JP3342589B2 - Machining method using NC lathe and method for creating machining program - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an NC comprising a plurality of spindles, a plurality of tool rests which can be machined in combination with the respective spindles, a single back spindle and a rear tool rest which can be machined in combination therewith. The present invention relates to a machining method using a lathe and a machining program creating method.

[0002]

2. Description of the Related Art In an NC (numerical control) lathe, a spindle is rotated according to a machining program and its spindle center line direction (Z
Direction) and the movement of the tool rest in the X and Y directions (two directions orthogonal to each other in a plane orthogonal to the Z direction).
A machine tool that processes the material (work) held on the spindle with a tool (knife) attached to the tool post,
Recently, CNC lathes equipped with computers are becoming mainstream.

[0003] In such NC lathes, the processing speed has been increased, the processing efficiency has been improved, the processing accuracy has been improved, and the functions have been expanded (versatility), flexibility and safety have been improved. Measured and used in a wide range of component processing. The NC spindle lathe or automatic lathe has a spindle arrangement of a single spindle with only one spindle for face machining, a dual spindle with two spindles,
There are a large number of multi-axes and the like, and some have a back main spindle used for back machining opposite to the main spindle for front machining.

In a conventional NC lathe having a back spindle and a single spindle, as shown in FIG. 2A, after the machining process on the spindle side is completed, the workpiece is delivered to the back spindle side to perform back machining. When all the machining steps for one work are completed, and the machined work is transferred to the back spindle on the spindle side, machining of the next new work is started.

A conventional two-axis NC with a back spindle
The lathe has two main spindles and two rear main spindles opposed to the respective main spindles. As shown in FIG. 2B, the same processing as the above-described machining process using the single-axis NC lathe is performed. Spindle 1
And the back spindle 1 and the back spindle 2 and back spindle 2 at the same time, and it takes 2 hours to process two workpieces with a single-axis NC lathe.
Four times as many workpieces can be machined.

On the other hand, a multi-axis automatic lathe has a large number of spindles,
A high productivity can be obtained by causing each of the spindles to grip a workpiece and simultaneously executing different processing steps as shown in FIG. 2C. This multi-spindle automatic lathe usually has a tool rest which has four to eight spindles which are indexed and rotated, and which can be moved relatively to a position where each spindle is indexed and rotated. Then, processes necessary for processing one work are distributed to each of the indexed spindle and the tool post, and multiple processes are executed simultaneously while indexing the spindle. That is, each time the spindle is indexed, machining of one work is completed.

A multi-spindle NC automatic lathe that achieves high productivity by causing a plurality of spindles to grip a workpiece without performing indexing of the spindles and simultaneously executing the same process on all the spindles, for example, as shown in Japanese Utility Model Application The one found in JP-A-51-10462 is proposed.

This multi-axis NC automatic lathe moves in the Z-axis direction parallel to the main-axis center line and the X-axis and Y-axis directions orthogonal to the Z-axis direction with respect to six main axes provided in parallel with each other. A possible tool post is provided, which tool post is provided with a plurality of tools facing each spindle. Therefore, six sets of tools opposed to the six spindles move at the same time according to the movement of the tool rest, and the same machining process is simultaneously performed on all the spindles, thereby completing the machining of six workpieces at once. .

[0009]

However, in the case of the above-described single-shaft NC lathe, the productivity cannot be increased more than the machining speed on the main spindle side and the back main spindle side. 2-axis N
The use of a C lathe can achieve twice the productivity of a single spindle, but the number of spindles and back spindles also doubles.
It is not much different from using two single-spindle NC lathes, and there is little cost advantage. Therefore, Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent Application Publication No. 8802, there has been proposed an apparatus in which two main spindles are driven to rotate by a common drive source. In this case, however, the machining steps by both main spindles must be exactly the same. There is a problem that the degree of freedom is limited.

The conventional multi-spindle automatic lathe has a very complicated and large-sized machine and is difficult to operate and set up. Therefore, it is used only for mass production. In addition, since numerical control (NC) requires many control axes, the machining program becomes extremely complicated. Further, when the processing contents of each axis are different, FIG.
As shown in (1), there is a difference in the processing time, and a waiting time occurs in a spindle having a short processing time, so that the maximum efficiency cannot be obtained.

On the other hand, in the above-described multi-axis NC automatic lathe, since the same process of the same work must be processed by a plurality of tools at the same time, the relation between the spindle and the tools is set to be the same for all the spindles. The tool must be set and tooling is very difficult. In addition, since independent tool correction cannot be performed for each tool even with NC, tooling remains very difficult.

The present invention solves the problems of various conventional NC lathes or automatic lathes, and uses a two-spindle, one-back-spindle NC lathe to perform machining with high productivity at a small increase in cost. A first object is to be able to perform the processing, and a second object is to efficiently create a machining program therefor.

[0013]

According to the present invention, there is provided a first spindle and a second spindle having a spindle center line parallel to each other and fixed in position, and provided at a predetermined interval. A first turret and a second turret that can be machined in combination with the first main spindle and the second main spindle, respectively, are disposed opposite to the first main spindle and the second main spindle, and connect the axes of the two main spindles. The present invention is directed to an NC lathe provided with a back spindle that can move relatively in a direction and a direction that approaches and separates from the two spindles, and a back tool rest that can be machined in combination with the back spindle. In order to achieve the first object, the following machining method using the NC lathe is provided.

