DE102011100808A1 - Clutch transmission, in particular dual-clutch transmission, with hydraulic actuation system - Google Patents

Abstract

The invention relates to a clutch transmission, in particular a dual clutch transmission, with a hydraulic actuation system for actuating at least one hydraulic gear actuator (155, 155 ', 157, 157') and at least one hydraulic clutch (K1, K2), comprising: a pressurized hydraulic medium supplying Hydraulic medium source (224), - at least one electrically controllable, hydraulic volume control valve (159, 159 ', 179, 179') for controlling the gear selector (155, 155 ', 157, 157'), - at least one electrically controllable, hydraulic first pressure control valve ( 141) for the selective connection of the volume control valve (159, 159 ', 179, 179') to the hydraulic medium source (224), - at least one electrically controllable, hydraulic second pressure control valve (101, 101 ') for the selective connection of the clutch (K1, K2) to the hydraulic medium source (224), - after the gear selector (155, 155 ', 157, 157') has engaged the gear, the volume control valve ntil (159, 159 ', 179, 179') and the first pressure regulating valve (141) are electrically de-energized and to hold the clutch (K1, K2) in the engaged state brought about by the application of hydraulic medium only the second pressure regulating valve (101, 101 ') is electrically energized.

Description

The invention relates to a clutch transmission, in particular dual-clutch transmission, with a hydraulic actuating system for actuating at least one hydraulic gear actuator and with at least one hydraulic clutch.

Clutch transmissions, in particular dual-clutch transmissions, are preferably used in passenger cars. A dual-clutch transmission generally has two transmission input shafts arranged coaxially with one another, which are each assigned to a partial transmission. Each of the transmission input shafts is assigned a clutch via which the transmission input shaft of the respective subtransmission can be frictionally coupled to the output of an engine, preferably an internal combustion engine of a motor vehicle.

During the drive, one of the partial transmissions is typically active, which means that the transmission input shaft assigned to this partial transmission is coupled to the engine via its associated clutch. In the active part transmission, a gear is engaged, which provides a current gear ratio. A controller determines whether, depending on the driving situation, the next higher or next lower gear should be engaged. This next expected gear is used in the second; Inactive partial transmission inserted. For a gear change then the clutch of the inactive sub-transmission is closed, while the clutch of the active sub-transmission is opened. It is preferred if the opening of the clutch of the active sub-transmission and the closing of the clutch of the inactive sub-transmission overlap such that no or only a slight force flow interruption is given by the engine to the drive shaft of the motor vehicle. as a result of the gear change, the previously active sub-transmission is inactive, while the previously inactive sub-transmission becomes the active sub-transmission. Subsequently, in the now inactive partial transmission of the expected next required gear can be inserted.

The laying and laying out of the gears via elements, preferably via shift rails, which are actuated by hydraulic cylinders, the so-called, already mentioned above switching cylinders. The hydraulic cylinders are preferably designed as double-acting cylinders, in particular as synchronizing cylinders or as differential cylinders, so that preferably two gears can be assigned to each switching cylinder.

Alternatively, the cylinders may also be designed as single-acting cylinders. The hydraulic cylinders, which actuate the elements, in particular shift rails, are also referred to as gear actuator cylinders. A trained as a synchronous cylinder gear actuator cylinder, which in particular two gears are assigned, preferably has three switching positions, so far in a first a certain gear, in a second another, certain gear and in a third none of the two gears is engaged.

The two partial transmissions associated clutches are hydraulically actuated, ie closed or opened. It is preferred that the clutches each close when subjected to hydraulic pressure while being opened when no hydraulic pressure is applied, i. h., One of the respective clutch associated hydraulic cylinder, which - as mentioned above - is also called clutch cylinder, pressure relieved.

Incidentally, the operation of a dual-clutch transmission is known per se, so that will not be discussed further here.

The construction described in the preceding paragraphs and the mode of operation described therein are also preferably valid for or in connection with the subject matter of the invention.

As already indicated, dual-clutch transmissions are both controlled or regulated by a hydraulic circuit and also cooled. This hydraulic circuit, or assemblies thereof, as well as associated methods are the subject of the invention.

In many vehicles on the market, associated with the clutch transmissions when driving in a gear engaged in a relatively high energy consumption. This is essentially electrical energy with which a plurality of solenoid valves of such a clutch transmission are energized when the gear is engaged. A high electrical energy consumption loads the electrical system and must be taken into account in the dimensioning of the electrical equipment of a motor vehicle.

