EP1207274B1 - Valve system for OHV-type four-cylinder internal combustion engine - Google Patents
Valve system for OHV-type four-cylinder internal combustion engine Download PDFInfo
- Publication number
- EP1207274B1 EP1207274B1 EP01121464A EP01121464A EP1207274B1 EP 1207274 B1 EP1207274 B1 EP 1207274B1 EP 01121464 A EP01121464 A EP 01121464A EP 01121464 A EP01121464 A EP 01121464A EP 1207274 B1 EP1207274 B1 EP 1207274B1
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- EP
- European Patent Office
- Prior art keywords
- valve
- cylinder
- intake
- portions
- operating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/02—Valve drive
- F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
- F01L1/047—Camshafts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/02—Valve drive
- F01L1/026—Gear drive
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/02—Valve drive
- F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/12—Transmitting gear between valve drive and valve
- F01L1/14—Tappets; Push rods
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/12—Transmitting gear between valve drive and valve
- F01L1/14—Tappets; Push rods
- F01L1/146—Push-rods
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/12—Transmitting gear between valve drive and valve
- F01L1/18—Rocking arms or levers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/12—Transmitting gear between valve drive and valve
- F01L1/18—Rocking arms or levers
- F01L1/185—Overhead end-pivot rocking arms
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/26—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/16—Engines characterised by number of cylinders, e.g. single-cylinder engines
- F02B75/18—Multi-cylinder engines
- F02B75/24—Multi-cylinder engines with cylinders arranged oppositely relative to main shaft and of "flat" type
- F02B75/243—Multi-cylinder engines with cylinders arranged oppositely relative to main shaft and of "flat" type with only one crankshaft of the "boxer" type, e.g. all connecting rods attached to separate crankshaft bearings
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L2305/00—Valve arrangements comprising rollers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
- F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
- F02B2075/027—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle four
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/16—Engines characterised by number of cylinders, e.g. single-cylinder engines
- F02B75/18—Multi-cylinder engines
- F02B2075/1804—Number of cylinders
- F02B2075/1816—Number of cylinders four
Definitions
- the present invention relates to a valve system suited for use with light-weight small OHV-type four-cycle internal combustion engines, particularly, horizontal opposed type and V-type internal combustion engines applicable to vehicles, to ships, to airplanes, to stationary use, and so on.
- a valve system for an OHV-type four-cylinder internal combustion engine according to the preamble of claim 1 is known from US-A-1,524,150.
- a further valve system is known from GB-A-138 803.
- GB-A-306212 discloses a further valve system for an internal combustion engine in which pull rods are connected to tip ends of valve-operating members which are swingably supported on cylinder head portions through shafts.
- OHV (overhead valve)-type four-cycle internal combustion engines have been widely used for vehicles, for ships, for airplanes, for stational use, and so on because of such advantages as excellent thermal efficiency, low emission of HC and the like harmful components, low exhaust noise, and excellent drivability in a wide range of operation (See, for example, Japanese Patent Laid-open No. 2000-110516).
- valve camshafts large in weight and valve mechanisms operating in connection therewith are disposed collectively at cylinder heads, namely, at head portions of the engine, leading to heavy head portions and large size, which tendency increases as the number of intake and exhaust valves is increased for raising the output of the engine.
- the above-mentioned publication discloses an example of application of an OHV-type valve mechanism to a horizontal opposed type four-cycle internal combustion engine.
- valve camshafts and valve systems are disposed in head portions located at left and right extreme ends farthest from a crankshaft and, necessarily, the left and right head portions are large in weight and size.
- a principal purpose of the invention is to make it possible to dispose the large-weight valve camshafts as near to the crankshaft as possible, to thereby contrive reductions in weight and size of the head portions of the internal combustion engine, thus providing a novel valve system for OHV-type four-cycle internal combustion engine.
- each of the cylinder banks comprises integrally a crankcase portion for rotatably supporting the crankshaft, a cylinder block portion on the outside of the crankcase portion, and a cylinder head portion on the outside of the cylinder block portion, valve camshafts operating in connection with the crankshaft are rotatably supported at the crankcase portions, while valve-operating members for operating intake and exhaust valves for opening and closing intake and exhaust ports of combustion chambers are provided at the cylinder head portions, and oscillating arms operating in connection with the valve camshafts are connected with the valve-operating members through pull rods disposed on lateral sides of the cylinder banks.
