Automatic measuring device and automatic measuring system

Abstract

The present invention provides an automatic measuring device, an automatic measuring system, and a measuring automation device for automating contact-type measuring equipment that are inexpensive and easy to use. The automatic measuring device (200) comprises: a measuring device support seat (400) that supports the measuring device (300); and a workpiece holding seat (460) that holds the workpiece (W) within the measuring area of the measuring device (300). The measuring device support seat (400) comprises: a measuring device holding portion (420) that holds a fixed component (310) of the measuring device (300); and an automatic operating portion (440) that can be loaded and unloaded relative to the measuring device (300). The automatic operating portion (440) uses the power of a motor to automatically advance and retreat a movable component (330) of the measuring device (300).

Description

Technical Field

[0001] The present invention relates to an automatic measuring apparatus for automatically measuring a workpiece using a small-sized measuring device for measuring the size of the workpiece. Background Art

[0002] As measuring devices (measuring tools) for measuring the dimensions of workpieces, micrometers and vernier calipers are known. These contact-type measuring devices (measuring tools) have advantages such as ease of use, good measurement stability, and relatively low cost, and are therefore widely used.

[0003] However, since the workpiece and the movable parts (styli and measuring claws) must be properly and tightly fitted together, and the same measuring pressure must be applied at all times, measurement is always a manual process. Therefore, measurement using such contact-type measuring tools is labor-intensive and time-consuming.

[0004] As an alternative to manual measurement, a method using non-contact measuring equipment such as air micrometers and laser scanning micrometers at the production site has been proposed (Japanese Patent Application Laid-Open No. 8-14871). However, air micrometers and laser scanning micrometers are expensive and have some maintenance difficulties.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 10-89903

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2019-100904

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 8-14871 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] There have been various proposals to automate contact measurement, such as using motor power, but no successful examples of practical application have been widely adopted (Japanese Patent Application Laid-Open No. 10-89903).

[0012] In addition, if a three-dimensional measuring machine (CMM) is used, contact measurement can certainly be automated (Japanese Patent Application No. 2019-100904), but it requires an investment of tens of millions to hundreds of millions of yen, and it is not appropriate to use it as an alternative to measurements performed using micrometers and vernier calipers.

[0013] An object of the present invention is to provide an automatic measuring device that automates a contact-type measuring instrument and is inexpensive and easy to use.

[0014] Solutions for solving problems

[0015] The automatic measuring device of the present invention uses a measuring device for measuring the size of a workpiece to automatically measure the workpiece, and is characterized in that the automatic measuring device comprises: the measuring device; a measuring device support seat that supports the measuring device; and a workpiece holding seat that holds the workpiece W within the measuring area of the measuring device, the measuring device having: a fixed part; a movable part that is configured to be displaceable relative to the fixed part and to advance and retreat in a manner of contacting or separating with the workpiece W; and a displacement detection part that detects the displacement of the movable part, the measuring device support seat having: a measuring device holding part that holds the fixed part of the measuring device; and an automatic operating part that can be loaded and unloaded relative to the measuring device, the automatic operating part automating the advance and retreat of the movable part using the power of a motor.

[0016] In one technical solution of the present invention, it is preferred that, for at least one of the workpiece held on the workpiece holding seat and the measuring device held on the measuring device holding portion, when the workpiece and the movable part abut against each other, the position and posture of the at least one are changed by using a pressure pre-set below a predetermined measuring pressure of the measuring device, so that the abutting surfaces of the workpiece and the movable part are maintained in close contact with each other.

[0017] In one aspect of the present invention, it is preferred that the workpiece holding seat portion is a workpiece placing table on which the workpiece is placed.

[0018] In one aspect of the present invention, it is preferred that the workpiece holding seat has a workpiece holding unit for holding the workpiece, and one of the workpiece holding unit and the measuring device holding portion is configured to allow relative displacement with respect to the other.

[0019] In one technical solution of the present invention, it is preferred that the measuring device has an operating part, which is originally used for manual operation, and the movable part is moved forward and backward by manual rotation operation or manual push-pull operation. The automatic operating part can be loaded and unloaded relative to the operating part, and the automatic operating part uses the power of the motor to operate the operating part, thereby automating the advance and retreat of the movable part.

[0020] In one technical solution of the present invention, preferably, the measuring device is a micrometer, and the micrometer comprises: a U-shaped frame as the fixed component, which has an anvil on the inner side of one end of the U-shape; and a measuring rod as the movable component, which is arranged on the other end side of the U-shaped frame and is configured to be able to move forward and backward axially relative to the anvil, and the automatic operation part comprises: a motor; and a power transmission part, which directly or indirectly connects the output shaft of the motor and the measuring rod so as to convert the power of the motor into the advancement and retreat of the measuring rod.

