JPH0387601A - Twist angle detecting device in rotary twisting tester - Google Patents

Abstract

PURPOSE:To exactly detect a twist angle applied to a test piece by taking a difference by a first adding means with respect to an analog voltage signal outputted by a D/A converting means and a voltage signal generated by a signal generating means. CONSTITUTION:A pulse generator 11 generates one piece of timing pulse PR being a reference signal whenever a rotary output shaft 1a makes one rotation, and also, generates N pieces of up-pulses PD being forward rotation pulses and N pieces of down-pulses being backward rotation pulses PU per one rotation in accordance with a rotation of the forward and the backward directions of the shaft 1a. Also, an absolute type encoder 13 generates a voltage signal EV being an angle position signal varied continuously extending from 0V to a prescribed voltage in accordance with one rotation of a first rotary shaft 3a of a rotary actuator. Subsequently, an arithmetic processing circuit 14 inputs the pulses PR, PU and PD generated by the generator 11, and the signal EV from the encoder 13, executes an arithmetic processing, based thereon and derives a twist angle applied actually to a test piece T . P.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is a test piece that is used in a rotating state where torsional force is applied, such as a driving part of an automobile, by repeatedly applying torsion to the test piece. The present invention relates to a torsion angle detection device that detects the angle of torsion applied to a test piece in a rotary torsion tester for testing torsion characteristics.

[Prior Art] Generally, a rotary torsion testing machine has a drive motor 1 for rotationally driving the test pieces T and P, as shown in FIG. 4, and the rotation output shaft 1a of the drive motor 1 has a One end of the test piece T-P is connected via a chuck 2a serving as a first connection means. The other ends of the test pieces T and P are connected to a first rotating shaft 3a of a row reactor 3 as a torsion generating means via a chaff 2b as a second connecting means.

The rotation output shaft 1a of the drive motor 1 and the second rotation shaft 3b of the low reactor 3 are connected to connecting gears 4a and 4.
b. They are connected via the connecting shaft 4c and the connecting gears 4d and 4e to form a power circulation loop that transmits the torque of the drive motor 1, and the test piece TP and the torsional torque generating means 3 are connected to the power circulation loop. A power circulation type rotary torsion testing machine is constructed, which is interposed in series in terms of power transmission.

The above-mentioned low reactor actuator 3 has a servo valve 3c controlled by a control device 5, for example,
As disclosed in Japanese Patent No. 415, the servo control of the servo valve 3c by the control device 5 works to impart relative rotation between the first and second rotating shafts 3a and 3b.

The control device 5 detects the amount of twist applied between both ends of the test piece T-P, calculates the difference between the detected amount of twist and the set amount of twist, and adjusts the amount of twist to the set value based on the calculated deviation. The servo valve 3C of the low reactor 3 is servo-controlled so that the test piece T-P is twisted by a predetermined amount.

When performing a torsion test on a test piece T-P using the above-mentioned rotary torsion testing machine, as shown in Fig. 5, a constant amount of static twist θ applied to the test piece T-P and a test One piece T-
The repetition frequency f3, which is repeatedly applied to the static twist amount θ, while P rotates once, the maximum twist amount θyo, X
and the dynamic torsion signal waveform θ of the minimum torsion amounts θ1 and 7, respectively, are set. In order to add such an amount of twist, the amount of twist actually applied to the test piece T-P is detected, and the detected amount of twist, the static twist amount θ, and the dynamic twist signal waveform θ are combined.
. It is necessary to servo-control the servo valve 3a of the low reactor 3 based on the deviation from the control signal obtained by adding .

The static twist amount θ is predetermined as described above.

and the dynamic torsion signal waveform θ, the test piece T・
In order to detect the amount of twist applied to P, the difference Δθ (= θ - θ2) between the rotation angles θ1 and θ2 of both ends A and B of the test piece T-P that changes as shown in Fig. 6 must be determined. However, in the conventional control device 5, a device configured as shown in FIG. 7 was used as a device for detecting the twist angle between both ends of the test piece TP.