- the intake and exhaust valve camshafts are disposed respectively on both sides of the crankcase portions with the crankshaft therebetween, and the oscillating arms operating in connection with the valve camshafts and the valve-operating members for operating the intake and exhaust valves are respectively connected to each other through the pull rods disposed on both sides of the cylinder banks.
- Fig. 1 is a sectional view taken along line 1-1 of Fig. 2 of the horizontal opposed type internal combustion engine according to the first embodiment
- Fig. 2 is a sectional view taken along line 2-2 of Fig. 1
- Fig. 3 is a sectional view taken along line 3-3 of Fig. 2
- Fig. 4 is a sectional view taken along line 4-4 of Fig. 3
- Fig. 5 is a sectional view taken along line 5-5 of Fig. 1
- Fig. 6 is an enlarged sectional view taken along line 6-6 of Fig. 1.
- a pair of left and right cylinder banks CB1, CB2 are disposed symmetrically on the left and right sides of a vertical imaginary line L2-L2 orthogonal to the axis line L1-L1 of the crankshaft 1 which is disposed roughly horizontally in a direction orthogonal to the surface of paper.
- the left and right cylinder banks CB1 and CB2 have the same configuration, and are extended roughly horizontally in the left-right direction.
- Each of the cylinder banks CB1, CB2 comprises a crankcase portion 2L, 2R for receiving and rotatably supporting the crankshaft 1, a cylinder block portion 3L, 3R connected integrally to an outside surface of the crankcase portion 2L, 2R by a plurality of connecting bolts 5, and a cylinder head portion 4L, 4R provided integrally on the outside of the cylinder block portion 3L, 3R.
- the left and right crankcase portions 2L and 2R are coupled integrally to each other by coupling means such as coupling bolts.
- crankcase portion 2L, 2R and the cylinder block portion 3L, 3R may be formed integrally with each other, while the cylinder block portion 3L, 3R and the cylinder head portion 4L, 4R may be formed as separate bodies and connected integrally by known connecting means.
- crankshaft 1 has a portion thereof formed hollow in order to contrive a reduction in weight.
- Journal shaft portions 1j of the crankshaft 1 are rotatably supported by a plurality of bearing halves provided respectively at the crankcase portions 2L, 2R of the left and right cylinder banks CB1, CB2.
- Large end portions of connecting rods 8 are rotatably connected to four crank pins of the crankshaft 1, namely, first to fourth crank pins 1p-1 to 1p-4. Concretely, as shown in Fig.
- the left and right cylinder block portions 3L, 3R are each provided with two cylinder barrels disposed side by side.
- the cylinder barrels of the left cylinder block portion 3L are provided with first and third cylinders 10-1 and 10-3, whereas the cylinder barrels of the right cylinder block portion 3R are provided with second and fourth cylinders 10-2 and 10-4.
- the pistons 9 connected with the small end portions of the connecting rods 8 are slidably fitted in the cylinders.
- the cylinder head portions 4L, 4R formed integrally with the left and right cylinder block portions 3L, 3R are respectively provided with combustion chambers 11 corresponding to the first and third cylinders 10-1, 10-3 and the second and fourth cylinders 10-2, 10-4.
- Two intake ports 12 and two exhaust ports 13 which are communicated to the combustion chambers 11 via valve ports are respectively communicated with each of the combustion chambers 11.
- the two intake ports 12 and two exhaust ports 13 are opened and closed respectively by intake and exhaust valves 14, 15 which are provided slidably in the cylinder head portions 4L, 4R.
- the intake and exhaust valves 14, 15 are energized in a closing direction by valve springs 17 as usual.
- the cylinder head portions 4L, 4R comprise valve-operating members, namely, swing arms 18i and 18e on the intake and exhaust sides, which are supported swingably through shafts. Slipper surfaces at tip ends of the swing arms 18i, 18e are disposed adjacently to end faces of the intake and exhaust valves 14 and 15. Pull rods 20i and 20e which will be detailed later are respectively connected by connection pins 22 to the tip ends of the swing arms 18i and 18e on the intake and exhaust sides.
- the intake and exhaust valves 14 and 15 are respectively opened when the swing arms 18i and 18e are swung to the inside against the springy force of the valve springs 17 by the pulling operation of the pull rods 20i and 20e.
- the intake ports 12 are each connected to an intake system In disposed on the upper side of the left and right cylinder banks CB1 and CB2 collectively, whereas the exhaust ports 13 are each connected to an exhaust system Ex disposed on the lower side of the left and right cylinder banks CB1 and CB2 collectively.
