Radial runout detection method based on pitch measurement in on-machine measurement process of gear

Abstract

The invention discloses a gear radial runout detection method based on pitch measurement, and the method comprises the steps: employing an on-machine measurement function of a numerical control machine tool, and measuring a point at a pitch circle of each tooth groove of a gear through a triggering type measuring head, so as to obtain an initial data value; when the radial jump is calculated, a calibration hypothetical ball is constructed, and the hypothetical ball and the contact of the tooth surfaces on the two sides are ensured to be located on a pitch circle. The involutes on the two sides of the tooth groove are oppositely rotated around the circle center of the gear by the angle beta till the involutes intersect, the intersection point position of the two involutes is solved through homogeneous coordinate transformation according to the geometrical relationship, and then the inner diameter jump value of one tooth groove is determined. The diameter of the hypothetical sphere needs to be calculated in advance according to the principle that the calibrated hypothetical sphere and the gear tooth groove contact are consistent with the detection point, a hypothetical sphere model is established, and more comprehensive and visual information of gear radial runout can be obtained through establishment of the hypothetical sphere model. The numerical value of the radial runout of each tooth groove is directly obtained through a solving equation, the model and rounding errors caused by a traditional modeling and calculation method are avoided, and the obtained radial runout value is more accurate and reliable.

Description

technical field [0001] The invention belongs to the technical field of parts processing quality detection, and in particular relates to a radial jump detection method based on tooth pitch measurement in a gear on-machine measurement process. Background technique [0002] Radial runout is a must-check item in the error detection of rotating moving parts. There are many reasons for the radial runout error of the gear ring, the most important one comes from the geometric eccentricity, that is, the coaxiality error caused by the gap between the shaft hole of the gear blank and the mandrel of the fixture. In the actual production process, if the production batch is small, a small clearance fit (gear hole and mandrel) can be used; if the batch is large, the sleeve-type centering method is mostly used to eliminate the gap. These methods can only reduce the tooth jump to a certain extent, but cannot completely avoid it. In addition, radial runout is also an important index for eva...

AI Technical Summary

Problems solved by technology

[0006] At present, in the on-machine detection gear error project, the calculation method for the radial runout is generally to calculate the gear eccentricity e through the cumulative error of the tooth pitch, and use 2e to approximately replace the radial runout value Fr, or use the extreme difference of a single pitch error value for calculation , the radial runout value determined by these methods often has a large deviation from the actual value, and cannot accurately reflect the change rule of the radial runout, the phase relationship between the maximum radial runout and the minimum radial runout, which affects the accuracy of the gear accuracy evaluation and the guide gear The reliability of the correction; secondly, simply use the triangular relationship to calculate through the imaginary sphere, there are certain errors in mathematical modeling and calculation, which reduces the measurement accuracy

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