That is, pulse encoders 7a and 7b are connected to one end A and the other end B of the test piece T-P via timing belts 6a and 6b, respectively, to generate pulse signals in accordance with the rotation of the test piece T-P. The pulse encoder 7a
As an increment pulse, the pulse signal generated by
The pulse signal generated by the pulse encoder 7b is input as a decrement pulse to the up/down counter 8, and the up/down counter 8 outputs a digital signal corresponding to the difference in the number of pulses generated by both pulse encoders 7a and 7b. The digital output of this up/down counter 8 is converted into a digital/analog CD/A) converter 9.
The amount of twist Δθ was determined by converting it into an analog signal. A signal representing the determined amount of twist Δθ and the static twist angle θ set above.

and the amount of dynamic twist θ. The low reactuator 3 is servo-controlled based on the deviation from the above control signal obtained by adding .

[Problem to be solved by the invention]

In the conventional apparatus described above, the torsion angle Δθ is determined by counting up and down the pulses generated by the pulse encoders 7a and 7b provided at both ends of the test piece T-P using an up-down counter, and constantly finding the difference in the number of pulses.
is detected, so once the pulse count value is deviated due to the introduction of pulse noise from the outside, this will cause an error to be included in the subsequent torsion amount Δθ. In addition, since this error increases each time pulse noise occurs, the test piece T,
It becomes impossible to test by adding a target amount of twist to P, and the reliability of the test is impaired.

Therefore, it is an object of the present invention to provide a torsion angle detection device for a rotary torsion testing machine that solves the above-mentioned problems of the conventional device and can accurately detect the torsion angle applied to a test piece.

[Means to solve the problem]

In order to solve the above-mentioned problems, the torsional angle detection device according to the present invention includes a drive motor that generates a rotational torque to be applied to a test piece, and a torsional torque generating means that generates a dynamic torsional torque to be applied to a test piece. In the torsion test machine,
a first signal generating means for generating one pulse per revolution and N pulses per revolution according to the rotation of one end of the test piece; a second signal generating means for generating a voltage signal that linearly changes in response to the rotational angular position of the other end; and a second signal generating means that is reset by a timing pulse generated by the first signal generating means and the first signal a counter means for counting the number of signals generated by the first signal generating means; a digital-to-analog conversion means for converting the count value of the counter means into an analog voltage signal; sample-and-hold means for sampling and holding an analog voltage signal outputted by the means; and first addition means for taking the difference between the analog voltage signal outputted by the digital-to-analog conversion means and the voltage signal generated by the second signal generation means. and a second addition means for adding the analog voltage signal held in the sample hold means and the analog voltage signal output from the digital-to-analog conversion means, and an output signal of the second addition means and the second signal. and third addition means for calculating the difference between the voltage signal generated by the second signal generation means and the period from the fall of the voltage signal generated by the second signal generation means to the generation of the timing pulse. The period from generation of the timing pulse to the fall of the voltage signal generated by the second signal generation means for the output signal of the addition means is determined by the third period.
The present invention is characterized in that the output signals of the adding means are selected and outputted, and the twist angle applied to the test piece is detected based on the output signals.

[Effect]

In the above configuration, the first signal generating means generates one timing pulse per revolution and N pulses per revolution in response to the rotation of one end of the test piece.

The pulses generated by the first signal generating means are counted by the counter means, and the count value of the counter means is reset by the timing pulses generated by the first signal generating means. Then, the count value of the counter means is converted into an analog voltage signal by the digital-to-analog conversion means. Therefore, the analog voltage signal output by the digital-to-analog conversion means represents the rotational angular position of one end of the test piece with respect to the position where the timing pulse is generated.

On the other hand, as the other end of the test piece rotates, the second signal generating means generates a voltage signal that varies linearly in accordance with the rotational angular position of the other end. The voltage signal represents the rotational angular position of the other end of the test piece.

A first addition means calculates the difference between the analog voltage signal outputted by the digital-to-analog conversion means and the voltage signal generated by the second signal generation means, and this difference determines the relative angular position of both ends of the test piece. The difference between them, that is, the amount of twist, is detected.

Further, the analog voltage signal outputted by the digital-to-analog conversion means is sampled and held by a sample and hold means in accordance with a timing pulse generated by the first signal generation means, and the held analog voltage signal is subjected to a second addition process. In the means, the analog voltage signal outputted from the digital-to-analog converting means is added, and the second
The difference between the output signal of the adding means and the voltage signal generated by the second signal generating means is calculated in the third adding means. The output signal outputted by the third adding means is a signal representing the amount of twist between both ends of the test piece until the voltage signal generated by the signal generating means of the rear cylinder 2 falls after the counter means is reset. .

