EP0287670A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Driving control apparatus for hydraulic construction machines
Assignee: Hitachi Construction Machinery Co Ltd
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Filing: 1987-10-02
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Granted: —
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Expires: 2007-10-02
Abstract
Abstract The driving control is provided with a motor (1) and at least one hydraulic actuator (3) driven by the oil discharged from the hydraulic pump. A lever (5) moves a linkage (7) for setting the number of revolutions per minute of the motor, which in turn operates an operator (8) to control the hydraulic actuator. The device is further provided with a controller unit (20) connected to the operator and adapted to output a revolution number control signal, by which the set number of revolutions of the motor is increased when the displacement of the operator has exceeded a predetermined level. A revolution number control unit is connected to the controlled which is adapted to make the number of revolutions set by the lever not exceed a predetermined level, and to set the control at the required number of revolutions.
Inventors
- 👤 Akira Tatsumi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 05:51
CPC Classifications
E; E02; E02F; E02F9/00; E02F9/20; E02F9/22; E02F9/2246; E02F9/2278; E02F9/2296; F; F02; F02D; F02D29/00; F02D29/04
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
263 words
A drive control system for a hydraulic construction machine, comprising a prime mover (1), a hydraulic pump (2; 90) driven by the prime mover (1), at least one hydraulic actuator (3) driven by discharge hydraulic fluid from the hydraulic pump (2, 90), first rotational speed setting means (7; 80) including first operating means (5) for setting rotational speed of the prime mover (1), and second operating means (8, 9) for controlling operation of the hydraulic actuator (3), characterized by comprising: second rotational speed setting means (20, 24; 60, 61; 81; 84; 85; 87; 92; 93) associated with the second operating means (8) for outputting a rotational speed control signal increasing the set rotational speed of the prime mover (1) when displacement of the second operating means exceeds a predetermined value (X 0 ; X' 0 ); and rotational. speed control means (21; 32; 40; 62; 77, 82; 86) associated with at least the second rotational speed setting means, for validating the rotational speed set by the first rotational speed setting means (7; 80) in a first region (Z 1 ) in which displacement of the second operating means (8) is at least equal to or less than said predetermined value (X 0 ; X' 0 ), and for setting a rotational speed higher than the rotational speed set by the first rotational speed setting means (7; 80), modified by the rotational speed control signal from the second rotational speed setting means in a second region (Z 2 ) in which the displacement of the second operating means is larger than the predetermined value.
Claim 2
Dependent Claim
263 words
A drive control system for a hydraulic construction machine, comprising a prime mover (1), a hydraulic pump (2; 90) driven by the prime mover (1), at least one hydraulic actuator (3) driven by discharge hydraulic fluid from the hydraulic pump (2, 90), first rotational speed setting means (7; 80) including first operating means (5) for setting rotational speed of the prime mover (1), and second operating means (8, 9) for controlling operation of the hydraulic actuator (3), characterized by comprising: second rotational speed setting means (20, 24; 60, 61; 81; 84; 85; 87; 92; 93) associated with the second operating means (8) for outputting a rotational speed control signal increasing the set rotational speed of the prime mover (1) when displacement of the second operating means exceeds a predetermined value (X 0 ; X' 0 ); and rotational. speed control means (21; 32; 40; 62; 77, 82; 86) associated with at least the second rotational speed setting means, for validating the rotational speed set by the first rotational speed setting means (7; 80) in a first region (Z 1 ) in which displacement of the second operating means (8) is at least equal to or less than said predetermined value (X 0 ; X' 0 ), and for setting a rotational speed higher than the rotational speed set by the first rotational speed setting means (7; 80), modified by the rotational speed control signal from the second rotational speed setting means in a second region (Z 2 ) in which the displacement of the second operating means is larger than the predetermined value.
Claim 3
Dependent Claim
57 words
A drive control system according to claim 1, characterized in that the second rotational speed setting means (20, 24; 60, 61; 81; 85; 92; 93) sets the rotational speed control signal so as to increase proportionally the set rotational speed in said second region (Z 2 ) in dependence upon displacement of the second operating means (8).
Claim 4
Dependent Claim
46 words
A drive control system according to claim 1, characterized in that the second rotational speed setting means (20, 24; 84; 87) sets said rotational speed control signal so as to bring the set rotational speed in said second region (Z 2 ) to a constant value.
