JPS6023045A - Intermittent driving apparatus of belt of automatic screen textile printing machine - Google Patents

Abstract

PURPOSE:To provide the titled apparatus capable of performing positional determination with high accuracy even if an printing endless belt is extended or contracted by subjecting the feed length of said belt to digital control. CONSTITUTION:An electric circuit starting from a position detector (pulse generator) 11 connected to the intermittent driving roll 1 of an endless belt 3 and reaching a DC electromotor 5 connected to the driving roller 1 through a deviation counter 19, a D/A converter 20 and a servo amplifier 21 is formed and function for discriminating the moving direction of the driving roller 1 is added to the deviation counter 19. When the driving roller 1 is rotated by the contraction of the belt in such a state that an electromotor 3 is stopped, a pulse signal is supplied to the deviation counter 19 from the pulse generator 11 connected to the roller 1 and brought to an electromotor driving order signal through the D/A converter 20. At this time, the signal of a driving direction is added with direction discriminating function.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intermittent driving device for a belt of an automatic screen printing machine, and more specifically, a digital control mechanism for an intermittent driving roller of an endless belt and an electric control mechanism for an intermittent driving roller of an endless belt. The present invention relates to a device equipped with a locking mechanism. The present invention further relates to an intermittent driving device for a belt that eliminates positioning defects caused by uneven thickness and expansion/contraction of an endless belt.

Conventionally, intermittent driving of an endless belt in an automatic screen printing machine has been achieved by installing a belt clamping device that horizontally reciprocates along the endless belt supported by a pair of rollers by the operation of a hydraulic cylinder, and moving this belt clamping device between the stroke bars. This is generally done by driving the This type of device requires many belt drive systems in addition to the belt support mechanism, and is still unsatisfactory in terms of making the device larger and more complicated. There is a problem in that adjustment also requires more effort and time than IA'.

It is already known that the intermittent drive of an endless belt can be controlled by pulse control.
In Publication No. 7, the repeat length is set as the number of pulses, and the actual feeding of the endless belt is detected as the number of pulses.
It is disclosed that the drive of the endless belt support roller is controlled so that the number of detected pulses is subtracted from the set number of pulses and the belt is stopped at the set number of pulses.

Although this intermittent drive device has the advantage of being able to easily set the repeat length and maintain belt feeding accuracy at a high level, the actual positioning accuracy is still not fully satisfactory. Something was discovered.

That is, the endless belt used in a textile printing machine is not a rigid body, but is generally made of reinforcing rubber, and inevitably tends to expand and contract to some extent. Thus, the elongation of the belt that occurs at the start of the drive and the contraction of the belt that occurs when the drive is stopped have a negative effect on positioning accuracy.

Therefore, an object of the present invention is to provide a digitally controlled intermittent belt drive device that can perform highly accurate positioning operations regardless of the tendency of the endless textile printing belt to expand or contract.

Another object of the present invention is to provide an intermittent drive device for an endless belt that includes a digitally controlled feeding mechanism for the endless belt and an electric locking mechanism for locking the belt at a stop position.

Further objects of the invention will become apparent from the description below.

According to the present invention, there is provided a device for intermittently driving an endless belt of a flat automatic screen printing machine with a roller, and the driving device sets the belt feeding length as a pulse number and controls the belt feeding speed. and a data setting mechanism for setting acceleration/deceleration; a position detector connected to the roller and detecting the belt feed length as a number of pulses; a deviation counter that performs a subtraction operation and stops belt feeding when the difference becomes zero, a digital/analog converter that converts a pulse signal from the deviation counter into a DC drive signal, and the converter. It consists of a servo amplifier that controls the roller drive straight 01f, Tfl, and motive according to signals from the position detector, and the deviation counter has a direction discrimination function 8 that discriminates the directionality of the pulse signal from the position detector.
Belts for automatic screen textile printing machines characterized by a position detector, deviation counter, digital/analog converter, and DC motor for driving the roller, forming an electrical lock circuit for the roller when the belt is stopped. An intermittent drive is provided.

The present invention will be explained in detail based on a specific example shown in the accompanying drawings.

In FIG. 1 showing the overall arrangement of the textile printing machine, a driving roller 1 and a driven roller 2 are provided at both ends of the machine frame (not shown), that is, on both sides of the textile printing work area P.
An endless belt 6 is stretched between the driven roller 2 and the driven roller 2. The material to be printed (not shown) is affixed to the side of the driven pulley 2 of the endless belt 6, and is moved to the printing work area by intermittent driving of a DC motor 5 connected to the drive roller 1 via a reducer 4 as necessary. 1 intermittently on P
Sent by repeat length.

In the textile printing work area P, one or more screen frames 6 are located above the endless belt 6, and an elevating frame 7 is used to move the screen frame 6 up and down relative to the endless belt 6. And this elevating frame 7
A drive mechanism 8 is provided for driving the drive up and down. The screen frame 6 is in a relatively raised position when the endless belt 6 is being fed, and is lowered by the drive mechanism 8 when the endless belt 6 is stopped, so that the screen and the material to be printed (both not shown) come into contact with each other. do.

In this way, the printing paste on the screen is printed on the material to be printed by the squeezing action, which is known per se, and when this squeezing action ends, the screen frame 6 is relatively driven upward by the drive mechanism 8, and the above-mentioned upward movement occurs. Return to position. In this relative positional relationship, the endless belt 6 is fed by one repeat length by the drive roller 1, and the above-described operation is repeated.

The intermittent driving of the endless belt 6 is performed by the data setting mechanism 9, digital/DC servo machine $7110, and position detector 11 shown in FIG.
This is done while controlling the drive of the DC motor 5. In the intermittent drive device of the present invention, an electric lock circuit for the drive roller 1 is provided between the position detector 11, the digital DC servo mechanism 10, and the DC motor 5. Its distinctive feature is that it is formed.

Connotator setting machine m9 and digital DC servo mechanism 10
In FIG. 2 showing the details of MfJ, this data setting mechanism 9 sets the feed length of the belt 6 as the number of pulses, and also sets the feed speed and acceleration/deceleration of the belt. It is composed of a repeat length setting switch 12, a data setting counter 16, an acceleration/deceleration device 14, and a belt speed setting device 15.

In this specific example, switch 12 causes repeat length C
L) is converted into electrical pulse number 16 and set as the number of pulses, and if necessary, the correction data setting switch 16
Accordingly, correction data (ΔRn) is set as the number of flattening pulses in response to variations in the thickness of each portion of belt B.

When the start signal is input, the adder/subtractor 17 calculates L±△.
Rn is calculated, and at the same time, data of L±ΔRn is set in the data setting counter 16.

The belt speed setting device 15 sets the belt feeding speed (
vo) is set, and upon completion of the data setting described above, the speed command pulse from the belt speed setting device 15 is sent to the accelerator/deceleration device 14. The accelerator/decelerator 14 controls the speed command pulse from the belt speed setting device 15 so that it becomes an acceleration/deceleration (acceleration - deceleration) that matches the load condition on the machine side. The output pulse signal is sent to the servo mechanism 10 via the wiring 18 as a command pulse signal to the digital DC servo mechanism 10 while subtracting the contents of the data setting counter 16. When becomes zero, the accelerator/decelerator 14 stops operating, and the sending of the command pulse is completed.

To explain this relationship in more detail, FIG. 6 explains the relationship between the feeding speed (v) and time (ri) of the endless belt 6, and the endless belt 6 is accelerated and then driven at a constant speed. The belt speed setter 15 sets this constant speed V. On the other hand, the acceleration/deceleration device 14 sets the acceleration/deceleration speed (α1, α2). The belt feed length CL) is the acceleration driving time Δt5 and the constant velocity driving time t. , if the deceleration driving time is Δt2, then Δt, Δt2 L=υ. Bo-Ci-].

It will be understood that this speed pattern can be obtained by controlling the amount of sending pulses per unit time as shown in FIG.

The digital DC servo mechanism 10 includes a deviation counter 19,
It consists of a digital-to-analog (D/A) converter 20 and a servo amplifier 21. The amount of pulses supplied from the data setting mechanism 9 to the deviation counter 19 through the wiring 18 is converted into an analog signal by the D/A converter 20, becomes a speed command signal, and is sent to the DC motor 5 via the servo amplifier 21. Control takes place. Similarly, a tacho generator 22 is connected to the drive shaft of the DC motor 5 to detect the actual rotational speed of the motor.
The detection signal from the servo amplifier 21 is fed back to the servo amplifier 21 via the connection 26.

When the drive row 21 is driven, a position detector (pulse generator) 11 attached to the roller or the drive shaft of the roller generates a pulse signal in response to the displacement of the roller 1 and therefore the belt 6.

This pulse signal is fed back to the deviation counter 19 via the connection B 24 f .
Subtract the contents of. When the number of pulses from the position IH detector 11 becomes equal to the number of command pulses supplied via the data setting counter ~16, the content of the deviation counter 19 becomes zero, and the rotation of the DC motor 5 and therefore the drive roll 1 stops. At the same time, the deviation of both pulse numbers is zero (M
The signal is sent to the data setting counter 16 via the connection 25, and the positioning completion signal R is sent from the counter via the connection 26.
is sent.

Based on this positioning completion signal R, for example, the lowering of the textile printing frame 7 and the subsequent squeezing action are performed in accordance with the procedure explained with reference to FIG.

In the present invention, a detector 14 (pulse generator) 11 connected to the drive roll 1, a deviation counter 1
9. An electric circuit is formed through the D/A converter 2o and the servo multiplier 21 to the DC electric tlJ machine 5 connected to the drive row 21 even after the positioning is completed. A direction determining function is added to determine in which direction the drive row 21 is rotated, that is, in which direction the belt is moved.

When the electric motor 4 is in a stopped state, that is, when positioning is completed, the content of the deviation counter 19 is zero. In this state, the drive roller 1 is compressed due to belt contraction or other external force.
A pulse signal from a pulse generator 11 connected to the line drive roller 1 is supplied to a deviation counter 19 when the line drive roller 1 is rotated. This pulse becomes a motor drive command signal via the D/A converter 20, but due to the direction determination function described above, it becomes a drive command signal in the opposite direction to the direction in which the roller 1 was forcibly rotated by an external force. Electric motor 4
is driven to generate a force that returns the amount of rotation of the roller 1 to its original state.

Since the endless belt for textile printing is made of reinforcing rubber, there is an unavoidable tendency for the belt to contract when it stops. However, according to the present invention, even when the electric motor 5 is stopped, the electric braking force (servo This prevents the belt from collapsing and enables highly accurate positioning operations.

[Brief explanation of the drawing]

Figure 1 is a side layout view of the device of the present invention;
This is a block diagram of a four-motion control system, and FIG. 6 is a diagram showing the relationship between the speed of an endless belt and time. 1 is a drive roller, 6 is an endless belt, 5 is a DC motor, 9 is a data setting mechanism, 11 is a position detector, 19 is a deviation counter, 20 is a digital/analog converter, 21
respectively indicate servo intensifiers. Patent applicant Toshin Kogyo Co., Ltd.

Claims (1)

[Claims] A device for intermittently driving an endless belt of a flat automatic screen printing machine with a roller, and the driving device uses data that sets the belt feeding length as the number of pulses and also sets the belt feeding speed and acceleration/deceleration. a setting mechanism, a position detector connected to the roller and detecting the belt feeding length as the number of pulses, and a position detector connected to the data setting mechanism and the position detector, which subtracts the feeding pulse from the setting pulse number and calculates the difference between the two. a deviation counter to stop the belt feeding when the value becomes zero; a digital/analog converter to convert the pulse signal from the deviation counter into a DC drive signal; It consists of a servo amplifier that controls the drive DC motor, and the deviation counter has a direction determination function that determines the directionality of the pulse signal from the detector, a position detector, a deviation counter, and a digital An intermittent drive device for a belt of an automatic screen printing machine, characterized in that an analog converter and a DC motor for driving the roller form an electrical lock circuit for the roller when the belt is stopped.