DE102017130920B4 - Actuator arrangement for a motor vehicle drive train and method for operating it - Google Patents

Abstract

Actuator arrangement (40) for a motor vehicle drive train (10), with - a pump (42) which has a pressure connection (48), - an electric motor (50) which drives the pump (42), - a piston / cylinder arrangement (54) for actuating a drive train component, the piston / cylinder arrangement (54) being connected via a connecting line (58) to the pressure connection (48) of the pump (42), - a low-pressure region (46), and - a control arrangement (62), which is used for this is designed to control the electric motor (50) in such a way that a hydraulic pressure (P) at the pressure connection (48) can be regulated by adjusting a speed (n) of the electric motor (50), at least one fluid holding valve (70) which is connected to the piston in this way / Cylinder arrangement (54) is connected such that an outflow of fluid from the piston / cylinder arrangement (54) to the low pressure region (46) can be blocked, characterized in that the fluid holding valve (70) in the connecting line (58) from the pressure connection ( 48) the Pump (42) towards the piston / cylinder arrangement (54) and is designed as a normally open valve.

Description

The present invention relates to an actuator arrangement for a motor vehicle drive train, with a pump which has a pressure connection, with an electric motor which drives the pump, with a piston / cylinder arrangement for actuating a drive train component, the piston / cylinder arrangement being connected to the pressure connection via a connecting line Pump is connected to a low pressure area and with a control arrangement which is designed to control the electric motor in such a way that a hydraulic pressure at the pressure connection can be regulated by adjusting a speed of the electric motor.

In the field of motor vehicle drive trains, automated transmissions such as automated manual transmissions, double clutch transmissions, converter automatic transmissions, etc. are known. Automated transmissions are equipped with suitable actuators with regard to both clutch actuation and shift actuation in order to allow these processes to take place automatically.

To actuate the friction clutch, it is known and preferred to use hydraulic actuators in which the friction clutch is actuated by means of a piston / cylinder arrangement. This enables sensitive and rapid control of the torque transmitted via the friction clutch, which is particularly important in the case of double clutch transmissions. This is because two friction clutches for torque transfer from one power transmission branch to another power transmission branch are overlapped.

As a shift actuator device, it is also known to use hydraulic cylinders for actuating individual clutch packs such as synchronizations. One advantage here is that a uniform fluid source can be used for the friction clutch actuation and for the clutch actuation.

However, it is also known to actuate the clutch assembly electrically, for example by means of electromagnetic actuators or by means of electric motors. In the latter case, it is known to use so-called shift drums for actuating shift clutches, which are driven by means of an electric motor.

It is also known to provide shift clutch arrangements with shift shafts which are moved in the shifting direction by means of a hydraulic cylinder and which are moved in the selection direction by means of an electric motor.

To regulate the pressure of a hydraulic fluid, it is known to use a pump to generate a line pressure which is kept constant by means of a pressure regulating valve. The pressures of individual hydraulic cylinders are then regulated by means of further pressure control valves. It is known to couple the pump to the internal combustion engine in the manner of a power take-off.

However, it is also known to connect the pressure connection of a pump directly to a hydraulic cylinder and to drive the pump by means of an electric motor. In this case, it is possible to regulate the pressure in the hydraulic cylinder by adjusting the speed of the electric motor. Such an arrangement is also referred to as a "pump actuator". It is particularly advantageous here that no proportional valves or other continuous valves have to be used for pressure control. Because such valves have increased cleanliness requirements during assembly, which then makes the manufacture of such actuator arrangements expensive overall.

From the document EP 1 236 918 A1 it is also known to provide such a direct connection between the pump and the hydraulic cylinder with a leak (for example an orifice) towards a low-pressure area. This is to reduce wear on the pump and / or increase the response speed of the pump. The document also discloses connecting a discharge valve to a low-pressure region to the connecting line between the pump and the piston / cylinder arrangement, the discharge valve being intended to enable particularly rapid pressure reduction in the piston / cylinder arrangement. In addition, a pressure relief valve can also be connected to the connecting line.

From the document WO 2013/120814 A1 An actuator arrangement for a motor vehicle drive train is known which has at least one friction clutch for transmitting drive torque, in particular in the form of a starting clutch, and a transmission with at least two gear stages, which can be engaged and disengaged by means of a clutch arrangement, with a hydraulic circuit having a pump , by means of which the friction clutch can be actuated, and with a shift actuator device for actuating the shift clutch arrangement, the shift actuator device having a shift drum which is coupled or can be coupled to the electric motor via a shift drum coupling device in such a way that the shift drum by means of the electric motor in Rotation is displaceable to actuate the clutch assembly.

