JPH0487792A - Three-axially controllable head driving device - Google Patents

Abstract

PURPOSE:To set a head posture in the direction appropriate for measurement and working of a three-dimensional shape by placing a reduction gear for rotating, a harmonic drive reduction gear for swinging and a harmonic drive reduction gear for rotating of a three-axially controllable head, around a rotation axis. CONSTITUTION:When a motor 26 for rotating is rotated, a reduction gear 20 for rotating applies a rotational motion to a head by rotating a rotation axis 3 of the head 9 independently and also transmits the rotation of the rotation axis 3 to a harmonic drive reduction gear 30 for swinging at the same time, so that a swing axis of the head and a rotation axis 7 of the head are driven in the canceling direction by a rotation amount required for canceling relative swinging motion and relative rotational motion accompanying the rotational motion. When a motor 36 for swinging is rotated, the harmonic drive reduction gear for swinging drives a swing axis of the head independently to apply swing motion to the head and also transmits rotation of the harmonic drive reduction gear 30 to a harmonic drive reduction gear 40 for rotating at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for driving a three-axis controllable head using a harmonic drive reducer and a motor.

[Conventional technology]

Japanese Patent Publication No. 61-47673 discloses a system in which a head at the tip of a robot arm is driven by two motors and a harmonic drive reducer on the robot body side, giving the head swinging motion and turning motion, and generating vibrations accompanying each of these motions. Relative motion is corrected by the interlocking relationship between two harmonic drive reducers.

Further, the invention of Japanese Patent Application No. 1-22992 drives a two-axis controllable head using two harmonic drive reducers, and the relative movement of the other axis as one axis is driven is controlled by two harmonic drive reducers. .

This is corrected by the interlocking relationship of the drive speed reducer.

[Issues with conventional technology]

However, since both heads are 2-axis controlled, these techniques cannot be used as they are for 3-axis controlled heads.

[Purpose of the invention]

Therefore, it is an object of the present invention to provide a process for driving a three-axis controllable head by a reducer, two harmonic drive reducers and a motor, in which the drive of one axis is controlled relative to each other of the other two axes. The purpose is to make it possible to cancel the motion by the interlocking relationship of the harmonic drive reducer.

[Means for solving the invention]

Under the above object, the present invention incorporates one reducer, two harmonic drive reducers, and a motor for each of the swing axis, swing axis, and rotation axis of the head in a three-axis controllable head. , each harmonic drive reducer and motor can be driven independently for each required movement, and the swing reducer is linked to the swinging harmonic drive reducer and the rotating harmonic drive reducer, and The harmonic drive reducer for swinging is linked with the harmonic drive reducer for rotation.

[Action of the invention]

When the rotation motor rotates, the rotation reduction gear independently rotates the rotation axis of the head to give the head rotation motion, and at the same time, a harmonic drive reduction gear is used to change the rotation of the rotation axis. It is also transmitted to a harmonic drive reducer for rotation, and drives the swing axis of the head and the rotation axis of the head by an amount of rotation necessary to cancel out the relative swing motion and relative rotational motion accompanying the turning motion.

Also, when the swinging motor rotates, the swinging harmonic drive reducer independently drives the swinging axis of the head, giving swinging motion to the head, and at the same time rotating the swinging harmonic drive reducer. By driving the rotating shaft of the head, the head is rotated by the amount of rotation necessary to cancel out the relative rotational movement of the head that accompanies the swinging movement.

Further, when the rotation motor rotates, the Harmoni Shift Drive reducer provides rotational motion to the head by independently driving the rotation shaft of the head. During this rotational movement, no relative movement occurs in the rotation axis or swing axis of the head, so the rotational harmonic drive reducer is not in a relationship of interlocking with other harmonic drive reducers.

〔Example〕

FIG. 1 and FIG. 2 show the configuration of a head drive device l capable of three-axis control.

This three-axis controllable head drive device l has a casing 2
incorporated into the part.