[0021] In one technical solution of the present invention, it is preferred that the automatic operation part is configured to be able to change its position in a direction orthogonal to the central axis of the measuring rod so that the rotation axis of the rotor of the motor is in the same straight line as the central axis of the measuring rod.

[0022] In one technical solution of the present invention, preferably, the micrometer has a micrometer sleeve, which is arranged at the other end of the measuring rod on the other end side of the U-shaped frame, and is originally used for rotation operation using fingers, and the power transmission part has: a fixed ring, which is embedded in the micrometer sleeve; a rotating plate, which is configured to rotate synchronously with the rotation axis of the rotor of the motor; and a transmission connecting rod, which is arranged parallel to the central axis of the measuring rod, and one end is fixed to the fixed ring and the other end is fixed to the rotating plate. The transmission connecting rod rotates with the central axis of the measuring rod as the center of rotation, thereby transmitting the rotation of the rotating plate to the fixed ring.

[0023] In one technical solution of the present invention, preferably, a constant pressure mechanism is provided between the micrometer sleeve and the stylus, and when a predetermined load is applied to the stylus, the constant pressure mechanism releases the engagement between the micrometer sleeve and the stylus, thereby causing the micrometer sleeve to idle relative to the stylus.

[0024] In one technical solution of the present invention, it is preferred that the automatic operation unit has a motor controller that controls the rotation of the motor, the motor controller has a torque detection function of the motor, and as a control mode of the motor speed, the motor controller has a high-speed rotation mode of high-speed rotation and a low-speed rotation mode of lower speed than the rotation speed of the high-speed rotation mode. When the motor rotation direction in the direction of advancing the stylus rod is set to forward rotation and the motor rotation direction in the direction of retracting the stylus rod is set to reverse rotation, the motor controller advances the stylus rod in the forward rotation of the high-speed rotation mode, and when the contact between the stylus rod and the workpiece is detected by the torque detection function, the motor controller retracts the stylus rod by a predetermined first number of rotations in the reverse rotation of the high-speed rotation mode, then advances the stylus rod by the first number of rotations in the forward rotation of the low-speed rotation mode, then further drives the motor by a predetermined second number of rotations in the forward rotation of the low-speed rotation mode, and thereafter drives the motor by a predetermined third number of rotations in the forward rotation of the high-speed rotation mode.

[0025] The automatic measuring system of the present invention is characterized by comprising: the automatic measuring device; and a workpiece conveying unit that picks up the workpieces and conveys the workpieces sequentially to the workpiece holding seat.

[0026] The measuring automation device of the present invention automates the measuring equipment, which is used to make a movable part contact with a workpiece to measure the size of the workpiece. The measuring automation device is characterized in that the measuring automation device has: a measuring equipment support seat, which supports the measuring equipment; and a workpiece holding seat, which holds the workpiece within the measuring area of the measuring equipment. The measuring equipment support seat has: a measuring equipment holding part, which holds the fixed part of the measuring equipment; and an automatic operation part, which can be loaded and unloaded relative to the measuring equipment, and the automatic operation part uses the power of a motor to automate the advance and retreat of the movable part. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is the overall structure diagram of the automatic measurement system.

[0028] Figure 2 This is an external view of an automatic micrometer device.

[0029] Figure 3 This is a flowchart for explaining the measurement operation of the automatic micrometer device.

[0030] Figure 4 This is a flowchart for explaining the measurement operation of the automatic micrometer device.

[0031] Figure 5This is a diagram illustrating the situation where the probe moves forward.

[0032] Figure 6 This is a diagram illustrating a state where a workpiece is clamped between a spindle and an anvil.

[0033] Description of Reference Numerals

[0034] 100. Automatic measuring system; 110. Belt conveyor; 120. Hopper; 130. Multi-jointed robotic arm; 140. Robotic claw; 150. Camera; 200. Automatic micrometer device (automatic measuring device); 300. Micrometer (measuring device); 310. U-shaped frame (fixed component); 320. Anvil; 330. Styling rod (movable component); 340. Micrometer sleeve; 350. Displacement detection unit; 400. Measuring device support base; 410. Base frame; 411. First long side; 412. Second long side; 413. First short side; 414. Second short side; 420. Measuring device holding portion; 440. Automatic operation portion; 441. Motor housing; 442. Motor; 443. Motor controller; 450. Power transmission portion; 451. Fixed ring; 452. Rotating plate; 453. Transmission connecting rod; 460. Workpiece holding seat; 461. Support pillar; 462. Workpiece loading plate. DETAILED DESCRIPTION

[0035] The embodiments of the present invention are illustrated and described with reference to the reference numerals assigned to the respective elements in the drawings.

[0036] (First embodiment)

[0037] A first embodiment of the present invention will be described.

