Automatic measuring device

Abstract

Provided is an automatic measuring device for automating a contact-type measuring instrument that is inexpensive and easy to use. This automatic measuring device is provided with a holding unit that holds at least one of a workpiece and a measuring instrument such that when the workpiece and a movable element are in contact with one another, the relative positions and attitudes of the workpiece and the measuring instrument are changed at a pressure equal to or less than a predetermined measuring pressure that is preset in the measuring instrument, thereby bringing the contacting surfaces of the workpiece and the movable element into close contact with one other. The holding unit comprises: a translation permitting mechanism unit that permits translational displacement within a plane parallel to a measuring axis direction; and a first rotation permitting mechanism unit that permits rotation with an axis that is non-parallel with respect to the measuring axis as the axis of rotation.

Description

Automatic Measuring Device

[0001] The present invention relates to an automatic measuring device that automatically measures a workpiece using a small measuring device for measuring the dimensions of the workpiece.

[0002] Known measuring instruments (measuring tools) for measuring workpiece dimensions include micrometers, calipers, HoleTest, cylinder gauges, and Borematic (registered trademark). These contact-type measuring instruments (measuring tools) are widely used due to their advantages, such as ease of use, measurement stability, and relatively low cost. However, because the workpiece and moving elements (spindle, measuring jaw, and measuring point) must be properly brought into close contact with each other and the same measuring pressure must always be applied, measurement is inevitably performed manually. Therefore, measurements using such contact-type measuring tools require time and effort.

[0003] As an alternative to manual measurement, the use of non-contact measuring devices such as air micrometers and laser scan micrometers has been proposed for use in production sites (Japanese Patent Laid-Open Publication No. 8-14871). However, air micrometers and laser scan micrometers themselves are extremely expensive and have problems such as being somewhat difficult to maintain.

[0004] JP 10-89903 JP 2019-100904 JP 8-14871

[0005] Although there have been various proposals to automate contact-type measurement, such as using motor power, there have been no examples of successful practical application that has led to widespread adoption (Patent Publication No. 10-89903). Furthermore, while it is possible to automate contact-type measurement using a coordinate measuring machine (CMM) or the like (Patent Publication No. 2019-100904), this requires an investment of tens to hundreds of millions of yen, making it unsuitable for use as a replacement for measurements performed with micrometers or vernier calipers.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic measuring device that automates a contact-type measuring instrument that is inexpensive and easy to use.

[0007] The automatic measuring device of the present invention comprises: a measuring instrument having a movable element that is displaceable relative to a fixed element and moves forward and backward so as to approach and separate from a workpiece, and a displacement detection unit that detects the displacement of the movable element; an automatic operation unit that automates the movement of the movable element by power; and a holding unit that holds at least one of the workpiece and the measuring instrument so that when the workpiece and the movable element come into contact, the relative positions and postures of the workpiece and the measuring instrument are changed at a pressure equal to or less than a predetermined measurement pressure that is preset in the measuring instrument, thereby bringing the contact surfaces of the workpiece and the movable element into close contact; and the automatic measuring device automatically measures a workpiece using a measuring instrument for measuring the dimensions of the workpiece, wherein when the direction in which the movable element moves forward and backward is defined as the measurement axis direction, the holding unit comprises: a translational movement allowance mechanism that allows translational displacement within a plane parallel to the measurement axis direction; and a first rotational movement allowance mechanism that allows rotation about an axis that is not parallel to the measurement axis.

[0008] In one embodiment of the present invention, it is preferable that the translational movement allowance mechanism has a translational body that translates in a plane parallel to the measurement axis direction, and the first rotational movement allowance mechanism is installed on the translational body and moves together with the translational body.

[0009] In one embodiment of the present invention, the first rotation allowance mechanism has a first rotating body that directly or indirectly holds a workpiece or a measuring instrument and rotates around the rotation axis, and the first rotation allowance mechanism is provided with a regulating means for regulating displacement of the first rotating body, and the regulating means regulates the displacement of the first rotating body when the movable element and the workpiece are separated, and the regulating means preferably allows displacement of the first rotating body when the movable element and the workpiece are in contact and the movable element is applying a measurement pressure to the workpiece.

[0010] In one embodiment of the present invention, it is preferable that the restricting means is a counterweight attached to the first rotating body.

[0011] In one embodiment of the present invention, the regulating means preferably has a restraining member that moves toward and away from the first rotating body, and the regulating means preferably switches between a hold state and a release state of the first rotating body by switching between a contact state and a separation state between the restraining member and the first rotating body.

[0012] In one embodiment of the present invention, the automatic operating unit advances the movable element so that it comes into contact with the workpiece, then retreats the movable element a predetermined distance, and then advances the movable element again so that a predetermined measurement pressure is generated between the workpiece and the movable element, and when the automatic operating unit advances the movable element again so that a predetermined measurement pressure is generated between the workpiece and the movable element, it is preferable that the regulating means releases the first rotating body and allows displacement of the first rotating body.

[0013] In one embodiment of the present invention, the movement positions of the translational body of the translational movement allowing mechanism include a non-measurement position for exchanging workpieces before the start of measurement and after measurement, and a measurement position for detecting the displacement of the movable element as a measurement value while a measurement pressure is applied from the movable element to the workpiece, and it is preferable that the translational movement allowing mechanism has return means for returning the position of the translational body from the measurement position to the non-measurement position.

[0014] In one embodiment of the present invention, it is preferable that an extension line of the rotation axis of the first rotation allowance mechanism intersects with the measurement axis.

[0015] In one embodiment of the present invention, it is preferable that the holding unit further has a second rotation allowance mechanism that allows rotation about an axis that is non-parallel to the measurement axis and the rotation axis of the first rotation allowance mechanism.

[0016] 1 is a diagram illustrating the overall configuration of an automatic measuring device in a first embodiment. FIG. 1 is a diagram illustrating a plan view of an automatic measuring unit. FIG. 2 is a perspective view of the automatic measuring unit from the front side. FIG. 3 is a perspective view of the automatic measuring unit from the rear side. FIG. 4 is a cross-sectional view of a first rotation allowance mechanism taken along a plane including the rotation axis of the first rotation allowance mechanism. FIG. 5 is a diagram illustrating a modified example of an installation position of a counterweight. FIG. 6 is a cross-sectional view of the first rotation allowance mechanism taken along a plane including the measurement axis. FIG. 7 is a diagram illustrating an X-rotation stage and a work holder. FIG. 8 is a diagram illustrating a measurement operation by an automatic micrometer device. FIG. 9 is a diagram illustrating a measurement operation by an automatic micrometer device. FIG. 10 is a diagram illustrating a measurement operation by an automatic micrometer device. FIG. 11 is a schematic diagram illustrating, as a comparative example, a case where the first rotation axis is offset from the measurement axis. FIG. 12 is a schematic diagram illustrating, as a comparative example, a case where the first rotation axis is offset from the measurement axis. FIG. 13 is a schematic diagram illustrating a case where the first rotation axis and the measurement axis are orthogonal in the first embodiment. FIG. 14 is a diagram illustrating a second embodiment. 10 is a flowchart illustrating a measurement operation by the automatic micrometer device in a second embodiment. FIG. 11 is a diagram illustrating a measurement operation by the automatic micrometer device. FIG. 12 is a diagram illustrating a measurement operation by the automatic micrometer device. FIG. 13 is a diagram illustrating a measurement operation by the automatic micrometer device. FIG. 14 is a diagram illustrating a case where the workpiece is a rectangular prism. FIG. 15 is a diagram illustrating an appearance of an automatic measuring unit according to a third embodiment. FIG. 16 is a diagram illustrating an appearance of an automatic measuring unit according to the third embodiment. FIG. 17 is a diagram illustrating an appearance of an automatic measuring unit according to the third embodiment. FIG. 18 is a diagram illustrating an appearance of an automatic measuring unit according to the third embodiment. FIG. 19 is a cross-sectional view of a part of the automatic micrometer device. FIG. 19 is a cross-sectional view of the automatic micrometer device. FIG. 19 is a cross-sectional view of the automatic micrometer device. FIG. 19 is a diagram illustrating a state where the rotation restricting means has been released to allow rotation of the rotary stage.Fig. 1 is a diagram illustrating a state in which the rotation restricting means returns the rotation angle of the rotary stage to an initial position and restricts rotation. Fig. 2 is a diagram illustrating a state in which the rotary stage is freed from constraint by the constraint plate and is able to rotate. Fig. 3 is a cross-sectional view of the automatic micrometer device, with a portion cut away, so that the linear guide of the workpiece holding unit can be seen. Fig. 4 is a cross-sectional view of the automatic micrometer device. Fig. 5 is a cross-sectional view of the automatic micrometer device. Fig. 6 is a diagram illustrating an example configuration in which the automatic micrometer device is attached to the hand of a robot arm unit.

