DE102017209648A1 - Gear arrangement with integrated four-wheel clutch and process for demand-based oil supply of the integrated four-wheel clutch - Google Patents

Abstract

It is a transmission arrangement for a vehicle with a hydraulic oil supply circuit a controlling transmission control and at least one oil supply pump in a transmission housing (1) and with a in the transmission housing (1) integrated four-wheel clutch (2) proposed, the four-wheel clutch (2) for situational driving and is connected to demand cooling with the oil supply circuit. Further, a method for demand-based oil supply in a transmission housing (1) integrated four-wheel clutch (2) is proposed, with activated four-wheel clutch (2) to realize a four-wheel drive an existing oil flow through an existing electric auxiliary pump (4) or by a combustion engine and electrically driven Oil pump is increased.

Description

The present invention relates to a transmission arrangement for a vehicle with an integrated in the transmission housing four-wheel clutch and a method for demand-based oil supply of the integrated four-wheel clutch according to the closer defined in the preamble of claim 1 and 9, respectively.

For example, from the document DE 10 2006 043 048 A1 a drive arrangement for all-wheel drive motor vehicles is known, in which one of a drive motor via the motor vehicle transmission permanently driven first axis and a coupling selectively engageable via a second axis is provided, wherein the four-wheel clutch is arranged in the transmission housing on the output shaft of the motor vehicle transmission.

Usually, such gear arrangements have an at least internal combustion engine driven, mechanical main oil pump, which generates the necessary oil delivery volume for the oil supply circuit of the gear assembly in normal operation, so when the internal combustion engine. When the internal combustion engine is switched off during vehicle operation, for example when the sail function is activated, an electrically driven auxiliary oil pump takes over the oil supply for the oil supply circuit. However, it has been shown that, for example, with activated four-wheel drive to realize the all-wheel drive in the vehicle, especially in highly dynamic four-wheel drive, the oil temperature within the four-wheel drive increases undesirably. To avoid overheating and failure of the four-wheel clutch, it is therefore provided that the four-wheel clutch is opened or deactivated to end the all-wheel drive. As a result, no off-road use with the vehicle is possible thereafter.

The present invention is based on the object to propose a gear arrangement and a method of the type described above, with which a needs-based oil supply of the all-wheel drive and the most unrestricted all-wheel drive can be realized.

This object is achieved by the features of claim 1 and 9, respectively, resulting from the respective dependent claims and the description and the drawings advantageous claimed developments.

Thus, a transmission assembly for a vehicle having a hydraulic transmission control controlling an oil supply circuit and at least one oil supply pump in a transmission case and having an all-wheel clutch integrated with the transmission case to realize four-wheel drive in the vehicle is proposed. In order to be able to realize a demand-based oil supply and the most unrestricted four-wheel drive in the transmission arrangement, it is provided that the four-wheel clutch is connected for situational control and demand-based cooling with the oil supply circuit in the transmission housing.

In this way, a gear assembly with integrated four-wheel clutch instead of a center differential with additional function by using the oil supply pump in four-wheel operation is proposed, which can be actuated situational on the existing transmission control or transmission hydraulics, with an existing oil supply circuit used for appropriate cooling of the four-wheel drive and controlled accordingly , Thus, a common use of the existing Getriebemechatronik also for controlling or driving and cooling of the integrated four-wheel clutch can be realized. Thus, undesirable temperature problems in the integrated four-wheel clutch can be avoided virtually without additional transmission components. By eliminating separate control devices, housing parts, pumps and other components not only a cost reduction, but also a weight optimization in the transmission assembly according to the invention can be realized. The common transmission control both for the existing shift elements and additionally for the integrated four-wheel clutch as well as the intelligent control of the integrated oil supply pump enables an ideal networking of the various functions.

In the proposed transmission arrangement, the oil supply circuit comprises as an existing oil supply pump at least one internal combustion engine driven transmission main oil pump and at least one electrically driven auxiliary oil pump. As an oil supply pump, only one oil pump can be provided, which, however, has a combined drive, namely an internal combustion engine drive and additionally an electric drive. For demand-based cooling, the four-wheel clutch is connected directly or indirectly with the electrically driven auxiliary oil pump or with the internal combustion engine and electrically driven oil pump. This results in an advantageous additional function for the existing additional electric oil pump or for the existing combined with respect to their drive oil pump for the integrated four-wheel drive.