The invention is therefore an object of the invention to provide a clutch transmission, in particular dual-clutch transmission, which in operation, in particular when driving a clutch transmission having the motor vehicle, in an engaged gear has only a low energy consumption.

This object is achieved in that the clutch transmission of the aforementioned type is provided that a pressurized hydraulic medium supplying hydraulic medium source, at least one electrically controllable, hydraulic volume control valve for controlling the gear actuator, at least one electrically controllable, hydraulic first pressure control valve for selectively connecting the volume control valve to the hydraulic medium source and at least one electrically controllable, hydraulic second pressure control valve for selectively connecting the clutch to the hydraulic medium source, wherein after the gear plate, made inserting a gear, the volume control valve and the first pressure control valve are switched electrically de-energized and to hold the clutch in the brought about by loading with hydraulic medium, engaged state only the second pressure control valve is electrically energized. Accordingly, in a vehicle having the clutch transmission when driving in a gear only the energization of a single solenoid valve, namely said second pressure control valve is required. This also applies if the clutch transmission is designed as a double-clutch transmission, wherein the actuating system has two similarly constructed sub-transmission circuits, but when driving only in one of the two sub-transmission circuits, a power flow via this sub-transmission circuit associated clutch takes place, so only the correspondingly associated pressure control valve to electrically is energized. The hydraulic concept according to the invention therefore has optimized energy efficiency.

According to a development of the invention, at least one hydraulic switching valve is provided for selectively connecting the second pressure regulating valve to the hydraulic medium source. The switching valve is used to connect the second pressure regulating valve in case of need to the hydraulic medium source and to separate in case of malfunction of the coupling of the hydraulic medium source.

The switching valve is preferably a hydraulically controllable switching valve.

According to a development of the invention, at least one electrically controllable, hydraulic pilot valve may be provided for selectively connecting the hydraulic control of the switching valve to the hydraulic medium source. This pilot valve is used to control the switching valve, wherein the pilot valve is electrically controlled and the switching valve hydraulically. If the pilot valve is de-energized, it connects the hydraulically displaceable piston of the switching valve to the hydraulic medium source, with the result that the switching valve has a position which connects the second pressure regulating valve with the hydraulic medium source. Accordingly, according to a development of the invention, it is thus provided that in order to hold the clutch in the engaged state, the pilot valve is electrically de-energized, so that the switching valve connects the second pressure regulating valve to the hydraulic medium source.

A preferred development of the invention provides that the volume control valve is a first volume control valve and that a first volume control valve exhibiting first subtransmission of the actuating system has a second volume control valve for controlling a second gear actuator, which is also connected via the first pressure control valve selectively to the hydraulic medium source. Consequently, only a single pressure regulating valve (first pressure regulating valve) is provided for both volume control valves, each of which controls one gear selector.

Due to the design of the clutch transmission as a dual-clutch transmission is particularly provided that the actuation system comprises a second sub-gear circuit having at least a third volume control valve for controlling a third gear actuator and a third pressure control valve for a further clutch. In particular, it is preferably provided that the second partial transmission circuit has a particular fourth volume control valve for controlling a preferred fourth gear actuator and a preferred further switching valve and a preferred further pilot valve. First and second subtransmission circuit have the same structure. Both sub-gear circuits have only a single pressure control valve (first pressure control valve) for selectively connecting the four volume control valves to the hydraulic medium source.

In the following, the clutch transmission according to the invention with hydraulic circuit based on 1 explained in more detail.

1 shows a hydraulic circuit 1 , which serves the operation, in particular the coupling and the insertion and disengagement of gears, a dual-clutch transmission and the cooling thereof. The hydraulic circuit 1 includes a tank 3 which serves in particular as a reservoir or sump for a hydraulic medium used for the actuation and cooling, and in which the hydraulic medium is preferably stored without pressure. It is an electric motor 5 provided, a first pump 7 and a second pump 9 drives. The electric motor 5 is preferably controllable with respect to its speed and direction of rotation, particularly preferably adjustable. The first pump 7 is with the electric motor 5 firmly connected, so without a partition is provided. This means that the pump 7 with the electric motor running 5 is always driven and preferably promotes hydraulic medium rectified in both directions of rotation. The pump 9 is over a separator 11 with the electric motor 5 connected. So it's possible the pump 9 from the electric motor 5 decouple so that it does not run when the electric motor 5 running. The separating element 11 is preferably designed as a clutch or as a freewheel, wherein in the second case on the direction of rotation of the electric motor 5 certainly can be, whether from the pump 9 Hydraulic medium is promoted or not.

