JPH01246152A - High-precision actuation controller in processing unit - Google Patents

Abstract

PURPOSE:To provide the title controller so designed that a processing unit and a conveyor are controlled by the counter output obtained by counting pulses corresponding to the carrying distance for an object to be processed thereby easily improving work for regulation and maintenance. CONSTITUTION:Firstly, preset data are inputted to (A) the first counter circuit 18 to count pulse sequences produced, at each specified carrying distance, from a programmable logic controller 8, and (B) the second counter circuit 19 to count clock pulses of a specified frequency from the beginning of producing counter output of the circuit 18. Second, an object to be processed such as a plate glass 10 is unloaded at high speed and passed through a photoelectric limit switch 24 followed by starting counting with the circuit 18 and said object is carried to a specified place through rolls 21, 22. Thence, the timing output of the circuit 19 is actuated to start counting along with controlling the actuation of the roll 21, 22 and the cylinders 12, 13 of a press molding machine 2 in the processing unit, and a mold 20, thereby controlling high-precision actuation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-precision operation control device for processing equipment used in a processing system equipped with a conveyor.

[Summary of the invention]

The first pulse train that counts the pulse train corresponding to the conveyance distance of the workpiece
This counter circuit and a second counter circuit that counts clock pulses of a constant frequency are operated in coordination, and the processing equipment and conveyor are controlled by the counter output, allowing for optimal control adjustment when changing the type of workpiece. This is a high-precision operation control device for processing equipment that facilitates processing.

[Conventional technology]

2. Description of the Related Art Automatic machining systems are often used in the manufacturing industry, in which a workpiece is guided to a processing position by a conveyor and a processing device such as a press molding machine is operated at a predetermined timing. The control system of such a rotation system generally consists of a sequence control system and a servo control system, and the two are designed in advance to work together.

Relay sequencers have traditionally been used for sequence control, but because the control program is fixed by hardware such as relays, they lack flexibility and cannot support high-mix, low-volume production.

For this reason, a programmable sequence controller (
A programmable general-purpose sequence control device called a programmable logic controller (PLC) is used to quickly change the sequence flow and timing for each type of workpiece. .

A suitable interface is provided between the sequence controller and the servo system, and sequence control is performed while monitoring the operation of the servo system.

For example, a sequence controller detects that the positioning of a workpiece has been completed and controls the process to proceed to the next step.

[Problem to be solved by the invention]

A general-purpose programmable controller interprets the entire program represented by a series of ladder diagrams (ladder circuits) once at a fixed cycle (scan time) and updates external output. This scan time is unavoidable because it is programmable, and although it varies depending on the program length, it is about 50 m5ec at the shortest. Therefore, it is not possible to create a sequence with high accuracy such as ±1 m5ec.

For example, in the hot press process of bending plate glass into the required shape, strict temperature control and positioning accuracy are required to improve the finish accuracy, so the plate glass that leaves the heating furnace is transferred to a press forming machine at a high speed of 1 m/sec. It is introduced and positioned, and immediately forcedly cooled for hardening after press forming. Therefore, the stop position (press position) of the glass after exiting the furnace, the opening/closing operation timing of the press mold, the timing of the cooling air blowing, etc., in other words, the operation timing of various actuators, has an accuracy of about ±1 m5ec, which is equivalent to ±1 mm in distance. A control system is required to command the operation.

Further, in the example of the plate glass forming machine described above, the lowering operation of the press mold must be started before the positioning of the glass is completed. III. If the positioning is completed, the operation will be slow and the temporary glass will naturally cool down.

Therefore, the program must be designed to allow partial parallel operation of the sequence controller and the servo system. However, this means that the sequence controller and the servo controller operate independently without any relationship on the time axis, making constant setting extremely complicated in the case of high-mix, low-volume production. That is, it is necessary to create a detailed program in advance for each product type so that the sequence operation and servo operation are consistent in time. For this reason, when there are many actuators that need to be sequence-controlled in a Canadian system and high-speed operation is required, the multiple operation timings of each actuator must be individually adjusted on the order of m5ec for each type of workpiece. Therefore, adjustment is not easy and requires a lot of time.