[0017] Embodiments of the present invention will be illustrated and described with reference to the reference numerals assigned to the elements in the drawings. Each embodiment may be implemented singly or in combination with two or more embodiments, and modifications supplemented in each embodiment may also be applied to other embodiments. (First Embodiment) A first embodiment of the present invention will be described. FIG. 1 is an overall configuration diagram of an automatic measuring device 100. The automatic measuring device 100 comprises a measuring device main body 120 and a control unit 800.

[0018] (Measuring Apparatus Main Body) The measuring apparatus main body 120 includes a robot arm 130 as a moving means, and an automatic measuring unit 200.

[0019] Although the moving means will be described using an articulated arm robot as an example, it may also be a simpler moving mechanism that combines one-axis or two-axis rotation and linear motion. The moving means may be capable of moving the workpiece W and the measuring instrument relative to one another. Therefore, the moving means may transport the workpiece W or the measuring instrument. In the first embodiment, the moving means transports the workpiece W. For example, a workpiece W (e.g., a part) machined by a machine tool (e.g., an NC lathe) is transported by a belt conveyor 111. The workpiece W is transferred to a pre-processing stocker 112. Pre-processing may involve degreasing and dust removal, for example, using an air blower. The pre-processed workpiece W is then transported into the measurement area of ​​the automatic measuring unit 200 by, for example, a robot arm 130 serving as a moving means. The robot arm 130 may be, for example, an articulated robot arm 130, and may have, at its tip, a robot hand 140 for grasping the workpiece W and a camera 150 for image recognition. The robot arm unit 130 recognizes the workpiece W by image recognition, grabs the workpiece W with the robot hand 140, and carries the workpiece W to the measurement area of ​​the automatic measuring unit 200. Here, the robot hand 140 places the workpiece W in the measurement area with its orientation (posture) set in a preset orientation (posture), and then temporarily releases the workpiece W. Note that, for a simpler system, the workpiece W may be picked up and carried manually by a person. The dimensions of the workpiece W carried to the measurement area in this manner are measured by the automatic measuring unit 200.

[0020] (Automatic Measuring Unit) The automatic measuring unit 200 measures the dimensions of the workpiece W by bringing a measuring element (movable member) into contact with the workpiece W. While it is possible to measure either the inner dimension (inner diameter) or the outer dimension (outer diameter) of the workpiece W, this embodiment will be described taking as an example a case where the outer dimension (outer diameter) is measured. FIG. 2 is a plan view of the automatic measuring unit. FIG. 3 is a perspective view of the automatic measuring unit from the front side. FIG. 4 is a perspective view of the automatic measuring unit from the rear side.

[0021] The automatic measuring unit 200 is an automated version of a micrometer 300, which is a small measuring instrument (small measuring tool). The automatic measuring unit 200 of the first embodiment will be referred to as an automatic micrometer device 200. FIG. 2 is an external view of the automatic micrometer device 200. The automatic micrometer device 200 includes a base plate portion 210, a micrometer (measuring instrument) 300, a measuring instrument support portion 400, an automatic operation portion 500, and a workpiece holding portion 600.

[0022] The base plate portion 210 is a base that supports the entire unit, and is a metal plate in this example.

[0023] The micrometer 300 is originally a small measuring instrument that is manually operated, and a micrometer 300 currently available on the market can be used as the micrometer 300 of this embodiment. For example, there are micrometers available with a measurement range of 0-25 mm and a resolution of 0.1 micrometers, and these can be used. The configuration of the micrometer 300 will now be briefly described. The micrometer 300 has a U-shaped frame (fixed element) 310, a spindle (movable element) 330, a thimble portion 340, and a displacement detection portion 350.

[0024] The U-shaped frame 310 has an anvil 320 inside one end of the U-shape. The spindle 330 is provided on the other end of the U-shaped frame 310 and is movable axially back and forth relative to the anvil 320. A measuring surface for contacting the workpiece W is provided on one end face of the spindle 330. Similarly, a measuring surface for contacting the workpiece W is also provided on the other end face of the anvil 320. The measuring surface is machined to a flat surface and is made of, for example, cemented carbide or ceramic.

[0025] Note that the anvil 320 may not be provided on the main body frame 310, as in a so-called micrometer head. The anvil 320, which is paired with the spindle 330 to clamp the workpiece W, may be installed on the measurement axis as a separate body from the micrometer 300. In this embodiment, both the measurement surface of the spindle 330 and the measurement surface of the anvil 320 are flat, but one of the measurement surfaces of the spindle 330 and the anvil 320 may be flat. For example, the other of the measurement surface of the spindle 330 and the measurement surface of the anvil 320 may be a spherical surface (spherical tip) or a pin, and may be in point contact.

[0026] The spindle 330 is fed axially back and forth by rotating the thimble portion 340. The spindle 330 can be fed either in a rotary feed type, in which the spindle 330 itself rotates, or in a linear feed type, in which the spindle 330 itself does not rotate. In the rotary feed type, a male thread is provided on the spindle 330 itself, and a female thread is provided on the U-shaped frame 310. The thimble and the spindle 330 are engaged so that they rotate together, and the spindle 330 is rotated by rotating the thimble. The spindle 330 then advances and retreats by the thread feed. In the linear feed type, a feed screw is provided on the inside of the thimble 340, and the spindle 330 is provided with a pin that engages with the feed screw. When the thimble 340 is rotated while the spindle 330 is prevented from rotating, the spindle 330 is advanced by the engagement of the pin and the feed screw. The type of micrometer 300 employed in this embodiment may be either a rotary feed type or a linear feed type.

[0027] The thimble 340 is disposed at the other end of the spindle 330, on the other end of the U-shaped frame 310. The thimble 340 is an operating part that moves the spindle 330 forward and backward when rotated. The micrometer 300 employed in this embodiment preferably has a constant pressure mechanism between the thimble 340 and the spindle 330. The constant pressure mechanism disengages the thimble from the spindle 330 and allows the thimble to rotate freely relative to the spindle 330 when a preset load is applied to the spindle 330. By consistently operating the constant pressure mechanism appropriately during measurement, the measurement pressure can be kept constant, thereby maintaining high measurement accuracy (repeatability). Constant pressure mechanisms are also incorporated into commercially available micrometers 300, and are disclosed in, for example, Patents 3115555, 3724995, 5426459, and 5270223. The constant pressure mechanism can be configured as a ratchet mechanism that causes slippage when a force greater than a predetermined load is applied between the thimble and spindle 330, or a leaf spring that is interposed between the outer sleeve and inner sleeve of the thimble portion 340 so that slippage occurs when a load greater than a predetermined load is applied.

[0028] Furthermore, the micrometer 300 employed in this embodiment preferably includes a measurement pressure detection mechanism that detects the load on the spindle 330. For example, measurement pressure detection mechanisms are disclosed in Japanese Patent No. 3751540, Japanese Patent No. 4806545, and Japanese Patent Application Laid-Open No. 2019-190916. The measurement pressure detection mechanism may directly or indirectly detect the load on the spindle 330 using a strain gauge or the like, or may detect that the load on the spindle 330 has reached a predetermined value due to activation of the constant pressure mechanism. The measurement pressure detection mechanism outputs a signal (measurement pressure signal) when it detects a predetermined measurement pressure. For example, the displacement detection unit 350 samples (latches) the measurement value (displacement amount) when the measurement pressure detection mechanism detects the predetermined measurement pressure.

[0029] The displacement detection unit 350 detects the amount of displacement (or position) of the spindle 330. The displacement detection unit 350 is configured by a rotary encoder or a linear encoder.

[0030] Note that the displacement detection unit 350 may be an analog type (scale type) instead of an encoder. In this case, for automation, the scale may be read by a digital camera 150 or the like, and the measurement value may be read by image analysis (image recognition). In this case, the displacement detection unit 350 may be configured by the analog scale, the digital camera 150, and the image recognition unit (image analysis unit).

[0031] Furthermore, a display panel 311 that displays measured values ​​and operation switches are provided on the front surface of the U-shaped frame 310. Also, as a function of the electric circuit section built into the U-shaped frame 310, a measured value output function that outputs measured values ​​to the outside via wired or wireless communication is provided.

[0032] Next, we will explain the measuring device support part 400. The measuring device support part 400 has a frame part 410 and a measuring device holding part 420.

