JP6249904B2 - Work processing control device for machine tool, work processing method using the control device, and work processing program - Google Patents

Description

  The present invention relates to a workpiece machining control device for a machine tool that turns a workpiece by cutting a tool in the X-axis direction and rotating the workpiece in the Z-axis direction while rotating the workpiece, a workpiece machining method thereof, and a workpiece machining program for executing the method About.

  In the turning of a workpiece in a machine tool, when the workpiece is a particularly difficult-to-cut material, there is a problem that the chip becomes longer without being cut and the tool life is shortened. As a conventional workpiece machining method that can avoid this problem, for example, there is a method disclosed in Patent Document 1. In this conventional method, when cutting the tool in the X axis direction and feeding it in the Z axis direction while rotating the workpiece, when the tool is moved forward by a predetermined distance in the Z axis direction, the tool is temporarily stopped there, and further retracted by a certain distance. It is moved and moved forward from there again, and this is repeated thereafter.

Japanese Patent Laid-Open No. 06-285701

  In the conventional method, it is said that chips can be divided and generation of continuous long chips can be prevented, but if the distance of the backward movement is too short, cutting of the chips is not sufficient and continuous chips are generated, It has been found that the problem of long processing time occurs if sufficient cutting of chips is ensured.

  In the conventional method, an intermittent stop function that temporarily stops after moving a predetermined distance is provided by the code Gg. 1 is specified as a special code that is not included in a general machine tool command code. Therefore, a general machine tool cannot be processed by the method described in the conventional method.

  The present invention has been made in view of the above-described conventional situation, and can be executed by a general machine tool, can reliably sever chips and extend the tool life, and can minimize the extension of the machining time. It is an object of the present invention to provide a workpiece machining control device for a machine tool, a workpiece machining method using the control device, and a machining program.

The invention according to claim 1 is a workpiece machining control device for a machine tool including a relative feed control unit that controls a drive unit that changes a relative position between a workpiece and a tool.
The relative feed control unit repeatedly executes forward feed control and reverse feed control of the drive unit in an exact stop mode.

  According to a second aspect of the present invention, in the work machining control apparatus for a machine tool according to the first aspect, the relative feed control unit moves the reverse feed distance in the reverse feed control during acceleration in the forward feed control. Alternatively, it is characterized in that it is larger than the deceleration distance that moves during deceleration and smaller than the sum of the acceleration distance, the deceleration distance, and the predetermined distance.

The invention of claim 3 is the machine tool control device for machine tools according to claim 1 or 2,
A work rotation control unit that controls a rotation driving unit that rotates the work;
The relative feed control unit controls the drive unit that changes a relative position between the work and the tool that are rotated by the rotation drive unit.

Invention of Claim 4 is the workpiece | work processing method using the workpiece processing control apparatus of the machine tool in any one of Claims 1-3,
In the exact stop mode, the forward feed control and the reverse feed control of the drive unit for changing the relative position between the workpiece and the tool are repeatedly executed.

  In the invention of claim 5, the computer repeatedly executes the forward feed control and the reverse feed control of the drive unit that changes the relative position between the workpiece and the tool in the exact stop mode, and the reverse feed distance in the reverse feed control is calculated as follows: A workpiece machining program for functioning as a relative feed control means that is larger than the acceleration distance moved during acceleration or the deceleration distance moved during deceleration in the forward feed control and smaller than the sum of the acceleration distance, the deceleration distance, and the predetermined distance. is there.

  Here, the exact stop mode in the present invention is instructed by the G09 code or G60 code, for example, as defined in JIS B6315-1, and the tool is decelerated at the end point of the block in which the G code is valid. This means a mode in which the next block is executed after it is confirmed that the position has been reached. Note that the exact stop mode usually prevents the tool from short-cutting the corner when moving the tool along the second axis after moving the tool along the first axis. It is used when you want to get the corner shape accurately. There was no prior art suggesting applying this exact stop mode to tool movement on a single axis.