[0038] Figure 1 1 is an overall structural diagram of the automatic measurement system 100.

[0039] For example, a workpiece W (eg, a component) processed by a machine tool (eg, an NC lathe) is transported by the belt conveyor 110 .

[0040] The workpiece W is moved to a pre-processing stocker 120. Pre-processing may include degreasing and dust removal using air blowing, for example. The pre-processed workpiece W is transported to the measurement area of the automatic measuring device 200 using, for example, a robotic arm 130. The robotic arm 130 is, for example, a multi-jointed type, and has a gripper 140 for gripping the workpiece W and a camera 150 for image recognition at its tip.

[0041] The robot arm 130 uses image recognition to identify the workpiece W, grasps the workpiece W with the gripper 140, and transports the workpiece W to the measurement area of the automatic measurement device 200. The gripper 140 places the workpiece W in the measurement area with the workpiece W in a predetermined orientation (posture), and then temporarily releases the workpiece W.

[0042] Alternatively, a simpler system may be provided in which the workpiece W is picked up and transported manually by a person.

[0043] The dimensions of the workpiece W thus transported to the measurement area are measured by the automatic measuring device 200 .

[0044] The automatic measuring device 200 is obtained by automating a micrometer 300 which is a small measuring device (a small measuring tool).

[0045] The automatic measuring device 200 of this embodiment is referred to as an automatic micrometer device 200 .

[0046] Figure 2 2 is an external view of the automatic micrometer device 200 .

[0047] The automatic micrometer device 200 includes a micrometer 300 , a measuring device support seat 400 , and a workpiece holding seat 460 .

[0048] The micrometer 300 is originally a small measuring device that is manually operated, and a currently commercially available micrometer 300 may be used as the micrometer 300 of this embodiment.

[0049] The structure of the micrometer 300 will be briefly described first.

[0050] The micrometer 300 includes a U-shaped frame (fixed member) 310 , a spindle (movable member) 330 , a thimble portion 340 , and a displacement detecting portion 350 .

[0051] The U-shaped frame 310 has an anvil 320 at an inner side of one end of the U-shape.

[0052] The spindle 330 is provided at the other end of the U-shaped frame 310 and is configured to be able to advance and retreat in the axial direction relative to the anvil 320 .

[0053] A measuring surface is provided on one end surface of the spindle 330 for contacting the workpiece W. Similarly, a measuring surface is provided on the other end surface of the anvil 320 for contacting the workpiece W. The measuring surface is processed into a flat surface and is formed of, for example, cemented carbide or ceramic.

[0054] The spindle 330 is fed and moved forward and backward in the axial direction by the rotation operation of the thimble portion 340 .

[0055] In addition, as a feeding method of the stylus 330, there are a rotation feeding method in which the stylus 330 itself rotates and a linear motion feeding method in which the stylus 330 itself does not rotate.

[0056] In the rotary feed method, external threads are pre-installed on the stylus 330 itself, and internal threads are pre-installed on the U-shaped frame 310. A micrometer quill and the stylus 330 are pre-engaged so that they rotate together. Rotating the micrometer quill rotates the stylus 330, thus advancing and retracting the stylus 330 through thread feed.

[0057] In the linear motion feed method, a feed thread is pre-cut inside the micrometer sleeve 340, and a pin that engages with the feed thread is pre-installed on the spindle 330. When the micrometer sleeve 340 is rotated while the spindle 330 is stationary, the engagement between the pin and the feed thread causes the spindle 330 to advance.

[0058] The micrometer 300 used in this embodiment may be of a rotary feed type or a linear motion feed type.

[0059] 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 .

[0060] The thimble portion 340 is an operating portion that moves the spindle 330 forward and backward by a rotation operation.

[0061] Here, as the micrometer 300 used in this embodiment, a type having a constant pressure mechanism between the micrometer sleeve portion 340 and the spindle 330 is preferable.

[0062] In the constant pressure mechanism, when a preset load is applied to the spindle 330 , the engagement between the quill and the spindle 330 is released, and the quill rotates idly relative to the spindle 330 .

[0063] By causing the constant pressure mechanism to operate appropriately at the same level at all times during measurement, the measurement pressure during measurement can be kept constant and the measurement accuracy (repeatability) can be maintained high.

[0064] A commercially available micrometer 300 is also equipped with a constant pressure mechanism, which is disclosed, for example, in Japanese Patent No. 3115555, Japanese Patent No. 3724995, Japanese Patent No. 5426459, and Japanese Patent No. 5270223. The constant pressure mechanism can be composed of a ratchet mechanism that causes sliding when a force exceeding a predetermined load is applied between the micrometer sleeve and the spindle 330, or a leaf spring inserted between the outer sleeve and inner sleeve of the micrometer sleeve so as to cause sliding when a force exceeding the predetermined load is applied.

