Inner diameter measuring device

Abstract

To provide an internal diameter measuring device capable of measuring an internal diameter precisely over the whole circumference in the same axial position.SOLUTION: An internal diameter measuring device includes a stopper part 10 and an internal diameter measurement part 40. The stopper part 10 comes into contact with an inner peripheral surface 101 of an object 100 to be measured and determines a position of the inner diameter measuring device in an axial direction of the inner peripheral surface 101. The inner diameter measurement part 40 measures an inner diameter of the object 100 to be measured. The inner diameter measurement part 40 is configured such that it cannot relatively travel in an axial direction of the inner peripheral surface 101 relative to the stopper part 10. The inner diameter measurement part 40 is configured so as to be capable of rotating in a circumferential direction of the inner peripheral surface 101 independent of the stopper part 10.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to an inner diameter measurement instrument. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2011-38814 (Patent Document 1) discloses a pipeline inner diameter measuring device. The pipeline inner diameter measuring device described in the above document includes a body and elastic force generating means. The body has a device main body that holds inner diameter measuring means capable of measuring the inner diameter of the pipeline and travels inside the pipeline. The device main body holds the inner diameter measuring means in a state where it is possible to measure the inner diameter. A plurality of elastic force generating means are fixed to the body so as to be positioned at equal intervals in the circumferential direction of the pipeline when introduced into the pipeline, and each of the elastic force generating means is pressed into contact with the inner wall of the pipeline and elastically deforms, supporting the body so that its center position approximately coincides with the center position of the pipeline. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-38814 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the device described in the above document, the device is held by an elastic body, and there is no means for completely suppressing the movement of the device. When attempting to rotate the device in the circumferential direction at the same axial position, the axial position may shift, making it difficult to measure the inner diameter at the same axial position accurately.

[0005] This disclosure proposes an inner diameter measurement device that is capable of measuring the inner diameter with high accuracy over the entire circumference at the same axial position. [Means for solving the problem]

[0006] According to the present disclosure, there is proposed an inner diameter measuring device for measuring the inner diameter of an object having a cylindrical inner peripheral surface. The inner diameter measuring device includes a stopper portion and an inner diameter measuring portion. The stopper portion contacts the inner peripheral surface of the object to be measured and determines the position of the inner diameter measuring device in the axial direction of the inner peripheral surface. The inner diameter measuring portion measures the inner diameter of the object to be measured. The inner diameter measuring portion is configured to be immovable relative to the stopper portion in the axial direction of the inner peripheral surface. Furthermore, the inner diameter measuring portion is configured to be rotatable in the circumferential direction of the inner peripheral surface independently of the stopper portion. Effect of the Invention

[0007] According to the inner diameter measurement device according to the present disclosure, the inner diameter can be measured with high accuracy over the entire circumference at the same axial position. [Brief description of the drawings]

[0008] [Figure 1] FIG. [Diagram 2] FIG. 2 is a perspective view of the inner diameter measurement device from a different angle. [Diagram 3] FIG. [Figure 4] 1 is a cross-sectional view of an inner diameter measurement instrument placed inside an object to be measured. [Diagram 5] 4 is a cross-sectional view of a stopper operating handle and a measuring unit operating handle. FIG. [Figure 6] 11 is a cross-sectional view showing the arrangement of a stopper body before the tapered shaft moves. FIG. [Figure 7] 11 is a cross-sectional view showing the arrangement of the stopper body after the tapered shaft is moved. FIG. [Figure 8] 4 is a cross-sectional view of an inner diameter measurement device showing the configuration of a guide portion. FIG. [Figure 9] FIG. 4 is a cross-sectional view of an electric motor and a measuring unit operating handle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the drawings. In the specification and drawings, the same or corresponding components are denoted by the same reference numerals, and redundant explanations will not be repeated. In addition, in the drawings, configurations may be omitted or simplified for the convenience of explanation.

