WO2009037170A1

WO2009037170A1 - Electrohydraulic control device

Info

Publication number: WO2009037170A1
Application number: PCT/EP2008/062015
Authority: WO
Inventors: Otto Ebner; Christoph RÜCHARDT; Reiner Keller; Martin Rossmann
Original assignee: Zf Friedrichshafen Ag
Priority date: 2007-09-18
Filing date: 2008-09-11
Publication date: 2009-03-26
Also published as: DE102007044431A1; EP2188543A1

Abstract

The invention relates to an electrohydraulic control device comprising a pressure supply device (2.1, 2.2) for guiding a pressurised medium from a storage tank (3) in a main pressure line (4). Said pressurised medium is guided over a pump element (10) that can be driven by a controllable electromotor (11). Said control device also comprises an adjusting device (5.1, 5.2) for actuating at least one hydraulic actuator (6, 7, 8), said actuator (6, 7, 8) being actuated by connecting at least one pressure chamber (22; 29, 30; 34, 35; 42) of the actuator (6, 7, 8) to the main pressure line (4) and/or to the non-pressurised line (26), said connection being made by at least one control valve (23, 24, 25; 31, 32; 36, 37; 43). In order to simplify the control device, the pump element (10) is embodied as a simple pressure cylinder (12), in which a piston (14) connected to the electromotor (11) is guided in an axially displaceable manner over the spindle mechanism (13), axially defines a pressure chamber on one side (15), said pressure chamber being connected to the main pressure line (4) via a suction line (18) and to the storage tank (3) via a suction line (17) that comprises a non-return valve (16).

Description

Electro-hydraulic control device

The invention relates generally to an electro-hydraulic control device, comprising a pressure supply device for conveying a pressure medium from a reservoir into a main pressure line, wherein the promotion of the pressure medium via a drivable by a controllable electric motor pump element, and with an actuating device for actuating at least one hydraulic actuator, wherein the Actuation of the actuator via a producible by at least one control valve connection of at least one pressure chamber of the actuator to the main pressure line and / or is carried out with a pressure-free line.

More particularly, the invention relates to an electrohydraulic control device of an automated step transmission, comprising a pressure supply device for conveying a pressure medium from a reservoir into a main pressure line, wherein the promotion of the pressure medium via a pump element drivable by a controllable electric motor, and with an actuating device for actuating at least one hydraulic Kupplungsaktuators and / or a hydraulic Wählaktuators and / or a hydraulic Schaltaktuators, wherein the actuation of the relevant actuator via a producible by at least one control valve connection of at least one pressure chamber of the actuator with the main pressure line and / or with a pressure-free line.

Electro-hydraulic control devices are preferably used in motor vehicles, for example for the actuation of clutches, brakes and transmissions; however, they may also be used in other technical equipment and installations. In particular for the control of automated step-variable transmissions, such as automated manual transmissions and automated dual-clutch transmissions, electro-hydraulic control erungsvorrichtungen particularly suitable, since they have in addition to compact dimensions and a high energy density generally good control properties, ie well metered actuating forces for engagement and disengagement of friction clutches and for synchronizing and loading and unloading of aisles. In addition, the components used in electrohydraulic control devices, such as control valves and actuating cylinders, are sufficiently tested and reliable due to many years of development and application practice.

The pressure supply device of an electrohydraulic control device typically has a hydraulic pump as the pumping element, by means of which a pressure medium (hydraulic oil) is conveyed via a check valve from a reservoir (oil sump) into the main pressure line which is under system pressure. The hydraulic pump used is usually a piston pump with crank mechanism, an axial piston pump or a gear pump, which is preferably driven by an electric motor. To the main pressure line of the pressure supply device usually a pressure accumulator, a pressure sensor and a pressure relief valve are connected.

Such a structure of the pressure supply device ensures that the hydraulic pump does not have to be driven permanently, but can be driven intermittently, ie as needed, whereby a higher overall efficiency of the control device is achieved. If, by means of the pressure sensor connected to the main pressure line, a drop in the system pressure prevailing in the main pressure line is determined below a lower first limit value, then the hydraulic pump is put into operation by switching on the electric motor and pressure medium thereby increasing the system pressure from the reservoir to the main pressure line and the pressure reservoir promoted. Then, by means of the pressure sensor, an increase in the pressure prevailing in the pressure line system pressure over an upper second Determined limit, the hydraulic pump is switched off by switching off the electric motor again. A subsequent consumption of pressure medium, which can be caused by the actuation of actuators and leaks in control valves and actuators, is compensated for as long as from the accumulator until the pressure prevailing in the main pressure line system pressure has again reached or fallen below the lower first limit. The pressure relief valve is usually designed to be effective automatically, that is not actively controlled, and limits the effective system pressure in the main pressure line system by a return, if necessary, of pressure medium from the main pressure line in the reservoir. As a result, an overload, which can be triggered, for example, by a defective pressure sensor, of the components in communication with the main pressure line, such as control valves and actuators, is avoided.