As shown in FIG. 1, all the machining steps for one work are executed by the machining step on the first spindle side and the machining step on the back spindle side, and the machining step on the second spindle side and the back spindle side. All the machining steps for one other work are executed by the machining process of the above, so that the machining time on the back spindle side is reduced to half or slightly shorter than the machining time on each spindle side. It is divided into the main spindle side and the rear main spindle side.

Furthermore, the processing steps of the spindle side, the Engineering
When the first half is completed and the first half is completed, another work is started on the second spindle and the first spindle is processed. When the latter half of the process is completed, the work is delivered to the back spindle side and the machining process on the back spindle side is executed, and the machining process of a new work is started on the first spindle side,
When the second half of the machining process on the second spindle is completed, the work is delivered to the rear spindle and the machining process on the rear spindle is executed, and the machining process of a new workpiece is started on the second spindle. Thereafter, the work after the completion of the latter half of the first spindle machining step is repeated.

Further, in order to achieve the second object, the present invention provides the following machining program creating method as the NC lathe machining program creating method. N
Create a part program which is a normal program of C machining, summarize the part program as a process subprogram for each machining process, calculate the machining time for each process subprogram, and then put all the process subprograms on the back The machining process on the spindle side is divided into a spindle side process and a back spindle side process so that the machining time on the spindle side is half or less than the machining time on the spindle side.

Furthermore, the spindle-side process divided into a first half and a second half in the above step subprogram units, the first spindle, the second
A program system is provided for each of the main spindle and the back spindle. The program system of the first main spindle has the sub-processes of the main spindle side process in the first half and the latter half, and the program sub-system of the second main spindle has the process of the main spindle side process. The sub-programs are arranged in the order of the latter half and the former half, and in the program system on the back spindle side, the process sub-programs of the back spindle side process are arranged in the order of the processes to form machining programs.

Also, a program number may be assigned to each of the process sub-programs, and the program number may be designated for each of the program systems to form a machining program. Then, before calculating the machining time for each of the process subprograms, it is preferable to perform a tool layout for determining the types of tools to be attached to the first and second turrets.
According to the tool layout, the first tool post and the second tool post are switched so that the machining with the tool of the first tool post and the machining with the tool of the second tool post are switched between the first half and the second half of the process subprogram of each spindle side process. The tool layout of the tool post can be determined.

The process subprogram of the spindle-side process is divided in units of process subprograms at half of the total machining time, and if it cannot be divided , the process subprogram spanning before and after the half is divided into two. If a separate process subprogram is used, the spindle-side process can be divided into the first half and the second half.

[0020]

The machining method using the NC lathe according to the present invention uses one (1) main spindle alternately with two (front) main spindles, that is, as shown in FIG. Perform the same machining by shifting the machining process by half a cycle with the spindle, move the work to the back spindle as soon as the machining is completed, and perform the same back machining on the workpiece received from any spindle in the machining process on the back spindle As a result, the machining efficiency of one type of part is twice as large as that of one axis (two spindles,
(Equivalent to using an NC lathe with two back spindles). In addition, since only one back spindle is required, the cost increase can be reduced. In this case, the tool layout of the first tool post and the tool post of the second tool post may be made different, and the combination of the first spindle and the second spindle may be exchanged between the first half and the second half.

Even when two types of parts are simultaneously machined, the machining process is divided so that the machining time on the back spindle side of each part is half or less than the machining time on each spindle side. If possible, the processing time according to the present invention can be shortened in the same manner as in the case of processing one type of component.

According to the NC lathe machining program creation method according to the present invention described above, the part program can be created without being conscious of the axis or tool post to be used, as in the case of the single axis. The program of the spindle system and the back spindle system is created with reference to the machining time of each process from the above, and the program of the spindle system is divided into two and the first half and the second half are exchanged, so that the first spindle system and the second spindle system are replaced. Therefore, three systems of machining programs for each axis can be easily created.

If a tool layout for determining the types of tools to be attached to the first and second turrets is performed before calculating the machining time for each step, a highly accurate machining time including the tool selection time can be obtained. Can be calculated.
As a result, the accuracy of dividing the subsequent whole process program into the main spindle side process and the rear side process, and dividing the main spindle side process into the first half and the second half becomes high.

In the case of an NC lathe having an interactive automatic programming function,
Although it can be easily created using the function of the C lathe itself, it can also be created using another system such as a personal computer for creating an NC machining program.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. FIG. 3 is an external perspective view showing an example of an NC lathe for implementing the processing method according to the present invention.

This is a headstock sliding type NC lathe for machining a bar material, and has two spindles and one back spindle. That is, as shown in FIG. 3, a first headstock 11A and a second headstock (not shown) are provided in the rear part of the upper surface of the bed 10 in a Z-axis direction (arrows Z1 and Z2 directions) parallel to the spindle center line. The first headstock 11A and the second headstock are slidably mounted along a guide rail (not shown). The first headstock 11A and the second headstock are respectively driven by a Z1-axis servomotor (not shown) and a Z2-axis servomotor (not shown). It is moved in the directions of arrows Z1 and Z2 independently of each other via a mechanism.

The first headstock 11A is rotatably supported by the first headstock 11A and the second headstock, and is independently rotated by a first spindle motor 12A and a second spindle motor (not shown). (Only the center line is indicated by A) and the second main axis (only the center line is indicated by B) are provided in parallel with each other at a predetermined interval.

