Automatic measuring device

Abstract

To provide an automatic measuring device for automating an inexpensive and easy-to-use contact type measuring instrument.SOLUTION: An automatic measuring device includes: a measuring instrument having a movable element that is provided displaceably relative to a fixed element and advances and retreats so as to contact and separate from a work, and a displacement detection section for detecting displacement or a position of the movable element; and an automatic operation section for automating advance / retreat of the movable element by power. Vibration is applied to at least one of a work and the measuring instrument directly or indirectly such that, when the work and the movable element are in contact with each other, the work and the measuring instrument change the relative positions and postures and abutting surfaces of the work and the movable element are brought into close contact.SELECTED DRAWING: Figure 2

Description

[Technical field]

[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. [Background technology]

[0002] Known measuring instruments (measuring tools) for measuring the dimensions of workpieces include micrometers, calipers, hole tests, cylinder gauges, and Borematic (registered trademark). These contact-type measuring instruments (measuring tools) have advantages such as ease of use, measurement stability, and relatively low cost, and are therefore widely used. However, the workpiece and the movable elements (spindle, measuring jaw, measuring element) must be appropriately brought into close contact with each other, and the same measuring pressure must always be applied during measurement, which means that manual measurement is essential. Therefore, measurements using such contact-type measuring tools require manpower and time.

[0003] As an alternative to manual measurement, the use of non-contact measuring instruments such as air micrometers and laser scan micrometers at production sites has been proposed (JP Patent Publication 8-14871). However, air micrometers and laser scan micrometers themselves are extremely expensive, and maintenance is somewhat difficult. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 10-89903 [Patent Document 2] Patent Publication 2019-100904 [Patent Document 3] JP 8-14871 Summary of the Invention [Problem to be solved by the invention]

[0005] Although there have been various proposals to use motor power to automate contact-type measurement, there have been no successful cases of practical application that has been widely adopted by the general public (JP Patent Publication No. 10-89903). In addition, contact-type measurement can of course be automated using a coordinate measuring machine (CMM) (JP Patent Publication No. 2019-100904), but this requires an investment of tens to hundreds of millions of yen, and it cannot be said that it is appropriate to adopt it as a replacement for measurements performed with micrometers or vernier calipers.

[0006] An object of the present invention is to provide an automatic measuring device that automates a contact type measuring instrument which is inexpensive and easy to use. [Means for solving the problem]

[0007] The automatic measuring device of the present invention comprises: A measuring instrument including a movable element that is displaceable relative to a fixed element and moves toward and away from a workpiece, and a displacement detection unit that detects the displacement or position of the movable element; and an automatic operation unit that automates the advancement and retreat of the movable element by power, An automatic measuring device that automatically measures a workpiece using a measuring device for measuring the dimensions of the workpiece, and a vibration actuator for directly or indirectly applying vibration to at least one of the workpiece and the measuring device to promote a change in the relative position and posture between the workpiece and the measuring device, so that when the workpiece and the movable element come into contact with each other, the relative position and posture between the workpiece and the measuring device are changed at a pressure equal to or lower than a predetermined measurement pressure preset in the measuring device, and the contact surfaces between the workpiece and the movable element come into close contact with each other. It is characterized by:

[0008] In one embodiment of the present invention, a moving means for moving the measuring device and the workpiece relative to each other so that the workpiece is within a measurement range of the measuring device; a floating joint portion interposed between the moving means and the measuring device to allow translation and rotation of the measuring device relative to the moving means, The vibration actuator is attached to the measuring device. It is preferred.

[0009] In one embodiment of the present invention, A workpiece holding unit is provided for holding the workpiece, The workpiece holding unit includes: The workpiece is held so that the position and posture of the workpiece can be changed with a pressure equal to or less than a predetermined measurement pressure preset in the measuring device when the movable element contacts the workpiece, The vibration actuator is attached to the workpiece holding portion. It is preferred.

[0010] In one embodiment of the present invention, The automatic operation unit includes: advancing the movable element so that the movable element contacts the workpiece; Then, the movable element is retracted a predetermined distance. Thereafter, the movable element is re-advanced so that a predetermined measurement pressure is generated between the workpiece and the movable element; The vibration actuator is actuated when the movable element is re-advanced so that a predetermined measurement pressure is generated between the workpiece and the movable element. It is preferred.

[0011] In one embodiment of the present invention, After the automatic operation unit stops the re-advancement of the movable element and the vibration actuator stops driving, The displacement detection unit obtains the displacement or position of the movable element as a measurement value. It is preferred.

[0012] The automatic measuring device of the present invention comprises: A measuring instrument including a movable element that is displaceable relative to a fixed element and moves toward and away from a workpiece, and a displacement detection unit that detects the displacement or position of the movable element; an automatic operation unit that automates the advancement and retreat of the movable element by power; a workpiece holding section that holds the workpiece so that the position and posture of the workpiece can be changed at a pressure equal to or less than a predetermined measurement pressure preset in the measuring device when the movable element contacts the workpiece. It is characterized by:

[0013] In one embodiment of the present invention, The workpiece holding unit includes: A base portion; A workpiece placement stage on which a workpiece is placed or placed; a floating joint portion that is interposed between the base portion and the workpiece setting stage and supports the workpiece setting stage so as to allow the workpiece setting stage to be displaced relative to the base portion. It is preferred.

[0014] In one embodiment of the present invention, The floating joint portion includes: a translational movement allowing mechanism that allows translational displacement of the workpiece placement stage relative to the base; a rotation allowing mechanism that allows the workpiece setting stage to rotate relative to the base portion, The base unit, the translational movement allowance mechanism unit, the rotational movement allowance mechanism unit, and the workpiece setting stage are provided in this order from the bottom. It is preferred.

[0015] In one embodiment of the present invention, the translational movement allowing mechanism has a translation body that allows the work setting stage to translate relative to the base, The rotation allowing mechanism has a flexible body that is deformable so as to allow displacement in a direction in which the work setting stage is tilted relative to the base. It is preferred.

[0016] In one embodiment of the present invention, The workpiece holding unit includes a restraining means for restricting the displacement of the workpiece setting stage, the restraining means restricts the displacement of the workpiece placement stage when the movable element and the workpiece are separated from each other; The restraining means allows the displacement of the workpiece setting stage when the movable element and the workpiece are in contact with each other and a measurement pressure is applied from the movable element to the workpiece. It is preferred.

[0017] In one embodiment of the present invention, The workpiece holding unit includes a vibration actuator for directly or indirectly applying vibration to the workpiece to promote a change in the relative position and attitude of the workpiece and the measuring device. It is preferred.

[0018] In one embodiment of the present invention, The workpiece holding unit includes: A restraining means for restricting the displacement of the workpiece placement stage; a vibration actuator for directly or indirectly applying vibration to the workpiece to promote a change in the relative position and attitude of the workpiece and the measuring instrument; The automatic operation unit includes: advancing the movable element so that the movable element contacts the workpiece; Then, the movable element is retracted a predetermined distance. Thereafter, the movable element is re-advanced so that a predetermined measurement pressure is generated between the workpiece and the movable element; When the movable element is advanced again so that a predetermined measurement pressure is generated between the workpiece and the movable element, the restraining means releases the workpiece setting stage to allow the workpiece setting stage to be displaced, and the vibration actuator is driven. It is preferred. [Brief description of the drawings]

[0019] [Figure 1] 1 is an overall configuration diagram of an automatic measuring device in a first embodiment. [Diagram 2] FIG. 2 is an external view of an automatic micrometer device. [Diagram 3] FIG. [Figure 4] 4 is a flowchart for explaining a measurement operation by the automatic micrometer device. [Diagram 5] 4 is a flowchart for explaining a measurement operation by the automatic micrometer device. [Figure 6] FIG. 13 is a diagram illustrating an example of the spindle moving forward. [Figure 7] 1 is a diagram illustrating a state in which a workpiece W is clamped between an anvil and a spindle. [Figure 8] FIG. 11 is an overall external view of an automatic inner diameter measuring device in a second embodiment. [Figure 9] FIG. 2 is an external perspective view of the electric inner diameter measurement unit, seen from a slightly front side. [Figure 10] FIG. 2 is an external perspective view of the side of the electric inner diameter measurement unit, seen from slightly behind. [Figure 11] FIG. 2 is a front view of the electric inner diameter measurement unit. [Figure 12] FIG. 2 is a cross-sectional view showing the internal structure of an electric inner diameter measuring instrument. [Figure 13] FIG. [Figure 14] FIG. [Figure 15] 11 is a diagram for explaining the position and attitude adjustment function of the electric inner diameter measuring instrument. FIG. [Figure 16] 11 is a diagram for explaining the position and attitude adjustment function of the electric inner diameter measuring instrument. FIG. [Figure 17] 11 is a diagram for explaining the position and attitude adjustment function of the electric inner diameter measuring instrument. FIG. [Figure 18] 11 is a diagram for explaining the position and attitude adjustment function of the electric inner diameter measuring instrument. FIG. [Figure 19] 11 is a diagram for explaining the position and attitude adjustment function of the electric inner diameter measuring instrument. FIG. [Figure 20] FIG. [Figure 21] FIG. 4 is a perspective view of the collision detection unit as seen slightly from the rear side. [Figure 22] FIG. 2 is a functional block diagram of a control unit. [Figure 23] 4 is a flowchart of the overall operation of automatic inner diameter measurement. [Figure 24] 13 is a flowchart showing an operation procedure of a hole insertion process. [Diagram 25] 10 is a flowchart showing an operation procedure of a measurement process. [Figure 26] 13 is a flowchart showing the operation procedure of a hole retraction process. [Figure 27] FIG. 11 is a schematic diagram of a workpiece holding table in a third embodiment. [Figure 28] 11 is a diagram illustrating a function of adjusting the attitude of a workpiece by the workpiece holding table; FIG. [Figure 29] 11 is a diagram illustrating a function of adjusting the attitude of a workpiece by the workpiece holding table; FIG. [Diagram 30] FIG. 13 is a diagram showing an example of a restraining means. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be illustrated and described with reference to the reference numerals given to the various elements in the drawings. Each embodiment may be implemented not only alone, but also in combination of two or more embodiments, and the modified examples supplemented in each embodiment may also be applied to the other embodiments. (First embodiment) A first embodiment of the present invention will be described. FIG. 1 is a diagram showing the overall configuration of an automatic measuring device 100. The automatic measuring device 100 includes a measuring device main body section 120 and a control unit section 800 .

[0021] (Measuring device main body) The measurement device main body 120 includes a robot arm 130 as a moving means, and an automatic measurement unit 200 .

