WO2020011832A1

WO2020011832A1 - Electrical circuit for a hybrid drive module of a motor vehicle drive train, and method for operating a motor vehicle drive train

Info

Publication number: WO2020011832A1
Application number: PCT/EP2019/068497
Authority: WO
Inventors: Markus Henneken
Original assignee: Zf Friedrichshafen Ag
Priority date: 2018-07-13
Filing date: 2019-07-10
Publication date: 2020-01-16
Also published as: DE102018211745A1

Abstract

The invention relates to an electrical circuit (EE) for a hybrid drive module (HY) of a motor vehicle drive train. The motor vehicle drive train comprises an internal combustion engine (VM), an electrical machine (EM), a disconnect clutch (K0) connected between the internal combustion engine (VM) and the electrical machine (EM), and a transmission (G) having a plurality of shifting elements (KG). The circuit (EE) is designed to supply electromagnetic and/or electromechanical actuators for actuating the shifting elements (KG) and the disconnect clutch (K0). The circuit (EE) has a first current circuit (EE1) for supplying the actuators associated with the shifting elements (KG) and a second current circuit (EE2) for supplying the actuator associated with the disconnect clutch (K0). The invention further relates to a control unit (ECU), to a hybrid drive module (HY), and to a method for operating a motor vehicle drive train.

Description

Electrical circuit for a hybrid drive module of a motor vehicle

Drivetrain and method for operating a motor vehicle drivetrain

The invention relates to an electrical circuit for a hybrid drive module of a motor vehicle drive train. The invention further relates to a control device for such a hybrid drive module, a hybrid drive module with such a control device and a method for operating a motor vehicle drive train.

Patent application DE 10 2008 000 046 A1 describes a method for operating a drive train of a motor vehicle, the drive train having at least one hybrid drive with an internal combustion engine and an electric motor, a transmission arranged between the hybrid drive and an output, and a transmission between the Combustion engine and clutch arranged electric motor. If a fault occurs in the drive train, particularly on a transmission control device of the transmission, an emergency gear is engaged in the transmission. If the motor vehicle decelerates to a standstill, the clutch arranged between the internal combustion engine and the electric motor is opened in order to prevent the internal combustion engine from stalling.

However, this presupposes that the clutch can still be actuated in the event of a fault in the transmission control device. However, if the malfunction in the transmission control device directly affects the actuation of the clutch, the method cannot be carried out. If the malfunction in the transmission control device concerns the actuation of switching elements of the transmission, it may be necessary to initiate a safe, de-energized state of the transmission depending on the malfunction. This can also affect the actuation of the clutch.

It is therefore an object of the invention to improve the functional scope of the motor vehicle drive train that is available in the event of a fault.

The object is achieved by the features of patent claim 1. Advantageous refinements result from the subclaims, the description and the figures. To achieve the object, an electrical circuit for a hybrid drive module of a motor vehicle drive train is proposed. The motor vehicle drive train has an internal combustion engine, an electrical machine, a separating clutch connected between the internal combustion engine and the electrical machine, and a transmission. The hybrid drive module can be formed by the transmission itself, which houses the electrical machine and the disconnect clutch. Alternatively, the hybrid drive module can be formed by a unit that is independent of the transmission and that houses the electrical machine and the disconnect clutch. Such a structural unit is connected to the transmission on the one hand and to the internal combustion engine on the other hand via suitably designed interfaces. The electrical circuit can be part of an electronic control device, which is preferably assigned to the hybrid drive module and is set up to control functions of the hybrid drive module.

The transmission has a transmission mechanism and several shifting elements. By selective actuation, ie by selective opening and closing of these shifting elements, different load paths of the transmission mechanism can be selected between an input shaft and an output shaft of the transmission, whereby different gear stages of the transmission can be represented. The electrical circuit is provided to supply electromagnetic and / or electromechanical actuators, which is used to actuate the switching elements and the disconnect clutch. These actuators can be formed, for example, by electromagnetically actuated hydraulic valves, by means of which a pressure for the hydraulic actuation of the switching elements or the separating clutch can be set. Alternatively, the disconnect clutch and / or at least some of the switching elements can be actuated directly by means of electromechanical actuators, for example by means of a spindle drive or a ramp drive.

The electrical circuit has a first circuit which is set up to supply power to those actuators which are assigned to the switching elements of the transmission. The circuit has a second circuit, which for Power supply is set up to that actuator which is assigned to the disconnect clutch.

Such a circuit can significantly improve the availability of the motor vehicle drive train in the event of a fault. If there is a fault in the control of the shift elements of the transmission, which requires the switching element actuator system to be in a safe, de-energized state, only the first circuit is affected by such a fault. The disconnect clutch can thus continue to be actuated, so that the internal combustion engine can be coupled to or disconnected from the drive train as required. If an existing gear remains engaged in the transmission when the switching element actuator system is de-energized, or if an emergency gear is automatically engaged by the hydraulics, for example, the motor vehicle can continue to be operated at least in a restricted manner. If there is a fault in the control of the disconnect clutch, which requires that the disconnect clutch actuator is in a safe, de-energized state, only the second circuit is affected by such an error. The control of the switching element actuator system of the transmission is not affected by this. In this case, the separating clutch preferably assumes the opened state, so that the motor vehicle can thus be driven further using the electrical machine.

