Internal diameter measuring unit, floating joint mechanism, and measuring unit

Abstract

To provide an inside diameter measuring unit capable of automating the inside diameter measurement and a control method of automatic inside diameter measurement.SOLUTION: An inside diameter measuring part is supported by a support frame via a floating joint part. The floating joint part includes a rotation allowing mechanism allowing the inside diameter measuring part to rotate with respect to the support frame part, and a translation allowing mechanism allowing such displacement that the inside diameter measuring part translates with respect to the support frame part. A measurement head of the inside diameter measuring part is inserted into a hole by a robot arm part. The inside diameter measuring part autonomously adjusts a position and an attitude by reaction force when a probe presses an inner wall of the hole, and accordingly, the axis of the inside diameter measuring part matches the axis of the hole. The inside diameter of the hole can be automatically measured by an electric inside diameter measuring unit (an electric inside diameter measuring instrument and a robot arm part).SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an inner diameter measuring unit, a floating joint mechanism unit, and a measuring unit.

Background Art

[0002] As measuring instruments for measuring the inner diameter of holes, inner diameter measuring instruments such as hole tests, cylinder gauges, and borematics (registered trademark) are used (see, for example, Patent Document 1). However, when using these inner diameter measuring instruments, operations such as advancing and retracting the measuring element and centering to some extent with the inner diameter measuring instrument inserted into the hole are required, so it inevitably becomes manual measurement by hand. Therefore, it has taken a lot of manpower and time to confirm the machining accuracy of holes with such inner diameter measuring instruments.

[0003] As an alternative to manual measurement, an air micrometer is available as an inner diameter measuring device for automating inner diameter measurement in a production site (see, for example, Patent Document 2). Since the air micrometer only needs to be inserted into the hole and blow out air, among the current options, it can be said that the air micrometer is a measuring device suitable for automating inner diameter measurement.

Prior Art Documents

Patent Documents

[0004] [[ID=2⑥]]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the air micrometer also has the following demerits. Firstly, due to its mechanism, an air micrometer is extremely expensive. Furthermore, it requires the provision and maintenance of an air compressor. In terms of measurement capabilities, its mechanism limits the repeatability of an air micrometer, and its measurement range is extremely short (around a few hundred micrometers).

[0006] A common problem with manual measurement using manual measuring instruments is the desire to automate the measurement process as inexpensively as possible.

[0007] There is a need for an inexpensive, user-friendly measuring unit and a control method for automated measurement. For example, there is a need for an inexpensive, user-friendly internal diameter measuring unit and a control method for automatic internal diameter measurement that can also measure hole diameters automatically. [Means for solving the problem]

[0008] The inner diameter measuring unit of the present invention is An internal diameter measuring unit having a measuring probe that moves back and forth in a direction perpendicular to the cylindrical axis of the cylindrical case, and measuring the inner diameter of a hole by bringing the measuring probe into contact with the inner wall of the hole while it is inserted inside the hole to be measured, A support frame portion that supports the inner diameter measuring portion, A floating joint is interposed between the support frame and the inner diameter measuring portion, allowing relative translation and rotation of the inner diameter measuring portion with respect to the support frame, The floating joint portion is, A rotation-allowing mechanism that allows the inner diameter measuring portion to rotate relative to the support frame portion, The inner diameter measuring section has a translational tolerance mechanism that allows for translational displacement relative to the support frame section, The rotation-allowing mechanism has a flexible body that allows deformation in a direction in which the inner diameter measuring section is tilted. The translation-permitting mechanism has a translation body that permits the inner diameter measuring section to translate in a direction intersecting the cylindrical axis of the cylindrical case section. One end of the flexible body is connected to the inner diameter measuring section. The other end of the flexible body is connected to the translation body, The translation body is supported so as to be translationally responsive with respect to the support frame portion. It is characterized by the following:

[0009] In one embodiment of the present invention, The support frame portion has a support base portion, and the support base portion has a first insertion hole through which the inner diameter measuring portion is inserted. The translation body has a second insertion hole through which the inner diameter measuring portion is inserted, The inner diameter measuring section is supported in a state where it is inserted through the first insertion hole and the second insertion hole. The floating joint portion is, The bearings provided between the translational body and the support base are located around the first and second insertion holes, and allow the translational body to translate relative to the support base. It is preferable.

[0010] In one embodiment of the present invention, The diameter of the first insertion hole is larger than the diameter of the second insertion hole. The diameter of the first insertion hole is a diameter that allows the inner diameter measuring section to translate. The diameter of the second insertion hole is a diameter that allows for the inclination of the inner diameter measuring portion. It is preferable.

[0011] In one embodiment of the present invention, The flexible body is an elastic body disposed between the inner diameter measuring section and the translational body, so as to surround the inner diameter measuring section. It is preferable.

[0012] In one embodiment of the present invention, The elastic body is a spring arranged to surround the inner diameter measuring portion. It is preferable.

[0013] In one embodiment of the present invention, The translation body is arranged above the support pedestal portion, The lower end of the flexible body is connected to the translation body as the other end, The upper end of the flexible body is connected to the inner diameter measuring portion as the one end which is preferable.

[0014] In one embodiment of the present invention, The position where one end of the flexible body is connected to the inner diameter measuring portion corresponds to the center of gravity of the inner diameter measuring portion which is preferable.

[0015] In one embodiment of the present invention, It is preferable to include an electric drive unit for advancing and retreating the measuring element which is preferable.

[0016] In one embodiment of the present invention, It is provided with restraint means for sandwiching the inner diameter measuring portion from a direction intersecting the cylinder axis, The restraint means, When the inner diameter measuring portion is not inserted into the hole to be measured, it holds and sandwiches the inner diameter measuring portion, When the inner diameter measuring portion is inserted into the hole to be measured, it releases the inner diameter measuring portion which is preferable.

[0017] In one embodiment of the present invention, The inner diameter measuring portion is supported by the support frame portion via the floating joint portion with the cylinder axis in the vertical direction as the reference posture <00001​​​​​​​​​​​​​​A floating joint mechanism interposed between an object to be supported and a support frame that supports the object, which allows relative translation and rotation of the object with respect to the support frame, The floating joint mechanism is, A rotation-allowing mechanism that allows the object to be supported to rotate relative to the support frame, The system includes a translation-allowing mechanism that allows the object to be supported to undergo translational displacement relative to the support frame, The rotation-allowing mechanism has a flexible body that allows deformation in a direction in which the supported object is tilted. The translation-permitting mechanism has a translation body that permits the supported object to translate, One end of the flexible body is connected to the object to be supported, The other end of the flexible body is connected to the translation body, The translation body is supported so as to be translationally responsive with respect to the support frame portion. It is characterized by the following:

[0020] The measuring unit of the present invention is A measuring unit that measures the dimensions of an object by bringing a measuring probe into contact with the object to be measured, A support frame portion that supports the measuring portion, A floating joint is interposed between the support frame and the measuring section, allowing relative translation and rotation of the measuring section with respect to the support frame, The floating joint portion is, A rotation-allowing mechanism that allows the measuring section to rotate relative to the support frame section, The measuring section has a translational tolerance mechanism that allows translational displacement relative to the support frame section, The rotation-permissible mechanism has a flexible body that allows deformation in the direction in which the measuring section is tilted. The translation-permitting mechanism has a translation body that permits the measuring unit to translate, One end of the flexible body is connected to the measuring unit, The other end of the flexible body is connected to the translation body, The translation body is supported so as to be translationally responsive with respect to the support frame portion. It is characterized by the following:

[0021] The inner diameter measuring unit of the present invention is An internal diameter measuring unit having a measuring probe that moves back and forth in a direction perpendicular to the cylindrical axis of the cylindrical case, and measuring the inner diameter of a hole by bringing the measuring probe into contact with the inner wall of the hole while it is inserted inside the hole to be measured, A support frame portion that supports the inner diameter measuring portion, A floating joint is interposed between the support frame and the inner diameter measuring portion, allowing relative translation and rotation of the inner diameter measuring portion with respect to the support frame, The floating joint portion is, A connecting block is fixedly connected to the inner diameter measuring section and moves in translation and rotation integrally with the inner diameter measuring section. A rotation-allowing mechanism that allows the connecting block to rotate relative to the support frame, The connecting block has a translation-allowing mechanism that allows the support frame portion to undergo translational displacement in a direction parallel to a plane perpendicular to the cylindrical axis, The rotation-allowing mechanism has a sphere positioned between the connecting block and the support frame, The aforementioned translational tolerance mechanism is, A guide shaft is provided on either the connecting block or the support frame portion, and extends in a direction parallel to the plane perpendicular to the cylindrical shaft, The other of the connecting block and the support frame portion includes a guide hole that receives the guide shaft and allows the guide shaft to slide in a direction parallel to a plane perpendicular to the cylindrical shaft. It is characterized by the following:

[0022] In one embodiment of the present invention, The aforementioned guide shafts are provided in two directions perpendicular to each other within a plane perpendicular to the cylindrical shaft. It is preferable.

[0023] In one embodiment of the present invention, The support frame portion has a support ring portion that surrounds the connecting block in a plane perpendicular to the cylindrical axis, The support ring portion is provided with two guide shafts. The connecting block has guide holes that allow the connecting block to translate and rotate while receiving the two guide shafts. It is preferable.

[0024] In one embodiment of the present invention, The connecting block is positioned above the upper end of the inner diameter measuring section. The inner diameter measuring section is supported by the support frame section via the floating joint section, in a state where it hangs down from the support frame section. It is preferable.

[0025] In one embodiment of the present invention, The point where the two guide shafts intersect lies on the extension of the cylindrical axis of the inner diameter measuring section. It is preferable.

[0026] In one embodiment of the present invention, The system includes an electric drive unit that moves the measuring probe forward and backward. It is preferable.

[0027] In one embodiment of the present invention, The system includes a restraining means for holding the inner diameter measuring section by sandwiching the inner diameter measuring section or the connecting block, The aforementioned restraining means is When the inner diameter measuring part is not inserted into the hole to be measured, the inner diameter measuring part is held in place. When the inner diameter measuring part is inserted into the hole to be measured, the inner diameter measuring part is released. It is preferable.

[0028] In one embodiment of the present invention, The inner diameter measuring section is supported by the support frame section via the floating joint section, with the cylindrical shaft in the vertical direction as the reference position. It is preferable.

[0029] In one embodiment of the present invention, The support frame portion connects the inner diameter measuring portion to a moving means for moving the inner diameter measuring portion. It is preferable.

