# US 11,993,917 B2 · Working vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,993,917 B2 - Document ID: US11993917B2 - Status: Granted - Kind: B2 - Application number: 17/849,868 - Filed: 2022-06-27 - Published: 2023-02-09 - Granted: 2024-05-28 - Earliest claimed: 2021-08-06 - Assignees: Takeuchi Mfg. Co., Ltd. - Applicants: Takeuchi Mfg. Co., Ltd. - Inventors: Shumpei Okutani - Web page: https://patentgrep.com/patent/US11993917B2 ## CPC - B60L 3/0046: {relating to electric energy storage systems, e.g. batteries or capacitors} - E02F 9/207: {of the type electric propulsion units, e.g. electric motors or generators} - E02F 9/2091: {Control of energy storage means for electrical energy, e.g. battery or capacitors (energy recovery arrangements in hydraulic or pneumatic drives E02F9/2217)} - E02F 9/2242: {including an electronic controller} - E02F 9/267: {Diagnosing or detecting failure of vehicles} - B60L 2200/40: Working vehicles - E02F 3/325: {Backhoes of the miniature type} - 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 - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) ## Abstract A working vehicle includes a drive unit having inverters, AC motors, hydraulic pumps, a battery, a controller, a battery management system, a switch, an electromagnetic contactor, and a display unit, and the switch is signal-connected to the controller, a stop signal is transmitted to the controller when the switch is turned off, and the controller performs stop control in which the AC motors are operated during a term to thereby set a residual voltage to be lower than a predetermined set voltage. ## Claims ### Claim 1 A working vehicle comprising: a drive unit including inverters, AC motors, and hydraulic pumps; a battery feeding direct current to the inverters; a controller signal-connected to the inverters; a battery management system signal-connected to the controller; a switch; an electromagnetic contactor operated by a command from the battery management system and connecting the battery to the inverters; and a display unit signal-connected to the controller, wherein the switch is signal-connected to the controller so as to transmit a stop signal, the electromagnetic contactor is controlled to be off by the battery management system and the stop signal is transmitted to the controller when the switch is turned off, and the controller having received the stop signal performs stop control in which the AC motors are operated during a term from a point when the switch is turned off until reaching a prescribed time to thereby set a residual voltage in the inverters at the point when reaching the prescribed time to be lower than a predetermined set voltage which has been previously set. ### Claim 2 (depends on 1) The working vehicle according to claim 1, wherein, when the controller determines that the residual voltage is equal to or higher than the predetermined set voltage, the controller transmits a first error signal to the display unit, and the display unit having received the first error signal displays a first error indication. ### Claim 3 (depends on 2) The working vehicle according to claim 2, wherein, when the controller determines that the residual voltage is equal to or higher than the predetermined set voltage, the controller transmits a second error signal to the display unit when the display unit is restarted, and the display unit having received the second error signal displays a second error indication. ### Claim 4 (depends on 1) The working vehicle according to claim 1, wherein the switch is signal-connected to the controller so as to transmit a start signal, the electromagnetic contactor is controlled to be on by the battery management system and the start signal is transmitted to the controller when the switch is turned on, and the controller having received the start signal performs start control of the AC motors. ### Claim 5 (depends on 1) The working vehicle according to claim 1, wherein the drive unit includes a first drive unit and a second drive unit, the inverters include a first inverter and a second inverter, the AC motors include a first AC motor and a second AC motor, the hydraulic pumps include a first hydraulic pump and a second hydraulic pump, the first drive unit has the first inverter, the first AC motor, and the first hydraulic pump, the second drive unit has the second inverter, the second AC motor, and the second hydraulic pump, and the controller having received the stop signal controls the first inverter and the second inverter respectively to operate the first AC motor and the second AC motor respectively during the term. ### Claim 6 (depends on 5) The working vehicle according to claim 5, wherein, when the switch is turned off, hydraulic oil from the first hydraulic pump is not discharged to a first actuator operated in response to the first hydraulic pump, and hydraulic oil from the second hydraulic pump is not discharged to a second actuator operated in response to the second hydraulic pump.