JPH0452664Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a shaft horsepower meter that automatically calculates the transmitted horsepower on the output shaft to which the output of the prime mover is transmitted, the torsional vibration characteristics of that shaft, etc. , is a field that calculates the output horsepower from the torsion angle signal detected in the power transmission shaft of a ship during navigation, adjusts the output of the prime mover during navigation based on the calculated horsepower, and determines the suitability of the operating status of the output device. It is something that is used.

[Conventional technology]

As a shaft horsepower meter, it detects relative torsion angle signals at two different points in the axial direction of the output shaft during power transmission, and calculates the torsion angle from the detected signals.
There is a method that calculates shaft horsepower based on this.

As a torsion angle signal detection means in such a shaft horsepower meter, gears are mounted at two positions on the circumference of the shaft with appropriate spacing in the axial direction, and non-contact sensors are mounted opposite the gears. What is installed is
For example, it is described in Japanese Patent Publication No. 51-16792.
In this example, an electromagnetic induction pickup is used as the sensor.

[The problem that the idea aims to solve]

However, since the detection mark in the above-mentioned apparatus uses a gear having tooth profiles at intervals of, for example, 1 mm, highly accurate machining is required for the gear. In addition, when performing zero point adjustment to correct the detected value prior to measuring the torsion angle during power transmission, the shaft is rotated at an extremely low speed with no load.
The sensor output of the electromagnetic induction pickup drops significantly. Therefore, the desired accuracy cannot be ensured, and a particularly expensive sensitivity adjustment circuit must be added.

In order to solve this problem and eliminate the movement of the axis and the flexural deformation of the hull that affect the zero point movement error, the outer cylinder with the sensor attached is supported on the shaft and the outer cylinder is rotated. something is proposed. Such a device has drawbacks such as a complicated structure, increased cost due to the need to improve the precision of machining of each component, and difficulty in mounting the device onto a shaft.

By the way, in addition to the above, there is a system in which sensors are provided at two locations separated along the axial direction of the power transmission shaft, and the shaft horsepower is determined based on the torsion difference between the two. As such an example,
There are shaft horsepower meters described in Publication No. 44781 and Japanese Unexamined Patent Publication No. 48-43683.

In Japanese Utility Model Application Publication No. 52-44781, the detector is installed only on one side of the transmission shaft. Therefore, measurement errors occur when the shaft moves in parallel or rotationally with respect to the hull. In addition, as a method to avoid the influence of deflection of the hull, the detector is installed on a mounting member with sufficient rigidity. However, both ends of the mounting member are connected to the hull, and when the hull flexes and deforms, both ends are also displaced. No matter how rigid the mounting member is, displacement of the mounting member itself is inevitable, resulting in errors in measured values.

Furthermore, a rotation pulse signal is detected once per rotation of the transmission shaft, and the number of rotations is calculated by counting this signal with a counter over a certain period of time. The horsepower is calculated by calculating the torque and torque using an integrator. Therefore, it is not possible to add and average the torques at each instant, and there is a drawback that only the harmonic components of each integer multiple of the average torque and rotation speed cannot be extracted.

On the other hand, Japanese Patent Application Laid-Open No. 48-43683 proposes a device in which two pairs of detectors are fixed to the ship's hull to avoid the effects of relative displacement between the transmission shaft and the ship's hull. However, since the displacement at each part of the shaft does not include the torsion of the hull, the difference in rotation angle due to the torsion of the hull at the front and rear detector positions is
This will appear as an error.

Furthermore, the two systems of phase difference signals sampled alternately by the chopper are averaged. There is no problem if only the average value is determined, but if torque fluctuation is the issue, it is necessary to determine time series data that combines the two systems.
However, in this case, each time the signal system is switched by the chopper, error fluctuation components due to relative displacement fluctuations between the shaft and the hull will be mixed in.

This invention was made in view of the above problems,
The purpose is to avoid complicating the structure by using an optical sensor as a detector, to make it easier to install structural parts, and to prevent cost increases by eliminating components that require precision machining. , even when two systems of detectors are integrally supported on a support stand, zero point movement errors due to displacement of the transmission shaft should be eliminated; Measured values can be averaged even if the unit moves parallel or rotationally relative to the hull, and errors are corrected as time-series data, making it possible to harmonically analyze not only average horsepower but also torque fluctuations. The purpose of the present invention is to provide a shaft horsepower meter that achieves the following.

[Means to solve the problem]

In this invention, the horsepower of a shaft in a rotating and transmitting state is measured through two parallel detection objects placed around the shaft at a certain distance apart in the axial direction. Applies to shaft horsepower meters.

