JPH0825105A - Main spindle head for machine tool - Google Patents

Abstract

PURPOSE:To prevent imbalance in the center of rotation of a main spindle by arranging a slide device sliding each slide head so as to equalize a distance from the center of a main spindle to it. CONSTITUTION:When work is machined by means of knife tools 59, slide heads 55 on both sides are moved by equal length toward a slide base 56 while putting the center of a main spindle 1 between them, and tool holders 58 are moved so that the points of the knife tools 59 are matched with a machining dimension. If the main spindle 1 is rotated by means of a driving device, a servomotor controller 4 continues to transmit electric power and control signals from a non-contact feeding device controller 7 without any contact Therefore, a signal changing the position of the tool holders 59 is transmitted from the non-contact feeding device controller 7 to a servomotor controller 4 even when the main spindle is rotated, and the servomotor 6 is driven so as to change positions of the tool holders 58, and as a result, a machining can be altered. In addition, two tool holders 58 can be moved the opposite direction by equal length at the same time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle head of a machine tool having a slide head movable in a direction perpendicular to an axial direction.

[0002]

2. Description of the Related Art Conventionally, as a spindle head of a machine tool, there is a spindle head which is supported by a bearing so as to be rotatable, and a claw of a chuck fixed to the spindle is opened / closed / driven by a motor with a constant torque. . In addition, it is equipped with one slide head that can move in the radial direction perpendicular to the axial direction of the main shaft, the blade tool is fixed to the slide head, and the slide head is moved in the radial direction while rotating the main shaft and the slide head main shaft. There is a boring machine that processes a workpiece fixed to the base with a cutting tool. In this case, in order to drive the chuck jaws and the slide head while rotating the spindle, a non-contact power feeding device is provided between the spindle head and the spindle.
It is disclosed that a spindle head is supplied with electric power and signals. That is, the contactless power supply device employs a high frequency transformer as the power transmission means and an electromagnetic induction type or optical coupler as the signal transmission means, and transmits the primary coil and the secondary coil of the transformer and the coupler transmission. The receiving side and the receiving side are separately arranged to face each other with a gap provided on the rotating shaft side and the fixed portion side (for example,
JP-A-6-36940).

[0003]

However, in the case where the one mounted on the spindle head is a chuck, when the rotation of the chuck is stopped, a constant torque is set to drive the motor,
Since the jaws of the chuck are moved to grip the work, when the speed is increased from low speed rotation to high speed rotation, the centrifugal force of the chuck jaws increases and the gripping force of the chuck work decreases, causing the work to rotate. There was a risk of coming off. In addition, when the one mounted on the spindle head is a slide head, since there is only one slide head, cutting is done by cantilever at a position distant from the axis of the spindle, resulting in unbalance between cutting resistance and mass. However, there is a problem in that stable cutting cannot be performed during high-speed rotation. An object of the present invention is to provide a spindle of a machine tool capable of controlling torque during rotation of the spindle as needed and preventing imbalance.

[0004]

In order to solve the above problems, the present invention provides a main shaft supported by a fixed portion via a bearing,
A mounting base having one end fixed to one end of the main shaft,
A slide device having one end fixed to the other end of the mounting base, a slide base extending in the direction perpendicular to the main shaft at the other end of the slide device, a slide head slidably provided on the slide base, and the slide head. A servo motor for driving the servo motor, and a servo motor controller for controlling the servo motor and provided on the mounting base,
In a spindle head of a machine tool including a contactless power feeding device that transmits electric power and a control signal between the fixed portion and the spindle, a plurality of slide bases and slide heads are provided, and each of the slide heads is the spindle. It is equipped with a slide device that slides so that the distance from the center of the same becomes the same. The slide device includes a position detector that detects the position of the slide head, and the detection output of the position detector is input to the servo motor controller. Further, the slide head is a chuck claw, a force sensor for detecting a gripping force for gripping a work is attached to the chuck claw, and a detection output of the force sensor is input to the servo motor controller. Further, a tool holder is fixed to the slide head.

[0005]

By the above means, the servo motor controller receives the electric power and the control signal through the contactless power feeding device and drives the servo motor even when the main shaft is rotating. Therefore, when the chuck is attached to the spindle, the centrifugal force of the chuck claws increases when the spindle rotates at high speed, and the gripping force detected by the force sensor decreases. The detection signal of the lowered gripping force is fed back to the servo motor controller, the servo motor is driven so that the gripping force becomes a predetermined value, and the chuck claw is pressed against the work to maintain the predetermined gripping force. Further, when the tool holder is attached to the spindle, the tool holders are simultaneously moved by the same length from the center of the spindle, so that the center of the spindle is easily balanced and high-speed cutting becomes possible. .