- fuel injection valves V are connected to downstream portions of the intake system In.
- An ignition plug P is screwed to a central portion of an upper wall of each of the combustion chambers 11.
- Portions of the valve mechanism described later are provided on the left and right cylinder head portions 4L, 4R, and the portions of the valve mechanism are covered by head covers 24 disposed on top surfaces of the cylinder head portions 4L, 4R.
- two valve camshafts 26i and 26e on the intake side and exhaust side parallel with the crankshaft 1 are rotatably supported at an upper portion and a lower portion of the left and right crankcase portions 2L, 2R.
- the valve camshaft 26i on the intake side is rotatably supported at an upper portion of the left and right crankcase portions 2L, 2R by a plurality of bearing halves 28 which are provided at the faying surface of the crankcase portions 2L, 2R and a bearing cap 29 which is fixed to flat top surfaces of the left and right crankcase portions 2L, 2R by a plurality of bolts 30.
- valve camshaft 26e on the exhaust side is also rotatably supported at a lower portion of the left and right crankcase portions 2L, 2R by a plurality of bearing halves 32 which are provided at the faying surface of the crankcase portions 2L, 2R and a bearing cap 33 which is fixed to flat top surfaces of the left and right crankcase portions 2L, 2R by a plurality of bolts 30.
- the two valve camshafts 26i, 26e on the intake and exhaust sides are each rotationally driven by the crankshaft 1 through a timing gear transmission mechanism T. Namely, as clearly shown in Fig. 4, driven gears 35 are respectively fixed to end portions (a right end portion in Fig.
- a plurality (two for each cylinder) of forked oscillating arms 39i are oscillatably supported with supporting shafts 40 at intervals along the direction of the crankshaft 1.
- One free end of each of the oscillating arms 39i is provided with a slipper, which is in contact with an intake cam formed on the valve camshaft 26i on the intake side.
- the other free end of each of the oscillating arms 39i is connected by a connection pin 41 with one end of the pull rod 20i.
- the left and right pull rods 20i penetrate through the crankcase portions 2L, 2R of the left and right cylinder banks CB1, CB2, and are extended downward toward the head portions of the cylinder banks CB1, CB2, namely, the cylinder head portions 4L, 4R. Tips of the left and right pull rods 20i are connected by connection pins 22 to free ends of the intake-side swing arms 18i which are shaft-supported on the cylinder head portions 4L, 4R. Those portions of the pull rods 20i which are exposed outside the cylinder banks CB1, CB2 are covered by tubular rod covers 42 bridgingly connected between the crank case portions 2L, 2R and the cylinder head portions 4L, 4R.
- base ends of a plurality (two for each cylinder) of forked oscillating arms 39e are oscillatably supported with supporting shafts 40 at intervals along the direction of the crankshaft 1. Slippers of the oscillating arms 39e are in contact with exhaust cams formed on the valve camshaft 26e on the exhaust side.
- the intake-side bearing cap 29 supporting the oscillating arm 39i by the supporting shaft 40 is covered by a cover 43 fixed to an upper surface of the faying part of the crankcase portions 2L, 2R, while the exhaust-side bearing cap 33 supporting the oscillating arm 39e by the supporting shaft 40 is covered by an oil pan 44 fixed to a lower surface of the faying part of the crankcase portions 2L, 2R.
- Incidentally numeral 45 in the figure denotes an oil filter supported on the oil pan 44.
- the oscillating arms 39i, 39e, the pull rods 20i, 20e, and the swing arms 18i, 18e as valve-operating members constitute the valve mechanism.
- valve camshafts 26i, 26e which are large in weight and mounting of which requires space for mounting bearings and other component members are provided at the crankcase portions 2L, 2R near the crankshaft 1.
- cylinder head portions 4L, 4R, i.e. the head portions, of the cylinder banks CB1, CB2 can be formed as light and small as possible.
- Fig. 7 is a vertical sectional view of a V-type internal combustion engine according to the second embodiment of the invention, wherein the same elements as those in the first embodiment are denoted by the same symbols as above.
- the second embodiment is application of the valve system of the invention to an OHV-type four-cycle and V-type four-cylinder internal combustion engine.
- a pair of left and right cylinder banks CB1, CB2 are disposed symmetrically on the left and right sides of an imaginary line L2-L2 orthogonal to the axis line L1 of the crankshaft 1 disposed in a roughly horizontal direction orthogonal to the surface of paper.