  Further, the predetermined distance in the backward feed distance of the present invention is a distance experimentally set according to the material of the workpiece, the cutting property, etc., and is set to a value equal to or smaller than the normal acceleration distance and deceleration distance. .

  According to the first and fourth aspects of the present invention, the chips can be reliably detected with a general machine tool by repeatedly executing the forward feed control and the reverse feed control in the exact stop mode commanded by the control code of the general machine tool. It is possible to prevent the generation of continuous and long chips, and the tool life can be extended.

  Further, according to the inventions of claims 2 and 5, since the reverse feed distance in the reverse feed control is set larger than the acceleration distance or the deceleration distance in the forward feed control, the chips are surely divided to generate long continuous chips. Can be prevented and the tool life can be extended. Incidentally, when the backward feed distance is smaller than the acceleration distance or the deceleration distance in the forward feed control, the chips are not sufficiently divided and long continuous chips are likely to be generated.

  In addition, the reverse feed distance is set to be smaller than the sum of the acceleration distance, the deceleration distance and the predetermined distance in forward feed control, so that even for difficult-to-cut materials, the cutting time can be reliably divided while extending the machining time to a minimum. Can be suppressed.

It is a block block diagram of the workpiece processing control apparatus of the machine tool which concerns on Example 1 of this invention. It is a speed-position characteristic diagram for explaining forward feed distance and reverse feed distance in forward feed control and reverse feed control in exact stop mode. FIG. 3 is a velocity-position characteristic diagram showing a specific example of forward feed control and reverse feed control in FIG. 2. 3 is a workpiece machining program for executing forward feed control and reverse feed control in FIG. 2. It is a figure which shows the experimental result for demonstrating the effect in the said forward feed control and reverse feed control. It is a speed-position characteristic diagram which shows forward feed control and reverse feed control which concern on Example 2 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 5 are diagrams for explaining a workpiece machining control device for a machine tool, a workpiece machining method using the device, and a machining program according to Embodiment 1 of the present invention.

  In the figure, 1 is a machine main body, and 2 is a workpiece machining control device. The machine body 1 includes a spindle device 3 that rotates the workpiece W, a cutting device 4 that moves the tool T in the X-axis direction (workpiece radial direction), and a feed device that moves the tool T in the Z-axis direction (workpiece axis direction). And 5.

  The spindle device 3 includes a workpiece spindle 3a that grips the workpiece W and a spindle motor 3b that rotationally drives the workpiece spindle 3a.

  The cutting device 4 includes an X-axis ball screw 4a that moves the tool T in the X-axis direction, and an X-axis drive servo motor 4b that rotationally drives the X-axis ball screw 4a.

  The feeding device 5 includes a Z-axis ball screw 5a that moves the tool T in the Z-axis direction, and a Z-axis drive servomotor 5b that rotationally drives the Z-axis ball screw 5a.

  The workpiece machining control device 2 controls the spindle motor 3b so that the rotation speed of the workpiece W becomes a command value, and the X-axis drive servo motor 4b controls the cutting amount or cutting of the tool T. The tool cutting control unit 7 that controls the speed to be in a desired state and the Z-axis drive servo motor 5b are used to move the relative position between the workpiece and the tool so that the feed speed and feed amount of the tool T in the Z-axis direction are in the desired state. And a relative feed control unit 8 for controlling.

  The relative feed control between the tool T and the workpiece W by the relative feed control unit 8 will be described in more detail with reference to FIG.

  In this relative feed control, forward feed control (first block) and reverse feed control (second block) are alternately repeated in the exact stop mode.

  In the forward feed control, the tool is accelerated in the forward direction at the first acceleration α1 to the maximum forward speed Vfmax, and after maintaining this speed for a predetermined time, it is decelerated at the first deceleration β1 to zero speed. It is confirmed that the rotation speed of the Z-axis drive servomotor 5b has become zero, and a predetermined forward feed distance Lf is secured (first block).

