JPH0690647B2 - Machining system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a machining system that sends NC machining data to one or a plurality of machine tools by a supervising computer to perform DNC operation, and in particular, a die and the like. The present invention relates to a machining system suitable for high-speed NC machining of a workpiece composed of complicated free-form surfaces.

[Conventional technology]

In conventional DNC operation, each NC
When sending NC machining data to the machine tool, it is made into a predetermined number of buckets, and each bucket is collectively transmitted to the buffer memory means, and from there to the NC machining program reading section of the NC device of each NC machine tool. It was sending one block of a smaller unit. The pulse is distributed by the information processing unit of the NC device, and signal command pulses for each feed motion axis of the NC machine tool are generated appropriately, and this is sent to the servo mechanism that controls the position of each axis, and each feed is performed in accordance with this command pulse. It was configured to operate the axis drive motor to execute NC machining.

[Problems to be solved by the invention]

When this method is applied to the machining of workpieces with complicated three-dimensional shapes such as dies in a high-speed machining center, the NC machining data supply cannot keep up with the machining speed of the machine tool and machining is often interrupted. However, there is a drawback that not only the machining efficiency is lowered, but also a cutter mark is left on the machined surface of the work, so that the machining quality is deteriorated. In particular, when a plurality of NC machine tools are used to perform die machining at the same time, many machine tools are often interrupted due to the limit of NC machining data sending speed of the supervising computer.

Generally, it is very difficult to create an NC machining program for a complicated free-form surface, and in practice, first, NC machining data is created by a known automatic programming device based on the approximate shape, and then this machining data is created. A model made of a material with good workability such as plastic is created by using a high-speed machining center in the minimum time, and the model is modified to obtain a desired shape, which is scanned and corrected by a known digitizer. Obtained NC processing data. There is also a need for a system that can consistently and reasonably perform this task.

[Means for solving problems]

In view of the above-mentioned problems of the prior art, the present invention improves the transfer rate of NC machining data from a supervising computer in a machining system in which a supervising computer controls a plurality of NC machine tools, and installs a high-speed NC data creating device. by
The objective is to improve the NC data processing speed and achieve a fully automatic NC machining system by introducing an automatic programming device and digitizer.

That is, the present invention is a machining system for transmitting NC machining data to one or a plurality of NC machine tools by a supervising computer for DNC operation, and writing NC machining data to and from the supervising computer. An external storage device for reading, writing means for bucketing NC machining data consisting of a number of blocks into a predetermined storage unit and writing it in the external storage device in advance, and the NC machining data in bucket form for each NC machining A sending means for sending to the machine by the storage unit at a time and simultaneously taking NC processing data to be sent next from the external storage device and making it stand by, from the governing computer to at least one NC machine tool. The NC machining data is converted to movement command data in advance according to the high-speed machining command provided in the middle of the line path leading to the attached NC device. Arithmetic processing means for performing arithmetic conversion, angle calculation means for successively calculating the angle formed by the front and rear two vectors in the movement command data, and the movement command according to the magnitude of the angle formed by the two vectors A high-speed NC data creation device having a deceleration calculation means for calculating and converting data into decelerated movement command data, interposed immediately before the NC device attached to the NC machine tool,
It is possible to store a plurality of units of data that have been packed in each storage unit, and send NC machining data by the amount requested by the NC device. When the stored amount decreases, new NC machining data is sent by the sending means. To automatically create NC machining data by scanning the buffer memory means, models and workpieces required for
At least one digitizer that inputs this to the supervising computer, at least one automatic programming device that automatically creates NC machining data from given shape dimensions and inputs this to the supervising computer, and the digitizer and automatic programming Read-out means for reading each NC machining data from the device and transmitting it to the writing means, and NC machining data input from the digitizer to the governing computer is created from the governing computer to the high-speed NC data. The present invention provides a machining system characterized in that it is sent to the NC machine tool via a device to perform high-speed NC machining.

With this configuration, the NC machining data from the supervising computer is packetized and stored in the external storage device, and from here it is transmitted packet by packet to the buffer memory means attached to each machine tool. Can be shortened. In addition, a machine tool for machining workpieces such as dies with complicated three-dimensional shapes is equipped with a high-speed NC data creation device, and if the machining program contains a high-speed machining command, NC machining data Since it is preprocessed for high speed machining and this is directly transmitted to the servo mechanism without going through the information processing section of the NC unit, there is no time delay in supplying the machining data even when machining complicated shapes. .

