JP2000205977A - Torque measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque measuring apparatus capable of measuring the rotational speed and torque per rotation of a rotor whose rotational speed varies subtly, by determining the rotational period of the rotor per rotation with a measuring accuracy of higher than 10 ns. SOLUTION: This apparatus includes an irradiation means 20 which irradiates a light beam, a beam adjustment means 21 which causes the light beam to branch into a plurality of light beams and irradiates the subject of measurement 37 with the light beams while adjusting the diameter of each light beam, a plurality of reflection means 22, 23 mounted on the surface of the subject of measurement 37 for varying the reflections of the plurality of light beams, a plurality of detection means 24, 25 for detecting changes in intensity of the plurality of reflected light beams, and a signal processing means 26 which determines the torque of the subject of measurement 37 by calculating its period of rotation on the basis of signals outputted from the detection means 24, 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque measuring device for remotely and non-contactly measuring the rotational speed and torque of a rotating device.

[0002]

2. Description of the Related Art As a technique for measuring the torque of a rotating device in a non-contact manner, there is known a "torque detecting device" disclosed in Japanese Patent Application Laid-Open No. 6-34462. This torque detection device detects a torque generated in a shaft portion of a power transmission device such as an automobile.

FIG. 17 shows the configuration of this torque detecting device. As shown in FIG. 17, in the torque detecting device, a linear light reflector 2 for efficiently reflecting light is provided on an outer peripheral surface of a shaft 1 which is a rotating body to be measured. First and second detectors 3 and 4 each including one light emitting element 3a, 4a and one light receiving element 3b, 4b are arranged. The detecting units 3 and 4 are configured to irradiate light beams to two different positions in the axial direction of the shaft 1 by the light emitting elements 3a and 4a, respectively, and to detect the reflected light by the light receiving elements 3b and 4b.

Therefore, when the shaft 1 is rotated,
The light receiving elements 3b and 4b detect a signal from the light reflector 2 at each period. Then, by shaping the detection signal by the waveform shaping circuit, a pulse signal of the light receiving element 3b and a pulse signal of the light receiving element 4b can be obtained as shown in FIG. The cycle T of the pulse signal is one cycle of the rotation time. Further, using the delay time t of the pulse signal of the light receiving element 4b to the pulse signal of the light receiving elements 3b, the torque according to the following formula (1): can be calculated F _t.

(Equation 1)

As described above, in the torque detecting device, light is emitted from the light emitting elements 3a and 4a to the shaft 1, and the light reflected by the light reflector 2 is detected by the light receiving elements 3b and 4b. And
The pulse signal shown in FIG. 18 is generated based on the detection signal of the light reflector 2 shown in FIG. 19, and the rotation speed and the torque are calculated from the cycle of the pulse signal.

As a technique capable of measuring the torque of a rotating device, there is a "rotation speed measuring device" disclosed in Japanese Patent Application Laid-Open No. 7-325095.

FIG. 20 shows the configuration of the rotation speed measuring device. In FIG. 20, only the main parts are denoted by reference numerals. In the rotation speed measuring device shown in FIG. 20, the light beam of the laser diode 5 which emits the pulse light at the set frequency is converted into parallel light by the collimator lens 6 and is irradiated on the rotating body 7 to be measured. Since the reflection of the irradiation light changes due to the unevenness 8 formed on the surface of the measured rotating body 7, the intensity of the reflected light changes in accordance with the rotation of the measured rotating body 7.

Therefore, the reflected light is received by the photodiode 10 using the lens 9, and the received light signal is processed to calculate the rotation speed. In signal processing,
First, a band-pass filter (BPF) 11 that passes a frequency component of 500 kHz extracts a pulse-modulated reflected light signal of a laser beam. Thereafter, a high-frequency signal component is removed by a low-pass filter (LPF) 12. The time change of the signal after the removal is a change in the intensity of the reflected light corresponding to the rotation cycle of the rotating body 7 to be measured.

Next, the control circuit 13 digitizes the signal and performs a fast Fourier transform to obtain a frequency distribution shown in FIG. The rotation frequency of the rotating body 7 to be measured is a frequency f ₀ having a large distribution frequency. The rotation cycle T is 1 / f ₀
It is.

When measuring the torque, the present rotational speed measuring device is installed at two places. In this case, since the delay time t of the detection signal shown in FIG. 18 can be obtained according to the equation (2), the torque can be calculated using the equation (1).

[0011]

(Equation 2)

[0012]

However, in the former device for measuring the torque of a rotating device in a non-contact manner, FIG.
The rise time of the detection signal shown in FIG. Therefore, it is impossible to generate a pulse signal with a time accuracy higher than the rise time and determine the period of the pulse signal. For this reason, when the rotation speed slightly changes every rotation, there is a problem that the rotation speed and torque for each rotation cannot be obtained with high accuracy. For example, in a power generation device having a shaft diameter of 850 mm and a rotation speed of 3000 rpm, in order to monitor the power generation efficiency with high accuracy, 100 units per rotation.
It is desired to obtain the torque by measuring the period of the pulse signal with a measurement accuracy of ns.

On the other hand, in the latter device for measuring the rotation speed of a rotating device in a non-contact manner, a signal corresponding to the rotation period of the rotating body 7 to be measured is extracted and Fourier-transformed, and the rotation frequency f ₀ is determined from the frequency distribution. Identify. In this apparatus, when the distribution frequency of the rotation frequency f ₀ is ideal as shown in FIG. 21, the rotation frequency f ₀ can be specified.

However, in general, the rotation speed of the rotating body usually slightly fluctuates, and has a distribution that spreads around the rotation frequency f ₀ as shown in FIG. When such a frequency distribution is shown, since it is difficult to specify the rotation frequency f ₀ , there is a problem that the rotation speed and the torque cannot be calculated with high accuracy using the equations (1) and (2). is there. Further, in this device, since the rotation frequency f ₀ is specified from the frequency distribution, there is a problem that the torque cannot be calculated by calculating the rotation speed for each rotation in principle.

Therefore, the present invention has been made in view of the above circumstances, and obtains a rotation period for each rotation with a measurement accuracy higher than 10 ns for a rotating body whose rotation speed slightly fluctuates.
It is an object of the present invention to provide a torque measurement device capable of measuring a rotation speed and a torque for each rotation with high accuracy.

[0016]

In order to achieve the above object, according to the first aspect of the present invention, there is provided an irradiation means for irradiating a light beam, the light beam is divided into a plurality of light beams, and the beam diameter of each light beam is adjusted. Beam adjusting means for adjusting and irradiating the object to be measured, a plurality of reflecting means attached to a surface of the object to be measured, and changing a reflection state of the plurality of light beams, and a reflected light of each of the plurality of light beams It is characterized by comprising a plurality of detecting means for detecting a change in intensity, and a signal processing means for calculating a rotation cycle based on an output signal of the detecting means to obtain a torque of the measured object.

According to the first aspect of the present invention, the light beam can be split into a plurality of light beams by the beam adjusting means, and the beam diameter of each light beam can be adjusted to several μm to irradiate the object to be measured. Since the object to be measured is provided with a plurality of reflecting means for reflecting light with high efficiency, the plurality of detecting means can obtain a pulse signal having a rapid rise time for each rotation. The rise time of this pulse signal is very short because the beam diameter of the irradiated light beam is several μm. The object to be measured has, for example, a shaft diameter of 850 mm and a rotation speed of 3000 rpm.
Is a pulse signal having a rise time of about 10 ns. The signal processing means can measure the rotation cycle with a predetermined high measurement accuracy by measuring the time interval between the pulse signals. The torque can be obtained by calculating a delay time from the pulse signals output from the plurality of detecting means.

According to a second aspect of the present invention, in the torque measuring device according to the first aspect, the light beam of the irradiation means is transmitted to the beam adjustment means through an optical fiber.

According to the second aspect of the present invention, by using an optical fiber, it is possible to easily transmit the light beam of the irradiating means to a place where spatial transmission is difficult, and to reduce the torque inside the device or a narrow portion. Measurement becomes possible.