From the DE297 14 652 U1 An actuator for an automated transmission is known, which has a fluid holding valve, so that an outflow of Fluid from the piston / cylinder arrangement to the low pressure area can be blocked.

Also the DE 10 2016 118 423 A1 as well as the DE 100 52 666A1 and the DE 10 2015 213 540 A1 show hydraulic circuits for operating gears and / or clutches. Fluid retention valves are used to prevent backflow to the low pressure area.

Against the above background, it is an object of the invention to provide an improved actuator arrangement for a motor vehicle drive train and an improved method for operating it.

The above object is achieved in the above-mentioned actuator arrangement in that at least one fluid holding valve is connected to the piston / cylinder arrangement in such a way that an outflow of fluid from the piston / cylinder arrangement to the low-pressure region can be blocked.

Furthermore, the above object is achieved by a method for operating an actuator arrangement for a motor vehicle drive train, which comprises a pump, an electric motor which drives the pump, a piston / cylinder arrangement for actuating a drive train component, the piston / cylinder arrangement being connected to the pump via a connecting line and has a low-pressure area, in particular for operating an actuator arrangement of the type according to the invention, wherein an outflow of fluid from the piston / cylinder arrangement to the low-pressure area is blocked when a predetermined condition is met.

In the case of actuator arrangements of the type described above, the invention can be used to ensure that the piston / cylinder arrangement is not completely or not emptied even in situations in which the pump is not being driven, for example, or in another type of intermediate situation. This can prevent a response behavior being delayed in subsequent operations, for example because the piston / cylinder arrangement has run empty.

This applies in particular if the piston / cylinder arrangement is connected to the low-pressure region via a leak, for example via a leakage line with an orifice or via a leak which is integrated in the pump.

The fluid holding valve is preferably designed as a directional valve, specifically as a binary or non-continuous directional valve. The fluid holding valve is preferably a 4/2-way valve. The fluid holding valve can be operated electromagnetically or hydraulically.

A hydraulic circuit with such an actuator arrangement can be implemented as a whole without proportional valves, so that the manufacturing outlay can be kept low due to the low purity requirements.

In general, the actuator arrangement according to the invention can be integrated in any type of motor vehicle drive train, in particular in automated motor vehicle drive trains, such as, for example, motor vehicle drive trains with an automated manual transmission and automatically actuated clutch, with a double clutch transmission, with an automatic converter transmission, etc.

The drive train component, which is actuated by means of the piston / cylinder arrangement, is particularly preferably a friction clutch of the motor vehicle drive train, in particular a wet-running multi-plate clutch.

The electric motor can be rigidly connected to the pump, or via a coupling arrangement. The pump can be a conventional type of pump, for example a gerotor pump or a vane pump. The pump can be a unidirectional pump or a bidirectional pump. The low pressure region can be a reservoir or a tank of a hydraulic circuit of the motor vehicle drive train.

The hydraulic fluid that can be used in the actuator arrangement can also be used, for example, for cooling and / or for lubricating a friction clutch of the motor vehicle drive train.

The predetermined condition under which an outflow of fluid from the piston / cylinder arrangement to the low-pressure region is blocked, in particular by means of a fluid holding valve, can be, for example, at least one of the following conditions: a speed of the pump is less than a speed threshold, a hydraulic pressure in the Connection line is less than a pressure threshold value, a volume flow in the connection line is less than a volume flow threshold value, a switchover of the actuator arrangement from a drive of the pump to a drive of an actuator device for actuating a further drive train component was detected.

In general, the predetermined condition can also include that an actuation pause of the actuator arrangement is recorded if it is not actuated for a certain period of time, for example.

The fluid holding valve is preferably a normally open valve, which is consequently included in the Integrated actuator arrangement is that normal operation is no different than if the fluid holding valve were not present if it is not actuated. If the fluid holding valve is actuated in this embodiment, the shut-off takes place in such a way that an outflow of fluid from the piston / cylinder arrangement to the low-pressure region is blocked.

In other words, the fluid holding valve is preferably used when the motor vehicle drive train is in operation. When the motor vehicle drive train is switched off, for example when the ignition key is removed, the fluid holding valve is in the open position in the embodiment in which hydraulic fluid can flow out of the piston / cylinder arrangement to the low-pressure region. In other words, the fluid holding valve is activated in particular and used to block an outflow from the piston / cylinder arrangement when the actuator arrangement is in operation, the fluid holding valve preferably being actively controlled for this purpose.

According to the inventive embodiment, the fluid holding valve is arranged in the connecting line from the pressure connection of the pump to the piston / cylinder arrangement and is designed as a normally open valve.