In view of this problem, one object of the present invention is to provide a high-precision operation control device for a processing device that can flexibly respond to high-mix, low-volume production and can set highly accurate timing.

Another object of the present invention is to provide a high-precision operation control device for processing equipment that allows for extremely easy program changes and readjustments in response to changes in the type of workpiece, even when parallel operations of sequence control and servo control are allowed. It is to be.

[Means to solve the problem]

The high-precision operation control device for a processing device of the present invention is applied to processing equipment that guides a workpiece to a processing position on a conveyor and operates the processing device at a predetermined timing.

A first counter circuit is provided that counts pulse trains generated every fixed transport distance from the time when the workpiece passes a predetermined position, and a constant frequency pulse train is provided from the time when one count output of the first counter circuit is generated. A second counter circuit is used to count clock pulses.

A controller is provided for supplying preset data to the first and second counter circuits, and the transport conveyor and the processing device are controlled based on the output timings of the first and second counter circuits. has been done.

[For production]

The timer operation by each counter circuit is performed by a simple routine consisting of a comparison between preset data and a count value. Therefore, timing settings on the order of ±1 m5ec can be achieved extremely easily.

The first counter circuit generates the operating timing required to be associated with the positioning servo of the workpiece to the processing position. The second counter circuit operates on its own time axis and generates the operation timing of various actuators in parallel with the servo operation.

Since the first counter circuit monitors the transport position of the workpiece, if the sequencer by the second counter circuit is started when the position is reached, the parallel operation of the positioning servo control and sequence control can be performed. Permissible. That is, various actuators are operated in a fixed procedure in conjunction with the progress of the positioning servo.

The preset value of the first counter circuit related to the position of the workpiece must be changed depending on the product type (wave force, shape of the workpiece, etc.), while the count value of the second counter circuit is affected by the product type (wave force, shape of the workpiece, etc.). Set this to a common timing that is not affected by changes in deceleration rate for each product during positioning.

That is, the various actuators that control the processing equipment can always be operated at the same timing regardless of the product type, if the starting point is the time (position) at which the positioning servo is started.

〔Example〕

An embodiment in which the present invention is applied to a heat forming apparatus for automobile window glass will be described below.

FIG. 1 is a side view of the main part of the thermoforming apparatus, and FIG. 2 is a plan view of the main part. The plate glass IO is placed on a conveyor roll 11 within the heating furnace 1 and heated while moving within the furnace. A press molding machine 2 is installed adjacent to the outlet of the heating furnace 1,
The sheet glass 10 is transferred to the in-machine conveyor roll 21 in the molding machine 2, and is transferred to the upper mold 20a and the lower mold 20 of the press mold 20.
b.

In order to minimize the temperature drop from the heating state set near the softening point, the plate glass 10 is heated at high speed (100 m).
m/sec) and introduced into the press molding machine 2. The speed of the drive motor 15 for the in-machine conveyor roll 21 is controlled by a positioning servo system, and the speed is reduced from the above speed to approximately zero. During this time, the temporary glass IO advances while being decelerated by about 1 m, hits a slitter (not shown), and is positioned at a predetermined position in the mold 20.

At the end of deceleration, a part of the conveyor roll 21,
Further, the lifting roll 22 located between the upper mold 20a and the lower mold 20b is lowered by the cylinder 13 together with its rotation drive unit. Therefore, almost at the same time when the horizontal conveyance of the temporary glass 10 is stopped, the lower mold 20b is clamped, and the plate glass 10 is bent and formed to follow the shape of the mold.

A ring mold 20c is provided around the lower mold 20b to improve the molding precision of the peripheral edge of the window glass that corresponds to the window flange of the automobile. This ring type 20c is a separate type in which the window glass is bent at both sides (wings) where the curvature is large.

