JPH07115149B2 - Cylinder position and output control method and device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and a device for controlling the position and pressure of a cylinder piston of a cylinder device, for example, by injecting and filling a material into a whole mold for molding. The present invention relates to a method and an apparatus for controlling the position and pressure of a cylinder piston such as an injection cylinder and a pressure cylinder of an injection molding machine or a die casting machine, and an extruder cylinder for extruding and molding a material through a die.

[Prior Art] Conventionally, a method of controlling a cylinder piston of an injection cylinder of an injection molding machine or a die casting machine is as shown in FIG. This controls the cylinder piston 2 at a predetermined speed with respect to the position of the cylinder piston 2 of the injection cylinder 1, and at the same time, controls the injection cylinder 1 from a predetermined switching point.
The method of adjusting the output of the cylinder piston 2 by controlling the pressure on the side of the head chamber is generally configured as follows. In the injection cylinder 1, 1a is a cylinder head chamber and 1b is a cylinder rod chamber.

Here, the output of the cylinder piston 2 means that when pressure oil is supplied to the cylinder head chamber 1a, a forward force is generated in the cylinder piston 2 so that a force for pushing an object is generated in the cylinder piston 2. It means the maximum power to obtain,
Usually expressed in units of ton.

As shown in the figure, the speed setter 20 is preset with a desired speed v with respect to the position st of the cylinder piston 2 detected by the position detector 3, and this speed command value v is given by a command from the outside. Output to the controller 22.
Here, at the position st, the operation in the illustrated fwd direction is represented by a positive symbol, and the operation in the bwd direction is represented by a negative symbol, with the state where the cylinder piston 2 is retracted most inside the injection cylinder 1 as 0. It represents. The same servo valve controller
22 is the speed command value v and the position detected by the position detector 3.
The opening signal vo for driving the servo valve 25 is calculated and output from the speed measurement value vm obtained by time-differentiating st with the speed detector 21. The illustrated servo valve 25 is of a flow rate control type and controls the speed of the cylinder piston 2 to a predetermined value by increasing or decreasing the flow rate of the hydraulic oil from the hydraulic pressure source 24 in accordance with the opening signal vo. There is. Reference numeral 23 is a direction switching valve, which functions to switch the moving direction of the cylinder piston 2 by exciting the solenoid 23a or 23b.

When the molding material is injected into a mold cavity (not shown) by operating the cylinder piston 2 in the direction of the illustrated fwd, the cylinder piston 2 is braked when the filling of the molding material is completed, and the pressure in the cylinder head chamber 1a is To rise. Normally, when a signal indicating that the pressure in the cylinder head chamber 1a has risen above a predetermined pressure is obtained, the pressure control valve 26 is operated to perform pressure control for the time shown below and switch to output control of the cylinder piston 2.

Pressure pb in cylinder head chamber 1a detected by pressure detector 27
However, when the switching pressure ps set in advance in the pressure switch 28 is exceeded, the pressure switch 28 outputs a pressure control command pst to the pressure setter 29. A desired pressure p is preset in the pressure setter 29 with respect to the time t as shown in the figure, and this pressure command value p is output to the pressure control valve controller 30 by the pressure control command pst. here,
The time t is represented by 0 when the pressure control command pst is input. The pressure control valve controller 30 calculates and outputs a pressure signal po that drives the pressure control valve 26 from the pressure command value p and the pressure pb detected by the pressure detector 27. The pressure control valve 26 controls the pressure pb of the cylinder head chamber 1a, that is, the output of the cylinder piston 2 to a predetermined value according to the pressure signal po.

As shown in the figure, the setting to the speed setter 20 is the speed v with respect to the position st of the cylinder piston 2, and it is also only the target values v ₁ , v ₂ , v ₃ , ... …… of the speed as illustrated. There
The shift process of v ₁ ≧ v ₂ , v ₂ ≧ v ₃ , ……… was basically stepwise adjustment that is not the target of control. Similarly, the setting in the pressure setter 29 is also the pressure p with respect to the time t after switching to the pressure control, which is only the target pressure values p1, p2, p3, ... , P ₁ ≧ p ₂ , p ₂ ≧ p ₃ ,
The transformation process of ……… was basically stepwise adjustment, which is not the target of control. In addition, the transient characteristics during gear shifting and voltage transformation are determined by the servo valve controller 22
It was done by the fixed gain adjustment of 30.

