Actuator device

Abstract

Actuator device with an electrohydraulic actuating device for actuating at least one hydraulic actuating component, in particular in a drive train of a motor vehicle with a pump driven by an electric motor (M) and a control device (1) with a main supply path (2) for supplying and controlling the electric motor (M) by means of a control unit and power electronics, wherein in the control device (1) a secondary supply path (3) arranged parallel to the main supply path (2) and a monitoring device (8) for detecting a fault in the main supply path (2) and activating the secondary supply path (3) in the event of a fault are provided, characterized in thatthat a commutation of the electric motor (M) is provided via the main supply path (2) depending on a power requirement of the pump by controlling a speed by means of a B6 driver (5) to set the requested power or via the secondary supply path (3) at a predetermined power and constant, predetermined speed.

Description

[0001] The invention relates to an actuator device with an electrohydraulic actuating device for actuating at least one hydraulic actuating component, in particular in a drive train of a motor vehicle with a pump driven by an electric motor and a control device with a main supply path for supplying and controlling the electric motor by means of a control unit and power electronics.

[0002] DE 10 2018 205 977 A1 discloses a generic actuator device. DE 10 2017 130 495 A1 discloses an actuator device with an electrohydraulic actuation device for actuating at least one hydraulic actuation component, in particular in a drive train of a motor vehicle with a pump driven by an electric motor. US 2016 / 0 126 879 A1, US 2015 / 0 263 651 A1, and DE 20 2013 002 022 U1 disclose actuator devices in a drive train of a motor vehicle.

[0003] Generic actuator devices serve to actuate hydraulic actuation components. As part of the progressive concepts of temporarily shutting down internal combustion engines for ecological reasons, actuator devices are being provided whose pump(s) are designed to supply an actuation hydraulic system independent of continuous operation by the internal combustion engine. For this purpose, the pumps are each driven by an electric motor, which is electronically commutated by a control unit depending on the power requirements of the hydraulic actuation device and supplied with electrical energy by power electronics. For example, a CVT transmission is known from the publication DE 10 2017 130 495 A1, in which a belt drive is electrohydraulically actuated between sets of tensioned pulleys by means of an actuator device.The actuator device is a pump, such as a hydraulic pump, driven by an electric motor that hydraulically preloads the pulley sets. The electric motor is controlled by a main supply path with power electronics and electronic commutation. A failure of the main supply path poses the risk of insufficient preload of the pulley sets, resulting in the belt slipping on the pulley sets.

[0004] The object of the invention is to further develop an actuator device. In particular, the object of the invention is to propose a fail-safe actuator device.

[0005] The object is solved by the subject matter of claim 1. The claims dependent on claim 1 represent advantageous embodiments of the subject matter of claim 1.

[0006] The proposed actuator device includes a hydraulic actuating device, for example, with a control device implemented in a control unit, an electrohydraulic pump controlled by the latter, with a hydraulic line supplied with pressure by the latter, and valves such as switching and / or proportional valves, orifices, cooling devices, filter devices, and / or the like for adjusting and switching the pressure or volume flow of a pressure medium contained in the hydraulic line for actuating at least one hydraulic actuating component. The at least one actuating component can be formed, for example, from an actuating cylinder, particularly in a drive train of a motor vehicle.For example, the actuating component can be formed from at least two actuating cylinders for pre-tensioning a belt means between two pulley sets of a CVT transmission, from an actuating cylinder of a friction clutch or two actuating cylinders of a dual clutch, from at least one shift cylinder for shifting a gear or a gear pair of a shift sleeve of an automated manual transmission, from an actuating cylinder of a separating clutch between an electric machine and a drive part of a hybrid drive train and / or the like.

[0007] The pump driven by the electric motor is effectively electrically connected to the control unit and power electronics to supply and control the electric motor. To prevent failure of the electric motor control system and thus failure of the hydraulic actuation of at least one actuating component and thus damage to the device actuated by it in the event of a malfunction in the main supply path, for example due to a malfunction such as a reset of a microprocessor such as a microcontroller and / or an assembly of the control unit that intelligently controls the main supply path, a secondary supply path arranged parallel to the main supply path and a monitoring device for detecting a malfunction in the main supply path and activating the secondary supply path in the event of a malfunction are provided.This allows a malfunction of the actuator device to be largely compensated for by means of redundancy in the electrical part of the actuator device. Additional mechanical safeguards in the hydraulic actuation device, such as spring preloads that impair function, can be dispensed with.

