CN-121973021-A - Workpiece dynamic locating method and system for machining connecting rod of overhead working truck

CN121973021ACN 121973021 ACN121973021 ACN 121973021ACN-121973021-A

Abstract

The invention relates to the technical field of machine tool machining, in particular to a workpiece dynamic locating method and a system for machining a connecting rod of an overhead working truck, wherein the workpiece dynamic locating method for machining the connecting rod of the overhead working truck comprises the steps of dividing the connecting rod workpiece of the overhead working truck into a plurality of independent local machining areas along the axial direction; the method comprises the steps of obtaining actual space coordinates of a plurality of measuring nodes in each local processing area, determining a deflection-torsion coupling response consistency coefficient of the local processing area, determining an envelope morphology index of the local processing area, determining a compensation factor, and dynamically adjusting a processing tool path in a local coordinate system of the local processing area. According to the method, the connecting rod is divided into a plurality of local processing areas, the compensation factors are determined based on the deflection-torsion coupling response consistency coefficient and the envelope morphology index, and the cutter path is dynamically adjusted in the local coordinate system, so that the self-adaptive compensation of long-span local nonlinear deformation is realized, and the processing rejection rate is reduced.

Inventors

YUE WENCHAO
LI LIAN

Assignees

湖南中钢智能装备有限公司

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (10)

1. A method for dynamically locating a workpiece for machining a connecting rod of an overhead working truck, the method comprising: dividing a connecting rod workpiece of the overhead working truck into a plurality of independent local processing areas along the axial direction; Acquiring actual space coordinates of a plurality of measuring nodes in each local processing area; Determining a deflection-torsion coupling response consistency coefficient of the local processing area based on the deviation of the actual space coordinate and the theoretical coordinate, wherein the deflection-torsion coupling response consistency coefficient is used for quantifying the variation synchronization degree of deflection deformation and torsion deformation in the local processing area; Determining an envelope morphology index of the local processing region based on the spatial offset distribution of each measuring node, wherein the envelope morphology index is used for quantifying the complexity of the spatial deformation in the local processing region; Determining a compensation factor based on the flex-to-torsion coupling response consistency coefficient and the envelope morphology index; And dynamically adjusting a processing tool path in a local coordinate system of the local processing area based on the compensation factors.
2. The method for dynamically locating a workpiece for link machining of an overhead working truck according to claim 1, wherein said determining a flex-to-torsion coupling response consistency factor for the local machining region based on a deviation of the actual spatial coordinates from theoretical coordinates comprises: Determining the flexural deformation characteristic and the torsional deformation characteristic of the local processing area based on the deviation of the actual space coordinate and the theoretical coordinate of each measuring node; and determining a flexural-torsional coupling response consistency coefficient according to the variation trend difference of the flexural deformation characteristic and the torsional deformation characteristic in the local processing area, wherein the smaller the variation trend difference is, the larger the flexural-torsional coupling response consistency coefficient is.
3. The method of dynamically locating a workpiece for machining a link of an overhead working truck according to claim 2, wherein said determining flexural and torsional deformation characteristics of the localized machining region comprises: Determining a cross-region node deflection drift index of the local processing region based on the deviation of the actual space coordinates of the measuring nodes and the theoretical coordinates corresponding to the measuring nodes on the theoretical central axis in the horizontal direction and the vertical direction, wherein the cross-region node deflection drift index is used for quantifying the overall deflection deformation level of the local processing region; And determining the local normal torsional distortion degree of the local processing area based on the difference of the included angles between the actual normal vector and the theoretical normal vector at each measuring node, wherein the local normal torsional distortion degree is used for quantifying the torsional distortion strength of the local processing area.
4. The method for dynamically locating a workpiece for link machining of an overhead working truck according to claim 3, wherein determining the flexural-torsional coupling response consistency coefficient based on the variation trend difference between the flexural deformation characteristic and the torsional deformation characteristic in the local machining region comprises: determining the variation trend difference of the flexural deformation characteristic and the torsional deformation characteristic in the local processing area according to the variation of the flexural deformation characteristic and the torsional deformation characteristic between adjacent measuring nodes in the local processing area; and determining a flexural-torsional coupling response consistency coefficient based on the variation trend difference and the local normal torsional distortion degree.
5. The method for dynamically locating a workpiece for machining a link of an overhead working truck according to claim 1, wherein determining an envelope morphology index of the local machining region based on a spatial offset distribution of each of the measurement nodes comprises: determining the spatial offset amplitude of each measuring node relative to theoretical coordinates; Determining the direction change degree of the space offset vector between adjacent measurement nodes; And determining the envelope morphology index based on the spatial offset amplitude and the direction change degree, wherein the envelope morphology index is larger as the spatial offset amplitude is larger and the direction change degree is larger.
6. The method of dynamic workpiece locating for overhead working truck link machining according to claim 1, wherein said determining a compensation factor based on said flex-to-torsion coupling response consistency coefficient and said envelope morphology index comprises: And determining the compensation factor according to the ratio of the envelope morphology index to the consistency coefficient of the flexural-torsional coupling response, wherein the larger the envelope morphology index is, the smaller the consistency coefficient of the flexural-torsional coupling response is, and the larger the compensation factor is.
7. The method for dynamically locating a workpiece for overhead working truck link machining according to claim 1, wherein said dynamically adjusting a machining tool path in a local coordinate system of the local machining area based on the compensation factor comprises: Determining a compensation amount of each of the measurement nodes based on the compensation factor; smoothing the compensation quantity of the adjacent measuring nodes to generate a continuous cutter path; Based on the continuous tool path, the spatial position of the machining tool is adjusted in real time in a local coordinate system.
8. The method for dynamic locating a workpiece for overhead working truck link machining according to claim 7, further comprising: and establishing a local coordinate system for each local processing area by taking the ideal cross-section center of the local processing area as an origin and the ideal central axis of the local processing area as an axial direction.
9. The method for dynamically locating a workpiece for machining a link of an overhead working truck according to any one of claims 1 to 7, wherein the method for acquiring theoretical coordinates comprises: Obtaining a design model of the connecting rod workpiece; And determining the spatial position of each measuring node in an ideal state based on the design model, and acquiring the theoretical coordinates of the measuring nodes.
10. A work piece developments system of locating for high altitude construction car connecting rod processing, its characterized in that includes the host computer and with host computer communication connection's actual coordinate acquisition device, wherein: The actual coordinate acquisition device is used for acquiring actual space coordinates of a plurality of measurement nodes in each local processing area and transmitting the actual space coordinates to the upper computer; The upper computer is used for dividing a connecting rod workpiece of the overhead working truck into a plurality of independent local machining areas along the axial direction, acquiring actual space coordinates of a plurality of measuring nodes in each local machining area, determining a deflection-torsion coupling response consistency coefficient of the local machining area based on deviation of the actual space coordinates and theoretical coordinates, wherein the deflection-torsion coupling response consistency coefficient is used for quantifying the change synchronization degree of deflection deformation and torsion deformation in the local machining area, determining an envelope morphology index of the local machining area based on the space deviation distribution of each measuring node, wherein the envelope morphology index is used for quantifying the complexity degree of space deformation in the local machining area, determining a compensation factor based on the deflection-torsion coupling response consistency coefficient and the envelope morphology index, and dynamically adjusting a machining tool path in a local coordinate system of the local machining area based on the compensation factor.

