JP2588090Y2 - Small position control mechanism using harmonic gear transmission - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention uses a harmonic gear transmission suitable as a drive mechanism of a member requiring minute positioning control in various machine tools or inspection devices. The present invention relates to a minute position control mechanism.

[Related Art and Problems to be Solved] Various mechanisms have been proposed as a mechanism for positioning a tip of a processing arm in a machine tool or a mechanism for positioning a tip such as a probe in an inspection apparatus. Such a positioning drive mechanism is required to have characteristics such as high responsiveness and high control accuracy and a small installation space.

It is an object of the present invention to realize a drive mechanism that focuses on the characteristics of a harmonic gear transmission and makes it possible to perform minute position control of a driven member using the same.

[Means for Solving the Problems] In order to solve the above problems, a minute position control mechanism of the present invention comprises a rotary disk coaxially connected to a speed change rotation output element of a hollow type harmonic gear transmission. And a driven member that is eccentrically moved by the rotating disk.The rotating disk includes an eccentric hollow portion formed by hollowing the inside of the rotating disk, and the center of the eccentric hollow portion is The driven member extends eccentrically with respect to the axis of the harmonic gear transmission by a predetermined amount, extends through the hollow portion of the harmonic gear transmission, and fits into the eccentric hollow portion of the rotating disk. A configuration in which the eccentric hollow portion extends through the eccentric hollow portion in a combined state is adopted.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

3 to 5 show an example in which the present invention is applied as a driving mechanism of a tip nozzle of a three-dimensional laser beam machine.

FIG. 3 shows a configuration of an arm portion of the three-dimensional laser beam machine. As shown in this figure, the arm portion 12 of the laser beam machine 11 is formed of a hollow shaft, has a crank shape bent at right angles at two points, and a laser beam 13 is provided inside the arm portion. An optical path for guiding to the tip nozzle 14 is formed. The arm portion 12 having this configuration is provided with a C-axis driving mechanism for turning the nozzle side around a so-called C-axis extending in the vertical direction.
An A-axis drive mechanism 16 for turning the nozzle side around a so-called A-axis extending in the horizontal direction at the lower end position is attached. The A-axis and C-axis drive mechanisms allow the arm portion tip nozzle 14 to be three-dimensionally positioned on the work 17. Then, a laser beam 13 from a laser light source (not shown) passes through the hollow portion of the arm portion, is reflected by the reflectors 51 and 52 disposed at the bent portion in this hollow portion, and is reflected from the nozzle 14 to the target on the work 17. To the position where Here, a hollow actuator 8 as a minute position control mechanism for minutely moving the nozzle 14 is arranged at an intermediate position of an arm portion extending vertically from the reflection plate 52 toward the nozzle 14.

The configuration of the hollow actuator 8 will be described with reference to FIG. 4 and FIG. This hollow actuator 8
Are arranged so as to surround the outer periphery of the vertical hollow member 121 constituting the arm portion. The hollow actuator 8 includes a hollow AC servomotor 82 incorporated in a housing 81.
And a hollow harmonic transmission 83 which is coaxially disposed adjacent to the transmission. In a hollow portion 84 extending through the central portion of these motors and speed reducers, a vertical hollow member 121 constituting an arm portion of the laser beam machine is provided.
Is penetrating. In the housing 81, the rotor 82a of the hollow motor 82 located on the upper side is connected to the hollow rotary shaft 82b forming the inner peripheral surface of the hollow portion. The hollow rotary shaft 82b is rotatably mounted on the housing 81 via a bearing.
, And the lower end thereof is a harmonic gear transmission.
It is coupled to a wave generator 83a which is a rotary input element of 83.

A cup-shaped elastic external gear 83b, which is a rotation output element of the harmonic gear transmission 83, is arranged on the outer periphery of the wave generator 83a. The gear 83c is arranged. This rigid internal gear 83c
Is fixed to the housing 81 side.

Next, an eccentric rotating disk 84 is connected to a lower end side of the elastic external gear 83b which is a rotation output element of the harmonic gear transmission 83. This eccentric rotating disk 84 is the axis of the harmonic gear transmission 83
A disk portion 84a arranged coaxially with 8a, and an eccentric hollow portion 84b formed by hollowing out the inside of the disk portion, the center axis 84c of the eccentric hollow portion 84b is the axis 8a
Is eccentric by e. And this eccentric hollow part
A vertical hollow member 121 constituting an arm portion of the laser processing machine is fitted in 84b. Here, this vertical hollow member 121
As shown in FIG. 3, the central axis 1 of the hollow member 121 is
The center axis 121a is maintained in a state where it can perform a swiveling motion such that the center axis 121a draws a conical shape having the point A as a vertex centering on the intersection A at which 21a (84c) intersects the reflector 52.

In the mechanism of this embodiment configured as described above, the nozzle 14
Is positioned by the A-axis and C-axis drive mechanisms 15 and 16 with respect to a target position on the work 17. Next, a minute positioning control of the nozzle position is performed by the hollow actuator 8. That is, the hollow motor 82
Is turned on, the reduced rotation is output from the elastic external gear 83b of the harmonic gear transmission 83. An eccentric rotary disk 84 is connected to the gear 83b, and in the eccentric hollow portion 84b,
A vertical hollow member 121 whose lower end is the nozzle 14 is fitted. Therefore, when the eccentric rotary disk 84 rotates, the eccentric hollow portion 84b rotates eccentrically about the axis 8a. As a result, the hollow member 121 also rotates eccentrically. As described above, the hollow member 121 is pivotally supported with the point A being hollow. Therefore, the nozzle 14 has an eccentric hollow portion 84b.
Due to the rotation of, the work 17 moves on the circumference around the point A on the surface of the work 17. Therefore, by setting the rotation angle of the eccentric rotating disk 84, the position of the nozzle 14
On the work surface, it can be positioned at a predetermined position on the circumference around the axis 8a. In other words, when viewed from one side on the work plane, the nozzle 14 can be slightly moved left and right about the axis 8a.

