JPH11257935A - Apparatus and method for measuring torsion of shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confirm the state of a rotation shaft in operation in real time. SOLUTION: While providing different-reflectivity areas on both end side surfaces of a shaft A, ray emitting means 4, 5 and photoelectric detecting means 6, 7 for reflected lights are provided, and a computing means which computes an angle of torsion by the time difference of detection of reflected lights from the reflectivity-different areas by individual photoelectric detecting means 6, 7, is provided. And time required for one rotation of the shaft A is measured, and an angle of rotation per unit time of the shaft is calculated. Besides, an angle of torsion is computed by multiplying the angle of rotation by the time difference obtained on the occasion of the detection of the detection of the reflected lights from the reflectivity-different areas, of rays emitted from the emitting means, in the shaft A in operation by the use of the photodetecting means 6, 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torsion of a rotating shaft capable of measuring in real time the torsion of a rotatable metal cylinder (referred to as a rotating shaft in this specification) used in various transmission mechanisms. The present invention relates to a measuring device and a measuring method.

[0002]

2. Description of the Related Art Generally, a rotary shaft has one end connected to a power side and a transmission means provided at the other end, so that a very small twist is generated during operation. In addition, metal fatigue accumulates due to the vibration during operation, and the worst case cannot be ruled out that the rotating shaft may be damaged.

[0003]

However, since the rotating shaft is almost incorporated in the machine and is hardly exposed to the outside, the machine must be disassembled and inspected, which is extremely troublesome. Further, the damage to the rotating shaft occurs during operation, and a device that can grasp the state of the rotating shaft during operation has been desired.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem that the state of a rotating shaft during operation cannot be grasped. One or more different areas are provided, and means for irradiating light beams to both end surfaces of the rotating shaft are provided, and a light receiving means for light reflected from the surface is provided. Means for detecting and reflecting the reflected light from the two waveforms converted into an electric signal, and a time difference when detecting the reflected light from the reflectance difference area in each light receiving means or a light ray from one of the irradiation means, After the reflected light from the detection start point on the rotating shaft in the operating state is detected by one light receiving unit, the reflected light of the light beam from the other irradiation unit from the detection starting point on the rotating shaft in the operating state is received by the other light receiving unit. One light receiving hand until detection by means In the number of detections of the reflected light from the detected reflectance difference area counted in computing means providing a calculation means for calculating a twist angle. Then, the time required for one rotation of the rotation axis is measured to calculate the rotation angle per unit time of the rotation axis, or the center distance of the reflectance difference area and the radius of the rotation axis are input, and the former is replaced with the latter. Calculate the divided constant,
In addition, the time difference when the light from the irradiation unit detects the reflected light from the reflectance difference area on the rotation axis in the operating state by the light receiving unit, or the detection of the light from one irradiation unit on the rotation axis in the operation state From the point at which the reflected light from the point is detected by one of the light receiving means to the point at which the light from the other irradiating means is detected by the other light receiving means from the detection start point on the rotating shaft in the operating state. By calculating the torsion angle by multiplying the number of times of detection of reflected light from the reflectance difference area detected by the light receiving means and counted by the calculating means by the rotation angle or the constant, the state of the rotating shaft in the operating state is made into a waveform. Alternatively, the above problem is solved by making the change visible by making a numerical value.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a rotation axis A having a radius R
In the torsion measuring device 1, the reflectors 2, 3 having a width W provided mainly on both end surfaces of the rotation axis A and irradiating light beams to both end surfaces of the rotation axis A, for example, like a laser Light ray L
i, irradiating means 4 and 5, and light receiving means 6 and 7 for detecting reflected light Lo from both end surfaces of the rotation axis A and converting them into electric signals. Also, the light receiving means 6 and 7 are connected to a display 8 such as an oscilloscope, and the two electric signals from the light receiving means 6 and 7 are formed into waveforms for display and comparison. In connection with this, two electric signals from the light receiving means 6 and 7, that is, data are arithmetically processed to calculate a twist angle Δθ, and the numerical value is displayed, recorded and stored. Alternatively, the light receiving means 6, 7 and the display 8 may be connected to the calculating means 9 to compare the two waveforms and display the calculated torsion angle Δθ. Therefore, either one or both of the comparison of the two waveforms on the display 8 or the display of the torsion angle Δθ calculated and quantified by the calculation means 9 is performed, so that the state of the rotating shaft A in the operating state can be viewed. .

