Shape measuring device

Abstract

To provide a shape measuring device capable of adjusting the zero point of a roughness detector even when performing skid measurement. [Solution] The shape measuring device (10) is a roughness detector (100) for measuring the surface roughness of an object to be measured, and comprises a roughness detector having an arm and a stylus attached to the arm, a skid (108A) fixed to the roughness detector, a displacement reading unit (56) that detects whether the skid has come into contact with the surface of the object to be measured, and a control device (200) that controls the attitude of the roughness detector relative to the object to be measured based on the detection signal from the displacement reading unit.

Description

[Technical field]

[0001] The present invention relates to a shape measuring device, and more particularly to a shape measuring device for measuring the roughness of the surface of a workpiece. [Background technology]

[0002] A shape measuring device has a detector with a stylus at the tip, and measures the surface properties such as surface roughness, waviness, shape, etc. of the object by reading the amount of displacement of the stylus using a processor when the stylus is moved while in contact with the surface of the object.

[0003] Some shape measuring devices switch between skid measurement (also called measurement with skid), in which a block called a skid is fixed to a detector and measurement is performed, and skidless measurement, in which measurement is performed after the skid is removed from the detector. For example, Patent Document 1 discloses a surface texture measuring instrument having a detector (also called a roughness detector) with a stylus for measuring surface texture and a skid at its tip that is detachable from the detector. The surface texture measuring instrument described in Patent Document 1 makes it possible to switch between skid measurement and skidless measurement by making the skid detachable from the detector. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-133247 A Summary of the Invention [Problem to be solved by the invention]

[0005] In skidless measurement, when it is detected that the stylus has come into contact with the workpiece, an auto-stop (automatic zero level adjustment) operation is performed to set the zero point of the stylus of the roughness detector (for example, the center point of the stylus stroke). In the auto-stop operation, the relative position (height) of the column on which the roughness detector is attached and the workpiece is adjusted to adjust (match) the relationship between the height of the roughness detector and the zero point of the stylus. This auto-stop operation makes the angle of the stylus with respect to the workpiece at the zero point approximately perpendicular. This makes it possible to reduce the change in the angle of the stylus with respect to the workpiece (approximately perpendicular) when measuring the surface roughness of the workpiece, thereby ensuring measurement accuracy.

[0006] However, conventional shape measuring devices (roughness detectors) do not have the function to determine whether the skid has come into contact with the workpiece, and therefore cannot perform the auto-stop operation to adjust the zero point of the roughness detector's stylus.

[0007] The present invention has been made in view of the above circumstances, and has an object to provide a shape measuring instrument that is capable of adjusting the zero point of a roughness detector even when performing skid measurement. [Means for solving the problem]

[0008] In order to solve the above problems, a shape measuring device according to a first aspect of the present invention comprises a displacement detector having a mounting section to which a probe for measuring the contour shape of an object to be measured can be removably attached and a displacement reading section to read the displacement of the probe, a height adjustment section to adjust the height of the displacement detector relative to the object to be measured, a roughness detector for measuring the surface roughness of the object to be measured, the roughness detector having an arm and a stylus attached to the arm and removably attachable to the mounting section of the displacement detector, a skid fixed to the roughness detector, and a control device that controls the height adjustment section to adjust the height of the displacement detector, wherein when performing skid measurement in which the skid is maintained in contact with the surface of the object to be measured while measuring the surface roughness of the object to be measured, the displacement reading section detects whether the skid has come into contact with the surface of the object to be measured, and the control device controls the attitude of the roughness detector relative to the object to be measured by adjusting the height of the displacement detector based on the detection signal from the displacement reading section.

[0009] According to the first aspect, an auto-stop operation can be performed to adjust the zero point of the stylus of the roughness detector even during skid measurement.

[0010] A second aspect of the present invention is a shape measuring device according to the first aspect, wherein the displacement detector further includes a regulating means for regulating the range of motion of the mounting part within a certain range, and when performing skidless measurement in which the surface roughness of the object to be measured is measured without bringing the skid into contact with the object to be measured, the control device controls the regulating means to regulate the range of motion of the roughness detector so that the skid is not in contact with the object to be measured. Effect of the Invention

[0011] According to the present invention, even during skid measurement, an auto-stop operation can be performed to adjust the zero point of the stylus of the roughness detector. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an external perspective view showing a shape measuring device according to an embodiment of the present invention. [Diagram 2]FIG. 2 is a perspective view showing a state in which a roughness detector is attached to a displacement detector. [Diagram 3] FIG. 3 is an exploded perspective view showing, on an enlarged scale, an engagement member when a roughness detector is attached to a displacement detector. [Figure 4] FIG. 4 is a side view showing the displacement detector during skid measurement. [Diagram 5] FIG. 5 is a side view showing the displacement detector during skidless measurement. [Figure 6] FIG. 6 is a partial cross-sectional view showing the roughness detector. [Figure 7] FIG. 7 is a block diagram showing a shape measuring device according to an embodiment of the present invention. [Figure 8] FIG. 8 is a diagram for explaining the auto-stop operation during skidless measurement. [Figure 9] FIG. 9 is a diagram for explaining the auto-stop operation during skid measurement. [Figure 10] FIG. 10 is a diagram for explaining the auto-stop operation during skid measurement. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a shape measuring device according to the present invention will be described with reference to the accompanying drawings.

