DE102016001039A1 - Method for operating an injection unit and injection unit - Google Patents

Abstract

Method for operating an injection unit for a casting process, wherein
- For filling a mold cavity a melt is displaced by means of an actuator from a melt vessel,
A regulation and / or control of a movement of the actuator is carried out according to a kinematic parameter,
A measured variable, which is characteristic for a pressure of the melt, is measured and
- From the measured value of a prevailing at any future time in the melt pressure is calculated
wherein a manipulated variable for the regulation and / or control of the kinematic parameter is predefined and / or corrected taking into account the pressure prevailing in the melt in each case in the future, and injection unit.

Description

The invention relates to a method for operating an injection unit for a casting process according to the features of the preamble of claim 1 and to an injection unit according to the features of the preamble of claim 13.

In the following, the prior art will be described by way of example in an injection molding process. The statements also apply more generally in relation to other casting processes.

• – zur Füllung einer Formkavität eine Schmelze mittels eines Aktuators aus einem Schmelzegefäß verdrängt,
• – eine Regelung und/oder Steuerung einer Bewegung des Aktuators nach einem kinematischen Parameter durchgeführt und
• – eine Messgröße, welche für einen Druck der Schmelze charakteristisch ist, gemessen.

In a generic method is

• - For the filling of a mold cavity, a melt displaced by means of an actuator from a melt vessel,
• A control and / or control of a movement of the actuator is carried out according to a kinematic parameter and
• A measured variable, which is characteristic for a pressure of the melt, measured.

The filling of the mold during injection usually takes place after an injection speed given by the operator (as a kinematic variable). Depending on the material and shape, the injection pressure is set during mold filling. In addition to the injection speed, an injection pressure limit can be set. This limit value must not be exceeded in order to protect the tool or, at maximum value, the operator and the machine (cylinder, nozzle, worm, lock, etc.).

In a known variant, the speed setting is followed until the injection pressure limit is reached and then the pressure control is activated, whereby the speed is reduced. However, this leads at high speeds to corresponding overshoot in the pressure, especially at steep pressure increases when the mold is already completely filled or z. B. the shutter nozzle does not open. (Please refer 6 .)

A further variant would be to parameterize a PID controller in such a way that it reduces the speed at a pressure increase at an early stage, that is, even before reaching the injection pressure limit, thus avoiding the pressure overshoot. However, this design is difficult to parameterize and in some cases leads to an unwanted premature deviation of the injection speed from the specification (and thus longer cycle times).

In the EP 1 612 027 A1 For example, the pressure increase during deceleration is predicted based on the current pressure change, the speed and a coefficient based on a simple arithmetic expression. If this precalculated pressure exceeds the injection pressure limit, the deceleration of the plasticizing screw is initiated, whereby a constant acceleration (in this case of course a deceleration) is specified.

This constant acceleration potentially gives cycle time away as a constant plasticizing screw delay will, of course, be ideal only for the few tool and melt combinations.

The object of the invention is to provide a method for operating an injection unit and an injection unit, which allow a shortened injection time.

With regard to the method, this object is solved by the features of claim 1. This is done by predefining and / or correcting a manipulated variable for the regulation and / or control of the kinematic parameter, taking into account the pressure prevailing in the melt at any future time.

With regard to the injection unit, this object is achieved by the features of claim 13. This is achieved in that the regulating or control unit is designed to predetermine and / or correct a manipulated variable for the regulation and / or control of the kinematic parameter, taking into account the pressure prevailing in the melt at any future time.

Thus, the information that is available from the measurement of the measured variable can also be used during the control and / or control phase according to a kinematic parameter. It is thereby achieved that the extension of the injection time, which results from the engagement of the pressure limit regulator in the profile predetermined by the operator, is minimized, whereby at the same time there are no excessive pressures in the melt.

In the measured variable, which is characteristic of a pressure of the melt, it may be, for example, a pressure measurement. As measured variables, any measured variables can be used which can describe the pressure behavior of the melt. For example, measured variables can be used that allow statements about the force exerted by the actuator on the melt (since the geometry of the actuator is usually known). These would be a pressure measurement of the hydraulic fluid in an injection piston or, if the actuator is moved by means of an electric drive, currents and voltages of the electric drive. Of course, melt pressure sensors can also be used in the mold cavity or other areas where the melt reaches. In fact, sensors could also be used which measure the increase in the closing force in a closing unit which serves to close the mold cavity in response to the urging force caused by the pressure of the melt.

