Motion parameter conversion method for three-dimensional free bending forming equipment

Abstract

The invention discloses a three-dimensional free bending forming equipment mold motion parameter conversion method. The method comprises the steps that a pipe axis space outline composed of a plurality of forming sections is established according to a bent pipe standard data format YBC and R; equivalently constructing a free bending motion structure based on the pipe axis space contour; in the bending forming process, according to free bending motion structure data, forming section data are sequentially analyzed into a bending die eccentric distance U, a motion direction D and a feeding mechanism propelling distance L; and three-dimensional free bending die space pose conversion is carried out, and XYZ servo motion parameters of three-dimensional free bending equipment are obtained. According to the method, the axis coordinate data YBC of the traditional numerical control bending equipment and the axis coordinate data XYZ of the three-dimensional free bending equipment are mutually converted, so that the operation universality of the three-dimensional free bending forming equipment is improved to a certain extent; the method is suitable for quantitative and accurate compensation in three-dimensional free bending forming equipment software after bent pipe detection equipment measures a bent pipe component to obtain error data.

Description

Technical Field

[0001] The present invention belongs to the technical field of advanced manufacturing of complex metal components, and in particular relates to a motion parameter conversion method for three-dimensional free bending forming equipment. Background Art

[0002] Bending parts with complex spatial configurations are widely used in aerospace, nuclear energy, new energy vehicles and other fields. In the aerospace field, metal conduits are key components for transporting fluids such as fuel, hydraulic oil, and gas, and usually need to meet extremely high performance standards. Compared with traditional forming processes, the advantage of three-dimensional free bending forming technology is that it can achieve integrated flexible forming of pipes and profiles with complex spatial axes. Due to the lack of traditional customized molds, the forming accuracy cannot reach the level of traditional forming technology, and it is difficult to accurately form the axis shape in one go. It is necessary to use a three-dimensional scanner to analyze the forming accuracy error of the formed component. The output result of the three-dimensional scanner is the standard data format YBC and R for bent pipes. A conversion method is needed to quantitatively convert the output result of the scanner into motion parameters that can be recognized by the three-dimensional free bending forming equipment to improve the efficiency of component contour accuracy correction. Summary of the Invention

[0003] The present invention addresses the deficiencies in the background technology and proposes a method for converting motion parameters of three-dimensional free bending forming equipment, thereby realizing rapid conversion of data formats in three-dimensional free bending and precision compensation of curved pipe components.

[0004] The present invention adopts the following technical solutions:

[0005] A method for converting motion parameters of three-dimensional free-form bending equipment comprises the following steps:

[0006] Step 1: Before bending, first establish the pipe axis profile of several forming segments (each forming segment consists of a straight line segment and an arc segment) based on the YBC and R parameters of the bent pipe;

[0007] Step 2: Equivalently construct a three-dimensional free-bending motion structure;

[0008] Step 3: Calculate the bending die eccentricity distance U, movement direction D and feeding mechanism advancement distance L in sequence according to each section of forming data;

[0009] Step 4: Convert the three-dimensional free bending motion parameter UDL into a spatial pose to obtain the XYZ servo motion parameters of the three-dimensional free bending device.

[0010] The method of establishing a plurality of forming segments (each forming segment is composed of a straight line segment and an arc segment) of the pipe axis profile based on YBC and R means that the bent pipe component is divided into n forming segments in sequence according to the geometric parameters formed by the YBC and R of the bent pipe, each forming segment is denoted as i (forming segment i is composed of a straight line segment and an arc segment), and is numbered in sequence: i.e., i=1, 2, 3...n, and the spatial posture of each forming segment is reconstructed in three-dimensional space to form the pipe axis profile.

[0011] The said construction of a free bending motion structure by equivalently using the spatial contour of the pipe axis means: the lengths of the straight segments and arc segments in the pipe axis are equivalent to the feeding mechanism in the three-dimensional free bending motion structure, and the radius and spatial direction of the arc segments in the pipe axis are equivalent to the bending mold mechanism in the three-dimensional free bending motion structure.

