JPS62270428A - Method for controlling press cylinder - Google Patents

Abstract

PURPOSE:To keep quality of glass article at a definite level, by detecting the time of each stage in one press cycle of a press-molding of a glass article and controlling the exhaustion volume of a cylinder so as to equalize the detected value to the prescribed value. CONSTITUTION:Molten glass is press-molded by driving a plunger 3 with compressed air of a pneumatic press cylinder 1. The lowering time t1, the contacting time t2, the ascension time t3 and the waiting time t4 of the plunger 3 are detected by a detection means 6 to detect the operation time of a press cylinder in each step in one press cycle. The detected times are outputted to a controlling means 7. The controlling means 7 compares the detected times t1, t2, t3 and t4 with the standard lowering time T1, the standard contacting time T2, the standard ascension time T3 and the standard waiting time T4 of the plunger 3 and the exhaustion valve 4 is controlled to coincide the detected value to each time in one press cycle and adjust the ascension and lowering time of the plunger 3. A glass article having definite quality can be produced by this process without using troublesome adjustment operation of the press cylinder 1.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Usage of the Invention] The present invention relates to a method of controlling a press cylinder in a press molding method for glass products.

[Background of the invention]

In general, in press forming of glass products, in which molten glass supplied into a mold is press-formed by a plunger attached to the tip of a press cylinder, the following four factors determine one press cycle of the press cylinder. .

(1) Niji cylinder stroke (2) 1lJf when nib plunger F descends and rises
The pressure on the cylinder (3) The timing of the lowering and raising of the nib lunger (4) The time it takes for the nib plunger to lower and rise, and the press cycle determined by these four factors. , the time required for one press cycle is the time required for the plunger to descend toward the mold from the top dead center of the cylinder stroke to the bottom dead center, as shown by the solid line in Figure 3. The contact time that keeps the plunger in compressed contact with the molten glass in the mold, the plunger rise time required for the plunger to rise from the bottom dead center of the cylinder stroke toward the top dead center; This is the total amount of waiting time until the next press molding cycle starts at the top dead center of the press molding cycle.

On the other hand, the press cylinder used in such a press molding machine for molten glass is driven by compressed air.

That is, when the mold supplied with molten glass moves and stops at the press position, the press cylinder supplied with compressed air descends from the top dead center. When the plunger reaches the dead center of the cylinder stroke, the plunger is pressed into contact with the molten glass for a predetermined contact time at a pressure necessary for press molding to form a glass product in a desired shape. and,
When the predetermined contact time between the plunger and the molten glass has elapsed, compressed air is supplied to the press cylinder again to raise the plunger from the bottom dead center toward the top dead center, and the plunger is extracted. The plunger that has reached the top dead center is kept waiting at the top dead center until the next mold moves to the press position.

If the descending time of the plunger changes during the vertical movement of the press cylinder, the amount of heat necessary for forming glass products cannot be removed from the molten glass.
The shape of the glass product may change during molding, or cracks may appear in the glass product, resulting in defective products.

Furthermore, if the rising speed of the plunger is extremely high, there is a risk that the glass product will be pulled out of the mold together with the plunger.

Since the descending time and rising time of the plunger differ depending on the glass product to be molded, it is necessary to adjust the descending time and rising time of the plunger, etc. before starting molding of the glass product.

The descent time and rise time of the plunger are adjusted by adjusting the pulp opening of the exhaust pulp provided in the exhaust pipe system of the press cylinder, but conventionally, the pulp opening of the exhaust valve was The temperature adjustment is not done by measuring the descending and rising times of the plunger, but by measuring the F descending and ascending times of the press cylinder, which have been recorded during previous production for each product. The exhaust valves of the press cylinders were manually adjusted to match the respective air pressures.

However, since the adjustment of such exhaust valves was performed by the operator, when reproducing a previously molded product, startup time is required to reproduce the previous production mode, and there is also a However, it is difficult to keep each press cycle the same, and when a product is found to be defective, it is necessary to respond to changes, which is one of the causes of reduced production efficiency.

[Purpose of the invention]

The present invention was developed in order to solve these conventional problems, and when performing repeated production, it is possible to create the same condition as the previous time by setting each time of the plunger during the previous production. For example, if the descending time of the plunger becomes longer than the standard time in one press cycle, the exhaust valve of the press cylinder can be adjusted to hasten the rising time of the plunger in order to make up for the delay time. It is an object of the present invention to provide a press cylinder control method that maintains the time required for one press cycle constant by adjusting the displacement amount and increasing the displacement.