The first circuit preferably has a first device for the switchable interruption of an energy supply of the first circuit, and the second circuit has a second device for the switchable interruption of an energy supply of the second circuit. The energy supply is formed, for example, by an electrical system of the motor vehicle. The devices for interrupting the energy supply can be designed as semiconductor switches or as relays.

If there is now a fault which requires the switching element actuator system to be in a safe, de-energized state, the energy supply to the first circuit is preferably interrupted by means of the first device, the energy supply to the second circuit being maintained. Should the force When starting the vehicle from standstill in this state, the separating clutch is preferably used as the starting element. Alternatively, the electric machine can be used for starting. In this case, the disconnect clutch can be closed as soon as the speed of the electrical machine reaches or exceeds the idling speed of the internal combustion engine. However, if there is a fault which requires the safe disconnection of the disconnect clutch actuator, the energy supply to the second circuit is preferably interrupted by means of the second device, the energy supply to the first circuit being maintained.

Exemplary embodiments of the invention are described in detail below with reference to the attached figures. Show it:

1 and 2 each show a motor vehicle drive train with a hybrid drive module; such as

Fig. 3 is a schematic representation of an electrical circuit.

1 shows a motor vehicle drive train which has an internal combustion engine VM, an electric machine EM, a transmission G, a differential gear AG and drive wheels DW. An output shaft of the internal combustion engine VM is connected to a rotor of the electrical machine EM via a clutch KO. The rotor is connected to an input shaft GW1 of the transmission G. The electrical machine EM and the separating clutch KO are arranged in an independent unit, and thus form a hybrid drive module HY. The hybrid drive module HY is arranged between the internal combustion engine VM and the transmission G. The transmission G is set up to display different gear stages between the input shaft GW1 and an output shaft GW2. To this end, the transmission G has, for example, a plurality of wheel sets and a plurality of frictional shifting elements. One of the wheel sets is shown symbolically and referred to as RS. Two of the switching elements are also shown symbolically and designated as KG1, KG2. The output shaft GW2 of the transmission G is connected via the differential gear AG to the drive wheels DW of the motor vehicle. The gearbox G has a hydraulic switching unit HCU. The switching unit HCU houses valves, not shown, by means of which hydraulic actuations KG1 H, KG2H of the switching elements KG1, KG2 can be controlled. The valves are actuated electromagnetically, either directly or in a piloted manner, the power supply to the electromagnetic actuation being controlled by an electronic control unit ECU. The electronic control unit ECU is powered by a battery BAT of a motor vehicle electrical system. In the given exemplary embodiment, a hydraulic actuation KOH of the separating clutch KO is also controlled by the hydraulic switching unit HCU or by the control unit ECU.

FIG. 2 shows a motor vehicle drive train which essentially corresponds to that in FIG.

1 corresponds to the motor vehicle drive train shown. The G transmission, the EM electrical machine and the KO separating clutch are now combined to form a common structural unit and together form the HY hybrid drive module.

In other words, the transmission G is now part of the hybrid drive module HY.

The drive trains shown in FIGS. 1 and 2 are only to be considered as examples. The transmission G could also be designed as a double clutch transmission, as an automated manual transmission or as a manual transmission. Individual or all of the switching elements KG1, KG2 could be designed as form-fitting switching elements, or instead of being actuated electrohydraulically by an electromechanical device. This also applies to the KO separating clutch. The rotor of the electrical machine EM could be connected to an internal gear shaft or to the output shaft GW2 instead of to the input shaft GW1.

FIG. 3 schematically shows an electrical circuit EE of the control unit ECU, which is supplied with electrical energy by the battery BAT. In addition to other components (not shown), the control unit ECU has a first circuit EE1 and a second circuit EE2. The first circuit EE1 serves to supply power to those valves of the hydraulic switching unit HCU by means of which the hydraulic actuation of the switching elements is controlled, including the actuations KG1 H, KG2H of the switching elements KG1, KG2. The second circuit EE2 is used to supply power to that valve hydraulic switching unit HCU, by means of which controls the hydraulic actuation KOH of the clutch KO. The circuit EE has a first device HSS1, which is used for the switchable interruption of an energy supply to the first circuit EE1. The circuit EE has a second device HSS2, which is used for the switchable interruption of a power supply to the second circuit EE2. The devices HSS1, HSS2 can be designed as semiconductor switches or as relays.

If, for example, a fault condition of that valve of the hydraulic switching unit HCU is determined by means of a diagnostic function of the control unit ECU, by means of which the hydraulic actuation KOH of the clutch KO is controlled, the second device HSS2 can be opened. As a result, the power supply to the valve is interrupted so that it takes on its safe, de-energized state. The first device HSS1 remains closed, so that the power supply to those valves which are intended to control the actuations KG1 H, KG2H is maintained.

If a fault state of that valve of the hydraulic switching unit HCU which is provided for controlling, for example, the actuation KG1 H of the switching element KG1 is determined by means of a diagnostic function of the control unit ECU, the first device HSS1 can be opened. As a result, the power supply to the valve is interrupted so that the valve assumes its safe, de-energized state. The second device HSS2 remains closed, so that the power supply to that valve is maintained which is provided for controlling the actuation KOH of the clutch KO.

REFERENCE CHARACTERS

HY hybrid drive module

VM combustion engine

EM electrical machine

KO separating clutch

KOH actuation

G gearbox

GW1 input shaft

GW2 output shaft

RS wheelset

KG1 switching element

KG1H actuation

KG2 switching element

KG2H actuation

HCU hydraulic switching unit

ECU control unit

BAT battery

AG differential gear

DW drive wheel

EE Electrical circuit

EE1 First circuit

HSS1 First setup

EE2 Second circuit

HSS2 Second facility

Claims

claims

1. Electrical circuit (EE) for a hybrid drive module (HY) of a motor vehicle drive train, which has an internal combustion engine (VM), an electrical machine (EM), one between the internal combustion engine (VM) and the electrical machine ( EM) connected clutch (KO) and a gearbox (G),

the transmission (G) comprises a plurality of shifting elements (KG), through the selective actuation of which different gear stages between an input shaft (GW1) and an output shaft (GW2) of the transmission (G) can be represented,

the circuit (EE) is set up to supply electromagnetic and / or electromechanical actuators for actuating the switching elements (KG) and the separating clutch (KO),

- The circuit (EE) has a first circuit (EE1) for supplying the actuators assigned to the switching elements (KG) and a second circuit (EE2) for supplying that actuator which is assigned to the clutch (KO).

2. Electrical circuit (EE) according to claim 1, characterized in that the first circuit (EE1) a first device (HSS1) for switchable interruption of a power supply to the first circuit (EE1), and the second circuit (EE2) a second Device (HSS1) for the switchable interruption of an energy supply to the second circuit (EE2) is assigned.

3. Electrical circuit (EE) according to claim 2, that the devices (HSS1, HSS2) for switchable interruption of the power supply to the circuits (EE1, EE2) are designed as semiconductor switches or as relays.

4. Control unit (ECU) for a hybrid drive module (HY) of a motor vehicle drive train, which has an internal combustion engine (VM), an electrical machine (EM), a separating clutch (KO) connected between the internal combustion engine (VM) and the electrical machine (EM). as well as a transmission (G), the transmission (G) comprises a plurality of shifting elements (KG), through the selective actuation of which different gear stages between an input shaft (GW1) and an output shaft (GW2) of the transmission (G) can be represented,

the switching elements (KG) and the separating clutch (KO) can be actuated by means of electromagnetic and / or electromechanical actuators,

characterized in that the control device (ECU) has an electrical circuit (EE) according to one of claims 1 to 3.

5. Hybrid drive module (HY), characterized by a control device according to claim 4.

6. Hybrid drive module (HY) according to claim 5, characterized in that the hybrid drive module (HY) either

- includes the gearbox (G), the electrical machine (EM) and the separating clutch (KO), or

- At least the electrical machine (EM) and the clutch (KO) comprises, which are arranged in a unit independent of the transmission (G).

7. Method for operating a motor vehicle drive train, which has an internal combustion engine (VM), an electrical machine (EM), a separating clutch (KO) connected between the internal combustion engine (VM) and the electrical machine (EM), and a transmission (G) includes

an electrical circuit (EE) is provided for supplying electromagnetic and / or electromechanical actuators, which are set up to actuate the switching elements (KG) and the separating clutch (KO),

the circuit (EE) has a first circuit (EE1) for supplying the actuators assigned to the switching elements (KG) and a second circuit (EE2) for supplying the actuator assigned to the disconnect clutch (KO), - The first circuit (EE1) has a first device (HSS1) for switchable interruption of an energy supply to the first circuit (EE1), and the second circuit (EE2) has a second device (HSS1) for switchable interruption of an energy supply to the second circuit ( EE2) is assigned.

- In the event of a fault in at least one of the switching elements (KG) or its actuation, the energy supply to the first circuit (EE1) is interrupted by the first device (HSS1), while the energy supply to the second circuit (EE2) is interrupted by the second facility (HSS2) is maintained, and

- In the event of a fault in the separating clutch (KO) or its actuation, the energy supply to the second circuit (EE2) is interrupted by means of the second device (HSS2), while the energy supply to the first circuit (EE1) is interrupted by the first device (HSS1 ) is maintained.

8. The method for operating a motor vehicle drive train according to claim 7, characterized in that in the fault state at least one of the shift elements (KG) or its actuation, a fixed gear stage in the transmission (G) remains engaged or is engaged, whereby for a starting process of the motor vehicle in the fault state of the transmission (G) the clutch (KO) serves as a starting element.

9. The method for operating a motor vehicle drive train according to claim 7 or claim 8, characterized in that in the fault condition of the disconnect clutch (KO) this opens automatically, the motor vehicle being driven in the fault condition of the disconnect clutch (KO) by means of the electrical machine (EM) ,