EP0372073B1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Transmission controller
Assignee: Komatsu Ltd
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Filing: 1988-06-24
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Granted: 1994-02-09
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Expires: 2008-06-24
Abstract
Abstract When a speed is to be changed, a transmission controller of the present invention judges a load, the quantity of a remaining oil in each transmission clutch (F, R, 1-4) and a speed change path, from which stage to which stage, and changes an electrical instruction pattern to be applied to pressure control valves (51-56) for required transmission clutches in accordance with the result of this judgement so that the speed change can be made always smoothly irrespective of a driving condition. The electrical instruction (C1-C4) to be applied to each pressure control valve (51-56) is compared with an output current (I1-I6) of a drive circuit and with the output (S1-S6) of clutch pressure detection means (101-106) and clutch abnormality is detected on the basis of the result of this comparison. When abnormality is detected, suitable measures are taken to reliably prevent double engagement of clutch.
Inventors
- 👤 Yoshio Asayama
- 👤 Makio Tsubota
- 👤 Yasunori Okura
- 👤 Takayuki Sato
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 10:54
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/02; F16H61/0202; F16H61/0204; F16H61/0206; F16H61/04; F16H61/06; F16H61/061; F16H61/12; F16H59/00; F16H59/68; F16H2059/6807; F16H2059/683; F16H2061/0209; F16H2061/1204; F16H2061/1208; F16H2061/1216; F16H2061/1232; F16H2061/1252; F16H2061/1256; F16H2061/126; F16H2061/1268; F16H2061/1276; F16H59/14; F16H59/24; F16H59/36; F16H59/44; F16H61/70; Y; Y10; Y10T; Y10T74/00; Y10T74/19; Y10T74/19219; Y10T74/19251
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
214 words
An apparatus for controlling a gear box having individual connections to a plurality of pressure control valves (51-56) actuable in response to electrical commands issued to a plurality of shift change clutches (F,R,1-4), said apparatus comprising: shift change stage discriminating means (80) for discriminating from which speed stage to which other speed stage is shift change to be effected; and load determining means, for determining the magnitude of a load exerted on a vehicle, including vehicle speed detecting means (65) for detecting the vehicle's speed, throttle opening extent detecting means (90) for detecting the extent of opening of a throttle, and loading state determining means for determining a loading state based on outputs from said vehicle speed detecting means and said throttle opening extent detecting means; and characterised in that the apparatus includes: residual oil quantity determining means for determining the quantity of residual hydraulic oil in each shift change clutch during a shift change; and controlling means (70) for variably controlling the pattern of said electrical commands to be issued to a pressure control valve via a required shift change clutch during the shift change in dependence on outputs from said shift change stage discriminating means, said load determining means and said residual oil quantity determining means, said pattern varying as time elapses.
Claim 2
Dependent Claim
34 words
An apparatus for controlling a gear box as claimed in claim 1, wherein said vehicle speed detecting means (65) detects said vehicle's speed from the speed of an output shaft of said gear box.
Claim 3
Dependent Claim
95 words
An apparatus for controlling a gear box as claimed in claim 1 or 2, wherein said loading state determining means is such that said loading state is classified into three states: an ultimate state, an intermediate state and a low state; corresponding to three operation states: a state of running of the vehicle on flat ground, a state of running of the vehicle on a slope and a state of excavating operation; said classification being achieved by comparing a value of input vehicle speed and the extent of opening of the throttle with preset values.
Claim 4
Independent Claim
63 words
An apparatus for controlling a gear box as claimed in any preceding claim, wherein said residual oil quantity determining means includes shift change time interval measuring means for measuring a time interval of shift changing, from the time when each relevant shift change clutch (F,R,1-4) is turned off to the time when it is turned on, for each of said shift change clutches.
Claim 5
Dependent Claim
67 words
An apparatus for controlling a gear box as claimed in claim 4, wherein said residual oil quantity determining means includes: vehicle speed detecting means for detecting the vehicle's speed and determining means for determining a quantity of residual hydraulic oil in each shift change clutch (F,R,1-4) during the shift change based on outputs from said shift change time interval measuring means and said vehicle speed detecting means.
Claim 6
Independent Claim
79 words
An apparatus for controlling a gear box as claimed in any preceding claim, wherein said pattern of electrical commands varying as time elapses to be issued by said controlling means (70) to a shift change clutch (F,R,1-4) to be brought into an engaged state includes a high-pressure level part appearing immediately after starting of the shift change; a low-pressure level part appearing subsequent to said high-pressure level part; and a gradually-increasing-pressure part appearing subsequent to said low-pressure level part.
Claim 7
Dependent Claim
62 words
An apparatus for controlling a gear box as claimed in claim 6, wherein said controlling means (70) carries out crossover control such that an electrical command to be issued to said shift change clutch (F,R,1-4) to be brought into an engaged state partially overlaps an electrical command to be issued to a shift change clutch to be released from the engaged state.
Claim 8
Dependent Claim
116 words
An apparatus for controlling a gear box as claimed in claim 7, wherein said controlling means (70) controls at least one pattern of electrical commands to vary, as time elapses, at least one of: in said electrical command to be issued to said shift change clutch (F,R,1-4) to be brought into an engaged state, a level holding-time or a level value of said high-pressure level part; and in said electrical command to be issued to said shift change clutch to be released from the engaged state, a level holding-time, a level value of a low-pressure level part, a rate of gradual increase of a gradually-increasing-pressure part or a rate of gradual decrease of a gradually-decreasing-pressure part.
Claim 9
Independent Claim
42 words
An apparatus for controlling a gear box as claimed in any of claims 6 to 8, wherein said controlling means (70) variably controls a holding time for said high-pressure level part depending on an output from said residual oil quantity determining means.
Claim 10
Independent Claim
93 words
An apparatus for controlling a gear box as claimed in any preceding claim, wherein said controlling means (70): includes storing means for storing a plurality of patterns of electrical commands varying as time elapses in dependence on outputs from: said shift change stage discriminating means (80), said load determining means and said residual oil quantity determining means; and performs variable controlling for a pattern varying as time elapses in dependence on outputs from: said storing means, said shift change stage discriminating means, said load determining means and said residual oil quantity determining means.
References Cited (Backward Citations)
US4653350A
Cited
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