JPS62294929A - Torque detector - Google Patents

Abstract

PURPOSE:To stabilize the detecting accuracy of a torque quantity by a simple construction by constructing a gate circuit in a torque detector such that the gate circuit and detect a phase difference signal between adjacent rise time points and that between adjacent fall time points among pulse signals. CONSTITUTION:A first gear 4 and a second gear 5 with the same number of teeth are mounted with a prescribed spacing apart from each other to a rotating shaft 6 for transmitting a power provided in the casing 1 of the power transmission of a vehicle. Then, first and second magnetoresistance type rotation detectors 2 and 3 are mounted to the casing 1 in proximity to the circumferential teeth of the first and second gears 4 and 5, respectively, and the rotating conditions of the two gears 4 and 5 are detected. That is, when a torque is generated in the rotating shaft 6, phase difference signals between the output signals of the rotational position detectors 2 and 3 change. Since gate circuits 10-14 are constructed such that they can detect the phase difference signal between adjacent rising time points and that between adjacent fall time points between pulse signals obtained from the rotation detectors, the detecting accuracy of a torque quantity can be stabilized by a simple construction regardless of an environment.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a torque detection device that detects the amount of torque generated on a rotating shaft of a vehicle, and particularly relates to a torque detection device that uses a rotation detector and is easy to use. The present invention relates to a torque detection device that can detect a stable amount of torque using a circuit configuration.

[Conventional technology]

At present, this type of conventional torque detection device has not yet been put into practical use for vehicles. The main reason for this is that the signal from the torque detection section fluctuates due to temperature, aging, or variations in the detection section.

For example, the torque detection device described in Japanese Patent Application Laid-Open No. 49-57880 only corrects the gain and zero point of the torque value once in the signal processing circuit. No consideration was given to change. To explain further, the conventional torque detection device described above obtains a phase difference signal proportional to the amount of torque using two pulse signals obtained by waveform shaping the output signals from two rotation detectors as torque detection sections. Yes, but
This phase difference signal depends on the duty ratio between the two types of pulse signals. That is, if the output signal of the rotation detector changes depending on the rotation state of the rotation shaft due to changes during temperature change processing, etc., the second waveform after the waveform shaping will change.
The duty ratio of different types of pulse signals will also vary. the result.

This also affects the phase difference signal between the two types of pulse signals, which causes an error in the torque value.

[Problem that the invention seeks to solve]

The above-mentioned conventional torque detection device has a torque detection section that is
Variations in the characteristics of the detection unit itself and temperature changes.

In the case of a method in which the applied torque generated on the shaft of one rotation is detected as a phase difference signal between the output signals of the detection unit and only at the time of the rise or fall of the output signal because the effects of changes over time etc. are not taken into consideration. However, there was a problem in that the amount of torque could not be measured stably. In other words, the output signal of the detection section is generally waveform-shaped and converted into a pulse signal, but the duty ratio of this pulse signal fluctuates due to the above-mentioned effects such as temperature changes and changes over time.As a result, the torque amount There is a problem in that the phase signal between the pulse signals, which is proportional to , also fluctuates.

An object of the present invention is to solve the above-mentioned problems and provide a torque detection device that can stably detect torque with a simple circuit configuration regardless of variations in characteristics, temperature changes, and changes over time.

[Means for solving problems]

A torque detection device according to the present invention, which solves the above problems and achieves the above objects, includes two gears fixed at a constant interval to a rotating shaft of a vehicle, and provided close to the outer periphery of each of the gears, A rotation detector detects the rotational state of each gear and outputs an electrical signal, and a gate circuit calculates a phase difference signal between a pulse signal obtained from the electrical signal from each rotation detector, and the phase difference signal is determined by a gate circuit. In the torque detection device, the gate circuit detects, between the pulse signals, a phase difference signal between rising points and a phase difference signal between falling points. The circuit is configured so that it can be detected.

[Effect]

The phase difference signal between the two types of pulse signals, which is proportional to the amount of torque obtained based on the two types of pulse signals obtained by waveform shaping the output signals of the two rotation detectors, is the two types of pulse signals. This can be obtained by detecting both the time at the rising point and the time at the falling point between signals.

As a result, when the phase difference signal fluctuates due to temperature change, aging, etc., that is, when the time at the rise point becomes shorter, the time at the fall point is reversed by the shortened time. becomes longer, and if the time at the rise point becomes longer, the time at the fall point becomes shorter by the lengthened time. That is, if the torque applied to the rotating shaft is always constant, a stable phase difference signal can be obtained regardless of temperature changes, changes over time, etc., and therefore the torque amount will also be a stable value.

Because it operates in this way, variations in the output characteristics of the rotation detector that is the torque detection section, positional deviation of the rotation detector,
Regardless of temperature changes or secular changes in the output characteristics of the rotation detector, a stable torque amount can always be detected with a simple circuit configuration.

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

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a time chart shown to explain the operation of the embodiment.

In the embodiment shown in FIG. 1 and FIG. 2, a first gear 4 having an equal number of teeth and spaced apart from each other by a certain distance on a rotating shaft 6 for transmitting power provided in a casing 1 of a power transmitting unit of a vehicle;
Attach the second gear 5.

