JP2001259905A - Tool decentering device for machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust a radial movement (decentering) of a tool provided on a main shaft with high accuracy. SOLUTION: A tool attaching plate 5 is provided on a main shaft 3 movable in a radial direction, and the tool attaching plate 5 and a transmission shaft 6 provided on an axial center portion of the main shaft 3 are coupled through a rotating and straight moving converting device 10. First and second planetary gear trains 22 and 23 are provided having gear ratios set to have a same rotation speed of sun gears 22a and 23a as the turning speed of planet gears 22c and 23c. The planet gears 22c and 23c facing each other are rotatably couple through a coupling shaft 24. The sun gear 22a and 23a of the first and second planetary gear trains 22 and 23 are coupled to the main shaft 3 and the transmission shaft 6, respectively. An internal gear 22b of the first planetary gear train 22 is fixed on a casing 2 supporting the main shaft 3, and a rotating angle adjusting device 25 for adjusting the rotating angle of an internal gear 23b of the second planetary gear train 23 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machine tool for machining an inner surface or an outer surface of a work with a tool provided on a spindle.
In particular, it relates to the tool eccentric device.

[0002]

2. Description of the Related Art As a conventional technique, a tool mounting plate for supporting a tool is mounted movably in a radial direction on a tip portion of a main shaft, a rod is inserted through a shaft portion of the main shaft, and the tip portion of the rod and the above By connecting the tool mounting plate via a rack and pinion, providing a hydraulic cylinder that moves the rod in the axial direction, and by operating the hydraulic cylinder,
There is a type in which the tool mounting plate is moved and adjusted in the radial direction with respect to the main shaft through the rod and the rack and pinion, and the amount of eccentricity of the tool mounted on the tool mounting plate is adjusted with respect to the main shaft. Was.

[0003]

In the above prior art, since a hydraulic cylinder was used, the rod could not be moved in small increments with high precision, and the eccentricity of the tool with respect to the main shaft was increased. The precision cannot be finely adjusted, and the type of processing is limited. An object of the present invention is to provide a new tool eccentric device for a machine tool that has solved the above-mentioned problems.

[0004]

Means for Solving the Problems The present invention is configured as follows to achieve the above object. That is, the invention according to claim 1 provides a tool mounting plate for supporting a tool at a tip portion of a main shaft so as to be movable in a radial direction, a transmission shaft at a shaft center portion of the main shaft, and a rotatable transmission shaft. And the tool mounting plate via a rotation-linear motion conversion device, and a first and second planetary gear device having a gear ratio set such that the rotation speed of the sun gear and the turning speed of the planetary gear are the same. Are provided facing each other, the respective planetary gears of the first and second planetary gear devices are rotatably connected to each other via a connection shaft, and a sun gear of the first planetary gear device is attached to the main shaft, The sun gear of the second planetary gear device is connected to the transmission shaft, the internal gear of the first planetary gear device is fixed to a case supporting the main shaft, and the internal gear of the second planetary gear device is The internal gear is rotatably provided on the case. Is obtained by a configuration in which a rotational angle adjusting device for adjusting the rotation angle. Further, according to the invention according to claim 2, in the rotation-linear motion conversion device, a nut connected to a tool mounting plate is screwed to a screw shaft orthogonally arranged with respect to a rotation axis of the main shaft, and the screw shaft and the main shaft are connected. And a transmission shaft provided at the shaft center portion of the vehicle through a gear.
The invention according to claim 3 is that the rotation angle adjusting device is a servomotor.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, FIG. 1 is a sectional side view showing an initial eccentric position of a tool showing an embodiment of the present invention, and FIG. 2 is a sectional side view showing a maximum eccentric position of the tool. In FIG.
Reference numeral 1 denotes a head portion of a machine tool, and 2 denotes a case thereof. The case 2 is moved in a front-rear direction (left and right in FIG. 1) by a feeder (not shown). Reference numeral 3 denotes a main shaft supported rotatably and immovably in the axial direction on the case 2. A large-diameter rotary plate 4 is attached to the tip (left end in FIG. 1) of the main shaft 3. A tool mounting plate 5 is slidably mounted on the front surface in a radial direction (vertical direction in FIG. 1), and a tool 8 is attached to the tool mounting plate 5 via a holder 7.
Attach.