[0030] The floating joint mechanism of the present invention is A floating joint mechanism interposed between an object to be supported and a support frame that supports the object, which allows relative translation and rotation of the object with respect to the support frame, The floating joint mechanism is, A connecting block fixedly connected to the object to be supported, which translates and rotates integrally with the object to be supported, A rotation-allowing mechanism that allows the connecting block to rotate relative to the support frame, The connecting block has a translation-allowing mechanism that allows translational displacement relative to the support frame portion, The rotation-allowing mechanism has a sphere positioned between the connecting block and the support frame, The aforementioned translational tolerance mechanism is, A guide shaft is provided on either the connecting block or the support frame portion and extends in the direction that guides translation, The other of the connecting block and the support frame portion is provided with a guide hole that receives the guide shaft and allows the guide shaft to slide. It is characterized by the following:

[0031] The measuring unit of the present invention is A measuring unit that measures the dimensions of an object by bringing a measuring probe into contact with the object to be measured, A support frame portion that supports the measuring portion, A floating joint is interposed between the support frame and the measuring section, allowing relative translation and rotation of the measuring section with respect to the support frame, The floating joint portion is, A connecting block is fixedly connected to the measuring unit and moves in translation and rotation integrally with the measuring unit. A rotation-allowing mechanism that allows the connecting block to rotate relative to the support frame, The connecting block has a translation-allowing mechanism that allows translational displacement relative to the support frame portion, The rotation-allowing mechanism has a sphere positioned between the connecting block and the support frame, The aforementioned translational tolerance mechanism is, A guide shaft is provided on either the connecting block or the support frame portion and extends in the direction that guides translation, The other of the connecting block and the support frame portion is provided with a guide hole that receives the guide shaft and allows the guide shaft to slide. It is characterized by the following:

[0032] The inner diameter measuring unit of the present invention is An internal diameter measuring unit having a measuring probe that moves back and forth in a direction perpendicular to the cylindrical axis of the cylindrical case, and measuring the inner diameter of a hole by bringing the measuring probe into contact with the inner wall of the hole while it is inserted inside the hole to be measured, A support frame portion that supports the inner diameter measuring portion, A floating joint is interposed between the support frame and the inner diameter measuring portion, allowing relative translation and rotation of the inner diameter measuring portion with respect to the support frame, The floating joint portion is, A first floating connector is fixedly connected to the inner diameter measuring section and translates and rotates integrally with the inner diameter measuring section, A second floating connector that supports the first floating connector so as to allow translation and rotation of the first floating connector, A third floating connector supporting the second floating connector so as to allow translation and rotation of the second floating connector, The third floating connector is fixedly attached to the support frame. It is characterized by the following:

[0033] In one embodiment of the present invention, The second floating connector supports the first floating connector via a first connecting shaft, which is an axis extending in a first direction parallel to a plane perpendicular to the cylindrical axis and allows axial movement and rotation around the axis. The third floating connector is supported by a second connecting shaft, which is an axis extending in a direction perpendicular to the first direction in a plane perpendicular to the cylindrical axis, and which allows for axial movement and rotation around the axis. It is preferable.

[0034] In one embodiment of the present invention, The first floating connector is ring-shaped or cylindrical and is provided so as to surround the inner diameter measuring portion in a direction perpendicular to the cylindrical axis. The second floating connector is ring-shaped or cylindrical and is provided so as to surround the first floating connector in a direction perpendicular to the cylindrical axis. It is preferable.

[0035] In one embodiment of the present invention, The point where the first virtual straight line, which is a virtual extension of the first connecting shaft, and the second virtual straight line, which is a virtual extension of the second connecting shaft, intersect is approximately the center of gravity of the inner diameter measuring section. It is preferable.

[0036] In one embodiment of the present invention, The system includes an electric drive unit that moves the measuring probe forward and backward. It is preferable.

[0037] In one embodiment of the present invention, The inner diameter measuring section is provided with a restraining means that clamps it from a direction intersecting the cylindrical shaft, The aforementioned restraining means is When the inner diameter measuring part is not inserted into the hole to be measured, the inner diameter measuring part is held in place by clamping it. When the inner diameter measuring part is inserted into the hole to be measured, the inner diameter measuring part is released. It is preferable.

[0038] In one embodiment of the present invention, The inner diameter measuring section is supported by the support frame section via the floating joint section, with the cylindrical shaft in the vertical direction as the reference position. It is preferable.

[0039] The floating joint mechanism of the present invention is A floating joint mechanism interposed between an object to be supported and a support frame that supports the object, which allows relative translation and rotation of the object with respect to the support frame, The floating joint mechanism is, A first floating connector is fixedly connected to the object to be supported and moves and rotates integrally with the object to be supported, A second floating connector that supports the first floating connector so as to allow translation and rotation of the first floating connector, A third floating connector supporting the second floating connector so as to allow translation and rotation of the second floating connector, The third floating connector is fixedly attached to the support frame. It is characterized by the following:

[0040] The measuring unit of the present invention is A measuring unit that measures the dimensions of an object by bringing a measuring probe into contact with the object to be measured, A support frame portion that supports the measuring portion, A floating joint is interposed between the support frame and the measuring section, allowing relative translation and rotation of the measuring section with respect to the support frame, The floating joint portion is, A first floating connector is fixedly connected to the measuring unit and translates and rotates integrally with the measuring unit, A second floating connector that supports the first floating connector so as to allow translation and rotation of the first floating connector, A third floating connector supporting the second floating connector so as to allow translation and rotation of the second floating connector, The third floating connector is fixedly attached to the support frame. It is characterized by the following:

[0041] The control method for the automatic internal diameter measuring device of the present invention is as follows: A measuring probe that moves back and forth in a direction perpendicular to the cylindrical axis of the cylindrical case, An electric drive unit for moving the measuring probe forward and backward, An inner diameter measuring unit having a displacement detection unit for detecting the displacement of the measuring probe, A moving means for moving the inner diameter measuring section relative to the object to be measured, thereby moving the inner diameter measuring section in and out of the hole to be measured, A control method for an automatic internal diameter measuring device comprising a control unit that controls the operation of the internal diameter measuring unit and the moving means, A hole insertion step in which the inner diameter measuring unit is inserted into the hole to be measured by the moving means, A measuring step of measuring the inner diameter of the hole by bringing the measuring probe into contact with the inner wall of the hole, The system includes a hole retraction step in which the inner diameter measuring portion is withdrawn from the hole by the moving means. It is characterized by the following:

[0042] In one embodiment of the present invention, The automatic internal diameter measuring device is moreover, A support frame portion that supports the inner diameter measuring portion and connects the inner diameter measuring portion to the moving means, A floating joint is interposed between the support frame and the inner diameter measuring portion, allowing relative translation and rotation of the inner diameter measuring portion with respect to the support frame, In the hole insertion step, after the inner diameter measuring unit is inserted into the hole to be measured by the moving means, the drive of the moving means is temporarily stopped. The measurement process described above is: When the electric drive unit advances the measuring probe and presses it against the inner wall of the hole to be measured, the inner diameter measuring unit undergoes a relative displacement with respect to the support frame due to the reaction force acting on the inner diameter measuring device from the inner wall of the hole to be measured. The inner diameter measuring unit includes an autonomous adjustment step in which it autonomously adjusts its own position and orientation so that the cylindrical axis of the cylindrical case portion and the axis of the hole to be measured coincide. It is preferable.

[0043] In one embodiment of the present invention, The automatic internal diameter measuring device is Furthermore, the inner diameter measuring section is provided with a restraining means that clamps it from a direction intersecting the cylindrical axis, The aforementioned restraining means is A holding step that restrains the inner diameter measuring section by sandwiching it, A release step is performed to release the constraint on the inner diameter measuring part, This device switches between the held state and the released state of the inner diameter measuring section. During the execution of the hole insertion step and the hole retraction step, the restraining means holds the inner diameter measuring section in a holding state. In the measurement process, the restraining means executes the release process before the autonomous adjustment process to release the restraint on the inner diameter measuring section. It is preferable.

[0044] In one embodiment of the present invention, The control unit has a drive control unit that controls the electric drive unit, In the measurement step, the drive control unit, A first forward movement step involves advancing the measuring probe until it first contacts the inner wall of the hole to be measured, After the first forward movement step, a backward movement step is performed in which the measuring probe is moved back slightly in the reverse direction. After the retraction step, a second forward step is performed, which involves moving the measuring probe forward again so that the autonomous adjustment step can be executed. It is preferable.

[0045] In one embodiment of the present invention, The release step is performed before the first forward step. It is preferable.

[0046] In one embodiment of the present invention, The release step is performed after the first forward step. It is preferable.

[0047] In one embodiment of the present invention, A constant pressure mechanism is provided in the force transmission path from the electric drive unit to the measuring probe to regulate the upper limit of the reaction force applied to the measuring probe from the inner wall of the hole to be measured. The drive control unit terminates the second forward process when the constant pressure mechanism is activated. It is preferable.

[0048] In one embodiment of the present invention, The automatic internal diameter measuring device further includes a collision detection unit that detects when the internal diameter measuring unit collides with an object. When the collision detection unit detects a collision, the hole insertion process is stopped. It is preferable.

[0049] The control method for the automatic measuring device of the present invention is: A measuring probe that is mounted to move back and forth relative to a fixed element, An electric drive unit for moving the measuring probe forward and backward, A measuring unit having a displacement detection unit for detecting the displacement of the measuring probe, A means for moving the measuring unit relative to the object to be measured, thereby bringing the measuring unit closer to or in contact with the object to be measured, A control method for an automatic measuring device comprising a control unit that controls the operation of the measuring unit and the moving means, An approach step of bringing the measuring unit closer to the object to be measured using the moving means, A measurement step of measuring the dimensions of an object by bringing the measuring probe into contact with the object to be measured, The system includes a retraction step in which the measuring unit is moved away from the object to be measured by the moving means. It is characterized by the following:

[0050] In one embodiment of the present invention, The automatic measuring device is, moreover, A support frame portion that supports the measuring unit and connects the measuring unit to the moving means, A floating joint is interposed between the support frame and the measuring section, allowing relative translation and rotation of the measuring section with respect to the support frame, In the approach step, after the measuring unit approaches or comes into contact with the object to be measured by the moving means, the drive of the moving means is temporarily stopped. The measurement process described above is: When the electric drive unit advances the measuring probe and presses it against the object to be measured, the measuring probe undergoes a relative displacement with respect to the support frame due to the reaction force acting on the measuring probe from the object to be measured, and the process includes an autonomous adjustment step in which the measuring probe autonomously adjusts its own position and orientation. It is preferable. [Brief explanation of the drawing]

[0051] [Figure 1] This is an overall view of the automatic internal diameter measuring device. [Figure 2] This is a perspective view of the electric internal diameter measuring unit, seen from a slightly forward angle. [Figure 3] This is a perspective view of the electric internal diameter measuring unit, taken from a slightly rearward angle. [Figure 4] This is a front view of the electric internal diameter measuring unit. [Figure 5] This is a cross-sectional view showing the internal structure of an electric internal diameter measuring instrument. [Figure 6] This is an exploded view of the floating joint in the first embodiment. [Figure 7]In the first embodiment, this is a cross-sectional view of the floating joint. [Figure 8] In the first embodiment, this is a diagram illustrating the function of adjusting the position and orientation of the electric internal diameter measuring instrument by the floating joint. [Figure 9] In the first embodiment, this is a diagram illustrating the function of adjusting the position and orientation of the electric internal diameter measuring instrument by the floating joint. [Figure 10] In the first embodiment, this is a diagram illustrating the function of adjusting the position and orientation of the electric internal diameter measuring instrument by the floating joint. [Figure 11] In the first embodiment, this is a diagram illustrating the function of adjusting the position and orientation of the electric internal diameter measuring instrument by the floating joint. [Figure 12] In the first embodiment, this is a diagram illustrating the function of adjusting the position and orientation of the electric internal diameter measuring instrument by the floating joint. [Figure 13] This is an exploded view of the collision detection unit. [Figure 14] This is a perspective view of the collision detection unit, seen from slightly behind. [Figure 15] This is a functional block diagram of the control unit. [Figure 16] This is a flowchart of the overall operation of the automatic internal diameter measurement system. [Figure 17] This is a flowchart showing the operation procedure for the hole insertion process (ST100). [Figure 18] This is a flowchart showing the operation procedure of the measurement process (ST200). [Figure 19] This is a flowchart showing the operation procedure for the hole retraction process (ST300). [Figure 20] This is a flowchart showing the operation procedure of the measurement process in the second embodiment. [Figure 21] This is a flowchart showing the operation procedure of the measurement process in the third embodiment. [Figure 22] This is a front view of the electric internal diameter measuring unit in the fourth embodiment. [Figure 23]In the fourth embodiment, this is a top view (plan view) of the floating joint. [Figure 24] This is a cross-sectional view along line XXIV-XXIV in Figure 23. [Figure 25] In the fourth embodiment, this is a perspective view showing the connecting block in a state where it has been rotated relative to the support frame (support base). [Figure 26] This is a cross-sectional view of the fourth embodiment, showing the state in which the connecting block is rotationally displaced relative to the support frame portion (support base portion). [Figure 27] In the fourth embodiment, this is a top view (plan view) of the connecting block in a state where it is translated horizontally. [Figure 28] In the fifth embodiment, this is a perspective view of the electric internal diameter measuring unit. [Figure 29] In the fifth embodiment, this is a top view (plan view) of the electric internal diameter measuring unit. [Figure 30] This figure illustrates a state in which the first floating coupling cup has rotated around the X axis in the fifth embodiment. [Figure 31] This figure illustrates a state in which the first floating connecting cup is translated in the horizontal plane in the fifth embodiment. [Figure 32] This is an external side view of the sixth embodiment. [Figure 33] This is an enlarged cross-sectional view of the floating joint portion in the sixth embodiment. [Modes for carrying out the invention]