Further, according to the configuration including the automatic programming device and the digitizer, as a procedure for obtaining a work of a given design, the design is first approximated by a mathematical formula and given to the automatic programming device, and this is input to the supervising computer and the above-mentioned operation is performed. Then, the mockup model is created by high-speed machining by a high-speed machining center called a so-called three-dimensional plotter or the like based on the packetized NC machining data. Then the detail of the model is adjusted to match the actual image, and then the surface is scanned by a digitizer to NC.
Obtain the processed data and input it to the controlling computer for storage. Then, based on this processing data, the actual work is processed as described above. As a result, a consistent work system from NC machining data generation to workpiece machining is completed.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to the preferred embodiments shown in the drawings.

FIG. 1 shows the overall configuration of a machining system according to the present invention, in which one supervising computer 1 is configured to DNC control a plurality of machining centers, that is, automatic machine tools 2. In the illustrated example, two high-speed machining centers 2a and one normal machining center 2b are shown as objects to be controlled, but this number can be arbitrarily selected as required.

The supervising computer 1 is an ordinary general-purpose type computer, and is characterized in that it has a reading means 3, a writing means 4 and a sending means 5 each having a unique function. The reading means 3 is input from external means such as an automatic programming device 14 and a digitizer 11 which will be described later.
It has a function to read NC machining data into the control computer 1. The writing means stores the NC processed data read by the reading means 3 in a predetermined storage unit, for example, 1024.
The magnetic disk device 10 is formed by byte-by-byte packetization, and each packet is sequentially provided outside the governing computer 1.
Etc. has a function of sequentially writing in advance in storage means. The sending means 5 has a function of fetching the data written in the magnetic disk device 10 one packet at a time and sending it to each of the machining centers 2a and 2b. It also has a function of fetching one packet of NC processed data to be sent to the magnetic disk device 10 from the magnetic disk device 10 and holding it for the next sending. As a result, the next data can be transmitted immediately, and time can be saved. Reference numeral 6 is a multiplex communication control device, that is, a communication interface, through which all data communication between the governing computer 1 and the machining center 2 or the like to be controlled is executed.

The first feature of the present invention is that the NC processed data packetized by the writing means 4 of the governing computer 1 for each predetermined unit is stored in an external storage device such as the magnetic disk device 10 and the sending means is also in the packet unit at the time of sending. 5 is taken out and supplied to the machining center side. That is, in the conventional system, the NC machining data is
At the time of sending to the device 8, disk I / O is carried out one block at a time with the magnetic disk device 10 in the controlling computer 1, and a predetermined unit of data, for example, 1024
The data for bytes was packetized and transmitted to the buffer memory means 7 provided in front of the NC device described later. In this method, there is a drawback that the load on the supervising computer 1 during the sending operation is large and the sending time is long, and in the case of controlling a large number of NC machine tools, a handheld machine is caused by a data supply delay. There was an occasion. In the present invention, the NC processed data to be sent out is stored in the magnetic disk device 10 in advance as divided into each packet as described above.
Through this, it is possible to read out the data for one packet with one disk I / O and immediately send it to the buffer memory means 7. Further, since the subsequent NC machining data can be read into the sending means 5 during the sending operation, the time required for the reading is substantially omitted, and a great time saving is achieved.

The system for controlling the normal type (non-high speed type) machining center 2b has substantially the same configuration as a conventionally known one,
It comprises a buffer memory means 7 for temporarily storing the NC data supplied from the governing computer 1, and an NC device 8 unique to the machining center 2b. The machining center 2b is provided with an MTC (machine control device) for controlling sequence operations such as tool exchange and pallet exchange. In this system, the packetized NC machining data given from the supervising computer 1 is temporarily stored in the buffer memory 7, and is transmitted to the NC device 8 one block at a time in accordance with the machining sequence. Then, the pulse distribution circuit converts into position command data for each feed motion axis of the machining center 2b, and according to this command data, the drive motor of each feed shaft is operated to perform NC machining.

