CN103857516A - Method of controlling pressure-maintaining step for injection-molding machine - Google Patents

Abstract

Provided is a method of controlling a pressure-maintaining step for an injection-molding machine capable of molding a high quality molded body, pressure control in a pressure maintaining step executed after an injection step being performed with high precision. A control method in an injection molding machine in which there are performed an injection-filling step for advancing a screw and injecting molten resin to fill a die cavity and a pressure maintaining step for retracting the screw and reducing the pressure, wherein a switch is made to the pressure maintaining step after injection filling has concluded in the injection filling step, the screw is rapidly retracted by reducing a primary pressure through pressure control in a primary pressure maintaining step which is the initial stage after the switch to the pressure maintaining step has been made, and pressure reduction is controlled so that the reduced primary pressure reaches in a short time a set pressure for a secondary pressure maintaining step performed after the primary pressure maintaining step.

Description

Pressurize operation control method in injection (mo(u)lding) machine

Technical field

The present invention relates to the compress control method in the pressurize operation that molten resin is at once carried out after the cavity injection of mould is filled, the pressurize operation control method in the injection (mo(u)lding) machine of the residual stress producing while relating to the thin materials such as LGP that display floaters such as can being controlled at accurately formation liquid crystal panel adopts.

Background technology

In recent years, in the display of liquid crystal that compares miniaturization, adopt and make light carry out equably the luminous LGP of face.In the time that the thinner sheet materials of wall thickness such as the LGP to such form or requiring in the precision form of high-precision shaping, for by mould filling the residual stress that produces after molten resin get rid of, require sharply to reduce pressure to low-pressure state from high pressure conditions, for example, in the time that decompression is slow, due to the residual stress that the pressure remaining in mould causes, formed body can produce the inhomogeneous of warpage or wall thickness.And, in the time that decompression is too fast, can produce and reach the authorized pressure excessive excess of stroke or fluctuation afterwards, thereby existence causes the problem of the obstruction of cob webbing or cast gate.

As the method associated with above-mentioned technology, the filling work procedure control method of following injection (mo(u)lding) machine is disclosed in patent documentation 1: in the filling work procedure carrying out before pressurize operation, before screw rod and then arrived behind the position of regulation, make this screw rod be back to desired location with setting speed, take out before pressure being about to carry out V-P switching (from speed control to pressure controlled switching) thus.And, a kind of following technology is disclosed in patent documentation 2: in injection moulding, after high-voltage high-speed injection, make screw rod temporarily stop or retreating, after high-voltage high-speed injection, carry out Decompression Controlling.

[formerly technical literature]

[patent documentation]

No. 3404652 communique of [patent documentation 1] Japan Patent

[patent documentation 2] Japanese kokai publication sho 59-165634 communique

Summary of the invention

[problem that invention will solve]

The technology of patent documentation 1 is the technology that makes screw rod retreat in filling work procedure, is not disclosed in the technology of wanting controlled pressure in the pressurize operation of carrying out after filling work procedure,, does not openly want to be controlled at the technology of the residual stress producing in pressurize operation that is.And, in the technology of patent documentation 2, before pressurize operation, reduce pressure, with patent documentation 1 be not similarly the technology of wanting to be controlled at the residual stress producing in pressurize operation.And, in patent documentation 2, while decompression screw rod is retreated, the sensor that only shift position based on to screw rod (going-back position) detects or the instrumentation value of timer are carried out Decompression Controlling, therefore be difficult to carry out trickle Decompression Controlling, have to be difficult in fact obtain the formed products of high-quality.

The present invention makes in view of above-mentioned problem, and object is to provide the pressure control in a kind of pressurize operation of carrying out accurately carrying out after injection fillers operation, and pressurize operation control method in the injection (mo(u)lding) machine of the formed body of the high-quality that can be shaped.

[for solving the means of problem]

A pressurize operation control method in injection (mo(u)lding) machine, this injection (mo(u)lding) machine advances screw rod and fills the injection fillers operation of molten resin and described screw rod is retreated and the pressurize operation that reduces pressure to the cavity injection of mould, it is characterized in that,

After the injection fillers of described injection fillers operation completes, be switched to described pressurize operation,

As being switched in a pressurize operation of the initial stage after this pressurize operation, make a packing pressure decompression that described screw rod is retreated fast by pressure control, so that the mode that this post-decompression packing pressure reaches the setting pressure of the secondary pressurize operation of carrying out after a described pressurize operation is at short notice carried out Decompression Controlling.