[Problems to be Solved by the Present Invention] The conventional system requires a control valve and a controller for speed control and pressure control, respectively.
The control circuit is complicated and expensive. Also, since both control valves and their controllers are basically independent of each other, there is no mutual relationship, so it is necessary to compensate accordingly when switching control from one to the other. It was also complicated.

For example, when the speed control is switched to the pressure control, the speed value at the final stage (v _{3 in} the example of FIG. 2) is set low, that is, the opening of the servo valve 25 becomes small. , When switching to the next stage pressure control,
It is throttled by the servo valve 25 and the pressure transmission to the injection cylinder 1 is delayed. That is, since the control by the pressure control valve largely depends on the speed value of the final stage, in order to prevent this, like the one described in JP-A-60-99470 previously invented by the present applicants, After the speed value at the final stage, at the time when the pressure control command pst is input, the servo valve 25 is separately provided with an opening for pressure control compensation, and in order to ensure the best controllability of the pressure control valve 29, It is necessary to open up to the maximum opening. By the way, the value of the switching pressure ps set in the pressure switch 28 is too low, or the sliding resistance of the injection device that injects the molding material into the mold cavity fluctuates.
If t is input early, the opening for pressure control compensation is opened to almost the maximum opening for the above reason, so a very large speed is generated at the completion of filling the molding material and Was blowing, and the mold was damaged.

In addition, with the recent trend toward precision molding and high-quality molding, the conventional stepwise adjustment of speed and pressure can stably satisfy delicate molding conditions such as when the load fluctuates greatly. There was also a problem that there was a limit.

[Means for Solving the Problems] In the present invention, by changing the cylinder chamber pressure for operating the cylinder piston, the movement stroke amount of the cylinder piston with respect to time and the output of the cylinder piston with respect to time are arbitrarily switched, The position and output of the cylinder are controlled.

In addition, the moving stroke amount of the cylinder piston is set in advance as a target locus with respect to time, and the cylinder stroke is determined according to the deviation amount between the moving stroke amount of the cylinder piston and the actual moving stroke amount of the cylinder piston. By independently changing the pressure acting on the cylinder head chamber and the cylinder rod chamber that drive the piston, the operation of the cylinder piston is controlled so that the movement stroke amount of the cylinder piston with respect to time follows the target locus, and Predetermine the output of the piston as a target trajectory based on time,
By independently changing the pressure acting on the cylinder head chamber and the cylinder rod chamber that drive the cylinder piston according to the amount of deviation between the actual output and the output of the cylinder piston that is the target locus, The operation of the cylinder piston is controlled so that the output follows the target locus, and the control of the movement stroke amount of the cylinder piston with respect to time and the control of the output of the cylinder piston with respect to time can be arbitrarily switched.

When supplying pressure oil to the cylinder head chamber to move the cylinder piston forward, the hydraulic pressure in the cylinder head chamber and the cylinder piston (also simply referred to as piston) are provided on the rear surface of the cylinder piston in the cylinder head chamber. The force acting to move the cylinder piston forward, which is the product of the area of the rear surface of the cylinder, acts on the front surface of the piston in the cylinder rod chamber. The product of the area of the rear surface-the cross-sectional area of the piston rod) acts to move the cylinder piston backward, but the force to move the cylinder piston forward and the force to move the cylinder piston backward. Difference becomes the forward force of the cylinder piston, and this force becomes the force that the cylinder piston pushes the object. To a maximum force cylinder piston may issue said that the output of the cylinder piston, usually,
Expressed in units of ton.

As a standard for switching this control, the control from the control of the movement stroke amount of the cylinder piston with respect to time to the control of the output of the cylinder piston with respect to time is
Cylinder piston movement stroke, output, deviation amount between the actual movement stroke amount and the cylinder piston movement stroke amount that is the target locus is adopted, and from the control of the cylinder piston output with respect to time, the movement stroke of the cylinder piston with respect to time When switching to control of quantity, time, moving stroke of cylinder piston, and output are adopted.