Its characteristics are as shown in Figure 1.
Detected object 3A, such as a reflective mark array film or a disc with a slit, attached to the shaft 2;
3B and an optical sensor 4 for non-contact detection of the reflective mark 3a or slit of the object to be detected.
A torsion angle signal detection means 1 is provided. Optical sensors 4a, 4b, 5
a, 5b constitute one sensor pair by facing each detected object, and the sensor pair is arranged facing each other at two or more locations in the circumferential direction of the shaft 2. , two or more strains are formed.

The two or more sensor pairs are integrally attached to a holding member 9 (see FIGS. 4a and 4b) fixed at one point on the hull or at several points on the hull aligned in the width direction of the ship.

The rotational speed signal detection means 12 includes a reflective mark 13 provided at one location on the axial circumference near the detected object 3A, and an optical sensor 14 that detects the reflective mark 13 in a non-contact manner. Each pair of optical sensors 4a, 4b and optical sensor 5 of the signal detection means 1
A phase difference detection means 18 detects the instantaneous value of each phase difference based on the signals of a and 5b, and the signal from the phase difference detection means 18 is tuned to the one rotation signal from the rotation speed signal detection means 12. , and an input control unit 19 for converting into an arithmetic processable signal;
Based on the output signal of the input control unit 19, an analysis calculation processing means 22 for calculating torsional vibration characteristics by horsepower calculation and frequency analysis, and a display means 26 for outputting and displaying the calculation results of the analysis calculation processing means 22 are provided. ing.

〔Example〕

The present invention will be described in detail below based on examples thereof.

1 in the figure is a torsion angle signal detection means, which detects two detected objects attached to the circumference of the transmission shaft 2 at a certain distance l in the axial direction, and It consists of an installed optical sensor.

The objects to be detected are, for example, reflective mark row films 3A and 3B, which will be described later. The optical sensor detects the reflective mark 3a of each reflective mark row film 3A, 3B from two or more locations in a non-contact manner. In this example, since detection is performed from two locations, four sensors 4a, 4b, 5 are used.
a and 5b are adopted. These optical sensors are connected to the respective reflective mark row films 3A and 3B.
The two front and rear optical sensors 4a, 4b facing each other constitute one sensor pair.

FIG. 2a shows the reflective mark row film 3 described above.
A and 3B are plan views, and as shown in FIG. 3B, the film 3 has white paint 6 applied to its back surface.
On its surface, there are a large number of equally spaced reflective marks 3a.
A reflective mark row 3M consisting of the following is phototypeset, and a horizontal reference line 3P and a vertical reference line 3Q, which serve as references when pasting on the circumference of the surface of the shaft 2, are drawn orthogonal to each other. Incidentally, each reflective mark 3a has a width w of 0.5 to 1 mm, and is photographically reproduced from a precisely drawn original plate. Therefore, it can be manufactured easily and has extremely high homogeneity, which is convenient for detecting torsion angle signals with high precision.

These reflective mark row films 3A, 3B are
As shown in FIG. 3, when pasting on the surface circumference of the shaft 2, the above-mentioned horizontal reference line 3P is aligned with the surface line 7 parallel to the axis 2a, and the surface circumference perpendicular to the line 7 is Align the vertical reference line 3Q with the upper score line 8, and set the interval l.
It can be pasted to maintain the

The four optical sensors 4a, 4b, 5a, 5 described above
As shown in FIG. 1, b faces the surfaces of the two reflective mark row films 3A and 3B attached to the surface of the shaft 2 in a non-contact state, and, for example, the pair of optical sensors 4a and 4b. is arranged opposite to another pair of optical sensors 5a and 5b, which are located across the axis 2a of the shaft 2. Therefore, two systems consisting of two sensor pairs are formed.

This is because when detecting a torsion angle signal caused by the initial bending or twisting of the shaft 2, which causes a zero point error, or the deflection deformation of an object to be attached, such as a ship's hull, each system has to calculate its magnitude. Taking advantage of the fact that they occur equally and in opposite directions,
This is to enable the cause of zero point error to be offset when calculating horsepower.

The two sensor pairs described above are integrally attached to one holding member 9, as shown in FIGS. 4a and 4b. The holding member 9 is not affected by the displacement of the shaft 2 and the deformation of the hull 10 during navigation, so that if the shaft 2 extends in the longitudinal direction of the hull, the deformation of the hull is prevented. For example, they are fixed at several points lined up in the width direction of the ship.
This is to prevent the relative positions of the front and rear optical sensors in the sensor pair from changing due to the deformation of the hull 10, that is, to prevent other factors from being mixed into the measured torsion angle signal. be.

