JP2015105931A - Measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure a surface roughness of a measurement object mounted on a machine tool, with high accuracy.SOLUTION: A measuring instrument 2 for measuring a surface roughness of a measurement object mounted on a machine tool is provided which includes: a frame 12 extending in one direction; an optical microscope 8 capable of sliding in an extending direction of the frame along the measurement object while the measuring instrument is mounted on the machine tool; a height adjustment part 20 for adjusting a height of the optical microscope with respect to a surface of the measurement object mounted on the machine tool; a frame adjustment part 16 for supporting the frame and for adjusting the height and inclination of the frame; and a grip part 14 to be gripped by a user when the measuring instrument is mounted on the machine tool or the measuring instrument is dismounted from the machine tool.

Description

  The present invention relates to a measuring instrument that measures the roughness of the surface of a workpiece processed by a machine tool such as a surface grinder.

  When performing precision processing such as grinding and polishing, the surface roughness of the processed parts is an important inspection item. Conventionally, as a device for measuring the surface roughness, there are a number of non-contact optical measuring machines such as a white interference microscope system and a confocal laser microscope system in addition to a stylus type measuring machine (see Patent Document 1). It has been.

JP 2004-098237 A

  A stylus type measuring machine is also commercially available, but there is a problem that the measurement accuracy is low. In addition, the size of the processed parts that can be measured is limited.

  On the other hand, non-contact optical measuring machines have special measuring machines equipped with a detection head mounted on a large measuring table to measure the surface roughness of large workpieces. However, it was necessary to remove the processed parts from the processing apparatus and transfer them to the measurement table of the measuring machine. Furthermore, when a good measurement result cannot be obtained and it is necessary to perform reworking, there is a problem that it takes time to remove the work part from the measuring machine and transfer it again to the work device. Note that once the processed part is removed from the processing apparatus, it becomes difficult to reproduce the processing conditions, which may result in processing failure.

  An object of the present invention is to provide a measuring machine that can measure the surface roughness of a measurement object placed on a machine tool with high accuracy.

  The measuring machine of the present invention is a measuring machine for measuring at least one of the surface roughness and the fine shape of an object to be measured placed on a machine tool, the frame extending in one direction, and the measuring machine as the machine tool. In the state of being mounted on the optical microscope, the height of the optical microscope can be adjusted with respect to the surface of the measuring object placed on the machine tool, and an optical microscope that can slide along the measuring object in the direction in which the frame extends. A height adjusting unit that supports the frame and adjusts the height and inclination of the frame, and the measuring machine is mounted on the machine tool, or the measuring machine is removed from the machine tool. And a handle portion that is gripped by the user when removing.

  In the measuring instrument of the present invention, the optical microscope is equipped with a non-contact measurement system capable of measuring a three-dimensional surface shape by a white interference microscope method or a confocal laser microscope method.

  Further, the measuring machine of the present invention is configured to slide the optical microscope in the extending direction of the frame by the control unit that slides the optical microscope along the measurement object in the extending direction of the frame. A generation unit that sequentially generates three-dimensional image data of the image of the measurement object observed through the objective lens of the optical microscope, and a plurality of the three-dimensional image data generated by the generation unit, And a synthesis unit for creating three-dimensional image synthesis data.

  Further, the measuring machine of the present invention includes a calculation unit that calculates the height of a plurality of measurement points of the measurement object, and the measurement object based on the heights of the plurality of measurement points calculated by the calculation unit. And a straightness measuring unit that measures the straightness of the head.

  Further, the measuring machine of the present invention includes a straightness storage unit that stores information on the straightness of the frame, and a straightness of the measurement object measured by the straightness measurement unit with reference to the information on the straightness. And a correction unit that corrects.

  Further, the measuring machine of the present invention refers to a straightness measuring unit that measures the straightness of the measurement object, a straightness storage unit that stores information related to the straightness of the frame, and the information related to the straightness. And a correction unit that corrects the three-dimensional image synthesized data created by the synthesis unit.

  Further, the measuring machine of the present invention is characterized in that two frame adjusting portions are provided at one end of the frame and one at the other end, and the frame is supported at three points.