The output signal outputted by the first addition means during the period from the fall of the voltage signal generated by the second signal generation means to the generation of the timing pulse, and Since the torsion angle applied to the test piece is detected by the output signal outputted by the third addition means during the period until the voltage signal generated by the signal generation means falls, pulse noise is eliminated. Even if this happens and is counted by the counter means, and the count value becomes incorrect, it is temporary;
This prevents the detected amount of torsion from going out of order continuously.

〔Example〕 Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a diagram showing an embodiment of a torsion angle detection device in a rotary torsion testing machine according to the present invention. In the figure, parts equivalent to those of the conventional device described above with reference to FIG. 7 are given the same reference numerals. are doing.

In FIG. 1, a pulse generator 11 including a rotary encoder as a first signal generating means is provided on a rotation output shaft 1a of a drive motor (1 in FIG. 4) having a chuck 2a attached to its tip. ing. This pulse generator 1
1 is the rotational output shaft 1a every time the rotational output shaft 1a rotates once.
Timing pulse P as one reference signal indicating the reference point of .

At the same time, it generates an up pulse Pυ as N forward rotation pulses per rotation and a down pulse P0 as N reverse rotation pulses per - rotation in accordance with the rotation of the rotational output shaft 1a in the forward and reverse directions. . That is, one up pulse and one down pulse are generated every 360''/N of forward and reverse rotation of the rotating output shaft 1a.

Further, an absolute type encoder 13 as a second signal generating means constituted by a potentiometer is connected to the first rotating shaft 3a of the low reactuator (FIG. 4, 3) via a timing belt 12. .

This absolute type encoder 13 generates a voltage signal Ev as an angular position signal that continuously changes from Ov to a predetermined voltage in response to one rotation of the first rotating shaft 3a of the low reactuator (Fig. 4, 3). occurs.

When there is no relative rotation between the first and second rotating shafts 3a and 3b of the row reactuator (Fig. 4, 3), the timing pulse PI+ is generated when the voltage signal Ev is Ov. The positions of the pulse generator 11 provided on each rotary output shaft 1a and the absolute encoder 13 connected to the rotary shaft 3a are respectively set so that the rotation output shaft 1a has the same position as that of the absolute encoder 13 connected to the rotary shaft 3a.

The pulses PR1Pt+ and Po generated by the pulse generator 11 and the voltage signal E generated by the absolute encoder 13 are input, and based on these, arithmetic processing is performed to determine whether the pulses are actually applied to the test piece T-P. An arithmetic processing circuit 14 is provided for determining the torsion angle Δθ. The torsion angle Δθ determined by the arithmetic processing circuit 14 is input as a feedback signal to the first input of the adder 15 of the servo control system, where the static torsion signal generator 1
The deviation from the static torsion signal θ and the dynamic torsion signal θ generated by the dynamic torsion signal generator 6 and the dynamic torsion signal generator 17, respectively, is taken. The deviation signal output by the adder 15 is applied to the servo valve 3c for servo-controlling the low reactor (3, FIG. 4).

FIG. 2 is a block diagram showing an example of a specific circuit configuration of the arithmetic processing circuit 14 in FIG. 1. In the figure, the arithmetic processing circuit 14 resets the reference timing pulse PR, up pulse PU, and down pulse PD generated by the pulse generator 11 by human power R, UP input, and DOW input.
Up/down counter 141 to be input to each of N human forces
has.

This up/down counter 141 resets the count value when the reference timing pulses P and l are input manually, and counts up and down according to the input of the up pulse Pυ. Count down according to the input. Therefore, the count value of this up/down counter 141 represents the rotational position of the rotational output shaft la with respect to the reference position. The count value output by the up/down counter 141 is input to a digital-to-analog (D/A) converter 142, where it is converted into an analog voltage signal.

The count value of the amplifier down counter 141 converted into an analog voltage signal by the D/A converter 142 is
A voltage signal generated by the absolute type encoder 13 between the sample and hold circuit 143, the other ten inputs of the second adder 145 to which the output signal of the sample and hold circuit 143 is applied to one input; Ev is input manually to each of the ten inputs of the first adder 144.

The output signal of the second adder 145 is the voltage signal Ev generated by the absolute encoder 13.
is applied to the ten input of the third adder 146 to which is input.