[0052] Embodiments of the present invention will be illustrated and described with reference to the reference numerals assigned to each element in the figures. (First Embodiment) A first embodiment of the present invention will be described. This embodiment is an automatic internal diameter measuring device 100 that automates the measurement of the internal diameter (hole diameter) of a hole to be measured.

[0053] (Automatic internal diameter measuring device) Figure 1 is an overall view of the automatic internal diameter measuring device 100. The automatic internal diameter measuring device 100 comprises a measuring device main body 110 and a control unit 140 that controls the overall operation.

[0054] (Measuring device main body 110) The measuring device main body 110 includes an electric internal diameter measuring unit 120 for measuring the diameter of a target hole, and a multi-joint robot arm (robot arm) 130 as a means of moving the electric internal diameter measuring unit 120.

[0055] (Electric internal diameter measuring unit 120) The electric internal diameter measuring unit 120 is attached to and held by the hand portion 131, which is the tip of the robot arm portion 130. The electric internal diameter measuring unit 120 is inserted into the inside of the hole to be measured to obtain the measurement of the internal diameter. Furthermore, the electric internal diameter measuring unit 120 includes a function to autonomously adjust its own position and orientation in order to accurately measure the hole to be measured.

[0056] The configuration of the electric internal diameter measuring unit 120 will be explained. Figure 2 is a perspective view of the electric internal diameter measuring unit 120, seen from a slightly forward position. Figure 3 is a perspective view of the side of the electric internal diameter measuring unit 120, seen from slightly behind. Figure 4 is a front view of the electric internal diameter measuring unit 120.

[0057] The electric internal diameter measuring unit 120 comprises an electric internal diameter measuring instrument (supported object) 200, a support frame section 300, a floating joint section (floating joint mechanism section) 400, a restraining means 500, a collision detection section 600, and a force sensor section 132.

[0058] (Electric inner diameter measuring device 200) The electric internal diameter measuring instrument 200 is an electric version of the rod feed mechanism used in existing manual internal diameter measuring instruments (such as hole testers). Figure 5 is a cross-sectional view showing the internal structure of the electric internal diameter measuring instrument 200. The electric internal diameter measuring instrument 200 comprises a cylindrical case section (fixed element) 210, a rod 230, a thimble section 240, a measuring probe (movable element) 250, a displacement detection section 260, an outer case section 270, a display unit section 233, and an electric drive section 280.

[0059] The cylindrical case section 210 is a cylindrical case overall. The rod 230 moves axially back and forth inside the cylindrical case portion 210. The cylindrical case portion 210 includes an upper cylindrical case portion 211 that constitutes the upper part, an intermediate cylindrical case portion 213 that constitutes the intermediate part, a lower cylindrical case portion 214 that constitutes the lower part, and a head cylindrical portion 215 that constitutes the measuring head portion 220. An intermediate cylinder case section 213 is attached to the lower end of the upper cylinder case section 211, a lower cylinder case section 214 is attached to the lower end of the intermediate cylinder case section 213, and a head cylinder section 215 is attached to the lower end of the lower cylinder case section 214.

[0060] The rod 230 is, as a whole, a long, rod-shaped body. The rod 230 has an upper rod 231 and a lower rod 233. The upper rod 231 is a spindle and has a feed screw (male thread) 232 on the outer surface of its base end (upper end). The upper cylindrical case portion 211 has a female thread 212, and the feed screw 232 is screwed into the female thread 212.

[0061] The thimble portion 240 is provided at the base end (upper end side) of the upper rod 231. The thimble section 240 includes a thimble sleeve 241, a ratchet sleeve 242, and a coil spring 243. The thimble sleeve 241 is fitted onto the base end of the upper rod 231 (rod 230) by the interlocking of its tapered surfaces, and is fixed to the base end of the upper rod 231 (rod 230). The ratchet sleeve 242 is a cylindrical body located further above the thimble sleeve 241, with a coil spring 243 interposed between the thimble sleeve 241 and the ratchet sleeve 242. A set screw is screwed into the base end face of the upper rod 231, and the flange on the head of the set screw pushes the ratchet sleeve 242. At this time, the coil spring 243 is sandwiched between the ratchet sleeve 242 and the thimble sleeve 241.

[0062] Furthermore, a ratchet mechanism (not shown) is provided between the ratchet sleeve 242 and the thimble sleeve 241. Now, the rotation direction of the ratchet sleeve 242, thimble sleeve 241, or rod 230 in the direction that moves the rod 230 downward (the direction that pushes the measuring probe 250 out) is defined as the positive rotation direction. Conversely, the rotation direction of the ratchet sleeve 242, thimble sleeve 241, or rod 230 in the direction that moves the rod 230 upward (the direction in which the measuring probe 250 is retracted) is defined as the negative rotation direction. The ratchet mechanism allows the ratchet sleeve 242 to rotate freely relative to the thimble sleeve 241 when rotating in the positive direction, but does not allow the ratchet sleeve 242 to rotate freely when rotating in the negative direction.

[0063] When the ratchet sleeve 242 is subjected to a (positive) rotational operation, the rotation of the ratchet sleeve 242 is transmitted to the rod 230 via the coil spring 243 and the thimble sleeve 241. There is an upper limit to the force (rotational force) transmitted from the ratchet sleeve 242 to the rod 230. That is, if an attempt is made to rotate the rod 230 with a force exceeding the frictional force (static friction force) acting between the ratchet sleeve 242, the coil spring (load-regulating elastic body) 243, and the thimble sleeve 241, the ratchet mechanism causes the ratchet sleeve 242 to rotate freely relative to the thimble sleeve 241. This thimble part 240 constitutes a constant pressure mechanism that regulates the upper limit of the force (measuring force) acting between the object to be measured and the measuring probe 250. Conversely, a predetermined force (measuring force) that can be defined by the amount the set screw is pushed in is generated between the object to be measured and the measuring probe 250, and when the measuring probe 250 applies a predetermined force (measuring force) to the object to be measured, the reaction force is applied to the side of the measuring probe 250, that is, to the side of the electric internal diameter measuring instrument 200.

[0064] The lower rod 233 is located inside the head cylinder portion 215. The upper end of the lower rod 233 is in contact with the lower end of the upper rod 231. The lower end of the lower rod 233 is conical in shape.

[0065] The measuring probe 250 is positioned in the head cylinder portion 215 so as to move back and forth in a direction perpendicular to the axial direction of the rod 230. Three measuring probes 250 are arranged in the head cylinder portion 215 at 120° intervals. Each measuring probe 250 has a thin, round shaft tip 252 made of carbide at its outer end. When each measuring probe 250 moves forward in the protruding direction, the round shaft tip 252 comes into contact with the inner wall of the object being measured.

[0066] Each measuring probe 250 has a tapered surface 251 formed on its inner end, which contacts the conical surface of the lower rod 233. The conical surface of the lower rod 233 and the tapered surface 251 of the measuring probe 250 form a displacement direction conversion means that changes the direction of force and displacement at a right angle.

[0067] Inside the head cylinder portion 215, there is a spring 216 (for example, a leaf spring) corresponding to each measuring probe 250. One end of each leaf spring 216 is fixed to the inner wall of the head cylinder portion 215, and the other end of each leaf spring 216 is fixed to each measuring probe 250. Each measuring probe 250 is biased by the leaf spring 216 to retract into the head cylinder 215. When the rod 230 is pulled upward by an external force, the force of the leaf spring 216 causes the measuring probe 250 to follow the rod 230 and move into the head cylinder 215.

[0068] The part of the head cylinder 215 from which the measuring probe 250 extends and retracts (the tip of the internal diameter measuring instrument) is sometimes referred to as the measuring head 220.

[0069] The displacement detection unit 260 is provided inside the intermediate cylindrical case portion 213 to detect the displacement of the upper rod 231. The displacement detection unit 260 is a so-called rotary encoder, comprising a rotor 261 provided to rotate integrally with the upper rod 231, a stator 262 for counting the rotation of the rotor 261, and a signal processing calculation unit (not shown). The detection method of the displacement detection unit 260 is not particularly limited, and examples include photoelectric encoders, capacitive encoders, electromagnetic induction encoders, and magnetic encoders.

[0070] The outer case portion 270 is an outer cylindrical portion that covers the outside of the cylindrical case portion 210. The outer case portion 270 is provided to cover the electric internal diameter measuring instrument 200 from the middle of the lower cylindrical case portion 214 upwards. The outer case portion 270 consists of two parts: an outer case main body portion 271 that houses the intermediate part inside, and an outer case upper part 272 that houses the upper part inside. The outer case main body portion 271 is a cylindrical body that covers the entire intermediate cylindrical case portion 213, which corresponds to the middle part of the electric internal diameter measuring instrument 200, as well as the upper end side of the lower cylindrical case portion 214 and the lower end side of the upper cylindrical case portion 211.

[0071] The outer case upper part 272 is connected to the upper end of the outer case main body 271 and is a cylindrical body that covers the upper cylindrical case part 211, which constitutes the upper part of the electric internal diameter measuring instrument 200.

[0072] The display unit 233 has a display unit 234, which is attached to the openings on the sides of the intermediate cylindrical case 213 and the outer case body 271, and closes the openings. The display unit 234 is a digital display type display unit 234 (for example, a liquid crystal display panel or an organic EL display panel) fitted into the central region of the display unit 233. The display unit 234 displays measured values ​​obtained by the signal processing calculation unit (not shown).

[0073] Furthermore, a connector is provided on the display unit 233, and the measured values ​​obtained by the signal processing unit (not shown) are output externally.

[0074] The electric drive unit 280 is a drive unit that rotates the ratchet sleeve 242 of the thimble unit 240. The electric drive unit 280 is mounted above the upper part 272 of the outer case. The electric drive unit 280 is, for example, a motor, and the rotational output of the motor is transmitted to the ratchet sleeve 242 via a power transmission mechanism (such as a gear train, connecting belt, connecting shaft, or connecting link).

