JPH05318206A - Nc lathe and its controlling method - Google Patents

Abstract

PURPOSE:To provide an NC lathe and a method of controlling the NC lathe, particularly of spindle sliding type fitted with a rotary guide bushing, in which the rotation of the spindle can precisely be synchronized with the rotation of the rotary guide bushing and the spindle can make high speed revolutions. CONSTITUTION:A pulley 22b of a rotary guide bushing 16 is coupled through a belt 22c with a pulley 22a of a pulse motor 20 for rotating the bushing. The bushing 16 can be rotated synchronously with the rotating speed of the spindle 9 by driving this pulse motor 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an NC lathe and a control method thereof, and more particularly to a main spindle sliding NC lathe provided with a rotary guide bush and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, a spindle-sliding NC lathe having a spindle slidable in the Z-axis direction has been used. The main spindle sliding NC lathe is characterized in that a main spindle that holds a workpiece and rotates together with the workpiece is slidable in the Z-axis direction, which is the rotational axis direction of the workpiece. A rotary guide bush support is fixed to the bed at one end of the movement range of the spindle in the Z-axis direction, and a rotary guide bush having an opening center on the extension of the rotary shaft of the workpiece is attached to the rotary guide bush support. Has been.

A work piece which is rotated and held by the main shaft has the main shaft +
When it is moved in the Z-axis direction, it is introduced into the rotary guide bush that is the rotation holding means of the workpiece, is supported by the rotary guide bush, and projects from the end of the rotary guide bush. The workpiece protruding from the end of the rotary guide bush is machined in a machining region near the end of the rotary guide bush by a tool such as a tool that can move in the X-axis direction orthogonal to the Z-axis.

As described above, the rotary guide bush plays a role of supporting the workpiece moving in the Z-axis direction while rotating with the spindle and guiding the workpiece to the machining area. At this time, the spindle is rotated so as not to damage the workpiece. It is designed to rotate in synchronization with the speed. By providing the rotary guide bush with a mechanism that rotates in synchronization with the rotation speed of the spindle,
It is possible to prevent the seizure of the workpiece in the rotary guide bush, and it is also possible to process the workpiece when it is a deformed material such as a square material or a hexagonal material.

Conventionally, the rotation of the rotary guide bush and the rotation of the main shaft have been mechanically synchronized. That is,
A rotary shaft for synchronization extending to the rotary guide bush including the sliding area of the main shaft is provided in parallel with the Z-axis, a gear is formed on the main shaft, and an appropriate gear train is interposed between the main shaft and the rotary shaft for synchronization. Is transmitted to the rotation shaft for synchronization. The rotary guide bush is rotated in synchronization with the rotational speed of the main shaft by transmitting the rotation of the synchronizing rotary shaft that is rotated by the rotation of the main shaft to the rotary guide bush through the transmission gear train.

[0006]

However, with such a method and structure for mechanically synchronizing the rotation of the main spindle and the rotary guide bush, the backlash existing in the gear and the sliding movement of the main spindle are caused. Since the gear attached to the rotating shaft for synchronization also needs to slide on the rotating shaft for synchronization, it is difficult to obtain a predetermined mechanical accuracy, and there is a limit to synchronizing rotation with high accuracy. The problem arises that there is.

Further, although recent machine tools are required to be cut at high speed, there is a problem that high speed rotation cannot be supported when mechanically synchronizing. An object of the present invention is to provide an NC lathe that can synchronize the rotations of a main shaft and a rotary guide bush with high precision and can rotate the main shaft at high speed, and a control method thereof.

[0008]

SUMMARY OF THE INVENTION The above-mentioned object is to hold a workpiece and rotate it, and to move the workpiece in a Z-axis direction, which is the direction of the axis of rotation of the workpiece. A rotary guide bush for penetrating the workpiece rotatably held by the main shaft to guide it to a machining area, and a tool for machining the workpiece, which is located in front of the rotary guide bush and holds the workpiece in the Z-axis direction. In an NC lathe equipped with a tool base movable in the X-axis direction orthogonal to each other, a rotary motor for rotating a rotary guide bush for rotating the rotary guide bush and the rotary guide bush rotate in synchronization with a rotation speed of a main shaft. And a control means for controlling rotation of the rotary guide bush rotating motor.

