WO2020202282A1 - Moteur à combustion interne - Google Patents

Moteur à combustion interne Download PDF

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Publication number
WO2020202282A1
WO2020202282A1 PCT/JP2019/014095 JP2019014095W WO2020202282A1 WO 2020202282 A1 WO2020202282 A1 WO 2020202282A1 JP 2019014095 W JP2019014095 W JP 2019014095W WO 2020202282 A1 WO2020202282 A1 WO 2020202282A1
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WO
WIPO (PCT)
Prior art keywords
internal combustion
combustion engine
cylinder
chamber
crankcase
Prior art date
Application number
PCT/JP2019/014095
Other languages
English (en)
Japanese (ja)
Inventor
逆井亨允
原田誠
宮▲崎▼栄一
Original Assignee
本田技研工業株式会社
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 本田技研工業株式会社 filed Critical 本田技研工業株式会社
Priority to CN201980095021.7A priority Critical patent/CN113661318B/zh
Priority to PCT/JP2019/014095 priority patent/WO2020202282A1/fr
Priority to BR112021019126A priority patent/BR112021019126A2/pt
Priority to JP2021510616A priority patent/JP7093892B2/ja
Publication of WO2020202282A1 publication Critical patent/WO2020202282A1/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F11/00—Arrangements of sealings in combustion engines 