That is, the casing 2 rotatably supports a hollow pivot shaft 3 by upper and lower bearings 4 inside a vertically cylindrical body, for example. In addition, this pivot shaft 3 has a lower end portion,
A hollow swing shaft 5 is rotatably supported by bearings 6 at both ends on a center line β perpendicular to the pivot shaft 3. Furthermore, this swing axis 5 is, for example, a center line α of the above-mentioned pivot axis 3.
Above, the rotating shaft 7 and the head 9 integrated therewith are connected to the rotating shaft 7.
It is rotatably supported on the center line T by bearings 8 at both ends.

The head 9 is for three-dimensional shape measurement or electron beam processing, and a distance sensor is installed at a position that intersects at a predetermined inclination angle θ with the point of action P on the center line T of the rotating shaft 7 as the intersection point. or equipped with an electron beam irradiation element.

The casing 2 accommodates, for example, a harmonic drive reduction gear 20, a swinging harmonic drive reduction gear 30, and a rotation harmonic drive reduction gear 40 as rotation reduction gears inside the box-like body. These no\-moni-tsuk drive reducers 20.30.4
0, as shown in FIGS. 3 and 4 in addition to FIG. 1, an oval web generator 21.31.41 and a ball hair ring 22. 32.42, flexspline 23.33.43 with deformable external teeth fitted on the outside of the 7 ring 22.32.42 to the pole, with internal teeth that mesh with the flexspline 23.33.43 on the long axis The first circular spline 24.34.44 and the second
It is assembled by circular splines 25.35.45. Note that the first circular spline 24.
The number of teeth 34, 44 is equal to the number of teeth of the corresponding flex spline 23, 33, 43, and is set smaller, for example, by 2 teeth than the number of teeth of the second circular spline 25, 35, 45.

These web generators 21.31.41 are in each case the input side of each movement and are connected to a motor 26 mounted on the outside of the casing 2 by means of a shaft coupling 27.37.47.
．． It is connected to the output shaft of 36.46. Further, the first circular spline 24 is directly fixed to the casing 2, and the first circular spline 34, 44 is
The bearings 39 and 49 as well as the interlocking gears 38 and 48 as interlocking wheels, respectively, are rotatably supported by the housing 12 and the gear 3 relative to the casing 2. Furthermore, the second circular spline 25.35.45
are fixed to the output gear 14.15.16 as an output wheel, and the auxiliary shafts 17.18.
Bearing 50.51.52.53.54.5 with 19
5 the bearing of casing 2 is housing 56.57
．． 58 so as to be rotatable. Note that the amount of rotation of these output gears 14, 15, and 16 can be detected by rotation detection means 59, 60, and 61, respectively.

The output gear 14 and the interlocking gear 38 mesh with a transmission gear 62 attached to the upper part of the pivot shaft 3, as shown in FIGS. 1 and 2. Here, the output gear 14 and the transmission gear 62 constitute a turning rotation transmission means for transmitting the output rotation of the turning harmonic drive reducer 20 to the turning shaft 3.

Further, the output gear 15 meshes with a transmission gear 63 fixed to the upper end of the swing transmission shaft 10.

The transmission shaft IO is hollow, and is connected to the pivot shaft 3 by upper and lower bearings 65 on the center line α inside the hollow pivot shaft 3.
It is rotatably supported by a bevel gear 66 at the lower end, a bevel gear 67 that meshes with this and is supported at the lower end of the rotating shaft 3, a chain wheel 68, 69, and a chain wheel 70 wrapped around these. Central axis 7 of axis 5
Transmit rotation to 1. Note that the center shaft 71 and bevel gear 67
The gear shafts 74 are each supported by bearings 72, 73 on the block-shaped part of the pivot shaft 3. Here, the output gear 15, the transmission gear 62, the transmission shaft 10, the bevel gear 6
6.67, the cheno wheel 68, 69, the cheno 70, and the center shaft 71 constitute a swing rotation transmission means for transmitting the output rotation of the swing harmonic drive reducer 30 to the swing shaft 5. .