[0010] Fig. 1 is a perspective view of an inner diameter measurement instrument 1 according to an embodiment. Fig. 2 is a perspective view of the inner diameter measurement instrument 1 shown in Fig. 1 from a different angle. Fig. 3 is a side view of the inner diameter measurement instrument 1 shown in Fig. 1. Fig. 4 is a cross-sectional view of the inner diameter measurement instrument 1 placed inside an object 100 to be measured.

[0011] The inner diameter measurement device 1 is a device for measuring the inner diameter of a measurement object 100 shown in Fig. 4. The measurement object 100 has an inner peripheral surface 101. The inner peripheral surface 101 is cylindrical. The measurement object 100 has, for example, a hollow cylindrical shape. The measurement object 100 is, for example, a pipe.

[0012] The inner diameter measurement device 1 can be placed inside the object 100 to be measured. The axial, circumferential and radial directions of the cylindrical inner peripheral surface 101 of the object 100 to be measured, in which the inner diameter measurement device 1 is placed, are used as directions for explaining the positional relationship and operation of each component of the inner diameter measurement device 1 in the embodiment. In Figures 3 and 4, the left-right direction in the figures is the axial direction. The radial direction is the direction perpendicular to the axial direction. The up-down direction in Figures 3 and 4 is the radial direction.

[0013] As shown in FIGS. 1 to 4, the inner diameter measurement instrument 1 mainly includes a stopper portion 10 and an inner diameter measurement portion 40.

[0014] The stopper portion 10 has a holding member 11 and three stopper bodies 14A, 14B, and 14C. The holding member 11 has three radial accommodating holes 11B extending in the radial direction, as shown in FIG. 4. The three radial accommodating holes 11B are arranged at equal intervals in the circumferential direction. The three stopper bodies 14A, 14B, and 14C are respectively accommodated in the radial accommodating holes 11B and held by the holding member 11.

[0015] The holding member 11 has a generally circular shape when viewed from the front (the left side in Figs. 3 and 4) of the inner diameter measurement instrument 1. The holding member 11 has three elongated holes 13A, 13B, and 13C that are equally spaced apart in the circumferential direction and extend in the radial direction.

[0016] A retaining bolt 12A is inserted into the elongated hole 13A. The retaining bolt 12A is fitted into the stopper body 14A by a screw action. The retaining bolt 12A and the stopper body 14A can move together in the radial direction relative to the retaining member 11. The retaining bolt 12A is disposed in the elongated hole 13A extending in the radial direction, and the stopper body 14A can move back and forth in the direction in which the elongated hole 13A extends.

[0017] Similarly, retaining bolts 12B and 12C are inserted into the long holes 13B and 13C, respectively. The retaining bolts 12B and 12C are fitted into stopper bodies 14B and 14C, respectively. The retaining bolt 12B and the stopper body 14B are integrally movable in the radial direction relative to the retaining member 11. The retaining bolt 12C and the stopper body 14C are integrally movable in the radial direction relative to the retaining member 11.

[0018] The stopper body 14A has a pressing surface 15A on the radially outermost circumference. The stopper body 14B has a pressing surface 15B on the radially outermost circumference. The stopper body 14C has a pressing surface 15C on the radially outermost circumference. As shown in Fig. 4, the stopper body 14A has a tapered surface 16A on the radially innermost circumference. The stopper bodies 14B and 14C also have tapered surfaces on the radially innermost circumference.

[0019] A stopper operating rod 20 for operating the stopper portion 10 is installed at the radial center position of the inner diameter measurement instrument 1. The stopper operating rod 20 extends in the axial direction. A bottomed fitting hole 21 is formed in a first end of the stopper operating rod 20. The inner peripheral surface of the fitting hole 21 is formed as a female thread surface 22.