In this embodiment, drainage of fluid from the piston / cylinder arrangement in spatial or functional proximity to the piston / cylinder arrangement is prevented when the fluid holding valve is actuated, i.e. when it is in the normally open position, when the fluid is unimpeded from the pressure connection to the Piston / cylinder assembly can get into the locked position. A leak in the actuator arrangement can be implemented in the pump or in a leakage line.

The task is thus solved completely.

It is particularly advantageous if the pressure connection of the pump is connected to the low-pressure region via such a leakage line, in which an orifice is arranged.

Here, when the fluid holding valve is not activated, that is to say in its open position, the controllability of the hydraulic pressure in the piston / cylinder arrangement can be improved, since a certain leakage fluid flow is always branched off via the leakage line and the orifice.

It is particularly advantageous here if the fluid holding valve is arranged between the piston / cylinder arrangement and a connection between the pressure connection and the leakage line.

In this case, the outflow of fluid from the piston / cylinder arrangement can be prevented if necessary.

According to a further embodiment, the fluid holding valve is arranged in a leakage line, which leads from the pressure connection of the pump to the low-pressure region and in which an orifice is arranged.

The fluid holding valve can be arranged upstream or downstream of the orifice, starting from a connection between the pressure connection and the leakage line to the low-pressure region.

According to a further preferred embodiment, the fluid holding valve is arranged in a suction line which connects a suction connection of the pump to the low-pressure area.

This embodiment can be particularly advantageous if a leak is set up by the pump itself.

The different arrangement options for a fluid holding valve can alternatively be implemented in the actuator arrangement, or any combination of such fluid holding valves can be implemented in the actuator arrangement.

Overall, it is further preferred if the electric motor is connected to an actuator device or can be connected if necessary, which is designed to actuate a further drive train component.

The actuator arrangement can therefore be implemented in a compact manner since the electric motor can be used for actuating two different drive train components.

The further drive train component is preferably a shift component of the drive train, by means of which one or more gear stages of a transmission arrangement of the drive train can be shifted.

In this embodiment, the electric motor can preferably be used to actuate a clutch arrangement of the drive train and to actuate a shift arrangement of the drive train. Clutch actuation and shift actuation generally take place at different times, so that such double use of the electric motor is functionally justifiable.

It is particularly advantageous if the actuator arrangement is a shift drum that can be driven by means of the electric motor. The shift drum can be connected to the electric motor, for example via a traction mechanism gearbox or via a wheel set, so that a suitable transmission ratio can be set up between the speed of the electric motor and the speed of the shift drum.

The shift drum can be designed to actuate one or more shift clutch packs of a gear arrangement, each shift clutch pack can contain one or two synchronous shift clutches for engaging or disengaging gear stages of a counter gear in a spur gear construction.

In one embodiment, the electric motor can always be rigidly connected to the pump, and the actuator arrangement can be connectable to the electric motor by means of a switchable coupling. In this case, it may make sense to connect the pressure connection of the pump to the low-pressure area as required by means of a switchable pressure relief valve, as is basically the case in the publication mentioned at the beginning WO 2013/120814 A1 is disclosed, the disclosure content of which is hereby fully referred to.

However, it is particularly preferred if the electric motor can alternatively be connected to the pump or to the actuator device by means of a coupling arrangement.

Here, the electric motor can be used either to drive the pump or to drive the actuator arrangement, that is to say to actuate the further drive train component.

The coupling arrangement can be implemented, for example, by a shift clutch package, as is generally also used for shifting gear stages in a transmission arrangement, for example as a dog clutch package.

It is particularly advantageous if the control arrangement is set up to control the coupling arrangement and the fluid holding valve in synchronism with one another.

As a result, the effort for operating the actuator arrangement can be reduced.

With others, for example, when the coupling arrangement has connected the electric motor to the pump, the fluid holding valve can remain uncontrolled, so that it is in the open position, that is, it does not interfere with the actuation, for example, of a clutch by means of the piston / cylinder arrangement. If, on the other hand, the coupling arrangement is switched such that the electric motor is connected to the actuator arrangement, the fluid holding valve can be activated synchronously with it so that it blocks. In this case, an outflow of fluid from the piston / cylinder arrangement can be prevented while the electric motor serves to actuate the further drive train component.

According to a further embodiment, an actuating device of the fluid holding valve and a coupling arrangement actuator are accommodated in a common actuator housing.

This may make it easier to operate these two components synchronously.

In a particularly preferred embodiment, it is provided that an actuating device of the fluid holding valve and a coupling arrangement actuator have a common actuating element.

The common actuator can be, for example, an armature of an electromagnet, which is controlled or excited by means of the control arrangement. The armature of this electromagnet can then be used both to place the fluid holding valve, for example, in a blocking position and to connect the coupling arrangement to the actuator device for the further drive train component.

