Abstract: When start control is initiated, the start control device operates in a first operating mode in which an upper limit value of an engine speed is limited to a first upper limit value (NErev1) that is lower than an upper limit value (NErev0) in a non-start control. When an elapsed period of time after a throttle opening has exceeded a predetermined opening in the first operating mode reaches a predetermined standby time, the start control device operates in a second operating mode in which the upper limit value of the engine speed is limited to a second upper limit value (NErev2) that is lower than the first upper limit value. The start control device transitions to an ordinary mode to thereby terminate the start control when a period of time of the second operating mode reaches a predetermined control period of time or a forced cancellation condition holds.

Abstract: To provide an air-inlet structure of a motorcycle in which air-inlet ducts can be connected to an air box without providing through holes for allowing passage of the air-inlet ducts on the main frame or bending the air-inlet ducts to bypass a main frame. An engine is supported on a pair of left and right front frames that extend from a head pipe that supports a front wheel rearward and downward. An air box supplies air to the engine and is arranged above the engine. Air-inlet ducts introduce air to the air box and extend on the outer sides of the front frames in a fore-and-aft direction of a vehicle body to be connected to an air-inlet port of the air box at the back of the front frames.

Abstract: A body structure of a motorcycle. Lengths of front frames are reduced and a size of a cylinder head is reduced in a motorcycle having a form where an engine is used as part of a body frame.

Abstract: To provide an air-inlet structure of a motorcycle in which air-inlet ducts can be connected to an air box without providing through holes for allowing passage of the air-inlet ducts on the main frame or bending the air-inlet ducts to bypass a main frame. An engine is supported on a pair of left and right front frames that extend from a head pipe that supports a front wheel rearward and downward. An air box supplies air to the engine and is arranged above the engine. Air-inlet ducts introduce air to the air box and extend on the outer sides of the front frames in a fore-and-aft direction of a vehicle body to be connected to an air-inlet port of the air box at the back of the front frames.

Abstract: The object of the present invention is to provide a three-way valve reduced in the number of component parts and man-hours for assembling the component parts. A pressure chamber of a piston for urging a first main valve in a valve-closing direction by a spring, and a pressure chamber of a piston for urging a second main valve in a valve-opening direction against the urging force of a spring are connected to a medium-pressure port B via a pilot valve and a pressure passage. When the pilot valve is open, the pressure in the pressure chambers into which high-pressure fluid is introduced from a high-pressure port A via an orifice is permitted to escape to the medium-pressure port B, whereby the piston is pushed upward by the high pressure to open the first main valve, and a plug is urged by the spring to close the second main valve.

Abstract: The object of the present invention is to provide a switching valve capable of increasing the opening stroke of a valve operated by a differential pressure while saving space, thereby reducing pressure loss. A first valve is disposed between an inlet port and a first outlet port. A pilot valve is provided between a back pressure chamber for a movable plug that holds a valve sheet disposed in a manner opposed to a valve seat, and the first outlet port, such that the first valve is operated by a solenoid. A second valve is arranged between the inlet port and a second outlet port. A back pressure chamber for a movable plug that holds a valve sheet disposed in a manner opposed to a valve seat and the first outlet port are communicated with each other. The second valve is opened by the differential pressure generated by closing of the first valve, and when the first valve is opened, the second valve is closed by the spring since the differential pressure is reduced to zero.

Abstract: The object of the present invention is to provide a simple-construction four-way switching valve which is simple in construction and excellent in sealability, performs switching of the operation mode without producing unusual noise, and is reduced in the number of manufacturing steps through elimination of externally-mounted parts for pressure passages. Main valves having a poppet valve structure constitute a three way switching valve which is operated by a pilot valve, for switching the high-pressure refrigerant introduced into the port T1 to the port T2 or to the port T3, and main valves which have a poppet valve structure and are switched by the differential pressure between the ports T2 and T3 constitute a low-pressure three-way switching valve. This makes it possible to improve the sealability, prevent unusual noise from being generated during switching of the operation mode, and simplify the construction.

