JP3383788B2 - Machine tool eccentricity device - Google Patents

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 movably mounted on a tip end portion of a spindle so as to be movable in a radial direction, and a rod is inserted through a shaft center portion of the spindle. By connecting a tool mounting plate via a rack and pinion, providing a hydraulic cylinder for moving the rod in the axial direction, and operating the hydraulic cylinder,
There is one in which the tool mounting plate is moved and adjusted in the radial direction with respect to the main shaft via the rod and the rack and pinion, and the eccentric amount of the tool mounted on the tool mounting plate is adjusted with respect to the main shaft. It was

[0003]

Since the above-mentioned conventional one uses the hydraulic cylinder, the rod cannot be moved in small increments and with high precision, and the tool is highly eccentric with respect to the spindle. It was not possible to make fine adjustments to the precision, and the types of processing were limited. It is an object of the present invention to obtain a new tool eccentric device for a machine tool that solves the above problems.

[0004]

The present invention is configured as follows to achieve the above object. That is, the invention according to claim 1 is such that a tool mounting plate for supporting a tool is provided movably in a radial direction at a tip end portion of a main shaft, a transmission shaft is rotatably provided at an axial center portion of the main shaft, and the transmission shaft is provided. First and second planetary gear devices in which the gear ratio is set so that the rotation speed of the sun gear and the rotation speed of the planetary gear are the same by connecting the tool mounting plate and the tool mounting plate via a rotation-linear motion conversion device. Are provided to face each other, and the opposing planet gears of the first and second planetary gear devices are rotatably connected via a connecting shaft, and the 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 that supports the main shaft, and the internal gear of the second planetary gear device is The case is rotatably mounted and the internal gear Is obtained by a configuration in which a rotational angle adjusting device for adjusting the rotation angle. According to a second aspect of the present invention, in the rotation-linear motion conversion device, a nut connected to a tool mounting plate is screwed onto a screw shaft arranged orthogonal to a rotation axis of the main shaft, and the screw shaft and the main shaft. The transmission shaft provided at the shaft center portion of is connected by transmission through a gear.
In the invention according to claim 3, the rotation angle adjusting device is a servo motor.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION 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 is a head portion of a machine tool, and 2 is a case thereof. The case 2 is moved in the front-rear direction (left and right in FIG. 1) by a feeding device (not shown). Reference numeral 3 denotes a main shaft which is rotatably and immovably supported by the case 2. A large-diameter rotary plate 4 is attached to a tip end portion (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.

A transmission shaft 6 is rotatably inserted through 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 conversion device 10. The rotation-linear motion conversion device 10 is as follows. That is, the screw shaft 11 is rotatably mounted on the rotary plate 4 so as to be orthogonal to the rotary shaft center C of the main shaft 3, and the nut 12 screwed onto the screw shaft 11 is connected to the tool mounting plate 5. . Further, bevel gears 13 and 14 are fixed to the left end portion of the transmission shaft 6 and the intermediate portion of the screw shaft 11, respectively, and both of them are meshed with each other. This causes the rotation of the transmission shaft 6 to rotate the bevel gears 13, 1
4 to the screw shaft 11, and the rotation of the screw shaft 11 causes the tool mounting plate 5 to move in the radial direction with respect to the rotating plate 4 via the nut 12 and the tool 8 mounted on the tool mounting plate 5. The eccentric amount L of the main shaft 3 with respect to the rotation axis C is adjusted.

A driven gear 17 is fixed to the rear portion of the main shaft 3, and the driven gear 17 is meshed with a drive gear 18 attached to a drive shaft 19. The drive shaft 19 is connected to a spindle motor 20 attached to the rear portion of the case 2, and the spindle motor 20
By activating the drive shaft 19 and 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 planetary gear unit 23 facing each other are attached to the rear ends of the main shaft 3 and the transmission shaft 6, and the first and second planetary gear units 22 and 23 are mounted.
The main shaft 3 and the transmission shaft 6 are synchronously connected via the. That is, each of the first and second planetary gear devices 22 and 28 described above has a rotation speed of the sun gears 22a and 23a and a planetary gear 22.
The gear ratios are set so that the turning speeds of 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 2c.
The number of teeth of 3c is set to 15, respectively, and the sun gear 22a of the first planetary gear device 22 is fixed to the main shaft 3,
The sun gear 23a of the planetary gear device is fixed to the transmission shaft 6.

The internal gear 22b of the first planetary gear unit 22 is fixed to the case 2, and the internal gear 23b of the second planetary gear unit 23 is rotatably supported by the case 2 and the case 2 The planetary gears 22c and 23c facing each other of the first and second planetary gear units 22 and 23 are rotatably coupled to each other via a coupling shaft 24. This allows the main shaft 3 and the transmission shaft 6 to rotate at a constant speed synchronously via the first and second planetary gear units 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. The driven gear 26 is fixed to the rear part of the internal gear 23b, and the driven gear 26 is rotated. Is engaged with a drive gear 27, the drive gear 27 is connected to an output shaft of a servo motor 28, and the servo motor 28 is drive-controlled,
The internal gear 23b of the second planetary gear device 23 is rotated by a predetermined angle. As a result, the planet gear 23c and the sun gear 23
The transmission shaft 6 rotates relative to the main shaft 3 by a predetermined angle via a, the screw shaft 11 rotates through a predetermined angle via the bevel gears 13 and 14, and the tool mounting plate 5 rotates via the nut 12 as a rotary plate. 4, an eccentric amount L of the tool 8 mounted on the tool mounting plate 5 with respect to the rotational axis C of the spindle 3
Will be adjusted.