Definitions

  • the present invention relates to an internal combustion engine having a cylinder chamber for accommodating a piston that performs reciprocating motion and a crankshaft that converts reciprocating motion into rotary motion.
  • Japanese Patent Application Laid-Open No. 2015-14242 discloses that stress (strain) caused by high-temperature exhaust is relaxed by inserting a gasket at a connecting portion of an exhaust system component of an internal combustion engine.
  • the cylinder chamber may be distorted due to the generation of a tightening force on the cylinder chamber due to the thermal expansion of the cylinder sleeve.
  • an object of the present invention is to provide an internal combustion engine capable of suppressing distortion of a cylinder chamber with a simple configuration.
  • aspects of the present invention relate to an internal combustion engine having at least one cylinder chamber accommodating at least one piston that performs reciprocating motion and a crankshaft that converts the reciprocating motion into rotary motion.
  • the internal combustion engine operates the crankcase that accommodates the crankshaft, the cylinder sleeve that forms the cylinder chamber, the cylinder block that covers the cylinder sleeve, and the valve in response to the rotational movement, thereby causing the cylinder chamber.
  • a valve operating mechanism that controls the inflow and outflow of air to and from the crankshaft, a power transmission mechanism that transmits the power of the rotational movement from the crankshaft to the valve operating mechanism, and a power that is formed in the cylinder block and accommodates the power transmission mechanism. It further has a transmission mechanism accommodating chamber and a gasket inserted between the cylinder block and the crankcase.
  • the gasket is formed in a substantially annular shape so as to surround the cylinder chamber or the power transmission mechanism accommodating chamber when viewed from the axial direction of the cylinder chamber. Further, at least a part of the annular portion of the gasket that surrounds the cylinder chamber forms a recess that separates from the cylinder chamber with respect to the other portion of the annular portion. Further, the recess is provided on the side of the power transmission mechanism accommodating chamber.
  • a plurality of chambers including at least one cylinder chamber and the power transmission mechanism accommodating chamber are provided across the wall.
  • the gasket is formed with a communication portion that communicates at least two of the plurality of adjacent chambers in the cylinder block, and the communication portion forms the recess.
  • the cylinder block and the gasket are formed with a plurality of insertion holes through which a fastening member to be fastened to the crankcase is inserted, and the communication portion is provided between the plurality of insertion holes.
  • connecting portion between the annular portion and the concave portion is formed in a curved shape.
  • the gasket is a non-metal member.
  • a recess of the gasket is provided from the cylinder chamber toward the power transmission mechanism accommodating chamber.
  • the cylinder chamber and the power transmission mechanism accommodating chamber communicate with each other through the gap portion formed by the recess between the cylinder block and the crankcase.
  • the stress (strain) of the gasket is suppressed and the strain of the cylinder chamber is reduced.
  • the rigidity of the gasket is lowered, and the effect of suppressing the distortion of the cylinder chamber is further improved.
  • the communication portion formed in the gasket forms a concave portion, the gasket can be easily processed.
  • the insertion holes are secured, and the positioning of the gasket with respect to the crankcase and the cylinder block becomes easy.
  • the communication portion can be secured to the maximum.
  • the connecting part in a curved shape, the stress applied to the gasket can be efficiently released.
  • the gasket is a non-metal member, the processing of the gasket becomes easier.
  • FIG. 1 is a left side view of a vehicle 12 equipped with the internal combustion engine 10 according to the present embodiment.
  • the front-rear, left-right, and up-down directions of the vehicle 12 will be described with reference to the direction seen from the driver seated on the seat 14 of the vehicle 12.
  • the pair of left and right components may be described by adding a reference number of "L” to the reference number of the left component and an "R" to the reference number of the right component.
  • This embodiment is applied to the cub-shaped motorcycle shown in FIG.
  • the present embodiment is not limited to the motorcycle shown in FIG. 1, and can be applied to various saddle-type vehicles and motors (internal combustion engines).
  • the vehicle 12 has a body frame 16.
  • the vehicle body frame 16 includes a head pipe 18, a single main frame 20 extending diagonally downward and rearward from the head pipe 18, and a seat frame 22 extending obliquely upward and rearward from the rear end portion of the main frame 20.
  • a steering handle 24 operated by the driver is pivotally supported at the upper end of the head pipe 18.
  • a pair of left and right front forks 28L and 28R are pivotally supported at the lower end of the head pipe 18 via a steering stem 26.
  • the lower ends of the front forks 28L and 28R pivotally support the front wheels 30.
  • the internal combustion engine 10 (power unit) is supported below the main frame 20.
  • a pair of left and right pivot brackets 32L and 32R extend downward at the rear end of the main frame 20.
  • the front end portion of the swing arm 34 is supported by the pivot bracket 32L so as to be swingable in the vertical direction.
  • the rear end of the swing arm 34 pivotally supports the rear wheel 36 (rotated moving portion).
  • a rear cushion 38 is connected between the seat frame 22 and the swing arm 34.
  • a seat 14 is arranged above the seat frame 22.
  • the body frame 16 is covered with the body cover 40.
  • the body cover 40 includes a front cover 42, a pair of left and right main frame covers 44L and 44R, a leg shield 46, an under cowl 48, a body cover 50, and the like.
  • the front cover 42 covers the head pipe 18 from the front.
  • the main frame covers 44L and 44R cover the main frame 20 and the like from the left and right.
  • the leg shield 46 connects the front cover 42 and the main frame covers 44L and 44R, and covers the driver's feet from the front.
  • the under cowl 48 connects the main frame covers 44L and 44R below.
  • the body cover 50 covers the rear end portion of the main frame 20, the seat frame 22, and the like.
  • the internal combustion engine 10 is mounted on the vehicle 12 below the main frame 20 while being supported by the main frame 20 and the pivot brackets 32L and 32R.
  • the internal combustion engine 10 includes a crankcase 52 (power unit case), a cylinder block 54 (cylinder) extending obliquely upward and forward from the front end of the crankcase 52, and a cylinder head 56 connected to the front end of the cylinder block 54. And have.
  • the crankcase 52 is a metal case. On the upper portion (upper wall, upper surface) of the crankcase 52, one coupling boss 58a that bulges toward the main frame 20 side is provided. Further, two coupling bosses 58b and 58c that bulge toward the pivot brackets 32L and 32R are provided on the rear portion (rear wall and rear surface) of the crankcase 52. On the other hand, a pair of left and right ribs 60L and 60R extending downward toward the upper part of the crankcase 52 are provided on the rear end side of the main frame 20.
  • a screw hole is formed in the coupling boss 58a on the upper part of the crankcase 52 in the vehicle width direction.
  • Two bolts 62a through which the holes formed in the pair of left and right ribs 60L and 60R are inserted are screwed into the screw holes.
  • screw holes are formed in the two coupling bosses 58b and 58c at the rear of the crankcase 52 in the vehicle width direction.
  • Two bolts 62b through which the holes formed in the pivot brackets 32L and 32R are inserted are screwed into the screw holes of the coupling boss 58b.
  • Two bolts 62c through which the holes formed in the pivot brackets 32L and 32R are inserted are screwed into the screw holes of the coupling boss 58c.
  • various components are connected to the internal combustion engine 10.
  • crankshaft 68 crankshaft, power generating unit
  • the electric motor 66 is arranged above the crankshaft 68 in the upper part of the crankcase 52.
  • a rotation speed detection unit 70 is attached in front of the electric motor 66 for starting.
  • the rotation speed detection unit 70 is a sensor (vehicle speed sensor, pickup sensor) that detects the rotation speed of the crankshaft 68 according to the vehicle speed of the vehicle 12, and the crankcase 52 is directed to the axial center of the crankshaft 68. It is attached to the crankcase 52 in a state of extending diagonally upward and forward from the upper part of the crankcase 52.
  • the cylinder block 54 has a cylinder chamber 74 (cylinder) that houses a piston 72 that reciprocates (see FIGS. 5 and 6).
  • a plurality of insertion holes 76 are formed in the cylinder block 54 along the axial direction of the cylinder chamber 74, that is, the direction diagonally upward and forward extending from the crankcase 52 to the cylinder block 54.
  • the cylinder head 56 is also formed with a plurality of insertion holes 78 along the axial direction of the cylinder chamber 74.
  • the plurality of insertion holes 76 of the cylinder block 54 and the plurality of insertion holes 78 of the cylinder head 56 communicate with each other, and a fastening member 80 such as a stud bolt is inserted into each of the insertion holes 76 and 78.
  • each of the plurality of fastening members 80 through which the plurality of insertion holes 76 are inserted is screwed into a screw hole (not shown) formed in the crankcase 52 at one end and a nut at the other end on the cylinder head 56 side. Screw with 82.
  • the cylinder block 54 and the cylinder head 56 are sequentially attached to the crankcase 52.
  • a plurality of cooling fins 84 are formed on the outer peripheral surface of the cylinder block 54 in a direction (intersection direction) substantially orthogonal to the axial direction of the cylinder chamber 74. Further, a frame plate-shaped stay member 86 is fixed to the upper portion (upper surface) of the cylinder block 54. An ignition coil 88 is attached to the upper surface of the stay member 86 in a state of being separated from the cylinder block 54.
  • the cylinder head 56 has a structure in which a valve operating mechanism 90 (valve valve structure) shown in FIGS. 5 and 6 and a main body portion accommodating an intake / exhaust system and a portion corresponding to a head cover are integrated.
  • a valve operating mechanism 90 valve valve structure
  • main body portion accommodating an intake / exhaust system and a portion corresponding to a head cover are integrated.
  • a plurality of cooling fins 92 are formed in a direction (intersection direction) substantially orthogonal to the axial direction of the cylinder chamber 74.
  • a plug hole 94 is formed in the central portion on the right side surface of the cylinder head 56 on the cylinder block 54 side.
  • a spark plug 96 is attached to the plug hole 94.
  • the spark plug 96 and the ignition coil 88 are connected via a high-voltage wiring 98.
  • the ignition coil 88 generates a high voltage required to ignite the spark plug 96, and supplies the generated high voltage to the spark plug 96 via the high voltage wiring 98.
  • An intake member 100 is connected to the upper part of the cylinder head 56.
  • the intake member 100 has an intake pipe 100b that connects a throttle body 100a that controls the intake amount of the internal combustion engine 10 and an intake port 104 (see FIG. 6) that communicates with the throttle body 100a and the combustion chamber 102 described later.