The invention can preferably be used in injection units with an electric drive, wherein the use is also possible in hydraulic drives.

Further advantageous embodiments of the invention are defined in the dependent claims.

It can preferably be provided that a pressure limit is specified as the limit value for the pressure of the melt. This serves to protect the injection unit and the tool, as too high pressures can cause damage. Excessively high pressures can also cause a degradation of the melt. Ultimately, this also serves to increase the safety for the operators.

In many cases, the speed only has to be reduced relatively slightly in order to keep the injection pressure during mold filling below the pressure limit. In the case of methods according to the prior art, however, a relatively large loss in the injection time must also be accepted in these cases.

In a particularly preferred embodiment it can be provided that the specification and / or the correction of the manipulated variable is carried out if the predicted pressure of the melt is greater than the pressure limit. This procedure enables a further optimized cycle time, since the pressure limit is utilized as well as possible without causing overshoots.

In order to further improve the control and / or control, it may be provided that a viscosity and / or a compressibility of the melt are taken into account in the preliminary calculation of the pressure prevailing in the melt at any future time.

A particularly simple implementation of the simultaneous control and / or control according to the kinematic parameter and the measured variable can be achieved by performing the correction of the manipulated variable as feedforward for the control and / or control according to a kinematic parameter.

It can be provided that the injection pressure limit is specified as a constant, time-dependent or path-dependent pressure profile.

As kinematic parameters, for example, a speed, a position and / or an acceleration can be used.

It can also be provided that an indication is issued to an operator and / or a component produced is declared as rejects and / or production is stopped, if a specification and / or a correction of the manipulated variable taking into account at any future time in the melt prevailing pressure is performed.

It may preferably be provided to design an injection unit according to the invention such that the specification and / or correction of the manipulated variable carried out during the regulation and / or control according to the kinematic parameter can be switched off.

The actuator may include an injection piston. The actuator may also comprise a plasticizing screw.

The melt vessel can be designed as plasticizing cylinder.

Protection is also desired for a molding machine with an injection unit according to the invention. Under shaping machines injection molding machines, transfer molding and pressing and the like can be understood.

The injection unit may be particularly suitable for filling a mold cavity with plasticized plastic.

Further advantages and details of the invention can be seen from the figures and the accompanying figures. Showing:

1a and 1b a pressure diagram and a velocity diagram in two examples of injection events,

2 a flow chart of an embodiment of a method according to the invention,

3 a diagram of control strategy in an embodiment according to the invention,

4 a pressure diagram and a velocity diagram with further examples of injection processes,

5a and 5b two diagrams for the control concept for the actuator of the injection unit as well

6 a pressure diagram and a speed diagram, as may occur in the prior art.

In the example off 1a the pre-calculated injection pressure SD reaches the set pressure limit DG, while the measured pressure (ie the measured variable) is still significantly lower. As soon as the pre-calculated injection pressure, but before the measured variable reaches the pressure limit DG (the time is represented by a vertical line), the set velocity profile GP is deviated and the speed manipulated variable SG is reduced to zero under pressure control. This avoids overshooting the pressure in the melt.

The concept of pressure limit control (hereinafter referred to as "pressure control") serves to limit the maximum pressure and is often used in injection units with electric drives. In order to fulfill the pressure limiting function due to the high system rigidity and the high injection speeds, a premature reduction of the speed is necessary.

In the 1b The set maximum pressure (pressure limit DG) is reached at reduced speed. The speed is reduced to the value needed for the set pressure limit DG. After reaching the pressure limit DG (also "injection pressure limit"), the speed is slowly reduced further by the control to keep the injection pressure. A reduction of the speed to a standstill in this case would mean that the mold can not be completely filled. The concept of pressure control achieves a higher speed and shortens the injection time.

These situations can be generated by an operation according to the invention. In the exemplary embodiment described here, first, by means of a model which takes into account the viscosity / compressibility of the melt and the elasticity of the injection unit (or its drive train), it is calculated in advance how high the pressure would rise if the predefined speed profile GP is maintained. (Models which take into account the viscosity / compressibility of the melt, are for example in the EP 0 478 788 A1 or the US 2013/0032961 A1 disclosed.)

In the machine model, the friction and rigidity of the drive train can be described by means of equations of motion. This allows the dynamic limits of the movement of the machine during operation to be taken into account. If this pressure value of the melt exceeds the pressure limit DG, the pressure regulator intervenes in the control of the actuator.