The first pump 7 and the second pump 9 are each over a line 13 . 15 with a turnoff 17 connected to another line 19 empties. This connects the tank 3 via a suction filter 21 with the diversion 17 , Overall, these are inlets of the pumps 7 . 9 over the wires 13 . 15 , the diversion 17 and the suction filter 21 having direction 19 with the tank 3 connected.

The outlet of the first pump 7 is with a lead 23 connected to a turnoff 25 leads. The turnoff 25 is via a pressure relief valve 27 with the tank 3 connected. The pressure relief valve 27 can overpressure in the direction of the tank 3 to open. It also starts from the junction 25 a line 29 out, over a pressure filter 31 to a connection 33 a switching valve 35 leads.

The pressure filter 31 is through a bypass 37 bridgeable, being in the bypass 37 a differential pressure valve 39 is arranged, which at overpressure bridging the filter 31 towards the connection 33 allows. An opening of the differential pressure valve 39 takes place from a predetermined differential pressure on the pressure filter 31 ,

The switching valve 35 is designed as a 5/2-way valve, which except the connection 33 four more connections 41 . 43 . 45 . 47 having. In a first, in 1 illustrated switching state of the switching valve 35 is the connection 33 with the connection 41 connected while the other connections 43 . 45 and 47 blind, so closed, are switched. The connection 41 flows into a line 49 in which a check valve 51 is arranged. The administration 49 leads to a pressure accumulator 53 , being in front of the accumulator 53 a pressure detection device 55 with the line 49 hydraulically connected.

In a second, from the 1 removable switching state of the switching valve 35 is the connection 33 with the connection 43 connected to a line 57 leads to a hydraulic subcircuit 59 leads, which serves in particular the cooling of clutches of the dual clutch transmission. In this second switching state is the connection 41 switched blind and the connection 45 is with the connection 47 connected. This leads to the connection 45 a line 61 that with the pressure of the hydraulic medium in the accumulator 53 is charged. The connection 47 flows into a line 63 that with a first valve surface 65 the switching valve 35 hydraulically connected. A second valve surface 67 the switching valve 35 is over a line 69 permanently with the pressure of the pressure accumulator 53 applied.

From the line 49 branches off at a junction 71 a line 73 from, in turn, in a turnoff 75 The administration 61 and in a turnoff 77 The administration 69 branches. The turnoff 71 is on the switching valve 35 opposite side of the check valve 51 connected to this.

The administration 73 flows into a junction 79 , from the wires 81 . 83 and 85 out.

The administration 81 leads into a subtransmission circle 87 to supply a first sub-transmission. The first partial transmission has a clutch K1. The administration 81 flows into a connection 89 a switching valve 91 , which is designed as a 3/2-way valve, and serves as a safety valve for the clutch K1. In a first, shown switching state of the switching valve 91 is the connection 89 with a connection 93 hydraulically connected while a connection 95 the switching valve 91 is switched blind. In a second, the 1 removable switching state of the switching valve 91 is the connection 93 with the connection 95 and about this with the tank 3 connected while the connection 89 is switched blind. As will become apparent below, the clutch K1 is depressurized in this second switching state.

The connection 93 is with a lead 97 and about this with a connection 99 a pressure control valve 101 connected. The pressure control valve 101 is designed as a 3/2-way proportional valve, which has a connection 103 which has a line 105 is connected to the clutch K1. The pressure control valve 101 also has a connection 107 on that with the tank 3 connected is. In a first extreme state of the pressure regulating valve 101 is the connection 99 with the connection 103 connected while the connection 107 is switched blind. In this case, the full, works in the line 97 prevailing pressure of the hydraulic medium on the clutch K1. In a second extreme state is the connection 103 with the connection 107 connected, so that the clutch K1 is depressurized. By proportional variation between these extremal states regulates the pressure control valve 101 in known manner the pressure prevailing in the clutch K1. From the clutch K1 leads a line 109 via a check valve 111 back to the line 97 , If the pressure in the clutch K1 exceeds the pressure in the line 97 rises, opens the check valve 111 , whereby a hydraulic connection between the clutch K1 over the line 109 with the line 97 is released. From the line 109 branches in a turnoff 113 a line 115 off that the pressure in the clutch K1 as a controlled variable to the pressure control valve 101 returns.