In order to realize a control but also an on-demand cooling of the four-wheel clutch in the common transmission housing of the proposed transmission arrangement, on the one hand, a connection of the existing Oil supply circuit provided via an additional supply line or the like with the cooling circuit of the four-wheel clutch and on the other a connection of the circuit via a second additional supply line or the like for driving the all-wheel drive.

A preferred application of the proposed transmission arrangement is in an automatic 8-speed stage transmission, since in this transmission by an integrated four-wheel clutch, the existing oil supply pump can be additionally and intelligently used for cooling the clutch plates during the four-wheel drive. This results in a significantly higher system or all-wheel availability and additional advantages in terms of weight, interfaces and higher added value compared to conventional transmission arrangements.

The object underlying the invention is also achieved by a method for demand-based supply of oil in the transmission housing integrated four-wheel clutch by activated with all-wheel clutch to realize an all-wheel drive an existing oil delivery volume of the existing electric auxiliary pump or the existing combined oil pump or controlled accordingly.

This can be achieved according to the invention, for example, by controlling the delivery volume of the electric auxiliary pump or the oil pump combined with respect to its drive in four-wheel drive as a function of a predetermined heat model on the four-wheel drive or as a function of a calculated differential speed on the four-wheel drive. In this way, a quasi-continuous regulation of the delivery volume of the additional electric oil pump or the combined oil pump is made possible.

Another possibility of the control can be realized that operating points are identified when recognized all-wheel drive, which predetermined power requirements of the auxiliary oil pump or the combined oil pump are assigned. For example, at a first operating point, which corresponds to a light all-wheel drive, a small oil flow volume can be generated by the electric auxiliary oil pump or the combined oil pump, while detected middle four-wheel drive as the second operating point, a mean flow volume is generated by the electric auxiliary pump or the combined oil pump and the in known high-dynamic four-wheel drive as the third operating point, a maximum delivery volume is generated by the electric auxiliary pump or the combined oil pump. In this way, a stepped oil supply is realized.

The principle of intelligent transmission oil pump use in addition to the use in sailing operating points, start-stop operating points or the like to use for all-wheel drive can thus also be transferred to combined gear oil pump systems consisting of mechanical and electrical drive for a shared pump. In this case, the electric drive of the pump could additionally be used for the abovementioned cooling properties in the four-wheel operating states. The pure electric drive of the pump is thus used for the start-stop conditions, sailing conditions or the like when the internal combustion engine, while the purely mechanical drive of the pump with running internal combustion engine for the basic supply of the transmission (clutch pressures, lubrication of the transmission) in normal driving without Four-wheel drive is used. The electric and mechanical drive of the combined pump could then be used as operating point with maximum delivery volume (boost function) for the basic supply of the transmission and the additional cooling of the four-wheel clutch for the hard four-wheel drive for permanent availability of the all-wheel function. This results in the same advantages as in the already described and subsequently described embodiment with a two-pump concept.

• 1 ein schematischer Getriebegehäuseschnitt einer möglichen Ausführungsvariante einer erfindungsgemäßen Getriebeanordnung mit integrierter Allradkupplung;
• 2 ein schematischer hydraulischer Schaltplan eines Ölversorgungskreislaufes der Getriebeanordnung im angesteuerten Zustand der Allradkupplung;
• 3 ein schematischer hydraulischer Schaltplan des Ölversorgungskreislaufes der Getriebeanordnung im nicht angesteuerten Zustand der Allradkupplung;
• 4 ein schematischer hydraulischer Schaltplan des Ölversorgungskreislaufes der Getriebeanordnung im angesteuerten Zustand der Allradkupplung mit einem regelbaren Druckregelventil;
• 5 ein Diagramm mit verschiedenen Fahrzuständen des Fahrzeuges;
• 6 ein Diagramm mit einem Temperaturverlauf in der Allradkupplung beim stufenlosen Ansteuern der Zusatzölpumpe;
• 7 ein Diagramm mit unterschiedlichen Betriebspunkten des Allradbetriebes zum nicht stufenlosen Ansteuern der Zusatzölpumpe;
• 8 ein Ablaufdiagramm eines erfindungsgemäßen Verfahrens zur bedarfsgerechten Ölversorgung einer in einem Getriebegehäuse integrierten Allradkupplung durch die Zusatzölpumpe; und
• 9 Ablaufdiagramme des erfindungsgemäßen Verfahrens zum nicht stufenlosen Ansteuern der Zusatzölpumpe.

Hereinafter, the present invention will be further explained with reference to the drawings. Show it:

• 1 a schematic Getriebegehäuseschnitt a possible embodiment of a transmission arrangement according to the invention with integrated four-wheel clutch;
• 2 a schematic hydraulic circuit diagram of an oil supply circuit of the transmission assembly in the activated state of the four-wheel clutch;
• 3 a schematic hydraulic circuit diagram of the oil supply circuit of the transmission assembly in the non-activated state of the four-wheel clutch;
• 4 a schematic hydraulic circuit diagram of the oil supply circuit of the transmission assembly in the activated state of the four-wheel clutch with a controllable pressure control valve;
• 5 a diagram with different driving conditions of the vehicle;
• 6 a diagram with a temperature profile in the four-wheel clutch for stepless activation of the auxiliary oil pump;
• 7 a diagram with different operating points of the all-wheel drive for not steplessly controlling the auxiliary oil pump;
• 8th a flow diagram of a method according to the invention for demand-based oil supply integrated in a transmission housing four-wheel clutch by the auxiliary oil pump; and
• 9 Flowcharts of the method according to the invention for not steplessly controlling the additional oil pump.

In 1 is a gearbox 1 a gear assembly according to the invention shown as an example cut. In addition to the usual transmission elements is also an all-wheel drive 2 provided, which in the transmission housing 1 is integrated. Further, an oil supply circuit is provided, which is a not shown in detail engine-driven main oil pump 3 and an electrically driven auxiliary oil pump 4 for oil supply. As already described in detail, the supply circuit can be used instead of the main oil pump 3 and the electrically driven auxiliary oil pump 4 also a combined oil pump with z. B. have two separate drives, namely an internal combustion engine drive and an electric drive. However, the further description of the invention is limited to the two-pump system, since when using the combined oil pump, the additional delivery volume for all-wheel drive is ensured by the electric drive of the oil pump and thus applies accordingly.

On the description of the other in 1 shown transmission elements is omitted, since these are known in the art.

In known gear arrangement, the additional oil pump 4 or the electric drive of the combined oil pump used to provide sufficient oil when the main oil pump 3 or the mechanical drive of the oil pump is no longer able to due to their operating condition. According to the invention it is now provided that the additional oil pump 4 or the electric drive of the oil pump is also used in relevant conditions in all-wheel drive, the four-wheel clutch 2 to cool and to control, for which purpose the existing oil supply circuit is also used with the transmission control provided.

In the 2 to 4 are shown various control options based on a hydraulic circuit diagram of the oil supply circuit of the transmission assembly according to the invention. The oil supply circuit has been modified so that the four-wheel clutch 2 is connected to the situational control and on-demand cooling with the oil supply circuit. This is the four-wheel clutch 2 directly or indirectly with the electrically driven additional oil pump 4 connected. For example, the oil supply circuit via a first additional supply line 5 . 5A with the cooling circuit 6 the four-wheel clutch 2 connected. Furthermore, the oil supply circuit via a second additional supply line 7 for driving the four-wheel clutch 2 via a control pressure control valve 8th with the four-wheel drive 2 connected.

A possible activation of the additional oil pump 4 is in the 2 and 3 shown at the additional oil pump 4 about one 3 - 2 -way valve 9 with the first additional supply line 5 for oil supply of the cooling circuit 6 the four-wheel clutch 2 connected is. In 2 is the controlled state of the additional oil pump 4 and in 3 the uncontrolled state is shown.

In 4 is a controllable or continuous control of the additional oil pump 4 shown at the first additional supply line 5A for stepless control of the cooling flow via a cooling oil pressure control valve 10 with the cooling circuit 6 the four-wheel clutch 2 connected is.

For controlling the four-wheel clutch 2 is the second additional supply lines 7 with a system pressure valve controlled by the transmission control 11 the transmission control connected to the system pressure supply. In addition to the existing in the oil supply circuit system pressure valve 11 are also a system pressure retention valve 12 and a system pressure relief valve 13 usually available.

In 5 are different operating states of the vehicle based on the times t1 to t5 shown. Current gear arrangements have the main oil pump 3 for the internal combustion engine operation of the vehicle and the additional electric oil pump 4 for operation when the internal combustion engine is switched off. In this concept, the additional electric oil pump 4 in use only to a very limited extent, for example during a start-stop phase (eg at the traffic light at the time t3 or during the sailing operation at the time t2 ), in which the vehicle is rolled out without an internal combustion engine or still rolling. Consequently, in 5 the operation or the additional oil pump until the time t5 without four-wheel drive shown according to known specification. The IEP bit control signal designates the switching state of the auxiliary oil pump 4 , in which " 0 "The state" not driven "and" 1 "The state" driven ".

According to the unused availability of the electric auxiliary oil pump in four-wheel drive 4 combined, so the all-wheel drive from the time t5 through the use of the additional oil pump 4 can be significantly improved. As a result, shows 5 from the time t5 the operation of the additional oil pump 4 according to the present invention. Specifically, in the diagrams, the vehicle speed v_Fahrzeug , the accelerator pedal position DKI , the engine speed n_mot , Engine Idle Speed, Engine Off, Sail Bit, and Extra Oil Pump Bit (IEP bit) over time axis t.

In 6 is a diagram with the temperature profile in the integrated four-wheel clutch 2 in four-wheel drive over the times t6 to t8 shown. From the moment t5 is driven in four-wheel drive. According to the invention is now dependent on the situation, the previously unused additional electric oil pump 4 switched on and increases the amount of cooling oil to the highly loaded four-wheel clutch 2 is encouraged. In the diagrams according to 6 It can be seen that through the targeted use of the additional electric oil pump 4 depending on a determined differential speed at the time t7 or depending on a stored temperature model at the time t8 the temperature in the starting clutch 2 can be regulated. Without additional cooling in the form of the additional electric oil pump 4 For example, at a very early stage, it would have to be less than the same time t7 the all-wheel drive are disabled. This is advantageously prevented in the gear arrangement proposed by the invention or by the method according to the invention.

In 6 shown over the time t are the differential speed Δn_iHOC the starting clutch 2 , the heat quantity calculated by a heat model Q_ heat model in the starting clutch 2 as well as from the differential speed Δn_iHOC resulting amount of heat Q -Differenzdrehzahl. Thus, the activation of the additional oil pump takes place 4 either as a function of a heat model stored in the transmission control or as a function of the calculated differential speed at the starting clutch 2 ,

This means in the method according to the invention, that the oil delivery volume of the electric auxiliary pump 4 in four-wheel drive depending on a predetermined heat model on the four-wheel drive 2 or is controlled as a function of a calculated differential speed at the four-wheel clutch.

In 7 is a diagram with different operating points I to III the all-wheel drive shown. It follows that, depending on the respective operating point I . II . III In four-wheel drive, a variable control of the electric auxiliary oil pump 4 is advantageous. So is at light terrain at the time t10 the first operating point I the additional electric oil pump 4 defined, which is associated with a low power consumption and thus only a small cooling effect. Furthermore, in hard terrain use at the time t11 the second operating point II the additional electric oil pump 4 defined, which is associated with an average power consumption and thus a mean cooling effect. At a time t12 in a highly dynamic four-wheel drive, z. B. on a racetrack or the like, the third operating point III the additional oil pump 4 defined, the maximum power consumption in the additional oil pump 4 to achieve maximum cooling effect on the starting clutch 2 assigned.

In the method according to the invention, this constitutes a variant in which, when light-duty four-wheel drive operation is recognized, the first operating point I a small oil delivery volume through the electric auxiliary pump 4 is generated that when detected middle four-wheel drive as the second operating point II a mean oil delivery volume through the electric auxiliary pump 4 is generated and that when detected highly dynamic four-wheel drive as the third operating point III a maximum oil delivery volume through the electric auxiliary pump 4 is produced.

In 8th is a flowchart according to the appropriate method in a four-wheel drive transmission with integrated four-wheel clutch 2 with additional cooling via the electrical transmission highlights or additional oil pump 4 described in order to realize an off-road use without restrictions.

In 9 are flowcharts for normal driving so without four-wheel drive, for easy off-road operation according to the first operating point I , for hard terrain operation according to the second operating point II and for the highly dynamic operation according to the third operating point III shown.

LIST OF REFERENCE NUMBERS

1

gearbox

2

All-wheel coupling

3

Main oil pump

4

Additional oil pump or IEP

5.5A

first additional supply line

6

Cooling circuit of the four-wheel clutch

7

second additional supply line

8th

Ansteuerdruckregelventil

9

3-2-way valve

10

Cooling oil pressure control valve

11

System pressure valve

I

first operating point in all-wheel drive

II

second operating point in four-wheel drive

III

third operating point in four-wheel operation

v_Fahrzeug

vehicle speed

DKI

Accelerator pedal position

n_mot

Engine speed

Δn_iHOC

Differential speed of the four-wheel clutch

Q

Amount of heat in the four-wheel clutch

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006043048 A1 [0002]

Claims (11)

Transmission arrangement for a vehicle, with a hydraulic oil supply circuit controlling a transmission control and at least one oil supply pump in a transmission housing (1) and with one in the transmission housing (1) integrated four-wheel clutch (2), characterized in that the four-wheel clutch (2) for situational driving and is connected to demand-based cooling with the existing oil supply circuit. Gear arrangement according to Claim 1 , characterized in that the oil supply circuit as an oil supply pump at least one internal combustion engine driven main oil pump (3) and at least one electrically driven auxiliary oil pump (4), wherein the four-wheel clutch (2) for demand-based cooling directly or indirectly with the electrically driven auxiliary oil pump (4) is connected , Gear arrangement according to Claim 1 , characterized in that the oil supply circuit as an oil supply pump comprises an internal combustion engine and electrically driven oil pump, wherein the four-wheel clutch (2) is connected to the demand-based cooling directly or indirectly with the oil pump. Transmission arrangement according to one of the preceding claims, characterized in that the oil supply circuit via a first additional supply line (5, 5A) to the cooling circuit (6) of the four-wheel clutch (2) is connected and that the oil supply circuit via a second additional supply line (7) for driving the four-wheel clutch (2) via a control pressure control valve (8) with the four-wheel clutch (2) is connected. Gear arrangement according to Claim 4 , characterized in that the auxiliary oil pump (4) via a 3-2-way valve (9) with the first additional supply line (5) for cooling the all-wheel clutch (2) is connected. Gear arrangement according to Claim 4 , characterized in that the first additional supply line (5A) for continuously controlling the cooling oil flow (6) via a cooling oil pressure control valve (10) to the cooling circuit (6) of the four-wheel clutch (2) is connected. Gear arrangement according to one of Claims 4 to 6 , characterized in that the second additional supply line (7) for driving the all-wheel clutch (2) is connected to a system pressure valve (11) controlled by the transmission control for system pressure supply. Gear arrangement according to one of the preceding claims, characterized in that the transmission is provided as an automatic eight-step transmission A method for demand-based oil supply in a transmission housing (1) integrated four-wheel clutch (2), characterized in that when activated four-wheel clutch (2) for realizing an all-wheel drive an existing oil delivery volume by an existing electric auxiliary pump (4) or by an internal combustion engine and electrically driven oil pump is increased. Method according to Claim 9 , characterized in that the oil delivery volume of the electric auxiliary pump (4) or the internal combustion engine and electrically driven oil pump in four-wheel drive in response to a predetermined heat model on the all-wheel clutch (2) or in response to a calculated differential speed at the four-wheel clutch (2) is driven. Method according to Claim 9 , characterized in that when detected light all-wheel drive as the first operating point (I) a small oil flow volume by the electric auxiliary pump (4) or by the internal combustion engine and electrically driven oil pump is generated that when detected average all-wheel drive as the second operating point (II), a mean oil delivery volume is generated by the electric auxiliary pump (4) or by the internal combustion engine and electrically driven oil pump and that when detected highly dynamic all-wheel drive as the third operating point (III) a maximum oil volume is generated by the electric auxiliary pump (4) or by the internal combustion engine and electrically driven oil pump.

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