WO2018003097A1 - Optical inner-surface measurement device - Google Patents

Abstract

[Problem] To enable stable measurement unaffected by surface shape or roughness, prevent the effects of heat generated by a motor housed in a measurement probe, eliminate the effects of vibration or deviation of bearings of the motor, and correctly perform accurate measurements of high-precision inside diameters and inner peripheral surfaces in an optical inner-surface measurement device. [Solution] The present invention has an optical fiber housed in a tube, and at least one optical path conversion means provided to the distal-end part of the optical fiber, and also has a motor for rotatably driving the optical path conversion means, the motor being provided inside the tube. A gas drawn in from a location further toward the distal-end side than the motor passes through the interior of the tube and is exhausted from a location further to the front side from the motor. The present invention is configured such that a hard translucent pipe is attached to the distal-end part of the tube, the translucent pipe is inserted into the inside diameter of a to-be-measured object, a light beam guided through the optical fiber is emitted from the optical path conversion means and radiated on the inner peripheral surface of the to-be-measured object through the translucent pipe, and light reflected from the inner peripheral surface is detected through the translucent pipe.

Description

Optical inner surface measuring device

The present invention allows an optical measurement probe to enter the inner peripheral surface or deep hole inner diameter of an object to be measured, emits a light beam to the inner surface or deep hole bottom surface, captures reflected light three-dimensionally, and observes the internal shape. The present invention relates to an optical inner surface measuring apparatus for measuring dimensions and geometric accuracy.

For example, the quality of finished processing and geometric accuracy of fuel injection nozzle parts for automobile engines greatly affects the power performance and fuel consumption efficiency of automobiles, but these inspections are generally performed by roundness measuring instruments, surface roughness meters, etc. Inspected using a contact-type measuring machine such as a length measuring machine using a linear scale. However, in recent years, optical non-contact measuring machines have been introduced for the purpose of not scratching the object to be measured.

As a means for observing or inspecting the inner surface of an object to be measured in a non-contact manner, an image diagnostic technique (optical imaging technique) is a technique that is widely used in equipment machines, medical sites, and the like. For example, in the manufacturing site of precision equipment, as a method of inspection of deep part of deep hole and image diagnosis, in addition to camera observation with a general endoscope, light sensor is used to irradiate the inner surface and detect the intensity of reflected light And a method of automatically inspecting for the presence or absence of surface scratches as judged by a computer is employed.

On the other hand, in the medical field, an X-ray CT capable of observing a tomographic image for observing an affected part inside a human body, nuclear magnetic resonance, an OCT image by an endoscope using light coherence (light interference using near-infrared light). Methods such as tomography are being studied and utilized. Then, using these optical techniques in the field of mechanical devices, observation or dimensional measurement of scratches on the inner peripheral surface by irradiating light on the inner peripheral surface of a machine part having a hole or a precision inner diameter has been studied. Typical structures of these observation and measurement devices are as shown in Patent Documents 1 to 3, for example.

In the hole shape measuring method and measuring apparatus shown in Patent Document 1, a light beam that has passed through a slit is irradiated obliquely into the small-diameter hole (1) of the object to be measured (2) in the document, and the small-diameter hole (1) The light reflected from the inner peripheral surface was captured by a camera, and the shape accuracy of the small-diameter hole was read.
However, with this configuration, measurement is possible if the surface of the object to be measured is a smooth surface such as a ring gauge. When making measurements, the camera is unable to capture the correct shape because the rays diverge and it becomes difficult to obtain reflected light due to the influence of the uneven shape on the inner surface of the small-diameter hole (1). It was impossible. Further, even when the object to be measured (2) was longer than expected, the reflected light could not be captured and measurement could not be performed.

Further, in the method of measuring the inner surface of the pore using the optical imaging probe shown in Patent Document 2, the probe is inserted into the inner peripheral surface of the hole to be measured, and the light beam from the condenser lens (3) is converted into an optical path changing means. The mirror 18 is rotated 360 degrees, and the angle of the mirror is changed due to the change in centrifugal force, and the radiation angle of the light beam is changed, whereby the light beam is emitted in a three-dimensional direction to measure the three-dimensional shape.
However, since the probe is inserted inside the object to be measured, the heat generated by the motor that rotates in the probe propagates to the object to be measured. It could not be measured.