According to a third aspect of the present invention, in the torque measuring device according to the first aspect, each of the plurality of reflecting means is a low-reflecting body having a light ray reflectance lower than the surface of the measured object. Things.

According to the third aspect of the present invention, by providing a low-reflector having a very low reflectance as a reflection means on the object to be measured, the reflected light of the light beam irradiated for a certain time every rotation is extremely small. Can be done. When the reflected light is detected by the detecting means, a pulse signal having a very short fall time is obtained for each rotation because the reflected light intensity at the reflecting means is very small as compared with the reflected light intensity at the surface of the measured object. be able to.

According to a fourth aspect of the present invention, in the torque measuring device of the first aspect, each of the plurality of reflecting means includes a high reflection area in which the light reflectance is higher than the surface of the object to be measured, and a light reflectance in the high reflection area. The reflector has a low reflection area lower than the high reflection area.

According to the fourth aspect of the present invention, by providing a reflector having a region for reflecting light rays with high efficiency and a region for absorbing light rays as a reflection means on the object to be measured, the light is irradiated for a fixed time every rotation. The reflected light intensity of the reflected light can be extremely varied. When this reflected light is detected by the detecting means, a pulse signal group having a very short rise and fall time can be obtained for each rotation.

According to a fifth aspect of the present invention, in the torque measuring device according to the first aspect, the plurality of reflecting means each reflect a light beam of the irradiating means in an installation direction of the plurality of detecting means; And a diffusely reflecting region for irregularly reflecting at least a part of the light beam in directions other than the installation direction of the plurality of detecting means.

According to the fifth aspect of the present invention, the plurality of reflection means include a reflection area for reflecting the light in the installation direction of the plurality of detection means, and at least a part of the light beam of the irradiation means. Since the reflector is provided with the irregular reflection region that irregularly reflects the light in a direction other than the direction, the intensity of the reflected light incident on the plurality of detection units can be extremely varied for a certain time every rotation. Therefore, the plurality of detecting means can obtain a pulse signal group having a very short rise and fall time for each rotation.

According to a sixth aspect of the present invention, in the torque measuring device according to the first aspect, the signal processing means changes a threshold value in accordance with output fluctuations of the plurality of detection means and extracts a signal of the reflection means. It is characterized by having means.

According to the sixth aspect of the present invention, the threshold value for extracting the signal of the reflection means from the ratio to the amplitude of the detection signal is set by the fluctuation threshold value setting means. Can be extracted. For this reason, it is possible to prevent a reduction in the temporal extraction accuracy of the detection signal due to the output fluctuation of the detection means.

According to a seventh aspect of the present invention, in the torque measuring device of the first aspect, filtering means for removing a signal component other than the detection signal from output signals of the plurality of detection means is provided. Things.

According to the seventh aspect of the present invention, noise components can be removed from the output signals of the plurality of detecting means by the filtering means. For this reason, the plurality of detecting means can obtain a pulse signal group having a very short rise and fall time every rotation even in a noise environment.

The invention according to claim 8 is characterized in that correlation processing means for obtaining the torque of the measured object by performing correlation processing on the outputs of the plurality of detection means is provided.

According to the eighth aspect of the present invention, the rotation cycle can be measured with high measurement accuracy by correlating the pulse signals obtained for each rotation by the plurality of detection means. The torque can be obtained by calculating a delay time from the pulse signals output from the plurality of detecting means.

According to a ninth aspect of the present invention, in the torque measuring device according to the first aspect, the plurality of detecting means include first and second detecting means, and the second detecting means is attached to the first detecting means. And a position fluctuation measuring means for measuring the position fluctuation of the second detecting means.

According to the ninth aspect of the present invention, the position variation measuring means attached to the first detecting means allows the second variation to be measured.
Can be monitored and monitored, and the change in position of the first and second detecting means caused by vibration, impact, or the like can be measured. As a result, it is possible to reduce a decrease in the accuracy of torque measurement that occurs due to a position change of the first and second detection units.

According to a tenth aspect of the present invention, in the torque measuring device according to the first aspect, the plurality of detecting means have first and second detecting means, and are attached to the first detecting means. An irradiating means for irradiating a light beam toward the second detecting means; and an irradiating light beam attached to the second detecting means for detecting the irradiating light beam to detect a position change of the first detecting means and the second detecting means. And a position variation measuring means for measuring.

According to the tenth aspect of the present invention, the light beam of the irradiating means attached to the first detecting means is detected by the position variation measuring means attached to the second detecting means, so that vibration, shock, etc. The position fluctuation of the second detecting means caused by the above can be measured. As a result, it is possible to reduce a decrease in the accuracy of torque measurement that occurs due to a position change of the first and second detection units.

According to an eleventh aspect of the present invention, in the torque measuring device according to any one of the first to tenth aspects, the apparatus main body is installed along a circumferential direction of the measured object.

According to the eleventh aspect of the present invention, the accuracy of torque measurement is improved by installing the apparatus main body along the circumferential direction of the measured object and averaging the torque values measured from each apparatus main body. Can be done.

According to a twelfth aspect of the present invention, in the torque measuring device according to any one of the first to eleventh aspects, the apparatus main body is installed along the axial direction of the measured object.

According to the twelfth aspect of the present invention, by installing the apparatus main body along the axial direction of the measured object, it is possible to measure a change in torque in the axial direction.

[0040]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a block diagram showing a first embodiment of a torque measuring device according to the present invention.

As shown in FIG. 1, the torque measuring device according to the first embodiment includes an irradiating device 20 for irradiating a light beam, splits the light beam into a first beam and a second beam, and adjusts the beam diameter of each beam. A beam adjusting device 21 for irradiating the object to be measured, and first and second reflectors 22 and 23 attached to the surface of the object to change the reflection state of the first and second light beams.
And first and second detection devices 24 and 25 for detecting a change in the intensity of the reflected light of the first and second light beams, and a rotation period is calculated from output signals of the detection devices 24 and 25 to measure the object to be measured. And a signal processing device 26 as signal processing means for calculating the torque of the motor.

The irradiation device 20 is constituted by a light source for irradiating a directional light beam. Here, the wavelength is 632.8 nm.
And a He-Ne laser TEM ₀₀ mode for irradiating continuous light. However, the laser is not limited to the He-Ne laser, and various lasers are applicable. Further, a pulse lighting type or continuous light type light source in which a high intensity light beam can be irradiated in a specific direction by combining a lens, a slit, a pinhole, and a reflector with a light emitting diode or a lamp can be applied. .

The light beam of the irradiation device 20 is
The light is split into reflected light and transmitted light by one beam splitter 27. On the reflected light side, lenses 29, 31, a beam splitter 33, and a condenser lens 35 are sequentially installed on the same optical path, and the reflected light is measured through the lenses 29, 31, the beam splitter 33, and the condenser lens 35. The body 37 is irradiated. On the other hand, on the transmitted light side, a mirror 28 for reflection is provided.
The lenses 30, 32, the beam splitter 34, and the condenser lens 36 are sequentially installed on the same optical path, and the transmitted light split by the beam splitter 27 is reflected by the mirror 28, and the lenses 30, 32, the beam splitter 34, The object to be measured 37 is irradiated via the condenser lens 36.

In this case, the beam splitters 27 and 3
Each of the reference numerals 3 and 34 may be constituted by a wave plate. The optical system composed of the lens 29 and the lens 31 is 40
It is a double magnification optical system and can be replaced by a beam expander. Similarly, the lenses 30 and 32 can be replaced by a beam expander.
The condenser lenses 35 and 36 may be formed of an achromatic lens capable of correcting spherical aberration, or may be formed of an aplanat lens such as an apochromatic lens or an aspheric lens.

The first and second reflectors 22 and 23 are attached so as to reflect the light beam emitted every time the object 37 is rotated. The reflective mirror is a reflective mirror. The reflectors 22 and 23 can be made of any material that reflects light rays with high efficiency.

