| 摘要 |
PROBLEM TO BE SOLVED: To ensure initial travel operability regardless of low or high speed traveling operation according to a traveling speed selection switch. SOLUTION: A traveling system includes a variable displacement hydraulic pump 2, a variable displacement traveling motor 4 connected to the hydraulic pump 2, the traveling speed selection switch 5, a solenoid valve 6 controlling a swash plate tilt angle of the traveling motor 4 according to a signal from the traveling speed selection switch 5, a traveling operation device 8 controlling a running spool 7 controlling the traveling motor 4, an manipulated variable sensor 9 sensing the manipulated variable of the traveling operation device 8, and a control part 11 outputting an electrical signal to a solenoid proportional control valve 10 variably controlling a delivery rate of the hydraulic pump 2. When high speed travel is selected by the traveling speed selection switch 5 and operation of traveling by the traveling operation device is sensed, a swash plate tilt angle of the hydraulic pump 2 is variably controlled in proportion to the electrical signal from the control part 11 to adjust a delivery rate of the hydraulic pump 2 to a delivery rate exceeding that of low speed traveling by a given amount. COPYRIGHT: (C)2010,JPO&INPIT |