[0033] The frame portion 410 is an L-shaped frame overall. For the sake of explanation, XYZ coordinate axes are taken as being perpendicular to each other as shown in FIG. 2 (this coordinate system is a left-handed system). Of the two sides that make up the frame portion 410, the side parallel to the Z-axis direction is referred to as the first long side portion 411, and the side parallel to the Y-axis direction is referred to as the first short side portion 413. The top surface of the base plate portion 210 is a surface parallel to the YZ plane. The normal direction of the top surface of the base plate portion 210 is a direction parallel to the X-axis.

[0034] The first long side portion 411 and the first short side portion 413 may be extendable so that the length can be adjusted. This allows the size of the frame portion 410 to be adjusted according to the size of the micrometer 300 and the workpiece W.

[0035] A measuring device holding unit 420 is provided on the first long side 411, and an automatic operation unit 500 is provided on the first short side 413. A portion of the first long side 411 near the front end is fixed to the base plate 210, so that the micrometer 300 and the automatic operation unit 500 are provided on the base plate 210 via the frame 410.

[0036] The measuring device holder 420 is fixedly attached to the first long side 411. The measuring device holder 420 holds the main body frame of the micrometer 300, and attaches the micrometer 300 to the frame portion 410 (first long side 411). The orientation of the micrometer 300 is such that the forward / backward direction (axial direction) of the spindle 330 is parallel to the Z axis, one end side of the U-shaped frame 310 (the anvil 320 side) is the negative side of the Z direction, and the other end side of the U-shaped frame 310 (the thimble side) is the positive side of the Z direction.

[0037] The automatic operating unit 500 automates the advance and retreat of the spindle (movable element) 330 by the power of the motor 520. The automatic operating unit 500 includes a motor housing 510, a motor 520, and a power transmission unit 530.

[0038] The motor housing 510 houses the motor 520 and the motor controller. The motor housing 510 is disposed on an extension of the center line of the spindle 330 (or the thimble portion 340) of the micrometer 300. In other words, the automatic operating unit 500 is installed so that the rotation axis of the rotor of the motor 520 is on the same straight line as the center axis of the spindle 330 (or the thimble portion 340). If necessary, the position of the motor housing 510 can be adjusted by moving it along the rail of the first short side portion 413.

[0039] Motor 520 may be a normal electric motor that outputs the rotation of a rotor to an output shaft. However, it is preferable that motor 520 be able to control the rotation angle (number of rotations) of forward and reverse rotation to some extent using control pulses. Motor 520 also preferably has a torque detection function. (Various methods are known for detecting torque of motor 520, such as determining torque from an increase or decrease in applied current (applied voltage).) Motor 520 may be, for example, a stepping motor. (Of course, a servo motor or synchronous motor may also be used, and the motor structure and drive method are not particularly limited.)

[0040] The power transmission unit 530 includes a fixed ring 531 fitted onto the thimble unit 340, a rotating plate 532 provided to rotate in synchronization with the rotation shaft of the rotor of the motor 520, and a transmission link rod 533 connecting the fixed ring 531 and the rotating plate 532. One end of the transmission link rod 533 is fixed to the fixed ring 531, and the other end is fixed to the rotating plate 532. The transmission link rod 533 is parallel to the central axis of the spindle 330. When the rotating plate 532 is rotated by the motor 520, the rotation is transmitted to the fixed ring 531 by the transmission link rod 533, and the fixed ring 531 rotates in synchronization with the rotating plate 532.

[0041] The workpiece holding unit 600 holds the workpiece W to be measured in the measurement area of ​​the micrometer (measuring instrument) 300. The workpiece holding unit 600 includes a translational movement allowance mechanism 610, a first rotational movement allowance mechanism 710, and a second rotational movement allowance mechanism 720.

[0042] First, the translational movement permitting mechanism 610 permits translational displacement within a plane parallel to the measurement axis direction. Here, the measurement axis is the axis of the spindle 330 or an extension of the axis of the spindle 330, and the direction parallel to the measurement axis is the direction parallel to the Z axis. The translational movement permitting mechanism 610 includes a rail 611, a translating body 612 that slides along the rail 611, a stopper 615, and a linear actuator (returning means) 616.

[0043] Rail 611 is a linear guide rail installed parallel to the measurement axis of the measuring instrument (micrometer 300). In this example, rail 611 is installed on the upper surface of base plate portion 210 directly below the axis of spindle 330 and anvil 320, parallel to the Z direction.

[0044] The translating body 612 has a slider 613 that straddles the rail 611 and slides along the rail 611, and a slightly wider Z movement stage 614 that is fixed to the upper surface of the slider 613 and moves integrally with the slider 613. As an expression of the movement direction of the translating body 612, movement in the positive Z direction will be referred to as "retraction," and movement in the negative Z direction will be referred to as "advancement," just like the forward and backward directions of the spindle 330.

[0045] A first rotation allowance mechanism 710 is installed on the Z movement stage 614. This will be described later.

[0046] The stopper 615 is fixedly installed on the base plate portion 210 on the positive side in the Z direction of the translating body 612. When the translating body 612 moves in the positive Z direction, the translating body 612 hits the stopper 615 and stops. The position at which the translating body 612 is stopped by the stopper 615 corresponds to the position of the translating body 612 when exchanging the workpiece W before and after measurement. This point will be explained in the explanation of the operation of the workpiece holding portion 600.

[0047] The linear actuator 616 is installed on the base plate portion 210 on the negative side in the Z direction of the translating body 612. The linear actuator 616 is, for example, an air piston cylinder, and a rod moves forward and backward. The linear actuator 616 serves as a return means that pushes the translating body 612, which has moved toward the anvil 320, back toward the stopper 615.

[0048] In this embodiment, the linear actuator 616 pushes back the translating body 612, so it is installed on the opposite side of the stopper 615 with the translating body 612 in between, but if it were to pull back the translating body 612, the linear actuator 616 and the stopper 615 would be installed on the same side. Instead of the linear actuator 616, the return means may be a (weak) elastic body (spring) that applies a biasing force to the translating body 612 toward the stopper 615.

[0049] The first rotation allowance mechanism will be described with reference to Fig. 5 to Fig. 7. Fig. 5 is a cross-sectional view of the first rotation allowance mechanism taken along a plane including the rotation axis of the first rotation allowance mechanism. Fig. 6 is a diagram showing a modified example of the installation position of a counterweight serving as a restricting means in the first rotation allowance mechanism. Fig. 7 is a schematic view of the first rotation allowance mechanism as viewed from a direction perpendicular to the measurement axis.

[0050] The first rotation allowance mechanism 710 is installed on the translating body 612 and slides in the Z direction together with the translating body 612. The first rotation allowance mechanism 710 has a support pillar 711 erected on the translating body 612, a first rotating body 712 rotatably provided on the support pillar 711, and a restriction means 716.

[0051] The support column 711 is installed on the upper surface of the Z movement stage 614, on the opposite side of the measurement axis from the U-shaped frame 310. The support column 711 axially supports a first rotating body 712. The rotation axis of the first rotating body 712 is parallel to the Y axis. The rotation axis of the first rotating body 712 is defined as the first rotation axis. As shown in the cross-sectional view of FIG. 5, the first rotating body 712 is an L-shaped member when viewed from the side.

[0052] The first rotating body 712 has a first rotating shaft portion 713 as a rotating shaft, an arm portion 714 extending vertically, and a Y swing stage 715 bent from the lower end of the arm portion 714 toward the negative side of the Y direction and extending horizontally. The arm portion 714 is perpendicular to the first rotating shaft, and the first rotating shaft portion 713, which is attached to the upper end of the arm portion 714 in the positive Y direction, is journaled on the support column portion 711 as the first rotating shaft. The first rotating shaft portion 713 is journaled on the support column portion 711 by a radial bearing 713A and a thrust bearing 713B. Note that the bearings may be angular bearings instead of the radial bearing 713A and the thrust bearing 713B. It is preferable that the first rotating shaft be perpendicular to the measurement axis. The reason for this will be explained later.

[0053] The Y swing stage 715 is located directly below the measurement axis and is cantilevered by the arm portion 714. The Y swing stage 715 rotates around a first rotation axis.

[0054] In this embodiment, the first rotating body 712 is cantilevered, but depending on the weight of the workpiece W, it may be changed to a double-sided support.

