Abstract: A cylinder block structure with a small number of ribs is provided which can favorably prevent the deformation of a crankshaft bearing portion. In a cylinder block having bolt holes formed on the upper surface for connecting a cylinder head with bolts, arcshaped coupling surfaces formed on the rear end surface for mounting a housing, such as a transmission housing, and a crankshaft bearing portion formed in the central part between the lower ends of the coupling surfaces, the upper parts of the coupling surfaces 5 are joined into an arch-shape by an arch-shaped rib, the lower ends of right and left bosses are extended and connected to the lower parts of the arch-shaped rib, and right and left main radial ribs extend from the outside of the lower end of the bolt hole boss to the center of the crankshaft bearing portion.

Abstract: The oil pan includes an oil introducing means that has an oil introducing plate. The oil introducing plate has an insertion hole for receiving a sucking portion of an oil strainer. The oil introducing plate extends from the periphery of the insertion hole toward a side wall of the oil pan. The oil returned from the first oil return passage is introduced to flow along the oil introducing plate via an oil falling hole formed in a baffle plate that is positioned at the bottom of a crank case of the internal combustion engine. The oil introducing means further includes a plurality of inclined wall portions mounted on a bottom portion of the oil pan in the vicinity of the side wall of the oil pan in order to support the oil introducing plate. Opening portions are formed between the inclined wall portions and the bottom portion of the oil pan. The oil introducing plate of the oil introducing means is located just below the oil falling hole formed in said baffle plate.

Abstract: A crankcase emission control device of an internal combustion engine comprises a gas/liquid separator that separates an oil mist from blow-by gases flowing therethrough. A first passage is defined in both a crankcase and a cylinder head to connect an interior of the crankcase to a valve rocker cover chamber defined by the cylinder head. A second passage extends from the valve rocker cover chamber to the gas/liquid separator. A third passage extends from the gas/liquid separator to an intake system of the engine. For reducing the height of the entire construction of the engine, the gas/liquid separator is integrally formed by the cylinder head at a position below intake ports of the cylinder head.

Abstract: An oil pan (6) is mounted to a lower surface of a cylinder block (1) in order to reserve an oil. An oil pump housing (7) is cast integrally with the inner side of the right side surface (6a) of the oil pan (6). A rib (14) is formed in order to connect the right side surface (6a) and a left side surface (6b) of the oil pan (6).

Abstract: In a flywheel 2, a central part of a thin plate portion 3 having a flywheel mass provided on an outer peripheral side of the plate portion is joined to an end surface of a crankshaft 1 through a plurality of bolts 7 disposed annularly at intervals. Within a contact zone of a substantially polygon defined by linking each center of the bolts 7 with straight lines excluding the bearing surfaces of the bolts 7, the plate portion 3 has a non-contacting part S2 in a followed fashion set not to contact with the end surface of the crankshaft 1, and the area of the non-contacting part S2 is set to be 40% to 75% of the whole area of the contact zone.

Abstract: A cooling system, in which any bubble is not transferred to the water pump (coolant pumping means), and thereby the efficiency of the water pump is prevented from lowering, so that the cooling performance is enhanced, and an internal combustion engine provided with the cooling system are to be provided. The interior of a water outlet (coolant distributing means) 3 mounted on a cylinder head (internal combustion engine) 1 is divided by a partition wall 3b to form a feeding chamber 3c to feed the coolant introduced from the cylinder head 1 to the first path A provided with a radiator, and a receiving chamber 3d composing the second path B to receive the coolant returned from a heater core. Between the receiving chamber 3d and the feeding chamber 3c is formed a channel (bubble introducing portion) 3e making one of both chambers communicate with the other.

Abstract: A flange structure includes a main part 10 having a flange 14, internally provided with a fluid passage 12 and serving also as a body of a fluid device, a plate member 16 attached to the joining surface of the flange 14 of the main part 10 so as to hold a gasket 17 on the joining surface, and a connecting tube 20 inserted through the plate member 16 into the fluid passage 12 and fixed to the plate member 16 so as to extend obliquely upward toward the outside of the plate member 16.

Abstract: An upper oil pan of an engine includes a flange with an oil pan abutment surface that is fixedly coupled to a flange formed on a cylinder block. The oil pan abutment surface comprises a flat portion that is substantially parallel to a cylinder block abutment surface of the cylinder block, a slanted portion that is slanted with respect to the flat portion, and a vertical wall portion connecting the flat portion and the slanted portion. The vertical wall portion is formed substantially perpendicular to the flat portion. The cylinder block and the upper oil pan are fixedly coupled together via an interposed liquid gasket. Thus, the seal structure in which the liquid gasket is adequately cured is provided, and sufficient sealing properties can be obtained with a small amount of material used.

Abstract: This invention provides an oil pan for internal combustion engine having an intensified stiffness and capable of suppressing vibration and radiating sound and of light weight achieved by reducing the quantity of components.

Abstract: An oil level gauge guide structure including an oil level gauge for measuring engine oil of a vehicle. An oil level gauge is held in an oil level gauge guide. A clip is provided having a first end section held to a resinous part fixed to an engine main body, and a second end section held to the oil level gauge guide. The oil level gauge is provided with two linear stoppers contactable with the second end section of the clip, and an O-ring fixed on an end section of the oil level gauge guide. The end section of the oil level gauge guide is inserted into the communication hole in a first direction, while the first end section of the clip is pressed to the resinous part in a second direction. The first and second directions are parallel with each other.

Abstract: An oil pan (6) is mounted to a lower surface of a cylinder block (1) in order to reserve an oil. An oil pump housing (7) is cast integrally with the inner side of the right side surface (6a) of the oil pan (6). A rib (14) is formed in order to connect the right side surface (6a) and a left side surface (6b) of the oil pan (6).