The measured object 37 has, for example, a rotation speed of 300.
A rotating device that rotates at 0 rpm and has a diameter of 850 mm is used, and a load can be applied to one end of the measured object 37 by the load device 38.

In the present embodiment, the measuring object 37 is used for a fine particle such as a fine particle, a fluid, or a gas, a moving object such as an automobile, an aircraft, a ship, or a train, or a device that causes torsion or expansion and contraction.
The displacement, speed, and acceleration can also be measured.

The light reflected by the first and second reflectors 22 and 23 is detected by first and second detectors 24 and 25 constituted by avalanche photodiodes. A photomultiplier, a photodiode and the like can be applied. And
The detection signals of the first and second detection devices 24 and 25 are transmitted to a signal processing device 26 constituted by a general-purpose computer. The signal processing device 26 includes a fluctuation threshold value setting unit that changes the threshold value according to the output fluctuation of the first and second detection devices 24 and 25 and extracts a detection signal.

The operation of the torque measuring device according to the first embodiment configured as described above will be described.

The diameter of the beam emitted from the irradiation device 20 is set to 0.
The 65 mm laser light is separated into a first laser light reflected by the beam splitter 27 and a second laser light transmitted therethrough. First, the beam diameter of the first laser light is enlarged to 25 mm by the enlargement optical system of the lens 29 and the lens 31. After being transmitted through the beam splitter 33, the expanded first laser light is irradiated on the surface of the measured object 37 by the condenser lens 35. In this case, the position of the condenser lens 35 is finely adjusted so that the beam diameter of the first laser light is focused on the surface of the measured object 37. The beam diameter of the focal point: W can be calculated from equations (3) and (4).

(Equation 3)

(Equation 4)

In this embodiment, λ = 632,8 nm, φ
= 25 mm, f = 50 mm, beam diameter: W = 1.
6 μm. Therefore, the first laser light on the surface of the measured object 37 has a Gaussian distribution with a beam diameter: W = 1.6 μm.

The first laser beam applied to the measured object 37 is reflected by the first reflector 22 attached to the measured object 37.
Is strongly reflected when the light is irradiated, but the reflection on the surface of the measured object 37 is extremely small. Therefore, it is possible to obtain the reflected light of the first laser light for a fixed time every rotation. This reflected light is specularly reflected by the reflector 22 and enters the condenser lens 35 along the same optical path as the irradiated light beam. With this condenser lens 35, the beam diameter of the reflected light: φ ′ becomes φ ′ = 25 mm. Here, if the beam diameter: φ of the irradiated light beam and the reflected light: φ ′ have the same value, it can be confirmed that the focal point is focused on the surface of the measured object 37.

The reflected light having a beam diameter of φ '= 25 mm is split by the beam splitter 33, and one of the lights is incident on a first detector 24 constituted by an avalanche photodiode. Since the first detecting device 24 detects the strong reflected light from the reflector 22 for a certain period of time for each rotation, the first detection signal 39 having a pulse shape shown in FIG. 2 can be obtained. Note that the beam diameter of the first laser light on the surface of the measured object 37 is
Since it is as small as 1.6 μm, the rise time of the first detection signal 39 is about 10 ns.

On the other hand, the second laser light transmitted through the beam splitter 27 is reflected at a right angle by the mirror 28. Thereafter, the second laser light is subjected to exactly the same operation as the first laser light, passes through the magnifying optical system of the lenses 30 and 32, and the beam splitter 34, and is then condensed by the condenser lens 36. Is focused on the surface of the substrate and irradiated so as to have a beam diameter of 1.6 μm. And the second
After the light reflected by the reflector 23 of the above becomes a beam diameter: 25 mm by the condenser lens 36, the beam splitter 3
4 and is incident on the second detection device 25.
The second detection device 24 detects the strong reflected light of the reflector 23 for a certain period of time for each rotation, so that the pulse-shaped second detection signal 40 shown in FIG. 2 can be obtained. Since the beam diameter of the second laser light on the surface of the measured object 37 is as small as 1.6 μm as in the case of the first laser light, the rise time of the second detection signal 40 is 10n.
s. Further, the signal processing device 26 takes in the first detection signal 39 and the second detection signal 40 and calculates the rotation period and the torque.

Here, as shown in FIG. 2, a threshold value is set for the amplitude of the first detection signal 39, and the rotation period is obtained from the time interval between adjacent threshold values. The first and second detection signals 39,
The amplitude voltage of 40 may change for each detection signal.
For this reason, the threshold is determined by a ratio to the amplitude voltage and set to 10% of the amplitude voltage. This ratio can be determined appropriately. FIG. 3 shows a change in the rotation cycle obtained by the present embodiment. Further, the rotation cycle can also be obtained from the second detection signal 40.

On the other hand, when the threshold value of the second detection signal 40 is set in the same manner as the first detection signal 39 and the first and second detection signals 39 and 40 are compared, FIG. The indicated delay time occurs. As a result, the torque for each rotation can be obtained using the delay time and equation (1).

As described above, according to the present embodiment, the first and second laser beams transmitted through the space and applied to the object 37 have a beam diameter of 1.6 μm on the surface of the object 37.
Becomes When the reflected light is detected by the detectors 24 and 25, the first and second detection signals 39 and 40 having a rise time of about 10 ns are rotated since the reflectors 22 and 23 are attached to the measured object 37. You can get every time. Then, in the signal processing device 26, the detection signal 39,
By setting a threshold value corresponding to the temporal amplitude fluctuation of 40, the rotation cycle of the measured object 37 can be measured with a predetermined accuracy shown in FIG. Then, using the delay time shown in FIG. 2 and Expression (1), the torque for each rotation can be obtained with a predetermined high accuracy.

[Second Embodiment] FIG. 4 is a configuration diagram showing a second embodiment of the torque measuring device according to the present invention. In addition,
The same parts as those in the first embodiment will be described with the same reference numerals. The same applies to the following embodiments.

As shown in FIG. 4, the torque measuring device according to the second embodiment includes an irradiating device 20 for irradiating a light beam, an optical transmission device 41 for transmitting the light beam of the irradiating device 20, and the first and second light transmitting devices. A beam adjusting device 44 that diverges to the second light beam, adjusts the beam diameter of each light beam, and irradiates the object 37 with the beam.
First and second low reflectors 51 and 52 attached to the surface of the measured object 37 to change the reflection state of the first and second light beams, and the intensity of reflected light of the first and second light beams First and second detection devices 24 and 25 for detecting a change,
A signal processing device 26 for calculating the rotation period from the output signals of these detecting means 24 and 25 to obtain the torque of the measured object 37
It is roughly composed of

The light transmission device 41 for transmitting the light beam of the irradiation device 20 is composed of a lens 42 for making the light beam enter the optical fiber and an optical fiber 43. The optical fiber 43 is, for example, an SI type single mode, and is a quartz fiber having a core diameter: φ _f = 5 μm and a numerical aperture: 0.11. Optical fiber 43
Is preferably as small as possible. Further, regarding the type of the optical fiber, since it is sufficient that the light of the He-Ne laser of the irradiation device 20 can be transmitted, the SI type, the GI type,
Various fibers such as a multi-component fiber, a plastic fiber, and a polymer clad fiber are applicable without being limited to the single mode or the multimode. Further, the optical connector 45 installed in the beam adjusting device 44 has a structure in which the optical fiber 43 is detachable, so that an optical fiber of a required length can be connected according to the situation.

The beam adjusting device 4 is controlled by the optical connector 45.
The light beam transmitted to 4 is branched by the branch connector 46 into optical fibers 47 and 48. The optical connector 45 joins the optical fiber 43 and the beam adjusting device 44 by butt connection (connection between planes) using a metal ring. Here, in addition to the above, the optical connector 45 can be configured by butt connection using a V-groove, transmission by a lens, or the like. The optical fibers 47 and 48 are the same optical fibers as the optical fiber 43. The branch connector 46 is formed of a prism, and is configured to branch in two directions.

