JPH11295106A - Torque sensor for elastic coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque sensor for an elastic coupling capable of a pulse- type display for easily displaying the detection displacement itself by constituting a displacement detection transmitting means on the rotating body side so as to be easily fitted to the outside of the coupling with regard to the elastic coupling of a Hook's characteristic, and constituting the above displacement detection transmitting means with low-cost equipment and materials. SOLUTION: A torque sensor is made up of a displacement detection transmitting means 26 and an arithmetic display part 27; and the detection signal detected by the displacement detection transmitting means 26 is input into the arithmetic display part 27 to arithmetically display the torque of the rotational system and the power of the transmitting shaft, and the displacement detection transmitting means 26 is made up of displacement graduations 15, displacement-indicating lines 16, photosensors 17, 18 for reading the graduations, and a cylindrical lens 19 for magnifying the displacement graduations 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque sensor of an elastic coupling having a hook characteristic (hereinafter referred to as an "elastic coupling") connected via an elastic member which deforms according to a load, and more particularly to a load of the coupling. The present invention relates to a torque sensor for an elastic coupling in which a displacement detection transmitting means at the time is structured such that a scale plate and an index can be easily attached to the outside without dismantling the coupling.

[0002]

2. Description of the Related Art Conventionally, torque detectors of mechanical type, magnetostrictive type, variable resistance type, variable inductance type, optical type, etc., which have respective advantages and disadvantages, have been developed and used. Is designed as a measurement-only machine, and is installed between power transmission shafts when used, for example. In most cases, the signal transmission device on the rotating body side is not so simple as to be mounted later, but is complicated.When measuring using them, the detector is placed between the left and right axes on the driving side and the driven side. Due to the structure of the insertion and interposition, there is a case where it is necessary to attach or change the installation position of the related equipment on the driving side and the driven side, and the installation area is enlarged.

Further, since the conventional torque detector is interposed between the power shafts as described above, it is necessary to appropriately select a torque capacity and a rotation speed when using the conventional torque detector. That is, although the nominal torque of the rotating machine is known, the magnitude of the fluctuating torque is often unknown, and the selection of the model of the torque detector must ultimately rely on estimation. This may result in damage to the detector or an unreproducible situation. In addition, since it is interposed between the shafts of the power shaft during installation, various problems such as lubrication method of the bearing of the detector, resonance of the shaft, and selection of the type and weight of the coupling associated therewith when the number of rotations is large are involved. Intervene.

That is, the coupling for connecting the two axes is the coupling itself, the torque sensor is a sensor dedicated to measurement, and when the coupling has the function of a torque sensor, the coupling is a coupling. , And also a torque sensor.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it has been proposed to simply attach a scale plate without modifying or processing an elastic coupling having hook characteristics. It is an object of the present invention to provide a torque sensor for an elastic coupling having a function of engraving the scales and measuring the deviation angle, torque and transmission power during rotation on the non-contact sensor side.

[0006] In a coupling that couples a rotating machine on the driving side and a load on the driven side, at least when a torque is generated on the driven side, a deflection angle (“displacement”) as a distortion thereof is at least a coupling that is a coupling on the driving side. In this case, for example, an elastic coupling is targeted. Also,
The target of torque detection is to detect a deviation angle, which is a "deviation" directly appearing on the coupling surface between the driving side and the driven side due to the generation of torque.

The coupling is an elastic coupling having hook characteristics.

[0008] Further, the displacement detecting and transmitting means on the rotating body side can be easily attached to the outside of the coupling,
The displacement detecting and transmitting means is constituted by low-cost equipment, and has a constitution capable of easily displaying the detected displacement itself in a pulse expression form.

Next, in the first method of measuring the relative deflection angle of the two axes to which a load is applied according to the present invention, the number of graduations provided on the rotating body is directly read by a light receiving element. A high-precision measurement is performed by increasing the resolution by reading the number of pulses generated by the frequency multiplying circuit and the light source multiplied by the frequency multiplying circuit within the angle of deviation with the light receiving element.

[0010]

For this purpose, a torque sensor for an elastic coupling according to the present invention detects a displacement angle of a relative position of an elastically coupled coupling and calculates and displays a torque and a transmission shaft power. A zero-scale reference indicating line and a subsequent displacement scale are provided on the driving-side coupling at no load, and a displacement indicating line is provided on the driven-side coupling at an extended position of the reference indicating line. And a displacement detecting and transmitting means configured to include a driving side sensor and a driven side sensor provided above the instruction line, and a displacement for detecting a displacement angle by controlling scale reading of the driving side sensor and the driven side sensor. It is characterized by comprising a detecting means and a calculation display section for calculating torque and transmission shaft power based on the detected value.