[0055] Restriction means 716 restricts the rotational displacement of first rotating body 712. Restriction means 716 has shaft 717 suspended from Y swing stage 715, and counterweight 718 attached to the lower end of shaft 717. Because shaft 717 is suspended from Y swing stage 715, counterweight 718 is located away from the first rotation axis, which is advantageous in terms of moment and allows for balancing using a small, light counterweight 718. In addition, the balance of the weight can be adjusted by changing the position of counterweight 718 along shaft 717 to move it closer to or farther away from the first rotation axis.

[0056] The position at which the counterweight 718 serving as the restricting means is installed may be any position that restricts the rotation of the first rotating body 712. Therefore, the counterweight 718 may be installed not only on the Y swing stage 715 as shown in FIG. 5 , but also so that the weight of the counterweight 718 is indirectly applied to the Y swing stage 715. For example, in FIG. 6 , the counterweight 718 is installed on the first rotating shaft 713 on the side opposite the Y swing stage 715. In this case, the load is applied to the first rotating shaft 713 in a balanced manner, not just on one side but on both sides, thereby reducing the load on the first rotating shaft 713. Furthermore, compared to installing the counterweight 718 below the Y swing stage 715, this reduces the space below the Y swing stage 715 and makes it easier to adjust the shape, weight, position, etc. of the counterweight 718, thereby increasing the degree of freedom in design. The counterweight 718 may be installed not only directly on the first rotating body 712, but also indirectly on the first rotating body 712.

[0057] Here, the regulating means 716 regulates the posture of the workpiece to a vertical posture by the weight of the counterweight, but other means may also be used, for example, an elastic body such as a spring or a biasing means, so that a biasing force is applied to the first rotating body 712 so that the first rotating body (or the workpiece) maintains a reference posture (for example, a vertical posture) when the measurement pressure is below a predetermined value.

[0058] The workpiece holder 600 includes a first rotation allowance mechanism 710 and a translation allowance mechanism 610 that allow displacement of the workpiece W. In this embodiment, it is considered preferable that the position adjustment of the workpiece W on the measurement axis function before the inclination adjustment of the workpiece W. In other words, the aim is for the first rotation allowance mechanism 710 to adjust the inclination of the workpiece after the translation allowance mechanism 610 has adjusted the position of the workpiece. Therefore, a restriction means 716 that slightly restricts movement is added to the first rotation allowance mechanism 710 so that the translation allowance mechanism 610 operates before the first rotation allowance mechanism 710 when the spindle 330 hits the workpiece W. In this embodiment, because the first rotation axis of the first rotation allowance mechanism 710 is parallel to the Y axis (horizontal), rotation is restricted by making the first rotor 712 slightly heavier.

[0059] Second rotation allowance mechanism 720 is a rotation mechanism provided on first rotation allowance mechanism 710. FIG. 8 is a diagram illustrating an X rotation stage and work holder. As shown in FIG. 5 or 8, second rotation allowance mechanism 720 is X rotation stage 721 provided on Y swing stage 715. X rotation stage 721 is rotatably supported on Y swing stage 715 by radial bearing 722. The rotation axis of X rotation stage 721 is in a direction intersecting (orthogonal to) the first rotation axis, and when first rotor 712 is not rotating, the rotation axis of X rotation stage 721 is parallel to the X axis.

[0060] In this embodiment, it is assumed that the workpiece W is cylindrical, and a pin-shaped workpiece holder 620 can be inserted into the X rotation stage 721. In this embodiment, the cylindrical workpiece W is placed over the workpiece holder 620. In other words, since the X rotation stage 721 supports the workpiece, the X rotation stage 721 can also be considered to be the workpiece placement stage.

[0061] Note that, when measuring the outer diameter of a cylindrical workpiece W, the largest outer dimension (diameter) must be measured, so it is necessary to restrict to some extent the sliding movement of the workpiece W in a direction intersecting the measurement axis. As for the workpiece holder, in addition to the one described above that enters inside the workpiece W to restrict its movement, several pins or walls (blocks) may be arranged around the X-rotation stage to restrict its movement from the outside. Two pins or walls (blocks) may be arranged on opposite sides of the measurement axis on the X-rotation stage 721. In other words, the two pins or walls (blocks) may be arranged so that their opposing directions intersect (orthogonal to) the measurement axis. Alternatively, various other methods are conceivable, such as sloping (tapering) the top surface of the X-rotation stage so that the workpiece W is centered.

[0062] The control unit section 800 controls the rotational drive of the motor 520 to control the advancement and retreat of the spindle 330, and also drives the linear actuator 616 of the translational movement allowing mechanism section 610 at appropriate timing. In addition, the control unit section 800 samples the measurement value from the micrometer 300 (displacement detection section 350) at appropriate timing.

[0063] The operation of the first embodiment will now be described. FIGS. 9 to 13 are diagrams illustrating the measurement operation by the automatic micrometer device 200. Please refer to FIG. 9 first. The workpiece W is placed on the X-rotation stage 721, which serves as a workpiece placement stage. This operation is performed by the robot hand 140. When placing the workpiece on the X-rotation stage 721, the spindle 330 and the anvil 320 must not get in the way. Therefore, the spindle 330 is retracted, and the translating body 612 is pushed by the linear actuator 616 and retracted until it abuts against the stopper 615. Here, the position of the workpiece holder 600 when exchanging the workpiece W is referred to as the workpiece exchange position. The workpiece exchange position of the workpiece holder 600 is the side farthest from the anvil 320 between the anvil 320 and the retracted spindle 330. The stopping position of the translation body 612 by the stopper 615 determines the work holding part 600 to the work replacement position before and after the measurement starts, and the position of the stopper 615 is set at a position adjusted in this way on the upper surface of the base plate part 210.

[0064] 9 to 13, the distortion of the workpiece W is exaggerated to make it easier to understand the function of the workpiece holding unit 600 of this embodiment. The center line of the workpiece W is tilted relative to the bottom surface (end surface), and the workpiece W is tilted when placed on the X rotation stage 721.

[0065] As shown in FIG. 9, once the workpiece W is placed on the X-rotation stage 721, the control unit 800 executes preset (programmed) motor drive control. The control unit 800 rotates the motor 520 in the forward direction, moving the spindle 330 forward toward the anvil 320 (see FIG. 10). At this time, the translation body 612 allows movement in the Z direction, so the workpiece W is pushed forward by the spindle 330 while placed on the workpiece holder 600. The first rotor 712 of the first rotation allowance mechanism 710 is made slightly heavier by the counterweight 718, so the rotation of the first rotor 712 is restricted accordingly. In other words, most of the displacement of the spindle 330 is not absorbed by the rotation of the first rotor 712, and the first rotation allowance mechanism 710 moves forward together with the workpiece W while placed on the translation body 612. FIG. 10 shows the state in which the workpiece W, pushed forward by the spindle 330, comes into contact with the anvil 320. However, in this state, the workpiece W is tilted between the spindle 330 and the anvil 320, and the displacement (position) of the spindle 330 at this time does not provide a correct measurement value for the workpiece dimensions.

[0066] In this embodiment, as will be described later, the first rotation axis intersects (is perpendicular to) the measurement axis, and therefore the movement of the translator 612 is completed when the workpiece W comes into contact with the anvil 320, and the Z direction position of the translator when measuring the workpiece W is determined by this. As shown in Fig. 10, the position of the translator 612 when the workpiece W is sandwiched between the spindle 330 and the anvil 320 may be considered to correspond to the measurement position of the translator 612. In contrast to the measurement position, the workpiece exchange position is a non-measurement position.

[0067] Next, the workpiece W is sandwiched between the spindle 330 and the anvil 320 so that the measurement surfaces of the spindle 330 and the anvil 320 come into close contact (combine) with the surface of the workpiece W. The control unit 800 further advances the spindle 330 until the constant pressure mechanism is activated. At this time, pressure (measurement pressure) is applied to the workpiece W from the spindle 330 and the anvil 320. Because the first rotation allowance mechanism 710 allows the workpiece W to rotate about the first rotation axis, the workpiece W rotates about the first rotation axis of the first rotation allowance mechanism 710 to adjust its own tilt. That is, as illustrated in FIG. 11 , the first rotating body 712 rotates about the first rotation axis, and at this time, the workpiece W is firmly sandwiched between the spindle 330 and the anvil 320, and the contact surfaces are firmly combined.

[0068] In order to restrict the rotation of the first rotating body 712 with the counterweight 718 of the restricting means 716, the first rotating body 712 must be able to rotate when a force equivalent to the measurement pressure is applied to (both) sides of the workpiece. The weight of the counterweight 718 is adjusted according to the magnitude of the measurement pressure or the moment when the measurement pressure is applied to the side of the workpiece.