The light transmitted to and emitted from the optical fiber 47 passes through the lens 49, the beam splitter 33, and the condenser lens 35 and irradiates the measured object 37. On the other hand, the light transmitted and emitted to the optical fiber 48 passes through the lens 50, the beam splitter 34,
Is irradiated. The lenses 49 and 50 may be formed of an achromatic lens capable of correcting spherical aberration, or may be formed of an aplanat lens such as an apochromatic lens or an aspheric lens.

The first and second low reflectors 51, 52 are:
It is attached so as not to reflect the irradiated light beam for a fixed time every time the measurement object 37 rotates. These low-reflectors 51 and 52 are made of black vinyl resin whose reflectance is extremely smaller than the surface of the measured object 37.
1 and 52 can be any materials that absorb light.

The operation of the torque measuring device according to the second embodiment configured as described above will be described.

The laser light having a beam diameter of, for example, 0.65 mm emitted from the irradiation device 20 is guided to the optical fiber 43 by the lens 42. The light beam transmitted by the optical fiber 43 is guided to a beam adjusting device 44 by an optical connector 45. Then, the light beam is transmitted to the branch connector 4.
The light is evenly split into optical fibers 47 and 48 by 6.
The first laser light transmitted and emitted to the optical fiber 47 is first converted into parallel light by the lens 49. The first laser light that has become parallel light is applied to the beam splitter 33.
After that, the light is irradiated on the surface of the measured object 37 by the condenser lens 35.

In this case, the beam diameter of the first laser beam is
The focusing lens 35 is focused on the surface of the measured object 37
Fine-tune the position of. Beam diameter at the surface of the measured body 37: W _f can be calculated from the approximately equation (5).

(Equation 5)

In this embodiment, NA _IN = 0.11 because the numerical aperture of the lens 49 is the same as the numerical aperture of the optical fiber. Since NA _OUT = 0.25 and φ _f = 5 μm,
Beam diameter: W _f = 2.2 μm. Therefore, the first laser light on the surface of the measured object 37 has a beam diameter of:
W _f = 2.2 μm.

The first laser beam applied to the measured object 37
Illuminates the first low reflector 51 attached to the measured object 37.
It does not reflect when it is radiated, but the other measured object 3
The surface 7 is reflected. For this reason, every rotation
It is only possible to obtain a state where there is no reflected light of the first laser light.
Wear. The reflected light is a speckle pattern on the surface of the measured object 37.
It is. The illuminated light, if reflected light is present
Then, the light enters the condenser lens 35 in the same optical path. And collection
The beam diameter of the reflected light by the optical lens 35: φ _f’
φ_f'= 25 mm. Here, the beam of the irradiated light beam
Beam diameter: φ and reflected light: φ_f’Are the same,
Make sure that the focus is on the surface of the fixed object 37.
Can be.

The reflected light having a beam diameter of φ _f ′ = 25 mm is split by a beam splitter 33, and one reflected light is incident on a first detector 24 constituted by an avalanche photodiode. The first detection device 24 can obtain a pulse-shaped first detection signal 53 shown in FIG. 5 in order to detect a state in which there is no reflected light of the first laser light for a fixed time every rotation. The beam diameter of the first laser light on the surface of the measured object 37 is 2.2 μm
Is very small, the fall time of the first detection signal 53 is about 10 ns.

On the other hand, the second laser light that is branched into the optical fiber 48 by the branch connector 46 and emitted is subjected to exactly the same operation as the first laser light, and is converted into parallel light by the lens 50 to be transmitted to the beam splitter 34. After transmission
The light is emitted by the condenser lens 36 so as to be focused on the surface of the measured object 37. The beam diameter on the surface of the measured object 37 is 2.2 μm.

The second laser light applied to the object to be measured 37 has reflected light when applied to the surface of the object to be measured 37 and reflected light when applied to the low reflector 52. Since it does not exist, it is possible to obtain a state in which there is no reflected light of the second laser light for a fixed time every rotation. When there is reflected light, the condenser lens 36 is placed on the same optical path as the irradiated light beam.
Incident on. If the beam diameter of the irradiated light beam and the reflected light beam have the same value, it can be confirmed that the focal point is focused on the surface of the measured object 37. The reflected light is split by a beam splitter 34, and one reflected light is incident on a second detector 25 constituted by an avalanche photodiode. This second detection device 25
In order to detect a state in which there is no reflected light of the second laser light for a fixed time every rotation, the second pulse shape shown in FIG.
Can be obtained. Since the beam diameter of the second laser light on the surface of the measured object 37 is very small, 2.2 μm, the fall time of the first detection signal 53 is about 10 ns. Further, the signal processing device 26 takes in the first detection signal 53 and the second detection signal 54 and calculates the rotation period and the torque.

Here, as shown in FIG. 5, the rotation cycle is obtained by setting a threshold value for the amplitude of the first detection signal 53 and from the time interval between adjacent threshold values. The first and second detection signals 53,
Since both of the amplitude voltages of 54 are about 1V, the threshold value is fixed to 0.9V by a voltage value. This threshold can be appropriately determined according to the amplitude voltage. The change of the rotation cycle obtained by the present embodiment was almost the same as the measurement result of the first embodiment shown in FIG. Further, the rotation cycle can also be obtained from the second detection signal 54.

On the other hand, when the threshold value of the second detection signal 54 is set in the same manner as the first detection signal 53 and the first and second detection signals 53 and 54 are compared, FIG. The indicated delay time occurs. As a result, the torque for each rotation can be obtained using the delay time and equation (1).

As described above, according to the present embodiment, the laser light of the irradiation device 20 can be transmitted to the inside of the device or a narrow portion by the optical fiber 43. And the first and second
Has a beam diameter of 2.2 on the surface of the measured object 37.
μm. When the reflected light is detected by the detection devices 24 and 25, the first and second detection signals 53 and 54 having a rise time of about 10 ns are generated because the low reflection bodies 51 and 52 are attached to the measured body 37. It can be obtained every rotation. Further, the signal processing device 26 can measure the rotation cycle of the measured object 37 with predetermined accuracy shown in FIG. 6 by fixing the threshold voltage based on the amplitude voltage values of the detection signals 53 and 54. Further, the torque for each rotation can be obtained with a predetermined high accuracy by using the delay time shown in FIG. 5 and Expression (1).

[Third Embodiment] FIG. 7 is a block diagram showing a third embodiment of the torque measuring device according to the present invention.

As shown in FIG. 7, the torque measuring device according to the third embodiment includes an irradiation device 20 for irradiating a laser beam, this laser beam is branched into first and second laser beams, and each laser beam is The beam adjusting device 21 that adjusts the beam diameter and irradiates the measured object 37,
First and second reflectors 55 and 56 for changing the reflection state of the first and second laser lights, and first and second detectors 24 and 24 for detecting the reflected lights of the first and second laser lights.
25, a filtering device 57 for removing signal components other than the detection signals from the output signals of the detection devices 24 and 25, and a correlation process of the output signals of the detection devices 24 and 25 to obtain the torque of the measured object 37. It is roughly constituted by a correlation processing device 58.

The first and second reflectors 55 and 56 are set to a size of 1 cm × 1 cm as shown in FIG.
Band-shaped reflecting portions that reflect the irradiated light beam with high efficiency and band-shaped absorbing portions that absorb the light beam with high efficiency are alternately arranged. The band width may be on the order of several tens of μm. Here, the reflecting portion is made of a mirror-shaped aluminum thin film, and the absorbing portion is made of black vinyl resin.
Any substance can be used as the material of the reflecting portion as long as it reflects light with high efficiency, and any material can be used as the material of the absorbing portion as long as it absorbs light. Further, a low-reflection portion can be formed by etching or half-etching a mirror-like aluminum thin film without using a low-reflection substance. In the case of etching, the surface of the non-measurement body 37 exposed by etching becomes a low reflection portion. In the case of half-etching, light is irregularly reflected in the half-etched portion and specular reflection is reduced, so that the half-etched portion becomes a low reflection portion. The first and second reflectors 55 and 56 are arranged such that the striped stripe pattern is parallel to the rotation axis of the measured object 37, and the intensity of the reflected light fluctuates extremely for a certain time for each rotation. It is attached to be.

