JPS6154502A - Numerical controller - Google Patents

Abstract

PURPOSE:To reset the power supply reset time by an amount equivalent to the shift of a mobile part when a power supply is cut off, by providing a back-up power supply which has no drop of voltage even in a power supply cut-off mode to an asynchronizing circuit, a reversible counter, a pulse generator, an encoder pulse discriminator and a memory for number of generated pulses respectively. CONSTITUTION:The number of pulses stored in a reversible counter 17 is backed up by a back-up power supply 23 and held even in case a service interruption occurs during the shift of a mobile part and the command pulse generated from a shaft command pulse generator 14 is stopped. A shift caused by the inertia of the mobile part is detected by pulse generators 7-9 which are packed up by a back-up power supply 23. While the revolving direction of the mobile part is discriminated by an encoder pulse discriminator 16 which is backed up also by the power upply 23. The discriminated pulses are supplied to asynchronizing circuits 19 and 20 and then supplied as they are to the counter 17. The number of pulses stored in the counter 17 is subtracted by an amount equal to the shift of the mobile part after the power supply is cut off and then stored again.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to positioning control of a large processing machine using a numerical control device (hereinafter referred to as an NC device) using a digital servo system.

[Prior art]

One of the shape machining mechanisms whose positioning is controlled by the digital servo system of the NO device, for example, the electric discharge machining device & the upper row will be explained.

FIG. 1 is a groove bottom diagram of a general electrical discharge machining apparatus.

In the figure, (1) is the workpiece, and (2) is the X-axis rotation support stand.

(3) is a Y-axis movable table, and a corrugated workpiece (1) and an X-axis movable table (2) are placed on this Y-axis movable table (3).

αO is an electrode and is attached to a conductive electrode surface plate (6).

(6) is a processing power source, and this processing power source (2) is used for wave-processed products (
1) and the electrode surface plate (b). Then, a discharge is generated between the workpiece (1) and the electric charge αO?
& The purpose is to obtain discharge marks on the workpiece (1). (
4) is an x@i rib motor that moves the X-axis movable table (2),
(5) is a Y-axis drive motor that moves the Y-axis movable table (3), (6) is a drive motor that moves the electrode surface plate (L return), (7), (8), and (9) are encoders. The pulse generator is directly connected to the drive motors (4), (5), and (6), and generates a pulse every time these drive motors (4, 5, and 6) change the position angle @J.

αa is pulse generation gg (7) < 8) The pulse 2 reception from (9) subsides, and the X-axis, Y-axis, Z @ drive drive -
4) This is a control device that fully automatically controls the drives of (5) and (6).

FIG. 2 is a block diagram of a positioning control groove groove using a digital servo system of a conventional NC device.

In (2), α4) is the axis command pulse generation outlet that generates the number of pulses corresponding to the distance to be moved by the movable table and electric power (菟αOt), and eυ is the number of pulses generated by the axis command pulse generation circuit a4. (A) is the pulse generation number memory that stores the pulse generation number? υ is the backup power supply that keeps the memory content from being lost when the power is turned off. αS is the encoder pulse discriminator. ,X
Axis drive motor (4), Y-axis drive motor (5),
Z @ Every time the output shaft of the drive motor (6) moves forward, a pulse is generated from the pulse generator (7), (8), and (9), and XIM, YM, Zllll[j-E:-
(4), (5), and (6) identify the rotational direction of the output shaft.

a*V is a desynchronization circuit that adds t to the command pulse from the axis command pulse generation circuit α and the feedback pulse.

Q″I) is a reversible counter with two desynchronized circuits 09ω
The number of υ pulses is added and subtracted by the pulses from .

(to) is a D/A conversion and amplification circuit which converts the number of pulses output by the reversible counter α from a digital Iv quantity to an analog quantity, and also amplifies the converted analog stopper. Axis command pulse generator α committee.

/<JV pulse generation number memory ■υ, backup power supply @5 encoder pulse discriminator (2), desynchronization circuit a1
(A), reversible counter α power, D/A conversion and amplification circuit 0 is the control device 'tj! The head is stored built-in.

Next, the operation will be explained.

X-axis movable table (2), Y-axis movable table (3), tonne wedge surface plate α
In order to move the entire axis η, a command pulse is generated by the axis command pulse generation circuit α4. The command pulse of this axis command pulse generation circuit α4 is 1, for example, when the rotation direction of the output shaft of the drive morph is clockwise, it is output as a command pulse in 10 directions, and when the rotation direction of the output shaft of the drive morph is counterclockwise, it is output as a command pulse in 1 direction. .

