JPH03250301A - Control system for correction of rotational synchronization - Google Patents

Abstract

PURPOSE:To attain the highly accurate rotational synchronization in a simple constitution by controlling the number of rotation of one of two rotary shafts against the other one via a differential mechanism in response to the rotational error produced between both rotary shafts. CONSTITUTION:A rotary drive shaft is connected to a rotary shaft 1, and a rotated shaft is connected to a rotary shaft 2 respectively. Both shafts 1 and 2 are connected to each other via a differential gear in a differential mechanism 10. The rotation detectors 5 and 6 detect the rotational angles of the shafts 1 and 2. Then a synchronization control means 14 detects the rotational error between both shafts 1 and 2 based on the output signals of detectors 5 and 6 and controls the mechanism 10 in order to eliminate the rotational error and to secure the synchronous rotations between both shafts 1 and 2. When a rotational error is produced between these two different shafts 1 and 2, the means 14 controls the number of rotation of the rotated shaft to the rotational frequency of the rotary drive shaft in the mechanism 10 in response to the rotational error. Thus the mechanism 10 is controlled so that the rotational error is reduced. In such a simple constitution, the highly accurate synchronous control is attained between two rotary shafts.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a rotation synchronization correction control system, which has two different rotation axes and requires rotational synchronization of mutual absolute angular positions of these rotation axes. It is useful when applied to mechanisms.

<Prior Art> An NC processing machine can be cited as a typical mechanism that requires rotational synchronization control of two different rotating axes. The rotation synchronization control system for two different rotating axes in this type of NC machine basically controls each rotation at a rotation ratio calculated to a numerical level commensurate with the machining accuracy required of the NC machine. The shaft is subjected to feedback correction control using a servo motor or the like.

<Problems to be Solved by the Invention> The rotation synchronization system in conventional NC processing machines basically controls two different rotating axes independently, so there is no direct connection between them. It is not possible to sufficiently correct rotational synchronization errors. That is, there is a problem in that the rotational angular position cannot be sufficiently controlled as an absolute amount between the instants of rotation.

SUMMARY OF THE INVENTION In view of the problems of the prior art described above, it is an object of the present invention to provide a rotation synchronization correction control system that performs highly accurate synchronization control with a simple configuration.

Means for Solving the Problems> The configuration of the present invention that achieves the above object is as follows: In a rotation synchronization correction control system that has two different rotation axes and requires rotational synchronization of these, one of the rotation axes is It has a rotation drive shaft connected to one rotation shaft and a rotation transmission shaft connected to the other rotation shaft,
A differential mechanism in which both are connected by differential gears, a rotation detection word that detects the rotation angle of each of the rotation shafts, and a rotation error of both rotation shafts is detected based on output signals of both rotation detectors 17. The present invention is characterized in that it has a synchronization control means for controlling the differential mechanism so that both rotating shafts rotate synchronously by removing rotational errors.

Effect> In the present invention having the above configuration, if a rotation error occurs between two different rotation axes, this can be determined from the position information detected by both rotation detectors. Therefore, the synchronization sub-section means increases or decreases the rotational speed of the rotational transmitted shaft of the differential mechanism with respect to the rotational speed of the rotational drive shaft according to the rotational error, and adjusts the differential mechanism so that the rotational error becomes small. Control.

<Example> Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is a block diagram showing a case where an embodiment of the present invention is applied to a gear cutting machine. The two different rotation axes in this embodiment are the rotation axis 1 of the gear cutting tool and the rotation axis 2 of the rotation table on which the workpiece is placed. Further, in this embodiment, the absolute rotational angle error from the time when the rotation of the rotating shafts 1 and 2 is started is determined, and the error in the absolute angular position is removed.

As shown in FIG.
and is directly connected to the rotary table. The gear train 7 transmits the rotation of the rotating shaft 1 of the tool. The gear train 8 transmits rotation to the rotating shaft 2 of the rotary table. Rotation ratio indexing gear train 9
The combination of gears is set in accordance with the rotation ratio of the rotating shafts 1 and 2 determined by the specifications of the workpiece. As will be described in detail later, the differential mechanism 10 has its rotary drive shaft connected to the rotary shaft 1, and its rotary transmitted shaft connected to the rotary shaft 2.
It is connected to the side, and normally transmits rotation of 1=1 from the rotational drive shaft to the rotationally transmitted shaft. Main motor 1
0 is the drive source of this gear cutting machine.

In such a gear cutting machine, the rotation of the main motor 11 is transmitted to the rotating shaft 1 through the gear train 7, and at the same time, the rotation of the main motor 11 is transmitted to the rotating shaft 1 through the gear train 7. is transmitted to the rotating shaft 2 via.

During such rotation, due to the influence of misalignment of the gear cutting machine and dynamic fluctuations during rotation, the rotation shaft 1 and the rotation shaft 2
An error will occur in the rotational synchronization of the This embodiment corrects this error.

That is, in this embodiment, the encoder 6 directly connected to the rotating shaft 1,
An encoder 5 directly connected to the rotating shaft 2. Synchronous control unit 14. It has a servo motor 12 and a servo amplifier 13 that constitute a local feedback system based on commands from a synchronous control unit 14.

In this way, the rotation of the rotary shaft 2 having the differential mechanism 10 in the middle of the gear transmission mechanism can be rotationally synchronously corrected with respect to the rotation of the rotary shaft 1 of the tool. More specifically, the signals indicating the rotational state output from the encoder 5 and encoder 6 are input into the synchronous control unit 14, and the specifications of the workpiece and the encoder 5. Based on the rotation ratio uniquely determined by the performance of the Korg 6, the synchronization III unit 14 calculates the instantaneous rotation synchronization error between the rotation shafts 1 and 2.