Pressurize operation control method in injection (mo(u)lding) machine is characterised in that,

Carry out the forward travel of described screw rod and the mode of carrying out the setback of described screw rod by pressure control in described pressurize operation with Negotiation speed control in described injection fillers operation, carry out V-P switching by the switching from described injection fillers operation to described pressurize operation.

Pressurize operation control method in injection (mo(u)lding) machine is characterised in that,

In a pressurize operation that makes screw rod retreat by described decompression, in the time that the observed pressure of a described packing pressure does not reach described setting pressure, calculate the amplitude that the retreats B of this screw rod while described screw rod being retreated reduce pressure by the mathematical expression of following mathematical expression 1, with the amplitude that the retreats B calculating by the mathematical expression of this mathematical expression 1, described screw rod is retreated

On the other hand, in a pressurize operation that makes screw rod retreat by described decompression, in the time that the observed pressure of a described packing pressure reaches described setting pressure, carry out computing by the mathematical expression of following mathematical expression 2,

In the time not meeting the mathematical expression of described mathematical expression 2,

The amplitude that the retreats B that calculates this screw rod while described screw rod being retreated reduce pressure by the mathematical expression of following mathematical expression 3, retreats described screw rod with the amplitude that the retreats B calculating by the mathematical expression of this mathematical expression 3,

[mathematical expression 1]

B=Cb/0.9a

[mathematical expression 2]

A/B＞0.98

[mathematical expression 3]

B=A/0.99

A: the mobile range (mm) of the screw rod till moving to when pressurize operation and secondary pressurize operation are switched when V-P a shot switches

C: the amplitude that retreats (mm) of the screw rod of the setting before a shot

A: the V-P of the actual measurement when V-P before a shot switches switches the differential pressure (MPa) of the observed pressure of a pressurize operation before pressure and a shot

B: the V-P of the actual measurement when V-P before a shot switches switches the differential pressure (MPa) of the setting pressure in pressure and secondary pressurize operation.

Pressurize operation control method in injection (mo(u)lding) machine is characterised in that,

In the time meeting the mathematical expression of described mathematical expression 2,

If frequency injection is k, time when described observed pressure reaches the setting pressure of described secondary pressurize operation is t, the amplitude that retreats retreating at time t screw rod is X(t), the injection speed at time t place is V(t), the injection pressure at time t place is P(t), the learning coefficient of arbitrary decision is α, β, evaluation function f(t)=α V(t)+β P(t)

Use this evaluation function, injection each time calculated and retreats amplitude X(t to the direction that becomes f(t) ≒ 0 by the mathematical expression of following mathematical expression 4), based on this calculated value of injecting each time, the amplitude that retreats of described screw rod is adjusted automatically,

[mathematical expression 4]

$X{\left(t\right)}_{k+1}=X{\left(t\right)}_k+\mathrm{\α}\frac{\mathrm{dV}\left(t\right)}{\mathrm{dt}}+\mathrm{\β}\frac{\mathrm{dP}\left(t\right)}{\mathrm{dt}}.$

[invention effect]

According to the pressurize operation control method in injection (mo(u)lding) machine of the present invention, after injection fillers operation switches to pressurize operation, in a pressurize operation of the initial stage of pressurize operation, be used in the packing pressure fast decompression that screw rod retreats, so that the mode that this packing pressure reaches the setting pressure of secondary pressurize operation is at short notice carried out Decompression Controlling, therefore by the so high-precision pressure control (control of the residual stress producing in pressurize operation) in pressurize operation, can manufacture the formed products (wall thickness of the thin molded article that is shaped equably) of high-quality.

In addition, use observed pressure value and the described mathematical expression of a packing pressure, in the time carrying out the Decompression Controlling of screw rod, carry out self-teaching based on described observed pressure value, according to the result obtaining thus, automatically adjust (inching) and carry out Decompression Controlling so that the amplitude that retreats of screw rod becomes the mode of the optimum amplitude that retreats.Thus, in pressurize operation, trickle pressure control can be carried out, the quality of the formed products of manufacture can be improved.

Brief description of the drawings

Fig. 1 is the brief configuration figure that represents the injecting unit of injection (mo(u)lding) machine.

Fig. 2 is the injection fillers operation of injecting unit and the coordinate diagram of pressurize operation that represents injection (mo(u)lding) machine.

Fig. 3 is the flow chart that is illustrated in a pressurize operation action when amplitude that retreats to screw rod is adjusted.

Fig. 4 A is illustrated in the too small situation of the amplitude that retreats of screw rod, for increase this retreat amplitude and the mathematical expression that is suitable for mathematical expression 1 adjust screw rod retreat amplitude time the key diagram of action of a pressurize operation, the longitudinal axis represents the speed of screw rod, transverse axis represents that the shift position of screw rod is as position, in a pressurize operation, waveform while screw rod being retreated with the amplitude that retreats calculating by the mathematical expression of mathematical expression 1 represents by solid line, and the waveform while screw rod being retreated with the amplitude that retreats of the screw rod of the setting before a shot is illustrated by the broken lines.