[0020] The stopper portion 10 further has a tapered shaft 24. The tapered shaft 24 is installed at the radial center of the inner diameter measuring device 1. The tapered shaft 24 has a tapered portion 25 and a shaft portion 27. An axial accommodation hole 11A is formed in the radial center of the holding member 11, and the tapered portion 25 is accommodated in this axial accommodation hole 11A. The tapered portion 25 has a tapered surface 26 on its outer circumferential surface. The tapered surface 16A of the stopper body 14A contacts the tapered surface 26 of the tapered shaft 24. At least a part of the shaft portion 27 is disposed inside the fitting hole 21. The outer circumferential surface of the shaft portion 27 is formed as a male thread surface 28. The male thread surface 28 of the shaft portion 27 meshes with the female thread surface 22 of the fitting hole 21.

[0021] A second end of the stopper operating rod 20 is disposed outside the object to be measured 100. Fig. 5 is a cross-sectional view of the stopper operating handle 23 and the measurement unit operating handle 73. As shown in Fig. 5, the stopper operating handle 23 is attached to the second end of the stopper operating rod 20. The stopper operating handle 23 is disposed outside the object to be measured 100.

[0022] The inner rings of bearings 32 and 33 are fixed to the outer circumferential surface of stopper operating rod 20. The outer rings of bearings 31, 32 and 33 are fixed to an inner diameter measuring part 40. The inner ring of bearing 31 is fixed to stopper part 10. Stopper part 10 and inner diameter measuring part 40 are connected via bearing 31. As a result, inner diameter measuring part 40 is configured to be rotatable in the circumferential direction independently of stopper part 10.

[0023] The inner diameter measuring part 40 is configured so as to be immovable relative to the stopper part 10 in the axial direction. The inner diameter measuring part 40 has laser displacement meters 41A, 41B and right-angle mirrors 42A, 42B. The laser displacement meter 41A and the right-angle mirror 42A are arranged facing each other with a gap in the axial direction. The laser displacement meter 41B and the right-angle mirror 42B are arranged facing each other with a gap in the axial direction. The laser displacement meters 41A, 41B and the right-angle mirrors 42A, 42B constitute a non-contact distance measuring device.

[0024] The laser displacement meter 41A emits a laser beam in the axial direction toward the right-angle mirror 42A. The right-angle mirror 42A reflects the laser beam at a right angle and directs the laser beam radially outward, causing the laser beam to reach the inner circumferential surface 101 of the object to be measured 100. The reflected laser beam that is reflected back from the inner circumferential surface 101 is reflected again at a right angle by the right-angle mirror 42A and detected by the laser displacement meter 41A. The distance that the laser beam has reached is detected, and the inner diameter of the object to be measured 100 is measured from the data of the detected laser beam reaching distance. The inner diameter of the object to be measured 100 is similarly measured by the laser displacement meter 41B and the right-angle mirror 42B.

[0025] The pair of right-angle mirrors 42A, 42B are held by a mirror holding portion 43. The mirror holding portion 43 has a substantially flat plate shape, and the right-angle mirror 42A is fixed to one surface of the mirror holding portion 43, and the right-angle mirror 42B is fixed to the other surface of the mirror holding portion 43.

[0026] The laser displacement meter 41A is held by a displacement meter holder 45A. The displacement meter holder 45A is fixed to one surface of the mirror holder 43 to which the right-angle mirror 42A is fixed. The laser displacement meter 41B is held by a displacement meter holder 45B. The displacement meter holder 45B is fixed to the other surface of the mirror holder 43 to which the right-angle mirror 42B is fixed. The laser displacement meters 41A, 41B and the right-angle mirrors 42A, 42B form an integrated structure via the mirror holder 43 and the displacement meter holders 45A, 45B.

[0027] A laser transmission path 44A is connected to the laser displacement meter 41A. The laser light emitted from the laser displacement meter 41A is transmitted from a laser light source (not shown) to the laser displacement meter 41A via the laser transmission path 44A. A laser transmission path 44B is connected to the laser displacement meter 41B. The laser light emitted from the laser displacement meter 41B is transmitted from a laser light source (not shown) to the laser displacement meter 41B via the laser transmission path 44B.