[0006] A transmission shaft 6 is rotatably inserted into the shaft center of the main shaft 3, and the transmission shaft 6 and the tool mounting plate 5 are connected via a rotation-linear motion converter 10. The rotation-linear motion converter 10 is as follows. That is, the screw shaft 11 is disposed on the rotating plate 4 at right angles to the rotation axis C of the main shaft 3 so as to be rotatable, and the nut 12 screwed to the screw shaft 11 is connected to the tool mounting plate 5. . In addition, bevel gears 13 and 14 are fixed to the left end of the transmission shaft 6 and an intermediate portion of the screw shaft 11, respectively, and these are meshed with each other. Thereby, the rotation of the transmission shaft 6 is changed to the bevel gears 13, 1
The tool 8 is transmitted to the screw shaft 11 via the nut 4, and the rotation of the screw shaft 11 causes the tool mounting plate 5 to move in the radial direction with respect to the rotary plate 4 via the nut 12, so that the tool 8 mounted on the tool mounting plate 5 Of the main shaft 3 with respect to the rotation axis C is adjusted.

A driven gear 17 is fixed to a rear portion of the main shaft 3, and the driven gear 17 is engaged with a driving gear 18 attached to a driving shaft 19. The drive shaft 19 is connected to a spindle motor 20 attached to a rear portion of the case 2.
The drive shaft 19, the drive gear 1
8, and the main shaft 3 is rotated at a predetermined speed via the driven gear 17.

A first planetary gear unit 22 and a second first planetary gear unit 23 facing each other are mounted on the rear ends of the main shaft 3 and the transmission shaft 6, and the first and second planetary gear units 22, 23 are provided.
The main shaft 3 and the transmission shaft 6 are synchronously connected via the. That is, each of the first and second planetary gear units 22 and 28 respectively controls the rotational speeds of the sun gears 22a and 23a and the planetary gear 22.
The gear ratio is set so that the turning speeds of the gears c and 23c are the same. For example, the number of teeth of the sun gears 22a and 23a is 60, the number of teeth of the internal gears 22b and 23b is 30, and the planetary gears 22c and 2 are.
3c is set to 15 respectively, the sun gear 22a of the first planetary gear unit 22 is fixed to the main shaft 3, and the second
The sun gear 23 a of the planetary gear device is fixed to the transmission shaft 6.

Further, the internal gear 22b of the first planetary gear device 22 is fixed to the case 2, and the internal gear 23b of the second planetary gear device 23 is rotatably supported by the case 2, and The planetary gears 22c and 23c of the first and second planetary gear devices 22 and 23 are rotatably connected to each other via a connection shaft 24. As a result, the main shaft 3 and the transmission shaft 6 can be rotated at a constant speed synchronously via the first and second planetary gear devices 22 and 28.

The rotation angle adjusting device 25 adjusts the rotation angle of the internal gear 23b of the second planetary gear device 23. A driven gear 26 is fixed to a rear portion of the internal gear 23b. Is meshed with a drive gear 27, and the drive gear 27 is connected to an output shaft of a servo motor 28. By controlling the drive of the servo motor 28,
The internal gear 23b of the second planetary gear unit 23 is rotated by a predetermined angle. As a result, the planet gear 23c and the sun gear 23
a, the transmission shaft 6 rotates relative to the main shaft 3 by a predetermined angle, the screw shaft 11 rotates by a predetermined angle via the bevel gears 13 and 14 described above, and the tool mounting plate 5 4, the amount of eccentricity L of the tool 8 attached to the tool mounting plate 5 with respect to the rotation axis C of the main shaft 3 moves in the radial direction.
Will be adjusted.

Next, the operation of the above embodiment will be described. First, a position where the tool mounting plate 5 has moved upward in FIG. 1 is set as an initial position, and in this state, a holder 7 is mounted on the tool mounting plate 5 coaxially with the main shaft 3. A tool 8 for mounting is installed. When the spindle motor 20 is started in this state, the drive shaft 1
The main shaft 3 rotates at a predetermined speed via the driving gear 9, the driving gear 18 and the driven gear 17, and the tool 8 rotates at a predetermined speed via the rotating plate 4, the tool mounting plate 5, and the holder 7.

On the other hand, the rotation of the main shaft 3 causes the first planetary gear device 22 to move its planetary gear 22c to the sun gear 22a.
The planetary gear 23c of the second planetary gear device 23 rotates at a constant speed with the main shaft 3 via the connecting shaft 24. When the internal gear 23b of the second planetary gear unit 23 is stopped, the sun gear 23a is rotated at the same speed as the main shaft 3 by the planetary gear 23c, and is transmitted through the sun gear 23a. The shaft 6 is rotated at the same speed as the main shaft 3. As a result, the rotary-linear motion device 10 does not operate, and the tool mounting plate 5 rotates at the above-mentioned initial position without being moved in the radial direction with respect to the rotary plate 4, so that the tool 8 rotates the spindle 3 Turns (rotates) while maintaining the amount of eccentricity L with respect to the rotation axis C.