Fig. 4 B is illustrated in the too small situation of the amplitude that retreats of screw rod, for increase this retreat amplitude and the mathematical expression that is suitable for mathematical expression 1 adjust screw rod retreat amplitude time the key diagram of action of a pressurize operation, the longitudinal axis represents pressure and the speed of screw rod, transverse axis represents the time, the waveform of the pressure while screw rod being retreated with the amplitude that retreats calculating by the mathematical expression of mathematical expression 1 representing by solid line than the top side of time shaft, and the waveform of the pressure while screw rod being retreated with the amplitude that retreats of the screw rod of the setting before a shot is being illustrated by the broken lines than the top side of time shaft.And, the waveform of the speed while screw rod being retreated with the amplitude that retreats calculating by the mathematical expression of mathematical expression 1 than time shaft on the lower side represented by solid line, the waveform of the speed when amplitude that retreats of the screw rod by the setting with before a shot retreats screw rod than time shaft on the lower side be illustrated by the broken lines.

Fig. 5 A is illustrated in the excessive situation of the amplitude that retreats of screw rod, for reduce this retreat amplitude and the mathematical expression that is suitable for mathematical expression 3 adjust screw rod retreat amplitude time the key diagram of action of a pressurize operation, the longitudinal axis represents the speed of screw rod, transverse axis represents that the shift position of screw rod is as position, in a pressurize operation, waveform while screw rod being retreated with the amplitude that retreats calculating by the mathematical expression of mathematical expression 1 represents by solid line, and the waveform while screw rod being retreated with the amplitude that retreats of the screw rod of the setting before a shot is illustrated by the broken lines.

Fig. 5 B is illustrated in the excessive situation of the amplitude that retreats of screw rod, for reduce this retreat amplitude and the mathematical expression that is suitable for mathematical expression 3 adjust screw rod retreat amplitude time the key diagram of action of a pressurize operation, the longitudinal axis represents pressure and the speed of screw rod, transverse axis represents the time, the waveform of the pressure while screw rod being retreated with the amplitude that retreats calculating by the mathematical expression of mathematical expression 3 representing by solid line than the top side of time shaft, and the waveform of the pressure while screw rod being retreated with the amplitude that retreats of the screw rod of the setting before a shot is being illustrated by the broken lines than the top side of time shaft.And, the waveform of the speed while screw rod being retreated with the amplitude that retreats calculating by the mathematical expression of mathematical expression 3 than time shaft on the lower side represented by solid line, the waveform of the speed while screw rod being retreated with the amplitude that retreats of the screw rod of the setting before a shot than time shaft on the lower side be illustrated by the broken lines.

Fig. 6 is the coordinate diagram that represents the variable gradient of learning coefficient.

Fig. 7 A be the mathematical expression that represents to be suitable for mathematical expression 1 adjust screw rod retreat amplitude time the coordinate diagram of action, the longitudinal axis represents that the speed of screw rod is as velocity determination, transverse axis represents that the shift position of screw rod is as position.

Fig. 7 B be the mathematical expression that represents to be suitable for mathematical expression 1 adjust screw rod retreat amplitude time the coordinate diagram of action, the longitudinal axis represents that the pressure of screw rod is as piezometry, transverse axis represents that the shift position of screw rod is as position.

Fig. 7 C be the mathematical expression that represents to be suitable for mathematical expression 1 adjust screw rod retreat amplitude time the coordinate diagram of action, the longitudinal axis represents that the speed of screw rod is as velocity determination, transverse axis represents the time.

Fig. 7 D be the mathematical expression that represents to be suitable for mathematical expression 1 adjust screw rod retreat amplitude time the coordinate diagram of action, the longitudinal axis represents that the pressure of screw rod is as piezometry, transverse axis represents the time.

Fig. 8 A be the mathematical expression that represents to be suitable for mathematical expression 3 adjust screw rod retreat amplitude time the coordinate diagram of action, the longitudinal axis represents that the speed of screw rod is as velocity determination, transverse axis represents that the shift position of screw rod is as position.

Fig. 8 B be the mathematical expression that represents to be suitable for mathematical expression 3 adjust screw rod retreat amplitude time the coordinate diagram of action, the longitudinal axis represents that the pressure of screw rod is as piezometry, transverse axis represents that the shift position of screw rod is as position.

