IP Library Granted Patent US 12703956
Granted Patent B2
US 12703956 · App. 18/687,853 · Granted Aug 11, 2026

Work vehicle

Inventors: Hiroaki Yada (Ryuugasaki, JP); Hiroyuki Kizaki (Nagareyama, JP); Shoroku Kawahara (Ushiku, JP)
Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
E02F3/3405E02F3/422E02F9/264
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Quick Facts
Patent No.
US 12703956
App. No.
18/687,853
Granted
Aug 11, 2026
Kind
B2
Abstract

The work vehicle includes a frame, a lift arm having a base end section attached to the frame, a work tool attached to the distal end section of the lift arm, a base-end link device attached to the frame and the base end section side of the lift arm, a distal-end link device attached to the work tool and the distal end side of the lift arm, and a work tool cylinder extending from the base-end link device toward the distal-end link device and driving the work tool via the distal-end link device. An angle detection device attached to the lift arm and detecting the angle formed by the lift arm and the distal-end link device is provided. The angle detection device is disposed between the portion of the lift arm to which the distal-end link device is connected and the base end section of the lift arm.

Claims (34)

1 . A work vehicle comprising:

a frame;

a lift arm having a base end section attached to the frame;

a work tool attached to a distal end section of the lift arm;

a base-end link device attached to the frame and the base end section side of the lift arm;

a distal-end link device attached to the work tool and the distal end section side of the lift arm;

a work tool cylinder extending from the base-end link device toward the distal-end link device and driving the work tool via the distal-end link device;

an angle detection device attached to the lift arm and detecting an angle formed by the lift arm and the distal-end link device;

a turning angle transmission mechanism coupling the distal-end link device and the angle detection device; and

a cover covering an upper side of the angle detection device and covering a surface of the angle detection device on which a rotation shaft is provided in a case of a posture in which the distal end section of the lift arm is lower than the base end section of the lift arm,

wherein:

the angle detection device is disposed between a portion of the lift arm to which the distal-end link device is connected and the base end section of the lift arm,

the rotation shaft is fixed to the turning angle transmission mechanism,

the base-end link device has:

a bell crank connecting the base end section of the work tool cylinder and the lift arm, and

a frame coupling rod connecting the bell crank and the frame, the distal-end link device has:

a work tool coupling rod connecting the distal end section of the work tool cylinder and the work tool, and

a guide member connecting the work tool coupling rod and the lift arm, the turning angle transmission mechanism has:

a first transmission bar having a base end section fixed to the rotation shaft of the angle detection device, and

a second transmission bar having a base end section turnably coupled to the distal end section of the first transmission bar and a distal end section turnably coupled to the guide member,

the first transmission bar is extensively provided downward from the rotation shaft of the angle detection device in the case of the posture in which the distal end section of the lift arm is lower than the base end section of the lift arm,

the cover is provided with an opening section, and

the lower side of the angle detection device in which the first transmission bar is extensively provided is opened through the opening section.

2 . The work vehicle according to claim 1 , further comprising

a lift arm cylinder having a base end section attached to the frame and a distal end section attached to the lift arm and driving the lift arm, wherein

the angle detection device is disposed between a portion of the lift arm to which the distal-end link device is connected and a portion of the lift arm to which the distal end section of the lift arm cylinder is connected.

3 . The work vehicle according to claim 1 , further comprising:

a piping connected to the work tool; and

a piping supporting member for fixing the piping to the lift arm, wherein

the lift arm is configured of a pair of vertical plates opposite to each other to be spaced apart from each other in a vehicle width direction,

the angle detection device is disposed between the pair of vertical plates of the lift arm, and

the piping supporting member is disposed above the angle detection device and between the pair of vertical plates of the lift arm in the case of the posture in which the distal end sections of the lift arm are lower than the base end sections of the lift arm.

4 . The work vehicle according to claim 3 , wherein

the lift arm is disposed adjacent to one side of the turning angle transmission mechanism, and the piping is disposed adjacent to the other side of the turning angle transmission mechanism.