In the flowchart in FIG 2 the rest of the injection process is shown until reaching the switching point. After the start of the injection movement takes place due to the predetermined and measured speed, the control of the injection speed. If there is no intervention of the pressure regulator, the speed control continues until the switchover point.

If the pressure regulator intervenes in the injection process up to the switching point, a message is displayed on the control screen. Depending on the setting by the operator, further actions can be linked with it.

The pressure control during the engagement of the pressure regulator is carried out in this embodiment with a pilot control of the actuator. For details in this regard is on the 5a and 5b directed.

After the procedure, the pressure control is performed based on the predetermined pressure profile DG and the measured variable (injection pressure).

The process variables during intervention (pressure, speed and position) are saved for later optimization. Preferably, only individual values can be determined for specific criteria for the following calculation. After switching to holding pressure, the adaptation of the control parameters is carried out based on the measured variables. The adapted parameters are used for the next cycle.

optimization

As already mentioned, in a preferred embodiment a model for the drive and the injection process is used. With the model, the pressure increases can be precalculated more accurately and the ideal time of intervention of the pressure regulator - that is, as late as possible but without exceeding the pressure limit - be determined. The models of the machine and the drive are usually well-known, but due to the dependence on the tool and the material, the process model is not exactly known in advance.

The controller includes a model for the drive and the process. On the one hand, this can be used to calculate material-specific or tool-specific variables and to carry out a precalculation of the pressure increase during deceleration to the required injection speed. This can set the time for activating the Pressure regulator can be determined, the model information can also be used for pressure control.

The model for the process is parameterized in the first step with nominal parameters. These nominal parameters provide a safe function for all tools and material properties, the pressure control is activated in time, the speed is reduced and pressure overshoot can be avoided. Due to the robust parameterization, however, the intervention usually takes place too early (the speed would not have had to be reduced at that time). If it is detected that the intervention takes place too early, the model parameters for the following injection movements are adapted according to a calculation rule on the basis of the measurement data of pressure, position and speed.

In one possible variant embodiment, a deviation of the predicted injection pressure with the measured injection pressure is determined. Depending on the deviation, one or more parameters of the model are adjusted to better match the prediction with the measurement. By way of example, the parameter adaptation can take place as follows: P _{k + 1} = f (P _k , p _M , p _act , v _act , c), so for example P _{k + 1} = P _k + c · (p _act -p _M ) where P _k , P _{k + 1 represent} the current and adapted model parameters, f is a mathematical function, p _M , p _{Act is} the model calculated and measured pressure, v _{Act is} the measured velocity, and c is a coefficient for evaluating the deviation.

This optimization is repeated as needed in the following cycles. Since this optimization changes the behavior of the machine and thus also changes the injection process, the operator can control this optimization.

It can be provided that the estimated model or controlled variables are used for a process or machine monitoring.

An embodiment:

During the cycle, a pre-calculated pressure is compared with the measured pressure. The deviation can be used as a factor multiplied by a model parameter modifier (or model inversion).

Activation of optimization

• • Der Bediener hat die Möglichkeit die Optimierung der Parameter für das im Regler hinterlegte Systemmodell bei Bedarf zu aktivieren. In diesem Fall werden die Modellparameter zyklisch, basierend auf den Messwerten des aktuellen Einspritzvorgangs, für den Folgezyklus adaptiert. Der Optimierungsvorgang geschieht ohne Interaktion mit dem Bediener.
• • Deaktiviert der Bediener die Optimierung hat er die Möglichkeit das Ergebnis mit dem Teiledatensatz zu verknüpfen (= Anhalten der Optimierung) oder zu verwerfen (= Zurücksetzen).
• • Wird der Teiledatensatz gespeichert während die Optimierung aktiv ist, hat der Bediener die Möglichkeit zu entscheiden ob der aktuelle Stand der Optimierung mit gesichert wird oder nicht.
• • Lädt der Bediener einen Teiledatensatz der ein Optimierungsergebnis enthält hat er die Möglichkeit dieses für die folgenden Produktionszyklen zu verwenden. Nutzt er diese Möglichkeit, so wird die Optimierung aktiviert und startet mit dem gesicherten Ergebnis. Auch in diesem Fall mit automatischer Aktivierung der Optimierung hat der Bediener beim manuellen Beenden der Optimierung die Wahl das Optimierungsergebnis mit den Teiledaten zu verknüpfen oder zu verwerfen.

