Start ratio selection system and method

• US 5,577,978 A
• Filed: 07/28/1995
• Issued: 11/26/1996
• Est. Priority Date: 08/05/1994
• Status: Expired due to Term

• Current Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Stasik, Anthony, Stainton, John E.
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): KWON, TAI CHOON
• Application Number:
  US08/506,988
• Time in Patent Office: 487 Days
• Field of Search: 74/335, 477/78, 477/77, 477/79, 477/80, 477/81
• US Class Current: 477/78
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 2510/1015 Input shaft speed, e.g. turbine speed
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 2710/021 Clutch engagement state
• CPC Class Codes: B60W 2710/0605 Throttle position
• CPC Class Codes: B60W 30/18 Propelling the vehicle
• CPC Class Codes: F16H 2059/0239 Up- and down-shift or range or mode selection by repeated movement
• CPC Class Codes: F16H 2061/023 Drive-off gear selection, i.e. optimising gear ratio for drive off of a vehicle
• CPC Class Codes: F16H 2312/02 Driving off
• CPC Class Codes: F16H 2312/022 Preparing to drive off
• CPC Class Codes: F16H 59/02 Selector apparatus
• CPC Class Codes: F16H 59/44 dependent on machine speed of the machine, e.g. the vehicle
• CPC Class Codes: F16H 59/56 dependent on signals from the main clutch
• CPC Class Codes: F16H 61/0248 Control units where shifting is directly initiated by the driver, e.g. semi-automatic transmissions generation of movements for final actuating mechanisms F16H61/28
• CPC Class Codes: F16H 61/66 specially adapted for continuously variable gearings control of exclusively fluid gearing F16H61/38

Abstract

A control system and method for a vehicular semi-automatic mechanical transmission system (10) is provided for allowing operator request, immediately after bringing a vehicle to rest, for both a direct shift into a preselected start ratio and a direct shift into neutral, under certain predefined conditions, by a single movement of the shift selection lever (1).

Claims

1. A method of controlling a semi-automatic mechanical change gear transmission system (10) comprising a fuel throttle control (24), a fuel throttle controlled engine (14), a multi-speed change gear mechanical transmission (12) having a lowest grouping of gear ratios (first-fifth) suitable for start from stop operation and having a specific ratio within said lowest grouping of ratios determined to be the predetermined start ratio, a friction master clutch (16) interposed the engine and transmission, a master clutch control (3), a manually operated shift selection lever (1) movable in a first direction from a centered position to select upshifts and in a second direction from said centered position to select downshifts, a central processing unit (38) for receiving input signals indicative of transmission input shaft rotational speed, of vehicle speed and of operation of said shift selection lever and for processing same according to predetermined logic rules to issue command output signals to non-manually controlled operators including a clutch operator (30), a fuel throttle control operator (26), and a transmission operator (34), said processing unit sensing operation of said manual shift selection lever including the direction of movement thereof and the number of displacements of said lever within a predetermined period of time from said centered position, and, in a first mode of operation, determining the transmission gear ratio selected by the operator to be shifted directly into from the currently engaged ratio by assuming each repetition of displacement from the centered position of said shift selection lever in a given direction indicates operator selection of a change of one additional consecutive ratio in said direction;

said method comprising;

providing said central processing unit with a signal indicative of disengagement of the friction master clutch; and

automatically selecting operation in a second mode of operation if (i) vehicle ground speed is less than a reference value after exceeding said reference value, (ii) the master clutch is disengaged and (iii) said selection lever has not been displaced from the centered position thereof after said vehicle ground speed became less than said reference value;

in said second mode of operation, interpreting a single displacement of said shift selection lever from the centered position thereof in said first direction as a request for a direct shift from an engaged gear ratio into said predetermined start ratio, and interpreting a single displacement of said shift selection lever from the centered position thereof in said second direction as a request for a direct shift from an engaged gear ratio into neutral.

2. The method of claim 1 further comprising immediately ceasing operation in said second mode of operation upon initiation of one shift.

3. The method of claim 1 wherein operation in both said first and said second modes of operation further comprises operation wherein a single displacement of said shift selection lever from the centered position in the first direction when said transmission is in neutral, vehicle ground speed is less than said reference value and said master clutch is disengaged, is interpreted as an operator selection of an upshift directly from neutral into the predetermined start ratio.

4. A system of controlling a semi-automatic mechanical change gear transmission system (10) comprising a fuel throttle control (24), a fuel throttle controlled engine (14), a multi-speed change gear mechanical transmission (12) having a lowest grouping of gear ratios (first-fifth) suitable for start from stop operation and having a specific ratio within said lowest grouping of ratios determined to be the predetermined start ratio, a friction master clutch (16) interposed the engine and transmission, a master clutch control (3), a manually operated shift selection lever (1) movable in a first direction from a centered position to select upshifts and in a second direction from said centered position to select downshifts, a central processing unit (38) for receiving input signals indicative of transmission input shaft rotational speed, of vehicle speed and of operation of said shift selection lever and for processing same according to predetermined logic rules to issue command output signals to non-manually controlled operators including a clutch operator (30), a fuel throttle control operator (26), and a transmission operator (34), said processing unit sensing operation of said manual shift selection lever including the direction of movement thereof and the number of displacements of said lever within a predetermined period of time from said centered position, and, in a first mode of operation, determining the transmission gear ratio selected by the operator to be shifted directly into from the currently engaged ratio by assuming each repetition of displacement from the centered position of said shift selection lever in a given direction indicates operator selection of a change of one additional consecutive ratio in said direction;

said system comprising;

sensing means (26) for providing said central processing unit with a signal indicative of disengagement of the friction master clutch; and

means for automatically selecting operation in a second mode of operation if (i) vehicle ground speed is less than a reference value after exceeding said reference value, (ii) the master clutch is disengaged and (iii) said selection lever has not been displaced from the centered position thereof after said vehicle ground speed became less than said reference value;

said central processing unit, in said second mode of operation, including logic rules for interpreting a single displacement of said shift selection lever from the centered position thereof in said first direction as a request for a direct shift from an engaged gear ratio into said predetermined start ratio, and interpreting a single displacement of said shift selection lever from the centered position thereof in said second direction as a request for a direct shift from an engaged gear ratio into neutral.

5. The system of claim 4 further comprising means for immediately ceasing operation in said second mode of operation upon initiation of one shift.

6. The system of claim 4 wherein said central processing unit further includes logic rules whereby operation in both said first and said second modes of operation further comprises operation wherein a single displacement of said shift selection lever from the centered position in the first direction when said transmission is in neutral, vehicle ground speed is less than said reference value and said master clutch is disengaged, is interpreted as an operator selection of an upshift directly from neutral into the predetermined start ratio.