AT524160A1 - Hydraulic drive device for a shaping machine - Google Patents

Abstract

Hydraulic drive device (1) for an injection molding machine with a hydraulic drive unit (2), a piston-cylinder unit (3), a hydraulic line system (4) and a control or regulating unit (5), the hydraulic drive unit (2) being Control or regulating unit (5) can be controlled to generate a certain hydraulic power, wherein in a first operating mode (B1) - in which the differential operation is active - the piston-cylinder unit (3) with low force (F) and with high Speed (V) can be controlled and in a second operating mode (B2) - in which the differential mode is inactive - the piston-cylinder unit (3) can be controlled with high force (F) and at low speed (V). To switch from the first operating mode (B1) to the second operating mode (B2), the hydraulic drive unit (2) is used to output a changed hydraulic power controllable.

Description

The present invention relates to a hydraulic drive device for a molding machine, in particular an injection molding machine or transfer press, with a hydraulic drive unit for generating hydraulic power, a piston-cylinder unit, a hydraulic line system connecting the hydraulic drive unit with the piston-cylinder unit, in which via the hydraulic Drive unit hydraulic power is adjustable. The hydraulic line system has a first connection point for connection to the hydraulic drive unit, a second connection point for connection to a rod-side chamber of the piston-cylinder unit, a third connection point for connection to a piston-side chamber of the piston-cylinder unit, a second connection point with the circulating line connecting the third connection point and at least one switching element for setting a differential operation, wherein in a differential position of the switching element the differential operation can be built up via the circulating line. In addition, a control or regulating unit is provided for controlling or regulating the hydraulic drive device, the hydraulic drive unit being controllable via the control or regulating unit to generate a specific hydraulic power and the switching element being controllable via the control or regulating unit, wherein in a first operating mode - in which the differential mode is active - the piston-cylinder unit can be controlled with low force and at high speed and in a second operating mode - in which the differential mode is inactive - the piston-cylinder unit can be controlled with high force and at low speed is. Furthermore, the invention relates to a shaping machine with such a hydraulic drive device, a method for operating such a hydraulic drive device and a computer program product

to perform a procedure.

Differential circuits of piston-cylinder units have been state of the art for years and are used in various applications with different transmission ratios. An increased pressure or an increased force is built up by increasing the effective diameter (or the effective piston area). In this way it is possible to use a differential piston-cylinder unit with the same hydraulic power (i.e. with the same pressure and

- High speed and therefore low effective force

In most cases, the operating state that is selected is selected before a movement. An example in the applicant's molding machines is the use in injection, with either “increased injection pressure” or “differential injection” being possible during the injection process. A typical cylinder ratio is 1:5. A further example of the applicant's shaping machines is the use when opening by means of an express lifting device. Opening usually takes place by means of the express lifting device at high speed in differential operation, while the differential circuit can be deactivated for increased opening force. A typical cylinder ratio here is 1:2.

However, applications in which switching occurs while the piston-cylinder unit is moving are also known. For example, in the case of a hydraulic toggle lever mechanism, in which the actual closing process is carried out at high speed and with low power requirement in differential operation, the differential switching can be canceled for pushing the toggle lever, whereby the maximum force (for the build-up of closing force) is available.

Examples of differential circuits are given below.

DE 37 35 123 A1 describes a hydraulic drive device for a punching or embossing tool. At the outset, the problem of switching over the differential hydraulic cylinder provided as the drive element in accordance with the load is discussed. For this purpose, the area changeover valve is designed as a valve that is controlled exclusively as a function of pressure, in which the response pressure can be adjusted by the adjustable closing force of a check valve. Nevertheless, such a configuration can lead to abrupt changes in force or speed, which can lead to increased wear or unfavorable behavior

the movement of the piston-cylinder unit.

additional opening is available to be able to push out a large volume.

