JPH05318202A - Nc machine tool and its controlling method - Google Patents

Abstract

PURPOSE:To provide an NC lathe of spindle slide type and an associate method of controlling it, with which restrictions on the processes made therewith are eliminated. CONSTITUTION:A spindle 9 rotated together with a work 14 while holding it, is installed slidably in the Zs axis direction which is identical to the shank of the work 14 rotating, and a main turret 20 holding a tool 18 is installed movably not only in the X-axis direction but also in the ZT-axis direction which is identical to the ZS-axis direction. The drive system for ZS-axis direction is put synchronous with the drive system for ZT-axis direction, and they are changed over so that only either system is in effect, and thus processing in the Z-axis direction is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an NC machine tool having an NC device for numerically controlling each multi-axis drive system so as to reach a target position, and a control method therefor, and more particularly, a spindle sliding NC. The present invention relates to a lathe and its control method.

[0002]

2. Description of the Related Art Conventionally, a spindle-sliding type 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 a bed at one end of the movement range of the spindle in the Z-axis direction, and the rotary guide bush support is provided with a rotary guide bush having an opening center on the extension of the rotary shaft of the workpiece. ing.

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 inner surface of the rotary guide bush is adapted to rotate in synchronization with the rotation of the main shaft so as not to damage the workpiece to be contacted.

The work piece protruding from the end of the rotary guide bush is machined by a tool such as a cutting tool in a machining region near the end of the rotary guide bush. Tool is Z
It can be moved in the X-axis direction orthogonal to the axis.
As described above, in the conventional spindle-sliding NC lathe, the rotation of the workpiece and the movement in the Z-axis direction are performed by the spindle, and the tool such as the cutting tool is movable only in the X-axis direction.

An example of processing by a conventional spindle-sliding NC lathe will be described with reference to FIG. First, the spindle is moved in the + Z direction so that the work piece tip projects from the end of the rotary guide bush by a predetermined amount, the coordinate origin is determined, and then the tool for machining the inner diameter is set (FIG. 5A). Next, the inner diameter of the workpiece is machined while moving the spindle in the + Z direction by a predetermined amount (Fig. 5).
(B)). Next, the spindle is moved in the -Z direction, and then a tool for outer diameter machining is set (Fig. 5 (c)). Next, the outer diameter of the workpiece is machined while moving the spindle in the + Z direction by a predetermined amount (FIG. 5 (d)).

[0006]

As described above, the conventional machining setup for the spindle-sliding NC lathe is that the inner diameter of the workpiece is first machined and then the outer diameter is machined. . If the outer diameter machining of the workpiece is done first,
Next, when performing inner diameter machining, it is necessary to return the spindle in the -Z-axis direction. Then, the outer diameter machining ends and the workpiece with the smaller outer diameter is returned to the rotary guide bush. There are problems that the guide bush cannot hold the work piece sufficiently and that the work piece plays around in the rotary guide bush and scratches the work surface. Therefore, the conventional spindle sliding type N
In the C-lathe, there is a restriction on the processing process that the inner diameter processing must be performed first as described above. This restriction on the machining process is not limited to the above example, and various restrictions such as a restriction in the case of first roughing and then finishing in the outer diameter machining, a tuning device or a bite offset required in the thread cutting process are required. There was a constraint.

An object of the present invention is to provide a spindle-sliding NC lathe that eliminates restrictions on machining steps and a control method therefor.

[0008]

SUMMARY OF THE INVENTION The above object is to provide a main shaft which holds and rotates a workpiece and is slidable in the Z _S axis direction which is the rotational axis direction of the workpiece, and which is located in front of the main spindle. A rotary holding means for penetrating and holding the workpiece rotatably held on the main spindle, and a rotary holding means positioned in front of the rotary holding means, the Z _T axis direction being the same direction as the Z _S axis direction and the Z _S
It is achieved by an NC machine tool characterized in that it is provided with a tool holding means for movably holding a tool in both the X-axis direction orthogonal to the axial direction.