The present invention is preferably used in a dual clutch transmission. In this case, a separate pump and its own further drive train component are often provided for each partial transmission, so that a separate coupling arrangement is generally also provided for each partial transmission. Preferred embodiments of such double clutch transmission actuator arrangements are in the document WO 2013/120814 A1 , to which, as mentioned above, reference is made in full, so that its disclosure is to be included in its entirety in the present case.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own without departing from the scope of the present invention.

• 1 eine schematische Darstellung einer Ausführungsform eines Kraftfahrzeugantriebsstranges mit einer Aktuatoranordnung;
• 2 eine schematische Darstellung einer weiteren Ausführungsform eines Antriebsstranges mit einer weiteren Ausführungsform einer Aktuatoranordnung;
• 3 eine schematische Darstellung eines weiteren Antriebsstranges mit einer weiteren Ausführungsform einer Aktuatoranordnung; und
• 4 eine schematische Darstellung eines weiteren Antriebsstranges mit einer Ausführungsform einer Aktuatoranordnung.

Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it:

• 1 a schematic representation of an embodiment of a motor vehicle drive train with an actuator arrangement;
• 2 is a schematic representation of another embodiment of a drive train with a further embodiment of an actuator arrangement;
• 3 a schematic representation of a further drive train with a further embodiment of an actuator arrangement; and
• 4 a schematic representation of a further drive train with an embodiment of an actuator arrangement.

In 1 A drive train for a motor vehicle is shown in schematic form and generally designated 10. The motor vehicle powertrain 10 has a drive motor 12 such as an internal combustion engine or a hybrid drive unit. The motor vehicle powertrain also includes 10 a clutch assembly 14 , The clutch assembly 14 can be a simple coupling, the input side with the drive motor 12 is coupled, however, can also be a double clutch arrangement. The coupling arrangement is on the output side 14 with a gear arrangement 16 connected, which can be a countershaft transmission in the form of an automated manual transmission or a double clutch transmission arrangement which consists of two sub-transmissions, one of which is assigned to the even gear stages and the other to the odd gear stages.

The clutch assembly 14 and the gear arrangement 16 can also be part of an automatic converter transmission, to give another example.

An output of the gear arrangement 16 is with a differential 18 connected, by means of its drive power to driven wheels 20L . 20R is distributable.

The gear arrangement 16 has a plurality of wheel sets, of which in 1 exemplary two wheel sets 24 . 26 are shown. The transmission arrangement also includes 16 a plurality of clutch assemblies 28 , of which in 1 one is shown schematically. The clutch assembly 28 includes a gearshift sleeve 30 using a switch actuator 32 is actuated to either the one wheel set 24 or the other wheelset 26 to switch into the power flow.

It is shown here that the switch actuator 32 a shift drum 34 has a switching contour, not shown, which has a driver or the like with the switching sleeve 30 is in operative connection. When the shift drum rotates 34 becomes the shift sleeve 30 axially offset to engage or disengage an associated clutch for shifting gear stages. The rotatability of the shift drum 34 is in 1 indicated at ns.

The motor vehicle powertrain 10 also includes an actuator arrangement 40 , with the switching actuator 32 Part of this actuator arrangement 40 can be.

The actuator arrangement 40 assigns a pump 42 on that a suction port 44 owns that with a low pressure area 46 , for example in the form of a tank or a reservoir. The pump 42 also has a pressure connection 48 on. The pump 42 is by means of an electric motor 50 driven. A motor shaft 52 of the electric motor 50 can be rigid with the pump 42 connected, but can also be connected to the pump via a coupling arrangement described below 42 be connectable.

The actuator arrangement 40 also has a piston / cylinder arrangement 54 on that of the clutch assembly 14 assigned.

The piston / cylinder arrangement 54 is used to operate the clutch assembly 14 , If the clutch assembly 14 has more than one clutch, contains the actuator arrangement 40 usually more than one piston / cylinder arrangement 54 ,

The piston / cylinder arrangement is present 54 by means of a spring 56 biased in an open position where the piston / cylinder assembly 54 the clutch assembly 14 not activated. The pressure space of the piston / cylinder arrangement 54 is via a connecting line 58 directly with the pressure connection 48 the pump 42 connected. On the connecting line 58 can be a pressure gauge 60 be connected.

In the present case, a direct connection is understood to mean that a pressure P in the connecting line 58 is not regulated by means of a proportional valve or the like, but only by setting a speed n _M of the electric motor 50 ,

For this purpose, the actuator arrangement 40 a control arrangement 62 on that with the pressure gauge 60 is connected (at “ A " in 1 ) and depending on the measured pressure P the electric motor 50 controls the pressure P to regulate to a desired value.