[0022] The moving means will be described taking an example of a multi-joint arm robot, but it may also be a simpler moving mechanism combining one-axis or two-axis rotation and straight lines. The moving means only needs to be able to move the workpiece W and the measuring device relative to one another, so there are cases where the moving means transports the workpiece W, and cases where the moving means transports the measuring device, but in this first embodiment, an example will be described where the moving means transports the workpiece W. For example, the workpiece W (e.g., a part) machined by a machine tool (e.g., an NC lathe) is carried on a belt conveyor 111. The workpiece W is transferred to a pre-treatment stocker 112. As the pre-treatment, for example, deoiling and dusting may be performed by air blowing. The pre-treated workpiece W is carried into the measurement area of ​​the automatic measurement unit 200 by, for example, a robot arm unit 130 serving as a moving means. The robot arm section 130 is, for example, an articulated robot arm section 130, and has at its tip a robot hand 140 for gripping the workpiece W, and a camera 150 for image recognition. The robot arm section 130 recognizes the workpiece W by image recognition, grips the workpiece W with the robot hand 140, and carries the workpiece W to a measurement area of ​​the automatic measurement 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 releases the workpiece W once. In a simpler system, the workpieces W may be picked up and transported manually by a person. The dimensions of the workpiece W thus transported to the measurement area are measured by the automatic measurement unit 200.

[0023] (Automatic measurement unit 200) The automatic measuring unit 200 brings a measuring element (movable member) into contact with the workpiece W to measure the dimensions of the workpiece W. Although the dimensions of the workpiece W may be either the inner dimension (inner diameter) or the outer dimension (outer diameter), the first embodiment will be described taking as an example a case where the outer dimension (outer diameter) is measured.

[0024] The automatic measuring unit 200 is an automated version of a micrometer 300 serving as a small measuring device (small measuring tool). The automatic measuring unit 200 of the first embodiment is 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 micrometer (measuring device) 300, a measuring device support frame unit 400, an automatic operation unit 500, a workpiece holding table unit (workpiece holding unit) 460, and a vibration motor (vibration actuator) 600.

[0025] The micrometer 300 is originally a small measuring instrument that is manually operated, and as the micrometer 300 of this embodiment, a micrometer 300 that is currently available on the market may 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 .

[0026] 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 side of the U-shaped frame 310, and is provided so as to be 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 into a flat surface, and is formed of, for example, cemented carbide material or ceramic.

[0027] Note that the anvil 320 may not be provided on the main body frame 310, such as a so-called micrometer head. The anvil 320 that 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.

[0028] The spindle 330 is fed and moved so as to advance and retreat in the axial direction by the rotation of the thimble portion 340. The feeding method of the spindle 330 includes a rotation feed type in which the spindle 330 itself rotates, and a linear feed type in which the spindle 330 itself does not rotate. In the rotation feed type, a male screw is provided on the spindle 330 itself, and a female screw is provided on the U-shaped frame 310. The thimble and the spindle 330 are engaged with each other so that they rotate together, and the spindle 330 is rotated by the rotation of the thimble. Then, the spindle 330 advances and retreats by the screw feed. In the linear feed type, a feed screw is cut on the inside of the thimble 340, and a pin that engages with the feed screw is provided on the spindle 330. When the thimble 340 is rotated while the spindle 330 is prevented from rotating, the spindle 330 is fed 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.

[0029] The thimble portion 340 is disposed at the other end of the spindle 330 on the other end side of the U-shaped frame 310. The thimble portion 340 is an operating portion that moves the spindle 330 forward and backward by a rotation operation. Here, the micrometer 300 used in this embodiment is preferably a type having a constant pressure mechanism between the thimble portion 340 and the spindle 330. The constant pressure mechanism disengages the thimble from the spindle 330 and causes the thimble to rotate freely relative to the spindle 330 when a preset load is applied to the spindle 330. By always operating the constant pressure mechanism in the same manner and appropriately during measurement, the measurement pressure during measurement can be made constant and the measurement accuracy (repeatable accuracy) can be kept high. Constant pressure mechanisms are also incorporated in commercially available micrometers 300, and are disclosed in, for example, Patents 3115555, 3724995, 5426459, and 5270223. The constant pressure mechanism can be configured with a ratchet mechanism that causes slippage when a force equal to or greater than a predetermined load is applied between the thimble and the spindle 330, or a leaf spring that causes slippage when a load equal to or greater than a predetermined load is applied between the outer sleeve and the inner sleeve of the thimble.

[0030] Furthermore, the micrometer 300 employed in this embodiment preferably has 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 Publication 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 the operation 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) in response to the detection of the predetermined measurement pressure by the measurement pressure detection mechanism.

[0031] The displacement detection unit 350 detects the amount of displacement (or the position) of the spindle 330. The displacement detection unit 350 is configured by a rotary encoder or a linear encoder.

[0032] 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 the 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).

[0033] 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 is provided that outputs measured values ​​to the outside via wired or wireless communication.

[0034] Next, the measuring device support frame portion 400 will be described. The measurement device support frame portion 400 has a base frame 410 and a measurement device holding portion 420 .

[0035] The base frame 410 is a rectangular frame overall. For the sake of explanation, XYZ coordinate axes are taken as being orthogonal to each other as shown in Fig. 2. Of the four sides constituting the base frame 410, the two sides parallel to the X-axis direction are designated as a first long side portion 411 and a second long side portion 412, and the two sides parallel to the Y-axis direction are designated as a first short side portion 413 and a second short side portion 414.

[0036] The first long side portion 411, the second long side portion 412, the first short side portion 413, and the second short side portion 414 may be extendable and contractible so that the lengths can be adjusted. This allows the size of the base frame 410 to be adjusted in accordance with the sizes of the micrometer 300 and the workpiece W.

[0037] The measuring device holding unit 420 is installed on the first long side 411, the automatic operation unit 500 is installed on the second short side 414, and the workpiece holding table unit 460 is installed on the second long side 412. In this case, the first long side 411 has rails so that the installation position of the measuring device holding unit 420 can be adjusted along the X-axis direction. Similarly, the second short side 414 has rails so that the installation position of the automatic operation unit 500 can be adjusted along the Y-axis direction. The second long side 412 has rails so that the installation position of the workpiece holding table unit 460 can be adjusted along the X-axis direction.

[0038] The measuring device holding part 420 is fixedly attached to the first long side part 411. The measuring device holding part 420 clamps the micrometer 300 between the upper and lower clamping pieces, and attaches the micrometer 300 to the base frame 410 (first long side part 411). FIG. 3 is a cross-sectional view of the measuring device holding part 420. The measuring device holding section 420 has a first clamping piece 421 and a second clamping piece 422, and the first clamping piece 421 and the second clamping piece 422 each have an elastic rubber sheet 423 as a cushioning material on the opposing surface. The cushioning material may be elastic rubber, foamed resin, a spring, or a bag sealed with air (e.g., an air cap). The cushioning material has a cushioning property that does not inhibit vibration when vibration is applied to the micrometer 300 from a vibration motor 600 described later. Alternatively, the clamping pieces 421 and 422 themselves may be thin plates, and the clamping pieces 421 and 422 may elastically hold the measuring device (micrometer 300). The U-shaped frame (fixing element) 310 of the micrometer (measuring device) 300 is sandwiched between the first clamping piece 421 and the second clamping piece 422. The orientation of the micrometer 300 is such that the forward and backward movement direction (axial direction) of the spindle 330 is parallel to the X-axis, one end side of the U-shaped frame 310 (the anvil 320 side) is on the first short side 413 side, and the other end side of the U-shaped frame 310 (the thimble side) is on the second short side 414 side.

[0039] The automatic operation unit 500 automates the advancement 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.

[0040] 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 operation 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 may be adjusted by moving it along the rail of the second short side portion 414.

[0041] Motor 520 may be a normal electric motor 520 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 with a control pulse. In addition, motor 520 preferably has a torque detection function. (Various methods are known for detecting the torque of motor 520, such as determining the 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 a synchronous motor may also be used, and the structure and drive method of motor 520 are not particularly limited.)

[0042] The power transmission unit 530 includes a fixing 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 fixing ring 531 and the rotating plate 532. One end of the transmission link rod 533 is fixed to the fixing 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 fixing ring 531 by the transmission link rod 533, and the fixing ring 531 rotates in synchronization with the rotating plate 532.

[0043] The workpiece holding table 460 holds the workpiece W to be measured in the measurement area of ​​the micrometer (measuring instrument) 300. The workpiece holding table 460 has a support pillar 461 and a workpiece placement plate 462. The support pillar 461 is attached to the first long side portion 411. The workpiece placement plate 462 is an L-shaped plate having a surface parallel to the XY plane, and is fixed to the support pillar 461. The position of the support pillar 461 is adjusted along the second long side portion 412 so that the workpiece W held by the workpiece holding table 460 is within the measurement area of ​​the micrometer (measuring instrument) 300, and further, the height (position in the Z-axis direction) of the workpiece placement plate 462 is adjusted so that the measurement target portion (measurement target part) of the workpiece W is sandwiched between the anvil 320 and the spindle 330.

[0044] Since the surface of the workpiece placement plate 462 on which the workpiece W is placed is flat, the workpiece W placed and held on this placement surface easily changes its position and posture when pushed by the spindle 330. In other words, when the spindle 330 hits the workpiece W, the workpiece W is pushed toward the anvil 320 and slides on the placement surface until it hits the anvil 320. When the workpiece W hits the anvil 320, the movement of the workpiece W is restricted, so that the workpiece W is sandwiched between the anvil 320 and the spindle 330. At this time, the measurement surface of the anvil 320 and the contact surface of the workpiece W come into close contact with each other, and the workpiece W changes its posture so that the measurement surface of the spindle 330 and the contact surface of the workpiece W come into close contact with each other. In this way, the workpiece W is not fixed and is allowed to move to a certain extent on the placement surface, so that the anvil 320 and the spindle 330 can tightly sandwich the measurement target portion of the workpiece W without any gaps.

[0045] If the friction of the workpiece mounting surface of the workpiece mounting plate 462 is too small, there is a concern that the workpiece W may slip and fall when placed by the robot hand 140 or a human hand, or may shift from the orientation or posture at the time of placement, so it is preferable that the workpiece mounting surface is unevenly processed to generate a certain degree of friction between the workpiece W and the mounting surface. It is preferable that the workpiece W be able to change its position and posture when a force equal to or less than a set measurement pressure (for example, about 1N to 5N) is applied to the workpiece W while the workpiece W is placed on the mounting surface.

[0046] The vibration motor (vibration actuator) 600 is attached to the micrometer 300. Here, the vibration motor 600 is attached to the surface of one end of the U-shaped frame 310 of the micrometer 300, but the position where the vibration motor 600 is attached may be any place of the micrometer 300 (measuring instrument), and may be on the spindle 330 side of the frame part of the micrometer 300. In the embodiment, since it is considered to use the micrometer 300 that is generally available on the market as it is in the automatic measuring device 100 as it is, the vibration motor 600 is attached to the outer surface of the micrometer 300 (measuring instrument), but it may be embedded in the electrical equipment part or the frame part. The vibration actuator may be a so-called eccentric motor, a piezoelectric actuator, a rotary vibration actuator, or a linear vibration actuator, as long as it can generate vibration. The vibration motor 600 may have a dedicated small battery built in, or may be powered from the micrometer 300. The vibration motor 600 and the control unit section 800 are connected wirelessly or by wire, and are driven by receiving a control signal from the control unit section 800.