[0006]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a side sectional view showing a first embodiment of the present invention in which a chuck is provided on a main shaft, and FIG. 2 is a plan view showing a surface on a chuck claw side. In the figure, 1 is a cylindrical main shaft,
Reference numeral 2 is a fixed portion provided with a drive portion for rotating the main shaft 1, and 11 is a bearing for supporting the main shaft 1 on the fixed portion 2 so as to be rotatable. 3 is a mounting base having a hollow portion 31 fixed to the end surface of the main shaft 1, 4 is a servo motor controller housed in the hollow portion 31, 5 is a cylindrical slide device fixed to the mounting base 3, and a hollow portion is provided in the central portion. 51 is provided. 6 is a servomotor fixed to the slide device 5, which is a mounting base 3
The rotary shaft 61 projects into the hollow portion 51 of the slide device 5 and the bevel gear 62 is fixed. Reference numeral 52 denotes three ball screws provided at equal intervals in the circumferential direction, the longitudinal directions of which are respectively arranged in the radial direction, and a bevel gear 53 is provided at an end portion thereof and meshes with the bevel gear 62. 5
4 is a nut part that meshes with the ball screw 52.
It is fixed to each slide head 55. A slide base 56 is provided in parallel with the ball screw 52 so that the slide head 55 can slide. Reference numeral 57 is a chuck claw fixed to the slide head 55, and a gripping surface is processed according to the shape of the work W.

Reference numeral 7 is a contactless power feeding device controller fixed to the fixed portion 2, and 71 is a contactless power feeding portion composed of a primary side of a ring-shaped rotary transformer provided on the surface of the fixed portion 2 facing the main shaft 1. Contact power supply controller 7 and cable 72
Connected by. Reference numeral 73 denotes a non-contact power receiving unit that is formed by the secondary side of a ring-shaped rotary transformer provided on the outer periphery of the main shaft 1 so as to face the non-contact power feeding unit 71 with a gap. Is transmitted. Reference numeral 81 denotes a non-contact signal transmitting section which is provided adjacent to the non-contact power feeding section 71 and which is composed of an optical or magnetic transmitting element, and is connected to the non-contact power feeding apparatus controller 7 by a cable 82. Reference numeral 83 denotes a non-contact signal transmitting section 81 made of an optical or magnetic receiving element provided on the outer circumference of the main shaft 1 so as to face the non-contact signal transmitting section 81 with a gap. The signal is transmitted from. The non-contact power feeding device controller, the non-contact power feeding unit 71, the cable 72, the non-contact power receiving unit 73, the non-contact signal transmitting unit 81, the cable 82, and the non-contact signal receiving unit 83 form a set of non-contact power feeding devices. ing. Reference numeral 74 denotes a non-contact power feeding section that is provided on the end surface of the main spindle 1 and is composed of a primary side of a ring-shaped rotary transformer that is concentric with the main spindle 1, and is connected to the non-contact power receiving section 73 by a cable 75. Reference numeral 84 is a non-contact signal transmitting section formed of an optical or magnetic transmitting element provided on the end surface of the main shaft 1, and is connected by a cable 85. Reference numeral 76 denotes a non-contact power receiving portion which is provided on the mounting base 3 so as to face the non-contact power feeding portion 74 and which is a secondary side of a ring-shaped rotary transformer.
Connected to Reference numeral 86 denotes a non-contact signal receiving section formed of an optical or magnetic receiving element provided on the mounting base 3 so as to face the non-contact signal transmitting section 84, and is connected to the servo motor controller 4 by a cable 87. 9 is a force sensor provided on the gripping surface of the chuck claw 57,
The gripping force for gripping is detected, and the detection signal is detected by the cable 9
1 is input to the servo motor controller 4. In addition, the non-contact power feeding section 74 and the non-contact power receiving section 7
6. The contactless signal transmitter 84 and the contactless signal receiver 86 may be plug-in type connectors.