[0065] Furthermore, the micrometer 300 used in this embodiment preferably includes a measurement pressure detection mechanism for detecting a load applied to the spindle 330 .

[0066] For example, Japanese Patent No. 3751540, Japanese Patent No. 4806545, and Japanese Patent Application Laid-Open No. 2019-190916 disclose a measurement pressure detection mechanism.

[0067] The measuring pressure detection mechanism can directly or indirectly detect the load applied to the measuring rod 330 using a strain gauge or the like, or it can detect when the load applied to the measuring rod 330 reaches a predetermined value by activating the constant pressure mechanism. The measuring pressure detection mechanism outputs a signal (measurement pressure signal) when it detects the predetermined measuring pressure. For example, the displacement detection unit 350 receives the detection of the predetermined measuring pressure by the measuring pressure detection mechanism and samples (latches) the measured value (displacement).

[0068] The displacement detecting unit 350 detects the displacement amount (or position) of the measuring rod 330. The displacement detecting unit 350 is composed of a rotary encoder or a linear encoder.

[0069] Furthermore, the displacement detection unit 350 may be an analog type (scale type) rather than an encoder. In this case, when automated, the scale may be read using a digital camera or the like, and the measured value may be read by image analysis (image recognition).

[0070] In this case, the displacement detection unit may be constituted by an analog scale, a digital camera, and an image recognition unit (image analysis unit).

[0071] Furthermore, a display panel 311 for displaying measured values and operation switches are provided on the front of the U-shaped frame 310. Furthermore, as a function of the circuit unit built into the U-shaped frame 310, a measured value output function is provided for outputting measured values to the outside via wired or wireless communication.

[0072] Next, the measuring device support base 400 will be described.

[0073] The measuring device support base 400 includes a base frame 410 , a measuring device holding portion 420 , and an automatic operation portion 440 .

[0074] The base frame 410 is a rectangular frame as a whole.

[0075] For illustration, Figure 2 As shown in , the XYZ coordinate axes are taken to be orthogonal to each other.

[0076] Of the four sides constituting the base frame 410 , two sides parallel to the X-axis direction are defined as a first long side 411 and a second long side 412 , and two sides parallel to the Y-axis direction are defined as a first short side 413 and a second short side 414 .

[0077] The first and second long sides 411 and 412 and the first and second short sides 413 and 414 are preferably extendable and retractable so that their lengths can be adjusted.

[0078] A measuring device holding portion 420 is provided on the first long side portion 411 , an automatic operation portion 440 is provided on the second short side portion 414 , and a workpiece holding seat portion 460 is provided on the second long side portion 412 .

[0079] In this case, the first long side 411 has a guide rail to adjust the installation position of the measuring device holding unit 420 along the X-axis. Similarly, the second short side 414 has a guide rail to adjust the installation position of the automatic operation unit 440 along the Y-axis. The second long side 412 has a guide rail to adjust the installation position of the workpiece holding seat 460 along the X-axis.

[0080] The measuring device holding portion 420 is fixedly attached to the first long side portion 411 .

[0081] The measuring device holding portion 420 is a pressing plate.

[0082] The micrometer (measuring device) 300 is mounted on the base frame 410 by sandwiching its U-shaped frame (fixing member) 310 between the first long side 411 and the pressure plate. The micrometer 300 (measuring device) is oriented so that the spindle 330's forward and backward directions (axial directions) are parallel to the X-axis. One end of the U-shaped frame 310 (the anvil 320 side) is aligned with the first short side 413, while the other end of the U-shaped frame 310 (the micrometer sleeve side) is aligned with the second short side 414.

[0083] The automatic operation unit 440 automatically controls the advance and retreat of the spindle 330 (movable member) using the power of the motor 442 .

[0084] The automatic operation unit 440 includes a motor housing 441 , a motor 442 , a power transmission unit 450 , and a motor controller 443 .

[0085] The motor housing 441 houses a motor 442 and a motor controller 443 .

[0086] The motor housing 441 is positioned on an extension of the centerline of the spindle 330 (or the thimble 340) of the micrometer 300. Specifically, the automatic operating unit 440 is configured so that the rotation axis of the rotor of the motor 442 is aligned with the centerline of the spindle 330 (or the thimble 340). The position of the motor housing 441 is preferably adjusted as needed by moving it along the guide rails of the second short side 414.

[0087] The motor 442 is preferably a normal electric motor that outputs the rotation of the rotor to an output shaft.

[0088] However, it is preferred that the motor 442 can control the forward and reverse rotation angles (number of revolutions) to some extent by controlling the pulses. In addition, it is preferred that the motor 442 has a torque detection function. (Regarding the torque detection of the motor 442 itself, various methods are known, such as determining the torque based on the increase or decrease of the applied current (applied voltage).) As the motor 442, for example, a stepping motor can be used. (Of course, a servo motor or a synchronous motor can also be used, and the structure and drive method of the motor 442 are not particularly limited.)