At this time, the finger from the axis command pulse generation circuit α4 is memorized by the pulse generation number memory memo U-(2η). b) Back up by -
Ru. The command pulses regularly generated by the axis command pulse generation circuit are input to the reversible counter αη, and
The digital Iv signal is converted into an analog voltage by the A/A conversion and amplification circuit α, and this analog voltage is amplified. This amplified analog voltage drives the X-axis drive motor (4), Y-axis drive motor (5), and Z-axis drive motor (4), Y-axis drive motor (5), and
@@The moving motor (6) is driven. These drive motors move the X-axis movable table (2), the Y-axis movable table (3), and the electrode surface plate αη. A pulse generator (7) (8) directly connected to the shaft end of the drive motor that drives the movable part.
The amount of rotation of each drive motor is detected by (9). The rotation amount of the drive motor detected by the pulse generators (7) (8) (91) is determined by the encoder pulse discriminator αQ.
The file will be packed into the file. This encoder pulse discriminator a9 identifies the rotational direction of the drive motor by the pulses generated by the pulse generator (n (8 bar 9).The rotational direction of the drive motor is, for example, clockwise, clockwise, or counterclockwise. Clockwise rotation is identified as unidirectional.

The signal is input to the desynchronization circuit a9 (a). At this time, the asynchronous northern time vI! The rayt head has an axis command pulse generation circuit 0.
The command pulse from D and the feedback pulse from the concoder pulse discriminator αθ are input simultaneously. That is, command pulses in ten directions from axis command pulse generation circuit α4,
The unidirectional feedback pulse from the encoder pulse discriminator α9 is sent to the desynchronization circuit φ to generate an axis command pulse [the unidirectional command pulse from the gll connection terminal 4 and the ten-directional feedback pulse from the encoder pulse discriminator α9] The pulse enters the desynchronization circuit and the desynchronization circuit α is not synchronized? The sum is added and output to the reversible counter αη. In the reversible counter αη, the number of pulses is calculated by subtracting the number of pulses input from the desynchronization circuit (A) from the number of pulses input from the desynchronization circuit Q, and is kept and stored from the constant change. Ru. This is repeated until the output from the reversible counter αη reaches ``1 zero''.
When it reaches zero, the drive motor stops.

However, the device is configured as described above, including one X-axis movable decoy (2), a Y-axis movable base (3), and an electric surface plate α].
) is moving when an unexpected power outage causes the pulses from the axis command pulse generator circuit to stop, and the command pulses from the command pulse generator circuit ) to memorize the number of pulse occurrences!1-(
21) Since it is backed up by '5', the number of command pulses can be stored even in the event of a power outage. However, in the event of a power outage, the X-axis movable platform (2), Y-axis movable platform (3),
The power supply surface plate (1) continues to move due to inertia, and the x4 drive motor (4) is directly connected to these moving parts.
, Y-axis drive motor (5), Z-axis drive motor (6)
Also, due to inertia, the belly is 1〈. In addition, movable parts may be moved by external force while the company is out of service. Therefore, the actual amount of movement may be greater than the amount of movement equivalent to the number of command pulses,
The amount of movement may be less than the command value. The number of command pulses generated by the axis command pulse generation circuit (b) when the power is restored is a memo of the number of pulses generated! J-@]) is stored as 1
However, since the actual position of the movable part is unknown, it takes time to confirm the actual position to restart the entire process, making one work step complicated. For this reason, in order to prevent the movable parts from moving due to inertia or external force when the power is turned off, methods such as restraining the movable parts with a brake to prevent them from moving have been used, but this method does not allow for precise positioning. I can't help it.

Also, in order to restrain and fix the movable parts with brakes, F
−1, it must be large-scale and expensive.−
There were two drawbacks.

[Summary of the invention]

Is this invention a drawback of the conventional ones mentioned above? The axis command pulse generation circuit that generates command pulses adds the command pulses generated by this axis command pulse generator path and the pulses fed back from the encoder pulse discriminator. A reversible counter that adds and subtracts the number of pulses in the ten and two directions from this desynchronization circuit, and a pulse that converts the number of rotations of the drive motor driven by the number of command pulses into the number of revolutions. a generator, an encoder pulse discriminator for identifying the rotational direction of the motor, a pulse generation number recorder or memory for storing the number of passes/I/passes generated in the axis command pulse generation path, and the desynchronization circuit. .

A reversible counter, pulse generator, encoder pulse discriminator, and pulse generation number storage memory each have a backup power supply unit that does not drop in voltage even when the power is turned off, making it possible to control the amount of movement of the movable parts when the power is turned off. The aim is to provide a number of control devices that can be restored only when the power is restored.