[0075] The electric internal diameter measuring device 200 operates essentially the same as an existing manual internal diameter measuring device, except that the rod is advanced by the electric drive unit 280. As the rod 230 moves forward and backward using electric power, the measuring probe 250 moves forward and backward in the direction of extending and retracting from the head cylinder portion 215 in accordance with the movement of the lower rod 233. By detecting the displacement (position) of the rod 230 when the three measuring probes 250 are in equal contact with the inner wall of the hole to be measured, the hole diameter of the hole to be measured is obtained as a measured value.

[0076] (Support frame section 300) The support frame portion 300 is an L-shaped member when viewed from the side. It has a support column portion 310 and a support base portion 320. The support base portion 320 is attached perpendicularly to the lower end of the vertically oriented support column portion 310.

[0077] The support column 310 is located adjacent to and parallel to the electric internal diameter measuring instrument 200. A restraining means 500 is provided on the front side of the support column 310, and the restraining means 500 switches between holding and releasing the electric internal diameter measuring instrument 200. This will be described later.

[0078] The support base portion 320 is provided so as to bend in an L-shape from the lower end of the support column portion 310 toward the electric internal diameter measuring instrument 200. The support base portion 320 has a first insertion hole 321 through which the head cylinder portion 215 of the electric internal diameter measuring instrument 200 is inserted. The electric internal diameter measuring instrument 200 is mounted such that, with the head cylinder portion 215 passing through the first insertion hole 321, the portion above the lower cylinder case portion 214 rests on the support base portion 320 via the floating joint portion 400.

[0079] (Floating joint section 400) The floating joint section 400 will be explained. Figure 6 is an exploded view of the floating joint section 400. Figure 7 is a cross-sectional view of the floating joint 400.

[0080] The floating joint section 400 is a joint (or connecting mechanism) that allows the electric internal diameter measuring instrument 200 to rotate relative to the support frame section 300, and also allows the electric internal diameter measuring instrument 200 to translate horizontally relative to the support frame section 300. Even if there is axial misalignment (tilt and positional misalignment) between the electric internal diameter measuring instrument 200 and the hole to be measured, the rotation and translation of the floating joint section 400 allows the electric internal diameter measuring instrument 200 to autonomously adjust its own position and orientation.

[0081] The floating joint section 400 includes a rotation-permissible mechanism section 410 and a translation-permissible mechanism section 420.

[0082] The rotation-permissible mechanism 410 includes a first spring support 411, a spring (coil spring) 412 (flexible body, elastic body), and a second spring support 413. The first spring support 411 and the second spring support 413 are generally ring-shaped, with flanges extending radially outward from the rings.

[0083] As shown in the cross-sectional view of Figure 7, the first spring retainer 411 is fitted onto the outer surface of the lower cylinder case portion 214 near the upper side of the lower cylinder case portion 214, thereby permanently attaching the first spring retainer 411 to the electric internal diameter measuring instrument 200. Here, the lower end surface of the outer case body portion 271 and the first spring retainer 411 are continuous and integral, and the position in which the first spring retainer 411 is attached to the electric internal diameter measuring instrument 200 is fixedly restricted.

[0084] As one embodiment, the first spring support 411 may be installed so that its height (position) corresponds to the height (position) of the center of gravity of the electric internal diameter measuring instrument 200. For example, the first spring support 411 may be installed so that its height (position) is approximately the same as the height (position) of the center of gravity of the electric internal diameter measuring instrument 200. Alternatively, the first spring support 411 may be installed so that its height (position) is within 20%, 15%, 10%, or 5% above or below the height (position) of the center of gravity of the electric internal diameter measuring instrument 200 (the vertical length of the electric internal diameter measuring instrument).

[0085] With the lower cylinder case portion 214 (electric internal diameter measuring instrument 200) inside the coil spring 412, the upper end of the coil spring 412 is supported by the first spring support 411. The lower end of the coil spring 412 is supported by the second spring support 413.

[0086] In one embodiment, instead of using a single coil spring 412, multiple elastic bodies or springs may be arranged to surround the electric internal diameter measuring device 200 (at equal angular intervals).

[0087] A larger spring diameter (a larger distance between the spring and the central axis of the electric internal diameter measuring device) is better for supporting the electric internal diameter measuring device. However, if the spring diameter is too large (the distance between the spring and the central axis of the electric internal diameter measuring device is too large), the measuring pressure of the internal diameter measuring device alone will not be sufficient to autonomously adjust the orientation of the electric internal diameter measuring device to align its tilt with the axis of the hole. If the spring diameter is increased (the distance between the spring and the central axis of the electric internal diameter measuring device is increased), it is best to decrease the spring constant (elastic modulus). If the spring diameter is decreased (the distance between the spring and the central axis of the electric internal diameter measuring device is decreased), the spring constant (elastic modulus) may be increased slightly. In addition, although the embodiment uses an elastic spring, if rotational orientation adjustment of the electric internal diameter measuring device is permitted, the member connecting the first spring support 411 and the second spring support 413 may be a non-elastic flexible member instead of the coil spring 412.

[0088] The second spring support 413 is connected to the translational tolerance mechanism 420. As shown in the cross-sectional view of Figure 7, the ring hole 414 of the second spring receiver 413 has a slightly longer length (height) in the axial direction, and the diameter of the ring hole 414 is slightly larger than the cylindrical case portion 210 (lower cylindrical case portion 214) of the electric internal diameter measuring instrument 200 to the extent that it allows for inclination of the electric internal diameter measuring instrument 200. The ring hole 414 may also be a tapered hole 414 in which the diameter of the ring hole increases as it goes downwards or upwards.

[0089] The translational tolerance mechanism 420 includes a horizontal plate (translational body) 421 and a ball roller 423. The horizontal plate 421 is a plate positioned above the support base 320. The horizontal plate 421 has a second insertion hole 422 through which the electric internal diameter measuring instrument 200 (lower cylinder case portion 214) is inserted. A second spring retainer 413 is fitted into the second insertion hole 422 from above. In other words, the rotation-permissible mechanism 410 is located on the horizontal plate 421, and the electric internal diameter measuring instrument 200 is supported by the rotation-permissible mechanism 410. To put it another way, the electric internal diameter measuring instrument 200 is supported on the horizontal plate 421 with the rotation-permissible mechanism 410 in between.

[0090] Ball rollers 423 are positioned on the upper side of the support base 320. Here, four ball rollers 423 are installed around the first insertion hole 321 and the second insertion hole 422 at 90-degree intervals, and a horizontal plate 421 is placed on top of these ball rollers 423.

[0091] The horizontal plate 421, mounted on the ball roller 423, can move horizontally with almost no friction and with very little force. On the other hand, to deform the coil spring 412 (elastic body) which serves as the rotation-permissible mechanism 410, a force is required to resist the elastic force. Therefore, in this embodiment, when a force (rotational force or translational force) acts on the electric internal diameter measuring instrument 200, the translation-permissible mechanism 420 tends to be displaced preferentially.

[0092] The adjustment operation of the position and orientation of the electric internal diameter measuring instrument 200 by the action of the floating joint 400 will be explained with reference to Figures 8 to 12. For example, as illustrated in Figure 8, suppose that the hole to be measured was machined with a deviation from the design value, resulting in a hole that should have been drilled vertically being inclined and shifted slightly to the right in the figure from its position in the design data. The electric internal diameter measuring unit 120 is carried to the hole by the robot arm 130, and the measuring head 220 is inserted into the hole. Even if the drive control of the robot arm 130 is accurate, because the hole to be measured has a deviation from the design value, there is a discrepancy in position and angle between the axis of the electric internal diameter measuring instrument 200 and the axis of the hole to be measured.

[0093] Now, in order for the inner diameter of the hole to be measured to be measured accurately, all three measuring probes 250 must contact the inner wall of the hole to be measured evenly. First, the electric drive unit 280 drives the rod 230, causing the rod 230 to move downward. Then, the tip (cone) of the lower rod 233 pushes out the measuring probe 250, and of the three measuring probes 250, the one closest to the inner wall of the hole to be measured makes contact with the inner wall of the hole to be measured. As the lower rod 233 continues to push out the probe 250, a reaction force is applied from the inner wall of the hole toward the probe 250. This reaction force pushes the electric internal diameter measuring instrument 200 in the opposite direction. The reaction force pushes from the probe 250 toward the lower end of the lower rod 233, but the displacement of the horizontal plate 421 occurs before the deformation of the coil spring 412 of the rotation-allowing mechanism 410. As illustrated in Figures 9 and 10, the displacement of the horizontal plate 421 first absorbs the axial misalignment between the electric internal diameter measuring instrument 200 and the hole being measured. Furthermore, the first insertion hole 321 of the support base portion 320 has a diameter large enough to allow horizontal movement of the electric internal diameter measuring instrument 200.

[0094] At the point shown in Figure 9 (Figure 10), the inclination of the axes of the electric internal diameter measuring instrument 200 and the hole being measured is still misaligned. As the lower rod 233 continues to push out the measuring probe 250 from the state shown in Figure 9 (Figure 10), the tip (round shaft) of the measuring probe 250 hits the inner wall of the hole. At this time, (because the three round shafts have lengths) the reaction force acting on the electric internal diameter measuring instrument 200 from the inner wall of the hole being measured has a rotational moment. At this time, in response to the reaction force from the inner wall of the hole, the coil spring 412 of the rotation-allowing mechanism 410 deforms, as illustrated in Figures 11 and 12, and the inclination of the electric internal diameter measuring instrument 200 is adjusted so that the axis of the electric internal diameter measuring instrument 200 matches the axis of the hole being measured. The ring hole 414 of the second spring receiver 413 allows for the inclination of the electric internal diameter measuring instrument 200.

[0095] Finally, when the three measuring probes 250 press against the inner wall of the hole to be measured with a predetermined measuring pressure, the floating joint section 400 (rotation-permissible mechanism section 410, translation-permissible mechanism section 420) autonomously adjusts the position and orientation of the electric internal diameter measuring instrument 200 so that it can accurately measure the diameter of the hole to be measured. In other words, if the robot arm section 130 can insert the measuring head section 220 of the electric internal diameter measuring instrument 200 into the hole to be measured, then the diameter of the hole can be accurately measured by automatic orientation adjustment without the need for manual adjustment or advanced feedback control.

[0096] (Restraint means 500) The restraining means 500 is provided on the support frame portion 300 (support column portion 310) and holds and supports the electric internal diameter measuring instrument 200. The restraining means 500 has two clamping pieces 510 that clamp the electric internal diameter measuring instrument 200 from directions perpendicular to the axis, as shown in Figures 2 and 3, for example. Here, the clamping pieces 510 clamp the outer case body portion 271 from both sides. The clamping pieces 510 are movable, and the restraining means 500 can switch between a held state of the electric internal diameter measuring instrument 200 and a released state where the hold is released.

[0097] Even though the clamping piece 510 is opened to release the electric internal diameter measuring instrument 200, it is advisable to limit the gap between the clamping piece 510 and the electric internal diameter measuring instrument 200 to a predetermined upper limit (around 5 mm or 10 mm), and to prevent the electric internal diameter measuring instrument 200 from being displaced (translated or tilted) excessively beyond that limit.