[0012] The conversion correspondence between the bending die eccentricity distance U, the movement direction D and the feeding mechanism advancement distance L of the forming segment data is analyzed in sequence according to the free bending motion structure data, including:

[0013] Step 3a) converting the radius value of the i-th forming segment (straight line segment and arc segment) into the forming segment data, which can be equivalently converted into the eccentric distance U of the bending die according to the UR relationship data formula of the three-dimensional free bending forming equipment;

[0014] U i =0

[0015]

[0016] Among them, U i is the eccentricity of the bending die of the straight segment in the i-th forming segment, R i 、U i ′ is the radius of the arc segment in the i-th forming segment and the corresponding eccentricity of the bending die, and A is the horizontal distance between the center of the bending die of the three-dimensional free bending forming equipment and the center of the front end of the guide mechanism.

[0017] Step 3b) The straight line segment length in the i-th forming segment (straight line segment and arc segment) converted into the forming segment data can be equivalently converted into the advancing distance L of the feeding mechanism in the three-dimensional free bending forming equipment;

[0018] L i =Y i

[0019] Among them, Y i 、L i is the linear feeding length of the straight segment in the i-th forming segment and the corresponding advancement distance of the feeding mechanism of the three-dimensional free bending forming equipment.

[0020] Step 3c) converting the arc segment direction value in the i-th forming segment (straight line segment and arc segment) into the shape segment data can be equivalently converted into the spatial direction angle D of the bending die rotation in the three-dimensional free bending forming equipment;

[0021] D i =0

[0022]

[0023] Among them, D i is the rotational spatial direction angle of the bending die of the straight segment in the i-th forming segment, B i 、D i ′ is the spatial rotation angle of the arc segment in the i-th forming segment and the corresponding spatial direction angle of the bending die rotation.

[0024] Step 3d) converts the arc segment angle value in the i-th forming segment (straight line segment and arc segment) into the forming segment data, which can be equivalently converted into the feeding mechanism advancement distance L and the bending die eccentricity distance U in the three-dimensional free bending forming equipment.

[0025]

[0026] Among them, R i 、C i 、L i ′ is the arc segment radius, arc segment angle and the advancement distance of the feeding mechanism of the three-dimensional free bending forming equipment in the i-th forming segment.

[0027] The three-dimensional free bending motion parameter UDL is converted into a spatial posture to obtain the XYZ servo motion parameter of the three-dimensional free bending device. The conversion relationship of the first forming section is:

[0028] X1=X1′=0

[0029] Y1=Y1′=0

[0030] Z1=0

[0031] Z1′=L1

[0032] X1″=X1″′=U1′cosD1′

[0033] Y1″=Y1″′=U1′sinD1′

[0034]

[0035] Z1″′=L1+L1′

[0036] Among them, X1, X1′, Y1, Y1′, Z1, and Z1′ are the absolute positioning positions of the XYZ-axis servo motors of the three-dimensional free bending forming equipment corresponding to the transition section and stable section of the straight line segment in the first forming section, and X1″, X1″′, Y1″, Y1″′, Z1″, and Z1″′ are the absolute positioning positions of the XYZ-axis servo motors of the three-dimensional free bending forming equipment corresponding to the transition section and stable section of the arc segment in the first forming section.

[0037] The three-dimensional free bending motion parameter UDL is converted into a spatial posture to obtain the XYZ servo motion parameter of the three-dimensional free bending device. The conversion relationship of the i-th forming segment (i>1) is:

[0038] X i =X i ′=0

[0039] Y i =Y i ′=0

[0040]

[0041] X i ″=X i ″′=U i ′cosD i '

[0042] Y i ″=Y i ″′=U i ′sinD i '

[0043]

[0044] Among them, V m 、V p The moving speed of the bending die and the advancing speed of the feeding mechanism for 3D free bending forming equipment; X i 、X i ′、Y i 、Y i ′、Z i , Z i ′ are the absolute positioning positions of the XYZ axis servo motors of the three-dimensional free bending forming equipment corresponding to the transition section and the stable section of the straight line segment in the i-th forming segment, respectively. i ″、X i ″′、Y i ″、Y i ″′、Z i ″、Z i ″′ are the absolute positioning positions of the XYZ axis servo motors of the three-dimensional free bending forming equipment corresponding to the transition section and the stable section of the arc segment in the i-th forming section.