Further, the interlocking gear 48 meshes with a transmission gear 63, and the output gear 16 meshes with a transmission gear 64 serving as a transmission wheel fixed to the upper end of the rotational transmission shaft 11. The transmission shaft 11 is concentrically combined with the hollow transmission shaft 10 on the center line α of the pivot shaft 3, and is rotatably supported by the bearing 75 relative to the casing 2 and the transmission shaft 10. There is. The rotation of the transmission shaft 11 is controlled by a hevel gear 76 at the lower end, a hevel gear 77 meshing with this, a cheno wheel 79.80, a cheno wheel 81,
It is transmitted to the rotating shaft 7 via bevel gears 82 and 83.

Note that the gear shaft 84 of the bevel gear 77 and the gear shaft 85 of the bevel gear 82 are supported by the block-shaped portion of the rotating shaft 3 by bearings 78 and 86, respectively. These output gear 16, transmission gear 64, transmission shaft 11, bevel gear 76.
77, the Cheno wheel 79.80, the Cheno wheel 81, and the Hevel gear 82.83 constitute a rotation transmission means for rotation.

The three-axis controllable head driving device 1 is assembled into a positioning device using an orthogonal coordinate system.

Next, the operation of the head driving device 1 capable of three-axis control will be explained.

The head 9 is arranged, for example, at ±
It can rotate within a range of 182.5 degrees, and the swing axis 5
Centered on the center line β of , 10 degrees in one direction and 9 degrees in the child direction
It is attached so that it can swing within a range of about 5 degrees, and can further rotate within a range of about ±182.5 degrees about the center line γ of the rotating shaft 7.

Here, the turning motion, the swinging motion, the cancellation motion of unnecessary relative motion accompanying these motions, and the rotating motion are given as follows.

Swiveling motion and relative motion cancellation operation When the motor 26 rotates by a predetermined amount in the required direction for the swiveling motion of the second hand 9, that rotation is given to the web generator 21 as an input to the harmonic drive reducer 20. , is decelerated to a reduction ratio of iaO, and via the output gear 14,
Because of the transmission to the transmission gear 62, the pivot shaft 3 gives a pivoting motion to the lower head 9 by pivoting by the required angle in a predetermined direction.

The reduction ratio ia of the harmonic drive reducer 20 in this input/output configuration is speed ratio R=(first circular spline 2
When the number of teeth is 4/the difference in the number of teeth between the first circular elastic spline 24 and the second circular spline 25), it is given by the following 2.

1a=1/(R+1) During this turning movement, if the swing transmission shaft 10 and the rotation transmission shaft 11 are stopped, the bevel gears 67.77 move around the stopped bevel gears 66.76. Since the head 9 rotates on its own axis according to the gear ratio thereof, the head 9 receives the rotation of the bevel gears 67 and 77 and performs unnecessary swinging motion and rotational motion as a relative motion accompanying the turning motion.

Therefore, the harmonic drive reducer 30, 40 works in conjunction with the harmonic drive reducer 20, generates rotation in a direction that cancels out the relative swinging motion and rotational motion, and absorbs unnecessary motion accompanying the turning motion of the head 9. . That is, when the output gear 14 rotates, this rotation is transmitted to the interlocking gear 38 via the transmission gear 62.

At this time, the web generator 31 is fixed,
Since the first circular spline 34 is on the input side and the second circular spline 35 is on the output side, the reduction ratio tb when the harmonic drive reducer 30 is interlocked in this input/output configuration is speed ratio R=(first circular The number of teeth of the spline 34/the difference in the number of teeth between the first circular spline 34 and the second circular spline 35) is given by the following equation.

i b=R/ (R+ 1) The rotation of the second circular spline 35, that is, the rotation of the output gear 15, is transmitted to the transmission gear 64 as rotation in the same direction as the transmission gear 62, and is transmitted to the transmission gear 64 as a rotation in the same direction as the transmission gear 62. 68, 69 and the unique transmission ratio of the chino 70, the amount of rotation necessary to cancel the swinging motion is transmitted to the swinging shaft 5. Therefore, when the pivot shaft 3 pivots, the unnecessary swing motion of the swing shaft 5 caused by the pivot shaft 3 pivots.
This is mechanically canceled out by the output of the harmonic drive reducer 30 which receives the rotation of the transmission gear 62 as an input.