Further, the above-mentioned object is to hold and rotate a workpiece, and a main spindle which is slidable in the Z-axis direction which is the rotation axis direction of the workpiece, and which is located in front of the main spindle and rotationally held on the main spindle. A rotary guide bush for guiding the processed workpiece to a machining area by penetrating the workpiece, and holding a tool for machining the workpiece, which is located in front of the rotary guide bush.
In a method for controlling an NC lathe equipped with a tool base movable in an X-axis direction orthogonal to the Z-axis direction, the rotary guide bush is rotated by a rotary guide bush rotating motor, and the rotary guide bush is rotated by the rotary shaft of the main spindle. This is achieved by a control method for an NC lathe, characterized in that the rotation speed of the rotary motor for rotating the rotary guide bush is controlled so as to rotate in synchronization with the rotation speed.

[0010]

According to the present invention, the rotary guide bush is provided with a motor for rotating the rotary guide bush, and the rotation of the motor is controlled to synchronize the rotation of the main spindle with that of the rotary guide bush. The rotation of the rotary guide bush can be synchronized with high precision, and the spindle can be rotated at high speed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An NC lathe according to an embodiment of the present invention and a control method therefor will be described with reference to FIGS. N in this embodiment
C lathe is a main spindle sliding type N equipped with a rotary guide bush.
It is a C lathe. The main spindle sliding NC lathe of this embodiment will be described with reference to FIG. A headstock 8 is mounted on the bed 2 so as to be slidable in the Z-axis direction. A spindle 9 rotatably supported is mounted in the spindle stock 8. A Z-axis feed screw 4 for feeding the headstock 8 in the Z-axis direction is attached to the bed 2. The Z-axis feed screw 4 is rotated by the Z-axis feed motor 6, and the headstock 8 on the bed 2 can be moved in the Z-axis direction by the rotation of the Z-axis feed screw 4.

The pulley 11b of the main shaft 9 is, for example, a pulley 1 of a main motor 10 of a pulse motor via a belt 11c.
1a, the main shaft 9 can be rotated by driving the main motor 10, for example, in the S1 direction in FIG. In this embodiment, the pulleys 11a and 11b have the same diameter, and the speed ratio between the main motor 10 and the main shaft 9 is 1.

A work piece 14 is held from the cylinder 12 side provided at one end of the main shaft 9 on the main motor 10 side, penetrating through the main shaft 9 along the rotation center of the main shaft 9. The work piece 14 is fixed to the main spindle 9 by a chuck provided at the other end of the main spindle 9, is rotated with the rotation of the main spindle, and is moved with the movement of the headstock 8 in the Z-axis direction.

A rotary guide bush support 15 is fixed to the bed 2 at the end of the sliding range of the headstock 8 in the + Z-axis direction. In the rotary guide bush support base 15,
A rotary guide bush 16 which has an opening center on the extension of the rotation axis of the workpiece 14 and which is a rotation holding means of the workpiece is attached. By moving the main shaft 9 in the + Z-axis direction, the workpiece 14 rotatably held by the main shaft 9 is introduced into the rotary guide bush 16 and supported by the rotary guide bush 16, and protrudes from the end of the rotary guide bush 16. The workpiece 14 protruding from the end of the rotary guide bush 16 is machined by a tool 18 such as a cutting tool that is movable in the X direction orthogonal to the Z axis direction in a machining region near the end of the rotary guide bush 16.

The pulley 22 of the rotary guide bush 16
b is connected to the pulley 22a of the rotary motor for rotating the rotary guide bush 20 via a belt 22c. By driving the pulse motor 20 for rotating the rotary guide bush, the rotary guide bush 16 can be rotated, for example, in the S2 direction which is the same direction as S1 in FIG. In this embodiment, the pulleys 22a and 22b have the same diameter, and the speed ratio between the rotary guide bush rotating pulse motor 20 and the rotary guide bush 16 is 1.