[0045] The present invention has the following beneficial effects:

[0046] First, the calculation conversion method of the present invention is simple and feasible, and can directly connect the processing parameters of CNC bending equipment and the detection feedback parameters of three-dimensional scanning equipment, providing a theoretical numerical basis for optimizing the processing contour accuracy of three-dimensional free bending forming equipment.

[0047] Second, the present invention can realize the indiscriminate conversion of traditional CNC bending processing data and three-dimensional free bending processing data, expand the flexibility of pipe processing technology selection, and solve the difficult problem of how to determine the bending die movement direction, offset distance and rotation angle according to the pipe axis profile. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a flow chart of the present invention;

[0049] Figure 2 Schematic diagram of the conversion between the YBCR parameters of the curved member and the pipe axis profile in the present invention;

[0050] Figure 3 Schematic diagram of the three-dimensional free bending forming equipment structure of the present invention;

[0051] Figure 4 Schematic diagram of the three-dimensional free bending forming equipment of the present invention; DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] like Figure 1 The figure shows a flow chart of the motion parameter conversion method of three-dimensional free bending forming equipment, the main steps of which include:

[0054] (1) Before bending, the bent pipe component is divided into n forming segments (consisting of straight line segments and arc segments) according to the geometric parameters of the bent pipe YBC and R. The segments are numbered in sequence: i = 1, 2, 3...n. The spatial position of each forming segment is reconstructed in three-dimensional space and combined into the pipe axis profile. The division result is as follows: Figure 2 shown.

[0055] (2) The composition of the three-dimensional free bending forming equipment is as follows Figure 3 As shown, the lengths of the straight segments and arc segments in the spatial contour of the tube axis are equivalent to the feeding mechanism in the three-dimensional free bending motion structure, and the radius and spatial direction of the arc segment in the tube axis are equivalent to the bending mold mechanism in the three-dimensional free bending motion structure.

[0056] (3) The forming section data is successively parsed into the bending die eccentricity distance U, the movement direction D, and the feeding mechanism advancement distance L.

[0057] (3a) The radius value of the i-th forming segment (straight line segment and arc segment) in the converted forming segment data is calculated based on the fitting formula of the eccentric distance U and the bending radius R of the bending die of the three-dimensional free bending forming equipment to calculate the eccentric distance value required for the current forming radius;

[0058] U i =0

[0059]

[0060] Among them, such as Figure 4 As shown, U i is the eccentricity of the bending die of the straight line segment in the i-th forming segment. When forming a straight line, the bending die does not deflect and is in the initial state. R i 、U i ′ is the radius of the arc segment in the i-th forming segment and the corresponding eccentricity of the bending die, and A is the horizontal distance between the center of the bending die of the three-dimensional free bending forming equipment and the center of the front end of the guide mechanism.

[0061] (3b) The length of the straight line segment in the i-th forming segment (straight line segment and arc segment) converted into forming segment data is based on the forming principle of three-dimensional free bending forming equipment. The straight line segment length Y is equivalent to the feeding mechanism advancement distance L;

[0062] L i =Y i

[0063] (3c) The arc segment direction value in the i-th forming segment (straight line segment and arc segment) of the forming segment data is converted. According to the forming principle of the three-dimensional free bending forming equipment, the arc segment direction space angle is based on the deflection angle of the arc surface of the previous forming segment. The angle increment value is converted into the absolute angle D in the bending module space of the three-dimensional free bending forming equipment;

[0064] D i =0

[0065]

[0066] Among them, D i is the rotational spatial direction angle of the bending die of the straight segment in the i-th forming segment. The bending die of the straight segment does not need to be rotated. B i 、D i ′ is the spatial rotation angle of the arc segment in the i-th forming segment and the corresponding spatial direction angle of the bending die rotation.

[0067] (3d) The arc segment angle value in the i-th forming segment (straight line segment and arc segment) of the converted forming segment data is based on the forming principle of three-dimensional free bending forming equipment. The feeding mechanism advancement distance L determines the arc segment arc length value, and the bending die eccentric distance U determines the arc segment radius value.

[0068]

[0069] Among them, R i 、C i 、L i ′ is the arc segment radius, arc segment angle and the advancement distance of the feeding mechanism of the three-dimensional free bending forming equipment in the i-th forming segment.