In the line 105 is a turnoff 117 provided by the pressure detecting device 119 hydraulically operatively connected. In this way, the pressure prevailing in the clutch K1 by the pressure detecting device 119 detected.

The switching valve 91 is from a pilot valve 121 driven. This is done by an electric actuator 123 actuated. It is designed as a 3/2-way valve and includes the connections 125 . 127 and 129 , The connection 125 is over a line 131 with one in the line 81 provided branch 133 connected. The connection 127 is over a line 135 with a valve surface 137 the switching valve 91 connected. In a first, shown here switching state of the pilot valve 121 is the connection 125 blinded while connecting 127 with the connection 129 and about this with the tank 3 connected, causing the valve surface 137 the switching valve 91 over the line 135 is depressurized. Preferably, the pilot valve takes 121 this switching state, if no electrical control signal to the actuator 123 is applied. In a second ingestible switching state of the pilot valve 121 is the connection 125 with the connection 127 connected while the connection 129 is switched blind. In this case, the effect in the line 81 prevailing pressure over the branch 133 , The administration 131 and the line 135 on the valve surface 137 the switching valve 91 , whereby this is switched counter to a biasing force in its second switching state, in which the connection 93 with the connection 95 is hydraulically connected, so that the clutch K1 is depressurized. Preferably, therefore, by electrical control of the pilot valve 121 the switching valve 91 be operated so that the clutch K1 is depressurized and thus opened.

The from the branch 79 outgoing line 83 serves to supply a clutch K2 a partial hydraulic circuit 139 a second sub-transmission. The control of the clutch K2 also includes a switching valve 91 ' , a pilot valve 121 ' and a pressure control valve 101 ' , The operation is the same as already described in connection with the first clutch K1. For this reason, the corresponding description of the sub-transmission circuit 87 directed. The hydraulic control of the clutch K2 corresponds to that of the clutch K1.

The from the branch 79 outgoing line 85 is with a pressure control valve 141 connected, over which the pressure of the hydraulic medium in a line 143 is controllable. The operation of the pressure control valve 141 preferably corresponds to the operation of the pressure control valves 101 . 101 ' , so that a re-description is not necessary here. The administration 143 is with a turnoff 145 connected, from the one line 147 and a line 149 out. In the line 149 is a turnoff 151 provided by the one line 153 emanating from those in the line 149 and with it in the line 143 prevailing pressure as a controlled variable to the pressure control valve 141 is returned. It is obvious that the diversion 151 also in the pipes 151 or 147 can be provided.

The administration 147 serves the supply of gear actuator cylinders 155 and 157 in the subtransmission circle 87 , which are designed as two double-acting cylinder, so synchronous cylinder.

For hydraulic control of the gear actuator cylinder 155 is a volume control valve 159 provided, which is designed as a 4/3-way proportional valve. It has four connections 161 . 163 . 165 and 167 on. The first connection 161 is with the line 147 connected, the second connection 163 is with a first chamber 169 the gear actuator cylinder 155 connected, the third connection 165 is with a second chamber 171 the gear actuator cylinder 155 connected and the fourth connection 167 is with the tank 3 connected. In a first extreme state of the volume control valve 159 is the first connection 161 with the second connection 163 connected while the third connection 165 with the fourth connection 167 connected is. In this case, hydraulic fluid from the line 147 in the first chamber 169 the gear actuator cylinder 155 flow while the second chamber 171 over the connections 165 . 167 to the tank 3 is depressurized. In this way, a piston 173 the gear actuator cylinder 155 moved in a first direction, for example, off a particular gear of the dual clutch transmission or engage another specific gear.

In a second extreme state of the volume control valve 159 Both will be the connection 163 as well as the connection 165 with the connection 167 connected, the connection 161 is switched blind. In this way both chambers are 169 . 171 the gear actuator cylinder 155 with the tank 3 connected so that they are depressurized. The piston 173 the gear adjusting cylinder 155 then remains in its current position, because no forces act on him.