Moreover, the rotation of the transmission gear 63 becomes the input rotation of the harmonic drive reduction gear 40 for rotation via the interlocking gear 48.

Again, the web generator 41 is fixed, and the first
Since the circular spline 44 is on the input side and the second circular spline 45 is on the output side, the reduction ratio ib when the harmonic drive reducer 40 is interlocked in this input/output configuration is speed ratio R=(first circular Spline 44
(number of teeth/difference in number of teeth between the first circular spline 44 and the second circular spline 45), it is given by the following equation.

1b=R/(R+1) The output of this harmonic drive reducer 40 is the second circular spline 45, the output gear 16, and the transmission gear 64.
, the amount of rotation in the direction of canceling the unnecessary rotational movement of the head 9 due to the turning movement through the unique transmission ratio of the transmission shaft 11, the hevel gear 76.77, the Cheno wheel 79.80, the Cheno 81, and the Hevel gear 82.83. It is finally transmitted to the rotating shaft 7 as a result.

In this way, when the pivot axis 3 turns around the center line α,
Along with this, the hend door performs unnecessary swinging and rotational movements, or the harmonic drive reducer 30, 40 that is interlocked with the rotation of the pivot shaft 3 rotates and rotates in a direction that cancels out the unnecessary swinging and rotational movements. A rotation amount is generated and transmitted to the swing shaft 5 and the rotation shaft 7, respectively. Of course, during this interlocking, the rotation of the interlocking gear 38.48 is
They are only transmitted to the output gear 15.16 at the reduction ratio ib, and do not affect the rotation of the web generator 31.41 on the input side at all. Therefore, the head 9 maintains the swing angle and rotation angle before turning, regardless of the turning movement.

Cancellation of swing motion and relative motion: Next, when the motor 36 rotates for the swing motion of the head 9, the first circular spline 34 is on the fixed side, the web generator 31 is on the input side, and the second circular spline 35
is on the output side, the rotation of the motor 36 is reduced by the reduction ratio ia of the harmonic drive reducer 30,
It is transmitted to the transmission shaft 10 via the output gear 15 and the transmission gear 63, and further to the bevel gear 66, 67 and the cheno wheel 6.
8.69 and the chino 70, it is transmitted to the swing shaft 5. As a result, the head 9 rotates about the swing shaft 5 by a required angle in a predetermined direction depending on the rotation direction and amount of rotation of the motor 36.

The reduction ratio ia of the harmonic drive reducer 30 in this input/output configuration is speed ratio R=(first circular spline 3
When the number of teeth is 4/the difference in the number of teeth between the first circular spline 34 and the second circular spline 35), it is given by the following 2.

1a=1/(R+2) When the bevel gear 82 is in a stopped state during this swinging motion, the hevel gear 83 rolls around the stopped hevel gear 82 and rotates due to the swinging motion of the swing shaft 5. The head 9 is subject to unnecessary rotational movement.

However, this unnecessary rotational movement is canceled by the rotational harmonic drive reducer 40 that is interlocked with the transmission gear 63. That is, the rotation of the transmission gear 63 is
It is transmitted to the first circular spline 44 by the interlocking gear 48, is decelerated by the reduction ratio ib when the harmonic drive reducer 40 is interlocked, and is transmitted to the rotational transmission shaft 11 via the second circular spline 45 and the transmission gear 16, Bevel gear 76.77, Cheno wheel 79.80
The rotation amount is adjusted by the transmission ratio of the chino 81, etc., and is finally transmitted to the rotating shaft 7 as a rotation amount in a direction to cancel unnecessary rotation. Therefore, even if the head 9 performs a swinging motion, the relative rotational motion of the head 9 accompanying the swinging motion is caused by the harmonic drive reducer 40 which is interlocked with the swinging harmonic drive reducer 3o.
will be canceled by.

