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CN-122007983-A - Five-degree-of-freedom geometric error automatic measurement device and method for machine tool turntable

CN122007983ACN 122007983 ACN122007983 ACN 122007983ACN-122007983-A

Abstract

The invention discloses an automatic five-degree-of-freedom geometric error measuring device for a machine tool turntable, which comprises an upper computer, a bracket, a measuring core rod, a handle, a standard ball and five displacement sensors, wherein the standard ball is fixed at the upper end of the measuring core rod, the measuring core rod is selectively arranged at the central axis of the machine tool turntable, the handle is arranged at the mounting position of the handle of a spindle of the machine tool, the bracket is fixed outside the handle, one displacement sensor is vertically arranged, the measuring end of the one displacement sensor is contacted with the standard ball, the other four displacement sensors are divided into two pairs, each pair is vertically arranged, the measuring end of one pair is contacted with the measuring core rod in the X direction, the measuring end of the other pair is contacted with the measuring core rod in the Z direction, and the five displacement sensors are connected to the upper computer through a sensor amplifier and a communication unit. The invention solves the problems that the prior art cannot rapidly measure the error of the turntable of the machine tool and the numerical control machine tool is required to be manually operated for a plurality of times in the measuring process.

Inventors

  • LIANG YAO
  • TAO TAO
  • MEI XUESONG
  • MA WEIGUANG
  • JIN LIBO

Assignees

  • 西安交通大学
  • 通用技术集团机床工程研究院有限公司

Dates

Publication Date
20260512
Application Date
20251205

Claims (9)

  1. 1. The five-degree-of-freedom geometrical error automatic measuring device for the machine tool turntable is characterized by comprising an upper computer, a bracket, a measuring core rod, a handle, a standard ball and five displacement sensors, wherein the standard ball is fixed at the upper end of the measuring core rod, the measuring core rod is selectively arranged at the central axis of the machine tool turntable, the handle is arranged at the mounting position of the handle of a spindle of the machine tool, the bracket is fixed outside the handle, one displacement sensor is vertically arranged, the measuring end of the one displacement sensor is contacted with the standard ball, the other four displacement sensors are divided into two pairs, each pair is vertically arranged, the measuring end of one pair is contacted with the measuring core rod in the X direction, the measuring end of the other pair is contacted with the measuring core rod in the Z direction, and the five displacement sensors are electrically connected to the upper computer through a sensor amplifier and a communication unit.
  2. 2. The automatic five-degree-of-freedom geometric error measuring device for a turntable of a machine tool according to claim 1, wherein a pressing plate (6) is arranged at the lower end of the measuring core rod (3), and the pressing plate (6) is fixedly connected with the turntable of the machine tool.
  3. 3. The automatic five-degree-of-freedom geometrical error measuring device for a turntable of a machine tool according to claim 2, characterized in that the pressing plate (6) is fixedly connected with a T-shaped groove in the turntable by means of a T-shaped nut.
  4. 4. The automatic five-degree-of-freedom geometric error measuring device for a turntable of a machine tool according to claim 3, wherein the bracket (2) comprises a spindle end connector (201) and a sensor mounting fixture (203), the spindle end connector (201) is fixedly connected with the tool shank (7), the sensor mounting fixture (203) is fixed below the spindle end connector (201), and five displacement sensors are mounted on the sensor mounting fixture (203).
  5. 5. The automatic five-degree-of-freedom geometrical error measuring device for a turret of a machine tool according to claim 4, characterized in that the support (2) further comprises a stiffener (202), the stiffener (202) being fixed between the spindle end connector (201) and the sensor mounting clamp (203).
  6. 6. The five-degree-of-freedom automatic geometric error measuring device for a turntable of a machine tool according to claim 5, wherein the displacement sensor is fixed to a sensor mounting jig (203) by a collet.
  7. 7. The automatic five-degree-of-freedom geometric error measuring device for a turntable of a machine tool according to claim 6, further comprising a numerical control system (7), wherein the numerical control system (7) is connected with the machine tool and the upper computer (1).
  8. 8. The automatic five-degree-of-freedom geometric error measuring method for the machine tool turntable is realized based on the automatic five-degree-of-freedom geometric error measuring device for the machine tool turntable according to any one of claims 1 to 7 and is characterized by comprising the steps of installing a measuring core rod through end face contact with a center hole of the turntable, ensuring that the rotation axis of the core rod is coaxial with the rotation axis of the turntable, measuring runout values of five positions of the core rod by using five sensors, and then analyzing five-degree-of-freedom errors of the turntable except for rotation positioning errors according to measured data.
  9. 9. The automatic five-degree-of-freedom geometric error measurement method for a turntable of a machine tool according to claim 8, characterized by specifically comprising the following steps: The following five-degree-of-freedom geometric errors of the B-axis turntable are analyzed according to real-time data of the five displacement sensors, and the method specifically comprises radial runout EXB of the B-axis turntable in the X direction, radial runout EZB of the B-axis turntable in the Z direction, axial runout EYB of the B-axis turntable in the Y direction, inclination error ECB of the B-axis turntable around the Z axis and inclination error EAB of the B-axis turntable around the X axis, and comprises the following steps of: The five displacement sensors are respectively marked as an x 4 displacement sensor, an x 5 displacement sensor, a y 8 displacement sensor, a z 10 displacement sensor and a z 11 displacement sensor, and the corresponding acquired data are respectively marked as x 4 (θ)、x 5 (θ)、y 8 (θ)、z 10 (θ)、z 11 (theta), wherein the jump values of the x 4 displacement sensor, the x 5 displacement sensor, the z 10 displacement sensor and the z 11 displacement sensor on the mandrel are measured, the display numerical values comprise eccentric installation errors e (theta), radial jump errors, mandrel roundness errors R and jump errors caused by mandrel inclination errors of the mandrel, the y 8 displacement sensor is used for measuring the jump values of the mandrel of the turntable, and the display numerical values are axial jump errors; Since the displacement sensor readings include five geometric errors of the rotation axis, namely EXB, EYB, EYZ, EAB and ECB, and the mounting position errors XOB and ZOB of the core rod; when the EBB is zero and the mandrel rotation axis is coaxial with the turntable rotation axis, the calculation formula of the sensor data is as follows: Wherein, the Respectively X, Z direction eccentric installation errors, e is the module length of the installation error vector, In order to install the initial angle of the error, The measuring core rod and the central hole of the rotary table ensure that the axis of the core rod is perpendicular to the plane of the rotary table through end surface matching, namely that the axis of the measuring core rod is parallel to the axis of the rotary table; The above formula derives the five-degree-of-freedom geometric error of the B-axis turntable as follows: in the above formula, the eccentric installation error e (θ) can be calculated by fourier analysis or a least-squares fitting method, and the core measuring rod is a high-precision custom-made test piece, and the roundness error thereof is negligible with respect to the rotation error R of the spindle.