[0014] [Shape measuring device] 1 is a perspective view showing the appearance of a shape measuring device according to an embodiment of the present invention. In the following description, a three-dimensional orthogonal coordinate system is used in which the XY plane is the horizontal plane and the Z direction is the vertical direction.

[0015] As shown in FIG. 1, the shape measuring device 10 includes a surface plate 12, a column 14, an X-axis drive unit 16X, a displacement detector 18, a probe 20, an input device 22, and a display device 24.

[0016] The shape measuring device 10 can be fitted with a roughness detector 100 in place of the contour measurement probe 20 attached to the displacement detector 18, and can measure the contour of the object to be measured (workpiece) and the roughness of the workpiece surface. Here, contour measurement detects a relatively long period of displacement on the workpiece surface, while surface roughness measurement detects a shorter period of displacement on the workpiece surface. In contour measurement, The measurement resolution is, for example, on the order of 0.01 μm, whereas the measurement resolution in measuring surface roughness is, for example, on the order of 0.1 nm to 10 nm.

[0017] The surface plate 12 is disposed so that its upper surface is substantially horizontal. A workpiece to be measured is placed on the upper surface of the surface plate 12.

[0018] The column 14 is set up approximately vertically on the upper surface of the base 12. An X-axis drive unit 16X is attached to the column 14. A Z-axis drive unit (omitted in FIG. 1; reference numeral 16Z in FIG. 7) for moving the X-axis drive unit 16X is provided to the column 14, and the X-axis drive unit 16X can be moved in the ±Z directions along the column 14 by this Z-axis drive unit 16Z. Here, the Z-axis drive unit 16Z functions as a height adjustment unit.

[0019] A displacement detector 18 is attached to the lower side (-Z side) of the X-axis driving unit 16X. The X-axis driving unit 16X holds the displacement detector 18 so that it can move in the ±X directions.

[0020] Furthermore, the shape measuring apparatus 10 according to this embodiment may include a Y-axis drive unit (not shown) that moves the surface plate 12 and the column 14 relatively in the ±Y directions.

[0021] For example, a feed screw mechanism having a ball screw, a nut member screwed onto the ball screw, and a motor for rotating the ball screw can be used as the X-axis drive unit 16X, the Y-axis drive unit, and the Z-axis drive unit 16Z. Note that for the X-axis drive unit 16X, the Y-axis drive unit, and the Z-axis drive unit 16Z, a mechanism other than the feed screw mechanism (for example, a mechanism for converting the rotational force of a motor into reciprocating linear motion, a rack-and-pinion mechanism, etc.) may also be used.

[0022] The displacement detector 18 has a housing 50 and an attachment portion 44 (see FIG. 2, etc.). The housing 50 is a substantially rectangular parallelepiped extending in the X direction, and incorporates a detection control portion (reference numeral 54 in FIG. 7) and a displacement reading portion (reference numeral 56 in FIG. 7) for reading the displacement of the probe 20. A fitting member 50A is provided on the upper surface of the housing 50. The displacement detector 18 is fixed to the X-axis driving portion 16X by fitting the fitting member 50A into a dovetail groove (not shown) formed on the lower surface of the X-axis driving portion 16X.

[0023] The mounting part 44 protrudes from the -X side surface of the housing 50. The mounting part 44 is capable of swinging in the vertical direction (±Z direction) about a rotation axis (not shown) as a fulcrum. A probe 20 for measuring the contour shape or a roughness detector (reference numeral 100 in FIG. 2 etc.) is attached to the mounting part 44.

[0024] 1, a probe 20 for measuring a contour shape is attached to the mounting portion 44 of the displacement detector 18. The probe 20 includes a probe arm 30 and a stylus 32 attached to the tip side of the probe arm 30. The stylus 32 is disposed approximately perpendicular to the longitudinal direction of the probe arm 30.

[0025] When the gauge head 20 is attached to the displacement detector 18, the shape measuring device 10 is able to measure the contour shape of the workpiece. On the other hand, when the roughness detector 100 is attached to the displacement detector 18 instead of the gauge head 20, the shape measuring device 10 is able to measure the roughness of the workpiece surface.

[0026] The input device 22 is a device for receiving operation input from an operator, and includes, for example, a keyboard, a mouse, etc. The input device 22 inputs a control signal corresponding to the operation input from the operator to the control device (reference numeral 200 in FIG. 7). Note that, as the input device 22, for example, a touch panel may be provided on the display screen of the display device 24.

[0027] The display device 24 is a device for displaying the measurement results and the like, and is, for example, a liquid crystal monitor.

[0028] [Roughness detector] Next, the roughness detector according to this embodiment will be described. Fig. 2 is a perspective view showing a state in which the roughness detector is attached to the displacement detector.

[0029] 2, the roughness detector 100 is detachably attached to a mounting portion 44 of the displacement detector 18. The mounting portion 44 is rotatable about an axis (rotation axis 42 in FIG. 4, etc.) parallel to the Y axis, and the roughness detector 100 is movable in the Z1 direction (see FIG. 4, etc.) along the ZX plane.