Further, as a device for implementing such a method for controlling the position and output of the cylinder, a cylinder device in which the cylinder head chamber and the cylinder rod chamber communicate with independent pressure sources respectively, and a device depending on the magnitude of the input signal An independent pressure control valve capable of controlling the pressure acting on the cylinder head chamber and the cylinder rod chamber, a pressure detector that detects the pressure acting on each cylinder chamber and outputs an electric signal according to the pressure, It has a position detector that detects the position of the cylinder piston and outputs an electrical signal corresponding to the position, and a stroke command signal setting unit that sets and commands the movement stroke amount of the cylinder piston as a target trajectory with respect to time.
Depending on the deviation amount between the output signal from the stroke command signal setting unit and the output signal from the position detector, the pressure of the pressure control valve is set via the independent stroke gain setting unit for the cylinder head chamber and the cylinder rod chamber. A stroke feedback controller that outputs a drive signal to the adjustment drive unit and an output command signal setting unit that sets and commands the output of the cylinder piston with respect to time as a target locus, and the output signal from this output command signal setting unit According to the deviation amount from the actual output value of the cylinder piston calculated from the output signal of each pressure detector, the pressure of the pressure control valve is output via an independent output gain setter for the cylinder head chamber and the cylinder rod chamber. An output feedback controller that outputs a drive signal to the adjustment driver, and these stroke feedback controllers A force feedback controller and a control switcher for selectively switching the time, the movement stroke of the cylinder piston, the output, and the deviation amount between the movement stroke amount of the cylinder piston as the target locus and the actual movement stroke amount. The cylinder position and output control device.

[Operation] In the present invention, the same operation as the control method shown in the means for solving the above problems is performed. As a result, according to the present invention, it becomes possible to arbitrarily switch the stroke and output of the cylinder piston with respect to time to perform feedback control, and in either control state, the control target is the cylinder head chamber and the cylinder rod. Since the pressure is applied to the chamber, smooth transition can be made without any compensation means when switching the control.

[Embodiment] An embodiment of the present invention will be described with reference to FIG. An injection cylinder 1 of an injection molding machine or a die casting machine has a cylinder piston 2 and forms a cylinder head chamber 1a and a cylinder rod chamber 1b. The cylinder head chamber 1a is connected to a pump 5a and a pressure control valve 6a which are independent hydraulic sources by a hydraulic circuit, and the cylinder rod chamber 1b is also a pump 5b and a pressure control valve which are independent hydraulic sources by a hydraulic circuit. It is connected to 6b. Reference numeral 4 is an electric motor that drives the pumps 5a and 5b. Here, the pressure control valves 6a, 6b are electromagnetic relief valves which are so-called electromagnetic proportional automatic pressure control valves,
The pressure of each hydraulic source can be arbitrarily controlled by a predetermined electric signal. That is, the pressure control valves 6a and 6b control the operating force of the cylinder piston 2 according to the magnitude of the input signal, and increase the control pressure of the pressure control valve 6a, for example.
If the control pressure of the pressure control valve 6b is reduced, the pressure oil from the pump 5a enters the cylinder head chamber 1a and the cylinder rod chamber
Since the hydraulic oil from 1b and the pump 5b is released to the tank 7 via the pressure control valve 6b, the cylinder piston 2 operates in the outflow direction (fwd direction) in the figure. Conversely, pressure control valve 6b
If the control pressure is increased and the control pressure of the pressure control valve 6a is decreased, the operation is the reverse of the above, and the cylinder piston 2 operates in the return direction (bwd direction). Furthermore, 3
Is a position detector composed of a potentiometer, which is capable of detecting the stroke position of the cylinder piston 2 and outputting an electric signal corresponding to the position. Reference numerals 18a and 18b are pressure detectors that detect the pressure in the cylinder head chamber 1a and the cylinder rod chamber 1b, respectively, and output an electric signal corresponding to the pressure. 17 is an output calculator, which is a pressure detector 18a, 18b
The operating force, that is, the output of the cylinder piston 2 is calculated from the pressures in the cylinder head chamber 1a and the cylinder rod chamber 1b detected by and the pressure receiving area of each cylinder chamber.

