JP2014070565A - Oil-water separation structure of engine for small vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently collect moisture generated in an engine without requiring a complex structure.SOLUTION: An oil-water separation structure of an engine for a small vehicle includes: a crank case (110) pivotally supporting a crank shaft (112); a pair of engine covers (150, 160) which covers the vehicle width direction outer side of the crank case (110); and an oil-water separation chamber (155) for accumulating water droplets condensed in the crank case (110). The oil-water separation chamber (155) is provided at a lower end part of at least one of the engine covers (150) so as to open at the upper side and is defined by utilizing a part of an inner wall surface of the engine cover (150).

Description

  The present invention relates to an oil / water separation structure for an engine for a small vehicle such as a motorcycle.

  Conventionally, in a four-cycle engine mounted on a small vehicle such as a motorcycle, moisture is accumulated inside the engine due to unburned gas (blow-by gas). In particular, such accumulation of moisture is noticeable in an environment where the temperature outside the engine is low, such as in a cold region. The water accumulated inside the engine evaporates when the temperature of the engine oil inside the engine reaches 100 ° C. or higher, but the temperature of the engine oil does not rise depending on the operating condition and continues to accumulate inside the engine. The accumulated moisture can be mixed into the engine oil inside the engine and deteriorate the lubrication performance of the engine oil.

  In this way, as an oil / water separation structure that discharges moisture accumulated in the engine, engine oil mixed with moisture is stored in a space provided in advance in the engine, and the engine oil is heated to evaporate the moisture. The thing which isolate | separates the oil component and water | moisture content of engine oil is proposed (for example, refer patent document 1).

Japanese Utility Model Publication No. 3-10015

  However, in the conventional oil-water separation structure as described above, there is a problem that a heat source for heating the engine oil accumulated in a specific space is required, and the internal structure of the engine is complicated.

  The present invention has been made in view of the above points, and provides an oil-water separation structure for a small vehicle engine that can efficiently recover moisture generated in the engine without requiring a complicated structure. Objective.

  The oil / water separation structure for a small vehicle engine according to the present invention stores a crankcase that supports a crankshaft, a pair of engine covers that cover the outer side of the crankcase in the vehicle width direction, and water droplets condensed in the crankcase. An oil-water separation chamber, wherein the oil-water separation chamber is opened upward at a lower end portion of at least one engine cover and is provided using a part of an inner wall surface of the engine cover. .

  According to this configuration, the oil / water separation chamber opens upward in the lower end portion of the engine cover and is provided by using a part of the inner wall surface of the engine cover, so that it is separated from the heat source such as the combustion chamber. The oil / water separation chamber can be disposed at a position where the temperature tends to be relatively low when exposed to outside air (that is, a position where moisture inside the engine is likely to condense). This makes it possible to store water droplets adhering to the inner wall of the engine cover due to condensation of the water in the engine in the oil-water separation chamber by its own weight before mixing with the engine oil. In addition, it is possible to recover the moisture generated in the engine.

  In the oil / water separation structure for an engine for a small vehicle, the oil / water separation chamber is preferably formed at an end portion of the pair of engine covers on the vehicle front side. In this case, the oil / water separation chamber is located at a position where it can be easily cooled by receiving the traveling wind, so that the water in the engine is easily condensed and water droplets adhering to the inner wall surface of the engine cover are separated from the water by the condensation. Since it can be accommodated in the chamber, it is possible to effectively recover the moisture generated in the engine.