[0030] As shown in FIG. 2, the roughness detector 100 includes an arm 102, a stylus 104, a detector body 106, and a nosepiece 108.

[0031] The arm 102 is a substantially rod-shaped member, and is disposed so as to be substantially parallel to the X-axis when the roughness detector 100 is attached to the attachment portion 44 of the displacement detector 18 .

[0032] A probe 104 is attached to the tip of the arm 102. The probe 104 is attached facing downward (-Z direction) in the figure at a substantially right angle to the arm 102. The probe 104 is brought into contact with the surface of the workpiece when measuring roughness, and is movable in the vertical direction (hereinafter referred to as the Z1 direction) following the roughness of the workpiece surface.

[0033] The detector body 106 includes a displacement sensor (reference numeral 120 in FIG. 6) for detecting the displacement of the stylus 104 (displacement in the Z1 direction).

[0034] The nosepiece 108 is a substantially rod-shaped member, and is attached substantially parallel to the arm 102. The base end of the nosepiece 108 is fixed to the detector body 106 using, for example, a bolt or the like.

[0035] The tip of the nosepiece 108 extends downward (in the -Z direction) in the figure, forming a skid 108A. The skid 108A is arranged so as to cover the front (-X side) of the stylus 104. The contact surface 108B of the skid 108A (the lower surface in FIG. 6, the end surface on the -Z side) is formed, for example, as a flat surface, a cylindrical surface, or a spherical surface, and may be mirror-finished. During skid measurement, the surface roughness is measured while the contact surface 108B of the skid 108A is kept in contact with the surface of the workpiece. On the other hand, during skidless measurement, the nosepiece 108 is removed from the detector body 106 to measure the surface roughness. In this embodiment, the nosepiece 108 is detachable from the detector body 106, but roughness detectors for skid measurement and skidless measurement may be provided separately.

[0036] The materials of the stylus 104 and the skid 108A can be selected according to the type of workpiece to be measured. In the example shown in Fig. 2, the skid 108A is disposed in front of the stylus 104 (-X side), but it may be disposed behind the stylus 104 (+X side).

[0037] In this embodiment, the nosepiece 108 is removed from the detector body 106 during skidless measurement, but it is also possible to perform skidless measurement with the nosepiece 108 attached. For example, the shape measuring device 10 changes the stroke (usage range) of the stylus 104, which is set as the range in which the tip of the stylus 104 moves, between skid measurement and skidless measurement. Specifically, when performing skidless measurement, the stroke of the stylus 104 is set below the contact surface of the skid 108A, so that the state in which the skid 108A and the surface of the workpiece W are not in contact with each other can be maintained. On the other hand, when performing skid measurement, the stroke of the stylus 104 is set near the contact surface of the skid 108A. Then, when performing skidless measurement and skid measurement, the control device 200 records only the measurement values ​​within the range of the stroke set for each as the measurement target. This makes it possible to switch between the skid measurement and the skidless measurement without removing the nosepiece 108 from the detector body 106.

[0038] Next, the mounting portion to which the roughness detector 100 is attached will be described with reference to Fig. 3. Fig. 3 is an exploded perspective view showing, in enlarged scale, an engagement member when the roughness detector is attached to the displacement detector.

[0039] 3, a roughness-detector-side engaging member 160 is provided on the base end side of the detector body 106 of the roughness detector 100. In addition, a displacement-detector-side engaging member 80 is provided on the tip side of the mounting portion 44 of the displacement detector 18. A magnetized member 168 and a magnet 90 are attached to an engaging surface 162 of the roughness-detector-side engaging member 160 and an engaging surface 82 of the displacement-detector-side engaging member 80, respectively. The engaging surfaces 162 and 82 are detachably attracted to each other by a magnetic catch consisting of the magnetized member 168 and the magnet 90. In this way, the roughness detector 100 is attached to the displacement detector 18.

[0040] The roughness detector side engaging member 160 and the displacement detector side engaging member 80 are made of, for example, metal and have a substantially rectangular parallelepiped shape. In the example shown in Fig. 3, the displacement detector side engaging member 80 is thinner in the Y direction than the roughness detector side engaging member 160. The roughness detector side engaging member 160 and the displacement detector side engaging member 80 are preferably made of a non-magnetic material so as not to hinder the attraction between the magnetized member 168 and the magnet 90.

[0041] A first groove 164 and a second groove 166 are formed on the engagement surface 162 of the engagement member 160 on the roughness detector side. The first groove 164 is a linear groove extending parallel to the axial direction of the arm 102 of the roughness detector 100. The second groove 166 is a linear groove extending in a direction perpendicular to the axial direction of the arm 102 of the roughness detector 100, i.e., in a direction perpendicular to the first groove 164. The cross-sectional shapes of the first groove 164 and the second groove 166 are, for example, substantially V-shaped. The first groove 164 is formed parallel to the arm 102 of the roughness detector 100 (in other words, in a direction substantially perpendicular to the direction of the normal force when the stylus 104 contacts the surface of the workpiece).

[0042] In addition, in FIG. 3, the first groove 164 and the second groove 166 intersect, but the first groove 164 and the second groove 166 do not have to intersect.