[0089] The power transmission unit 450 includes a fixed ring 451 externally fitted to the micrometer sleeve 340 , a rotating plate 452 configured to rotate synchronously with the rotation axis of the rotor of the motor 442 , and a transmission connecting rod 453 connecting the fixed ring 451 and the rotating plate 452 .

[0090] One end of the transmission connecting rod 453 is fixed to the fixed ring 451, and the other end is fixed to the rotating plate 452. The transmission connecting rod 453 is parallel to the central axis of the measuring rod 330. When the rotating plate 452 is rotated by the motor 442, the rotation is transmitted to the fixed ring 451 via the transmission connecting rod 453, causing the fixed ring 451 and the rotating plate 452 to rotate synchronously.

[0091] The motor controller 443 controls the rotational drive of the motor 442, thereby controlling the forward and backward movement of the spindle 330. The control of the motor 442 by the motor controller 443 will be described in detail later.

[0092] Next, the workpiece holding seat portion 460 will be described.

[0093] The workpiece holding seat 460 holds the workpiece W to be measured in the measurement area of the micrometer 300 (measuring device).

[0094] The workpiece holding seat portion 460 includes a support column 461 and a workpiece placement plate 462 .

[0095] The support pillar 461 is attached to the first long side 411 .

[0096] The workpiece mounting plate 462 is an L-shaped plate having a surface parallel to the XY plane, and is fixed to the support pillar 461. Preferably, the position of the support pillar 461 is adjusted along the second long side 412 so that the workpiece W held by the workpiece holder 460 enters the measurement area of the micrometer (measuring device) 300. Furthermore, the height (Z-axis position) of the workpiece mounting plate 462 is adjusted so that the measurement target portion (measurement target part) of the workpiece W is clamped between the anvil 320 and the stylus 330.

[0097] The surface of the workpiece mounting plate 462 that supports the workpiece W is flat. Therefore, when the workpiece W, placed and held on this mounting surface, is pressed by the stylus 330, the position and posture of the workpiece W can be easily changed. Specifically, when the stylus 330 contacts the workpiece W, the workpiece W is pressed toward the anvil 320 and slides on the mounting surface, moving to a position in contact with the anvil 320. Furthermore, while the workpiece W is in contact with the anvil 320, its movement is restricted, resulting in the workpiece W being clamped between the anvil 320 and the stylus 330. At this point, the posture of the workpiece W is changed so that the measuring surface of the anvil 320 and the contact surface of the workpiece W are in close contact, and so that the measuring surface of the stylus 330 and the contact surface of the workpiece W are in close contact. This allows a certain degree of movement on the mounting surface without fixing the workpiece W, allowing the anvil 320 and the stylus 330 to tightly clamp the measurement target portion of the workpiece W without any gap.

[0098] If the friction on the workpiece W loading surface of the workpiece loading plate 462 is too low, there is a concern that the workpiece W may slip and fall when being loaded by the gripper 140 or a person's hand, or may deviate from its original orientation or posture. Therefore, it is preferable to have a concave-convex surface to generate a certain degree of friction between it and the workpiece W. It is also preferable to change the position and posture of the workpiece W when a force less than a set measurement pressure (e.g., approximately 1N to 5N) acts on the workpiece W while the workpiece W is loaded on the loading surface.

[0099] (Action Description)

[0100] The operation of the automatic micrometer device 200 will be described.

[0101] Figure 3 、 Figure 4 This is a flowchart for explaining the measurement operation of the automatic micrometer device 200 .

[0102] When it is detected that the workpiece W is placed on the workpiece placement plate 462 by the robot arm 130 ( ST110 : YES), the motor controller 443 executes a preset (programmed) motor drive control.

[0103] First, the motor controller 443 rotates the motor 442 forward at a relatively high speed, thereby moving the spindle 330 forward toward the anvil 320 (ST120). The rotation speed of the motor 442 at this time is, for example, 180 rpm. (Or about 100 rpm to 200 rpm.)

[0104] For example Figure 5 This is a diagram illustrating a state where the probe rod 330 moves forward.

[0105] In ST120, from the perspective of shortening the measurement time, it is preferable to increase the rotation speed as much as possible. However, if the rotation speed is increased excessively, the workpiece W may be damaged when the stylus 330 contacts the workpiece W. In addition, if the rotation speed is increased excessively, the centrifugal force generated in the power transmission unit 450 is high, and the motor torque is large. Therefore, in the case of a structure that detects the contact between the stylus 330 (anvil 320) and the workpiece W based on the magnitude of the torque, there is also the problem of the torque detection function erroneously detecting the contact between the stylus 330 (anvil 320) and the workpiece W. Therefore, it is preferable to first predetermine a torque threshold for detecting the contact between the stylus 330 and the workpiece W, and rotate the motor at a speed that does not exceed the torque threshold.