  • An injector 106 that injects fuel into the combustion chamber 102 is attached to the intake pipe 100b. Therefore, the intake member 100 and the injector 106 are arranged in front of the ignition coil 88.
  • the internal combustion engine 10 has various configurations supported by the vehicle body frame 16 directly under the main frame 20 and connected to the internal combustion engine 10 in the dead space between the main frame 20 and the internal combustion engine 10.
  • the elements are arranged. Therefore, as shown in the plan view of FIG. 4, various components are arranged above the internal combustion engine 10 so as to overlap the internal combustion engine 10 and the main frame 20.
  • the ignition coil 88 is arranged above the cylinder block 54 so as to overlap the cylinder block 54 in the plan view of FIG. Further, the ignition coil 88 is rearward of the cylinder head 56 and the intake member 100 (throttle body 100a, intake pipe 100b), three coupling bosses 58a to 58c, and a rotation speed detection unit in the side views of FIGS. 2 and 3. It is arranged in front of the 70 and the electric motor 66. Further, the ignition coil 88 is arranged so as to overlap the intake member 100 and the electric motor 66 in a front view when viewed from the front with reference to FIG. Moreover, in the side view of FIGS.
  • the internal combustion engine 10 is an air-cooled single-cylinder engine in which the axial direction (axis line) of the crankshaft 68 is along the vehicle width direction.
  • the main components of the internal combustion engine 10 are disclosed in, for example, Japanese Patent Application Laid-Open No. 2016-160812 and Japanese Patent No. 60022269. Therefore, in the description of the internal configuration of the internal combustion engine 10, the same components as those disclosed in these publications will be described schematically, and the description thereof will be simplified or omitted. ..
  • the crankcase 52 is divided into a first case 112L on the left side and a second case 112R on the right side with a dividing surface (left and right center surfaces 110 shown in FIGS. 5, 7 and 8) substantially orthogonal to the vehicle width direction as a boundary.
  • a first case cover 114L (see FIGS. 1, 2, 4, and 5) is attached to the left side of the first case 112L.
  • the second case cover 114R (see FIGS. 3 to 5) is attached to the right side of the second case 112R.
  • the crankcase 52 also serves as a transmission case for accommodating a transmission such as a manual transmission. Inside the internal combustion engine 10 including the crankcase 52, a lubricating liquid as engine oil is appropriately circulated and stirred.
  • the cylinder block 54 has a cylindrical cylinder sleeve 116.
  • the cylinder sleeve 116 has an axis along the left and right central surfaces 110 and forms the cylinder chamber 74.
  • a piston 72 is fitted in the cylinder chamber 74 so as to be reciprocating along the left and right central surfaces 110 (the axis of the cylinder chamber 74).
  • the piston 72 is connected to the crank pin 120 of the crankshaft 68 via the connecting rod 118.
  • the crankshaft 68 has left and right crank webs 122L and 122R that support the crank pin 120, journal portions 124L and 124R that project outward from the crank webs 122L and 122R, respectively, and further left and right outside from the journal portions 124L and 124R. It has extension shafts 126L and 126R extending to, respectively. Therefore, the power of the reciprocating motion of the piston 72 is converted into the power of the rotary motion by the crankshaft 68.
  • a cam drive sprocket 128 is provided on the base end side of the extension shaft 126L on the 112L side (left side) of the first case.
  • a power transmission mechanism accommodating chamber 130 along the axial direction of the cylinder chamber 74 is formed on the left side of the cylinder block 54.
  • the power transmission mechanism accommodating chamber 130 accommodates a power transmission mechanism 132 as a chain type transmission mechanism including a cam drive sprocket 128.
  • a camshaft 134 rotatably connected to the power transmission mechanism 132 is provided in the cylinder head 56.
  • the power transmission mechanism 132 including the cam drive sprocket 128 transmits the power of the rotational movement of the crankshaft 68 to the cam shaft 134 to rotationally drive the cam shaft 134 in conjunction with the crankshaft 68.
  • a plurality of rotation shafts extending in the vehicle width direction are arranged substantially parallel to each other.
  • the plurality of rotating shafts are arranged behind the crank shaft 68, the first shift shaft 136 (first driven shaft) which is the main shaft arranged behind the crank shaft 68, and the first shift shaft 136.
  • the left side wall 140L of the first case 112L and the right side wall 140R of the second case 112R form a pair of side walls 140L and 140R facing each other.
  • the pair of side walls 140L and 140R are formed with support holes 142L and 142R (see FIG. 8) that rotatably support both ends of the plurality of rotating shafts described above. Therefore, in the crankcase 52, the crankshaft 68, the first transmission shaft 136, and the second transmission shaft 138 are rotatably supported by two support holes 142L and 142R formed in the pair of side walls 140L, respectively. Moreover, it is arranged in the vehicle width direction.
  • a first power transmission device 144 is provided between the crankshaft 68 and the first transmission shaft 136. Further, in the crankcase 52, a second power transmission device 146 is provided between the first shift shaft 136 and the second shift shaft 138. Further, in the crankcase 52, a kick spindle 148 is arranged behind the second transmission shaft 138.
  • the first power transmission device 144 is provided on the second case 112R side in the crankcase 52, and transmits the power of the rotational movement by the crankshaft 68 to the first transmission shaft 136.
  • the second power transmission device 146 is provided in the crankcase 52 so as to straddle the left and right central surfaces 110, and transmits the power of the rotational movement by the first shift shaft 136 to the second shift shaft 138.
  • the second transmission shaft 138 outputs the power transmitted from the second power transmission device 146 to the engine output unit 150 on the rear left side of the first case 112L, and the chain type transmission mechanism in the swing arm 34 from the engine output unit 150. It is transmitted to the rear wheel 36 (see FIG. 1) via 152.
  • the first power transmission device 144 includes a centrifugal clutch 154 connected to the right end portion (right extension shaft 126R) of the crankshaft 68 on the second case 112R side in the crankcase 52, and a second case 112R in the crankcase 52. It has a multi-plate clutch 156 connected to the right end of the first speed change shaft 136 on the side.
  • the centrifugal clutch 154 is coaxially supported by the extension shaft 126R on the right side, and has a clutch outer 154a, a clutch inner 154b, and a centrifugal weight 154c.
  • the clutch outer 154a is a bottomed cylindrical member that opens to the right, and is supported by an extension shaft 126R on the right side so as to be relatively rotatable.
  • the clutch inner 154b is rotatably supported by the extension shaft 126R on the right side on the inner peripheral side of the clutch outer 154a.
  • the centrifugal weight 154c is supported by the clutch inner 154b on the inner peripheral side of the clutch outer 154a so as to be expandable.
  • a centrifugal oil filter 158 is formed on the right side of the clutch inner 154b.
  • the centrifugal weight 154c is separated from the inner peripheral surface of the clutch outer 154a when the crankshaft 68 is stopped and at low speed, and the centrifugal clutch 154 is in a disconnected state where power cannot be transmitted. Further, the centrifugal weight 154c expands and operates as the rotation speed of the crankshaft 68 increases, frictionally engages with the inner peripheral surface of the clutch outer 154a at a predetermined rotation speed or higher, and is in a connected state capable of transmitting power to the centrifugal clutch 154. And.
  • a one-way clutch 160 is fitted in the center of the clutch outer 154a.
  • the one-way clutch 160 is in a free state and does not transmit torque.
  • the clutch inner 154b and the crankshaft 68 idle with respect to the clutch outer 154a.
  • the forward rotation of the crankshaft 68 corresponds to the rotation of the internal combustion engine 10 during operation.
  • the clutch inner 154b and the crankshaft 68 rotate forward ahead of the clutch inner 154b and the crankshaft 68, or when the clutch inner 154b and the crankshaft 68 reverse with respect to the clutch outer 154a, the clutch inner 154b If the rotation speed is less than the predetermined speed, the clutch is not transmitted while maintaining the free state. As a result, the clutch outer 154a idles with respect to the clutch inner 154b and the crankshaft 68.
  • the one-way clutch 160 goes into a one-way operating state when the rotation speed of the clutch inner 154b exceeds a predetermined speed. If the clutch outer 154a rotates in the normal direction prior to the clutch inner 154b and the crankshaft 68 in this state, torque transmission becomes possible, and the clutch outer 154a, the clutch inner 154b, and the crankshaft 68 can rotate in the normal direction.
  • a cylindrical transmission cylinder 154d extending to the left is provided on the left side of the central portion of the clutch outer 154a.
  • a primary drive gear 162 is integrally rotatable on the left end side of the transmission cylinder 154d.
  • the primary drive gear 162 meshes with the primary driven gear 164 rotatably supported on the right side of the first transmission shaft 136.
  • the primary drive gear 162 and the primary driven gear 164 form a primary reduction mechanism of the internal combustion engine 10.
  • the right end of the first speed change shaft 136 is terminated to the left of the right end of the centrifugal clutch 154, and the multi-plate clutch 156 is coaxially supported.
  • the multi-plate clutch 156 is a speed change clutch, and has a clutch outer 156a, a clutch inner 156b, and a plurality of clutch plates 156c.
  • the clutch outer 156a is a bottomed cylindrical member that opens to the right, and is supported on the right end of the first transmission shaft 136 so as to be relatively rotatable.
  • a primary driven gear 164 is integrally rotatably supported on the left side of the clutch outer 156a.
  • the clutch inner 156b is arranged on the inner peripheral side of the clutch outer 156a and is integrally rotatably supported by the right end portion of the first transmission shaft 136.
  • Each clutch plate 156c is laminated in the vehicle width direction between the clutch outer 156a and the clutch inner 156b.
  • the multi-plate clutch 156 presses and engages the clutch plate 156c by the urging force of a diaphragm spring (not shown).
  • the multi-plate clutch 156 temporarily releases the pressure welding of the clutch plate 156c in conjunction with the shift operation of the shift pedal (not shown), and smoothly shifts the shift change in the second power transmission device 146, which is the transmission of the vehicle 12. To do.
  • the second power transmission device 146 is a transmission provided between the first transmission shaft 136 and the second transmission shaft 138, and includes a plurality of gear trains 166a to 166d that enable alternative establishment.
  • the power generated by the rotational movement of the crankshaft 68 is transmitted from the first transmission shaft 136 to the second transmission shaft 138 via any gears constituting the gear trains 166a to 166d.
  • the left end portion of the second transmission shaft 138 projects to the rear left side of the crankcase 52 and becomes an engine output portion 150.