[0098] The electric internal diameter measuring instrument 200 is mounted on the support base 320 (support frame 300) via a floating joint 400. For the electric internal diameter measuring device 200 to autonomously adjust its posture to match the hole being measured using its own measuring pressure, the floating joint section 900 needs to be flexible. Therefore, if the electric internal diameter measuring device 200 is merely resting on the floating joint section 400, depending on the rigidity (flexibility) of the floating joint section 400, the electric internal diameter measuring device 200 may wobble, tilt significantly, or fall over. From a safety standpoint, it is undesirable for the electric internal diameter measuring device 200 to shake or tip over. Furthermore, if the posture of the electric internal diameter measuring device 200 is not fixed, the position of the measuring head 220 will fluctuate, making it impossible for the robot arm 130 to insert the measuring head 220 of the electric internal diameter measuring device 200 into the hole to be measured.

[0099] Therefore, when the electric internal diameter measuring device 200 is not inserted into the hole to be measured, the restraining means 500 holds the electric internal diameter measuring device 200 in place. Then, when the measuring head portion 220 of the electric internal diameter measuring device 200 is inserted into the hole to be measured, the restraining means 500 releases the electric internal diameter measuring device 200, allowing the electric internal diameter measuring device 200 to autonomously change its posture and adjust (autonomous adjustment) by the floating joint portion 400.

[0100] (Collision detection unit 600) The collision detection unit 600 detects when the electric internal diameter measuring instrument 200 collides with something with a force exceeding a predetermined value. Figure 13 is an exploded view of the collision detection unit. Figure 14 is a perspective view of the collision detection unit, seen from a slightly rearward angle. The collision detection unit 600 is positioned between the rear side of the support column 310 and the hand portion 131 of the robot arm 130. Here, the collision detection unit 600 detects when the electric internal diameter measuring instrument 200 approaches an object (e.g., a workpiece) from above, and a large force is applied to the electric internal diameter measuring instrument 200 in the Z direction (vertical direction), pushing it upward from below. In other words, the collision detection direction of the collision detection unit 600 is approximately parallel to the direction in which the electric internal diameter measuring instrument 200 approaches the hole to be measured.

[0101] The collision detection unit 600 includes a fixed plate 601, a mounting plate 602, a linear guide 610, a biasing means 620, and a contact sensor 630.

[0102] The fixing plate 601 is attached directly or indirectly to the robot's hand portion 131 and is fixedly mounted to the hand portion 131. Here, a force sensor portion 132 is disposed between the robot's hand portion 131 and the collision detection unit 600. Therefore, the collision detection unit 600 is attached to the hand portion 131 of the robot arm portion 130 via the force sensor portion 132.

[0103] The mounting plate 602 is attached directly or indirectly to the back surface of the support column 310 and is fixedly provided with respect to the support column 310 (support frame 300). The linear guide 610 is positioned between the fixing plate 601 and the mounting plate 602 and guides the movement direction of the mounting plate 602 relative to the fixing plate 601 in the vertical direction. The linear guide 610 has a groove frame 611 with vertical grooves and a slide body 612 that slides vertically in the grooves of the groove frame 611. Here, the groove frame 611 is attached to the fixing plate 601 and the slide body 612 is attached to the mounting plate 602.

[0104] The biasing means consists of two coil springs 620. One end of the coil spring 620 is locked to the fixing plate 601, and the other end of the coil spring 620 is locked to the mounting plate 602. The coil spring 620 constantly biases the mounting plate 602 in a direction that pulls it downward relative to the fixing plate 601. That is, the mounting plate 602's reference position is one that is vertically downward relative to the fixing plate 601 due to its own weight, the weight of the electric internal diameter measuring instrument 200, and the biasing force of the coil spring 620.

[0105] The contact sensor 630 includes a contact detection block 631 positioned on the fixed plate 601 side and a ball plunger 632 provided on the mounting plate 602 side. As illustrated in Figure 14, when the mounting plate 602 is in a reference position relative to the fixed plate 601, the ball plunger 632 on the mounting plate 602 side is in contact with (fitted with) the contact detection block 631.

[0106] Here, let's consider a scenario where, for example, the position of a hole machined in the workpiece deviates significantly from the design value. In this state, if the robot arm 130 attempts to insert the electric internal diameter measuring instrument 200 into the hole to be measured from above, the measuring head 220 of the electric internal diameter measuring instrument 200 will hit the workpiece. The electric internal diameter measuring instrument 200 (measuring head 220) will shift out of the hole and hit the workpiece, and the electric internal diameter measuring instrument 200 (measuring head 220) will be pushed further into the workpiece. When a force exceeding the gravity of the electric internal diameter measuring instrument 200 and the biasing force of the biasing means (coil spring 620) is applied to the collision detection unit 600, the mounting plate 602 slides upward, and the ball plunger 632 of the mounting plate 602 detaches from the contact detection block 631. The contact sensor 630 emits a signal (collision detection signal) when the contact detection block 631 detects the separation of the ball plunger 632 (or when it can no longer detect contact of the ball plunger 632).

[0107] If the collision detection unit 600 detects that the electric internal diameter measuring instrument 200 has collided with something, the control unit 140 immediately stops the operation of the robot arm 130.

[0108] (Force sensor unit 132) The force sensor unit 132 is, for example, a 6-axis force sensor (force in the orthogonal 3-axis directions and rotational force around the axis). While the collision detection unit 600 was specialized in detecting upward force in the vertical direction (Z direction), the force sensor unit 132 detects the force applied to the electric internal diameter measuring instrument 200 in all directions.

[0109] The articulated robot arm 130 is a so-called robot arm, and its hand portion 131, which is the tip of the robot arm 130, moves three-dimensionally using vertical and horizontal rotational drive axes. The hand portion 131 of the robot arm 130 is connected to the support frame 300 via a force sensor 132 and a collision detection unit 600. The force sensor 132 detects when the electric internal diameter measuring instrument 200 collides with an object with an unexpected force exceeding a predetermined value, even in directions in which the collision detection unit 600 does not detect a collision (i.e., directions other than the vertical direction (Z direction)). If the force sensor 132 detects an unexpected collision of the electric internal diameter measuring instrument 200, the control unit 140 immediately stops the operation of the robot arm 130. This ensures even greater safety.

[0110] (Control unit 140) Figure 15 is a functional block diagram of the control unit 140. The control unit 140 comprises a measurement operation control unit 150, a robot arm drive control unit 160, and a central control unit 170.

[0111] The measurement operation control unit 150 controls the measurement operation of the electric internal diameter measuring instrument 200. The measurement operation control unit 150 comprises a constraint control unit 151, a drive control unit 152, and a measurement value acquisition unit 153.

[0112] The restraint control unit 151 controls the opening and closing operation of the clamping piece 510 of the restraint means 500, and controls the timing of holding and releasing the electric internal diameter measuring instrument 200. The drive control unit 152 controls the drive of the electric drive unit 280, and controls the forward and backward movement of the rod 230, that is, the forward and backward movement of the measured value. The measurement value acquisition unit 153 obtains the measurement value from the electric internal diameter measuring instrument 200. That is, the measurement value acquisition unit 153 receives the sensor value from the displacement detection unit 260 and obtains the measurement value of the internal diameter of the hole to be measured from the displacement (position) of the rod 230.

[0113] The robot arm drive control unit 160 controls the movement of the robot arm unit 130. The central control unit 170 integrally controls the measurement motion control unit 150 and the robot arm drive control unit 160.

[0114] (Control operation of the automatic internal diameter measuring device 100) This section describes a series of operations in which the measuring device main unit 110 (electric internal diameter measuring unit 120, robot arm unit 130) automatically measures the internal diameter of the hole to be measured under the control of the control unit 140. Figure 16 is a flowchart of the overall operation of the automatic internal diameter measurement system (automatic internal diameter measurement operation). A workpiece (object to be measured) having a hole (hole to be measured) is transported by a conveyor belt or rail on the manufacturing line and brought to a predetermined position in front of the measuring device main body 110 (electric internal diameter measuring unit 120, robot arm 130). The automatic internal diameter measuring device 100 automatically performs internal diameter measurements sequentially on the holes designated (set) as targets for measurement within the workpiece (object to be measured) that are being transported. The positions (coordinates) of the holes to be measured within the workpiece (object to be measured) are set (stored) as part of the measurement part program in the central control unit 170. Alternatively, the device may automatically perform internal diameter measurements sequentially while searching for the holes to be measured using image recognition such as a camera.

[0115] In the first embodiment, the hole to be measured is a hole that is drilled so that its upper surface is open in the vertical direction, and the electric internal diameter measuring instrument 200 is assumed to be inserted into the hole from above while maintaining a nearly vertical position.

[0116] The automatic internal diameter measurement operation comprises a hole insertion process (approach process) (ST100), a measurement process (ST200), and a hole retraction process (retraction process) (ST300).

[0117] The hole insertion process (ST100) involves moving the electric internal diameter measuring unit 120 with the robot arm 130 and inserting the measuring head 220 of the electric internal diameter measuring instrument 200 into the hole to be measured (in other words, approaching the workpiece from above).

[0118] Figure 17 is a flowchart showing the operation procedure of the hole insertion process (ST100). In the hole insertion process (ST100), first, the destination (target coordinates) of the electric internal diameter measuring instrument 200, which is moved by the robot arm 130, is set to the hole to be measured (ST110). Next, it is confirmed whether the electric internal diameter measuring device 200 is restrained by the restraining means 500 (ST120). In this embodiment, the default state (which may also be called the standard state or reference state) is when the restraint means 500 restrains (holds) the electric internal diameter measuring instrument 200. However, if maintenance or replacement of the electric internal diameter measuring instrument 200 is performed, the restraint means 500 may be released. In such cases, the hold status is checked, and if the instrument is not held (ST120:NO), a signal is sent from the restraint control unit 151 to perform the holding process (ST130) by the restraint means 500. By restraining (holding) the electric internal diameter measuring instrument 200 when moving the electric internal diameter measuring unit 120 with the robot arm 130, the electric internal diameter measuring instrument 200 can be moved stably and safely by the robot arm 130.

[0119] The robot arm section 130 is started to move (ST140), the electric internal diameter measuring unit 120 is moved, and the measuring head section 220 of the electric internal diameter measuring instrument 200 is inserted into the hole to be measured.

[0120] In this case, for example, if the machining position of the hole to be measured deviates from the design value, the electric internal diameter measuring device 200 (measuring head unit 220) may unexpectedly collide with the workpiece. In this regard, the robot arm drive control unit 160 monitors signals from the collision detection unit 600 and the force sensor unit 132 (ST150). If a collision is detected between the electric internal diameter measuring instrument 200 (measuring head unit 200) and the workpiece (ST150: YES), the drive of the robot arm unit 130 is immediately stopped (emergency stop) (ST180). After this, the central control unit 170 may report the abnormality to the operator.

[0121] When the measuring head 220 of the electric internal diameter measuring device 200 is inserted into the hole to be measured and reaches the target coordinates, the robot arm 130 stops moving (ST170).

[0122] Next, we proceed to the measurement process (ST200). Figure 18 is a flowchart showing the operation procedure of the measurement process (ST200). In the measurement process (ST200), first, the hold by the restraining means 500 is released (ST211), and the electric internal diameter measuring instrument 200 is put into a released state. As a result, the electric internal diameter measuring instrument 200 is supported by the support frame 300 via the floating joint 400, so that the position and orientation of the electric internal diameter measuring instrument 200 can be adjusted autonomously.