[0047] The control unit section 800 has an arithmetic device and a storage device constituted by a computer having a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and a motor drive circuit that generates a drive signal (voltage signal or current signal) and applies it to the motor 520. The control unit section 800 controls the rotation drive of the motor 520 to control the advance and retreat of the spindle 330, and also drives the vibration motor 600 at an appropriate timing to promote a change in the posture of the workpiece W. In addition, the control unit section 800 samples a measurement value from the micrometer 300 (displacement detection section 350) at an appropriate timing. The control operation by the control unit section 800 will be described later with reference to a flowchart.

[0048] (Operation description) The operation of the automatic micrometer device 200 will now be described. 4 and 5 are flow charts for explaining the measurement operation by the automatic micrometer device 200. FIG. When it is detected that the workpiece W has been set on the workpiece placement plate 462 by the robot arm section 130 (ST110: YES), the control unit section 800 executes a preset (programmed) motor drive control. The control unit section 800 rotates the motor 520 forward at a relatively high speed to advance the spindle 330 toward the anvil 320 (ST120). The rotation speed of the motor 520 at this time is, for example, 180 rpm (or about 100 rpm to 200 rpm). For example, FIG. 6 is a diagram illustrating the manner in which the spindle 330 advances.

[0049] In the ST120, it is considered that the rotation speed should be as high as possible from the viewpoint of shortening the measurement time. However, if the rotation speed is too high, there is a risk that the workpiece W may be damaged when the spindle 330 hits the workpiece W. In addition, if the rotation speed is too high, the centrifugal force generated in the power transmission unit 530 increases, and the motor torque increases. Then, due to the configuration that detects the contact between the spindle 330 (anvil 320) and the workpiece W by the magnitude of the torque, there is a problem that the torque detection function erroneously detects the contact between the spindle 330 (anvil 320) and the workpiece W. Therefore, it is considered that it is best to first set a torque threshold value for detecting the contact between the spindle 330 and the workpiece W, and rotate the motor 520 at a speed that does not exceed this torque threshold value.

[0050] As the spindle 330 advances toward the anvil 320, the spindle 330 comes into contact with the workpiece W. Since the workpiece W is not fixed in place on the workpiece mounting plate 462, it is pushed by the spindle 330 and moves until the workpiece W comes into contact with the anvil 320. 7 is a diagram illustrating a state in which the workpiece W is clamped between the anvil 320 and the spindle 330. At the moment when the workpiece W is clamped between the anvil 320 and the spindle 330, the motor torque increases, and the motor controller detects by the torque detection function 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 (ST130: YES).

[0051] 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 revolutions to move the spindle 330 backward (ST140). The rotation speed of the reverse rotation is, for example, 180 rpm. The rotation speed of the reverse rotation is, for example, 0.5 revolutions. Note that this rotation speed (180 rpm) is merely an example, and the rotation speed during forward rotation (ST120) and the rotation speed during reverse rotation (ST140) may be the same or different.

[0052] Here, it is preferable to once move the spindle 330 backward by rotating 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 once move the spindle backward, rather than simply stopping the spindle, can more reliably prevent the spindle 330 from biting into the workpiece W. In addition, the constant pressure mechanism is operated when generating the measurement pressure, and in order to operate the constant pressure mechanism while always moving the spindle 330 forward at the same speed, it is necessary to ensure the operating distance of the spindle 330. Therefore, it is considered to be better to once step back the spindle 330 so that the operation of applying the measurement pressure to the workpiece W can always be the same.

[0053] Thereafter, the spindle 330 is moved forward again to bring the spindle 330 and the workpiece W into intimate contact with each other at a predetermined measurement pressure (ST150, ST160). At this time, the vibration motor 600 is driven in accordance with the forward movement of the spindle 330 again (ST141). That is, after the first high-speed retreat step (ST140) and before the start of the low-speed forward movement step (ST150), the control unit section 800 starts driving the vibration motor 600 (ST141).

[0054] The motor 520 is rotated forward at a relatively low speed to move the spindle 330 forward toward the anvil 320 (ST150, ST160). As the low-speed forward movement step (ST150), the motor 520 is rotated forward at a relatively low speed. The number of rotations is the same as the number of rotations in the previous backward movement (ST140). Here, for example, 0.5 rotations at 9 rpm. The work W is pushed slowly to ensure contact between the work W and the anvil 320 and between the work W and the spindle 330. At this time, the vibration of the vibration motor 600 is transmitted to the micrometer 300, causing the spindle 330 and the anvil 320 to vibrate slightly, thereby reducing friction at the interface between the work W and the spindle 330 and the interface between the work W and the anvil 320, and encouraging a change in the posture of the work W.

[0055] Next, as a measurement surface contact step (ST160), the motor 520 is rotated forward at a relatively low speed (ST160). The number of rotations corresponds to, for example, the amount of thimble rotations (amount of spindle 330 rotations) 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 0.5 rotations at 9 rpm. (This is the same as ST150, but the rotation speed and number of rotations may be changed as appropriate.) Here, the constant pressure mechanism is slowly activated once to ensure that the contact surfaces between the workpiece W and the anvil 320 and the contact surfaces between the workpiece W and the spindle 330 are made to blend (closely contact) with each other.

[0056] In this state, the workpiece W is firmly clamped between the anvil 320 and the spindle 330. The driving of the vibration motor 600 is stopped (ST161).

[0057] In the measurement pressure application step (ST170), the motor 520 is rotated in the forward direction at a relatively high speed. For example, it is rotated three times at 180 rpm. At this time, the constant pressure mechanism is operated again, and a predetermined measurement pressure is applied.

[0058] The motor rotation speed in this step (ST170) may be faster (for example, 150 rpm-250 rpm). The break-in has been completed in the previous step (ST160), and the contact surfaces of the spindle 330 (anvil 320) and the workpiece W are firmly broken in. Therefore, it is considered that the spindle 330 (anvil 320) and the workpiece W are unlikely to bite into each other. In addition, since the spindle 330 (anvil 320) and the workpiece W are already in contact with each other, there is no restriction that the torque detection function will erroneously detect the contact between the spindle 330 (anvil 320) and the workpiece W. In addition, the number of rotations in this step (ST170) is the number of rotations required to operate the constant pressure mechanism, and may be about 1.5 to 3.5 rotations, which depends on the specifications of the micrometer 300 (constant pressure mechanism) used.

[0059] The micrometer 300 samples a measurement value (ST180) at the moment when the constant pressure mechanism is activated in the measurement pressure application step (ST170). The sampled measurement value (measurement data) is output to the outside by wired or wireless communication (ST190), and the measurement data is collected and processed by an external PC (personal computer) or data processing device via the control unit 800.

[0060] 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. This measurement operation is continued while changing the workpiece W.

[0061] 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). Since the micrometer 300 is expected to already be available in a typical factory, automation of the micrometer 300 can be realized by simply preparing the measuring device support frame unit 400, the workpiece holding table unit 460, the automatic operation unit 500, and the vibration motor 600. In other words, the cost required for introducing automatic measurement can be made extremely low, which greatly contributes to resolving labor shortages.

[0062] Since the micrometer 300 is a contact type, it has extremely high measurement stability. In addition, the micrometer 300 has a long history and is widely used around the world, so it can be said that it is the measuring instrument that measurement workers are most familiar with. Therefore, workers are fully familiar with the necessary handling procedures, such as the calibration of the micrometer 300, and there is almost no need for them to learn or train difficult work procedures again.

[0063] Various automatic measuring devices 100 have been proposed up until now, but most of them use non-contact measuring tools. For example, many of them use air micrometers or laser scan micrometers. However, such non-contact measuring instruments are extremely expensive and somewhat difficult to maintain. In this regard, the automatic micrometer device 200 of this embodiment, which can automate the micrometer 300, has the advantage of being inexpensive and easy to handle.

[0064] One of the reasons why it has been difficult to automate the micrometer 300, which is a representative small-sized contact measuring instrument (small-sized measuring tool), is that it has been difficult to properly clamp the workpiece W from both sides and make the contact surface (measurement surface) familiar. In this respect, in this embodiment, the relative positions of the workpiece W and the micrometer 300 are not fixed, and the position and posture can be changed with a force equal to or less than the measurement pressure. In addition, the constant pressure mechanism of the micrometer 300 and the torque detection mechanism of the motor 520 are used comprehensively to move the spindle 330 forward and backward in several stages, and in particular, a process (ST160) of making the measurement surface (contact surface) familiar (close contact) firmly and a process (ST170) of applying a predetermined measurement pressure are performed. Furthermore, in this embodiment, the vibration motor 600 is driven at an appropriate timing to encourage the posture change of the workpiece W, thereby ensuring close contact between the workpiece W and the spindle 330 and between the workpiece W and the anvil 320. Usually, when rotating the thimble manually, it is rotated at a constant speed and a constant pressure is applied at that constant rotation for measurement, and there is no need to back up or operate the constant pressure mechanism in two stages, slow and fast. However, by repeatedly experimenting under different conditions, we devised a control process different from manual operation, and it became possible to obtain stable measurement values ​​even with automatic measurement. This made it possible to automate the Micrometer 300. In addition, since the motor control makes it possible to always measure the workpiece W with the same movement, the problem of differences in measurement values ​​due to the proficiency and movement habits of each worker was also resolved.

[0065] Although the contact between the workpiece W and the spindle 330 is detected by torque detection, the contact between the spindle 330 (movable member) and the workpiece W can also be detected from the detection value by the displacement detection unit 350. For example, by comparing the number of times that drive pulses are sent to the motor 520 with the displacement of the spindle 330, if the spindle 330 stops without moving forward as expected for a predetermined number of consecutive times, it may be determined that the spindle 330 has come into contact with the workpiece W.

[0066] Although an example in which the vibration motor 600 is provided on the measuring device (micrometer) side has been described, the vibration motor may be provided on the workpiece holding table side to apply vibration to the workpiece. Also, the vibration motor may be provided on both the measuring device and the workpiece holding table side.

[0067] Second Embodiment A second embodiment of the present invention will now be described. This embodiment is an automatic inner diameter measuring device 2100 that automates the measurement of the inner diameter (hole diameter) of a hole that is a measurement target.

[0068] (Automatic inner diameter measuring device 2100) FIG. 8 is a general external view of the automated inner diameter measuring device 2100. The automated inner diameter measuring device 2100 comprises a measuring device main body 2110 and a control unit 2140 that controls the overall operation.

[0069] (Measuring device main body) The measuring device main body 2110 comprises an electric inner diameter measuring unit 2120 that measures the diameter of a hole of an object, and an articulated robot arm 2130 as a moving means for moving the electric inner diameter measuring unit 2120 .

[0070] (Electric inner diameter measuring unit 2120) The electric inner diameter measurement unit 2120 is attached to and held by a hand unit 2131 which is the tip of a robot arm unit 2130. The electric inner diameter measurement unit 2120 is inserted into the inside of a hole to be measured to obtain a measured value of the inner diameter. Furthermore, the electric inner diameter measurement unit 2120 includes a function of autonomously adjusting its own position and attitude so as to accurately measure the hole to be measured.

[0071] The configuration of the electric inner diameter measurement unit 2120 will be described. FIG. 9 is an external perspective view of the electric inner diameter measurement unit 2120 as seen from a slightly front side. FIG. 10 is an external perspective view of the side surface of the electric inner diameter measurement unit 2120, seen slightly from behind. FIG. 11 is a front view of the electric inner diameter measurement unit 2120.