The structure of the rotary guide bush 16 will be described in more detail with reference to FIG. FIG. 2 is a sectional view of the rotary guide bush 16 of this embodiment. The guide bush main body 52 for penetrating and holding the workpiece 14 (not shown) is inserted from the tool side (left side in the drawing) of the hole of the spindle 54, and the pipe 50 is inserted from the spindle side (right side in the drawing) to guide the guide. The bush main body 52 and the pipe 50 are fitted and connected.

The guide bush main body 52 is formed such that the inner diameter on the tool side is narrower than the inner diameter on the spindle side, and the work 1 has an inner surface on the tool side.
It is designed to hold 4. The inner diameter of the pipe 50 is formed to be substantially the same as the inner diameter of the guide bush main body 52 on the main shaft side, so that the workpiece 14 can be easily inserted. A key groove is formed in the axial direction on the outer diameter portion of the guide bush body 52.
Is fixed to the spindle 54 by a pin 56 which is driven from the spindle 54 to the center of the key groove.

An adapter 70 is attached to an end of the spindle 54 on the spindle side by an adapter attaching screw 68 to fix the pipe 50. A pulley 22b is fixedly attached to the outer surface of the spindle 54 from the center of the spindle 54. On the other hand, two ball bearings 62, 64 are attached to the tool side from the center of the spindle 54.
It is rotatably connected to the housing 58 via 2, 64. Therefore, by winding the belt around the pulley 22b, connecting the belt to the motor, and rotating the motor, the guide bush main body 52 can be rotated together with the spindle 54 in the fixed housing 58.

The housing 58 is mounted on the rotary guide bush support base 1 by a rotary guide bush mounting screw 60.
5 (not shown). Next, an NC lathe and its control method according to an embodiment of the present invention will be described with reference to FIG. The NC lathe of this embodiment and the control method thereof are a spindle-sliding NC lathe provided with a rotation speed control device for controlling the rotation speed of the rotary guide bush 16 and a method of controlling the rotation speed of the rotary guide bush 16.

First, a rotation speed control device for the rotary guide bush 16 will be described. A spindle rotation speed command that specifies the rotation speed of the spindle 9 issued from an NC device 40 that numerically controls the spindle sliding NC lathe of this embodiment is input to the synchronization control unit 38. Synchronization control unit 38
Is connected to the spindle motor control unit 34 and the rotary guide bush rotation motor control unit 36, and the spindle motor control unit 34
To the rotary guide bush rotation motor control unit 36, and to the rotary guide bush rotation motor control unit 36 to output a rotary guide bush rotation speed command for synchronizing the rotation speed of the spindle 9 with the rotation of the rotary guide bush 16. It is like this.

A spindle motor control unit 34, which receives the spindle rotation speed command and controls the rotation speed of the spindle 9, is connected to the pulse generator 30. The spindle motor control section 34 outputs a spindle rotation control value for generating a predetermined spindle rotation pulse to the pulse generator 30.
The pulse generator 30 receiving the spindle rotation control value is adapted to generate a prescribed number of pulses within a prescribed time in order to rotate the spindle 9. The pulse generator 30 is connected to the main motor 10.

On the other hand, the rotary guide bush rotation motor control unit 36 for controlling the rotation speed of the rotary guide bush 16 in response to the rotary guide bush rotation speed command output from the synchronization control unit 38 is connected to the pulse generator 32. There is. The rotary guide bush rotation motor control unit 36 outputs a rotary guide bush rotation control value for generating a predetermined pulse for synchronizing the rotation speed of the main shaft 9 to the rotation of the rotary guide bush 16 to the pulse generator 32. Is becoming
The pulse generator 32, which has received the rotary guide bush rotation control value, rotates the rotary guide bush 16 in synchronism with the main shaft to generate a predetermined number of pulses within a predetermined time. The pulse generator 32 is connected to the rotary guide bush rotating pulse motor 20.

