EP0174787A1
Expired / Lapsed
EP
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Automatic transmission control
Assignee: Eaton Corp
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Filing: 1985-09-02
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Granted: —
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Expires: 2005-09-02
Abstract
Abstract 57 An improved control system for an automatic change gear transmission (10) driven by a throttle (18) controlled engine (12) is provided. The control system includes a processing unit (30) for receiving inputs indicating at least throttle position (18), engine speed (20) and vehicle speed (28) and for processing these inputs in accordance with a program to determine the correct engaged gear ratio and for issuing command signals to a transmission shifting mechanism (26). The processing unit includes of operator actuated selection means (32) for selecting a mode of operation (D, or D L ) wherein vehicle performance is maximized and the control will evaluate and execute allowable skip downshifts.
Inventors
- 👤 Eneas James Lane
- 👤 Ronald Keith Markyvech
- 👤 Donald Speranza
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 19:36
CPC Classifications
B; B60; B60W; B60W10/00; B60W10/04; B60W10/06; B60W10/10; B60W10/11; B60W30/00; B60W30/18; B60W2510/00; B60W2510/06; B60W2510/0604; B60W2510/0638; B60W2552/00; B60W2552/15; B60W2710/00; B60W2710/10; B60W2710/1005; F; F16; F16H; F16H61/00; F16H61/02; F16H61/0202; F16H61/0204; F16H61/0213; F16H2061/0216
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
387 words
Claim 1. An improved automatic transmission system for vehicles having a throttle-controlled engine (12), an operator actuated throttling control means (18) and a transmission (10) having a plurality of gear ratio combinations selectively engageable between a transmission input shaft and a transmission output shaft (16), said transmission input shaft being operatively connected to said engine, said transmission system including an information processing unit (30) having means for receiving a plurality of input signals including (1) an input signal (18) indicative of the position of said throttle controlling means, (2) an input signal (20) indicative of the rotational speed of said engine, and (3) an input signal (28) indicative of the speed of said vehicle, said processing unit including means for processing said input signals in accordance with a program to select a desirable gear ratio for a given combination of input signals and for generating output signals whereby said transmission system is operated in accordance with said program, and means (28) associated with said transmission effective to actuate said transmission to effect engagement of one of said gear ratio combinations in response to said output signals from said processing unit, the automatic transmission system characterized by: said processing unit including means for processing said input signals to provide a calculated expected engine speed value indicative of the expected rotational speed of the engine at a selected vehicle speed in various selectable gear ratio combinations; said program having a first mode of operation (D 1 or D L ) wherein upon sensing an engine speed equal to or less than the engine speed at which downshifts to a lower gear ratio are required is effective to: (a) first compute a first expected engine speed value at the current vehicle speed and in the Nth lower gear ratio where N is an integer greater than 1; (b) then to command initiation of a downshift into a gear ratio intermediate the currently engaged gear ratio and the Nth lower than the currently engaged gear ratio if the first computed expected engine speed value is equal to or greater than the magnitude thereof at the maximum allowable speed of the engine and to command initiation of a downshift into the Nth lower gear ratio if the first computed expected engine speed value is less than the maximum allowable engine speed magnitude.
Claim 2
Dependent Claim
137 words
Claim 2. The improved system of claim 1, wherein said program is additionally effective to: (c) after initiation of a downshift to the Nth lower gear ratio and prior to engagement of the Nth lower gear ratio, compute a second expected engine speed value at the then current vehicle speed in the Nth lower gear ratio; (d) then to command engagement of a gear ratio intermediate the previously engaged ratio and the Nth lower than the previously engaged ratio if the second computed engine speed value equals or exceeds the engine speed value at which upshifts are commanded from the Nth lower ratio and to command engagement of the Nth lower gear ratio if the second calculated engine speed value is less than the engine speed value at which upshifts from the Nth lower ratio are commanded.
Claim 3
Dependent Claim
96 words
Claim 3. The improved system of claim 1 additionally comprising operator actuated mode of operation selection means (32) and said input signals additionally including (4) an input signal indicative of operator selection of one of at least two selectable modes of forward vehicle operation (D, D 1, D L ), said program having a second mode of operation wherein said program is effective to command a downshift to only the next lower gear ratio upon sensing an engine speed equal to or less than the engine speed at which downshift to a lower ratio are indicated.
Claim 4
Dependent Claim
89 words
Claim 4. The improved system of claim 2 additionally comprising operator actuated mode of operation selection means and said input signals additionally including (4) an input signal indicative of operator selection of one of at least two selectable modes of forward vehicle operation, said program having a second mode of operation wherein said program is effective to command a downshift to only the next lower gear ratio upon sensing an engine speed equal to or less than the engine speed at which downshift to a lower ratio are indicated.
Claim 5
Dependent Claim
19 words
Claim 5. The improved system of claim 1, wherein the Nth lower ratio is the second lower gear ratio.
Claim 6
Dependent Claim
22 words
Claim 6. The improved system of claims 2, 3 or 4, wherein the Nth lower ratio is the second lower gear ratio.
Claim 7
Dependent Claim
37 words
Claim 7. The improved system of claims 2, 4, 6 or 8, wherein said processing means includes means for increasing the engine speed at which an upshift will be commanded after a command to initiate a downshift.
Claim 8
Dependent Claim
40 words
Claim 8. The improved system of claims 1, 2, 3 or 4, wherein said program will command downshifts only to the next lower gear ratio if the sensed throttle position is equal to a less than a reference throttle position.
Claim 9
Dependent Claim
23 words
Claim 9. The improved system of claim 8 wherein said reference throttle position is equal to or greater than 60% of full throttle.
Claim 10
Dependent Claim
53 words
Claim 10. The improved system of claims 1, 2, 3, 4. 6 or 8, additionally comprising an input signal (5) indicative of the operator applying the vehicle brakes (29) and wherein said program will command downshifts only to the next lower gear ratio if the operators application of the vehicle brakes is sensed.
Claim 11
Dependent Claim
42 words
Claim 11. The improved system of claims 4, 6 , 7, 8, or 10 wherein the engine speeds at which upshifts are commanded in said second mode is less than the engine speed at which upshifts are commanded in said first mode.
Claim 12
Dependent Claim
265 words
Claim 12. An improved automatic transmission system for vehicles having a throttle-controlled engine, an operator actuated throttling control means and a transmission having a plurality of gear ratio combinations selectively engageable between a transmission input shaft and a transmission output shaft, said transmission input shaft being operatively connected to said engine, said transmission system including an information processing unit having means for receiving a plurality of input signals including (1) an input signal indicative of the position of said throttle controlling means, (2) an input signal indicative of the rotational speed of said engine, and (3) an input signal indicative of the speed of said vehicle, said processing unit including means for processing said input signals in accordance with a program to select a desirable gear ratio for a given combination of input signals and for generating output signals whereby said transmission system is operated in accordance with said program, and means associated with said transmission effective to actuate said transmission to effect engagement of one of said gear ratio combinations in response to said output signals from said processing unit, the improvement characterized by: said system including selector means whereby the operator may select a first mode of operation wherein downshifts from the currently engaged gear ratio to the Nth lower gear ratio, where N is an integral greater than one, are initiated if the expected engine speed at current vehicle speed does not exceed a predetermined maximum value and a second mode of operation wherein downshifting is limited to engagement of the next lower gear ratio from the current engaged gear ratio only.
References Cited (Backward Citations)
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