[0106] When the stylus 330 moves toward the anvil 320 , it contacts the workpiece W. Since the workpiece W is not fixed while being placed on the workpiece mounting plate 462 , the stylus 330 directly presses the workpiece W and moves it, causing it to contact the anvil 320 .

[0107] Figure 6 3 is a diagram illustrating a state where the workpiece W is sandwiched between the anvil 320 and the spindle 330 .

[0108] At the moment when the workpiece W is clamped by the anvil 320 and the measuring rod 330, the motor torque increases, and the motor controller 443 uses the torque detection function to detect the contact between the measuring rod 330 and the workpiece W. In other words, the contact between the anvil 320 and the measuring rod 330 and the workpiece W is detected (ST130: yes).

[0109] When the motor controller 443 detects that the stylus rod 330 is in contact with the workpiece W, it immediately reverses the motor 442 at a relatively high speed by a predetermined number of revolutions to move the stylus rod 330 backward ( ST140 ).

[0110] The rotation speed of the reverse rotation is, for example, 180 rpm. In addition, the number of revolutions of the reverse rotation is, for example, 0.5 rpm. In addition, the rotation speed (180 rpm) is an example, and the rotation speed during forward rotation (ST120) and the rotation speed during reverse rotation (ST140) may be the same or different.

[0111] Here, it is preferable that the spindle 330 is not “stopped” or “decelerated” but is temporarily retracted at a relatively high speed in reverse.

[0112] The first reason is to reliably prevent the stylus rod 330 from biting into the workpiece W. Sending a control signal to temporarily retract the stylus rod 330 is more reliable than simply stopping the workpiece. Furthermore, while the constant pressure mechanism is activated when measuring pressure is generated, the operating distance of the stylus rod 330 must be ensured in advance in order to ensure that the stylus rod 330 always moves forward at a constant speed. Therefore, to ensure that the application of measuring pressure to the workpiece W is always consistent, it is advisable to temporarily retract the stylus rod 330.

[0113] Next, the motor 442 is rotated forward at a relatively low speed to move the spindle 330 forward toward the anvil 320 ( ST150 , ST160 ).

[0114] As a slow forward movement step (ST150), the motor 442 is rotated forward at a relatively slow speed. The number of revolutions is the same as that used in the previous backward movement (ST140). Here, for example, the motor 442 rotates 0.5 revolutions at 9 rpm. This gently presses the workpiece W, ensuring contact between the workpiece W and the anvil 320, as well as between the workpiece W and the spindle 330.

[0115] Next, as a measuring surface contact step (ST160), the motor 442 is rotated forward at a relatively low speed (ST160). The number of revolutions is set, for example, to a number of revolutions equivalent to the amount of rotation of the micrometer sleeve (the amount of rotation of the stylus 330), which is equivalent to the amount of rotation from the time the workpiece W contacts the anvil 320 and the stylus 330 until the constant pressure mechanism is activated. Here, for example, the rotation is performed at 9 rpm for 0.5 revolutions. (This is the same as ST150, but the rotation speed and number of revolutions can also be appropriately changed.)

[0116] Here, by slowly operating the constant pressure mechanism once, the contact surfaces between the workpiece W and the anvil 320 and the contact surfaces between the workpiece W and the spindle 330 are reliably brought into close contact (tight contact).

[0117] In this state, the workpiece W is firmly clamped between the anvil 320 and the spindle 330. Then, as a measuring pressure application step (ST170), the motor 442 is driven at a relatively high speed, rotating in the forward direction. For example, it is rotated at 180 rpm for three revolutions. At this point, the constant pressure mechanism is activated again, applying the predetermined measuring pressure.

[0118] Furthermore, the motor rotation speed in this step (ST170) can be set to a higher speed (e.g., 150-250 rpm). Having achieved close contact in the previous step (ST160), the contact surfaces of the stylus 330 (anvil 320) and the workpiece W are firmly in contact. Therefore, it is believed that the stylus 330 (anvil 320) and the workpiece W are less likely to bite into each other.

[0119] Furthermore, since the spindle 330 (anvil 320 ) and the workpiece W are already in contact, there is no limitation of erroneously detecting the contact between the spindle 330 (anvil 320 ) and the workpiece W using the torque detection function.

[0120] The number of revolutions in this step (ST170) is the number of revolutions required to activate the constant pressure mechanism, and may be approximately 1.5 to 3.5 revolutions, depending on the specifications of the micrometer (constant pressure mechanism) used.