The detection signals of the first and second detection devices 24 and 25 are transmitted to a filtering device 57 for performing a filtering process and a correlation processing device 58 for performing a correlation process. Filtering device 57 and correlation processing device 58
Is composed of a general-purpose computer. The filtering device 57 converts the detection signal into a sampling frequency of 1 GHz.
This is a device that performs a filtering process by digitizing with a filter, and can be configured by a filtering circuit using LCR, and can also directly perform a filtering process on a detection signal. Also, regarding the correlation processing device 58,
It can also be constituted by a correlator.

The operation of the torque measuring device according to the third embodiment configured as described above will be described.

The diameter of the beam emitted from the irradiation device 20
The 65 mm laser light is separated into a first laser light reflected by a beam splitter 27 of the beam adjusting device 21 and a second laser light transmitted therethrough. The first laser beam has a beam diameter of 25 mm due to the magnifying optical system of the lens 29 and the lens 31. And the expanded first
Is transmitted through the beam splitter 33,
The light is focused on the surface of the measurement object 37 by the condenser lens 35 and irradiated so that the beam diameter becomes 1.6 μm.

Here, when the first laser beam applied to the measurement target 37 is applied to the first reflector 55,
Although the reflected light has a unique reflection state of alternating strength, the reflection on other surfaces is extremely small. For this reason, the reflected light has a unique reflection state in which the reflected light alternately repeats the intensity for a fixed time every rotation. In the case of a strong reflection state, the light enters the condenser lens 35 along the same optical path as the irradiated light beam. With this condenser lens 35, the beam diameter of the reflected light: φ ′ becomes φ ′ = 25 mm. If the beam diameter of the irradiated light beam: φ and the reflected light: φ ′ are the same value, it can be confirmed that the focal point is focused on the surface of the measured object 37. Then, the reflected light having the beam diameter: φ ′ = 25 mm is split by the beam splitter 33,
One reflected light is incident on a first detection device 24 constituted by an avalanche photodiode.

The first detecting device 24 detects the reflected light, but does not detect a signal when the reflected light is weakly reflected. Since the intensity of the reflected light is alternately repeated, a comb-shaped first detection signal 59 can be obtained for each rotation as shown in FIG. The measured object 3
7 has a beam diameter of 1.6 μm on the surface of the first laser beam.
m, the rise and fall times of the first detection signal 59 are about 10 ns.

On the other hand, the second laser light is reflected at a right angle by the mirror 28, and then receives exactly the same action as the first laser light, and is enlarged by the magnifying optical system of the lenses 30 and 32 and the condenser lens 36. Focus on the surface of the measured object 37,
Irradiation is performed so that the beam diameter becomes 1.6 μm. When the light is irradiated in the weak reflection state of the second reflector 66, there is no reflected light, but when the light is irradiated in the strong reflection state, the light enters the condenser lens 36 along the same optical path as the irradiated light. . Then, the beam diameter: 2
After reaching 5 mm, the light is separated by the beam splitter 34 and enters the second detection device 25.

In the second detector 25, the intensity of the reflected light is alternately repeated, so that a second comb-shaped detection signal 60 similar to the first detection signal shown in FIG. 9 is obtained for each rotation. be able to. Since the beam diameter of the second laser beam on the surface of the measured object 37 is very small, 1.6 μm, the rise and fall times of the second detection signal 60 are about 10 ns.

Further, the first detection signal 59 and the second detection signal 60 are taken into the filtering device 57 and the correlation processing device 58 to calculate the rotation period and the torque. That is, first, the filtering device 57 discretizes the first and second detection signals 59 and 60 into digital values at a sampling frequency of 1 GHz. Then, noise frequency components are removed from the first and second detection signals 59 and 60, which are discretized into digital values. The frequency component to be removed is reflected by the reflector 55 to be processed.
Since the frequency of the detection signal is several KHz,
The frequency component is not less than Hz.

Next, the first and second detection signals 59 and 60 which have been digitized and from which noise has been removed are transmitted to the correlation processing device 58. In the correlation processing device 58, a rotation period is obtained from a cross-correlation function of the two first detection signals 59 different in time.

In the present embodiment, as shown in FIG. 10, an output signal including two temporally different pulse signals is extracted and set as a function: F (t). Equation (6) defines the cross-correlation function: Φ (τ).

[0089]

(Equation 6) Here, the value of the cross-correlation function: Φ (τ) is calculated by increasing the delay time: τ from 0. This calculation corresponds to an operation of delaying the first pulse signal shown in FIG. 10 in time and examining the degree of overlap with the next pulse signal. Delay time:
When τ approaches the rotation cycle, this pulse signal coincides with the next pulse signal, and the value of the cross-correlation function: Φ (τ) increases. This value becomes maximum when the two pulse signals are most matched, and the delay time τ at this time is the rotation cycle.

FIG. 11 shows the calculation result of the cross-correlation function Φ (τ) in the present embodiment. As a result, the rotation cycle is 41.821255 ms. This rotation cycle is the same as the first detection signal 59 and the second detection signal 6
It can also be obtained from zero.

The torque is obtained from a cross-correlation function between the first detection signal 59 and the second detection signal 60. In the present embodiment, as shown in FIG. 12, the output signal of the first detection signal 59 is extracted and set as a function: G ₁ (t), and the second detection signal 60 is extracted.
Is extracted and set as a function: G ₂ (t). The definition of the cross-correlation function: Φ _i (τ) is represented by Expression (7).

[0092]

(Equation 7) Here, the value of the cross-correlation function: Φ _i (τ) is calculated by increasing the delay time: τ from 0. This calculation corresponds to an operation of delaying the pulse signal of the first detection signal 59 in time and examining the degree of overlap with the pulse signal of the second detection signal 60. Since the pulse signal of the first detection signal 59 and the pulse signal of the second detection signal 60 have the same shape,
When there is no load by the load device 38, they match without delay time. On the other hand, when a load from the load device 38 exists, a delay time occurs in the pulse signal of the second detection signal 60. This delay time is the first time shifted
Is the delay time when the cross-correlation function: Φ _i (τ) is maximized by the coincidence of the pulse signal of the detection signal 59 with the pulse signal of the second detection signal 60.

The cross-correlation function in this embodiment: Φ
FIG. 13 shows the calculation result of _i (τ). As a result, the delay time: τ becomes τ = 111 ns. Then, the torque for each rotation can be obtained using the delay time and the equation (1).

As described above, according to the present embodiment, the first and second laser beams transmitted through the space and irradiated on the object 37 have a beam diameter of 1.6 μm on the surface of the object 37.
Becomes Then, when the reflected light is detected by the detecting devices 24 and 25, the reflector 55 whose intensity of the reflected light fluctuates extremely fluctuates so that the rise and fall times shown in FIG. The first and second detection signals 59 and 60 can be obtained for each rotation. In response to the first and second detection signals 59 and 60,
Since the noise component having a frequency of 50 kHz or more is removed by the filtering device 57, the signal has a rise and fall time of about 10 ns even under a noise environment.

The correlator 58 correlates the first or second detection signal 59 or 60, which has a very short rise and fall time of about 10 ns and has a complicated comb shape, to obtain a diagram. As shown in FIG. 11, the rotation cycle of each rotation of the measured object 37 can be measured with a predetermined high accuracy. Further, the delay time shown in FIG. 13 is obtained by correlating the first detection signal 59 and the second detection signal 60, and the delay time and the equation (1) are used to obtain a predetermined high precision for each rotation. Can be obtained.

In the first to third embodiments, the beam adjustment devices 21 and 44, the first and second detection devices 2
4, 25 are physically connected and fixed.

[Fourth Embodiment] FIG. 14 is a configuration diagram showing a fourth embodiment of the torque measuring device according to the present invention.