Fig. 8 C be the mathematical expression that represents to be suitable for mathematical expression 3 adjust screw rod retreat amplitude time the coordinate diagram of action, the longitudinal axis represents that the speed of screw rod is as velocity determination, transverse axis represents the time.

Fig. 8 D be the mathematical expression that represents to be suitable for mathematical expression 3 adjust screw rod retreat amplitude time the coordinate diagram of action, the longitudinal axis represents that the pressure of screw rod is as piezometry, transverse axis represents the time.

Detailed description of the invention

Below, by Fig. 1～Fig. 8, embodiments of the present invention are described.Certainly, the present invention is in the scope of purport of not violating this invention, and situation that also can be easily applicable for the structure beyond illustrating in embodiment is self-evident.

Fig. 1 is the front view that is illustrated in the injecting unit 2 forming in injection (mo(u)lding) machine 1, as shown in the drawing, forms and has: being put into granular raw material is the hopper 3 of resin (particle) in injecting unit 2; Supply with the heating cylinder 4 of the cartridge type of granular resin from this hopper 3; The interior supply of subtend heating cylinder 4 screw rod 5 that utilizes molten resin that heat plastifies to measure; The molten resin of metering is carried out to injection nozzle 6 injection fillers, that be assemblied in heating cylinder 4 front ends to the die cavity of mould; Carry out kneading of molten resin etc. in heating cylinder 4 time, the motor 8 for the metering as drive source that screw rod 5 is rotated via Timing Belt 7; In the time that the molten resin of metering is injected from injection nozzle 6 front ends, via Timing Belt 9, ball screw framework 10 and the injection motor 11 as drive source that screw rod 5 is advanced; Detection is accompanied by advancing of screw rod 5 etc. and the power (injection pressure) of extrusion molten resin is load cell 12 as the pressure sensor of counter-force; Carry out the control module 13 of the various controls of injection (mo(u)lding) machine 1 entirety such as the calculation process of mathematical expression 1～4 described later; The memory cell 14 of various numerical value, the described mathematical expressions etc. such as the measured value of storage injection (mo(u)lding) machine 1 etc.

Next, the pressurize operation of the injection (mo(u)lding) machine 1 of present embodiment is below described.In Fig. 2, that the longitudinal axis represents that pressure and speed and transverse axis represent the coordinate diagram of time, as shown in the drawing, before making screw rod 5 and then carried out after the cavity injection of mould is filled the injection fillers operation of molten resin, carry out pressurize operation, the screw rod 5 that has been carried out speed control in injection fillers operation is in the time that injection fillers operation completes, and machine carries out V-P switching at this moment, does not carry out speed control and carry out pressure control in pressurize operation.It should be noted that, in Fig. 2, the waveform of pressure represents by solid line, and the waveform of speed is illustrated by the broken lines.

Pressurize operation is carried out pressurize operation one time in the initial stage of switching from injection fillers operation, after this pressurize operation, carry out secondary pressurize operation (formal pressurize operation), in order to make a packing pressure of a pressurize operation reach at short notice the setting pressure of secondary pressurize operation, control module 13 retreats fast screw rod in a pressurize operation, carries out the Decompression Controlling of a packing pressure.

At this, about a described pressurize operation, further illustrate by Fig. 3～Fig. 5.The adjustment of the amplitude that the retreats B of the screw rod 5 while decompression by retreating of screw rod 5 in a pressurize operation is carried out according to the sequence of movement shown in the flow chart of Fig. 3.By the running of injection (mo(u)lding) machine 1, the (step 1) when observed pressure of a pressurize operation of actual measurement does not reach the setting pressure of predefined secondary pressurize operation, shift to step 2, the amplitude that the retreats B that makes screw rod 5 retreat the screw rod 5 while decompression carries out according to the calculating of following mathematical expression 1 by control module 13.

[mathematical expression 1]

B=Cb/0.9a

C: the amplitude that retreats (mm) of the screw rod of the setting before a shot

A: the V-P of the actual measurement when V-P before a shot switches switches the differential pressure (MPa) of the observed pressure of a pressurize operation before pressure and a shot

B: the V-P of the actual measurement when V-P before a shot switches switches the differential pressure (MPa) of the setting pressure in pressure and secondary pressurize operation