Claim 5
Dependent Claim
43 words
A drive control system according to claim 1, characterized in that the rotational speed control means (21; 32; 62; 77, 82) is so arranged as to validate the rotational speed of the rotational speed control signal in said second region (Z 2) .
Claim 6
Dependent Claim
46 words
A drive control system according to claim 1, characterized in that the rotational speed control means (40; 77, 86) is so arranged as to add the rotational speed of the rotational speed control signal to the set rotational speed in said second region (Z 2 ).
Claim 7
Dependent Claim
88 words
A drive control system according to claim 1, characterized in that the second rotational speed setting means comprises detecting means (23) for detecting displacement of the second operating means (8), and control means (20, 24; 60, 61; 92; 93) for obtaining said rotational speed control signal on the basis of the displacement detected by the detecting means, and that the rotational speed control means (21; 32; 40; 62; 7 7, 8 2; 86) comprises an actuator (26; 31; 44) driven by an output signal from this control means.
Claim 8
Dependent Claim
137 words
A drive control system according to claim 1, characterized in that the first rotational speed setting means comprises means (80) having inputted thereinto a displacement signal from the first operating means (5) for obtaining the set rotational speed on the basis of the displacement, that the second rotational speed setting means comprises means (81; 84; 85; 87) having inputted thereinto a displacement signal from the second operating meaηs (8) for obtaining the rotational speed control signal on the basis of the displacement, and that the rotational speed control means comprises means (82; 86) for obtaining a final rotational speed on the basis of output signals from the respective first and second rotational speed setting means (20, 24; 60, 61; 81; 84; 85; 87; 92, 93), and an actuator (77) driven by an output signal from this means.
Claim 9
Dependent Claim
63 words
A drive control system according to claim 1 wherein said hydraulic pump (90) is of variable capacity type, characterized by further comprising: displacement volume control means (91; 96, 97) for controlling said hydraulic pump (90) so as to decrease a displacement volume of the hydraulic pump (90) when displacement of the second operating means (9) exceeds said predetermined value (X0; X' 0 ).
Claim 10
Dependent Claim
51 words
A drive control system according to claim 8, characterised in that said displacement volume control means is arranged to reduce the displacement volume so as to bring a discharge quantity of the hydraulic pump (90) to a substantially constant value with respect to increasing rotational speed of the prime mover (1).
Claim 11
Dependent Claim
108 words
A drive control system according to claim 1 or claim 8 wherein a control valve (4) is connected between said hydraulic pump (2; 90) and the hydraulic actuator (3) for controlling flow rate and direction of discharge hydraulic fluid from the hydraulic pump (2; 90), the control valve being controlled in position by said second operating means (8) to control operation of the hydraulic actuator (3), characterized in that the control valve (4) is so arranged that when displacement of the second operating means (8) reaches said predetermined value (X o ; X' 0 ), an opening degree of the control valve is brought to a maximum value.
Claim 12
Dependent Claim
76 words
A drive control system according to claim 1 or claim 8, including a plurality of hydraulic actuators (3) and a plurality of second operating means (8), characterized in that said second rotational speed setting means (102) is so arranged as to increase the rotational speed of said rotational speed control signal as a sum of displacements of the plurality of respective second operating means (8, 71) exceeds said predetermined value (X o ; X' 0 ).
Claim 13
Dependent Claim
148 words
12 . A drive control system according to any one of claims 1, 8 and 11, wherein a control valve (4) is connected between said hydraulic pump (2; 90) and the hydraulic actuator or actuators (3), for controlling flow rate and direction of discharge hydraulic fluid from the hydraulic pump (2; 90), the control valve being controlled in position by said second operating means (8) to control operation of the hydraulic actuator or actuators (3), characterized in that the second rotational speed setting means (20, 24; 81; 85; 92, 93) calculates an opening degree of said control valve (4) on the basis of a detecting signal indicative of displacement or displacements of the second operating means (8, 71), and calculates the rotational speed control signal capable of obtaining discharge quantity of the hydraulic pump (2; 90) which corresponds to a requisite flow rate prescribed by the opening degree.
References Cited (Backward Citations)
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