# US 8,739,906 B2 · Hybrid-type construction machine and control method for hybrid-type construction machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,739,906 B2 - Document ID: US8739906B2 - Status: Granted - Kind: B2 - Application number: 13/377,254 - Filed: 2010-06-15 - Published: 2012-04-12 - Granted: 2014-06-03 - Earliest claimed: 2009-06-19 - Assignees: Sumitomo Heavy Industries, Ltd. - Applicants: Koji Kawashima - Inventors: Koji Kawashima - Web page: https://patentgrep.com/patent/US8739906B2 ## CPC - B60W 10/06: including control of combustion engines - B60K 6/485: Motor-assist type - B60W 10/08: including control of electric propulsion units, e.g. motors or generators - B60W 10/30: including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps - B60W 20/00: Control systems specially adapted for hybrid vehicles {(hybrid vehicle design, B60K6/00; electric vehicles B60L)} - E02F 9/123: {Drives or control devices specially adapted therefor (E02F9/125 and E02F9/128 take precedence)} - E02F 9/2075: {of the hybrid type (for vehicles in general B60W20/00)} - E02F 9/2246: {Control of prime movers, e.g. depending on the hydraulic load of work tools} - F02D 29/04: peculiar to engines driving pumps - F02D 29/06: peculiar to engines driving electric generators - B60W 2510/1075: fluid pressure, e.g. oil pressure - Y02T 10/62: Hybrid vehicles - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT - B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES - 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) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A hybrid-type construction machine includes a controller configured to control a revolution speed of an engine; a hydraulic pump configured to be driven by the engine; a motor generator configured to assist the engine; and a hydraulic circuit configured to supply an operating oil discharged from the hydraulic pump to a hydraulic load, wherein when the controller determines that the hydraulic circuit is in an excessive output state, the controller controls the revolution speed of the engine so as to be lower than an ordinary revolution speed of the engine while controlling the motor generator to generate electricity. ## Claims ### Claim 1 A hybrid-type construction machine comprising: a controller configured to control a revolution speed of an engine; a hydraulic pump configured to be driven by the engine; a motor generator configured to assist the engine; a hydraulic circuit configured to supply an operating oil discharged from the hydraulic pump to a hydraulic load; a first pressure sensor configured to detect a pressure of the operating oil discharged from the hydraulic pump; a control valve provided in the hydraulic circuit and configured to control a flow of the operating oil into the hydraulic load; a negative control metering valve provided between the control valve and a tank; and a second pressure sensor provided between the control valve and the negative control metering valve and configured to detect negative control pressure, wherein the controller compares a first discharge quantity of the hydraulic pump acquired from a detection value of the first pressure sensor with a second discharge quantity of the hydraulic pump acquired from a detection value of the second pressure sensor, and wherein, when the controller determines that the hydraulic circuit is in an excessive output state, the controller controls the revolution speed of the engine so as to be lower than an ordinary revolution speed of the engine while controlling the motor generator to generate electricity depending on a result of the comparison between the first discharge quantity of the hydraulic pump with the second discharge quantity of the hydraulic pump. ### Claim 2 (depends on 1) The hybrid-type construction machine according to claim 1, further comprising: a relief valve configured to return the operating oil discharged from the hydraulic pump to a tank when a pressure inside the hydraulic circuit exceeds a predetermined pressure, wherein, while the operating oil is returned to the tank via the relief valve, the controller controls the revolution speed of the engine so as to be lower than the ordinary revolution speed of the engine while controlling the motor generator to generate the electricity. ### Claim 3 (depends on 2) The hybrid-type construction machine according to claim 2, wherein the controller determines that the hydraulic circuit is in the excessive output state using the result of the comparison between the first discharge quantity of the hydraulic pump with the second discharge quantity of the hydraulic pump. ### Claim 4 (depends on 1) The hybrid-type construction machine according to claim 1, wherein the controller controls the motor generator so as to run as a motor when the revolution speed of the engine is increased. ### Claim 5 (depends on 1) The hybrid-type construction machine according to claim 1, wherein the controller controls the motor generator with a torque control when the revolution speed of the engine is maintained to have a predetermined value. ### Claim 6 (depends on 1) The hybrid-type construction machine according to claim 1, wherein the controller controls the motor generator with a revolution speed control when the revolution speed of the motor generator is increased or decreased. ### Claim 7 (depends on 1) The hybrid-type construction machine according to claim 1, wherein the controller determines that the hydraulic circuit is in the excessive output state relative to an operation condition of the hydraulic load. ### Claim 8 A control method of a hybrid-type construction machine including a hydraulic pump configured to be driven by the engine, a motor generator configured to assist the engine, a hydraulic circuit configured to supply an operating oil discharged from the hydraulic pump to a hydraulic load, a first pressure sensor configured to detect a pressure of the operating oil discharged from the hydraulic pump, a control valve provided in the hydraulic circuit and configured to control a flow of the operating oil into the hydraulic load, a negative control metering valve provided between the control valve and a tank, and a second pressure sensor provided between the control valve and the negative control metering valve and configured to detect negative control pressure, the control method comprising: comparing a first discharge quantity of the hydraulic pump acquired from a detection value of the first pressure sensor with a second discharge quantity of the hydraulic pump acquired from a detection value of the second pressure sensor; determining whether the hydraulic circuit is in an excessive output state; and controlling a revolution speed of the engine so as to be lower than an ordinary revolution speed of the engine by controlling the motor generator to generate electricity depending on a result of the comparison between the first discharge quantity of the hydraulic pump with the second discharge quantity of the hydraulic pump. ### Claim 9 (depends on 8) The control method of the hybrid-type construction machine according to claim 8, wherein the controlling is to run the motor generator as a motor when the revolution speed of the engine is increased. ### Claim 10 (depends on 8) The control method of the hybrid-type construction machine according to claim 8, wherein the controlling is to control the motor generator with a torque control when the revolution speed of the engine is maintained to have a predetermined value. ### Claim 11 (depends on 8) The control method of the hybrid-type construction machine according to claim 8, wherein the controlling is to control the motor generator with a revolution speed control when the revolution speed of the motor generator is increased or decreased. ### Claim 12 (depends on 8) The control method of the hybrid-type construction machine according to claim 8, wherein the controlling is to determine that the hydraulic circuit is in the excessive output state relative to an operation condition of the hydraulic load. ### Claim 13 A hybrid-type construction machine comprising: a controller configured to control a revolution speed of an engine; a hydraulic pump configured to be driven by the engine; a motor generator configured to assist the engine; and a hydraulic circuit configured to supply an operating oil discharged from the hydraulic pump to a hydraulic load, wherein when the controller determines that the hydraulic circuit is in an excessive output state, the controller controls the revolution speed of the engine so as to be lower than an ordinary revolution speed of the engine while controlling the motor generator to generate electricity, and wherein the controller controls the motor generator at least with a torque control or a revolution speed control, and the torque control is switched to the revolution speed control when the revolution speed of the motor generator is decreased.