As the torsion angle signal detection means 1, a disk perpendicular to the axis 2a of the shaft 2 may be fixed, although not shown, in place of the reflective mark array films 3A and 3B described above. The disk may be provided with a large number of radial slits, and the slits may be detected by optical sensors placed across the disk.

Incidentally, the detection signals from the two sensor pairs described above are generally voltage sine wave signals containing low frequency noise, as shown in FIG. 5a.
In detecting the phase difference, which will be described later, since the rising zero cross point of the sine wave signal is used as the phase starting point, as shown in Figure b, the sine wave signal with the mark row period from which low frequency noise and direct current have been removed is In order to correct this, a four-channel high-pass filter amplifier 11 is provided as shown in FIG. However, if a sine wave signal of the mark row period can be obtained in the optical sensor, there is no particular need to provide it.

Reference numeral 12 denotes a rotation speed detecting means that detects a reflective mark 13 attached near the reflective mark row film 3A on the circumference of the surface of the shaft 2, and detects this reflective mark to detect the rotation speed of the shaft 2.
and an optical sensor 14 that detects the rotational speed of the motor in a non-contact manner. This optical sensor 14 is a reflection mark 13
It is provided on a stationary body other than the shaft 2 so as to face the shaft 2. As the stationary body, a mounting member erected on the hull 10 or the above-mentioned holding member 9 is used. Note that the optical sensor 14 employs, for example, a phototransistor, like the aforementioned optical sensors 4a, 4b, 5a, 5b, etc., and its sensor power supply 1
5 is used in common, so that the responsiveness of each of the above-mentioned optical sensors due to voltage fluctuations of the sensor power supply 15 is not relatively different.

The optical sensor 14 outputs a signal as shown in FIG. 6a, but a pulse shaping circuit 16 is attached as shown in FIG. 1 to stabilize the signal, and a signal as shown in FIG. 6b is attached. It is shaped into a pulse signal. This signal is for detecting the timing of one revolution, and after being input to the large-capacity data record unit 17 described below, it is used for horsepower calculation and harmonic analysis in the input control unit 19 and analysis calculation processing means 22. Used as a reference period signal.

A large-capacity data record unit 17 is installed to store the detection signals from the five optical sensors of the torsion angle signal detection means 1 and the rotation speed detection means 12 mentioned above and output them to the phase difference detection means 18 described later. There is. This is a magnetic media storage device and is also used for zero correction and offline processing. However, in normal horsepower calculation, the detection signal is simply passed through.

Reference numeral 18 denotes a phase difference detection means, which consists of two phase difference detection sections 18A and 18B. A real-time sine wave signal or a reproduction signal is inputted to this from the large-capacity data record unit 17, and one pair of optical sensors 4a, 4b and another pair of optical sensors 5a, 4b are input.
The phase difference between the rising and zero crossing points of the two-phase sine wave 5b is detected by a time counting method.

Reference numeral 19 denotes an input control unit, which includes an input interface 20 and a buffer memory 21. The former converts the phase difference detected by the phase difference detection units 18A and 18B into a digital signal, and then
It is sent to the buffer memory 21. Since the data acquisition timing needs to be synchronized with the mark train period, a pulse synchronized with the rise and zero cross points of the sine wave generated inside the phase difference detection section 18A, for example, is used for data acquisition control. In addition, buffer memory 21
Data for one rotation of the shaft 2 is processed as a unit, and a one-rotation timing pulse synchronized with the signal from the optical sensor 14 is used as a control signal for this purpose.

Reference numeral 22 denotes an analytical calculation processing means, which includes a harmonic analysis calculation processing section 23, a memory 24, and an input section 25. The harmonic analysis calculation processing unit 23 receives data for one rotation of the buffer memory 21 in synchronization with the rotation timing pulse signal, adds the data to address memories corresponding to individual reflection marks for one rotation, and stores the data. be done. Then, the input section 25
are added a predetermined number of times, and an average calculation is performed by dividing the memory value of the address for each mark by the number of additions.

This process removes aharmonic noise components that are not synchronized with the rotation speed, and furthermore, the optical sensors 4a and 4b
Then, the average of the two systems of data from the optical sensors 5a and 5b is calculated, and error components due to relative displacement and vibration between the shaft 2 and all the optical sensors are removed. That is,
Horse power is now calculated based on the average phase difference and torsional vibration characteristics are calculated using frequency analysis.
In addition to specifying in advance the number of additions in the harmonic analysis calculation processing unit 23 as described above, the input unit 25 also
It is also used to enter other bibliographic information.