[0028] 4 and 5, the measurement unit operating rod 70 is disposed radially outward of the stopper operating rod 20. The measurement unit operating rod 70 is formed hollow, and the stopper operating rod 20 is housed in the hollow space inside the measurement unit operating rod 70. The stopper operating rod 20 and the measurement unit operating rod 70 are disposed in a non-contact state with each other. The measurement unit operating rod 70 extends in the axial direction.

[0029] A plate member 62 is fixed near a first end of the measurement unit operating rod 70. The plate member 62 has a roughly flat plate-like shape extending perpendicular to the axial direction. A plurality of pillar members 63 extending in the axial direction are fixed to the plate member 62. The pillar member 63 has one end fixed to the plate member 62 and the other end fixed to the plate member 61. The plate member 61 is disposed parallel to the plate member 62. The plate member 61 is fixed to the mirror holding unit 43, further forward of the inner diameter measurement device 1 than the plate member 62 and separated from the plate member 62 in the axial direction. The plate members 61 and 62 are connected together by the plurality of pillar members 63.

[0030] The encoder 46 is disposed between the plate member 61 and the plate member 62. The encoder 46 detects the rotation angle of the inner diameter measurement unit 40 in the circumferential direction relative to the inner circumferential surface 101 of the object 100 to be measured.

[0031] A second end of the measurement unit operating rod 70 is disposed outside the object to be measured 100. As shown in Fig. 5, a measurement unit operating handle 73 is attached to the second end of the measurement unit operating rod 70. The measurement unit operating handle 73 is disposed outside the object to be measured 100.

[0032] FIG. 6 is a cross-sectional view showing the arrangement of the stopper body 14A before the tapered shaft 24 moves. The tapered portion 25 of the tapered shaft 24 has a shape that tapers toward the front. In the tapered shaft 24 shown in FIG. 6, the entire shaft portion 27 is disposed inside the fitting hole 21, and the small diameter portion at the tip of the tapered portion 25 is in contact with the tapered surface 16A of the stopper body 14A. At this time, the pressing surface 15A of the stopper body 14A is separated from the inner peripheral surface 101 of the object 100 to be measured. The pressing surface 15A is not in contact with the inner peripheral surface 101, and the inner diameter measuring instrument 1 can freely move in the axial direction relative to the object 100 to be measured.

[0033] In this state, an operator who intends to use the inner diameter measurement device 1 to measure the inner diameter of the object 100 can axially move the measurement unit operation handle 73 to axially move the entire inner diameter measurement device 1. Since the relative axial positions of the stopper portion 10 and the inner diameter measurement portion 40 are fixed, by operating the measurement unit operation handle 73 in the axial direction, both the stopper portion 10 and the inner diameter measurement portion 40 can be moved axially as a unit.

[0034] Fig. 7 is a cross-sectional view showing the arrangement of the stopper main body 14A after the tapered shaft 24 has moved. When the operator rotates the stopper operating handle 23 (Fig. 5), the stopper operating rod 20 rotates integrally with the stopper operating handle 23. Since the female thread surface 22 formed on the stopper operating rod 20 and the male thread surface 28 of the tapered shaft 24 are engaged with each other, when the stopper operating rod 20 rotates, the tapered shaft 24 moves in the axial direction.

[0035] The female thread surface 22 of the stopper operating rod 20 and the male thread surface 28 of the tapered shaft 24 form a power conversion mechanism that converts the rotation of the stopper operating handle 23 into axial movement of the tapered shaft 24.

[0036] As the tapered shaft 24 moves forward (to the left in FIG. 7), the tapered surface 16A of the stopper body 14A comes into contact with the larger diameter portion of the tapered section 25. The stopper body 14A is pushed radially by the tapered shaft 24 and moves radially outward. Similarly, the other two stopper bodies 14B, 14C also move radially outward as the tapered surfaces 26 of the tapered shaft 24 move in the axial direction.

