its hole center.

[0045] In this embodiment, it should be noted that due to the large manufacturing error and deformation after welding of the welding assembly, it is impossible to directly and accurately establish a processing coordinate system. Therefore, before processing, a boring hole center of the part is arbitrarily selected as the coordinate origin, and the initial processing reference is established at the hole center, and the corresponding initial processing coordinate system is established.

[0046] Step S2. Based on the initial machining datum and the initial machining coordinate system, the coordinates of the holes to be bored on the part that are located on the same assembly plane as the initial machining datum are measured.

[0047] In this embodiment, it should be noted that in this embodiment, the coordinates of the holes to be bored on the parts are measured by a three-dimensional coordinate measuring machine, and the hole coordinates refer to the coordinates of the center of the bored holes.

[0048] Step S3: Calculate the hole spacing deviation.

[0049] In this embodiment, it should be noted that the hole spacing deviation refers to the deviation value δ between the actual hole spacing and the theoretical hole spacing.

[0050] In the present embodiment, it should also be noted that the actual hole spacing refers to the X-direction distance, Y-direction distance and Z-direction distance between two boring holes on the part, and the distance is calculated through the coordinates between the two. For example, the distance in the X-direction is obtained by taking the difference between the X-coordinates of the two, and the same is true for the Z-direction and Y-direction. In the present embodiment, since a horizontal machine tool is used, the hole spacing mainly refers to the distance in the X-direction and the Z-direction. Furthermore, the theoretical hole spacing is formulated according to processing specifications and requirements.

[0051] In this embodiment, it is also necessary to further explain that when calculating the actual hole spacing between two boring holes, the two boring holes must be two boring holes located in the same assembly plane. That is to say, in the same assembly plane, any two boring holes can be selected to calculate the actual hole spacing, as long as the two holes are located in the same assembly plane.

[0052] Step S4. Based on the hole spacing deviation, make an initial reference direct processing condition judgment.

[0053] In this embodiment, based on the hole spacing deviation, the initial reference direct processing condition is judged as follows:

[0054] First, determine whether the hole spacing deviation value δ satisfies the initial datum direct processing condition. If so, use the initial processing datum as the final processing datum to directly perform the part boring process. If not, further determine whether the offset initial datum condition is met. If the offset initial datum condition is met, the initial processing datum is offset according to the offset value, and then the offset processing datum is used as the final processing datum to perform the part boring process. If the offset initial datum condition is not met, it means that there is a problem with the part position and the part needs to be corrected. Then return to step S1 and execute the above steps until the final processing datum and processing coordinate system are established, thereby completing the boring process.

[0055] In this embodiment, it should be noted that the initial reference direct processing judgment conditions are specifically as follows:

[0056] -Δ11-λ<δ1<Δ12+λ;

[0057] -Δ21-λ<δ2<Δ22+λ;

[0058] The offset initial reference judgment conditions are as follows:

[0059] -Δ11-2λ<δ1<Δ12+2λ;

[0060] -Δ21-2λ<δ2<Δ22+2λ;

[0061] Among them, -Δ11 is the lower tolerance of the hole spacing in the X direction that needs to be met by the part boring; Δ12 is the upper tolerance of the hole spacing in the X direction that needs to be met by the part boring; -Δ21 is the lower tolerance of the hole spacing in the Z direction that needs to be met by the part boring; Δ22 is the upper tolerance of the hole spacing in the Z direction that needs to be met by the part boring; λ is the difference between the wall thickness of the part boring blank and the minimum allowable wall thickness of the part boring; δ1 is the hole spacing deviation in the X direction; δ2 is the hole spacing deviation in the Z direction.

[0062] In this embodiment, it should also be noted that the offset value of the initial processing reference is obtained by the following calculation expression:

[0063]

[0064] Among them, ΔX is the value that the initial datum needs to be offset in the X direction; ΔZ is the value that the initial datum needs to be offset in the Z direction.

[0065] After calculating the above offset value, the coordinates of the initial processing datum are offset as a whole to the processing coordinate system according to the above offset value. In this embodiment, if the hole spacing deviation in a certain direction meets the requirements when judging the direct processing conditions of the initial datum, if the hole spacing deviation in a certain direction meets the direct processing judgment requirements, then the initial processing datum and the processing coordinate system do not need to be offset in that direction, and there is no need to calculate the offset value in that direction, but it is still necessary to calculate the offset value in the direction that does not meet the conditions, and offset the initial processing datum and the processing coordinate system in the direction that does not meet the conditions.

[0066] Step S5: Establish the final machining reference coordinate system and process the boring hole.

[0067] In this embodiment, it should be noted that the machining coordinate system established through the above steps is mainly for boring holes located in the same assembly plane. That is to say, the boring holes located in the same assembly plane can be bored using the machining coordinate system established through the above steps, and a good machining effect can be obtained. However, boring holes in other assembly planes can also be processed with reference to the machining coordinate system. However, a machining datum and machining coordinate system suitable for the assembly plane can also be re-established with reference to the above steps.