  • the gear trains 166a to 166d are composed of gears corresponding to the number of gears supported by the first shift shaft 136 and the second shift shaft 138, respectively.
  • the second power transmission device 146 is of a constant meshing type in which the corresponding gears of the gear trains 166a to 166d are always meshed between the first transmission shaft 136 and the second transmission shaft 138.
  • Each gear has a free gear that can rotate relative to the transmission shaft that supports itself, a fixed gear that can rotate integrally with the transmission shaft that supports itself, and a slide that spline fits to the transmission shaft that supports itself. It is classified as a gear.
  • the second power transmission device 146 moves the slide gear by operating a change mechanism (not shown), and selects gear trains 166a to 166d according to the shift stage.
  • a change mechanism not shown
  • gear trains 166a to 166d are arranged side by side.
  • An ACG (alternator) starter 168 is coaxially supported at the left end of the extension shaft 126L on the left side of the crankshaft 68.
  • the ACG starter 168 is a three-phase AC generator motor, which functions as a starter motor (starter motor) for starting the internal combustion engine 10 and also as an AC generator for generating power when the internal combustion engine 10 is operated.
  • the ACG starter 168 is an outer rotor type rotary electric machine, and has an outer rotor 168a and an inner stator 168b.
  • the outer rotor 168a is a bottomed cylindrical member that opens to the left, and is integrally rotatably supported by the left end portion of the left extension shaft 126L.
  • the inner stator 168b is arranged on the inner peripheral side of the outer rotor 168a and is fixedly supported by the first case cover 114L.
  • a plurality of magnets 168c arranged in the circumferential direction are fixed to the inner peripheral side of the outer rotor 168a.
  • a plurality of coils 168d arranged in the circumferential direction are formed on the outer peripheral side of the inner stator 168b.
  • a detection gear 170 containing a magnetic material is attached to the ACG starter 168 side of the extension shaft 126L on the left side.
  • the rotation speed detection unit 70 is attached to the crankcase 52 so as to face the tooth surface of the detection gear 170 so as to face the axial center of the crankshaft 68. Therefore, when the detection gear 170 rotates with the rotation of the crankshaft 68, the rotation speed detection unit 70 detects the number of teeth of the detection gear 170, so that the crankshaft 68 corresponds to the detected number of teeth. Detect the number of revolutions.
  • the right end of the kick spindle 148 projects to the rear right of the second case 112R and is connected to a kick arm (not shown).
  • a kick drive gear 172 is coaxially supported at the left end of the kick spindle 148.
  • the kick drive gear 172 rotates integrally with the kick spindle 148 via a meshing mechanism (not shown) only when the kick spindle 148 rotates in one direction by stepping down on the kick arm.
  • the kick drive gear 172 meshes with the driven gear of the first gear train 166a.
  • the rotational power of the kick drive gear 172 is input as forward rotation to the clutch outer 154a of the centrifugal clutch 154 via the first gear train 166a, the first transmission shaft 136, the multi-plate clutch 156, the primary driven gear 164 and the primary drive gear 162. Will be done. If the forward rotation torque is equal to or higher than a predetermined torque, the one-way clutch 160 is in the one-way operating state. When the one-way clutch 160 is locked by the further forward rotation, the forward rotation torque can be transmitted from the clutch outer 154a to the clutch inner 154b and the crankshaft 68. That is, the kick starter can crank the internal combustion engine 10.
  • FIG. 6 schematically shows a portion of the internal combustion engine 10 with a crankcase 52.
  • a first wall portion 176 is provided above the lubricating liquid holding portion 174 in the crankcase 52 and below the first shift shaft 136 or the second shift shaft 138. There is. Further, a second wall portion 178 is provided above the lubricating liquid holding portion 174 and below the crankshaft 68 in the crankcase 52.
  • crankshaft 68, the first shift shaft 136, and the second shift shaft 138 are arranged in this order from the front to the rear. Therefore, in the crankcase 52, a second wall portion 178 is provided in front of the crankshaft 68, the first shift shaft 136, the second shift shaft 138, and the lubricating liquid holding portion 174, and the first wall portion is provided.
  • the 176 is provided rearward so as to be connected to the second wall portion 178.
  • the first wall portion 176 is formed in a downwardly convex arc shape centered on the first transmission shaft 136 or the second transmission shaft 138.
  • at least a part of the second wall portion 178 is formed in a downwardly convex arc shape centered on the crankshaft 68.
  • the first wall portion 176 is formed so that the arc of the first wall portion 176 deviates from the cylinder chamber 74.
  • the second wall portion 178 is formed in an arc shape so as to extend to the cylinder block 54.
  • the crankcase 52 can be divided into a first case 112L and a second case 112R. Therefore, the first wall portion 176 is in the vehicle width direction (crankshaft 68, first shift shaft 136) from the first shift shaft 136 and the second shift shaft 138 side of the side wall 140L of the first case 112L toward the left and right center surface 110. And the first wall portion 176L on the first case side as an arc-shaped rib extending in each axial direction of the second transmission shaft 138, and the first transmission shaft 136 and the second transmission shaft 138 side of the side wall 140R of the second case 112R. It is composed of a first wall portion 176R on the second case side as an arc-shaped rib extending from the left and right central surfaces 110 in the vehicle width direction.
  • a first gap 180 is formed between the first wall portion 176L on the first case side and the first wall portion 176R on the second case side. That is, the gap formed in the front-rear direction between the right end portion of the first wall portion 176L on the first case side and the left end portion of the first wall portion 176R on the second case side is the first gap 180.
  • the first gap 180 is composed of a first narrow gap 180a that is narrow in the vehicle width direction and a first wide gap 180b that is wide in the vehicle width direction.
  • the first narrow gap portion 180a and the first wide gap portion 180b one gap portion is formed in the front and the other gap portion is formed in the rear. 7 and 8 show a case where the first wide gap portion 180b is formed in the front and the first narrow gap portion 180a is formed in the rear.
  • the second wall portion 178 is a second wall portion 178L on the first case side as an arcuate rib extending in the vehicle width direction from the crankshaft 68 side of the side wall 140L of the first case 112L toward the left and right central surfaces 110.
  • the second wall portion 178R on the second case side as an arcuate rib extending in the vehicle width direction from the crankshaft 68 side of the side wall 140R of the second case 112R toward the left and right central surfaces 110.
  • a second gap 182 is formed between the second wall portion 178L on the first case side and the second wall portion 178R on the second case side. Also in this case, the gap formed in the front-rear direction between the right end portion of the second wall portion 178L on the first case side and the left end portion of the second wall portion 178R on the second case side is the second gap 182.
  • the second gap 182 is composed of a second narrow gap portion 182a that is narrow in the vehicle width direction and a second wide gap portion 182b that is wide in the vehicle width direction. Of the second narrow gap portion 182a and the second wide gap portion 182b, one gap portion is formed in the front and the other gap portion is formed in the rear. 7 and 8 show a case where the second narrow gap portion 182a is formed in the front and the second wide gap portion 182b is formed in the rear.
  • a pump (not shown) is driven.
  • the pump pumps out the lubricating liquid held in the lubricating liquid holding portion 174.
  • the pumped lubricating liquid passes through the supply passage 184 provided in the crankcase 52, and is injected into the cylinder chamber 74 from the injection hole 185 toward the bottom surface of the piston 72 (see FIG. 5). As a result, the cylinder chamber 74 and the piston 72 are lubricated.
  • crankcase 52 is formed with a branch passage 186 that branches from the supply passage 184 to the second case 112R side and reaches the extension shaft 126R on the right side of the crankshaft 68.
  • a crankshaft passage 188 communicating with the branch passage 186 is formed in the axial portion of the extension shaft 126R on the right side in the vehicle width direction.
  • a plurality of communication holes 190 opening in the radial direction from the crankshaft passage 188 are formed.
  • the lubricating liquid supplied from the supply passage 184 to the crankshaft passage 188 via the branch passage 186 is in the crankcase 52 in the radial direction of the crankshaft 68 from the plurality of communication holes 190 as the crankshaft 68 rotates. Scatter to. Thereby, each part in the crankcase 52 can be lubricated.
  • crank pin 120 is formed with a crank pin passage 192 that communicates with the crank shaft passage 188. A portion of the lubricating liquid supplied to the crankshaft passage 188 is also supplied to the crankpin passage 192. As a result, the crank pin 120 can be lubricated.
  • the lubricating liquid that lubricates the internal space above the first wall portion 176 and the second wall portion 178 in the crankcase 52 falls on the lower first wall portion 176 and the second wall portion 178.
  • a first gap 180 is formed in the first wall portion 176
  • a second gap 182 is formed in the second wall portion 178. Therefore, the lubricating liquid that has fallen on the first wall portion 176 falls on the lubricating liquid holding portion 174 through the first gap 180. Further, the lubricating liquid that has fallen on the second wall portion 178 falls on the lubricating liquid holding portion 174 through the second gap 182.
  • Gasket 194 is inserted between the cylinder block 54 and the crankcase 52.
  • Gasket 194 is a non-metal sealing member such as paper.
  • the gasket 194 is formed in a substantially annular shape so as to surround the cylinder chamber 74 or the power transmission mechanism accommodating chamber 130 when viewed from the axial direction of the cylinder chamber 74. That is, as shown in FIG. 9, the gasket 194 has an annular portion 194a surrounding the cylinder chamber 74 and a recess 194b formed on the power transmission mechanism accommodating chamber 130 side from the annular portion 194a so as to be separated from the cylinder chamber 74.
  • the annular portion 194a of the gasket 194 surrounds the cylinder chamber 74, and the recess 194b connected to the annular portion 194a encloses the power transmission mechanism accommodating chamber 130.
  • a plurality of chambers including the cylinder chamber 74 and the power transmission mechanism accommodating chamber 130 are provided with the wall 196 interposed therebetween.
  • the annular portion 194a and the recess 194b of the gasket 194 are formed as a communication portion 194c which is a gap portion for communicating at least two of the plurality of adjacent chambers in the cylinder block 54.
  • FIG. 9 illustrates a case where the cylinder chamber 74 and the power transmission mechanism accommodating chamber 130 are communicated with each other by the communication portion 194c. Therefore, the recess 194b is formed by providing the communication portion 194c.