The output signals of the first and third adders 144 and 146 are input to the first and second fixed contacts a and b of the changeover switch 147, and by switching the movable contact C of the changeover switch 147, the output signals of the adder 144 or One output signal of 146 is selected and output as the torsion detection signal Δθ. The movable contact C of the changeover switch 147 operates to switch to the fixed contact a side when the control human power is at the H level, and to switch to the fixed contact side when the control force is at the L level. The control signal for this changeover switch 147 is applied to the RS flip-flop (FF) 1.
49 Q output. This R3-FF149 is
A detection signal generated by the Ev fall detection circuit 148 by detecting the falling of the voltage signal Ev generated by the absolute type encoder 13 to 0. Each is input to the set human power S.

The operation of the torsion angle detection device whose configuration has been explained above will be explained below with reference to the timing chart shown in FIG.

First, test pieces T and P are connected between chucks 2a and 2b of a rotary torsion testing machine as shown in the figure. Thereafter, a static torsion signal generator 16 generates a static torsion signal θ, and a dynamic torsion signal generator 17 generates a dynamic torsion signal θ. are set respectively, and in this state, the drive motor (FIG. 4, 1) is rotated to rotate the rotation output shaft 1a and the first rotation shaft 3a. In response to the rotation of these axes, the pulse generator 11 generates timing pulses PR% up pulse PU and down pulse PD.
An absolute encoder 13 generates a voltage signal Ev, and these pulses and voltage signals are supplied to an arithmetic processing circuit 14.

The up pulse Pu and down pulse PI+ supplied to the arithmetic processing circuit 14 are sent to the up/down counter 141.
The count value of the up/down counter 141 is input to the up input PU and down input DOWN of the up/down counter 141, respectively, and is counted up and down. D/
The analog voltage signal of the A converter 142 increases linearly as shown by the dotted line in FIG. 3(a) when no dynamic twist is applied by the low reactuator (FIG. 4, 3); When dynamic torsion is applied, it increases while changing according to the dynamic torsion, as shown by the solid line in FIG. 3(b).

The analog voltage signal outputted from the D/A converter 142 is supplied to the ten inputs of the adder 144, where the analog voltage signal is supplied to the human input from the absolute encoder 13 in a sawtooth shape as shown in FIG. 3(a). The output signal of the adder 144 is added to the voltage signal Ev which changes to
Manual power is applied to fixed contact a of 7.

The above-mentioned timing pulse Pi is generated at the timing shown in FIG.
149 reset human powers R are applied respectively.

The up/down counter 141 to which the timing pulses P and l are manually applied to the reset manual R has its count value reset, and the D/A to which this count value is input is reset.
The analog voltage signal of converter 142 is Ov at the reset origin.
become.

The sample and hold circuit 143 to which the timing pulse PR is applied samples and holds the value E of the analog voltage signal output from the D/A converter 142 immediately before being reset by the timing pulse PR. The voltage value E sampled and held in this sample and hold circuit 143
, is added to the output voltage signal of the D/A converter 142 in the adder 145. The output signal of this adder 145 is supplied to an adder 146, where it is added to the voltage signal Ev from the absolute encoder 13 that is supplied to the - input, and the output signal of this adder 146 is added to the voltage signal Ev from the absolute encoder 13 that is supplied to the - input. 147 fixed contacts.

R3-FFI49, which is manually powered by the timing pulse P and the set human power R, is set by inputting the pulse to the set human power S, and its Q output becomes H level,
When the timing pulse Pi is input to the reset human power R, it is reset and its Q output becomes L level.

The pulse inputted to the set input S of R3-FFI 49 is generated by the Ev fall detection circuit 14. That is, as shown in FIG. 3(a), a detection pulse is generated when the Ev fall detection circuit 48 detects that the voltage signal Ev from the absolute encoder 13, which changes in a sawtooth pattern, falls to Ov. be. Q of R3-FF14.9 above
The output is applied to the changeover switch 147 as a control signal, and when the Q output is at the H level, the changeover switch 147 switches its movable contact C to the fixed contact a side, and when it is at the L level, the changeover switch 147 is switched to the fixed contact side. .

As a result, during periods T1 and T2 (Fig. 3) until timing pulses P and l are generated, R5-F
The F 149 is in the set state, its Q output is at H level, and the changeover switch 147 is switched to the fixed contact a side. Therefore, the output of the changeover switch 147 is the sum of the output signal of the adder 144, that is, the inverted version of the voltage signal Ev from the absolute encoder 13, and the analog voltage signal of the D/A converter 142. As shown by the solid line in FIG. 3(d), it is output as Δθ (=θ, 10θゎ).

