JPH01305334A - Measuring device for transmission error of differential gear system - Google Patents

Abstract

PURPOSE:To make two output shafts free and to enable detection of a transmission error under the actual conditions of use wherein a load is applied thereon by taking an average of speeds of the two output shafts one of which decreases the speed when the other increases it. CONSTITUTION:Motors 22 and 21 are driven in a state wherein prescribed power absorption is conducted by a motor 23. Thereby pulse trains are generated from rotary encoders 31-33 every time when corresponding shafts 11-13 rotate at prescribed minute angles. On the occasion, the speeds of rotations of the shafts 12 and 13 are varied by a slight difference of loads applied thereto. Concretely, one speed decreases as the other increases, and the periods of the pulse trains generated from the encoders 32 and 33 are varied in accordance with the above variations. These periods are added up asynchronously and mixed in an addition circuit 1. Then, in a frequency-division circuit 2, the pulse train from the encoder 31 and said pulse trains added up asynchronously are frequency-divded at a prescribed rate. A phase difference between the two frequency-divided outputs is measured in a phase-difference measuring circuit 3, and this difference increases or decreases corresponding to the magnitude of a transmission error when it exists.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for measuring a transmission error between a differential gear system and an output shaft of, for example, an automobile.

It is impossible to precisely synchronize the two output shafts of a conventional differential gear system because it is difficult to completely match the magnitude of the load applied to each wheel.

When measuring transmission errors, this synchronization is an essential condition (if it is asynchronous, the rotation will increase or decrease, and the transmission deviation with the input shaft cannot be determined), so conventionally when measuring, one output shaft side is was locked, and the transmission error between the other output shaft and input shaft was measured.

In other words, a pulse generator such as a rotary encoder is attached to the input shaft and the output shaft on the non-locking side, and a pulse train is generated every time each shaft rotates by a certain minute angle, and both pulse trains are sent to one side of the differential gear system. The frequency was divided by a frequency divider according to the rotational transmission ratio with the output shaft locked, and the phase difference between the two frequency-divided pulse trains was determined by a phase difference measuring circuit. In this way, the other output shaft will rotate at a predetermined ratio with respect to the input shaft because one is locked, and the transmission error will be the output shaft through the predetermined transmission ratio with respect to the rotation of that input shaft. It is determined as the minute advance or delay in the rotation of , that is, the phase difference.

Kaimei will solve the problem. However, the transmission error obtained from the above is under the special condition of locking one of the output shafts, and is different from the original usage condition where both output shafts are free and a load is applied to them. The transmission error below cannot be determined.

Means to Solve the Problem - n This invention provides that in two output shafts of a differential gear system, if one speeds up, the other slows down, and if the speed is balanced, the two output shafts will be in a synchronous rotation state. Focusing on the fact that a rotation corresponding to the rotation can be obtained, the present invention provides an apparatus for determining the transmission error in an unlocked state.

That is, the present invention includes a drive section coupled to an input shaft of a differential gear system, a power absorption section coupled to two output wheels of the differential gear system, and a drive section coupled to an input shaft of a differential gear system, a power absorption section coupled to two output wheels of the differential gear system, and a microscopic drive section of the input shaft and two output shafts. first, second, and tJIJ3 pulse generators that send out first, second, and third pulse trains every time they rotate by a certain angle;
An adder circuit that forms an asynchronous addition pulse train of the second and third pulse trains, a frequency divider circuit that divides the frequency of the first pulse train and the asynchronous addition pulse train at a predetermined ratio, and measurement of the phase difference between the divided outputs. It consists of a circuit.

In the above-mentioned device, when the input shaft is driven by the drive section with a suitably determined load applied to each output shaft by the power absorption section, each shaft is outputted from tjSl to the third pulse generator at a very constant level. The first to third pulse trains are sent out every time the angle rotates. At this time, the second
The frequency of the third pulse train increases due to differences in load fluctuations, etc.
The pulse train is added to an adder circuit and added asynchronously.