[0123] Then, the drive control unit 152 sends a drive signal to drive the electric drive unit 280. First, the first forward movement process (ST220) is performed. The first forward movement process (ST220) is the process of advancing the measuring probe 250 until it first contacts the inner wall of the hole to be measured. The electric drive unit 280 (e.g., a motor) is driven to advance the rod 230 (in this case, move it downwards), and the measuring probe 250 is advanced toward the inner wall of the hole. In the first forward movement process (ST220), in order to improve measurement efficiency, it is preferable to drive the motor at high speed to move the rod 230 and the measuring probe 250 as quickly as possible. (For example, if the rod 230 is a screw feed, the rotation speed of the rod 230 should be 100 rpm to 200 rpm. In terms of the speed at which the rod 230 or the measuring probe 250 moves, it may be 10 μm / s to 20 μm / s.)

[0124] As the measuring probe 250 advances toward the inner wall of the hole, it comes into contact with the inner wall of the hole. In this embodiment, there are three measuring probes 250. If the axis of the electric internal diameter measuring instrument 200 and the axis of the hole to be measured were perfectly aligned, the three measuring probes 250 could contact the inner wall of the hole simultaneously. However, due to the driving error of the robot arm 130 and the machining error of the workpiece, there is a misalignment between the axis of the electric internal diameter measuring instrument 200 and the axis of the hole to be measured. In this case, one of the three measuring probes 250 will contact the inner wall of the hole first. If one of the measuring probes 250 contacts the inner wall of the hole (ST213: YES), the first forward step (ST212) is immediately stopped, and the process moves to the first reverse step (ST214). Contact of the measuring probe 250 with the inner wall of the hole can be determined, for example, by calculating the motor torque from the applied current (applied voltage) of the motor, and if the torque exceeds a predetermined value, it can be determined that one of the measuring probes 250 has contacted the inner wall of the hole.

[0125] In the first retraction step (ST214), the rod 230 and the measuring probe 250 are slightly retracted in the opposite direction. This prevents the measuring probe 250 from digging into the inner wall of the hole due to the momentum after it contacts the inner wall of the hole in the first forward step (ST212). The distance the measuring probe 250 is retracted in the first retraction step (ST214) is very small, for example, 0.001 mm to 0.01 mm.

[0126] The retraction speed of the measuring probe 250 in the first retraction process (ST214) may be as fast as possible. For example, if the rod 230 is a screw feed, the rotational speed of the rod 230 may be 100 rpm to 200 rpm. The advancement speed of the rod 230 or the measuring probe 250 may be 10 μm / s to 20 μm / s.

[0127] After slightly retracting the probe 250 in the first retraction step (ST214), the probe 250 is advanced again in the second advance step (ST215). In the second advance step (ST215), the probe 250 is advanced slowly (at a low speed, with small movements).

[0128] In the second forward stroke (ST215), the feed rate of the probe 250 is preferably low (fine movement). For example, if the rod 230 is a screw feed, the rotational speed of the rod 230 is set to 10 rpm-20 rpm. The speed at which the rod 230 or the probe 250 moves may be 1 μm / s-2 μm / s.

[0129] The position and tilt of the electric internal diameter measuring device 200 are autonomously adjusted by the reaction force when the measuring probe 250 presses against the inner wall of the hole. The function of the floating joint 400 in autonomously adjusting the position and tilt of the electric internal diameter measuring device 200 is as described above.

[0130] When the three measuring probes 250 contact the inner wall of the hole evenly with a predetermined measuring pressure, the autonomous adjustment of the position and tilt of the electric inner diameter measuring device 200 is completed. When the three measuring probes 250 contact the inner wall of the hole with a predetermined measuring pressure, the ratchet mechanism (constant pressure mechanism) is activated. That is, the electric drive unit 280 rotates the thimble unit 240 (ratchet sleeve 242) until the ratchet mechanism (constant pressure mechanism) is activated, so that the measuring probes 250 contact the inner wall of the hole evenly with a predetermined measuring pressure.

[0131] The second forward process (ST215) can also be referred to as the autonomous adjustment process.

[0132] In this state, the displacement detection unit 260 detects the displacement (position) of the rod 230. The measurement value acquisition unit 153 obtains the inner diameter of the hole from the displacement (position) of the rod 230 (ST216).

[0133] After obtaining the measurement value, the measuring probe 250 is retracted in the second retraction step (ST217) to separate the measuring probe 250 from the inner wall of the hole.

[0134] After the measurement process (ST200), the electric internal diameter measuring device 200 is removed from the hole to be measured during the hole retraction process (ST300). Figure 19 is a flowchart showing the operation procedure for the hole retraction process (ST300). In the hole retraction process (ST300), first the electric internal diameter measuring instrument 200 is restrained (held) by the restraining means 500 (ST320), and then the electric internal diameter measuring unit 120 is moved out of the hole by the robot arm 130 (ST330).

[0135] This completes the measurement of the inner diameter of one hole. Repeat steps ST100-ST300 until the measurement of all target holes is complete (ST400).

[0136] Thus, according to this embodiment, it is no longer necessary to hold and operate the internal diameter measuring instrument by hand, and the internal diameter of the hole can be automatically measured by the electric internal diameter measuring unit (electric internal diameter measuring instrument 200, robot arm unit 130).

[0137] (Second embodiment) In the first embodiment described above, it was assumed that the hole to be measured was drilled in a vertical direction. As a second embodiment, we will describe a case in which the automatic internal diameter measuring device 100 automatically measures the internal diameter even when the hole to be measured is inclined from the vertical direction. Figure 20 is a flowchart showing the operation procedure of the measurement process in the second embodiment.

[0138] Since the hole to be measured is inclined with respect to the vertical, in the hole insertion process (ST100) in which the robot arm 130 inserts the electric internal diameter measuring instrument 200 into the hole, the electric internal diameter measuring instrument 200 is inserted into the hole at an angle to match the inclination of the hole. As a result, because the electric internal diameter measuring instrument 200 is inclined, if the hold of the electric internal diameter measuring instrument 200 by the restraining means 500 is released, the flexibility of the floating joint 400 may cause the electric internal diameter measuring instrument 200 to be displaced significantly (translationally and inclined). If the electric internal diameter measuring instrument 200 is displaced significantly (translationally and tilted), there is a possibility that the measuring head 220 may collide with the inner wall of the hole. Furthermore, if the electric internal diameter measuring instrument 200 is displaced significantly (translationally and tilted) in the direction of gravity, it may take time, or even be difficult, for it to autonomously correct that displacement (translationally and tilted) solely by the reaction force of the measuring pressure.

[0139] Therefore, in the second embodiment, in the measurement process, the first forward step (ST221) is performed before the release step (ST224). That is, after performing the first forward step (ST221) and detecting that one of the measuring probes 250 has come into contact with the inner wall of the hole (ST222: YES), the measuring probe 250 is moved back slightly (first retraction step (ST223)). In this state, the release step (ST224) is performed.

[0140] By performing the first forward step (ST221) first, the measuring probe 250 is brought into contact with the inner wall of the hole. Since at least one of the measuring probes 250 is in contact with the inner wall of the hole, it can be expected that the electric internal diameter measuring device 200 will not be significantly displaced (translationally and inclined) even if the holding mechanism 500 is released. This makes it possible to appropriately perform automatic internal diameter measurement even for inclined holes to be measured.

[0141] (Third embodiment) In the second embodiment (flowchart in Figure 20), the release process (ST224) is performed after the first reverse process (ST223), but the release process (ST224) may be performed before the first reverse process (ST223). As illustrated in the flowchart in Figure 21, if it is detected that the measuring probe 250 has come into contact with the inner wall of the hole during the first forward movement step (ST231) (ST232: YES), the forward movement of the measuring probe 250 is immediately stopped. In this state, the release process (ST233) is performed. Then, after the measuring probe 250 is retracted once (first retraction process (ST234)), the measuring probe 250 is advanced again so that the position and orientation of the electric internal diameter measuring device 200 can be automatically adjusted, and the measuring probe 250 makes even contact with the inner wall of the hole at a predetermined measuring pressure. With this sequence of operations, as in the second embodiment, automatic internal diameter measurement can be appropriately performed on inclined holes to be measured.

[0142] (Fourth embodiment) A fourth embodiment will be described. The basic configuration of the fourth embodiment is the same as that of the first embodiment, but it is characterized by the structure of the floating joint section (floating joint mechanism section) 800. Figure 22 is a front view of the electric internal diameter measuring unit 120 in the fourth embodiment. Figure 23 is a top view (plan view) of the floating joint 800 in the fourth embodiment. Figure 24 is a cross-sectional view taken along the line XXIV-XXIV in Figure 23.

[0143] In the fourth embodiment, the electric internal diameter measuring instrument 200 is supported in such a manner that it is suspended from the support frame portion 300 via the floating joint portion 800, with its axis (cylindrical axis or rod axis) in a vertical direction. In the fourth embodiment, the support frame portion 300 is an L-shaped member when viewed from the side, similar to the first embodiment, and includes a support column portion 310 and a support base portion 710.

[0144] Here, the support base portion 710 is annular in shape, having walls perpendicular to the horizontal direction so as to form a vertical hole (a cylindrical hole). The annular wall surrounds and supports the floating joint section 800, so the annular wall will be referred to as the support ring section 720. Two beams 721 are provided on the lower surface of the support ring section 720, spanning in the front-to-back and left-to-right directions and intersecting in a cross shape. As shown in the cross-sectional view of Figure 24, recesses 722 are provided at the intersections of the beams 721.

[0145] The floating joint portion 800 of the fourth embodiment has a connecting block 810. The connecting block 810 is fixedly connected to the electric internal diameter measuring instrument 200, and the connecting block 810 translates and rotates integrally with the electric internal diameter measuring instrument 200. The connecting block 810 is positioned inside the support ring 720, on the beam 721, and surrounded by the walls of the support ring 720. The connecting block 810 is rectangular prism-shaped (cube, rectangular prism). Four suspension rods 811 hang down from the four corners of the lower end face of the connecting block 810, and the suspension rods 811 are connected to the upper end of the electric internal diameter measuring instrument 200. In other words, the electric internal diameter measuring instrument 200 is suspended from the connecting block 810 via the suspension rods 811.

[0146] As a rotation-allowing mechanism for the floating joint 800, a sphere 820 is positioned between the connecting block 810 and the support base 710. A sphere 820 is placed in a recess 722 of the support base 710, and a connecting block 810 rests on top of this sphere 820. The rotation of the connecting block 810 is permitted when the connecting block 810 is placed on the sphere 820. Figure 25 is a perspective view showing the connecting block 810 in a state where it has been rotated relative to the support frame 300 (support base 710). Figure 26 is a cross-sectional view of the state in which the connecting block 810 is rotationally displaced relative to the support frame portion 300 (support base portion 710).

[0147] Furthermore, a raised base (a ring-shaped, convex edge) is provided on the bottom surface of the connecting block 810 to prevent it from coming off the sphere 820. While a pin could be used instead of the sphere if the only requirement was to allow rotation of the connecting block 810, a sphere 820 is preferred here because it does not hinder the translation of the connecting block 810.

[0148] The support ring portion 720 is provided with two guide shafts 723 that extend horizontally and intersect in a cross shape. The connecting block 810 is provided with guide holes 812 that are drilled in two directions, front-to-back and left-to-right, to receive the two guide shafts 723 that intersect in a cross shape. The guide holes 812 are formed as elongated holes to allow the connecting block 810 to be guided by the guide shafts 723 and move horizontally. Figure 27 is a top view (plan view) of the connecting block 810 in a state where it is translated horizontally. Furthermore, the guide hole 812 has a certain width in the height direction so that the rotation of the connecting block 810 is not obstructed by the guide shaft 723 when it rotates.

