JPH10240330A - Numerical control unit - Google Patents

Abstract

(57) [Summary] [Purpose] Even if the real-time processing capability of the personal computer is low,
An NC device that does not cause an operation delay as an NC device is provided. A personal general-purpose computer having a main bus, a plurality of expansion slots on the main bus, an NC control unit attached to the expansion slot for controlling a servo motor, a sequence control, etc. PL that performs
An NC expansion board 8 having a C control unit 82, wherein the NC expansion board connects the NC control unit and the PLC control unit in addition to the main bus and transmits a signal between the control units. A road 83 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerical control device (hereinafter referred to as an NC device) for a machine tool or the like.
In particular, general-purpose personal computers (hereinafter referred to as personal computers)
The present invention relates to an NC device using the same.

[0002]

2. Description of the Related Art Recently, numerical control of machine tools has advanced, and N
Demand for C devices is increasing. The current NC device includes a CPU such as a microprocessor inside, and has a portion that analyzes an NC program and sends a control signal to a servomotor of each control axis, and a portion that performs sequence control such as tool change. I have. It is possible to realize such an NC device using a general-purpose computer. In particular, if the NC device is realized using a personal computer that has become available at a low cost, it is possible to reduce the cost of the NC device. Become. The personal computer referred to here is a small general-purpose computer for personal use (single user), and includes an FA personal computer (factory personal computer) in addition to a so-called OA personal computer (office personal computer).

Recently, the performance of personal computers has been improved and real-time processing has been able to achieve a certain level.
An NC device using a personal computer has become feasible.
The NC device using a personal computer had a configuration as shown in FIG. The personal computer 1 includes a CPU such as a microprocessor,
It has a motherboard 2 including a main memory, an interrupt controller, a bus controller, and the like, a main bus 3 connected to the motherboard 2, and a plurality of expansion slots 4 provided on the main bus 3. An expansion board for various input / outputs, an interface board for an external storage device, and the like can be attached to the expansion slot 4, and the functions of the personal computer 1 can be expanded. The main bus 3 is a bus for connecting these extension boards to the motherboard 2, and the CPU on the motherboard 2 accesses each extension board via the main bus 3.

An NC board 6 for sending a control signal to a servomotor of each control axis is attached to one of the expansion slots 4. Further, a PLC (programmable logic control) board 7 is attached to another expansion slot 4. The PLC board 7 is for outputting a control signal for sequence control and for inputting position information of each movable member. For example, when the table is forcibly stopped at the stroke end of the machine tool table,
The personal computer 1 accesses the PLC board 7 to know that the stroke end has been reached, and outputs a table movement stop command to the NC board 6.

[0005]

Although the performance of personal computers has been improved, there is still a problem in real-time processing performance for performing numerical control. In particular, when a non-preemptive multitask process is performed or a long-term interrupt process for accessing an auxiliary storage device or an external storage device occurs, a time delay that is unacceptable as a real-time process occurs. Sometimes. In the case of performing an emergency stop at the stroke end of the above-described table using a personal computer NC device having a conventional configuration, due to a delay in processing of the personal computer 1,
In some cases, the detection of the stroke end is delayed, or the command to the NC board is delayed, so that the table collides with the fixed member. When such a collision occurs, the machine tool body may be damaged.

Accordingly, an object of the present invention is to provide an NC device which does not cause an operation delay as an NC device even if the real-time processing capability of a personal computer is low.

[0007]

In order to achieve the above object, a numerical controller according to the present invention comprises a main bus, a personal computer having a plurality of expansion slots on the main bus, and a personal computer. An NC expansion board provided with an NC control unit for controlling a servo motor and the like and a PLC control unit for performing sequence control and the like, wherein the NC expansion board has a connection line other than a connection line with the main bus. A signal path between the control units for connecting the NC control unit and the PLC control unit and transmitting a signal is provided.

Further, the numerical control device of the present invention comprises a CPU,
Main memory, a motherboard including a bus controller, a main bus connected to the motherboard, a personal general-purpose computer having a plurality of expansion slots provided on the main bus, and connected to the motherboard,
An NC operation board for inputting and editing an NC program, an NC control board attached to the expansion slot and provided with an NC control section for controlling a servomotor and the like and a PLC control section for performing a sequence control and the like. The NC expansion board has a signal path between the control units for transmitting signals by connecting the NC control unit and the PLC control unit in addition to the connection line to the main bus.

In the above-mentioned numerical control device, it is preferable that an auxiliary storage device for storing an NC program is connected to the motherboard without passing through a main bus.