[0072] The electric inner diameter measurement unit 2120 comprises an electric inner diameter measurement instrument 2200, a measurement instrument support frame section 2300, a floating joint section (floating joint mechanism section) 2400, a restraining means 2500, a collision detection section 2600, a force sensor section 2132, and a vibration motor (vibration actuator) 2700.

[0073] (Electric inner diameter measuring instrument 2200) The electric inner diameter measuring instrument 2200 is an existing manual inner diameter measuring instrument (such as a Holtest) in which the rod feed has been motorized. FIG. 12 is a cross-sectional view showing the internal structure of the electric inner diameter measuring instrument 2200. The electric inner diameter measuring instrument 2200 comprises a cylindrical case portion (fixed element) 2210, a rod 2230, a thimble portion 2240, a measuring element (movable element) 2250, a displacement detection portion 2260, an outer case portion 2270, a display unit portion 2233, and an electric drive portion (automatic operation portion) 2280.

[0074] The cylindrical case part 2210 is a cylindrical case as a whole. A rod 2230 advances and retreats in the axial direction inside the cylindrical case part 2210. The cylindrical case part 2210 has an upper cylindrical case part 2211 constituting an upper part, an intermediate cylindrical case part 2213 constituting an intermediate part, a lower cylindrical case part 2214 constituting a lower part, and further a head cylindrical part 2215 constituting a measurement head part 2220. The intermediate cylindrical case part 2213 is attached to the lower end of the upper cylindrical case part 2211, the lower cylindrical case part 2214 is attached to the lower end of the intermediate cylindrical case part 2213, and the head cylindrical part 2215 is attached to the lower end of the lower cylindrical case part 2214.

[0075] The rod 2230 is a long rod-like body as a whole. The rod 2230 has an upper rod 2231 and a lower rod 2233. The upper rod 2231 is a spindle, and has a feed screw (male thread) on the outer surface of the base end side (upper end side) thereof. A female thread is cut in the upper cylindrical case portion 2211, and the feed screw is screwed into the female thread.

[0076] The thimble portion 2240 is provided at the base end (upper end side) of the upper rod 2231. The thimble portion 2240 has a thimble sleeve 2241, a ratchet sleeve 2242, and a coil spring 2243. The thimble sleeve 2241 is fitted onto the base end of the upper rod 2231 (rod 2230) by fitting the tapered surface 2251, and is fixed to the base end of the upper rod 2231 (rod 2230). The ratchet sleeve 2242 is a cylindrical body provided further above the thimble sleeve 2241, and a coil spring 2243 is interposed between the thimble sleeve 2241 and the ratchet sleeve 2242. A push screw is screwed into the end face on the base end side of the upper rod 2231, and the ratchet sleeve 2242 is pushed by the flange of the head of the push screw. At this time, the coil spring 2243 is sandwiched between the ratchet sleeve 2242 and the thimble sleeve 2241 .

[0077] A ratchet mechanism (not shown) is provided between the ratchet sleeve 2242 and the thimble sleeve 2241. The direction of rotation of the ratchet sleeve 2242, the thimble sleeve 2241, or the rod 2230 in the direction in which the rod 2230 is sent downward (the direction in which the probe 2250 is protruding) is defined as the positive rotation direction. Conversely, the direction of rotation of the ratchet sleeve 2242, the thimble sleeve 2241, or the rod 2230 in the direction in which the rod 2230 is sent upward (the direction in which the probe 2250 is retracted) is defined as the negative rotation direction. The ratchet mechanism allows the ratchet sleeve 2242 to rotate idly relative to the thimble sleeve 2241 in the positive rotation direction, and does not allow idling when the ratchet sleeve 2242 rotates in the negative direction.

[0078] When the ratchet sleeve 2242 is rotated (positively), the rotation of the ratchet sleeve 2242 is transmitted to the rod 2230 via the coil spring 2243 and the thimble sleeve 2241. There is an upper limit to the force (rotational force) transmitted from the ratchet sleeve 2242 to the rod 2230. That is, if an attempt is made to rotate the rod 2230 with a force exceeding the frictional force (static frictional force) acting between the ratchet sleeve 2242, the coil spring (load regulating elastic body) 2243, and the thimble sleeve 2241, the ratchet mechanism causes the ratchet sleeve 2242 to rotate freely relative to the thimble sleeve 2241. The thimble portion 2240 constitutes a constant pressure mechanism that regulates the upper limit of the force (measuring force) acting between the measurement object and the measurement element 2250. Conversely, a certain force (measuring force) that can be determined by the amount of depression of the set screw is generated between the object to be measured and the measuring probe 2250, and when the measuring probe 2250 applies the certain force (measuring force) to the object to be measured, a reaction force is applied to the measuring probe 2250 side, i.e., the electric inner diameter measuring instrument 2200 side.

[0079] The lower rod 2233 is disposed inside the head cylinder portion 2215. The upper end of the lower rod 2233 abuts against the lower end of the upper rod 2230. The lower end side of the lower rod 2233 is conical.

[0080] The probe 2250 is provided in the head tube portion 2215 so as to advance and retreat in a direction perpendicular to the axial direction of the rod 2230. Three probes 2250 are arranged at 120° intervals in the head tube portion 2215. Each probe 2250 has a thin, round shaft tip 2252 made of carbide at its outer end. When each probe 2250 advances in the protruding direction, the round shaft tip 2252 comes into contact with the inner wall of the measurement target.

[0081] A tapered surface 2251 is formed on the inner end side of each probe 2250, and this tapered surface 2251 is adapted to come into contact with the conical surface of the lower rod 2233. The conical surface of the lower rod 2233 and the tapered surface 2251 of the probe 2250 serve as a displacement direction conversion means for changing the direction of force and displacement at a right angle.

[0082] A spring (e.g., a leaf spring 2216) corresponding to each of the probes 2250 is provided inside the head tube portion 2215, and one end of each leaf spring 2216 is fixed to the inner wall of the head tube portion 2215, and the other end of each leaf spring 2216 is fixed to each of the probes 2250. The leaf springs 2216 urge each of the probes 2250 in a direction to retract into the inside of the head tube portion 2215. When the rod 2230 is pulled upward by an external force, the force of the leaf springs 2216 causes the probes 2250 to move in a direction to enter the head tube portion 2215, following the rod 2230.

[0083] The portion of the head cylinder portion 2215 from which the measuring element 2250 appears (the tip portion of the inner diameter measuring instrument) may be referred to as a measuring head portion 2220.

[0084] The displacement detection unit 2260 is provided to detect the displacement of the upper rod 2231 inside the intermediate cylinder case portion 2213. The displacement detection unit 2260 is a so-called rotary encoder having a rotor 2261 provided to rotate integrally with the upper rod 2231, a stator 2262 that counts the rotations of the rotor 2261, and a signal processing calculation unit (not shown). The detection method of the displacement detection unit 2260 is not particularly limited, and examples include a photoelectric encoder, a capacitance encoder, an electromagnetic induction encoder, and a magnetic encoder.

[0085] The outer case part 2270 is an outer cylinder part that covers the outer side of the cylinder case part 2210. The outer case part 2270 is provided so as to cover the electric inside diameter measuring instrument 2200 above the middle of the lower cylinder case part 2214. The outer case part 2270 is made up of two parts, that is, it has an outer case main body part 2271 that houses the middle part therein, and an outer case upper part 2272 that houses the upper part therein. The outer case main body part 2271 is a cylinder that covers the upper end side of the lower cylinder case part 2214 and the lower end side of the upper cylinder case part 2211 in addition to the entire intermediate cylinder case part 2213 that corresponds to the intermediate part of the electric inside diameter measuring instrument 2200.

[0086] The outer case upper part 2272 is connected to the upper end side of the outer case main body 2271 and is a cylindrical body that covers the upper cylindrical case part 2211 that constitutes the upper part of the electric inside diameter measuring instrument 2200.

[0087] The display unit 2233 has a display 2234, and is attached to openings on the sides of the intermediate tube case 2213 and the outer case main body 2271 to close said openings. The display 2234 is a digital display type display 2234 (for example, a liquid crystal display panel or an organic EL display panel) fitted in the central region of the display unit 2233. The display 2234 displays measured values ​​and the like obtained by a signal processing calculation unit (not shown).

[0088] Furthermore, a connector is provided in the display unit 2233, and the measured values ​​obtained in a signal processing and calculation unit (not shown) are output to the outside.

[0089] The electric drive unit 2280 is a drive unit that rotates the ratchet sleeve 2242 of the thimble portion 2240. The electric drive unit 2280 is attached above the outer case upper part 2272. The electric drive unit 2280 is, for example, a motor, and the rotation output of the motor is transmitted to the ratchet sleeve 2242 via a power transmission mechanism (such as a gear train, a connecting belt, a connecting shaft, or a connecting link).

[0090] The electric inner diameter measuring instrument 2200 operates basically the same as an existing manual inner diameter measuring instrument, except that the rod is fed by an electric drive unit 2280. When the rod 2230 advances or retreats due to electric force, the probe 2250 advances or retreats in the direction of entering or retracting from the head cylinder portion 2215 in accordance with the movement of the lower rod 2233. The displacement (position) of the rod 2230 when the three probes 2250 are evenly in contact with the inner wall of the hole to be measured is detected, thereby obtaining the measured diameter of the hole to be measured.

[0091] (Measuring instrument support frame part 2300) The support frame portion 2300 is an L-shaped member when viewed from the side, and has a support pillar portion 2310 and a support base portion 2320. The support base portion 2320 is attached at a right angle to the lower end of the vertical support pillar portion 2310.

[0092] The support column 2310 is adjacent to and parallel to the electric inner diameter measuring instrument 2200. A restraining means 2500 is provided on the front surface side of the support column 2310, and the restraining means 2500 switches between holding and releasing the electric inner diameter measuring instrument 2200. This point will be discussed later.

[0093] The support base 2320 is provided so as to bend in an L shape from the lower end of the support pillar 2310 towards the electric inner diameter measuring instrument 2200. The support base 2320 has a first insertion hole 2321 through which the head tube portion 2215 of the electric inner diameter measuring instrument 2200 is inserted. The electric inner diameter measuring instrument 2200 is attached so that the portion above the lower tube case portion 2214 is placed on the support base 2320 via a floating joint portion 2400 with the head tube portion 2215 passing through the first insertion hole 2321.

[0094] (Floating joint part 2400) The floating joint 2400 will now be described. FIG. 13 is an exploded view of the floating joint 2400. FIG. 14 is a cross-sectional view of a floating joint 2400.

[0095] The floating joint 2400 is a joint (or connecting mechanism) that allows the electric inner diameter measurement device 2200 to rotate relative to the support frame 2300 and also allows the electric inner diameter measurement device 2200 to translate horizontally relative to the support frame 2300. Even if there is an axial misalignment (tilt and positional misalignment) between the electric inner diameter measuring instrument 2200 and the hole to be measured, the floating joint section 2400 is allowed to rotate and translate, allowing the electric inner diameter measuring instrument 2200 to autonomously adjust its own position and attitude.