[0121] The micrometer 300 samples the measured value (ST180) at the moment the constant pressure mechanism is activated during the measuring pressure application step (ST170). The sampled measured value (measurement data) is output to the outside via wired or wireless communication (ST190), and the measurement data is collected and processed by an external PC (personal computer) or data processing device.

[0122] Since one measurement value has been acquired so far, the motor controller 443 reverses the motor 442 at a relatively high speed to retract the spindle 330. The workpiece W is replaced and the measurement operation is continued.

[0123] According to the automatic measuring system 100 of this embodiment, the measuring operation of the workpiece W is substantially automated.

[0124] The automatic micrometer device 200 of this embodiment automates a micrometer 300, a small contact-type measuring device (small measuring tool). Since the micrometer 300 is a tool that is likely already present in typical factories, automation of the micrometer 300 can be achieved simply by preparing a measuring device support base 400, a workpiece holding base 460, and an automatic operation unit 440. This significantly reduces the cost of implementing automated measurement, significantly helping to alleviate labor shortages.

[0125] Because the micrometer 300 is a contact-type device, it offers extremely high measurement stability. Furthermore, the micrometer 300 has a long history and widespread use, making it a familiar measuring device for measurement workers. Consequently, workers are already highly proficient in the necessary operations, such as calibration, and rarely need to relearn or retrain difficult procedures.

[0126] Various automatic measuring devices have been proposed, but most utilize non-contact measuring tools. For example, many use air micrometers and laser scanning micrometers. However, such non-contact measuring equipment is expensive and somewhat difficult to maintain. In contrast, the automatic micrometer device 200 of this embodiment, which automates the micrometer 300, offers the advantages of being inexpensive and easy to operate.

[0127] One of the reasons why automation of the micrometer 300, a representative small contact measuring device (small measuring tool), has been difficult so far is that it is difficult to accurately clamp the workpiece W from both sides so that the contact surfaces (measuring surfaces) are in close contact.

[0128] In this regard, in the present embodiment, the relative position of the workpiece W and the micrometer 300 is not fixed, and the position and posture can be changed by a force equal to or less than the measuring pressure.

[0129] In addition, the constant pressure mechanism of the micrometer 300 and the torque detection mechanism of the motor 442 are comprehensively utilized to advance and retreat the measuring rod 330 in multiple stages, especially the process of making the measuring surface (contact surface) firmly adhere (closely fit) (ST160) and the process of applying a predetermined measuring pressure (ST170).

[0130] Typically, when the micrometer sleeve is rotated manually, it rotates at a constant speed, and in this state, a constant pressure is applied at a constant rotational state for measurement. There is no need to retract or operate the constant pressure mechanism in two stages, slow and high speed. However, in this application, through repeated experiments with varying conditions, a control process different from manual operation was studied, thereby enabling stable measurement values to be obtained even with automatic measurement.

[0131] This enables automation of the micrometer 300. Furthermore, since the workpiece W can be measured by always performing the same operation through motor control, the problem of differences in measurement values due to the proficiency and operating habits of each operator can be eliminated.

[0132] The present invention is not limited to the above-described embodiment, and can be modified appropriately without departing from the spirit and scope of the invention.

[0133] In the above embodiment, the workpiece W is placed on the workpiece mounting plate 462, but the workpiece W can also be gripped (held). In this case, the workpiece gripping unit can be attached to and supported by the workpiece holding seat 460 using a floating joint that allows parallel movement, such as a parallel leaf spring. Alternatively, the workpiece gripping unit can be a robotic arm. (In this case, the robotic arm or mechanical claw serving as the workpiece gripping unit can also have a floating joint that allows parallel movement, such as a parallel leaf spring.)

[0134] Of course, the measuring device support base 400 may be allowed to move in parallel. In this case, the measuring device holding portion 420 may be mounted on the base frame 410 via a floating joint.

[0135] The direction of parallel movement to be allowed is at least a direction parallel to the forward and backward direction of the stylus 330 (the axial direction of the stylus 330 ).

[0136] In cases where a slight degree of rotational freedom is required to bring the contact surface between the spindle (anvil) and the workpiece into close contact, a rotation axis may be provided, or changes in orientation (posture) may be permitted using the elasticity of a leaf spring, for example.

[0137] As an example of the operation in the above embodiment, the operation of measuring the workpiece W is taken as an example, but it is obvious that the setting of the base point and the calibration using the gauge block can also be performed by the same operation.