Next, a torsion measuring device 1 according to a second invention
In this case, the light emitting device includes irradiating means 4 and 5, light receiving means 6 and 7, display 8, and calculating means 9 in the same manner as described above.
Further, a plurality of reflectors 10 having a width W are provided on both end surfaces of the rotation axis A,
10a…, 11, 11a… and non-reflectors 12, 12a…, 13, 13a
Are alternately arranged in the circumferential direction of the rotation axis A. That is, by alternately arranging the areas having different reflectivities, the electric signal of the reflected light Lo detected by the light receiving means 6 and 7 has a substantially sinusoidal waveform. Also, the reflectors 10, 10a ..., 1
It is not necessary to arrange 1, 11a... And non-reflectors 12, 12a.
It is only necessary to be able to measure the allowable range of torsion. In this case,
The foremost reflectors 10, 11 in the rotation direction of the rotation axis A are defined as detection start points S, Sa by the light receiving means 6, 7. Also, if the reflectors 10, 10a ..., 11, 11a ... and the non-reflectors 12, 12a
When arranging…, 13, 13a… over the entire circumference, the reflector
.., 11, 11a... Are arranged at positions where any one of them is to be arranged.
14 and 15 are detection start points S and Sa by the light receiving means 6 and 7, respectively. , 11, 11a... And non-reflectors 12, 12a..., 13, 13a... Are preferably arranged on the surface of an adhesive tape and adhered to the rotation axis A. .

The reflectors 2, 3, 10, 10a of the light beam Li
, 11, 11a... And the reflectors 2, 3,.
It is desirable that the width W of 10, 10a..., 11, 11a.

Next, a torsion measuring device 1 according to the first invention.
The method for measuring the torsion of the rotation axis A by the following will be described. The light beam Li irradiated from the irradiation means 4 and 5 to the surfaces on both ends of the rotation axis A is moved by the rotation of the rotation axis A and is reflected by the reflectors 2 and 3 reaching the irradiation position. The light is detected by the light receiving means 6 and 7. Next, the two reflected lights Lo are converted into two electric signals by the light receiving means 6 and 7, and two waveforms are displayed on the display 8, as shown in FIG. Can be confirmed that the rotation axis A is twisted, and the magnitude of the twist angle Δθ can be determined based on the magnitude of the deviation (time difference Δt).

Further, the electric signals from the light receiving means 6 and 7 are inputted to the arithmetic means 9 to calculate the torsion angle Δθ, which is displayed, recorded and stored as a numerical value. Specifically, the torsion angle Δθ of the rotation axis A at the rotation speed p is calculated by the following equation (1). Δθ = 2πp · Δt (1) Further, since the rotation number p is p = 1 / T, where T is the time required for one rotation of the rotation shaft A, the torsion angle Δθ is expressed by the following equation (2). Is calculated. Δθ = 2π · Δt / T (2) Since the error δ occurs in the time difference Δt due to the vibration during the operation of the rotating shaft A, the torsion angle Δθ is calculated with the error δ included. Then, the reflected light Lo
The average value Δt1 of the number of times of the time difference Δt when the light receiving means 6 and 7 detect the is calculated by the following equation (3).

(Equation 1) However, since the vibration takes the values on both the positive and negative sides approximately equally,
Since the second term on the right side of equation (3) is “0”, the following equation (4) is obtained.
To calculate the average value Δt1.

(Equation 2) That is, it is desirable to calculate the torsion angle Δθ by the following equation (5). Δθ = 2π · Δt1 / T (5)

Next, a torsion measuring device 1 according to the second invention
The method for measuring the torsion of the rotation axis A by the following will be described. The light beams Li irradiated from the irradiation means 4 and 5 to the surfaces on both ends of the rotation axis A sequentially move with the rotation of the rotation axis A and are reflected by the reflectors 10, 10a..., 11, 11a. Thus, the reflected light Lo is detected by the light receiving means 6 and 7. Next, the two reflected lights Lo are converted into two electric signals by the light receiving means 6 and 7, and the reflectors 10, 10a..., 11, 11a.
, 13, 13a... Are alternately arranged, so that the amount of luminous flux detected by the light receiving means 6, 7 changes with time. Therefore, as shown in FIG. 8, two substantially sinusoidal waveforms are displayed, and it can be confirmed that the rotation axis A is twisted by the shift of the waveform, and the magnitude of the twist angle Δθ can be determined by the magnitude of the shift.