Therefore, although the individual periods of the asynchronous addition pulse train that is combined into one of the second and third pulse trains vary, when looking at the average period of some of them, the synchronization of both outputs is approximately constant. is proportional to the period of the pulse train in the state.

A frequency dividing circuit extracts the average period pulse of several pulses of this asynchronous addition pulse train, and in this, a pulse train is divided into a predetermined number of pulses according to the transmission ratio between the input shaft and the output shaft. is taken out and sent to the phase difference measurement circuit together with the divided output of the first pulse train, which is also formed according to the transmission ratio, and the lead of one of them relative to the other,
The phase difference between the two outputs, which is the delay, or the transmission error is determined.

Example In FIG. 1, 10 is a test differential gear system with a transmission ratio ^/B consisting of an automobile differential gear device, and its input shaft 11
is connected to a drive motor 21, and its two output shafts 1
2.13 are connected to power absorption motors 22, 23, respectively, and corresponding rotary encoders 31, 32.33 are attached to each shaft 11, 12.13, respectively.

Reference numeral 1 denotes an adder circuit for asynchronously adding input pulses, into which the outputs of the encoders 32 and 33 are introduced, and the asynchronous addition output is introduced into the frequency dividing circuit 2 together with the output of the rotary encoder 31. The frequency dividing circuit 2 divides the asynchronous addition output by 1728 times and the output of the rotary encoder 31 by 17'B times according to the transmission ratio ^/B, and sends the divided outputs to the measurement circuit 3. do.

In the above configuration, the motor 22. Drive the motor 21. As a result, a pulse train is generated from the rotary encoders 31, 32.33 each time the corresponding pongee 11, 12.13 rotates by a small fixed angle. At this time, the output ml 2
．． The rotational speed of 13 varies as shown in FIG. 2 due to slight differences in the load applied thereto. That is, if one of them increases, Ikekata decreases accordingly, and the period of the pulse train generated by the rotary encoders 32 and 33 changes accordingly. These two pulse trains are asynchronously added in the next adding circuit 1, thereby mixing a short period pulse train and a long period pulse train. Therefore, in a fluctuating state, although the periods of adjacent individual pulses are different from each other, we focus on the period of each pulse of a certain number of pulses, that is, the period that is the sum of the individual periods by a certain number of pulses. As a result, the length of each period is canceled out internally, and as a result, it becomes approximately constant. The frequency dividing circuit 2 divides the above asynchronous addition pulse train into 17
The frequency is divided into 28, that is, pulses are extracted every 2A from the pulse train, and the rotary encoder 3
The frequency of the output pulse train of 1 is divided by 1/B. As a result, the frequencies of these two frequency-divided outputs are made the same, and if there is a transmission error in the output shaft due to the rotation of the human-powered pongee 11, the magnitude will be adjusted between the two frequency-divided outputs. An increase or decrease in the phase difference occurs.

Therefore, the transmission error can be obtained by determining this phase difference using a phase difference measuring device.

In the above embodiment, the output shafts 12, 13 are connected to different motors 22, 23 to absorb power, but the output shafts 12, 13 are connected to separate motors 22, 23 to absorb power, It may also be combined with a power absorption device.

As described above, it is possible to easily determine the transmission error under actual usage conditions without locking one output side of the differential gear system. It is possible to provide effective information for improvement research, etc.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, tJS2
The figure is a diagram showing a model of the speed fluctuation state of two output shafts. 1: Addition circuit 2: Frequency divider circuit 3: Phase difference measurement circuit 11.12.13: Tsumugi 21.22, 23: Motor 31.32, 33: Encoder

Claims (1)

[Claims] 1. A drive unit connected to the input shaft of the differential gear system, a power absorption unit connected to the two output shafts of the differential gear system, and a drive unit connected to the input shaft of the differential gear system; a first, which sends out first, second, and third pulse trains for each movement;
second and third pulse generators, an adder circuit that forms an asynchronous addition pulse train of the second and third pulse trains, and a frequency divider circuit that divides the frequency of the first pulse train and the asynchronous addition pulse train at a predetermined ratio. and a phase difference measuring circuit for the divided outputs of the two frequency-divided outputs.