[0070] (4) The three-dimensional free bending motion parameters (UDL) are converted into spatial poses to obtain the XYZ servo motion parameters of the three-dimensional free bending device. The free bending process of the forming segment (straight line segment and arc segment) consists of a transition segment and a stable segment. During the conversion, one line of forming segment data will be converted into four lines of XYZ servo motion data consisting of a straight line transition segment, a straight line stable segment, an arc transition segment, and an arc stable segment.

[0071] The conversion relationship of the first forming section is:

[0072] X1=X1′=0

[0073] Y1=Y1′=0

[0074] Z1=0

[0075] Z1′=L1

[0076] X1″=X1″′=U1′cosD1′

[0077] Y1″=Y1″′=U1′sinD1′

[0078]

[0079] Z1″′=L1+L1′

[0080] Among them, X1, X1′, Y1, Y1′, Z1, and Z1′ are the absolute positioning positions of the XYZ-axis servo motors of the three-dimensional free bending forming equipment corresponding to the transition section and stable section of the straight line segment in the first forming section, and X1″, X1″′, Y1″, Y1″′, Z1″, and Z1″′ are the absolute positioning positions of the XYZ-axis servo motors of the three-dimensional free bending forming equipment corresponding to the transition section and stable section of the arc segment in the first forming section.

[0081] The conversion relationship of the i-th forming segment (i>1) is:

[0082] X i =X i ′=0

[0083] Y i =Y i ′=0

[0084]

[0085] X i ″=X i ″′=U i ′cosD i '

[0086] Y i ″=Y i ″′=U i ′sinD i '

[0087]

[0088] Among them, V m 、V p The moving speed of the bending die and the advancing speed of the feeding mechanism for 3D free bending forming equipment; X i 、X i ′、Y i 、Y i ′、Z i , Z i ′ are the absolute positioning positions of the XYZ axis servo motors of the three-dimensional free bending forming equipment corresponding to the transition section and the stable section of the straight line segment in the i-th forming segment, respectively. i ″、X i ″′、Y i ″、Y i ″′、Z i ″、Z i ″′ are the absolute positioning positions of the XYZ axis servo motors of the three-dimensional free bending forming equipment corresponding to the transition section and the stable section of the arc segment in the i-th forming section.

[0089] It should be understood that for ordinary technicians in this field, improvements or modifications can be made based on the above description without departing from the spirit and scope of this application. If these modifications and variations of this application fall within the scope of this application and its equivalent technology, this application is also intended to include these modifications and variations.

Claims

1. A method for converting motion parameters of a three-dimensional free-form bending equipment mold, characterized in that: The following steps are involved: Step 1: Before bending, first establish several forming segments based on the YBC and R parameters of the elbow. Each forming segment consists of a straight line segment and an arc segment to define the axis profile of the pipe. Step 2: Equivalently construct a three-dimensional free-bending motion structure; Step 3: Calculate the bending die eccentricity distance U, movement direction D and feeding mechanism advancement distance L in sequence according to each section of forming data; Step 4: Convert the three-dimensional free bending motion parameter UDL into a spatial pose to obtain the XYZ servo motion parameters of the three-dimensional free bending device.

2. The method for converting motion parameters of a mold of a three-dimensional free bending forming equipment according to claim 1, characterized in that: The method of establishing a plurality of forming segments based on YBC and R, wherein each forming segment is composed of a straight line segment and an arc segment, and the pipe axis profile is as follows: dividing the bent pipe component into n forming segments in sequence according to the geometric parameters formed by YBC and R of the bent pipe, wherein each forming segment is denoted as i, and the forming segment i is composed of a straight line segment and an arc segment, and is numbered in sequence: i.e., i=1, 2, 3...n, and reconstructing the spatial posture of each forming segment in three-dimensional space to form the pipe axis profile.

3. The method for converting motion parameters of a mold of a three-dimensional free-form bending forming equipment according to claim 1, characterized in that: The said construction of a free bending motion structure by equivalently using the spatial contour of the pipe axis means: the lengths of the straight segments and arc segments in the pipe axis are equivalent to the feeding mechanism in the three-dimensional free bending motion structure, and the radius and spatial direction of the arc segments in the pipe axis are equivalent to the bending mold mechanism in the three-dimensional free bending motion structure.

