Apparatus for controlling tilt of axle for industrial vehicle, and apparatus and method for estimating center of gravity for industrial vehicle

An apparatus for controlling the tilt of an axle, the axle being supported by a body frame of an industrial vehicle to be tiltable in a vertical direction, wherein the vehicle has a front wheel and a rear wheel that are spaced apart by a predetermined distance in the fore-and-aft direction of the vehicle, a carrier for carrying an object and a locking mechanism for locking the axle against tilt, wherein the front wheel is a drive wheel that transmits driving force to a road surface, and wherein the rear wheel is a steered wheel that is supported by the axle and is steered for turning the vehicle, the apparatus comprising:

• a first determiner for determining whether the traveling state of the vehicle satisfies a locking condition, which is predetermined in consideration of the height of the center of gravity of the vehicle;
• means for detecting the location of the center of gravity in the fore-and-aft direction of the vehicle;
• a second determiner for determining whether the location of the center of gravity detected by the means for detecting satisfies a predetermined locking permitting condition;
• and
• wherein the means for detecting includes a controller for actuating the locking mechanism to lock the axle when the first determiner determines that the locking condition is satisfied and the second determiner determines that the locking permitting condition is satisfied.

An apparatus for estimating the location of the center of gravity in the fore-and-aft direction of an industrial vehicle, wherein the vehicle has a carrier for carrying an object, and wherein the carrier is tiltable with respect to a body frame of the vehicle and is lifted and lowered with respect to the body frame, the apparatus comprising:

• an angle detector for detecting the tilt angle of the carrier;
• a height detector for detecting the height of the carrier;
• a weight detector for detecting the weight of an object on the carrier;
• and
• an estimator for estimating the location of the center of gravity in the fore-and-aft direction of the vehicle based on the detected tilt angle, height and weight.

An apparatus for estimating the location of the center of gravity in the fore-and-aft direction of an industrial vehicle, wherein the vehicle has a carrier for carrying an object, and wherein the carrier is tiltable with respect to a body frame of the vehicle and is lifted and lowered with respect to the body frame, the method comprising the steps of:

• detecting the tilt angle of the carrier;
• detecting the height of the carrier;
• detecting the weight of an object on the carrier;
• and
• estimating the location of the center of gravity in the fore-and-aft direction of the vehicle based on the detected tilt angle, height and weight.