The operator has the possibility to start, stop and reset the optimization:

• • The operator has the option of activating the optimization of the parameters for the system model stored in the controller as required. In this case, the model parameters are adapted cyclically, based on the measured values of the current injection process, for the subsequent cycle. The optimization process happens without interaction with the operator.
• • If the operator deactivates the optimization, he has the option of linking the result to the part data record (= stopping the optimization) or discarding (= resetting).
• • If the parts data record is saved while the optimization is active, the operator has the opportunity to decide whether or not to save the current state of optimization.
• • If the operator loads a part data record that contains an optimization result, he has the possibility to use it for the following production cycles. If he uses this option, the optimization is activated and starts with the saved result. In this case too, with automatic activation of the optimization, when the optimization is ended manually, the operator has the choice of linking or rejecting the optimization result with the parts data.

Other variants for start and duration of optimization

• • The optimization runs constantly and checks the criteria for adjusting the parameters internally (no activation by the operator necessary). If no intervention takes place, no adjustment happens. During an intervention it is checked whether the behavior can be improved by a parameter adjustment. If this is positive, the parameters are saved and used for the next shot.
• • The optimization takes place only once after manually triggering the optimization after an intervention. The operator himself determines whether a change of the controller behavior is permissible. After optimization, the parameters are saved and used for the next shot.
• • Optimization runs for a certain number of cycles. Within the cycles, the parameters can be adjusted several times. Furthermore, the adjustment can be averaged over several shots. After optimization, the parameters are saved and used for the following molding cycles.
• • The optimization runs until an optimization criterion or a max. Number of cycles is reached. After optimization, the parameters become saved and used for the following shots.
• • Optimization runs continuously after activation until it is deactivated by the operator.

The optimized parameters are stored as pieces of data. Thus, the process can be repeated reproducibly with the parameters determined so high product consistency can be achieved.

In 3 is shown how the inventive method embeds in the entire shaping cycle, or which states of the pressure regulator (also: pressure limit controller) can assume. First, the control of the actuator is carried out according to a kinematic parameter and without intervention of the pressure regulator (monitoring, 1 ), ie without the target profile for the speed of the actuator is changed.

• • Aus dem gemessenen Druckanstieg und dem Modell des Kompressionsverhaltens wird der benötigte Geschwindigkeitsverlauf bestimmt und der Verlauf des Einspritzdruckes vorausberechnet.
• • Es wird überprüft, ob der vorausberechnete Druck die Druckgrenze übersteigt.

Wird die Druckgrenze nicht erreicht, wird die vorgegebene Profilgeschwindigkeit nicht verändert (kein Eingriff). Der Druckregler verbleibt also im Zustand „Überwachen”.The following steps are performed in the "Monitor" state in each sampling step:

• • From the measured pressure increase and the model of the compression behavior of the required speed curve is determined and the course of the injection pressure precalculated.
• • It is checked if the predicted pressure exceeds the pressure limit.

If the pressure limit is not reached, the specified profile speed is not changed (no intervention). The pressure regulator thus remains in the "monitor" state.

As soon as the pressure limit DG is reached by the pre-calculated pressure of the melt, the pressure regulator intervenes (braking, 2 ) and reduces the speed with the aid of the pilot control and the slave controller. (For the details will again on the 5a and 5b referenced.) As soon as the pressure increase is completed, the sequence control regulates the pressure according to the predetermined pressure limit (pressure regulation, 3 ). As soon as the changeover point has been reached, a predefined pressure profile is traversed by the pressure regulator (without regulation of a kinematic parameter).

During the intervention of the pressure regulator, the speed is reduced by a pilot control. In addition, a slave controller becomes active. If the pressure increase is less than the predicted, the delay is reduced by the pilot control. If the pressure does not increase any further, the speed will not be further reduced by the pilot control.

After completion of the feedforward control, the pressure is kept at the pressure limit with the help of the slave controller. If the current pressure is below the pressure limit, the slave controller increases the speed until the currently valid profile speed is reached.

The intervention is completed when the pressure has fallen below a certain value and the profile speed is reached again. Thus, the pressure regulator behaves again as before the procedure.

The effect of a pressure limit regulator according to the invention is in 4 clarified, wherein in the first diagram, the pressure in the melt and in the second diagram, the injection speed is plotted against time. The diagrams contain several examples of different activation times.

In example I the speed of the actuator has been reduced too early, whereby the pressure limit DG is not reached. It is the task of the controller to increase the speed so that the pressure limit is reached.