In the measuring machine shown in Patent Document 3, the temperature difference between the ring gauge that is the measurement standard of the inner diameter and the object to be measured (2) is measured with a thermometer (6), and the amount of thermal expansion due to this temperature difference is calculated. The measurement dimension is corrected.
However, since the expansion of the object to be measured is not constant and changes in a complicated manner depending on the material and shape, correct correction is difficult to perform. For example, correct correction calculation of 0.01 micrometer level and high-accuracy measurement have not been achieved.

Japanese Unexamined Patent Publication No. 08-233545 Japanese Unexamined Patent Publication No. 2015-008995 Japanese Unexamined Patent Publication No. 05-31557

The present invention has been made in view of the above-described conventional circumstances, and the problem is that the measurement probe is inserted into the inner peripheral surface or deep hole inner diameter of the object to be measured, or the hole of a long and bent pipe. Rotating and radiating light rays to the inner peripheral surface or deep hole bottom, collecting reflected light three-dimensionally, computer processing, observing 3D image data, measuring dimensions and measuring geometric accuracy. And to completely eliminate the influence of the mechanical vibration of the measuring probe itself that radiates light on the inner circumferential surface of the measurement, and the shaft vibration that occurs on the rotating radiation motor rotating shaft. A more important requirement is to prevent the heat generated from the rotating motor from propagating to the object to be measured and its own rotating radiation section. By solving these problems, we have provided an optical inner surface measurement device that eliminates data variability due to temperature changes that were previously caused by heat generated by rotary motors and enables accurate and accurate three-dimensional measurement of inner and inner diameters. It is to be.

One means for solving the above-mentioned problems is that an optical inner surface measuring apparatus that measures the inner peripheral surface of a measured object and measures the dimensional accuracy by using an optical measurement method (such as optical interference method or spectral interference method) The built-in optical fiber and at least one or more optical path conversion means at the distal end of the optical fiber, a motor for rotating the optical path conversion means in the tube, and the gas taken from the distal end side from the motor is The tube is evacuated from the front side of the motor through the inside of the tube, and a hard light-transmitting pipe is attached to the tip of the tube, the light-transmitting pipe is inserted into the inner diameter of the object to be measured, and the light beam guided through the optical fiber is It is emitted from the optical path changing means, irradiated to the circumferential surface of the object to be measured through the translucent pipe, and the reflected light is detected through the translucent pipe. It was.

According to the present invention, since the optical probe for measurement can enter the hole of the object to be measured and the light can be emitted, the measurement can be performed stably without the influence of the surface shape and roughness, and the motor built in the optical probe can be used. It has a cooling function that prevents the propagation of heat generation, and the influence of bearing runout and vibration of the motor in the probe for measurement can be eliminated by measurement using a translucent pipe, which is the standard for measurement. The accuracy of the inner peripheral surface can be measured.

1 is a configuration diagram of an optical inner surface measuring apparatus according to an embodiment of the present invention. First optical probe sectional view of the optical inner surface measuring apparatus Rotation operation explanatory diagram of the same optical probe Illustration of scanning angle of the same optical probe Illustration of scanning angle of the same optical probe 3D scanning range explanatory diagram of the same optical probe Explanatory drawing of calibration method for the same optical probe Explanatory diagram of temperature change of the optical probe Measurement variation explanation of the optical inner surface measuring device Second optical probe sectional view of the optical inner surface measuring apparatus Explanatory drawing of load limiting mechanism of slider for optical probe Operation diagram when the slider is overloaded

The first feature of the optical inner surface measuring apparatus of the present embodiment is that an optical inner surface measuring apparatus for observing and measuring an object to be measured includes an optical fiber built in the tube and at least one optical path at the tip of the optical fiber. The tube has a motor for rotating the optical path conversion means in the tube, and the gas taken in from the tip side of the motor is exhausted from the front side of the motor through the tube, and the tip of the tube is hard light-transmitting A light pipe is inserted into the inner diameter of the object to be examined, and the light beam guided from the optical fiber by the optical path changing means emits a light beam in the circumferential direction through the light transparent pipe, and the reflected light Is again detected through the translucent pipe.
With this configuration, since the measurement probe is allowed to enter the hole of the object to be measured and light can be emitted from the vicinity of the hole to the inner peripheral surface at a substantially right angle, stable measurement can be performed without the influence of the surface shape and roughness. Further, the propagation of heat generated from the motor built in the optical probe can be prevented by the cooling action caused by the inflow of gas. In addition, the influence of bearing vibration and vibration of the motor with a built-in optical probe, which is a cause of variation in measurement accuracy, can be eliminated by measuring the inner surface of the object to be measured with reference to the dimension of the light-transmitting pipe. By these things, it is possible to accurately and accurately measure the inner diameter and inner peripheral surface.

