JPH0850506A - Data transfer device - Google Patents

Abstract

PURPOSE:To transfer numerical control data without frequently stopping the moving operation of a machine tool by using both a semiconductor memory and an external storage device. CONSTITUTION:The numerical control data are divided for each prescribed block (step 106), and a moving command for each divided block is detected (steps 108 and 110). This detected moving command is analyzed (steps 112 and 122) and based on transfer speed decided in advance, the critical feeding speed of each movable element at the machine tool is operated so as to secure the enough time for transferring the numerical control data (step 126). Based on the critical feeding speed, the numerical control data are corrected (step 130).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transfer device for transferring numerical control data from an external storage device storing numerical control data to the numerical control device.

[0002]

2. Description of the Related Art Conventionally, a numerical control device has an external storage device such as a hard disk and an internal semiconductor memory. Numerical control data is stored in the external storage device and the semiconductor memory is stored as necessary. The numerical control data is transferred to and the data is exchanged between the semiconductor memory and the central processing unit (CPU) in the numerical control device while controlling the machine tool connected to the numerical control device.

As described above, data is exchanged between the semiconductor memory and the CPU. Since the semiconductor memory has a very fast response time and can quickly respond to the request of the CPU, the operation of the machine tool can be performed. The operation is smooth without being affected by the data read time. However, since the storage capacity of this semiconductor memory is smaller than that of an external storage device such as a hard disk device having another equivalent storage capacity, conventionally, a semiconductor memory and an external storage device are used together.
When the amount of data stored in the semiconductor memory decreases,
The CPU makes a data transfer request to an external storage device by utilizing the idle time during which the machine tool is executing an instruction, and executes the operation of the machine tool while transferring the data.

[0004]

However, when the machine tool makes a data transfer request to the external storage device by utilizing the idle time during which the command is being executed as described above, for example, as shown in FIG.
As shown in (a), if one command that moves from the start point A to the end point B with a long movement distance is executed by one-axis control, secure a sufficient free time for data transfer processing. Although it is also possible, when a short distance is executed at a plurality of points as shown in FIG. 5B, it does not take much time to execute the one instruction, and therefore it is necessary to perform the transfer. However, there is a problem that the movement of the machine tool is often stopped and the accuracy of the machined surface is deteriorated especially when the machined object is machined.

The present invention has been made in view of the above-mentioned circumstances, and is to use a semiconductor memory and an external storage device together and to transfer numerical control data without stopping the movement operation of the machine tool. .

[0006]

In order to solve the above-mentioned problems, the present invention collects numerical control data transferred from an external storage device to a numerical control device in a predetermined block number unit as claimed in claim 1, and A movement command detecting means for detecting a movement command for instructing the movement of each movable element of the machine tool in a unit of a predetermined number of blocks, and a numerical value from the external storage device determined in advance by analyzing the content of the detected movement command. Limiting feed rate calculating means for obtaining a limiting feed rate of the movable element based on a transfer rate of numerical control data between control devices, and correcting the numerical control data so that the movable element is fed at this limiting feed rate. It is provided with a numerical data correction means.

According to a second aspect of the present invention, the correction means is provided with a feed speed determination means for correcting the numerical control data only when the limit feed speed is slower than the current commanded feed speed. Is.

[0008]

According to the above structure, in the first aspect, the movement command is detected for each predetermined block number unit of the numerical control data, the detected movement command is analyzed, and based on the predetermined transfer speed, Calculate the limit feed speed of each movable element of the machine tool that can secure the time to transfer the numerical control data, and use the numerical control data correction means to correct the speed command of the numerical control data based on the limit feed speed. I chose

Further, in claim 2, the limit feed speed is compared with the instructed feed speed, and only when the limit feed speed is slower, it is judged that the transfer of the numerical control data will not be in time, and the command speed is limited. The feed rate was corrected.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 10a to 10n denote a plurality of machine tools 1.
1a to 11n are provided adjacent to each of the numerical control devices for controlling the movements of the machine tools 11a to 11n, and the numerical control devices 10a to 10n are respectively connected to the numerical control devices via transfer devices 12a to 12n. A central control unit 20 composed of a mini computer is connected.