In this known construction, a largely constant system pressure for the adjusting device is generated by the pressure supply device, which is available even in case of failure for a certain amount of time and thus allows an emergency operation of the actuators. However, the components of the pressure supply device are relatively expensive due to the required precision and take a relatively large amount of space to complete. Another disadvantage of the known pressure supply device consists in the constantly pending relatively high system pressure, which leads in particular in control valves, which are designed as proportional valves, to relatively large leakage losses.

In order to avoid high leakage, it is known to connect a shut-off valve to proportional valves, with which they can be shut off outside of their operating phases against the main pressure line and thus relieved of the system pressure. However, shut-off valves represent an additional expenditure on equipment and form an additional potential source of error. Thus, from DE 198 49 488 C2, an electro-hydraulic control device of an automated manual transmission is known, in accordance with the local Fig. 1 designed as a proportional solenoid valve control valve designed as a single-acting actuator cylinder Wählaktua- and the two formed as a proportional solenoid valves control valves designed as a double-acting actuator cylinder Schaltaktuators together upstream of a pressure-controlled shut-off valve. The shut-off valve is closed in the unactuated state and controlled by the actuating pressure of the clutch actuator so that it is opened when a certain pressure limit is exceeded and closed when the pressure falls below the pressure limit. Thus, the control valves of the selector and the Schaltaktuators are connected only with the clutch disengaged to perform dialing and switching operations with the main pressure line and thus acted upon by the system pressure.

From EP 0 933 564 B1, a further electrohydraulic control device of an automatic transmission is known, in accordance with the local Fig. 1 designed as a proportional solenoid valve control valve designed as a double-acting actuating cylinder Wählaktua- sector and formed as a proportional solenoid valve control valve designed as a double-acting actuating cylinder Schaltaktuators together a solenoid switching valve is connected upstream, by which the pressure chambers of the actuating cylinder are depressurized in the unactuated state. In each case a pressure chamber of the actuating cylinder is connected via the associated control valve with the magnetic switching valve in connection. The other pressure chamber of the Wählaktuators is directly connected to the magnetic switching valve in connection, whereas the other pressure chamber of the Schaltaktuators a pressure reducing valve is connected upstream, which is mechanically controlled by a selector rod via a piston rod. Also in this control device, the control valves and the associated actuators only as needed, so if a circuit should take place, connected to the main pressure line and thus subjected to the system pressure or a reduced pressure.

In the operation of the described actuators usually there is the difficulty that in a related control device these are available in several different designs that are to be operated with different high and / or variable control pressures and speeds. Thus, in an automated transmission of the clutch actuator usually requires a higher actuating pressure than the selector and shift actuators. When a synchronized gear is engaged, the shift actuator should first be displaced from its neutral position to the synchronizer rings of the relevant gear clutch with a lower actuating pressure and high actuating speed, then the gear is to be synchronized with a relatively high actuating pressure and low actuating speed, and then the gear clutch in question be engaged with a low signal pressure and high positioning speed. In addition, the required control pressure for synchronizing the gears may be different levels, since the synchronizer rings of the frequently used low gears are mostly larger than those of the high gears.

These control functions are only insufficiently and relatively inaccurately realizable with a single, each pressure chamber associated control valve. To improve the control properties of hydraulic actuators, it is therefore generally known, in each case a series arrangement of a flow control valve, with which substantially the volume flow of the pressure medium and thus the control speed of the respective actuator is controlled, and this usually upstream pressure control valve, with the substantially the control pressure the pressure medium and thus the actuating force of the relevant actuator is controlled to provide. With such an additional pressure regulating valve, however, the expenditure on equipment and the disturbances increase. liability of the controller, and the control operations for actuating the actuators become more complex.

Thus, from DE 199 31 973 A1 discloses an electro-hydraulic control device of an automatic transmission is known, in accordance with the local Fig. 1, the control valves of each formed as a double-acting actuating cylinder selector and switching actuators together a clock valve is connected upstream, in conjunction with a to the Manifold between the timing valve and the control valves connected pressure sensor fulfills the function of an upstream pressure control valve.

In another, known from EP 0 933 564 B1 electrohydraulic control device of an automatic transmission, the control valves of each designed as a double-acting actuating cylinder selection and switching actuators according to the local Fig. 9, a proportional solenoid valve connected upstream, in addition to a shutdown function in conjunction with a connected to the output side manifold pressure sensor also fulfills the function of an upstream pressure control valve.

Due to the disadvantages of the known control devices, the present invention has the object to provide a generally usable, preferably also suitable for controlling an automated step transmission suitable electro-hydraulic control device having a functional structure and improved control properties without function restrictions.

The solution to this problem arises from the two independent claims 1 and 2, while advantageous refinements and developments are defined in the associated subclaims. Accordingly, the invention initially relates to an electro-hydraulic control device, comprising a pressure supply device for conveying a pressure medium from a reservoir into a main pressure line, wherein the promotion of the pressure medium via a drivable by a controllable electric motor pump element, and with an actuating device for actuating at least one hydraulic actuator, wherein the actuation of the actuator via a producible by at least one control valve connection of at least one pressure chamber of the actuator to the main pressure line and / or is carried out with a pressure-free line. It is further provided that the pumping element is designed as a single-acting pressure cylinder, in which a connected via a spindle gear with the electric motor piston is axially movable and axially bounded on one side a pressure chamber, which is provided with a check valve with a suction line to the reservoir and a pressure line communicates with the main pressure line.

With regard to a special use, the invention according to the independent claim 2 is based on an electrohydraulic control device of an automated step transmission, with a pressure supply device for conveying a pressure medium from a reservoir into a main pressure line, wherein the promotion of the pressure medium via a drivable by a controllable electric motor pumping element, and with an adjusting device for actuating at least one hydraulic Kupplungsaktuators and / or a hydraulic Wählaktuators and / or a hydraulic Schaltaktuators, wherein the actuation of the relevant actuator via a manufacturable by at least one control valve connection of at least one pressure chamber of the actuator with the main pressure line and / or with a Pressure-free line takes place. In addition, it is provided that the pumping element is designed as a single-acting pressure cylinder, in which a connected via a spindle gear to the electric motor piston is axially movably axially bounded on one side and a pressure chamber over a suction line provided with a check valve with the reservoir and via a pressure line to the main pressure line is in communication.

Thus, the invention is therefore based on an electro-hydraulic control device, for example a control device of an automated step transmission, the pressure supply device for conveying a pressure medium from a reservoir into a main pressure line and an actuating device for actuating at least one hydraulic actuator, in particular a hydraulic Kupplungsaktuators and / or a hydraulic Wählaktuators and / or a hydraulic Schaltaktua- sector comprises. Within the pressure supply device, the delivery of the pressure medium is effected via a pump element which can be driven by a controllable electric motor. Within the adjusting device, the actuation of an actuator, such as a hydraulic Kupplungsaktuators, a hydraulic Wählaktuators and / or a hydraulic Schaltaktuators, via a producible by at least one control valve connection of at least one pressure chamber of the actuator to the main pressure line and / or with a pressure line.

The inventive design of the pumping element as a single-acting pressure cylinder whose piston is driven by a spindle gear from the electric motor, resulting in conjunction with a simplified construction of the pressure generating device good control properties for setting a desired system pressure in the main pressure line and to supply the actuator with a required Pressure medium volume flow, which is due to the actuation of the hydraulic actuators and leakage in the actuators and in the associated control valves.

By generating a certain drive torque of the electric motor, the piston of the pressure cylinder is loaded via the spindle gear with an axial force in the direction of the pressure chamber, whereby the pressure in the pressure chamber and in the main pressure line connected to these increases and, if necessary, pressure medium is conveyed from the pressure chamber into the main pressure line. By reducing the drive torque of the electric motor, the pressure in the pressure chamber and in the main pressure line is reduced accordingly. On the drive torque of the electric motor, which is proportional to the controllable load current of the electric motor, therefore, a sufficiently accurate adjustment of the system pressure prevailing in the main pressure line is possible. On the usually connected to the main pressure line auxiliary elements, such as a pressure sensor, a pressure relief valve and a pressure accumulator, thus space and cost can be dispensed with.

Since the system pressure via a corresponding control of the electric motor, if necessary, if no actuation of one of the actuators should take place, can be lowered to almost zero, leakage losses are easily avoidable, and this purpose usually provided in the actuator shut-off valves can also be saved.

Since the height and also the chronological course of the system pressure can be controlled as desired by a corresponding activation of the electric motor, the control valve arrangement of the adjusting device can be made simpler, since the function of a pressure regulating valve can be fulfilled by a corresponding control of the pressure cylinder by the pressure generating device. By reversing the direction of rotation of the electric motor, the piston of the printing cylinder is loaded via the spindle gear with a directed away from the pressure chamber axial force and moved away from the pressure chamber, so that the volume of the pressure chamber is increased and the pressure prevailing therein is reduced, whereby pressure medium over with a check valve provided suction line is conveyed from the reservoir into the printing cylinder. Since a refilling of the printing cylinder is required by the piston at the latest with the reaching of the pressure chamber limiting bottom of the pressure cylinder, there are short-term functional breaks for the actuator. In many applications, for example, in a control device provided with a passively closable clutch automatic transmission, in which the actuators are not permanently but only briefly, eg to disengage the clutch and the gear change, operated, but this is not a significant functional restriction.

Although a similarly designed pressure cylinder whose piston is drivingly connected to a controllable electric motor via a spindle gear is known from DE 44 39 447 C1 and DE 10 2004 015 185 A1, it always forms a control pressure transducer of a disengagement device of a passively closable clutch , In the control device according to DE 44 39 447 C1, a primary actuating pressure for disengaging a clutch is generated via the relevant hydraulic pressure cylinder, which is supported by a servo pressure of a pneumatic pressure cylinder, wherein the pneumatic pressure cylinder is driven by means of a control pressure applied by the control pressure. In the control device according to DE 10 2004 015 185 A1, a servo pressure is generated via the relevant hydraulic pressure cylinder, which is used in parallel or serial arrangement to support a manually generated control pressure for disengaging a clutch, wherein the control of the associated electric motor and thus the servo pressure in response to the sensory detected encoder pressure and / or the encoder travel of a manually operated master cylinder takes place.

In order to avoid the disadvantage of a pressure which can not be controlled for a short time during the suction operation of the printing cylinder, the control device according to the invention is provided in a first development that the pressure supply device comprises two pumping elements designed as single-acting impression cylinders which mirror axially on both sides of the electric motor. are arranged symmetrically, the pistons are connected via a provided with a common spindle shaft spindle gear to the electric motor, and the pressure chambers are each provided via a provided with a check valve suction with the reservoir and a provided with a check valve pressure line with the main pressure line in combination.

As a result, when the electric motor is rotating, alternately the one printing cylinder in the suction mode and the other printing cylinder in the printing mode, that is to say in automatic mode, are alternately automatically. the piston of a pressure cylinder sucks pressure medium from the reservoir into its pressure chamber, while the piston of the other pressure cylinder promotes pressure medium from its pressure chamber with a corresponding pressure in the main pressure line. Thus, in this embodiment of the pressure supply device, the permanent supply of the main pressure line and the adjusting device connected thereto is ensured with a pressure medium pressure and with a pressure medium volume flow.

Another development of the control device according to the invention, with a non-stop pressure and flow power is achievable, is that the pumping element is designed as a double-acting pressure cylinder, the piston axially on both sides each delimiting a pressure chamber, and its pressure chambers each provided with a check valve Suction line to the reservoir and via a provided with a check valve pressure line with the main pressure line in conjunction.

In this embodiment, when a rotating electric motor alternately automatically one of the pressure chamber of the printing cylinder in the suction mode and the other pressure chamber of the printing cylinder in the printing operation. The effect is thus the same as in the above-described embodiment with two in mirror-symmetrical arrangement with the electric motor in drive connection standing single-acting pressure cylinders. In extreme cases, the combination of both types is possible, ie an arrangement of two double-acting pressure cylinders whose pistons are connected via a spindle gear with the electric motor in drive connection.

To improve the control properties of the pressure supply device, the spindle gear is preferably designed as a ball screw screw drive. Such a spindle gear is particularly free of play and low in resistance, so that this results in a particularly accurate and low-hysteresis relationship between the torque of the electric motor and prevailing in the pressure chamber and the main pressure line connected thereto system pressure.

The electric motor used to drive the piston or the piston is preferably designed as an electronically commutating brushless DC motor, since this type of electric motor is particularly precisely controlled and has a long service life due to a largely wear-free operation.

To dampen pressure fluctuations, which can be caused for example by the switching on and off of actuators, the pressure cylinder or the pressure cylinder of the pressure supply device according to another embodiment advantageously has a resilient portion. This resilient portion is expediently designed in each case as a ring-cylindrical diaphragm and arranged at the front end of the pressure chamber between a rigid cylinder portion and a rigid bottom of the impression cylinder. However, it is also possible that the resilient portion of the printing cylinder is formed as a plate-shaped membrane and is arranged in the pressure chamber limiting the bottom or forms the pressure chamber bounding bottom. In order to determine the respective position of the piston, the pressure cylinder of the pressure supply device is expediently assigned a displacement sensor which is mechanically or non-contactly in operative connection with the piston, the piston rod or the spindle of the spindle transmission. When using two pressure cylinders and only one displacement sensor is required because the pistons of both pressure cylinders are coupled together via the spindle gear. The determination of the position of the piston is particularly important when reaching the cylinder near the bottom end position important, since at the latest a reversal of the direction of rotation of the electric motor must be carried out, whereby the respective pressure cylinder or pressure chamber in the suction operation and optionally a second pressure cylinder or pressure chamber in the printing operation passes.

In order to allow a change in the height and / or the time course of the prevailing in the main pressure line system pressure at a time overlapped actuation of multiple actuators of the actuator without harmful effects, a shut-off device for inclusion of a control pressure in at least one of the actuators is suitably provided. The shut-off device may be formed by at least one shut-off valve, which is connected upstream of a control valve which is associated with one of the actuators and is closed to include the control pressure.

Likewise, the shut-off device can also be formed by a shut-off position of at least one control valve assigned to one of the actuators, wherein the control valve is controlled to include the setting pressure in the shut-off position. Without further effort, the shut-off device can also be formed by the formation of at least one control valve assigned to one of the actuators as a clock valve, which is closed to include the pressure medium. For optimum control of one of the other actuators, the system pressure which is effective as pilot pressure can then be increased, lowered or changed with a desired passage of time in a suitable manner via the pressure cylinder of the pressure-generating device. To clarify the invention, the description is accompanied by a drawing with exemplary embodiments. In this shows

1 shows an electro-hydraulic control device of an automated manual transmission with a first embodiment of the pressure supply device according to the invention in a schematic representation,

FIG. 2 shows an electro-hydraulic control device that is advantageously developed in comparison with the embodiment according to FIG. 1, FIG.

3 shows the electrohydraulic control device according to FIG. 1 with a second embodiment of the pressure supply device according to the invention, and FIG

4 shows the electrohydraulic control device according to FIG. 1 with a third embodiment of the pressure supply device according to the invention.

1 comprises a pressure supply device 2.1 for conveying a pressure medium from a reservoir 3 into a main pressure line 4, an actuating device 5.1 for actuating hydraulic clutch and gear actuators 6, 7 and 8, and an electronic control unit 9 for controlling the pressure supply device 2.1 and the actuators 6, 7, 8 of the actuating device 5.1.

The pressure supply device 2.1 has a pump element 10 which can be driven by an electric motor 9 which can be actuated by the control device 9 via electrical supply lines which are not particularly designated. According to the invention, the pumping element 10 is designed as a single-acting pressure cylinder 12, in which a via a spindle gear 13 with the electric motor 1 1 connected piston 14 is guided axially movable and axially bounded on one side a pressure chamber 15. The pressure chamber 15 is connected via a provided with a check valve 16 suction line 17 with the reservoir (oil sump) 3 and a pressure line 18 to the main pressure line 4 in connection.

By generating a certain drive torque of the electric motor 11, the piston 14 of the pressure cylinder 12 is loaded via the spindle gear 13 with an axial force in the direction of the pressure chamber 15, whereby the pressure in the pressure chamber 15 and in the main pressure line 4 connected thereto and, if necessary, pressure medium is conveyed from the pressure chamber 15 in the main pressure line 4. By reducing the drive torque of the electric motor 1 1, the pressure in the pressure chamber 15 and in the main pressure line 4 is reduced accordingly. By reversing the direction of rotation of the electric motor 1 1, the piston 14 of the pressure cylinder

12 charged via the spindle gear 13 with a directed away from the pressure chamber 15 axial force and moves in the direction of the electric motor 1 1, so that the volume of the pressure chamber 15 is increased and the pressure prevailing therein is reduced, whereby pressure medium via the suction line 17 and the check valve sixteenth is conveyed from the reservoir 3 in the printing cylinder 12.

To achieve the most precise possible control of the set over the pumping element 10, effective in the main pressure line 4 system pressure of the electric motor 1 1 are preferably designed as an electronically commutating brushless DC motor and the spindle gear 13 advantageously as a ball screw drive.

To monitor the system pressure is connected to the main pressure line 4 pressure sensor 19 and for monitoring the position of the piston 14 of the pressure cylinder 12, a mechanical or non-contact with the piston 14 in operative connection path sensor 20 is provided over in each case a not further designated sensor line with the control unit 9 are in communication. Due to the control properties of the pressure supply device 2.1 according to the invention can be dispensed with a pressure relief valve and a pressure accumulator, which are usually connected as part of a pressure supply device to the main pressure line 4.

The adjusting device 5.1 comprises a clutch actuator 6 for engagement and disengagement of a passively closable clutch, a Wählaktuator 7 for selecting a shift gate, ie for selective change of the internal transmission actuating connection between a shift shaft and a plurality of shift rails, and a shift actuator 8 for engaging and disengaging one of selected shift gate or shift rod associated gear.

The clutch actuator 6 is designed as a single-acting actuating cylinder 21 with a single pressure chamber 22, the three as 2/2-way solenoid valves seated control valves 23, 24, 25 are assigned. Via the first control valve 23, the pressure chamber 22 of the clutch actuator 6 can be connected to the disengagement of the associated clutch connected to the main pressure line 4. Via the second control valve 24, the pressure chamber 22 of the clutch actuator 6 can be connected to the rapid engagement of the clutch regulated with a leading to the reservoir 3 pressure line 26. Via the third control valve 25, which is connected via a throttle 27 to the pressure-free line 26, the pressure chamber 22 of the clutch actuator 6 can be connected to the slow engagement of the clutch connected to the pressure-free line 26.

The Wählaktuator 7 is designed as a double-acting actuator cylinder 28 with two pressure chambers 29, 30, each of which a valve as a 3/2-way solenoid valve, for example, as a ball seat valve, formed control valve 31, 32 is assigned. Via the first control valve 31, the first pressure chamber 29 of the Wählaktuators 7 for controlling a change of the shift gate by Pulsed control pulse width modulated mutually connected to the main pressure line 4 and the pressure line 26 are connected. Alternatively, by opening the valve to the main pressure line 4, with the valve also being open to the pressure-free line 26, the pressure and the piston travel of the selector 7 can be regulated by a displacement or current control of the piston 14 of the pressure supply device 2.1. Via the second control valve 32, the second pressure chamber 30 of the Wählaktuators 7 for controlling a change of the shift gate with the main pressure line 4 and the pressure line 26 can be connected in the same way.

The shift actuator 8 is also formed as a double-acting Stellzylin- 33 with two pressure chambers 34, 35, each associated with a designed as a 3/2-way solenoid valve control valve 36, 37 are assigned. Via the first control valve 36, the first pressure chamber 34 and the second control valve 37 of the second pressure chamber 35 of the Schaltaktuators 8 for controlling a gear change with the main pressure line 4 and the pressure line 26 are connected. For the sensitive control of a gear change, the first starting the synchronous position with a lower setting pressure and high positioning speed, then the synchronization with relatively high setting pressure and low positioning speed and finally the engagement of the respective gear coupling with low setting pressure and high positioning speed requires when inserting a synchronized gear are the immediately upstream control valves 36 and 37 formed in the art as flow control valves and this upstream of a pressure control valve. Such a pressure control valve is advantageously saved here, since the function of the pressure modulation can be effected in the present case by a corresponding control of the system pressure in the main pressure line 4 by means of the pressure cylinder 12 of the pressure supply device 2.1.

In order to detect the respective positioning position of the clutch and transmission actuators 6, 7, 8, a displacement sensor 38, 39, 40 is assigned to each of them. which are connected via not further designated sensor lines with the control unit 9 in connection. Likewise, the solenoid valves designed as control valves 23, 24, 25; 31, 32; 36, 37 of the actuators 6, 7, 8 connected to their control via non-designated control lines to the control unit 9.

The electrohydraulic control device 1.2 according to FIG. 2 is significantly simplified compared with the embodiment according to FIG. Thus, in the pressure supply device 2.2, the pressure sensor 19 is dispensed with, since the system pressure prevailing in the main pressure line 4 due to exact controllability of the pressure applied to the piston 14 or caused by the piston 14 in the pressure chamber 15 of the pressure cylinder 12 via the electric motor 1 1 from the height of the load current of the electric motor 1 1 can be derived. In the adjusting device 5.2, the control valves 24 and 25, over which in the embodiment of FIG. 1, the emptying of the pressure chamber 22 of the clutch actuator 6 is controlled to engage the associated clutch, saved. For engaging the clutch is now provided that the emptying of the pressure chamber 22 by a corresponding control of the electric motor 1 1 takes place by receiving the corresponding pressure medium volume in the pressure chamber 15 of the pressure cylinder 12 of the pressure supply device 2.2.

Furthermore, in the present case, in the adjusting device 5.2, the selector actuator 7, in contrast to the embodiment according to FIG. 1, is designed as a single-acting actuating cylinder 41 with a single pressure chamber 42, to which a control valve 43 designed as a 2/2-way solenoid clock valve is assigned. Via the control valve 43, the pressure chamber 42 of the Wählaktuators 7 can be controlled to control a change of the shift gate in one direction with the main pressure line 4. For the control of a change of the shift gate in the opposite direction is provided as in the clutch actuator 6, that the emptying of the pressure chamber 42 of the Wählaktuators 7 by a corresponding control of the electric motor 1 1 by a recording of the speaking pressure medium volume in the pressure chamber 15 of the pressure cylinder 12 of the pressure supply device 2.2 is carried out. This type of control is possible because the actuation of the actuators 6, 7 and 8 are not overlapped in time, but serially successively, the position of the other actuators 6, 7, 8 via a corresponding control of the relevant control valves 23; 43; 36, 37 by the inclusion of the setting pressures in the pressure chambers 22, 42, 34, 35 of the actuators 6, 7, 8 is maintained.

The electrohydraulic control device 1.3 according to FIG. 3 has an altered pressure supply device 2.3 compared with the embodiment according to FIG. 1 with the same positioning device 5.1. This now comprises two designed as a single-acting pressure cylinder 12 pump elements 10, which are axially symmetrically arranged on both sides of the electric motor 1 1, the pistons 14 are connected via a provided with a common spindle shaft spindle gear 44 to the electric motor 1 1, and their pressure chambers 15 each via a each with a check valve 16 provided with suction line 17 to the reservoir 3 and a provided with a check valve 45 pressure line 18 with the main pressure line 4 are in communication.

When rotating electric motor 11 is now alternately the one pressure cylinder 12 in the suction mode and the other pressure cylinder 12 in the printing operation, which means that the piston 14 of a pressure cylinder 12 pressure medium from the reservoir 3 promotes its pressure chamber 15, while the piston 14 of the other Pressure cylinder 12 promotes pressure medium from its pressure chamber 15 with a corresponding pressure in the main pressure line 4.

In contrast to the above-described embodiments of FIG. 1 and FIG. 2, in which upon reaching the cylinder bottom by the piston 14 of the pressure cylinder 12, a control pause for refilling the pressure chamber 15 is obtained, in the embodiment shown in FIG Pressure supply device 2.3, the supply of the main pressure line 4 and the associated adjusting device 5.1 with a controllable pressure medium pressure and a controllable pressure medium flow permanently available.

The same effect is alternatively achieved in that, as shown in FIG. 4, the pumping element 10 is formed as a double-acting pressure cylinder 46, the piston 47 axially on both sides each defining a pressure chamber 48, and its pressure chambers 48 each have a provided with a check valve 16 suction line 17 with the Reservoir 3 and via a provided with a check valve 45 pressure line 18 with the main pressure line 4 are in communication. In this illustrated in Fig. 4 variant of the pressure supply device 2.4 is at rotating electric motor 1 1 with the same effect alternately automatically a pressure chamber 48 of the pressure cylinder 46 in the suction mode and the other pressure chamber 48 of the pressure cylinder 46 in the printing operation.

REFERENCE CHARACTERS

1.1 control device

1.2 Control device

1.3 control device

1.4 Control device

2.1 pressure supply device

2.2 Pressure supply device

2.3 Pressure supply device

2.4 Pressure supply device

3 storage tank, oil sump

4 main pressure line

5.1 adjusting device

5.2 Adjustment device

6 clutch actuator

7 gear actuator, selector actuator

8 gear actuator, shift actuator

9 control unit

10 pumping element

11 electric motor

12 impression cylinders (single acting)

13 spindle gear

14 pistons

15 pressure chamber

16 check valve

17 suction line

18 pressure line

19 pressure sensor

20 way sensor

21 actuating cylinders (single acting) pressure chamber

control valve

unpressurized

throttle

Actuating cylinder (double-acting)

pressure chamber

control valve

Actuating cylinder (double-acting)

pressure chamber

control valve

displacement sensor

Actuating cylinder (single acting)

pressure chamber

control valve

spindle gear

check valve

Impression cylinder (double-acting)

piston

pressure chamber

Claims

Patent claims

1. Electrohydraulic control device, with a pressure supply device (2.1, 2.2) for conveying a pressure medium from a reservoir (3) in a main pressure line (4), wherein the promotion of the pressure medium via a by a controllable electric motor (11) drivable pump element (10) , and with an adjusting device (5.1, 5.2) for actuating at least one hydraulic actuator (6, 7, 8), wherein the actuation of the actuator (6, 7, 8) via a by at least one control valve (23, 24, 25, 31 , 32, 36, 37, 43) producible connection of at least one pressure chamber (22, 29, 30, 34, 35, 42) of the actuator (6, 7, 8) with the main pressure line (4) and / or with a pressure-less line (26 ), characterized in that the pumping element (10) is formed as a single-acting pressure cylinder (12) in which via a spindle gear (13) to the electric motor (1 1) connected to the piston (14) is guided axially movable and axially einse itig limited a pressure chamber (15) which communicates with the reservoir (3) via a suction line (17) provided with a check valve (16) and with the main pressure line (4) via a pressure line (18).

2. Electrohydraulic control device of an automated step transmission, with a pressure supply device (2.1, 2.2) for conveying a pressure medium from a reservoir (3) in a main pressure line (4), wherein the promotion of the pressure medium via a by a controllable electric motor (1 1) drivable pumping element (10), and with an adjusting device (5.1, 5.2) for actuating at least one hydraulic Kupplungsaktuators (6) and / or a hydraulic Wählaktuators (7) and / or a hydraulic Schaltaktuators (8), wherein the actuation of the relevant actuator (6 7, 8) via a connection of at least one which can be produced by at least one control valve (23, 24, 25, 31, 32, 36, 37, 43) Pressure chamber (22; 29, 30; 34, 35; 42) of the actuator (6, 7, 8) with the main pressure line (4) and / or with a pressure-free line (26), characterized in that the pumping element (10) as a single-acting pressure cylinder (12) is formed, in which a via a spindle gear (13) to the electric motor (11) connected to the piston (14) is guided axially movable and axially on one side a pressure chamber (15) limited, via a with a check valve (16 ) provided suction line (17) with the reservoir (3) and via a pressure line (18) with the main pressure line (4) is in communication.

3. Control device according to claim 1 or 2, characterized in that the pressure supply device (2.3) comprises two single-acting pressure cylinder (12) formed pumping elements (10) axially on both sides of the electric motor (11) are arranged mirror-symmetrically, the piston (14) via a provided with a common spindle shaft spindle gear (44) to the electric motor (11) are connected, and their pressure chambers (15) each with a check valve (16) provided with a suction line (17) with the reservoir (3) and one with a Check valve (45) provided pressure line (18) with the main pressure line (4) are in communication.

4. Control device according to at least one of claims 1 to 3, characterized in that the pumping element (10) of the pressure supply device (2.4) as a double-acting pressure cylinder (46) is formed, the piston (47) axially on both sides each delimiting a pressure chamber (48) , and the pressure chambers (48) in each case via a provided with a check valve (16) suction line (17) with the reservoir (3) and via a check valve (45) provided with a pressure line (18) with the main pressure line (4) are in communication ,

5. Control device according to at least one of claims 1 to 4, characterized in that the spindle gear (13, 44) is designed as a recirculating ball screw drive.

6. Control device according to at least one of claims 1 to 5, characterized in that the electric motor (11) is designed as an electronically commutating brushless DC motor.

7. Control device according to at least one of claims 1 to 6, characterized in that the pressure cylinder (12, 46) for damping pressure fluctuations has a resilient portion.

8. Control device according to claim 7, characterized in that the resilient portion is formed as a ring-cylindrical diaphragm and at the front end of the pressure chamber (15, 48) between a rigid cylinder portion and a rigid bottom of the impression cylinder (12, 46) is arranged.

9. Control device according to claim 7, characterized in that the resilient portion is formed as a plate-shaped membrane and in which the pressure chamber (15, 48) delimiting bottom is arranged or the pressure chamber (15, 48) defining the bottom.

10. Control device according to at least one of claims 1 to

9, characterized in that the pressure cylinder (12, 46) has a displacement sensor (20) for determining the position of the piston (14, 47).

11. Control device according to at least one of claims 1 to

10, characterized in that in an adjusting device with a plurality of actuators (6, 7, 8) which can be actuated over time, a shut-off device is provided. direction for the inclusion of a control pressure in at least one of the actuators (6, 7, 8) is provided.

12. Control device according to claim 11, characterized in that the shut-off device is formed by at least one shut-off valve which is connected upstream of a control valve (31, 32, 36, 37) which is associated with one of the actuators (6, 7, 8).

13. Control device according to claim 11 or 12, characterized in that the shut-off device is formed by a shut-off position of at least one control valve (31, 32, 36, 37) which is associated with one of the actuators (6, 7, 8).

14. Control device according to at least one of claims 11 to 13, characterized in that the shut-off device is formed by the formation of at least one control valve (23, 24, 25, 43) as a clock valve, which associated with one of the actuators (6, 7, 8) is.