Next, a method of controlling the rotation speed of the rotary guide bush 16 will be described. A spindle rotation speed command that specifies the rotation speed of the spindle 9 is input from the NC device 40 to the synchronization control unit 38. The synchronous control unit 38 calculates the rotation speed of the rotary guide bush to rotate from the spindle rotation speed command, and outputs it to the rotary guide bush rotation motor control unit 36 as the rotary guide bush rotation speed command. In the present embodiment, the pulley 1 of the main motor 10
1a and the pulley 11b of the main shaft 9 have the same diameter, the speed ratio of the main motor 10 and the main shaft 9 is 1, and the pulley 22a of the rotary guide bush rotating pulse motor 20 is also provided.
And the diameter of the pulley 22b of the rotary guide bush 16 are the same, and the rotary guide bush rotating pulse motor 2
Since the speed ratio of 0 and the rotary guide bush 16 is also 1, if the rotation speeds of the main motor 10 and the pulse motor 20 for rotating the rotary guide bush are made equal, the rotation in synchronization with the rotation speed of the main shaft 9 is synchronized with the rotary guide bush 16.
You will be able to Therefore, in this case, the rotary guide bush rotation speed command may be the same as the spindle rotation speed command.

The spindle rotation speed command is input to the spindle motor controller 34 via the synchronization controller 38. The spindle motor control unit 34 controls the rotation speed of the spindle 9 and outputs a spindle rotation control value to the pulse generator 30. According to the spindle rotation control value, the pulse generator 34 generates a prescribed number of spindle rotation pulses within a prescribed time so that the spindle 9 reaches a prescribed rotation speed. Main motor 1 by main shaft rotation pulse
0 is rotated to rotate the spindle 9 at a predetermined rotation speed.

On the other hand, the rotary guide bush rotation speed command from the synchronization control unit 38 is input to the rotary guide bush rotation motor control unit 36. The rotary guide bush rotation motor control unit 36 is the rotary guide bush 1
The rotation speed of 6 is controlled to output the rotary guide bush rotation control value to the pulse generator 32. The pulse generator 32 generates a predetermined number of rotary guide bush rotation pulses within a predetermined time so that the rotary guide bush 16 has a predetermined rotation speed. The rotary motor for rotating the rotary guide bush 16 can be rotated by the rotary pulse for rotating the rotary guide bush to rotate the rotary guide bush 16 in synchronization with the rotation speed of the main shaft 9.

As described above, the rotary guide bush 1
6 is provided with a motor for rotating the rotary guide bush 16 and the rotation of the motor is controlled to synchronize the rotations of the main shaft 9 and the rotary guide bush 16. It is possible to synchronize rotation with high precision without being affected by the limited mechanical precision due to backlash etc., and also to perform cutting at high speed rotation required for machine tools in recent years. become.

The present invention is not limited to the above embodiment, but various modifications can be made. For example, in the above embodiment, the case where the speed ratio between the main motor 10 and the main shaft 9 is 1 and the speed ratio between the rotary motor 20 for rotary guide bush rotation and the rotary guide bush 16 is also 1 has been described. Of course, the present invention can be applied even when the pulleys have different diameters and the speed ratios thereof are not 1. For example, the pulley 1 of the main motor 10
1a and the pulley 11b of the main shaft 9 have the same diameter, and the pulley 22a of the rotary guide bush rotating pulse motor 20
Is twice the diameter of the pulley 22b of the rotary guide bush 16, the speed ratio between the main motor 10 and the main shaft 9 is 1, but the pulse motor 20 for rotating the rotary guide bush and the rotary guide bush 16 are used.
Has a speed ratio of 2. In this case, the synchronous control unit 38 may issue a rotary guide bush rotation speed command such that the rotation speed of the rotary guide bush rotation pulse motor 20 is half that of the main motor 10.

[0028]

As described above, according to the present invention, the rotary guide bush is provided with a motor for rotating the rotary guide bush, and the rotation of the motor is controlled to synchronize the rotation of the main shaft and the rotary guide bush. Therefore, the rotation of the spindle and the rotary guide bush can be synchronized with high accuracy, and the spindle can be rotated at a high speed.

[Brief description of drawings]

FIG. 1 is a diagram showing a spindle sliding NC lathe according to an embodiment of the present invention.

FIG. 2 is a sectional view of a rotary guide bush used in one embodiment of the present invention.

FIG. 3 is a diagram illustrating a spindle sliding NC lathe according to an embodiment of the present invention and a control method therefor.