In front of the first main spindle and the second main spindle, a tool rest base 13 is fixed to the bed 10 and stands upright over its entire width. The tool rest base 13 has a first position at a position concentric with the respective center lines of the first and second spindles.
A guide bush 14A and a second guide bush 14B are provided, and the workpieces 15A and 15B gripped by the first and second spindles are slid in the Z-axis direction by the first and second guide bushes 14A and 14B. Guided movably.

The tool rest base 13 is further provided on both sides of a line (hereinafter referred to as a "reference straight line") L which intersects orthogonally with both center lines A and B of the first and second spindles (the upper side in FIG. 3). The first tool rest 17A and the second tool rest 17B are disposed on the lower and upper sides, respectively. The first and second turrets 17
A and 17B are guide rails 16 formed on the front surface of the tool rest base 13 in parallel with the reference straight line L over the entire width thereof.
A, 16B, which are fitted to A, 16B and slide in a Y-axis direction (Y1, Y2 directions indicated by arrows) parallel to the reference straight line L.
A and 18B are mounted on X-axis tables 19A and 19B which slide in X-axis directions (X1 and X2 directions) orthogonal to both the Y-axis and the Z-axis.

The Y-axis table 18A is moved in the direction of the arrow Y1 by a Y1-axis servomotor 20A mounted on the tool rest base 13, and the Y-axis table 18B is driven by the Y2-axis servomotor 20B mounted on the tool rest base 13.
Are driven along the guide rails 16A and 16B by the feed screw mechanism in the direction indicated by the arrow Y2, and can reciprocate over substantially the entire length thereof.

The X-axis table 19A is a Y-axis table 18A
The X-axis table 19B is moved in the X1 direction with respect to the Y-axis table 18A by the X1-axis servo motor 21A attached to the Y-axis table 18B by the X2-axis servo motor 21B attached to the Y-axis table 18B. In the direction, each is driven by a feed screw mechanism and is capable of reciprocating a predetermined stroke.

Each of the first and second tool rests 17A, 17B has a plurality (four in the illustrated example) of tools 22A,
, 22B,... Are attached in a comb-like shape at predetermined intervals in the Y-axis direction. In the illustrated example, the tool 22A,
, 22B,... Indicate the case where each of them is an outer diameter cutting tool such as a cutting tool.

Further, a rear tool post 23 is fixed to the tool post base 13 at an extended position of the reference line L at the right end in FIG. 3, and a plurality of (three in the illustrated example) are provided on the rear tool post 23.
Are arranged such that their centers are arranged at predetermined intervals on the extension of the reference line L. This tool 24, ...
Is a tool for back processing, for example, a relative rotary tool such as a drill and an end mill. Even if the tools 24,... Do not necessarily rotate, they can be processed by rotating a work chucked to a back spindle described later.

On the front side of the tool rest base 13 of the bed 10, a groove 10a is formed over the entire width in the Y-axis direction, and the upper surface of the step portion on the front side of the groove 10a is parallel to the reference line L. Forming a guide rail 25 extending in the direction
A rear headstock base 26 is slidably fitted to the guide rail 25, and a rear headstock 27 is slidable thereon in the arrow Z3 direction parallel to the center line of the rear main shaft provided therein. Is provided. The direction of the arrow Z3 is parallel to the directions of the arrows Z1 and Z2, which are the moving directions of the first and second headstocks described above.

The back headstock base 26 is moved by a Y3-axis servomotor 28 attached to the bed 10 through a feed screw mechanism (not shown) in the direction indicated by the arrow Y3 (the direction orthogonal to the direction indicated by the arrow Z3 in the horizontal plane). Driven, bed 10
Can be reciprocated over substantially the entire width of. Rear headstock 27
Is driven by a Z3-axis servomotor 29 attached to the rear headstock base 26 via a feed screw mechanism (not shown), and is capable of reciprocating a predetermined stroke in the arrow Z3 direction with respect to the rear headstock base 26.

The rear spindle provided inside the rear spindle head 27 has a center line at the height of the reference line L, a tip end provided with a chuck for gripping a work, and a spindle motor 30 for the rear spindle. Rotated by The work held on the back spindle is mainly the back tool post 2 described above.
3 are attached to the first tool post 17A or the second tool post 17B. If a tool for back processing is attached to the first tool post 17A or the second tool post 17B, it is also possible to carry out machining with them.

Further, an opposed turret 31 is fixedly provided on the left side surface of the rear headstock 27 in FIG. 3, and a plurality of (three in the illustrated example) tools 32,. At the same height, they are mounted so as to be arranged at predetermined intervals in the direction of arrow Y3. These tools 32,... Are also relatively rotating tools such as drills and end mills, and can perform drilling, thread cutting, and the like on the front end face of a rotating work held on the first or second spindle. It is.

Here, the minimum necessary configuration of the NC lathe is a first lathe provided in parallel with each other and separated by a predetermined distance.
A main shaft and a second main shaft (provided behind the turret base 13 and their center lines A and B), and a first turret 17A and a second turret that can be processed in combination with the first main shaft and the second main shaft, respectively. and the base 17B, disposed opposite to the first spindle and the second spindle, the direction of approach and away from the both spindles and a direction connecting the axial center of the both spindles (arrow Y 3 direction) (an arrow Z3 ), And a back tool rest 23 that can be machined in combination with the back spindle.