As a second feature, the first motor and a second motor disposed on the rear side of the first motor, the first optical path changing means operated by the first motor, and the second motor operated by the second motor. A fixed-side optical fiber that has two optical path conversion means and is disposed in a non-rotatable manner on the tube via a fixture on the rear side of the second motor, and rotates integrally with the rotary shaft of the first motor or the second motor. The rotating shafts of the first motor and the second motor are each hollow, and at least a part of the rotating side optical fiber on the tip side is rotated by the first motor. The shaft is hollowly inserted into the hollow hole of the shaft portion, and at least a part of the rear side is fixed to the hollow hole of the rotation shaft portion of the second motor. The first optical path conversion means is the second optical path conversion means. On the tip side, the rotating shaft of the first motor Are rotatably disposed in the integral, the second optical path changing means is configured so as to be located between the rotation-side first optical path changing means and the first motor located on the tip of the optical fiber with.
With this configuration, light is emitted in a three-dimensional direction, and three-dimensional data acquisition and three-dimensional precision measurement of the inner peripheral surface can be performed.

As a third feature, the gas taken in from the front end side of the motor is guided to the front side of the motor via the gap between the rotating portion and the fixed portion of the motor in the tube and exhausted.
With this configuration, the motor coil part, which is the heat source of the motor, can be directly cooled with the introduced gas, so that propagation of heat from the motor in the measurement probe can be prevented more reliably and more accurate accuracy measurement is possible. .

As a fourth feature, at least one of the tube and the light transmissive pipe is fixed to the sliding member, and when the light transmissive pipe or the tube is in contact with the test object, a contact load of a certain level or more. Thus, the sliding member is configured to slide together with the translucent pipe to prevent damage.
According to this configuration, the tube or the light-transmitting pipe, which has a low strength and is easily damaged because of the intake hole, prevents damage when it comes into contact with the object to be examined. Accuracy measurement is possible.

Next, preferred embodiments of the present invention will be described with reference to the drawings.

An embodiment of an optical inner surface measuring apparatus according to the present invention will be described.
1 to 8 show an embodiment of an optical inner surface measuring apparatus according to the present invention.

FIG. 1 is a configuration diagram of an optical inner surface measuring apparatus according to an embodiment of the present invention. A stand 81 is fixed to the measuring machine base 80, and a slider 82 is moved up and down together with the optical probe 34 by a slider motor 83. The device under test 100 is set on a measurement base 80, and the tip of the optical probe 34 or the translucent pipe 21 is configured to enter and exit the deep hole of the device under test 100. The light beam irradiates the inner peripheral surface of the object to be measured 100 through the translucent pipe 21 fixed to the tip of the tube 6, and this reflected light passes through the inside of the tube 6 through the translucent pipe 21 and is fixed to the fixed side optical fiber. 1, and further passes through the connection part 84 of the measuring machine main body 85, enters the optical interference analysis part 88, analyzes by the computer 89, and displays an image or measurement numerical value on the monitor 90.

This optical inner surface measuring device has a diameter measuring function, a roundness measuring function, and a cylindricity measuring function obtained by three-dimensional display.

FIG. 2 is a sectional view of the tip of the optical probe 34 of the optical inner surface measuring apparatus according to the embodiment of the present invention. The fixed-side optical fiber 1 for guiding the light beam from the rear end side to the front end side of the optical probe 34 is inserted into a sufficiently long tube 6 and fixed by the optical fiber fixture 4.

Rotating side optical fiber 2 is rotatably arranged at the front end side of fixed side optical fiber 1. First optical path conversion means 3a, 3b made of a substantially flat mirror or the like is further attached to the distal end side of the rotation side optical fiber 2 independently of the rotation side optical fiber 2 and rotated by the first motor 12. In this case, the light beam is radiated in a 360-degree circumferential direction.

The end surfaces of the rotation-side optical fiber 2 and the fixed-side optical fiber 1 are opposed to each other with a minute distance of about 5 microns, and the rotation-side optical fiber 22 including the rotating light-shielding plate 5 and the optical fiber fixing tool 4 is formed. High transmittance can be maintained between the optical fiber 2 and the fixed-side optical fiber 1, and the optical connection is made with almost no loss.