Next, the operation mode of the above embodiment will be described. First, the position where the tool mounting plate 5 is moved upward in FIG. 1 is set as an initial position, and in this state, the holder 7 is mounted coaxially with the spindle 3, and the outer surface of the tip end of the holder 7 is processed, for example, on the inner surface. Attach the tool 8 for. When the spindle motor 20 is started in this state, the drive shaft 1
The spindle 3 rotates at a predetermined speed via the drive gear 18, the driven gear 17, and the driven gear 17, and the tool 8 rotates at a predetermined speed via the rotary plate 4, the tool mounting plate 5, and the holder 7.

On the other hand, due to the rotation of the main shaft 3, the planetary gear 22c of the first planetary gear unit 22 is changed to the sun gear 22a.
Via the connection shaft 24, so that the planetary gear 23c of the second planetary gear device 23 turns at a uniform speed with respect to 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 by the planetary gear 23c at the same speed as the main shaft 3 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 in the above-mentioned initial position without being moved in the radial direction with respect to the rotary plate 4, so that the tool 8 is rotated by the spindle 3. It rotates (rotates) while maintaining the eccentricity L with respect to the rotation axis C of.

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, that is, the servomotor 28,
The transmission shaft 6 rotates relative to the main shaft 3 through the planetary gear 23c and the sun gear 23a of the planetary gear device 23 in the traveling direction by a predetermined angle, and the screw shaft 11 rotates through the bevel gears 13 and 14 by a predetermined angle. Then, the tool mounting plate 5 moves in the radial direction (downward in the figure) with respect to the rotary plate 4 via the nut 12, as shown in FIG. As a result, the tool 8 mounted on the tool mounting plate 5 is, as shown in FIG.
The eccentric amount L1 of the main shaft 3 with respect to the rotational axis C increases more than the eccentric amount L described above, and the inner surface of the workpiece is machined to have a large diameter.

The angle of the internal gear 23b of the second planetary gear unit 23 may be adjusted manually. For example, the driven gear 26 may be a worm wheel, the worm may be meshed with the worm wheel, and the worm may be manually rotated. Further, the bevel gears 13 and 14 of the rotary-linear motion device 10 may be replaced with 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 of claim 1, the main shaft and the transmission shaft provided in the shaft center portion of the main shaft are set to a gear ratio such that the rotation speed of the sun gear and the rotation speed of the planetary gear are the same. Two planetary gear devices are connected, and the internal gear of the second planetary gear device on the transmission shaft side is rotationally adjusted to rotate the transmission shaft relative to the main shaft, and by this relative rotation, a tool mounting plate ( Since I tried to move (eccentric) the tool) in the radial direction,
The tool can be moved and adjusted with high accuracy in the radial direction with respect to the spindle. In the invention according to claim 2, a tool mounting plate is connected to a screw shaft arranged orthogonal to the main shaft via a nut,
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 in the radial direction with high accuracy with respect to the main shaft. Further, in the invention according to claim 3, since the internal gear of the second planetary gear device is rotated by the servomotor, the control device controls the movement of the tool mounting plate in the radial direction between the spindle motor and the case. It can be controlled together with the feed motor that feeds in the direction, and spherical processing and complicated uneven processing can be easily performed, and the types of processing will be expanded.

[Brief description of drawings]

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

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

[Explanation of symbols]

1 head 2 cases 3 spindles 4 rotating plate 5 Tool mounting plate 6 conduction axis 7 holder 8 tools 10 rotation-linear motion conversion device 11 screw shaft 12 nuts 13,14 Bevel gear 17 Driven gear 18 drive gear 19 Drive shaft 20 spindle motor 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 adjustment device 26 Driven gear 27 drive gear 28 Servo motor

Claims (3)

(57) [Claims] 1. A tool mounting plate (5) for supporting a tool (8) is provided at the tip of a main shaft (3) so as to be movable in the radial direction, and a transmission shaft (6) is provided at the axial center 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) to rotate the sun gears (22a, 23a) and the planets. Gear (22
(c, 23c), the first and second planetary gear devices (22, 23) having a gear ratio set so as to have the same turning speed are provided so as to face each other, and the first and second planetary gear devices ( (22, 23) opposing planetary gears (22c, 23)
c) are rotatably connected to each other via a connecting shaft (24),
The sun gear (22a) of the first planetary gear device (22) is connected to the main shaft (3), and the sun gear (23a) of the second planetary gear device (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) that supports the main shaft (3), and the internal gear (23b) of the second planetary gear device (23) is The case (2) is rotatably provided and the internal gear (23
A tool eccentric device for a machine tool, comprising a rotation angle adjusting device (25) for adjusting the rotation angle of b). 2. A rotation-linear motion conversion device (10) comprises a screw shaft (11) in which a nut (12) connected to a tool mounting plate (5) is arranged orthogonally to the rotation axis of a main shaft (3). The screw shaft (11) and the transmission shaft (6) provided at the axial center of the main shaft (3) are screwed together and transmission-coupled via gears (13, 14). Machine tool eccentricity device. 3. The tool eccentric device for a machine tool according to claim 1, wherein the rotation angle adjusting device (25) is a servomotor (28).