  According to the measuring machine of the present invention, the surface roughness of the measurement object placed on the machine tool can be measured with high accuracy.

It is the figure which looked at the measuring machine which concerns on embodiment from the front. It is the figure which looked at the measuring machine concerning an embodiment from the upper part. It is the figure which looked at the measuring machine which concerns on embodiment from the side. It is a figure which shows the structure of the microscope which concerns on embodiment. It is a figure which shows the machine tool which concerns on embodiment. It is a flowchart which shows the process of the surface roughness measurement using the measuring machine which concerns on embodiment. It is a figure which shows the state which mounted the measuring machine which concerns on embodiment on the machine tool. It is a figure which shows the state which mounted the measuring machine which concerns on embodiment on the surface plate. It is a figure which shows the position of the frame adjustment part which concerns on embodiment.

  Hereinafter, with reference to the drawings, a measuring machine according to an embodiment will be described by taking a measuring machine used when measuring the surface roughness and the fine shape of a workpiece processed by a machine tool as an example. FIG. 1 is a front view of a measuring machine according to an embodiment. Moreover, FIG. 2 is the figure which looked at the measuring device based on Embodiment from upper direction, and FIG. 3 is the figure which looked at this from the side.

  In the following description, an XYZ orthogonal coordinate system is set, and description will be made with reference to this XYZ orthogonal coordinate system. In the XYZ rectangular coordinate system, as shown in FIGS. 1 to 3, the XY plane is set to a plane parallel to the horizontal plane on which the measuring machine is placed, and the Z axis is set to the vertically upward direction.

  As shown in FIGS. 1-3, the measuring machine 2 moves the microscope 8 and the microscope 8 which measure the measuring object 6 (refer FIG. 4) processed with the machine tool 4 (refer FIG. 5) to a Z-axis direction. A focusing unit 10, a microscope 8 and a slider 11 on which the focusing unit 10 is mounted, and a frame 12 having sufficient rigidity for supporting the slider 11 so as to be slidable in the X-axis direction are provided. The measurement object 6 is, for example, a large workpiece having a flat surface with a length in the X-axis direction of 1 m or more and a length in the Y-axis direction of 1 m or more.

  Here, the frame 12 includes a convex 13 that is a scale that is referred to when the user recognizes the position of the microscope 8 in the X-axis direction. In addition, a handle portion 14 that is gripped by the user is provided on the upper side (+ Z direction side) of both ends of the frame 12, and on the lower side (−Z direction side) of both ends of the frame 12, A frame adjustment unit 16 for adjusting the height and inclination is provided.

  Here, the height and the inclination of the frame 12 are adjusted by changing the length of the adjusting screw 16a exposed from the lower part of each frame adjusting unit 16 by rotating the dial 16b. Note that two frame adjustment units 16 are provided at the end of the frame 12 on the −X direction side, and one frame adjustment unit 16 supports the frame 12 at three points.

  Further, on both sides of the focusing unit 10, coarse / fine adjustment dials 20 for adjusting the position of the microscope 8 in the vertical direction (Z-axis direction) are provided.

  FIG. 4A is a diagram illustrating a configuration of the microscope 8 according to the embodiment. As shown in FIG. 4A, the microscope 8 includes an optical path box 22 that serves as an optical path of light, and Michael observes the measurement object 6 at a predetermined magnification (for example, objective 5 times) below the optical path box 22. A Son type interference objective lens 24 and a piezo actuator 33 for driving the Michelson type interference objective lens 24 in the vertical direction (Z-axis direction) are provided.

  In addition, a first lens barrel 26 and a second lens barrel 28 are provided on the upper portion of the optical path box 22. The first lens barrel 26 includes an illumination unit 30 that emits illumination light that illuminates the measurement object 6 via the Michelson interference objective lens 24, and the second lens barrel 28 is illuminated by the illumination light. A camera 32 that captures an image of the measurement object 6 is provided.

  FIG. 4B is a diagram showing the Michelson interference objective lens 24 provided in the microscope 8. As shown in FIG. 4B, the Michelson interference objective lens 24 includes a lens 34 and a reference mirror 35 described later.