Further, the detecting means according to claim 1 starts reading of the driving side sensor by passing through a reference indicating line which is a zero scale line of the displacement scale, and by reading output of the driven side sensor passing through the displacement indicating line. The reading of the sensor is stopped.

In the driving-side sensor according to the first aspect, a plurality of subdivision scales are provided on the projection side of the cylindrical lens, and a plurality of individual sensors for reading the subdivision scales are provided on each subdivided scale line to improve resolution. A sensor is configured.

Another method of reading the deflection angle is as follows. In the above case, when the minimum graduation angle that can be read and identified by the sensor with respect to one rotating graduation is θmin or its arc length Lmin, In order to further increase the resolution, the pulse light source of the light emitting element of the sensor is formed by an electric circuit at a division ratio of 1 division / σ, that is, a pulse frequency obtained by multiplying the resolution by σ, without using an optical system. It is characterized in that the number of pulses within the generated deviation angle is measured for each rotation.

[0014]

Therefore, according to the first method for the torque sensor for elastic coupling of the present invention, when no load is applied,
The driving side coupling is provided with a reference indicating line which is zero scale and a displacement scale following the reference scale on the outer periphery thereof, and the driven coupling is provided with a displacement indicating line extending from the reference indicating line, and the optical sensor for reading the scale is provided. Are provided on the driving side and the driven side, respectively, so that the "deviation angle" corresponding to the torque generated by the load can be detected by reading work via the optical sensor operating according to the displacement detecting means, and the detected value With this, the torque and the power of the transmission shaft can be calculated and displayed.

[0015] In this way, without resorting to a large-scale remodeling means for the existing coupling, the displacement indicating line and the zero indicating the reference indicating line can be obtained by simply engraving the scale or attaching the scale paper. A torque sensor that can be easily attached to an elastic universal coupling having a hook characteristic by simply providing a displacement scale and providing an optical sensor for reading the scale can easily attach a low-cost displacement detection transmitting means. Can be provided.

Further, according to the configuration of the detecting means of the present invention, the displacement scale including the reference indicating line and the displacement indicating line including the reference indicating line which is loaded with a constant relative deviation angle by the torque of the rotating system are driven and driven by the moving direction. When the side sensor is operated, the driving side sensor starts reading the displacement scale from the passage of the zero scale, and the reading of the displacement scale corresponds to the “deviation angle” by the read output of the driven side sensor passing the displacement instruction line. When the reading is completed, the reading can be stopped. When no load is applied, the displacement instruction line and the zero graduation line of the displacement graduation, which is the reference instruction line, are provided so as to coincide with the same rotation angle. And can be detected as a “deflection angle amount”.

Further, according to the structure of the driving side sensor according to the third aspect, an enlarging cylindrical lens is provided above the displacement scale, a plurality of subdivisions are provided on the projection side, and the scale reading light is provided on each subdivision. Since the sensor is provided, a plurality of subdivision scales are provided on each scale of the displacement scale, and the resolution can be improved.

According to a fourth aspect of the present invention, the division ratio of one scale during rotation is 1 / σ.
The total number of graduations engraved on the outer periphery of the coupling by a pulse having the central angle θmin of one graduation is (2π) / θmin, and if the number of rotations is n, the number of pulses is [ (2π) / θmin] × n, and taking the division ratio 1 / σ into consideration, the number of pulses becomes [(2π) / θmin] × n × σ. here,
The division ratio 1 / σ of one division for increasing the resolution can be doubled by a frequency multiplier.

That is, this can be easily generated by extracting a higher harmonic from the non-linear waveform, or by a difference circuit using a non-linear waveform and a linear-wave type bridge, or another known circuit. By using this as a pulse light source of the light emitting element, two lines of a reference indicating line and a displacement indicating line on the coupling are irradiated, and the light receiving element starts reading the reference indicating line of the pulse of the light emitting element every one rotation, The reading is terminated at the displacement indicating line, and the number of pulses read by the light receiving element during that time is σ times the fundamental frequency for the minimum identifiable scale, the resolution is increased accordingly, and the relative deviation angle of the two axes or the relative deviation angle with respect thereto. The arc length is measured with high accuracy.

That is, in the first aspect, the number of graduations between the reference indicating line and the displacement indicating line is read for the relative displacement of the two axes. , The reading start time and the reading end time are set, the angle between them becomes the biaxial relative deviation angle θ. In this case, if the number of pulses measured from the light source side is P, P
Is a pulse light source of σ times by the above-mentioned frequency multiplication circuit, and the number of pulses of [(2π) / θmin] × n × σ is counted. For one rotation, this is divided by n to obtain [(2π)
/ Θmin] × σ pulses are counted. That is, θ =
P / (2π × σ / θmin) = P × (θmin / 2π) ×
(1 / σ), and the resolution is improved by 1 / σ.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not merely intended to limit the scope of the present invention, but are merely illustrative examples unless otherwise specified. Absent. FIG.
3A and 3B are views showing the state of attachment of the displacement detection transmitting means of the torque sensor for elastic coupling according to the first invention of the present invention, wherein FIG. 3A is a partially cutaway side view, and FIG. FIG. FIG. 2 is a developed view showing a displacement scale including the reference indicating line in FIG. 1, a relational position between the displacement indicating line and the light receiving element. FIG. 3 is a system diagram showing a schematic configuration of a calculation display circuit of the torque sensor for elastic coupling according to the first method of the present invention. FIG. 4 is a waveform diagram of a frequency multiplying circuit for increasing the resolution when measuring the number of pulses from the pulse light source in the second method of the present invention.

