Abstract: A portable-blower duct has a bendable portion (22) whose inner peripheral surface (221A) is a cylindrical surface without any protrusions or recesses in a normal state or in an expanded state, that is, unless it is greatly curved. With this construction, no turbulence is generated in air passing through a tube (221), thereby making it possible to suppress pressure loss. Thus, the flow velocity of air guided through the duct is not reduced, thereby suppressing a deterioration in air blowing efficiency. Even when the tube (221) is curved, the outer side of the curved portion is expanded, and the corresponding portion of the inner peripheral surface remains a smooth surface, thus making it possible to minimize the air pressure loss.

Abstract: A transmissible connecting mechanism having a cam plate and a lever are attached respectively to a lead air control valve shaft and an air-fuel mixture throttle valve shaft which are arranged so as to form an angle. A length of a contact element provided in the lever is extended in parallel to an axis of the air-fuel mixture throttle valve shaft, and the length of the contact element is such that the contact element and a cam surface formed in a cam plate are always brought into contact with each other. The lead air control valve shaft and the air-fuel mixture throttle valve shaft of the carburetor are connected in a transmissible manner, and it is possible to make a stratified scavenging two-cycle engine compact.

Abstract: A construction machine where a load acting on a vehicle body during an operation is transferred to ensure the strength of the vehicle body, thereby improving reliability including welding reliability. In the construction machine, at least one of the height differences between an upper face or a lower face of the center frame at a joining portion between the center frame and the connecting member and an upper face or a lower face of a center joining portion of the connecting member is set respectively at a dimension that is approximately equal to or less than the thickness of an upper face plate or a lower face plate of the center frame.

Abstract: A construction machine where an operating load is transferred to a location having good rigidity, thereby ensuring the strength of a vehicle body and increasing the load-withstanding strength in relation to running loads. The frame of the lower traveling body of the construction machine comprising a hollow center frame having an upper plate with an attachment ring, a lower plate, and side plates that surrounding sides of the frame and that jut out from the attachment ring, and reinforcing ribs which connect the upper plate to the lower plate in the interior of the center frame beneath the attachment ring.

Abstract: An operation unit is provided with an engine operation box storing a control operation portion controlling an opening degree of a throttle valve and a start switch terminal connected to a start motor; a throttle operating lever for controlling the opening degree from an idle position to a full-open position; and a start switch connecting and disconnecting the start switch terminal, wherein the throttle operating lever has a switch shielding portion which enables to operate the start switch without an interference between the throttle operating lever and an operating portion of the start switch when the throttle operating lever is at an idle position, and disables to operate the start switch by shielding at least a part of the operating portion of the start switch by means of a part of the throttle operating lever when the throttle operating lever is operated to be apart from the idle position.

Abstract: A work vehicle with a tilt floor, which is capable of improving the maintainability around an engine and the operability and comfortability of a driver's seat and its periphery, is provided. The work vehicle with a tilt floor includes a hinge mechanism which is provided on the front end of the tilt floor to enable to turn the tilt floor toward the front of the vehicle body, the rear of the tilt floor is formed to be higher than the front of the tilt floor so to cover the headroom of an engine disposed on the rear of the vehicle body, and an operator seat is disposed on the top surface at the rear of the tilt floor.

Abstract: The invention provides an operation unit of an engine provided with a throttle operating lever operating a throttle valve of the engine from an idle position to a full-open position, two terminals connected to an inner side of a drive circuit of a start motor, a contact element interposed between the terminals and setting a region between both the terminals to a conduction state or a non-conduction state, and a start switch making the region between the terminals conductive or non-conductive, the operation unit further comprising interlocking means for relatively moving a contact position between at least one terminal of the two terminals and the contact element in correspondence to an operation amount of the throttle operating lever, and the terminals and the contact element being brought into contact with each other only at a time when the throttle operating lever is at an idle position.

Abstract: A rotary valve which can securely shut off a fluid flow without improving a working accuracy of an outer peripheral surface of a valve and an inner diameter portion of a body, and which has a simple and compact structure, wherein a gap is formed between the outer peripheral surface of the valve and the inner diameter portion of the body, a lip portion of seal means attached within a second lead air flow path is brought into contact with the outer peripheral surface of the valve on the basis of an elastic force of a support portion, and the lip portion securely seals between the second lead air flow path and the gap.

Abstract: A work vehicle comprises a counter weight (1) manufactured by casting, an outer surface thereof being formed in a substantially arc shape, the counter weight (1) including at a lower section thereof an extended portion extending in leftward and rightward directions to have a substantially arc shape, tip ends of the extended portion and a lower part of a center section of the counter weight (1) being provided with a lower attachment base, and an upper face thereof being provided with a canopy attachment base; and a canopy (2) including a roof (22), pillars (21) standing at left side and right side for supporting the roof (22), and a lower attachment member (23) manufactured by casting for fixing lower ends of the pillars (21), the canopy (2) being mounted on the counter weight (1).

Abstract: In an insulator (21) inserted between a carburetor (30) and a cylinder (3) for a purpose of insulating heat, there are formed an intake passage (22) connected to the carburetor (30), and a pair of first air passages (23) connected to respective air flow paths (14) communicated with a pair of scavenging ports (10) formed in the cylinder (3). Air control valves (25) are respectively provided within a pair of first protruding portions (33) communicating with an air cleaner (32), and are connected to the pair of first air passages (23) via a pair of connection members (35). Portions from the air passages within the pair of first protruding portions (33) to the pair of first air passages (23) are respectively formed as smooth air passages in which a change of an inner diameter cross sectional area in a connection portion is small.

Abstract: In a hydraulic cylinder having a shock absorbing function, and capable of stopping as desired by an accumulator disposed within a cylinder rod. The accumulator includes an accumulator piston that divides the cylinder rod interior into first and second cylinder rod chambers, gas hermetically charged into the second cylinder rod chamber, and an accumulation port that is communicated with the first cylinder rod chamber and flows the operating oil from outside into the first cylinder rod chamber.

Abstract: A hydraulic circuit for a hydraulic cylinder capable of executing and adjusting a shock absorbing function at the time of stopping the operation of a cylinder piston rod and releasing the function, comprises a damping control valve (v1) having a first switching position (v11) which blocks the connection of the accumulation port (22) with outside and performs supply and discharge or discharge and supply of the operating oil with respect to the first cylinder chamber (3) and the second cylinder chamber (4), a second switching position (v12) connecting at least the accumulation port (22) and the second cylinder chamber (4), and a third switching position (v13) connecting at least the accumulation port (22) and the first cylinder chamber (3).

Abstract: A work vehicle cooling system comprises a cooling fan (18) driven by the output from an engine (16), and a flow path for allowing an airflow (27) generated by the cooling fan (18) to be flown between the engine (16) and an operator's seat (14) without having passed through any of a radiator (20) and an oil cooler (21) for the engine (16). With this simple configuration, the heat generated by the engine (16) is prevented from being transmitted to the operator's seat (14).