JPH0565095B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a device for measuring transmission errors between the input and output shafts of a differential gear system, such as in an automobile.

Prior Art Two output shafts of a differential gear system cannot be precisely synchronized because it is difficult to completely match the magnitude of the load applied to each shaft.

When measuring transmission error, 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 when measuring conventionally, one output shaft side is 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 to generate a pulse train every time each axis rotates by a certain minute angle, and both pulse trains are sent to one output of the differential gear system. The frequency was divided by a frequency divider according to the rotational transmission ratio with the shaft locked, and the phase difference between the two frequency-divided pulse trains was determined by a phase difference measuring circuit. In this way, since the other output shaft is locked, the other output shaft will rotate at a predetermined ratio with respect to the input shaft, and the transmission error is the rotation of the output shaft through the predetermined transmission ratio with respect to the rotation of the input shaft. It is determined as the minute advance or delay in the rotation of , that is, the phase difference.

Problems to be Solved by the Invention However, the transmission error obtained as described above occurs under special conditions in which one of the output shafts is locked, and is different from the original usage condition in which both output shafts are free and a load is applied to them. The transmission error cannot be determined.

Means for Solving the Problems This invention provides two output shafts of a differential gear system.
By focusing on the fact that when one speeds up, the other slows down, and by taking the average, a rotation corresponding to the synchronous rotation state of the two output shafts can be obtained, and provides a device for determining the transmission error in an unlocked state. It is something.

That is, the present invention includes a driving section coupled to an input shaft of a differential gear system, a power absorption section coupled to two output shafts of the differential gear system, and a power absorbing section coupled to the input shaft and two output shafts of the differential gear system. First, second, and third pulse generators that send out first, second, and third pulse trains every time they rotate by a fixed angle, and an asynchronous addition of the second and third pulse trains to form a pulse train. A frequency dividing circuit divides the frequencies of the first pulse train and the asynchronous addition pulse train at a predetermined ratio, and a phase difference measuring circuit for the outputs of both frequency divisions.

Function In the above 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 output from the first to third pulse generators. The first to third pulse trains are sent out every time the device rotates by a small fixed angle. At this time,
The frequencies of the second and third pulse trains corresponding to the rotation of the output shaft repeatedly increase and decrease due to differences in load fluctuations, etc., and the pulse trains are added to an adding circuit and asynchronously added. Therefore, although the individual periods of the mixed asynchronous addition pulse train of the second and third pulse trains vary, when looking at the average period of some of them, the synchronization of both output shafts is approximately constant. It 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 measuring circuit along with the divided output of the first pulse train, which is similarly formed according to the transmission ratio, and the phase difference between the two outputs, which is the lead or lag of one with respect to the other, that is, the transmission error is determined. It will be done.

Example In FIG. 1, 10 is a test differential gear system with a transmission ratio A/B consisting of an automobile differential gear device,
The input shaft 11 is connected to a drive motor 21, and its two output shafts 12 and 13 are connected to power absorption motors 22 and 23, respectively.
Corresponding rotary encoders 31, 32, and 33 are attached to 1, 12, and 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 thereof 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 1/2A and the output of the rotary encoder 31 by 1/B according to the transmission ratio A/B, respectively.
The frequency-divided output is sent to the measurement circuit 3.

In the above configuration, the motor 22 and the motor 21 are driven while the motor 23 absorbs a predetermined power. As a result, the rotary encoder 31, 3
2 and 33, the respective corresponding axes 11 and 1
A pulse train is generated every time 2 and 13 rotate by a small fixed angle. At this time, the rotational speeds of the output shafts 12 and 13 vary as shown in FIG. 2 due to slight differences in the loads applied thereto. That is, if one increases, the other decreases accordingly, and the period of the pulse train generated by the rotary encoders 32, 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, the period for each pulse of a certain number of pulses, that is, the period of each pulse by a certain number of those individual periods is added. If we focus on
It remains almost constant. The frequency dividing circuit 2 divides the asynchronous addition pulse train by 1/2A, that is, extracts pulses every 2A from the pulse train, and divides the output pulse train of the rotary encoder 31 by 1/B times. . 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 with respect to the rotation of the input shaft 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 addition, in the above embodiment, the output shafts 12, 13
Although a case has been illustrated in which the motors 22 and 23 are respectively coupled to separate motors 22 and 23 for power absorption, they may be coupled to one common power absorption device via a transmission device such as a belt or a gear.

Effects of the Invention As described above, the transmission error under actual usage conditions can be easily determined without locking one output side of the differential gear system.
Effective information can be provided for research on improving differential gear systems.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention;
FIG. 2 is a diagram showing a model of the speed fluctuation state of the two output shafts. 1: Adder circuit, 2: Frequency divider circuit, 3: Phase difference measurement circuit, 11, 12, 13: Axis, 21, 22, 2
3: Motor, 31, 32, 33: Encoder.

Claims (1)

[Claims] 1 a drive unit coupled to an input shaft of a differential gear system;
A power absorption unit coupled to the two output shafts of the differential gear system, the input shaft, and the two output shafts each send out first, second, and third pulse trains each time the input shaft and the two output shafts rotate by a slightly constant angle. first, second, and third pulse generators; an addition circuit that forms an asynchronous addition pulse train of the second and third pulse trains; and a frequency division circuit that divides the first pulse train and the asynchronous addition pulse train at a predetermined ratio. A differential gear system transmission error measuring device consisting of a frequency dividing circuit and a phase difference measuring circuit for the outputs of both frequency divisions.