JPS61207940A - Measuring method for torque - Google Patents

Abstract

PURPOSE:To measure torque working on a revolving shaft by a device of a low cost, and also with a high accuracy, by receiving light which has transmitted through a superposed part of a slit, counting a high frequency electric pulse transmitted from a pulse transmitter, and calculating the torque. CONSTITUTION:A driving shaft 1 and a shaft to be driven 2 are connected by a torsion bar 3, a slit is cut at every interval in a slit disk 4 and 5, and an optical fiber 6 and 7 are opposed and placed by placing the slit between them. A continuous light emitted from a light source 8 is irradiated toward the slit disk 5 from the end face of the optical fiber 6. The optical fiber 7 receives a light transmitting through a gap being proportional to a magnitude of a shift quantity of the slit caused by a superposed state of the slits of the slit disk 5 and 6, namely, a magnitude of a torque applied to a torsion bar 1, and propagates it to a light-receiving element 9. The light-receiving element 9 generates a rectangular pulse by the received light, and by taking AND with a pulse signal from a pulse transmitter 10, the number of pulses being proportional to a gap is obtained, and the torque is derived.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for measuring torque acting on a single rotation shaft system.

[Prior Art] Conventionally, a gear ring and an electromagnetic pickup are often used to measure the torque acting on a rotating shaft. This required precision in manufacturing the tooth ring, and also required accurate determination of the mounting position of the tooth ring and the electromagnetic pickup, making it difficult to use even after repeated use.

Therefore, two slit disks are fixed on both sides of the easily deformable part of the torsion bar as a device to optically measure the torque, and a light source that irradiates the slit disks with light and a slit between the two slit disks are installed. A light-receiving element that receives light transmitted through the light receiving element is provided.

In other words, it utilizes the fact that the amount of overlap between the slits in two slit disks changes depending on the amount of twist of the torsion bar, and calculates the torque by measuring the amount of change in the amount of light received by the light receiving element. It is.

Two methods are provided for determining the change in the amount of light.

One method for sheep is to measure the amount of light itself.For example, there is a method described in Japanese Patent Laid-Open No. 111029/1983.

This uses a photoelectric converter that generates a voltage according to the intensity of light to determine the amount of light from the voltage, that is, the degree to which the slits overlap, and then measure the torque.

Another method is to measure the time during which light passes, such as the one described in Japanese Utility Model Application No. 58-163840. This uses a high-frequency pulsed light source as a light source, counts the number of pulses that pass through the gap between the slits, and measures the degree of overlap of the slits.

[Problems to be Solved by the Invention] The first method described above is used to measure the torque of a torque wrench, etc., but when measuring the torque of a single rotation shaft, a separate device is required to determine the rotation speed of the shaft. Is required. Also,
As the rotation speed of the shaft increases, the amount of light that passes through the slit decreases, making it impossible to maintain sufficient accuracy.

On the other hand, in the second method, it is not necessary to determine the number of rotations of one rotating shaft, but if the accuracy of torque measurement is to be improved, the frequency of the high-frequency pulse light source must be increased. However, current commercially available light sources are extremely expensive, and their frequencies are not sufficient for torque measurement.

[Means for solving problems] The present invention is a method for solving the above problems.

A slit disk is fixed on each side of the torsion bar, which has an easily deformable part where twisting deformation easily occurs, and a continuous light parallel to the torsion bar is irradiated to the two slit disks, and the overlapping part of the slits is The light that passes through is received by a light receiving element, and the high frequency electric pulse transmitted from the pulse transmitter is opened and closed by the output of the above light receiving element to count the number of pulses, and from this counted number, the torque acting on both ends of the torsion bar is calculated. I tried to measure it.

[Effect]

The method of the present invention is similar to the conventional method described above.

The degree to which the slits of the two slit disks overlap.

It takes advantage of the fact that it changes depending on the torque. Also.

This method is also the same as the second method in that the time taken for light to pass through the slit is measured.

However, high-frequency electric pulses were used to measure the time, and the high-frequency electric pulses were opened and closed by a light-receiving element operated by light transmitted through the slit. In other words, an AND circuit or the like is used to start counting electrical pulses when the light-receiving element receives light, and to stop counting the pulses when it finishes receiving light.

Then, a value proportional to the number of pulses counted by a counter or the like and the time interval at which the light-receiving element receives light, that is, the rotational speed of the torsion bar, is obtained.

Calculate torque.

[Example] Hereinafter, a device embodying the present invention as shown in FIGS. 1 to 3 will be described.

In FIG. 1, 1 is a drive shaft, 2 is a driven shaft rotated by the drive shaft 1, and both are connected by a torsion bar 3. 4 and 5 are slit disks fixed to both ends of the torsion bar 3, respectively. In these slit disks 4 and 5.

Slits are cut at equal intervals, and optical fibers 6 and 7 are placed facing each other with the slits in between. (Second
(Details are enlarged in the figure) In Figure 3, 8 is a light source,
A light receiving element 9 introduces continuous light into the optical fiber 6, and a light receiving element 9 converts the light propagated through the optical fiber 7 into an electrical signal.

10 is a high frequency pulse oscillator, and 11 is a counter which starts counting pulses from the pulse oscillator 10 at the rising edge of the light receiving element 9, and repeats the operation of stopping the count and holding data at the falling edge.

12 is a torque calculator, which outputs the output of the counter 11;

It receives the output of the light receiving element 9 and calculates the torque, and is constructed of the same circuit as that used in the conventional method.

Now, the continuous light emitted from the light source 8 is propagated by the optical fiber 6, and is irradiated toward the slit disk 5 from its end face. The optical fiber 7 receives light passing through a gap proportional to the degree of overlapping of the slits in the slit discs 5 and 6, that is, the amount of deviation of the slits due to the amount of torque applied to the torsion bar 1, and the light is transmitted to the light receiving element 9. propagate.

The light receiving element 9 receives light via the optical fiber 7,
A rectangular pulse as shown in FIG. 4A is generated. Figure 4 shows the output when TI receives light at the mouth and the cycle until TO receives the next light. A pulse signal is output from the pulse transmitter 10, and by ANDing it with the light receiving element 9, that is, counting starts at the rising edge of the light receiving element 9 and ends at the falling edge, thereby achieving the above T1. The number of pulses proportional to is obtained,
Conversely, the torque is determined from 1 hour T1.

In FIG. 5, one circuit for determining one period To is proposed. The difference from FIG. 3 is that the frequency divider 13 is composed of a flip-flop circuit or the like.

It has a clock transmitting device 14 and a pulse counter 15. The frequency divider 13 constituted by the flip-flop circuit divides the output pulse of the light receiving element 9 by A and outputs a rectangular pulse signal (duty ratio 50%) with one cycle of 2TO. The output signal is input to the torque calculator 12 and is also input to the gate terminal 15G of the pulse counter 15.
is also connected to.

Open and close that gate. The data input terminal 15D of the pulse counter 15 is connected to the oscillation output signal of the clock oscillator 14 (the oscillation frequency does not have to be as high as the oscillation frequency of the high-frequency pulse oscillator 10). Counting starts when the frequency divider 13 rises, and stops counting and holds data when the frequency divider 13 falls.

The torque calculator 12 detects the fall of the frequency divider 13, reads the output data of the counter 15, and calculates the -period time To of the light reception pulse signal (FIG. 4A).

Note that for 9 hours TO, the oscillation frequency of the clock generator 14 is f (llz), and the count data of the counter 15 is m.

TO=m/f (sec) Calculated at

〔effect〕

According to the method of the present invention, it is possible to measure torque acting on nine rotating axes with a low-cost device and with high accuracy.

[Brief explanation of drawings]

FIG. 1 is an illustrative diagram of an apparatus for embodying the method of the present invention, FIG. 2 is an enlarged view of its main parts, FIG. 3 is a block diagram of a processing circuit, FIG. 4 is an exemplary diagram of signals, and FIG. The figure is a processing circuit block diagram of another embodiment. 3... Torsion bar, 4: 5... Slit disk, 6:
7. Optical fiber, 8. Light source. 9... Light receiving element, 10... High frequency pulse transmitter. 11...Counter, 12...Torque calculator. Firstly

Claims (1)

[Claims] A slit disk is fixed on each side of the torsion bar, which has an easily deformable part where twisting deformation easily occurs, and a continuous light parallel to the torsion bar is irradiated to the two slit disks, and the overlapping part of the slits is The light that passes through is received by a light receiving element, and the high frequency electric pulse transmitted from the pulse transmitter is opened and closed by the output of the above light receiving element to count the number of pulses, and from this counted number, the torque acting on both ends of the torsion bar is calculated. A torque measuring device characterized by measuring torque.