[0149] Four springs (coil springs) 724 are interposed between the connecting block 810 and the inner wall of the support ring portion 720 in order to center the connecting block 810 at its normal position (equilibrium position). Here, the springs (coil springs) 724 are wound around the guide shaft 723, and the springs (coil springs) 724 are positioned between the connecting block 810 and the inner wall of the support ring portion 720.

[0150] Here, a translation-allowing mechanism is configured, which allows the translation of the connecting block 810 by means of the guide shaft 723 and the guide hole 812.

[0151] Alternatively, the translational tolerance mechanism may be configured such that the guide shaft is provided in the connecting block 810 and the guide hole is provided in the support ring portion 720.

[0152] When the restraining means 500 holds the electric internal diameter measuring instrument 200, it may directly restrain the electric internal diameter measuring instrument 200 itself by clamping it with the clamping piece 510, as in the first embodiment. However, it may also indirectly hold the electric internal diameter measuring instrument 200 by restraining the connecting block 810, for example.

[0153] Even with the floating joint 800 of this fourth embodiment, the electric internal diameter measuring instrument 200 can be allowed to translate and rotate relative to the support frame 300. In other words, even if there is an axial misalignment (tilt and positional misalignment) between the electric internal diameter measuring instrument 200 and the hole to be measured, the allowance of rotation and translation of the floating joint 800 allows the electric internal diameter measuring instrument 200 to autonomously adjust its own position and orientation.

[0154] Compared to the floating joint section 400 of the first embodiment, the floating joint section 800 of the fourth embodiment has fewer components, as the connecting block 810 is a block that handles both rotation and translation. Even if the floating joint section 800 of the fourth embodiment is attached to the electric internal diameter measuring instrument 200, an overall increase in size can be suppressed. For example, since the floating joint section 800 of the fourth embodiment is small in size, even if the floating joint section 800 of the fourth embodiment is positioned further above the electric internal diameter measuring instrument 200, an increase in the overall size of the electric internal diameter measuring unit 120 is suppressed, and it does not have an extreme effect on fluctuations in the center of gravity. Therefore, by positioning the floating joint section 800 above the electric internal diameter measuring instrument 200 rather than to the side of the electric internal diameter measuring instrument 200, the automatic internal diameter measuring device 100 of the fourth embodiment becomes suitable for automatic internal diameter measurement of deep holes, such as measuring the internal diameter near the bottom of a deep hole.

[0155] (Fifth embodiment) A fifth embodiment will be described. The basic configuration of the fifth embodiment is the same as that of the first embodiment, but it is characterized by the structure of the floating joint section (floating joint mechanism section) 900. Figure 28 is a perspective view of the electric internal diameter measuring unit 120 in the fifth embodiment. Figure 29 is a top view (plan view) of the electric internal diameter measuring unit 120 in the fifth embodiment.

[0156] In the fifth embodiment, the electric internal diameter measuring instrument 200 is supported on the support frame portion 300 via the floating joint portion 900 in a position where its axis (cylindrical axis or rod 230 axis) is in the vertical direction. The structure of the floating joint 900 of the fifth embodiment will now be described.

[0157] The floating joint section 900 comprises a first floating connector 910, a second floating connector 920, and a third floating connector 930.

[0158] The first floating connector 910 is cup-shaped and is referred to as the first floating connector cup 910. The electric internal diameter measuring instrument 200 is received inside the cup shape, and the first floating connector cup 910 and the electric internal diameter measuring instrument 200 are fixedly connected. A measuring head portion 220, corresponding to the lower cylindrical case portion 214 and the head cylindrical portion 215 of the electric internal diameter measuring instrument 200, protrudes downward from the bottom surface of the first floating connector cup 910. The first floating connector cup 910 also has first connecting shafts 911 that protrude on both sides in the front-rear direction (Y-axis).

[0159] The second floating connector 920 is a ring-shaped member and is referred to as the second floating connector ring 920. The second floating connector ring 920 is provided so as to surround the first floating connector cup 910 in a direction perpendicular to the axis of the electric internal diameter measuring instrument 200. The second floating connector ring 920 first has a hole provided in the front-rear direction (Y-axis direction). This hole is a hole that supports the first connector shaft 911 of the first floating connector cup 910, and is therefore referred to as the first connector hole 921. The first connector hole 921 allows the first connector shaft 911 to rotate around its axis and to slide in the axial direction. That is, the electric internal diameter measuring instrument 200 and the first floating connector cup 910 can translate in the front-rear direction (Y-axis direction) and rotate around the Y-axis with respect to the second floating connector ring 920.

[0160] Furthermore, the second floating connecting ring 920 is provided with second connecting shafts 922 that protrude from both sides in the left-right direction (X-axis).

[0161] The third floating connection body 930 is a horizontally parallel plate member that supports the second floating connection ring 920 so as to allow the translation and rotation of the second floating connection block 810, and is referred to as the third floating connection plate 930. The third floating connection plate 930 has a U-shaped recessed (concave) curved portion 931 so as to receive the electric inside diameter measuring device 200 in the horizontal direction. At the tips of the arm portions constituting both sides of the curved portion 931, there are holes opened in the left-right direction (X-axis).

[0162] Since this hole is a hole for bearing the second connection shaft 922 of the second floating connection cup, it will be referred to as the second connection hole 932. The second connection hole 932 allows the second connection shaft 922 to rotate around its axis and slide in the axial direction. That is, the electric inside diameter measuring device 200, the first floating connection cup 910, and the second floating connection ring 920 can translate in the left-right direction (X-axis direction) with respect to the third floating connection plate 930 and can rotate around the X-axis.

[0163] The third floating connection plate 930 is connected to the support pedestal portion 710 of the support frame portion 300.

[0164] When considering a first virtual straight line obtained by virtually extending the first connection shaft 911 and a second virtual straight line obtained by virtually extending the second connection shaft 922, it is preferable that the intersection of the first virtual straight line and the second virtual straight line substantially coincides with the center of gravity of the electric inside diameter measuring device 200.

[0165] Such a floating joint portion 900 of the fourth embodiment can also allow the electric inside diameter measuring device 200 to translate and rotate with respect to the support frame portion 300. That is, even if there is an axial misalignment (inclination and positional deviation) between the electric inside diameter measuring device 200 and the hole to be measured, it is possible to allow the electric inside diameter measuring device 200 to autonomously adjust its own position and posture by allowing the rotation and translation of the floating joint portion 900. FIG. 30 is a diagram illustrating a state in which the first floating connection cup 910 rotates around the X-axis. FIG. 31 is a diagram illustrating a state in which the first floating coupling cup 910 is translated in a horizontal plane. For ease of viewing, in FIGS. 30 and 31, illustration of the electric inside diameter measuring device 200 is omitted.

[0166] With the structure of the floating joint portion 900 of the fifth embodiment, it is easy to align the positions of the rotation axis and the translation axis with the center of gravity of the electric inside diameter measuring device 200. Thereby, the posture of the electric inside diameter measuring device 200 is likely to be stabilized.

[0167] As described above, according to the present invention, the inside diameter measurement that has been conventionally manually operated is automated, and full automation of the inside diameter measurement becomes possible. It becomes possible to introduce automatic in-line measurement of the hole diameter in a processing factory or the like, and a significant improvement in production efficiency can be expected.

[0168] (Sixth Embodiment) The sixth embodiment will be described. FIG. 32 is a side view showing the overall appearance of the sixth embodiment. FIG. 33 is an enlarged cross-sectional view of the floating joint portion in the sixth embodiment. The basic configuration of the sixth embodiment is the same as that of the first embodiment. However, in the sixth embodiment, the floating joint portion 400 is disposed above the electric inside diameter measuring device 200. That is, the electric inside diameter measuring device 200 is supported as if it is suspended from the support frame portion 300 via the floating joint portion 400. Substantially the entire electric inside diameter measuring device 200 is below the support frame portion 300 and is supported by being suspended from the support frame portion 300. Otherwise, the configuration is substantially the same as that of the first embodiment. In the sixth embodiment (FIGS. 32 and 33), the same reference numerals are given to the elements corresponding to those in the first embodiment.

[0169] In Figures 32 and 33, a suspension rod 430 for suspending the electric internal diameter measuring instrument 200 extends upward from the electric internal diameter measuring instrument 200. The suspension rod 430 is on the central axis of the electric internal diameter measuring instrument 200, and the suspension rod 430 and the electric internal diameter measuring instrument 200 are fixedly connected. (Please interpret the suspension rod 430 as part of the electric internal diameter measuring instrument (electric internal diameter measuring unit) 200.) The suspension rod 430 passes through the first insertion hole 321 of the support base 320, and a first spring receiver 411 is connected near the upper end of the suspension rod 430. A floating joint 400 is formed between the first spring receiver 411 and the support base 320. Specifically, the floating joint 400 is configured as follows: a ball roller 423 is provided on the support base 320, and a horizontal plate (translational body) 421 is provided so as to be translated by the ball roller 423. A second spring support 413 is provided in the second insertion hole 422 of the horizontal plate (translational body) 421, and a coil spring 412 is placed between the first spring support 411 and the second spring support 413.

[0170] In this sixth embodiment with such configuration and arrangement, as in the first embodiment, the position and orientation of the electric internal diameter measuring instrument 200 can be autonomously adjusted by the action of the floating joint 400. In addition, according to the sixth embodiment, since the floating joint 400 is located above the electric internal diameter measuring instrument 200, it is suitable for automatic internal diameter measurement for deep holes, such as measuring the internal diameter near the bottom of a deep hole.

[0171] It should be noted that the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. In the above description of the embodiment, when driving the rod 230, in addition to screw feeding by rotation, the rod 230 may also be raised and lowered in a linear motion. In the above embodiment, a multi-joint robot arm was exemplified as the means of movement, but it does not have to be a large-scale device; for example, a one-dimensional drive device with a vertical lifting mechanism may also be used. For example, a one-dimensional drive device may have a column, a slider that slides along the column, a motor that drives the slider, and a power transmission mechanism (such as a ball screw or belt pulley) that connects the motor and the slider.

[0172] In the above embodiment, a so-called hole test (Borematic®) was given as an example of the structure of the tip of the internal diameter measuring section, but any internal diameter measuring instrument in which the measuring probe 250 moves back and forth in conjunction with the rod 230 and contacts the inner wall is acceptable. For example, the head of a cylinder gauge has one moving measuring probe 250, and for centering, it has an anvil facing the opposite direction on the same axis as the measuring probe 250, and guide heads on both sides in a perpendicular direction.

[0173] In the above embodiment, an internal diameter measuring instrument (internal diameter measuring unit) was described as an example of a measuring instrument (measuring unit), but instead of an internal diameter measuring instrument (internal diameter measuring unit), a measuring instrument (measuring unit) that measures the dimensions (internal dimensions, external dimensions) of the workpiece (object to be measured) by contact may be used. The above embodiment can be applied to any measuring instrument (measuring part) in which a movable element (which may be called by various names such as measuring probe, measuring jaw, or spindle) is provided in a displaceable manner relative to a fixed element, and the dimensions of a workpiece are measured by bringing the measuring probe into contact with the workpiece or by gripping the workpiece with the measuring probe. The position or orientation of the measuring instrument (measuring part) can be autonomously adjusted by a floating joint (floating joint mechanism) by utilizing the reaction force applied from the workpiece to the measuring probe when the measuring probe contacts the workpiece at a predetermined measuring pressure or when the measuring probe grips the workpiece at a predetermined measuring pressure. (Therefore, the direction in which the translation-allowing mechanism allows translation of the supported object (measuring instrument) can be considered to be approximately parallel to the direction in which the measuring probe contacts the workpiece (or approximately parallel to the direction of the reaction force applied from the workpiece to the measuring instrument).) Examples of measuring instruments (measuring parts) include calipers, micrometer heads, micrometers, digital dial gauges (indicators), and test indicators (lever-type dial gauges).