[0043] A first positioning pin 84, a second positioning pin 86, and a third positioning pin 88 are attached to the engagement surface 82 of the displacement detector side engagement member 80. The first positioning pin 84, the second positioning pin 86, and the third positioning pin 88 are each substantially spherical, conical, or truncated conical. The first positioning pin 84, the second positioning pin 86, and the first groove 164 are arranged to face each other when the engagement surface 162 and the engagement surface 82 are opposed to each other. Furthermore, the third positioning pin 88 and the second groove 166 are arranged to face each other when the engagement surface 162 and the engagement surface 82 are opposed to each other.

[0044] The magnetized members 168 are attached to the engagement surface 162 at positions that are approximately line-symmetrical with respect to the second groove 166. There are no limitations on the material of the magnetized members 168 as long as they are magnetic bodies that can be attracted to the magnet 90 described later.

[0045] Two magnets 90 are attached to the engagement surface 82. The magnets 90 are arranged so as to face each of the two magnetized members 168 attached to the engagement surface 162 when the engagement surface 162 and the engagement surface 82 are placed opposite each other.

[0046] 3, the magnetized member 168 and the magnet 90 have a substantially circular planar shape and are substantially the same size. The shapes and sizes of the magnetized member 168 and the magnet 90 are not limited to this. For example, the magnetized member 168 and the magnet 90 may be arranged so as to overlap each other with their planar shapes being substantially congruent. Furthermore, the number of magnetized members 168 and magnets 90 is not limited to two, and may be, for example, one, or three or more.

[0047] When attaching the roughness detector 100 to the displacement detector 18, the engagement surface 162 of the engagement member 160 on the roughness detector side and the engagement surface 82 of the engagement member 80 on the displacement detector side are placed face to face and overlapped, as shown by the white arrow in Fig. 3. Then, the magnetized member 168 and the magnet 90 are attracted to each other by magnetic force. At this time, the first positioning pin 84 and the second positioning pin 86 are engaged with the first groove 164, and the third positioning pin 88 is engaged with the second groove 166. This fixes the relative positions of the engagement member 160 on the roughness detector side and the engagement member 80 on the displacement detector side.

[0048] When removing the roughness detector 100 from the displacement detector 18, the roughness detector side engagement member 160 is pulled in the +Y direction to separate the magnetized member 168 from the magnet 90. This makes it possible to easily remove the roughness detector 100 from the displacement detector 18.

[0049] 3, engagement surfaces 162 and 82 are parallel to the direction of the normal force when stylus 104 contacts the surface of the workpiece, and first groove 164 is formed in a direction perpendicular to the direction of the normal force. Therefore, even when a normal force acts on stylus 104, the position of roughness detector 100 is unlikely to shift and is stable. In addition, the cross-sectional shape of first groove 164 and second groove 166 is V-shaped, which makes it easy to ensure machining accuracy, and therefore it is easy to ensure installation accuracy.

[0050] The engagement member 60 of the gauge head 20 is similar to the engagement member 160 on the roughness detector side, and therefore a description thereof will be omitted.

[0051] Here, the roughness detector side engaging member 160 and the displacement detector side engaging member 80 do not need to be rigid in their entirety. The roughness detector side engaging member 160 only needs to have a rigidity that allows at least deformation of the first groove 164 and the second groove 166 to be negligible even when the roughness detector 100 is repeatedly attached and detached. For example, the roughness detector side engaging member 160 may be a composite material in which the metal forming the first groove 164 and the second groove 166 is bonded to carbon. Similarly to the roughness detector side engaging member 160, the displacement detector side engaging member 80 only needs to have a rigidity that allows at least deformation of the engaging surface 82 to be negligible even when the roughness detector 100 and the measuring element 20 are repeatedly attached and detached, and may be the composite material described above.

[0052] Similarly, the first positioning pin 84, the second positioning pin 86 and the third positioning pin 88 may also have a rigidity that allows negligible deformation even when the roughness detector 100 and the probe 20 are repeatedly attached and detached.

[0053] 3, in the shape measuring instrument 10 according to this embodiment, a first seating sensor 92A and a second seating sensor 92B are arranged side by side on the engagement surface 82 of the displacement detector-side engagement member 80. The first seating sensor 92A and the second seating sensor 92B are pressure sensors that detect pressure applied to their respective detection surfaces and output an electric signal (detection signal), and are, for example, piezoelectric sensors.

[0054] An operating pin 170 is attached to the engagement surface 162 of the roughness detector-side engagement member 160 of the roughness detector 100. The operating pin 170 and the detection surface of the second seating sensor 92B are arranged so as to face each other when the engagement surface 162 and the engagement surface 82 are opposed to each other.

[0055] The operating pin 170 protrudes from the engagement surface 162, and when the roughness detector side engagement member 160 and the displacement detector side engagement member 80 engage with each other, it comes into contact with and presses the detection surface of the second seating sensor 92B. When the second seating sensor 92B is pressed by the operating pin 170, it outputs a detection signal to the control device 200. When the control device 200 receives the detection signal from the second seating sensor 92B, it determines that the roughness detector 100 is attached to the attachment portion 44, and switches the measurement mode of the shape measuring device 10 to the roughness measurement mode.