  FIG. 5 is a diagram illustrating the machine tool 4 according to the embodiment. As shown in FIG. 5, the machine tool 4 is placed on a table portion 42 on which the measurement object 6 is placed, a slider 44 that supports the table portion to be slidable in the horizontal direction, a base 46, and the table portion 42. A processing unit 48 for processing the measured object 6 is provided. Here, a processing member 48 a such as a grindstone is provided below the processing unit 48 to polish or grind the surface of the measuring object 6.

  Next, a procedure for measuring the measuring object 6 using the measuring instrument 2 according to the embodiment will be described with reference to the flowchart shown in FIG. The flowchart is described with a control unit (not shown) of the measuring device 2 as a main component. First, the user places the measuring object 6 on the table 42 of the machine tool 4 and processes the measuring object 6 using the processing unit 48. Next, the user moves the measurement object 6 to a place away from the machining unit 48 by sliding the position of the table unit 42 with the slider 44, and the machining unit 48 is used when measuring the measurement object 6. Try not to get in the way.

  Next, the user grasps the handle part 14 of the measuring machine 2 placed at a predetermined position with both hands, and transfers the measuring machine 2 to the table part 42 of the machine tool 4 as shown in FIG. To do. Next, the user rotates the dial 16b to change the length of the adjustment screw 16a exposed from the lower part of each frame adjustment unit 16, so that the frame 12 is positioned at a predetermined height from the table unit 42. And the height and inclination of the frame 12 are adjusted so that the frame 12 is horizontal.

  Next, the user slides the slider 11 in the X-axis direction to position the microscope 8 immediately above a predetermined measurement point, and turns on a power supply (not shown) of the measuring instrument 2. When the power is turned on, the control unit of the measuring instrument 2 turns on the illumination unit 30 and emits illumination light (see FIG. 4A) from the illumination unit 30 (step S1). The emitted illumination light A is reflected by the reflection mirror 62 and the beam splitter 64, passes through the lens 34, and is divided into two optical paths by the beam splitter 66.

  Here, the illumination light A ′ transmitted through the beam splitter 66 (see FIG. 4B) irradiates the measurement point, and the illumination light A ″ reflected by the beam splitter 66 enters the reference mirror 35. Then, the light B reflected by the measurement point and the light C reflected by the reference mirror 35 are combined by the beam splitter unit to become interference light D, and after passing through the lens 34, are imaged on the camera 32. Thereby, an image of the measurement point by the interference light D imaged on the camera 32 is displayed on a monitor (not shown).

  Next, the user operates the coarse / fine adjustment dial 20 (see FIG. 1) while viewing the image displayed on the monitor, and moves the Michelson interference objective lens 24 upward or downward. Then, a range in which interference fringes are displayed on the image is set, and a measurement start button (not shown) displayed on the monitor is clicked.

  When the measurement start button is clicked, the control unit continuously captures images of measurement points while stepping the Michelson interference objective lens 24 upward or downward at a predetermined pitch (step S2). Image data of a plurality of captured images is stored in an image storage unit (not shown).

  Next, for each image data stored in the image storage unit, the control unit obtains an envelope of the luminance value for each pixel from the luminance value of each pixel constituting the image data, and the value of the envelope is maximized. The Z position is calculated, and the relative height of each pixel is determined (step S3). Next, the control unit creates a height table that records the coordinates and relative heights of each pixel and stores them in an information storage unit (not shown).

  Next, the control unit measures the surface roughness of the measurement point (step S4). For example, 3D image data of the measurement point is generated based on the height table stored in the information storage unit, and a 3D image based on the 3D image data is displayed on the monitor. In this case, the user can visually recognize the surface roughness of the measurement point while looking at the monitor. In addition, when the user operates a cursor (not shown) to indicate a predetermined position on the 3D image displayed on the monitor, the control unit conforms to the JIS standard from the cross-sectional profile data at the specified predetermined position. The roughness parameter is calculated by the calculated formula, and the calculated roughness parameter is displayed on the monitor. Thereby, the user can grasp | ascertain the grade of the surface roughness of a measurement point concretely.