When the work W is gripped by the chuck claws 57, the work W is inserted between the chuck claws 57, the servo motor 6 is driven until the force sensor 9 detects a predetermined gripping force, the rotary shaft 61, and the umbrella. Gears 62, 53, ball screw 5
2. The slide head 55 is slid on the slide base 56 via the nut portion 54 to move the chuck claw 57. When the main shaft 1 is rotated by a driving device (not shown), the servo motor controller 4 continues to transmit electric power and control signals from the contactless power feeding device controller 7 in a contactless manner to maintain a gripping force. When the spindle 1 rotates at high speed, the centrifugal force of the chuck claw 57 increases, and the gripping force detected by the force sensor 9 decreases. The detection signal of the lowered gripping force is fed back to the servo motor controller 4,
The servo motor 6 is driven so as to obtain a predetermined gripping force, and the chuck claws 57 are pressed against the work W to maintain the predetermined gripping force. Thus, even if the rotational speed of the main shaft 1 changes and the gripping force is affected by the centrifugal force, a constant gripping force can always be maintained. Further, when the work W is transferred from the rough finishing process to the fine finishing process, the cutting load is changed, so that the gripping force of the work W needs to be changed according to the cutting load, but the rotation of the main spindle 1 is not stopped, and there is no contact. A signal for changing the gripping force is sent from the power supply device controller 7 to the servo motor controller 4, the servo motor 6 is driven to change the gripping force of the chuck claws 57, and the rough finishing process to the precision finishing process can be continuously performed. In addition, for example, when the electromagnetic adsorption type hand disclosed in Japanese Patent Laid-Open No. 61-288954 is used, the
When transferring a workpiece to the receiving chuck that has been rotated in synchronization with it, the rotation of the spindle can be prevented by causing the receiving chuck to grip the workpiece while driving the servo motor to loosen the gripping force of the chuck claws while the spindle is rotating. The work can be transferred from the rotating chuck to the receiving chuck without stopping. In the above embodiment, the three-jaw chuck provided with three chuck claws is described as an example, but four chuck claws and four slide heads are provided so that each chuck claw can be independently driven by a plurality of servomotors. You may

FIG. 3 is a side sectional view showing a second embodiment of the present invention in which a tool holder is provided on the spindle. Reference numeral 1 is a hollow cylindrical main shaft, 2 is a fixed portion provided with a drive unit for rotating the main shaft 1, and 11 is a bearing for rotatably supporting the main shaft 1 on the fixed portion 2. Reference numeral 12 denotes a tapered hole portion provided on the inner periphery of the main shaft 1, 3 is a mounting base having a cavity 31 fixed to the main shaft 1, 32 is a tapered shank protruding from the mounting base 3, and is fitted into the tapered hole portion 12. The main shaft 1 is fixed together. Reference numeral 4 denotes a servo motor controller housed in the hollow portion 31, 5 is a box-shaped slide device fixed to the mounting base 3, and a hollow portion 51 is provided. Reference numeral 6 denotes a servomotor fixed to the slide device 5, which is housed in the hollow portion 31 of the mounting base 3, and the rotary shaft 61 serves as the slide device 5.
The bevel gear 62 is fixed by protruding into the hollow portion 51. 5
Reference numeral 2 denotes two ball screws provided on both sides of the center of a straight line passing through the center of the main shaft 1, and a bevel gear 53 is provided at an end thereof and meshes with a bevel gear 62. Reference numeral 54 is a nut portion that meshes with the ball screw 52, and each has two slide heads 5.
It is fixed at 5. Reference numeral 56 denotes a slide base provided on the slide device 5 in parallel with the ball screw 52, and a slide head 55 slides on the slide base 55. Reference numeral 58 is a tool holder fixed to the slide head 55, and the cutting tool 59 is fixed to the tip.

Reference numeral 21 is a mounting plate mounted on a fixed portion 2 on the side opposite to the side where the mounting base 3 of the main shaft 1 is mounted, 7 is a contactless power feeding device controller fixed to the mounting plate 21, and 71 is the main shaft of the mounting plate 21. A ring-shaped non-contact power feeding unit provided concentrically with the main shaft 1 is connected to the non-contact power feeding device controller 7 by a cable 72 on the surface facing the end face of the No. 1. 7
Reference numeral 3 denotes a ring-shaped non-contact power receiving portion provided on the end surface of the main shaft 1 so as to face the non-contact power feeding portion 71 via a gap, and power is transmitted from the non-contact power feeding portion 71 in a non-contact manner. Reference numeral 81 denotes a ring-shaped non-contact signal transmission unit provided adjacent to the non-contact power feeding unit 71, and the non-contact power feeding device controller 7
And a cable 82. Reference numeral 83 denotes a ring-shaped non-contact signal receiving portion provided on the end face of the main shaft 1 so as to face the non-contact signal transmitting portion 81 with a gap, so that a signal can be transmitted from the non-contact signal transmitting portion 81 without contact. There is.
Reference numeral 74 denotes a ring-shaped non-contact power feeding portion which is concentric with the main shaft 1 and is provided on the end surface of the main shaft 1 on which the mounting base 3 is mounted, and is connected to the non-contact power receiving portion 73 by a cable 75. 84
Is a ring-shaped non-contact signal transmitting unit concentric with the spindle 1 provided on the end face of the spindle 1, and is connected by a cable 85. 7
Reference numeral 6 denotes a ring-shaped non-contact power receiving portion provided on the mounting base 3 so as to face the non-contact power feeding portion 74, and is connected to the servo motor controller 4 by a cable 77. Reference numeral 86 denotes a ring-shaped contactless signal receiving portion provided on the mounting base 3 so as to face the contactless signal transmitting portion 84, and is connected to the servomotor controller 4 by a cable 87.