[0068] Example 2

[0069] Refer to the instruction manual Figure 2-4 The aviation structural parts shown are typical welded components. The CNC machining content is boring holes 1-4. After machining, the hole spacing deviation between hole 1 and hole 2 in the X direction is required to be ±0.57mm, the hole spacing deviation in the Z direction is required to be ±0.37mm, the blank hole wall thickness is 3mm, and the minimum allowable wall thickness tolerance after machining is 1.5mm.

[0070] Due to the large manufacturing error and welding deformation, when performing CNC machining, it is impossible to find a fine hole or reference surface on the part to establish a machining coordinate system, so the method of the present application is used for boring machining.

[0071] Step S1. Before processing, select any boring hole of the part, take its hole center as the coordinate origin, and establish the initial processing datum at its hole center.

[0072] Take the center of boring hole 1 as the origin of the coordinate system, the line between the centers of hole 1 and hole 3 as the Y axis, the plane parallel to the machine tool working plane as the xoy plane, and the plane perpendicular to the machine tool working plane as the Z axis to establish the initial reference coordinate system for machining.

[0073] Step S2: measuring the coordinates of the holes to be bored on the parts.

[0074] Based on the coordinate origin of hole 1 (0, 0, 0), the coordinates of the center of hole 2 are measured by a three-coordinate measuring machine as (231.554, 0, 56.120), the coordinates of the center of hole 3 are (-0.005, 578.91, 0.003), and the coordinates of the center of hole 4 are (231.552, 578.91, 56.125).

[0075] Step S3: Calculate the hole spacing deviation.

[0076] In this aviation structure, hole 1 and hole 2 are located in the same assembly plane, and hole 3 and hole 4 are located in the same assembly plane. Therefore, when calculating the hole spacing deviation, the hole spacing deviation of hole 1 and hole 2 and the hole spacing deviation of hole 3 and hole 4 are calculated separately. The calculation methods of the two are introduced in this embodiment by taking hole 1 and hole 2 as an example.

[0077] The theoretical hole spacing deviation between hole 1 and hole 2 is: 229.261mm in the X direction and 55.04mm in the Z direction. The actual hole spacing deviation between hole 1 and hole 2 calculated based on the measurement data is: 231.554mm in the X direction and 56.120mm in the Z direction. Therefore, the deviation value of the actual hole spacing from the theoretical hole spacing in the X direction is δ1 = 2.293mm, and the deviation value of the Z direction is δ2 = 1.08mm.

[0078] Step S4. Based on the hole spacing deviation, make an initial reference direct processing condition judgment.

[0079] This embodiment is introduced by taking hole 1 and hole 2 as an example. The calculation method of hole 3 and hole 4 is the same as above and will not be repeated.

[0080] Through calculation, it can be known that the lower tolerance of the X-direction hole spacing between hole 1 and hole 2 needs to be -Δ11=-0.57mm, the upper tolerance of the X-direction hole spacing needs to be Δ12=0.57mm, the lower tolerance of the Z-direction hole spacing needs to be -Δ21=-0.37mm, the upper tolerance of the Z-direction hole spacing needs to be Δ22=0.37mm, and λ=3-1.5=1.5mm.

[0081] The initial benchmark direct processing conditions are determined as follows:

[0082] -Δ11-λ<δ1<Δ12+λ;

[0083] -Δ21-λ<δ2<Δ22+λ;

[0084] Through calculation, it can be known that the deviation value between hole 1 and hole 2 in the X direction is δ1=2.293mm>Δ12+λ=0.57+1.5, and the deviation value in the Z direction is -Δ21-λ=-0.37-1.5<δ2=1.08mm<Δ22+λ=0.37+1.5.

[0085] Therefore, the conditions for using the primary reference coordinate system for direct machining are not met at this time, and the primary reference machining coordinate system must be offset according to the calculated offset value before machining can be performed.

[0086] From the above steps, it can be seen that the hole spacing deviation between hole 1 and hole 2 meets the following conditions:

[0087] -Δ11+2λ=0.57+1.5×2<δ1=2.293<0.57+1.5×2=Δ12+2λ;

[0088] -Δ21-2λ=-0.37-1.5×2<δ2=1.08<0.37+1.5×2=Δ22+2λ.

[0089] Therefore, boring processing can be performed by offsetting the origin of the coordinate system.

[0090] Furthermore, the offset value of the origin of the coordinate system is obtained by the following calculation expression:

[0091]

[0092] It is calculated that the offset value of the coordinate system origin in the X direction is ΔX=0.6385 mm. Since the Z direction satisfies the reference non-offset condition, the Z direction coordinate system does not offset.

