Abstract: Provided is an apparatus provided in a working machine to lower a load, comprising a hydraulic pump, a hydraulic actuator, a manipulation device having a manipulation member, a meter-in flow control device, a meter-out flow control device, a back pressure valve, a regeneration fluid passage branched from the meter-out fluid passage at a position upstream of the back pressure valve and merged with the meter-in fluid passage, and a check valve. The meter-in flow control device controls a meter-in flow rate in a region of the meter-in fluid passage upstream of a merging point with the regeneration fluid passage. The meter-out flow control device controls a meter-out flow rate in a region of the meter-out fluid passage upstream of a branching point of the regeneration fluid passage so as to make the meter-out flow rate be greater than the meter-in flow rate.

Abstract: Provided is an apparatus to lower a load, comprising a hydraulic pump, a hydraulic actuator having first and second ports, a manipulation device, a hydraulic circuit including meter-in and meter-out flow passages for the first and second ports respectively and a regeneration flow passage with a check valve, a control valve, a meter-out flow controller adjusting a meter-out flow rate according to the manipulation device, a back pressure valve, and a non-regeneration operation relief valve whose set pressure is not less than a sum of a minimum set pressure of the back pressure valve, an inlet-outlet pressure difference of the meter-out flow controller when the meter-out flow rate is maximum and a discharge flow rate of the hydraulic pump is maximum, and an actuator pressure difference for driving the hydraulic actuator with no load, and not less than a maximum set pressure of the back pressure valve.

Abstract: A motorcycle having a vehicle body and a vehicle body frame. The vehicle body frame includes a head pipe; a pair of left and right tank rail portions including a widening portion having a width increasing in a vehicle width direction extending rearward of the vehicle from the head pipe, a parallel portion having a substantially fixed width, and a narrowing portion having a width decreasing the vehicle width direction, the widening portion, the parallel portion and the narrowing portion extend along left and right sides of the vehicle body of a motorcycle; and a pair of left and right rear arm bracket portions bending and extending from rear ends of the tank rail portions. The vehicle body frame has a front frame part and a rear frame part connected through a frame connecting surface substantially perpendicular to an axial direction of the parallel portion.