A disk device 21 as an external storage device is connected to the central control device 20, and a plurality of numerical control data to be transferred to the numerical control devices 10a to 10n are previously stored in the disk device 21. There is.
As shown in FIG. 2, the transfer units 12a to 12n temporarily receive the receiving unit 13 for receiving the numerical control data transferred from the central control unit 20, and the numerical control data transferred from the central control unit 20. Temporary storage device 1
4, a control unit 15 for controlling the creation of execution numerical control data described later, and a transfer unit 16 for transferring the execution numerical control data in serial mode to the numerical control devices 10a to 10n.

The temporary storage device 14 stores the numerical control data transferred from the central control device 20 via the receiving unit 13 for one step in which the machine tools 11a to 11n process the workpiece. And an execution numerical control data storage area ENDM for storing the numerical control data stored in the numerical control data storage area NDM into the data necessary for actually executing the numerical control devices 10a to 10n. Has been.

The transfer unit 16 is a numerical controller 10a ...
Based on the transfer enable signal output from 10n, the numerical control devices 10a to 10n execute numerical control data area ENDM.
The numerical control data stored in the numerical control device 10a.
Transfer to 10n. In addition, the numerical control devices 10a to 10
n is provided with a semiconductor memory 17 for storing about 100 blocks of execution numerical control data transferred from the transfer devices 12a to 12n, and the numerical control devices 10a to 10n are the execution numerical control stored in the semiconductor memory 17. When the amount of data is reduced to about half, the transfer devices 12a-12
A transfer signal indicating that transfer is possible is output to n.

The operation of data transfer with the above configuration will be described. Since the processes between the transfer devices 12a to 12n and the numerical control devices 10a to 10n are all the same, as an example, the transfer device 12a and the numerical control device 10a.
Will be described only. First, the central controller 20
In response to the transfer request from the transfer device 12a, numerical control data is stored in the numerical control data storage area NDM of the temporary storage device 14 via the receiving unit 13 according to the processing schedule.
It is transferred to every one step.

The numerical control data storage area ND
When the numerical control data is stored in M, the control unit 15
Executes the process of the flowchart shown in FIG. First,
In step 100, the numerical control data storage area ND
One block of the numerical control data stored in M is read and the content of the numerical control data is analyzed.

Then, at step 102, it is judged whether the content of the analyzed numerical control data indicates a file end. If it is a file end, the process proceeds to step 104, and if it is not a file end. Step 1
Proceed to 06. In step 106, it is determined whether the number I of blocks of the numerical control data currently read has reached 100 blocks. If the number of blocks I has reached 100 blocks, the process proceeds to step 108 and 100 blocks have been reached. If not, the process proceeds to step 110.

In step 110, it is determined whether the read numerical control data is a movement command. If it is not a movement command, the process proceeds to step 114. If it is a movement command, in step 112 according to equation 1 The movement amount L is integrated.

[0018]

[Equation 1]

However, X, Y, and Z are incremental movement amounts. After accumulating the movement amount L in step 112, the process proceeds to step 114, in which the number of characters in one block is integrated to obtain the integrated number of characters S, the numerical control data read in step 115 is stored in the buffer memory 15a, and step 116 is performed. Proceed to. Then, in step 116, 1 is added to the block number I and the process returns to step 100.

On the other hand, when it is determined in step 106 that the number of blocks has reached 100, and when the process proceeds to step 108, it is determined whether or not the read numerical control data is a movement command. If it is a movement command, the movement amount L is integrated by the equation 1 in step 122, and the numerical control data of one block read in step 123 is stored in the buffer memory 15a. The number of characters is integrated to obtain the integrated number of characters S, and the process proceeds to step 126.

At step 126, the limit feed speed is calculated by the equation (2).

[0022]

[Equation 2]

Here, the average moving amount is a value obtained by dividing the integrated moving amount L by 100 in the total number of blocks, and the average number of characters is a value obtained by dividing the integrated number of characters S by 100 in the total number of blocks. Then, when the limit feed speed is obtained in step 126,
In step 128, it is determined whether or not the current feed speed is higher than the limit feed speed. If the current feed speed is faster than the limit feed speed, the process proceeds to step 130 and the current feed speed is lower than the limit feed speed. Step 13 if late
Go to 2.