  When it is confirmed that the commanded position has been reached when the rotational speed of the Z-axis drive servomotor 5b becomes zero, the reverse feed control is subsequently started, and the servomotor 5b is accelerated and rotated in the reverse direction. The tool T is accelerated in the reverse direction at the second acceleration α2 to obtain the maximum reverse speed Vbmax, and after maintaining this speed for a predetermined time, it is decelerated at the second deceleration β2 and the commanded position when the speed is zero. Is confirmed, and a predetermined backward feed distance Lb is secured (second block).

  In the reverse feed control, the reverse feed distance Lb is larger than the acceleration distance Lα1 that moves during acceleration in the forward feed control or the deceleration distance Lβ1 that moves during deceleration, and the deceleration distance Lβ1, the acceleration distance Lα1, and the predetermined distance Lbmin. Is set smaller than Lb.

  Here, as shown in FIG. 3, the first block and the second block are alternately repeated until the substantial feed distance Le (= forward feed distance Lf−reverse feed distance Lb) reaches the machining full length.

The first acceleration α1 and the second acceleration α2, and the first deceleration β1 and the second deceleration β2 are normally set to the same value. The maximum reverse speed Vbmax is set to be equal to or lower than the maximum forward speed Vfmax. Furthermore, the predetermined distance Lbmin is set for turning of a material in which chips such as difficult-to-cut materials are difficult to cut.

FIG. 4 is a diagram for explaining a workpiece machining program for executing the workpiece machining method in FIG.

This workpiece machining program is used to load the computer of the workpiece machining control device 2 into the workpiece W
The workpiece rotation control unit 6 for controlling the rotation of the tool, the tool cutting control unit 7 for controlling the cutting of the tool, and the forward feed control and the reverse feed control by the Z-axis drive servomotor 5b in the exact stop mode are repeatedly executed. The reverse feed distance Lb in the reverse feed control is larger than the acceleration distance Lα1 or the deceleration distance L β1 that moves during acceleration in the forward feed control, and smaller than the sum of the deceleration distance Lβ1, the acceleration distance Lα1, and the predetermined distance Lbmini. This is a program for causing the relative feed control unit 8 to function.

Specifically, in FIG. 4, # represents a code representing a machining condition (set value), G represents a code for instructing machining content, and details are as follows, for example.

Because # 1 = 0.45, forward feed distance = 0.45 mm
With # 2 = 0.03, the reverse feed distance = 0.03 mm
Because # 102 = 0.15, forward feed amount = 0.15mm / rev
With # 103 = 0.2 (BACK FEED), the reverse feed amount = 0.2 mm / rev is set.

Then, G09G1W- # 1F # 102 commands forward feed command = # 1 = 0.45mm and forward feed amount # 102 = 0.15mm / rev in the negative Z-axis direction,
Also, G09G1W # 2F # 103 commands reverse feed command = # 2 = 0.03 mm and reverse feed amount # 103 = 0.2 mm / rev in the positive Z-axis direction. In this embodiment, as shown in FIG. 1, the forward feed of the tool is in the left direction (Z-axis negative direction).

  According to this embodiment, since the forward feed control and the reverse feed control are repeatedly executed in the exact stop mode, specifically, the maximum forward speed Vfmax in the forward feed control is decelerated by the first deceleration β1 and the speed becomes zero. When it is confirmed that the commanded position has been reached, the reverse feed control is started, and the reverse feed distance Lb in the reverse feed control is set larger than the deceleration distance Lβ1 in the forward feed control. It can be surely divided and it can be prevented that continuous long chips are generated, and as a result, the tool life can be extended. Incidentally, when the backward feed distance Lb is smaller than the deceleration distance Lβ1 in the forward feed control, the chips are not sufficiently divided and long continuous chips are likely to be generated.

  Further, since the backward feed distance Lb is set to be smaller than the sum of the acceleration distance Lα1, the deceleration distance Lβ1 and the predetermined distance Lbmin in the forward feed control, it is possible to suppress the extension of the machining time while reliably dividing the chips.