  For example, the oil / water separation structure for a small vehicle engine further includes a gasket disposed on a joint surface between the crankcase and the engine cover, and is provided to extend upward from the inner bottom surface of the engine cover. A partition wall partitioning a space in the engine cover, and an inner wall surface, an inner bottom surface and the partition wall portion of the engine cover, and a wall surface portion of the gasket provided facing the inner wall surface of the engine cover. It is conceivable to provide the oil / water separation chamber in the space to be formed. In this case, since the oil / water separation chamber is formed by the inner wall surface, inner bottom surface and partition wall portion of the engine cover, and the wall surface portion of the gasket, a special configuration for forming the oil / water separation chamber on the crankcase side is provided. There is no need to provide the oil / water separation chamber with a simple configuration. Moreover, since the oil / water separation chamber is disposed outside the gasket disposed between the crankcase and the engine cover, the oil / water separation chamber can be separated from a part of the cylinder or the crankcase provided with the heat source. It is possible to suppress the influence of the heat source on the oil and stably hold it in a state separated from the engine oil.

  In the oil / water separation structure for a small vehicle engine, the upper end portion of the partition wall and the upper end portion of the wall surface portion of the gasket are substantially the same as or higher than the oil level height in a state where the standard amount of engine oil is maintained. Is preferably arranged at a higher position. In this case, since the upper end of the oil / water separation chamber is disposed at a position equal to or higher than the oil level height in the state where the standard amount of engine oil is maintained, the normal operation, that is, during the circulation of the engine oil, is performed. Since the engine oil in the oil / water separation chamber can be isolated from the engine oil outside the oil / water separation chamber, the recovered water can be held in a state separated from the engine oil without being affected by the engine oil outside the oil / water separation chamber.

  Furthermore, in the oil / water separation structure for a small vehicle engine, it is conceivable that a support piece is provided on a part of the crankcase for supporting the gasket wall surface portion between the upper end portion of the partition wall portion. . In this case, the support piece provided on the crankcase can be supported by sandwiching the wall surface of the gasket with the upper end of the partition wall, so that the shape of the oil / water separation chamber can be stably maintained and recovered. It is possible to reliably retain the moisture in the engine.

  In particular, in the oil / water separation structure for a small vehicle engine, it is preferable that a part of a fastening member for fixing the engine cover to the crankcase is received by the support piece. In this case, since the wall surface of the gasket can be supported by using the component for fixing the engine cover, the wall surface of the gasket is strengthened without providing a dedicated component for supporting the wall of the gasket. It becomes possible to support.

  According to the present invention, it is possible to efficiently recover moisture in the engine without requiring a complicated structure.

1 is a right side view showing an appearance of a motorcycle to which an oil / water separation structure for a small vehicle engine according to an embodiment is applied. It is a right side view of an engine provided in the motorcycle according to the present embodiment. It is a left side view of the engine with which the motorcycle concerning this embodiment is provided. 1 is a front view of an engine provided in a motorcycle according to the present embodiment. It is sectional drawing in the continuous line AA shown in FIG. It is an enlarged view of the oil-water separation chamber periphery shown in FIG. It is explanatory drawing of the clutch cover which the engine with which the motorcycle concerning this Embodiment is provided has. It is explanatory drawing of the structure in the engine with which the motorcycle concerning this Embodiment is provided. It is sectional drawing of the engine of the oil-water separation chamber periphery in the continuous line BB shown in FIG. It is sectional drawing.

  Hereinafter, the present embodiment will be described in detail with reference to the accompanying drawings. In the following, an example in which the oil / water separation structure for a small vehicle engine according to the present invention is applied to a sports type motorcycle engine will be described. However, the small vehicle engine to which the present invention is applied is not limited to this and can be changed as appropriate. For example, the present invention can also be applied to other types of motorcycle engines, buggy-type motor tricycles or motor vehicles engines.

  Hereinafter, the overall configuration of a motorcycle to which the oil / water separation structure for a small vehicle engine according to the present embodiment is applied will be described with reference to FIG. FIG. 1 is a right side view showing the appearance of a motorcycle to which the oil / water separation structure for a small vehicle engine according to the present embodiment is applied. In FIG. 1, the front side of the vehicle body is indicated by an arrow FR and the rear side of the vehicle body is indicated by an arrow RE as appropriate. The same applies to the drawings subsequent to FIG.

