System and method for reversing the movement of a vehicle, in particular for an agricultural tractor

• US 20060096824A1
• Filed: 09/29/2005
• Published: 05/11/2006
• Est. Priority Date: 11/09/2004
• Status: Active Grant

• Current Assignee: Same Deutz-Fahr Italia S.p.A. (Intractor BV)
• Original Assignee: Same Deutzfahr Group SPA (Intractor BV)
• Inventors: Ribaldone, Massimo, Paggi, Bruno
• Granted Patent: US 7,445,101 B2
• Time in Patent Office: Days
• US Class Current: 192/12.00C
• CPC Class Codes: F16H 2059/088 Fast forward-reverse-sequence mode
• CPC Class Codes: F16H 59/44 dependent on machine speed of the machine, e.g. the vehicle
• CPC Class Codes: F16H 59/54 dependent on signals from the brakes, e.g. parking brakes
• CPC Class Codes: F16H 61/0246 characterised by initiating reverse gearshift

Abstract

System for reversing the movement of a vehicle, in particular for an agricultural tractor, comprising: an electro-hydraulic reverser including a hydraulic clutch and a valve assembly able to activate the clutch in conditions of forward travel or of rearward travel and able to modulate the engagement of the clutch, a control member which can be operated by the driver to select an operative condition of the reverser selected among: neutral, forward travel, and rearward travel, and an electronic control unit adapted to receive a first signal indicating the position of said control member, a second signal indicating the operative state of a braking system of the vehicle, and a third signal indicating the speed of the vehicle, the electronic control unit being adapted to control said valve assembly according to said first, second and third signal.

Claims

1. System for reversing the movement of a vehicle, in particular for an agricultural tractor, comprising:

an electro-hydraulic reverser including a hydraulic clutch and a valve assembly able to activate the clutch in conditions of forward travel or of rearward travel and able to modulate the engagement of the clutch,

a control member which can be operated by the driver to select an operative condition of the reverser selected among;

neutral, forward travel, and rearward travel,

an electronic control unit adapted to receive a first signal indicating the position of said control member, a second signal indicating the operative state of a braking system of the vehicle, and a third signal indicating the speed of the vehicle, the electronic control unit being adapted to control said valve assembly according to said first, second and third signal.

2. System as claimed in claim 1, wherein, when the electronic control unit senses that the control member is in forward travel or rearward travel position, that the vehicle is stopped or substantially stopped and that the braking system is activated, the control unit commands a stand-by state of the electro-hydraulic reverser in which the hydraulic clutch is subjected to a sufficient pressure to fill the clutch but not sufficient to transmit torque.

3. System as claimed in claim 2, wherein, when the electronic control unit senses that the braking system is deactivated in conditions of stopped or substantially stopped vehicle and with the control member set in forward travel or rearward travel condition, the electronic control unit commands a modulation phase for the progressive engagement of the hydraulic clutch.

4. Method for controlling an electro-hydraulic reverser of a vehicle including a hydraulic clutch and a valve assembly to set the clutch in neutral, forward travel or rearward travel condition and to modulate the engagement of the clutch, comprising the steps of:

sensing the position of a control member which can be operated by the driver, indicating an operative condition of the reverser selected among;

neutral, forward travel, rearward travel,

sensing the operative state of the braking system of the vehicle,

measuring the speed of movement of the vehicle, and

commanding the operative state of the electro-hydraulic reverser according to the sensed conditions.

5. Method as claimed in claim 4, comprising the step of placing the electro-hydraulic reverser in a stand-by state in which the clutch is subjected to a sufficient hydraulic pressure to fill the chambers of the clutch but not sufficient to transmit torque when the control member indicates an operative position of forward travel or rearward travel, the braking system is activated and the vehicle is stopped or substantially stopped.

6. Method as claimed in claim 5, comprising the step of modulating the engagement of the hydraulic clutch starting from said stand-by operative state when the deactivated state of the braking system is sensed.