And, with the amplitude that the retreats B calculating by the mathematical expression of mathematical expression 1, screw rod 5 is retreated, a pressurize operation packing pressure is reduced pressure rapidly thus.It should be noted that, the inching (retreating in the too small situation of amplitude B) of the amplitude that the retreats B while screw rod 5 being retreated about the amplitude that the retreats B to calculate by the mathematical expression of mathematical expression 1, based on Fig. 4 A, Fig. 4 B, further illustrates at this.In Fig. 4 A, the longitudinal axis represents the speed of screw rod 5, transverse axis represents that the shift position of screw rod 5 is as position, in a pressurize operation, waveform while screw rod 5 being retreated with the amplitude that the retreats B calculating by the mathematical expression of mathematical expression 1 is represented by solid line, waveform while screw rod 5 being retreated with the amplitude that the retreats C of the screw rod 5 of the setting before a shot is illustrated by the broken lines, and, in Fig. 4 B, the longitudinal axis represents pressure and the speed of screw rod 5, transverse axis represents the time, the waveform of the pressure while screw rod 5 being retreated with the amplitude that the retreats B calculating by the mathematical expression of mathematical expression 1 is being represented by solid line than the top side of time shaft, the waveform of the pressure while screw rod 5 being retreated with the amplitude that the retreats C of the screw rod 5 of the setting before a shot is being illustrated by the broken lines than the top side of time shaft, and, the waveform of the speed while screw rod 5 being retreated with the amplitude that the retreats B calculating by the mathematical expression of mathematical expression 1 than time shaft on the lower side represented by solid line, the waveform of the speed while screw rod 5 being retreated with the amplitude that the retreats C of the screw rod 5 of the setting before a shot than time shaft on the lower side be illustrated by the broken lines.And, as shown in Figure 4 B, based on the amplitude that retreats calculating by the mathematical expression of mathematical expression 1, the amplitude that retreats of screw rod 5 is carried out to inching, can make thus screw rod 5 with the suitable amplitude that retreats B action.

In addition, in step 1, in the time that the observed pressure of a pressurize operation of surveying reaches the setting pressure of predefined secondary pressurize operation, shift to step 3, by control module 13, carry out according to the calculating of following mathematical expression 2.

[mathematical expression 2]

A/B＞0.98

A: the mobile range (mm) of the screw rod till moving to when pressurize operation and secondary pressurize operation are switched when V-P a shot switches

And (step 3) in the time not meeting the mathematical expression of mathematical expression 2, shifts to step 4, the amplitude that the retreats B that makes screw rod 5 retreat the screw rod 5 while decompression passes through control module, carries out according to the calculating of following mathematical expression 3.

[mathematical expression 3]

B＝A/0.99

And, with the amplitude that the retreats B calculating by the mathematical expression of mathematical expression 3, screw rod 5 is retreated, a pressurize operation packing pressure is depressurized rapidly thus.It should be noted that, the inching (retreating in the excessive situation of amplitude B) of the amplitude that the retreats B while screw rod 5 being retreated about the amplitude that the retreats B to calculate by the mathematical expression of mathematical expression 3, based on Fig. 5 A, Fig. 5 B, further illustrates at this.In Fig. 5 A, the longitudinal axis represents the speed of screw rod 5, transverse axis represents that the shift position of screw rod 5 is as position, in a pressurize operation, waveform while screw rod 5 being retreated with the amplitude that the retreats B calculating by the mathematical expression of mathematical expression 1 is represented by solid line, waveform while screw rod 5 being retreated with the amplitude that the retreats C of the screw rod 5 of the setting before a shot is illustrated by the broken lines, and, in Fig. 5 B, the longitudinal axis represents pressure and the speed of screw rod 5, transverse axis represents the time, the waveform of the pressure while screw rod 5 being retreated with the amplitude that the retreats B calculating by the mathematical expression of mathematical expression 3 is being represented by solid line than the top side of time shaft, the waveform of the pressure while screw rod 5 being retreated with the amplitude that the retreats C of the screw rod 5 of the setting before a shot is being illustrated by the broken lines than the top side of time shaft, and, the waveform of the speed while screw rod 5 being retreated with the amplitude that the retreats B calculating by the mathematical expression of mathematical expression 3 than time shaft on the lower side represented by solid line, the waveform of the speed while screw rod 5 being retreated with the amplitude that the retreats C of the screw rod 5 of the setting before a shot than time shaft on the lower side be illustrated by the broken lines.And, as shown in Figure 5 B, based on the amplitude that retreats calculating by the mathematical expression of mathematical expression 3, the amplitude that retreats of screw rod 5 is carried out to inching, can make thus screw rod 5 with the suitable amplitude that retreats B action.

In addition, in step 3, in the time meeting the mathematical expression of mathematical expression 2, shift to step 5.

(based on the inching of gradient method)

In step 5, even if carried out the inching of the amplitude that retreats of screw rod 5 in step 2 or step 4, in the time that this inching is not optimum, sometimes after switching to pressure control, also can show unsettled pressure behavior.As the inching unit for eliminating this problem, use effective steepest descent method in order to obtain local solution.At this, steepest descent method is represented by following formula.