Description

Five-degree-of-freedom geometric error automatic measurement device and method for machine tool turntable Technical Field The invention belongs to the technical field of numerical control machine tool equipment, and particularly relates to an automatic five-degree-of-freedom geometric error measuring device for a machine tool turntable and an automatic five-degree-of-freedom geometric error measuring method for the machine tool turntable. Background The spatial geometrical errors of the machine tool are the results of the combined action of 6 geometrical errors of the linear shaft and the rotary shaft, the perpendicularity error between the linear shafts and the parallelism error of the T-shaped grooves of the workbench and the linear shaft, the spatial geometrical errors of the machine tool need to be accurately compensated for in order to improve the machining precision of the machine tool, and the six geometrical errors, the perpendicularity error and the parallelism error of the linear shaft are mature measurement schemes and engineering products. For six geometrical errors of the rotating shaft (as shown in fig. 5), the angular positioning errors can use mature measurement schemes and products such as a circular grating encoder, a laser interferometer and the like, while for other geometrical errors, although translational errors (2 radial runout, 1 axial runout) can be measured by using an eddy current sensor, a dial indicator and the like, only single error measurement can be realized by using the single sensors, and multiple errors cannot be evaluated by one measurement. In addition, the error measured by the method is also an error value related to the measured position, and cannot truly reflect the error of the rotating shaft. In addition, there are also devices (e.g., lion) that use high-precision capacitive displacement sensors to measure non-contact pivot errors. However, the measurement scheme mainly aims at a main shaft with high rotating speed and high precision, and has high cost. Aiming at the low-rotation speed and medium-precision application working conditions of the horizontal five-axis machine tool turntable, the contact type displacement sensor with low cost is more suitable. In addition, the device for measuring the spindle error is mainly used for measuring and evaluating the precision error of the spindle, communication with a numerical control system is not achieved, and the spindle action is required to be controlled manually in the measuring process. The technology not only realizes communication with a numerical control system by designing a reliable measuring device and designing a corresponding automatic measuring program so as to control the turntable to rotate to finish turntable error measurement without excessive manual operation, but also realizes the separation of five geometric errors of the turntable. Disclosure of Invention The invention aims to provide an automatic five-degree-of-freedom geometric error measuring device for a machine tool turntable, which solves the problems that the error of the machine tool turntable cannot be measured quickly in the prior art and a numerical control machine tool needs to be manually operated for many times in the measuring process. The five-degree-of-freedom geometrical error automatic measuring device for the machine tool turntable comprises an upper computer, a bracket, a measuring core rod, a handle, a standard ball and five displacement sensors, wherein the standard ball is fixed at the upper end of the measuring core rod, the measuring core rod is selectively arranged at the central axis of the machine tool turntable, the handle is arranged at the main shaft handle mounting position of the machine tool, the bracket is fixed outside the handle, one displacement sensor is vertically arranged, the measuring end of the displacement sensor is contacted with the standard ball, the other four displacement sensors are divided into two pairs, each pair is vertically arranged, the measuring end of one pair is contacted with the measuring core rod in the X direction, the measuring end of the other pair is contacted with the measuring core rod in the Z direction, and the five displacement sensors are connected to the upper computer through a sensor amplifier and a communication unit. As a preferable technical scheme of the invention, the lower end of the measuring core rod is provided with a pressing plate, and the pressing plate is fixedly connected with a turntable of a machine tool. As a preferable technical scheme of the invention, the pressing plate is fixedly connected with the T-shaped groove in the turntable through a T-shaped nut. The support comprises a main shaft end connecting piece and a sensor mounting clamp, wherein the main shaft end connecting piece is fixedly connected with the tool handle, the sensor mounting clamp is fixed below the main shaft end connecting piece, and five displacement sensors are mounted on the se