The pressure P can, for example, correspond to a torque that is generated via the clutch arrangement 14 can be transferred. The pressure P can by adjusting the speed n _M are regulated so sensitively that the coupling arrangement 14 can either be closed, open can be, but can preferably also assume any intermediate slip state. This is particularly important in the case of double clutch transmissions which have two such clutch arrangements which are actuated in overlapping fashion in order to be able to carry out gear changes without interruption in tractive force.

Furthermore, the hydraulic circuit shown has the actuator arrangement 40 a leakage line 64 on that at an unspecified connection to the connecting line 58 is connected and in the low pressure area or section 46 leads. In the leakage line 64 is an aperture 66 arranged.

Because of the leakage line 64 can the pressure P can be regulated more sensitively, the response behavior can be improved. Possibly. can the components of the pump 42 and / or the lines involved are protected.

A leak in the connecting line 58 can either through the leakage line shown 64 and the aperture included in it 66 be set up. Such leakage with limited backflow into the low pressure area 46 can also be done by the pump 42 be set up, although this is in 1 is not shown.

Unless the pump is in operation of the motor vehicle powertrain 10 is turned off, the piston / cylinder assembly could 54 drain via the leakage, such as via the leakage line 64 ,

In order to be able to prevent this, the actuator arrangement contains 40 in the present case a fluid holding valve 70 , The fluid holding valve 70 is designed as a directional valve, in particular as a 4/2-way valve, which is biased into an open position by means of a spring (not specified) (normally open).

In this unactuated, normally set position of the fluid holding valve 70 this forms a free passage in the connecting line 58 , The fluid holding valve 70 is preferably arranged between the connection that the connecting line 58 with the leakage line 64 connects, and the piston / cylinder assembly 54 ,

If necessary, for example if a predetermined condition is met, the fluid holding valve 70 are operated, namely by means of an actuator 72 , An actuation of the fluid holding valve 70 leads to the connecting line 58 is blocked, i.e. no fluid from the piston / cylinder arrangement 54 can flow out.

The operation can, as is the case with B in 1 is indicated, electromagnetically via a control signal of the control arrangement 62 respectively. The actuator 72 can however also be a direct actuation or a hydraulically controlled actuation.

In 1 is the open position of the fluid holding valve 70 marked with O, the blocking position with S.

The predetermined condition may exist, for example, when the speed n _M the pump 42 falls below a predetermined speed threshold. The predetermined condition at which the fluid holding valve 70 is actuated, but may also be when the pressure P in the connecting line 58 falls below a pressure threshold and / or if a volume flow in the connecting line 58 falls below a volume flow threshold.

Another alternative or accumulative condition for actuating the fluid holding valve 70 can be that a coupling arrangement 80 between a coupling of the electric motor 50 with the pump 42 is switched to a coupling of the electric motor 50 with a further drive train component, in the present case in the form of a shift actuator 32 , for example, by a shift drum 34 can be formed. This is in 1 shown in dashed lines.

The coupling arrangement 80 can be switchable by means of the control arrangement 62 as it is in 1 is also represented by a chain line.

In other words, if the electric motor 50 used to switch the actuator 32 to drive in order to engage or disengage a gear is the electric motor 50 preferably from the pump 42 decoupled so that it is not set in rotation and consequently an emptying process of the piston / cylinder arrangement 54 could take place. In this case the fluid holding valve 70 actuated to prevent such emptying.

In 1 is shown that the fluid holding valve 70 immediately adjacent to the piston / cylinder arrangement 54 is arranged, namely between this and the connection between the connecting line 58 and leakage line 64 ,

Alternatively or in addition to this, a fluid holding valve can also be located in the leakage line 64 be arranged, either upstream of the aperture 66 how it at 70A is shown, or downstream of the aperture 66 how it at 70B is shown.

Alternatively or accumulatively, it is also possible to use a fluid holding valve 70C in the line between the suction connection 44 and the low pressure area 46 to be arranged, this arrangement being particularly advantageous if there is leakage through the pump 42 is set up.

If there is a leak through the pump 42 and via the leakage line 64 is set up, for example, both a fluid holding valve 70C as well as a fluid holding valve 70B be provided.

These valves can optionally be integrated in a valve body and can be implemented, for example, as an 8/2-way valve. Alternatively, such a combined valve can also be provided by the fluid holding valves 70C . 70A be realized.

In the following 2 to 4 become further embodiments of motor vehicle drive trains 10 and assigned actuator arrangements, which generally relate to the actuator arrangement in terms of structure and mode of operation 1 correspond. The same elements are therefore identified by the same reference numerals. The differences are essentially explained below.