When the bending force is increased, the cylinders 12 and 14 are driven to raise and lower the upper mold 20a and the lower mold 20b, respectively, and the cooling air is blown to the desired position. In this state, the plate glass 10 is held in the air above the ring mold 2OC so as not to interfere with the upper mold 20a and the lower mold 20b. Next, an oscillation device (not shown) connected to the ring type 20c is activated to swing the temporary glass 10 in an elliptical shape within a horizontal plane. At the same time, cooling air is blown from a large number of nozzles 23 embedded in the surfaces of the upper mold 20a and the lower mold 20b, and the plate glass 10 is
quench and strengthen.

After that, actuate the cylinder 13 again, raise the elevator J-ru 22 to remove the plate glass IO from the ring mold 2Qc, then start the drive motor 16 to move the in-machine conveyor roll 21 and the elevator roll 22, respectively. Rotate the plate glass 10
is transferred to the next process.

FIG. 3 is a block diagram of a main part of a circuit that performs sequence control of various operations of the above-mentioned molding apparatus.

The PLC controls the sequence of the entire system.
8 (programmable sequence controller), and a first counter circuit 18 and a second counter circuit 19 subordinate to the PLC 8 perform precise sequence control on the order of m5ec.

These counter circuits 18,19 are available as counter modules and typically include a number (e.g. eight) of registers 18a-18 storing preset data.
b, 19a-19h and 1" each) counters 18i, 19
i, and is configured to generate a timing output every time the counted value of the counter 181.19i matches the pre-mono l-data of the register 18a--119a--.

Note that counter modules that incorporate a CPU and have more functions are also known.

The first counter circuit 18 counts the pulse train corresponding to the conveyance distance of the plate glass 10 conveyed by the in-machine conveyor roll 21 and the lifting roll 22. This pulse train is obtained from a pulse generator 16 attached to the drive motor 15 of each roll 2L22. Therefore, the first counter circuit 1
The timing output 8 is assigned to the timing control of the control unit and actuator that must be related to the moving position and the stopped position of the glass plate 10.

That is, the first counter circuit 18 controls the control unit 2 of the drive motor 15 of the conveyor roll 21 and the lifting roll 22.
5, some timing outputs are derived, and an output of the roll lowering timing is derived to the electromagnetic valve 26 for the cylinder 13 that operates the lifting roll 22. A photoelectric limit switch 24 is provided on the exit side of the heating furnace 1 to indicate the absolute position of the glass plate 10, and its output resets the count value of the counter circuit 18 to zero.

On the other hand, the second counter circuit 19 is
The count is reset to zero in response to one timing output of
Clock pulses with a constant frequency of (period uJ1100 psec) are counted. The output of this second counter circuit 19 is assigned to various timing controls performed in parallel with the positioning operation of the temporary glass 10.

That is, the second counter circuit outputs timing signals to the control unit 27 of the cylinder 12 that drives the L-type 20a and the solenoid valve 28 of the cylinder 4 that drives the lower mold 20b. The second counter circuit 19 also controls the @haiben 30 of the cylinder 29 that drives both wings of the ring type 20c, the control unit 33 of the drive motor 31 of the Ososhire-Noyon device connected to the ring type 20c, the old type 20a, and the lower Type 20b
Timing outputs are respectively derived from solenoid valves 331, 34 of the cooling air nozzles 23 provided in the cooling air nozzles 23.

FIG. 4 is a flowchart illustrating the operation of the sequence control circuit of FIG. 3. First, in step Sl, each register 18 a of the first and second counter circuits is sent from the PLC 8.
---1.-119a----1.- is loaded with preset data and enters a standby state. Next, in step S2, the plate glass 10 is outputted from the heating furnace 1 at high speed, and in step S
When the front end passes the photoelectric limit switch 24 at 3, the first counter circuit 18 starts counting the output pulses of the pulse generator 16 (step S4). As a result, the count value of the first counter circuit 18 becomes roll 21.2.
When the front end of the glass plate 10 reaches point A in FIG. 2, the start timing output P8 of the second counter circuit 19 is obtained from the first counter circuit 18.