  According to the measuring machine 2 according to this embodiment, the microscope 8 capable of measuring the measuring object 6 by the non-contact optical method is mounted on the measuring machine 2, and the measuring machine 2 is placed on the machine tool 4 to perform the work. Since the surface roughness of the measuring object 6 processed by the machine 4 is measured, the surface of the measuring object 6 remains mounted on the machine tool 4 with high accuracy even when the size of the measuring object 6 is large. Coarse measurements can be made. Thereby, it is possible to realize a reduction in the defective rate of the measurement object as well as a reduction in the measurement time.

  In addition, when an on-board type measuring machine device in which a measuring machine device is mounted on a machine tool is manufactured, an expensive microscope is arranged in each machine tool, which increases the cost per machine tool. However, according to the measuring instrument 2 according to this embodiment, the cost can be reduced because it can be reused by one unit.

  In addition, since the frame 12 is supported by the frame adjusting unit 16 at three points, the height and inclination of the frame 12 can be accurately adjusted even when the measuring machine 2 is not fixed to the machine tool 4.

  In the above-described embodiment, the measurement point may be imaged while the microscope 8 is automatically moved along the frame 12 in the X-axis direction. For example, as described above, the control unit first performs continuous imaging in the Z-axis direction for a predetermined measurement point, and acquires 3D image data of the predetermined measurement point. Next, the control unit moves the microscope 8 along the frame 12 in the X-axis direction by a drive unit (not shown), and performs continuous imaging in the Z-axis direction for the next measurement point adjacent to the predetermined measurement point. 3D image data of the measurement point is acquired. Thereafter, by repeating the same processing, the control unit sequentially acquires 3D image data of measurement points continuous in the X-axis direction.

  Next, the control unit stitches the 3D image data, and displays a 3D image based on the stitched 3D image data on the monitor. Thereby, the user can recognize the surface roughness of the measuring object 6 in a wider range as compared with the case where the 3D image for each measurement point is confirmed on the monitor.

  In the above-described embodiment, the straightness of the measuring object 6 may be measured. For example, when the user performs an operation to start measuring the straightness of the measurement object 6, the control unit performs continuous imaging in the Z-axis direction for a predetermined measurement point, creates a height table, The height of a predetermined measurement point is calculated based on the height table. Here, the height of the predetermined measurement point is the average height or the center height of all the pixels. Next, the control unit moves the microscope 8 in the X-axis direction along the frame 12, performs continuous imaging in the Z-axis direction for the next measurement point, creates a height table, and based on the height table Calculate the height of the next measurement point. The movement of the microscope 8 may be performed manually by the user.

  Hereinafter, by repeating the same processing, the control unit calculates the heights of a plurality of measurement points adjacent in the X-axis direction. Next, the control unit calculates the straightness of the measurement object 6 based on the heights of a plurality of measurement points adjacent in the X-axis direction.

  Alternatively, the straightness of the frame 12 itself (hereinafter referred to as “frame straightness”) may be stored in advance in the information storage unit, and the height of the measurement point may be corrected with reference to the frame straightness. In this case, first, the frame straightness is measured in advance by the measuring machine manufacturer, and information on the measured frame straightness is stored in the information storage unit. The operation for measuring the straightness of the frame is usually performed on the surface plate by the measuring machine manufacturer, but may be performed periodically by the user.

  Next, when an operation for starting the measurement of the straightness of the measurement object 6 is performed, the control unit moves the microscope 8 along the frame 12 in the X-axis direction, and a plurality of measurement points adjacent in the X-axis direction. Calculate the height of. Next, the control unit refers to the information on the frame straightness stored in the information storage unit, corrects the height of the plurality of measurement points, and based on the corrected height, the straightness of the measurement object 6 Is calculated. Thus, the straightness of the measuring object 6 can be measured with high accuracy by referring to the information on the frame straightness.

  In addition, when performing processing to join 3D image data, the information on the frame straightness stored in the information storage unit is referred to, and the relative height of the pixels constituting the 3D image data at each measurement point is corrected. Also good. Thereby, the roughness of the surface of the measurement object 6 joined together can be measured with high accuracy.