[0069] When the constant pressure mechanism is activated, a predetermined measurement pressure is applied, and the micrometer 300 samples the displacement (position) of the spindle 330 at this time as a measurement value. The sampled measurement value (measurement data) is output to the outside via wired or wireless communication, and the measurement data is collected and processed by an external PC (personal computer) or data processing device via the control unit 800.

[0070] Now that the measurement value has been obtained, the spindle 330 moves backward. Then, as shown in Figure 12, the first rotating body 712 returns to a vertical position due to its own weight. After this, in order to change over to the next workpiece W, as shown in Figure 13, the linear actuator 616 pushes the translating body 612, returning the position of the translating body 612 to the workpiece exchange position (non-measurement position).

[0071] According to the automatic measuring device 100 of this embodiment, the measurement work of the workpiece W is almost entirely automated. The automatic micrometer device 200 of this embodiment automates the micrometer 300, which is a small contact-type measuring device (small measuring tool). One of the reasons why it has been difficult to automate small contact-type measuring devices (small measuring tools, such as the micrometer 300) until now is that it has been difficult to properly contact the workpiece W with the measuring element (movable element) and make the measurement surface conform to each other. In this regard, in this embodiment, the workpiece W is supported by a workpiece holder 600, which allows translational and rotational movement, and allows the position and posture of the workpiece W to be changed with a force equal to or less than the measurement pressure.

[0072] Furthermore, in this embodiment, the first rotation axis intersects (is perpendicular to) the measurement axis. In other words, in this embodiment, the first rotation axis is not offset from the measurement axis. Here, Figures 14, 15, and 16 are schematic diagrams illustrating, for comparison, a case in which the first rotation axis is offset from the measurement axis. For example, as shown in Figure 15, when the workpiece is rotated around a rotation axis offset from the measurement axis to adjust its posture, the position of the anvil 320 does not move. Therefore, when correcting the tilt, the first rotation axis must be displaced along the measurement axis. In other words, when adjusting the tilt of the workpiece W, rotation of the first rotating body 712 and translation of the translating body 612 are required. However, when attempting to adjust both simultaneously using only a weak measurement pressure, they often do not function properly. This results in measurement errors that cause variations in the measurement values. Furthermore, as illustrated in Figure 16, when the rotation axis is offset from the measurement axis, the rotational moment applied to the workpiece W from the spindle 330 and the moment applied to the workpiece W from the anvil 320 partially cancel each other out with respect to the rotation axis, and even a slight difference in magnitude generates a rotational force, but this often results in the workpiece W not rotating properly.

[0073] In contrast, if the first rotation axis and the measurement axis are made to intersect (orthogonal to each other) as illustrated in FIG. 17 , the translation of the workpiece W can be minimized even when the workpiece W rotates due to tilt adjustment of the workpiece W. Furthermore, the rotational moment applied to the workpiece W from the spindle 330 and the moment applied to the workpiece W from the anvil 320 act as forces that rotate in the same direction relative to the rotation axis. Therefore, in this embodiment, the first rotating body 712 is shaped so that the first rotation axis portion 713 and the Y swing stage 715 are connected by an arm portion 714. With this configuration, the posture adjustment of the workpiece W can be stably and reliably performed even with a small measurement pressure such as that of the micrometer 300, and high-precision dimensional measurement can be performed automatically.

[0074] It is primarily preferable that the line connecting the center line of the anvil 320 and the center line of the spindle 330 (strictly speaking, the measurement axis) intersect (orthogonalize) with (the extension of) the first rotation axis, but if the first rotation axis is located between the end face of the anvil 320 and the end face of the spindle 330, it should be interpreted that the extension of the rotation axis of the first rotation allowance mechanism 710 intersects (orthogonalize) with the measurement axis. Furthermore, the present invention does not exclude the first rotation axis being offset from the measurement axis.

[0075] Second Embodiment A second embodiment of the present invention will be described. In the first embodiment, the regulating means 716 is a counterweight 718, whereas in the second embodiment, the regulating means 716 is a restraining member 719 that moves toward and away from the first rotating body 712. In FIG. 18 , instead of the counterweight 718, the regulating means 716 is a clamping piece (restraining member) 719 that clamps the shaft 717 from both sides. The clamping piece 719 is located below the Y swing stage 715 and opens and closes to clamp the shaft 717 from the negative and positive sides in the Z direction. A state in which the clamping piece 719 is closed to clamp the shaft 717 is called a hold state, and a state in which the clamping piece 719 is opened to release the shaft 717 is called a release state. Various actuators, such as an air cylinder, can be used as the opening and closing mechanism for the clamping piece 719. 18, the rotation of the first rotating body 712 is restricted by clamping the shaft 717 from both sides, but if it is only necessary to restrict the rotation of the first rotating body 712 when the workpiece W is pushed by the spindle 330, then only a restraining member on the positive side in the Z direction will suffice. However, since it is also necessary to restrict the rotation of the first rotating body 712 when the automatic micrometer device 200 is being transported, it is better to clamp the shaft 717 to stop its movement.

[0076] It is also possible to have both the restraining member 719 and the counterweight 718. If the counterweight 718 is provided, the rotation of the first rotating body 712 is restricted to some extent by its weight even when the power is turned off.

[0077] (Explanation of Operation) The operation of the automatic micrometer device 200 in the second embodiment will now be described. FIG. 19 is a flowchart for explaining the measurement operation by the automatic micrometer device 200. First, as illustrated in FIG. 20, the regulating means 716 is driven to clamp the shaft 717 with the clamping pieces 719, thereby restricting the rotation of the first rotating body 712. In the second embodiment, the first rotating body 712 is fixed by being clamped by the clamping pieces 719 (ST201). Then, when the workpiece W is set on the X-rotating stage 721 by the robot arm 130, the control unit 800 executes pre-set (programmed) motor drive control. The control unit 800 rotates the motor 520 forward to advance the spindle 330 toward the anvil 320 (ST201). The rotational speed of the motor 520 at this time is, for example, 180 rpm (or approximately 100 rpm to 200 rpm). From the perspective of shortening the measurement time, it is considered best to increase the rotational speed as much as possible. As the spindle 330 advances toward the anvil 320, the spindle 330 comes into contact with the workpiece W. At this time, the translating body 612 allows movement in the Z direction, so the workpiece W is pushed forward by the spindle 330 while placed on the workpiece holder 600. Pushed by the spindle 330, the workpiece W moves together with the translating body 612, and the workpiece W comes into contact with the anvil 320.

[0078] The moment the workpiece W is clamped between the anvil 320 and the spindle 330, the motor torque increases, and the torque detection function causes the motor controller to detect that the spindle 330 has come into contact with the workpiece W, in other words, that the anvil 320 and the spindle 330 have come into contact with the workpiece W (ST230: YES).

[0079] The mechanism for detecting that the anvil 320 and the spindle 330 have come into contact with the workpiece W may be one that detects this based on the displacement of the spindle (movable element) 330. While monitoring the displacement of the spindle 330 with the displacement detection section 350, when it is detected that the displacement of the spindle 330 is small in response to the drive signal issued from the control unit section 800, or that the movement of the spindle 330 has stopped, it may be determined that the anvil 320 and the spindle 330 have come into contact with the workpiece W.

[0080] When the control unit 800 detects that the spindle 330 has come into contact with the workpiece W, it immediately rotates the motor 520 in the reverse direction at a relatively high speed for a predetermined number of rotations, causing the spindle 330 to move backward (ST204). The rotation speed of the reverse rotation is, for example, 180 rpm. The number of rotations of the reverse rotation is, for example, 0.5 rotations. Note that this rotation speed (180 rpm) is an example, and the rotation speed during forward rotation (ST202) and the rotation speed during reverse rotation (ST204) may be the same or different.

[0081] Here, it is preferable to temporarily retract the spindle 330 by rotating it in the reverse direction at a relatively high speed, rather than "stopping" or "decelerating." The first reason is to reliably prevent the spindle 330 from biting into the workpiece W. Sending a control signal to temporarily retract the spindle 330, rather than simply stopping the spindle, can more reliably prevent the spindle 330 from biting into the workpiece W. Also, a constant pressure mechanism is activated when generating the measurement pressure, and in order to activate the constant pressure mechanism while always advancing the spindle 330 at the same speed, it is necessary to ensure the operating distance of the spindle 330. Therefore, it is considered preferable to temporarily step back the spindle 330 so that the operation of applying the measurement pressure to the workpiece W can always be the same.