[0056] Similarly, an actuation pin (not shown) is attached to the engagement surface of the probe 20, protruding at a position opposing the first seating sensor 92A when the probe 20 is placed facing the engagement surface 82. When the first seating sensor 92A is pressed by the actuation pin, it outputs a detection signal to the control device 200. When the control device 200 receives the detection signal from the first seating sensor 92A, it determines that the probe 20 is attached to the attachment portion 44, and switches to the contour measurement mode.

[0057] In this embodiment, the first seating sensor 92A and the second seating sensor 92B are used to identify the gauge head 20 and the roughness detector 100, but the present invention is not limited to this. For example, IC (Integrated Circuit) tags storing identification information of the gauge head 20 and the roughness detector 100 may be attached to the engagement member of the gauge head 20 and the roughness detector side engagement member 160, respectively, and an IC tag reader may be attached to the displacement detector side engagement member 80 to identify the gauge head 20 and the roughness detector 100. In this case, only one IC tag reader may function as a seating sensor.

[0058] [Displacement detector] Next, the internal configuration of the displacement detector 18 will be described with reference to Figures 4 and 5. Figures 4 and 5 are side views showing the displacement detector during skid measurement and skidless measurement, respectively. For convenience of illustration, the outline of the nosepiece 108 is shown by a dashed line in Figure 4.

[0059] 4 and 5, during skid measurement, the nosepiece 108 is attached to the detector body 106. On the other hand, during skidless measurement, the nosepiece 108 is detached from the detector body 106.

[0060] As shown in FIGS. 4 and 5, the displacement detector 18 according to this embodiment includes a drive unit connecting portion 40, a mounting portion 44, a counterweight 48, and a retract mechanism 52.

[0061] The drive unit connecting portion 40 is a member that is connected and fixed to the X-axis drive unit 16X via a fitting member 50A. The drive unit connecting portion 40 is provided with a rotation shaft 42 that extends in the Y direction.

[0062] The arm 46 is a rod-shaped member rotatably supported by the rotating shaft 42. An attachment part 44 is provided at the end of the arm 46 on the left side in the figure (-X side), and a displacement detector side engagement member 80 is provided thereon. The arm 46 extends to the right side in the figure (+X side) with respect to the rotating shaft 42. A counterweight 48 is attached to the right side in the figure (+X side) of the arm 46.

[0063] The counterweight 48 is attached via a slider (not shown) so as to be slidable on the arm 46. By adjusting the position of the counterweight 48, the measuring force (pressing force) when performing contour measurement using the probe 20 is adjusted.

[0064] The retract mechanism (regulating means) 52 includes a slide shaft 52A, an arm stopper 52B, and a pin 52C.

[0065] The slide shaft 52A is a rod-shaped member extending in the Z-axis direction, and is connected to the drive unit connection portion 40.

[0066] The arm stopper 52B is a substantially C-shaped member in side view (viewed from the +Y direction). The arm stopper 52B is attached so as to be slidable in the ±Z directions along the slide shaft 52A, independent of the arm 46 of the displacement detector 18. As a mechanism for sliding the arm stopper 52B, for example, a mechanism for performing reciprocating linear motion, such as a ball screw or a rack-and-pinion mechanism, can be used.

[0067] The pin 52C is a rod-shaped member that protrudes from the arm 46 in the +Y direction. The C-shaped arm stopper 52B is disposed so as to surround the pin 52C. As shown in FIG. 4, when the pin 52C is located in the middle between the upper and lower parts of the arm stopper 52B, the pin 52C can move up and down in accordance with the up and down movement of the arm 46. The arm stopper 52B restricts the range of motion of the pin 52C. This restricts the range of motion of the attachment part 44 and the arm 46 to a certain range.

[0068] When performing contour measurement, when the stylus 32 moves up and down in the Z1 direction along the surface of the workpiece, the arm 46 moves up and down in response to the up and down movement of the stylus 32. When the arm 46 rotates until the pin 52C contacts the upper and lower parts of the arm stopper 52B, the arm stopper 52B restricts the upward and downward movement of the arm 46.

[0069] On the other hand, when performing roughness measurement, the roughness detector 100 is attached to the mounting part 44 by the magnet catch mechanism. Then, the weight of the roughness detector 100 pushes down the arm 46 of the displacement detector 18, and the pin 52C of the retract mechanism 52 is pressed against and fixed to the lower end of the arm stopper 52B. This makes it possible to perform roughness measurement using the stylus 104 of the roughness detector 100.

[0070] As described above, the skid 108A is movable within the movable range defined by the retract mechanism 52. When performing skid measurement, the weight of the roughness detector 100 is used to maintain the contact surface 108B of the skid 108A pressed against the workpiece, and roughness measurement is performed. Here, the measuring force applied from the skid 108A to the surface of the workpiece can be adjusted using the counterweight 48. On the other hand, when performing skidless measurement, the retract mechanism 52 is controlled to move the roughness detector 100 (specifically, the arm 102) horizontally (parallel to the XY plane) to perform roughness measurement.

[0071] In the example shown in FIGS. 4 and 5, retract mechanism 52 is provided on the +Y side of arm 46, but it may be provided on the -Y side, or on both sides of arm 46.

[0072] In addition, the retract mechanism 52 is not limited to the present embodiment, and for example, a configuration including a retract plate described in JP 2018-163094 A may be applied. Note that instead of the retract mechanism 52, a mechanism (for example, a mechanical restriction means) for restricting the range of motion of the arm 46 (and the measuring element 20 or the roughness detector 100 attached to the attachment portion 44) may be provided.

