Abstract:
Several embodiments of variable valve timing mechanisms for an internal combustion engine wherein the timing of two valves associated with the same combustion chamber of the engine may be driven at the same time interval and at the same speed from the engine output shaft and both valves may have their timing adjusted simultaneously by a first variable valve timing mechanism and only one of the valves may have its timing adjusted relative to the other valve by a second variable valve timing mechanism to provide a simpler operational control and lower cost assembly.
Abstract:
A method for measuring interference between a valve and a piston, includes the steps of measuring a standard torque value, related to camshaft distortion caused by engine RPM, through voltage detecting means; measuring torsional distortion deviation of a crankshaft and an injection pump shaft by fixing the camshaft and forcibly rotating the crankshaft by said standard torque value; measuring vibration generated when the camshaft, the crankshaft, and the injection pump shaft are rotated, and measuring a crankshaft rotational angle to detect a piston TDC position, both measurements being conducted at a predetermined level of engine RPM; displaying piston and intake/exhaust valve movement on a graph at the piston TDC position after analyzing torsional distortion deviation and vibration of each shaft; and determining whether there is interference between the intake/exhaust valve and the piston by comparing design values with that displayed on the graph.
Abstract:
A water pump for circulating the cooling water of an internal combustion engine, facilitates the formation of the water passage connecting the water pump to the cooling water passage in the cylinder block and can reduce manufacturing costs thereof. A water pump for circulating the cooling water of an internal combustion engine is connected to one end of a cam shaft for a valve system arranged in a cylinder head and is driven by the cam shaft. A delivery port of the water pump is extended near to a cooling water supply port formed in the side wall of a cylinder block and is connected to a cooling water passage in the cylinder block. The delivery poll of the water pump is extended to a position directly opposite to the cooling water supply port, and is connected to the cooling water supply port with a connection pipe. A mounting structure of a camshaft is capable of applying high speed rotation by shortening a length of push rods and also capable of facilitating maintenance such as replacement of cams. In an overhead valve type internal combustion engine, a camshaft is located and mounted in space surrounded by an upper portion of a cylinder and cylinder head.
Abstract:
An outboard motor with an engine where the exposed ends of the crankshaft and camshaft project downward toward the bottom surface of the engine. An accommodation chamber is recessed within the bottom surface of the engine. A chain driven camshaft drive mechanism fits within this accommodation chamber. An oil pump, mounted below the accommodation chamber, is driven by the crankshaft. The bottom end of the crankshaft is sandwiched between the bottom surface of the engine and an oil seal housing. The oil seal housing fits within a recessed opening in a plate-like engine holder positioned below the engine. A plurality of positioning and fastening bosses are used to align and fix the oil seal housing to the engine. When the engine is removed from the outboard motor, its bottom surface is flat enabling the engine sit upright on a workbench.
Abstract:
The housing of a ratchet tensioner is formed of an aluminum-containing metallic material in order to decrease the weight of the tensioner. A hard alumite layer having a thickness of 5 to 50 &mgr;m is formed on the inner circumferential surface of a plunger accommodation bore formed in the housing, and a lubricant is incorporated into the alumite layer. Thus, the service life before occurrence of seizure is increased.
Abstract:
A camshaft drive arrangement for an internal combustion engine wherein the drive includes first and second intermediate shafts journaled directly within the cylinder block. The first intermediate shaft is driven directly to the crankshaft and the second intermediate shaft is driven from the first intermediate shaft by a flexible transmitter drive. The second intermediate shaft drives a camshaft journaled in the cylinder head by a second flexible transmitter drive.
Abstract:
A timing belt system for an engine includes a first timing belt coupling the camshaft to the crankshaft and a parallel second timing belt coupling the camshaft to the crankshaft. A belt sensor provides an alarm signal upon failure of either timing belt. While the other belt continues to function and thereby prevents damage to the engine from occurring, the alarm signal alerts the operator that a broken belt should be replaced.
Abstract:
A chain tensioning arrangement arranged in a timing case for an internal-combustion engine which acts upon a timing chain that can be driven by the crankshaft of the internal-combustion engine. The chain tensioning arrangement provides a simple device with respect to assembly and operational reliability. The chain tensioning arrangement includes a tensioning member which can be adjusted between a mounting position, releasing chain tension and a tensioning position acting upon the chain. In the mounting position, the tensioning member is clamped by a releasable locking pin which extends beyond the floor of the timing case of the internal-combustion engine.
Abstract:
To facilitate construction of internal combustion engines rotating in opposite directions using the same crankcase, three recessed bearings 5, 5a, 5b, are formed in the crankcase. For engines operating in a first direction of rotation, a first bearing 5 supports a first intermediate gear 4 to provide the driving connection between the crankshaft 2 and the camshaft 7, and for an engine having an opposite direction of rotation the second and third bearings 5a, 5b, support a second intermediate gear 4 and the first intermediate gear 8 to provide the driving connection between the crankshaft 2 and the camshaft 7. This construction permits a simple conversion operation to change the rotation direction of the internal combustion engine.
Abstract:
A variable valve timing mechanism for an internal combustion engine wherein the camshaft is supported at one end by a combined bearing and valve body member that is detachably connected to the supporting engine body. The connection is such that fluid from the engine lubricating system can be delivered to this body and distributed by control valves mounted in it. This simplifies machining of the engine body and permits a more compact, lower cost construction without sacrificing any function.