JPH057301B2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a numerical control device for conveyance.

(Prior art) In the case of press processing, a plate material (conveyed object) wound by an uncoiler etc. is fed intermittently to a press machine using a roll feed mechanism (conveyance mechanism) equipped with a pair of rolls. .

This roll feed mechanism is controlled by a numerical control device. This numerical control device includes a rotary encoder (detection means) that sends out a pulse every 0.1 mm, a subtraction counter (counting means), and a unit feed amount set as 1 to set an integer value. It has a feed amount setting device (feed amount setting means). Each time the subtraction counter receives a pulse from the rotary encoder, it subtracts 1 from the initial value of the integer set by the feed amount setting device, and sends this subtraction value signal to the servo system (drive control means) of the roll feed mechanism. It is something. Then, when this subtraction value becomes zero, the feeding operation by the roll feed mechanism is stopped.

In the above numerical control device, the feed amount corresponding to the count number "1" in the subtraction counter, that is, the unit feed amount is the minimum value that can be controlled. Therefore, an error smaller than the unit feed amount occurs between the set value of the feed amount for one time, which is set as an integer value with the unit feed amount as 1, and the actual feed amount for one time. This error can be ignored in one feeding, but it accumulates when feeding is repeated many times. For this reason, even if the total feed amount based on a predetermined number of feeds is specified, the actual total feed amount may not fall within the range of the specified total feed amount.

As a countermeasure for this, in the past, the unit feed amount was
It was lowered by one digit from 0.1mm to 0.01mm.

(Problems to be Solved by the Invention) With the above-mentioned device, the number of counts of the rotary encoder increases by 10 times, requiring the use of a precise and expensive rotary encoder.
The number of subtractions performed by the subtraction counter also increased tenfold, necessitating the use of an expensive subtraction counter with a large capacity.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and its gist consists of (a) drive control means for a transport mechanism that intermittently transports objects to be transported; (b) a detection means that sends out a pulse for each unit feed amount of the transported object by the transport mechanism; and (c) a detection means that counts by one each time it receives a pulse from the detection means, and combines this count value with an initial value of an integer. (d) a feed amount setting means for setting a unit feed amount to 1 and substantially setting an integer value; (e) a correction value setting means for setting a correction value whose absolute value is smaller than the unit feed amount; and (f) cumulatively adding or subtracting the correction value input from the correction value setting means for each feed; When the absolute value of this cumulative calculation value is smaller than the unit feed amount, the initial value of the counting means is determined to be equal to the integer value set by the feed amount setting means,
When the absolute value of the cumulative calculation value becomes equal to or exceeds the unit feed amount, the initial value of the counting means is determined to be the value obtained by adding or subtracting 1 to the integer value set by the feed amount setting means. There is provided a numerical control device for conveyance, characterized in that it is equipped with a calculation means that performs the following steps.

(Function) In the calculation means, the correction value is cumulatively added for each feed, and when the absolute value of this cumulative addition value becomes equal to or exceeds the unit feed amount, the initial value of the counting means is set to the above-mentioned feed amount. By adding or subtracting 1 to the integer value set by the amount setting means, the total feed amount can be brought into the specified feed amount range by actually feeding the feed a plurality of times.

(Example) Hereinafter, an example of the present invention will be described based on FIG. A press plate material 1 (object to be transported) wound around an uncoiler (not shown) is intermittently fed by a roll feed mechanism 10 (transport mechanism) and supplied to a press machine (not shown). The roll feed mechanism 10 has a servo motor 11, and a small pulley 12 connected to an output shaft 11a of the servo motor 11 is connected to a large pulley 1 via a belt 13.
4 are connected. The large pulley 14 has a shaft 14a.
A lower roller 15 is connected through the lower roller 15, and an upper roller 16 is pressed against the lower roller 15. And these roll 1
The plate material 1 is fed by rotating the lower roll 15 as the servo motor 11 is driven while holding the plate material 1 between the rollers 5 and 16.