[0009] The above-described object, the holding and rotating the workpiece, the a rotational axis of the workpiece Z _S axis direction Z _S axis drive for moving the slidable spindle in the Z _S axis direction System, a Z _T axis drive system for moving a tool located in front of the main spindle in the Z _T axis direction which is the same as the Z _S axis direction, and the Z _S axis drive system which receives a Z axis direction movement command. and Z _S axis position control unit for controlling the position of the Z _T axis position control unit that the receiving movement command in the Z-axis direction to control the position of the Z _T axis driving system, the Z _S axis position control unit or the characterized in that a drive shaft switching unit for driving only one of said Z _S axis position control unit emits one to drive stop command of Z _T axis position control unit or the Z _T axis position control unit Achieved by NC machine tools.

Further, the above object is to hold a workpiece and rotate it.
Z, which is the direction of the rotation axis of the workpiece._SAxial sliding
The movable spindle position control receives a movement command in the Z-axis direction.
Z _SZ by axis position controller_SDrive the axis drive system
Located in front of the main shaft, the Z_SSame as axial direction
Z_TPosition control of a tool that can move in the axial direction is performed by using the Z-axis.
Z that has received a direction movement command_TZ by axis position controller_Taxis
Drive the drive system to perform_SAxis position controller or front
Note Z_TDrive stop finger that stops only one of the axis position control units
By the above Z_SAxial drive system or the Z_TOne side of shaft drive system
Drive is stopped and only one drive system is driven.
The drive system is switched so as to perform machining in the Z-axis direction.
Achieved by the NC machine tool control method characterized by
To be done.

[0011]

According to the present invention, a linear motion axis that can move in the same direction as the linear motion axis of the main shaft is provided on the tool side, and both axes are alternately switched and driven while giving the same coordinate value to both axes. Therefore, it is possible to realize a spindle-sliding NC lathe that does not need to be concerned with the setup of machining such as outer diameter machining and inner diameter machining, that is, the restrictions on the machining process are eliminated.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A spindle-sliding NC lathe and a control method therefor according to an embodiment of the present invention will be described with reference to FIGS. In the spindle-sliding NC lathe according to this embodiment, a spindle that holds a workpiece and rotates together with the workpiece is provided slidably in the Z-axis direction that is the rotation axis direction of the workpiece, and holds the tool. The feature is that the tool base is provided so as to be slidable not only in the X-axis direction but also in the Z-axis direction.

A spindle-sliding NC lathe according to this embodiment is shown in FIG.
Will be explained. 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 _S axis feed screw 4 for feeding the headstock 8 in the Z _S axis direction is attached to the bed 2. The Z _S axis feed screw 4 is rotated by the Z _S axis servo motor 6, and the head stock 8 on the bed 2 can be moved in the Z _S axis direction by the rotation of the Z _S axis feed screw 4.

The main shaft 9 is rotated by the drive of a main motor 10 connected via a belt 11. The workpiece 14 is held from the cylinder 12 side provided at one end of the main shaft 9 on the main motor 10 side, penetrating the inside of the main shaft 9 along the rotation center of the main shaft 9.
The workpiece 14 is fixed to the spindle 9 by a chuck provided at the other end of the spindle 9, and is rotated with the rotation of the spindle, and is also moved with the movement of the spindle stock 8 in the Z _S 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 _S axis direction. The rotary guide bush support base 15 has an opening center on an extension of the rotation axis of the workpiece 14, and is a rotary guide bush 16 which is a rotation holding means for the workpiece.
Is attached. By moving the main shaft 9 in the + Z _S axis direction, the workpiece 14 rotated and 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 inner surface of the rotary guide bush 16 prevents the work piece 14 coming into contact with the spindle 9 from being damaged.
It is designed to rotate in synchronization with the rotation of.

The workpiece 14 protruding from the end of the rotary guide bush 16 is machined by a tool 18 such as a cutting tool in a machining region near the end of the rotary guide bush 16. Several kinds of tools 18 are prepared according to machining and are attached to a main turret 20 which is tool holding means. By driving the index motor 22, the main turret 20 is rotated so that the necessary tool 18 is
It is designed to be indexed on the processed surface of 4.