Abstract: A cylinder block structure with a small number of ribs is provided which can favorably prevent the deformation of a crankshaft bearing portion and the like. In a cylinder block 1 having bolt holes 3 formed on the upper surface for connecting a cylinder head with bolts, arc-shaped coupling surfaces 5 formed on the rear end surface for mounting a housing, such as a transmission housing, and a crankshaft bearing portion 6 formed in the central part between the lower ends of the coupling surfaces: the upper parts of the coupling surfaces 5 are joined into an arch-shape by an arch-shaped rib 7; the lower ends of right and left bosses 4 respectively having bolt hole 3 formed therein, are extended and connected to the lower parts of the arch-shaped rib 7; and right and left main radial ribs 10, respectively extend from the outside of the lower end of the bolt hole boss 4 to the center of the crankshaft bearing portion 6.

Abstract: A cooling water passage structure of internal combustion engines is provided which can contribute to a scale-down of the external form of the engine and also can prevent deformation of the cylinder bores. The cooling water passage structure comprises a water jacket for the flow of cooling water provided on the peripheries of a plurality of cylinder bores; and a lateral suction passage 9a, 9b integrally formed with a side wall of a cylinder block 2 having bolt holes formed for fastening a cylinder head 3. The lateral suction passage runs through by the cylinder bores at a height in the vicinity of the water jacket bottom and is arranged on the outside of, and perpendicular to the bolt holes. On the rear surface of the cylinder head 3 is mounted a water passage block 15 and on the front end part of the cylinder block 2 is provided a water pump housing 10.

Abstract: A constitution of protecting a fuel delivery tube of an engine, includes: 1) an engine body including: a) a cylinder head, and b) a ladder cam bracket defining an outer wall on a side section thereof, including: i) an outer frame, ii) an intake cam bracket, and iii) an exhaust cam bracket integrated with the outer frame and holding an exhaust cam shaft; 2) the fuel delivery tube disposed beside the engine body and extending in a direction substantially along a row of a cylinder; and 3) an intake manifold made of a material free from a metal. The outer wall of the ladder cam bracket is formed with a protrusion which protrudes toward a branch section of the intake manifold in such a manner as to prevent the branch section of the intake manifold from causing an interference with the fuel delivery tube.

Abstract: A crankcase emission control device of an internal combustion engine comprises a gas/liquid separator that separates an oil mist from blow-by gases flowing therethrough. A first passage is defined in both a crankcase and a cylinder head to connect an interior of the crankcase to a valve rocker cover chamber defined by the cylinder head. A second passage extends from the valve rocker cover chamber to the gas/liquid separator. A third passage extends from the gas/liquid separator to an intake system of the engine. For reducing the height of the entire construction of the engine, the gas/liquid separator is integrally formed by the cylinder head at a position below intake ports of the cylinder head.

Abstract: A cam bracket is disclosed for lubricating the vicinity of a thrust plate sufficiently even during starting of the engine. In the cam bracket adapted to support a camshaft for rotation in cooperation with a cylinder head and provided with a support portion having a slot for supporting a thrust plate of the camshaft for rotation, an oil sump is formed in a hollow fashion on the upper surface of the support portion around the edge of the slot at least on one side in a rotation direction of the thrust plate.

Abstract: A constitution of protecting a fuel delivery tube of an engine, includes: 1) an engine body including: a) a cylinder head, and b) a ladder cam bracket defining an outer wall on a side section thereof, including: i) an outer frame, ii) an intake cam bracket, and iii) an exhaust cam bracket integrated with the outer frame and holding an exhaust cam shaft; 2) the fuel delivery tube disposed beside the engine body and extending in a direction substantially along a row of a cylinder; and 3) an intake manifold made of a material free from a metal. The outer wall of the ladder cam bracket is formed with a protrusion which protrudes toward a branch section of the intake manifold in such a manner as to prevent the branch section of the intake manifold from causing an interference with the fuel delivery tube.

Abstract: A cam bracket is disclosed for lubricating the vicinity of a thrust plate sufficiently even during starting of the engine. In the cam bracket adapted to support a camshaft for rotation in cooperation with a cylinder head and provided with a support portion having a slot for supporting a thrust plate of the camshaft for rotation, an oil sump is formed in a hollow fashion on the upper surface of the support portion around the edge of the slot at least on one side in a rotation direction of the thrust plate.

Abstract: An air-intake manifold includes a plurality of air-intake pipes connecting between a collector and an air-intake pipe mount. Each air-intake pipe 3 is bent to have a predetermined shape. Each air-intake pipe 3 is fabricated by bending a substantially straight double metal pipe that has an outer pipe 3a and an inner pipe 3b with a clearance 3c therebetween equal to or less than 0.2 mm, such that the outer pipe 3a and the inner pipe 3b locally contact with each other at an intermediate region. Accordingly, while the outer pipe 3a and the inner pipe 3b of the air-intake pipe 3 locally contact with each other at the contact point 3e (in the relatively slidable relationship), an air layer having a thickness equal to or less than about 0.2 mm is formed between the outer pipe 3a and the inner pipe 3b at portions except for the contact point 3e.

Abstract: A thrust ratio calculation section 50 calculates a thrust ratio based on driving pulley thrust from a driving pulley thrust calculation section 44 and following pulley thrust from a following pulley thrust calculation section 48. A thrust ratio state of change identifying section 52 detects a peak of a thrust ratio caused by changing of the following pulley thrust, based on the thrust ratio and the following pulley thrust. The following pulley thrust is maintained such that the thrust ratio remains at the peak. This enables appropriate control of the pulley thrust.