  Here, when a difficult-to-cut material is machined by the conventional method, as shown in FIG. 5 (b), compared to the tip a of the cutting edge T 'of the tool T, the base end side is slightly more than the tip a (the same figure). Wear of the boundary portion b between the portion where the workpiece located on the left side) and the cutting edge are in contact with the portion where it is not in contact is increased. On the other hand, in the method of the present invention, when the workpiece moves backward, the workpiece and the cutting edge T ′ are separated from each other and the cutting oil enters the gap, thereby obtaining a cooling effect and a lubricating effect, as shown in FIG. Moreover, the wear of the boundary portion b can be suppressed. FIG. 5A shows the cutting edge T ′ before processing.

Further, the longer the distance the tool T is rubbed against the workpiece, the shorter the life of the cutting edge T 'becomes. Since the length is not increased, the life of the cutting edge T can be extended.

  FIG. 6 is a diagram for explaining a second embodiment of the present invention. In the second embodiment, the reverse feed distance Lb is set to a value slightly larger than the deceleration distance Lβ1 that moves during deceleration in the forward feed control. It is an example when set.

  That is, in the backward feed control in the second embodiment, the tool T is accelerated in the backward direction at the second acceleration α2 until the backward feed distance becomes slightly larger than the deceleration distance Lβ1 × 1/2, and then the second deceleration β2. Decelerate to zero speed. After confirming that the commanded position has been reached when the speed is zero, forward feed control is started.

In the second embodiment, since the backward feed distance Lb is set to a value slightly larger than the deceleration distance Lβ1, it is possible to minimize the extension of the machining time while reliably cutting off the chips.

In the first embodiment, an example of a workpiece machining program transmitted / received via a communication circuit such as the Internet has been described. However, the workpiece machining program of the present invention is stored on a computer-readable recording medium (CD-ROM or the like). It may be recorded and traded.

1 Machine tool body 2 Work machining control device (computer)
6 Work rotation controller (work rotation control means)
7 Tool cutting control part (Tool cutting control means)
8 Relative feed control unit (relative feed control means)
Lb Reverse feed distance Lα1 Acceleration distance LB1 Deceleration distance Lbmin Predetermined distance T Tool W Workpiece

Claims (5)

In a workpiece machining control device of a machine tool provided with a relative feed control unit that controls a drive unit that changes a relative position between a workpiece and a tool,
The relative feed control unit repeatedly executes forward feed control and reverse feed control of the drive unit in an exact stop mode. In the machine tool control apparatus of the machine tool according to claim 1,
The relative feed control unit is configured such that a reverse feed distance in the reverse feed control is larger than an acceleration distance moved during acceleration or a deceleration distance moved during deceleration in the forward feed control, and the acceleration distance, the deceleration distance, and the predetermined distance. Machine tool control device for machine tools characterized by being smaller than the sum. In the work processing control apparatus of the machine tool according to claim 1 or 2,
A work rotation control unit that controls a rotation driving unit that rotates the work;
The work feed control unit for a machine tool, wherein the relative feed control unit controls the drive unit that changes a relative position between a work and a tool that are rotated by the rotation drive unit. A workpiece machining method using the workpiece machining control device for a machine tool according to any one of claims 1 to 3,
A workpiece machining method comprising repeatedly executing forward feed control and backward feed control of a drive unit that changes a relative position between the workpiece and a tool in an exact stop mode. The computer repeatedly executes forward feed control and reverse feed control of the drive unit that changes the relative position between the workpiece and the tool in the exact stop mode, and the reverse feed distance in the reverse feed control is determined by the acceleration in the forward feed control. A work machining program for functioning as a relative feed control means that is larger than a moving acceleration distance or a deceleration distance that moves during deceleration and smaller than a sum of the acceleration distance, the deceleration distance, and a predetermined distance.

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