# US 7,607,296 B2 · Device and method of controlling hydraulic drive of construction machinery > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,607,296 B2 - Document ID: US7607296B2 - Status: Granted - Kind: B2 - Application number: 10/581,883 - Filed: 2004-12-08 - Published: 2007-05-10 - Granted: 2009-10-27 - Earliest claimed: 2003-12-09 - Assignees: Komatsu Ltd. - Inventors: Koji Ohigashi; Takashi Kawakami; Kenzo Kimoto - Web page: https://patentgrep.com/patent/US7607296B2 ## CPC - E02F 9/2235: {including an electronic controller} - E02F 9/2246: {Control of prime movers, e.g. depending on the hydraulic load of work tools} - E02F 9/2292: {Systems with two or more pumps} - E02F 9/2296: {Systems with a variable displacement pump} - F02D 29/02: peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers - F02D 31/007: {controlling fuel supply} - F02D 41/2422: {Selective use of one or more tables} - F04B 49/065: {and making use of computers} - F02D 2250/18: Control of the engine output torque - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F) ## Abstract In construction machinery, control is conducted to keep a work machine to operate at a constant speed regardless of the operation thereof. Different engine output lines T0-T3 and pump torque lines M1-M4 are defined for different operation types. All the matching points of the engine output lines T0-T3 and pump torque lines M1-M4 designate a constant engine speed N1. One engine output line and one pump torque line are selected according to the operation type presently selected. An output horsepower of the engine is controlled on an equal horsepower line corresponding to a sum of a horsepower for an auxiliary machine and a horsepower at a matching point of the selected lines. The pump torque for the work machine is controlled on the selected pump torque line. The engine operates at a constant speed N1 even when the operation type varies or the horsepower for the auxiliary machine changes. ## Claims ### Claim 1 A hydraulic drive control device of a construction machine comprising an engine and a hydraulic pump for a work machine that is driven by said engine, said device comprising: an operation state detector for detecting an operation state of said work machine; and a controller for receiving a signal from said operation state detector and controlling said engine and said hydraulic pump for said work machine, wherein said controller receives the signal from said operation state detector and identifies an operation mode performed with respect to said work machine; determines an engine output torque control line and a pump torque control line having a desired matching point according to said identified operation mode so that different engine output torque control lines and different pump torque control lines are designated for different operation modes; controls an output torque of said engine based on said determined engine output torque control line; and controls an absorption torque of said hydraulic pump for said work machine based on said determined pump torque control line, wherein said controller determines said engine output torque control line and said pump torque control line so that an engine revolution speed at said matching point of said determined engine output torque control line and said determined pump torque control line assumes a substantially constant predetermined value for any identified operation mode, when said identified operation mode corresponds to any of a plurality of predetermined operation modes. ### Claim 2 A hydraulic drive control device of a construction machine comprising an engine and a hydraulic pump for a work machine that is driven by said engine, said device comprising: an operation state detector for detecting an operation state of said work machine; and a controller for receiving a signal from said operation state detector and controlling said engine and said hydraulic pump for said work machine, wherein said controller receives the signal from said operation state detector and identifies an operation mode performed with respect to said work machine; determines an engine output torque control line and a pump torque control line having a desired matching point according to said identified operation mode so that different engine output torque control lines and different pump torque control lines are designated for different operation modes; controls an output torque of said engine based on said determined engine output torque control line; and controls an absorption torque of said hydraulic pump for said work machine based on said determined pump torque control line, wherein said controller determines said engine output torque control line and said pump torque control line so that a torque at said matching point of said determined engine output torque control line and said determined pump torque control line assumes a substantially constant predetermined value for any identified operation mode, when said identified operation mode corresponds to any of a plurality of predetermined operation modes. ### Claim 3 A hydraulic drive control device of a construction machine comprising an engine and a hydraulic pump for a work machine that is driven by said engine, said device comprising: an operation state detector for detecting an operation state of said work machine; and a controller for receiving a signal from said operation state detector and controlling said engine and said hydraulic pump for said work machine, wherein said controller receives the signal from said operation state detector and identifies an operation mode performed with respect to said work machine; determines an engine output torque control line and a pump torque control line having a desired matching point according to said identified operation mode so that different engine output torque control lines and different pump torque control lines are designated for different operation modes; controls an output torque of said engine based on said determined engine output torque control line; controls an absorption torque of said hydraulic pump for said work machine based on said determined pump torque control line; and a hydraulic pump for an auxiliary machine, which is driven by said engine and serves to drive said auxiliary machine of said construction machine, wherein said controller determines an absorption horsepower of said hydraulic pump for said work machine that is to be absorbed by said hydraulic pump for said work machine, according to said identified operation mode so that different absorption horsepower of said hydraulic pump for said work machine is designated for different operation modes; detects a predetermined state value relating to an operation of said auxiliary machine and determines an absorption horsepower of said hydraulic pump for said auxiliary machine that