Patent ID: 8607917
Filing Date: 2013-12-17
Classification: B60K,B60Y,F03C,F04B,F15B,F16H,Y10T

Abstract:
1. An electrically-operated hydraulic actuator unit comprising a variable displacement hydraulic actuator, an electrically-operated motor that generates an operating force for actuating a volume adjusting mechanism included in the variable displacement hydraulic actuator, and a control apparatus that controls action of the electrically-operated motor, wherein the electrically-operated hydraulic actuator unit further comprises a clutch mechanism interposed between the volume adjusting mechanism and the electrically-operated motor, wherein the clutch mechanism includes a driving-side member that is rotated around a clutch reference axis by a rotational power from the electrically-operated motor, a driven-side member that is rotated around the clutch reference axis by the driving-side member and that is operatively linked to the volume adjusting mechanism, a clutch case that surrounds the driving-side member and the driven-side member, and a contact member accommodated in the clutch case so as to be rotated around the clutch reference axis along with the driven-side member by the driving-side member, the clutch mechanism being configured such that, when the driven-side member is pressed around the clutch reference axis by a force from the volume adjusting mechanism in a case where the electrically-operated motor is in a non-actuated state, the driven-side member presses the contact member against the clutch case to cause the driven-side member to be in a non-rotational locked state, whereby a power transmission from the driven-side member to the driving-side member is prevented, wherein the control apparatus includes a drive signal output portion that outputs a drive signal having a predetermined cycle to the electrically-operated motor, and a duty setting portion that sets a duty of the drive signal to be output by the drive signal output portion, wherein the duty setting portion sets a duty of a first drive signal that is to be output to the electrically-operated motor within a neutral-side start period having a predetermined time duration from a starting point in time at which an actuation of the motor toward the neutral side is started and a duty of a second drive signal that is to be output to the electrically-operated motor within a neutral-side ordinary period after the neutral-side start period when the volume adjusting mechanism has to be activated to the neutral side, while setting a duty of a third drive signal that is to be output to the electrically-operated motor within a higher-volume-side start period having a predetermined time duration from a starting point in time at which an actuation of the motor toward the higher-volume side is started and a duty of a fourth drive signal that is to be output to the electrically-operated motor within a higher-volume-side ordinary period after the higher-volume-side start period when the volume adjusting mechanism has to be activated to the higher-volume side, and wherein the duties of the first to fourth drive signal are set so that the duties of the first and fourth drive signals are larger than the duty of the second drive signal, and the duty of the third drive signal is larger than the duty of the fourth drive signal, while an integrated value of the time during which the third drive signal that is to be output within the higher-volume-side start period is on-state is larger than an integrated value of the time during which the first drive signal that is to be output within the neutral-side start period is on-state.