[0073] [Roughness detector] Next, the internal configuration of the roughness detector 100 will be described with reference to Fig. 6. Fig. 6 is a partial cross-sectional view showing the roughness detector.

[0074] The roughness detector 100 includes an arm 102 , a screw 112 , a spring 114 and a displacement sensor 120 .

[0075] The arm 102 is attached so as to be rotatable around a rotation axis 110 extending in the Y direction. A stylus 104 is attached to the tip of the arm 102 substantially perpendicular to the longitudinal direction of the arm 102. A countersunk portion (recess) 102B is formed in a base end portion 102A of the arm 102.

[0076] As the spring 114, for example, a biasing means such as a compression spring (compression coil spring) can be used, but the type is not limited as long as it can bias the base end portion 102A of the arm 102 upward (in the +Z direction) in the figure. One end of the spring 114 is fitted into the countersunk portion 102B, and the other end is engaged with the tip of the screw 112.

[0077] The screw 112 is, for example, a pointed screw whose tip is formed in a conical or pyramidal shape. The screw 112 is screwed into a screw hole provided in the Z direction of the roughness detector 100. The measuring force of the stylus 104 is set in advance by the amount of screwing in of the screw 112. Here, the measuring force is set based on standards such as JIS B 0651:2001 (ISO 3274:1996) relating to the characteristics of stylus-type surface roughness measuring instruments. Here, JIS stands for Japanese Industrial Standards, and ISO stands for International Organization for Standardization.

[0078] A displacement sensor 120 is disposed at the base end of the arm 102. The displacement sensor 120 measures the amount of displacement of the stylus 104. The control device 200 receives a detection signal from the displacement sensor 120 and calculates the amount of displacement of the stylus 104. As the displacement sensor 120, for example, a differential transformer consisting of a core 116 and a coil 118 can be used.

[0079] [Control system of shape measuring device] Next, a control system of the shape measuring device 10 will be described with reference to Fig. 7. Fig. 7 is a block diagram showing a shape measuring device according to an embodiment of the present invention.

[0080] The control device 200 shown in FIG. 7 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and receives operation input from an operator via the input device 22, transmits control signals to each part of the shape measuring device 10, and controls the operation of each part.

[0081] The control device 200 detects whether the probe 20 or the roughness detector 100 is attached to the attachment portion 44, and switches the measurement mode (contour measurement mode and roughness measurement mode).

[0082] As shown in FIG. 7, the displacement detector 18 includes a detection control unit 54 and a displacement reading unit 56.

[0083] The detection control unit 54 controls each unit of the displacement detector 18. The detection control unit 54 controls the positions of the retract mechanism 52 and the counterweight 48.

[0084] The displacement reading unit 56 is a device for reading the displacement of the gauge 20 when measuring the contour shape of a workpiece, and is, for example, a linear scale, a circular scale, an LVDT (Linear Variable Differential Transformer), or the like.

[0085] (Contour measurement mode) The control device 200 detects, by a detection signal from the first seating sensor 92A, that the stylus 20 has been attached to the attachment portion 44. Then, the control device 200 switches the measurement mode of the form measuring device 10 to the contour measurement mode. Here, the control device 200 starts an application for measuring the contour shape, and transmits an instruction to switch to the contour measurement mode to the detection control unit 54.

[0086] When the detection control unit 54 receives an instruction to switch to the contour measurement mode from the control device 200, it controls the retract mechanism 52 and the displacement reading unit 56 to perform contour measurement.

[0087] The displacement reading unit 56 reads the displacement (displacement in the Z1 direction) when the stylus 32 attached to the tip side of the probe arm 30 of the probe 20 comes into contact with the surface of the workpiece.

[0088] The control device 200 acquires the X coordinate of the displacement detector 18 from the X-axis drive unit 16X via the detection control unit 54, and calculates the position of the probe 32 from size information of the probe 20, etc. Then, the control device 200 calculates the contour shape of the workpiece based on the position of the probe 32 and the displacement of the probe 32 in the Z1 direction acquired from the displacement reading unit 56, and outputs the result to the display device 24.

[0089] (Roughness measurement mode) On the other hand, when measuring the roughness of the workpiece surface, a roughness detector 100 is attached to the mounting portion 44. When the roughness detector 100 is attached, the arm 46 of the displacement detector 18 is pressed down by the weight of the roughness detector 100, and the pin 52C of the retract mechanism 52 is pressed against the lower end of the arm stopper 52B and fixed.

[0090] The control device 200 detects, by a detection signal from the second seating sensor 92B, that the roughness detector 100 has been attached to the attachment portion 44. Then, the control device 200 switches the measurement mode of the profile measuring device 10 to a roughness measurement mode. Here, the control device 200 starts an application for roughness measurement.

[0091] The control device 200 then receives an instruction input as to whether to perform skid measurement or skidless measurement, and performs an auto-stop operation in response to the instruction input.

[0092] [Auto stop operation] Next, the auto-stop operation will be described with reference to FIG. 8 and FIG.

[0093] (Skidless measurement) FIG. 8 is a diagram for explaining the auto-stop operation during skidless measurement.