In a third extreme state of the volume control valve 159 is the connection 161 with the connection 165 connected and the connection 163 with the connection 167 , In this case, hydraulic fluid flows from the line 147 in the second chamber 171 the gear position cylinder 155 and the first chamber 169 will be over the connection 163 and the connection 167 to the tank 3 switched off depressurized. The hydraulic medium then exerts a force on the piston 173 the gear actuator cylinder 155 such that it is displaced in a direction opposite to the first direction second direction. In this way, the previously mentioned certain other gear off or the mentioned specific gear can be engaged.

As already described, the volume control valve 159 designed as a proportional valve. The one from the line 147 incoming hydraulic fluid flow is by varying the valve states between the three extremal states on the chambers 169 . 171 divided, so that it is possible to specify by controlling the volume flow, a defined speed for the input or Auslegevorgang a gear.

From the line 147 branches in a turnoff 175 a line 177 starting in a volume control valve 179 opens, which the control of the gear actuator cylinder 157 serves. The operation of the hydraulic control of the gear cylinder 157 is the same one related to the gear actuator cylinder 155 has been described. A new description is therefore not necessary.

The administration 149 serves to supply geared cylinders 155 ' and 157 ' of the second partial transmission in the partial transmission circuit 139 , Also for their control are volume control valves 159 ' and 179 ' intended. The sub-transmission circuits 87 and 139 are with respect to the control of the gear actuator cylinder 155 . 155 ' respectively 157 . 157 ' identical, so that reference is made to the preceding description.

The outlet of the pump 9 is with a lead 181 connected to the hydraulic subcircuit 59 leads, which preferably serves in particular the cooling of the clutches K1, K2. The administration 181 leads over a cooler 183 to a volume control valve 185 , Behind the outlet of the pump 9 and in front of the radiator 183 is a turnoff 187 in the pipe 181 provided by the one line 189 Turned off, one over toward the tank 3 opening pressure relief valve 191 to the tank 3 leads. Behind the diversion 187 and in front of the radiator 183 is a turnoff 193 provided in the line 57 opens, that of the switching valve 35 comes and with its connection 43 connected is. About the line 57 is it possible to use the hydraulic circuit 59 with from the pump 7 supplied hydraulic medium when the switching valve 35 is in its second switching state. It also branches off the turn-off 193 a bypass 195 starting, which is a differential pressure valve 197 and to the radiator 183 lies parallel. The differential pressure valve 197 If there is overpressure, it will bypass the bypass valve in the direction of the volume control valve 185 free. That way, the cooler can 183 be bridged.

The volume control valve 185 is designed as a 4/3-way proportional valve, the connections 199 . 201 . 203 . 205 and 207 having. The connection 199 is with the line 181 over the radiator 183 or the Differenzdruckveritil 197 connected, as well as the connection 201 who has a lead 209 and a turnoff 211 with the line 181 connected is. The connections 199 and 201 form so, since they are both with the line 181 downstream of the radiator 183 are connected, a common connection of the volume control valve 185 , Just for clarity, there are two connections 199 . 201 drawn, in fact, however, is only one connection, for example 199 or 201 , for the lead 181 on the volume control valve 185 provided, according to an alternative embodiment, the volume control valve 185 in fact with the two separate connections 199 . 201 can be designed as a 5/3-way proportional valve. For a better understanding, the following statements relate to the illustrated embodiment, wherein it should be noted that it is at the terminals 199 and 201 Actually, this is just a connection, which is switched accordingly. The connection 203 is with a lead 213 connected via a pressure filter 215 to the tank 3 leads. The pressure filter 215 is through a bypass 217 with in the direction of the tank 3 opening differential pressure valve 219 bridged.

The connection 205 of the volume control valve 185 is with a cooling 221 in particular connected to the first clutch K1. The connection 207 is with a second cooling 223 in particular connected for the second clutch K2.

In a first, in the 1 illustrated extreme state of the volume control valve 185 is the connection 201 with the connection 203 connected while the connections 199 . 205 and 207 are switched blind. The whole in the hydraulic line 181 or through the radiator 183 flowing hydraulic fluid flow is thus over the connections 201 . 203 into the pipe 213 and thus over the pressure filter 215 in the tank 3 directed.

In a second extreme state are the connections 199 and 205 connected together while the connections 201 . 203 and 207 are switched blind. In this state, the entire volume control valve 185 incoming hydraulic media stream of the first cooling 221 fed.