  Moreover, in the above-mentioned embodiment, although the case where the surface roughness measurement of the measuring object 6 is performed by the white interference microscope method is described as an example, for example, other non-contact optical methods such as a confocal laser microscope method are used. You may measure the surface roughness of the measuring object 6 using a system. The objective lens is not limited to the Michelson interference objective lens 24, and other types of objective lenses such as a Mirau interference objective lens may be used.

  In the above-described embodiment, when the measuring machine 2 is transferred to the table unit 42 of the machine tool 4, the position of the table unit 42 is slid using the slider 44 so that the processing unit 48 does not get in the way. However, instead of this, the position of the processing unit 48 may be retracted to a place away from the measurement object 6.

  In the embodiment, as shown in FIG. 8, the measuring device 2 may be installed on the surface plate 70 to be a desktop measuring device. In this case, unlike the conventional desktop measuring machine, the measuring object 6 is placed on the surface plate 70, so that a large workpiece can be measured as the measuring object 6. Further, by extending the length of the frame 12 in the X-axis direction, it is possible to measure a larger workpiece.

  Further, in the above-described embodiment, the case where two frame adjustment units 16 are provided at the end portion on the −X direction side and one piece at the end portion on the + X direction side is described as an example. Two frame adjustment units 16 may be provided at the end on the + X direction side, and one frame adjustment unit 16 may be provided on the −X direction side end. Further, as shown in FIG. 9, the position of the frame adjustment unit 16 may be provided on the −Y direction side (the side where the microscope 8 is located) of the frame 12.

2 ... Measuring machine, 4 ... Machine tool, 6 ... Measuring object, 8 ... Microscope, 10 ... Focusing unit, 12 ... Frame, 14 ... Handle part, 16 ... Frame adjusting part, 20 ... Coarse / fine adjustment dial, 24 ... Michael Son-type interference objective lens, 30 ... illumination unit, 32 ... camera, 33 ... piezo actuator, 48 ... processing unit

Claims (7)

A measuring machine that measures at least one of surface roughness and fine shape of a measurement object placed on a machine tool,
A frame extending in one direction;
In a state where the measuring machine is mounted on the machine tool, an optical microscope that can slide in the direction in which the frame extends along the measurement object;
A height adjusting unit for adjusting the height of the optical microscope with respect to the surface of the measurement object placed on the machine tool;
A frame adjustment unit that supports the frame and adjusts the height and inclination of the frame;
A measuring machine comprising: a grip portion that is placed on the machine tool or gripped by a user when the measuring machine is detached from the machine tool.   The measuring machine according to claim 1, wherein the optical microscope is equipped with a non-contact measurement system capable of measuring a three-dimensional surface shape by a white interference microscope method or a confocal laser microscope method. A control unit that slides the optical microscope along the measurement object in the extending direction of the frame;
A generation unit that generates three-dimensional image data of the image of the measurement object that is sequentially observed through the objective lens of the optical microscope while sliding the optical microscope in the extending direction of the frame by the control unit;
The measuring device according to claim 1, further comprising a combining unit that combines the plurality of three-dimensional image data generated by the generating unit to create three-dimensional image combined data. A calculation unit for calculating the height of a plurality of measurement points of the measurement object;
The straightness measurement part which measures the straightness of the said measurement object based on the height of the said several measurement point calculated by the said calculation part is provided, The any one of Claims 1-3 characterized by the above-mentioned. The measuring machine described in 1. A straightness storage unit that stores information on the straightness of the frame;
The measuring machine according to claim 4, further comprising: a correction unit that corrects the straightness of the measurement object measured by the straightness measurement unit with reference to information on the straightness. A straightness measuring unit for measuring the straightness of the measurement object;
A straightness storage unit that stores information on the straightness of the frame;
The measuring machine according to claim 3, further comprising: a correction unit that corrects the three-dimensional image synthesized data created by the synthesis unit with reference to information on the straightness.   7. The frame adjustment section is provided at two ends at one end of the frame and at one end at the other end, and supports the frame at three points. The measuring machine described in 1.

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