Rotational movement: Next, when the motor 46 rotates due to the rotational movement of the head 9, the rotation is transmitted to the web generator 41 on the input side of the harmonic drive reducer 40 for rotation,
The speed is reduced by the reduction ratio ia, and is transmitted to the transmission gear 64 and the transmission shaft 11 via the second circular spline 45 on the output side and the output gear 16, and is further transmitted to the bevel gear 76.77, the Cheno wheel 79.80, the Cheno wheel 81, etc. It is finally transmitted to the rotating shaft 7 according to the ratio.

The speed ratio ia of the harmonic drive reducer 40 in this input/output configuration is the gear ratio R=(first circular spline 4
4 (number of teeth/difference in number of teeth between the first circular spline 44 and the second circular spline 45), it is given by the following formula.

1a=1/(R+1) The direction and amount of rotation necessary for this rotational movement are determined by the direction and amount of rotation of the motor 46. As a result of this rotational movement, no unnecessary turning or swinging movements occur.

In addition, for the purpose of simplifying the explanation, the above description is similar to the rotation calculation method of a differential gear train or a planetary gear train, and is based on the case where one axis of the rotation axis 3, the swing axis 5, or the rotation axis 7 is driven. , the other two axes are in a stopped (fixed) state. However, in the actual control process, the swing shaft 3, the swing shaft 5, and the rotation shaft 7 are driven almost simultaneously, so the harmonic drive reducers 3o and 40 work differentially.

Note that each gear can be replaced with a timing pulley, timing belt, Cheno wheel, Cheno, etc., and the Cheno wheel and Cheno can also be replaced with a gear train. Further, when the harmonic drive reducer 20.30.40 is in an interlocking relationship, the speed can be increased by switching the input/output relationship between the first circular spline 24.34.44 and the second circular spline 25.35.45. It can also be used in relation to ratios.

Moreover, the harmonic drive reduction gear 20 for turning can also be configured with other types of reduction gears.

〔Effect of the invention〕

The present invention provides the following unique effects.

A 3-axis controllable head rotation reducer, a swinging harmonic drive reducer, and a rotating harmonic drive reducer are arranged around the swing axis, and the swing axis, swing axis, and rotation axis are arranged around the swing axis. Because it can be driven by a motor, a swing motor, and a rotation motor, the swinging, swinging, and rotational movements of the head can be controlled independently, making it possible to control the posture of the head by measuring three-dimensional shapes, etc. It can be set in the appropriate direction for processing.

A reduction gear for swinging, a harmonic drive reduction gear for swinging and rotation are located around the swing shaft and a transmission wheel integrated with this to form a transmission gear train, and the output rotation of the reduction gear for swinging is used for swinging and rotation. It is in an interlocking relationship with the first circular spline of the harmonic drive reducer for rotation, and unnecessary swinging motion and unnecessary rotational motion accompanying the turning movement of the head are caused by the interlocking rotation of the harmonic drive reducer for swing and rotation. Because the relationship is mechanically canceled by
Since the mechanical components can be simplified and the amount of rotation required for cancellation is accurate, the movement of the head can be controlled with high precision.

In particular, the rotational force for cancellation is inputted from the first circular spline of the harmonic drive reducer and outputted via the second circular spline, and has no effect on the rotation of the web generator on the input side connected to the motor. Therefore, in the process of cancellation, there is no need for a clutch for cutting off the rotational force or a gear train for switching the rotation transmission path in the rotational force transmission system, and of course, on/off control and switching control of these is also required. Therefore, it is easy to handle, and the head can be controlled in three axes by simply controlling the direction and amount of rotation of the motor.