(Reference Example) FIGS. 1 and 2 show a drive mechanism applicable to minute position control of a probe of various inspection apparatuses. As shown in FIG. 1, this drive mechanism 1 includes a harmonic gear reducer 2
And an eccentric rotating member 3 integrally formed with the reduced rotation output element of the speed reducer, and a probe 4 driven by the eccentric rotating member 3.

The harmonic gear reducer 2 includes an elliptical wave generator 21 connected to a high-speed rotation output shaft 5 of a motor (not shown), and an annular elastic external gear 22 disposed outside the wave generator.
And two annular rigid internal gears 23A, 23B arranged outside the elastic external gear. The rigid internal gear 23A disposed on the motor output shaft 5 side has the same number of teeth as the elastic external gear 22 and is fixed to the housing 25 side. On the other hand, the rigid internal gear 23B on the other side has an even number, for example, two more teeth, than the elastic external gear, and is rotatable with respect to the housing 25 via the bearing 26. It is supported by. In the harmonic gear reducer 2 of this configuration, the elastic external gear 22 is bent into an elliptical shape by the wave generator 21, and both ends of the long axis of the elliptical shape mesh with the rigid internal gears 23A and 23B. . These meshing positions are rotated at the same speed in the circumferential direction by the rotation of the wave generator 21. As a result, the rigid internal gear 23B relatively rotates with respect to the rigid internal gear 23A fixed to the housing at a reduced rotational speed corresponding to the difference in the number of teeth from the elastic external gear. Thus, the rigid internal gear 23
B provides a reduced rotation output.

The rigid internal gear 23B, which is a deceleration rotation output element, has a cylindrical portion projecting coaxially from the outer end face thereof in the direction of the rotation axis 2a, and this cylindrical portion is the eccentric rotating member 3. That is, as can be seen from FIG. 2, the eccentric rotating member 3 is coaxial with the rotation axis 2a as a whole, but has a cylindrical hollow portion 31 formed therein.
The center axis 3a is set to be eccentric with respect to the rotation axis 2a by e. And this eccentric hollow part 31
The base end of the probe 4 is fitted therein.

In the drive mechanism 1 of the present example, when the motor is driven to rotate the harmonic gear reducer 2, the hollow portion 31 of the eccentric rotary member 3 integrally formed with the rigid internal gear 23B, which is the reduced rotation output element, It rotates eccentrically about the rotation axis 2a. As a result, the probe 4 connected thereto also rotates eccentrically. Due to this eccentric rotation, the tip 41 of the probe 4 reciprocates on the circumference of the radius e on the plane 7 orthogonal to the rotation axis 2a. Therefore, when viewed from one side on the plane 7, the tip 41 of the probe 4 is finely moved left and right around the center axis 2 a to a maximum of e, respectively, according to the rotation angle of the eccentric rotation member 3. Can be moved.

[Effects of the Invention] As described above, in the minute position control mechanism of the present invention, the eccentric rotating member is connected to the output element of the harmonic transmission, and the eccentric rotating member uses the eccentric rotating motion of the eccentric rotating member. The minute position control of the driving member is performed. Therefore, according to the present invention, it is possible to realize a minute position control mechanism which has higher responsiveness and higher control accuracy and requires less installation space than conventional similar mechanisms.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a drive mechanism according to a reference example, FIG. 2 is a transverse sectional view of a part taken along line II-II of the mechanism in FIG. 1, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a schematic configuration diagram showing a main part of the mechanism of FIG. 3,
FIG. 5 is a cross-sectional view showing a portion cut along the line VV in FIG. [Explanation of Symbols] 1 ... Control Mechanism 2 ... Harmonic Gear Reducer 3 ... Eccentric Rotating Member 31 ... Eccentric Hollow Section 4 ... Probe (Driven Member) 5 ... Motor Output Shaft 8 ... Hollow Actuator 82 Hollow AC servomotor 83 Hollow harmonic gear transmission 84 Eccentric rotating disk 84b Eccentric hollow 121 121 Vertical hollow member (driven member)

Claims (1)

(57) [Scope of request for utility model registration] 1. A rigid internal gear, an elastic external gear that can mesh with the rigid internal gear, and an elastic external gear that is bent in a radial direction to mesh with the rigid internal gear at a plurality of locations. A harmonic gear transmission having a wave generator for moving these meshing positions in the circumferential direction; and a rotating disk coaxially connected to a variable speed rotation output element of the harmonic gear transmission. A driven member that is eccentrically moved by a rotating disk, wherein the harmonic gear transmission is a hollow harmonic gear transmission in which a hollow portion extending through the axial direction is formed, The plate includes an eccentric hollow portion formed by hollowing out the inside of the rotating disk, the center of the eccentric hollow portion is eccentric by a fixed amount with respect to the axis of the harmonic gear transmission, and the driven member is In the harmonic gear transmission A small position control using the harmonic gear transmission, wherein the small position control extends through the eccentric hollow portion of the rotary disk while being fitted through the eccentric hollow portion of the rotating disk. mechanism.