Hitachi Construction Machinery Co., Ltd.

Takeshi Iwaki

Kazunori Ishihara

Atsushi Kitaguchi

Jun Ikeda

Takayuki Satou

Yasuki Kita

Yoshifumi Nabeshima

Takashi Sasaki

Tomoya Ishii

When a tilt in a right-and-left direction occurs in a cargo bed () being raised due to imbalance of excavated materials, the tilt is detected as a roll angle (θR), and it is determined whether the absolute value (|θR|) of the roll angle is not less than an imbalance determination value (θ) (S). When the absolute value is not less than the imbalance determination value (θ) (Yes in S) and the roll angle (θR) is positive (the cargo bed () is rising to the right) (Yes in S), an oil supply amount (VL) to a hoist cylinder () on the left side is increased, and an oil supply amount (VR) to a hoist cylinder () on the right side is decreased (S). When the roll angle (θR) is negative (the cargo bed () is rising to the left) (No in S), the oil supply amount (VL) on the left side is decreased, and the oil supply amount (VR) on the right side is increased (S).

Cargo bed raising and lowering apparatus of dump truck

A dump truck pitching control system that can improve the ride quality of a vehicle body and the drive stability during traveling is provided. The present invention includes: a pitching state amount detection sectionthat detects a state amount of the pitching movement of the vehicle body; a spring characteristics calculation sectionthat calculates spring characteristics of suspension cylinders, based on detection results of stroke sensors, pressure sensors, and temperature sensors; a pitching target amount calculation sectionthat calculates a target amount of the pitching movement of the vehicle body, according to the spring characteristics calculated by the spring characteristics calculation section; and a torque correction value calculation sectionthat calculates a torque correction value required to correct the pitching amount, according to the spring characteristics calculated by the spring characteristics calculation section

Dump truck pitching control system

Stresses are decreased at joints of a support structure disposed on a body of a dump truck. The dump truck includes a body frame (), a body (), a support structure () disposed on the body and supported by the body frame, and load transmission structures configured to transmit a load from the support structure to the body frame and, to transmit a reaction force from the body frame to the support structure. The support structure has a plurality of vertical plates () and a bottom plate (). The vertical plates are arranged along a direction in which the reaction force is received from the body frame, and the bottom plate is maintained in upward contact with these vertical plates. The bottom plate is divided into first areas and a second area. The first areas include areas where the bottom plate is in contact with the vertical plates, and the second area is an area other than the first areas. The load transmission structures are configured to transmit the reaction force from the body frame such that a reaction force to be transmitted to each of the first areas becomes greater than a reaction force to be transmitted to the second area.

Dump truck and load transmission structure for same

A dump truck is provided with a frame, hinge pins and a body (). The body is provided on a lower surface of a floor board () thereof with a rail () along a longitudinal direction of the frame. The rail is a hollow structure member comprised of two side rail plates () and a bottom rail plate (). The two side rail plates () extend downwardly from the lower surface of the floor board () of the body and oppose each other with an interval therebetween in a lateral direction of the frame, and the bottom rail plate () is arranged in contact with respective lower end surfaces (-) of these two side rail plates (). The dump truck () satisfies a relationship of Ts&#x3c;Tb&#x3c;Tf, where Ts is a thickness of the side rail plates, Tb is a thickness of the bottom rail plate, and Tf is a thickness of a top frame plate (-) of the frame.

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Tsuchiura, Japan

Takeshi Iwaki