[0174] In the first, fourth, and fifth embodiments, different types of floating joints 400, 800, and 900 were described, respectively. These may be used individually or in combination. For example, the floating joint portion 400 of the first embodiment may be provided to the side of the electric internal diameter measuring instrument 200, and at the same time, the floating joint portion 800 of the fourth embodiment may be provided above the electric internal diameter measuring instrument 200. Similarly, for example, the floating joint portion 900 of the fifth embodiment may be provided to the side of the electric internal diameter measuring instrument 200, and at the same time, the floating joint portion 800 of the fourth embodiment may be provided above the electric internal diameter measuring instrument 200. Because internal diameter measuring instruments are long, if you try to support them with flexible fittings, they tend to wobble, tilt significantly, and slide back and forth and side to side, making them quite unstable. On the other hand, if the rigidity of the joint is increased, autonomous position and orientation adjustment cannot be achieved with only a weak measurement pressure, and it becomes necessary to introduce advanced feedback control or the like. However, this requires the introduction of an expensive system and also increases the time required for position and orientation adjustment. Therefore, by connecting and supporting with appropriate floating joints at two locations on the side and above the inner diameter measuring instrument, it can be expected that both flexibility and stability of the joint can be achieved while maintaining the flexibility of the joint.

[0175] In the above embodiment, it is assumed that the electric inner diameter measuring instrument is inserted into the hole from above while maintaining a substantially vertical posture. However, the electric inner diameter measuring instrument may be used in a horizontal posture in addition to the vertical posture, or in a vertical posture with the top and bottom reversed, approaching the measurement target (measurement target hole) from below the workpiece upward.

Explanation of Signs

[0176] 100 Automatic Inner Diameter Measuring Device 110 Measuring Device Main Body 120 Electric Inner Diameter Measuring Unit 200 Electric Inner Diameter Measuring Instrument 210 Cylindrical Case Part 211 Upper Cylindrical Case Part 212 Female Screw 213 Intermediate Cylindrical Case Part 214 Lower Cylindrical Case Part 215 Head Cylindrical Part 216 Leaf Spring 220 Measuring Head Part 230 Rod 231 Upper Rod 232 Feed Screw 233 Lower Rod 240 Cylinder Part 241 Cylinder Sleeve 242 Ratchet Sleeve 243 Coil Spring (Load Regulation Elastic Body) 250 Measuring Element 251 Tapered Surface​​​​​261 Rotor 262 stata 270 Outer case section 271 Outer case main body 272 Outer case upper part 233 Display Unit 234 Display section 280 Electric drive unit 300 Support frame section 310 Support column section 320 Support base 321 First insertion hole 400 Floating joint section (floating joint mechanism section) 410 Rotation-permissible mechanism 411 First spring support 412 Coil spring 413 Second spring support 414 ring holes 420 Translation tolerance mechanism 421 Horizontal Plate 422 Second insertion hole 423 Ball Roller 430 Hanging rod 500 Restraint Means 510 Clamping piece 600 Collision detection unit 601 Fixed plate 602 Mounting plate 610 Linear Guide 611 Groove frame 612 Slide body 620 Coil Spring 630 Contact Sensor 631 Contact detection block 632 Ball Plunger 132 Force sensor unit 130. Multi-joint robot arm section (robot arm section) 131 Hand Section 140 Control Unit Section 150 Measurement Operation Control Unit 151 Restraint Control Unit 152 Drive Control Unit 153 Measurement value acquisition unit 160 Robot Arm Drive Control Unit 170 Central Control Unit 710 Support base 720 Support ring 721 Beam 722 recesses 723 Guide Axis 724 Spring (coil spring) 800 Floating joint section (Floating joint mechanism section) 810 Connecting Block 811 Hanging rod 812 Guide hole 820 spheres 900 Floating joint section (Floating joint mechanism section) 910 First floating coupling cup (first floating coupling body) 911 First connection shaft 920 Second floating connecting ring (second floating connector) 921 First connection hole 922 Second connection shaft 930 Third floating connection plate (third floating connection body) 931 Bay area 932 Second connection hole

Claims

1. An internal diameter measuring unit having a measuring probe that moves back and forth in a direction perpendicular to the cylindrical axis of the cylindrical case, and measuring the inner diameter of a hole by bringing the measuring probe into contact with the inner wall of the hole while it is inserted inside the hole to be measured, A support frame portion that supports the inner diameter measuring portion, A floating joint is interposed between the support frame and the inner diameter measuring portion, allowing relative translation and rotation of the inner diameter measuring portion with respect to the support frame, The floating joint portion is, A rotation-allowing mechanism that allows the inner diameter measuring portion to rotate relative to the support frame portion, The inner diameter measuring section has a translational tolerance mechanism that allows for translational displacement relative to the support frame section, The rotation-allowing mechanism has a flexible body that allows deformation in a direction in which the inner diameter measuring section is tilted. The translation-permitting mechanism has a translation body that permits the inner diameter measuring section to translate in a direction intersecting the cylindrical axis of the cylindrical case section. One end of the flexible body is connected to the inner diameter measuring section. The other end of the flexible body is connected to the translation body, The translation body is supported so as to be translationally responsive with respect to the support frame portion. An internal diameter measuring unit characterized by the following features.

2. In the inner diameter measuring unit according to claim 1, The support frame portion has a support base portion, and the support base portion has a first insertion hole through which the inner diameter measuring portion is inserted. The translation body has a second insertion hole through which the inner diameter measuring portion is inserted, The inner diameter measuring section is supported in a state where it is inserted through the first insertion hole and the second insertion hole. The floating joint portion is, The bearings provided between the translational body and the support base are located around the first and second insertion holes, and allow the translational body to translate relative to the support base. An internal diameter measuring unit characterized by the following features.

3. In the inner diameter measuring unit according to claim 2, A ring-shaped receiver having a ring hole is fitted into the second insertion hole of the translational body, and the other end of the flexible body is connected to the translational body by this receiver. The diameter of the first insertion hole is larger than the diameter of the ring hole. The diameter of the first insertion hole is a diameter that allows the inner diameter measuring section to translate. The diameter of the ring hole is a size that allows for the inclination of the inner diameter measuring portion. An internal diameter measuring unit characterized by the following features.

4. In the inner diameter measuring unit according to claim 1 or claim 2, The flexible body is an elastic body disposed between the inner diameter measuring section and the translational body, so as to surround the inner diameter measuring section. An internal diameter measuring unit characterized by the following features.

5. In the inner diameter measuring unit according to claim 4, The elastic body is a spring arranged to surround the inner diameter measuring portion. An internal diameter measuring unit characterized by the following features.

6. In the inner diameter measuring unit according to claim 1, claim 3 to claim 5, The support frame portion has a support base portion, The translation body is positioned above the support base portion. The lower end of the flexible body is connected to the translation body as the other end. The upper end of the flexible body is connected to the inner diameter measuring section as one end. An internal diameter measuring unit characterized by the following features.

7. In the inner diameter measuring unit according to Claim 2, The translation body is positioned above the support base portion. The lower end of the flexible body is connected to the translation body as the other end. The upper end of the flexible body is connected to the inner diameter measuring section as one end. An internal diameter measuring unit characterized by the following features.

8. In the inner diameter measuring unit according to any one of claims 1 to 7, The position at which one end of the flexible body is connected to the inner diameter measuring section corresponds to the center of gravity of the inner diameter measuring section. An internal diameter measuring unit characterized by the following features.

9. In the inner diameter measuring unit according to any one of claims 1 to 8, The system includes an electric drive unit that moves the measuring probe forward and backward. An internal diameter measuring unit characterized by the following features.

10. In the inner diameter measuring unit according to any one of claims 1 to 9, The inner diameter measuring section is provided with a restraining means that clamps it from a direction intersecting the cylindrical shaft, The aforementioned restraining means is When the inner diameter measuring part is not inserted into the hole to be measured, the inner diameter measuring part is held in place by clamping it. When the inner diameter measuring part is inserted into the hole to be measured, the inner diameter measuring part is released. An internal diameter measuring unit characterized by the following features.

11. In the inner diameter measuring unit according to any one of claims 1 to 10, The inner diameter measuring section is supported by the support frame section via the floating joint section, with the cylindrical shaft in the vertical direction as the reference position. An internal diameter measuring unit characterized by the following features.

12. In the inner diameter measuring unit according to any one of claims 1 to 11, The support frame portion connects the inner diameter measuring portion to a moving means for moving the inner diameter measuring portion. An internal diameter measuring unit characterized by the following features.

13. A floating joint mechanism interposed between an object to be supported and a support frame that supports the object, which allows relative translation and rotation of the object with respect to the support frame, The floating joint mechanism is, A rotation-allowing mechanism that allows the object to be supported to rotate relative to the support frame, The system includes a translation-allowing mechanism that allows the object to be supported to undergo translational displacement relative to the support frame, The rotation-allowing mechanism has a flexible body that allows deformation in a direction in which the supported object is tilted. The translation-permitting mechanism has a translation body that permits the supported object to translate, One end of the flexible body is connected to the object to be supported, The other end of the flexible body is connected to the translation body, The translational body is supported so as to be translationally responsive with respect to the support frame portion. The support frame portion has a support base portion, and the support base portion has a first insertion hole through which the object to be supported is inserted. The translation body has a second insertion hole through which the object to be supported is inserted, The object to be supported is supported in a state where it is inserted through the first insertion hole and the second insertion hole. A floating joint mechanism characterized by the following.

14. A floating joint mechanism interposed between an object to be supported and a support frame that supports the object, which allows relative translation and rotation of the object with respect to the support frame, The floating joint mechanism is, A rotation-allowing mechanism that allows the object to be supported to rotate relative to the support frame, The system includes a translation-allowing mechanism that allows the object to be supported to undergo translational displacement relative to the support frame, The rotation-allowing mechanism has a flexible body that allows deformation in a direction in which the supported object is tilted. The translation-permitting mechanism has a translation body that permits the supported object to translate, One end of the flexible body is connected to the object to be supported, The other end of the flexible body is connected to the translation body, The translational body is supported so as to be translationally responsive with respect to the support frame portion. The flexible body is an elastic body disposed between the object to be supported and the translational body, so as to surround the object to be supported. A floating joint mechanism characterized by the following.

15. A measuring unit that measures the dimensions of an object by bringing a measuring probe into contact with the object to be measured, A support frame portion that supports the measuring portion, A floating joint is interposed between the support frame and the measuring section, allowing relative translation and rotation of the measuring section with respect to the support frame, The floating joint portion is, A rotation-allowing mechanism that allows the measuring section to rotate relative to the support frame section, The measuring section has a translational tolerance mechanism that allows translational displacement relative to the support frame section, The rotation-permissible mechanism has a flexible body that allows deformation in the direction in which the measuring section is tilted. The translation-permitting mechanism has a translation body that permits the measuring unit to translate, One end of the flexible body is connected to the measuring unit, The other end of the flexible body is connected to the translation body, The translation body is supported so as to be translationally responsive with respect to the support frame portion. A measuring unit characterized by the following features.

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