# US 10,767,342 B2 · Work vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,767,342 B2 - Document ID: US10767342B2 - Status: Granted - Kind: B2 - Application number: 16/489,795 - Filed: 2018-09-04 - Published: 2020-01-09 - Granted: 2020-09-08 - Earliest claimed: 2017-09-26 - Assignees: Hitachi Construction Machinery Co., Ltd. - Applicants: Hitachi Construction Machinery Co., Ltd. - Inventors: Koji Hyodo; Isamu Aoki; Tetsuji Tanaka; Koji Shimazaki - Web page: https://patentgrep.com/patent/US10767342B2 ## CPC - E02F 9/003: {Devices for transporting the soil-shifting machines or excavators, e.g. by pushing them or by hitching them to a tractor} - F01P 7/044: {using hydraulic drives} - B60K 11/02: with liquid cooling - B60K 11/04: Arrangement or mounting of radiators, radiator shutters, or radiator blinds - E02F 9/226: {Safety arrangements, e.g. hydraulic driven fans, preventing cavitation, leakage, overheating} - F01P 5/04: Pump-driving arrangements - F01P 5/043: {Pump reversing arrangements} - F01P 11/12: Filtering, cooling, or silencing cooling-air - B60L 2200/40: Working vehicles - B60W 2300/17: Construction vehicles, e.g. graders, excavators - E02F 9/2264: {Arrangements or adaptations of elements for hydraulic drives} - F01P 11/14: Indicating devices; Other safety devices - F01P 11/16: concerning coolant temperature (F01P11/20 takes precedence) - F01P 2025/08: Temperature - F01P 2025/13: Ambient temperature - F01P 2025/32: Engine outcoming fluid temperature - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) - F01P: COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES (arrangements in connection with cooling of propulsion units in vehicles B60K11/00; heat-transfer, heat-exchange or heat-storage materials C09K5/00; {cooling of gas-turbine engines F02C7/12}; heat exchange in general, radiators F28) - 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 - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED 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 ## Abstract The work vehicle includes an engine, a radiator; a hydraulic pump; a cooling fan that blows a cooling air to the radiator; a hydraulic motor which is driven by a pressure oil delivered from the hydraulic pump, and rotates the cooling fan; a directional control valve that switches a flow direction of the pressure oil from the hydraulic pump to rotate the hydraulic motor in forward and reverse directions; and a controller that controls the directional control valve so as to cause the repetitive operation of the forward and reverse rotation of the cooling fan to be performed at predetermined time intervals, in which the controller reduces the time intervals more than a normal time initially set when a relationship between the outside air temperature detected by the outside air temperature sensor and the refrigerant temperature detected by the refrigerant temperature sensor satisfies a predetermined condition. ## Claims ### Claim 1 A work vehicle comprising: an engine; a radiator that cools a refrigerant of the engine; a hydraulic pump that is driven by the engine; a refrigerant temperature sensor that detects a temperature of the refrigerant; an outside air temperature sensor that detects a temperature of an outside air; a thermostat that opens and closes a flowpath between a fully closed state and a fully opened state in accordance with the temperature of the refrigerant on the flowpath for supplying the refrigerant to the radiator; a hydraulic motor which is driven by a pressure oil delivered from the hydraulic pump, and rotates a cooling fan for blowing a cooling air to the radiator; a directional control valve that switches the flow direction of the pressure oil from the hydraulic pump to rotate the hydraulic motor in forward and reverse directions; and a control device that controls the directional control valve to cause the repetitive operation of the forward and reverse rotation of the cooling fan to be performed at predetermined time intervals, wherein the control device changes setting of the time intervals when a relationship between the outside air temperature detected by the outside air temperature sensor and the refrigerant temperature detected by the refrigerant temperature sensor satisfies a predetermined condition defined in advance, the predetermined condition includes a high temperature condition in which the outside air temperature detected by the outside air temperature sensor is higher than a reference value, and a low temperature condition in which the outside air temperature is lower than the reference value, and the control device reduces the time interval more than a normal time initially set when the refrigerant temperature detected from the refrigerant temperature sensor reaches a first set temperature under the low temperature condition or when the refrigerant temperature detected from the refrigerant temperature sensor reaches a second set temperature higher than the first set temperature under the high temperature condition. ### Claim 2 (depends on 1) The work vehicle according to claim 1, wherein the control device returns the time intetrval to the normal time when the refrigerant temperature detected from the refrigerant temperature sensor reaches a low temperature side reference value lower than the first set temperature under the low temperature condition, or when the refrigerant temperature detected from the refrigerant temperature sensor reaches a high temperature side reference value lower than the second set temperature under the high temperature condition, after the time interval is reduced more than the normal time. ### Claim 3 (depends on 2) The work vehicle according to claim 2, wherein the first set temperature and the low temperature side reference value are defined within a temperature range of the refrigerant in which the thermostat fully opens from fully closed. ### Claim 4 (depends on 2) The work vehicle according to claim 2, wherein the second set temperature is equal to or higher than the temperature of the refrigerant at which the thermostat is fully opened. ### Claim 5 (depends on 1) The work vehicle according to claim 1, wherein the control device returns the interval time to the normal time when the engine is stopped after the interval time is reduced more than the normal time. ### Claim 6 (depends on 3) The work vehicle according to claim 3, wherein the second set temperature is equal to or higher than the temperature of the refrigerant at which the thermostat is fully opened.