2 shows an actuator arrangement 40 ' for a first partial transmission of a double clutch transmission and a second actuator arrangement 40'a for a second sub-transmission of the dual clutch transmission.

The partial transmission, that of the actuator arrangement 40 ' is assigned includes the odd gear stages of the dual clutch transmission. Corresponding to the shift drum are the gear steps 1-3-5 assigned. The shift drum 34 is used to operate only gear stages of the sub-transmission with the odd gear stages.

The actuator arrangement 40'a includes a shift drum 34a , which is exclusively assigned to the partial transmission with the even gear steps.

Below is the actuator arrangement 40 ' described. The function of the actuator arrangement 40'a is identical to this. The corresponding elements are in 2 each with the appendix "a".

In the actuator arrangement 40 ' is the fluid holding valve 70A in the leakage line 64 provided, upstream of the aperture 66 , Alternatively, the fluid holding valve 70 also in the connecting line 58 be arranged as in the 1

Furthermore, in 2 a coupling arrangement 80 ' shown as an example.

The coupling arrangement 80 ' includes a coupling clutch package 82 with a shift drum clutch 84 and a pump coupling 86 , The coupling clutch package 82 can be designed in the manner of a clutch pack (with synchronizers or with dog clutches), such that, alternatively, the shift drum clutch 84 or the pump coupling 86 is closed, the other clutch then being open.

In 1 it is shown that the pump coupling 86 is closed and the shift drum clutch 84 is open. Furthermore, in 2 shown that in the actuator assembly 40'a the shift drum clutch 84a is closed and the pump clutch 86a is open.

In the actuator arrangement 40 ' can due to the closed pump coupling 86 the same operation can be set up as in the embodiment of 1 ,

If the shift drum 34 by means of the electric motor 50 to be operated, the coupling clutch package 82 switched so that the the shift drum clutch 84 is closed. In this case, the electric motor 50 used to change the shift drum 34 to twist. An output member of the shift drum clutch 84 is connected to a wheel set, by means of which a speed n _M of the electric motor in one rotation n _p the shift drum 34 can be implemented.

For switching the coupling clutch package 82 serves a coupling arrangement actuator 90 who, for example, an electromagnet 92 can have, preferably by means of the control arrangement 62 is controllable.

The coupling arrangement actuator 90 is preferably biased by means of a schematically indicated spring into a position in which the pump clutch 86 is closed and the shift drum clutch 84 is open. By driving the electromagnet 92 becomes the coupling clutch package 82 switched so that the shift drum clutch 84 is closed and the pump clutch 86 is opened. This is done via a control signal B of the control arrangement 62 ,

In 2 it is shown that the same control signal B can be used to control the fluid holding valve 70A (or the fluid holding valve 70 ) to control, so that the leakage line 64 is blocked. In other words, when the pump 42 from the electric motor 50 is decoupled, the fluid holding valve synchronously 70A actuated to prevent the piston / cylinder assembly from emptying.

When switching the coupling clutch package again 82 becomes the control signal B simply set back to zero so that the switch assembly actuator 90 by means of the spring back into the Basic position is set at which the pump coupling 86 closed is. Furthermore, the normally open fluid holding valve 70A by means of the spring in the open position at which the leakage line 64 is consistent.

In 3 Another embodiment is shown, with an actuator arrangement 40 " for a first partial transmission of a double clutch transmission and an actuator arrangement 40 "a for a second sub-transmission of the dual clutch transmission. The general structure corresponds to the embodiment of FIG 2 ,

However, fluid holding valves are present 70 " . 70 "a each in the connecting line 58 . 58a between the pressure connection 48 . 48a the respective pump 42 . 42a and the respective piston / cylinder arrangement 54 . 54a arranged. Furthermore, it is indicated schematically that diaphragms 66 " . 66 "a in the pumps 42 . 42a are arranged to indicate that there is a leak through the pumps 42 . 42a itself is set up.

Alternatively, it is possible to use the connecting line 58 via respective leakage lines (not shown) with the low pressure area 46 connect to.

The coupling arrangements 80 " . 80 "a the embodiment of 3 are identical to the coupling arrangements 80 ' . 80'a the 2 , However, the coupling clutch packages 82 . 82a in the embodiment of 3 not actuated electromagnetically, but hydraulically via coupling arrangement actuators 90 " . 90 "a ,

The coupling arrangement actuators 90 " . 90 "a are biased into a basic position by means of respective springs, in which the coupling clutch packs 82 . 82a are switched so that the respective pump couplings 86 are closed.