As shown in FIG. 14, the torque measuring device according to the fourth embodiment includes an irradiating device 20 for irradiating a laser beam, this laser beam is branched into a first laser beam and a second laser beam, First and second optical transceivers 61 and 62 for adjusting the beam diameter and irradiating the measured object 37 with the measured object 3
And first and second reflectors 65 and 66 which are attached to the surface of the first and second laser beams 7 to change the reflection state of the first and second laser beams.
And a first for detecting reflected light of the first and second laser beams.
And second detecting devices 24 and 25, and these detecting devices 2
A filtering device 57 for removing signal components other than the detection signal from the output signals of the detection devices 24 and 2;
And a correlation processing device 58 that obtains the torque of the measured object 37 by performing a correlation process on the output signal of the measuring device 5.

The laser beam from the irradiation device 20 is split into reflected light and transmitted light by the beam splitter 27 of the first optical transceiver 61. The reflected light is transmitted to the first optical transceiver 61.
The object 37 is irradiated through the lenses 29 and 31, the beam splitter 33, and the condenser lens 35. The transmitted light is
The light enters the second optical transmission / reception device 62, is reflected by the lens 30, and irradiates the measured object 37 through the lenses 30, 32, the beam splitter 34, and the condenser lens 36.

The first optical transmitting / receiving device 61 has the second
A surveillance camera 63 is installed as a position change measuring means for measuring the position change of the optical transmitting / receiving device 62. The monitoring camera 63 may be any device capable of displaying an image, and here, a CCD camera is used. The second optical transmitting / receiving device 62 is provided with a mark 64 for recognizing a position change. The mark 64 may be any mark that can be easily recognized by the surveillance camera 63.
An aluminum thin film having a width of 1 cm and a thickness of 1 cm is used. Also, the mark 64 can be used in place of the second optical transmitting / receiving device 62 by making a specific damage.

As shown in FIG. 15, each of the first and second reflectors 65 and 66 has a radiating region for irregularly reflecting light rays and a reflecting region for reflecting light in the same direction as the irradiation direction. It is composed of a retroreflector having a shape, and the irregular reflection area is composed of a scattering reflector having a minute shape. The substance in the reflection area is applicable as long as it reflects in the same direction as the irradiation direction, and the substance in the irregular reflection area is applicable as long as it is a substance that causes irregular reflection.

The operation of the torque measuring device according to the fourth embodiment configured as described above will be described.

The diameter of the beam irradiated from the irradiation device
The 65 mm laser light is separated into a first laser light reflected by the beam splitter 27 of the first optical transmission / reception device 61 and a second laser light transmitted and incident on the second optical transmission / reception device 62. .

The first traveling inside the first optical transmitting / receiving device 61
Has a beam diameter of 25 mm due to the magnifying optical system of the lens 29 and the lens 31. After being transmitted through the beam splitter 33, the expanded first laser beam is focused by the condenser lens 35 on the surface of the measured object 37, and is irradiated so that the beam diameter becomes 1.6 μm.

When the first laser beam applied to the object 37 is applied to the first reflector 65, reflection and irregular reflection are repeated alternately, so that a specific reflection is exhibited. However, other reflections on the surface of the measured object 37 are extremely small. For this reason, it shows a unique reflection in which the reflection and the irregular reflection alternately repeat for a certain period of time every rotation.

When the light enters the reflection state, the light enters the condenser lens 35 along the same optical path as the irradiated light beam. The beam diameter of the reflected light: φ ′ is φ ′ = 25 mm. The reflected light is split by the beam splitter 33, and one reflected light is incident on the first detection device 24. The first detecting device 24 detects the reflected light, but does not detect a signal in the case of the irregular reflection state. Since such reflection and irregular reflection are alternately repeated, a first detection signal 59 having a comb shape similar to that of FIG. 9 can be obtained every rotation. Since the beam diameter of the first laser light on the surface of the measured object 37 is very small, 1.6 μm, the rise and fall times of the first detection signal 59 are about 10 ns.

On the other hand, the second laser light incident on the second optical transmitting / receiving device 62 is reflected at a right angle by the mirror 28,
It receives exactly the same action as the first laser light, focuses on the surface of the measurement object 37 by the magnifying optical system of the lenses 30 and 32, and the condenser lens 36, and has a beam diameter of 1.6 μm.
m. There is no reflected light when irradiating the irregular reflection area of the second reflector 66, but the reflected light when irradiating the strong reflection area enters the condenser lens 36 along the same optical path as the irradiated light beam. I do. Then, after the beam diameter becomes 25 mm by the condenser lens 36, the beam is separated by the beam splitter 34 and enters the second detector 25.

In the second detector 25, the reflection and irregular reflection of the second laser light are alternately repeated, so that the second detection signal 60 having a comb shape similar to the first detection signal shown in FIG. Can be obtained for each rotation. The measured object 37
Since the beam diameter of the second laser beam on the surface of the second detection light is very small, 1.6 μm, the rise and fall times of the second detection signal 60 are about 10 ns.

Further, the first detection signal 59 and the second detection signal 60 are taken into the filtering device 57 and the correlation processing device 58, and the rotation period and the torque are calculated. That is, the filtering device 57 converts the first and second detection signals 59 and 60 into digital values at a sampling frequency of 1 GHz, and the frequency of the detection signal by the reflector 65 to be subjected to signal processing is several KHz. , 50 kHz or more are removed.

In the correlation processing device 58, the rotation period is obtained by calculating the cross-correlation function: Φ (τ) defined by the equation (6) using the two first detection signals 59 that are different in time. . Then, the torque is equal to the first detection signal 5
9 and the second detection signal 60, and is calculated by calculating a cross-correlation function: Φ _i (τ) defined by Expression (7). Cross-correlation function of this embodiment: Φ (τ), Φ _i (τ)
Is the same as that of the third embodiment, and the rotation cycle and the torque are the same as those of the third embodiment.

The monitoring camera 63 installed in the first optical transmission / reception device 61 monitors a position change of the mark 64 provided in the second optical transmission / reception device 62. By monitoring the change in the position of the mark 64, a change in the positional relationship between the first optical transmitting / receiving device 61 and the second optical transmitting / receiving device 62 due to a shock from vibration from the surrounding environment is detected. When receiving a vibration or an impact, the rotation speed and the torque are calculated by the correlation processing device 58.
, The detection of vibration or shock is displayed.

On the other hand, in order to correct the change in the positional relationship, the first detection signal 59 and the second detection signal 60 are used to calculate a cross-correlation function: Φ _i (τ) defined by the equation (7).
Calculate the delay time when receiving vibration or shock. This delay time is not the delay time caused by the load device 38,
A delay time τ ′ caused by a change in the positional relationship between the first optical transceiver 61 and the second optical transceiver 62 due to vibration or shock. Therefore, when the positional relationship changes, the cross-correlation function: Φ _i (τ) defined by the equation (7) is calculated to obtain the delay time: τ ′, and the delay time: τ ′ caused by the change in the positional relationship is calculated. The torque: _Ft is obtained according to the equation (8) considering the influence.

(Equation 8)

Further, by providing a plurality of the torque measuring devices of this embodiment along the axial direction, it is possible to measure changes in the rotational speed and torque in the axial direction.

As described above, according to the present embodiment, the first and second laser beams transmitted through the space and applied to the object 37 have a beam diameter of 1.6 μm on the surface of the object 37.
Becomes Then, the first and second transmission / reception devices 61, 6
2, when the reflected light is detected by the reflectors 65 and 66, the rising and falling times of which are very short, about 10 ns, as shown in FIG. Detection signals 59 and 60 can be obtained for each rotation.

The filtering device 57 applies a frequency of 50 kHz to the first and second detection signals 59 and 60.
Since a noise component equal to or more than z is removed, the signal has a rise and fall time of about 10 ns even in a noise environment.

The correlation processing unit 58 performs correlation processing on the first or second detection signal 59 or 60 having a very short rise and fall time of about 10 ns and having a complicated comb shape. As shown in FIG. 11, the rotation cycle of each rotation of the measured object 37 can be measured with a predetermined high accuracy. Further, a delay time is obtained as shown in FIG. 13 by correlating the first detection signal 59 and the second detection signal 60, and by using this delay time and Expression (1), the rotation can be performed with a predetermined high accuracy. Each torque can be obtained.