In step 132, it is judged whether or not the current feed speed is slower than the limit feed speed by 100 mm / min or more. If it is slow, the process proceeds to step 130, and if it is not slow, the process proceeds to step 134. In step 130, the feed speed is changed to the limit feed speed, and this limit feed speed is stored as a speed command command (F code) at the beginning of the numerical control data of 100 blocks stored in the buffer memory 15a, and in step 134, This buffer memory 15
The numerical control data stored in a is output to the execution numerical control data area ENDM as the execution numerical control data to create the numerical control data that can be executed by the machine tool 11a.

Then, in step 136, the number of blocks I
Is cleared to 0, and the routine proceeds to step 116. In this way, by repeating steps 100 to 136, the numerical control data is prefetched to obtain the limit feed speed for every 100 blocks, and whether the feed speed is changed by comparing the limit feed speed with the command speed. To judge. When the file end is detected in step 102, the process proceeds to step 104, and the numerical control data remaining in the buffer memory 15 is executed as the numerical control data area END.
Output to M and complete the process.

By performing the processing of the flowchart of FIG. 3, the numerical control data shown in FIG. 4 (a) is added to the speed command command F1800, every 100 blocks based on the limit feed speed as shown in FIG. 4 (b). F1700 will be inserted. After that, when a numerical control data transfer request is issued from the numerical control device 11a, the transfer unit 16 of the transfer device 12a monitors the output of the transfer signal to the semiconductor memory 17 while monitoring the execution numerical control data area E.
Transfer numerical control data of NDM.

At this time, the execution speed is commanded so that the transfer speed from the transfer unit 16 to the numerical control device 10a is sufficiently in time with the execution speed of the machine tool 11a controlled by the numerical control device 10a. . Therefore, the operation of the machine tool 11a does not stop due to the delay in the transfer of the numerical control data.

In the above embodiment, the numerical control data in which the feed speed command is inserted is stored in the execution numerical control data area ENDM, and the execution numerical control data area ENDM is stored in the execution numerical control data area ENDM by a transfer request from the numerical control device 10a. The stored numerical control data is output, but the present invention is not limited to this, and when the transfer request is made, the numerical control data is not accumulated in the execution numerical control data area ENDM, and the sequential buffer memory 1
Alternatively, the data may be directly transferred from 5a to the numerical controller 10a.

Further, in the above-mentioned embodiment, the limit feed speed is obtained for every 100 blocks, but the number of blocks and the block unit for obtaining the limit feed speed can be appropriately set other than the above.

[0030]

As described above, according to the present invention, the content of the movement command is analyzed for each predetermined block unit of the numerical control data, and the limit of the movable element is determined based on the predetermined transfer rate of the numerical control data. Since the feed rate is calculated and the numerical control data is corrected so that the movable element is fed at this limit feed rate, smooth operation can be obtained without stopping the machine tool by the transfer processing of the numerical control data. The accuracy of the machined surface is not deteriorated even during machining of the workpiece.

Further, the limit feed speed is compared with the command speed, and only when the limit feed speed is slower, it is judged that the transfer of the numerical control data is not in time, and the command speed is corrected to the limit feed speed. Therefore, it is only necessary to reduce the feed rate in a specific block, and it is possible to machine at a high feed rate as a whole, and productivity can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a transfer device according to an embodiment.

FIG. 3 is a flowchart showing processing executed by a control unit in the embodiment.

FIG. 4 is a diagram illustrating correction of numerical control data according to an embodiment.

FIG. 5 is a diagram for explaining a conventional technique.

[Explanation of symbols]

 10a-10n Numerical control device 11a-11n Machine tool 12a-12n Transfer device 13 Receiving unit 14 Temporary storage device (external storage device) 15 Control unit 16 Transfer unit 17 Semiconductor memory

Claims (2)

[Claims] 1. A data transfer device for transferring numerical control data from an external storage device storing numerical control data for controlling a machine tool to the numerical control device, wherein the numerical control data transferred from the external storage device to the numerical control device. To a predetermined block number unit, and a move command detecting means for detecting a move command for instructing the movement of each movable element of the machine tool in the predetermined block number unit, and the content of the detected move command is analyzed. Then, a limit feed rate calculation means for obtaining a limit feed rate of the movable element based on a transfer rate of numerical control data of the numerical controller from a predetermined external storage device, and the movable element is fed at the limit feed rate. A data transfer device comprising a numerical data correction means for correcting the numerical control data as described above. 2. The correction means comprises a feed speed determination means for correcting the numerical control data only when the limit feed speed is slower than a commanded feed speed. The data transfer device according to item 1.