As shown in FIG. 1, the torque sensor for elastic coupling according to the first invention of the present invention comprises a displacement detecting and transmitting means 26 and a calculation display section 27,
6 is input to the calculation display unit 27 to calculate and display the torque and transmission shaft power of the rotating system. The displacement detecting and transmitting means 26 includes a displacement scale 15, a displacement instruction line 16, optical sensors 17 and 18 for reading the scale, and a cylindrical lens 19 for enlarging the displacement scale 15.

The displacement scale 15 and the displacement indicating line 16 are
The driving-side drive shaft 11 and the driven shaft 12 are stamped or formed in a sheet shape on the outer peripheral surfaces of the driving-side coupling 13 and the driven-side coupling 14 which are elastically connected via an elastic member 25, and the rotating system is When no load is applied, as shown in FIG. 1 (A), the displacement indicating line 16 and the zero scale line 15a, which is the reference indicating line of the displacement scale 15, are formed so as to form a straight line at the outer peripheral position at the same rotation angle of the coupling. During load operation, the displacement instruction line 16 on the driven side displaces the rotational position in the direction of the dotted arrow to generate torque.

As shown in FIGS. 1A and 1B, the columnar lens 19 is arranged such that the graduation line of the displacement graduation 15 and its optical axis are parallel and located on the axis XX of the coupling. Subdivision scale 1 obtained by dividing one scale of the displacement scale enlarged on the cylindrical surface on the projection side of the lens into a plurality of divisions.
9a, 19a,..., And a plurality of optical sensors (not shown) are provided on each subdivision scale instead of the optical sensor 17. The optical sensors 17, 1
As shown in FIG. 2, the plurality of optical sensors provided on the projection side of the lens 8 and the columnar lens 19 can reliably adjust the displacement scales 15 and displacement indication lines 16 provided on the outer circumferences of the couplings 13 and 14, respectively. I read it.

The reading of each scale by the optical sensor is performed at the time of rotation of the load. At this time, the driven-side coupling 14 rotates with a certain delay with respect to the driving-side coupling in response to the load. The displacement scale 15 on the coupling 13 reaches the detection position of the optical sensor 17 in advance in the direction of arrow A. That is, at the time of detection, the optical sensor 17 is activated by the detection means in the calculation display unit 27 by passing through the zero scale line 15a, which is the reference indicating line of the displacement scale 15, and starts reading each scale following the zero scale. Then, one pulse for each scale line is input to the pulse selection circuit 31 of FIG. 3 to form a displacement pulse train.

On the other hand, the displacement indicating line 16 moves in the direction of arrow B with a delay corresponding to the aforementioned "deviation angle",
When the displacement of the displacement scale 15 by the optical sensor 17 is read out by the pulse selection circuit 31 in FIG. 3 by the output of the optical sensor 18 reading the scale 16, the displacement pulse train forms a "deviation angle". Its formation is stopped.

Then, the torque calculating circuit 32 calculates the torque based on the "deviation angle" which is the total number of displacement pulses corresponding to each of the displacement scales from the start of reading of the optical sensor 17 to the stop of reading. The calculation of the torque is 1
It can be repeatedly performed for each rotation, and it is preferable to store this and set an average value as the formal torque of the rotation system. The calculated torque is input to the shaft power calculation circuit 35 via the distribution circuit 33. On the other hand, the number of passage readings of the displacement instruction line 16 per unit time detected by the optical sensor 18 is input to the circuit 35 as the number of revolutions, and the shaft power is calculated by the product of the torque and the number of revolutions. Calculate with. Next, the torque display 34 and the shaft power display 36
, The above calculated values are input to enable display.

In the case where the cylindrical lens 19 is provided, the interval between the scales of the displacement scale 15 is enlarged, and one scale of the scale is enlarged to a plurality of scales on the cylindrical surface on the projection side of the lens. Divided scale 19a, 19
are provided, and a plurality of optical sensors (not shown) are provided on each subdivision instead of the optical sensor 17, so that the resolution can be improved.