Then, with the monitoring camera 63 and the mark 64, the position fluctuation of the first and second optical transmitting / receiving devices 61 and 62 due to vibration and impact from the surrounding environment can be detected, and the position is calculated according to the equation (8). It is possible to reduce a decrease in measurement accuracy due to the fluctuation.

It should be noted that a plurality of the torque measuring devices of the present embodiment can be provided in the axial direction, so that it is possible to measure changes in the rotational speed and torque in the axial direction.

[Fifth Embodiment] FIG. 16 is a block diagram showing a fifth embodiment of the torque measuring device according to the present invention.

As shown in FIG. 16, the torque measuring device according to the fifth embodiment comprises an irradiating device 20 for irradiating a laser beam and a lens 42
, A multi-branch connector 69 for branching the laser light incident on the optical fiber 43, optical fibers 70, 71, 72, 73 connected to the multi-branch connector 69, and connected to these optical fibers 70 to 73, respectively. First, second, third, and fourth optical transceivers 74, 75, 76, and 77, and first and second reflectors 22, 23 that are attached to the surface of the measured object 37 to change the reflection state. And the optical fiber 70 ~
A correlation processing device 58 for obtaining a torque of the measured object 37 by performing a correlation process on the detection signal of each laser beam branched to 73.

The optical fibers 70, 71, 72 and 73 are the same optical fibers as the optical fiber 43, are of the SI single mode, have a core diameter: φ _f = 5 μm, and have a numerical aperture of 0.11.
Quartz fiber. The multi-branch connector 69 for branching fiber light is formed of a prism, and is configured to branch in four directions.

First, second, third and fourth optical transmitting / receiving devices 7
Reference numerals 4, 75, 76, and 77 each include a first optical transmission / reception device 61 including a beam adjustment unit and a detection unit that detects reflected light of an irradiated light beam. Then, the measured object 3
The rotation speed and torque of the first and second optical transmission / reception devices 74 and 75 are used for the first measurement system and the third and fourth optical transmission and reception devices 76 and 77 are used for the second measurement It is measured by a total of two systems. The first and second measurement systems are installed in the circumferential direction of the measured object 37. In addition, it is possible to install a plurality of optical transmitting / receiving devices 74 to 77 in the circumferential direction and measure the rotation speed and the torque in multiple systems. Here, two systems are used because they are the same in principle.

First and third optical transceivers 74 and 76
, LEDs 78 and 80 are attached. Then, in order to detect a change in the position of these LED lights, the second and fourth light transmitting / receiving devices 7 installed at opposing positions are arranged.
5, 77 are provided with two-dimensional vertical and horizontal position sensors 79, 81 as position fluctuation measuring means. L
Although the EDs 78 and 80 are infrared LEDs, they are not particularly limited.

The operation of the torque measuring device according to the fifth embodiment configured as described above will be described.

The diameter of the beam emitted from the irradiation device
The 65 mm laser light enters the optical fiber 43 through the lens 42. The incident light beam is equally branched by the multi-branch connector 69 to the optical fibers 70, 71, 72, 73.

Here, the first laser beam split into the optical fiber 70 enters the first optical transmitting / receiving device 74. In the first optical transmitting / receiving device 74, the same operation as that of the optical transmitting / receiving device 61 is performed on the first laser light so that the first laser light is focused on the surface of the measured object 37 and irradiated so that the beam diameter becomes 2.2 μm. You. Then, a detection signal of the reflector 22 can be obtained every rotation. The first laser beam detection signal is a pulse signal having a rise time of about 10 ns as shown in FIG.

On the other hand, the second laser beam split into the optical fiber 75 enters the second optical transmitting / receiving device 75. In the second optical transmitting and receiving device 75, the same operation as that of the first optical transmitting and receiving device 74 is performed on the second laser light, and the reflector 2 is rotated every rotation.
3 detection signals can be obtained. The detection signal of the second laser beam has a rise time of 10n as shown in FIG.
It becomes a pulse signal of about s.

The correlation processing device 58 uses the detection signals of the first and second laser beams to obtain the equations (1), (6),
Equation (7) is calculated, and the first and second optical transceivers 7 are calculated.
Rotation speed by the first measurement system composed of 4,75: v
_1, torque: it is possible to determine the F _1.

The third and fourth optical transmitters and receivers 76 and 77 perform the same processing on the third and fourth laser beams branched by the optical fibers 72 and 73, and the second processor in the correlation processor 58. The rotation speed: v ₂ and the torque: F ₂ can be obtained by the measurement system of FIG.

Then, in the correlation processor 58, the rotational speeds v ₁ , v ₁ obtained by the first measurement system and the second measurement system are obtained.
The rotation speed v _ave and the torque F _ave are obtained by performing an averaging process shown in Expressions (9) and (10) with respect to v ₂ and the torques F ₁ and F ₂ assuming that the number of systems is n = 2.

(Equation 9)

(Equation 10)

Second and fourth optical transmission / reception devices 75 and 77
The position sensors 79 and 81 attached to the
And, the light beams emitted from the LEDs 78, 80 attached to the third optical transceivers 74, 76 are detected. Since the position sensors 79 and 81 can detect a change in the position of the irradiated light beam, when vibration or impact occurs due to the surrounding environment, the light between the first and second and the third and fourth light is emitted. A change in the position of the transmitting / receiving device can be detected. When vibration or shock is received, the rotation speed or torque is not displayed on the correlation processing device 58, and the detection of vibration or shock is displayed.

When the positional relationship changes, the cross-correlation defined by equation (7) in each of the first and second measurement systems:
Φ _i (τ) is calculated to obtain a delay time due to position fluctuation: τ ′, and the torques F ₁ and F ₂ of the first and second measurement systems are calculated according to equation (8). Then, the torque F _ave can be obtained by the averaging process according to the equation (10).

As described above, according to the present embodiment, the irradiation device 20 is controlled by the optical fibers 43, 70, 71, 72, 73.
Laser light can be transmitted to the inside of a device or to a narrow portion. The first, second, third, and fourth laser beams transmitted through the fiber and applied to the measurement target 37 are focused on the surface of the measurement target 37, and have a beam diameter of 2.2 μm.

When the first to fourth optical transmission / reception devices 74 to 77 detect the reflected light of the first to fourth laser beams, the respective light transmission / reception devices are reflected by the reflectors 22 and 23 attached to the measured object 37. Then, the rise time is 10 as shown in FIG.
A detection signal having a pulse shape of about ns can be obtained for each rotation.

The correlation processing device 58 calculates the cross-correlation function: Φ (τ) shown in the equation (6), calculates the rotation speed obtained from each optical transceiver, and further performs the averaging processing shown in the equation (9). By doing so, the rotation cycle of each rotation of the measured object 37 can be measured with a predetermined high accuracy. Further, by calculating a cross-correlation function: Φ _i (τ) shown in Expression (7) and further performing an averaging process shown in Expression (10), the torque for each rotation of the measured object 37 with a predetermined high accuracy is obtained. Can be measured.

Further, the LEDs 78 and 80 and the positions 79 and 81 can detect positional fluctuations of the first to fourth optical transmission / reception devices 74 to 77 due to vibration and impact from the surrounding environment. Then, by correcting the position variation and performing the averaging process in accordance with Expressions (8) and (10), it is possible to reduce a decrease in torque measurement accuracy due to the position variation of the optical transceiver.

Further, by installing a plurality of the torque measuring devices (apparatus main bodies) of the present embodiment along the circumferential direction of the object to be measured, the torque values measured from each of the main bodies are subjected to an average value processing. The accuracy of torque measurement can be improved.

Note that the present invention is not limited to the above embodiments, and various changes can be made. For example, the first
In the fourth to fourth embodiments, the case where two reflectors and two detection devices are installed has been described, but the present invention is not limited to this, and two or more reflectors and two or more detection devices may be installed.