[0008] The monitoring device can, for example, take the form of a so-called watchdog, which records and evaluates key operating variables of the main supply path and, if necessary, activates the secondary supply path. This provides redundant control of the electric motor, with its power being supplied alternatively via the main supply path during normal operation and via the secondary supply path during fault operation.

[0009] According to the invention, commutation of the electric motor via the main supply path is controlled depending on a power requirement of the pump by regulating a speed using a B6 driver (5) to set the requested power, so that normal, finely controlled operation of the electric motor can be provided by an intelligent microcontroller of the control unit. According to the invention, electrical operation of the electric motor at a predetermined power and constant, predetermined speed is provided via the secondary supply path for a simple and robust design of the control of the electric motor. The electric motor can be supplied with electrical energy by means of the power electronics of the main supply path or by means of separate power electronics.Operation of the electric motor in the auxiliary supply path can be provided without fine commutation and control corresponding to the main supply path at a specified constant speed of the electric motor's rotor. This will enable not only a simple design of the auxiliary supply path but also component-safe operation of the auxiliary supply path.

[0010] The control unit can contain all components of the main supply path and the auxiliary supply path within a single housing. Alternatively, components of the main supply path and the auxiliary supply path can be provided in separate housings or mechanically separated from one another within a single housing. For example, commutation and control of the electric motor in the main supply path can be provided in separate modules of the control unit. The power electronics of the main supply path can be used by the auxiliary supply path. Alternatively, separate power electronics can be provided for the auxiliary supply path. The auxiliary supply path can be provided in a module that is electrically separate from the control unit.For example, the main supply path and the auxiliary supply path can be powered by the same power source, such as a low-voltage or high-voltage accumulator, possibly with appropriate transformation to a working voltage. Alternatively, the main and auxiliary supply paths can be designed to be fed by different power sources. For example, for completely autonomous operation of the auxiliary supply path, a low-capacity power source adapted to the generally short-term and low electrical power requirements of the auxiliary supply path, such as a small accumulator, a power capacitor, and / or the like, can be provided.

[0011] Furthermore, a malfunction in the main supply path caused by a drop in a supply and / or control line of the main supply path between the electric motor and the control unit can be counteracted by connecting the main supply path and the secondary supply path using different plug connections between a motor housing of the electric motor and supply cables, as well as plug connections between the supply cables and the control unit. In this case, the drop in a plug of the main supply path can be detected by the monitoring device, and the secondary supply path can be activated. A drop in a plug of the secondary supply path can be monitored and documented, for example, by means of an error log entry in the error log of the control unit and, if necessary, indicated to the driver by means of a warning signal.

[0012] A power electronics used by the main supply path and / or the secondary supply path is preferably designed as a three-phase inverter supplying the electric motor with three-phase alternating voltage, for example as a B6 bridge.

[0013] In order to counteract a failure of electrically operated valves between the hydraulic pump and the at least one actuating component in the event of a malfunction caused by a failure of the electrical power in the main supply path, valves arranged between the pump and the at least one actuating component can be designed to switch through in the de-energized state. Alternatively, the valves can be operated with a power source assigned to the secondary supply path. Alternatively or additionally, a protection management system can be designed such that the main supply path and the secondary supply path are electrically protected differently. At least the electrically operated valves required for fail-safe operation of the actuator device can be protected separately or together with the secondary supply path.According to an advantageous implementation of a redundant motor control system for an electric motor to provide a protective / emergency function for the drive train, protection of the mechanical components is to be provided that is designed to be unproblematic for the functional reliability of the actuator device and the drive train actuated by it. This protective / emergency function is designed to be cost-effective and energy-saving by implementing redundancy in the electrical part of the actuator device.

[0014] For individual drive trains, the following operating states are provided using the proposed actuator device: - in a CVT transmission, the contact pressure of the belt on the pulley sets must be maintained, at least until a load on the belt is removed, - the functional reliability of the drive train is maintained until a traction machine of the drive train, for example an internal combustion engine, a hybrid drive with an internal combustion engine and an electric motor or a purely electric drive, no longer transmits torque or is regulated down accordingly, - a transmission input shaft of a partial drive train of a dual-clutch transmission enables emergency operation in a low gear, for example second gear, when the associated friction clutch is engaged, so that in emergency operation at least a rudimentary drive torque can be provided without any load change reactions that might otherwise occur, - if necessary by engaging a parking lock in emergency mode, for example a hydraulically operated one that is open in the unloaded state, if operation of the electric motor in the secondary supply path is possible.

[0015] For normal operation via the main supply path, the actuator device is operated, for example, using a so-called power-on-demand system, i.e., with precise speed and position control when power is delivered on demand, in order to be able to shift specified volume increments of the pressure medium in a connected hydraulic actuation device. A complex and intelligent motor control system is used for this purpose. Commutation and control of the electric motor are implemented in different modules. The control system is implemented in a powerful microcontroller together with other functional modules of a software for operating the actuator device. The software can perform monitoring functions, which in turn are monitored by another hardware module, the so-called watchdog.This microcontroller can contain additional components that, for example, derive the necessary voltage levels from the supply voltage and ensure input filtering of the on-board network and communication. For simpler tasks, such as simply controlling the speed of a pump in the auxiliary supply path, simplified components exist that include voltage supply, control, and simple commutation.

[0016] Such a component for providing the secondary supply path is connected in parallel to the corresponding functional scope of the main supply path and is activated in real time by the watchdog in the event of a failure or reset of the microcontroller or in the absence of a control signal issued by the watchdog.

[0017] For example, this component of the auxiliary supply path can control a fixed speed of the electric motor for a predetermined time with at least simple block commutation, so that at least one already rotating rotor of the electric motor is kept rotating. Through appropriate wiring, for example in the actuating device actuated by the pump, a safe state that cannot be reached or maintained without current can be maintained until either the main supply path is restarted or the drive train with the actuator device or the motor vehicle with this or its components has reached a safe operating state. The two control paths can access a B6 bridge of the electric motor according to a corresponding electrical wiring.

[0018] In a further redundancy level, the auxiliary supply path can have a redundant power supply with its own input circuitry and interference suppression, as well as its own supply protection in the vehicle's fuse box. To also protect against the failure of a connector located between the control unit and the electric motor, the auxiliary supply path can preferably be supplied via a separate cable connection and connector. In this case, the two power supplies act in parallel on the B6 bridge.

[0019] An example application of the proposed actuator device is for operating a CVT transmission. The actuator device serves to protect transmission components such as the belt and pulley sets by preventing a sudden drop in hydraulic pressure in the event of a malfunction. By interconnecting the valves of the hydraulic actuation device, the pressure control of the variator becomes volume flow control in the event of a malfunction via a built-in orifice effect of the control valves in their de-energized position. The orifices, in conjunction with the constant speed of the pump drive motor, establish a fixed pressure ratio between the two pulley sets, preventing slippage of the belt, for example, a chain.At the same time, depending on the output pressure ratio, the CVT transmission ratio optimally adjusts toward a faster ratio to avoid over-revving the traction motor and excessive acceleration jerks. In another application, a drivetrain with multiple clutches for different ratios, for example, a dual-clutch transmission with a multi-speed input shaft, a dedicated hybrid transmission (DHT), a multi-step automatic transmission, or the like, can be operated with the proposed actuator device. This ensures that a safe speed level is achieved through its interconnection in the event of a malfunction, thus avoiding the sudden, complete loss of drive torque that otherwise defines the safe state.This at least makes it possible for the vehicle to be driven to the nearest workshop or to leave an immediately dangerous situation, for example a breakdown on a motorway without a hard shoulder or at a railway crossing.

[0020] The invention is explained in more detail using the exemplary embodiment illustrated in the single figure. This shows a circuit diagram of a fail-safe control system for an actuator device.

[0021] The figure shows the control device 1 for controlling an actuator device. During normal operation, control and regulation take place via the main supply path 2 and, in the event of a fault, via the secondary supply path 3. The main supply path 2 is supplied with electrical energy by means of the power source S1. The electrical energy from the power source S1 operates the microcontroller 4 and supplies the B6 driver 5. The microcontroller 4 and the B6 driver 5 are designed as different hardware components. The control of the B6 driver 5 for commutation of the electric motor M of an electrohydraulically operating pump of the actuator device, which is supplied with voltage via the three phases u, v, w from the three-phase inverter 6, is carried out based on the rotational parameters of the rotation sensor 7, for example, several angularly offset Hall sensors, detected by the microcontroller 4.The microcontroller 4 determines the commutation based on a power request from the pump, for example from a higher-level transmission control unit, and regulates corresponding speeds using the B6 driver 5 to set the requested power.

[0022] The relevant operating data for the operation of the electric motor M are monitored by the monitoring device 8, for example, a watchdog. A function signal from the monitoring device 8 is recorded and evaluated by the control module 9 of the auxiliary supply path 3. If a fault in the main supply path 2 is detected based on the function signal, the auxiliary supply path 3 is activated and the control module 9 generates a simple control signal for the electrical commutation of the electric motor by accessing the three-phase inverter 6. Based on the control signal, the electric motor M is commutated to a constant, predetermined speed using phases u, v, w until the main supply path 2 is restored or a motor vehicle with a drive train actuated by the actuator device is in a secure operating state.In the embodiment shown, the secondary supply path 3 is supplied by the current source S2, which is separated from the current source S1, for example, is separately fused and / or operated by means of its own power supply. List of reference symbols 1 control device 2 Main supply path 3 Secondary supply path 4 microcontrollers 5 B6 drivers 6 three-phase inverters 7 Rotation sensor 8 Monitoring device 9 Control module M electric motor S1 current source S2 power source u Phase v Phase w phase

Claims

[1] Actuator device with an electro-hydraulic actuating device for actuating at least one hydraulic actuating component, in particular in a drive train of a motor vehicle with a pump driven by an electric motor (M) and a control device (1) with a main supply path (2) for supplying and controlling the electric motor (M) by means of a control unit and power electronics, wherein in the control device (1) a secondary supply path (3) arranged parallel to the main supply path (2) and a monitoring device (8) for detecting a fault in the main supply path (2) and activating the secondary supply path (3) in the event of a fault are provided, characterized bythat a commutation of the electric motor (M) is provided via the main supply path (2) depending on a power requirement of the pump by controlling a speed by means of a B6 driver (5) to set the requested power or via the secondary supply path (3) at a predetermined power and constant, predetermined speed. [2] Actuator device according to claim 1, characterized by that commutation and control of the electric motor (M) in the main supply path (2) is provided in separate modules (4, 5) of the control unit and in the secondary supply path (3) in a control module (9) which is electrically separate from the control unit. [3] Actuator device according to one of claims 1 to 2, characterized by that the main supply path (2) and the secondary supply path (3) can be fed from different power sources (S1, S2). [4] Actuator device according to one of claims 1 to 3, characterized bythat the main supply path (2) and the secondary supply path (3) are connected by means of different plug connections between a motor housing of the electric motor (M) and the control unit. [5] Actuator device according to one of claims 1 to 4, characterized by that both the main supply path (2) and the secondary supply path (3) use the same three-phase inverter (6) which supplies the electric motor (M) with three-phase alternating voltage. [6] Actuator device according to one of claims 1 to 5, characterized by that valves arranged between the pump and the at least one actuating component are designed to switch through in the currentless state. [7] Actuator device according to one of claims 1 to 6, characterized bythat the at least one actuating component is designed as a pressure cylinder set for pressing a belt between two pulley sets of a continuously adjustable belt transmission. [8] Actuator device according to one of claims 1 to 6, characterized by that the at least one actuating component is designed as an actuating cylinder for at least one friction clutch of a dual clutch of a dual clutch transmission and / or for shifting a gear of the dual clutch transmission

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