In example III the actuator slows down too late. The (in the 5a and 5b described) pressure regulator will intervene in this case, since the pre-calculated melt pressure exceeds the pressure limit DG.

example II represents the ideal situation, wherein the pressure limit DG only at the end of the deceleration process to the pressure limit DG - zoom - without overshoot - enough.

The job of the pressure regulator is to situation III to avoid and influence the actuator so that situation II established. An example of such a pressure regulator is in 5a and 5b given.

The structure of the cruise control is in shown. The set speed is calculated in the profile generator as a function of the current worm position (x_akt). If no intervention of the pressure limit controller is necessary, the profile speed (v_Prof) corresponds to the set speed (v_setpoint) of the drive. In the pressure limit controller, the current pressure (p_akt), the current injection speed (v_akt) and the current screw position (x_akt) are used as measured variables to limit the injection pressure (p_limit).

gives an overview of the parameterizable components of this example of a pressure limit controller and their scope. Below is a brief description of the individual components.

Actual value:

The actual value filter can be designed as a band-stop filter and / or as a low-pass filter. The band-stop filter is a special filter that makes it possible to almost completely suppress a certain (disturbing) frequency. In this control loop, the band-stop filter offers the possibility of suppressing pressure oscillations with a known and approximately constant frequency.

A low-pass filter suppresses all signal components with frequencies that are above the set limit frequency. The signal is smoothed out by filtering out high-frequency components.

Model:

In the model, the precalculation of the pressure takes place based on the model parameters and measured values. Therein, the intervention time and also the input signals for the precontrol and the slave controller are determined.

Pilot:

In summary, a feedforward control offers the possibility of predetermining the input of the system to be controlled so that its output follows a desired course under ideal conditions. As a result, the system behavior is known in advance and it is possible to use the full dynamics of the system.

If the pre-calculated pressure reaches the pressure limit, the speed is reduced so that the pressure rises to the pressure limit as predicted. When calculating the pressure, the model parameters and the current measured values are taken into account. If the pressure increases more slowly than expected, the deceleration is reduced accordingly so that it does not deviate more than absolutely necessary from the given velocity profile. If the pressure remains constant before reaching the pressure limit, the setpoint speed (v_Vorst) output by the pilot control is also kept constant.

Slave controller:

In the pressure limit controller, the slave controller is used to correct deviations between the set pressure limit and the measured pressure. The sum of the output of the feed forward control and the output of the slave controller is used as the new setpoint speed for the system. If the pressure limit is not reached, the speed is increased again until either the pressure limit or the set profile speed is reached.

Operator interface

The method according to the invention can result in a speed profile for the actuator entered by the operator being changed by the pressure regulator as a function of the situation. In order to make the behavior of the machine more transparent, in the first step, the operator is informed about the intervention of the pressure control during injection with a message and pointed to possible remedies.

Furthermore, in a preferred embodiment of the invention, it is possible to select further actions in addition to an information message. Material and process fluctuations can cause a change in the operating point, which can lead to an intervention of the pressure regulator.

If the process requires a cyclic intervention of the controller or if the required product quality is achieved despite intervention, the warning message can also be deactivated.

• – Keine
• – Hinweismeldung (default)
• – Deklarierung des produzierten Teils als Ausschuss (und Hinweismeldung)
• – Produktionsstopp (und Hinweismeldung und Ausschussdeklarierung)

The action at injection pressure regulator intervention can be determined by a drop-down selection:

• - None
• - Information message (default)
• - Declaration of the produced part as reject (and notification)
• - Production stop (and notice message and reject declaration)

The message informs the operator about the intervention of the pressure regulator, which reduces the specified injection speed and points out possible remedies via the help. By specifying the position or the injection volume, for example, the operator can specifically adjust the speed in certain areas.