The servo motor 11 is drive-controlled by a servo system 20 (drive control means). This servo system 2
0 is a tachometer generator 21 connected to the output shaft 11a of the servo motor 11, and a speed signal amplifier 2.
2, and a servo amplifier 23 that controls the voltage supplied to the servo motor 11 based on the deviation between the feedback voltage from the tacho generator 21 and the output voltage from the speed signal amplifier 22. The speed signal amplifier 22 has a D/A converter and a function conversion amplifier, and converts and amplifies the digital signal of the subtraction value from the subtraction counter 40 (counting means) into a voltage that becomes speed information.

Rolls 31 and 32 for measuring feed length are arranged near the rolls 15 and 16, and are adapted to sandwich the plate material 1. A rotary encoder 30 is attached to the shaft 31a of the lower measuring roll 31.
(detection means) are connected. And board material 1
When the rolls 31 and 32 are fed by the roll feed mechanism 10, the rolls 31 and 32 are rotated, and this rotation is detected by the rotary encoder 30. That is, plate material 1
A pulse is sent to the subtraction counter 40 every unit feed amount, for example, every 0.1 mm.

An initial value signal is sent to the subtraction counter 40 from a microcomputer 50 (calculating means).

A feed amount setting device 60 (feed amount setting means) and a correction value setting device 70 (correction value setting means) are connected to the microcomputer 50. The feed amount setter 60 sets the unit feed amount to 0.1 as described above.
When mm is set, an integer value is set with this 0.1 mm as "1". The correction value setter 70 is used to input a correction value whose absolute value is smaller than the unit feed amount of 0.1 mm.

A detection signal is sent to the microcomputer 50 from a limit switch 80 that closes when the crankshaft of the press reaches a predetermined rotation angle. This detection signal is sent out for each press, in other words, each time the plate material 1 is fed.

In the above configuration, a desired feed amount is set using the feed amount setting device 60. For example, the desired feed amount is 10.0mm
In this case, since the unit feed amount is 0.1 mm,
Set the integer "100".

Further, a correction value is set using a correction value setting device 70.
The correction value is determined as follows. That is,
As mentioned above, when the unit feed amount is 0.1 mm and the feed amount for one time is set to 10.0 mm using the feed amount setting device 60, the total feed amount when sending 50 times is 500~
If a range of 501 mm is specified, the average specified total feed amount is 500.5 mm. On the other hand, when the actual total feed amount is in the range of 499.6 to 500.4 mm, the average actual total feed amount is 500 mm. Therefore,
The difference between the specified and actual average total feed amount is 0.5 mm,
The difference in the average feed amount per run is 0.5mm ÷ 50 runs = 0.01mm
becomes. Therefore, if the feed amount for one time is increased by 0.01 mm, the actual total feed amount will fall within the range of the specified feed amount. This 0.01mm becomes the correction value.
Note that in this case, the correction value is a positive value.

The feed amount and correction value for one time are stored in the register of the microcomputer 50. This microcomputer 50 performs the calculation shown in FIG. 2 every time it receives a detection signal from the limit switch 80. To be more specific, first, an integer value (A) corresponding to the set feed amount stored in a register is substituted into another register, and is set as an initial value (B) for the subtraction counter 40.

Next, it is determined whether the set correction value (D) is zero. If it is zero, the calculation ends without performing cumulative addition, which will be described later. In this case, the above initial value
(B) is sent to the subtraction counter 40 without being updated.

If the correction value (D) is not zero, the correction value (D) is further added to the cumulative addition value (C) obtained in the previous calculation to update the cumulative addition value (C).

Next, the updated cumulative addition value (C) is the unit feed amount (E)
Determine whether the value is greater than or not. If it is smaller, the calculation ends, the initial value (B) is sent to the subtraction counter 40 without being updated, and the cumulative addition value (C), which will be described later, is not updated.

If the cumulative addition value (C) is larger than the unit feed amount (E), 1 is added to the initial value (B) to update the initial value (B).
This updated initial value (B) is "101" (feed amount that is the set feed amount 10.0 mm plus unit feed amount 0.1 mm).
10.1 mm) is sent to the subtraction counter 40.

Furthermore, the cumulative addition value (C) is updated by subtracting the unit feed amount (E) from the cumulative addition value (C) before and after the above calculation. As a result, the updated cumulative addition value (C) becomes smaller than the unit feed amount (E), is temporarily stored in the register, and in the next calculation, the correction value (D) is cumulatively added to this value.