Reference numeral 9 is a model portion created in the microcomputer that sets and designates a change amount of the movement stroke of the cylinder piston 2 with respect to time as a target trajectory, that is, a stroke instruction signal setting portion, and 10 is an input from the position detector 3. It is a stroke deviation detector that compares a signal with an input signal from the stroke command signal setting unit 9 and outputs an output signal according to a deviation amount between these two input signals. Reference numerals 8a and 8b denote stroke gain setting sections that receive signals from the stroke deviation detecting section 10 and appropriately process the signals, and output predetermined output signals corresponding to the signals, respectively corresponding to the pressure control valves 6a and 6b. ing. These stroke command signal setting section 9, stroke deviation detection section 10
The stroke gain setting units 8a and 8b form a stroke feed bag controller 11.

Reference numeral 14 is a model portion created in the microcomputer which sets and outputs a change amount of the output of the cylinder piston 2 as a target locus with respect to time, that is, an output instruction signal setting portion, and 15
Is an output deviation detection unit that compares the input signal from the output calculation unit 17 with the input signal from the output command signal setting unit 14 and outputs an output signal according to the deviation amount between these two input signals. 13a,
Reference numeral 13b denotes an output gain setting unit that receives a signal from the output deviation detection unit 15 and appropriately processes the signal, and outputs a predetermined output signal corresponding to the signal, which correspond to the pressure control valves 6a and 6b, respectively. . These output command signal setting unit 14, output deviation detection unit 1
5 and the output gain setting units 13a and 13b constitute an output feedback controller 16.

12a and 12b are respectively from the stroke gain setting units 8a and 8b,
Alternatively, it is a driver that controls the pressures of the pressure control valves 6a and 6b in accordance with the magnitudes of the output signals from the output gain setting units 13a and 13b, respectively, and constitutes a pressure adjustment drive unit.

Reference numeral 19 is a control switching device for selectively switching between the stroke feed bag controller 11 and the output feed bag controller 16.

Now, a controller (not shown) gives an operation command c for the injection cylinder 1 to the control switch 19. In the control switch 19,
For example, it is programmed as shown in FIG. 3 (a). First, the time point at which the operation command of the injection cylinder 1 is input is set to t = 0 to start time measurement, and the preset time ts is not reached. We give the stroke feed bag controller 11 an operation command cs to operate it.

As shown in FIG. 1, a desired trajectory of the moving stroke st of the cylinder piston 2 with respect to time t ₁ is programmed in advance in the stroke command signal setting unit 9 of the stroke feed-bag controller 11, and the above-mentioned operation is performed. Command cs
In response, the target moving stroke st is time-divisionally processed, for example, every few milliseconds, and is input to the stroke deviation detection unit 10. Here, the time t ₁ starts counting at the time when the operation command cs is input as 0, and the moving stroke st is 0 when the state where the cylinder piston 2 is retracted most into the cylinder 1 is set as 0 in the illustrated fwd direction. The positive sign is used to indicate the operation of, and the negative sign is used to indicate the operation in the bwd direction. In the stroke deviation detection unit 10, the deviation amount es (es from the actual position stb of the cylinder piston 2 detected by the position detector 3
= St-stb) is calculated, and this is calculated by the stroke gain setting unit 8
Input in a and 8b. Here, the stroke gain setting units 8a, 8
b is obtained by multiplying a predetermined P (proportional) I (integral) gain k ₁ , k ₂ based on the result of the deviation amount es, and the pressure command value v ₁ , which is a control amount, with respect to the stroke deviation amount es. Convert to v ₂ . Here, the characteristics of the gains k ₁ and k ₂ are, as shown in the figure, basically:
It has a sign characteristic that is contradictory to the deviation amount es, and the magnitude of the inclination is usually determined by actually operating it, making the most of experience, and determining it so that the following capability is most improved. In order to maintain the force balance of the cylinder piston 2, a value that roughly takes into consideration the area difference between the cylinder head chamber 1a and the cylinder rod chamber 1b, that is, the distribution of the inverse ratio of both areas is distributed.
In addition, the drivers 12a and 12b include stroke gain setting units 8a and 8b.
Side pressure command values v ₁ and v ₂ are obtained and converted into signals p ₁ and p ₂ that actually drive the electromagnetic relief valves 6a and 6b, and the pressures in the cylinder head chamber 1a and the rod chamber 1b are controlled. ing.