Abstract: The object of the present invention is to provide a switching valve capable of increasing the opening stroke of a valve operated by a differential pressure while saving space, thereby reducing pressure loss. A first valve is disposed between an inlet port and a first outlet port. A pilot valve is provided between a back pressure chamber for a movable plug that holds a valve sheet disposed in a manner opposed to a valve seat, and the first outlet port, such that the first valve is operated by a solenoid. A second valve is arranged between the inlet port and a second outlet port. A back pressure chamber for a movable plug that holds a valve sheet disposed in a manner opposed to a valve seat and the first outlet port are communicated with each other. The second valve is opened by the differential pressure generated by closing of the first valve, and when the first valve is opened, the second valve is closed by the spring since the differential pressure is reduced to zero.

Abstract: To provide a control valve for a variable displacement compressor, including a first control valve that controls the flow rate of refrigerant flowing from a discharge chamber into a crankcase, and a second control valve that controls the flow rate of refrigerant flowing from the crankcase into the suction chamber, wherein suction pressure is sensed, and pressure in the crankcase is controlled such that suction pressure is held constant, which control valve is simplified in construction of the first and second control valves. A port (Ps) at suction pressure is formed on a side of a port (Pd) at discharge pressure, toward a solenoid, and ports (Pc1) and (Pc2) leading to and from a crankcase are formed on an opposite side of the port (Pd) to the aforementioned side, and a hollow cylindrical member is disposed in a manner extending over these ports.

Abstract: To provide a control valve for a variable displacement compressor, which is improved in slidability of a shaft that transmits a change in suction pressure to a valve element, and enhanced in controllability. In a control valve for a variable displacement compressor in which a plunger of a solenoid is divided into two, i.e. a first plunger and a second plunger, and a diaphragm is disposed therebetween for sensing suction pressure, the second plunger is held by a spring urging the second plunger in a direction away from the diaphragm, and is caused to be simply in contact with a shaft that transmits a change in the suction pressure sensed by the diaphragm to a valve element. With this construction, even when an attractive force is generated by a solenoid to move the second plunger, no couple of forces act on the shaft, and hence the shaft is prevented from being spoiled in slidability, which makes it possible to enhance controllability.

Abstract: The object of the present invention is to provide a switching valve capable of increasing the opening stroke of a valve operated by a differential pressure while saving space, thereby reducing pressure loss. A first valve is disposed between an inlet port and a first outlet port. A pilot valve is provided between a back pressure chamber for a movable plug that holds a valve sheet disposed in a manner opposed to a valve seat, and the first outlet port, such that the first valve is operated by a solenoid. A second valve is arranged between the inlet port and a second outlet port. A back pressure chamber for a movable plug that holds a valve sheet disposed in a manner opposed to a valve seat and the first outlet port are communicated with each other. The second valve is opened by the differential pressure generated by closing of the first valve, and when the first valve is opened, the second valve is closed by the spring since the differential pressure is reduced to zero.

Abstract: The object of the present invention is to provide a three-way switching valve having a valve mechanism compact in size, and capable of changing a flow of a high-pressure fluid, without internal leakage of the fluid. A compact pilot-operated three-way switching valve changes a flow of a fluid introduced into an inlet port such that the fluid is caused to flow into a first outlet port or a second outlet port. Pressures in pressure-regulating chambers above pistons are selectively guided into a passage by a pilot valve having a pilot valve element, plugs including respective valve seats, and a spring. The passage leads one of the pressures to the first outlet port or the second outlet port via a check valve having valve, and a valve element. The check valve causes a very small amount of fluid permitted to flow so as to keep main valves open and closed, respectively, to flow to the downstream side of an open one of the main valves, whereby internal leakage of fluid is prevented.

Abstract: To provide an expansion device that is configured compact in size and capable of effectively preventing an abnormal rise in pressure within the expansion device caused by the differential pressure across the expansion device. An expansion device according to the present invention cancels part of refrigerant pressure by a pressure-canceling structure. More specifically, by the amount of pressure received by a valve-closing pressure-receiving surface, the elastic force required of a spring can be reduced. As a result, a small-sized spring can be employed as the spring, and the entire expansion device can be made compact in construction. Further, when the differential pressure across the expansion device has become equal to or higher than a predetermined value, a relief mechanism enables refrigerant flowing in from the upstream side to escape into a passage other than a refrigerant passage through a valve element.