[0096] The floating joint portion 2400 has a rotation allowing mechanism portion 2410 and a translation allowing mechanism portion 2420 .

[0097] The rotation allowing mechanism 2410 has a first spring receiver 2411, a coil spring (flexible body, elastic body) 2412, and a second spring receiver 2413. The first spring receiver 2411 and the second spring receiver 2413 are generally ring-shaped, and a flange further protrudes radially outward from the ring.

[0098] 14, the first spring bearing 2411 is fitted onto the outer surface of the lower barrel case part 2214 near the upper side of the lower barrel case part 2214, whereby the first spring bearing 2411 is fixedly attached to the electric inside diameter measuring instrument 2200. Here, the lower end surface of the outer case main body part 2271 and the first spring bearing 2411 are integrally continuous, and the position at which the first spring bearing 2411 is attached to the electric inside diameter measuring instrument 2200 is fixedly restricted.

[0099] As one embodiment, the first spring bearing 2411 may be installed so that the height (position) of the first spring bearing 2411 corresponds to the height (position) of the center of gravity of the electric inside diameter measuring instrument 2200. For example, the first spring bearing 2411 is installed so that the height (position) of the first spring bearing 2411 is substantially the same as the height (position) of the center of gravity of the electric inside diameter measuring instrument 2200. Alternatively, the first spring bearing 2411 may be installed so that the height (position) of the first spring bearing 2411 is within 20%, 15%, 10%, or 5% (of the vertical length of the electric inside diameter measuring instrument 2200) above or below the height (position) of the center of gravity of the electric inside diameter measuring instrument 2200.

[0100] The coil spring 2412 has an upper end received in a first spring bearing 2411 with the lower cylinder case portion 2214 (electric inner diameter measuring instrument 2200) received inside the coil spring 2412. The coil spring 2412 has a lower end received in a second spring bearing 2413.

[0101] As one embodiment, instead of using a single coil spring 2412, a plurality of elastic bodies or springs may be arranged to surround the electric inside diameter measuring instrument 2200 (at equal angular intervals).

[0102] A larger spring diameter (larger distance between the spring and the central axis of the electric inside diameter measuring instrument 2200) is good for supporting the electric inside diameter measuring instrument 2200, but if the spring diameter is too large (if the distance between the spring and the central axis of the electric inside diameter measuring instrument 2200 is too large), the measurement pressure of the inner diameter measuring instrument alone will not be enough to autonomously adjust the attitude of the electric inside diameter measuring instrument 2200 so that the inclination of the electric inside diameter measuring instrument 2200 is aligned with the axis of the hole. If the spring diameter is increased (if the distance between the spring and the central axis of the electric inside diameter measuring instrument 2200 is increased), it is better to reduce the spring constant (elasticity coefficient). If the diameter of the spring is reduced (if the distance between the spring and the central axis of the electric inner diameter measuring instrument 2200 is reduced), the spring constant (elastic coefficient) may be made slightly larger. Also, in the embodiment, the spring has elasticity, but if the attitude adjustment in the rotational direction of the electric inner diameter measuring instrument 2200 can be allowed, the member connecting the first spring bearing 2411 and the second spring bearing 2413 may be a flexible member without elasticity instead of the coil spring 2412.

[0103] The second spring bearing 2413 is connected to the translational movement allowing mechanism 2420. As shown in the cross-sectional view of Fig. 14, the ring hole 2414 of the second spring bearing 2413 has a slight length (height) in the axial direction, and the diameter of the ring hole 2414 is slightly larger than that of the tube case 2210 (lower tube case 2214) of the electric inside diameter measuring instrument 2200 to an extent that allows tilting of the electric inside diameter measuring instrument 2200. The ring hole 2414 may be a tapered hole whose diameter increases toward the bottom or toward the top.

[0104] The translation allowing mechanism 2420 has a horizontal plate (translator) 2421 and a ball roller 2423. The horizontal plate 2421 is a plate disposed on the upper side of the support base portion 2320. The horizontal plate 2421 has a second insertion hole 2422 through which the electric inner diameter measuring instrument 2200 (the lower cylinder case portion 2214) is inserted. The second spring receiver 2413 is fitted into the second insertion hole 2422 from above. That is, the rotation allowance mechanism 2410 is provided on the horizontal plate 2421, and the electric inner diameter measurement device 2200 is supported by the rotation allowance mechanism 2410. In other words, the electric inner diameter measurement device 2200 is supported on the horizontal plate 2421 with the rotation allowance mechanism 2410 therebetween.

[0105] Ball rollers 2423 are disposed on the upper surface side of the support base portion 2320. Here, four ball rollers 2423 are installed at 90 degree intervals around the first insertion hole 2321 and the second insertion hole 2422, and the horizontal plate 2421 is placed on the ball rollers 2423.

[0106] The horizontal plate 2421 placed on the ball rollers 2423 can move horizontally with almost no friction and with an extremely small force. On the other hand, a force that resists the elastic force is required to deform the coil spring 2412 serving as the rotation allowing mechanism 2410. Therefore, in this embodiment, when a force (rotational force or translational force) acts on the electric inner diameter measuring instrument 2200, if anything, the translation allowing mechanism 2420 takes precedence in displacement.

[0107] The operation of adjusting the position and posture of the electric inside diameter measuring instrument 2200 by the action of the floating joint 2400 will be described with reference to Figs. 15 to 19. For example, as illustrated in Fig. 15, suppose that the hole to be measured is machined with a deviation from the design value, and as a result, the hole that should have been drilled vertically is inclined and is slightly deviated to the right in the figure from the position of the design data. The electric inside diameter measuring unit 2120 is carried to the hole by the robot arm 2130, and the measuring head 2220 is inserted into the hole. Even if the drive control of the robot arm 2130 is accurate, there is a deviation in position and angle between the axis of the electric inside diameter measuring instrument 2200 and the axis of the hole to be measured, because the hole to be measured has a deviation from the design value.

[0108] Now, in order to accurately measure the inner diameter of the hole to be measured, all three probes 2250 need to be evenly in contact with the inner wall of the hole to be measured. First, the rod 2230 is driven by the electric drive unit 2280, and the rod 2230 moves downward. Then, the tip (cone) of the lower rod 2233 pushes out the probe 2250, and the one of the three probes 2250 closest to the inner wall of the hole to be measured comes into contact with the inner wall of the hole to be measured. When the lower rod 2233 continues to push out the probe 2250, a reaction force is applied from the inner wall of the hole toward the probe 2250. This reaction force pushes the electric inner diameter measuring instrument 2200 in the opposite direction. The reaction force pushes the vicinity of the lower end of the lower rod 2233 from the probe 2250, but since the displacement of the horizontal plate 2421 occurs before the deformation of the coil spring 2412 of the rotation allowing mechanism 2410, the axial misalignment between the electric inside diameter measuring instrument 2200 and the hole to be measured is first absorbed by the displacement of the horizontal plate 2421, as illustrated in Figures 16 and 17. The first insertion hole 2321 of the support base 2320 has a diameter large enough to allow horizontal movement of the electric inside diameter measuring instrument 2200.

[0109] At the time of FIG. 16 (FIG. 17), the inclination of the axis of the electric inner diameter measuring instrument 2200 and the axis of the hole to be measured still do not match. When the lower rod 2233 continues to push out the probe 2250 from the state of FIG. 16 (FIG. 17), the tip (round shaft) of the probe 2250 hits the inner wall of the hole, and at this time, the reaction force acting from the inner wall of the hole to be measured to the electric inner diameter measuring instrument 2200 has a rotation moment (because the three round shafts have lengths). At this time, the coil spring 2412 of the rotation allowance mechanism 2410 is deformed by the reaction force from the inner wall of the hole, as illustrated in FIG. 18 and FIG. 19, and the inclination of the electric inner diameter measuring instrument 2200 is adjusted so that the axis of the electric inner diameter measuring instrument 2200 and the axis of the hole to be measured match. The ring hole 2414 of the second spring receiver 2413 allows the inclination of the electric inner diameter measuring instrument 2200.

[0110] Finally, when the three probes 2250 press the inner wall of the hole to be measured with a predetermined measurement pressure, the floating joint section 2400 (rotational tolerance mechanism section 2410, translational tolerance mechanism section 2420) causes the electric inner diameter measuring instrument 2200 to autonomously adjust its own position and posture so that it can accurately measure the diameter of the hole to be measured. In other words, if the robot arm section 2130 can insert the measuring head section 2220 of the electric inner diameter measuring instrument 2200 into the hole to be measured, then the hole diameter can be accurately measured by automatic posture adjustment without the need for manual sensory adjustment or advanced feedback control.

[0111] (Restraint means 2500) The restraining means 2500 is provided on the support frame portion 2300, and holds and supports the electric inside diameter measuring instrument 2200. The restraining means 2500 has two clamping pieces 2510 that clamp the electric inside diameter measuring instrument 2200 from a direction perpendicular to the axis, as shown in Fig. 9 and Fig. 10, for example. Here, the clamping pieces 2510 clamp the outer case main body portion 2271 from both sides. The clamping pieces 2510 are movable, and the restraining means 2500 can switch between a holding state of the electric inside diameter measuring instrument 2200 and a release state in which the hold is released.

[0112] Even though the clamping pieces 2510 are opened to release the electric inner diameter measuring instrument 2200, it is advisable to limit the gap between the clamping pieces 2510 and the electric inner diameter measuring instrument 2200 to a predetermined upper limit (approximately 5 mm or 10 mm) to prevent the electric inner diameter measuring instrument 2200 from being displaced (translated or tilted) significantly beyond the limit.

[0113] The electric inner diameter measuring instrument 2200 is mounted on the support base 2320 via the floating joint 2400. In order for the electric inner diameter measuring instrument 2200 to autonomously adjust its posture to match the measurement target hole by its own measurement pressure, the floating joint 2400 needs to be soft (softness, flexibility). Therefore, if the electric inner diameter measuring instrument 2200 is only mounted on the floating joint 2400, depending on the rigidity (softness) of the floating joint 2400, the electric inner diameter measuring instrument 2200 may sway, tilt significantly, or fall. It is not desirable from the viewpoint of safety that the electric inner diameter measuring instrument 2200 sways or falls. Furthermore, if the posture of the electric inner diameter measuring instrument 2200 is not fixed, the position of the measuring head 2220 will be unstable, and the robot arm 2130 will not be able to insert the measuring head 2220 of the electric inner diameter measuring instrument 2200 into the measurement target hole.

[0114] Therefore, when the electric inside diameter measuring instrument 2200 is not inserted into the hole to be measured, the restraining means 2500 clamps and holds the electric inside diameter measuring instrument 2200. Then, when the measurement head portion 2220 of the electric inside diameter measuring instrument 2200 is inserted into the hole to be measured, the restraining means 2500 releases the electric inside diameter measuring instrument 2200, so that the electric inside diameter measuring instrument 2200 can autonomously change its posture and adjust (autonomous adjustment) by the floating joint portion 2400.