Further, at a position between the first optical path changing means 3a and 3b and the first motor 12, the light beam transmitted through the fixed-side optical fiber 1 and the rotating optical connector 22 is condensed and rotated at a slight angle toward the distal end. The second optical path changing means 20 that emits a light beam toward the first optical path changing means 3 a and 3 b is attached to the tip of the rotation side optical fiber 2.

In the first motor 12, the first hollow rotating shaft 10 to which the first motor coil 7, the first bearings 9b and 9a, and the motor thrust plate 8 are fixed to the motor case 24 and the first rotor magnet 11 is attached rotates. A voltage is applied to the first motor coil 7 from the electric wire 17, and the first optical path changing means 3 using a mirror or the like is attached to the rotating first hollow rotating shaft 10.

The second motor 19 is located behind the first motor 12, and the second bearings 16 a and 16 b and the second motor coil 15 are attached to the motor case 24. The second bearings 16 a and 16 b are the second rotor magnets 14. The second hollow rotating shaft 13 having a rotation is supported rotatably, and a voltage is applied from the second electric wire 18 to rotate. The rotation-side optical fiber 2 is inserted and fixed in the hole 13a of the second hollow rotary shaft 13, and the second optical path conversion means 20 made of a prism or the like is attached to the tip of the rotation-side optical fiber 2, and these rotate integrally. A part of the rotation-side optical fiber 2 is rotatably inserted into the hole of the first hollow rotation shaft of the first motor 12 and rotates relatively.

The first motor 12 and the second motor 19 are fixed to the motor case 24 with a gap by the fixing dowels 33a and 33b. At the tip side of the first motor 12, at least one intake hole 6 a is formed in the tube 6 or the translucent pipe 21, and the pipe temperature sensor 31 is provided in the translucent pipe 21 or the tube 6. Is provided. In FIG. 1, an intake tube 29 and an intake fan 30 are attached to the tube 6. Gas is sucked from the intake hole 6 a in FIG. 2, and the sucked gas is exhausted from the intake fan 29 until the first time. The motor 12 and the second motor 19 are cooled to prevent heat generated from these motors from propagating to the translucent pipe 21 and the device under test 100, and the measurement dimensions of the device under test due to thermal expansion are prevented.

The first motor 12 shown in FIG. 2 is supplied with electric power from the first motor driver circuit 86 shown in FIG. 1 and driven to rotate. The second motor 19 is supplied with voltage from the second motor driver circuit 87 and driven to rotate. .

In the vicinity of the outer periphery of the first optical path changing means 3 from which the light rays 26 and 27 are radiated, a translucent pipe 21 capable of transmitting light rays is attached integrally with the tube 6. The inner peripheral surface or outer peripheral surface of the translucent pipe 21 is coated with a coating or the like for reducing surface reflection and increasing light transmittance as necessary. Further, the first optical path changing means 3 is constituted by a rotatable mirror or prism, and has high reflection efficiency and can reduce the optical loss and perform highly accurate measurement.

The second optical path conversion means 20 is composed of a prism having a substantially flat surface inclined at the tip, and has high light-collecting properties, and can perform high-precision measurement with reduced optical loss.

Next, the characteristic operation and effects of the optical inner surface measuring apparatus of FIG. 1 using the three-dimensional scanning type optical probe shown in FIG. 2 will be described in detail.

1 and FIG. 2, light rays such as near infrared rays or laser light emitted from the measuring instrument main body 85 travel through the fixed-side optical fiber 1 built in the tube 6.

When electric power is supplied from the electric wires 17 and 18, and the two motors of the first motor 12 and the second motor 19 are synchronously rotated at the same rotational speed in the range of about 900 to 20,000 rpm, the guided light beam is a rotating optical connector. 2 and the rotation-side optical fiber 2, as shown in FIG. 2, it is emitted from the second optical path changing means 20, reflected by a substantially flat portion of the first optical path changing means 3a, and in a certain angular direction (in FIG. 2, θ1 The direction of the radiation is rotated 360 degrees and the radiation range at this time becomes an umbrella-shaped range of angle θ1 as shown in FIG.

The light further passes through the translucent pipe 21, and the light reflected from the inner peripheral surface of the object to be inspected 100 is transmitted in the reverse direction along the same optical path as above. The translucent pipe 21⇒first optical path conversion means 3⇒second optical path conversion Means 20 => rotation side optical fiber 2 => rotation optical connector 22 => pass through the fixed side optical fiber 1 and be guided to the optical interference analysis unit 88.