In a third extreme state of the volume control valve 185 are the connections 199 and 207 connected with each other. The connections 201 . 203 and 205 are switched blind. In this state, therefore, the entire in the line 181 flowing hydraulic fluid flow of the second cooling 223 fed.

As already stated, the volume control valve 185 designed as a proportional valve, so that intermediate states between the described extremal states can be adjusted, whereby the flow to the cooling 221 . 223 or to the pressure filter 215 is controllable. It is also possible the volume control valve 185 operated in a timed manner, wherein in each case at least one of the three extremal states is assumed for a short time. Also in this mode, the volume flow is controlled or regulated in the time average, the cooling 221 . 223 or the pressure filter 215 and with it the tank 3 is forwarded.

The 1 shows that in addition to being in the line 181 existing hydraulic medium flow a hydraulic medium flow of the line 57 and the hydraulic circuit 59 can be supplied. Alternatively, it is also possible that only the line 57 Feeds hydraulic medium. It should also be mentioned that the proportional valves 101 . 101 ' . 141 . 159 . 159 ' . 179 . 179 ' . 185 in each case in particular are electrically proportionally adjustable against spring force.

The operation of the invention will be explained in more detail below. It is assumed that by means of the gear actuator cylinder 155 (Gangsteller) a gear at the dual-clutch transmission to be inserted. In the from the 1 resulting position of the pressure control valve 141 becomes the gear actuator cylinder 155 not supplied with hydraulic medium. By means of electromagnetic control is therefore the piston of the pressure control valve 141 shifted, so that the pressure of the hydraulic medium in the accumulator 53 on the line 143 and from there via the line 147 to the volume control valve 159 is switched. The volume control valve 159 forms a first volume control valve 159 , wherein the associated gear actuator cylinder 155 belongs to a first gear shifter. By electromagnetic control of the volume control valve 159 can be the piston shift against a restoring force (spring), such that the piston 173 the gear actuator cylinder 155 is moved to the desired position. In this position, a gear of the dual-clutch transmission is engaged. Once this is done, both pressure control valve 141 as well as volume control valve 159 de-energized switched. The piston 173 retains its position, ie the selected gear remains engaged.

Below will be discussed on an actuation of the clutch K1, the part of the gear train 87 is controlled. The hydraulic medium pressure in the accumulator 53 lies over the wires 49 . 73 and 81 at the switching valve 91 and is used by this in the from the 1 resulting position the pressure control valve 101 fed. In this situation, the pilot valve 121 not electrically energized. Due to a biasing element (spring), this has the from the 1 prominent position so that the line 131 is interrupted and the pressure of the pressure accumulator 53 not over the pilot valve 121 and the line 135 on the piston of the switching valve 91 can work. Depending on the electrical control of the pressure control valve 101 the clutch is engaged or opened. In the 1 the unpressurized state is shown, so an open clutch. Will it with the pressure of the hydraulic medium of the pressure accumulator 153 is applied, it goes into the engaged state. From all this it becomes clear that only the pressure control valve 101 must be energized, but no energization of the pilot valve 121 , the pressure regulating valve 141 or the volume control valve 159 must be present in order to take the gear engaged.

It should be mentioned that the accumulator 53 as in the claims mentioned hydraulic medium source 224 is to be considered. Furthermore, the gear actuator cylinder belongs 157 a second gear actuator, wherein the volume control valve 179 forms a second volume control valve. The pressure control valve 141 forms a first pressure control valve, the pressure control valve 101 a second pressure regulating valve and the pressure regulating valve 101 ' a third pressure control valve. The switching valve 91 forms a first switching valve and the switching valve 91 ' a second switching valve. The pilot valve 121 forms a first pilot valve and the pilot valve 121 ' a second pilot valve. The volume control valve 159 ' forms a third volume control valve and the volume control valve 179 ' a fourth volume control valve 179 ' , The volume control valve 159 ' assigned gear actuator cylinder 155 ' belongs to a third gear actuator and the volume control valve 179 ' assigned gear actuator cylinder 157 ' belongs to a fourth gear plate.