FIG. 4 is a diagram showing an example of a simple frequency multiplication circuit used to measure the number of pulses from the pulse light source and to increase the resolution when obtaining the relative deviation angle, and shows the waveform thereof. (A) is a basic waveform having a minimum graduation angle at which one scale angle can be read and identified. It is assumed that the waveform is converted into a rectangular wave having a period T as shown in the figure. Next, if this is passed through a differentiating circuit, the waveform shown in (B) will be obtained, and if it is further passed through a rectifying circuit, the waveform will be shown in (C). This is apparently compared with the waveform shown in FIG.
The cycle is halved and the frequency is doubled, which means that pulse multiplication conversion has been performed. If this is used in this case, the resolution is doubled on the electric circuit.

A torsion coil spring is inserted between the couplings shown in FIG. 5A, or a torsion bar shown in FIG. 5B for a propeller shaft of a ship, for example. For couplings without the phenomenon, even if the couplings are far apart,
As long as the displacement graduation and the reference graduation are accurately positioned, the first method of the present invention, the torque sensor for elastic coupling, can be used.

Further, a static shaft torque calibration value can be obtained by applying a pseudo load to the driven side.

[0032]

According to the above-described structure of the present invention, the elastic coupling can be easily attached to the existing elastic coupling without changing the internal structure and the attaching position, and the relative displacement angle of the two axes due to the load can be easily reduced. Can be measured accurately,
Therefore, the calculation display of the torque and the transmission shaft power of the rotating system can be performed. Further, the calibration of the static shaft torque is possible.

[Brief description of the drawings]

FIG. 1 is a view showing a state of attachment of a displacement detection transmitting unit of a torque sensor for an elastic coupling of the present invention. FIG. 3A is a partially cutaway side view, and FIG.
It is an I view.

FIG. 2 is a developed view showing a relative position of a reference scale, a displacement scale, and a light receiving element in FIG.

FIG. 3 is a system diagram showing a schematic configuration of an operation display circuit of FIG. 1;

FIG. 4 shows a waveform diagram of a frequency multiplication circuit for increasing the resolution when measuring the number of pulses from a pulse light source.

FIG. 5 is a view showing a specific example of an elastic coupling to which the torque sensor for elastic coupling according to the present invention can be applied;
Is a coupling using a torsion coil spring as an elastic body,
(B) is a figure which shows the coupling which used the torsion bar for the elastic body.

[Explanation of symbols]

REFERENCE SIGNS LIST 11 drive shaft 12 driven shaft 13 driving-side coupling 14 driven-side coupling 15 displacement scale 15 a zero-scale line serving as reference indicating line 16 displacement indicating line 17, 18 optical sensor 19 cylindrical lens 20 a, 20 b, 25 elastic member 26 displacement Detection and transmission means 27 Calculation display unit 31 Pulse selection circuit 32 Torque calculation circuit 33 Distribution circuit 34 Torque display 35 Shaft power calculation circuit 36 Shaft power display

Claims (4)

[Claims] 1. A torque sensor which detects a displacement angle of a relative position of a coupling which elastically couples with a hook characteristic and calculates and displays a torque and a transmission shaft power. A reference indicator line and a displacement scale following the reference indicator line are provided, a displacement indicator line is provided on the driven-side coupling at an extended position of the reference indicator line, and a driving-side sensor provided above the two sets of indicator lines, A displacement angle detection transmitting means having a configuration including a side sensor; a displacement angle detection means for controlling a scale reading of the driving side sensor and the driven side sensor to detect a displacement angle; A torque sensor for an elastic coupling, comprising: a calculation display section for calculating. 2. The detecting means starts reading of a displacement scale following the reference instruction line at the same time as reading the passage of the reference instruction line by the driving-side sensor, and reading the passage of the displacement instruction line by the driven-side sensor. 2. The torque sensor for an elastic coupling according to claim 1, wherein the reading of the data is stopped. 3. The resolution improving sensor according to claim 1, wherein the driving side sensor is provided with a plurality of subdivision scales on the projection side of the cylindrical lens, and a plurality of individual sensors for reading the subdivision scales on each subdivided scale line. 2. The method according to claim 1, wherein
A torque sensor for an elastic coupling as described in the above. 4. The sensor according to claim 1, wherein a division ratio of one scale is 1 / σ with respect to a minimum scale angle θmin or an arc length Lmin at which the sensor reads one scale during rotation and identifies the scale.
A pulse frequency to be generated on an electric circuit as a pulse light source of the sensor, the displacement angle detecting means, a reference indicating line on the coupling,
The light receiving element starts reading the pulse at the reference indicating line every rotation, and stops reading the pulse at the displacement indicating line, during which the light receiving element reads the pulse from the light source. 2. The torque sensor for an elastic coupling according to claim 1, wherein a relative deviation angle or an arc length of two axes whose resolution is multiplied by σ is detected from the number of pulses.