On the other hand, in the case of the control system of the high-speed machining center 2a,
A feature is that a high speed NC data creating device 9 is installed between the buffer memory means 7 and the supervising computer 1. This is to enable high-speed processing of a mold or the like having a complicated shape of a three-dimensional curved surface.
That is, when processing a three-dimensional curved surface shape, linear interpolation,
Curved surface processing is realized by using interpolation components such as circular interpolation as minute vectors. Moreover, in order to achieve the formation of a smooth curved surface with such a series of minute vectors, it is necessary to speed up the processing of the NC machining program that commands each minute interpolation component, or otherwise the processing commands will not be supplied. The machine speed cannot be supplemented by the machine speed given to the machine, and the work is often interrupted to reduce the machine efficiency. In the unique NC device 8 attached to the machining center 2a, the calculation processing speed of each data block including the NC command data that commands the minute interpolation component is limited, and therefore the overall NC processing speed becomes slower. It was difficult to realize high-speed NC machining without interruption. Further, in high-speed NC machining, the path error due to the droop of the servo mechanism tends to become large, so it is necessary to take measures against this as well. Here, droop is for NC command
It is the delay in following the NC machine tool. The high-speed NC data creation device 9 is installed for this purpose, which will be described in detail below.

The machining program supplied from the supervising computer 1 to the high-speed NC data creating device 9 includes a standard NC machining command and a high-speed mode for executing NC machining in the normal or standard speed mode.
Both of the high-speed NC machining commands for executing the NC machining are included, and are transmitted to the high-speed NC data creating device 9 sequentially in the known block unit. At this time, the high-speed NC
In the data creating device 9, as shown in the NC program of FIG. 3, the start of high-speed NC machining is instructed in advance by the preparation function G05 at the NC programming stage. Of course, external operation means capable of instructing high-speed NC machining from the outside according to the progress situation may be provided.

When the NC program including the high-speed NC machining command 05 is supplied in this way, the high-speed NC data creation device 9 receives the NC machining program in the data receiving section 24 shown in FIG. The data receiving unit 24 is the NC of each block of the NC program.
Depending on the presence or absence of high-speed machining command G05 for each command data, high-speed N
The NC command data is transmitted to the data transmission unit 28 via the C data processing unit 26 or bypassing the high speed NC data processing unit 26. In the high speed mode, the NC command data is interpolated in the high speed NC data processing unit 26 and converted into binary data movement command data (distributed pulse number) which can be directly supplied to the servo mechanism of the NC device. On the other hand, in the standard speed mode, the NC command data is
Is directly transmitted to the data transmission unit 28. Here, the command data for performing high-speed NC machining is used when performing NC machining for each minute interpolation distance such as a three-dimensional curved surface shape to obtain a smooth machining curved surface. It should be noted. This is because, in order to perform such a large number of NC machining operations for each minute interpolating distance, if the NC device 8 unique to the machining center is normally operated, the enormous amount of processing causes a large amount of processing. Takes time, NC
This is because it is not possible to achieve high efficiency, which is one of the merits of automatic processing by processing. That is, the high-speed NC data creation device 9 sends the data that can be directly sent to the servo mechanism in the NC device 8 to the NC device.
Created at a high speed in advance by an arithmetic processing means different from the device 8,
The NC device 8 has a function that allows all offset processing and interpolation calculation processing to be omitted.

The NC command data transmitted from the data transmission unit 28 of the high speed NC data creation device 9 is stored in the buffer memory means 7 as it is, and further sequentially transmitted to the NC device 8. The buffer memory means 7 has a function of temporarily storing all NC command data including NC machining command data created at high speed and sequentially sending the NC command data to the NC device 8 in the subsequent stage. The operation panel 30 is connected to the high-speed NC data creation device 9,
As mentioned above, it is possible to manually input a high-speed machining command in addition to the high-speed NC machining command G05, and it is also possible to change the feed speed according to the command in the NC program. There is.

In the high speed mode, the NC device 8 reads the high speed NC machining data already converted into the movement command data of each axis from the buffer memory means 7 at a constant time interval and immediately sends it to the servo mechanism as described above. NC processing is executed. In the case of standard speed mode, NC machining data is
The arithmetic processing unit in the NC device 8 receives the necessary processing such as offset processing, linear interpolation processing, circular interpolation processing, etc., and then sends it to the servo mechanism, and there is no difference from the function of a normal NC apparatus.

Generally, during NC machining, the mechanical operation parts such as the servo mechanism and the feed mechanism of the machining center tend to cause a delay, that is, droop, when the command speed due to the NC command becomes large and the operation cannot follow the command. is there. This is particularly remarkable at the corner portion, and an error occurs in the instructed machining path. Therefore, even in the case of high-speed NC machining based on the movement command data calculated and converted by the above-mentioned high-speed NC data creation device 9, the machining along the path of the corner portion, the machining at the inflection point, and the large curvature such as the arc are provided. In the processing of the route, since the tendency of the processing error due to the droop is the same, it is necessary to prevent this.