Next, the rotation speed of the first motor 12 and the second motor 19 is, for example, the rotation speed of the first motor 12 is constant at 3600 rpm, while the rotation speed of the second motor 19 is rotated at a constant speed of 3570 rpm. Switch to a rotation state that gives a slight difference in rotation speed. In this state, as shown in FIG. 3, the first optical path conversion unit 3 rotates, and at the same time, the relative rotation angle phase with the second optical path conversion unit 21 gradually changes, and the light beam eventually rotates. The light beam reflected by the means 3 is radiated in the entire circumferential direction at 360 degrees, and the radiation angle in the longitudinal direction gradually changes and changes as indicated by θ2 in FIG. That is, the radiation range of the light beam at this moment is changed to an inclined umbrella-shaped scanning range as shown in FIG.

This rotation angle phase difference is shifted by 30 rotations (that is, 3600-3570 = 30 rotations / minute) which is a difference from the rotation speed of the second motor 19 while the first motor 12 rotates 3600 times per minute, that is, This operation in which a rotation angle phase difference occurs 30 times per minute (that is, 30 reciprocations), and subsequently, a rotation phase difference between the first optical path conversion means 3 and the second optical path conversion means 20 continues to occur slowly 30 times per minute. Thus, as shown in FIG. 6, the radiation direction of the light beam continuously changes in the range of θ1 to θ2, and the radiation region 79 of the light beam is repeatedly irradiated three-dimensionally in the range of θ1 + θ2.

In FIG. 2, the rotation pulse generator 28 generates one pulse per one rotation of the first optical path changing means 3 or the first hollow rotating shaft 10, and this pulse signal is sent to the first motor driver circuit of FIG. The rotational speed of the first motor 12 is adjusted and sent to the computer 89 to be used as a trigger signal for rendering a three-dimensional digital image for each frame.

In the optical inner surface measuring apparatus of the present invention, the procedure for measuring the inner diameter 100a of the DUT 100 is as follows.

First, calibration is performed as preparation before measurement. As shown in FIG. 7, the translucent pipe 21 of the optical probe 34 is inserted into the hole of the ring gauge 78 whose inner diameter dimension (D1) is known, and the inner peripheral surface of the ring gauge 78 from the outer diameter of the translucent pipe 21. Difference (L1−L2) and (L1′−L2 ′) and distances L1 and L1 ′ from the inner peripheral surface of the ring gauge to the virtual midpoint of the optical probe 34 are obtained. Here, the radius values (R = D1 / 2− (L1−L2), R ′ = D1 / 2− (L1′−L2 ′)) of the translucent pipe 21 are obtained, and the reference radius values of R and R ′ are obtained. Is stored in the computer 89 as the reference radius data of the translucent pipe 21 to complete the calibration, and this calibration is periodically performed about once a month.

When calibration (calibration) is completed, the next measurement is started. The translucent pipe 21 of the optical probe 34 is inserted into the inner peripheral surface 100a of another object to be inspected, the first motor 12 and the second motor 19 are rotated to emit light, and the inner diameter dimension (D ) = R + (L1−L2) + R ′ + (L1′−L2 ′).

FIGS. 8 and 9 show the case where the gas is sucked from the intake hole 6a in FIGS. 1 and 2, and the first motor 12 and the second motor 19 are cooled by the operation of the intake fan 30, and the intake fan 30 is stopped. The difference when not cooled is shown. As shown in FIG. 8, with cooling, the translucent pipe 21 rises by 0.5 ° C. in about 20 seconds, but thereafter, the rise stops and a constant temperature is maintained, and there is almost no temperature propagation to the object 100 to be measured. It is possible to prevent the measurement accuracy from being wrong. On the other hand, without cooling, the temperature of the translucent pipe 21 rises by 3 ° C. in about 1 minute and continues to rise gradually thereafter, and the device under test 100 also starts to rise in temperature, making it difficult to perform highly accurate measurement.

FIG. 9 shows the magnitude of measurement variation when the inner diameter dimension is repeatedly measured on the DUT 100 with the inner surface measuring apparatus of the present invention. The variation in the results of repeated measurements 100 times within 30 minutes under the condition with cooling was (repeated reproducibility: σ) within 0.05 micrometers, and high-accuracy measurement was possible. In the case where there was not, there was a variation of 0.15 micrometers, and high-precision measurement was difficult.