4. The method for converting motion parameters of a three-dimensional free-form bending equipment mold according to claim 1, characterized in that: The conversion correspondence between the bending die eccentricity distance U, the movement direction D and the feeding mechanism advancement distance L of the forming segment data is analyzed in sequence according to the free bending motion structure data, including: Step 3a) converting the radius value of the i-th forming segment into the forming segment data, which can be equivalently converted into the eccentric distance U of the bending die according to the UR relationship data formula of the three-dimensional free bending forming equipment; U i ＝0 Among them, U i is the eccentricity of the bending die of the straight segment in the i-th forming segment, R i 、U i ′ is the radius of the arc segment in the i-th forming segment and the corresponding eccentricity of the bending die, A is the horizontal distance between the center of the bending die of the three-dimensional free bending forming equipment and the center of the front end of the guide mechanism; Step 3b) Converting the straight line length in the i-th forming segment into the forming segment data can be equivalently converted into the advancing distance L of the feeding mechanism in the three-dimensional free bending forming equipment; L i =Y i Among them, Y i 、L i is the linear feeding length of the straight segment in the i-th forming segment and the corresponding advancement distance of the feeding mechanism of the three-dimensional free bending forming equipment; Step 3c) converting the arc segment direction value in the i-th forming segment into the shape segment data can be equivalently converted into the spatial direction angle D of the bending die rotation in the three-dimensional free bending forming equipment; D i ＝0 Among them, D i is the rotational spatial direction angle of the bending die of the straight segment in the i-th forming segment, B i 、D i ′ is the spatial rotation angle of the arc segment in the i-th forming segment and the corresponding spatial direction angle of the bending die rotation; Step 3d) converting the arc segment angle value in the i-th forming segment into the forming segment data can be equivalently converted into the feeding mechanism advancement distance L and the bending die eccentricity distance U in the three-dimensional free bending forming equipment; Among them, R i 、C i 、L i ′ is the arc segment radius, arc segment angle and the advancement distance of the feeding mechanism of the three-dimensional free bending forming equipment in the i-th forming segment.

5. The method for converting motion parameters of a three-dimensional free-form bending equipment mold according to claim 1, characterized in that: The three-dimensional free bending motion parameter UDL is converted into a spatial posture to obtain the XYZ servo motion parameter of the three-dimensional free bending device. The conversion relationship of the first forming section is: X1=X1′=0 Y1=Y1′=0 Z1＝0 Z1′=L1 X1″=X1″′=U1′cosD1′ Y1″=Y1″′=U1′sinD1′ Z1″′=L1+L1′ Among them, X1, X1′, Y1, Y1′, Z1, and Z1′ are the absolute positioning positions of the XYZ-axis servo motors of the three-dimensional free bending forming equipment corresponding to the transition section and stable section of the straight line segment in the first forming section, and X1″, X1″′, Y1″, Y1″′, Z1″, and Z1″′ are the absolute positioning positions of the XYZ-axis servo motors of the three-dimensional free bending forming equipment corresponding to the transition section and stable section of the arc segment in the first forming section.

6. The method for converting motion parameters of a three-dimensional free-form bending equipment mold according to claim 1, characterized in that: The three-dimensional free bending motion parameter UDL is converted into a spatial posture to obtain the XYZ servo motion parameter of the three-dimensional free bending device. For the i-th forming segment, i>1, the conversion relationship is: X i =X i ′=0 AND i =And i ′=0 X i ″=X i ″′=U i ′cosD i ′ AND i "And i "U" i ′withoutD i ′ Among them, V m 、V p The moving speed of the bending die and the advancing speed of the feeding mechanism for 3D free bending forming equipment; X i 、X i ′、Y i 、Y i ′、Z i 、Z i ′ are the absolute positioning positions of the XYZ axis servo motors of the three-dimensional free bending forming equipment corresponding to the transition section and the stable section of the straight line segment in the i-th forming segment, respectively. i ″、X i ″′、Y i ″、Y i ″′、Z i ″、Z i ″′ are the absolute positioning positions of the XYZ axis servo motors of the three-dimensional free bending forming equipment corresponding to the transition section and the stable section of the arc segment in the i-th forming section.

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