[Explanation of symbols]

 2 ... Bed 4 ... Z-axis feed screw 6 ... Z-axis feed motor 8 ... Spindle base 9 ... Spindle 10 ... Main motor 11a, 11b ... Pulley 11c ... Belt 12 ... Cylinder 14 ... Workpiece 15 ... Rotary guide bush support stand 16 ... Rotary guide bush 18 ... Tool 20 ... Rotary guide bush rotation pulse motor 22a, 22b ... Pulley 22c ... Belt 30,32 ... Pulse generator 34 ... Spindle motor controller 36 ... Rotary guide bush rotation motor controller 38 ... Synchronous controller 40 ... NC device 50 ... Pipe 52 ... Guide bush main body 54 ... Spindle 56 ... Pin 58 ... Housing 60 ... Rotary guide bush mounting screw 62, 64 ... Ball bearing 68 ... Adapter mounting screw 70 ... Adapter

Claims (5)

[Claims] 1. A spindle that holds and rotates a workpiece and is slidable in the Z-axis direction, which is the rotation axis direction of the workpiece, and the spindle that is positioned in front of the spindle and is rotatably held by the spindle. A rotary guide bush for penetrating a workpiece to guide it to a machining area and a tool for machining the workpiece, which is located in front of the rotary guide bush and is movable in the X-axis direction orthogonal to the Z-axis direction. With a simple tool stand
In a lathe, a rotary motor for rotating the rotary guide bush for rotating the rotary guide bush, and a control means for controlling the rotation of the rotary motor for the rotary guide bush so that the rotary guide bush rotates in synchronization with the rotation speed of the main shaft. NC lathe characterized by having. 2. The NC lathe according to claim 1, wherein said control means receives a spindle rotation speed command designating a rotation speed of said spindle, and synchronizes the rotation of said rotary guide bush with the rotation speed of said spindle. A synchronous control unit that issues a rotary guide bush rotation speed command, and a rotary that outputs a rotary guide bush rotation control value that controls the rotation speed of the rotary guide bush in response to the rotary guide bush rotation speed command from the synchronization control unit. A motor control unit for rotating the guide bush, and a rotary guide bush for generating a predetermined number of rotation pulses for rotating the rotary guide bush within a predetermined time according to the rotary control value of the rotary guide bush from the motor control unit for rotating the rotary guide bush. And a pulse generator for rotation. NC lathe that. 3. The NC lathe according to claim 1 or 2, wherein the rotary motor for rotating the rotary guide bush is a pulse motor. 4. A spindle that holds and rotates a workpiece and is slidable in the Z-axis direction that is the rotation axis direction of the workpiece, and the spindle that is located in front of the spindle and is rotatably held by the spindle. A rotary guide bush for penetrating a workpiece to guide it to a machining area and a tool for machining the workpiece, which is located in front of the rotary guide bush and is movable in the X-axis direction orthogonal to the Z-axis direction. With a simple tool stand
In a lathe control method, the rotary guide bush is rotated by a rotary motor for rotating the rotary guide bush, and the rotary speed of the rotary motor for rotating the rotary guide bush is adjusted so that the rotary guide bush rotates in synchronization with the rotary speed of the main shaft. A method for controlling an NC lathe characterized by controlling. 5. A spindle that holds and rotates a workpiece and is slidable in the Z-axis direction that is the rotation axis direction of the workpiece, and the spindle that is positioned in front of the spindle and is rotatably held by the spindle. A rotary guide bush for penetrating a workpiece to guide it to a machining area and a tool for machining the workpiece, which is located in front of the rotary guide bush and is movable in the X-axis direction orthogonal to the Z-axis direction. With a simple tool stand
In a lathe control method, a rotary guide bush rotation speed command that synchronizes the rotation of the rotary guide bush with the rotation speed of the main spindle in response to a main spindle rotation speed command that specifies the rotation speed of the main spindle is issued, and the rotary guide bush rotation In response to the speed command, the rotary guide bush rotation control value for controlling the rotation speed of the rotary guide bush is output, and according to the rotary guide bush rotation control value, a predetermined number of rotation pulses for rotating the rotary guide bush within a predetermined time. Is generated, and the rotary guide bush driving pulse motor is rotated by the rotation pulse to rotate the rotary guide bush in synchronization with the rotation speed of the main shaft.