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CN-116134233-B - Method for controlling at least one hydraulically actuated torque transmission device

CN116134233BCN 116134233 BCN116134233 BCN 116134233BCN-116134233-B

Abstract

The invention relates to a method for controlling at least one torque transmission device (D1, D2) by means of a hydraulic system (1), comprising a pump unit (7) in which an electronically controlled electric motor (12) drives a pump (13) which delivers a volume flow into a pressure line (10), a system pressure control valve (11) which is arranged between an oil sump (8) and the pressure line (10), slave cylinders (3, 4), and actuating pressure control valves (14, 15) which act on the slave cylinders (3, 4) and have a connection to the pressure line (10) and a connection to the oil sump (8). In order to make it possible to design the pump unit (7) in a small manner and to achieve an efficient actuation of the at least one torque transmission device (D1, D2), the pressure medium quantity preset for setting the contact point of the at least one torque transmission device (D1, D2) is fed to the slave cylinder (3, 4) for actuating the at least one torque transmission device (D1, D2) when the system pressure control valve (11) is closed in an unregulated manner relative to the oil sump (8) and the actuation pressure control valve (14, 15) is fully opened in an unregulated manner relative to the slave cylinder (3, 4), and after reaching the contact point, the system pressure control valve (11) and the actuation pressure control valve (14, 15) are operated in a pressure-regulating manner until the at least one torque transmission device (D1, D2) is fully actuated.

Inventors

  • Erhard Hodluth
  • CHRISTIAN EBERLE

Assignees

  • 舍弗勒技术股份两合公司

Dates

Publication Date
20260508
Application Date
20210707
Priority Date
20200916

Claims (10)

  1. 1. A method for controlling at least one torque transmission device (D1, D2) by means of a hydraulic system (1), comprising a pump unit (7) in which an electronically controlled electric motor (12) drives a pump (13) which delivers a volume flow into a pressure line (10) as a function of the rotational speed, a system pressure control valve (11) which is arranged between an oil sump (8) and the pressure line (10) and is used for controlling a system pressure (p (S)) in the pressure line (10), a slave cylinder (3, 4) for actuating the at least one torque transmission device (D1, D2), and an actuating pressure control valve (14, 15) which acts on the slave cylinder (3, 4) with an actuating pressure (p (D1), p (D2)) and has a connection to the pressure line (10) and a connection to the oil sump (8), characterized in that for the purpose of actuating the at least one actuating pressure control valve (3, 4) the torque transmission device (D1, D2) is completely closed with respect to the oil sump (8) in the event that the at least one actuating pressure control valve (4) is not fully closed with respect to the torque transmission device (1, D2), t (D2)) is fed to the slave cylinder (3, 4), and after reaching the contact point (T (D1), T (D2)), the system pressure regulating valve (11) and the actuating pressure regulating valve (14, 15) are operated in a pressure-regulating manner until the at least one torque transmission device (D1, D2) is actuated completely.
  2. 2. Method according to claim 1, characterized in that two alternately actuated torque transmission devices (D1, D2) are actuated by means of the hydraulic system (1), wherein an actuating pressure regulating valve (14, 15) is connected upstream of each slave cylinder (3, 4) provided for actuating the torque transmission devices (D1, D2) respectively, and that the other slave cylinder (4, 3) is completely decoupled from the actuating pressure regulating valve (15, 14) of the other slave cylinder with respect to the pressure line (10) when one slave cylinder (3, 4) is filled by means of the predetermined pressure medium quantity (V (D1, g), V (D2, g)).
  3. 3. Method according to claim 1, characterized in that the predetermined pressure medium quantity (V (D1, g), V (D2, g)) is determined independently of the system pressure (p (S)) applied in the pressure line (10).
  4. 4. A method according to claim 3, characterized in that the preset pressure medium quantity (V (D1, g), V (D2, g)) is determined from the rotation characteristic value of the electric motor (12) and the rotation angle-dependent pressure medium displacement of the pump (13).
  5. 5. Method according to claim 4, characterized in that the electric motor (12) is electronically commutated and the rotation angle increment for controlling the electric motor is associated with the displacement volume of the pump (13).
  6. 6. Method according to claim 5, characterized in that the filling pulse of the electric motor (12) is maintained until the preset pressure medium quantity (V (D1, g), V (D2, g)) is fed by the pump (13) into the pressure line (10) as a function of the number of detected rotation angle increments.
  7. 7. Method according to claim 6, characterized in that the electric motor (12) is switched off at least briefly before the start of the filling pulse and the system pressure regulating valve (11) and the operating pressure regulating valve (14, 15) are connected at least briefly to the oil sump (8) for eliminating an operating pressure (p (D1), p (D2)) that may be present.
  8. 8. Method according to any one of claims 1 to 7, characterized in that, in order to disconnect the at least one torque transmission device (D1, D2), the operating pressure regulating valve (14, 15) is connected with the oil sump (8) and the slave cylinder (3, 4) is completely emptied.
  9. 9. Method according to any one of claims 1 to 7, characterized in that a non-return valve (16, 17) is connected between the pressure line (10) and the slave cylinder (3, 4) and that an operating pressure (p (D1), p (D2)) set at the slave cylinder (3, 4) due to leakage, which is reduced when at least one torque transmission device (D1, D2) is operated, is reconstructed by means of the pump (13).
  10. 10. Method according to claim 9, characterized in that after dosing the preset pressure medium quantity (V (D1, g), V (D2, g)), the system pressure (p (S)) and the operating pressure (p (D1), p (D2)) exerted on the slave cylinder (3, 4) are kept constant by adjusting the system pressure regulating valve (11) and the operating pressure regulating valve (14, 15) at least for a short time before the at least one torque transmitting device (D1, D2) is completely closed.

Description

Method for controlling at least one hydraulically actuated torque transmission device Technical Field The present invention relates to a method for controlling at least one hydraulically operated torque transmitting device. Hydraulic or conventional power trains with hydraulically operated torque transmitting devices are well known. Background From publications WO2015/086009 A1 and DE 10 2015 210 877 A1, for example, hydraulic units for actuating torque transmission devices in the form of friction clutches of double clutches and methods for controlling the hydraulic units are known, wherein a system pressure is generated by means of a pump unit and a corresponding one slave cylinder is pressurized by means of a pressure control valve in dependence on the switching state of the pressure control valve by means of the system pressure and the other slave cylinder is relieved during a staggered switching in order to alternately switch the torque transmission devices. Disclosure of Invention The object of the invention is an improvement of a method for hydraulically actuating at least one torque transmission device. In particular, it is an object of the invention to quickly and efficiently operate at least one torque transmission device with a power-minimized pump unit. The object is achieved by the following subject matter. The proposed method is used for controlling at least one torque transmitting device by means of a hydraulic system. The at least one torque transmission device may be configured as a wet or dry friction clutch or as a brake. In this case, in the case of a friction clutch, two clutch parts arranged in a manner rotatable relative to one another about the same rotational axis can be connected to one another in a friction fit, i.e. can be actuated, by means of a hydraulic system, while in the case of a brake, a fixed brake part and a brake part arranged in a manner rotatable about the rotational axis can be connected to one another in a friction fit by means of a hydraulic system. At least one torque transmission device can be pressed from the contact point at which the torque transmission device begins to transmit torque by the slave cylinder of the hydraulic system until the maximum transmittable torque is transmitted, so that it can be constructed in a positively locking manner. The at least one torque transmitting device may be directly connected to a drive unit having an electric machine and an internal combustion engine or to a powertrain between the internal combustion engine and a transmission as a disconnect clutch. Alternatively, at least one torque transmitting device may be designed as a brake for fastening a transmission component, such as a ring gear, a web or a sun gear of a planetary gear, or as a clutch for connecting two transmission components. The two torque transmitting devices may, for example, each alternately couple two different transmission components to one another and/or brake with respect to a stationary housing. The hydraulic system comprises a pump unit in which an electronically controlled, e.g. commutated, electric motor drives the pump. In this case, a torsionally rigid connection is preferably provided between the rotor of the electric motor and the pump shaft of the pump, so that the rotational speed of the rotor can be correlated in a one-to-one correspondence with the rotational speed of the pump. The pump is configured as a volumetric pump, for example a gear pump, which has a delivery volume that is associated with its rotational speed in a one-to-one manner. The pump conveys a volume flow of pressure medium, for example oil, from the substantially pressureless oil sump into the pressure line as a function of the rotational speed, and in this case generates a system pressure in the pressure line. The system pressure can be detected and evaluated, for example, by means of a pressure sensor arranged in the pressure line or in the pump. In order to control or regulate the system pressure in the pressure line, a system pressure regulating valve, for example in the form of a proportional valve, is arranged between the oil sump and the pressure line. For controlling the actuating pressure applied to the slave cylinder for actuating the at least one torque transmission device, an actuating pressure control valve is provided, which is designed, for example, as a proportional valve, with a connection to the pressure line and a connection to the oil sump. For detecting the manipulation pressure, a pressure sensor may be provided upstream of the slave cylinder and downstream of the manipulation pressure adjusting valve. In order to be able to design the pump unit in a small manner and to be able to operate the at least one torque transmission device efficiently and quickly, the pressure medium quantity preset for setting the contact point of the at least one torque transmission device is fed to the slave cylinder for actuating the at least one torque transmission devi