[0115] (Collision detection unit 2600) The collision detection unit 2600 detects when the electric inside diameter measuring instrument 2200 collides with something with a force equal to or greater than a predetermined value. FIG. 20 is an exploded view of the collision detection unit 2600. FIG. 21 is a perspective view of the collision detection unit 2600 seen slightly from the rear side. The collision detection unit 2600 is disposed between the rear side of the support column 2310 and the hand unit 2131 of the robot arm unit 2130 . Here, the collision detection unit 2600 detects that when the electric inner diameter measuring instrument 2200 approaches an object (e.g., the workpiece W) from above, the electric inner diameter measuring instrument 2200 collides with the workpiece W and a large force is applied to the electric inner diameter measuring instrument 2200 in a direction in which the electric inner diameter measuring instrument 2200 is pushed upward from below in the Z direction (up-down direction). In other words, the collision detection direction of the collision detection unit 2600 is approximately parallel to the direction in which the electric inner diameter measuring instrument 2200 approaches the hole to be measured.

[0116] The collision detection unit 2600 includes a fixed plate 2601 , an attachment plate 2602 , a linear guide 2610 , a biasing means 2620 , and a contact sensor 2630 .

[0117] The fixed plate 2601 is directly or indirectly attached to the hand unit 2131 of the robot and is fixedly provided with respect to the hand unit 2131. Here, a force sensor unit 2132 is disposed between the hand unit 2131 of the robot and the collision detection unit 2600. Therefore, the collision detection unit 2600 is attached to the hand unit 2131 of the robot arm unit 2130 via the force sensor unit 2132.

[0118] The mounting plate 2602 is directly or indirectly attached to the back surface of the support column portion 2310, and is fixedly provided with respect to the support column portion 2310 (support frame portion 2300). The linear guide 2610 is disposed between the fixed plate 2601 and the mounting plate 2602, and guides the movable direction of the mounting plate 2602 relative to the fixed plate 2601 in the up-down direction. The linear guide 2610 has a groove frame body 2611 having a groove in the up-down direction, and a slide body 2612 that slides in the groove of the groove frame body 2611 in the up-down direction. Here, the groove frame body 2611 is attached to the fixed plate 2601, and the slide body 2612 is attached to the mounting plate 2602.

[0119] The biasing means are two coil springs 2620. One end of the coil spring 2620 is engaged with the fixed plate 2601, and the other end of the coil spring 2620 is engaged with the mounting plate 2602. The coil spring 2620 constantly biases the mounting plate 2602 in a direction that pulls the mounting plate 2602 down relative to the fixed plate 2601. That is, the mounting plate 2602 is lowered vertically downward relative to the fixed plate 2601 by its own weight, the weight of the electric inside diameter measuring instrument 2200, and the biasing force of the coil spring 2620, and this position becomes the reference position.

[0120] The contact sensor 2630 has a contact detection block 2631 arranged on the fixed plate 2601 side, and a ball plunger 2632 provided on the mounting plate 2602 side. As illustrated in FIG. 21, when the mounting plate 2602 is in a reference position with respect to the fixed plate 2601, the ball plunger 2632 on the mounting plate 2602 side abuts (fits) against the contact detection block 2631.

[0121] Here, for example, assume that the position of a hole machined in the workpiece W is significantly deviated from the design value. In this state, when the robot arm unit 2130 tries to insert the electric inner diameter measuring instrument 2200 into the hole to be measured from above, the measuring head unit 2220 of the electric inner diameter measuring instrument 2200 hits the workpiece W. The electric inner diameter measuring instrument 2200 (measuring head unit 2220) deviates from the hole and hits the workpiece W, and the electric inner diameter measuring instrument 2200 (measuring head unit 2220) is further pushed into the workpiece W. Then, when a force exceeding the gravity of the electric inner diameter measuring instrument 2200 and the biasing force of the biasing means (coil spring 2620) is applied to the collision detection unit 2600, the mounting plate 2602 slides upward, and the ball plunger 2632 of the mounting plate 2602 comes off the contact detection block 2631. The contact sensor 2630 generates a signal (collision detection signal) when the contact detection block 2631 detects the separation of the ball plunger 2632 (or becomes unable to detect the contact of the ball plunger 2632).

[0122] When the collision detection section 2600 detects that the electric inside diameter measuring instrument 2200 has collided with something, the control unit section 2140 immediately stops the operation of the robot arm section 2130.

[0123] (Force sensor part) The force sensor unit 2132 is, for example, a six-axis force sensor (forces in three orthogonal axial directions and rotational forces around the axes). The collision detection unit 2600 is specialized for detecting forces pushing up from below in the vertical direction (Z direction), but the force sensor unit 2132 detects forces acting on the electric inside diameter measuring instrument 2200 in all directions.

[0124] The articulated robot arm section 2130 is a so-called robot arm section 2130, and moves the hand section 2131, which is the tip of the robot arm section 2130, three-dimensionally with a vertical rotation drive shaft and a horizontal rotation drive shaft. The hand section 2131 of the robot arm section 2130 is connected to the support frame section 2300 via the force sensor section 2132 and the collision detection section 2600. The force sensor section 2132 detects that the electric inner diameter measuring instrument 2200 has collided with an object with an unexpected force of a predetermined value or more, even in a direction in which the collision detection section 2600 does not detect a collision (i.e., a direction other than the up-down direction (Z direction)). When the force sensor section 2132 detects an unexpected collision of the electric inner diameter measuring instrument 2200, the control unit section 2140 immediately stops the operation of the robot arm section 2130. This makes it possible to ensure further safety.

[0125] (Vibration motor) The vibration motor (vibration actuator) 2700 is attached to the electric inner diameter measuring instrument 2200. A mounting support 2710 is attached to the housing of the electric drive unit 2280, and the vibration motor 2700 is installed above the electric drive unit 2280 by the mounting support. Here, the vibration motor 2700 is installed on the central axis of the electric inner diameter measuring instrument 2200, on the side farther from the gauge head 2250. The vibration motor 2700 is installed on the central axis because it is convenient for balancing the overall weight, but the vibration motor 2700 may be installed at a position off the central axis. In this case, it would be preferable to attach a counterbalance so that the center of gravity of the inner diameter measuring instrument does not deviate from the central axis.

[0126] Here, the reason for installing the vibration motor 2700 on the side farther from the measuring element 2250 is that it is advantageous in terms of moment, and it is considered that even a small vibration motor 2700 can provide sufficiently effective vibration to the measuring element 2250. Note that the vibration motor 2700 may be installed as close as possible to the measuring element 2250. In this case, the vibration of the vibration motor 2700 is directly transmitted to the measuring element 2250. For example, this is suitable when it is desired to delicately control the vibration of the measuring element 2250 depending on the material of the workpiece W.

[0127] (Control unit part 2140) 22 is a functional block diagram of the control unit section 2140. The control unit section 2140 includes a measurement operation control section 2150, a robot arm drive control section 2160, and a central control section 2170.

[0128] The measurement operation control unit 2150 controls the measurement operation of the electric inside diameter measuring instrument 2200. The measurement operation control unit 2150 includes a constraint control unit 2151, a motor drive control unit 2152, and a measurement value acquisition unit 2153.

[0129] The constraint control unit 2151 controls the opening and closing operation of the clamping pieces 2510 of the constraint means 2500, and controls the hold and release timing of the electric inner diameter measuring instrument 2200. The motor drive control unit 2152 controls the drive of the electric drive unit 2280 and the vibration motor 2700. The measurement value acquisition unit 2153 obtains the measurement value of the electric inner diameter measuring instrument 2200. That is, the measurement value acquisition unit 2153 receives the sensor value of the displacement detection unit 2260, and obtains the measurement value of the inner diameter of the measurement target hole from the displacement (position) of the rod 2230.

[0130] The robot arm drive control section 2160 controls the operation of the robot arm section 2130. The central control section 2170 controls the measurement operation control section 2150 and the robot arm drive control section 2160 in an integrated manner.

[0131] (Control operation of the automatic inner diameter measuring device 2100) A series of operations in which the measuring device main body 2110 (electric inner diameter measuring unit 2120, robot arm 2130) automatically measures the inner diameter of the measurement target hole under the control of the control unit 2140 will be described. FIG. 23 is a flowchart of the entire operation of automatic inner diameter measurement (automatic inner diameter measurement operation). A workpiece W (measurement object) having a hole to be measured (measurement target hole) is transported by a conveyer belt or rails of a production line to a predetermined position in front of the measuring device main body 2110 (electric inner diameter measuring unit 2120, robot arm unit 2130). The automatic inner diameter measuring device 2100 automatically performs inner diameter measurements on the measurement target holes designated (set) as measurement targets in the workpiece W (measurement object) that is transported. The position (coordinates) of the measurement target hole in the workpiece W (measurement object) is set (stored) as part of a measurement part program in the central control unit 2170. Alternatively, the inner diameter measurements may be performed automatically in order while searching for the measurement target holes by image recognition using a separate camera 150 or the like.

[0132] Here, it is assumed that the hole to be measured is a hole that is opened vertically at the top, and that the electric inner diameter measuring instrument 2200 is inserted into the hole from above while maintaining an approximately vertical posture.

[0133] The automatic inner diameter measurement operation includes a hole insertion step (approach step) (ST2100), a measurement step (ST2200), and a hole retraction step (retraction step) (ST2300).

[0134] The hole insertion process (ST2100) is a process in which the electric inner diameter measurement unit 2120 is moved by the robot arm section 2130 and the measurement head section 2220 of the electric inner diameter measurement instrument 2200 is inserted into the hole to be measured (in other words, approaching the workpiece W from above the workpiece W).

[0135] FIG. 24 is a flowchart showing the operation procedure of the hole insertion step (ST2100). In the hole insertion step (ST2100), first, the destination (target coordinates) of the electric inside diameter measuring instrument 2200 by the robot arm unit 2130 is set to the measurement target hole (ST2110). Next, it is confirmed whether the electric inside diameter measuring instrument 2200 is restrained by the restraining means 2500 (ST2120). In this embodiment, the state in which the restraining means 2500 restrains (holds) the electric inside diameter measuring instrument 2200 is the default state (which may be rephrased as the standard state or reference state). However, when maintenance or replacement of the electric inside diameter measuring instrument 2200 is performed, the hold state of the restraining means 2500 may be released, so the hold state is confirmed, and if it is not held (ST2120: NO), a signal is sent from the restraint control unit 2151 to perform the hold step (ST2130) by the restraining means 2500. By restraining (holding) the electric inner diameter measuring instrument 2200 when the electric inner diameter measuring unit 2120 is moved by the robot arm section 2130, the electric inner diameter measuring instrument 2200 can be moved stably and safely by the robot arm section 2130.

[0136] Driving of the robot arm section 2130 is started (ST2140), the electric inner diameter measurement unit 2120 is moved, and the measurement head section 2220 of the electric inner diameter measurement instrument 2200 is inserted into the hole to be measured.