As an example, when the cylinder piston 2 is moved in the fwd direction, the deviation amount es is defined as above (es = st
According to −stb), the fact that es has a positive value is nothing but the fact that the actual movement stroke amount stb has not reached the target locus st. Therefore, the stroke feedback controller 11 determines, based on the characteristics of the gains k ₁ and k ₂ , the pressure v ₁ (p ₁ ) on the cylinder chamber (cylinder head chamber 1a in this embodiment) side that contributes to the moving direction of the cylinder piston 2. ) Is increased according to the deviation amount es, and conversely, the pressure v ₂ (p ₂ ) on the side of the other cylinder chamber (cylinder rod chamber 1b in this embodiment) side
Is reduced in accordance with the deviation amount es, so that the cylinder piston 2 acts to push it further in the fwd direction.
Further, if the actual movement stroke amount stb is over with respect to the target trajectory st, the deviation amount es takes a negative value, so the stroke feedback controller 11 determines from the characteristics of the gains k ₁ and k ₂ that: Pressure v on the cylinder chamber (cylinder head chamber 1a in this embodiment) side that contributes to the moving direction of the cylinder piston 2
₁ (p ₁ ) is decreased according to the deviation amount es, and conversely, the pressure v ₂ (p ₂ ) on the other cylinder chamber (cylinder rod chamber 1b in this embodiment) side is changed according to the deviation amount es. To increase,
It works to push the cylinder piston 2 back in the bwd direction. As described above, the actual movement of the cylinder piston is made to follow the target locus st.

Next, as shown in FIG. 3A, a preset time ts from the time point (t = 0) when the operation command c is input.
After a lapse of time, the control switching device 19 starts detecting the output of the cylinder piston 2. That is, the stroke feedback controller 11 continues the control until the actual output fb of the cylinder piston 2 from the output calculator 17 does not reach the preset output value fs, but when fb becomes fs or more,
The control by the stroke feedback controller 11 is stopped, the operation command cf is given to the output feedback controller 16, and this is operated. The fs shown here is a reference for the injection molding machine or die casting machine to know the time when the injection of the molding material is completed in the mold (not shown) by the operation of the cylinder piston 2 of the injection cylinder 1. The output is not detected until the time ts has elapsed since the working pressure is prevented from increasing due to an accidental change in the sliding resistance of the cylinder piston 2 during the filling and the false detection of the filling completion time is prevented. In order to do so, a timer is provided for that purpose.

As shown in FIG. 1, the desired trajectory of the output f of the cylinder piston 2 with respect to the time t ₂ is programmed in advance in the output signal setting unit 14 of the output feedback controller 16, and the operation command cf is received. Target output f is time-divisionally processed, for example, every few milliseconds, and output deviation detection unit 15
To enter. Here, the time t ₂ starts counting with the time point when the operation command cf is input as 0, and the output f with the state where the cylinder piston 2 is in force balance as 0 is shown in the figure.
The acting force in the fwd direction is represented by a positive sign, and the acting force in the bwd direction is represented by a negative sign. The output deviation detecting unit 15 calculates a deviation amount ef (ef = f−fb) from the actual output f of the cylinder piston 2 from the output calculator 17, and inputs this to the output gain setting units 13a and 13b. Here, the output gain setting units 13a and 13b determine the predetermined P based on the result of the deviation amount ef.
(Proportion) I (Integration) Multiply the gains k ₃ and k ₄ and output deviation
ef is converted into pressure command values v ₁ and v ₂ which are control amounts.
Similar to the gains k ₁ and k ₂ described above, the characteristics of the gains k ₃ and k ₄ basically have opposite sign characteristics with respect to the deviation amount ef, and the magnitude of the slope is Actually, try operating it, make use of the experience,
Normally, each value is determined, but in order to maintain the force balance of the cylinder piston 2, roughly, a value that takes into consideration the area difference between the cylinder head chamber 1a and the rod chamber 1b, that is, the distribution of the inverse ratio of both areas. Becomes Further, the drivers 12a, 12b obtain the pressure command values v ₁ , v ₂ from the output gain setting units 13a, 13b side, and convert them into signals p ₁ , p ₂ for actually driving the electromagnetic relief valves 6a, 6b, The pressures of the cylinder head chamber 1a and the rod chamber 1b are controlled.

