Work machine

A work machine comprising:

• a machine body;
• an articulated work device that has a boom, an arm, and work equipment and is attached to the machine body;
• an operation device that operates the machine body and the work device;
• a position sensor that senses a position of the machine body;
• a posture sensor that senses posture of the work device;
• and a controller having an input interface, an output interface, a CPU, and memory that sets a target surface, and is configured to calculate a work equipment-to-target surface distance that is a distance from the work equipment to the target surface on a basis of the position of the machine body sensed by the position sensor and the posture of the work device sensed by the posture sensor, and control the boom and carry out deceleration control to decelerate the arm to keep the work equipment from excavating ground beyond the target surface when operation of the arm is carried out by the operation device and the work equipment-to-target surface distance has become shorter than a predetermined distance, wherein
• the controller is configured to calculate an angle between a predetermined straight line parallel to a line segment that links an arm pin, the arm pin joining the boom and the arm, with the work equipment and the target surface on the side of the machine body relative to the predetermined straight line when the predetermined straight line is located on the target surface, on a basis of the target surface that is set, the position of the machine body sensed by the position sensor, and the posture of the work device sensed by the posture sensor,
• the controller is configured to determine that the posture of the work device is not an entry posture at which the work equipment enters the target surface when the angle between the predetermined straight line and the target surface is equal to or larger than 90° when a crowding operation of the arm is carried out,
• the controller is configured to determine that the posture of the work device is not the entry posture when the angle between the predetermined straight line and the target surface is smaller than 90° when a dumping operation of the arm is carried out, and
• the controller is configured not to carry out the deceleration control when the work equipment-to-target surface distance is shorter than the predetermined distance in a case in which it is determined that the posture of the work device is not the entry posture,
• wherein the controller is further configured to
• gradually change velocity of the arm upon transitioning from a state in which the deceleration control is carried out to a state in which the deceleration control is not carried out according to change in the angle formed by the line segment and the target surface being larger than 90° when a crowding operation of the arm is carried out and it is determined that the posture of the work device is not the entry posture, and
• gradually change velocity of the arm upon transitioning from a state in which the deceleration control is carried out to a state in which the deceleration control is not carried out according to change in the angle formed by the line segment and the target surface being smaller than 90° when a dumping operation of the arm is carried out and it is determined that the posture of the work device is not the entry posture.