On the other hand, after the timing pulse PR is generated, E
During the period ΔT (FIG. 3) until the v falling detection circuit 148 generates a detection pulse at its output, the R3-FFI 49 is in a reset state due to the timing pulse P8, its Q output becomes L level, and the changeover switch 147 is turned off. The fixed contact is switched to the side. Therefore, the output of the changeover switch 147 includes the output signal of the adder 146, that is, the inverted version of the voltage signal Ev from the absolute encoder 13, the voltage value E held in the sample and hold circuit 143, and the D/A converter 145
The sum of the output signals is output as Δθ (=θ, +θ.) as shown by the dotted line in FIG. 3(d).

The signal passed through the changeover switch 147 is
-Detection signal Δθ (=83
+θ. ), which is applied to the adder 15 in FIG. dynamic torsion signal θ. The deviation from the set value is determined, and the servo valve 3c of the low reactor (FIG. 4, 3) is servo-controlled.

〔effect〕

As explained above, according to the present invention, the output signal outputted by the first addition means during the period from the fall of the voltage signal generated by the second signal generation means to the generation of the timing pulse, and the generation of the timing pulse. Since the torsion angle applied to the test piece is detected by the output signal outputted by the third addition means during the period from 1 to 3 until the voltage signal generated by the second signal generation means falls, the torsion angle applied to the test piece is detected. Even if noise occurs, which may cause the count value of the counting means to be incorrect, it is temporary because the counter means is reset by the timing pulse every time one end of the test piece rotates. This does not continuously deviate the detected twist amount, and the twist angle applied to the test piece can be accurately detected.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of a torsion angle detection device in a rotary torsion testing machine according to the present invention, FIG. 2 is a block diagram showing a specific example of the configuration of the arithmetic processing circuit in FIG. 1, and FIG. A timing chart diagram showing the status of each part of the device. Figure 4 is a diagram showing the general configuration of a rotary torsion testing machine. Figure 5 is a waveform showing static torsion and dynamic torsion applied to the test piece in a superimposed manner. 6 is a diagram showing the rotation angle of both ends of the test piece when the waveform twist shown in FIG. 5 is applied, and FIG. 7 is a diagram showing an example of a conventional torsion angle detection device. T-P... Test piece, 1... Drive motor, 3... Low reactuator (torsion torque generating means), 11.
...First signal generating means (pulse generator, 13...Second signal generating means (absolute type encoder), 1
4... Arithmetic processing circuit, 141... Counter means (up/down counter), 142... Digital-to-analog conversion means (D/A converter), 143... Sample hold means (sample hold circuit), 144 ...First
adding means (first adder), 145... second adding means (second adder), 146... third adding means (
third adder), 147... changeover switch, 148
...Ev fall detection circuit, 149...R3-FF.

Claims (1)

[Claims] A drive motor that generates rotational torque to be applied to a test piece;
In a rotary torsion testing machine equipped with a torsion torque generating means for generating a dynamic torsion torque applied to a test piece, one timing pulse per rotation and N pulses per rotation according to the rotation of one end of the test piece are provided. and a second signal generating means that generates a voltage signal that linearly changes in accordance with the rotational angular position of the other end as the other end of the test piece rotates. , a counter means that is reset by a timing pulse generated by the first signal generation means and counts the pulses generated by the first signal generation means; and a digital counter means that converts the count value of the counter means into an analog voltage signal. an analog conversion means, a sample hold means for sampling and holding an analog voltage signal outputted by the digital-analog conversion means in response to a timing pulse generated by the first signal generation means, and an analog voltage outputted by the digital-analog conversion means. a first addition means for calculating the difference between the signal and the voltage signal generated by the second signal generation means; and an analog voltage signal held in the sample and hold means and an analog voltage signal output from the digital-to-analog conversion means. a second addition means for adding the second signal; and a third addition means for taking the difference between the output signal of the second addition means and the voltage signal generated by the second signal generation means; During the period from the fall of the voltage signal generated by the generation means to the generation of the timing pulse, the output signal of the first addition means is used, and the voltage signal generated by the second signal generation means from the generation of the timing pulse is The torsion angle is characterized in that during the period until the fall, the output signals of the third adding means are selected and outputted, and the torsion angle applied to the test piece is detected based on the output signals. Detection device.