The electric signals from the light receiving means 6 and 7 are input to the arithmetic means 9 so that the detection of the detection start point S by the one light receiving means 6 and the detection of the detection start point Sa by the other light receiving means 7 are performed. The number of times n the reflected light Lo is detected from the reflectors 10, 10a by the one light receiving means 6 is counted to calculate the twist angle Δθ, which is displayed, recorded, and stored as a numerical value. Specifically, at the radius R, the torsion angle Δθ of the rotation axis A having the width W of each of the reflectors 10, 10a,..., 11, 11a and the non-reflectors 12, 12a. ). Δθ = 2 nW / R (6) Since the radius R and the width W are input to the calculating means 9 in advance,
2W / R is a constant, and the twist angle Δθ can be calculated very easily. However, unless the width W is set to be extremely small, the accurate twist angle Δθ cannot be calculated. For example, to calculate the torsion angle Δθ in units of π / 180 radians (1 degree), W =
It must be 2πR / 720, and thus this measurement method is not suitable for the rotation axis A having a small radius R. Also, 2W corresponds to the distance between the centers of the adjacent reflectors 10, 10a..., 11, 11a.

If the deviation of the waveform displayed on the display 8 exceeds the preset allowable range or the torsion angle Δθ exceeds the allowable range, the rotation axis A is stopped.

When the rotating shaft A is rotated in a no-load state, the reflected light Lo from the reflectors 2 and 3 or the detection start points S and Sa is simultaneously detected by both light receiving means 6 and 7. ,
It is desirable to set the reflectors 2, 3, the irradiation means 4, 5 and the light receiving means 6, 7. However, even if they cannot be detected at the same time, the time axis on the display 8 is corrected in advance so that the peaks of the two waveforms coincide with each other, or the time axis or the number of detections measured during rotation in a no-load state. Using the calculated deviation angle as a correction value, the calculated torsion angle Δθ
It may be programmed in advance so that it is reduced from The unit of all the torsion angles Δθ is radian (rad), and when displayed in degrees (deg), 1 is added to the calculated numerical value.
What is necessary is just to program to multiply by 80 / π.

[0014]

In short, according to the present invention, sections (reflectors 2 and 3) having different reflectivities from the surface of the rotating shaft A are provided on a part of the both end surfaces of the rotating shaft A. Irradiation means 4 and 5 for irradiating the light beam Li on both end surfaces are provided, and light receiving means 6 and 7 for reflected light Lo from the surface are provided. 3) means for displaying and comparing two waveforms converted into electric signals by detecting the reflected light Lo from (3) or each light receiving means 6 and 7 from a different reflectance area (reflectors 2 and 3). Since one or both of the calculation means 9 for calculating the torsion angle Δθ based on the time difference Δt when the reflected light Lo is detected is provided, the area (reflectors 2 and 3) having different reflectances on the rotation axis A is irradiated. Means 4, 5, light receiving means 6, 7, electric signal waveform display / comparison means (display 8 And only set the operating means 9, without the conventional such overhaul, the rotation axis A in Thus also running
Of the rotating shaft A can be visually confirmed by numerical values and waveforms, so that the rotating shaft A can be reliably prevented from being damaged and can be operated safely.

A plurality of sections (reflectors 10, 10a..., 11, 11a...) Arranged at predetermined intervals in the circumferential direction on both end surfaces of the rotation axis A and having different reflectances from each other. At the same time, the detection start points S and Sa are set in some of them, and the same irradiating means 4 and 5 and the light receiving means 6 and 7 as above are provided. From the detection of the detection start point S by one of the light receiving means 6, Until the detection start point Sa is detected by the other light receiving means 7, the number n of times of detection of the reflected light Lo from the reflectance difference area (reflectors 10, 10 a. Since the calculation means 9 for calculating Δθ is provided, the numerical processing by the calculation means 9 can be simplified in addition to the same effects as described above.

Further, the time T required for one rotation of the rotation axis A is measured, and the rotation angle of the rotation axis A per unit time is calculated.
Further, the light beams Li from the irradiation means 4 and 5 and the reflected light Lo from the reflectance difference areas (reflectors 2 and 3) on the rotating axis A in the operating state are detected by the light receiving means 6 and 7, and the time difference Δt at that time is detected.
Is multiplied by the rotation angle to calculate the torsion angle Δθ, so that the state of the rotating shaft A in operation can be quantified.

Further, since vibration also acts on the rotating shaft A during operation, the torsion angle Δθ is calculated by multiplying the rotation angle by the average value Δt1 of the time difference Δt at an arbitrary number of times. The error δ becomes “0” by taking an arbitrary number of times, so that a more accurate twist angle Δθ can be calculated.