- the structures of the left and right cylinder banks CB1, CB2 are the same as those of the left and right cylinder banks CB1, CB2 in the first embodiment above, except for the V-type layout; and, accordingly, description of the same structures will be omitted.
- a single valve camshaft 26 is rotatably supported by left and right crankcase portions 2L, 2R on the imaginary line L2-L2 directly below the crankshaft 1.
- Pull rods 20i, 20e connected with intake-side and exhaust-side oscillating arms 39i, 39e in adjacent contact with intake and exhaust cams of the valve camshaft 1 are extended upward respectively on the lateral sides of the left and right crankcase portions 2L, 2R, and top ends of the pull rods 20i, 20e are connected to valve-operating members, i.e. swing arms 18i, 18e on the intake and exhaust sides.
- the system according to the second embodiment makes the same effects as the system according to the first embodiment above. It is possible to largely reduce the weight and size of the cylinder head portions 4L, 4R, i.e. head portions, of the pair of cylinder banks CB1, CB2 disposed in a V-type configuration.
- crankcase portions 2L, 2R may be split into upper and lower portions with respect to a line in a direction intersecting the imaginary line L2-L2, or may be split into left, right, front and rear portions in forward and rearward directions with respect to the surface of paper.
- the invention is not limited to or by the embodiments, and various embodiments can be made within the scope of the invention.
- the above embodiments have been described as application of the invention to horizontal opposed type and V-type internal combustion engines, the invention can also be applied to other types of internal combustion engines.
- the invention has been described referring to application to four-valve type internal combustion engines, the invention can naturally be applied to other valve types of internal combustion engines, e.g. two- or three-valve type.
- Valve camshafts 26i, 26e are provided at crankcase portions 2L, 2R for supporting a crankshaft 1, of left and right cylinder banks CB1, CB2 disposed on opposite sides of the crankshaft 1.
- Intake and exhaust valves 14, 15 provided at cylinder heads 4L, 4R are opened and closed by pull rods 20i, 20e operated by the valve camshafts 26i, 26e.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Valve-Gear Or Valve Arrangements (AREA)
- Cylinder Crankcases Of Internal Combustion Engines (AREA)
- Valve Device For Special Equipments (AREA)
Abstract
Description
- The present invention relates to a valve system suited for use with light-weight small OHV-type four-cycle internal combustion engines, particularly, horizontal opposed type and V-type internal combustion engines applicable to vehicles, to ships, to airplanes, to stationary use, and so on.
- A valve system for an OHV-type four-cylinder internal combustion engine according to the preamble of
claim 1 is known from US-A-1,524,150. - A further valve system is known from GB-A-138 803.
- GB-A-306212 discloses a further valve system for an internal combustion engine in which pull rods are connected to tip ends of valve-operating members which are swingably supported on cylinder head portions through shafts.
- OHV (overhead valve)-type four-cycle internal combustion engines have been widely used for vehicles, for ships, for airplanes, for stational use, and so on because of such advantages as excellent thermal efficiency, low emission of HC and the like harmful components, low exhaust noise, and excellent drivability in a wide range of operation (See, for example, Japanese Patent Laid-open No. 2000-110516).
- This type of internal combustion engines, however, have the problem that valve camshafts large in weight and valve mechanisms operating in connection therewith are disposed collectively at cylinder heads, namely, at head portions of the engine, leading to heavy head portions and large size, which tendency increases as the number of intake and exhaust valves is increased for raising the output of the engine. The above-mentioned publication discloses an example of application of an OHV-type valve mechanism to a horizontal opposed type four-cycle internal combustion engine. In the example disclosed, however, valve camshafts and valve systems are disposed in head portions located at left and right extreme ends farthest from a crankshaft and, necessarily, the left and right head portions are large in weight and size.
- The present invention has been made in consideration of the above-mentioned circumstances. Namely, a principal purpose of the invention is to make it possible to dispose the large-weight valve camshafts as near to the crankshaft as possible, to thereby contrive reductions in weight and size of the head portions of the internal combustion engine, thus providing a novel valve system for OHV-type four-cycle internal combustion engine.