The main turret 20 can be moved in the Z _T axis direction which is the same direction as the Z _S axis of the main shaft by the Z _T axis servo motor 26, and the X axis direction which is orthogonal to the Z _S axis by the X axis servo motor 24. It can be moved to. Therefore, the tool 18 attached to the main turret 20 and indexed on the machining surface of the workpiece 14 has an X-axis orthogonal to the Z _T- axis direction and the Z _S- axis direction that are the same as the movement of the spindle 9 in the Z _S- axis direction. It can move in the axial direction.

Thus, the main spindle sliding type N according to the present embodiment
The C-lathe is capable of rotating a workpiece and moving in the Z-axis direction by a spindle, and a tool such as a cutting tool can move not only in the X-axis direction but also in the Z-axis direction of the spindle.
A control method of the spindle sliding NC lathe according to this embodiment will be described with reference to FIG. The X axis servo motor 24, the Z _S axis servo motor 6 and the Z _T axis servo motor 26 shown in FIG.
X-axis position control unit 30, Z _S- axis position control unit 32,
It is connected to and controlled by the Z _T axis position controller 34 and a speed controller (not shown).

The X-axis position control unit 30 is connected to the X-axis from the NC device side.
An X-axis movement command including the coordinate value (target value) of the axis is input. The X-axis servomotor 24 is driven according to the difference between the X-axis coordinate value input to the X-axis position control section 30 and the current coordinate value, and the position signal from the position detecting means (not shown) is fed back. The X-axis servomotor 24 is controlled accordingly.

A Z-axis movement command including a Z-axis coordinate value (target value) is input to the Z _S axis position control unit 32 from the NC device side. Feedback position signal from the position detecting means drives the Z _S axis servo motor 6 (not shown) in accordance with the difference between the coordinate values and the current coordinate value of Z axis that is input to the Z _S axis position control unit 32 Then, the Z _S axis servo motor 6 can be controlled.

[0021] Similarly, Z to Z _T axis position control unit 34
A Z-axis movement command including the same Z-axis coordinate value (target value) as that input to the _S- axis position control unit 32 is input from the NC device side to the Z _S- axis position control unit 32 at the same time. Feedback position signal from the position detecting means drives the Z _T axis servo motor 26 (not shown) in accordance with the difference between the coordinate values and the current coordinate value of Z axis that is input to the Z _T axis position control unit 34 Then, the Z _T axis servo motor 26 can be controlled.

As described above, the Z-axis movement command synchronizes the Z _S axis position control section 32 for moving the spindle 9 in the Z axis direction and the Z _T axis position control section 34 for moving the tool 18 in the Z axis direction. It is designed to be input to both parties. Also, Z
_{The S} axis position control unit 32 and the Z _T axis position control unit 34 are the PMC.
It is connected to a (programmable machine controller) 36. The PMC36 has various functions, but Z _S
The following swap control is performed on the axis position controller 32 or the Z _T axis position controller 34.

That is, from the NC device to each position control unit 32, 3
In response to the Z-axis movement command given to No. 4, only the servo motor of the drive system of either the Z _S axis position control unit 32 or the Z _T axis position control unit 34 drives so that the Z of the NC device is driven.
A drive stop command for ignoring the axis movement command and holding the drive system in a stopped state is output from the PMC 36 to either the Z _S axis position control unit 32 or the Z _T axis position control unit 34, and the drive stop command is output for each position. This is a control (hereinafter referred to as "swap control") for alternately switching the drive shafts by alternately giving the control units 32 and 34.

In this swap control, the Z-axis movement command from the NC device input to the position control unit that receives the drive stop command is ignored, but the Z-axis coordinate value (target value) in the position control unit is updated. It Therefore, the Z _S axis position control unit 32 and Z
The Z-axis coordinate value (target value) of the _T- axis position control unit 34 is always updated with the same coordinate value. By doing this,
Even if the drive axes are switched alternately, the coordinate value from the coordinate origin to the current machining position is always the position control units 32, 34 for both drive axes.
Will be remembered in.