[0082] Here, as illustrated in FIG. 21, the restricting means 716 is driven to release the shaft 717, thereby allowing the first rotor 712 to rotate (ST205).

[0083] With the first rotating body 712 released, the motor 520 is rotated forward at a relatively slow speed to advance the spindle 330 toward the anvil 320 (second advancement step ST206). The motor 520 is rotated forward at a relatively slow speed. The rotation speed is the same as the rotation speed achieved in the previous retreat (ST204). Here, for example, the rotation speed is set to 0.5 rotations at 9 rpm. The workpiece W is slowly pushed to ensure contact between the workpiece W and the anvil 320 and between the workpiece W and the spindle 330. At this time, the rotation of the first rotating body 712 is permitted, and the posture of the workpiece W is adjusted by the rotation of the first rotating body 712 (see, for example, FIG. 22).

[0084] Next, the motor 520 is rotated forward at a relatively slow speed. The rotation speed is set to, for example, the amount of thimble rotation (the amount of spindle 330 rotation) from when the workpiece W comes into contact with the anvil 320 and spindle 330 until the constant pressure mechanism is activated. Here, for example, it is set to 0.5 rotations at 9 rpm. (The rotation speed and number of rotations may be changed as appropriate.) Here, by slowly activating the constant pressure mechanism once, the contact surfaces between the workpiece W and the anvil 320, and the contact surfaces between the workpiece W and the spindle 330 are reliably brought into contact (close contact).

[0085] In this state, the workpiece W is firmly clamped between the anvil 320 and the spindle 330. In this state, the motor 520 is rotated forward at a relatively high speed (measurement pressure application step), the constant pressure mechanism is activated again, and a predetermined measurement pressure is applied. For example, three rotations at 180 rpm are performed. The number of rotations required to activate the constant pressure mechanism depends on the specifications (of the constant pressure mechanism) of the micrometer 300 used.

[0086] After the constant pressure mechanism is activated in the measurement pressure application step and the operation of applying a predetermined measurement pressure is completed, the micrometer 300 samples the measurement value (ST207). The sampled measurement value (measurement data) is output to the outside via wired or wireless communication, and the measurement data is collected and processed by an external PC (personal computer) or data processing device via the control unit 800.

[0087] Since one measurement value has been acquired up to this point, the control unit section 800 rotates the motor 520 in the reverse direction at a relatively high speed to move the spindle 330 backward (ST208). Then, as illustrated in FIG. 23, the first rotating body 712 returns to a vertical position due to its own weight. Then, the regulating means 716 is driven to clamp the shaft 717 with the clamping pieces 719, thereby restricting the rotation of the first rotating body 712. In the second embodiment, the first rotating body 712 is fixed by being clamped by the clamping pieces 719 (ST209). Thereafter, in order to change to the next workpiece W, as illustrated in FIG. 24, the linear actuator 616 pushes the translating body 612, returning the position of the translating body 612 to the workpiece exchange position (non-measurement position).

[0088] According to the second embodiment, the movement of the first rotating body 712 can be restricted (fixed) by the clamping piece 719 of the restricting means 716, and the operation of the translational movement allowance mechanism 610 and the operation of the first rotational movement allowance mechanism 710 can be completely separated. This increases the accuracy of the position and attitude adjustment of the translational movement allowance mechanism 610 and the first rotational movement allowance mechanism 710. From this perspective, the release process (ST205) that allows the rotation of the first rotating body 712 is reserved until the workpiece W is initially clamped between the spindle 330 and the anvil 320, and the clamping piece 719 is opened and released when it becomes necessary to adjust the inclination of the workpiece W using the first rotational movement allowance mechanism 710.

[0089] It should be noted that, simultaneously with the start of the measurement process, for example, before the first forward movement process (ST202), the clamping pieces 719 may be opened to release the first rotating body 712. However, if translational movement and rotational displacement are performed simultaneously, variations in the posture adjustment of the workpiece W may occur, which is likely to lead to measurement errors. Therefore, as described in the second embodiment, it is considered preferable to use an operating procedure in which the clamping pieces 719 are opened immediately before the application of the measurement pressure to allow the first rotating body 712 to rotate.

[0090] (Variation 1) In the explanation up to this point, it has been assumed that the workpiece W is cylindrical, and therefore there is no need to operate the second rotation allowance mechanism 720. For example, if the workpiece W is a rectangular pillar as illustrated in Fig. 25, when the spindle 330 and the anvil 320 clamp both sides of the workpiece W, the rotation of the second rotation allowance mechanism 720 (X rotation stage 721) allows the workpiece W to rotate (rotate around the X axis), and the workpiece W can be firmly clamped between the spindle 330 and the anvil 320.

[0091] (Variation 2) The first rotation allowance mechanism 710 is provided on the translational movement allowance mechanism 610, and the first rotation allowance mechanism 710 moves on the translational body 612 of the translational movement allowance mechanism 610. This relationship may be reversed. The translational movement allowance mechanism 610 may be provided on the first rotation allowance mechanism 710, and the translational movement allowance mechanism 610 may rotate together with the first rotating body 712 of the first rotation allowance mechanism 710. However, if the weight on the rotation allowance mechanism increases, this may increase the resistance to adjusting the attitude of the workpiece about its rotation axis using the measurement pressure. Furthermore, a linear moving body such as a linear guide is considered to be more suitable for supporting the weight, and therefore the configuration of the embodiment is considered to be preferable.

[0092] Third Embodiment In the above embodiment, the measuring device 300 is fixedly mounted on the base plate 210, and the workpiece is displaced (translated and rotated) by the workpiece holder 600. However, this relationship may be reversed. The measuring device 300 may be mounted on a holder having at least one of the translational movement allowance mechanism 610 and the first and second rotational movement allowance mechanisms 710 and 720. When measuring dimensions using a compact measuring device, the object to be measured (the workpiece) is likely to be smaller and lighter than the measuring device itself. Therefore, it is more logical to install the measuring device in a fixed position and allow the workpiece to be displaced. However, dimensions of parts of a large, heavy workpiece (such as the inner diameter, outer diameter, and spacing of holes, protrusions, etc.) may be measured. In such cases, it may be better to allow the measuring device 300 to be displaced (translated and rotated). Furthermore, both the workpiece W and the measuring device 300 may be held by their respective holders and be displaceable or movable. For example, the workpiece W may be held by a translational movement permitting mechanism so as to be able to move in translation, and the measuring device 300 may be held by a rotational movement permitting mechanism so as to be able to be rotationally displaced, thereby enabling translational movement and rotational displacement relative to the workpiece W and the measuring device 300. Conversely, for example, the measuring device 300 may be held by a translational movement permitting mechanism so as to be able to move in translation, and the workpiece W may be held by a rotational movement permitting mechanism so as to be able to be rotationally displaced, thereby enabling translational movement and rotational displacement relative to the workpiece W and the measuring device 300.

[0093] A third embodiment will be described with reference to Figures 26 to 35. In the third embodiment, the workpiece holding unit holds the workpiece W fixedly, and the measuring unit holding unit holds the measuring unit so as to allow displacement (translation and rotation) of the measuring unit. Note that the configuration example shown in the third embodiment is designed so that displacement of the workpiece W in the Z direction can also be allowed if the workpiece holding unit is unlocked. This point will be explained further at the end.

[0094] 26 to 29 are external views of an automatic measuring unit (automatic micrometer device) 3200 according to the third embodiment. In Fig. 27 and Fig. 29, the column of the workpiece holding part 3300 is removed so that the parts hidden by the column of the workpiece holding part 3300 can be seen.

[0095] The workpiece holding section 3300 has two workpiece holding supports 3310 spaced apart in the X direction. The two workpiece holding supports 3310 are two supports that are provided at both ends of the base plate section 210 in the X direction and rise in the Y direction. The two workpiece holding supports 3310 are connected by a connecting plate 3312. The upper end of the workpiece holding support 3310 has a V-shaped groove 3311 that enables it to hold a rod-shaped workpiece W in a state that is approximately parallel in the X direction. The workpiece holding support 3310 may be configured to firmly hold the workpiece W, or a single workpiece holding support 3310 may be used as long as the workpiece holding support 3310 can hold the workpiece W in a cantilevered manner.

[0096] In the third embodiment, the measuring device holder 3400 holds the measuring device so as to allow displacement (translation and rotation) of the measuring device. The measuring device holder 3400 has a translation allowance mechanism 3500 and a rotation allowance mechanism 3600. FIG. 30 is a cross-sectional view of the automatic micrometer device 3200 partially cut along the YZ plane so that the translator 3520 of the translation allowance mechanism 3500 and the rotary shaft 3610 of the rotation allowance mechanism 3600 are visible. FIGS. 31 and 32 are cross-sectional views of the automatic micrometer device 3200 cut along the YZ plane so that the gauge translation control linear actuator 3530 of the translation allowance mechanism 3500 is visible.