- This object is achieved by the features of
claim 1. - In an OHV-type four-cylinder internal combustion engine comprising a pair of cylinder banks disposed symmetrically on opposite sides of an imaginary line orthogonal to the axis line of a crankshaft, each of the cylinder banks comprises integrally a crankcase portion for rotatably supporting the crankshaft, a cylinder block portion on the outside of the crankcase portion, and a cylinder head portion on the outside of the cylinder block portion, valve camshafts operating in connection with the crankshaft are rotatably supported at the crankcase portions, while valve-operating members for operating intake and exhaust valves for opening and closing intake and exhaust ports of combustion chambers are provided at the cylinder head portions, and oscillating arms operating in connection with the valve camshafts are connected with the valve-operating members through pull rods disposed on lateral sides of the cylinder banks. This feature makes it possible to reduce greatly the weight and size of the head portions of the engine, and the adoption of the pull rods enables to narrow the valve mechanism as a whole notwithstanding that the valve camshafts are located away from the cylinder heads.
- According to a further aspect of the invention, the intake and exhaust valve camshafts are disposed respectively on both sides of the crankcase portions with the crankshaft therebetween, and the oscillating arms operating in connection with the valve camshafts and the valve-operating members for operating the intake and exhaust valves are respectively connected to each other through the pull rods disposed on both sides of the cylinder banks. This characteristic feature makes it possible, in a system having valve camshafts disposed on both sides of a crankcase, to reduce greatly the weight and size of the head portions of the engine, and the adoption of the pull rods enables to narrow the valve mechanism as a whole notwithstanding that the valve camshafts are located away from the cylinder heads.
- Now, modes for carrying out the present invention will be described based on the embodiments of the invention illustrated by the attached drawings, in which:
- Fig. 1 is a sectional view taken along line 1-1 of Fig. 2 of a horizontal opposed type internal combustion engine according to the first embodiment of the invention.
- Fig. 2 is a sectional view taken along line 2-2 of Fig. 1.
- Fig. 3 is a sectional view taken along line 3-3 of Fig. 2.
- Fig. 4 is a sectional view taken along line 4-4 of Fig. 3.
- Fig. 5 is a sectional view taken along line 5-5 of Fig. 1.
- Fig. 6 is an enlarged sectional view taken along line 6-6 of Fig. 1.
- Fig. 7 is a vertical sectional view of a V-type internal combustion engine according to the second embodiment of the invention.
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- First, referring to Figs. 1 to 6, a first embodiment of the invention will be described. The first embodiment pertains to application of the valve system for OHV-type four-cycle internal combustion engine of the invention to a horizontal opposed type four-valve four-cylinder engine. Fig. 1 is a sectional view taken along line 1-1 of Fig. 2 of the horizontal opposed type internal combustion engine according to the first embodiment; Fig. 2 is a sectional view taken along line 2-2 of Fig. 1; Fig. 3 is a sectional view taken along line 3-3 of Fig. 2; Fig. 4 is a sectional view taken along line 4-4 of Fig. 3; Fig. 5 is a sectional view taken along line 5-5 of Fig. 1; and Fig. 6 is an enlarged sectional view taken along line 6-6 of Fig. 1.
- In the description below, of a pair of cylinder banks disposed on opposite sides of a
crankshaft 1, the one on the left side in Fig. 1 will be called left cylinder bank, and the other on the right side will be called right cylinder bank. - In Fig. 1, a pair of left and right cylinder banks CB1, CB2 are disposed symmetrically on the left and right sides of a vertical imaginary line L2-L2 orthogonal to the axis line L1-L1 of the
crankshaft 1 which is disposed roughly horizontally in a direction orthogonal to the surface of paper. The left and right cylinder banks CB1 and CB2 have the same configuration, and are extended roughly horizontally in the left-right direction. Each of the cylinder banks CB1, CB2 comprises acrankcase portion crankshaft 1, acylinder block portion crankcase portion cylinder head portion cylinder block portion right crankcase portions - The
crankcase portion cylinder block portion cylinder block portion cylinder head portion - As shown in Figs. 2 and 3, the
crankshaft 1 has a portion thereof formed hollow in order to contrive a reduction in weight.Journal shaft portions 1j of thecrankshaft 1 are rotatably supported by a plurality of bearing halves provided respectively at thecrankcase portions rods 8 are rotatably connected to four crank pins of thecrankshaft 1, namely, first tofourth crank pins 1p-1 to 1p-4. Concretely, as shown in Fig. 2, small end portions of the connectingrods 8 connected to the first andthird crank pins 1p-1, 1p-3 are connected topistons 9 on the side of the left cylinder bank CB1, whereas small end portions of the connectingrods 8 connected to the second andfourth crank pins 1p-2, 1p-4 are connected topistons 9 on the side of the right cylinder bank CB2. - As shown in Figs. 1 and 2, the left and right
cylinder block portions cylinder block portion 3L are provided with first and third cylinders 10-1 and 10-3, whereas the cylinder barrels of the rightcylinder block portion 3R are provided with second and fourth cylinders 10-2 and 10-4. Thepistons 9 connected with the small end portions of the connectingrods 8 are slidably fitted in the cylinders. - As clearly shown in Figs. 1 and 2, the