In the above numerical control device, it is preferable that the data bus width of the main bus is 16 bits or more, and the data bus width of the signal path between the control units is 8 bits.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of the NC device of the present invention. The personal computer 1 includes a CPU such as a microprocessor,
It has a motherboard 2 including a main memory, an interrupt controller, a bus controller, and the like, a main bus 3 connected to the motherboard 2, and a plurality of expansion slots 4 provided on the main bus 3. An expansion board for various input / outputs, an interface board for an external storage device, and the like can be attached to the expansion slot 4, and the functions of the personal computer 1 can be expanded. The main bus 3 is a bus for connecting these extension boards to the motherboard 2, and the CPU on the motherboard 2 accesses each extension board via the main bus 3. Main bus 3
Has a data bus width of 16 bits or 32 bits.

An auxiliary storage device 5 built in a personal computer is connected to the motherboard 2 without passing through the main bus 3. The auxiliary storage device includes a flexible disk device, a hard disk device, a CD-ROM device, a magneto-optical disk device, and the like. Also, motherboard 2
Via serial port, CRT interface, etc.
The NC operation panel 10 is connected. The NC operation panel 10 is provided with a display such as a CRT and a keyboard including a film switch and the like, and can input and edit an NC program. The display of the NC operation panel 10 can also display the coordinate values of the control axes, for example, the position of a tool or the position of a table in the case of controlling a machine tool. Further, if necessary, a flexible disk device or a paper tape reader as an NC program input device is installed on the NC operation panel 10.

One of the expansion slots 4 includes an NC control unit 81
And PLC (Programmable Logic Control)
The NC expansion board 8 having the control unit 82 is attached.
The NC control unit 81 in the NC expansion board 8 is for sending a control signal to the servo motor of each control axis,
The control unit 82 is for outputting a control signal for sequence control and for inputting position information of each movable member. The NC control unit 81 and the PLC control unit 82
Since the plurality of NC expansion boards 8 are mounted together, only one expansion slot 4 needs to be used.

For example, when the table is forcibly stopped at the stroke end of the table of the machine tool, the PLC control unit 8
The stroke end detection signal input to
It is necessary to transmit the information to the NC control unit 81 within seconds and perform the table stop control. As in the conventional example of FIG. 2 described above, the CPU of the motherboard 2 of the personal computer 1
If the stroke end was reached by accessing the control unit 82, and the table movement stop command was output to the NC control unit 81, control could not be performed within the allowable time in some cases. . Therefore, in the personal computer NC device of the present invention, the NC control unit 81 and the PLC control unit 8
2 is directly connected by a signal path 83 between the control units other than the main bus 3. It is sufficient that the data bus width of the signal path 83 between the control units is 8 bits.

FIG. 3 shows an NC program for machining a machine tool. Such N
The C program is input from the NC operation panel 10 and stored in an auxiliary storage device 5 built in the personal computer 1 by an appropriate code such as an ASCII code. The NC program is read by a flexible disk drive or a paper tape reader of the NC operation panel 10 from a program created by another NC device or a CAD / CAM device and stored on a flexible disk or a paper tape. It can also be stored on a hard disk device.

Briefly describing the NC program shown in FIG. 3, "O0020" on the first line is the program number of this program. “N001” in the next line is the sequence number of the actual program part, and is “G92 X
"0 Y0 Z0" is the instruction portion of the program. The content of the command is the setting of the work coordinate system, and sets the current tool position to the work coordinate origin (X, Y, Z) = (0, 0, 0). The part from the sequence number at the beginning of the line to the semicolon ";" (end of block: EOB) at the end of the line is called a block. NC for such machine tools
Instructions follow one after another.

The CPU circuit in the motherboard 2 of the personal computer 1 loads the NC program as shown in FIG. 3 stored in the auxiliary storage device 5 into the main memory, analyzes it, and separates it into NC instructions for each block. , Into a command format that can be interpreted by the NC control unit 81, and confirming the receivable state of the NC control unit 81 for each command of one block,
To send to. The NC control unit 81 performs pulse distribution and the like according to the received NC command, and sends a drive signal to a servo amplifier of a control motor of each control axis. NC instruction is completed,
When the buffer for the NC command becomes available, the motherboard 2 is notified of the receivable state. Such an operation is repeated for each block.

The "N0004" line in FIG. 3 shows that the spindle is rotated at 1500 revolutions per minute (S1500) and the spindle is rotated forward (M1).
3) This command is issued by the PLC control unit 8
2 and the PLC control unit 82 receives the external I / O
It outputs a control signal to the board. Thus, among the NC instructions, the instructions executed by the NC control unit 81 and the instructions executed by the PLC control unit 82 are mixed. Assuming that the I / O addresses of the two control units are different, the CPU circuit of the motherboard 2 may appropriately distribute these instructions to the two control units and transmit them, or the I / O addresses of the two control units may be shared. Alternatively, each control unit may determine an instruction for itself from among instructions output to a common I / O address, and fetch and execute the instruction.