A process for processing a workpiece (part) having a shape shown in FIG. 4 from a material of a round bar by using the NC lathe according to the present invention will be described. FIG. 5 shows an example of a tool layout of the first and second tool rests 17A and 17B, the rear tool rest 23, and the opposed tool rest 31 in this case.
The work W shown in FIG. 4 (work 15A, 1 shown in FIG. 3)
5B) are shaded, and the respective tools are denoted by 1 to 12 (circled numbers in the figure).

Each tool name is as follows. 1: Center drill, 2: Drill, 3: Front turning tool,
4: Thread cutting tool, 5: Front turning tool, 6: Grooving tool, 7: End mill, 8: Back turning tool, 9: Cut off tool, 10: Back center drill, 11: Back drill, 12: Back tap

The round bar material is previously guided through the first and second spindles of the NC lathe shown in FIG. 3 and guided by the first guide bush 14A and the second guide bush 14B to slightly project. Then, the first spindle side having the first guide bush 14A and the second guide bush 14B perform the simultaneous machining by shifting the machining process by a half cycle.

The machining process will be described for the work on the first spindle side. First, the opposite tool post 31 is attached to the center of the front end face of a round bar (work W) chucked by the first spindle and protruding from the first guide bush 14A. The back spindle 27 is moved so that the center drill 1 faces the first spindle spindle motor 12A, and the first spindle is rotated by the first spindle spindle motor 12A.
While rotating the first headstock 11A or the back headstock 2
7 is moved in the Z-axis direction to make a center hole in the front end face of the work W. Next, the same operation as described above is performed using the drill 2 of the opposed tool post 31, and a hole having a predetermined inner diameter and a predetermined depth is formed in the front end of the work W.

Thereafter, the first tool rest 17A is moved so that the front cutting tool 3 is positioned on the center line A of the first spindle.
The workpiece W is lowered in the direction indicated by the arrow X1 to process the outer periphery of the thread portion of the work W into a predetermined diameter and length. And the first tool post 17A
Thread the outer periphery using a threaded cutting tool 4.

Next, after the large diameter portion of the work W is machined to a predetermined diameter using the front cutting tool 5 (same as 3) of the first tool post 17A, the first tool post 17A is moved toward the second spindle. , Second
The tool post 17B is moved to the first spindle side to switch the combination of the spindle and the tool post. Then, a groove having a predetermined depth is cut at the rear portion of the large-diameter portion of the work W using the grooving bit 6 of the second tool post 17B, and then the work W is fixed and the end mill 7 is used. Is reciprocated in the direction of the arrow X1 to form a plane portion parallel to a position facing the outer periphery of the large diameter portion behind the groove of the work W. Then, the work W is rotated again, and the rear small diameter portion is machined into a predetermined diameter by using the rear cutting tool 8 of the second tool rest 17B.

Thereafter, the rear headstock 27 is moved in the direction indicated by arrow Z3 to hold and hold the front end of the work W with the chuck of the rear spindle.
7B is reciprocated in the direction of arrow X1 to perform cut-off processing, and the work W is cut off from the round bar. This delivery of the work W is called pick-off.

Then, the rear headstock 27 is moved to the rear tool post 23.
Then, the back spindle is rotated and the back spindle is rotated, and a center hole is made in the back (rear end face) of the work W using the back center drill 10. Further, a hole having a predetermined inner diameter and a predetermined depth is formed by using the back drill 11, and a tap is cut on the inner periphery thereof by using the back tap 12, thereby completing the entire machining process for the work W.

The machining of the same work as that of the first spindle is performed in the second
On the main spindle side as well, the processing is started with a half cycle delay as described with reference to FIG. 1, and the processing on the back main spindle side is started after all the first processes on the first main spindle side are completed. Thereafter, each time the work is completed on the first spindle side and the second spindle side, the work is received on the back spindle side and the back processing is performed alternately within a half cycle of all the processes on the spindle side.

FIG. 7 shows the relationship between the use order of each tool described above and the time required for each machining on each axis side in the second and subsequent cycles according to this embodiment. In this figure, # 1 indicates machining on the first spindle side, # 2 indicates machining on the second spindle side, # 3 indicates machining on the back spindle side, and the numbers with circles indicate the reference numerals of tools used as in FIGS. , # 3 is a process of gripping and receiving a workpiece cut off on the first spindle side or the second spindle side on the rear spindle side. The vertical axis is time (seconds), and the length of each hatched frame in the vertical direction is proportional to the processing time by each tool (indicated by a circled number in the frame).

As described above, in this embodiment, the time required for the back spindle side machining step (including the pick-off step) is less than half the time required for the first and second spindle side machining steps. Efficiency is closer to half because the waiting time is reduced. If it exceeds half, a waiting time will occur on the spindle side, but if it is slightly longer, there is no practical problem. In order to shift the machining steps on the first spindle side and the second spindle side by a half cycle, if all the steps are divided so that the former half and the latter half are exactly 1/2 (1: 1) as in this embodiment. It is ideal, but if it is divided into about half, there will be no problem even if there is a slight difference, with only a little waiting time.

FIG. 6 shows an example of another tool layout for processing the work shown in FIG. Back turret 2
3 includes back surface processing tools 10 to 12 as in the example of FIG.
Are attached but are not shown. In this example, the opposed tool post 31 is not used, and all the tools 1 to 9 necessary for machining on the first and second spindle sides are attached to the first tool post 17A and the second tool post 17B, respectively. The center drill 1 and the drill 2 are attached via a tool holder 33 so as to face the front end face of the work W in a direction orthogonal to the paper surface. Therefore, according to this tool layout,
Since there is no need to replace the first tool rest 17A and the second tool rest 17B during the machining process on the first spindle side and the second spindle side, the machining time can be shortened accordingly.