By performing the swap control, when the workpiece 14 is machined using the spindle-sliding NC lathe according to this embodiment, the NC device controls the Z _S axis and the Z axis in the Z axis direction control.
_{It suffices to} simply send a movement command as the Z axis without managing the coordinate values of each of the _T axes. Further, the spindle 9 holding the workpiece 14 is moved in the Z _S axis direction, or a tool is used. By arbitrarily selecting and switching whether or not to move 18 in the Z _T axis direction, it becomes possible to perform processing of the workpiece 14 with restrictions on the processing process eliminated.

Control of a spindle-sliding NC lathe according to this embodiment
An example of the program is shown in FIG. M51 and M52 are swallow
This is a drive stop command used for the up control. NC program
51 of M code used as auxiliary function in ramming
This is an example in which and 52 are used for swap control. M51 is Z_S
Axis drive and Z_TAxis stop command, M52 is Z _TAxis drive
And Z_SThis is an axis stop command.

When M51 is sent from the PMC 36 to the Z _S axis position control section 32 and the Z _T axis position control section 34, it is switched to drive only the Z _S axis, and when M52 is sent, Z _T
It will be switched to drive only the axis. In this program, first, M5 with sequence number 101
The Z _S axis, that is, the headstock 8 is switched so as to be movable by 1 and the tool 18 is in a state of not moving in the Z _T axis direction. Hereinafter, description will be given with reference to a machining example in which the present program is applied to the spindle sliding NC lathe of this embodiment shown in FIG.

Next, G00 X of sequence number 102
Due to 8.0, the outer diameter machining tool 18 has X = φ8 mm, Z
Is moved to the position of = 0 and positioned (FIG. 4).
(A)). Next, G01 Z2 of sequence number 103
0.0 F0.08 drives the Z _S axis servo motor 6 that moves the headstock 8 in the Z-axis direction, and the headstock 8 becomes + Z.
The outer diameter of the workpiece 14 is cut by the tool 18 while moving axially by a distance of 0.08 by a distance of 20 mm from the coordinate origin (FIG. 4B). At this time, the Z _T axis position control unit 34 also receives the G01 Z20.0 of the N103 from the NC device.
Receiving a command to F0.08, but updating the coordinate value to 20.0, by command M51, Z _T axis servo motor 26
Is stopped without driving.

Next, G00 X1 of sequence number 104
According to the command of 3.0, the tool 18 for outer diameter machining is set to X13.
After moving to the coordinate system setting position of 0, the drive axis is switched from the Z _S axis to the Z _T axis by M52 of sequence number 105. According to this M52 command, the Z _S axis position control unit 32
The drive system is stopped, Z _T axis servo motor 26 of the Z _T axis position control unit 34 is a tool 18 side is drivable. Next, the tool 18 for inner diameter machining of a predetermined tool number is indexed by T0101 of sequence number 106, and the tool 18 for inner diameter machining is rotated by G00 X0 Z-0.5 of the next sequence number 107. a central positioning by moving by driving the X-axis servo motor 24 and the Z _T axis servo motor 26 in the + Z direction from the coordinate origin to the position of 0.5 mm (FIG. 4 (c)).

Next, the sequence number 108 Z15.0
F0.08 drives the Z _T- axis servo motor 26 to feed the inner diameter machining tool 18 in the + Z direction and move it 15.0 mm from the coordinate origin at 0.08 to perform inner diameter machining of the workpiece 14 (FIG. 4). (D)). By doing so, it becomes possible to perform the same processing as the conventional processing example shown in FIG. 5 without any restrictions on the processing steps.

Therefore, according to the spindle sliding NC lathe of this embodiment and the control method thereof, unlike the conventional setup of the spindle sliding NC lathe, the outer diameter of the workpiece is machined first. Then, it is also possible to freely perform the inner diameter processing. Even if the outer diameter machining of the workpiece is performed first, there is no need to return the spindle to the -Z axis direction when performing the inner diameter machining next, and instead the tool side can be moved in the + Z axis direction. Is. Therefore, the workpiece with the reduced outer diameter after the outer diameter machining is not returned to the rotary guide bush, and the problem that the rotary guide bush cannot hold the workpiece sufficiently and the workpiece is There is no problem of playing in the guide bush and scratching the machined surface.