26 is a display means, and analysis calculation processing means 22
a display unit 27 for displaying the results on a CRT;
A printer output unit 28 and the like are installed as necessary.

Measuring shaft horsepower, etc. using this configuration example,
This will be explained below with reference to the flowchart shown in FIG.

When measuring the shaft horsepower and torsional vibration characteristics of the shaft 2 while the power of the prime mover is being transmitted to the propulsion propeller etc. via the shaft 2, first
In step 5, for example, bibliographical items such as ship number, date of implementation, time, and place of navigation are input, as well as the number of data collection N, and stored in the memory 24 (Step 1 of the flowchart, hereinafter referred to as S1, etc.).

When the ship is moving forward, the shaft 2 rotates forward in the direction of the arrow 30 shown in FIG.
The optical sensor 14 outputs the pulse signal shown in FIG. 6a from the reflective mark 13 once per rotation (S2). The pulse signal is passed through the pulse shaping circuit 1
After being formatted in step 6 as shown in FIG. 6b (S3), the data is input to the large-capacity data record unit 17 (S4).

On the other hand, the optical sensor 4a of the torsion angle signal detection means 1,
4b and the optical sensors 5a, 5b detect the reflective marks 3a of the reflective mark array films 3A, 3B (S5), and a detection signal as shown in FIG.
Therefore, the signal is corrected to a sine wave signal from which low frequency noise and DC components are removed, as shown in FIG. 2B (S6). The modified sine wave signal is input from the 4-channel high-pass filter amplifier 11 to the large-capacity data record unit 17 (S4).

Each detection signal inputted to the large-capacity data record unit 17 is detected by the phase difference detection unit 18A, 18B of the phase difference detection means 18, which detects the phase difference between each pair of optical sensors 4a, 4b and optical sensors 5a, 5b. Δφi ₄ and Δφi ₅ are detected (S7).
That is, a pair of optical sensors 4a shown in FIG. 8a,
The pulse train generation period between the rising zero cross points X1 and X2 of the i-th sine wave signal during one rotation of the shaft 2 from the optical sensor 4a in 4b is shown in FIG.
As in, it becomes Ti.

On the other hand, the pulse train generation period between the rising and zero cross points Y1 and Y2 of the sine wave signal under load, which is shown by the solid line from the optical sensor 4b shown in FIG. 8c, is as shown in FIG. Zero cross point X
1, X2, as shown in the figure e, ΔTi
This results in a pulse time difference of . As will be described later, since it has been previously measured and stored that the pulse time difference between the i-th sine wave signals of the optical sensors 4a and 4b in the case of no load is ΔToi, the instantaneous phase difference Δφi
Δφi=2π(ΔTi−ΔToi)/Ti (1) where Δφi ₄ is detected by the phase difference detection section 18A using this time counting method. Similarly, regarding the sine wave signals of the optical sensors 5a and 5b,
Δφi ₅ is detected by the phase difference detection section 18B.

The detected instantaneous phase differences Δφi ₄ and Δφi ₅ are
In order to synchronize the reflection mark rows 3M of the two reflection mark row films 3A and 3B and input them into the buffer memory 21 as digital signals, the sine wave rise and zero cross points generated by the phase difference detection section 18A are used for timing control. Along with the marker timing pulse of the pulse signal synchronized with Z1,
Input interface 2 of input control unit 19
It is input to 0.

On the other hand, since the buffer memory 21 processes data for one rotation of the shaft 2 as one unit, a single rotation synchronized with the signal from the optical sensor 14 shaped by the large-capacity data record unit 17 is used as the activation control signal for that purpose. A rotation timing pulse is input as a trigger signal (S8). When the data from the input interface 20 is input as a digital signal to the buffer memory 21 of the input control unit 19 (S9), the harmonic analysis calculation processing section 23 of the analysis calculation processing means 22 receives the data for one rotation of the buffer memory 21. , is input in synchronization with the rotation timing pulse signal (S10).

These are two systems of phase difference detection sections 18A, 18.
The input value is input to the address memory assigned corresponding to each reflective mark detected at B (S11), and the input value for the number of rotations of the shaft 2 (number of sampling N) specified in the input section 25 is added, The average value is calculated for each memory value each time, and the difference from the zero point phase angle Δφo stored in advance is calculated.