[0139]

As described above, according to the present invention,
For an optical fiber that can be measured inside equipment or in narrow spaces, or for an irradiated light beam transmitted through space, the light beam is split into multiple light beams by beam adjustment means, and the beam diameter of each light beam is adjusted to several μm Thus, the object to be measured can be irradiated.

Since the object to be measured is provided with a plurality of reflection means whose reflection state changes, the plurality of detection means generates a plurality of pulse signals having a sharp rise and fall time and a unique waveform shape. It can be obtained every rotation.
The rise and fall times of the plurality of pulse signals are about 10 ns because the beam diameters of the plurality of light beams are several μm.

The signal processing means performs signal processing or correlation processing in consideration of a plurality of output fluctuations on a plurality of pulse signals having steep rise and fall times and a unique waveform shape, thereby achieving a desired 10 ns. The rotation cycle and torque can be measured with high measurement accuracy.

Also, the filtering means for removing noise and the position fluctuation measuring means for measuring the position fluctuation of the detecting means due to vibration or impact prevent the deterioration of the measurement accuracy of the rotational speed and torque generated by noise, vibration, impact and the like. can do.

Furthermore, the torque measuring device according to the present invention
Since a plurality of objects can be installed in the axial direction of the measured object, it is possible to measure changes in the rotational speed and torque in the axial direction. In addition, by averaging a plurality of objects to be measured in a circumferential direction, it is possible to improve the measurement accuracy of the rotational speed and the torque.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a torque measuring device according to the present invention.

FIG. 2 is a timing chart showing measurement results obtained by the first embodiment of the present invention.

FIG. 3 is a diagram showing a rotation speed obtained by the first embodiment of the present invention.

FIG. 4 is a configuration diagram showing a second embodiment of the torque measuring device according to the present invention.

FIG. 5 is a timing chart showing measurement results obtained by a second embodiment of the present invention.

FIG. 6 is a diagram showing a rotation speed obtained by a second embodiment of the present invention.

FIG. 7 is a configuration diagram showing a third embodiment of the torque measuring device according to the present invention.

FIG. 8 is an enlarged view showing the reflector in FIG. 7;

FIG. 9 is a timing chart showing measurement results obtained by a third embodiment of the present invention.

FIG. 10 is a diagram showing a method for determining a rotation speed in a third embodiment of the present invention.

FIG. 11 is a diagram showing a rotation speed obtained by a third embodiment of the present invention.

FIG. 12 is an explanatory diagram showing a method for obtaining torque in a third embodiment of the present invention.

FIG. 13 is a diagram showing a torque obtained by a third embodiment of the present invention.

FIG. 14 is a configuration diagram showing a fourth embodiment of the torque measuring device according to the present invention.

FIG. 15 is an enlarged view showing the reflector in FIG. 14;

FIG. 16 is a configuration diagram showing a fifth embodiment of the torque measuring device according to the present invention.

FIG. 17 is a configuration diagram showing a torque detection device as a first conventional example.

FIG. 18 is a timing chart showing measurement results obtained by the first conventional example.

FIG. 19 is a timing chart showing another measurement result obtained by the first conventional example.

FIG. 20 is a block diagram showing a rotation speed measuring device as a second conventional example.

FIG. 21 is a diagram showing measurement results obtained by a second conventional example.

FIG. 22 is a diagram showing another measurement result obtained by the second conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 20 irradiation device 21 beam adjusting device 22 first reflector 23 second reflector 24 first detector 25 second detector 26 signal processor 27 beam splitter 28 mirror 29 lens 30 lens 31 lens 32 lens 33 beam Splitter 34 beam splitter 35 condenser lens 36 condenser lens 37 device under test 38 load device 39 first detection signal 40 second detection signal 41 optical transmission device 42 lens 43 optical fiber 44 beam adjustment device 45 optical connector 46 branch connector 47 Optical Fiber 48 Optical Fiber 49 Lens 50 Lens 51 First Low Reflector 52 Second Low Reflector 53 First Detection Signal 54 Second Detection Signal 55 First Reflector 56 Second Reflector 57 Filtering Device 58 Correlation processing device 59 First detection signal 0 second detection signal 61 first optical transmission / reception device 62 second optical transmission / reception device 63 monitoring camera (position variation measuring means) 64 mark 65 first reflector 66 second reflector 69 multi-branch connector 70 optical fiber 71 Optical Fiber 72 Optical Fiber 73 Optical Fiber 74 First Optical Transceiver 75 Second Optical Transceiver 76 Third Optical Transceiver 77 Fourth Optical Transceiver 78 LED 79 Position Sensor (Position Fluctuation Measurement Means) 80 LED 81 Position Sensor (Position fluctuation measuring means)

Continued on the front page (72) Inventor Kazuo Saito 4-1 Egasaki-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside the Energy and Environmental Research Laboratory, Tokyo Electric Power Company (72) Hidehiko Kuroda Shin-Sugita-cho, Isogo-ku, Yokohama-shi, Kanagawa No. 8 In the Toshiba Yokohama office of the Company Limited (72) Inventor Shigeru Shigemoto 8 in Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside of the Toshiba Yokohama office in Japan (72) Michio Sato 8, Shinsugita-machi, Isogo-ku, Yokohama-shi, Kanagawa Address Toshiba Corporation Yokohama Business Office (72) Inventor Takuhisa Kondo 2-4 Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Keihin Business Office Toshiba Corporation (72) Inventor Makoto Ochiai 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside Toshiba Yokohama Office Co., Ltd.

Claims (12)

[Claims] An irradiating means for irradiating a light beam; a beam adjusting means for splitting the light beam into a plurality of light beams; adjusting a beam diameter of each light beam to irradiate the light beam to the object; and a surface of the object to be measured. A plurality of reflecting means attached to the light source to change the reflection state of the plurality of light rays, a plurality of detecting means for detecting a change in the intensity of the reflected light of each of the plurality of light rays, and based on output signals of these detecting means. A signal processing means for calculating a rotation cycle to obtain a torque of the object to be measured. 2. The torque measuring device according to claim 1, wherein the light beam of the irradiating means is transmitted to the beam adjusting means through an optical fiber. 3. The torque measuring device according to claim 1, wherein each of the plurality of reflecting means is a low-reflector having a lower light reflectance than a surface of the measured object. 4. The torque measuring device according to claim 1, wherein each of the plurality of reflecting means has a high reflection area in which the reflectance of the light beam is higher than the surface of the measured object and a reflectance of the light ray is lower than the high reflection area. A torque measuring device comprising a reflector having a low reflection area. 5. The torque measuring device according to claim 1, wherein the plurality of reflecting units each reflect a light beam of the irradiating unit in a direction in which the plurality of detecting units are installed, and at least a part of the light beam of the irradiating unit. And a diffused reflection area for irregularly reflecting the light in a direction other than the installation direction of the plurality of detection means. 6. The torque measuring device according to claim 1, wherein the signal processing means includes a fluctuation threshold value setting means for extracting a detection signal by changing a threshold value in accordance with an output fluctuation of the plurality of detection means. Torque measuring device. 7. The torque measuring device according to claim 1, further comprising filtering means for removing a signal component other than the detection signal from output signals of the plurality of detection means. 8. The torque measuring device according to claim 1, further comprising correlation processing means for performing correlation processing on the outputs of the plurality of detection means to obtain the torque of the measured object. 9. The torque measuring device according to claim 1, wherein the plurality of detecting means have first and second detecting means, and are attached to the first detecting means to monitor and monitor the second detecting means. And a position fluctuation measuring means for measuring a position fluctuation of the second detecting means. 10. The torque measuring device according to claim 1, wherein the plurality of detecting means have first and second detecting means, and are attached to the first detecting means and directed to the second detecting means. Irradiating means for irradiating a light beam, and a position change measuring means attached to the second detecting means for detecting the irradiating light beam and measuring a position change between the first detecting means and the second detecting means. And a torque measuring device. 11. The torque measuring device according to claim 1, wherein a main body of the device is installed along a circumferential direction of the measured object. 12. The torque measuring device according to claim 1, wherein a device main body is installed along an axial direction of a measured object.