cylinder head portions cylinder block portions combustion chambers 11 corresponding to the first and third cylinders 10-1, 10-3 and the second and fourth cylinders 10-2, 10-4. Twointake ports 12 and twoexhaust ports 13 which are communicated to thecombustion chambers 11 via valve ports are respectively communicated with each of thecombustion chambers 11. The twointake ports 12 and twoexhaust ports 13 are opened and closed respectively by intake andexhaust valves cylinder head portions exhaust valves valve springs 17 as usual. Thecylinder head portions swing arms swing arms exhaust valves rods connection pins 22 to the tip ends of theswing arms exhaust valves swing arms valve springs 17 by the pulling operation of thepull rods - The
intake ports 12 are each connected to an intake system In disposed on the upper side of the left and right cylinder banks CB1 and CB2 collectively, whereas theexhaust ports 13 are each connected to an exhaust system Ex disposed on the lower side of the left and right cylinder banks CB1 and CB2 collectively. As shown in Fig. 1, fuel injection valves V are connected to downstream portions of the intake system In. An ignition plug P is screwed to a central portion of an upper wall of each of thecombustion chambers 11. - Portions of the valve mechanism described later are provided on the left and right
cylinder head portions head covers 24 disposed on top surfaces of thecylinder head portions - As shown in Figs. 1 and 3 to 5, on the vertical imaginary line L2-L2 orthogonal to the axis line L1-L1 of the
crankshaft 1 mentioned above, twovalve camshafts crankshaft 1 are rotatably supported at an upper portion and a lower portion of the left andright crankcase portions valve camshaft 26i on the intake side is rotatably supported at an upper portion of the left andright crankcase portions bearing halves 28 which are provided at the faying surface of thecrankcase portions bearing cap 29 which is fixed to flat top surfaces of the left andright crankcase portions bolts 30. On the other hand, thevalve camshaft 26e on the exhaust side is also rotatably supported at a lower portion of the left andright crankcase portions bearing halves 32 which are provided at the faying surface of thecrankcase portions bearing cap 33 which is fixed to flat top surfaces of the left andright crankcase portions bolts 30. The twovalve camshafts crankshaft 1 through a timing gear transmission mechanism T. Namely, as clearly shown in Fig. 4, drivengears 35 are respectively fixed to end portions (a right end portion in Fig. 5) of the twovalve camshafts driving gear 37 is fixed to an end portion of thecrankshaft 1, andidle reduction gears 36 respectively meshed with thegears right crankcase portions crankshaft 1 is rotated, the upper andlower valve camshafts driving gear 37, theidle reduction gears 36 and the drivengear 35. - As shown in Figs. 1 and 5, on the left and right sides of the
bearing cap 29 supporting the intake-side valve camshaft 26i disposed at upper portions of the left and right cylinder banks CB1 and CB2, base ends of a plurality (two for each cylinder) of forked oscillatingarms 39i are oscillatably supported with supportingshafts 40 at intervals along the direction of thecrankshaft 1. One free end of each of the oscillatingarms 39i is provided with a slipper, which is in contact with an intake cam formed on thevalve camshaft 26i on the intake side. The other free end of each of the oscillatingarms 39i is connected by aconnection pin 41 with one end of thepull rod 20i. In Fig. 1, the left andright pull rods 20i penetrate through thecrankcase portions cylinder head portions right pull rods 20i are connected byconnection pins 22 to free ends of the intake-side swing arms 18i which are shaft-supported on thecylinder head portions pull rods 20i which are exposed outside the cylinder banks CB1, CB2 are covered by tubular rod covers 42 bridgingly connected between thecrank case portions cylinder head portions bearing cap 33 supporting the exhaust-side valve camshaft 26e disposed at lower portions of the left and right cylinder banks CB1 and CB2, base ends of a plurality (two for each cylinder) of forked oscillatingarms 39e are oscillatably supported with supportingshafts 40 at intervals along the direction of thecrankshaft 1. Slippers of the oscillatingarms 39e are in contact with exhaust cams formed on thevalve camshaft 26e on the exhaust side. The left andright pull rods 20e connected byconnection pins 41 to the other free ends of the oscillatingarms 39e penetrate through thecrankcase portions cylinder head portions rods 20e are connected byconnection pins 22 to free ends of the exhaust-side swing arms 18e which are shaft-supported on thecylinder head portions side bearing cap 29 supporting theoscillating arm 39i by the supportingshaft 40 is covered by acover 43 fixed to an upper surface of the faying part of thecrankcase portions side bearing cap 33 supporting theoscillating arm 39e by the supportingshaft 40 is covered by anoil pan 44 fixed to a lower surface of the faying part of thecrankcase portions oil pan 44. - The oscillating
arms pull rods swing arms - Now, the operation of the first embodiment will be described. When the
crankshaft 1 is rotated by operation of the internal combustion engine, the upper-lower pair of the intake-side and exhaust-side valve camshafts side oscillating arms valve camshafts pull rods arms valve camshafts exhaust valves swing arms pull rods exhaust valves side valve camshafts exhaust valves - According to the valve system, the
valve camshafts crankcase portions crankshaft 1. As a result,cylinder head portions - Next, a second embodiment of the invention will be described.