[0037] As each of the stopper bodies 14A-14C moves radially outward relative to the holding member 11, each of the pressing surfaces 15A-15C comes into contact with the inner circumferential surface 101 of the object to be measured 100. As each of the pressing surfaces 15A-15C is pressed against the inner circumferential surface 101, a frictional force is generated between the pressing surfaces 15A-15C and the inner circumferential surface 101. This frictional force fixes the stopper part 10 to the object to be measured 100. Since the inner diameter measurement part 40 is structured so that it can rotate independently in the circumferential direction with respect to the stopper part 10 but cannot move relatively in the axial direction, positioning of the inner diameter measurement device 1 in the axial direction is achieved.

[0038] The three stopper bodies 14A to 14C are arranged at equal intervals in the circumferential direction, and the three stopper bodies 14A to 14C slide radially outward by a single tapered shaft 24 and are evenly pressed against the inner circumferential surface 101, so that the center of the inner diameter measuring instrument 1 and the center of the object to be measured 100 can be accurately aligned.

[0039] With the stopper portion 10 in contact with the inner peripheral surface 101 and the position of the inner diameter measuring instrument 1 in the axial direction determined, the operator rotates the measuring portion operating handle 73 (FIG. 5), causing the inner diameter measuring portion 40 to rotate in the circumferential direction independently of the stopper portion 10. Laser light emitted from the laser displacement meters 41A, 41B scans the inner peripheral surface 101 over the entire circumferential direction. This allows the inner diameter to be measured over the entire circumference with high accuracy at the same axial position.

[0040] After the inner diameter of the object 100 to be measured at one axial position has been measured, the operator rotates the stopper operating handle 23 in the reverse direction. The tapered shaft 24 moves axially backward, the stopper bodies 14A-14C move radially inward, and the pressing surfaces 15A-15C move away from the inner circumferential surface 101. This releases the fixation of the axial position of the inner diameter measuring device 1 by the stopper part 10. In this state, the operator can move the measuring part operating handle 73 axially to move the entire inner diameter measuring device 1 axially, thereby measuring the inner diameter at another axial position, or remove the inner diameter measuring device 1 from the object 100 to the outside.

[0041] 1 to 4 again, the inner diameter measuring part 40 further has a guide part 50. Distance measuring devices, i.e., laser displacement meters 41A and 41B and right-angle mirrors 42A and 42B, are disposed between the guide part 50 and the stopper part 10 in the axial direction.

[0042] Fig. 8 is a cross-sectional view of the inner diameter measurement instrument 1 showing the configuration of the guide part 50. As shown in Fig. 8, the guide part 50 has three pressing members 51A, 51B, and 51C and a holding part 53. The pressing member 51A has a sliding surface 52A on the outermost circumference in the radial direction. The pressing member 51B has a sliding surface 52B on the outermost circumference in the radial direction. The pressing member 51C has a sliding surface 52C on the outermost circumference in the radial direction.

[0043] The holding portion 53 is formed with three radially extending accommodation holes 54A, 54B, 54C. The accommodation holes 54A, 54B, 54C are arranged at equal intervals in the circumferential direction. The root portions of the pressing members 51A, 51B, 51C are arranged in the accommodation holes 54A, 54B, 54C, respectively. A biasing member 55A is also accommodated in the accommodation hole 54A. A biasing member 55B is also accommodated in the accommodation hole 54B. A biasing member 55C is also accommodated in the accommodation hole 54C. The biasing members 55A to 55C are, for example, coil springs.

[0044] The biasing member 55A biases the pressing member 51A radially outward. The pressing member 51A is biased toward the inner circumferential surface 101 by the biasing force of the biasing member 55A, so that the sliding surface 52A comes into contact with the inner circumferential surface 101. The sliding surfaces 52B and 52C of the pressing members 51B and 51C are also biased by the biasing members 55B and 55C, respectively, so that they come into contact with the inner circumferential surface 101.