As an example, the case where the output is applied in the fwd direction of the cylinder piston 2 will be described. If the deviation amount ef is in accordance with the above definition (ef = f−fb), ef has a positive value.
It is nothing but the fact that the actual output fb has not reached the target trajectory f. Therefore, the output feedback controller 16
Is the deviation ef of the pressure v ₁ (p ₁ ) on the cylinder chamber (cylinder head chamber 1a in this embodiment) side that contributes to the output action direction of the cylinder piston 2 from the characteristics of the respective gains k ₃ and k _4.
The pressure v ₂ (p ₂ ) on the side of the other cylinder chamber (cylinder rod chamber 1b in this embodiment) side is increased by the deviation amount.
Since it decreases according to ef, fwd of cylinder piston 2
It acts to increase the output in the direction. Further, if the actual output fb is over the target locus f, the deviation amount ef takes a negative value, and therefore the output feedback controller 16 determines that the cylinder piston has the characteristics of the gains k ₃ and k _4. The pressure v ₁ (p ₁ ) on the side of the cylinder chamber (cylinder head chamber 1a in the present embodiment) that contributes to the output action direction of _{No. 2} is reduced according to the deviation amount ef, and conversely the other cylinder chamber (the present embodiment Then, since the pressure v ₂ (p ₂ ) on the cylinder rod chamber 1b) side is increased according to the deviation amount ef, the output of the cylinder piston 2 in the fwd direction is further reduced. As described above,
The actual output of the cylinder piston is made to follow the target trajectory f.

In the present embodiment, the control switching device 19 switches the control based on the output of the cylinder piston 2 after providing a certain time range, as shown in FIG. 3 (b) and FIG. As described above, the control may be switched based on the deviation amount es between the target locus st of the cylinder piston 2 and the actual movement stroke amount stb. That is, if the target locus st of the cylinder piston 2 is set to be gradually increased near the completion of the filling of the molding material, the increase of the load of the cylinder piston 2 does not follow the increase of the load, and as a result, Positive deviation amount es accumulates. When the deviation amount es exceeds the preset deviation amount ess, the control by the stroke feedback controller 11 is stopped and the output feedback controller 16 is commanded to operate.
Give it cf to activate it. With this configuration, the same operation and result as those of the above-described embodiment can be obtained.

FIG. 4 shows another embodiment in which the method and apparatus of the present invention are applied to a pressurizing cylinder 31 of a die-casting machine for disk wheel molding, and those functionally similar to those in FIG. Similarly, the description is omitted. As shown in the figure, the upper mold 33, the lower mold 35 that can be opened and closed in the vertical direction, and the four cores 34 that can move in the horizontal direction are combined, and the mold clamping mechanism (not shown) allows The cavity 38 formed by clamping is filled with the molten metal 37 in the injection sleeve 39 by the ascending action of the injection plunger 36 and the plunger tip 36a by the action of an injection cylinder (not shown). (The state where the molten metal 37 is completely filled inside). Cylinder piston of the pressurizing cylinder 31 after a predetermined time (pressurizing time lag) has elapsed from the completion of filling the molten metal 37.
A pressure plunger 40 attached to 32 is projected into the cavity 38 to pressurize the molten metal 37 in the cavity 38 to perform a feeder action.