[Embodiments of the invention]

Hereinafter, an embodiment of the present invention will be explained with reference to the drawings. Third
In the figure, the same reference numerals as in FIG. 2 indicate corresponding parts, so the explanation will be omitted.

In the figure, 7) is a backup power source such as a storage battery that does not drop in voltage even when the power is cut off, and the pulse generator (7)
(8) (9) The encoder pulse discriminator (to), the reversible counter αη, the desynchronization concave “Jk&oco”, and the pulse generation number storage memory Qρ are backed up, respectively.

Next, as a specific example of operation, a case will be described in which a power outage occurs while the movable part is moving and the command pulses of the axis command pulse generators α4 and υ are stopped.

A power outage occurs while the movable part is moving, and the command pulses from the axis command pulse generator α4 are stopped.

The command pulse from this axis command pulse generator α4) is.

Even if it is stopped, the number of pulses stored in the reversible counter Q7) at the time of the power outage Q is backed up and maintained by the backup NL7. Even in the event of a power outage, the movable parts will continue to move for a while due to inertia. The amount of movement of this movable part is detected by the pulse generators (7), (8), and (9) backed up by the backup power supply (c), and the driving motor (3) is detected by the encoder pulse discriminator 09, which is also backed up. 4) Identify the rotation direction of (5>(6)).Then, this pulse that was not identified is
It is fed back and input to the desynchronization circuit Q1 or the desynchronization circuit signal. Desynchronization circuit QIj.

Since no command pulse is generated in (1), the feedback pulse from the encoder pulse discriminator Q61 is inputted to the reversible counter α force by -1 and multiplied by 3.

Then, the number of pulses stored in the reversible counter αη at the time the power was turned off is subtracted by the amount of movement of the movable part after the power was turned off, and the number is recorded as 2.

When the power is restored, the pulses 7 and ζda accumulated in the reversible counter αh are converted to analog voltage from the digital circuit by DA\conversion 2 and j・d width conversion α・, and this analog voltage is amplified. This amplified analog voltage drives the rotation motor and powers the other parts. And pulse generators (7) (8) (
9) After passing through the encoder pulse discriminator (to), the feedback signal enters the desynchronization circuit a1 and is output to the reversible counter α. Since the power has been restored, the generation of command pulses from the axis command pulse generation circuit α4 is resumed, and the movement is continued until the number of pulses of the reversible counter αη becomes "1 zero".In other words, the axis command pulse generation circuit C
The movable part moves at a position corresponding to the number of pulses 7 where L(a) occurs. As a result, the position of the movable part completely matches the position command from the control device.

In the above embodiments, the explanation has been focused on an electric discharge machining apparatus, but a shape processing machine such as a wire cut electric discharge machining apparatus or a laser machining apparatus may be used.

The same effect as in the above embodiment is lacking.

〔Effect of the invention〕

As described above, the present invention provides a pack-up "l power source section and a groove bottom because the voltage melts in the desynchronization circuit, reversible counter, pulse generator AS, encoder pulse discriminator, and pulse generation number storage memory even when the power is disconnected. By doing so, even if the movable part moves due to external force during a power outage such as a power outage, after the power is restored, it can be moved to the position that matches the commanded position immediately before the power was cut off, providing highly accurate positioning and movable parts. There is no need for a brake to fix the parts, so the device can be made inexpensive and compact.

[Brief explanation of drawings]

Fig. 1 is a groove bottom diagram of a general electrical discharge machining device, Fig. 2 is a block diagram of a positioning control mechanism of a conventional No. It is a block diagram. In the figure, (7), (8), and (9) are pulse generators, α
Q is an encoder pulse discriminator, αη is a reversible counter, α
LJ wire is a desynchronization circuit, ■ force is a memory that stores the number of pulses generated, and @ is a backup power source. Note that the same reference numerals in Figure 1 indicate corresponding parts.

Claims (1)

[Claims] an encoder pulse discriminator that identifies the rotational direction of the drive motor; an axis command pulse generation circuit that generates command pulses;
A desynchronization circuit adds the command pulses generated by this axis command pulse generation circuit and the pulses fed back from the encoder pulse discriminator, and adds and subtracts the number of pulses in the + direction and - direction from this desynchronization circuit. a reversible counter, a pulse generator that converts the number of rotations of the drive motor driven by the number of command pulses into a number of pulses, a pulse generation number storage memory that stores the number of pulses generated in the axis command pulse generation circuit, and the asynchronous counter. circuit,
A numerical control device equipped with a reversible counter, a pulse generator, an encoder pulse discriminator, a memory for storing the number of pulses generated, and a backup power supply unit that backs up the voltage to prevent voltage drop even when the power is cut off.