Method of operating a transmission system valve configuration

• US 8,165,762 B2
• Filed: 02/11/2009
• Issued: 04/24/2012
• Est. Priority Date: 02/15/2008
• Status: Active Grant

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Popp, Christian, Schmidt, Thilo, Steinhauser, Klaus, Braun, Christoph
• Primary Examiner(s): Dickson, Paul N
• Assistant Examiner(s): Wilhelm, Timothy
• Application Number:
  US12/369,333
• Publication Number:
  US 20090206292A1
• Time in Patent Office: 1,168 Days
• Field of Search: 701/51, 701/87, 474/18, 474/28, 251/129.01, 251/129.05, 251/129.08, 251/129.15
• US Class Current: 701/51
• CPC Class Codes: F16H 2061/0255 Solenoid valve using PWM or duty-cycle control
• CPC Class Codes: F16H 61/0251 Elements specially adapted for electric control units, e.g. valves for converting electrical signals to fluid signals

Abstract

A method of operating a valve system of a transmission comprising part of the vehicle drive train through a valve unit and said valve unit'"'"'s electro-magnetic activator configuration. In a transmission'"'"'s hydraulic system and is part of the vehicle drive train, its hydraulic pressure value (p_EDS) can be employed and adjusted through a valve unit configuration by applying a pulse-width-modulated current signal (i_EDS) to the electro-magnetic activator system. The pulse-width modulated current signal (i_EDS) and its amplitude (A) and/or its pulse duration (pw1) will periodically change, during the applied Dither-Modulation, by maintaining the required pressure value (p_EDS) at the same time, whereby a lengthwise movable anchor, which is attached a valve shaft of the valve system, receives hereby an imposed vibrating oscillation. According to the invention, the Dither-Modulation is activated or deactivated during pre-defined operating conditions of the vehicle drive train.

Claims

1. A method to operate a valve system of a drive train of a vehicle transmission system with a valve system unit and an engaging electro-magnetic activator unit, whereby through the valve system unit a hydraulic pressure value of the hydraulic system in the transmission of a vehicle'"'"'s drive train can be set, depending on a pulse-width modulated current signal (i_EDS), present at the electro-magnetic activator unit, and at least one of an amplitude (A) and a pulse duration (pw1) of a pulse-width modulated signal, during a Dither-Modulation which is, by maintaining the pressure value to be set, whereby the valve system'"'"'s lengthwise movable anchor and the connected valve shaft are now exposed to a vibration, thereby characterized that the Dither-Modulation will be activated or deactivated depending on gear shifts that are activated within a range of gear ratios, the range of gear ratios being pre-defined by a shifting strategy.

2. The method according to claim 1, further comprising the step of varying the current signal (i_EDS), through the Dither-Modulation, depending on a gradient of a set pressure (p_EDS) of the valve system.

3. A method of operating a valve system of a vehicle drive train of a transmission system including a valve system unit and an engaging electro-magnetic activator unit, whereby a hydraulic pressure of the hydraulic system in the transmission of the vehicle drive train can be set, through the valve system unit, depending on a pulse-width modulated current signal (i_EDS) present at the electro-magnetic activator unit, and one of an amplitude (A) and a pulse duration (pw1) of a pulse-width modulated signal, during a Dither-Modulation which is, by maintaining the pressure value to be set, whereby a lengthwise movable anchor, attached a valve shaft of the valve system, is exposed to a vibration;

the method comprising the steps of;

one of activating and deactivating the Dither-Modulation in accordance with existing, pre-defined operating conditions of the vehicle drive train; and

varying the pulse-width current signal (i_EDS), through the Dither-Modulation, depending on a gradient of a set pressure (p_EDS) of the valve system.

4. The method according to claim 3, further comprising the step of one of activating and deactivating the Dither-Modulation upon exceeding a pressure value which was pre-defined through the valve system.

5. The method according to claim 4, further comprising the step of varying and altering the pre-defined pressure value, depending on temperature.

6. The method according to claim 3, further comprising the step of one of enabling and disabling the Dither-Modulation depending on at least one torque parameter of the transmission.

7. The method according to claim 3, further comprising the step of one of activating and deactivating the Dither-Modulation, depending on a pre-defined gear ratio change, and changing the current signal (i_EDS) during the Dither-Modulation depending on said gear ratio change.

8. The method according to claim 3, further comprising the step of one of activating the Dither-Modulation within pre-defined shift strategy ranges.

9. The method according to claim 3, further comprising the step of one of activating and deactivating the Dither-Modulation depending on defined operating temperature ranges of the vehicle drive train.

10. The method according to claim 3, further comprising the step of setting an activation pressure for the gear system of the transmission through a valve system, which is designated to provide different gear ratios for the transmission, whereby different support factors are in existence for different gear ratios, and activating and deactivating the Dither-Modulation based on these support factors.

11. The method according to claim 3, further comprising the step of altering the current signal (i_EDS) of the valve system through the Dither-Modulation in pre-defined operating conditions depending on tolerances of a pressure activated switch element of the valve system.

12. The method according to claim 3, further comprising the step of setting the at least one of the amplitude and the frequency of the Dither-Modulation depending on an accuracy and a resonance stability of the valve system.

13. The method according to claim 3, further comprising the step of varying the at least one of the amplitude and the frequency of the Dither-Modulation depending on different operating condition parameters of the drive train of the vehicle.

14. The method according to claim 3, further comprising the step of activating the Dither-Modulation during gear ratio shifts that are activated during a shift strategy for comfortable driving.

15. The method according to claim 14, further comprising the steps of defining the shift strategy for comfortable driving as a shift strategy which does not cause reactions in drive that are noticeable to a driver;

and

de-activating the Dither-Modulation during gear ratio shifts that are activated outside the pre-defined range of gear ratios.

16. A method of operating a valve system of a vehicle drive train of a transmission system including a valve system unit and an engaging electro-magnetic activator unit, whereby a hydraulic pressure of the hydraulic system in the transmission of the vehicle drive train can be set, through the valve system unit, depending on a pulse-width modulated current signal (i_EDS) present at the electro-magnetic activator unit, and one of an amplitude (A) and a pulse duration (pw1) of a pulse-width modulated signal, during a Dither-Modulation which is, by maintaining the pressure value to be set, whereby a lengthwise movable anchor, attached a valve shaft of the valve system, is exposed to a vibration;

the method comprising the steps of;

one of activating and deactivating the Dither-Modulation in accordance with existing, pre-defined operating conditions of the vehicle drive train; and

calculating a self-induction in a vicinity of the electro-magnetic activation unit and, in case of exceeding a self-induction threshold, recognizing bouncing inside a mechanical fitting of the valve as part of the valve system.