Next, the configuration of the control unit of the NC lathe shown in FIG. 3 will be described with reference to the block diagram of FIG. The control unit includes a system control unit 40 including a CPU, a program input unit 41, a keyboard 42a, and a switch 42.
b, an operation panel 44 having a display 43, an input / output control unit 45 thereof, and a system control program memory (RO).
M) 46, an automatic programming unit 47, a machining program memory 48, a display data storage unit 49, a RAM 50 for storing other data, a machining program processing unit 51, a communication control unit 52, and a machining operation control unit 53, A drive unit 60 that directly drives and controls the mechanism unit shown in FIG. 3 via the operation control unit 53 is controlled.

The drive section 60 is provided with a servomotor (20A, 20B, 21A, 21B, 28, 29) for each axis shown in FIG.
Etc.), a control drive unit 62 for each axis for driving and controlling a servo mechanism 61 for each axis motor, and a spindle motor (12
A, 30 etc.) 63 includes a spindle motor control drive section 64 for controlling the drive, a sensor input section 66 for inputting a detection signal of each sensor (rotational speed sensor of each spindle motor, position sensor of each table, etc.) 65 and the like. .

The system control section 40 is a section for controlling the entire control unit, that is, the entire NC lathe. The automatic programming section 47 is used to create a machining program according to the present invention, and the machining program created together with the machining program processing section 51. Processing such as system identification, conversion, division, editing, etc., input of data and commands from the keyboard 42a or switch 42b of the operation panel 44 via the input / output control unit 45, and processing related to processing programs and other displays on the display 43; Based on the machining program stored in the machining program memory 48 together with the machining operation control section 53, the drive section 60 is operated to perform processing for performing NC machining.

The program input section 41 is a paper tape reader or a floppy disk device (FDD) for inputting a processing program created by an external program creating device (a personal computer or the like) from a paper tape or a floppy disk. The operation panel 44 issues an operation command from the keyboard 42a or the switch 42b when performing the NC processing.
A driving operation means for confirming the operation based on the display on the display 43. The automatic programming unit 47
When the machining program necessary for the NC lathe itself is created by using the function (1), it becomes an interactive input means for performing interactive automatic programming.

The input / output control unit 45 determines commands and inputs from the keyboard 42 a or the switch 42 b of the operation panel 44, and controls the display data stored in the display data storage unit 49 on the display 43. Do. The system control program memory 46 is a ROM that stores programs and fixed data used by the CPU of the system control unit 40 to control the operation of the control unit.

The automatic programming unit 47 includes an operation panel 44
A function unit for creating a machining program according to the present invention, which is actually a function of the system control unit 40, is shown as another block for easy understanding. The machining program memory 48 includes a machining program storage unit 48a for storing a part program and a process subprogram to be described later, a process editing program storage unit 48b for storing a process editing program created by the method according to the present invention, and a backup used when a trouble occurs. Backup program storage 48 for storing programs
c and the like.

The display data storage section 49 is a memory (RAM) for storing various data to be displayed on the display 43 of the operation panel 44, and also stores process subprogram display data and process edit program display data corresponding to each axis system. It is stored here. The RAM 50 is a memory that stores data of each tool (tool) used for machining, various initial set data, and the like. If the storage capacity of the RAM 50 is sufficient, the machining program memory 48 and the display data storage unit 49 can also be used.

The machining program processing section 51 is a functional section for performing processing such as system identification, conversion, division, and editing of the created machining program.
This is a function that 0 has. The communication control unit 52 is a circuit that controls communication with an external system such as a DNC device. The communication control unit 52 transfers the created machining program to the external system and stores the created machining program in the storage medium, or fetches the machining program from the external system. Used when

Here, a method of creating a machining program according to this embodiment will be described. Creating a machining program
As described above, it is created by the system control unit 40, the automatic programming unit 47, and the operation panel 44 of the control unit shown in FIG. The creation procedure at that time is shown in the flowchart of FIG. FIG. 10 shows an example of the created part program and its process subprogram, and FIG. 11 shows an example of the process editing program.

According to the flowchart of FIG.
First, a part program which is a normal program of NC machining is created.
It is stored in the machining program storage section 48a of the machining program memory 48 shown in FIG. This part program is created by an external device, fetched from the program input unit 41 or the communication control unit 52, and stored in the machining program storage unit 4
8a.

This part program is, for example, shown in FIG.
As shown in FIG. 1A, a series of programs are described in the order of operation without considering which spindle side is to execute a program of each process necessary for processing one target part. Here, a code consisting of N and a four-digit number such as N0010 and N0020 is a program number for each process. G
00, the code marked with digits after the G as G50 indicates the command contents of the preparation function (G function), G00 is fast forward,
G50 indicates an offset position.

[0062] M03, encoding the auxiliary functions marked with digits after M as M06 (G function), i.e. including performing ON / OFF of a motor other than a servo motor, the actual function to perform some action In the contents of the command, M03 commands clockwise rotation of the spindle, and M06 commands tool change. S5
A code consisting of S and a four-digit number, such as 200, is a code for an S function for selecting the rotation speed of the spindle, and S5200 is a command for setting the rotation speed of the spindle to 5200 rpm.