[0094] 8 indicates the entire stroke of the stylus 104. In the following description, the coordinates of the upper limit, the lower limit, and the zero point between the upper limit and the lower limit of the stroke R are respectively designated as Z1 U , Z1 L and Z1 O Here, Z1 O =(Z1 U -Z1 L ) / 2, and Z1 O is below (on the -Z side) in the figure from the contact surface 108B of the skid 108A. The stroke R is determined by, for example, the size of the opening for the arm 102 in the detector body 106, the range of motion of the arm 102 inside the detector body 106, etc.

[0095] As described above, when the roughness detector 100 is attached to the attachment portion 44, the pin 52C of the retract mechanism 52 is pressed down to the lower end of the arm stopper 52B by the weight of the roughness detector 100. Therefore, in the state before the auto-stop operation is performed (hereinafter referred to as the initial state), the arm 102 is pressed down by the biasing force of the spring 114, and the stylus 104 is at the lower limit Z1 of the stroke R. L Located in.

[0096] In the auto-stop operation during skidless measurement, first, the control device 200 controls the Z-axis drive unit 16Z to move the displacement detector 18 in the -Z direction to bring the tip of the stylus 104 into contact with the workpiece W. When the tip of the stylus 104 is brought into contact with the workpiece W, the roughness detector 100 and the workpiece W are moved relative to each other so that the stylus 104 is approximately perpendicular to the surface of the workpiece W. The angle of the stylus 104 with respect to the workpiece W can be adjusted, for example, by operating the retract mechanism 52 to adjust the attitude (inclination) of the roughness detector 100. Then, when the control device 200 detects that the arm 102 has reached a horizontal position based on the detection signal from the displacement reading unit 56, it stops the movement of the displacement detector 18 in the Z direction by the Z-axis drive unit 16Z. The angle of the stylus 104 with respect to the surface of the workpiece W may be adjusted by adjusting the attitude of a clamp mechanism (not shown) that holds the workpiece W using an actuator (not shown) or the like.

[0097] The control device 200 detects whether the stylus 104 has come into contact with the surface of the workpiece W based on a detection signal from the displacement sensor (differential transformer) 120.

[0098] When the control device 200 detects that the contact of the contact stylus 104 with the surface of the workpiece W, it controls the Z-axis drive unit 16Z to move the displacement detector 18 in the -Z direction, and performs an auto-stop operation to set the zero point of the contact stylus 104. Then, based on the detection signal from the displacement sensor 120, the control device 200 determines whether the tip of the contact stylus 104 is at the zero point Z1. O When it is detected that the tip of the stylus 104 has reached (matched) the upper limit Z1, the control device 200 stops the movement of the displacement detector 18 in the Z direction by the Z-axis drive unit 16Z. U , lower limit Z1 L and zero point Z1 O Alternatively, the output value of the detection signal from the displacement sensor 120 when the tip of the stylus 104 is positioned at the position indicated by the arrows may be stored in advance, and the position of the tip of the stylus 104 may be detected based on the previously stored output value.

[0099] Next, the control device 200 controls the X-axis drive unit 16X to scan the displacement detector 18 in the X direction to measure the surface roughness of the workpiece W. As a result, the operating range of the stylus 104 during roughness measurement is set to zero point Z1 O Since the area can be limited to the vicinity of the center, the change in angle of the stylus 104 with respect to the surface of the workpiece W can be made small.

[0100] (Skid measurement) 9 and 10 are diagrams for explaining the auto-stop operation during skid measurement.

[0101] As described above, in the initial state, the stylus 104 is at the lower limit Z1 of the stroke R. L Located in.

[0102] In the auto-stop operation during skid measurement, first, as shown in Fig. 9, the control device 200 controls the Z-axis drive unit 16Z to move the displacement detector 18 in the -Z direction and bring the tip of the stylus 104 into contact with the workpiece W. Here, it is preferable to move the roughness detector 100 and the workpiece W relatively so that the stylus 104 is approximately perpendicular to the surface of the workpiece W.

[0103] When the skid 108A comes into contact with the surface of the workpiece W, the roughness detector 100 is pushed up to the +Z side.

[0104] The control device 200 determines whether or not the skid 108A has contacted the surface of the workpiece W based on the detection signal from the displacement reading unit 56. Note that in this embodiment, it is determined whether or not the skid 108A has contacted the surface of the workpiece W based on the detection signal from the displacement reading unit 56 of the displacement detector 18, but for example, a pressing force sensor or the like may be provided to detect the pressing force applied by the pin 52C of the retract mechanism 52 to the arm stopper 52B.

[0105] When the control device 200 detects, based on the detection signal from the displacement reading unit 56, that the skid 108A has come into contact with the surface of the workpiece W, it controls the Z-axis driving unit 16Z to move the displacement detector 18 further in the -Z direction. Then, when the control device 200 detects, based on the detection signal from the displacement reading unit 56, that the arm 102 has reached a horizontal position (a position where the arm 102 is parallel to the surface of the workpiece W), it stops the movement of the displacement detector 18 in the Z direction by the Z-axis driving unit 16Z. As a result, the retract mechanism 52 becomes free with the pin 52C separated from the arm stopper 52B, and the skid 108A becomes movable along the surface of the workpiece W within the movable range of the roughness detector 100 regulated by the retract mechanism 52.