  • the gasket 194 is formed with a plurality of insertion holes 198 for inserting the fastening member 80 (see FIGS. 2 and 3) screwed into the screw holes of the crankcase 52. That is, the gasket 194 is formed with a plurality of insertion holes 198 corresponding to the plurality of insertion holes 76 and 78 of the cylinder block 54 and the cylinder head 56 and the plurality of screw holes.
  • the communication portion 194c is provided between the plurality of insertion holes 198 so as to avoid the plurality of insertion holes 198.
  • the annular portion 194a and the recess 194b are connected by a curved connecting portion 200.
  • a power transmission mechanism accommodation chamber 202 communicating with the power transmission mechanism accommodation chamber 130 (see FIGS. 5 and 9) of the cylinder block 54 is formed on the left end side of the cylinder head 56.
  • a valve mechanism accommodating chamber 204 for accommodating the valve mechanism 90 described later is formed on the right end side of the cylinder head 56.
  • the valve operating mechanism accommodating chamber 204 and the power transmission mechanism accommodating chamber 202 are separated by a wall 206.
  • the power transmission mechanism accommodation chamber 202 can be accessed from the outside by removing the cover member 208 on the left side of the cylinder head 56. Further, the valve operating mechanism accommodating chamber 204 can be accessed from the outside by removing the cover members 210 and 212 on the upper and lower sides of the cylinder head 56. In this case, the valve mechanism accommodating chamber 204 has one adjusting hole 214 that opens upward and the other adjusting hole 216 that opens downward. One of the adjusting holes 214 is closed by the upper cover member 210. Further, the other adjusting hole 216 is closed by the lower cover member 212. Therefore, with the cover members 210 and 212 removed from the cylinder head 56, the valve operating mechanism 90 is accessed through the adjusting holes 214 and 216.
  • the valve operating mechanism accommodating chamber 204 holds a valve operating mechanism 90 for controlling the inflow and outflow of air to and from the cylinder chamber 74 (combustion chamber 102).
  • the valve operating mechanism 90 includes the above-mentioned camshaft 134, two rocker arm shafts 218 and 220, two rocker arms 222 and 224, an intake valve 226 (valve, valve) and an exhaust valve 228 (valve, valve).
  • the camshaft 134 extends in the vehicle width direction in the valve mechanism accommodating chamber 204.
  • the left end of the camshaft 134 penetrates the wall 206, is inserted into the valve operating chamber 204, and is connected to the power transmission mechanism 132.
  • the right end of the cam shaft 134 is rotatably supported on the inner wall 230 on the right side of the cylinder head 56. Therefore, the cam shaft 134 can rotate by receiving a driving force (power of rotational movement) from the crank shaft 68 via the power transmission mechanism 132.
  • the two rocker arm shafts 218 and 220 are arranged vertically in the valve operating mechanism accommodating chamber 204 with the cam shaft 134 in between, and extend in the vehicle width direction.
  • the inner wall 230 on the right side of the cylinder head 56 is formed with a head boss 232 protruding to the left side corresponding to the upper rocker arm shaft 218.
  • One end (right end) of the rocker arm shaft 218 is fitted into a hole 234 formed in the head boss 232.
  • the other end (left end) of the two rocker arm shafts 218 is fitted into a hole formed in the wall 206.
  • one end (right end) of the lower rocker arm shaft 220 is fitted into a hole formed in the inner wall 230.
  • a head boss 236 protruding to the right is formed on the wall 206 corresponding to the lower rocker arm shaft 220.
  • the other end (left end) of the rocker arm shaft 220 is fitted into a hole 238 formed in the head boss 236.
  • the two head bosses 232 and 236 are formed with two holes 234 and 238, that is, insertion holes 240 and 242 facing the central axes (axis centers) of the two rocker arm shafts 218 and 220, respectively.
  • Each insertion hole 240, 242 is a substantially cylindrical through hole having a central axis.
  • the insertion hole 240 (the insertion hole 240 on the intake valve 226 side) provided in the upper head boss 232 is formed so as to face the upper adjustment hole 214.
  • the insertion hole 242 (the insertion hole 242 on the exhaust valve 228 side) provided in the lower head boss 236 is formed so as to face the adjustment hole 216 on the lower side.
  • the central axes of the insertion holes 240 and 242 provided in the head bosses 232 and 236 are substantially orthogonal to the adjustment holes 214 and 216 facing the insertion holes 240 and 242, respectively.
  • insertion holes 244 and 246 penetrating in the radial direction of the rocker arm shafts 218 and 220 are also formed at one end of the rocker arm shaft 218 and the other end of the rocker arm shaft 220.
  • the insertion holes 240 and 242 of the head boss 232 and 236 and the insertion holes 244 and 246 of the rocker arm shafts 218 and 220 fitted into the holes 234 and 238 of the head boss 232 and 236 are the rocker arm shaft 218.
  • a rod-shaped member 248 for regulating the relative rotation of the rocker arm shaft 218 is inserted into the pair of insertion holes 240 and 244. Further, a rod-shaped member 250 for restricting the relative rotation of the rocker arm shaft 220 is inserted into the pair of insertion holes 242 and 246.
  • the two rod-shaped members 248 and 250 have rod-shaped insertion portions 248a and 250a that are inserted into the pair of insertion holes 240 to 246, and head bosses 232 and 236 sides (adjustment holes 214 and 216 sides) of the insertion portions 248a and 250a, respectively. It has heads 248b and 250b having a diameter larger than that of the insertion portions 248a and 250a.
  • the insertion portions 248a and 250a sides of the heads 248b and 250b are formed in a flat shape. Further, on the adjustment holes 214 and 216 sides of the head bosses 232 and 236, when the insertion portions 248a and 250a are inserted into the pair of insertion holes 240 to 246, the flat surface portions 252 that come into surface contact with the flat surface portions of the head 248b and 250b. It is formed as 254. In this case, it is desirable that the flat surface portions 252 and 254 are flat surfaces substantially parallel to the adjusting holes 214 and 216.
  • the rod-shaped members 248 and 250 are screw members on which a spiral male screw portion is formed. Further, a spiral female screw portion is formed on the inner peripheral surface of the pair of insertion holes 240 to 246 corresponding to the rod-shaped members 248 and 250.
  • the rod-shaped members 248 and 250 as the screw members can be screwed into the female screw portions of the pair of insertion holes 240 to 246. Thereby, the rotation of the rocker arm shafts 218 and 220 can be easily regulated.
  • the rod-shaped members 248 and 250 are not limited to the screw members, and any member can be used as long as the rotation of the rocker arm shafts 218 and 220 can be regulated.
  • the insertion portions 248a and 250a of the rod-shaped members 248 and 250 are paired with insertion holes 240.
  • the rotation of the rocker arm shafts 218 and 220 can be easily regulated by inserting the rocker arm shafts 218 and 220.
  • the two rocker arms 222 and 224 are rotatably supported by the rocker arm shafts 218 and 220, respectively.
  • One end of each rocker arm 222 and 224 is connected to the cam shaft 134 via rollers 256 and 258.
  • the rocker arms 222 and 224 swing around the rocker arm shafts 218 and 220 by the driving force transmitted from the cam shaft 134 via the rollers 256 and 258.
  • the combustion chamber 102 is formed by the cylinder head 56 and the piston 72 of the cylinder chamber 74.
  • an intake port 104 having one end communicating with the intake pipe 100b and the other end communicating with the combustion chamber 102 is formed in the upper portion.
  • an exhaust port 260 is formed in the lower portion, one end of which can communicate with the combustion chamber 102 and the other end of which communicates with an exhaust device (not shown). ..
  • the intake valve 226 opens and closes the combustion chamber 102 with the driving force transmitted from the other end of the rocker arm 222 on the intake port 104 side (upper side), thereby opening and closing the combustion chamber 102 from the intake port 104 to the combustion chamber 102.
  • the exhaust valve 228 opens and closes the combustion chamber 102 with a driving force transmitted from the other end of the rocker arm 224 on the exhaust port 260 side (lower side), so that the exhaust valve 228 is exhausted from the combustion chamber 102 via the exhaust port 260.
  • a spark plug 96 is attached to the plug hole 94 of the cylinder head 56 so that the tip portion faces the combustion chamber 102.
  • an intake side adjusting mechanism 262 for adjusting the tappet clearance is provided between the intake valve 226 and the other end of the upper rocker arm 222. Therefore, the upper adjusting hole 214 also serves as an adjusting hole for accessing the intake side adjusting mechanism 262.
  • an exhaust side adjusting mechanism 264 for adjusting the tappet clearance is provided between the exhaust valve 228 and the other end of the lower rocker arm 224. Therefore, the lower adjustment hole 216 is an adjustment hole for accessing the exhaust side adjustment mechanism 264.
  • the cylinder head 56 opens on the cylinder block 54 side (bottom side of the cylinder head 56) from the outer peripheral surface of the cylinder head 56 toward the cooling fin 84 of the cylinder block 54.
  • An opening 266 is formed.
  • an air jacket 268 for communicating the side portion of the spark plug 96 (plug hole 94), the side portion of the intake port 104, and the side portion of the exhaust port 260 with the outside is provided inside the cylinder head 56.
  • the opening 266 opens from the air jacket 268 toward the cooling fin 84.
  • the opening 266 is formed so as to be located on the lower side of the cylinder block 54 in the cylinder head 56.
  • the air jacket 268 and the intake port 104 and the exhaust port 260 are separated by a wall 270.
  • the traveling wind is introduced into the air jacket 268 from the side portion (plug hole 94) of the spark plug 96.
  • the introduced running wind passes through the side portion of the intake port 104 and the side portion of the exhaust port 260, and exits (guides) rearward through the opening 266. Since there is a cooling fin 84 on the cylinder head 56 side of the cylinder block 54 behind the opening 266, the running wind that has passed backward from the opening 266 can suitably cool the cooling fin 84. A part of the running wind passing through the air jacket 268 also escapes downward.
  • the present embodiment is not limited to a single-cylinder internal combustion engine, and can be applied to a multi-cylinder internal combustion engine. Therefore, in the present embodiment, an internal combustion engine in which one piston 72 is provided in each of the plurality of cylinder chambers 74, an internal combustion engine in which a plurality of pistons 72 are provided in one cylinder chamber 74, and a plurality of cylinder chambers 74. It is also applicable to an internal combustion engine provided with a piston 72 of the above.
  • crankshaft 68, first shifting shaft 136, second shifting shaft 138 a case where a plurality of rotating shafts (crankshaft 68, first shifting shaft 136, second shifting shaft 138) are arranged in the vehicle width direction.
  • a plurality of rotation axes are arranged in a direction different from the vehicle width direction (for example, a front-rear direction and a vertical direction).
  • support holes 142L and 142R for axially supporting both ends of the plurality of rotating shafts are formed on the two side walls 140L and 140R orthogonal to each other in the different directions and facing each other.
  • the rod-shaped members 248 and 250 described above may be used as screw members, and may also serve as screw members for fixing the cover members 210 and 212 that close the adjusting holes 214 and 216.