As a measure against this, in the high-speed NC data creation device 9, each axis on the side of the machining center 2a (generally orthogonal to each other in the technical field of machine tools) according to the degree of change in the traveling direction of the machining operation path of the machining center 2a. X axis,
It also has a function of correcting the movement command data so as to reduce the feed rate of the Y-axis and the Z-axis (three axes are used). That is, in the high-speed NC data creation device 9, for the vector indicating the minute interpolation straight line instructed by each block of the movement command data for machining along the above-mentioned complicated path, the two blocks before and after the adjacent The angular displacement between the vectors is sequentially calculated, and the movement command data for decreasing the feed speed is created according to the magnitude of these angular change rates.

Generally, in the NC system in which the movement command data is given to the servo mechanism at fixed time intervals, the feed rate is controlled by changing the movement amount (pulse distribution number) given at one time. For example, if the movement command data is given at 10 millisecond intervals, the movement amount given at one time is
If it is 0.5 mm, the feed rate will be 3000 mm / min and the moving amount will be 0.
1mm is 600mm / min.

Further, referring to FIG. 4 which is a vector display of a minute interpolation straight line for each block when performing high-speed NC machining by linear interpolation, the angular displacement between the vectors A and B of the adjacent front and rear blocks is determined by the inner product theorem. , Cos θ = A · B / | A | · | B | According to the change in the angle of θ from 0 to 90 °, for example, when the angle is around 0 °, the amount of movement given at one time corresponds to the commanded speed, and the amount of movement is divided into several numbers as θ increases. If it is given over multiple times, the feed rate will be reduced, and as a result, it is possible to minimize the error due to droop when performing high-speed NC machining. The high-speed NC data creating device may be provided in the same housing as the NC device 8 specific to the machining center.

Next, using the basic machining system described above, create an NC machining program based on the given design, and then use it to create an integrated machining system that can actually process a workpiece. It will be described with reference to FIG.

An automatic programming device 14 is connected to the supervising computer 1 of this machining system, and the NC machining programming created by the automatic programming device 14 can be input by the reading means 3 (FIG. 1). Further, the reading means 3 is connected to the digitizer 11 via a multiplex communication controller 6 (not shown). The desired design created by the designer is converted into an approximate mathematical model by a known method, and is mounted on the automatic programming device 14. A series of created by this
The NC machining program is read by the reading means 3 of the supervising computer 1, packetized in the memory of the magnetic disk device 10 through the writing means 4 and stored sequentially in the same manner as described above. Then, it is transmitted to one of the high-speed machining centers 2a through the sending means 5 according to the above-mentioned method, and based on this, the prototype of the model is prototyped. In this case, as the material of the work, a suitable workable material such as an appropriate plastic is selected, and a prototype model is created at high speed in a short time. Next, the original model is observed and measured, and the error from the desired design is manually corrected to create a corrected model. Since it is generally impossible to reflect this manual correction using an automatic programming device, the corrected model is mounted on the digitizer 11, the surface is automatically scanned, and the displacement amount is reversed by the NC device. It is converted into processed data and input to the supervising computer 1. In the supervising computer 1, the modified NC machining program is again supplied to the machining center 2a or 2b in the system to actually machine the workpiece, and the desired machined product can be obtained.

Further, as an application example of the present invention, a subprogram included in the NC machining program may be stored in the magnetic disk device 10 separately from the main program, and may be appropriately retrieved and used. More specifically, in general, standard unit work for NC machining in a machining center, such as a pallet change command, is commonly set as a subprogram in each machining center.
In the conventional system, this subprogram is stored in the NC unit 8 attached to each machining center, and when the information processing unit in the NC unit 8 reads the main program for NC machining from the supervising computer 1. In addition, when the subprogram call command is encountered, the reading of the main program is interrupted and the stored subprogram is read.
However, since the NC device 8 peculiar to this machining center is relatively small and has a small storage capacity, it is impossible to store too many subprograms, and it is inconvenient that only the frequently used subprograms are stored. was there. In the present invention, as described above, the subprogram is stored in the memory of the magnetic disk device 10 separately from the main program. This magnetic disk unit 10
Since has a large storage capacity, it is possible to store more subprograms than before. In the present invention, as shown in FIG. 6, if the INCLUDE command is encountered while the reading means 12 is reading the main program, the reading is once interrupted and the subprogram in the magnetic disk device 10 by the inserting means 13 is interrupted. Is read out, and this is supplied to each machining center via the sending means 5 in accordance with the above-mentioned method. When the reading of the sub program is completed, the procedure returns to the reading of the main programming, and this is repeated. This makes it possible to save the memory of the NC device 8. Further, it is possible to store the main program in the magnetic disk device 10 as a sub program separately from the main program even in a machining procedure such as a sub program unique to the work, which is relatively infrequently used, so that the main program can be shortened. Becomes