[mathematical expression 4a]

$X{\left(t\right)}_{k+1}=X{\left(t\right)}_k+\frac{f\left(t\right)}{\mathrm{dt}}$

K: frequency injection

T: time when observed pressure reaches the setting pressure of secondary pressurize operation

X(t): at time t and the amplitude that retreats that screw rod retreats

F(t): with the evaluation of estimate using in this specification, output retreats the adjustment amount of amplitude.

At this, prepare following function as evaluation function.

f（t）=αV（t）+βP（t）

V(t): the injection speed at time t place

P(t): the injection pressure at time t place

α, β: the learning coefficient of arbitrary decision

And, use above-mentioned evaluation function, to becoming f(t) and the direction of ≒ 0 will retreat amplitude X(t) when injection is upgraded each time, become the formula of mathematical expression 4.

[mathematical expression 4]

$X{\left(t\right)}_{k+1}=X{\left(t\right)}_k+\mathrm{\α}\frac{\mathrm{dV}\left(t\right)}{\mathrm{dt}}+\mathrm{\β}\frac{\mathrm{dP}\left(t\right)}{\mathrm{dt}}.$

Now, learning coefficient α, β make constant variable as the coordinate diagram of Fig. 6, the overfitting while suppressing to be similar to local solution.

It should be noted that, at this, decide parameter according to following specification.

[mathematical expression 5]

When Δ V (t) <=Δ V1 ... α=α _min

Δ V ₁< Δ V (t) < Δ V ₂time $\mathrm{\&alpha;}={\mathrm{\&alpha;}}_{\min }+({\mathrm{\&alpha;}}_{\max }-{\mathrm{\&alpha;}}_{\min })\frac{\mathrm{\&Delta;V}\left(t\right)-{\mathrm{\&Delta;<figure-callout\; id="1"\; label="V"\; filenames="HDA0000487266900000081.png,HDA0000487266900000082.png"\; state="\{\{state\}\}">V</figure-callout>}}_1}{\mathrm{\&Delta;}{V}_2-{\mathrm{\&Delta;<figure-callout\; id="1"\; label="V"\; filenames="HDA0000487266900000081.png,HDA0000487266900000082.png"\; state="\{\{state\}\}">V</figure-callout>}}_1}$

Δ V ₂when <=Δ V (t) ... α=α _max

Δ P (t) <=Δ P ₁time ... β=β _min

Δ P ₁< Δ P (t) < Δ P ₂time $\mathrm{\&beta;}={\mathrm{\&beta;}}_{\min }+({\mathrm{\&beta;}}_{\max }-{\mathrm{\&beta;}}_{\min })\frac{\mathrm{\&Delta;P}\left(t\right)-\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="HDA0000487266900000081.png,HDA0000487266900000082.png"\; state="\{\{state\}\}">P</figure-callout>}}_1}{\mathrm{\&Delta;}{P}_2-\mathrm{\&Delta;}{\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="HDA0000487266900000081.png,HDA0000487266900000082.png"\; state="\{\{state\}\}">P</figure-callout>}}_1}$

Δ P ₂when <=Δ P (t) ... β=β _max

And, use above-mentioned evaluation function, by control module, according to the mathematical expression of mathematical expression 4, to becoming f(t) direction of ≒ 0 calculates and retreats amplitude X(t injection each time), automatically adjust the amplitude that retreats of described screw rod 5 based on this calculated value of injecting each time.

Next, an example of the action while carrying out inching about the mathematical expression by mathematical expression 1 to retreating amplitude B, describes by Fig. 7.In Fig. 7 A, the longitudinal axis represents that the speed of screw rod 5 is as velocity determination, and transverse axis represents that the shift position of screw rod 5 is as position, in Fig. 7 B, the longitudinal axis represents that the pressure of screw rod 5 is as piezometry, transverse axis represents that the shift position of screw rod 5 is as position, and in Fig. 7 C, the longitudinal axis represents that the speed of screw rod 5 is as velocity determination, transverse axis represents the time, in Fig. 7 D, the longitudinal axis represents that the pressure of screw rod 5 is as piezometry, and transverse axis represents the time.In Fig. 7 A～Fig. 7 D, the waveform of injection (1.00mm) is represented by solid line for the first time, and the waveform of injection (2.70mm) is illustrated by the broken lines for the second time, and the waveform of injection (3.38mm) is represented by single-point line for the third time.And the amplitude that retreats of the screw rod 5 of injection is made as 1mm for the first time, the goal pressure suitable with the setting pressure of secondary pressurize operation is made as 10MPa, injection (mo(u)lding) machine 1 turned round and form.So, according to Fig. 7 B, be about 66MPa at the position of 1mm pressure, therefore for the first time injection in, miss the mark pressure.Therefore, for be adjusted to screw rod 5 to retreat amplitude larger, and use the mathematical expression (B=Cb/0.9a) of described mathematical expression 1.

