JPS5965737A - Torque detector - Google Patents

Abstract

PURPOSE:To obtain a torque having high responsiveness over a wide range of rotational frequencies of a shaft, by projecting sine waves having a phase shift every 90 deg. to each other to each overlap part among four pairs of slit trains having a phase shift every 90 deg. to each other. CONSTITUTION:Slit trains 14 are formed with equal pitches on a disk 13; while slit trains 15-18 having a 1/4-pitch shift to each other are provided at the circumference of another disk 23 with the same pitch as the trains 14. Both sine and cosine waves of a prescribed angular speed omega are oscillated by an oscillator 51 based on a time interval T with which a torque is requested and supplied to driving circuits 54 and 55. At the same time, these waves are inverted by inverters 52 and 53 and supplied to driving circuits 56 and 57. If the output obtained when photodetecting elements 41-44 overlap perfectly to each other is set at 2B and an electric angle corresponding to an angle displacement theta with the slit pitch angle thetap set at 2pi is set at alpha(=2pitheta/thetap), the synthetic output B [cos(omegat-alpha)+2] is equal to a sine wave output of angular speed omega. Thus it is possible to obtain a torque which is proportional to the angle displacement with each prescribed period T by measuring a phase alpha.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a torque detector that photoelectrically converts a torsion angle proportional to the magnitude of torque generated on a torque transmission shaft into a phase difference signal.

Industrial ApplicationsTorque is an important characteristic that indicates the performance of prime movers such as engines and motors, and is used not only for inspection of prime movers or evaluation tests in research and development, but also for pumps, etc. connected to the prime mover. Performance test of load equipment, 1~
Measuring the amount of light is essential. Torque detectors are widely used for such tests.

Conventional technology First, the known ones will be briefly explained.

In FIG. 1, two points on the axis 1 spaced apart in the axial direction have a binomial field 11. [Discs 12.22 to which the base of 1 is fixed and integrally fixed to each open end surface thereof are closely opposed, and with equal pinch holes bored around the periphery of the discs 12.22,
A light emitting element 30 and a light receiving element 40 are arranged to face each other with one slit row in between.

6 and now, 1i11. l ] or 1
~ torque is reached, and it (from this, shaft 1 is twisted, ring body 1
When a torsion angle θ occurs between the bases of 1° and 21, the two discs 12 and 22 also produce a relative angular displacement θ, and therefore the overlapping area of the slits of the two discs 12 and 22 also becomes an angle. displacement θ
As a result, the light property reaching the light receiving element 40 from the light projecting element 30 through its overlapping area changes (IJ), which changes the output of the light receiving element 10.

Now, Figure 2 shows the slits and ts 12' and 2 of the disk 12.22.
2' is a diagram showing the relationship between the polymerization state of 2′ and the output of the light receiving element 40. FIG. , First, the disc 22 is angularly displaced with respect to the two discs 12, and as a result, the angular displacement θ and both slots 1-12' when 22' moves to the right with respect to the slots 1-12',
In order to examine the relationship between the overlapping areas of 22', we will now turn the disk 22 to the right from a completely non-polymerized state (the left end of the stop 12' and the right end of 22' are in the same position). Then, one polymerization area increases in proportion to the rotational angular displacement, and when the angular displacement reaches 1/2 of the slit pitch angle θ, complete polymerization occurs. Next, turn further to the right from θp/2! 1
Then, contrary to the above, it decreases in proportion to one rotational angular displacement, reaches θp a little, and becomes non-polymerized again in the original state.

As described above, the polymerization area of s') l-12' and 22' changes in a triangular wave shape with respect to the angular displacement θ. next.

To see the relationship between the overlapping area and the output of the light receiving element 40,
Ideally, both should have the same change, but in reality, the changes described above are influenced by the diffraction of light between the two disks 12 and 22, and the fact that the light-emitting and light-receiving surfaces are circular. When the overlapping area changes in a triangular waveform as shown in FIG.

Therefore, even if the output Vθ of the light receiving element 40 is measured, it is not proportional to the angular displacement θ, and θ cannot be directly determined.

In order to improve this, a two-phase difference method is also used for disc 1 in the figure.
A cylindrical body is supported on the shaft between 2 and 22 by a hair link, and another disc is placed on the left and right end surfaces of the cylindrical body so as to face the 2 discs 12 and 22, respectively. The light-emitting element and the light-receiving element were made to face each other by using two disk pairs on each side, and the cylindrical body was engaged with the outer HH moke so that it was always rotated in the opposite direction to the rotational direction of 1IIIll. It is something. According to this,
Even if +gl+ is stationary, the disks 12 and 22 and the other disks facing each other are being rotated, so each rotation of the slit pinch θp generates one period of a sine wave in the valley photodetector, and The fourth order difference α between the two sine waves is proportional to the angular displacement θ.

However, this method avoids increasing the overall size, and also makes the structure complicated.

It takes a lot of effort to assemble, and there are so many different configurations? r
VS products also have problems that require high processing precision.

Also, in this case, the lower the shaft rotation speed, the longer the protrusion gap becomes.

The problem remains that it is not possible to obtain torque with uniform response characteristics over a wide range of shaft rotational speeds.

The problem that the invention aims to solve The present invention eliminates the drawbacks of the prior art described above.

The present invention aims to provide a torque extractor that has a small number of parts and is small in size, yet has high response characteristics over a wide range of shaft rotational speeds including a stationary state and an extremely high response characteristic.

Means for Solving the ProblemsThe present invention utilizes the detection principle of the 1-phase shift-4 detection force type for detecting the torsion angle.

Two disks, each having its base fixed at two points spaced apart in the axial direction, are placed close together and facing each other, and a first row of slits are formed at equal pitches on the periphery of one disk. , on the periphery of the other disk having a different radius, there are second slit rows arranged at the same pitch as the first slit row, and arranged 1/4 pitch apart from each other. m
3. A fourth and a fifth slit row are respectively formed, and the first and second slit rows are respectively drilled. 1st and 3rd. 1st and 4th. Each pair of 1-columns of 1st and 5th rows is held separately and 1st. Second. Third
．． The fourth light emitting element is placed on the other side, and the first light emitting element is placed on the other side. Second. Third. The fourth light-receiving element is arranged and faced, and the j-th to fourth light-emitting elements are controlled to be lit by the two lighting control units υ11 with sine wave outputs having a phase difference of 901 W from each other.
The phase change of the combined output of the fourth light-receiving element output is measured.

The following two actual MLli columns are detailed based on the drawings for the implementation of the present invention ^, (
Things are getting better.

In FIG. 3 showing the 1 shallow groove section, m111. The mounting rings 11.21 are similar to those shown in FIG. 1, and disks 13.23 are fixed to the open ends of the opposing rings 11, 21, respectively. The disc 13 has a chip 1 arranged at equal pitches as shown in the figure.
:1 first slit row 14 is formed, and around the other disk 23 facing it, a first slit row 14 is formed as shown in FIG.
has the same pitch as the slit rows 14 of
The 2nd to 5th 4 slots, where g is 1/4 of each other, are arranged in rows 5 to 18 from the outer circumference to the inner circumference.
ffl has been formed. Then, the first slit row 14 and each image 2. Third. 4th. 5th Pickpocket) Tota 1
] A pair of the first light emitting element 31 and the light receiving element 41, a pair of the second light emitting element 32 and the light receiving element 12, and a third light emitting element 33 and the light receiving element 4 are placed facing each other with 15 to 18 sandwiched between them.
The third pair and the fourth pair of light emitting element 34 and light receiving element 44 are self-provided.

FIG. 6 shows lighting for controlling the amount of light emitted from the light emitting elements 31 to 34 on the first to fourth sides. 1ull 1i1 This is an example of Iichi 50, with one oscillation;
The output terminals of ω [cos ωt are respectively the same as those of the above-mentioned wave 1. Second
It is connected to the input terminals of 'Hoshikodenshi 54 and '55.

It is connected to each input terminal of Impark 52 and 53, respectively. And the output terminal of Impark 52.53 is
They are connected to input terminals of drive circuits 56 and 57 of the light receiving elements 33 and 34, respectively.

(Here, the two oscillators 51 are now driven by oscillating a sine wave and a cosine wave with a predetermined angular velocity ω (-2π/T) based on the time 1-interval T at which the torque is to be determined. When the circuits 54 +' 55 are manually operated, the signals are simultaneously 0?-, inverted by the inverters 52 and 53, and inputted to the drive circuits 56 and 57. -34 is controlled by a norsine wave, a cosine wave, two inverted sine waves, and two inverted cosine waves.However, in this case, a negative amount of light is unlikely, so a certain positive amount of light An example of range 1 would be to cause periodic changes between 0 and 2A.

The amount of light emitted from the first to fourth light emitting elements 31 to 34 is as follows:
A(sinωt+1), A(cosωt+])
, A(-5inωt+1), A(-cosω1
+1). The amounts of light are different from each other in the first slit rows 1.1 and the second slit rows 1.1 and 2.1. Third. 4th. The light passes through the overlapping portions of the fifth slit rows 15 to 18 and reaches the corresponding light receiving elements 41 to 4, where it is converted into an electrical signal. Therefore, the light receiving element 41~
The IN electric signal generated at 44 is also a sine wave of angular velocity ω, j cosine wave 9 inverted in wave 2 inverted cosine wave, and the wave height is the transmission area of light, that is, the size of the overlapping area of the slits facing each other. It will change depending on.

Now, as explained in FIG. 2 above.

The overlapping area of the two slit rows changes like a triangular wave while the angular displacement θ changes from 〇 to the slit pitch θ, or the relationship between the overlapping area and the amount of light transmitted through it changes like a sine wave. Therefore, the outputs of the light-receiving elements 41 to 44 change periodically at the angular velocity ω, and the output also changes in accordance with the angular displacement θ in the form of a sine wave, a cosine wave, a 2-inverted sine wave, and a 1-inverted cosine wave. The amount of light emitted by each of the light emitting elements 31 to 34 described above is
When the two opposing slit rows are completely non-polymerized, it is assumed that the outputs of the light-receiving elements 41-44 do not reach the light-receiving elements 41-44, and the output of the light-receiving elements 41-44 at that time is set to 0. Also.

The light receiving element 41 passes through the electrical angle α (-2πθ/θp) guided to an angular displacement θ that is 2π positive from the slit pitch angle θ.
The outputs e1 to c4 of ~44 are expressed as follows.

CI ”” (13/2X sin α+1) (5i
n(vj + 1)c2-(13/2)(cosα
+IXcosωt+1)e3 = (B/2)(
−sinα+1 )(−s■(υt+1)c 4
= (B/2)(-cosa+1)(-cos
(υt-1-1) After all, these outputs e and ~e4 are angular velocities (V), and each output has a phase shift of 90 degrees and corresponds to the angular displacement θ. The amplitude is modulated sinusoidally by the electrical angle α.

Hereinafter, each of these outputs el-e4 will be added and combined by the adder 60, and the output e will be as follows.

e = B [CO5'(ωt-α)+2]71) This composite output e is a sine wave output of angular velocity ω, and its phase α changes in response to angular displacement θ. . Therefore, the phase α of this composite output C is set by the oscillator 5.
θ based on either the output of 1 or its inverted output.
By determining 1j, the angular displacement θ, that is, the torque proportional to it, can be determined every predetermined period T (−2π/ω).

In the above embodiment, the case where the outputs of the light receiving elements 41 to 44 are added as they are is exemplified, but the same effect can be obtained by adding the outputs of the light receiving elements 41 to 44 as they are, but the same effect can be achieved by adding the outputs of the light receiving elements 41 to 44 as they are. 44 may be replaced with a co-propelling light receiving element to also have a combining function.

The effects are as described above. 1. The present invention provides a group of four pairs of slit rows having a phase shift of 90 degrees from each other by means of a disk that is relatively angularly displaced according to the torsion angle θ. In addition to causing a polymerization change, the amount of light emitted to each polymerization part is also changed in a sine wave shape with a phase shift of 90 degrees from each other, and the torsion angle is synthesized by extracting the combined output of the amount of light that has passed through it. Since it is converted into a phase change in the output, the torque is proportional to the torsion angle.

The combined output can be extracted at regular intervals, and the torque can be determined with excellent responsiveness over a wide range of lq1 rotation speeds, from when the shaft is stationary to high speed.

[Brief explanation of drawings]

FIG. 1 is a front view showing a known detection unit. Figure 2432 is an explanatory diagram of the operation, and Figure 3 is the detection 1 of the present invention.
4 and 5 are side views showing an embodiment of the disc, and FIG. 6 is a block diagram showing an embodiment of the lighting control section of the present invention. 13.23: Disc, 14-18 Nislit example, 31-3
4: Light-emitting element, 41-44: Light-receiving element, 502 lighting system Phloem output 1 customer 1 country + 2 same

Claims (1)

[Claims] ], Two disks having their respective bases fixed at two points spaced apart in the H111 direction are brought close to each other and opposed to each other. On the periphery of one of the discs, a first row of slits is drilled evenly in a pinch, and iI! On the peripheries of the two disks with different radii, the first slit row and the same pinch are arranged at one position/month each other.
2nd, g3. g4. A fifth slit row is formed, and the first and second slit rows are respectively bored. 1st and 3rd. 1st and 4th. Each pair of first and fifth slit rows has a first slit row on one side. Second. Third. A fourth light emitting element is provided, and the light emission amount thereof is controlled by the illumination control unit separately in a sine wave shape with a phase shift of 90 degrees, and the output phase corresponds to the combined light amount of the transmitted light amount. Torque detection device that extracts the amount of change.