[0106] The arm stopper 52B of the retract mechanism 52 may be moved in the +Z direction to set the pin 52C free from the arm stopper 52B.

[0107] Next, the control device 200 controls the X-axis drive unit 16X to scan the displacement detector 18 in the X direction to measure the surface roughness of the workpiece W. The pressing force applied from the skid 108A to the surface of the workpiece W is adjusted according to the relationship between the weight of the roughness detector 100 and the position of the counterweight 48.

[0108] In this embodiment, it is preferable that the length of the stylus 104 is adjusted so that the arm 102 and the nosepiece 108 are approximately parallel to each other when the tip of the stylus 104 is at the same height as the contact surface 108B of the skid 108A.

[0109] According to this embodiment, even during skid measurement, the zero point Z1 of the stylus of the roughness detector 100 O An auto-stop operation can be performed to adjust the

[0110] Furthermore, according to this embodiment, when the roughness detector 100 is attached to the attachment portion 44, the pin 52C of the arm 46 of the displacement detector 18 is pressed against the arm stopper 52B by the weight of the roughness detector 100 and fixed in place. This eliminates the need for an auxiliary biasing means as in Patent Document 1.

[0111] Furthermore, in this embodiment, the roughness detector 100 is positioned relative to the displacement detector 18 by the weight of the roughness detector 100. Therefore, even if an impact including a component in the +Z direction is applied to the stylus 104, for example, the roughness detector 100 can move to the +Z side, so that damage to the stylus 104 can be avoided.

[0112] In the above embodiment, the roughness detector 100 is attached to the displacement detector 18 for contour measurement, but the present invention is not limited to this. For example, the present invention can be realized as long as the configuration includes a retract mechanism 52 and a counterweight 48 for controlling the roughness detector 100. [Explanation of symbols]

[0113] 10...shape measuring device, 12...base plate, 14...column, 16X...X-axis drive unit, 16Z...Z-axis drive unit, 18...displacement detector, 20...measuring element, 22...input device, 24...display unit, 30...measuring element arm, 40...drive unit connection unit, 42...rotating shaft, 44...mounting unit, 46...arm, 48...counterweight, 50...housing, 52...retract mechanism, 54...detection control unit, 56...displacement reading unit, 80...displacement detector side engaging member, 82...engagement surface, 84...first positioning pin, 86...second positioning pin, 88...third positioning pin, 90...magnet, 92A...first seating sensor, 92B...second seating sensor, 100...roughness detector, 102...arm, 102A...base end, 102B...countersink portion, 104...contact pin, 106...detector body, 108...nosepiece, 108A...skid, 108B...contact surface, 110...rotating shaft, 112...screw, 114...spring, 116...core, 118...coil, 120...displacement sensor, 160...engagement member on roughness detector side, 162...engagement surface, 164...first groove, 166...second groove, 168...magnetized member, 170...operation pin, 200...control device

Claims

1. A roughness detector for measuring the surface roughness of a workpiece, comprising: an arm; a roughness detector having a stylus attached to the surface; a skid fixed to the roughness detector; a displacement reading unit capable of reading a displacement amount of the roughness detector and detecting whether or not the skid has come into contact with the surface of the object to be measured according to the presence or absence of the displacement of the roughness detector; a control device which, after detecting contact of the skid with the surface of the workpiece by the displacement reading unit, controls the attitude of the roughness detector with respect to the workpiece based on a detection signal of the amount of displacement from the displacement reading unit so that the stylus is approximately perpendicular to the surface of the workpiece; A shape measuring device comprising:

2. 2. A shape measuring device as described in claim 1, wherein when performing skid measurement in which the surface roughness of the object is measured while maintaining the skid in contact with the surface of the object, the attitude of the roughness detector relative to the object is controlled based on a detection signal from the displacement reading unit.

3. The roughness detector further includes a limiting means for limiting the movable range of the roughness detector to a certain range.

3. The shape measuring device according to claim 1 or 2, wherein the control device controls the regulating means to regulate the range of motion of the roughness detector so that the skid does not come into contact with the object when performing skidless measurement in which the surface roughness of the object is measured without bringing the skid into contact with the object.

4. A roughness detector for measuring the surface roughness of a measurement object, the roughness detector comprising an arm and a stylus attached to the arm; a skid fixed to the roughness detector; a restricting means for restricting a movable range of the roughness detector to a certain range, the restricting means including a detecting means for detecting whether or not the skid has come into contact with the surface of the object to be measured; a control device for controlling the attitude of the roughness detector with respect to the object to be measured based on a detection result by the detection means; A shape measuring device comprising:

5. 5. A shape measuring device as claimed in claim 4, wherein when performing skid measurement in which the surface roughness of the object is measured while maintaining the skid in contact with the surface of the object, the attitude of the roughness detector relative to the object is controlled based on the detection result by the detection means.

6. 6. A shape measuring device as described in claim 4 or 5, wherein the control device controls the regulating means to regulate the range of motion of the roughness detector so that the skid does not come into contact with the object when performing skidless measurement in which the surface roughness of the object is measured without bringing the skid into contact with the object.

Images