In any case, in order for the NC program as shown in FIG. 3 to be executed in order according to the order of each block, each NC instruction is completed from one of the NC control unit 81 and the PLC control unit 82 to the other. It is necessary to inform that. For example, in the execution (tapping) of the “N005” line in FIG. 3, there is no time delay between the feed control performed by the NC control unit 81 and the spindle reverse rotation control performed by the PLC control unit 82 at the bottom of the hole. It is necessary.

In the conventional NC apparatus as shown in FIG. 2, there is no signal path for directly connecting the NC board 6 and the PLC board 7, and the transmission of such an end signal of the NC command is transmitted to the personal computer via the main bus 3. 1 through the CPU circuit, there is a time delay due to the processing delay of the personal computer 1,
In some cases, the allowable range was exceeded. In the present invention, the signal path 83 between the control units is provided as shown in FIG. 1, and these signals are directly transmitted through the signal path 83 between the control units. Is gone. Signal transmission via the inter-controller signal path 83 is performed directly by CPUs provided in the NC controller 81 and the PLC controller 82 in accordance with a predetermined protocol.

Signals transmitted via the inter-controller signal path 83 include not only the end signal for synchronizing the NC program but also the forced stop of the table at the stroke end and the position signal from the outside. There is a position signal or the like when a deceleration command is issued by the above. If a time delay occurs in these position signals, the machine tool may be damaged or a positioning error may occur due to the collision of the members.
msec. Such a position signal is also transmitted from the PLC control unit 82 to the NC control unit 8 via the signal path 83 between the control units.
1 can be transmitted with a time delay within an allowable range.

In this embodiment, the NC command to the PLC control unit 82 is sent directly from the CPU circuit in the motherboard 2 to the PLC control unit 82 via the main bus 3. May be sent to the NC control unit 81 via the main bus 3 once, and then sent from the NC control unit 81 to the PLC control unit 82 via the inter-control unit signal path 83. Further, the signal path 83 between the control sections directly connects the NC control section 81 and the PLC control section 82. However, a buffer circuit, a waveform shaping circuit, a phase matching circuit, etc. May be provided.

[0023]

Since the present invention is configured as described above, it has the following effects.

Even if the real-time processing capability of the personal computer is low, there is no delay in the operation of the NC device.
The reliability and safety of the C device can be increased.

Even if an expensive personal computer having a very high processing speed is not used, sufficient real-time performance can be achieved, and the manufacturing cost of the NC device can be reduced.

The NC control unit and the PLC control unit are
Since the memory card is mounted on the expansion board, the number of expansion slots to be used is reduced, the limitation on the expandability of the personal computer is reduced, and the cost as the NC device can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an NC apparatus according to the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional NC device.

FIG. 3 is a diagram illustrating an example of an NC program;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Personal computer 2 ... Motherboard 3 ... Main bus 4 ... Expansion slot 5 ... Auxiliary storage device 6 ... NC board 7 ... PLC board 8 ... NC expansion board 10 ... NC operation panel 81 ... NC control part 82 ... PLC control part 83 ... Control Intersection signal path

Claims (4)

[Claims] 1. A personal computer having a main bus (3), a general-purpose personal computer (1) having a plurality of expansion slots (4) on the main bus (3), and a servomotor attached to the expansion slot (4). An NC expansion board (8) provided with an NC control unit (81) for performing control and the like and a PLC control unit (82) for performing sequence control and the like. The NC expansion board (8) Numerical control device having a signal path between control units (83) for connecting the NC control unit (81) and the PLC control unit (82) and transmitting signals in addition to the connection line to the bus (3) . 2. A motherboard (2) including a CPU, a main memory, and a bus controller, a main bus (3) connected to the motherboard (2), and a plurality of expansion units provided on the main bus (3). A general-purpose personal computer (1) having a slot (4), an NC operation panel (10) connected to the motherboard (2) for inputting and editing an NC program, and attached to the expansion slot (4). An NC expansion board (8) including an NC control unit (81) for controlling a servo motor and the like and a PLC control unit (82) for performing sequence control and the like, wherein the NC expansion board (8) A signal path (83) between control units for connecting the NC control unit (81) and the PLC control unit (82) and transmitting signals, in addition to the connection line to the main bus (3). number The control device. 3. A numerical control device according to claim 2, wherein an auxiliary storage device (5) for storing an NC program is connected to said motherboard (2) without passing through a main bus (3). Control device. 4. The numerical controller according to claim 1, wherein a data bus width of said main bus is not less than 16 bits, and said signal path between said control units is not limited to 16 bits.
3) A numerical controller having a data bus width of 8 bits.