Excavator
An excavator includes: a traveling lower body including left and right crawlers; a revolving upper body on the traveling lower body, to be capable of revolving; hydraulic motors to drive the crawlers; left and right traveling operation device to drive the hydraulic motors; a hydraulic pump to supply hydraulic oil to the hydraulic motors; and a detector to detect states of the traveling operation devices. The excavator causes the detector to detect whether there is a predetermined difference between amounts of operations of the left and right traveling operation devices, and upon detecting the predetermined difference between the amounts of operations of the left and right traveling operation devices, suppresses an amount of change in a command value related to a flow rate of the hydraulic oil discharged by the hydraulic pump.
1 . An excavator comprising:
a traveling lower body including a crawler, the crawler including a left crawler and a right crawler;
a revolving upper body installed on the traveling lower body, and configured to be capable of revolving;
a traveling hydraulic motor configured to drive the crawler;
a traveling operation device configured to operate the traveling hydraulic motor, the traveling operation device including a left traveling operation device corresponding to the left crawler and a right traveling operation device corresponding to the right crawler;
a hydraulic pump configured to supply hydraulic oil to the traveling hydraulic motor;
a detector configured to detect an operation state of the traveling operation device; and
a hardware processor configured to
determine whether there is a predetermined difference between an amount of operation of the left traveling operation device and an amount of operation of the right traveling operation device based on an output of the detector, and
upon determining that there is the predetermined difference between the amount of operation of the left traveling operation device and the amount of operation of the right traveling operation device, suppress an amount of change in a command value related to a flow rate of the hydraulic oil discharged by the hydraulic pump so that the flow rate of the hydraulic oil discharged by the hydraulic pump changes within a predetermined range defined by an upper limit and a lower limit.
2 . The excavator as claimed in claim 1 , wherein the hardware processor is configured to determine that the traveling lower body is turning and suppress the change in the flow rate of the hydraulic oil discharged by the hydraulic pump, upon determining that there is the predetermined difference between the amount of operation of the left traveling operation device and the amount of operation of the right traveling operation device.
3 . The excavator as claimed in claim 2 , wherein the predetermined difference occurs in a case where, with respect to operation amounts of the left traveling operation device and the right traveling operation device, one of the operation amounts is increased; one of the operation amounts is decreased; both of the operation amounts are increased; or both of the operation amounts are decreased.
4 . The excavator as claimed in claim 1 , wherein the hardware processor is configured to suppress the amount of change in the command value related to the flow rate of the hydraulic oil discharged by the hydraulic pump, based on a pressure of the hydraulic oil flowing through a hydraulic circuit or an amount of operation of the traveling operation device.
5 . The excavator as claimed in claim 1 , wherein a value corresponding to the upper limit and a value corresponding to the lower limit are set for the amount of change in the command value.
6 . The excavator as claimed in claim 5 , wherein the hardware processor is configured to suppress the amount of change in the command value within a range between the value corresponding to the upper limit and the value corresponding to the lower limit.
7 . The excavator as claimed in claim 6 , wherein the range of the command value is set so that a difference between the command value used in a previous control period and the command value used in a current control period is less than or equal to a predetermined value.
8 . The excavator as claimed in claim 1 , wherein the hydraulic pump is an electronically-controlled variable-capacity hydraulic pump.
9 . The excavator as claimed in claim 1 , further comprising:
a pump regulator configured to control a discharge amount of the hydraulic pump,
wherein the hardware processor is further configured to suppress the amount of change in the command value transmitted from the hardware processor to the pump regulator.
10 . The excavator as claimed in claim 1 , further comprising:
an attachment attached to the revolving upper body;
an attachment actuator configured to drive the attachment; and
an attachment operation device configured to operate the attachment actuator,
wherein the detector is further configured to detect an operation state of the attachment operation device, and
the hardware processor is further configured to
determine whether the traveling operation device alone is operated without the attachment operation device being operated, based on the output of the detector, and
detect the amount of operation of the left traveling operation device and the amount of operation of the right traveling operation device based on the output of the detector and determine whether there is the predetermined difference between the detected amount of operation of the left traveling operation device and the detected amount of operation of the right traveling operation device, in response to determining that the traveling operation device alone is operated without the attachment operation device being operated.