Based on these data, harmonic analysis is performed, and the average torque, average rotational speed, shaft horsepower, and the amplitude phase and period of harmonics of torque fluctuations due to torsional vibration are calculated by frequency analysis using, for example, the FFT method. (S12 and S13).

In addition, the torque Q (Kg・m) is Q=πD ⁴ GΔφ/32lM×10 ^-3 ...(2) where, D: Shaft diameter (mm) G: Shear modulus of elasticity (Kg/mm) l: Two Distance M of reflective mark train film: Number of reflective marks Δφ: Phase difference of pulse train (rad). Shaft horsepower P (SHP) is calculated as: P=2πNQ/75×60 =1.3708×10 ^-7 ×D ⁴ GN× Δφ/lM...(3) However, N: Number of revolutions (rpm).

The calculation results such as horsepower are displayed on the CRT screen of the display section 27 of the display means 26, and printed out on the printer output section 28 as necessary (S14).
The input unit 25 instructs the arithmetic processing means 22 to perform calculations in advance, but if the above-mentioned N is instructed to collect data at, for example, 100 rotations or more, the accuracy of calculations such as horsepower can be improved. can be increased.

This analysis calculation processing means 22 can adjust the reproduction output level of the data stored in the large capacity data record unit 17, so that the phase difference detection section 18
Optimal matching with A and 18B can also be performed in offline processing. In addition, since the scale of the time axis can be changed, the frequency signal of the reflective mark row 3M can be changed as necessary, that is,
Calculations can also be performed by increasing the speed of the time axis and adjusting the playback speed.

Here, the zero point verification prior to measuring the shaft horsepower will be explained.

As shown in FIG. 1, the shaft 2 is turned in both forward and reverse directions in the direction of the arrow 30 at a rate of one revolution per approximately five minutes. Similar to the above-described detection procedure during normal operation, one pair of optical sensors 4a, 4b and the other pair of optical sensors 5a, 5b of the torsion angle signal detection means 1 operate on the reflective mark row film 3A facing each other. , 3B reflective mark 3
a and step 1 of the above flowchart.
The operations from step 7 to step 7 are performed. Note that in step 7, the optical sensor 4b shown in FIG.
The rise zero cross points of the sine wave signal during no load, which are indicated by broken lines from , are Z1 and Z2, and the zero cross points X1 and
As shown in , a pulse time difference of ΔToi occurs, and this is applied to the above-mentioned equation (1).

Then, by off-line processing of the reproduced signal of the large-capacity data record unit 17, from the memory value of the address for each reflection mark 3a, it is possible to determine the normal rotation by the sine wave signal of each sensor pair of the torsion angle detection means 1 under no load. The average value Δφos of the instantaneous phase differences Δφo ₄ and Δφo ₅ and the average value Δφor of the instantaneous phase differences during reversal are calculated. Then, Δφo=(Δφos+Δφor)/2 is calculated, and this zero point verification initial phase angle Δφo is stored in the memory 24 of the analytical calculation processing means 22 and used to improve calculation accuracy.

In addition, since the data at the time of reverse turning in the zero point test is detected by the edge of the reflective mark 3a at the time of forward rotation, by reversing the reproduction time axis in the large-capacity data record unit 17, the data is apparently exactly the same as the normal rotation. It is recommended to perform a zero point test. By performing such a zero point verification, it is possible to eliminate the initial torque caused by a bearing (not shown) that supports the shaft 2, and the calculation accuracy in the analysis calculation processing means 22 is improved.

Incidentally, the initial displacement of the shaft 2 is minute. As mentioned above, this initial deformation, such as the torsion angle, can be found by first rotating the shaft at a slow speed for zero point measurement, but if the shaft is then rotated at a normal rotation speed, the bearing This means that a relative displacement occurs between the shaft and the hull due to reaction force and deflection of the hull. Although the amount is minute, it significantly impairs the accuracy of shaft horsepower.
There are two types of such relative displacements: those due to parallel translation, rotational movement, or bending deformation of the shaft relative to the hull, and those due to torsional deformation of the hull. Regarding the former, for example, if detection systems are installed in two systems on the left and right sides of the shaft, the effects of deformation on the two systems will occur in opposite directions, so if the average of both is taken, the error will be canceled out.

