Work vehicle and method of controlling work vehicle

Abstract

A first switch valve is connected to a cap-side circuit of a lift cylinder. A second switch valve is connected to a head-side circuit of the lift cylinder. A first accumulator is connected to the cap-side circuit of the lift cylinder with the first switch valve being interposed. A second accumulator is connected to the head-side circuit of the lift cylinder with the second switch valve being interposed. A third switch valve is connected between the first accumulator and the second accumulator.

1 . A work vehicle comprising:
 a work implement;   a cylinder which drives the work implement;   a first switch valve connected to a cap-side circuit of the cylinder;   a second switch valve connected to a head-side circuit of the cylinder;   a first accumulator connected to the cap-side circuit of the cylinder with the first switch valve being interposed;   a second accumulator connected to the head-side circuit of the cylinder with the second switch valve being interposed; and   a third switch valve connected between the first accumulator and the second accumulator.   
     
     
         2 . The work vehicle according to  claim 1 , the work vehicle further comprising a controller configured to control the first switch valve, the second switch valve, and the third switch valve such that the first switch valve is open and the second switch valve and the third switch valve are closed in a shock absorption mode of the work implement and such that the first switch valve is closed and the second switch valve and the third switch valve are open in a vibration suppression mode of the work vehicle. 
     
     
         3 . The work vehicle according to  claim 1 , the work vehicle further comprising a manual switch which allows selection between a state that the first switch valve is open and the second switch valve and the third switch valve are closed and a state that the first switch valve is closed and the second switch valve and the third switch valve are open. 
     
     
         4 . The work vehicle according to  claim 1 , the work vehicle further comprising a front wheel and a rear wheel, wherein the work implement is arranged between the front wheel and the rear wheel. 
     
     
         5 . The work vehicle according to  claim 4 , wherein the work implement is at least one of a blade and a scarifier. 
     
     
         6 . The work vehicle according to  claim 1 , the work vehicle further comprising a front wheel and a rear wheel, wherein
 the work implement is arranged at least one of a position in front of the front wheel and a position in rear of the rear wheel.   
     
     
         7 . The work vehicle according to  claim 6 , wherein the work implement is at least one of a front blade and a ripper. 
     
     
         8 . The work vehicle according to  claim 1 , the work vehicle being a grader. 
     
     
         9 . A method of controlling a work vehicle, the work vehicle including a work implement, a cylinder which drives the work implement, a first switch valve connected to a cap-side circuit of the cylinder, a second switch valve connected to a head-side circuit of the cylinder, a first accumulator connected to the cap-side circuit of the cylinder with the first switch valve being interposed, a second accumulator connected to the head-side circuit of the cylinder with the second switch valve being interposed, and a third switch valve connected between the first accumulator and the second accumulator, the method comprising:
 controlling the first switch valve to open and controlling the second switch valve and the third switch valve to close in a shock absorption mode of the work implement and controlling the first switch valve to close and controlling the second switch valve and the third switch valve to open in a vibration suppression mode of the work vehicle.