Claims

1. An automatic measuring device for automatically measuring a workpiece using a measuring device for measuring the size of the workpiece, characterized in that The automatic measuring device comprises: said measuring device; a measuring device support seat that supports the measuring device; and a workpiece holding seat, which holds the workpiece (W) within the measuring area of the measuring device, The measuring device has: Fixed components; a movable member configured to be displaceable relative to the fixed member and to advance and retreat in a manner of coming into contact with or separating from the workpiece (W); as well as a displacement detecting unit for detecting the displacement of the movable member; The measuring device support seat has: a measuring device holding portion that holds the fixed component of the measuring device; and An automatic operating unit capable of being attached to and detached from the measuring device, the automatic operating unit automating the advance and retreat of the movable member by using the power of a motor, The automatic operation unit advances the movable member so that the movable member contacts the workpiece, then retreats the movable member by a predetermined amount, and then advances the movable member again so that a predetermined measurement pressure is generated between the workpiece and the movable member.

2. The automatic measuring device according to claim 1, characterized in that For at least one of the workpiece held on the workpiece holding seat and the measuring device held on the measuring device holding portion, when the workpiece and the movable part abut against each other, the position and posture of the at least one are changed by using a pressure pre-set below the predetermined measuring pressure of the measuring device, so that the abutting surfaces of the workpiece and the movable part are maintained in close contact with each other.

3. The automatic measuring device according to claim 2, characterized in that The workpiece holding seat portion is a workpiece mounting table on which the workpiece is mounted.

4. The automatic measuring device according to claim 2 or 3, characterized in that: The workpiece holding seat has a workpiece holding unit for holding the workpiece. One of the workpiece gripping unit and the measuring device holding portion is configured to allow relative displacement with respect to the other.

5. The automatic measuring device according to any one of claims 1 to 3, characterized in that: The measuring device has an operating portion that is originally used for manual operation, and the operating portion moves the movable member forward and backward by manual rotation operation or manual push-pull operation. The automatic operation portion is attachable to and detachable from the operation portion, and operates the operation portion using power from a motor to automate the forward and backward movement of the movable member.

6. The automatic measuring device according to any one of claims 1 to 3, characterized in that: The measuring device is a micrometer, The micrometer has: A U-shaped frame as the fixing member, having an anvil on the inner side of one end of the U-shape; and The measuring rod as the movable part is provided at the other end of the U-shaped frame and is capable of advancing and retreating in the axial direction relative to the anvil. The automatic operation unit has: motor; and A power transmission unit connects the output shaft of the motor and the spindle directly or indirectly to convert the power of the motor into the advance and retreat of the spindle.

7. The automatic measuring device according to claim 6, characterized in that: The automatic operation portion is configured to be positionally variable in a direction perpendicular to the central axis of the spindle so that the rotation axis of the rotor of the motor and the central axis of the spindle are aligned on the same straight line.

8. The automatic measuring device according to claim 6, characterized in that: The micrometer has a micrometer sleeve, which is arranged at the other end of the measuring rod on the other end side of the letter U-shaped frame and is originally used for rotating operation using fingers. The power transmission unit has: A fixed ring, which is externally embedded in the micrometer sleeve; a rotating plate configured to rotate synchronously with the rotation axis of the rotor of the motor; and A transmission connecting rod is arranged parallel to the central axis of the measuring rod, and one end is fixed to the fixed ring and the other end is fixed to the rotating plate. The transmission connecting rod rotates with the central axis of the measuring rod as the center of rotation, thereby transmitting the rotation of the rotating plate to the fixed ring.

9. The automatic measuring device according to claim 8, characterized in that: A constant pressure mechanism is provided between the micrometer sleeve and the stylus. When a preset load is applied to the stylus, the constant pressure mechanism releases the engagement between the micrometer sleeve and the stylus, thereby causing the micrometer sleeve to rotate idly relative to the stylus.

10. The automatic measuring device according to claim 6, characterized in that: The automatic operation unit includes a motor controller that controls the rotation of the motor. The motor controller has a torque detection function of the motor, As a control mode of the motor speed, the motor controller has: a high-speed spin mode for high-speed spin; and a low-speed rotation mode, which is lower than the rotation speed of the high-speed rotation mode, When the motor rotation direction in the direction of moving the spindle forward is set to forward rotation and the motor rotation direction in the direction of moving the spindle backward is set to reverse rotation, The motor controller advances the spindle in the forward rotation of the high-speed rotation mode, and When the contact between the spindle and the workpiece is detected by the torque detection function, the spindle is retracted by a predetermined first number of rotations in the reverse rotation mode of the high-speed rotation mode. Next, the spindle is advanced by the first number of revolutions in the forward rotation in the low-speed rotation mode, and then the motor is driven by the predetermined second number of revolutions in the forward rotation in the low-speed rotation mode. Thereafter, the motor is driven in the forward rotation of the high-speed rotation mode by a predetermined third number of rotations.

11. An automatic measurement system, characterized in that: The automatic measurement system has: The automatic measuring device according to any one of claims 1 to 10; and A workpiece conveying unit picks up the workpieces and conveys the workpieces successively to the workpiece holding seat.

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