Description

Workpiece dynamic locating method and system for machining connecting rod of overhead working truck Technical Field The invention relates to the technical field of machine tool machining, in particular to a workpiece dynamic locating method and system for machining a connecting rod of an overhead working truck. Background The working arm connecting rod system of the overhead working truck is a core bearing and transmission part as key special equipment in the fields of modern engineering construction and municipal maintenance. The connecting rod is a large-scale slender welding structural member generally, and extremely high parallelism, coaxiality and hole center distance precision among a plurality of hinge holes need to be ensured in the machining process so as to ensure lifting stability and operation safety of the whole machine. In precision machining processes such as boring and milling of a connecting rod, a trigger type measuring head is generally adopted to perform touch detection on a workpiece reference surface and a hinge hole, a machine tool coordinate system is established based on detection data, and a tool path is generated, so that the determination and the guide of the spatial position of the workpiece are realized. However, the prior art generally calculates a single global coordinate offset based on the measurement data of a few key fiducials and directs the entire long-stroke machining process in this global coordinate system. Because the connecting rod is used as an elongated welding piece and has welding residual stress and dead weight sagging, partial bending and distortion deformation which are unevenly distributed along the length direction can be inevitably generated, and the deformation forms of the head part, the middle part and the tail part of the connecting rod are different. When the machine tool utilizes the extended stroke to carry out long-span processing, the single global coordinate compensation based on the whole averaging cannot give consideration to different deformation states of each local area, so that the center of the cutter and the actual center of the local blank are seriously misplaced, the machining allowance is extremely uneven, and finally, the parallelism and the coaxiality between connecting rod hole systems are difficult to ensure, and the rejection rate of products is increased. Disclosure of Invention The invention provides a workpiece dynamic locating method and system for machining a connecting rod of an overhead working truck, which are used for solving the existing problems. The invention discloses a workpiece dynamic locating method and a system for processing a connecting rod of an overhead working truck, which adopt the following technical scheme: According to the first aspect, the application provides a workpiece dynamic locating method for machining a connecting rod of an overhead working truck, which comprises the steps of dividing the workpiece of the overhead working truck into a plurality of independent local machining areas along the axial direction, obtaining actual space coordinates of a plurality of measuring nodes in each local machining area, determining a deflection-torsion coupling response consistency coefficient of the local machining area based on deviation of the actual space coordinates and theoretical coordinates, wherein the deflection-torsion coupling response consistency coefficient is used for quantifying the change synchronization degree of deflection deformation and torsion deformation in the local machining area, determining an envelope morphology index of the local machining area based on the space deviation distribution of each measuring node, wherein the envelope morphology index is used for quantifying the complexity degree of the space deformation in the local machining area, determining a compensation factor based on the deflection-torsion coupling response consistency coefficient and the envelope morphology index, and dynamically adjusting a machining tool path in a local coordinate system of the local machining area based on the compensation factor. Further, the method for determining the consistency coefficient of the flexural-torsional coupling response of the local processing area based on the deviation of the actual space coordinates and the theoretical coordinates comprises the steps of determining the flexural deformation characteristic and the torsional deformation characteristic of the local processing area based on the deviation of the actual space coordinates and the theoretical coordinates of each measuring node, and determining the consistency coefficient of the flexural-torsional coupling response according to the variation trend difference of the flexural deformation characteristic and the torsional deformation characteristic in the local processing area, wherein the smaller the variation trend difference is, the larger the consistency coefficient of the flexural-torsional coupling response is. F