At this, C=1.0mm, the V-P of the actual measurement when V-P before a shot switches switches pressure for 105aMPa, the differential pressure (MPa) that the V-P of the actual measurement when V-P before a shot switches switches the observed pressure of a pressurize operation before pressure and a shot is 105MPa-66MPa=39MPa, a=39MPa, the setting pressure of bis-pressurize operations of b=95MPa(105MPa-10MPa()), therefore, B=Cb/0.9a=(1.0 × 95)/(0.9 × 39) ≒ 2.70mm, thus, inject for the second time with B=2.70mm, goal pressure is made as 10MPa and forms.

And, consequently, in the time of B=2.70mm, pressure is about 20.7MPa, in the time of the 10MPa that cannot reach as goal pressure, in order to reach as the 10MPa of goal pressure and reuse the mathematical expression (B=Cb/0.9a) of mathematical expression 1, C=2.7mm, the V-P of the actual measurement when V-P before a shot switches switches pressure for 105aMPa, as shown in Figure 7 B, position pressure at the 2.70mm injecting is for the second time 20.7MPa, therefore, the differential pressure (MPa) that the V-P of the actual measurement when V-P before a shot switches switches the observed pressure of a pressurize operation before pressure and a shot is 105MPa-20.7MPa=84.3MPa, a=84.3MPa, the setting pressure of bis-pressurize operations of b=95MPa(105MPa-10MPa()), therefore B=Cb/0.9a=(2.7 × 95)/(0.9 × 84.3) ≒ 3.38mm, thus, inject for the third time with B=3.38mm, goal pressure 10MPa is shaped, in the time of B=3.38mm, result is, pressure becomes 12.2MPa, but the pressure of a pressurize operation of this 12.2MPa() miss the mark pressure (setting pressure of secondary pressurize operation), therefore used the inching of the amplitude that retreats of the screw rod 5 of the mathematical expression of mathematical expression 1 on one side, convergence on one side.

On the other hand, in the time that the pressure of a pressurize operation reaches the setting pressure of secondary pressurize operation, also as shown in the flow process of Fig. 3, shift from step 1 to step 3, whether meet the judgement of the important document of the mathematical expression (A/B>0.98) of mathematical expression 2 by control module 13, in the time not meeting this important document, use the inching of the amplitude that retreats of the screw rod 5 of the mathematical expression of mathematical expression 3.One example of the action when carrying out this inching, below describes by Fig. 8.

In Fig. 8 A, the longitudinal axis represents that the speed of screw rod 5 is as velocity determination, and transverse axis represents that the shift position of screw rod 5 is as position, in Fig. 8 B, the longitudinal axis represents that the pressure of screw rod 5 is as piezometry, transverse axis represents that the shift position of screw rod 5 is as position, and in Fig. 8 C, the longitudinal axis represents that the speed of screw rod 5 is as velocity determination, transverse axis represents the time, in Fig. 8 D, the longitudinal axis represents that the pressure of screw rod 5 is as piezometry, and transverse axis represents the time.In Fig. 8 A～Fig. 8 D, the waveform of injection (5.00mm) is represented by solid line for the first time, and the waveform of injection (4.05mm) is illustrated by the broken lines for the second time, and the waveform of injection (3.57mm) is represented by single-point line for the third time.And, for example, if the amplitude that retreats of the screw rod of injection is 5.00mm for the first time, when the goal pressure suitable with the setting pressure of secondary pressurize operation is made as 10MPa and forms, in order to make a packing pressure of a pressurize operation reach the setting pressure of secondary pressurize operation, making to retreat amplitude B is that 4.01mm reaches, but in injection for the first time, B=5.00, A=3.97, therefore do not meet the important document of the mathematical expression (A/B>0.98) of mathematical expression 2, therefore for the mode reducing with the amplitude that retreats of screw rod 5 is adjusted, and use the mathematical expression (B=A/0.99) of described mathematical expression 3.

And, as the mathematical expression with mathematical expression 3 (B=A/0.99), retreat amplitude B=4.05mm, goal pressure be 10MPa inject for the second time shaping time, the amplitude that retreats B when a packing pressure of a pressurize operation reaches the setting pressure of secondary pressurize operation becomes 3.53mm, therefore again calculates according to the mathematical expression of mathematical expression 3 (B=A/0.99).