[Effect of idea]

As described above in detail, the present invention allows the use of an inexpensive reflective mark array film with high drawing accuracy or an easy-to-manufacture slitted disk for detecting the torsion angle signal of the transmission shaft. It is extremely easy to attach or mount these on the surface circumference of the shaft, enabling highly accurate detection. The four optical sensors of the torsion angle signal detection means each constitute a pair of two optical sensors to form two or more systems, so that small initial displacements of the axis that cause zero point movement or Detection errors in torsion angle signals due to bending deformation of the attached object, such as a ship or vehicle body or plant equipment, are canceled out, making it possible to perform highly accurate horsepower measurements.

All optical sensors are integrally attached to a holding member that is fixed at one point on the mounted object or at several points on the mounted object aligned at right angles to the axial direction of the shaft, so each sensor pair is connected to the transmission shaft. The sensor is not affected by the displacement of the optical sensor or the deformation of the object to be attached such as a ship's body, and there is no relative displacement between the optical sensors, and the accuracy of the zero point verification can be improved. These configurations have a particularly simple structure compared to conventional examples, and do not require high machining accuracy, so in practical terms, manufacturing, installation, and operability are improved, and
It can be a compact device. moreover,
A stable detection signal can be obtained regardless of the rotational speed of the shaft.

Further, the signal from the phase difference detection means is synchronized with the one rotation signal from the rotation speed signal detection means, and
Based on the output signal of the input control unit, which is converted into a processable signal, an analysis calculation processing means is provided that calculates the torsional vibration characteristics through horsepower calculation and frequency analysis. Even if the transmission shaft moves in parallel or rotationally with respect to the hull, the two systems of signals are sampled separately and independently, added and averaged using buffer memory allocated at an appropriate density per revolution, and converted into time series data. It is also possible to correct errors.
Therefore, harmonic analysis of not only average horsepower but also torque fluctuations is possible.

[Brief explanation of the drawing]

Figure 1 is the overall system diagram of the shaft horsepower meter of the present invention, Figure 2
Figure a is a plan view of the reflective mark array film that is the object to be detected, Figure 2b is a sectional view taken along the line -2 in figure a, and Figure 3
The figure shows how the reflective mark array film is attached to the shaft.
Fig. 4a is a front view showing the installation state of the optical sensor, Fig. 4b is a view taken along the - arrow in Fig. 4a, Fig. 5a is a torsion angle detection sine wave signal diagram, and Fig. 5b is a modified Figure 6a is a rotational speed detection signal diagram, Figure 6b is a shaped pulse signal diagram, Figure 7 is a flowchart showing the operating procedure, Figure 8a is a pair of lights. Figure 8b is a diagram of the sine wave signal detected by one of the sensors, Figure 8c is a diagram of the generation cycle of the sine wave signal, and Figure 8c is the load detected by the other of the pair of optical sensors. FIG. 8(d) is a diagram of the generation period of these sine wave signals, and FIG. 8(e) is a pulse time difference diagram during loaded and unloaded states. 1... Torsion angle signal detection means, 2... Axis, 3A,
3B...Object to be detected (reflective mark row film), 3
a, 13... Reflective mark, 4a, 4b, 5a, 5
b, 14... optical sensor, 9... holding means, 12...
...Rotational speed signal detection means, 18...Phase difference detection means, 19...Input control unit, 22...Analysis calculation processing means, 26...Display means, l...Constant distance.

Claims (1)

[Claims for Utility Model Registration] The horsepower of a shaft in a rotating and transmitting state is measured through two parallel objects to be detected placed around the shaft at positions separated by a certain distance in the axial direction. In a shaft horsepower meter configured as shown in FIG. A torsion angle signal detection means is provided, the two optical sensors facing each detected object constitute one sensor pair, and
Two or more systems are formed by arranging the sensor pairs at two or more locations facing each other in the circumferential direction of the above-mentioned shaft, and the two or more sensor pairs are arranged at one point on the hull or lined up in the width direction of the ship. A reflective mark that is integrally attached to a holding member fixed at several points on the hull and provided at one location on the axial circumference near the object to be detected, and an optical sensor that detects this reflective mark in a non-contact manner. a rotational speed signal detection means having: a phase difference detection means for detecting the instantaneous value of each phase difference based on the signals of the optical sensors forming each pair of the torsion angle signal detection means; and this phase difference detection means an input control unit that synchronizes the signal from the rotation speed signal with the one rotation signal from the rotation speed signal detection means and converts it into an arithmetic processable signal; and based on the output signal of the input control unit,
A shaft horsepower meter comprising: an analysis calculation processing means for calculating torsional vibration characteristics by horsepower calculation and frequency analysis; and a display means for outputting and displaying the calculation results of the analysis calculation processing means.