In this state, when the internal gear 23b of the second planetary gear device 23 is rotated by a predetermined angle in the traveling direction by the angle adjusting device 25, ie, the servomotor 28, the second
The transmission shaft 6 rotates relative to the main shaft 3 by a predetermined angle via the planetary gear 23c and the sun gear 23a of the planetary gear device 23, and the screw shaft 11 rotates by a predetermined angle via the bevel gears 13 and 14 described above. Then, the tool mounting plate 5 advances in the radial direction (downward in FIG. 2) with respect to the rotary plate 4 as shown in FIG. Thereby, the tool 8 attached to the tool attachment plate 5 is, as shown in FIG.
The eccentric amount L1 of the main shaft 3 with respect to the rotation axis C is larger than the eccentric amount L described above, and the inner surface of the work is machined to have a large diameter.

The angle of the internal gear 23b of the second planetary gear set 23 may be manually adjusted. For example, the driven gear 26 may be a worm wheel, the worm meshes with the worm wheel, and the worm may be rotated manually. Further, the bevel gears 13 and 14 of the rotary-linear motion device 10 may be changed to a rack and a pinion or a worm and a worm wheel.

[0015]

As is apparent from the above description, claim 1
According to the invention, the first and second gear ratios of the main shaft and the conduction shaft provided at the shaft center of the main shaft are set such that the rotation speed of the sun gear and the turning speed of the planetary gear are the same. The transmission shaft is relatively rotated with respect to the main shaft by rotating and adjusting the internal gear of the second planetary gear device on the transmission shaft side, and the tool mounting plate ( Tool) is moved (eccentric) in the radial direction,
The tool can be moved and adjusted with high precision in the radial direction with respect to the main shaft. Further, the invention according to claim 2 connects a tool mounting plate via a nut to a screw shaft arranged orthogonally to the main shaft,
Since the screw shaft and the transmission shaft are transmission-coupled via the gear, the tool mounting plate can be firmly supported, and can be moved with high precision in the radial direction with respect to the main shaft. In the invention according to claim 3, since the internal gear of the second planetary gear device is rotated by the servomotor, the movement of the tool mounting plate in the radial direction is controlled by the control device to move the main shaft motor and the case back and forth. It can be controlled together with a feed motor for feeding in the direction, so that spherical processing and complicated uneven processing can be easily performed, and the types of processing can be expanded.

[Brief description of the drawings]

FIG. 1 is a sectional side view showing an initial eccentric position of a tool according to an embodiment of the present invention.

FIG. 2 is a sectional side view showing a maximum eccentric position of the tool.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Head part 2 Case 3 Main shaft 4 Rotating plate 5 Tool mounting plate 6 Conduction shaft 7 Holder 8 Tool 10 Rotation-linear motion converter 11 Screw shaft 12 Nut 13,14 Bevel gear 17 Driven gear 18 Drive gear 19 Drive shaft 20 Main shaft motor Reference Signs List 22 first planetary gear device 22a sun gear 22b internal gear 22c planetary gear 23 second planetary gear device 23a sun gear 23b internal gear 23c planetary gear 24 connecting shaft 25 rotation angle adjusting device 26 driven gear 27 drive gear 28 servo motor

Claims (3)

[Claims] 1. A tool mounting plate (5) for supporting a tool (8) is provided at a tip end of a main shaft (3) so as to be movable in a radial direction, and a transmission shaft (6) is provided at an axis of the main shaft (3). Is rotatably provided, and the transmission shaft (6) and the tool mounting plate (5) are connected via a rotation-linear motion conversion device (10) so that the rotation speed of the sun gear (22a, 23a) and the planet Gear (22
First and second planetary gear units (22, 23) whose gear ratios are set so as to be the same as the turning speeds of the first and second planetary gear units (c, 23c). (22c, 23).
c) rotatably connecting each other via a connecting shaft (24),
The sun gear (22a) of the first planetary gear unit (22) is connected to the main shaft (3), and the sun gear (23a) of the second planetary gear unit (23) is connected to the transmission shaft (6). The internal gear (22b) of the first planetary gear device (22) is fixed to the case (2) supporting the main shaft (3), and the internal gear (23b) of the second planetary gear device (23) is fixed to the aforementioned The internal gear (23) is provided rotatably on the case (2).
A tool eccentricity device for a machine tool, comprising a rotation angle adjustment device (25) for adjusting the rotation angle of b). 2. A rotary-to-linear motion converter (10) is provided on a screw shaft (11) in which a nut (12) connected to a tool mounting plate (5) is arranged orthogonally to a rotation axis of a main shaft (3). 2. The screw shaft (11) and a transmission shaft (6) provided at the shaft center of the main shaft (3) are operatively connected via gears (13, 14). Eccentric tool for machine tools. 3. The tool eccentric device for a machine tool according to claim 1, wherein the rotation angle adjusting device (25) is a servomotor (28).