Next, a first magnetoresistive rotation detector 2. A second magnetoresistive rotation detector 3 is mounted on the casing 1 to detect the rotational state of the two gears 4 and 5. In other words, when torque is generated on the rotating shaft 6, the phase difference signal between the output signals of the two rotational position detectors 2.3 changes. The structure is such that the amount of torque generated can be detected.

That is, when the rotating shaft 6 is rotating at a constant rotation speed and a constant torque, the output signals of the two rotation detectors 2 and 3 become 30° 32 as shown in FIG. When the reference voltage signals of the comparators in the first waveform shaping circuit 7 and the second waveform shaping circuit 8 are designated as 31.34 shown in FIG. 2, after the waveform shaping of the rotation detectors 2 and 3, The signals 35 and 36 shown in FIG. 2 are as shown in FIG. Said signal 35.36
The signals 35 and 36 are input to the gate circuit 10 in order to obtain a phase difference signal at the rising time and a phase difference signal at the falling time. The signal 38 shown in FIG. 2 is the output signal of the gate circuit 1o, and the signal 35.36
Considering only one period, Δt1 is the phase difference signal at the rising time, and Δt2 is the phase difference signal at the falling time. 0 Next, count the phase difference time of the phase difference signal 38. In order to obtain the signal 4o, the output clock signal of the reference time generator 23 and the signal 38 from the gate circuit 10 are input to the gate circuit 12, and the signal 4o is input to the gate circuit 14. , counts the clock signal, and inputs the counted value to the microcomputer 24 via the signal line 22.

Here, the signal line 18 is a control signal line for determining whether or not to count the clock signal of the signal 40, and is in a counting state only when the voltage level is high. Further, the signal [20] is a control signal line for resetting the count value of the counter 16.

Further, the signal 35 is used to detect the rotation speed of the rotating shaft.
is first input to the 1/2 frequency divider 9 to obtain a signal 42. In order to measure the period T of the signal 35, the signal 42 is input to the gate circuit 11 together with the output clock signal of the reference time generator 23 to obtain a signal 43, as in the case of the phase difference signal described above. Therefore, in order to count the clock signal of the signal 43, after inputting it to the gate circuit 13, the clock signal of the signal 43 is counted by the counter 15, and the counted value is input to the microcomputer 24 via the signal line 21. do.

Here, the signal line 17 is a control signal line for determining whether or not to count the clock signal of the signal 43, and is in a counting state only when the voltage level is high. Further, the signal line 19 is connected to the counter 15.
Since 1 or more is a control signal line for resetting the count value of , the amount of torque generated on the rotating shaft 6 is expressed by the following equation.

Z − [(Δtz+Δt2) at no load)) where π: Pi.

T; period Z of the signal 35; number of teeth Δt1 of gears 4, 5; phase difference signal Δt2 at the time of rising; phase difference signal at the time of falling; change,
Assume that the signal changes due to changes over time and becomes signal 33.

Since the reference voltage signal of the comparator in the waveform shaping circuit 8 is in the same state as the signal 34, the output signal of the waveform shaping circuit 8 is 37. Here, since the signals 32 and 33 are approximately sine wave signals, Δt^=ΔtB holds true.

In other words, t1'=Δt^+t1+Δta.

tt, tt' +, high voltage level time Δt^, ΔtB in one cycle of signal 36.37; change in time ti of signal 36 Δt1. Δt2: Phase difference between the signal 35 and the signal 36 Δt1', Δt2': Phase difference between the signal 35 and the signal 37 Therefore, the phase difference signal between the signal 37 and the signal 35 becomes the signal 39. Here, the phase difference signal, Δt1'
From the above Δt^=Δta, the sum of Δ1 and / is Δt
It is equal to the sum of 1 and Δt2.

This is because even if the output characteristics of the rotation detectors 2 and 3 vary due to temperature or changes over time, a stable phase difference signal can always be obtained when the rotation shaft 6 has a constant torque. , which means that the detected torque amount is also a stable value.6 [Effects of the Invention] As described above, according to the present invention, variations in detector characteristics, phase shift of the detector, temperature changes, The effect is that the torque amount can be detected stably regardless of the year and with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a time chart shown to explain the operation of the embodiment of FIG. 1...Casing, 2.3...Rotation detector, 4,5
... Gear, 6 ... Rotating shaft, 7, 8 ... Waveform shaping circuit, 9 ... Branch circuit, 10 to 14 ... Gate circuit, 15゜16 ... Counter, 23 ... -Reference time generator, 24...microcomputer.

Claims (1)

[Claims] 1. Two gears fixed at a constant interval to the rotating shaft of the vehicle, and a rotating mechanism that is provided close to the outer periphery of each gear and detects the rotational state of each gear and outputs an electric signal. It consists of a detector, and means for obtaining a phase difference signal between the pulse signals obtained from the electrical signals from each rotation detector using a gate circuit, and counting a reference time based on the phase difference signal to obtain the torque amount. In the torque detection device, the gate circuit generates a phase difference signal between rising points between the pulse signals;
A torque detection device characterized by having a circuit configuration capable of detecting a phase difference signal between falling points.