A switchover of the coupling clutch package 82 takes place in the present case via the actuator arrangement 40 "a , A switchover of the coupling clutch package 82a takes place in the present case via the actuator arrangement 40 " , For this purpose the actuator arrangements are 40 " . 40 "a via a cross circuit arrangement 98 coupled with each other.

The cross circuit arrangement 98 includes on the actuator assembly side 40 " a first shuttle valve 100 , the inlet side with the suction connection 44 and with the pressure connection 48 the pump 42 connected is. An outlet of the shuttle valve 100 is with the coupling arrangement actuator 90 "a the actuator arrangement 40 "a connected.

The cross circuit arrangement 98 also includes another shuttle valve 100a that of the actuator assembly 40 "a is assigned and its inputs with the suction connection 44a and the pressure connection 48a the pump 42a are connected. An outlet of the other shuttle valve 100a the cross circuit arrangement 98 is with the coupling arrangement actuator 90 " the actuator arrangement 40 " connected.

In 3 is shown by bold lines that a switching of the coupling clutch package 82a can be done as follows. The electric motor 50 is driven. The coupling clutch package 82 is (uncontrolled) switched so that the electric motor 50 the pump 42 drives. Consequently, at the pressure connection 48 generates a pressure that is greater than the pressure at the suction connection 44 , As a result, the shuttle valve switches 100 so that the one on the pressure port 48 generated line pressure to the actuating cylinder of the coupling arrangement actuator 90 "a is created so that the coupling clutch package 82a is switched over and against the bias of the coupling arrangement actuator 90 "a so the electric motor 50 with the shift drum 34 is coupled.

The spring preload of the coupling arrangement actuators 90 " , 90 "a using the cross circuit arrangement 98 are preferably designed so that a switchover of the respective coupling clutch packets 82 . 82a only occurs when the pressure at the respective pressure connection 48 . 48a corresponds to an overpressure pressure. The overpressure pressure is a pressure which is greater than is necessary to close the respective clutch arrangement 14 that by means of the associated piston / cylinder arrangement 54 . 54a is operated.

Consequently, it is possible with this arrangement to actuate the respective clutch arrangements in a slipping manner, for example, without having to switch over the clutch arrangement actuator 90 the other actuator arrangement takes place. Only when the assigned friction clutch is completely closed by means of the one actuator arrangement and then the pressure is increased once again, is the coupling arrangement actuator of the respective other actuator arrangement actuated.

In 3 it is also shown that the connecting line between the outputs of the shuttle valves 100 . 100a and the respective actuating cylinders of the coupling arrangement actuators 90 " . 90 "a with hydraulic actuators 72 " . 72 "a of the fluid holding valves 70 " . 70 "a can be connected (as indicated by the reference symbol "C").

In this embodiment, fluid holding valves can consequently 70 " . 70 "a can also be operated hydraulically.

In 4 Another embodiment is shown, in which a coupling arrangement 80 is identical to the embodiments of FIG 2 and 3 , There is also a fluid holding valve 70 '' provided that is designed as a 4/2-way valve. The fluid holding valve 70 '' is both between the suction port 44 the pump 42 and the low pressure area 46 switched, as well as in the leakage line 64 , As a result, both a leakage can be shut off in the leakage line 64 as well as a leak inside the pump. This can be done by a single actuator, by the fluid holding valve 70 '' take place, which is controlled electromagnetically in the present case.

The fluid holding valve 70 '' is biased in a position where the suction line to the suction port 44 and the leakage line 64 are completely consistent. By controlling the actuator 72 '' both lines are completely blocked.

It can also be seen that the coupling arrangement 80 by means of an electromagnetic coupling arrangement actuator 90 '' is switchable.

In 4 is indicated that the coupling arrangement actuator 90 '' and the actuator 72 '' in a common actuator housing 106 can be included.

Because the switch actuator 90 '' and the fluid holding valve 70 '' preferably actuated synchronously with one another, preferably simultaneously with one another, it is also possible to implement the actuation by means of a single actuator device, which in the present case is, for example, an electromagnetic coil 108 in the actuator housing 106 and an electromagnetic armature 110 can be realized, the electromagnet armature 110 preferably both the coupling arrangement actuator 90 '' as well as the fluid holding valve 70 '' assigned. Driving the electromagnetic coil 108 and the electromagnetic armature 110 consequently simultaneously leads to a switchover of the coupling arrangement actuator 90 '' and the fluid holding valve 70 '' ,

It goes without saying that such an integrated actuation is also possible when the fluid holding valve 70 is formed as in any of the embodiments of FIG 1 to 3 , for example as a simple 4/2-way valve in the connecting line 58 is realized.