• – Eingriff Einspritzdruckregler reduziert Geschwindigkeit (eventuell unter Angabe der Geschwindigkeit des Aktuators, bei der eigegriffen wurde);
• – Auswirkung: Der Einspritzdruckregler reduziert die Spritzgeschwindigkeit, die eingestellte Spritzgeschwindigkeit kann dadurch nicht erreicht werden.
• – Möglichkeiten zur Behebung:
• – Überprüfen von Kavitäten und Temperatureinstellungen
• – Spritzdruckgrenze erhöhen
• – Eingestellte Einspritzgeschwindigkeit (im Bereich des Reglereingriffs) reduzieren
• – Aktivierung der Optimierung der Spritzdruckbegrenzung für den Prozess
• – Deaktivierung der Hinweismeldung

An appropriate notification message could include, for example:

• - intervention injection pressure regulator reduces speed (possibly indicating the speed of the actuator in which eigegriffen was);
• - Effect: The injection pressure regulator reduces the injection speed, which means that the set injection speed can not be achieved.
• - Remedies:
• - Check cavities and temperature settings
• - increase the injection pressure limit
• - Reduce the set injection speed (in the range of the controller intervention)
• - Activation of the optimization of the injection pressure limitation for the process
• - deactivation of the information message

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1612027 A1 [0007]
• EP 0478788 A1 [0039]
• US 2013/0032961 A1 [0039]

Claims (20)

A method for operating an injection unit for a casting process, wherein - for filling a mold cavity, a melt is displaced by means of an actuator from a melt vessel, - a control and / or control of a movement of the actuator is carried out according to a kinematic parameter, - a measure, which for a pressure of the melt is characteristic, is measured and - from the measured value is precalculated a prevailing at any future time in the melt pressure is characterized in that a manipulated variable for the control and / or control of the kinematic parameter taking into account each of a future Time is given in the melt prevailing pressure and / or corrected. A method according to claim 1, characterized in that a pressure limit is set as the limit value for the pressure of the melt. A method according to claim 2, characterized in that the specification and / or the correction of the manipulated variable is performed if the pre-calculated pressure of the melt is greater than the pressure limit. Method according to one of Claims 1 to 4, characterized in that a viscosity and / or a compressibility of the melt is taken into account in the preliminary calculation of the pressure prevailing in the melt at a respectively future point in time. Method according to one of claims 1 to 5, characterized in that the correction of the manipulated variable with a feedforward control for the control and / or control is carried out according to a kinematic parameter. A method according to claim 2, characterized in that the pressure limit is specified as a constant, time- and / or path-dependent pressure profile. Method according to one of claims 1 to 6, characterized in that as a kinematic parameter, a speed, a position and / or an acceleration is used. Method according to one of claims 1 to 7, characterized in that an indication is issued to an operator and / or a produced component is declared as rejects and / or the production is stopped, if a specification and / or a correction of the manipulated variable under consideration the pressure prevailing at a future time in the melt is carried out. A method according to claim 3, characterized in that an indication is issued to an operator and / or a produced component is declared as broke and / or the production is stopped if the pre-calculated pressure of the melt is greater than or equal to the pressure limit. Method according to one of claims 1 to 9, characterized in that based on a process model, the measured variable and / or measurements of the kinematic parameter adapted control and / or control parameters and / or adapted model parameters are calculated A method according to claim 10, characterized in that the adapted control and / or control parameters and / or the adapted model parameters are used in a subsequent injection process. A method according to claim 10 or 11, characterized in that the adaptation of the parameters controlled by the operator and / or displayed to the operator. Injection unit, in particular operated according to a method of claims 1 to 12, comprising - a melt vessel in which a melt is provided, - an actuator for displacing a melt from the melt vessel for filling a mold cavity, - connected to the actuator control unit for controlling and / or controlling movements of the actuator according to a kinematic parameter and - a connected to the control unit or control unit for measuring a measured variable which is characteristic of a pressure of the melt, wherein the control or regulating unit is adapted to, off the value to be predicted in a prevailing at any future time in the melt pressure, characterized in that the control or control unit is adapted to a manipulated variable for the control and / or control of the kinematic parameter taking into account at a respective future Zei specify and / or correct point in the melt prevailing pressure. Injection unit according to claim 13, characterized in that a connected to the control or control unit memory is provided in which a pressure limit as the limit value for the pressure of the melt can be stored. Injection unit according to claim 14, characterized in that the control and / or control unit is adapted to perform the specification and / or the correction of the manipulated variable, if the pre-calculated pressure of the melt is greater than the injection pressure limit. Injection unit according to one of claims 13 to 15, characterized in that during the control and / or control carried out according to the kinematic parameter specification and / or correction of the manipulated variable can be switched off. Injection unit according to one of claims 13 to 16, characterized in that the actuator comprises an injection piston. Injection unit according to one of claims 13 to 17, characterized in that the actuator has a plasticizing screw. Injection unit according to one of claims 13 to 18, characterized in that the melt vessel is designed as a plasticizing cylinder. Shaping machine with an injection unit according to one of claims 13 to 19.

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