The present invention is not limited to the above embodiment, but various modifications can be made. For example, although swap control is performed on the Z axis in the above embodiment, swap control can be performed on other axes, for example, a plurality of axes that can move in the X axis direction. Furthermore, a plurality of independent axes, for example, the X axis and Z
It is also possible to perform swap control between axes.

In the above embodiment, the main spindle sliding NC lathe is controlled by swap control.
It may control the C machine tool.

[0034]

As described above, according to the present invention, a linear movement axis that can move in the same direction as the linear movement axis of the main shaft is provided on the tool side, and both axes are alternately given while giving the same coordinate value. Since the control can be performed, it is possible to eliminate the restriction on the processing process that does not require consideration of the procedure of the outer diameter processing and the inner diameter processing.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a control method of a spindle sliding NC lathe according to an embodiment of the present invention.

FIG. 3 is a diagram showing a control program for a spindle sliding NC lathe according to an embodiment of the present invention.

FIG. 4 is a diagram showing an example of processing by a spindle sliding NC lathe according to an embodiment of the present invention.

FIG. 5 is a diagram showing an example of processing by a conventional spindle-sliding NC lathe.

[Explanation of symbols]

2 ... Bed 4 ... Z _S- axis feed screw 6 ... Z _S- axis servo motor 8 ... Spindle base 9 ... Spindle 10 ... Main motor 11 ... Belt 12 ... Cylinder 14 ... Workpiece 15 ... Rotary guide bush support stand 16 ... Rotary guide bush 18 ... Tool 20 ... Main turret 22 ... Index motor 24 ... X-axis servo motor 26 ... Z _T- axis servo motor 30 ... X-axis position control unit 32 ... Z _S- axis position control unit 34 ... Z _T- axis position control unit 36 ... PMC

Claims (3)

[Claims] 1. A spindle which holds and rotates a workpiece and is slidable in a Z _S axis direction which is a rotation axis direction of the workpiece, and a spindle which is located in front of the spindle and is rotated and held by the spindle. a rotation holding means for rotating and holding by penetrating the workpiece, the positioned in front of the rotary holding means, X-axis direction orthogonal to the Z _S axis direction and the Z _T axis direction and the Z _S axis direction in the same direction An NC machine tool, characterized by comprising tool holding means for movably holding a tool on both sides. 2. A holding and rotating the workpiece, and Z _S axis drive system the Z _S axis slidable main shaft is moved in the Z _S axis is the rotational axis of the workpiece, the A Z _T- axis drive system that moves a tool located in front of the spindle in the Z _T- axis direction, which is the same direction as the Z _S- axis direction, and a position control of the Z _S- axis drive system in response to a Z-axis direction movement command. A Z _S axis position control section for performing, a Z _T axis position control section for performing position control of the Z _T axis drive system in response to a movement command in the Z axis direction, the Z _S axis position control section or the Z _T axis An NC machine tool comprising: a drive axis switching means for issuing a drive stop command to one of the position control sections to drive only one of the Z _S axis position control section or the Z _T axis position control section. 3. A workpiece is held and rotated, and the workpiece is rotated.
The direction of the rotation axis of Z_SPosition of the spindle that can slide in the axial direction
The control is performed by the Z which receives the movement command in the Z-axis direction._SAxis position controller
By Z_SIt is carried out by driving a shaft drive system, and is located in front of the main shaft, and_SZ in the same direction as the axial direction
_TPosition control of a tool that can move in the axial direction is performed in the Z-axis direction.
Received the movement command of Z_TZ by axis position controller _TAxis drive
The system is driven and Z_SAxis position controller or Z_TOne of the axis position control units
The drive stop command to stop only Z_SAxial drive system
Or the above Z_TStop driving one of the shaft drive systems
Switch the drive system so that only one drive system drives.
NC machining characterized by performing machining in the Z-axis direction instead
Machine control method.