The numbers with decimal points after X, Y, Z are
The moving distance in each of the X, Y, and Z directions is shown, and the sign of the numerical value indicates the positive moving direction. The value after F commands the feed rate. A code following T followed by a number indicates a tool selection command . This part program is compiled as a process subprogram for each machining process (for each program number such as N0010 and N0020) as shown in FIG. 10B.

Then, the processing time for each process subprogram is calculated. The machining time can be calculated based on the feed speed and the feed distance of the work or tool described in the process subprogram and the initial data stored in advance, but before calculating the machining time for each process subprogram. , The first tool post 17A and the second tool post 17B
By performing a tool layout that determines the type of tool to be mounted on the tool, it is possible to calculate the machining time in consideration of the time required for actual tool change.

The calculated machining time for each process subprogram and the accumulated machining time can also be displayed on the display 43 of the operation panel 44. An example of the display will be described later. Thereafter, it is determined whether or not the machining time of the entire process subprogram is divided into about 2: 1 on the main spindle side and the back spindle side. This may be automatically determined by the system control unit 40, or the operator may input a result determined by looking at the accumulated machining time displayed on the display 43.

If the processing is divided, all the process sub-programs are processed so that the machining time on the spindle side and the back spindle side is about 2: 1.
Then, a process editing program is created by dividing into a main spindle system and a rear main spindle system. Further, it is determined whether or not the process editing program of the spindle system can be divided into process subprogram units at approximately half of the total machining time. This determination is also made automatically or by interactive input as in the above-described determination.

In the case of division, the process editing program of the main spindle system is divided into the first half and the second half so that the processing time is approximately 1: 1. Is created and stored in the process editing program storage unit 48b of the machining program memory 48 as a machining program on each axis side.

FIG. 11 shows an example of the result of the creation of the process editing program. Here, the spindle systems 1, 2, and 3 are a first spindle system, a second spindle system, and a rear spindle system, respectively. The broken lines of each system indicate the first and second half divided lines. In the main spindle system 1 and the main spindle system 2, the first and second half process subprograms are switched. In the spindle system 3 (back spindle system), the first half and the second half are configured by the same process subprogram.

In this example, each process subprogram constituting the process editing program has a program number (N001).
0, N0020, etc.), the program number and the tool code (T1200, T1300) used in the process.
Etc.) are stored in pairs. M02 is a command indicating the end of the machining program. This process editing program can be displayed on the display 43 for confirmation.

In this way, a program system is provided for each of the first main spindle, the second main spindle, and the back main spindle, and the program sub-system of the first main spindle is provided with the process subprograms of the main spindle side process in the order of the first half and the second half. In the second spindle program system, the process sub-programs of the spindle-side process are arranged in the latter half and the first half in order, and in the rear spindle-side program system, the process sub-programs of the back spindle process are arranged in the order of the processes. I do.

In the embodiment shown in FIG. 9, the process subprogram of the main spindle side process is not divided in units of process subprograms so that the machining time on the main spindle side and the back side is 2: 1. If the process editing program cannot be divided by about half of the machining time, the process subprogram is re-edited, and the process subprogram that extends before and after the place to be divided is divided into two to form separate process subprograms. The process after the calculation of the machining time in the unit of the process subprogram is executed to create the process editing program.

By doing so, it is possible to distribute the process subprograms that are close to ideal to each system, and it is possible to maximize the processing efficiency. The process editing program of FIG. 11 is a parent program,
The part program or the process subprogram in FIG. 10 can be viewed as a child program. As a result, it is possible to disassemble the two thoughts of the details of the tool path and the entire method of arranging the processes, and to arrange the operations.

Basically, a child program is considered as a single system program that determines the operation by X and Z on a plane, and a parent program is considered as a program in which the order of processes and the queuing relationship between processes are developed in multiple systems. At the time of editing or execution, if you look at only the parent program, you can understand the whole situation, but it is difficult to understand individual operations. Therefore, in the state where the parent program is displayed, the child program (process subprogram) can be displayed in a window by designating the program number (N0010, N0020, etc.) as necessary.

FIG. 12 shows a display example of a machining program having a single-layer structure for each spindle system according to this embodiment. Part programs (child programs) are displayed in a table format for each spindle system, and are scrolled up and down. The whole of each child program can be displayed. Thereby, it is possible to confirm the details of the part program of each spindle system.

FIG. 13 shows an example in which the accumulated machining time when the machining program of each spindle system in FIG. 12 is executed is displayed in a graph showing the ratio of the machining time by each process subprogram (N ****). FIG. The length in the vertical direction of the hatched area in which the number of each process subprogram is displayed is proportional to the processing time of the process.

In the spindle system 1, the process subprogram N00
10 to N0030 are the first half, and N0040 to N0070 are the second half. In the spindle system 2, only the first half and the second half are interchanged. The machining time of all the process subprograms of the spindle system 3 (the back spindle system) is slightly shorter than half of the machining time of all the process subprograms of the spindle systems 1 and 2, and the machining time of each of the spindle systems 1 and 2 is one time. It can be seen that the same processing is performed twice during the processing.

FIG. 14 is a view showing a display example of a machining program of a two-layer structure for each spindle system according to this embodiment. In this case, the process edit program (parent program) is tabulated for each spindle system in the form of a table. The program number (N ****) of each process subprogram and the tool number (T
****), and if any of the program numbers of the process sub-programs composing it are designated with the cursor, the child program (part program indicating the contents of the process sub-program) is displayed in the display box of the spindle system. A window is displayed at the bottom.