  • the insertion portions 248a and 250a of the rod-shaped members 248 and 250 are screwed into the pair of insertion holes 240 to 246 to prevent the rocker arm shafts 218 and 220 from rotating and to close the adjustment holes 214 and 216. be able to.
  • the lubricating liquid may be supplied into the cylinder head 56, and the valve operating mechanism 90 may be lubricated with the supplied lubricating liquid.
  • the insertion holes 76 and 78 may be used as a lubricating liquid supply passage, or a lubricating liquid supply passage from the crankcase 52 to the cylinder head 56 via the cylinder block 54 may be separately provided. ..
  • each part in the cylinder head 56 can be suitably lubricated by scattering the lubricating liquid in the radial direction of the cam shaft 134 as the cam shaft 134 rotates.
  • the first embodiment is an internal combustion engine 10 (power unit) including a crankshaft 68 (power generation unit) that generates power by rotational movement, and performs rotational movement on the rear wheels 36 (rotated movement unit).
  • crankshaft 68 1st speed change shaft 136, 2nd speed change shaft 138
  • 1st power transmission device 144 and 2nd power transmission device 146 and a plurality of rotation shafts.
  • a crank case 52 power unit case for holding the first power transmission device 144 and the second power transmission device 146 inside is further provided.
  • the plurality of rotating shafts include a crankshaft 68 (drive shaft) as a power generating unit, and a first speed change shaft 136 (first driven shaft) in which power is transmitted from the crankshaft 68 via the first power transmission device 144.
  • the second shift shaft 138 (second driven shaft), in which power is transmitted from the first shift shaft 136 via the second power transmission device 146 and the transmitted power is transmitted to the rear wheels 36.
  • the crankcase 52 includes a cylinder block 54 and a lubricating liquid holding portion 174 that holds the lubricating liquid that lubricates the inside of the crankcase 52 below the inside of the crankcase 52.
  • a first wall portion 176 is provided above the lubricating liquid holding portion 174 in the crankcase 52 and below the first shift shaft 136 or the second shift shaft 138.
  • the first wall portion 176 is provided between the lubricating liquid holding portion 174 and the first shift shaft 136 or the second shift shaft 138.
  • the first wall portion 176 is formed in an arc shape centered on the first transmission shaft 136 or the second transmission shaft 138, a large acceleration is generated in the vehicle 12 including the crankcase 52. Even so, it is possible to effectively prevent the lubricating liquid from fluttering greatly and unnecessarily applying the lubricating liquid to the first transmission shaft 136, the second transmission shaft 138, and the like.
  • the internal combustion engine 10 is mounted on the vehicle 12.
  • the crankcase 52 is a case that can be divided into a first case 112L and a second case 112R along the vehicle width direction (axial direction of the crankshaft 68).
  • the first wall portion 176 is composed of a first case-side first wall portion 176L extending from the first case 112L in the vehicle width direction and a second case-side first wall portion 176R extending from the second case 112R in the vehicle width direction. Will be done. By extending the wall portion from both cases in this way, the assembling property of the crankcase 52 can be improved.
  • a first gap 180 is formed between the first wall portion 176L on the first case side and the first wall portion 176R on the second case side.
  • a second wall portion 178 is provided above the lubricating liquid holding portion 174 and below the crankshaft 68 in the crankcase 52.
  • the crankcase 52 has a pair of side walls 140L and 140R facing each other along at least the vehicle width direction of the vehicle 12.
  • the first wall portion 176 and the second wall portion 178 extend from the pair of side walls 140L and 140R in the vehicle width direction, and the crankshaft 68, the first transmission shaft 136 and the second transmission shaft 138 have the pair of side walls 140L and 140L, respectively. It is rotatably supported by the support holes 142L and 142R provided in 140R.
  • the crankcase 52 can be easily processed.
  • the second wall portion 178 is composed of a first case-side second wall portion 178L extending from the first case 112L in the vehicle width direction and a second case-side second wall portion 178R extending from the second case 112R in the vehicle width direction. Will be done. Thereby, the assembling property of the crankcase 52 can be further improved.
  • a second gap 182 is formed between the second wall portion 178L on the first case side and the second wall portion 178R on the second case side.
  • the first gap 180 and the second gap 182 are a narrow gap portion (first narrow gap portion 180a, second narrow gap portion 182a) and a wide wide gap portion (first gap portion 182a) along the front-rear direction of the vehicle 12, respectively. It is composed of one wide gap portion 180b and a second wide gap portion 182b).
  • one of the gaps is formed in the front and the other gap is formed in the rear.
  • the efficiency of discharging the lubricating liquid can be further improved by providing the wide gap portion in the direction in which the acceleration of the vehicle 12 is likely to be applied. For example, when the vehicle 12 accelerates or brakes, the lubricating fluid moves forward. Therefore, if the wide gap portion is provided in the front, the lubricating liquid can be efficiently discharged to the lubricating liquid holding portion 174.
  • the internal combustion engine 10 generates a rotary motion by a piston 72 that reciprocates in the cylinder chamber 74 (cylinder), and the first shift shaft 136 and the second shift shaft 138 are a plurality of gears capable of selectively transmitting power. Power is transmitted by rows 166a-166d. As a result, the internal combustion engine 10 can be suitably mounted on the vehicle 12.
  • the cam shaft 134 that receives the driving force from the crank shaft 68 (crankshaft), the rocker arm shafts 218 and 220, and the rocker arm shafts 218 and 220 are supported so as to be relatively rotatable. At least, the rocker arms 222 and 224 swinging around the rocker arm shafts 218 and 220 by the driving force transmitted from the cam shaft 134 and the combustion chamber 102 by the driving force transmitted from the rocker arms 222 and 224 are opened and closed.
  • the present invention relates to a valve operating mechanism 90 (valve valve structure) of an internal combustion engine 10 including one valve (intake valve 226, exhaust valve 228).
  • the valve operating mechanism 90 further includes head bosses 232 and 236 that support rocker arm shafts 218 and 220 on the cylinder head 56 of the internal combustion engine 10, and rod-shaped members 248 and 250.
  • the head bosses 232 and 236 and the rocker arm shafts 218 and 220 are formed with a pair of insertion holes 240 to 246 that communicate with each other by rotating the rocker arm shafts 218 and 220 in an arbitrary phase around the axis.
  • the rod-shaped members 248 and 250 are inserted into the pair of insertion holes 240 to 246 to regulate the relative rotation of the rocker arm shafts 218 and 220.
  • the rod-shaped members 248 and 250 are inserted into the pair of insertion holes 240 to 246 formed in the rocker arm shafts 218 and 220 and the head bosses 232 and 236 to allow the rocker arm shafts 218 and 220 to rotate relative to each other. regulate.
  • the relative rotation of the rocker arm shafts 218 and 220 is regulated by a simple configuration, so that the component cost and the manufacturing cost can be reduced.
  • the cam shaft 134, the rocker arm shafts 218 and 220, the rocker arm 222 and 224, the intake valve 226 and the exhaust valve 228 have an integral structure housed in the cylinder head 56.
  • An adjustment mechanism (intake side adjustment mechanism 262, exhaust side adjustment mechanism 264) for adjusting the tappet clearance is provided between the intake valve 226 and the exhaust valve 228 and the rocker arm 222 and 224 in the cylinder head 56.
  • the cylinder head 56 is formed with adjustment holes 214 and 216 for accessing the intake side adjustment mechanism 262 and the exhaust side adjustment mechanism 264 from the outside.
  • the pair of insertion holes 240 to 246 have a substantially cylindrical shape having a central axis, and the central axes of the insertion holes 240 and 242 on the head boss 232 and 236 sides are directed to the adjustment holes 214 and 216.
  • the central axes of the pair of insertion holes 240 to 246 are oriented substantially at the centers of the rocker arm shafts 218 and 220. That is, insertion holes 240 to 246 are formed in the radial direction of the rocker arm shafts 218 and 220. As a result, the total length of the insertion holes 240 to 246 can be secured to the maximum. As a result, the effect of detenting the rocker arm shafts 218 and 220 by the rod-shaped members 248 and 250 can be further improved.
  • the rod-shaped members 248 and 250 are provided on the head bosses 232 and 236 of the insertion portions 248a and 250a and the rod-shaped insertion portions 248a and 250a that are inserted into the pair of insertion holes 240 to 246, and are more than the insertion portions 248a and 250a. It has large diameter heads 248b and 250b.
  • the head bosses 232 and 236 have flat surfaces 252 and 254 that come into surface contact with the heads 248b and 250b when the insertion portions 248a and 250a are inserted into the pair of insertion holes 240 to 246.
  • the flat surface portions 252 and 254 are flat surfaces substantially parallel to the adjusting holes 214 and 216.
  • the central axis of the insertion holes 240 and 242 on the head boss 232 and 236 side and the adjustment holes 214 and 216 are substantially orthogonal to each other. This makes it easier to access the rod-shaped members 248 and 250 via the adjusting holes 214 and 216.
  • a spiral female screw portion is formed on the inner peripheral surface of the pair of insertion holes 240 to 246, and a spiral male screw portion is formed on the outer peripheral surfaces of the rod-shaped members 248 and 250.
  • the female screw portion and the male screw portion have substantially the same shape.
  • the present embodiment is attached to at least one cylinder chamber 74 (cylinder) accommodating at least one piston 72 that performs reciprocating motion and a cylinder block 54 having the cylinder chamber 74, and the cylinder.
  • the present invention relates to an internal combustion engine 10 having a cylinder head 56 forming a combustion chamber 102 together with a chamber 74, and an ignition plug 96 attached to the cylinder head 56 so as to face the combustion chamber 102.
  • the internal combustion engine 10 further has an ignition coil 88 that generates a voltage required to ignite the spark plug 96, and is mounted on the vehicle 12 in a state of being supported by the vehicle body frame 16 of the vehicle 12. ..
  • the ignition coil 88 is arranged on the upper portion (upper surface) of the cylinder block 54 so as to overlap the cylinder block 54 including the cylinder chamber 74 in a plan view.
  • the ignition coil 88 since the ignition coil 88 is arranged on the upper part of the cylinder block 54, the ignition coil 88 can be arranged close to the spark plug 96. As a result, the expensive high-voltage wiring 98 can be made as short as possible. Further, it is possible to prevent the ignition coil 88 and the high-voltage wiring 98 from protruding from the internal combustion engine 10 in the vehicle width direction of the vehicle 12. As a result, the appearance of the vehicle 12 on which the internal combustion engine 10 is mounted is improved. Further, it is possible to suppress the failure of the ignition coil 88 and the disconnection of the high-voltage wiring 98 due to a side collision or a stepping stone during traveling of the vehicle 12.
  • the internal combustion engine 10 further includes an intake member 100 connected to the cylinder head 56.
  • the ignition coil 88 is arranged behind the cylinder head 56 or the intake member 100 in a side view. By arranging the ignition coil 88 near the intake member 100 that easily protrudes in the vertical direction in this way, the dead space between the vehicle body frame 16 and the internal combustion engine 10 can be effectively utilized.
  • the intake member 100 includes a throttle body 100a that controls the intake amount of the internal combustion engine 10, and an intake pipe 100b that connects the throttle body 100a and the intake port 104 that communicates with the combustion chamber 102.
  • the ignition coil 88 is arranged behind the throttle body 100a in a side view.
  • the throttle body 100a in particular takes up space, so dead space is likely to occur. Therefore, by arranging the ignition coil 88 behind the throttle body 100a, the dead space can be effectively utilized. Further, the wirings connected to the throttle body 100a and the wirings connected to the ignition coil 88 can be efficiently combined.
  • the internal combustion engine 10 further includes an electric motor 66 for starting.
  • the ignition coil 88 is arranged in front of the electric motor 66 in a side view.
  • the most protruding component on the crankcase 52 side is often the starter motor.
  • the front portion where the distance between the vehicle body frame 16 and the internal combustion engine 10 is wide is likely to be a dead space. Therefore, by arranging the ignition coil 88 in front of the electric motor 66, the dead space can be utilized more effectively. Further, the wiring of the electric motor 66 and the wiring of the ignition coil 88 can be efficiently combined.
  • the internal combustion engine 10 further includes a crankshaft 68 (rotational shaft) that rotates due to the reciprocating motion of the piston 72, and a rotation speed detection unit 70 that detects the rotation speed of the crankshaft 68.
  • the ignition coil 88 is arranged in front of the rotation speed detection unit 70 in a side view.
  • a pickup sensor such as the rotation speed detection unit 70 is often provided in the front portion of the upper surface of the crankcase 52.
  • the circumference of the rotation speed detection unit 70 tends to become a dead space. Therefore, by arranging the ignition coil 88 in front of the rotation speed detection unit 70, the dead space can be effectively utilized. Further, the wiring of the rotation speed detection unit 70 and the wiring of the ignition coil 88 can be efficiently combined.
  • the internal combustion engine 10 further includes a crankcase 52 that accommodates a plurality of shaft members (crankshaft 68, first shift shaft 136, second shift shaft 138).
  • a coupling boss 58a for coupling to the vehicle body frame 16 is provided on the upper portion of the crankcase 52.
  • the ignition coil 88 is arranged in front of the coupling boss 58a in a side view. In the vehicle 12 of a turnip-type motorcycle, it is often coupled to the vehicle body frame 16 on the upper surface of the crankcase 52. As a result, the circumference of the coupling boss 58a tends to become a dead space. Therefore, by arranging the ignition coil 88 in front of the coupling boss 58a, the dead space can be effectively utilized.
  • the ignition coil 88 is arranged so as to overlap the vehicle body frame 16 in a plan view.
  • the ignition coil 88 like the cylinder block 54, tends to have a high temperature. Therefore, with the above configuration, it is possible to prevent the member having a high temperature from protruding in the vehicle width direction and to make the arrangement difficult to touch.
  • the internal combustion engine 10 further includes an intake member 100 connected to the combustion chamber 102 and an electric motor 66 for starting.
  • the ignition coil 88 is arranged so as to overlap the intake member 100 and the electric motor 66 in front view. As a result, it is possible to save space in the internal combustion engine 10 while preventing the ignition coil 88 from protruding in the vertical direction.
  • the ignition coil 88 is attached to the cylinder block 54 via the stay member 86. As a result, it is possible to prevent the ignition coil 88 from becoming hot due to the heat from the cylinder block 54.
  • the internal combustion engine 10 further has a crankcase 52 connected to the cylinder head 56 via the cylinder block 54.
  • a crankcase 52 connected to the cylinder head 56 via the cylinder block 54.
  • at least a part of the ignition coil 88 or the stay member 86 is located below the virtual line 108 connecting the top of the cylinder head 56 and the top of the crankcase 52 in a side view.
  • the area formed by connecting the virtual line 108 with the upper portions of the crankcase 52, the cylinder block 54, and the cylinder head 56 tends to be a dead space. Therefore, by arranging the ignition coil 88 or the stay member 86 in such a region, the dead space can be effectively utilized.
  • the vehicle 12 is a saddle-mounted vehicle, the above-mentioned effect can be easily achieved.
  • a fourth configuration at least one cylinder chamber 74 (cylinder) accommodating at least one piston 72 that performs reciprocating motion, and a valve operating mechanism that controls the inflow and outflow of air into and out of the cylinder chamber 74.
  • the present invention relates to an internal combustion engine 10 having a 90, a cylinder block 54 for holding a cylinder chamber 74, and a cylinder head 56 which is attached adjacent to the cylinder block 54 and holds a valve operating mechanism 90.
  • a plurality of cooling fins 84 that intersect in the axial direction of the cylinder chamber 74 are provided on the outer peripheral surface of the cylinder block 54. Further, on the cylinder block 54 side of the cylinder head 56, an opening 266 that opens from the outer peripheral surface of the cylinder head 56 toward the cooling fins 84 is formed.
  • the internal combustion engine 10 further includes a spark plug 96 attached to the cylinder head 56 so as to face the combustion chamber 102 formed by the cylinder chamber 74 and the cylinder head 56.
  • the cylinder head 56 has an intake port 104 for supplying air to the combustion chamber 102 from the outside, an exhaust port 260 for exhausting air from the combustion chamber 102 to the outside, a side portion of the spark plug 96, and a side of the intake port 104.
  • An air jacket 268 that communicates the side portion of the portion and the exhaust port 260 with the outside is provided.
  • the opening 266 opens from the air jacket 268 toward the cooling fin 84. In this way, since the opening 266 is provided at the position where the running wind flows, the efficiency of guiding the air from the cylinder head 56 side to the cooling fin 84 of the cylinder block 54 is improved.
  • the internal combustion engine 10 further includes a crankshaft 68 that converts the reciprocating motion of the piston 72 into a rotary motion, and a crankcase 52 that houses the crankshaft 68.
  • the internal combustion engine 10 is mounted on the vehicle 12, and the cylinder block 54 projects upward or forward from the front portion of the crankcase 52.
  • the axis of the cylinder chamber 74 (cylinder block 54) is inclined upward from the horizontal toward the front.
  • the running wind hits the outer peripheral surface of the cylinder head 56 and is guided to the cooling fins 84 of the cylinder block 54 through the opening 266.
  • the air conduction efficiency can be further improved.
  • the opening 266 is formed in the cylinder head 56 in the front-rear direction.
  • the opening 266 in the same direction as the flow of the running wind, the amount of air guided to the opening 266 can be improved.
  • the running wind can be easily applied to the cooling fins 84 on the cylinder head 56 side of the cylinder block 54, which is arranged behind the cylinder head 56 so that the running wind is less likely to hit.
  • the opening 266 is formed in the cylinder head 56 so as to be located on the lower side of the cylinder block 54. As a result, a negative pressure is generated between the lower surface side of the cylinder block 54 facing the opening 266 and the ground, and more running wind from the front can be taken into the opening 266.
  • an internal combustion engine 10 having at least one cylinder chamber 74 accommodating at least one piston 72 that performs reciprocating motion and a crankshaft 68 that converts reciprocating motion into rotary motion. Regarding.
  • the internal combustion engine 10 includes a crankcase 52 that houses a crankshaft 68, a cylinder sleeve 116 that forms a cylinder chamber 74, a cylinder block 54 that covers the cylinder sleeve 116, and an intake valve 226 and an exhaust valve 228 (in response to rotational movement).
  • the valve mechanism 90 that controls the inflow and outflow of air to and from the cylinder chamber 74 by operating the valve), the power transmission mechanism 132 that transmits the power of rotational movement from the crankshaft 68 to the valve mechanism 90, and the inside of the cylinder block 54. It further has a power transmission mechanism accommodating chamber 130 formed in the above and accommodating the power transmission mechanism 132, and a gasket 194 interposed between the cylinder block 54 and the crankcase 52.
  • the gasket 194 is formed in a substantially annular shape so as to surround the cylinder chamber 74 or the power transmission mechanism accommodating chamber 130 when viewed from the axial direction of the cylinder chamber 74. At least a part of the annular portion 194a surrounding the cylinder chamber 74 in the gasket 194 forms a recess 194b away from the cylinder chamber 74 with respect to the other portion of the annular portion 194a.
  • the recess 194b is provided on the side of the power transmission mechanism accommodating chamber 130.
  • the recess 194b of the gasket 194 is provided from the cylinder chamber 74 toward the power transmission mechanism accommodating chamber 130.
  • the cylinder chamber 74 and the power transmission mechanism accommodating chamber 130 communicate with each other through the gap portion formed by the recess 194b between the cylinder block 54 and the crankcase 52.
  • the stress (strain) of the gasket 194 is suppressed, and the strain of the cylinder chamber 74 is reduced.
  • the rigidity of the gasket 194 is lowered, and the effect of suppressing distortion of the cylinder chamber 74 is further improved.
  • a plurality of chambers including at least one cylinder chamber 74 and a power transmission mechanism accommodating chamber 130 are provided with a wall 196 (wall portion) interposed therebetween.
  • the gasket 194 is formed with a communication portion 194c for communicating at least two chambers among a plurality of adjacent chambers in the cylinder block 54, and the communication portion 194c forms a recess 194b. This facilitates the processing of the gasket 194.
  • the cylinder block 54 and the gasket 194 are formed with a plurality of insertion holes 76 and 198 through which the fastening member 80 to be fastened to the crankcase 52 is inserted.
  • the communication portion 194c is provided between the plurality of insertion holes 76 and 198. By securing the insertion holes 76 and 198 in this way, the positioning of the gasket 194 with respect to the crankcase 52 and the cylinder block 54 becomes easy. Further, by providing the communication portion 194c between the insertion holes 76 and 198, the communication portion 194c can be secured to the maximum.
  • connecting portion (connecting portion 200) between the annular portion 194a and the concave portion 194b is formed in a curved shape. As a result, the stress applied to the gasket 194 can be efficiently released.
  • gasket 194 is a non-metal member, the processing of the gasket 194 becomes easier.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Cylinder Crankcases Of Internal Combustion Engines (AREA)