Abstract: To provide a four-way solenoid valve having a three-way solenoid valve of which non-concentricity between a valve element and a valve hole is small, if any. A core of a three-way solenoid is integrally formed with a refrigerant passage extending axially therethrough, an annular projection forming a valve seat, and a guide for guiding reciprocating motion of a needle forming a valve element. A plug closing a cylinder of a body to define the pressure control chamber is also integrally formed with a valve seat and a guide for guiding reciprocating motion of a needle forming a valve element associated with the valve seat. This causes the needles to be seated on the valve seats associated therewith in respective states guided by the guides substantially concentric with the valve holes, which makes it possible to impart sufficient sealing properties to the valve portions when each valve is closed.

Abstract: The object of the present invention is to provide a three-way valve reduced in the number of component parts and man-hours for assembling the component parts. A pressure chamber of a piston for urging a first main valve in a valve-closing direction by a spring, and a pressure chamber of a piston for urging a second main valve in a valve-opening direction against the urging force of a spring are connected to a medium-pressure port B via a pilot valve and a pressure passage. When the pilot valve is open, the pressure in the pressure chambers into which high-pressure fluid is introduced from a high-pressure port A via an orifice is permitted to escape to the medium-pressure port B, whereby the piston is pushed upward by the high pressure to open the first main valve, and a plug is urged by the spring to close the second main valve.

Abstract: A four-way switching valve free from leakage of a refrigerant is disclosed. The valve includes two three-way switching valves arranged side by side, each having a pressure-regulating chamber, a piston, and a plug coaxially arranged. One of the pressure-regulating chambers selectively communicates with a low-pressure chamber or a high-pressure chamber via a three-way solenoid valve. The other pressure-regulating chamber communicates with another chamber in which the pressure increases or decreases as the pressure within one of the pressure-regulating chambers decreases or increases. As a result, refrigerant leakage is prevented, in turn preventing degradation of the refrigerating power of a system.

Abstract: The object of the present invention is to provide a simple-construction four-way switching valve which is simple in construction and excellent in sealability, performs switching of the operation mode without producing unusual noise, and is reduced in the number of manufacturing steps through elimination of externally-mounted parts for pressure passages. Main valves having a poppet valve structure constitute a three way switching valve which is operated by a pilot valve, for switching the high-pressure refrigerant introduced into the port T1 to the port T2 or to the port T3, and main valves which have a poppet valve structure and are switched by the differential pressure between the ports T2 and T3 constitute a low-pressure three-way switching valve. This makes it possible to improve the sealability, prevent unusual noise from being generated during switching of the operation mode, and simplify the construction.

Abstract: A four-way switching valve includes a first three-way switching valve having a valve element for connecting a port B to a port A, or to a port D via a sleeve, in a switching manner; a second three-way switching valve having a valve element for connecting a port C to the port A, or to the port D, in a switching manner; and a piston for actuating these three-way switching valves. The three-way valves and piston are coaxially arranged within a hollow cylindrical body. A three-way solenoid valve introduces high pressure into a pressure chamber on the upper side of the piston to actuate the valve elements held on the sleeve downward, while the upward actuation is effected with a driving force produced by reducing the pressure in the pressure chamber and configuring guides to have a larger pressure-receiving area than that of a guide.

Abstract: A body structure of a motorcycle. Lengths of front frames are reduced and a size of a cylinder head is reduced in a motorcycle having a form where an engine is used as part of a body frame.

Abstract: To provide a small-sized and low-cost proportional solenoid valve which is capable of controlling a bidirectional fluid flow. A core is fixed in a pipe, and a hollow shaft having an extreme end thereof closed by a valve seat and a portion adjacent thereto formed with valve holes is fixed in the core. Within the pipe, there are arranged a hollow cylindrical valve element axially movable using the shaft as a guide and urged in a direction away from the core by a spring, for opening and closing the valve holes, and a plunger, while outside the pipe, there is arranged a solenoid coil. The proportional solenoid valve has a body formed by the pipe, and the component parts for opening and closing the valve are arranged within the pipe, so that it is possible to reduce the size of the proportional solenoid valve, the number of component parts, and machining costs and material costs, which contributes to reduction of costs of the valve.