In FIG. 14, the designated program number is indicated by hatching with a frame surrounding the designated program number. In this example, in the spindle system 1, N
0010, the child program of N0040 in the spindle system 2 and the child program of N0080 in the spindle system 3 are displayed in each window of the display column for each system. The window for each system can be associated with a tool post mainly used in each system.

FIG. 15 shows another display example. In this example, the program number N0010
Is displayed in the window of its own column, and the child program of program number N0200 for performing simultaneous machining using the tool (T2600) of the second turret is displayed in the window of the display column of the spindle system 2. are doing.
In this way, child programs of a plurality of process sub-programs of the same spindle system can be simultaneously displayed using windows of other spindle systems. In this case, the windows that display the child programs of the same spindle system can be easily recognized as having the same system by using the same frame type or the same display color in the case of a display capable of color display.

In the display shown in FIGS. 14 and 15, the child program of the program number designated by the cursor on the parent program is displayed in the window at the time of editing. Located)
Are sequentially displayed in the window.

FIG. 16 is a diagram showing a display example of the machining time for each process subprogram before the main spindle system 2 of the process editing program according to this embodiment is created. This is displayed by touching "hour display" once after touching and specifying "process edit" among the selection keys displayed at the bottom of the display screen. That is, in the time display window provided in the display column for each spindle system, the time is displayed in seconds in correspondence with each program number. Thus, the machining time calculated for each process subprogram can be determined.

When the "hour display" key is touched again, as shown in FIG. 17, the accumulated machining time by machining of each process subprogram for each spindle system is the time provided in the display column for each spindle system. It is displayed in the display window. As a result, it is possible to easily determine which process subprogram should be used to divide all the processes into approximately half of the processing time.

FIG. 18 is a diagram showing a display example of the accumulated machining time for each spindle system after the process editing program for each spindle system has been created. Here, when the "hour display" key is touched once more, the graph shows the cumulative machining time when the machining program of each spindle system is executed and the ratio of the machining time by each process subprogram as shown in FIG. The time is displayed in a time display window provided in a display column for each spindle system.

In each of the embodiments described above, the case where the same parts are machined on the first spindle side and the second spindle side and the same machining is performed twice in one cycle on the back spindle side has been described. The present invention is not limited to such a case, and even if different parts are simultaneously machined on the first spindle side and the second spindle side, the total machining time of both parts is substantially the same, and the entire machining is performed. Approximately 1/3 or less of the time can be performed by back machining, and the process subprograms to be executed on the first and second spindles respectively are divided into the first half and the second half in process units at approximately half of the total machining time. , The working method according to the present invention can be carried out similarly, whereby a sufficient effect can be obtained.

[0085]

As described above, according to the present invention, the N
If a machining method using a C lathe is performed, machining with high productivity can be performed with a small increase in cost by using an NC lathe with two spindles and one back spindle. Generally, when processing a component using an NC lathe having a rear spindle, there are many component processes in which the processing can be divided so that the processing time on the rear spindle becomes approximately half or less than the processing time on the spindle. In that case,
In terms of time, one NC lathe with two spindles and one back spindle can perform almost the same processing as two NC lathes with one spindle and one back spindle. Further, according to the method for creating a machining program for an NC lathe of the present invention, a machining program for performing the machining method can be efficiently created.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a relationship between machining steps on each axis side in a machining method using an NC lathe according to the present invention.

FIG. 2 is an explanatory diagram showing the relationship between machining steps on each axis side in machining by various conventional NC lathes or automatic lathes.

FIG. 3 is an external perspective view showing an example of an NC lathe that implements the processing method according to the present invention.

FIG. 4 is an explanatory diagram of an example of a work (part) to be machined using the NC lathe shown in FIG. 3 and a machining process thereof.

5 is a diagram showing an example of a tool layout for each tool post for performing the machining shown in FIG. 4;

FIG. 6 is a diagram showing an example of a tool layout when the machining shown in FIG. 4 is performed using only the first and second turrets.

FIG. 7 is a diagram showing a relationship between machining times by each tool on each axis side when the machining shown in FIG. 4 is performed by the machining method of the present invention.

FIG. 8 is a block diagram showing a configuration of a control unit of the NC lathe shown in FIG.

FIG. 9 is a flowchart showing a machining program creation procedure by the control unit of FIG. 8;

FIG. 10 is a diagram showing an example of a part program created by this embodiment and its process subprogram.

FIG. 11 is a diagram showing an example of a process editing program created by this embodiment.

FIG. 12 is a diagram showing a display example of a machining program having a single-layer structure for each spindle system according to the embodiment.

13 is a diagram showing an example in which the accumulated machining time when the machining program of each spindle system of FIG. 12 is executed is displayed in a graph showing the ratio of the machining time by each process subprogram.

FIG. 14 is a diagram showing a display example of a machining program having a two-layer structure for each spindle system according to the embodiment.

FIG. 15 is a diagram showing another display example.

FIG. 16 is a diagram showing a display example of a machining time for each process subprogram before creating the spindle system 2 of the process editing program according to this embodiment.

FIG. 17 is a view showing a display example of the accumulated machining time.

FIG. 18 is a diagram showing a display example of the accumulated machining time for each spindle system after the process editing program for each spindle system has been created.

