| US 7,475,753 B2 | ||
| Drive control apparatus for forklift | ||
| Hidenori Oka, Kariya (Japan); Tadashi Yamada, Kariya (Japan); and Toshikazu Kamiya, Kariya (Japan) | ||
| Assigned to Kabushiki Kaisha Toyota Jidoshokki, Kariya-Shi (Japan) | ||
| Filed on Sep. 29, 2006, as Appl. No. 11/541,183. | ||
| Claims priority of application No. 2005-288243 (JP), filed on Sep. 30, 2005. | ||
| Prior Publication US 2008/0011530 A1, Jan. 17, 2008 | ||
| Int. Cl. B60L 8/00 (2006.01) | ||
| U.S. Cl. 180—306 [180/282; 180/54.1; 187/224] | 6 Claims |
| 1. A drive control apparatus for a forklift, wherein the forklift includes a vehicle, a drive wheel provided to the vehicle,
an engine, a power transmission mechanism capable of transmitting power of the engine to the drive wheel, a loading device
that is provided at a front portion of the vehicle and mounts a load, and a loading pump that supplies hydraulic oil to actuate
the loading device,
wherein the forklift uses the power of the engine as a driving force for driving the vehicle and as a loading force for actuating
the loading pump,
the drive control apparatus comprising:
a disconnection detection section that detects whether the power transmission mechanism is in a disconnection state, in which
the driving force is not transmitted to the drive wheel, wherein, when at least the disconnection detection section detects
the disconnection state, a limitation canceling condition is met;
an acceleration operation section that instructs acceleration of the vehicle in response to an operation by a driver;
a limitation determining section, wherein the limitation determining section determines whether to limit a maximum vehicle
speed during driving of the vehicle based on a determination of a load state or an input from an instruction section that
instructs driving limitation, and when the result of the determination is positive, the limitation determining section determines
a speed limit; and
a control section that adjusts a speed of the engine based on the amount of operation of the acceleration operation section,
and controls the driving of the vehicle;
wherein, when the determination result of the limitation determining section during the driving of the vehicle is negative,
the control section adjusts the engine speed in accordance with the operation amount of the acceleration operation section
without limiting the vehicle speed,
wherein, when the determination result of the limitation determining section during the traveling of the vehicle is positive,
the control section limits the vehicle speed and adjusts the engine speed such that the vehicle speed does not exceed the
speed limit, and
wherein, if the limitation canceling condition is met while the vehicle speed is limited, the control section cancels the
vehicle speed limitation state, and executes a loading priority control in which the actuation of the loading device is prioritized,
and wherein, in the loading priority control, the control section adjusts the engine speed in accordance with the operation
amount of the acceleration operation section.
|