[0045] The stopper portion 10 in front of the distance measuring device suppresses the displacement of the distance measuring device in the radial direction, and the guide portion 50 in the rear of the distance measuring device suppresses the displacement of the distance measuring device in the radial direction. This allows the distance measuring device to be positioned more accurately, making it possible to measure the inner diameter of the object 100 to be measured more accurately.

[0046] By appropriately setting the biasing force of the biasing members 55A-55C so as not to impede the sliding of the sliding surfaces 52A-52C against the inner circumferential surface 101, but so as to evenly press each of the pressing members 51A-51C against the inner circumferential surface 101, it is possible to achieve both support by the guide portion 50 and free movement of the inner diameter measurement portion 40 in the axial and circumferential directions.

[0047] Fig. 9 is a cross-sectional view of the electric motor 83 and the measurement unit operating handle 73. In the above explanation with reference to Fig. 5, the stopper operating handle 23 is attached to the second end of the stopper operating rod 20, and the operator manually rotates the stopper operating handle 23 to fix and release the inner diameter measurement instrument 1 by the stopper unit 10. Instead of the stopper operating handle 23, as shown in Fig. 9, an electric motor 83 may be attached to the second end of the stopper operating rod 20.

[0048] By rotating the stopper operating rod 20 with the driving force of the electric motor 83, the tapered shaft 24 can be moved in the axial direction, and the stopper bodies 14A to 14C of the stopper portion 10 can be moved in the radial direction, as described above. This makes it possible to fix and release the inner diameter measurement instrument 1 by the stopper portion 10 with a simpler operation, such as operating a switch to drive the electric motor 83.

[0049] Although some of the description overlaps with the above description, the characteristic configurations and effects of the embodiments of the present disclosure can be summarized as follows.

[0050] As shown in Figures 1 to 4, the inner diameter measurement device 1 includes a stopper portion 10 and an inner diameter measurement portion 40. The stopper portion 10 contacts an inner peripheral surface 101 of the object 100 to determine the position of the inner diameter measurement device 1 in the axial direction. The inner diameter measurement portion 40 measures the inner diameter of the object 100 to be measured. The inner diameter measurement portion 40 is configured so as to be immovable relative to the stopper portion 10 in the axial direction. Moreover, the inner diameter measurement portion 40 is configured so as to be rotatable in the circumferential direction independently of the stopper portion 10.

[0051] A structure is realized in which the stopper portion 10 can firmly suppress the axial movement of the entire inner diameter measuring instrument 1, and the inner diameter measuring portion 40 can easily rotate in the circumferential direction independently of the stopper portion 10. This allows the inner diameter measuring instrument 1 to continuously measure the inner diameter of the object to be measured 100 over the entire circumference at exactly the same axial position.

[0052] 3 and 4, the inner diameter measuring unit 40 may have a non-contact distance measuring device. By measuring the inner diameter using a non-contact distance measuring device, it is possible to easily follow the change in the inner diameter of the object 100 to be measured, and to measure the inner diameter of the object 100 to a high degree of accuracy.

[0053] 3 and 4, the inner diameter measuring unit 40 may have laser displacement meters 41A, 41B that emit laser light, and right-angle mirrors 42A, 42B that reflect the laser light at a right angle to reach the inner peripheral surface 101. The laser displacement meters 41A, 41B and the right-angle mirrors 42A, 42B constitute a non-contact distance measuring device, which can measure the inner diameter of the object 100 to be measured with high accuracy.

[0054] The distance measuring device is not limited to a device that measures distance using a laser beam, and may be a non-contact distance measuring device of another specification, such as an ultrasonic type. Also, the distance measuring device is not limited to a non-contact type, and may be a contact type.

