EP1439337A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Hydraulic transmission vehicle
Assignee: Yanmar Agricultural Equipment Co Ltd
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Filing: 2002-10-21
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Granted: —
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Expires: 2022-10-21
Abstract
Abstract A hydraulic transmission (21) has an electric actuator (86) for changing its output/input rotation speed ratio. A controller (90) of the actuator memorizes a command current value to the actuator supposing that load is not applied on the hydraulic transmission, and calculates a value of load applied on the hydraulic transmission by calculating a difference between an actual command current value to the actuator and the memorized command current value. A command current value is compensated based on the value of load, and the actuator receives feedback to be controlled. A vehicle may have a differential mechanism (10), which combines rotation powers on input side and output side of the hydraulic transmission. A detector (82) detects rotation speed of a main speed change output shaft (27) serving as an output shaft of the differential mechanism. If the detected rotation speed differs from target rotation speed of the shaft (27) determined based on operation of a speed change operation tool, the actuator is forcedly controlled. This difference is supposed to be caused by load applied on the hydraulic transmission, whereby the load is calculated.
Inventors
- 👤 F; c/o YANMAR AGR. EQUIPMENT CO. LTD ISHIBASHI
- 👤 Y.; c/o YANMAR AGR. EQUIPMENT CO. LTD KUBOTA
- 👤 Y.; c/o YANMAR AGR. EQUIPMENT CO. LTD NOMA
- 👤 A.; c/o YANMAR AGR. EQUIPMENT CO. LTD KURODA
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 15:48
CPC Classifications
B; B60; B60W; B60W10/00; B60W10/10; B60W10/101; B60W10/103; B60W30/00; B60W30/18; B60W30/188; B60W30/1886; B60W30/1888; F; F16; F16H; F16H61/00; F16H61/38; F16H61/40; F16H61/42; F16H61/439; F16H61/46; F16H61/465; F16H61/468; F16H61/47; B60W2510/00; B60W2510/06; B60W2510/0638; B60W2510/0642; B60W2510/18; B60W2510/186; B60Y; B60Y2200/00; B60Y2200/20; B60Y2200/22; B60Y2200/221; F16H37/00; F16H37/02; F16H37/06; F16H37/08; F16H37/0833; F16H37/084; F16H2037/088; F16H2037/0886; F16H59/00; F16H59/14; F16H2059/148; F16H61/16; F16H2061/168; F16H47/00; F16H47/02; F16H47/04; F16H59/16; F16H59/18; F16H59/22; F16H59/36; F16H59/46; F16H59/50; F16H59/54; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/40; Y02T10/80; Y02T10/84
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
81 words
A hydraulic drive vehicle, comprising: a hydraulic transmission; an electronic actuator for changing an output/input rotation speed ratio of the hydraulic
transmission; and a controller of the actuator, characterized in that the controller memorizes a command current value for the actuator
supposing that load is not applied on the hydraulic transmission, and calculates a value of
load applied on the hydraulic transmission by calculating a difference between an actual
command current value for the actuator and the memorized command current value.
Claim 2
Dependent Claim
27 words
A hydraulic drive vehicle according to claim 1, further comprising: a differential mechanism which combines rotation powers of input side and output side
of the hydraulic transmission.
Claim 3
Dependent Claim
37 words
A hydraulic drive vehicle according to claim 1 or 2, wherein a command current
value is compensated based on the value of load applied on the hydraulic transmission,
and the actuator is controlled by feedback control method.
Claim 4
Dependent Claim
43 words
A hydraulic drive vehicle according to one of claims 1 to 3, further comprising: a PTO shaft, wherein a value of load applied on the PTO shaft is calculated based on
load applied on the hydraulic transmission and load applied on an engine.
Claim 5
Dependent Claim
150 words
A hydraulic drive vehicle, comprising: speed change operation means; a hydraulic transmission having a swash plate; an actuator, wherein a slant angle of the swash plate is changed via the actuator
corresponding to operation of the speed change operation means so as to change an
output/input rotation speed ratio of the hydraulic transmission; an axle; and a drive shaft interlocking with the axle, characterized by rotation speed detection means for detecting a rotation speed of the
drive shaft interlocking with the axle, wherein a target rotation speed of the drive shaft is
set to a value corresponding to the slant angle of the swash plate set by operation of the
speed change operation means, and wherein, if a rotation speed of the drive shaft detected
by the rotation speed detection means differs from the target rotation speed, the slant
angle of the swash plate is compensatively controlled via the actuator.
Claim 6
Dependent Claim
27 words
A hydraulic drive vehicle according to claim 5, wherein a compensational degree of
the swash plate slant angle is detected as load applied on the hydraulic transmission.
Claim 7
Dependent Claim
25 words
A hydraulic drive vehicle according to claim 5, wherein a compensational operation
degree of the actuator is detected as load applied on the hydraulic transmission.
Claim 8
Dependent Claim
39 words
A hydraulic drive vehicle according to claim 5, further comprising: a PTO shaft, wherein a value of load applied on the PTO shaft is calculated based on
load applied on the hydraulic transmission and load applied on an engine.