  As shown in FIG. 1, a motorcycle 1 is configured by attaching various covers as a vehicle body exterior to a steel or aluminum alloy double cradle type vehicle body frame 2 on which various parts such as a power unit and an electrical system are mounted. Yes. An engine 3 is mounted on the inner side of the double cradle part in the substantially front half of the body frame 2. The engine 3 is supported by a frame member surrounding the periphery in a side view through an engine mount. A fuel tank 4 is provided on the upper surface of the cradle portion of the vehicle body frame 2 so as to be positioned above the engine 3.

  The engine 3 includes, for example, a parallel two-cylinder engine and a transmission, and is suspended at an appropriate position on the body frame 2. Air is taken into the engine 3 via an intake duct (not shown), and air and fuel are mixed by a fuel injection device (not shown) and supplied to the combustion chamber. Exhaust gas after combustion in the combustion chamber is discharged from the muffler 32 via a plurality of exhaust pipes 31 extending downward from the engine 3.

  A vehicle body cover 41 is provided in front of the fuel tank 4 so as to cover the vicinity of the upper end portion of the vehicle body frame 2. A headlight 42 that illuminates the front of the vehicle body is integrally provided in front of the vehicle body cover 41. Further, a mirror 43 is provided in the vicinity of the upper end portion of the vehicle body cover 41 for the driver to check the field of view behind the vehicle body.

  On the other hand, a rider seat 21 a and a pillion seat 21 b are connected to the rear of the fuel tank 4. The rider seat 21 a and the pillion seat 21 b are supported by the seat rail 22 in the substantially rear half of the body frame 2. Footrests 23 and 24 are provided below the rider seat 21a and the pillion seat 21b, respectively. A brake pedal 25 for the rear wheel 6 is provided in front of the driver's footrest 23 on the right side of the vehicle body, and a shift change pedal (not shown) is provided in front of the driver's footrest 23 on the left side of the vehicle body. Is provided.

  A front fork 51 is rotatably connected to the head pipe of the body frame 2. The front fork 51 is provided with a handle bar 52, and grips 53 are attached to both ends of the handle bar 52. A brake lever 54 for the front wheel 5 is arranged on the right front side of the handle bar 52, and a clutch lever (not shown) is arranged on the left front side of the handle bar 52. A front wheel 5 is rotatably supported at a lower portion of the front fork 51, and a brake disk 55 is provided on the front wheel 5.

  A rear swing arm 61 is connected to a position corresponding to substantially the latter half of the body frame 2 so as to be swingable in the vertical direction, and a suspension (not shown) is provided between the body frame 2 and the rear swing arm 61. It is attached. The rear wheel 6 is rotatably supported at the rear part of the rear swing arm 61. A driven sprocket (not shown) is provided on the left side of the rear wheel 6 so that the power of the engine 3 is transmitted to the rear wheel 6 by a drive chain. A brake disk 62 for the rear wheel 6 is provided on the right side of the rear wheel 6.

  Next, the outline of the engine 10 provided with the oil-water separation structure according to the present embodiment will be described with reference to FIGS. FIG. 2 is a right side view of engine 10 provided in motorcycle 1 according to the present embodiment. FIG. 3 is a left side view of engine 10 provided in motorcycle 1 according to the present embodiment. FIG. 4 is a front view of engine 10 provided in motorcycle 1 according to the present embodiment. FIG. 5 is a cross-sectional view taken along the solid line AA shown in FIG. 4 and 5, the left side of the vehicle body in the motorcycle 1 is indicated by an arrow L, and the right side of the vehicle body is indicated by an arrow R.

  As shown in FIGS. 2 to 4, the engine 10 includes a crankcase 110. Above the crankcase 110, a cylinder 120 having a substantially cylindrical shape is disposed, and a cylinder head 130 and a head cover 140 are attached to the cylinder 120. A clutch cover 150 is attached to the right side surface of the crankcase 110 (see FIG. 2). On the other hand, a magnet cover 160 is attached to the left side surface of the crankcase 110 (see FIG. 3). An oil pan 170 is attached below the crankcase 110. The clutch cover 150 and the magnet cover 160 constitute an engine cover.