- Fig. 7 is a vertical sectional view of a V-type internal combustion engine according to the second embodiment of the invention, wherein the same elements as those in the first embodiment are denoted by the same symbols as above. The second embodiment is application of the valve system of the invention to an OHV-type four-cycle and V-type four-cylinder internal combustion engine. In Fig. 7, a pair of left and right cylinder banks CB1, CB2 are disposed symmetrically on the left and right sides of an imaginary line L2-L2 orthogonal to the axis line L1 of the
crankshaft 1 disposed in a roughly horizontal direction orthogonal to the surface of paper. The structures of the left and right cylinder banks CB1, CB2 are the same as those of the left and right cylinder banks CB1, CB2 in the first embodiment above, except for the V-type layout; and, accordingly, description of the same structures will be omitted. - A
single valve camshaft 26 is rotatably supported by left andright crankcase portions crankshaft 1. Pullrods side oscillating arms valve camshaft 1 are extended upward respectively on the lateral sides of the left andright crankcase portions pull rods swing arms - When the
pull rods arms valve camshaft 1, intake andexhaust valves pull rods valve camshaft 26, the intake and exhaust valves are closed by springy force of valve springs with predetermined timings, as usual. - The system according to the second embodiment makes the same effects as the system according to the first embodiment above. It is possible to largely reduce the weight and size of the
cylinder head portions - Incidentally, the left and
right crankcase portions - Although the embodiments of the present invention have been described above, the invention is not limited to or by the embodiments, and various embodiments can be made within the scope of the invention. For example, although the above embodiments have been described as application of the invention to horizontal opposed type and V-type internal combustion engines, the invention can also be applied to other types of internal combustion engines. Further, although the invention has been described referring to application to four-valve type internal combustion engines, the invention can naturally be applied to other valve types of internal combustion engines, e.g. two- or three-valve type.
- As has been described above, according to the invention as set forth in the claims, it is possible to largely reduce the weight and size of the head portions of an internal combustion engine. In addition, adoption of pull rods for operating intake and exhaust valves promises narrowing of the valve mechanism for connecting the operation of the valve camshaft and the operations of intake and exhaust valves.
- Problem: In a valve system for OHV-type horizontal opposed type four-cycle internal combustion engine, to contrive large reduction of the weight and size of piston heads at which intake and exhaust valves of the internal combustion engine are disposed.