Further, the reflectance difference areas (reflectors 10, 10a...
, 11a...) And the radius R of the rotation axis A are input, a constant is calculated by dividing the former by the latter, and the rotation axis A of the light beam Li from one of the irradiation means 4 in the operating state is calculated. , The reflected light Lo from the detection start point S on one end side is detected by one of the light receiving means 6, and then the light beam Li from the other irradiation means 5
Until the reflected light Lo from the detection start point Sa on the other end is detected by the other light receiving means 7, the reflectance difference area (reflector 1) detected by one light receiving means 6 and counted by the arithmetic means 9
0, 10a..., 11, 11a...) Are multiplied by the above constant to calculate the torsion angle Δθ. Therefore, the torsion angle Δ is calculated simply by counting the number of detections n.
Since the θ can be calculated, the practical effect is extremely large, such that the torsion angle Δθ can be easily calculated without any complicated calculation.

[Brief description of the drawings]

FIG. 1 is a schematic view of a torsion measuring device according to a first invention.

FIG. 2 is an enlarged view of a main part of an end face of FIG. 1;

FIG. 3 is a diagram showing a waveform displayed by the torsion measuring device of FIG. 1;

FIG. 4 is a schematic view of a torsion measuring device according to a second invention.

FIG. 5 is an enlarged view of a main part of the end face of FIG. 4;

FIG. 6 is a diagram showing a waveform displayed by the torsion measuring device of FIG.

FIG. 7 is a schematic diagram of a torsion measuring device in which a reflectance difference area is provided over the entire circumference of a rotation axis.

FIG. 8 is an enlarged view of a main part of the end face of FIG. 7;

FIG. 9 is a diagram showing a waveform displayed by the torsion measuring device of FIG. 7;

[Description of Signs] 2,3 Reflector 4,5 Irradiation means 6,7 Light receiving means 8 Display 9 Operation means 10,10a ..., 11,11a ... Reflector A Rotation axis Li ray Lo Reflected light R Radius S, Sa detection Start point T Required time n Number of detections Δt Time difference Δt1 Average value Δθ Torsion angle

Claims (5)

[Claims] 1. An area having a different reflectance from the surface of the rotating shaft is provided on a part of the surface on both ends of the rotating shaft, and means for irradiating light to both surfaces of the rotating shaft is provided. Means for detecting reflected light from the different reflectance areas with each light receiving means and displaying and comparing two waveforms converted into electric signals, or each light receiving means from the different reflectance areas. A torsion measuring device provided with one or both of calculation means for calculating a torsion angle based on a time difference when the reflected light is detected. 2. A method according to claim 1, further comprising: providing a plurality of sections arranged at predetermined intervals in a circumferential direction on both end surfaces of the rotating shaft and having different reflectances from each other, and setting a detection start point in a part thereof.
In addition, means for irradiating light beams to both surfaces on both ends of the rotating shaft are provided, and means for receiving light reflected from the surface are provided. Means for displaying and comparing two waveforms, or the reflection from the area with the different reflectance at one light receiving means from the detection of the detection start point by one light receiving means to the detection of the detection start point by the other light receiving means A torsion measuring device for a rotating shaft, comprising one or both of arithmetic means for calculating a torsion angle by counting the number of times of light detection. 3. A measuring method using the torsion measuring device according to claim 1, wherein a time required for one rotation of the rotating shaft is measured, a rotation angle of the rotating shaft per unit time is calculated, and irradiation means is provided. The reflected light from the reflectance difference area on the rotating shaft in the operating state is detected by the light receiving means, and the time difference at that time is multiplied by the rotation angle to calculate the torsion angle. A method for measuring the twist of a rotating shaft. 4. The method according to claim 3, wherein an average value of the time difference is multiplied by an arbitrary number of times. 5. A measuring method using the torsion measuring device according to claim 2, wherein a constant obtained by dividing the former by the latter is calculated by inputting a center-to-center distance of the reflectance difference area and a radius of the rotation axis. Further, after detecting the reflected light from the detection start point on the rotating shaft in the operating state of the light beam from the one irradiating means with one light receiving means, detecting the light beam from the other irradiating means on the rotating shaft in the operating state. Until the reflected light from the starting point is detected by the other light receiving means, the torsion angle is calculated by multiplying the above constant by the number of times of detection of the reflected light from the reflectance difference area detected by one light receiving means and counted by the calculating means. A torsion measurement method for a rotating shaft, characterized in that: