JPH04194631A - Torque detector - Google Patents

Abstract

PURPOSE:To measure torque per rotation angle by acquiring number of counted reference pulses indicating pulse width of a phase difference pulse while timing is shifted for each rotation of a torque transmission shaft. CONSTITUTION:When a torque transmission shaft 1 rotates with torsion, there is a difference in phases between rotation pulses (a) and (b) output from rotation sensors 4,5 so that a phase difference pulse (e) is generated 9. Pulse width of this pulse (e) is converted 11 into the number of reference pulses (f) and the number of the pulses (f) is counted 13. Pulse width of either pulse (a) or (b) is converted 12 into the number of the pulses (f) and counted 14. Further in a post-counter 18, with the counted number of reference rotation pulses (l) by a pre-counter 17 as a preset value, the umber is output as a measurement pulse (g) at the time of counting termination. The pulse (g) delays by one cycle of rotation pulses per rotation of the shaft 1. A CPU 21 acquires the counted numbers of the counters 13,14, and torque at each rotation angle is calculated and then stored in a RAM 22.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a non-contact torque detection device using a rotation sensor such as a photointerrupter or an electromagnetic pickup.

<Prior Art> Conventional torque detection devices include non-contact type devices that use a rotation sensor such as a photo interrupter or an electromagnetic pickup. In the case where a photo-interrupter is used, a slit disk is attached to two positions in the axial direction of the torque transmission shaft, and the photo-interrupter is provided at a position facing the slit of the slit disk. The electromagnetic pickups are respectively installed opposite to a pair of gears attached to two locations in the axial direction of the torque transmission shaft.

In the above torque detection device, when torque is applied to the torque transmission shaft and the pongee is twisted, the amount of twist appears as a phase difference between the rotation pulses of the pair of rotation sensors. Therefore, a phase difference pulse corresponding to the phase difference is created from both rotational pulses, and the pulse width of the phase difference pulse is measured.

By the way, the pulse interval between the rotation pulses obtained from each rotation sensor varies depending on the rotation angle for various reasons, and the torque for each rotation angle is not constant.

Therefore, normally, the pulse width of the phase difference pulse is measured over a wide angular range of one rotation or less, and the average value within the measurement range is output as measurement data.

Alternatively, two photoelectric sensors are provided at two locations in the diametrical direction for each slit disk, the rotational pulses obtained from these photoelectric sensors are combined, and a phase difference pulse is generated from the rotational pulse thus obtained. This eliminates variations in measurement data for each rotation angle.

<Problems to be Solved by the Invention> In the conventional method described above, fluctuations in torque for each rotation angle are averaged, and stable measurement data can be obtained.
In some cases, measurement data for each rotation angle may be required.

For example, the drive shaft of an engine or the rotating shaft of a rotating machine driven by an engine has periodic angular velocity fluctuations, and torque also fluctuates periodically. It is desirable to collect measurement data regarding the fluctuation state of torque, such as torque.

In view of the above-mentioned needs, it is an object of the present invention to provide a torque detection device that can detect torque for each rotation angle and also obtain maximum torque and minimum torque values.

<Means for Solving the Problems> In order to achieve the above-mentioned problems, the present invention is a device for detecting torque using non-contact type rotation sensors installed at two locations in the axial direction of a torque transmission shaft. The phase difference circuit, the reference oscillator, both the first and second AND gates, both the first and second counters, the basic rotation pulse generating means, the front stage counter, the rear stage counter, and the calculation means. , and a memory, the phase difference circuit generates a phase difference pulse corresponding to the phase difference between the rotation pulses of both rotation sensors, and the first AND gate introduces the reference pulse and the phase difference pulse from the reference oscillator. However, the second AND gate introduces the rotation pulse of one of the rotation sensors and the reference pulse, and each of the first and second counters counts the reference pulse passing through the corresponding AND gate. The rotation pulse generating means generates a single basic rotation pulse for each rotation of the torque transmission shaft, and the first-stage counter counts the basic rotation pulses and gives the counted number as a preset value to the second-stage counter, and the second-stage counter One rotation pulse is counted based on the preset value from the previous stage counter, a measurement pulse is output when the count ends, and this measurement pulse regulates the counting operation of the reference pulse in both the first and second counters. The calculation means calculates the torque for each rotation angle by taking in the count numbers of the first and second counters at each measurement timing by the measurement pulse, and the memory calculates the torque for each rotation angle. The structure was designed to store measurement data.

<Operation> In the above configuration, when the torque transmission shaft rotates in a twisted state, there is a phase difference between the rotation pulses output from the pair of rotation sensors, and a phase difference corresponding to this phase difference occurs. A phase difference pulse is generated in a phase difference circuit. The pulse width of the phase difference pulse is converted into the number of reference pulses by a first AND gate in the next stage, and the number of reference pulses is counted by a first counter. Further, in order to calculate the phase difference ratio, the pulse width of the rotation pulse of one of the rotation sensors is converted into the number of reference pulses by the second AND gate, and the number is counted by the second counter.

Here, each of the first and second counters counts the number of reference pulses at each rotation angle at the timing of the measurement pulse.

That is, the second stage counter counts the rotation pulses using the number of basic rotation pulses counted by the first stage counter as a preset value, and outputs the end signal as a measurement pulse when the count ends. Therefore, one measurement pulse is generated per rotation of the torque transmission shaft, and its timing is delayed by one cycle of the rotation pulse for each rotation.

Now, each counter sequentially counts the number of gate passages of the reference pulse at the subsequent rotation angle each time the torque transmission shaft rotates, and in this way, the torque calculation at each rotation angle is performed over the entire circumference. You can get the count number for The calculation means takes in these counts and calculates the torque at each rotation angle, and the memory stores measurement data at each rotation angle.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 is a circuit configuration diagram of an embodiment of the present invention, FIG. 2 is a front view of a slit disk, and FIGS. 3 and 4 are timing charts for explaining the operation.

As shown in FIG. 1, the torque detection device of this embodiment is
Torque transmission shaft l and both first and second slit discs 2
．． 3, first and second photointerrupters 4.5 as rotation sensors, and a third photointerrupter 6 as basic rotation pulse generation means.

The first and second slit disks 2.3 are respectively attached to two locations in the axial direction of the torque transmission shaft 1.
As shown in Fig. 2, a large number of slits 2a, 3a are formed at the same pitch (in this example, 120 at 3° pitch) on the circumference.
is formed. Among these, in the first slit circular plate 2, in addition to the row of slits 2a, there are through holes 2b at positions in the circumferential direction.
is formed.

The first photo interrupter 4 is connected to the slit 2a of the first slit disk 2, and the second photo interrupter 5 is connected to the second
They respectively face the slits 3a of the slit disk 3. The third photo interrupter 6 is provided at a position that can face the through hole 2b of the first slit disc 2.

The torque detection device of this embodiment also has first and second
D flip-flop 7.8 and A as a phase difference circuit
ND gate (hereinafter referred to as AND gate for phase difference) 9, reference oscillator 1o, and first and second AND gates 1
1. +2, first and second counters 13.14,
It includes a microcomputer 15, an EEPROM 16, a front counter 17, a rear counter 18, an operation section 19, and a display 20.

The first D flip-flop 7 introduces the rotation pulse from the first rotation sensor 4, and the second D flip-flop 8 introduces the rotation pulse from the second rotation sensor 5, and both divide the rotation pulse by half, and Duty ratio 50
Shape the waveform into a % square wave.

The phase difference AND gate 9 inputs the outputs of both the first and second D flip-flops 7.8 and outputs an overlapping portion of the output pulses, that is, a phase difference pulse corresponding to the phase difference of both forces.

The first AND gate II introduces the reference pulse and the phase difference pulse from the reference oscillator 1o, and by passing the reference pulse while the phase difference pulse is rising, the pulse width of the phase difference pulse is set as the reference. Convert to number of pulses.

The second AND gate 12 inputs the frequency-divided rotation pulse and the reference pulse, which are the outputs of the second D flip-flop, and converts the pulse width of the frequency-divided rotation pulse into the number of reference pulses.

Both AND gates 11 and 12 are connected to the subsequent counter 18.
We have also introduced a measurement pulse that is the count end signal.
Each gate operation is also controlled by a measurement pulse, but this point will be described later in conjunction with the explanation of the subsequent counter 18.

The first and second counters 13 and 14 count reference pulses passing through the first and second AND gates 11 and 12, respectively, and the counting operation is performed by the microcomputer 5 and the subsequent counter 18.
controlled by

The microcomputer I5 has a pre-stage counter 17 and a first
The CPU 2+ controls the operation of the second counters 13 and 14, and also takes in the counts from the first and second counters 13 and 14, and the CPU 2+ is the computing means described in the claims. Also, RAM22
function as a memory for measurement data. CPt
J21 introduces a measurement pulse to its interrupt terminal via the delay circuit 23, and provides a clear signal to the pre-stage counter 17 via the OR gate 24. EEPROM+
6 stores calculation formulas, calculation constants, correction amounts associated with zero point adjustment, etc. necessary for torque calculation by the CPU 21.

The front-stage counter 17 is an up-counter that inputs the basic rotation pulse from the third photo-increment club taro and counts the basic rotation pulse, and provides the counted number to the rear-stage counter 18 as a preset value. Further, a count number discrimination circuit 25 is connected to the count output terminal of the pre-stage counter 17, and when the count number reaches a certain number (59 in this case), the discrimination circuit 25 outputs a discrimination signal to indicate that. The signal is applied to the clear terminal of the pre-stage counter 17 through the OR gate 24.

The second stage counter 8 is a down counter which takes in a preset value from the first stage counter 17 in response to the input of the basic rotation pulse, and counts the divided rotation pulse from the 27th rib flop 8 based on the preset value. A countdown signal indicating the end of the count is used as a measurement pulse for each of the first and second AND gates II, +
2, and each of the first and second counters 13
14 as a store signal via an inverter 26.

Therefore, each first and second AND gate 11.1
2, the reference pulse is passed while the measurement pulse is rising, and each of the first and second counters 13 and 14 counts the passing reference pulse.

Next, the operation of the above configuration will be explained based on the timing charts of FIGS. 3 and 4.

When the torque transmission shaft 1 is rotating in a twisted state, each of the first and second photo ink actuators 4
．． 5 outputs the rotation pulse shown in (a Xb ) in FIG.

Each of the rotational pulses (a) and (b) is frequency-divided by the corresponding D flip-flop 7.8 to become the pulses shown in (c) and (d) of the figure. These divided rotation pulses (C) (d
), there is a phase difference corresponding to the amount of torsion of the torque transmission shaft 1, so from the AND gate 9 for phase difference to which both frequency division rotation pulses (c Xd ) are input, both frequency division rotation pulses (c A phase difference pulse (e) corresponding to the phase difference between the two is outputted at a temporally overlapping portion of the pulses cXd).

This phase difference pulse (e) is a high-frequency reference pulse (
f) is input to the second AND gate 12, so
The reference pulse (f) passes while the phase difference pulse (e) is rising, and the pulse width of the phase difference pulse (e) is converted into the number of reference pulses (f). Since the measurement pulse (g) is also input to the AND gate 11, the pulse of the phase difference pulse (e) is output only while the measurement pulse (g) is rising, as shown in (h) of FIG. A reference pulse (f) indicating the width is passed.

Similarly, the rotation pulse (b
) is also frequency-divided to provide the second AN along with the reference pulse (f ).
Since it is input to the D gate 12, the divided rotation pulse (d
) is converted into the number of reference pulses (f ). Since the measurement pulse (g) is also input to the second AND gate 12, as shown in (]) in FIG. 3, only while the measurement pulse (g) is rising, is the reference pulse ( f) passes.

Now, the measurement pulse (g) corresponds to the -foot angle range (6° range in this example) and has a pulse width of one cycle from the rise of the second divided rotation pulse to the next rise. , the third photo interrupter 6, the front-stage counter 17, and the rear-stage counter 18. The related operation will be explained based on FIG. 4.

First, every rotation of the torque transmission shaft l, the third photo interrupter 6 outputs a negative basic rotation pulse (a). As shown in FIG. 4(m), the front stage counter 17
The basic rotation pulse (counts 0. On the other hand, in response to the input of the basic rotation pulse (C), the subsequent counter 18 takes in the count number of the previous stage counter 7 as a preset value, and outputs it from the second D flip-flop 8. Start counting the frequency-divided rotation pulses (d).

Now, when one basic rotation pulse (ri) is input to the front stage counter 17, the preset value at the rear stage counter 18 is "1", and the rear stage counter 18 is set to (n) in FIG.
), the counting ends after just one divided rotation pulse (d) and the measurement pulse (g
) occurs. Next, when the second basic rotation pulse (evening) is input to the front-stage counter 17, the second-stage counter 18 counts two frequency-divided rotation pulses (d), and the third basic rotation pulse (returns to 0). In this way, as the cumulative count of the basic rotation pulse (ff) increases, the number of divided rotation pulses (d) at the subsequent counter 18 increases. The number of counts increases, the time until the count ends becomes longer, and the timing of the generation of the measurement pulse (g) changes from the basic rotation pulse (0
is sequentially delayed by I periods of the frequency-divided rotation pulse (d).

In this way, by sequentially delaying the generation timing of the measurement pulse (g), each of the first and second AND gates 11.12 sequentially adjusts the subsequent rotation angle as the rotation of the torque transmission shaft l progresses. A reference pulse (f
), and each corresponding counter l3.14 counts the number of times the reference pulse (f) passes through the gate, and then stores the counted number. In this way, counts for torque calculation at each rotation angle can be obtained over the entire circumference.

Next, each time the measurement pulse (g) is generated, the CPU 21 takes in the counts stored in the first and second counters 13 and 14, and calculates the torque.

In this calculation, the ratio To(-S o+/S
Similarly, the ratio T m (
−5m+/S m2), and these values To, T
m is stored in EEPROMI 6.

Then, from the counts Snl and Sn2 of each counter 13 and 14 obtained during actual measurement, the ratio T n (=S
n+/S nx), then use the following formula to calculate the torque
Find t.

X t= ((T n -T o)/ (T m - T
o)) XFXK (1) Here, F indicates the rated torque, and K is a constant for obtaining a predetermined dimension.

Each time the CPU 21 calculates the torque at a certain rotation angle, it compares the torque with the previous calculation result to obtain the maximum and minimum values of the torque. The torque values at each rotation angle calculated by the CPU 21 are stored in the RAM 22 one after another. The RAM 22 may store counts for torque calculation.

In the above embodiment, a photo ink club taro was used as a means for generating the basic rotation pulse (g), but the slits 2a and 3a of the slit disk 2.3 were connected to the first or second photo interrupter 4°5. It is also possible to connect a counter that counts the same number as the number of , and generate one pulse from this counter for each rotation of the torque transmission shaft 1 .

<Effects of the Invention> As described above, in the present invention, the count number of the reference pulse indicating the pulse width of the phase difference pulse etc. is taken in while shifting the timing for each rotation of the torque transmission shaft. Torque can be measured for each angle, and the maximum and minimum values of torque can also be calculated, making it easy to analyze the operation of machines with torque fluctuations.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram of an embodiment of the present invention, FIG. 2 is a front view of a slit disk, and FIGS. 3 and 4 are timing charts for explaining the operation. ■...Torque transmission shaft, 4.5...1st. 2nd photo interrupter (rotation sensor), 6... 3rd photo interrupter (basic rotation pulse generation means), 9... AND gate for phase difference (phase difference circuit), IO... reference oscillator,
11.12...1st. 2nd AND gate, 13.14
...First. Second counter, 17...previous stage counter,
18...Late stage counter, 21...CPU (calculation means), 22...RAM0

Claims (1)

[Claims] (1) A device that detects torque using non-contact rotation sensors installed at two locations in the axial direction of a torque transmission shaft, which includes a phase difference circuit, a reference oscillator, and both first and second AN
A D gate, both first and second counters, basic rotation pulse generating means, a front stage counter, a rear stage counter,
It includes a calculation means and a memory, the phase difference circuit generates a phase difference pulse corresponding to the phase difference between the rotation pulses of both rotation sensors, and the first AND gate generates a phase difference pulse between the reference pulse from the reference oscillator and the phase difference pulse. The second AND gate introduces the rotation pulse of one rotation sensor and the reference pulse, and each of the first and second counters has a corresponding AN
It counts the reference pulses passing through the D gate, and the basic rotation pulse generation means generates a single basic rotation pulse for each rotation of the torque transmission shaft, and the front-stage counter counts the basic rotation pulses and calculates the number of basic rotation pulses. The count number is given to the subsequent counter as a preset value, and the latter counter counts one rotation pulse based on the preset value from the previous counter, outputs a measurement pulse when the count ends, and uses this measurement pulse to generate the first rotation pulse. and a second counter, and the calculation means takes in the counts of the first and second counters at each measurement timing by the measurement pulse and calculates the count for each rotation angle. What is claimed is: 1. A torque detection device, wherein the torque is calculated, and the memory stores measurement data at each measurement timing.