[0137] At this time, for example, if the machining position of the hole to be measured deviates from the design value, the electric inside diameter measuring instrument 2200 (measuring head unit 2220) may unexpectedly collide with the workpiece W. In this regard, the robot arm drive control unit 2160 monitors signals from the collision detection unit 2600 and the force sensor unit 2132 (ST2150). Then, when a collision between the electric inside diameter measuring instrument 2200 (measuring head unit 2220) and the workpiece W is detected (ST2150: YES), the drive of the robot arm unit 2130 is immediately stopped (emergency stop) (ST2180). After this, the central control unit 2170 may be configured to report the abnormality to the operator.

[0138] When the measuring head unit 2220 of the electric inner diameter measuring instrument 2200 is inserted into the hole to be measured and reaches the target coordinates, the driving of the robot arm unit 2130 is temporarily stopped (ST2170).

[0139] Next, the process proceeds to the measurement process (ST2200). Fig. 25 is a flow chart showing the operational procedure of the measurement process (ST2200). In the measurement process (ST2200), first, the hold by the restraining means 2500 is released (ST2210) to put the electric inside diameter measurement device 2200 into a released state. This puts the electric inside diameter measurement device 2200 into a state supported by the support frame portion 2300 via the floating joint portion 2400, making it possible to autonomously adjust the position and attitude of the electric inside diameter measurement device 2200.

[0140] Then, a drive signal is sent from the motor drive control unit 2152 to drive the electric drive unit 2280. First, a first advancement step (ST2220) is performed. The first advancement step (ST2220) is a step in which the probe 2250 advances until it first comes into contact with the inner wall of the hole to be measured. The electric drive unit 2280 (e.g., a motor) is driven to advance the rod 2230 (here, move it downward), and advance the probe 2250 toward the inner wall of the hole. In the first advancement step (ST2220), in order to improve the measurement efficiency, it is preferable to drive the motor at high speed to move the rod 2230 and the probe 2250 as fast as possible. (For example, the rod 2230 is screw-fed, and the rotation speed of the rod 2230 is 100 rpm-200 rpm. In terms of the advancement speed of the rod 2230 or the probe 2250, it may be 10 μm / s-20 μm / s.)

[0141] When the probe 2250 advances toward the inner wall of the hole, the probe 2250 comes into contact with the inner wall of the hole. Here, in this embodiment, there are three probes 2250. If the axis of the electric inner diameter measuring instrument 2200 and the axis of the hole to be measured were perfectly aligned, the three probes 2250 could come into contact with the inner wall of the hole at the same time, but due to a driving error of the robot arm unit 2130 and a processing error of the workpiece W, there is a deviation between the axis of the electric inner diameter measuring instrument 2200 and the axis of the hole to be measured. In this case, one of the three probes 2250 will come into contact with the inner wall of the hole first. If one of the probes 2250 comes into contact with the inner wall of the hole (ST2230: YES), the first advance step (ST2220) is immediately stopped and the process proceeds to the first retreat step (ST2240). The contact of the probe 2250 with the inner wall of the hole may be determined, for example, by calculating the motor torque from the applied current (applied voltage) of the motor, and when the torque exceeds a predetermined value, it may be determined that (one of) the probes 2250 has come into contact with the inner wall of the hole.

[0142] In the first retraction step (ST2240), the rod 2230 and the probe 2250 are slightly retracted in the opposite direction. This prevents the probe 2250 from biting into the inner wall of the hole due to the momentum after the probe 2250 comes into contact with the inner wall of the hole in the first advancement step (ST2220). The distance by which the probe 2250 is retracted in the first retraction step (ST2240) may be extremely small, for example, 0.001 mm to 0.01 mm.

[0143] The retraction speed of the probe 2250 in the first retraction step (ST2240) may be as fast as possible. For example, the rod 2230 is a screw feed and the rotation speed of the rod 2230 is 100 rpm-200 rpm. The advancement speed of the rod 2230 or the probe 2250 may be 10 μm / s-20 μm / s.

[0144] After the tracing stylus 2250 is slightly returned in the first retraction step (ST2240), the motor drive control unit 2152 starts driving the vibration motor 2700 (ST2241). That is, after the first retraction step (ST2240) and before the start of the second advancement step (ST2250), the motor drive control unit 2152 starts driving the vibration motor 2700 (ST2241).

[0145] The probe 2250 is advanced again by a second advancement step (ST2250). In the second advancement step (ST2250), the probe 2250 is advanced slowly (at a low speed, with slight movement).

[0146] The feed speed of the probe 2250 in the second forward movement step (ST2250) is preferably low (slight). For example, the rod 2230 is screw-fed and the rotation speed of the rod 2230 is 10 rpm-20 rpm. The advance speed of the rod 2230 or the probe 2250 may be 1 μm / s-2 μm / s.

[0147] The position and inclination of the electric inner diameter measuring instrument 2200 are autonomously adjusted by the reaction force when the measuring element 2250 presses the inner wall of the hole. The action of autonomously adjusting the position and inclination of the electric inner diameter measuring instrument 2200 by the translation and rotational tolerance of the floating joint 2400 is as described above. At this time, the vibration of the vibration motor 2700 is transmitted to the measuring element 2250 (round shaft tip 2252), which causes the measuring element 2250 (round shaft tip 2252) to vibrate slightly, thereby reducing friction at the interface between the measuring element 2250 (round shaft tip 2252) and the workpiece W (inner wall of the hole) and promoting a change in the posture of the electric inner diameter measuring instrument 2200.

[0148] When the three probes 2250 come into contact with the inner wall of the hole evenly with a predetermined measurement pressure, the autonomous adjustment of the position and inclination of the electric inner diameter measuring instrument 2200 is completed. When the three probes 2250 come into contact with the inner wall of the hole with a predetermined measurement pressure, the ratchet mechanism (constant pressure mechanism) is activated. That is, the electric drive unit 2280 rotates the thimble unit 2240 (ratchet sleeve 2242) until the ratchet mechanism (constant pressure mechanism) is activated, whereby the probes 2250 come into contact with the inner wall of the hole evenly with a predetermined measurement pressure.

[0149] The second forward movement step (ST2250) may be rephrased as an autonomous adjustment step.

[0150] At this point, the motor drive control section 2152 stops driving the vibration motor 2700 (ST2251).

[0151] In this state, the displacement detection unit 2260 detects the displacement (position) of the rod 2230. In acquiring the measured value, the displacement detection unit 2260 may detect the displacement (position) of the rod 2230 immediately after stopping the driving of the vibration motor 2700, or the electric drive unit 2280 may be driven at a relatively high speed again as a measurement pressure application step to operate the ratchet mechanism (constant pressure mechanism) and sample the measured value when the constant pressure is applied. The measurement acquisition unit 2153 obtains the inner diameter of the hole from the displacement (position) of the rod 2230 (ST2260).

[0152] After the measurement value is obtained, in a second retracting step (ST2270), the probe 2250 is retracted so that the probe 2250 is separated from the inner wall of the hole.

[0153] After the measurement step (ST2200), in the hole evacuation step (ST2300), the electric inside diameter measuring instrument 2200 is removed from the hole to be measured. Figure 26 is a flow chart showing the operation procedure of the hole evacuation step (ST2300). In the hole evacuation step (ST2300), first, the electric inside diameter measuring instrument 2200 is restrained (held) by the restraining means 2500 (ST2320), and then the electric inside diameter measuring unit 2120 is moved by the robot arm section 2130 so as to retreat from the hole (ST2330).

[0154] This completes the measurement of the inner diameter of one hole. ST2100-ST2300 are repeated until the measurement of all target holes is completed (ST2400).

[0155] Thus, according to this embodiment, it is no longer necessary to hold and operate the inner diameter measuring instrument by hand, and the inner diameter of the hole can be automatically measured by the electric inner diameter measuring unit 2120 (electric inner diameter measuring instrument 2200, robot arm unit 2130). In the case of inner diameter measurement, the three probes 2250 need to be in close contact with the inner wall of the hole appropriately. However, depending on the weight of the inner diameter measuring instrument and the surface properties (roughness) of the workpiece W, the probe 2250 (round shaft tip 2252) may not be able to slide smoothly on the inner wall of the hole and the posture of the inner diameter measuring instrument may not be changed appropriately. In this regard, in this embodiment, the vibration motor 2700 is driven at an appropriate timing to reduce the friction between the probe 2250 (round shaft tip 2252) and the workpiece W (inner wall of the hole) and to encourage the posture of the inner diameter measuring instrument to be changed. As a result, the inside measurement value of the hole can be obtained stably even in automatic measurement.

[0156] In the above embodiment, the release step (ST2210) is performed before the first forward movement step (ST2220). The release step (ST2210) may be reserved until the contact between the probe 2250 and the inner wall of the hole is detected (ST2230: Yes), and the release step (ST2210) may be performed before the first backward movement step (ST2240) after the contact between the probe 2250 and the inner wall of the hole is detected in the first forward movement step (ST2220). Alternatively, the release step (ST2210) may be performed after the contact between the probe 2250 and the inner wall of the hole is detected (ST2230: Yes) and the first backward movement step (ST2240) is performed. However, the driving of the vibration motor 2700 is started after the release step and before the second forward movement step (ST2250).

[0157] Third embodiment A third embodiment of the present invention will now be described. In the second embodiment, the floating joint part 3400, the restraining means 3500, and the vibration motor 3700 were provided in the electric inner diameter measurement unit 2120. In the third embodiment, the floating joint part 3400, the restraining means 3500, and the vibration motor 3700 are provided in a work holding part.

[0158] FIG. 27 is a schematic diagram of the third embodiment. In the third embodiment, the electric inner diameter measuring instrument 2200 is directly attached to the measuring instrument support frame 2300. As in the second embodiment, the hand 2131 of the robot arm 2130 is connected to the support frame 2300 via the force sensor 2132 and the collision detection unit 2600. Therefore, it is not assumed that the hand 2131 of the robot arm 2130 and the electric inner diameter measuring instrument 2200 will change their relative positions or postures.

[0159] In the third embodiment, a workpiece holding table portion (workpiece holding portion) 3000 is provided. The workpiece holding table 3000 includes a base section 3100 , a workpiece setting stage 3200 , a floating joint section 3400 , a restraining means 3500 , and a vibration motor 3700 .

[0160] A workpiece W is placed on the workpiece setting stage 3200. It is assumed that the workpiece W is transported by a moving means for transporting the workpiece (robot), but the workpiece W may be manually changed. Here, it is assumed that the workpiece W does not slip and move on the surface of the workpiece setting stage 3200. For example, if the surface of the workpiece setting stage 3200 is treated to have an anti-slip coating and the workpiece W has a certain weight, the workpiece W will not move easily on the workpiece setting stage 3200. Alternatively, a depression (recess) for receiving the workpiece W or a plurality of pins (protrusions) for restricting the movement of the workpiece W may be provided on the surface of the workpiece setting stage 3200.

[0161] The configuration of the floating joint 3400 is basically the same as that of the second embodiment. That is, the floating joint 3400 has a translational movement allowance mechanism 3420 that allows translational displacement of the work mounting stage 3200 relative to the base 3100, and a rotational movement allowance mechanism 3410 that allows rotation of the work mounting stage 3200 relative to the base 3100. The translational movement allowance mechanism 3420 and the rotational movement allowance mechanism 3410 are provided in this order from the bottom between the base 3100 and the work mounting stage 3200.

