Power take-off clutch control system

• US 6,564,915 B2
• Filed: 08/10/2001
• Issued: 05/20/2003
• Est. Priority Date: 08/10/2001
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Lorentz, Timothy A., Vernagus, Kevin A.
• Primary Examiner(s): Rodriguez, Saul
• Application Number:
  US09/925,529
• Publication Number:
  US 20030029691A1
• Time in Patent Office: 648 Days
• Field of Search: 192/85.R, 192/3.58, 192/103.F, 74/11, 74/156, 74/156.3, 477/97, 477/174, 477/175, 477/176, 477/180
• US Class Current: 192/3.58
• CPC Class Codes: A01B 71/063 for enabling transmission coupling and connection between tractor and implements to be controlled from the driver's seat
• CPC Class Codes: B60K 17/28 characterised by arrangement, location, or type of power take-off
• CPC Class Codes: B60K 25/06 from the transmission power take-off transmissions having power-take-off B60K17/28
• CPC Class Codes: F16D 2500/1026 Hydraulic
• CPC Class Codes: F16D 2500/10437 Power Take Off clutch
• CPC Class Codes: F16D 2500/3024 Pressure
• CPC Class Codes: F16D 2500/3067 Speed of the engine
• CPC Class Codes: F16D 2500/30803 Oil temperature
• CPC Class Codes: F16D 2500/30816 Speed of the input shaft
• CPC Class Codes: F16D 2500/30825 Speed of the output shaft
• CPC Class Codes: F16D 2500/70406 Pressure
• CPC Class Codes: F16D 2500/70418 Current
• CPC Class Codes: F16D 2500/70663 State analysis; Analysing potential states of the machine and developing control strategies at each state
• CPC Class Codes: F16D 2500/7109 Pulsed signal; Generating or processing pulsed signals; PWM, width modulation, frequency or amplitude modulation
• CPC Class Codes: F16D 48/066 Control of fluid pressure, e.g. using an accumulator F16D48/062, F16D48/068 take precedence

Abstract

A method is provided for controlling a PTO clutch of a transmission subject to a varying inertial load. The method includes providing a signal to a pressure control valve selectively engaged with the PTO clutch configured to engage a drive source of the transmission with an implement. The signal to the pressure control valve is modulated based on a single predetermined profile.

Claims

1. A method for controlling a PTO clutch of a transmission being subject to a varying inertial load, comprising:

providing an electrical signal to a pressure control valve selectively engaged with the PTO clutch configured to engage a drive source of the transmission with an implement; and

modulating the signal to the pressure control valve based on a single predetermined profile of clutch pressure with respect to time.

2. The method of claim 1, wherein the single profile is a non-linear function.

3. The method of claim 2, wherein the single profile is an exponential function.

4. The method of claim 1, wherein the signal is modulated by a closed loop control.

5. The method of claim 1 wherein the single profile is a piece-wise linear approximation of a non-linear function.

6. The method of claim 1, wherein the signal provided to the pressure control valve is determined by considering at least one of an engine speed signal, a transmission input speed signal, a PTO output speed signal, a temperature signal, and a clutch pressure signal.

7. The method of claim 1, further including engaging the PTO clutch at a full clutch pressure.

8. The method of claim 1, wherein the signal is modulated by an open loop control.

9. A method for controlling a PTO clutch of a transmission being subject to a varying inertial load, comprising:

providing a signal to a pressure control valve selectively engaged with the PTO clutch configured to engage a drive source of the transmission with an implement; and

modulating the signal to the pressure control valve based on a single predetermined profile, wherein the single profile is one of the following non-linear, exponential functions;

10. A power take-off clutch control system for controlling a PTO clutch, the system comprising:

a pressure control valve to actuate the clutch; and

a control unit in communication with the pressure control valve, the control unit being configured to provide an electrical input signal to the pressure control valve and modulate the input signal based on a single predetermined profile of clutch pressure with respect to time.

11. The system of claim 10, wherein the predetermined profile is based on a non-linear function.

12. The system of claim 11, wherein the predetermined profile is based on an exponential function.

13. The system of claim 10, wherein the input signal is controlled by an open loop system.

14. The system of claim 10, wherein the profile is a piece-wise linear approximation of a non-linear function.

15. The system of claim 10, wherein the input signal is controlled by a closed loop system.

16. The system of claim 10, wherein the control unit receives at least one of an engine speed signal, a transmission input speed signal, a PTO output speed signal, a temperature signal, and a clutch pressure signal, and provides the signal to the pressure control valve based on the received signal.

17. A power take-off clutch control system for controlling a PTO clutch, the system comprising:

a pressure control valve to actuate the clutch; and

a control unit in communication with the pressure control valve, wherein an input signal to the pressure control valve tracks a single predetermined profile, wherein the predetermined profile is based on a non-linear, exponential function, and is based on one of the following functions;

18. A power take-off clutch control system for controlling a PTO clutch, the system comprising:

a pressure control valve to actuate the clutch; and

a control unit in communication with the pressure control valve, wherein an input signal to the pressure control valve tracks a single predetermined profile, wherein the input signal gradually increases the clutch pressure between an on-coming clutch and an off-going clutch of the PTO clutch.

19. A vehicle, comprising:

a motor;

a transmission coupled to the motor and having a PTO clutch;

a pressure control valve coupled to the PTO clutch to actuate the PTO clutch;

a control unit coupled to the pressure control valve for providing an electrical signal to the pressure control valve, the signal including a single profile modulation signal of clutch pressure with respect to time to control the clutch pressure suitable over a varying load; and

a drive train coupled to the transmission.

20. The vehicle of claim 19, wherein the modulation signal is based on a non-linear function.