Due to the invention, it is possible, while driving a motor vehicle having the dual-clutch transmission according to the invention, to carry out the electrical energization only with a single valve when engaged, so that only a very low energy consumption is present. It is also important that only a single pressure control valve 141 for all the gear actuator pistons 155 . 155 ' . 157 . 157 ' is provided. When the gears are engaged, the pressure on the gear regulators can be minimized, whereby a leakage to a minimum decreases, since only the upstream valve (pressure control valve 141 ) is pressurized. Consequently, there is a common pressure regulator for the gear plate, regardless of pressure regulators for the clutches. The invention Hydraulic concept is therefore optimized for maximum energy efficiency and there are leakage-optimized valves through the arrangement. The leakage optimization results from the fact that as few valves are pressurized, this applies to different operating conditions. There is a high availability due to separate pressure control valves for the clutches. With regard to the sub-transmission circuits, there is an independent pressure control for the clutch and gear actuator operation. Since only one valve is electrically energized, the other valves are de-energized. Preferably, the gear plates are designed such that they or their respective gear actuator piston is latched, in particular latched in non-energization of the corresponding valve. This ensures that when the valve is not energized the corresponding gear actuator does not change its position and thus the engaged gear.

As already stated above, the line flows 57 in the hydraulic circuit 59 , more specifically in the line 181 downstream of the pump 9 , According to an alternative, not shown embodiment, the line opens 57 into the pipe 181 preferably downstream of the radiator 183 , By supplying the hydraulic medium from the high pressure circuit in the hydraulic circuit 59 According to the alternative embodiment, the total volume flow through the radiator 183 reduced. Due to the reduced volume flow, the pressure drop across the radiator 183 reduces, thereby providing the necessary drive energy for the pumps 7 and or 9 is reduced. By reducing the back pressure, that is for the electric motor 5 required drive energy reduced. With a sufficiently high reduction of the back pressure or the pressure level - regardless of how the reduction is achieved - is provided according to a further embodiment, the pump 9 with the electric motor 5 directly to connect, the disconnect clutch shown 11 So to remove.

According to a further, not shown embodiment with respect to the arrangement of the pressure filter 215 is provided that this is not between volume control valve 185 and tank 3 in the pipe 213 but preferably in the line 181 , especially between the radiator 183 and the volume control valve 185 , is arranged. Preferably, the line opens 57 downstream of the pressure filter 215 into the pipe 181 , Due to the alternative arrangement of the pressure filter 215 , which is now in the main flow of the hydraulic medium, the time intervals are increased, within which the hydraulic medium through the pressure filter 215 is filtered. The bypass valve 219 is preferably designed for a minimal back pressure on the flow.

Alternatively to the illustrated and described embodiment of the volume control valve 185 is provided according to a further embodiment that the switching positions are preferably reversed such that in the first extreme state, the terminals 199 and or 201 with the connection 205 or 207 connected and the other connections of the volume control valve 185 are switched blind, in the second extreme state, the connections 201 and or 199 with the connection 203 connected and the other terminals are switched blind, and in the third extreme state, the connections 199 and or 201 with the connection 207 or 205 connected and the other connections are switched blind. By such a swapping of the switching positions is avoided that in a clocked driving the volume control valve 185 for adjusting a desired hydraulic medium flow for one of the clutches K1 or K2, a volumetric flow also flows to the other clutch K2 or K1. Instead, when the clocked, not to the respective clutch K1 or K2 guided flow into the tank 3 directed. In the actual design of the volume control valve 185 as 4/3-way proportional valve are the connections 199 and 201 always as joint or single connection of the line 181 on the volume control valve 185 to understand, so that in fact only one of the two connections 199 . 201 on the volume control valve 185 is provided.

LIST OF REFERENCE NUMBERS

1

hydraulic circuit

3

tank

5

electric motor

7

first pump

9

second pump

11

separating element

13

management

15

management

17

Tee

19

management

21

Suction

23

management

25

diversion

27

Pressure relief valve

29

management

31

pressure filters

33

connection

35

switching valve

37

bypass

39

Differential pressure valve

41

connection

43

connection

45

connection

47

connection

49

management

51

check valve

53

accumulator

55

Pressure sensing device

57

management

59

Hydraulic pitch

61

management

63

management

65

valve surface

67

valve surface

69

management

71

diversion

73

management

75

diversion

77

diversion

79

diversion

81

management

83

management

85

management

87

Sub-transmission loop

89

connection

91

switching valve

91 '

switching valve

93

connection

95

connection

97

management

99

connection

101

Pressure control valve

101 '