In this way, by using the optical probe 34 shown in FIG. 2, the computer 89 calculates the reflected light introduced from the inner peripheral surface 100 a of the DUT 100 of FIG. 1 through the optical fibers 1 and 2. Dimensional measurements can be performed with the light pipe as a reference, three-dimensional data can be collected with the slider 82 stationary, and the propagation of heat from the motors 12 and 19 in the measurement probe 34 can be prevented. This eliminates the effects of bearing runout and vibration of the measuring probe internal motor, and enables accurate and accurate measurement of the inner diameter and inner peripheral surface.

FIG. 10 shows a cross section of the second optical probe of the optical surface measuring apparatus according to the present invention.
In FIG. 10, the motor case 24 is directly fixed inside the tube 6, and the gas introduced from the intake hole 6 a passes through a vent hole 8 a appropriately provided in the motor thrust plate 8, and at least the first motor 12. The first motor is configured to be efficiently cooled by passing through the gap between the first motor coil 7 and the first rotor magnet 11. Further, the second motor 19 is also configured so that the gas can pass through the gap between the second motor coil 15 and the first rotor magnet 14 as necessary, and cooling can be performed further.

With this configuration, the gas taken in from the intake hole is guided to the near side of the motor (measuring instrument main body side with respect to the probe tip side) via the gap between the rotating part and the fixed part of the motor in the tube. Since the motor coil portion, which is a heat generation source, can be directly cooled with the introduced gas, propagation of heat from the motor in the measurement probe can be surely prevented, and more precise accuracy measurement can be performed.

In FIG. 10, other configurations and functions are the same as those of the first optical probe in FIG.

11 and 12 show a third embodiment of the optical surface measuring apparatus according to the present invention.
In FIG. 11, the tube 6 with the vent holes 6a or the light-transmitting pipe 21 made of thin quartz or glass has a low strength, and it breaks if it is inadvertently brought into contact with the object 100 during measurement. There is a risk of doing. Therefore, as shown in FIG. 11, the tube 6 is slidably set with respect to the probe fixture 37, and is fixed to the sliding member 38 pressed by preload means 39a, 39b, 39c such as a ball, for example, to be measured. When the object 100 is in strong contact with the object 100, for example, the load limiter 40 composed of a combination of a ball and a notch is removed, and the optical probe 34 is slid upward in the drawing, and damage due to collision is prevented. ing. The magnifying glass (camera) 35 always displays the state near the hole 100a of the object 100 to be measured on the monitor 90, and serves to urge the user of the measuring machine not to collide with the optical probe 34.

According to this configuration, the optical probe 34 is fixed to the sliding member 38, and when the translucent pipe 21 or the tube 6 is in strong contact with the DUT 100, the sliding is caused by a certain contact load or more. The member 38 can slide upward together with the translucent pipe 21 to prevent damage, and the accurate and accurate measurement of the inner diameter and inner peripheral surface can be performed safely.

2 and 10, the tube 6 has a diameter of about 2 millimeters or less, and the fixed-side optical fiber 1 penetrating through the tube 6 is a bendable glass fiber and has a diameter of 0.085 to 0.125 millimeters. The thing of the grade is adopted.

The first optical path conversion means 3 is composed of a mirror or a prism having a smooth reflecting surface, and its surface roughness and flatness are polished to an accuracy equal to or higher than that of a general optical component in order to increase the reflectance.

The first hollow rotating shaft 10 is made of metal or ceramics, and a hollow is formed by drawing with a die of molten metal or extrusion with a die of ceramics before firing, and finished by a polishing method or the like after the curing process. The

The hole of the first hollow rotating shaft 10 has a diameter of 0.1 to 0.5 mm and is sufficiently larger than the diameter of the rotating optical fiber 2, so that the fixed optical fiber 1 fixed by the optical fiber fixture 4 is the first one. 1 There is no risk of contact with the hollow rotating shaft 10, and even if lightly touched, wear powder is not generated. Further, there is no problem that the rotational friction torque varies in this portion.

According to the present invention, by allowing the measurement probe 34 to enter the hole of the object to be measured 100 and radiating light from the hole, the measurement can be stably performed without the influence of the surface shape and roughness of the inner peripheral surface, Propagation of heat generation from the motors 12 and 19 in the optical probe 34 is prevented. In addition, it is possible to eliminate the effects of bearing vibration and vibration of the motor in the optical probe, which has been a problem in the past, and by providing a load limiter that prevents damage to the optical probe, it is possible to accurately and accurately measure the inner diameter and inner peripheral surface. Can be done safely.

