Working machine

A working machine comprising:

• a machine body;
• a boom swingably attached to the machine body,
• an arm pivotally supported at a basal end portion thereof by the boom;
• a working tool supported by a tip end portion of the arm via a pivot, the tip end portion being an opposite side of the basal end portion;
• a linkage including a first link and a second link, the first link being pivotally supported at a first end thereof by the tip end portion of the arm, the second link being pivotally supported at a first end thereof by the working tool and pivotally connected at a second end thereof to a second end of the first link;
• a working tool cylinder including a cylinder tube and a piston rod extended and contracted with respect to the cylinder tube, the working tool cylinder
• having a first end in a longitudinal direction pivotally supported by the second end of the first link and the second end of the second link, and having a second end in the longitudinal direction pivotally supported by the basal end portion of the arm via a cylinder shaft,
• being configured to have a swing angle that, when the working tool cylinder is being extended from a fully contracted state to a fully extended state, gradually increases and becomes maximum in a halfway point, and then gradually reduces and the working tool cylinder reaches the fully extended state, the swing angle being defined as an angle of the working tool cylinder swinging around the cylinder shaft,
• wherein a telescopic movement of the working tool cylinder in the longitudinal direction causing the working tool to swing in a crowd direction, which is a direction approaching the arm, and to swing around the pivot in a dump direction, which is a direction opposite to the crowd direction;
• an angle sensor which detects the swing angle of the working tool cylinder around the cylinder shaft, the angle sensor detecting the swing angle of the working tool cylinder when the working tool is disposed on a dump side with respect to a neutral position, and detecting the swing angle of the working tool cylinder when the working tool is disposed on a crowd side with respect to the neutral position, the neutral position being a swing position of the working tool in a state where the swing angle of the working tool cylinder is at the maximum;
• a detection device including:
• a detected object provided on one of the cylinder tube and the piston rod;
• and
• a detector provided on the other of the cylinder tube and the piston rod wherein the detector detects the detected object,
• the detection device detecting, in response to whether the detected object is detected by the detector or not, ON and OFF signals indicating whether the working tool cylinder is extended past the state where the swing angle is at the maximum or is contracted further from the state where the swing angle is at the maximum;
• and
• a controller for determining a swing position of the working tool based on the swing angle detected by means of the angle sensor and a result of detection by means of the detection device,
• wherein the controller determines
• whether the working tool is on the dump side or the crowd side in accordance with a first detection pattern appearing in detection of the ON and OFF signals by means of the detection device when the working tool is moved in a first direction from the dump side to the crowd side, and a second detection pattern appearing in detection of the ON and OFF signals by means of the detection device when the working tool is moved in a second direction from the crowd side to the dump side, and
• based on a result of the determination whether the working tool is on the dump side or the crowd side and the swing angle of the working tool cylinder detected by the angle sensor, a location of the working tool in a swing range, which is a range where the working tool swings around the pivot.