[Explanation of symbols]

W: Work (part to be processed) 10: Bed 1
0a: Groove 11A: First spindle head 12A: Spindle motor for first spindle 13: Tool post base 14A: First guide bush 14B: Second guide bush 15A, 15B: Work 16A, 16B, 25: Guide rail 17A: First 1
Tool post 17B: 2nd tool post 18A, 18B: Y axis table 19A, 19B: X axis table 20A: Y1 axis servo motor 20B: Y2 axis servo motor 21A: X1 axis servo motor 21B: X2 axis servo motor 22A, 22B, 2
4, 32: Tool 23: Back tool post 26: Rear headstock base 2
7: Back spindle head 28: Servo motor for Y3 axis 29: Servo motor for Z3 axis 30: Spindle motor for rear spindle 31: Opposite turret 33 : Tool holder 40: System control unit 41:
Program input unit 42a: Keyboard 42b: Switch 43: Display 44: Operation panel 45: Input / output control unit 46: System control program memory (ROM) 47: Automatic programming unit 48: Processing program memory 49: Display data storage unit 50: RAM 51: machining program processing unit 52: communication control unit 53: machining operation control unit 60: drive unit 61: servo mechanism for each axis motor 62: control drive unit for each axis 63: spindle motor for each spindle 64: spindle motor control Driving unit 65: Each sensor 66: Sensor input unit

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kenji Sugimoto 840 Citizen Watch Co., Ltd., Tokorozawa, Tokorozawa, Saitama Prefecture (56) References JP-A-4-107706 (JP, A) JP-A-62- 246459 (JP, A) JP-A-4-256547 (JP, A) JP-A-5-169350 (JP, A) JP-A-7-241749 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23Q 15/00-15/28 G05B 19/18-19/46 B23Q 37/00-41/08 B23B 1/00-25/06

Claims (6)

(57) [Claims] 1. A first tool rest and a second tool which can be machined in combination with a first main spindle and a second main spindle which are provided at predetermined intervals in parallel with each other, and which can be combined with the first main spindle and the second main spindle, respectively. A table, a back main shaft disposed opposite to the first main shaft and the second main shaft, and movable relative to a direction connecting the axes of the main shafts and a direction approaching / separating from the main shafts; An NC lathe having a back tool post that can be machined in combination with a back spindle, performs all machining steps on one workpiece by the first spindle side machining step and the back spindle side machining step, (2) The entire machining process for one other workpiece is also performed by the machining process on the main spindle side and the machining process on the back spindle side, and the machining time on the back spindle side in the entire machining process is the same for each of the spindle sides. plastic half of the processing time of Divided into a spindle side sub spindle side to be equal to or less than, divided into first and second halves of the spindle side of the processing steps in step units and the first half after the start of the workpiece processing step in the first spindle side is completed At the point in time, the second spindle side starts another machining step for the workpiece, and when the second half of the first spindle side machining step is completed, the workpiece is transferred to the back spindle side to process the back spindle side machining step. At the same time, a new work processing step is started on the first spindle side, and when the second half of the processing step on the second spindle side is completed, the work is delivered to the rear spindle side and NC, wherein a new workpiece machining process is started on the second spindle side, and thereafter, operations after the second half of the first spindle side machining process are completed are repeated. Processing method by lathe. 2. A first tool spindle and a second tool spindle, which are provided parallel to each other and separated by a predetermined distance, and a first tool rest and a second tool which can be machined in combination with the first spindle and the second spindle, respectively. A table, a back main shaft disposed opposite to the first main shaft and the second main shaft, and movable relative to a direction connecting the axes of the main shafts and a direction approaching / separating from the main shafts; A method of creating a machining program for an NC lathe having a back tool post that can be machined in combination with a back spindle, wherein a part program which is a normal program of NC machining is created, and the part program is processed for each machining process. together as a subprogram, the after calculating the machining time of each step subprogram, as the processing time of the entire process subprogram rear spindle side is equal to or less than that or half the processing time at the spindle side Divided into shaft side step and the rear spindle side step, further dividing the spindle side step into a first half and a second half in the step subprogram units, the first spindle, the second spindle, the program lines in the respective back spindle is provided, that In the first spindle program system, the process subprograms of the spindle-side process are arranged in the first half and second half, and in the second spindle program system, the process subprograms of the spindle process are arranged in the second half and the first half. A method for creating a machining program for an NC lathe, wherein a process program is formed by arranging, in a program system, process sub-programs of the back spindle side process in the order of processes. 3. A machining program for an NC lathe according to claim 2, wherein a program number is assigned to each of the process subprograms, and the program number is designated for each of the program systems to form a machining program. Method. 4. A method for creating a machining program for an NC lathe according to claim 2, wherein a tool attached to said first tool post and said second tool post is calculated before calculating a machining time for each of said step sub-programs. A method for creating a machining program for an NC lathe, characterized by performing a tool layout for determining a type. 5. The method according to claim 5, wherein the tool layout switches between machining with the tool of the first tool post and machining with the tool of the second tool post in the first half and the second half of the process subprogram of each spindle side process. The method according to claim 4, wherein the tool layout of the first tool post and the tool post of the second tool post are determined. 6. The NC lathe machining program creating method according to claim 2, wherein the machining sub-program of the spindle-side process is performed at a half of a total machining time thereof. It is characterized in that the process is divided into subprograms , and if the process cannot be divided , the process subprogram that extends before and after the half is divided into two separate process subprograms, whereby the spindle-side process is divided into the first half and the second half. NC lathe machining program creation method.