[0097] The translational movement allowing mechanism 3500 allows translational displacement of the measuring device (micrometer) within a plane parallel to the measurement axis direction. The translational movement allowing mechanism 3500 includes a rail 3510, a translator 3520 that slides along the rail 3510, and a linear actuator 3530 for controlling gauge translation.

[0098] The rail 3510 is installed parallel to the Z direction on the upper surface of the base plate portion 210. The translating body 3520 has a slider 3521 that slides along the rail 3510, and a Z movement stage 3522 that is fixed to the upper surface of the slider 3521 and moves integrally with the slider 3521.

[0099] The gauge translation control linear actuator 3530 is installed on the base plate portion 210 on the negative side in the Z direction of the translator 3520. The gauge translation control linear actuator 3530 is, for example, an air piston cylinder, and a rod 3531 advances and retreats. The gauge translation control linear actuator 3530 serves as a return means that pulls back the translator 3520 that has moved (retreated) in the positive Z direction so that it moves (advances) in the negative Z direction. In FIG. 31 , a locking piece 3523 is provided on the side of the translator 3520, and the rod 3531 of the gauge translation control linear actuator 3530 is configured to hook onto this locking piece 3523. As shown in FIG. 31 , when the rod 3531 of the gauge translation control linear actuator 3530 is retracted in the negative Z direction, the translator 3520 is pulled by the rod 3531 and moves (advances) in the negative Z direction. When the rod 3531 of the linear actuator 3530 for gauge translation control is fixed at the return end in the negative Z direction, the translator 3520 is locked at this position. On the other hand, as shown in Figure 32, when the rod 3531 of the linear actuator 3530 for gauge translation control is extended in the positive Z direction, the translator 3520 is allowed to move backward in the positive Z direction.

[0100] The rotation allowance mechanism 3600 is mounted on the Z movement stage 3522 and slides in the Z direction together with the Z movement stage 3522. The rotation allowance mechanism 3600 includes a rotating shaft 3610, a rotating stage 3620, and a rotation restriction means 3630.

[0101] The rotating shaft body 3610 is mounted on a Z-movement stage 3522 and rotates around an axis parallel to the Y-axis as its central axis of rotation. A ball bearing 3611 is interposed between the rotating shaft body 3610 and the Z-movement stage 3522, allowing the rotating shaft body 3610 to rotate with low friction and high precision. It is preferable that the end face of the anvil 320 of the micrometer 300 is located exactly on an extension of the rotation axis of the rotating shaft body 3610. In other words, even if the measuring device (micrometer) rotates around the rotation axis, the end face of the anvil 320 serves as the center of rotation, and the attitude of the measuring device (micrometer) is adjusted (rotated) with the end face of the anvil 320 (i.e., the point of contact between the measuring device and the workpiece W) as a fixed point.

[0102] A rotation stage 3620 is fixedly attached to the upper end of the rotation shaft body 3610. A measuring device (micrometer) 300 equipped with an automatic operation unit 500 is fixedly installed on this rotation stage 3620. That is, in this third embodiment, the measuring device (micrometer) 300 equipped with the automatic operation unit 500 moves back and forth in the Z direction and rotates around the Y axis.

[0103] The rotation restricting means 3630 switches between holding and releasing the rotation stage 3620, and also returns the rotation angle of the rotation stage 3620 to zero degrees (a predetermined initial angle). Fig. 33 (or Fig. 30) is a diagram illustrating a state in which the rotation restricting means 3630 has released the rotation stage 3620 to allow rotation. Fig. 34 (or Figs. 28, 29, and 31) is a diagram illustrating a state in which the rotation restricting means 3630 has returned the rotation angle of the rotation stage 3620 to the initial position and is restricting rotation.

[0104] The rotation restricting means 3630 includes an engagement pin 3631, a restraining plate 3632, and a linear actuator 3634 for controlling gauge rotation.

[0105] The engagement pin 3631 is a pin provided at a position offset from the rotation axis of the rotation stage 3620. Here, the pin is provided on a center line along the Z direction. The constraint plate 3632 has a hole 3633 that receives the engagement pin 3631 and is a plate provided so as to be movable toward and away from the rotation stage 3620. The engagement hole 3633 of the constraint plate 3632 receives the engagement pin 3631 and further has a wide portion that allows the engagement pin 3631 to move within the engagement hole 3633 and a narrow portion that allows the engagement pin 3631 to be sandwiched and restrict the movement of the engagement pin 3631. Typically, the engagement hole 3633 may be triangular, but it may also be an irregularly shaped hole with a small curvature and a large curvature. Note that the constraint plate 3632 may have the engagement pin 3631, and the engagement hole 3633 may be located on the rotation stage 3620 side.

[0106] The linear actuator 3634 for gauge rotation control is an actuator that moves the constraint plate 3632 forward and backward. In this example, the linear actuator 3634 for gauge rotation control moves the constraint plate 3632 forward and backward along the Z direction. As shown in FIG. 33 , when the linear actuator 3634 for gauge rotation control is at the return end in the negative Z direction, it allows rotation of the rotation stage 3620. On the other hand, as shown in FIG. 34 , when the linear actuator 3634 for gauge rotation control is at the outgoing end in the positive Z direction, the engagement pin 3631 fits deeply into the engagement hole 3633, thereby returning the rotation angle of the rotation stage 3620 to its initial position.

[0107] In the third embodiment having such a configuration, the procedure for measuring the dimension (outer diameter) of the workpiece W is roughly as follows. First, the rod 3531 of the linear actuator 3530 for controlling gauge translation is returned in the minus Z direction, and then the linear actuator 3634 for controlling gauge rotation is driven in the plus Z direction to push the constraint plate 3632 in the plus Z direction. The state of the automatic micrometer device 3200 at this time is as shown in FIG. 31 or 34. That is, the translator 3520 is pulled to the furthest position on the minus Z side, and the angle of the rotation stage 3620 is reset to the initial position (initial angle). The position of the Z movement stage 3522 and the attitude (angle) of the rotation stage 3620 at this time may be referred to as the workpiece exchange position (non-measurement position).

[0108] In this state, the workpiece W is placed on the workpiece holder 3300. Then, the rod 3531 of the linear actuator 3530 for gauge translation control is extended in the plus Z direction. At this time, the state of the automatic micrometer device 3200 is as shown in Figure 32. In this state, movement of the translating body 3520 (Z movement stage 3522) in the plus Z direction is permitted.

[0109] The spindle 330 is advanced in the minus Z direction by the motor drive of the automatic operation unit 500. As the spindle 330 advances in the minus Z direction, the workpiece W is sandwiched between the anvil 320 and the spindle 330, and the spindle 330 further pushes the workpiece W so that a predetermined measurement pressure is applied. As the spindle 330 pushes the stationary workpiece W forward (in the minus Z direction), the Z movement stage 3522 moves relatively in the plus Z direction. As a result, as illustrated in FIG. 35, the engagement pin 3631 separates from the narrow portion of the engagement hole 3633 of the constraint plate 3632, allowing the rotation stage 3620 to rotate. The workpiece W is sandwiched between the end faces of the anvil 320 and the spindle 330, and measurement pressure is applied so that the workpiece W is in close contact with the end faces of the anvil 320 and the spindle 330. At this time, the rotation stage 3620 rotates as necessary so that the end faces of the anvil 320 and the spindle 330 fit closely to the workpiece W and come into close contact with each other. When the constant pressure mechanism is activated, a predetermined measurement pressure is applied, and the micrometer 300 samples the displacement (position) of the spindle 330 at this time as a measurement value. After sampling the measurement value, the spindle 330 is retracted in the positive Z direction.

[0110] This is then repeated to return rod 3531 of linear actuator 3530 for gauge translation control in the minus Z direction, and further drive linear actuator 3634 for gauge rotation control in the plus Z direction to push constraint plate 3632 in the plus Z direction. In other words, the position of Z movement stage 3522 and the attitude (angle) of rotation stage 3620 are returned to the workpiece replacement position (non-measurement position) (FIG. 31 or FIG. 34).

[0111] According to this configuration, when automatically measuring the dimensions of a heavy, long workpiece W, the displacement (translation, rotation) of the measuring device 300 is allowed for workpieces that are difficult to move, making it possible to appropriately and accurately measure the dimensions of the workpiece W.