[0055] As shown in Figs. 1 to 4, the inner diameter measuring section 40 may have a guide section 50. The guide section 50 may be arranged in the axial direction with the distance measuring device sandwiched between it and the stopper section 10. The stopper section 10, the distance measuring device, and the guide section 50 are arranged in this order in the axial direction so that the distance measuring device is sandwiched between the stopper section 10 and the guide section 50. This makes it possible to suppress deviation of the distance measuring device in the radial direction, thereby improving the measurement accuracy of the inner diameter of the object 100 to be measured.

[0056] 8, the guide portion 50 may have pressing members 51A-51C and biasing members 55A-55C. The biasing members 55A-55C bias the pressing members 51A-51C toward the inner circumferential surface 101, respectively. This causes the pressing members 51A-51C to come into contact with the inner circumferential surface 101. In this manner, the guide portion 50 can reliably suppress displacement of the distance measuring device in the radial direction.

[0057] 1 to 4, the inner diameter measurement instrument 1 may further include an encoder 46. The encoder 46 is configured to accurately detect the circumferential rotation angle of the inner diameter measurement part 40 relative to the inner peripheral surface 101, so that the inner diameter measurement instrument 1 can continuously measure the inner diameter of the object 100 to be measured over the entire circumference.

[0058] 5, the inner diameter measurement device 1 may further include a measurement unit operation handle 73. The measurement unit operation handle 73 is disposed outside the object 100 to be measured. By rotating the measurement unit operation handle 73, the inner diameter measurement unit 40 rotates in the circumferential direction. By rotating the inner diameter measurement unit 40 in this manner, the inner diameter measurement device 1 can continuously measure the inner diameter of the object 100 to be measured over the entire circumference.

[0059] The rotary drive unit that rotates the inner diameter measurement unit 40 is not limited to the measurement unit operation handle 73, and an electric motor may be attached to the second end of the measurement unit operation rod 70.

[0060] 6 and 7, the stopper portion 10 has a tapered shaft 24 having a tapered surface 26 and a stopper body 14A in contact with the tapered surface 26, and the stopper body 14A may move in the radial direction in association with the axial movement of the tapered surface 26. The stopper body 14A is moved radially outward to bring the pressing surface 15A of the stopper body 14A into contact with the inner peripheral surface 101, thereby realizing positioning of the inner diameter measuring device 1 in the axial direction by the stopper portion 10. The stopper body 14A is moved radially inward to separate the pressing surface 15A from the inner peripheral surface 101, thereby releasing the fixing of the inner diameter measuring device 1 by the stopper portion 10 and making it possible to move the inner diameter measuring device 1 in the axial direction.

[0061] As shown in FIG. 5, the inner diameter measuring instrument 1 may further include a stopper operating handle 23. The stopper operating handle 23 is disposed outside the object 100 to be measured. As shown in FIGS. 4, 6 to 7, the stopper operating handle 23 is rotated to move the tapered shaft 24 in the axial direction. By operating the stopper operating handle 23 from outside the object 100 to be measured, the tapered shaft 24 is moved in the axial direction, and the diameter of the tapered shaft 24 at the portion in contact with the stopper main body 14A is changed. This allows the stopper main body 14A to slide in the radial direction, thereby fixing the axial position of the inner diameter measuring instrument 1 or releasing the fixation.

[0062] As shown in Figs. 6 and 7, the stopper operating rod 20 has a female thread surface 22. The tapered shaft 24 has a male thread surface 28. The female thread surface 22 and the male thread surface 28, which mesh with each other, constitute a power conversion mechanism. The stopper operating handle 23 can be rotated to rotate the stopper operating rod 20 together with the stopper operating handle 23, and at this time, the female thread surface 22 rotates without changing its axial position. The male thread surface 28, which meshes with the female thread surface 22, moves in the axial direction. The tapered shaft 24, which has the male thread surface 28, moves in the axial direction. In this way, by using a power conversion mechanism that converts the rotation of the stopper operating handle 23 into the axial movement of the tapered shaft 24, the inner diameter measuring instrument 1 can be easily fixed and released in the axial direction by the stopper part 10.