[0162] A first spring bearing 3411 is provided on the back surface of the workpiece setting stage 3200, a second spring bearing 3413 is provided on the upper surface of the horizontal plate (translation body) 3421, and a coil spring 3412 is interposed between the first spring bearing 3411 and the second spring bearing 3413. A ball roller 3423 is disposed on the upper surface side of the base unit 3100, and a horizontal plate (translation body) 3421 is provided on the ball roller 3423. The floating joint unit 3400 is interposed between the base unit 3100 and the workpiece setting stage 3200, so that the workpiece setting stage 3200 can be allowed to move in translation and to be displaced in rotation. That is, the workpiece holding table unit 3000 can allow the workpiece W set on the workpiece setting stage 3200 to move in translation and to be rotated.

[0163] The restraining means 3500 restricts the displacement of the workpiece mounting stage 3200, and has a configuration substantially similar to that of the restraining means 3500 of the second embodiment, in which the workpiece mounting stage 3200 is clamped from both sides by two clamping pieces 3510. By closing and opening the movable clamping pieces 3510, the restraining means 3500 can switch between a holding state of the workpiece mounting stage 3200 and a release state in which the hold is released.

[0164] The vibration motor 3700 is installed on the workpiece setting stage 3200. The vibration motor 3700 is preferable, but not necessary. The workpiece holding platform (workpiece holding unit) 3000 of the third embodiment allows the workpiece setting stage to be displaced by the floating joint 3400, so the workpiece can be displaced by being pushed by the measuring device even without a vibration motor. However, if the workpiece is heavy, it is preferable to have a vibration motor to promote the displacement of the workpiece.

[0165] The difference between the third embodiment and the second embodiment is that the object held / released by the restraining means 3500 is the workpiece setting stage 3200, and the object to which the vibration motor 3700 applies vibration is the workpiece W via the workpiece setting stage 3200, and the process of the automatic inner diameter measurement operation is the same as that of the second embodiment. The action of the workpiece holding table 3000 in the third embodiment is that the workpiece setting stage 3200 translates and tilts (rotates) so that the inner wall of the workpiece W and the measuring probe 2250 (round shaft tip 2252) of the electric inner diameter measuring instrument 2200 come into close contact with each other. For example, as shown in FIG. 28, when the center line of the workpiece is deviated from the center of the hole, the workpiece setting stage 3200 translates and the position of the workpiece is adjusted so that all the measuring probes 2250 (round shaft tips 2252) come into close contact with the inner wall of the workpiece. 29, when the center line of the work is inclined with respect to the bottom surface of the work, the work setting stage 3200 is inclined (rotated) and the posture of the work is adjusted so that all the probes 2250 (round shaft tips 2252) come into close contact with the inner wall of the work. Also, by applying vibration to the work W from the vibration motor 3700 to the work setting stage 3200, friction at the interface between the probes 2250 (round shaft tips 2252) and the work (inner wall of the hole) can be reduced, and the posture of the work W on the work setting stage 3200 can be encouraged to change.

[0166] In the third embodiment, since the electric inner diameter measuring instrument 2200 is not supported by the floating joint 3400, the attitude of the electric inner diameter measuring instrument 2200 can be controlled almost as intended by the hand (hand unit 2131) of the robot (movement means), and can also be controlled to maintain a vertical attitude, for example. Since a power supply cable, a control signal or a transmission cable for measurement data is connected to the electric inner diameter measuring instrument 2200, a force due to the rigidity of the cables and the weight of the cables is applied. If the electric inner diameter measuring instrument 2200 is supported by a displacement allowance mechanism such as the floating joint 3400 as in the second embodiment, the attitude may be affected by the influence of disturbance. In this respect, in the third embodiment, since the electric inner diameter measuring instrument 2200 is not supported by the floating joint 3400, it is less susceptible to disturbances such as cables. Furthermore, the workpiece setting stage 3200 that supports the workpiece W is supported by the floating joint 3400, but since there is no need to connect a thick cable to the workpiece setting stage 3200, there is no need to worry about the workpiece setting stage 3200 being subjected to disturbances from cables, etc. This allows stable measurement of the workpiece dimensions.

[0167] In the above embodiment, the base unit 3100 and the workpiece mounting stage 3200 are connected by the floating joint unit 3400, and the floating joint unit 3400 has a rotation allowing mechanism 3410 and a translation allowing mechanism 3420. Since it is sufficient for the workpiece mounting stage 3200 to translate and rotate (tilt) to a certain extent relative to the base unit 3100, the floating joint unit 3400 may be, for example, elastic rubber, foamed resin, a spring, or a bag sealed with air (e.g., an air cap).

[0168] The restraining means 3500 has clamping pieces 3510 that clamp the workpiece setting stage 3200 from both sides, but any means capable of restricting the displacement of the workpiece setting stage 3200 may be used. For example, as illustrated in Fig. 30, a hole 3210 may be provided on the underside of the workpiece setting stage 3200, a pin 3110 may be provided from below the workpiece holding base 3000 so as to move up and down, and the workpiece setting stage 3200 may be switched between hold and release by inserting and removing the pin into the hole. Similarly, a pin may be provided on the underside of the workpiece setting stage 3200, and a cylinder may be provided from below the workpiece holding base 3000 so as to move up and down, and the workpiece setting stage 3200 may be switched between hold and release by inserting and removing the cylinder into and from the pin.

[0169] 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. In the above embodiment, the floating joint portion is provided only on either the measuring device side or the workpiece holding portion, but both the measuring device and the workpiece holding portion may have a floating joint portion. Similarly, in the above embodiment, the vibration motor is provided only on either the measuring device side or the workpiece holding portion, but both the measuring device and the workpiece holding portion may have vibration motors. [Explanation of symbols]

[0170] 100 Automatic measuring device 111 Conveyor Belt 112 Stocker 120 Measuring device main body 130 Robot Arm Part 140 Robot Hand 150 Camera 200 Automatic measuring unit (automatic micrometer device) 300 micrometer (measuring instrument) 310 U-shaped frame (fixing element) 311 Display Panel 320 Anvil 330 Spindle (moving element) 340 Thimble part 350 Displacement detection unit 400 Measuring instrument support frame 410 Base frame 411 First long side 412 Second long side 413 First short side 414 Second short side 420 Measuring instrument holder 421, 422 clamping piece 423 Elastic rubber sheet 460 Workpiece holding table (workpiece holding part) 461 Support column 462 Workpiece placement plate 500 Automatic operation unit 510 Motor housing 520 Motor 530 Power transmission section 531 Fixing Ring 532 Rotating Plate 533 Transmission link rod 600 Vibration motor (vibration actuator) 800 Control unit 2100 Automatic inner diameter measuring device 2110 Measuring device main body 2120 Electric inner diameter measuring unit 2130 Articulated Robot Arm 2131 Hand section 2132 Force sensor part 2140 Control Unit 2150 Measurement operation control section 2151 Constraint control unit 2152 Motor drive control unit 2153 Measurement acquisition unit 2160 Robot arm drive control unit 2170 Central Control Unit 2200 Electric inner diameter measuring device 2210 Cylinder case part (fixing element) 2211 Upper tube case part 2213 Intermediate cylinder case part 2214 Lower barrel case part 2215 Head tube 2216 Leaf spring 2220 Measuring head 2230 Rod 2230 Upper Rod 2231 Upper Rod 2233 Display unit 2233 Lower Rod 2234 Display section 2240 Thimble part 2241 Thimble Sleeve 2242 Ratchet Sleeve 2243 Coil spring (load-regulated elastic body) 2250 Probe (movable element) 2251 Tapered surface 2252 Round Shaft Tip 2260 Displacement detection unit 2261 Rotor 2262 Stator 2270 Outer case part 2271 Outer case body 2272 Outer case upper part 2280 Electric drive unit (automatic operation unit) 2300 Measuring instrument support frame 2300 Support frame part 2310 Support column section 2320 Support base 2321 First insertion hole 2400 Floating joint part (floating joint mechanism part) 2410 Rotational tolerance mechanism 2412 Coil spring (elastic body) 2414 Ring hole 2420 Translational tolerance mechanism 2421 Horizontal plate (translation body) 2422 Second insertion hole 2423 Ball Roller 2500 Restraint means 2510 Clamping piece 2600 Collision detection unit 2601 Fixed plate 2602 Mounting plate 2610 Linear Guide 2611 Grooved frame 2612 Slide body 2620 Coil spring 2630 Contact Sensor 2631 Contact detection block 2632 Ball Plunger 2700 Vibration motor (vibration actuator) 2710 Mounting support 3000 Workpiece holding table (workpiece holding part) 3100 Base 3110 Pin 3200 Workpiece installation stage 3210 Hole 3400 Floating joint 3410 Rotational tolerance mechanism 3412 Coil spring 3420 Translational tolerance mechanism 3421 Horizontal plate (translation body) 3423 Ball roller 3500 Restraint Means 3510 Clamping piece 3700 Vibration Motor

Claims

1. A measuring instrument including a movable element that is displaceable relative to a fixed element and moves toward and away from a workpiece, and a displacement detection unit that detects the displacement or position of the movable element; and an automatic operation unit that automates the advancement and retreat of the movable element by power, An automatic measuring device that automatically measures a workpiece using a measuring device for measuring the dimensions of the workpiece, and a vibration actuator for directly or indirectly applying vibration to at least one of the workpiece and the measuring device to promote a change in the relative position and posture between the workpiece and the measuring device, so that when the workpiece and the movable element come into contact with each other, the relative position and posture between the workpiece and the measuring device are changed at a pressure equal to or lower than a predetermined measurement pressure preset in the measuring device, and the contact surfaces between the workpiece and the movable element come into close contact with each other.

1. An automatic measuring device comprising:

2. 2. The automatic measuring device according to claim 1, a moving means for moving the measuring device and the workpiece relative to each other so that the workpiece is within a measurement range of the measuring device; a floating joint portion interposed between the moving means and the measuring device to allow translation and rotation of the measuring device relative to the moving means, The vibration actuator is attached to the measuring device.

1. An automatic measuring device comprising:

3. 2. The automatic measuring device according to claim 1, A workpiece holding unit is provided for holding the workpiece, The workpiece holding unit includes: The workpiece is held so that the position and posture of the workpiece can be changed with a pressure equal to or less than a predetermined measurement pressure preset in the measuring device when the movable element contacts the workpiece, The vibration actuator is attached to the workpiece holding portion.

1. An automatic measuring device comprising:

4. 6. The automatic measuring device according to claim 5, The automatic operation unit includes: advancing the movable element so that the movable element contacts the workpiece; Then, the movable element is retracted a predetermined distance. Thereafter, the movable element is re-advanced so that a predetermined measurement pressure is generated between the workpiece and the movable element; The vibration actuator is actuated when the movable element is re-advanced so that a predetermined measurement pressure is generated between the workpiece and the movable element.

1. An automatic measuring device comprising:

5. 6. The automatic measuring device according to claim 5, After the automatic operation unit stops the re-advancement of the movable element and the vibration actuator stops driving, The displacement detection unit obtains the displacement or position of the movable element as a measurement value.

1. An automatic measuring device comprising:

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