WO 2006/042500 A2 describes and shows a hydraulically actuated casting unit, showing the hydraulic circuit diagram of a casting unit of a die-casting machine. The casting unit has a casting cylinder, the piston of which actuates a casting piston guided in a casting sleeve, not shown. The molten mold material is introduced into this casting sleeve or filling chamber and then moved in the direction of a mold by the axial feed of the casting plunger, so that the mold is filled with melt during the mold filling phase and the melt contained in the mold is compressed during the holding pressure phase and any shrinkage is compensated for. The casting cylinder is actuated via the control arrangement, which essentially consists of a continuously adjustable directional control valve, a counter-pressure valve, a counter-pressure control valve, two lockable check valves, an LP check valve, an HP control valve and a directional seat switching valve. It is also stated that switching to the mold filling phase also takes place without pressure. The continuously adjustable directional control valve is designed in such a way that, during the pre-filling phase, the pressure from an annulus of the

Finally, reference can also be made to DE 10 2017 206 581 A1, which shows a valve arrangement for stick cylinders with two operating states. Specifically, this is about a valve arrangement for a non-generic excavator. An advantage of the invention is that a particularly smooth transition is made possible when the direction of movement of the differential cylinder or the actuator is reversed. In the third position, the actuator would be braked abruptly because of its inertia, preventing a smooth movement. This is prevented by the second position of the second valve. In this, a fluid flow path is opened starting from the first working connection via the second valve via a return connection to the tank. This fluid flow path bypasses the first check valve to allow fluid flow from the first workport to the tank. The second working port is connected to the tank via an optional second check valve. This only allows fluid flow from the tank to the rod side of the differential cylinder. This prevents cavitation from occurring on the rod side when the differential cylinder moves in the second mode. In doing so, pressurized fluid is sucked from the tank to the rod side. Thus, while the differential circuit effect is described as having a smooth transition, abrupt changes in force or speed can still occur, particularly when the hydraulic power supplied to the differential circuit is very high

come.

In the prior art, it is generally disadvantageous that an abrupt change in speed or force occurs in accordance with the cylinder surface ratios when the differential circuit is activated or deactivated during the movement of the piston-cylinder unit.

unit should be avoided as much as possible.

This is solved by a hydraulic drive device with the features of claim 1. Accordingly, the invention provides that, on the one hand, for switching from the first operating mode to the second operating mode to at least partially compensate for an increase in force and/or a drop in speed of the piston-cylinder unit that occurs during switching, the hydraulic drive unit can be controlled to output a changed hydraulic power. On the other hand, it is provided that for switching from the second operating mode to the first operating mode to at least partially compensate for a drop in force and/or an increase in speed of the piston-cylinder unit that occurs during switching, the hydraulic drive unit can be controlled to output a changed hydraulic power.

The change in speed or force of the piston-cylinder unit is therefore controlled and regulated. In other words, switching between the operating modes is implemented via a switching element (e.g. via a proportional or control valve) and the drive source (hydraulic drive unit, e.g. in the form of a pump or also a proportional valve) is controlled in parallel in such a way that a predetermined speed and/or force profile can be driven without a noticeable shifting process.

Preferred embodiments of the present invention are given in the dependent claims.

For general explanation it should be mentioned that the hydraulic power of a

Product of one conveyed by the hydraulic drive unit per unit of time

Hydraulic quantity and generated by the hydraulic drive unit

To put it another way: The hydraulic power is made up of the speed or quantity and the pressure. The hydraulic power itself is not determined or adjusted. Rather, the speed is set and the limits for the pressure are set. It can also be reversed

pressure can be set and the speed limits can be set.

A hydraulic fluid, in particular a hydraulic oil, can be used as the hydraulic medium

be used.

Provision is made for the hydraulic drive unit to be connected to a hydraulic source. The hydraulic source can be in the form of a hydraulic tank, for example. In order to convey the hydraulic fluid, it is preferably provided that the hydraulic drive unit has a hydraulic pump and/or a proportional valve.

According to a preferred exemplary embodiment, it is provided that the hydraulic drive unit—at least for switching between the operating modes—can be controlled on the basis of a predetermined performance profile. This makes it possible for the piston-cylinder unit to be operable with a predetermined speed and/or force profile. Predetermined speed and/or force profiles can be stored in a memory of the control or regulation unit, for example.

According to a first variant, for the operation of the drive device it can be provided that in the first operating mode in a certain period of time (e.g. 0.05 to 0.7 seconds) before switching to the second operating mode, the hydraulic drive unit can be controlled in such a way to output a reduced hydraulic power is that the hydraulic quantity delivered by the hydraulic drive unit goes from a constantly high level to a

constantly low level and thus the speed of the piston

Furthermore, in this first variant, it is preferably provided that, preferably at the same time as switching from the first operating mode to the second operating mode, the hydraulic drive unit can be controlled in such a way that the hydraulic power of the hydraulic drive unit increases and at the same time that exerted by the piston-cylinder unit Force increases from a low level to a high level and the speed of the piston-cylinder unit remains constant at the low level.

According to a second variant, for the operation of the drive device it can be provided that the changeover from the first operating mode to the second operating mode takes place in the form of a gradual changeover (lasting for example 0.1 to 0.4 seconds).

Furthermore, in this second variant, it is preferably provided that, during the gradual switchover, the hydraulic drive unit for outputting the hydraulic power can be controlled in such a way that the hydraulic quantity delivered by the hydraulic drive unit first increases from an initial level and then falls back to the initial level, with during the gradual switching, the force exerted by the piston-cylinder unit simultaneously increases and the speed of the piston-cylinder unit decreases.

According to a preferred exemplary embodiment, a detection device is provided for detecting the time of switching between the operating modes. This detection device can be integrated into the control or regulation unit or with

these are in signaling connection.

In order to achieve switching between the operating modes that is as smooth as possible, it is preferably provided that the hydraulic power output by the hydraulic drive unit is dependent on the power detected by the detection device

Switching time is changeable.

Protection is also sought for a molding machine, in particular an injection molding machine or transfer press, with a hydraulic drive device according to the invention.

The molding machine is preferably constructed to include an injection unit and a clamping unit. Such a molding machine may have one piston-cylinder unit for a particular component, or it may have multiple piston-cylinder units. For example, it is provided that an injection piston of the injection unit, a clamping force application device of the clamping unit, an express lifting device of the clamping unit or an ejector can be moved via the hydraulic drive device and its piston-cylinder unit(s)—preferably each.

According to a preferred exemplary embodiment, it is provided that the shaping machine has a machine controller, with the control or regulating unit being integrated into the machine controller or being connected to the machine controller by means of signals. This machine control can also be a control unit with a screen and a

Have input device for an operator.

In a method for operating a hydraulic drive device for a molding machine, in particular an injection molding machine or transfer press, with the features of the preamble of claim 15, the solution to the above-mentioned object provides that the hydraulic drive device is controlled in such a way that, for switching from the first operating mode to the second operating mode for at least partially compensating for an increase in force and/or a drop in speed of the piston-cylinder unit that occurs when switching over, the hydraulic drive unit for outputting a changed

Furthermore, protection is sought for a computer program product comprising instructions which, when a program is executed by a computing unit, cause the latter to carry out the method according to the invention on a shaping machine

to execute.

Further details and advantages of the present invention are explained in more detail below on the basis of the description of the figures with reference to the exemplary embodiments illustrated in the drawings. Show in it:

Fig. 1 shows a schematic of a shaping machine, Fig. 2 shows a force-speed-power diagram of the differential circuit, Fig. 3 shows a hydraulic circuit diagram of the hydraulic drive device,

4a+4b flow charts of the speed, hydraulic power and force according to a first exemplary embodiment,

5a+5b flow charts of the speed, hydraulic power and force according to a second embodiment,

Fig. 6a-6c different variants of a hydraulic circuit diagram of a hydraulic drive device and

7 shows a hydraulic circuit diagram with a parallelism control of several piston-cylinder units.

A molding machine 100 is shown schematically in FIG. 1 . This molding machine 100 has an injection unit 7 and a clamping unit 8

on.

The injection unit 7 comprises an injection cylinder 72 and an injection piston 71 which is movably mounted in the injection cylinder 72. The injection piston 71

can be driven or moved via a hydraulic drive device 1, which is indicated only schematically.

In the exemplary embodiment shown, the closing unit 8 is designed as a two-platen machine. Alternatively, the clamping unit can also be designed in the form of a tie-bar-less machine or as a vertical machine. In any case, the clamping unit 8 comprises a movable mold mounting plate 84 and a stationary mold mounting plate 85, with these two plates being penetrated by bars 86. The mold halves of a shaping tool 87 are fastened to the mold clamping plates 84 and 85, with at least one cavity K being formed in the closed shaping tool 87. A liquid plastic starting material can be injected into this cavity K via the injection unit 7

be injected.

An express lifting device 82 is indicated schematically in FIG. The express lifting device 82 has a schematically indicated piston-cylinder unit 3 , which in turn can be part of a hydraulic drive device 1 .

A clamping force application device 81 is also shown schematically in FIG. 1 . This can be designed, for example, as a toggle lever system or as a plunger cylinder. With this clamping force application device 81, clamping force can be applied when the shaping tool 87 is closed. This closing force application device 81 can also be driven by a hydraulic drive device 1 or can include it. In order to apply the closing force, it is also necessary for the bars 86 to be locked in the area of the movable mold clamping plate 84 via locking devices 83

can become. Fig. 1 also shows an ejector 9 for ejecting one in the cavity K

cured molding part. It can be seen that this ejector 9 a

Piston-cylinder unit 3 of a hydraulic drive device 1 includes.

A machine control 10 is indicated schematically in FIG. As shown, this machine control 10 can include a screen 11 and an input device 12 . In addition, the machine control 10 has a memory 13 .

1 also shows a control or regulating unit 5 which is part of the hydraulic drive device 1 and is designed to control or regulate this hydraulic drive device 1 . In the exemplary embodiment shown, this control or regulation unit 5 has a signal connection with the machine controller 10 . This control or regulation unit 5 has a memory 51 . For example, predetermined performance profiles for the hydraulic drive unit 2 can be stored in this memory 51 .

Before the details and components of the hydraulic drive device 1 are discussed, the principle of the differential circuit should be explained with reference to FIG. The time in seconds s is plotted on the abscissa. The ordinate shows the hydraulic pressure p, the hydraulic quantity Q, the force F and the speed V. In terms of time, the hydraulic drive device 1 is initially operated in the first operating mode B1, in which the differential operation is active. The hydraulic quantity Q and the hydraulic pressure p are constant. The hydraulic power is therefore also constant. The speed Vpign is at a high level while the force Fiow is at a low level. The vertical dashed line then illustrates the switchover from the first operating mode B1 to the second operating mode B2. The differential operation B1 is inactive in this second operating mode B?2. As can be seen in Fig. 2, the velocity changes abruptly from the high level Vpign to a low Vıow, while the force also changes abruptly from the low level Fıow to a high level Fpign. Meanwhile, the hydraulic quantity Q and the hydraulic pressure p remain the same.

3 shows a hydraulic drive device 1 which has a hydraulic drive unit 2 , a piston-cylinder unit 3 , a hydraulic line system 4 and a control or regulating unit 5 .

In the exemplary embodiment shown, the hydraulic drive unit 2 has a hydraulic pump 21 and a proportional valve 22 . The hydraulic medium is conveyed into the hydraulic line system 4 by the hydraulic drive unit 2 with a specific hydraulic power. This hydraulic power is controlled via the control or regulating unit 5 . For example, a type of performance profile can be stored in the memory 51 of the control or regulation unit 5 . Specifically, a quantity profile and/or a force or pressure profile can be stored.

The piston-cylinder unit 3 has a cylinder 31 and a piston 32 guided in the cylinder 31 . The piston 32 divides the space formed in the cylinder 31 into a rod-side chamber 3s and a piston-side chamber 3k.

The hydraulic line system 4 has a first connection point 41 for connection to the hydraulic drive unit 3 . In this case, the outlets of the proportional valve 22 form this first connection point 41. The hydraulic line system 4 has a second connection point 42 for connection to the rod-side chamber 3s of the piston-cylinder unit 3 and a third connection point 43 for connection to the piston-side chamber 3k of the piston -cylinder unit 3 on. Furthermore, the hydraulic line system 4 has a circulating line 44 connecting the second connection point 42 to the third connection point 43 . In addition, the hydraulic line system 4 has a switching element 45 for setting a differential operation. In a differential position D of the switching element 45, differential operation can be built up via the circulating line 44. The switching element 45 can

be designed as a proportional or control valve.

The control or regulating unit 5 has a signal connection with the hydraulic drive unit 2 and with the switching element 45 (see dashed line). Both the hydraulic drive unit 2 and the switching element 45 are over

the control or regulation unit 5 can be controlled or regulated.

When switching over the differential circuit, a movement of the piston-cylinder unit 3 should be implemented in such a way that there is no sudden change in speed or force, but rather this takes place in a controlled and regulated manner. This is achieved in that the switching is realized via the switching element 45 and the hydraulic drive unit 2 is controlled or regulated in parallel in such a way that a predetermined speed and/or force profile can be driven without a noticeable switching process.

Specifically, it is provided that for switching from the first operating mode B1 to the second operating mode B2 to at least partially compensate for an increase in force and/or a drop in speed of the piston-cylinder unit 3 that occurs when switching over, the hydraulic drive unit 2 is used to output a changed, preferably reduced, hydraulic power can be controlled. This means that both the switching element 45 and the hydraulic drive unit 2 are actuated accordingly via the control or regulating unit 5 . In order to switch from the second operating mode B2 to the first operating mode B1, at least partial compensation for a drop in force and/or an increase in speed of the piston-cylinder unit 3 that occurs during the switchover is provided for the hydraulic drive unit 2 to output a changed,

preferably increased hydraulic power can be controlled.

Finally, FIG. 3 also shows a detection device 6 for detecting the time of switching between the operating modes B1 and B?2 in dashed lines. The detection device has at least one pressure sensor and/or a distance or displacement sensor (not shown). This detection device 6 is connected to the control or regulating unit 5, and this detection device 6 can be used to detect the changeover point as a function of time, as a function of distance, as a function of pressure, or via a learning process. The hydraulic power output by the hydraulic drive unit 2 can vary as a function of the switchover point in time detected by the detection device 6

be changeable.

In Fig. 4a is a speed-time diagram is shown, the time t in seconds s is plotted on the abscissa, while the ordinate

Speed V and hydraulic quantity Q is applied. The dot-dash line illustrates the actuation of switching element 45.

A force-time diagram is shown in FIG. 4b—matching FIG. 4a and with the same time sequence—where the time t in seconds s is plotted on the abscissa, while the force F is plotted on the ordinate. The lower dashed line in FIG. 4b indicates which maximum force F+ would be possible based on the switching position of the switching element 45 in the first operating mode B1. This maximum force F+ results from the product of the area difference (A2 - A1) of the piston 32 and the hydraulic pressure p. The upper dashed line in FIG. 4b indicates which maximum force F» would be possible based on the switching position of the switching element 45 in the second operating mode B2. This maximum force F> results from the product of the area A2 of the piston 32 and the hydraulic pressure p. In addition, the individual phases of the movement of the hydraulic drive device 1 are entered in FIG. 4b below, with this phase for both diagrams according to FIG

4b and 4a apply.

In the first phase (fast driving phase i), the piston 32 is moved at a high speed Vpign. The delivered hydraulic quantity is also at a high level Qnign. The switching element 45 is controlled in such a way that the hydraulic drive unit 1 is operated in the first operating mode B1 (see dot-dash line). The force is at a low level Fıow far below the maximum force F+.

In the second phase li, the speed V is reduced in a targeted manner by the hydraulic quantity Q being reduced. The hydraulic drive unit 2 is therefore controlled in such a way that a low hydraulic power is made available, as a result of which the speed V is reduced. It can be seen that in this second phase ii the force F is already increasing slightly.

In the third phase iii, the hydraulic quantity supplied has a constant low

Level Qww reached, which also keeps the speed constant

low level viow has been reached.

In other words, in the second phase ii up to the start of the third phase il, the hydraulic drive device 1 is actuated in such a way that in the first operating mode B1 in a certain period of time before switching to the second operating mode B2, the hydraulic drive unit 2 outputs a reduced hydraulic power can be controlled, the hydraulic quantity Q delivered by the hydraulic drive unit 2 dropping from a constantly high level Qhnign to a constantly low level Qjew and thereby the speed V of the piston-cylinder unit 3 from a constantly high level Vhign to a constantly low level Viow sinks.

This is followed by the fourth phase iv, in which there is a controlled switchover to an increased force. In this fourth phase iv, switching element 45 switches from the first operating mode B1 to the second operating mode B2 (differential switching is deactivated). In addition, the supplied hydraulic quantity Q or the hydraulic power is increased again, which does not lead to an increase in speed V, but to an increase in force F. Specifically, the force F already exceeds the maximum force F+4 in the first operating mode B1.

In the fifth phase v, the hydraulic quantity has again reached the high level Qnign. The speed remains at a low level Viow. The force is approaching

maximum force F>.

In other words, it is provided in the fourth phase iv and fifth phase v that, preferably at the same time as switching from the first operating mode B1 to the second operating mode B?2, the hydraulic drive unit 2 can be controlled in such a way that the hydraulic power of the hydraulic drive unit 2 increases and at the same time the force F exerted by the piston-cylinder unit 3 increases from a low level Fıow to a high level Fhign and the speed V of the piston-cylinder unit 3 remains constant at the low level View.

Finally, the sixth phase vi follows (force control phase). In this force control phase

the force F (e.g. the closing force during injection) is constantly high

Level maintained close to the maximum force F». The speed V quickly decreases towards zero. The supplied hydraulic quantity Q also decreases rapidly.

In principle, the same values as in the diagrams of FIGS. 4a and 4b are again entered in the diagrams shown in FIGS. 5a and 5b. However, FIGS. 5a and 5b show another embodiment.

The first phase a illustrated in FIGS. 5a and 5b corresponds to the rapid phase and is equivalent to the first phase i according to FIGS. 4a and 4b.

The switchover from the first operating mode B1 to the second operating mode B2 already takes place in the second phase b. This switchover takes place during the increase in force, with the switchover from the first operating mode B1 to the second operating mode B2 taking place in the form of a gradual switchover. At the same time, the speed drops from the high Vhpign level to the low View level. the

Hydraulic quantity Q or hydraulic power remains essentially constant.

In other words, in the second phase b, it is provided that during the gradual switchover, the hydraulic drive unit 2 can be controlled to output the hydraulic power in such a way that the hydraulic quantity Q delivered by the hydraulic drive unit 2 initially increases from an initial level Ostart and then increases again to the starting level Qgstart sinks, during the gradual switchover the force F exerted by the piston-cylinder unit 3 simultaneously increases and the speed V of the piston-cylinder unit 3 decreases.

Then comes the third phase c, which is to be equated with the third fifth phase v. The force F almost reaches the maximum force F». the

Speed V remains constant at low level Viow-

Finally, the fourth phase d is reached, which corresponds to the force control phase according to the sixth phase vi.

6a to 6c show different variants of how a hydraulic drive device 1 can be constructed hydraulically with a differential circuit.

In Fig. 6a the structure is very similar to that in Fig. 3. It is shown that the hydraulic pump 21 is driven by a motor M. In addition, the hydraulic power (see arrow) and also the speed V of the piston 32

recognizable.

In Fig. 6b the switching element 45 is positioned differently.

In FIG. 6c, the lines of the hydraulic line system 4 are partially arranged or connected differently.

Fig. 7 shows a hydraulic drive device 1 with several piston-cylinder units 3 which are arranged in a parallelism control. A proportional valve 22 and a switching element 45 as well as the corresponding lines of the hydraulic line system 4 are provided for each piston-cylinder unit 3 . The tax-

or control unit 5 is not specifically shown.

Reference list:

1 hydraulic drive device 2 hydraulic drive unit 21 hydraulic pump

22 proportional valve

3 piston-cylinder unit

31 cylinders

32 pistons

3s rod side chamber

3k piston side chamber

4 hydraulic line system

41 first junction

42 second connection point

43 third junction

44 circulation line

45 switching element

5 control or regulation unit

51 memory

6 detection device

7 injection unit

71 injection piston

72 injection cylinder

8 locking unit

81 closing force application device

82 rapid lifting device

83 locking device

84 movable platen 85 fixed platen 86 bars

87 shaping tool

88 machine frames

9 ejectors

10 machine control

11 screen

12 input device

100 shaping machine

Qp hydraulic power

F force

Fiow low level of force

Fprign high level of vigor

F+ maximum force in B1

F> maximum force in B2

V speed

Vpigan high level of speed Viow low level of speed Q hydraulic quantity

Qnign high level of hydraulic flow Qiow low level of hydraulic flow Ostart initial level of hydraulic flow D differential position

B1 first mode of operation

B2 second mode of operation

K cavity

Ss seconds

p hydraulic pressure

t time

i first phase (fast driving phase)

il second phase (phase of reduction of Q)

ill third phase (constant speed phase) IV fourth phase (controlled switching phase)

V fifth phase (phase with constant speed and increased force) vi sixth phase (force control phase)

A1 Area of the piston

A2 Area of the piston

a first phase (fast driving phase) b second phase

C third phase

d fourth phase (force control phase M motor

Innsbruck, August 19, 2020

Claims (1)

patent claims Hydraulic drive device (1) for a shaping machine (100), in particular injection molding machine or transfer press, with - a hydraulic drive unit (2) for generating hydraulic power, - a piston-cylinder unit (3), - a hydraulic line system (4) connecting the hydraulic drive unit (2) to the piston-cylinder unit (3), in which hydraulic power can be adjusted via the hydraulic drive unit (2), the hydraulic line system (4) having e a first connection point (41) for connection to the hydraulic drive unit (2), e a second connection point (42) for connection to a rod-side chamber (3s) of the piston-cylinder unit (3), e a third connection point (43) for connection to a piston-side chamber (3k) of the piston-cylinder unit (3), e a circulation line (44) connecting the second connection point (42) to the third connection point (43) and e at least one switching element (45) for setting a differential mode, wherein in a differential position (D) of the switching element (45) the differential mode can be built up via the circulation line (44), and - a control or regulating unit (5) for controlling or regulating the hydraulic drive device (1), wherein the hydraulic drive unit (2) can be controlled via the control or regulating unit (5) to generate a specific hydraulic power and wherein the switching element (45 ) can be controlled via the control or regulation unit (5), wherein in a first mode of operation (B1) -- in which the differential operation is active — the piston-cylinder unit (3) with low force (F) and with high Speed (V) can be controlled and in a second operating mode (B2) - in which the differential operation is inactive - the piston-cylinder unit (3) with high force (F) and low speed (V) can be controlled, characterized marked that - for switching from the first operating mode (B1) to the second operating mode (B2) to at least partially compensate for an increase in force and/or a drop in speed of the piston-cylinder unit (3) that occurs when switching over, the hydraulic drive unit (2) to output a changed hydraulic power is controllable and - for switching from the second operating mode (B2) to the first operating mode (B1) to at least partially compensate for a drop in force and/or an increase in speed of the piston-cylinder unit (3) that occurs during switching, the hydraulic drive unit (2) for output a changed hydraulic power can be controlled. Drive device according to claim 1, characterized in that the hydraulic drive unit (2) is a hydraulic pump (21) and / or Has proportional valve (22). Drive device according to Claim 1 or 2, characterized in that the hydraulic drive unit (2) - at least for switching between the operating modes (B1, B2) - on the basis of a predetermined performance profile is controllable. Drive device according to one of Claims 1 to 3, characterized in that in the first operating mode (B1) in a certain period of time before switching to the second operating mode (B2) the hydraulic drive unit (2) can be controlled to output a reduced hydraulic power in such a way that the hydraulic quantity (Q) delivered by the hydraulic drive unit (2) drops from a constantly high level (Qpign) to a constantly low level (Qjw) and as a result the speed (V) of the piston-cylinder unit (3) decreases from a constantly high level (Vhpign) to a constantly low level (Viow). Drive device according to claim 4, characterized in that, preferably simultaneously, with the switching from the first operating mode (B1) to the second operating mode (B2), the hydraulic drive unit (2) such can be controlled that the hydraulic power of the hydraulic drive unit 11. 3 (2) increases and at the same time the force (F) exerted by the piston-cylinder unit (3) increases from a low level (Fıow) to a high level (Fpign) and the speed (V) of the piston-cylinder unit ( 3) remains constant at a low level (Viow). Drive device according to one of claims 1 to 3, characterized in that the switching from the first operating mode (B1) to the second Operating mode (B2) takes place in the form of a gradual switching. Drive device according to Claim 6, characterized in that during the gradual switchover, the hydraulic drive unit (2) can be controlled to output the hydraulic power in such a way that the hydraulic quantity (Q) delivered by the hydraulic drive unit (2) initially increases from an initial level (Qgstart). and then falls back to the starting level (Qgstart), during which the gradual switchover simultaneously increases the force (F) exerted by the piston-cylinder unit (3) and the speed (V) of the piston-cylinder unit (3) decreases. Drive device according to one of Claims 1 to 7, characterized by a detection device (6) for detecting the time of switching between the operating modes (B1, B2). Drive device according to claim 8, characterized in that the hydraulic power output by the hydraulic drive unit (2) depends on the detected by the detection device (6). Switching time is changeable. Drive device according to one of Claims 1 to 9, characterized in that the control or regulating unit (5) is connected to the hydraulic drive unit (2) and is in signaling connection with the switching element (45). Drive device according to one of Claims 1 to 10, characterized in that that the drive device (1) comprises several piston-cylinder units (3), which can be controlled in parallel operation via the control or regulating unit (5). 13. 14 15 4 are and which can each be operated in one of the two operating modes (B1, B2). are. Shaping machine (100), in particular injection molding machine or injection press, with a hydraulic drive device (1) according to one of Claims 1 to 11. Shaping machine according to claim 12, with an injection unit (7) and a clamping unit (8), wherein an injection piston (71) of the injection unit (7), a clamping force application device ( 81) of the closing unit (8), an express lifting device (82) of the closing unit (82) or an ejector (9) can be moved. Shaping machine according to Claim 12 or 13, characterized in that the shaping machine (100) has a machine controller (10), the control or regulating unit (5) being integrated into the machine controller (10) or is in signaling connection with the machine control (10). Method for operating a hydraulic drive device (1), in particular according to one of Claims 1 to 11, for a shaping machine (100), in particular an injection molding machine or transfer press - a hydraulic drive unit (2) for generating hydraulic power, - a piston-cylinder unit (3), - a hydraulic line system (4) connecting the hydraulic drive unit (2) to the piston-cylinder unit (3), in which hydraulic power can be adjusted via the hydraulic drive unit (2), the hydraulic line system (4) having e a first connection point (41) for connection to the hydraulic drive unit (2), e a second connection point (42) for connection to a rod-side chamber (3s) of the piston-cylinder unit (3), e a third connection point (43) for connection to a piston-side chamber (3k) of the piston-cylinder unit (3), 24/40 e a circulating line (44) connecting the second connection point (42) to the third connection point (43) and e at least one switching element (45) for setting differential operation, wherein in a differential position (D) of the switching element (45) via the circulating line (44 ) the differential operation can be built up, and - a control or regulating unit (5) for controlling or regulating the hydraulic drive device (1), the hydraulic drive unit (2) being controlled via the control or regulating unit (5) to generate a specific hydraulic power and the switching element (45 ) is controlled via the control or regulating unit (45), with the steps: - Operating the hydraulic drive device (1) in a first operating mode (B1) in which the differential operation is active, the piston-cylinder unit (3) being controlled with low force (F) and at high speed (V), and - Operating the hydraulic drive device (1) in a second operating mode (B2) in which the differential operation is inactive, the piston-cylinder unit (3) being controlled with high force (F) and at low speed (V), characterized in that the hydraulic drive device (1) such is controlled that - for switching from the first operating mode (B1) to the second operating mode (B2) to at least partially compensate for an increase in force and/or a drop in speed of the piston-cylinder unit (3) that occurs when switching over, the hydraulic drive unit (2) to output a changed hydraulic power is controlled and - for switching from the second operating mode (B2) to the first operating mode (B1) to at least partially compensate for a drop in force and/or an increase in speed of the piston-cylinder unit (3) that occurs during switching, the hydraulic drive unit (2) for output a changed hydraulic power is controlled. 16. A computer program product, comprising instructions which, when a program is executed by a computing unit, cause the latter to carry out the method according to Claim 15 to be carried out on a molding machine (100). Innsbruck, August 19, 2020