As this pressurizing method, the present applicants have previously described Japanese Patent Application No. 63-24.
No. 4552 presents the method and apparatus. At this time,
The operation of the pressurizing plunger 40 is a predetermined target such that the history of the amount of protrusion stroke into the cavity 38 with the passage of time from the start of operation is commensurate with the contraction allowance (solidification contraction) accompanying the cooling of the molten metal 37. Controls to follow the trajectory,
In the final stage of pressurization, the pressurizing plunger 40 needs to be reliably lowered (fwd direction) to the position of the gate portion 38a of the cavity 38 (gate seal position). That is,
By lowering the pressure plunger 40 having a diameter slightly smaller than that of the gate portion 38a to the gate seal position, a thin molten metal solidified product is formed and penetrated, and then the upper mold 33
The molten metal is cut from this thin portion by the mold opening operation between the core 34 and the lower mold 35 to prevent distortion of the disk wheel, which is a molded product.

In the present invention, the program as shown in FIG. 3 (c) is given to the control switch 19 to deal with this. Now, when a controller (not shown) gives an operation command c of the pressurizing cylinder 31 to the control switch 19, the timing starts at t = 0 from this point, and stroke feedback is performed before the preset time ts is reached. The operation command cs is given to the controller 11 to operate it. The stroke feedback controller 11 causes the actual movement of the cylinder piston, that is, the pressurizing plunger 40, to follow the target locus st by the same operation as described with reference to FIG. Next, when the time t has passed the preset time ts, the control switching device 19 stops the control by the stroke feedback controller 11,
By giving an operation command cf to the output feedback controller 16 and operating it, the actual output of the cylinder piston, that is, the pressurizing plunger 40 is made to follow the target locus f by the same operation as described in FIG. There is.

Here, as the time ts, the stroke command signal setting unit 9
Referring to the relationship of the moving stroke st of the pressure plunger 40 with respect to the time t ₁ set at
Obtain the time t ₁ g required for the gate seal position from, and set a slightly earlier value, or with the volume of the cavity 38,
In consideration of the surface area and the cooling ability of the dies 33, 34, 35, the moving stroke amount of the pressure plunger 40 or the solidification shrinkage time converted from the solidification shrinkage allowance of the molten metal 37 is determined for reference.
As for the output target locus f, the prevention of so-called cavities caused by the solidification contraction of the molten metal 37 is almost completed by controlling the moving stroke st of the preceding stage, so that the pressure plunger 40 can be reliably moved to the gate seal position. It is only necessary to concentrate on lowering the output to, and then the output may be increased to almost the maximum value in a short time. When the gate seal position is completely reached, a controller (not shown) detects it by the position detector 3, stops the operation command c itself of the pressurizing cylinder 31, and completes the overall control. By doing so, it is possible to reliably lower the gate seal position in a shorter time. In this example, the control switch 19 is switched on the basis of time, but as is clear from the above description, the same operation and result can be obtained by switching on the basis of the moving stroke.

As described above, in each of the embodiments of the present invention shown in FIG. 1 or FIG. 4, the switching from the control of the movement stroke of the cylinder piston to the control of the output has been described.
On the contrary, it goes without saying that the switching from the control of the output of the cylinder piston to the control of the moving stroke can be applied only by the program of the control switching device 19 so that it can be easily understood. Also, after switching from the control of the movement stroke of the cylinder piston to the control of the output, again
The combination can be arbitrarily performed such as switching to the control of the moving stroke.

In the present invention, the control from the control of the movement stroke amount of the cylinder piston with respect to time to the control of the output of the cylinder piston with respect to time is performed by changing the time, the movement stroke of the cylinder piston, the output, and the movement of the cylinder piston as the target trajectory. The amount of deviation between the stroke amount and the actual movement stroke amount can be used as a reference, and switching from control of the cylinder piston output with respect to time to control of the cylinder piston movement stroke amount with respect to time is The movement stroke, output, etc. can be used as a reference.

Further, in the above embodiment, the example of the cylinder device for injecting, filling and pressurizing the molding material in the mold is shown. However, this is a cylinder device for press molding the molding material with a die and other cylinders. It can also be applied to a device.

[Advantages of the Invention] In the present invention, since the configuration as described in the claims is adopted, it is relatively possible during the injection of the molding material into the mold cavity like an injection cylinder of an injection molding machine or a die casting machine. Even if the load fluctuates greatly during one stroke so that the load is light and increases as soon as the filling is completed, or if the sliding resistance fluctuates over time, such as with a pressure cylinder. The cylinder piston position with respect to time can be controlled responsively and reliably, and the output control can be smoothly switched to the following control. This is a great effect for stably satisfying delicate molding conditions. Can be demonstrated.

[Brief description of drawings]

FIG. 1 is a diagram showing one embodiment of an apparatus for carrying out the method of the present invention, FIG. 2 is a diagram showing a conventional example similar to the present invention, and FIG. 3 (a) is FIG. Fig. 3 is a diagram showing an example of a program state in the control switch shown in Fig. 3, Fig. 3 (b) is a diagram showing another embodiment corresponding to Fig. 3 (a), and Fig. 4 is a diagram for carrying out the method of the present invention. FIG. 3 (c) is a diagram showing an example of a program state in the control switch shown in FIG. 4, and FIG. 5 is a stroke command shown in FIG. It is a diagram which shows the other example of the time-stroke diagram in a signal setting part. 1 ... Injection cylinder, 2 ... Cylinder piston, 3 ...
Position detectors, 8a, 8b ... Stroke gain setting section, 9 ...
… Model part (stroke command signal setting part), 10 …… Stroke deviation detection part, 11 …… Stroke feedback controller, 12a, 12b …… Driver, 13a, 13b …… Output gain setting part, 14 …… Model part ( Output command signal setting section), 15 ...
… Output deviation detector, 16… Feedback controller, 17…
Output calculator, 18a, 18b Pressure detector, 19 Control switch, 31 Pressurizing cylinder, 36 Injection plunger, 38
...... Cavity, 40 ...... Pressure plunger.

Claims (3)

[Claims] 1. The pressure in a cylinder chamber for operating a cylinder piston is changed so as to arbitrarily control the moving stroke amount of the cylinder piston with respect to time and the output of the cylinder piston with respect to time. Cylinder position and output control method. 2. A moving stroke amount of a cylinder piston is predetermined as a target locus with respect to time, and a moving amount of the cylinder piston is set as a target locus according to a deviation amount between an actual moving stroke amount of the cylinder piston. By controlling the pressure in the cylinder head chamber and the pressure in the cylinder rod chamber that operate the cylinder piston independently, the stroke of movement of the cylinder piston is controlled and the output of the cylinder piston is set as the target locus with respect to time. By setting in advance, the pressure of the cylinder head chamber and the pressure of the cylinder rod chamber that actuate the cylinder piston are independently changed according to the amount of deviation between the output of the cylinder piston and the actual output that is the target locus. The feature is that the output of the cylinder piston is controlled. Position and output control method as in claim 1 wherein the cylinder to. 3. A cylinder device in which a cylinder head chamber and a cylinder rod chamber are respectively connected to independent pressure sources, and an independent cylinder device capable of controlling the pressure acting on the cylinder head chamber and the cylinder rod chamber according to the magnitude of an input signal. A pressure control valve, a pressure detector that detects each pressure acting on the cylinder head chamber and cylinder rod chamber, and outputs an electrical signal corresponding to that pressure, and detects the position of the cylinder piston and responds to that position. A position detector that outputs an electric signal and a stroke command signal setting unit that sets and commands the movement stroke amount of the cylinder piston with respect to time as a target locus. The output signal from this stroke command signal setting unit and the above-mentioned Depending on the amount of deviation from the output signal from the position detector,
A stroke feedback controller that outputs a drive signal to the pressure adjustment drive unit of the pressure control valve via independent stroke gain setters for the cylinder head chamber and the cylinder rod chamber, and the output of the cylinder piston with respect to time as a target trajectory. The output command signal setting unit for setting and commanding is provided, and according to the deviation amount between the output signal from the output command signal setting unit and the actual output value of the cylinder piston calculated from the output signal of each pressure detector, An output feedback controller that outputs a drive signal to the pressure adjustment drive section of the pressure control valve via independent output gain setting devices for the cylinder head chamber and the cylinder rod chamber, a stroke feedback controller and an output feedback controller. Based on time, cylinder stroke movement stroke amount or output Position and the output control device of the cylinder, characterized in that the selectively switching control switch, comprising a.