The optical inner diameter measuring device for observing and measuring the object to be measured using the optical measuring method of the present invention enables high-accuracy three-dimensional observation and geometric accuracy measurement of the inner surface of the deep hole. High precision measurement of industrial precision mechanism parts such as fuel injection parts and water jet nozzle parts can be performed. In addition, it is expected to be used for numerical diagnosis and treatment of minute lesion dimensions in the medical field.

DESCRIPTION OF SYMBOLS 1 Fixed side optical fiber 2 Rotation side optical fiber 3a, 3b 1st optical path conversion means (mirror)
4 Optical fiber fixture 5 Rotation shielding plate 6 Tube 6a Intake hole 7 First motor coil 8 Motor thrust plates 9a, 9b First bearing 10 First hollow rotating shaft 11 First rotor magnet 12 First motor 13 Second hollow rotating shaft 13a Hole 14 Second rotor magnet 15 Second motor coils 16a, 16b Second bearing
17 electric wire 18 electric wire 19 2nd motor 20, 20a, 20b 2nd optical path conversion means (prism etc.)
21 Translucent pipe 22 Rotating optical connector (optical rotary connector)
23a Pulse generator 24 Motor case
25, 25a, 25b Scanning range 26, 27 Ray 28 Rotating pulse generator 29 Intake tube 30 Intake fan 31 Pipe temperature sensor 32 Work temperature sensor 33a, 33b Fixed dowel 34 Optical probe 35 Magnifier (camera)
37 Probe fixture 38 Sliding member 38a Notch 39a, 39b, 39c Preload means 40 Load limiter 78 Ring gauge 79 Scanning range 80 Measuring machine base 81 Stand 82 Slider 83 Slider motor 84 Connection part 85 Measuring machine main body 86 First motor Driver circuit 87 Second motor driver circuit 88 Optical interference analysis unit 89 Computer 90 Monitor 100 Measured object 100a Measured inner surface

Claims (4)

In an optical inner surface measuring device for observing and measuring an object to be measured,
An optical fiber built into the tube,
Having at least one or more optical path changing means at the tip of the optical fiber;
The tube has a motor for rotating the optical path changing means,
The gas taken from the tip side from the motor is exhausted from the front side of the motor through the tube,
A hard translucent pipe is attached to the tip of the tube,
Insert the translucent pipe into the inner diameter of the object to be measured,
An optical inner surface measurement characterized in that the light beam guided from the optical fiber by the optical path changing means emits a light beam in the circumferential direction through the translucent pipe and the reflected light is detected again through the translucent pipe. apparatus.
The motor includes a first motor and a second motor disposed on the rear side of the first motor,
The optical path conversion means comprises a first optical path conversion means operated by the first motor and a second optical path conversion means operated by the second motor,
The optical fiber is composed of a fixed-side optical fiber that is non-rotatably disposed on the tube via a fixture on the rear side of the second motor, and a rotation-side optical fiber that is rotated by the second motor.
Each of the rotating shaft portions of the first motor and the second motor has a hollow shape,
The rotation-side optical fiber has at least a part on the front end side thereof rotatably inserted into a hollow hole of the rotation shaft part of the first motor, and at least a part on the rear side is hollow in the rotation shaft part of the second motor. Fixed in the hole,
The first optical path changing means is disposed so as to be rotatable integrally with a rotary shaft portion of the first motor on the tip side of the second optical path changing means,
2. The optical inner surface measurement according to claim 1, wherein the second optical path conversion unit is located at a distal end of the rotation-side optical fiber and is positioned between the first optical path conversion unit and the first motor. apparatus.
The gas taken in from the tip side of the motor is guided to the front side of the motor via a gap between a rotating part and a fixed part of the motor in the tube, and is forcibly exhausted. The optical inner surface measuring apparatus according to 1 or 2.
At least one of the tube or the translucent pipe is fixed to a sliding member, and when the translucent pipe or the tube abuts on an object to be measured, the sliding member is brought into contact with a certain contact load. The optical inner surface measuring apparatus according to any one of claims 1 to 3, wherein said optical inner surface measuring apparatus slides with said translucent pipe to prevent damage.

Images