is to be absorbed by said hydraulic pump for said auxiliary machine, according to said detected state value; and controls said engine so that an output horsepower of said engine becomes a sum of said determined absorption horsepower of the pump for the work machine and said determined absorption horsepower of said hydraulic pump for said auxiliary machine. ### Claim 4 (depends on 3) The hydraulic drive control device of a construction machine according to claim 3, wherein said controller controls said hydraulic pump for said work machine so that the absorption torque of said hydraulic pump for said work machine follows said determined pump torque control line; and determines a target revolution speed of said auxiliary machine according to said detected state value and controls a capacity of said hydraulic pump for said auxiliary machine so that said auxiliary machine can be driven at said determined target revolution speed. ### Claim 5 A method for controlling hydraulic drive of a construction machine comprising an engine and a hydraulic pump for a work machine that is driven by said engine, said method comprising: a step of identifying an operation mode performed with respect to said work machine; a step of determining an engine output torque control line and a pump torque control line having a desired matching point according to said identified operation mode so that different engine output torque control lines and different pump torque control lines are designated for different operation modes; a step of controlling an output torque of said engine based on said determined engine output torque control line; a step of controlling an absorption torque of said hydraulic pump for said work machine based on said determined pump torque control line, wherein said engine output torque control line and said pump torque control line are controlled so that an engine revolution speed at said matching point of said determined engine output torque control line and said determined pump torque control line assumes a substantially constant predetermined value for any identified operation mode, when said identified operation mode corresponds to any of a plurality of predetermined operation modes. ### Claim 6 A method for controlling hydraulic drive of a construction machine comprising an engine and a hydraulic pump for a work machine that is driven by said engine, said method comprising: a step of identifying an operation mode performed with respect to said work machine; a step of determining an engine output torque control line and a pump torque control line having a desired matching point according to said identified operation mode so that different engine output torque control lines and different pump torque control lines are designated for different operation modes; a step of controlling an output torque of said engine based on said determined engine output torque control line; a step of controlling an absorption torque of said hydraulic pump for said work machine based on said determined pump torque control line, wherein said engine output torque control line and said pump torque control line are determined so that a torque at said matching point of said determined engine output torque control line and said determined pump torque control line assumes a substantially constant predetermined value for any identified operation mode, when said identified operation mode corresponds to any of a plurality of predetermined operation modes. ### Claim 7 A method for controlling hydraulic drive of a construction machine comprising an engine and a first hydraulic pump for a work machine that is driven by said engine, and a second hydraulic pump for an auxiliary machine, which is driven by said engine and serves to drive said auxiliary machine of said construction machine said method comprising: a step of identifying an operation mode performed with respect to said work machine; a step of determining an engine output torque control line and a pump torque control line having a desired matching point according to said identified operation mode so that different engine output torque control lines and different pump torque control lines are designated for different operation modes; a step of controlling an output torque of said engine based on said determined engine output torque control line; a step of controlling an absorption torque of said hydraulic pump for said work machine based on said determined pump torque control line, wherein an absorption horsepower of said hydraulic pump for said work machine that is to be absorbed by said hydraulic pump for said work machine is determined, according to said identified operation mode so that different absorption horsepower of said hydraulic pump for said work machine is designated for different operation modes, wherein a predetermined state value relating to an operation of said auxiliary machine is detected and an absorption horsepower of said hydraulic pump for said auxiliary machine that is to be absorbed by said hydraulic pump for said auxiliary machine is determined, according to said detected state value, and wherein said engine is controlled so that an output horsepower of said engine becomes a sum of said determined absorption horsepower of the pump for the work machine and said determined absorption horsepower of said hydraulic pump for said auxiliary machine. ### Claim 8 A method for controlling hydraulic drive of a construction machine comprising an engine and a first hydraulic pump for a work machine that is driven by said engine, and a second hydraulic pump for an auxiliary machine, which is driven by said engine and serves to drive said auxiliary machine of said construction machine, said method comprising: a step of identifying an operation mode performed with respect to said work machine; a step of determining an engine output torque control line and a pump torque control line having a desired matching point according to said identified operation mode so that different engine output torque control lines and different pump torque control lines are designated for different operation modes; a step of controlling an output torque of said engine based on said determined engine output torque control line; a step of controlling an absorption torque of said hydraulic pump for said work machine based on said determined pump torque control line, wherein said hydraulic pump for said work machine is controlled so that the absorption torque of said hydraulic pump for said work machine follows said determined pump torque control line; and wherein a target revolution speed of said auxiliary machine is determined according to said detected state value and a capacity of said hydraulic pump for said auxiliary machine is controlled so that said auxiliary machine can be driven at said determined target revolution speed.