After that, the second counter circuit 19 becomes the first counter circuit 18.
and in parallel with the timing output related to the positioning servo by the output of the first counter circuit 18,
Timing outputs of various actuators are generated (step S5).

The reason why the reset position of the second counter circuit 19 is shifted to point A is that when the subsequent glass enters the molding machine 2, the processing of the portion where the second counter circuit 19 is held is completed. This is to prevent it from being reset inadvertently.

The first counter circuit 18 derives a deceleration timing output P1 of the in-machine conveyor roll 21 and the lifting roll 22 when the glass plate IO has advanced a predetermined distance from point A, and then derives a roll stop timing output P2 (step S6
). The roll control unit 25 receives these timing outputs and performs deceleration and stop control in order to position the plate glass 10 at a predetermined position in the horizontal direction of the forming machine 2. Also, before the rolls 21 and 22 stop, the lifting roll 22
The timing output P3 of the lowering command is derived from the counter circuit 18, and the glass plate 10 is placed on the ring mold 20C at the same time as the deceleration and stopping are completed (step S7). Note that if the lowering of the lifting roll 22 is delayed, the plate glass 22 will be supported by the roll 22 in a stationary state, and the glass will be deformed by its own weight. Therefore, the timing output P3 for starting the descent of the lifting roll 22 is strictly set during deceleration.

On the other hand, the second counter circuit 19 derives timing outputs T1 to T8 in a predetermined order in parallel with the above-described positioning operation (step S8). First, the timing output Tl determines the lowering timing of the upper die 20a. If the upper mold 20a is lowered after the plate glass 10 has come to a complete standstill, the temperature of the glass will change and the pressing precision will deteriorate, so the timing TI is set so that the lowering of the upper mold 20a is started during deceleration. There is. Furthermore, the timing output T2 is determined so that both wings of the ring mold 20c are closed in parallel with the positioning operation of the glass plate 10.

The timing outputs T3 and T4 are respectively for the D-type 20 immediately after molding.
The tings for the lowering of b and the upper mold 20a are determined. If these operations are delayed, the time required for mold clamping (press hold) becomes longer, and the glass becomes more deformed due to temperature changes. Further, the timing output T5 is a start command for the oncillation device, and the timing outputs T6 and T7 determine the timing for blowing cooling air. If these timings after the end of pressing are delayed, natural cooling of the glass will proceed, and strengthening (annealing) due to forced cooling will become insufficient.

The lifting of the lifting roll 22 after annealing and the rotational drive of the conveyor roll 21 and the lifting roll 22 are controlled by the PLC 8, which is a general-purpose timing controller. These timing controls do not need to be very precise. In addition to this, the PLC8 also performs sequence control for manual operation circuits controlled by the operation panel, sequence control for automatic operation circuits whose timing is not strict, and speed control (digital numerical control) for mold exchange circuits, conveyor rolls 21, etc. )It is carried out.

FIG. 5 shows a control circuit for the entire system, in which the CPU of the PLC 8, two sets of first and second counter circuits 18 and 19, and various output interface circuits are connected through a lotus 37. Of the interface circuits, the digital input circuit 38 detects the outputs of various limit switches LS and push buttons PB and transfers them to the CPU. Further, the digital sequence circuit 39 derives on/off outputs of solenoid valves and the like from the CPU to the outside. Register input circuit 40
A digital output circuit 41 handles digital input for preset data setting, data output to a display panel, alarm output, etc. The A/D converter 42 converts the plate glass 1
0 temperature is detected and transferred to CP tJ, and the D/A converter 43 receives the count value (P
Based on the C count value), a deceleration command voltage for the conveyor roll 21 and the lifting roll 22 is derived to the roll control unit 25 for positioning servo.

Furthermore, the PLC 8 via the communication interface circuit 44
and a higher-level CPU 45 for production control are coupled, and based on commands from the higher-level CPU 45, data for sequence control is exchanged when changing the type of sheet glass 10, etc.