Each time the subtraction counter 40 receives a pulse from the rotary encoder 30, it subtracts 1 from the initial value sent from the microcomputer 50 for each feed, and sends this subtracted value to the speed signal amplifier 22. The feeding of the plate material 1 is controlled.

Since the correction value is 0.01 mm and the unit feed amount is 0.1 mm, the microcomputer 50 sends out the initial value "100" almost 9 times out of 10 to execute a feed of 10.0 mm, and almost 1 out of 10 times. At this time, the initial value "101" is sent to the subtraction counter 40, and a feed of 10.1 mm is executed. Therefore, the total feed distance can be set within the specified range of 50 to 501 mm by 50 actual feeds.

The present invention is not limited to the above embodiments, and various embodiments are possible. For example, the microcomputer may also include the counting means.

The subtraction counter may have a reversible function. That is, if the roll feed mechanism feeds the plate too much, the subtraction value becomes negative, and the plate 1 is fed backward based on this negative subtraction value. During this reverse feeding, the subtraction counter performs addition until the subtraction value becomes zero. In this case, it is necessary to add direction discrimination means.

As a counting means, a deviation counter may be used instead of a subtraction counter. In this case, an oscillation controller and an oscillator are interposed between the microcomputer and the deviation counter. Initial value information determined by the microcomputer is stored in the oscillation controller. This oscillation controller controls the total number of pulses sent from the oscillator to the deviation counter to be the same as the initial value. The deviation counter adds the pulses sent from the oscillator, subtracts the pulses sent from the rotary encoder, and outputs the deviation value of the addition and subtraction to the DA converter. The DA converter converts this deviation value into a voltage level and outputs it as a speed signal to the servo amplifier. As a result, when the deviation value is large, the motor rotates quickly, and when the deviation value is small, the motor rotates slowly. The motor stops when the deviation is zero.

When inputting on the feed rate setting device, set the unit feed rate to 0.1.
For example, "10.1" may be input as mm. In this case, the above set value is converted into an integer using a microcomputer. Therefore, the feed amount setter essentially sets an integer value.

A negative correction value may be entered in the correction value setting device.

In a microcomputer, the initial value may be corrected by subtracting 1 from the set value. In such a case, a negative correction value may be input using the initial value setter. Alternatively, the correction value may be cumulatively subtracted using a microcomputer.

(Effects of the Invention) As explained above, in the present invention, by simply adding a correction value setting means and a calculation means, it is possible to bring the total feed amount within the specified feed amount range by actually feeding multiple times. , a numerical control device can be provided at low cost without requiring expensive detection means or counting means.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a numerical control device according to the present invention, and FIG. 2 is a flow sheet diagram illustrating calculations performed by a microcomputer of the same device. DESCRIPTION OF SYMBOLS 1...Plate material (transported object), 10...Transportation mechanism (roll feed mechanism), 20...Drive control means (servo system), 30...Detection means (rotary encoder), 40...Counting means (subtraction counter) , 50... calculation means (microcomputer), 60... feed amount setting means (feed amount setting device),
70... Correction value setting means (correction value setting device).

Claims (1)

[Scope of Claims] 1. (a) drive control means for a transport mechanism that intermittently transports the transported object; (b) detection means for sending out a pulse for each unit feed amount of the transported object by the transport mechanism; (c) Control is performed via the drive control means to count by 1 each time a pulse is received from the detection means, and to stop the transport mechanism when the difference between this count value and the initial value of the integer becomes 0. (d) feed amount setting means for setting a substantially integer value with the unit feed amount as 1; and (e) correction value setting means for setting a correction value whose absolute value is smaller than the unit feed amount. (f) The correction value input from the correction value setting means is cumulatively added or subtracted for each feed, and when the absolute value of this cumulative calculation value is smaller than the unit feed amount, the initial value of the counting means is set. , is determined to be equal to the integer value set by the feed amount setting means, and when the absolute value of the cumulative calculation value becomes equal to or exceeds the unit feed amount, the initial value of the counting means is set as the feed amount. 1. A numerical control device for conveyance, comprising: arithmetic means for determining a value obtained by adding or subtracting 1 to the integer value set by the amount setting means.