[Summary of the invention]

The method for controlling a press cylinder according to the present invention is a press cylinder control method for glass products, in which the descending time of the plunger, the contact time between the plunger and molten glass, the rising time of the plunger, and the The waiting time at the dead center is detected respectively, and the pressure from the press cylinder is adjusted so that each detection time matches each set time of the standard one press cycle time set in advance, when the plunger is lowered or raised. The feature is that the displacement is controlled.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

FIG. 1 is a block diagram showing an embodiment of the basic configuration of the present invention.

In the figure, reference numeral 1 denotes a press cylinder of a molten glass press molding machine, and a plunger 3 is provided at the tip of a cylinder rod 2. Reference numeral 4 denotes a remotely controllable exhaust valve made of, for example, a solenoid valve connected to the exhaust pipe system 5 of the press cylinder 1;
When the air cylinder 1 is lowered and raised, the amount of air discharged from the air cylinder 1 is controlled by a control means to be described later. Reference numeral 6 denotes a press cylinder operation time detection means for detecting the operation time of each step in one press cycle, which detects the descending time t1, contact time t3, and rising time "ms" of the plunger 3, and the waiting time t, and detects these detection times. is output to the control means. Reference numeral 7 denotes a control means consisting of, for example, a microcomputer, which outputs the standard lowering time T8, the standard contact time T3, the standard rising time Ta, of the plunger 3.
A reference standby time T4 is set, and each of the input actual plunger lowering time t1, contact time t, plunger rising time t, plunger standby time t, and each of these standards set in advance Time T, , 'I', ,
III□T, and the exhaust valve 4 is controlled to adjust the rise and fall times of the plunger so as to match each time of one press cycle.

That is, the sum of the actual plunger lowering time t and the contact time t is compared with the sum of the reference plunger lowering time T and the reference contact time T, and if there is a time difference, The plunger rising time is accelerated or delayed by the time difference, and when the time difference is large and simply increasing the plunger rising time is insufficient, the waiting time is reduced.

That is, ts +t*-T4 + TI+ ja+t
"I""*> so that a= T@-l-T,
If TI +T* then in the next few press cycles t+ <
T + binding, then t.

+ "4 > Ts + TI" In the next few press cycles, "4 < T number" is controlled.

FIG. 2 is a schematic diagram showing an embodiment of a press cylinder that embodies the embodiment shown in FIG. The air supply pipe 13 for lowering the piston is connected to the exhaust pipe 14 for raising the piston, and the air supply pipe 16 for raising the piston and the exhaust pipe 17 for lowering the piston are connected to the other compartment 15 side. has been done. Cylinder rod 2 fixed to this piston 11
When the air supply valve 18 provided in the air supply pipe 13 is opened, the air starts descending, and at this time, the first exhaust valve 19 provided in the exhaust pipe 17 is adjusted to open the exhaust needle in the other compartment 15. By controlling , the descending time of the plunger 3 is adjusted.

The first exhaust valve 19 is an electromagnetic valve, and the exhaust amount can be controlled by repeatedly opening and closing the valve many times within a predetermined period of time. The opening/closing operation of the exhaust valve 19 is controlled by a microcomputer 20 to adjust the exhaust amount.

When the plunger 3 reaches the dead center of the cylinder rod 2, the plunger 3 continues to suppress the molten glass for a predetermined period of time, and a glass product is press-molded.

After press molding, when the air supply valve 21 provided in the air supply pipe 16 is opened, the plunger 3 starts to rise, and at this time, the second exhaust valve 22 provided in the exhaust pipe 14 is opened.
The rising time of the plunger 3 is adjusted by controlling the exhaust amount in one of the chambers 12. This second
The exhaust valve 22 is a solenoid valve similar to the first exhaust valve 19, and its opening/closing operation is controlled by a microcomputer 20.

23 is an endless belt installed between a pair of belts 724 and 25 spaced apart from each other in parallel to the cylinder rod 2, and is connected to the cylinder rod 2 through a connecting rod 26. , is rotated following the vertical movement of the cylinder rod 2.