In some variants, the actuator housing 106 with a housing of the electric motor 50 to get integrated. The outlay for housings etc. can thereby be further reduced.

LIST OF REFERENCE NUMBERS

10

Motor vehicle drive train

12

drive motor

14

clutch assembly

16

transmission assembly

18

differential

20L, 20R

bikes

24, 26

wheelsets

28

Clutch arrangement

30

shift sleeve

32

shift actuator

34, 34a

shift drum

40, 40 ', 40'a

actuator

42, 42a

pump

44

suction

46

Low pressure area

48, 48a

pressure connection

50

electric motor

52

motor shaft

54, 54a

Piston / cylinder assembly

56

feather

58

connecting line

60

pressure monitor

P

print

64

leakage line

66, 66 ", 66" a

cover

70, 70A, 70B, 70C, 70 ", 70" a, 70 '"

Fluid retention valve

72, 72 ", 72" a, 72 '"

actuator

80, 80 ', 80 ", 80" a

Coupling clutch pack

82, 82a

Dome clutch pack

84, 84a

Switching roller clutch

86

pump coupling

90, 90 '', 90''a, 90 '' '

Koppelanordnungaktuator

92

electromagnet

98

Cross circuitry

100,100A

shuttle valve

106

casing

108

electromagnetic coil

110

Solenoid armature

Claims (9)

Actuator arrangement (40) for a motor vehicle drive train (10), with - a pump (42) which has a pressure connection (48), - an electric motor (50) which drives the pump (42), - a piston / cylinder arrangement (54) for actuating a drive train component, the piston / cylinder arrangement (54) being connected via a connecting line (58) to the pressure connection (48) of the pump (42), - a low-pressure region (46), and - a control arrangement (62), which are used for this is designed to control the electric motor (50) in such a way that a hydraulic pressure (P) at the pressure connection (48) can be regulated by setting a speed (n _M ) of the electric motor (50), at least one fluid holding valve (70) operating in this way the piston / cylinder arrangement (54) is connected such that an outflow of fluid from the piston / cylinder arrangement (54) to the low pressure region (46) can be blocked, characterized in that the fluid holding valve (70) in the connecting line (58) from the pressure connection ss (48) of the pump (42) towards the piston / cylinder arrangement (54) and is designed as a normally open valve. Actuator arrangement after Claim 1 , characterized in that a pressure connection (48) of the pump (42) is connected to the low-pressure region (46) via a leakage line (64) in which an orifice (66) is arranged. Actuator arrangement after Claim 2 , characterized in that the fluid holding valve (70) is arranged between the piston / cylinder arrangement (54) and a connection between the pressure connection (48) and the leakage line (64). Actuator arrangement according to one of the Claims 1 - 3 , characterized in that at least one fluid holding valve (70A; 70B) is arranged in a leakage line (64) which leads from the pressure connection (48) of the pump (42) to the low pressure region (46) and in which an orifice (66) is arranged is. Actuator arrangement according to one of the Claims 1 - 4 , characterized in that a fluid holding valve (70C) is arranged in a suction line, which connects a suction connection (44) of the pump (42) with the low-pressure region (46). Actuator arrangement according to one of the Claims 1 - 5 , characterized in that the electric motor (50) is connected to a shift actuator (32) or can be connected if necessary, which is designed to actuate a clutch arrangement (28). Actuator arrangement after Claim 6 , characterized in that the electric motor (50) can alternatively be connected to the pump (42) or to the switching actuator (32) by means of a coupling arrangement (80). Actuator arrangement after Claim 7 , characterized in that the control arrangement (62) is set up to control the coupling arrangement (80) and the fluid holding valve (70) in synchronism with one another, and / or wherein an actuating device (72 "') of the fluid holding valve (70"') and a coupling arrangement actuator (90 '") are accommodated in a common actuator housing (106) and / or have a common actuator (110). A method of operating an actuator assembly (40) for a motor vehicle powertrain (10) that includes a pump (42), an electric motor (50) that drives the pump (42), a piston / cylinder assembly (54) for actuating a powertrain component, the Piston / cylinder arrangement (54) is connected to the pump (42) via a connecting line (58), and has a low pressure region (46), as well as an actuator arrangement according to one of the Claims 1 - 8th wherein flow of fluid from the piston / cylinder assembly (54) to the low pressure region (46) is blocked when a predetermined condition is met, such as a speed of the pump is less than a speed threshold, a hydraulic pressure in the connecting line is less than a pressure threshold value, a volume flow in the connecting line is less than a volume flow threshold value, a switchover of the actuator arrangement from a drive of the pump to a drive of an actuator device for actuating a further drive train component was recorded, an actuation pause of the actuator arrangement was recorded.

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