[0063] By appropriately selecting the axial length of the stopper operating rod 20 to match the object to be measured 100, it becomes easy to fix and release the inner diameter measuring device 1 in the axial direction by rotating the stopper operating handle 23, even when the axial length of the object to be measured 100 is large.

[0064] Although the embodiment has been described above, the disclosed embodiment is illustrative in all respects and should not be considered as being limiting. The scope of the present invention is indicated by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0065] 1 inner diameter measuring device, 10 stopper portion, 11 holding member, 11A axial accommodation hole, 11B radial accommodation hole, 12A, 12B, 12C holding bolt, 13A, 13B, 13C long hole, 14A, 14B, 14C stopper body, 15A, 15B, 15C pressing surface, 16A, 26 tapered surface, 20 stopper operating rod, 21 fitting hole, 22 female thread surface, 23 stopper operating handle, 24 tapered shaft, 25 tapered portion, 27 shaft portion, 28 male thread surface, 31, 32, 33 bearing, 40 inner diameter measuring portion, 41A, 41B laser displacement meter, 42A, 42B right angle mirror, 43 mirror holding portion, 44A, 44B laser transmission path, 45A, 45B displacement meter holding portion, 46 Encoder, 50 guide portion, 51A, 51B, 51C pressing members, 52A, 52B, 52C sliding surfaces, 53 holding portion, 54A, 54B, 54C accommodation holes, 55A, 55B, 55C biasing members, 61, 62 plate members, 63 column members, 70 measuring unit operating rod, 73 measuring unit operating handle, 83 electric motor, 100 object to be measured, 101 inner surface.

Claims

1. An inner diameter measuring device for measuring the inner diameter of an object having a cylindrical inner peripheral surface, a stopper portion that contacts the inner circumferential surface to determine a position of the inner diameter measurement instrument in an axial direction of the inner circumferential surface; an inner diameter measuring part configured to be immovable relative to the stopper part in the axial direction and rotatable in the circumferential direction of the inner peripheral surface independently of the stopper part, and to measure the inner diameter; The stopper portion includes a tapered shaft having a tapered surface and a stopper body that contacts the tapered surface, the stopper body moves in a radial direction of the inner circumferential surface in association with the movement of the tapered surface in the axial direction, A stopper operating handle is further provided outside the object to be measured, An inner diameter measuring instrument in which the tapered shaft moves in the axial direction by rotating the stopper operating handle.

2. The inner diameter measuring instrument according to claim 1 , wherein the inner diameter measuring section has a non-contact distance measuring device.

3. 3. The inner diameter measuring device according to claim 2, wherein the distance measuring device comprises a laser displacement meter that emits a laser beam, and a right-angle mirror that reflects the laser beam at a right angle to reach the inner peripheral surface.

4. the inner diameter measuring unit has a guide unit that suppresses positional deviation of the distance measuring device in a radial direction of the inner circumferential surface, 4. The inner diameter measurement instrument according to claim 2, wherein the guide portion is disposed in the axial direction with the distance measuring device sandwiched between the guide portion and the stopper portion.

5. 5. The inner diameter measurement instrument according to claim 4, wherein the guide portion has a pressing member that contacts the inner circumferential surface, and a biasing member that biases the pressing member toward the inner circumferential surface.

6. 6. The inner diameter measurement instrument according to claim 1, further comprising an encoder that detects a rotation angle of the inner diameter measurement part relative to the inner peripheral surface in the circumferential direction.

7. A measuring unit operation handle is further provided outside the object to be measured, 7. The inner diameter measurement instrument according to claim 1, wherein the inner diameter measurement part is rotationally moved in the circumferential direction by rotating the measurement part operating handle.

8. 8. The inner diameter measurement instrument according to claim 1, further comprising a power conversion mechanism that converts rotation of the stopper operating handle into movement of the tapered shaft in the axial direction.

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