[0093] Step S5. The coordinate system established by the initial datum is offset in the X direction by 0.6385 mm for boring processing, which can meet the hole spacing tolerance and minimum wall thickness requirements.

[0094] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as an obstacle to the scope of protection of the present application.

[0095] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", and "connect" 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 an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0096] The above is only a preferred embodiment of the present application and does not constitute any form of obstruction to the present application. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present application shall fall within the protection scope of the present application.

Claims

1. A method for establishing a boring process benchmark for a welding assembly, characterized in that: The specific steps include: Step S1. Before processing, select any boring hole of the part and establish the initial processing reference at the center of the hole; Step S2. Based on the initial machining datum, measuring the coordinates of the holes to be bored on the part; Step S3. Calculate the hole spacing deviation; Step S4. Based on the hole spacing deviation, the initial reference direct processing condition is judged; Step S5. Establish the final processing benchmark and process the boring hole; In the step S4, firstly, it is determined whether the hole spacing deviation value δ satisfies the initial datum direct processing condition. If so, the initial processing datum is used as the final processing datum to directly perform the boring processing of the part. If not, it is further determined whether the offset initial datum condition is met. If the offset initial datum condition is met, the initial processing datum is offset according to the offset value, and then the offset processing datum is used as the final processing datum to perform the boring processing of the part. If the offset initial datum condition is not met, the part needs to be calibrated, and then the process returns to step S1 again. The initial reference conditions of the offset are as follows: -Δ11-2λ<δ1<Δ12+2λ; -Δ21-2λ<δ2<Δ22+2λ; Among them, -Δ11 is the lower tolerance of the hole spacing in the X direction that needs to be met by the part boring; Δ12 is the upper tolerance of the hole spacing in the X direction that needs to be met by the part boring; -Δ21 is the lower tolerance of the hole spacing in the Z direction that needs to be met by the part boring; Δ22 is the upper tolerance of the hole spacing in the Z direction that needs to be met by the part boring; λ is the difference between the wall thickness of the part boring blank and the minimum allowable wall thickness of the part boring; δ1 is the hole spacing deviation in the X direction; δ2 is the hole spacing deviation in the Z direction.

2. A method for establishing a boring processing benchmark for a welding assembly according to claim 1, characterized in that: In the step S2, the coordinates of the holes to be bored on the part are measured by a three-dimensional coordinate measuring machine.

3. A method for establishing a boring process benchmark for a welding assembly according to claim 2, characterized in that: The hole position coordinates refer to the coordinates of the center of the boring hole.

4. The method for establishing a boring processing benchmark for a welding assembly according to claim 1, characterized in that: In step S3, calculating the hole spacing deviation means first calculating the actual hole spacing between the two bored holes based on the hole position coordinates measured in step S2, and then calculating the hole spacing deviation value δ between the actual hole spacing and the theoretical hole spacing according to the theoretical hole spacing of the two holes.

5. A method for establishing a boring processing benchmark for a welding assembly according to claim 4, characterized in that: When calculating the actual hole spacing between two bores, the two bores are located in the same assembly plane.

6. A method for establishing a boring process benchmark for a welding assembly according to claim 1, characterized in that: The initial benchmark direct processing conditions are as follows: -Δ11-λ<δ1<Δ12+λ; -Δ21-λ<δ2<Δ22+λ; Among them, -Δ11 is the lower tolerance of the hole spacing in the X direction that needs to be met by the part boring; Δ12 is the upper tolerance of the hole spacing in the X direction that needs to be met by the part boring; -Δ21 is the lower tolerance of the hole spacing in the Z direction that needs to be met by the part boring; Δ22 is the upper tolerance of the hole spacing in the Z direction that needs to be met by the part boring; λ is the difference between the wall thickness of the part boring blank and the minimum allowable wall thickness of the part boring; δ1 is the hole spacing deviation in the X direction; δ2 is the hole spacing deviation in the Z direction.

7. A method for establishing a boring process benchmark for a welding assembly according to claim 1, characterized in that: The offset value is obtained by the following calculation expression: Among them, ΔX is the value that the initial datum needs to be offset in the X direction; ΔZ is the value that the initial datum needs to be offset in the Z direction; -Δ11 is the lower tolerance of the hole spacing in the X direction that needs to be met by the part boring; Δ12 is the upper tolerance of the hole spacing in the X direction that needs to be met by the part boring; -Δ21 is the lower tolerance of the hole spacing in the Z direction that needs to be met by the part boring; Δ22 is the upper tolerance of the hole spacing in the Z direction that needs to be met by the part boring; λ is the difference between the wall thickness of the part boring blank and the minimum allowable wall thickness of the part boring; δ1 is the hole spacing deviation in the X direction; δ2 is the hole spacing deviation in the Z direction.

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