US 12,352,012 B2 · Working machine

Abstract

A working machine includes a prime mover, a traveling pump driven by power of the prime mover to deliver hydraulic fluid, a traveling motor rotated by the hydraulic fluid delivered from the traveling pump, an operation valve configured to change a pilot pressure of pilot fluid output therefrom to the traveling pump according to operation of an operation member, an actuation valve to be activated according to a control signal so as to change a primary pressure supplied to the operation valve, a controller to perform setting of the control signal to be output to the actuation valve, and a pressure detection device to detect a secondary pressure output from the operation valve. The controller includes a setting change unit to change, based on the primary pressure and the secondary pressure, the setting of the control signal to be output to the actuation valve.

Claims20

Dependent claims

A working machine comprising:

a prime mover;
a traveling pump configured to be driven by power of the prime mover so as to deliver hydraulic fluid;
a traveling motor configured to be rotated by the hydraulic fluid delivered from the traveling pump;
an operation valve configured to change a pilot pressure of pilot fluid output therefrom to the traveling pump according to operation of an operation member;
an actuation valve configured to be activated according to a control signal so as to change a primary pressure that is the pilot pressure of the pilot fluid to be supplied to the operation valve;
a controller configured or programmed to perform setting of the control signal to be output to the actuation valve;
and
a pressure detection device configured to detect a secondary pressure that is the pilot pressure output from the operation valve, wherein
the controller includes
a setting change unit configured or programmed to change, based on the primary pressure and the secondary pressure, the setting of the control signal to be output to the actuation valve.

7 more elements

A working machine comprising:

a prime mover;
a traveling pump configured to be driven by power of the prime mover so as to deliver hydraulic fluid;
a traveling motor configured to be rotated by the hydraulic fluid delivered from the traveling pump;
an operation valve configured to change a pilot pressure of pilot fluid output therefrom to the traveling pump according to operation of an operation member;
an actuation valve configured to be activated according to a control signal so as to change a primary pressure that is the pilot pressure of the pilot fluid to be supplied to the operation valve;
a rotation speed detection device configured to detect an actual rotation speed of the prime mover;
and
a controller configured or programmed to perform setting of the control signal to be output to the actuation valve, wherein
the controller includes
a calculation unit configured or programmed to calculate a derivative representing a rate of change of the actual rotation speed per unit time, and
a setting change unit configured or programmed to change, based on the derivative calculated by the calculation unit, the setting of the control signal to be output to the actuation valve.

8 more elements

A working machine comprising:

a prime mover;
a traveling pump configured to be driven by power of the prime mover so as to deliver hydraulic fluid;
a traveling motor configured to be rotated by the hydraulic fluid delivered from the traveling pump;
an operation valve configured to change a pilot pressure of pilot fluid output therefrom to the traveling pump according to operation of an operation member;
an actuation valve configured to be activated according to a control signal so as to change a primary pressure that is the pilot pressure of the pilot fluid to be supplied to the operation valve;
a controller configured and programmed to perform setting of the control signal to be output to the actuation valve;
a circulation fluid passage fluidly connecting the traveling pump to the traveling motor;
and
a pressure detection device configured to detect a traveling pressure that is a pressure of the hydraulic fluid in the circulation fluid passage, wherein
the controller includes
a setting change unit configured or programmed to change, based on the traveling pressure, the setting of the control signal to be output to the actuation valve.

8 more elements

Dependencies are inferred from the claim text.

Working machine

Life of this patent

Working machine

Life of this patent

Abstract

Claims20