Of course, since there is no drive motor or reducer in the head, the weight of the head itself can be reduced, speeding up motion control, and positioning errors due to inertia during acceleration and deceleration can be kept low. There is no need for wiring for control to be drawn out from the head, and there is no need for electric wires or part of the head to interfere with other parts.

[Brief explanation of the drawing]

Fig. 1 is a partially expanded vertical sectional view of a head drive device capable of three-axis control, Fig. 2 is a partially cutaway view of the meshing relationship of the gear train, and Fig. 3 is an enlarged sectional view of the harmonic drive reducer. FIG. 4 is a partially cutaway enlarged front view of the harmonic drive reducer. 1. Three-axis controllable head drive device, 2. Casing, 3. Swivel axis, 5. Swing axis, 7. Rotation axis, 9.
- Head, 10... Transmission shaft for swinging, 11... Transmission shaft for rotation, 14.15.16... Output gear as an output wheel, 20... Harmonic drive reducer as a reduction gear for turning, 21... Web generator, 23... Flex spline, 24... First circular spline, 2
5...Second circular spline, 26...Motor, 3
0...harmonic drive reducer for swing, 31...
Web generator, 33...Flex spline, 34
...First circular spline, 35..Second circular spline, 36..Motor, 38..Interlocking gear as a connecting ring, 40..Harmonic drive reducer for rotation, 41..Web generator, 42.. Ball bearing, 43... Flex spline, 44... 1st
Circular spline, 45...Second circular spline, 46...Motor, 48...Interlocking gear as a connecting wheel, 62, 63.64...Transmission gear as a transmission wheel. Patent Applicant: Nichitoyama Co., Ltd. Attorney: Kunio Nakagawa Figure 2

Claims (1)

[Claims] A hollow pivot shaft is rotatably supported inside the casing,
A swinging shaft is rotatably supported at one end of this swinging shaft, a rotating shaft is rotatably supported on this swinging shaft, a head is attached to this rotating shaft, and a hollow transmission shaft for swinging is mounted within the swinging shaft. The rotation transmission shaft is arranged concentrically 3
In a head that can control the axis, a reducer for turning, a harmonic drive (registered trademark, the same hereinafter) reducer for swinging, and a harmonic drive reducer for rotation are built into the casing, and the input side of each harmonic drive reducer is The output shafts of the respective motors are connected, and the output shaft of the swing reducer is engaged with a transmission wheel fixed to the swing shaft, and the output is fixed to the second circular spline of the swing harmonic drive reducer. The output wheel attached to the second circular spline of the harmonic drive reducer for rotation is engaged with the transmission wheel fixed to the transmission shaft for swing, and the output wheel attached to the second circular spline of the harmonic drive reducer for rotation is engaged with the transmission wheel fixed to the transmission shaft for rotation. At the same time, the interlocking wheel attached to the first circular spline of the harmonic drive reducer for swinging is engaged with the transmission wheel fixed to the rotation shaft, and the first harmonic drive reducer for rotation is engaged with the transmission wheel fixed to the rotation shaft. The interlocking ring fixed to the circular spline is meshed with the transmission ring fixed to the swing transmission shaft, and the swing transmission shaft and the rotation transmission shaft are connected to the swing rotation transmission means and the rotation transmission, respectively. said swing shaft and said rotation shaft are interlocked by means, and when said swing shaft is driven, said swing shaft has a reduction ratio of said harmonic drive reducer for said swing, a transmission ratio of said swing rotation transmission means, and said rotation shaft. The reduction ratio of the harmonic drive reducer for rotation and the transmission ratio of the rotation transmission means for rotation are both set to values necessary to cancel unnecessary relative motion accompanying the rotation of the rotation shaft, and When the shaft is driven, the reduction ratio of the harmonic drive reducer for rotation and the transmission ratio of the rotation transmission means for rotation with respect to the rotation shaft are changed to cancel unnecessary relative motion of the rotation shaft accompanying rotation of the shaft. A 3-axis controllable head drive device characterized by being set to a value.