The rotational synchronization error here does not simply refer to the rotational fluctuations of the tool's rotational axis 1 and the rotary table, but rather the absolute rotational angular position of each rotational axis 1 and 2 from the time when rotational synchronization is started. This refers to the deviation of Therefore, the synchronization control unit 14 has a function of storing the absolute rotation angle positions of each of the rotation shafts 1 and 2, and calculating the difference therebetween as a rotation synchronization error. From this rotation synchronization error, the synchronous control unit 1-14 calculates a control signal based on the performance of the servo motor 12 and the rotation transmission ratio from the servo motor 12 to the rotating shaft 2, and sends the signal to the servo amplifier 13. do. As a result, the servo amplifier 13 controls the rotation of the servo motor 12, and rotation synchronization correction is achieved.

That is, in this embodiment, with the signal of the encoder 6 as a reference,
Encoder 5. Synchronous control unit 14, servo amplifier 1
The servo motor 12 passing through the servo motor 3 and the gear transmission mechanism from the differential mechanism 10 to the rotating shaft 2 constitute one feedback correction system.

FIG. 2 is an explanatory diagram showing a typical structural example of the differential mechanism 10. As shown in the figure, when the worm wheel 19 is stopped, the main rotational movement is from the bevel gear 16 directly connected to the rotation drive shaft 15 to the pinion gear 22 whose position is fixed to the worm wheel 19 by the rotation shaft 21. It is transmitted to a small gear 24 whose position is fixed by a rotating shaft 23,
Furthermore, the pinion 22 and the pinion 24 cause the bevel gear 18 to
is transmitted to. Since the rotational transmission shaft 17 is directly connected to the bevel gear 18, the rotational motion of the rotational drive shaft 15 is transmitted to the rotational transmission shaft 17 at a ratio of 1:1.

At this time, when the ohm wheel 19 is rotated by the □-memory 20, if the rotation is in the same direction as the rotation transmission shaft 15, the rotation of the rotation transmitted shaft 17 advances, and the rotation is directed to the rotation transmission shaft. If it is in the opposite direction to 15, the rotation transmitted shaft 17
The rotation of the rotationally transmitted shaft 17 can be advanced or delayed in the direction in which the rotation of the shaft 17 is delayed. By utilizing this effect, rotation synchronization correction is realized in this embodiment.

The simplest method for minimizing the influence of the backlash of the differential mechanism 10 on the rotational synchronization error is to use a rotation ratio indexing gear so that the rotational speed of the rotating shaft 2 lags behind the rotational speed that it should originally rotate. This is achieved by setting train 9. That is, at this time, in order to maintain the rotation period of the rotating shaft 1 and the rotating shaft 2, the worm wheel 19 of the differential mechanism 10 is rotated almost constantly in the opposite direction to the rotation of the rotational drive shaft 15, that is, in the same direction as the rotational transmitted shaft 17. Rotate. This rotation is in the same transmission direction as the main rotation, and it always rotates at a substantially constant rotation.

That is, the rotary drive shaft 15 is connected to the main motor 11 side of the rotary shaft 11, the rotational transmission shaft 17 is connected to the rotary shaft 2 side, and by rotating the worm 20 with the servo motor 12, the worm wheel 19 Rotate the rotation transmission shaft 17
The number of revolutions is increased or decreased.

FIG. 3 is a block diagram showing a case where the embodiment of the present invention is applied to an NC gear cutting machine. Since this application example is almost the same as that in FIG. 1, only the differences will be explained. That is, this N
In the C-gear cutting machine, the main rotations of the rotating shaft 1 of the tool and the rotating shaft 2 of the rotary table are each configured by independent feedback drive mechanisms.

In other words, depending on the conditions determined by the specifications of the work, the NC device! 2
According to the control signal output from 9, the main rotation of the rotation axis l of the tool is controlled by the servo motor 2 through the servo amplifier 26.
5, and the main rotation of the rotating shaft 2 of the rotary table is provided by a servo motor 27 through a servo amplifier 28. At this time, the rotation drive by the servo motor 25 through the servo amplifier 26 and the rotation drive by the servo motor 27 through the servo amplifier 28 are drives in which only higher rotations are applied.

<Effects of the Invention> As specifically explained above in conjunction with the embodiments, according to the present invention, the rotation speed of one rotation shaft relative to the other rotation shaft is controlled by the differential mechanism according to the rotation error of the two rotation shafts. Since it is designed to increase and decrease, highly accurate rotational synchronization can be realized with a simple structure.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a case where an embodiment of the present invention is applied to a gear cutting machine, Fig. 2 is an explanatory diagram for explaining the structure of the differential mechanism, and Fig. 3 is an embodiment of the present invention. FIG. 2 is a block diagram showing a case where the method is applied to an NC gear cutting machine. In the drawings, 1.2 is a rotating shaft, 5.6 is a rotary encoder, 10 is a differential mechanism, 14 is a synchronous control unit, 15 is a rotational drive shaft, and 17 is a rotationally transmitted shaft. Patent applicant Mitsubishi Heavy Industries, Ltd. Agent

Claims (1)

[Claims] In a rotation synchronization correction control system that has two different rotating shafts and requires rotational synchronization between the two, the rotational drive shaft is connected to one of the rotating shafts, and the It has a rotationally transmitted shaft connected to the rotating shaft,
A differential mechanism in which both are connected by differential gears, a rotation detector that detects the rotation angle of each of the rotation shafts, and a rotation error of both rotation shafts is detected based on the output signals of both rotation detectors. 1. A rotation synchronization correction control system comprising: synchronization control means for controlling a differential mechanism so that both rotary shafts rotate synchronously by removing rotational errors.