When a workpiece (not shown) is processed by the cutting tool 59, the servomotor 6 is driven to move the center of the spindle 1 through the rotary shaft 61, the bevel gears 62 and 53, the ball screw 52, and the nut portion 54. By sandwiching the slide heads 55 on both sides and sliding them on the slide base 56 by the same length,
Tool holder 58 so that the tip of 9 fits the processing size
To move. When the spindle 1 is rotated by a driving device (not shown), the servo motor controller 4 is contactless,
Since the power and control signals are continuously transmitted from the contactless power feeding device controller 7, even when the spindle 1 is rotating, the contactless power feeding device controller 7 sends a signal for changing the position of the tool holder 58 to the servo motor controller 4 so that the servo motor 6 is driven. It is possible to change the position of the tool holder 58 by driving to change the processing size. Further, since the two tool holders 58 are simultaneously moved in the opposite directions by the same length, it is easy to balance with respect to the center of the spindle 1 and high speed cutting becomes possible. In the above-mentioned embodiment, the example in which the tool holders 58 are respectively attached to the two slide heads 55 has been described. However, the tool holders 58 are attached to one slide head 55 and the balance weights are attached to the other slide head 55 to achieve balance. You may do it. Further, as shown in FIG. 4, a linear scale 90 for detecting the moving position of the slide head 55 is attached to the slide device 5, and the position of the cutting tool 59 is fed back to the servo motor controller 4 to control the machining size. Good. In the above embodiment, an example in which two slide heads are provided has been described, but two or more slide heads may be moved by the same length from the center of the main shaft. Further, a plurality of slide heads may be independently driven by a plurality of servo motors.

[0012]

As described above, according to the present invention, the contactless power feeding device is provided between the fixed part and the main shaft so that the servomotor provided on the main shaft and its controller can be contactlessly supplied with electric power. Since the chuck and tool holder attached to the spindle are driven by transmitting the control signal and the control signal, it is possible to reduce the chucking force of the chuck due to high speed rotation and correct the tool holder position even when the spindle is rotating. It has the effect of providing a machine tool spindle that enables high-speed cutting and prevents unbalance.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment of the present invention.

FIG. 2 is a plan view showing a chuck according to a first embodiment of the present invention.

FIG. 3 is a side sectional view showing a second embodiment of the present invention.

FIG. 4 is a side sectional view of an essential part showing a second embodiment of the present invention.

[Explanation of symbols]

1 main shaft, 11 bearings, 12 taper parts, 2 fixed parts,
21 mounting plate, 3 mounting base, 31 hollow part, 4 servo motor controller, 5 slide device, 51 hollow part, 52 ball screw, 53 bevel gear, 54 nut part, 55 slide head, 56 slide base, 5
7 Chuck claws, 58 Tool holders, 59 Cutting tools, 6
Servo motor, 61 rotating shaft, 62 bevel gear, 63 rotation detector, 7 non-contact power feeding device controller, 71, 7
4 Non-contact power supply, 72, 75, 77 cable, 7
3,76 Non-contact power receiving part, 81,84 Non-contact signal transmitting part, 82,85,87 Cable, 83,86 Non-contact signal receiving part, 9 Force sensor, 90 Linear scale, 9
1 cable

Claims (5)

[Claims] 1. A main shaft supported by a fixed portion via a bearing,
A mounting base having one end fixed to one end of the main shaft,
A slide device having one end fixed to the other end of the mounting base, a slide base extending in the direction perpendicular to the main shaft at the other end of the slide device, a slide head slidably provided on the slide base, and the slide head. A servo motor for driving the servo motor, and a servo motor controller for controlling the servo motor and provided on the mounting base,
In a spindle head of a machine tool including a contactless power feeding device that transmits electric power and a control signal between the fixed portion and the spindle, a plurality of slide bases and slide heads are provided, and each of the slide heads is the spindle. A spindle head for a machine tool, comprising a slide device that slides so that the distance from the center of the machine is the same. 2. The spindle of a machine tool according to claim 1, wherein the slide device includes a position detector that detects a position of the slide head, and a detection output of the position detector is input to the servo motor controller. head. 3. The slide head is a chuck claw, a force sensor for detecting a gripping force for gripping a work is attached to the chuck claw, and a detection output of the force sensor is input to the servo motor controller. A spindle head for a machine tool according to Item 1 or 2. 4. The spindle head for a machine tool according to claim 2, wherein a tool holder is fixed to the slide head. 5. The slide device comprises the servomotor, a bevel gear fixed to a rotary shaft of the servomotor, a plurality of ball screws provided at equal intervals in a circumferential direction, and each of which is longitudinally arranged in a radial direction. And a bevel gear that is provided at an end portion of the ball screw and that meshes with a bevel gear that is fixed to the rotation shaft of the servo motor, a nut portion that meshes with the ball screw, and a slide head that is fixed to the nut portion. A spindle head for a machine tool according to any one of claims 1 to 4.