Abstract

Dans ce moteur à combustion interne (10), un joint d'étanchéité (194) interposé entre un bloc-cylindres (54) et un boîtier de manivelle (52) est formé en une forme annulaire de manière à renfermer une chambre de cylindre (74) ou une chambre de réception de mécanisme de transmission de puissance (130) telle que vue depuis la direction axiale de la chambre de cylindre (74). Un évidement (194b) est formé dans au moins une partie d'une partie annulaire (194a) entourant la chambre de cylindre (74) dans le joint d'étanchéité (194), l'évidement (194b) étant séparé de la chambre de cylindre (74) par rapport au reste de la partie annulaire (194a). L'évidement (194b) est prévu sur le côté ayant la chambre de réception de mécanisme de transmission de puissance (130).
PCT/JP2019/014095 2019-03-29 2019-03-29 Moteur à combustion interne WO2020202282A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
CN201980095021.7A CN113661318B (zh) 2019-03-29 2019-03-29 内燃机
PCT/JP2019/014095 WO2020202282A1 (fr) 2019-03-29 2019-03-29 Moteur à combustion interne
BR112021019126A BR112021019126A2 (pt) 2019-03-29 2019-03-29 Motor de combustão interna
JP2021510616A JP7093892B2 (ja) 2019-03-29 2019-03-29 内燃機関

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2019/014095 WO2020202282A1 (fr) 2019-03-29 2019-03-29 Moteur à combustion interne

Publications (1)

Publication Number Publication Date
WO2020202282A1 true WO2020202282A1 (fr) 2020-10-08

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PCT/JP2019/014095 WO2020202282A1 (fr) 2019-03-29 2019-03-29 Moteur à combustion interne

Country Status (4)

Country Link
JP (1) JP7093892B2 (fr)
CN (1) CN113661318B (fr)
BR (1) BR112021019126A2 (fr)
WO (1) WO2020202282A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08135501A (ja) * 1994-11-11 1996-05-28 Kioritz Corp エンジン
JPH09500944A (ja) * 1993-07-27 1997-01-28 キャタピラー インコーポレイテッド シリンダヘッド密封装置及び方法
JPH11148555A (ja) * 1997-11-14 1999-06-02 Suzuki Motor Corp 金属ガスケット
JP2006266099A (ja) * 2005-03-22 2006-10-05 Fuji Heavy Ind Ltd ガスケット
JP3136776U (ja) * 2007-07-20 2007-11-08 真樹 橋本 エンジンのガスケット

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3589328B2 (ja) * 1996-01-12 2004-11-17 本田技研工業株式会社 内燃機関の組付け構造
JP3975150B2 (ja) * 2002-10-09 2007-09-12 本田技研工業株式会社 頭上弁式内燃機関のブリーザ構造
CN102734040A (zh) * 2011-03-30 2012-10-17 本田技研工业株式会社 车辆用火花点火四冲程发动机
JP6251633B2 (ja) * 2014-05-09 2017-12-20 本田技研工業株式会社 内燃機関
JP6333787B2 (ja) * 2015-09-25 2018-05-30 本田技研工業株式会社 内燃機関のブリーザ室構造

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09500944A (ja) * 1993-07-27 1997-01-28 キャタピラー インコーポレイテッド シリンダヘッド密封装置及び方法
JPH08135501A (ja) * 1994-11-11 1996-05-28 Kioritz Corp エンジン
JPH11148555A (ja) * 1997-11-14 1999-06-02 Suzuki Motor Corp 金属ガスケット
JP2006266099A (ja) * 2005-03-22 2006-10-05 Fuji Heavy Ind Ltd ガスケット
JP3136776U (ja) * 2007-07-20 2007-11-08 真樹 橋本 エンジンのガスケット

Also Published As

Publication number Publication date
BR112021019126A2 (pt) 2021-11-30
CN113661318A (zh) 2021-11-16
JP7093892B2 (ja) 2022-06-30
JPWO2020202282A1 (ja) 2021-10-21
CN113661318B (zh) 2024-04-19

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