  As shown in FIG. 5, a crank chamber 111 is formed inside the crankcase 110. A crankshaft 112 is accommodated in the crank chamber 111 so that the rotation shaft is arranged in parallel to the vehicle width direction. The crankshaft 112 includes substantially disc-shaped crank webs 112a and 112b having side surfaces substantially perpendicular to the rotation axis, and crank pins 112c connecting the crank webs 112a and 112b. The case 110 is rotatably supported.

  In the cylindrical space inside the cylinder 120, a piston is accommodated so as to be able to reciprocate in the cylinder axial direction (vertical direction). The piston and the crankshaft 112 are connected via a connecting rod (connecting rod) so that the reciprocating motion of the piston is converted into the rotational motion of the crankshaft 112. The connecting rod has a small end portion provided at the upper end portion and a large end portion provided at the lower end portion, and is connected to the piston at the small end portion and connected to the crankshaft 112 at the large end portion. ing.

  A combustion chamber defined by the upper surface of the piston, the inner wall surface of the cylinder 120, and the lower surface of the cylinder head 130 is formed inside the cylinder head 130. An intake port 131 for sending air into the combustion chamber and an exhaust port 132 for discharging combustion gas to the outside of the combustion chamber are provided on the side surface of the cylinder head 130. The intake port 131 and the exhaust port 132 are provided with an intake valve and an exhaust valve, respectively. An ignition plug (not shown) is disposed on the lower surface of the cylinder head 130 so as to protrude, and the air-fuel mixture in the combustion chamber can be ignited by electric discharge.

  Note that the intake and exhaust mechanism of the engine 10 uses an OHC (Overhead Camshaft) format in which an intake valve and an exhaust valve are opened and closed by a camshaft. The camshaft includes a cam having a shape corresponding to the opening / closing timing of the intake valve or the exhaust valve. One end of the camshaft is connected to the crankshaft 112 via a power transmission mechanism such as a sprocket or cam chain. The rotational force of the crankshaft 112 is transmitted to the camshaft, and the intake valve and the exhaust valve can be opened and closed so as to correspond to the rotation of the crankshaft 112.

  In the engine 10 that operates in four strokes, the intake valve opens when the piston descends, and the air-fuel mixture is sent to the combustion chamber through the intake port 131 (intake stroke). Thereafter, the intake valve is closed and the piston rises to compress the air-fuel mixture (compression stroke). When the piston reaches top dead center, the compressed air-fuel mixture ignited by the spark plug is combusted (combustion stroke). When the pressure in the combustion chamber increases due to combustion of the air-fuel mixture, the piston descends. The downward movement of the piston is transmitted to the crankshaft 112 through the connecting rod, and the crankshaft 112 rotates. Thereafter, when the piston descends to the bottom dead center and starts to rise again due to inertia, the exhaust valve is opened and the combustion gas is discharged from the exhaust port 132 (exhaust stroke).

  As shown in FIGS. 2 and 4, the clutch cover 150 is fixed to the right end surface of the crankcase 110 at a plurality of locations by fastening members such as screws. The clutch cover 150 has a shape opened to the crankcase 110 side (the vehicle left side), and a recess 151 is formed therein (see FIG. 5). The recess 151 communicates with the crank chamber 111 in the crankcase 110. A clutch mechanism 180 that controls the on / off of power generated from the engine 10 is housed inside the clutch cover 150 (recessed portion 151).