〔The invention's effect〕

As described above in detail, according to the present invention, the external storage means (magnetic disk device) is connected to the supervising computer,
By storing the packetized NC machining data in advance in this, it becomes possible to read the next data into the transmission means while transmitting one unit of NC machining data, and NC machining data for each machining center. Transfer speed improved. As a result, processing data can be supplied to a large number of machining centers without interrupting the processing work. In addition, a high-speed NC machining data creation device is installed in the system as needed, and in the case of machining complicated three-dimensional shapes such as molds, fine movement command data is calculated without relying on the NC device unique to the machining center. Since it is configured so that it is possible to prevent the interruption of the work of the machining center that has conventionally occurred during such work, it is possible to realize high-speed and high-precision work processing.

Furthermore, by using the digitizer attached to the system of the present invention, it is possible to perform consistent processing from design to product for complex die machining that is not possible to create sufficient NC machining data only with an automatic programming device, batch management of NC machining data, Machining schedule management, etc. can also be performed efficiently, streamlining the DNC operation of NC machine tools using a supervising computer, and realizing high-speed NC machining and highly accurate machining of complex workpieces by bidirectional data communication. -ing

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of a machining system according to the present invention, FIG. 2 is a block diagram showing the configuration of a high-speed NC machining data creation device, and FIG. 3 is a NC program containing a high-speed NC machining command. An example of an NC program, Fig. 4 is an explanatory diagram of angular displacement of a vector representing a minute interpolating straight line instructed by sequential blocks in high-speed NC machining data, and Fig. 5 is from the creation of an NC program based on a given design. FIG. 6 is a block diagram for explaining an application example of the system of the present invention in which a subprogram is stored in a magnetic disk device, and FIG. 1 ... Controlling computer 2 ... Machining center 2a ... High-speed type machining center 2b ... Normal type machining center 3 ... Reading means 4 ... Writing means 5 ... Sending means 6 ... Multiplex communication control device 7 ... Buffer memory means 8 …… NC device 9 …… High-speed NC data creation device 10 …… Magnetic disk device 11 …… Digitizer 14 …… Automatic programming device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-58-129606 (JP, A) JP-A-60-262212 (JP, A) JP-A-59-47144 (JP, A) JP-A-61- 178149 (JP, A)

Claims (1)

[Claims] 1. A unitary computer or a plurality of units depending on the controlling computer.
A machining system that sends NC machining data to an NC machine tool for DNC operation, and an external storage device that writes and reads NC machining data to and from the supervising computer, NC machining data consisting of multiple blocks Writing means for packetizing a predetermined storage unit into the external storage device in advance, and sending the packetized NC machining data to the respective NC machine tools for each storage unit at the same time, Sending means for fetching NC machining data to be sent from the external storage device and making it stand by, high speed provided in the middle of a line path leading from the supervising computer to the NC device attached to at least one NC machine tool An arithmetic processing unit for preliminarily performing arithmetic conversion of NC machining data into movement command data according to a machining command, and the movement command data. Angle calculation means for successively calculating the angle formed by the two front and rear vectors, and deceleration calculation for converting the movement command data into movement command data that is decelerated according to the magnitude of the angle formed by the two vectors. A high-speed NC data creation device comprising means, which is interposed immediately before the NC device attached to the NC machine tool,
A plurality of units of data packed by each storage unit can be stored, NC machining data is transmitted by the amount requested by the NC device, and when the stored amount is further reduced, new NC machining data is transmitted by the transmitting means. To automatically create NC machining data by scanning the buffer memory means, models and workpieces required for
At least one digitizer that inputs this to the supervising computer, at least one automatic programming device that automatically creates NC machining data from given shape dimensions and inputs this to the supervising computer, and the digitizer and automatic programming Read-out means for reading each NC machining data from the device and transmitting it to the writing means, and NC machining data input from the digitizer to the governing computer is created from the governing computer to the high-speed NC data. A machining system characterized in that it is sent to the NC machine tool via a device to perform high-speed NC machining.