Consequently, become B=3.57mm, therefore in injection for the third time, with B=3.57mm, goal pressure is that 10MPa forms, the amplitude B of retreating is 3.57mm, when the setting pressure (goal pressure) that a packing pressure of a pressurize operation reaches secondary pressurize operation is 10MPa, has used the inching of the amplitude that retreats of the screw rod 5 of the mathematical expression of mathematical expression 3 to finish.

[label declaration]

1 injection (mo(u)lding) machine

2 injecting units

3 hoppers

4 heating cylinders

5 screw rods

6 injection nozzle

7 Timing Belts

8 metering motor

9 Timing Belts

10 ball screw frameworks

11 injection motor

12 load cells

13 control modules

14 memory cell

Claims (4)

1. the pressurize operation control method in injection (mo(u)lding) machine, this injection (mo(u)lding) machine advances screw rod and fills the injection fillers operation of molten resin and described screw rod is retreated and the pressurize operation that reduces pressure to the cavity injection of mould, it is characterized in that,

After the injection fillers of described injection fillers operation completes, be switched to described pressurize operation,

As being switched in a pressurize operation of the initial stage after this pressurize operation, make a packing pressure decompression that described screw rod is retreated fast by pressure control, so that the mode that this post-decompression packing pressure reaches the setting pressure of the secondary pressurize operation of carrying out after a described pressurize operation is at short notice carried out Decompression Controlling.

2. the pressurize operation control method in injection (mo(u)lding) machine according to claim 1, is characterized in that,

Carry out the forward travel of described screw rod and the mode of carrying out the setback of described screw rod by pressure control in described pressurize operation with Negotiation speed control in described injection fillers operation, carry out V-P switching by the switching from described injection fillers operation to described pressurize operation.

3. the pressurize operation control method in injection (mo(u)lding) machine according to claim 2, is characterized in that,

In a pressurize operation that makes screw rod retreat by described decompression, in the time that the observed pressure of a described packing pressure does not reach described setting pressure, calculate the amplitude that the retreats B of this screw rod while described screw rod being retreated reduce pressure by the mathematical expression of following mathematical expression 1, with the amplitude that the retreats B calculating by the mathematical expression of this mathematical expression 1, described screw rod is retreated

On the other hand, in a pressurize operation that makes screw rod retreat by described decompression, in the time that the observed pressure of a described packing pressure reaches described setting pressure, carry out computing by the mathematical expression of following mathematical expression 2,

In the time not meeting the mathematical expression of described mathematical expression 2,

The amplitude that the retreats B that calculates this screw rod while described screw rod being retreated reduce pressure by the mathematical expression of following mathematical expression 3, retreats described screw rod with the amplitude that the retreats B calculating by the mathematical expression of this mathematical expression 3,

[mathematical expression 1]

B＝Cb/0.9a

[mathematical expression 2]

A/B＞0.98

[mathematical expression 3]

B＝A/0.99

A: the mobile range (mm) of the screw rod till moving to when pressurize operation and secondary pressurize operation are switched when V-P a shot switches

C: the amplitude that retreats (mm) of the screw rod of the setting before a shot

A: the V-P of the actual measurement when V-P before a shot switches switches the differential pressure (MPa) of the observed pressure of a pressurize operation before pressure and a shot

B: the V-P of the actual measurement when V-P before a shot switches switches the differential pressure (MPa) of the setting pressure in pressure and secondary pressurize operation.

4. the pressurize operation control method in injection (mo(u)lding) machine according to claim 3, is characterized in that,

In the time meeting the mathematical expression of described mathematical expression 2,

If frequency injection is k, time when described observed pressure reaches the setting pressure of described secondary pressurize operation is t, the amplitude that retreats retreating at time t screw rod is X(t), the injection speed at time t place is V(t), the injection pressure P(t at time t place), the learning coefficient of arbitrary decision is α, β, evaluation function f(t)=α V(t)+β P(t)

Use this evaluation function, injection each time calculated and retreats amplitude X(t to the direction that becomes f(t) ≒ 0 by the mathematical expression of following mathematical expression 4), based on this calculated value of injecting each time, the amplitude that retreats of described screw rod is adjusted automatically,

[mathematical expression 4]

$X{\left(t\right)}_{k+1}=X{\left(t\right)}_k+\mathrm{\&alpha;}\frac{\mathrm{dV}\left(t\right)}{\mathrm{dt}}+\mathrm{\&beta;}\frac{\mathrm{dP}\left(t\right)}{\mathrm{dt}}.$

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