  As shown in FIG. 2, an oil injection port 152 is provided on the outer wall surface of the clutch cover 150 and in the vicinity of the upper end portion on the vehicle body front side. The oil injection port 152 is used when injecting engine oil into the crankcase 110. On the other hand, an oil amount check window 153 is provided on the outer wall surface of the clutch cover 150 and in the vicinity of the lower end portion on the vehicle body rear side. The oil amount check window 153 is a window for a driver or the like to check the injection amount (remaining amount) of engine oil injected into the crankcase 110. Further, a drain hole 154 is provided on the outer wall surface of the clutch cover 150 and in the vicinity of the lower end portion on the front side of the vehicle body (see FIG. 5). The drain hole 154 communicates with an oil / water separation chamber 155, which will be described later, and is used when water in the crankcase 110 is discharged during vehicle maintenance or the like. The drain hole 154 is closed with a drain bolt 154a during traveling or the like.

  As shown in FIGS. 3 and 4, the magnet cover 160 is fixed to a left end surface of the crankcase 110 at a plurality of locations by fastening members such as screws. The magnet cover 160 has a shape opened to the crankcase 110 side (the vehicle right side), and has a recess 161 formed therein (see FIG. 5). The recess 161 communicates with the crank chamber 111 in the crankcase 110. Inside the magnet cover 160 (recessed portion 161), a power generator 190 that generates electric power according to the power generated from the engine 10 is provided.

  As shown in FIG. 5, the power generator 190 includes an outer rotor 192 provided with a magnet 191 and attached to the crankshaft 112, and a stator 193 provided with a coil (not shown) and attached to the magnet cover 160. Is done. Electric power is generated by the outer rotor 192 rotating as the crankshaft 112 rotates. Thus, the electric power generated by the power generator 190 is charged in a battery (not shown).

  As shown in FIGS. 2 to 4, a plurality of cooling water hoses 200 are disposed in the vicinity of the front side of the magnet cover 160. These cooling water hoses 200 are connected to a cooling water pump and a radiator (not shown). The engine 10 is cooled by circulating cooling water cooled by traveling wind or the like in the radiator.

  A recess 171 extending in the front-rear direction is provided in an oil pan 170 attached to the lower surface of the crankcase 110 (see FIG. 5). The recess 171 is provided to open upward and communicate with the crank chamber 111. Engine oil (engine oil) injected from oil injection port 152 is stored in recess 171. The engine oil stored in the recess 171 is used to prevent wear and seizure on the surfaces of the movable parts such as the piston and the crankshaft 112 in the cylinder 120 and the parts such as the cylinder 120 that come into contact with the movable parts. The engine oil that has lubricated the piston, the crankshaft 112, the cylinder 120, and the like falls by gravity and collects in the recess 171. The oil pan 170 is formed with an oil drain hole for discharging engine oil, and a drain bolt 172 for closing the oil drain hole.

  An oil filter 210 is provided on the front surface of the crankcase 110 at a position corresponding to the recess 171 of the oil pan 170. Inside the oil filter 210, for example, a filter paper that removes impurities contained in engine oil is provided. The engine oil stored in the oil pan 170 (recessed portion 171) is sucked up by an oil pump 211 described later and sent to the oil filter 210. The engine oil from which impurities are removed by the oil filter 210 is supplied to each part of the engine 10 through an oil passage (not shown).

  As shown in FIG. 5, an oil / water separation chamber 155 that stores water droplets (water) condensed in the crankcase 110 is provided near the lower end of the clutch cover 150. Hereinafter, the configuration of the oil / water separation chamber 155 will be described with reference to FIGS. FIG. 6 is an enlarged view around the oil / water separation chamber 155 shown in FIG. FIG. 7 is an explanatory diagram of a clutch cover 150 included in the engine 10 provided in the motorcycle 1 according to the present embodiment. FIG. 8 is an explanatory diagram of a configuration inside the engine 10 provided in the motorcycle 1 according to the present embodiment. FIG. 9 is a cross-sectional view of the engine 10 around the oil / water separation chamber 155 along the solid line BB shown in FIG.

  7 shows a side surface (left side surface) of the clutch cover 150 as viewed from the inside (crankcase 110 side). Further, in FIG. 7, for convenience of explanation, a gasket disposed between the crankcase 110 and the clutch cover 150 is shown, and the gasket is hatched. FIG. 8 shows the left side surface of the crankcase 110 with the clutch cover 150 removed. Moreover, in FIG. 8, the area | region corresponding to the oil-water separation chamber 155 is shown with the broken line for convenience of explanation.

  As shown in FIGS. 6 to 9, the oil / water separation chamber 155 is arranged near the lower end of the recess 151 in the clutch cover 150 and at the end on the front side of the vehicle, and has an opening upward. Yes. More specifically, as shown in FIGS. 6 and 7, the oil / water separation chamber 155 includes an inner wall surface (an inner wall surface facing the crankcase 110) 156a, an inner bottom surface 156b, and an inner bottom surface 156b of the clutch cover 150. Is formed in a space surrounded by a front surface portion 157a of a partition wall portion 157 provided to extend upward from a wall surface portion 222 of a gasket 220 described later.

  Thus, the oil / water separation chamber 155 formed by using a part of the clutch cover 150 is disposed below the oil injection port 152 (see FIG. 7). Further, the oil / water separation chamber 155 is disposed at a position separated from the oil pump 211 disposed in the crank chamber 111 (see FIG. 8). The oil pump 211 serves to suck up the engine oil stored in the recess 171 of the oil pan 170, remove impurities, and send the removed engine oil to the oil filter 210.

  The partition wall portion 157 defining the oil / water separation chamber 155 is provided to extend upward from the inner bottom surface 156b so as to partition the space (recessed portion 151) in the clutch cover 150. The partition wall 157 is provided integrally with the inner wall surface 156a. Moreover, the front-end | tip part (upper end part) of the partition part 157 is extended and provided in the front side slightly from the center vicinity of the inner bottom face 156b of the clutch cover 150 (refer FIG. 7).

  Here, the upper end portion 157b of the partition wall portion 157 is disposed at a position higher than the oil level height OL when the motorcycle 1 is in the standard amount holding state. For example, the upper end portion 157b of the partition wall portion 157 is arranged at a position above the upper end portion of the oil amount check window 153 provided in the clutch cover 150, so that it is slightly above the oil level height OL described above. It becomes possible to arrange | position in the position of. Normally, the oil amount check window 153 is formed by arranging the oil level height OL in the standard amount holding state in the vicinity of the center. For this reason, the upper end portion 157b of the partition wall portion 157 is arranged at a position above the upper end portion of the oil amount check window 153 provided in the clutch cover 150, so that the above-mentioned can be easily performed without requiring a special design. It becomes possible to arrange at a position slightly above the oil level height OL.

  The gasket 220 that defines the oil / water separation chamber 155 includes an annular outer peripheral portion 221 provided in accordance with the end face shape of the clutch cover 150, and a wall surface portion 222 provided at a part of the outer peripheral portion 221. The gasket 220 is a member that prevents leakage of engine oil and moisture from the joint surface between the crankcase 110 and the clutch cover 150. For example, it is composed of a non-metallic material such as paper or rubber, or a metallic material such as a copper plate. By fastening the clutch cover 150 to the crankcase 110 with the gasket 220 sandwiched between the end surface of the crankcase 110, leakage of engine oil or the like housed in the crank chamber 111 is prevented.

  Here, the wall surface part 222 that constitutes a part of the gasket 220 is provided to extend upward from the front lower end of the outer peripheral part 221. The wall surface portion 222 has a generally parallelogram shape, and the upper end portion thereof is disposed at the same height as the upper end portion 157 b of the partition wall portion 157 of the clutch cover 150. In a state of being sandwiched between the crankcase 110 and the clutch cover 150, the wall surface portion 222 is formed between the partition wall portion 157 of the clutch cover 150 and an inner wall surface 156a (an inner wall surface 156a facing the vehicle rear side) facing the partition wall portion 157. It is arranged at the corresponding position.

  Of the inner wall surface of the crankcase 110, the inner wall surface 113 facing the clutch cover 150 is provided with a support piece 113a that supports the wall surface portion 222 of the gasket 220 (see FIGS. 6 and 9). The support piece 113a has a generally cylindrical shape and is provided to protrude toward the clutch cover 150. The support piece 113 a is disposed at a position corresponding to the upper end portion 157 a of the partition wall portion 157 of the clutch cover 150. When the clutch cover 150 is fixed to the crankcase 110, the support piece 113a sandwiches the wall surface portion 222 (near the upper end portion) of the gasket 220 with the upper end portion 157a of the partition wall portion 157.

  In addition, it is preferable as an embodiment that a part of a fastening member for fixing the clutch cover 150 to the crankcase 110 is received by the support piece 113a. In this case, since the wall portion 222 of the gasket 220 can be supported by using the component for fixing the clutch cover 150, the gasket is not provided with a dedicated component for supporting the wall portion 222 of the gasket 220. Thus, the wall surface portion 222 of 220 can be firmly supported.

  Hereinafter, a method for recovering moisture generated in the engine 10 having such a configuration will be described. The water generated in the engine 10 (crankcase 110) accompanying the combustion of the air-fuel mixture sent into the combustion chamber condenses under the influence of the temperature in the engine 10 and forms water droplets at various locations in the engine 10. Adhere to. In the engine 10 according to the present embodiment, the oil / water separation chamber 155 is provided at the lower end portion of the clutch cover 150 upward and is provided using a part of the inner wall surface 156a of the clutch cover 150. For this reason, the oil / water separation chamber 155 is located at a position that is away from a heat source such as a combustion chamber formed in the cylinder 120 and is likely to be relatively low in temperature by being exposed to outside air (that is, a position where moisture inside the engine 10 is likely to condense). Can be placed. As a result, since the water in the engine 10 condenses and adheres to the inner wall surface 156a of the clutch cover 150, it can be stored in the oil / water separation chamber 155 by its own weight before being mixed with the engine oil, thus requiring a complicated structure. Therefore, it is possible to efficiently recover the water generated in the engine 10.

  The oil / water separation chamber 155 is disposed on the outer surface of the engine 10 in the vehicle width direction. For this reason, the oil / water separation chamber 155 can be provided apart from the lubricating structure including the oil pump 211 of the crankshaft 112, so that it can be separated from the engine oil circulation route in the engine 10, and the engine oil in the oil / water separation chamber 155 can be separated. Can hardly flow. As a result, the water collected in the oil / water separation chamber 155 can be stably held in a state separated from the engine oil.

  In particular, the oil / water separation chamber 155 is formed at the end of the clutch cover 150 on the vehicle front side. As a result, the oil / water separation chamber 155 is disposed at a position where it is easily cooled by receiving the traveling wind, so that water in the engine 10 is easily condensed and water droplets attached to the inner wall surface 156a of the clutch cover 150 due to the condensation. Since it can be accommodated in the oil / water separation chamber 155, the water generated in the engine 10 can be effectively recovered.

  The oil / water separation chamber 155 includes a space formed by the inner wall surface 156 a, the inner bottom surface 156 b and the partition wall portion 157 of the clutch cover 150, and the wall surface portion 222 of the gasket 220. For this reason, it is not necessary to provide a special configuration for forming the oil / water separation chamber 155 on the crankcase 110 side, and the oil / water separation chamber 155 can be configured with a simple configuration. In addition, since the oil / water separation chamber 155 is disposed outside the gasket 220 disposed between the crankcase 110 and the clutch cover 150, the oil / water separation chamber 155 is provided from a part of the cylinder 120 or the crankcase 110 having a heat source. Since they can be separated, the influence from the heat source on the recovered moisture can be suppressed, and it can be stably held in a state separated from the engine oil.