A rotary shaft 27 rotates integrally with the lower pulley 25, and a rotary encoder 28 is connected to the end of the shaft. This encoder 28 corresponds to each step in one press cycle of the cylinder rod 2, that is, the lowering step of the plunger 3, the forming step in which the plunger 3 contacts molten glass and press-forming, the rising step of the plunger 3, and the plunger 3 The microcomputer 20
Output to.

A set value is set in the encoder 28 corresponding to the top dead center of the cylinder rod 2 during a predetermined stroke, and when the set value changes due to the descent of the cylinder rod 2, the plunger lowering time timer is reset. , start counting the plunger descent time. When the plunger 3 reaches the bottom dead center of a predetermined stroke of the cylinder rod 2, a proximity switch 29 consisting of a limit switch or the like provided corresponding to the bottom dead center is activated by, for example, the connecting rod 26 and turned on. A signal is output to the encoder 28 to stop the count of the plunger lowering time timer to detect the plunger lowering time t1, and at the same time a contact time timer for detecting the contact time between the plunger and the molten glass starts counting. . When the press forming process by the plunger 3 is completed, the cylinder rod 2 starts to rise, and at this time, the count of the contact time timer is stopped by the off signal from the proximity switch 29 to detect the contact time t, and at the same time, the plunger Starts the rise time timer. Next, when the cylinder rod reaches the top dead position of the predetermined stroke, that is, when the count of the encoder reaches the set value, the count of the plunger rise time timer is stopped and the plunger rise time 1. is detected, and at the same time starts counting the plunger standby time when the cylinder rod rises. Then, when the next press cycle is started, the set value changes, the plunger standby time timer stops counting, the stay time t is detected, and at the same time the plunger lowering time timer starts counting.

The required time tlet□t□- for each process in one press cycle detected in this way for each press cycle is outputted to the microcomputer 20, and the time required for each process in one press cycle is outputted to the microcomputer 20, and the time required for each process in one press cycle is detected in each press cycle. Each process time T, , T□T, , T number of the standard is compared. Sample time by microcomputer 201. ．． 1□
T.

A comparison between t4 and the reference time T, , T, , Ts, T, is performed using the numbers ti+t, Tl-4-T, tlI+ and the numbers T11-1-T, for example, as shown in FIG. As shown by the middle broken line, the actual plunger lowering time t1
If the time difference Δt is slower than the reference plunger lowering time T1, the exhaust amount of the second exhaust valve 22 is increased in the next few press cycles so that the time difference Δt becomes zero.

Further, when ts<Ta, the exhaust amount of the first exhaust valve 19 is increased in the next few press cycles so that the time difference becomes zero.

Further, in the case of % tl > T+ + ts > Tm, the exhaust valves 19 and 22 are adjusted in each of the next several press cycles to reduce the displacement so that the time difference becomes zero.

Note that in this embodiment, the first exhaust valve 19 and the second
Although the exhaust valves 22 are all electromagnetic valves, a stepping motor may be used to adjust the valve opening degree.

〔Effect of the invention〕

As described above, according to the present invention, the reference time for each plunger operation in one press cycle is set before the start of molding of glass products. A lot of things,
The effect of this method is that the quality of glass products can be maintained at a constant level.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the basic configuration of the present invention, FIG. 2 is a schematic diagram of an air cylinder, and FIG. 3 is a diagram showing the relationship between operating time and stroke of a press cylinder. 1.10... Press cylinder 2... Cylinder rod 3... Plunger 4.
... Exhaust valve 5 ... Exhaust pipe system 11 ... Piston 12.15 ... Chamber 13.16 ...
Air supply pipe 14.17 =...Exhaust pipe 18.21...Air supply valve 19.22...Exhaust valve 20...Microcomputer 23...Endless bell) 24.25...Pulley 26...・Connecting rod 27...Rotating shaft 28...
・Encoder 29...Proximity switch.

Claims (1)

[Claims] In a press molding machine for glass products, the plunger descending time, the contact time between the plunger and the molten glass, the plunger rising time, and the waiting time at the plunger top dead center in one press cycle of the press cylinder. are detected respectively, and the displacement of the press cylinder is controlled during the descending or ascending operation of the plunger so as to match each detection time with each preset time of the standard 1 press molding cycle time. A method for controlling a press cylinder, characterized in that: