CN104526462A - Two-time clamping machining workpiece benchmark coincidence method - Google Patents

Abstract

A two-time clamping machining workpiece benchmark coincidence method includes the steps of selecting a straight line as a probe benchmark line in the workpiece machining sensitive direction; selecting two end points in the probe benchmark line as probe points; probing the two points with a probe to obtain actual coordinate values of the two points; building a right triangle through the two s probe points; calculating a workpiece deviation rotation angle in the built right triangle; compensating the deviation rotation angle to an original coordinate system to enable a new coordinate system to be consistent with the actual position of a workpiece. The two-time clamping machining workpiece benchmark coincidence method performs probe probing and calculation on the rotation angle deviation appearing in two-time clamping of the workpiece through a numerical control machining tool, completely coincides the secondary clamping machining coordinate system with an actual state of the workpiece through a numerical control machining program angle compensation method, solves the problem of the rotation angle deviation of the two-time clamping of the workpiece, is suitable for solving the technical problem that the positioning benchmark of the same workpiece can not be unified in the two-time forward and backward clamping, obtains the unified height of the benchmark of the two-time forward and backward clamping machining, achieves significant application results of the two-time forward and backward machining of workpieces, such as end walls of rail vehicles and floors, improves the machining accuracy of the workpiece from the manufacturing source and ensures the machining quality of the workpiece.

Description

A kind of datum coincidence method of twice clamping processing work

Technical field

The present invention discloses a kind of method ensureing twice clamping datum coincidence in process, belongs to machinery manufacturing technology field.

Background technology

When workpiece needs twice clamping to add man-hour, due to second time clamping be difficult to ensure and first time clamping state completely the same, so the machining benchmark of twice is difficult to overlap, and then cause machining accuracy to decline.After deliberation, the deviation of twice clamping generally occurs with the form of straight line variation and corner deviation.The traditional compensation method of straight line variation can be resolved, but does not up to the present also have a kind of effective solution for corner deviation.

Summary of the invention

The object of this invention is to provide a kind of method of benchmark centering, during solution secondary clamping, theoretical position and physical location corner deviation are on the impact of machining accuracy.

For achieving the above object, the invention provides a kind of datum coincidence method of twice clamping processing work, it is characterized in that comprising the following steps:

(1) on workpiece, a straight line is chosen as detection datum line;

(2) on detection datum line, two-end-point is chosen as sensing point;

(3) detect at 2 with probe and obtain this actual coordinate value of 2;

(4) by two sensing point structure right angled triangles;

(5) in the right angled triangle of structure, the workpiece deviation anglec of rotation is calculated;

(6) deviation corner is compensated in former coordinate system, make new coordinate system consistent with workpiece physical location.

The inventive method is that the corner deviation occurred workpiece twice clamping utilizes numerical control machine tool to carry out probe detection calculating, by nc program angle compensation process, Cutter coordinate system during secondary clamping is overlapped completely with the virtual condition of workpiece, solve the corner offset issue of workpiece twice clamping, be applicable to the technical problem that the positive and negative twice Set and Positioning benchmark of same workpiece can not be unified, make positive and negative twice clamping machining benchmark high unity, as at end wall of railway vehicle, positive and negative twice processing of the parts such as floor achieves significant effect, the machining accuracy of workpiece is improved from manufacture source, ensure that the crudy of workpiece.

Accompanying drawing explanation

Fig. 1 is the step schematic diagram choosing detection datum line;

Fig. 2 is the step schematic diagram choosing sensing point;

Fig. 3 is new and old coordinate system schematic diagram after rotating by the angle of deviation.

Detailed description of the invention

(1) with reference to Fig. 1, when second time clamping there is a deviation corner with theoretical position (dotted line frame) in the physical location (solid box) of workpiece, and this angle is the principal element causing mismachining tolerance.Workpiece is chosen AB line as detection datum line;

(2) on detection datum line AB, choose A and B as sensing point, the effect of these two points is for subsequent calculations deviation corner provides data.The distance of two points will be separated by far as far as possible, can improve the degree of accuracy of the corner deviate calculated like this;

(3) detection of lathe probe is used to obtain the actual coordinate value of AB 2, A point coordinates (X1, Y1), B point coordinates (X2, Y2);

(4) with reference to Fig. 2, cross A point and do the straight line parallel with X-axis, cross B point and do the straight line parallel with Y-axis, with the intersection point of A, B 2 and two straight lines structure right angled triangle ABC, A, B are two sensing points, and C is intersection point;

(5) in the triangle ABC of structure, obtain AC=X1-X2, BC=Y2-Y1, then included angle A BC is exactly required deviation corner, application trigonometric function can calculate angle ∠ ABC=arctan (AC/BC), wherein BC is the known distance that programming personnel chooses, and AC is exactly the actual deviation value between A, B 2 detected;

(6) with reference to Fig. 3, by numerical control program, original coordinate system XY is carried out angle rotation, the anglec of rotation is exactly the misalignment angle ∠ ABC calculated in (5) step, new Cutter coordinate system X'Y' is obtained after rotating, ensure new coordinate system X'Y' and workpiece virtual condition completely the same, as long as programming just can meet figure paper size accurately under this postrotational new coordinate system during secondary operations, eliminate corner deviation to the impact of machining accuracy.

Claims (1)

1. a datum coincidence method for twice clamping processing work, is characterized in that comprising the following steps:

(1) on workpiece, a straight line is chosen as detection datum line;

(2) on detection datum line, two-end-point is chosen as sensing point;

(3) detect at 2 with probe and obtain this actual coordinate value of 2;

(4) by two sensing point structure right angled triangles;

(5) in the right angled triangle of structure, the workpiece deviation anglec of rotation is calculated;

(6) deviation corner is compensated in former coordinate system, make new coordinate system consistent with workpiece physical location.