[0112] (Supplementary Explanation) As shown in Figures 36, 37, and 38, in the third embodiment, it is also possible to allow translation of the workpiece holding part 3300. Figure 36 is a cross-sectional view cut so as to show the linear guide 3320 that allows translation of the workpiece holding part 3300. This linear guide 3320 allows the workpiece holding column 3310 to translate in the Z direction.

[0113] Figures 37 and 38 are cross-sectional views of the automatic micrometer device 3200 cut along the YZ plane so that the workpiece translation control linear actuator 3330 is visible. As shown in Figure 37, when the workpiece translation control linear actuator 3330 is extended in the positive Z direction and stopped at its extension end, the workpiece holder 3300 is locked and immobile. On the other hand, as shown in Figure 38, when the workpiece translation control linear actuator 3330 is pulled in the negative Z direction to its return end, translation of the workpiece holder 3300 is permitted. To permit translation of the workpiece holder 3300 while fixing the translation of the gauge, it is advisable to move the gauge rotation control actuator 3634 to its return end in the negative Z direction to permit rotation of the rotation stage 3620. The movement of the measuring instrument or the workpiece W may be switched appropriately, taking into account the weight and shape of each.

[0114] (Fourth embodiment) The automatic measuring unit (automatic micrometer device) 3200 may be attached to a moving means (for example, the robot arm section 130). The automatic measuring unit (automatic micrometer device) 3200 may be attached to a moving means (for example, the robot arm section 130), and the automatic measuring unit 3200 may be moved toward the location to be measured, thereby automatically measuring the dimensions (shape) of the workpiece W. The example shown in FIG. 39 is a configuration example in which the automatic micrometer device 3200 of the third embodiment is attached to the hand 140 of the robot arm section 130. With this configuration, it becomes possible to automatically measure the dimensions of a large workpiece W.

[0115] The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit and scope of the present invention. As the measuring instrument, in addition to a micrometer, a measuring instrument (measuring unit) such as a vernier caliper, a digital dial gauge (test indicator), a hole test, a cylinder gauge, or a Borematic (registered trademark) may be used.

[0116] 100 Automatic measuring device 111 Belt conveyor 112 Stocker 120 Measuring device main body 130 Robot arm 140 Robot hand 150 Camera 200 Automatic micrometer device 210 Base plate 300 Micrometer (measuring device) 310 U-shaped frame (fixed element) 311 Display panel 320 Anvil 330 Spindle (movable element) 340 Thimble 350 Displacement detection unit 400 Measuring device support unit 410 Frame 411 First long side 413 First short side 420 Measuring device holder 500 Automatic operation unit 510 Motor housing 520 Motor 530 Power transmission unit 531 Fixing ring 532 Rotating plate 533 Transmission link rod 600 Workpiece holder 610 Translational allowance mechanism unit 611 Rail 612 Translational body 613 Slider 614 Z movement stage 615 Stopper 616 Linear actuator (return means) 620 Work holder 710 First rotation allowance mechanism 711 Support column 712 First rotating body 713A Radial bearing 713B Thrust bearing 714 Arm 715 Y swing stage 716 Regulating means 717 Shaft 718 Counterweight 719 Clamping piece (restraint member) 720 Second rotation allowance mechanism 721 X rotation stage 722 Radial bearing 800 Control unit 3300 Workpiece holding section 3310 Workpiece holding column 3311 V-groove 3320 Linear guide 3330 Linear actuator for workpiece translation control 3400 Measuring instrument holding section 3500 Translation allowance mechanism 3510 rail 3520 translational body 3521 slider 3522 Z movement stage 3523 locking piece 3530 linear actuator for controlling translation of gauge 3531 rod 3600 rotation allowance mechanism 3610 rotating shaft body 3611 ball bearing 3620 rotation stage 3630 rotation restriction means 3631 engagement pin 3632 restraint plate 3633 engagement hole 3634 linear actuator for controlling rotation of gauge

Claims

1. A measuring instrument having a movable element that is displaceably mounted relative to a fixed element and moves back and forth to move toward and away from a workpiece, and a displacement detection unit that detects the displacement of the movable element, An automatic operation unit that automates the movement of the movable element by power, The device includes a holding part that holds at least one of the workpiece and the measuring instrument so that when the workpiece and the movable element come into contact, the relative position and orientation of the workpiece and the measuring instrument are changed by a pressure below a predetermined measuring pressure set in the measuring instrument, so that the contact surfaces of the workpiece and the movable element come into close contact. An automatic measuring device that automatically measures a workpiece using a measuring instrument for measuring the dimensions of the workpiece, When the direction in which the movable element moves forward and backward is the measurement axis, The aforementioned retaining part is A translational tolerance mechanism that allows translational displacement in a plane parallel to the measurement axis, The system includes a first rotation-permitting mechanism that allows rotation with an axis non-parallel to the measuring axis as the axis of rotation. An automatic measuring device characterized by the following features.

2. In the automatic measuring device according to claim 1, The translation tolerance mechanism has a translation body that translates in a plane parallel to the measuring axis, The first rotation-allowing mechanism is installed on the translation body and moves together with the translation body. An automatic measuring device characterized by the following features.

3. In the automatic measuring device according to claim 2, The first rotation-permissible mechanism has a first rotating body that directly or indirectly holds a workpiece or measuring instrument and rotates about the rotation axis as its center of rotation. The first rotation-permitting mechanism includes a restricting means for restricting the displacement of the first rotating body, The restricting means restricts the displacement of the first rotating body when the movable element and the workpiece are separated. The regulating means allows the displacement of the first rotating body when the movable element and the workpiece are in contact and the movable element is applying a measuring pressure to the workpiece. An automatic measuring device characterized by the following features.

4. In the automatic measuring device according to claim 3, The regulating means is a counterweight attached to the first rotating body. An automatic measuring device characterized by the following features.

5. In the automatic measuring device according to claim 3, The aforementioned regulatory means are It has a restraining member that moves toward and away from the first rotating body, The regulating means switches between a held state and a released state of the first rotating body by switching between a contact state and a separated state between the restraining member and the first rotating body. An automatic measuring device characterized by the following features.

6. In the automatic measuring device according to claim 5, The automatic operation unit is, The movable element is advanced so that it comes into contact with the workpiece. Next, the movable element is retracted by a predetermined amount, Subsequently, the movable element is moved forward again so that a predetermined measuring pressure is generated between the workpiece and the movable element. When the automatic operation unit moves the movable element forward again so that a predetermined measuring pressure is generated between the workpiece and the movable element, the regulating means releases the first rotating body and allows the displacement of the first rotating body. An automatic measuring device characterized by the following features.

7. In the automatic measuring device according to claim 1, As the movement position of the translation body in the translation-allowing mechanism, Non-measurement positions for exchanging workpieces before and after measurement, The measurement position is used to detect the displacement of the movable element as a measured value while applying a measuring pressure to the workpiece from the movable element. The translation tolerance mechanism has a return means that returns the position of the translation body from the measurement position to the non-measurement position. An automatic measuring device characterized by the following features.

8. In the automatic measuring device according to claim 1, The extension of the rotation axis of the first rotation-allowing mechanism intersects the measuring axis. An automatic measuring device characterized by the following features.

9. In the automatic measuring device according to claim 1, The aforementioned retaining part is moreover, The second rotation-allowing mechanism allows rotation with an axis that is not parallel to the measuring axis and the rotation axis of the first rotation-allowing mechanism. An automatic measuring device characterized by the following features.

10. A measuring instrument having a movable element that is displaceably mounted relative to a fixed element and moves back and forth to move toward and away from a workpiece, and a displacement detection unit that detects the displacement of the movable element, An automatic operation unit that automates the movement of the movable element by power, An automatic measuring unit having a holding part that holds the measuring instrument so that when the workpiece and the movable element come into contact, the relative position and orientation of the workpiece and the measuring instrument are changed at a pressure below a predetermined measuring pressure set in the measuring instrument, so that the contact surfaces of the workpiece and the movable element come into close contact. An automatic measuring device comprising the automatic measuring unit to which the automatic measuring unit is attached, and a robot arm as a means of moving the automatic measuring unit to the part of the workpiece to be measured, wherein the device automatically performs dimensional measurement of the workpiece, When the direction in which the movable element moves forward and backward is the measurement axis, The holding portion includes a translation-permissible mechanism that allows displacement in a plane parallel to the measuring axis, and a first rotation-permissible mechanism that allows rotation with an axis non-parallel to the measuring axis as the axis of rotation. An automatic measuring device characterized by the following features.