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JP-7854591-B2 - Surface shape measuring device and control method thereof

JP7854591B2JP 7854591 B2JP7854591 B2JP 7854591B2JP-7854591-B2

Inventors

  • 岡野 貴央

Assignees

  • 株式会社東京精密

Dates

Publication Date
20260507
Application Date
20251021

Claims (4)

  1. A detector that detects the displacement of a stylus in contact with the surface of the object being measured, A movable part that holds the detector and is movable in an approach-to-across direction so as to move closer to and further away from the surface of the object to be measured, When the moving part starts moving from a stationary state toward the approaching side of the approaching direction, in which the stylus approaches the surface of the object to be measured, the control unit moves the moving part to the separation side, where the stylus moves away from the surface of the object to be measured, and then moves the moving part toward the approaching side. A surface shape measuring device equipped with the following features.
  2. The system includes a detection unit that detects the contact state between the surface of the object to be measured and the stylus, If the detection unit detects the contact state, the control unit moves the moving part to the separation side and then moves the moving part to the approach side; if the detection unit does not detect the contact state, it moves the moving part to the approach side without moving the moving part to the separation side. The surface shape measuring device according to claim 1.
  3. A control method for a surface shape measuring device comprising a detector that detects the displacement of a stylus that contacts the surface of an object to be measured, and a movable part that holds the detector and is movable in an approach-to-across direction so that the stylus approaches and moves away from the surface of the object to be measured, When the moving part starts moving from a stationary state toward the approaching direction in which the stylus approaches the surface of the object to be measured, the control step includes moving the moving part to the separation direction in which the stylus moves away from the surface of the object to be measured, and then moving the moving part toward the approaching direction. A control method for a surface shape measuring device.
  4. The detection step includes detecting the contact state between the surface of the object to be measured and the stylus, The control step, if the contact state is detected in the detection step, moves the moving part to the separation side and then moves the moving part to the approach side, and if the contact state is not detected in the detection step, moves the moving part to the approach side without moving the moving part to the separation side. A control method for a surface shape measuring device according to claim 3.

Description

This invention relates to a surface shape measuring device and a control method thereof. A shape measuring device is known that measures the surface roughness, contour, and other surface characteristics of a workpiece by moving a detector equipped with a stylus along the surface of the workpiece using a drive unit, and measuring the displacement of the stylus. Such shape measuring devices require preventing damage to the stylus, the workpiece, or both, improving stylus life, and preserving the workpiece. For example, in the measuring device described in Patent Document 1, the holder of the micro-stylus is attached to a micro-actuator. When the micro-stylus contacts the object to be measured in its axial direction, the device pulls the stylus up to move it away from contact to prevent buckling. Furthermore, when there is no risk of buckling, the device prevents the stylus from moving away from contact. Japanese Patent Publication No. 2002-340544 Figure 1 is a schematic diagram of a surface shape measuring device.Figure 2 is a schematic diagram of the horizontal drive unit and detector.Figure 3 is a schematic diagram of the column and the vertical movement section.Figure 4 is a diagram illustrating the force exerted on the vertically moving section by the column.Figure 5 illustrates the movement of the stylus due to the switch from static friction to kinetic friction during the movement of the vertical moving part.Figure 6 shows the results of measuring workpiece damage.Figure 7 is a graph showing the relationship between the thrust required to start movement and the stopping time.Figure 8 is a block diagram showing the configuration of a surface shape measuring device.Figure 9 is a flowchart showing the control method for a surface shape measuring device.Figure 10 is a diagram illustrating the minute retraction movement of the vertical movement unit and the movement in the specified direction when the measurement direction is downward.Figure 11 is a diagram illustrating the speed command value, actual speed, and actual position of the vertical movement unit during minute retraction movement of the vertical movement unit and movement in the specified direction.Figure 12 shows an example of the movement of the vertical movement unit when the stylus and the workpiece are not in contact.Figure 13 shows an example of the movement of the vertical movement unit when the stylus and the workpiece are in contact, and the movement instruction direction and the measurement direction are in opposite directions.Figure 14 is a diagram illustrating the slight retraction movement and movement in the specified direction when the measurement direction is upward.Figure 15 is a diagram illustrating the setting of the amount of movement in minute evacuation movements.Figure 16 is a schematic diagram of another form of surface shape measuring device.Figure 17 is a diagram illustrating the minute retraction and rotational movement of the tilt drive unit and the rotation of the tilt drive unit. The following describes preferred embodiments of the present invention with reference to the attached drawings. <Surface shape measuring device> Figure 1 is a schematic diagram of the surface shape measuring device 10. As shown in Figure 1, the surface shape measuring device 10 measures the shape of the surface of the workpiece W, specifically the contour shape or surface roughness, etc. Here, the workpiece W corresponds to the object to be measured in the present invention. Also, among the mutually orthogonal XYZ directions in the figure, the XY plane, which includes the XY direction, is a plane parallel to the horizontal direction, and the Z direction is the vertical direction perpendicular to the horizontal direction. The surface shape measuring device 10 comprises a flat plate-shaped base 12 with a flat top surface, a column 14, a vertical movement unit 16, a horizontal drive unit 18, a detector 20 having a stylus 22, an operation unit 24, a monitor 26, and a control device 30. A workpiece W is placed on the upper surface of the base 12, which is parallel to the XY plane. A column 14 is erected vertically in the Z direction (perpendicular to the upper surface of the base 12). A vertical movement section 16 is attached to the column 14 so as to be slidable along its longitudinal direction. The horizontal drive unit 18 is supported by the vertical movement unit 16. The horizontal drive unit 18 holds the detector 20 so that it can move in a direction perpendicular to the longitudinal direction of the column 14 (X direction). By driving the horizontal drive unit 18, the detector 20 (stylus 22) can be moved in the X direction relative to the workpiece W. The control unit 24 uses, for example, a keyboard, mouse, control panel, and control buttons to receive input from the operator for various operations. The monitor 26 uses various displays, such as a known liquid crystal display. This monitor 26 displays the surface shape measurement results f