- Means of Solution:
Valve camshafts crankcase portions crankshaft 1, of left and right cylinder banks CB1, CB2 disposed on opposite sides of thecrankshaft 1. Intake andexhaust valves cylinder heads pull rods valve camshafts
Claims (3)
- A valve system for an OHV-type four-cylinder internal combustion engine comprising a pair of cylinder banks (CB1, CB2) disposed symmetrically on opposite sides of an imaginary line (L2-L2) orthogonal to the axis line (L1-L1) of a crankshaft (1), wherein
each of said cylinder banks (CB1, CB2) comprises integrally a crankcase portion (2L, 2R) for rotatably supporting said crankshaft (1), a cylinder block portion (3L, 3R) on the outside of said crankcase portion (2L, 2R), and a cylinder head portion (4L, 4R) on the outside of said cylinder block portion (3L, 3R), and wherein at least one valve camshaft (26i, 26e; 26) operating in connection with said crankshaft (1) is rotatably supported at said crankcase portions (2L, 2R), while valve-operating members (18i, 18e) for operating intake and exhaust valves (14, 15) for opening and closing intake and exhaust ports (12, 13) of combustion chambers (11) are provided at said cylinder head portions (4L, 4R), and oscillating arms (39i, 39e) operating in connection with said valve camshaft (26i, 26e; 26) are connected with said valve-operating members (18i, 18e) through pull rods (20i, 20e) disposed on lateral sides of said cylinder banks (CB1, CB2), wherein said pull rods (20i, 20e) are connected to tip ends of the valve operating members (18i, 18e) which are swingably supported on the cylinder head portions (4L, 4R) through shafts,
characterized in that
the valve operating members (18i, 18e) are provided with protrusions extending from said tip ends in the direction of the axis of said shafts, wherein said protrusions are provided with slipper surfaces for operating said intake and exhaust valves (14, 15). - A valve system for OHV-type four-cylinder internal combustion engine as set forth in claim 1, wherein
intake and exhaust valves (14, 15) are arranged V-type and covered by head covers (24) disposed on top surfaces of the cylinder head portions (4L, 4R). - A valve system for OHV-type four-cylinder internal combustion engine as set forth in claim 1 or 2, wherein
said intake and exhaust valve camshafts (26i, 26e) are disposed respectively on both sides of said crankcase portions (2L, 2R) with said crankshaft (1) therebetween, and said oscillating arms (39i, 39e) operating in connection with said valve camshafts (26i, 26e) and said valve-operating members (18i, 18e) for operating said intake and exhaust valves (14, 15) are respectively connected to each other through said pull rods (20i, 20e) disposed on both sides of said cylinder banks (CB1, CB2).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2000349705 | 2000-11-16 | ||
JP2000349705 | 2000-11-16 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP1207274A2 EP1207274A2 (en) | 2002-05-22 |
EP1207274A3 EP1207274A3 (en) | 2003-03-19 |
EP1207274B1 true EP1207274B1 (en) | 2005-02-23 |
Family
ID=18823057
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP01121464A Expired - Lifetime EP1207274B1 (en) | 2000-11-16 | 2001-09-07 | Valve system for OHV-type four-cylinder internal combustion engine |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP1207274B1 (en) |
AT (1) | ATE289653T1 (en) |
CA (1) | CA2360399A1 (en) |
DE (1) | DE60109010T2 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6883485B2 (en) | 2001-12-07 | 2005-04-26 | Honda Giken Kogyo Kabushiki Kaisha | OHV and gear mechanism for engine |
JP2005042653A (en) * | 2003-07-24 | 2005-02-17 | Honda Motor Co Ltd | Liquid cooled engine |
JP2005042667A (en) * | 2003-07-25 | 2005-02-17 | Honda Motor Co Ltd | Multiple cylinder engine |
DE102018125388B4 (en) * | 2018-10-15 | 2021-04-15 | Dr. Ing. H.C. F. Porsche Aktiengesellschaft | Two-part crankcase for a boxer engine |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1524150A (en) * | 1919-02-06 | 1925-01-27 | Willys Overland Co | Valve-operating mechanism |
GB138803A (en) * | 1919-06-16 | 1920-02-19 | Herbert Woodgate | Improvements in the valve gear of internal combustion engines |
US1725672A (en) * | 1928-01-17 | 1929-08-20 | Richard A Peglar | Pull rod |
CH260172A (en) * | 1943-06-08 | 1949-02-28 | Julien Maurice Francois Alexan | Internal combustion engine. |
JP3133040B2 (en) * | 1989-01-20 | 2001-02-05 | 富士重工業株式会社 | Horizontally opposed engine crankcase |
JP4030201B2 (en) * | 1998-10-05 | 2008-01-09 | 本田技研工業株式会社 | engine |
-
2001
- 2001-09-07 EP EP01121464A patent/EP1207274B1/en not_active Expired - Lifetime
- 2001-09-07 AT AT01121464T patent/ATE289653T1/en not_active IP Right Cessation
- 2001-09-07 DE DE60109010T patent/DE60109010T2/en not_active Expired - Fee Related
- 2001-10-29 CA CA002360399A patent/CA2360399A1/en not_active Abandoned
Also Published As
Publication number | Publication date |
---|---|
CA2360399A1 (en) | 2002-05-16 |
DE60109010D1 (en) | 2005-03-31 |
DE60109010T2 (en) | 2005-07-14 |
ATE289653T1 (en) | 2005-03-15 |
EP1207274A3 (en) | 2003-03-19 |
EP1207274A2 (en) | 2002-05-22 |
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