Pressure control valve

103

connection

105

management

107

connection

109

management

111

check valve

113

diversion

115

management

117

diversion

119

Pressure sensing device

121

pilot valve

121 '

pilot valve

123

electric control

125

connection

127

connection

129

connection

131

management

133

diversion

135

management

137

valve surface

139

Sub-transmission loop

141

Pressure control valve

143

management

115

diversion

147

management

149

management

151

diversion

153

management

155

Gear actuator cylinder

155 '

Gear actuator cylinder

157

Gear actuator cylinder

157 '

Gear actuator cylinder

159

Volume control valve

159 '

Volume control valve

161

connection

163

connection

165

connection

167

connection

169

chamber

171

chamber

173

piston

175

diversion

177

management

179

Volume control valve

179 '

Volume control valve

181

management

183

cooler

185

Volume control valve

187

diversion

189

management

191

Pressure relief valve

193

diversion

195

bypass

197

Differential pressure valve

199

connection

201

connection

203

connection

205

connection

207

connection

209

management

211

diversion

213

management

215

pressure filters

217

bypass

219

Differential pressure valve

221

cooling

223

cooling

224

Hydraulic fluid source

K1

clutch

K2

clutch

Claims (8)

Clutch transmission, in particular dual-clutch transmission, with a hydraulic actuation system for actuating at least one hydraulic gear actuator ( 155 . 155 ' . 157 . 157 ' ) and with at least one hydraulic clutch (K1, K2), comprising: - a hydraulic medium source supplying pressurized hydraulic medium ( 224 ), - at least one electrically controllable, hydraulic Volume control valve ( 159 . 159 ' . 179 . 179 ' ) for controlling the gear selector ( 155 . 155 ' . 157 . 157 ' ), - at least one electrically controllable, hydraulic first pressure regulating valve ( 141 ) for selectively connecting the volume control valve ( 159 . 159 ' . 179 . 179 ' ) to the hydraulic medium source ( 224 ), - at least one electrically controllable, hydraulic second pressure regulating valve ( 101 . 101 ' ) for selectively connecting the coupling (K1, K2) to the hydraulic medium source ( 224 ), - according to which of the gear plate ( 155 . 155 ' . 157 . 157 ' ) inserting a passage the volume control valve ( 159 . 159 ' . 179 . 179 ' ) and the first pressure regulating valve ( 141 ) are electrically de-energized and for holding the clutch (K1, K2) brought about by being acted upon with hydraulic medium, engaged state, only the second pressure control valve ( 101 . 101 ' ) is electrically energized. Clutch transmission according to claim 1, characterized by at least one hydraulic switching valve ( 91 . 91 ' ) for selectively connecting the second pressure regulating valve ( 101 . 101 ' ) to the hydraulic medium source ( 224 ). Clutch transmission according to one of the preceding claims, characterized in that the switching valve ( 91 . 91 ' ) as a hydraulically controllable switching valve ( 91 . 91 ' ) is trained. Clutch transmission according to one of the preceding claims, characterized by at least one electrically controllable, hydraulic pilot valve ( 121 . 121 ' ) for selectively connecting the hydraulic control of the switching valve ( 91 . 91 ' ) to the hydraulic medium source ( 224 ). Clutch transmission according to one of the preceding claims, characterized in that for holding the clutch (K1, K2) in the engaged state, the pilot valve ( 121 . 121 ' ) is electrically de-energized, so that the switching valve ( 91 . 91 ' ) the second pressure control valve ( 101 . 101 ' ) to the hydraulic medium source ( 224 ). Clutch transmission according to one of the preceding claims, characterized in that the volume control valve ( 159 ) a first volume control valve ( 159 ) and that a first volume control valve ( 159 ) having the first subtransmission circuit ( 87 ) of the actuating system a second volume control valve ( 179 ) for controlling a second gear actuator ( 157 ), which also via the first pressure control valve ( 141 ) selectively to the hydraulic medium source ( 224 ) connected. Clutch transmission according to one of the preceding claims, characterized in that the actuating system comprises a second sub-transmission gear ( 139 ), the at least one third volume control valve ( 159 ' ) for controlling a third gear actuator ( 155 ' ) and a third pressure control valve ( 101 ' ) for a further clutch (K2). Clutch transmission according to one of the preceding claims, characterized in that the second sub-transmission gear ( 139 ) a fourth volume control valve ( 179 ' ) for controlling a fourth gear actuator ( 157 ' ) and another switching valve ( 91 ' ) and another pilot valve ( 121 ' ) having.

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