When changing the product type, only the preset data for the first counter circuit 18 needs to be rewritten, and the preset data for one second counter circuit need not be changed. That is, the first counter circuit 18 controls the deceleration and stopping of the rolls 21 and 22, and the lowering control of the lifting roll 22.
The control timing is changed so that optimal control can be obtained in accordance with the product type of 0. On the other hand, the second counter circuit 19
By operating in accordance with the timing corrected by the counter circuit 18, the output timing will be shifted all at once. Therefore, the preset data itself may not be changed (i.e., the first counter The sequence of the second counter circuit 19, which operates based on the count value formed by the circuit I8, may always be the same regardless of the product type, and the various related actuators may be operated in the same pattern sequence even if the type of sheet glass 10 changes. That's fine.

Since the preset data for the first and second counter circuits 18 and 19 are set in this way, the adjustment work for the sequence control of the system is extremely simple.

In other words, when a new type of flat glass is introduced, the sequence control of the entire system can be adjusted by gradually modifying at most three preset data of the first counter circuit 18 in consideration of its shape, etc. The optimal timing can be determined in a very short time.

〔Effect of the invention〕

According to the present invention, by changing the preset data of the first counter circuit 18 and the second counter circuit 19,
High-precision sequence control becomes possible by flexibly adapting to a wide variety of products. In particular, the first counter circuit 18 is synchronized with the conveyor conveyance of the workpiece, and the second counter circuit 1
9 are synchronized with one output of the first counter circuit 18 and are operated on independent time axes, so that parallel sequence control can be programmed by the output of each counter. In this parallel operation, the second counter circuit 19
starts from the position of the conveyor conveyance as a reference, and decelerates the workpiece for positioning. In other words, it derives a fixed timing output for the sequence on a fixed time axis, regardless of temporal position changes. . When the product type is changed, by changing the preset data of the first counter circuit 18, the timing output of the second counter circuit 19 is shifted as a whole. In other words, there is no need to substantially change the preset data of the second counter circuit 19, and the preset data of the first counter circuit 18 can be used alone to accommodate changes in product types. Therefore, since there is no need to program the timing of various actuators in detail for each type of workpiece, adjustment work and maintenance work for sequence control of the entire system are extremely easy.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a plate glass heating forming apparatus to which the present invention is applied, FIG. 2 is a plan view of the main parts, FIG. 3 is a circuit diagram of the main parts of the sequence controller, and FIG. 4 is a flowchart of sequence control. FIG. 5 is a block diagram of the control system. In addition, in the symbols used in the drawings, 8-.
Logic controller 10-----1--Mutan glass 11-
−−−−−−−−−−1.− In-furnace conveyor roll 12,
13.14--Cylinder 15-------Drive motor 16-
−−−−−−−−−−−−−−Pulse generator 1
7-----...--------Pulse oscillator 18-
−1−−−−−・−−11−First counter circuit 19−
-----------------Second counter circuit 20a--...---Upper mold 20b--111---Lower mold 20c・--------1----Ring type 21--
-------・--11-----------In-machine conveyor roll 22-'----- Lifting roll 23--
−−−−−−−−−−1 Cooling air nozzle 24−−−−−
--------~Photoelectric limit switch 25------
---1--Control unit 26-----・---1--
1--1 Solenoid valve 27--------Upper cylinder control unit 28--1--Solenoid valve 29-- -1111--Cylinder 30
−−−−−−−−−−−111−・−Solenoid valve 31−−−
-------One drive motor 32------------Control unit 33.34
-------------It is a solenoid valve.

Claims (1)

[Claims] A high-precision operation control device for a processing device that guides a workpiece to a processing position on a conveyor and operates the processing device at a predetermined timing, wherein the workpiece passes through a predetermined position. a first counter circuit that counts pulse trains generated every fixed conveyance distance from a point in time; a second counter circuit that counts clock pulses of a constant frequency from a point in time when one count output of the first counter circuit is generated; a controller that provides preset data to first and second counter circuits, and controls the conveyor and the processing device based on the output timing of the first and second counter circuits.