Claim 9
Dependent Claim
55 words
A hydraulic drive vehicle according to one of claims 5 to 8, further comprising: a differential mechanism which combines rotation powers of input side and output side
of the hydraulic transmission, wherein an output shaft of the differential mechanism
serves as the drive shaft whose rotation speed is detected by the rotation speed detection
means.
Claim 10
Dependent Claim
153 words
A hydraulic drive vehicle, comprising: speed change operation means; a hydraulic transmission having a swash plate; an actuator, wherein a slant angle of the swash plate is changed via the actuator
corresponding to operation of the speed change operation means so as to change an
output/input rotation speed ratio of the hydraulic transmission; and a differential mechanism which combines powers of input side and output side of the
hydraulic transmission, wherein a drive mode of the vehicle can be switched between a
mode setting output of the hydraulic transmission without passing the differential
mechanism as traveling drive power and a mode setting output of the differential
mechanism as traveling drive power, characterized in that the actuator is controlled so as to reduce a change rate of the
swash plate position at the time of switching the drive mode while moving the movable
swash plate to a set target position of the swash plate.
Claim 11
Dependent Claim
98 words
A hydraulic drive vehicle, comprising: a hydraulic transmission including a hydraulic pump and a hydraulic motor provided
with respective movable swash plates; and an electronic actuator for moving one of the movable swash plates of the hydraulic
pump and the hydraulic motor so as to change an output/input rotation speed ratio of the
hydraulic transmission, the electronic actuator being provided with a dead zone against
command current, characterized in that , when the actuator is moved across the dead band, the command
current is changed between upper and lower thresholds demarcating the dead band
without a time lag.
Claim 12
Dependent Claim
34 words
A hydraulic drive vehicle, comprising: an engine; a brake pedal; and a hydraulic transmission, characterized in that the hydraulic transmission is turned into neutral by depressing the
brake pedal while the engine is idling.
Claim 13
Dependent Claim
60 words
A hydraulic drive vehicle according to claim 11, further comprising: a switch disposed in the vicinity of the brake pedal so that the switch can be operated
simultaneously with the brake pedal, wherein the switch is provided to select whether the
hydraulic transmission is turning into neutral or not when the brake pedal is depressed
and the engine is idling.
Claim 14
Dependent Claim
91 words
A hydraulic drive vehicle, comprising: an engine whose rotation speed is detected; and a hydraulic transmission, characterized in that an output rotation of the hydraulic transmission is detected after
the hydraulic transmission is operated for speed changing, that an output/input rotation
speed ratio of the hydraulic transmission is changed in proportion to the rotation speed of
the engine, and that the hydraulic transmission is provided with a dead band for
preventing the output/input speed ratio of the hydraulic transmission from changing
regardless of change of the rotation speed of the engine.
Claim 15
Dependent Claim
124 words
A hydraulic drive vehicle, comprising: an engine; an electronic governor of the engine; and an engine rotation speed detector; characterized by a hydraulic transmission whose output/input rotation speed ratio can be changed by
electronic control; and a controller controlling the governor and the hydraulic transmission, and memorizing a
map concerning torque and rotational speed of the engine for obtaining an optimal fuel
consumption, wherein the controller compares engine torque detected by the governor
and engine rotation speed detected by the engine rotation speed detector with torque and
rotation speed on the map, and wherein, when the detected values differ from the values
on the map, the controller controls one or both of the governor and the hydraulic
transmission so as to cancel the difference.
Claim 16
Dependent Claim
141 words
A hydraulic drive vehicle, comprising: an engine; an electronic governor provided to the engine and calculating engine load; and an engine rotation speed detector detecting a rotation speed of the engine; characterized by a hydraulic transmission whose output/input rotation speed ratio can be changed by
electronic control; and a controller controlling the output/input rotation speed ratio of the hydraulic
transmission and memorizing a map of maximum engine torque corresponding to the
detected engine rotation speed, wherein, when the engine load detected by the governor is
higher than engine load equivalent to the maximum engine torque corresponding to the
engine rotation speed detected by the engine rotation speed detector, the controller
reduces the output/input rotation speed ratio of the hydraulic transmission, and when the
former is lower than the later, the controller increases the output/input rotation speed ratio
of the hydraulic transmission.
Claim 17
Dependent Claim
183 words
A transmission for a hydraulic drive vehicle, comprising: a working machine vertically movably attached to the vehicle; an engine; an electronic governor of the engine; and an engine rotation speed detector, characterized by a hydraulic transmission whose output/input rotation speed ratio can be changed by
electronic control, and a controller controlling the governor and the hydraulic transmission, wherein, when the
vehicle starts turning and a command signal for pulling the working machine up is
emitted, the controller controls the governor so as to reduce the engine rotation speed and
increases the output/input rotation speed ratio of the hydraulic transmission so as to
compensate for the decrease of vehicle speed accompanying with the decrease of the
engine rotation speed, and when the vehicle stops turning and a command signal for
pulling the working machine down is emitted, the controller controls the governor so as to
return the engine rotation speed to the set rotation speed and decreases the output/input
rotation speed ratio of the hydraulic transmission so as to restrict the increase of vehicle
speed accompanying with the increase of the engine rotation speed.
References Cited (Backward Citations)
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