  In particular, the upper end portion 157a of the partition wall portion 157 and the upper end portion of the wall surface portion 222 of the gasket 220 constituting the oil / water separation chamber 155 are arranged at positions higher than the oil level height OL in the state where the standard amount of engine oil is retained. . Since the upper end portion of the oil / water separation chamber 155 is disposed at a position higher than the oil level height OL in the state where the standard amount of engine oil is maintained, the oil / water separation chamber 155 can be used during normal driving, that is, during circulation of engine oil. Since the engine oil can be isolated from the engine oil outside the oil / water separation chamber 155, the recovered water can be held in a state separated from the engine oil without being affected by the engine oil outside the oil / water separation chamber 155.

  In the above embodiment, the case where the upper end portion 157a of the partition wall portion 157 and the upper end portion of the wall surface portion 222 of the gasket 220 are arranged at a position higher than the oil level height OL is described. Is not limited to this. The upper end 157a of the partition wall 157 and the upper end of the wall surface 222 of the gasket 220 may be disposed at substantially the same oil level height OL. Even in this arrangement, the recovered water can be held in a state separated from the engine oil without being affected by the engine oil outside the oil / water separation chamber 155, although it does not reach the above embodiment. Become.

  Further, the wall surface portion 222 of the gasket 220 that defines the oil / water separation chamber 155 is sandwiched between the upper end portion 157 a of the partition wall portion 157 of the clutch cover 150 by the support piece 113 a provided on the inner wall surface 113 of the crankcase 110. ing. For this reason, the shape of the oil / water separation chamber 155 can be stably maintained, and the recovered water in the engine 10 can be reliably retained.

  The support piece 113a that supports the wall surface portion 222 of the gasket 220 is particularly effective when the gasket 220 is made of a non-metallic material such as paper or rubber. When the gasket 200 is made of a metal plate having a predetermined rigidity, it is not always necessary. In this way, when the gasket 220 is made of a metal plate having a predetermined rigidity, the configuration on the crankcase 110 side can be further simplified. Further, the support piece 113a that supports the wall surface portion 222 of the gasket 220 is not limited to being supported only by the upper end portion of the wall surface portion 222, and may be supported at a plurality of locations where the partition wall portions 157 exist. In this case, the shape of the oil / water separation chamber 155 can be more stably maintained.

  Further, the oil / water separation chamber 155 is provided in a region disposed on the lower side of the oil injection port 152. The engine oil injected into the engine 10 from the oil injection port 152 is first accommodated in the oil / water separation chamber 155. Since engine oil into the engine 10 can be first injected into the oil / water separation chamber 155 in this way, it is possible to suppress fluctuations in the oil level height OL after oil circulation.

  It is preferable as an embodiment to arrange the cooling water hose 200 described above in the vicinity of the oil / water separation chamber 155 (for example, the vehicle front side of the oil / water separation chamber 155). In this case, the cooling function of the cooling water hose 200 can further condense the water generated in the engine 10 in the engine 10, and the water droplets adhering to the inner wall surface 156 a of the clutch cover 150 due to the condensation can be removed. Since it can be accommodated in 155, the water generated in the engine 10 can be effectively recovered.

  In the present embodiment, the case where an oil / water separation chamber 155 that collects moisture in the crankcase 110 is provided in the clutch cover 150 is described. However, an oil / water separation chamber having a similar function can be provided in the magneto cover 160. In this case, the oil / water separation chamber includes, for example, an inner wall surface, an inner bottom surface, a protruding piece (corresponding to the partition wall portion 157) provided on the inner bottom surface, and an extended portion of the gasket (the extended portion 221 of the gasket 220). Equivalent to). As described above, even when the oil / water separation chamber is provided on the magnet cover 160 side, the water in the engine can be efficiently recovered without requiring a complicated structure as in the above-described embodiment.

  In particular, it is preferable as an embodiment to provide the oil / water separation chamber provided in the magneto cover 160 together with the oil / water separation chamber 155 provided in the clutch cover 150 described above. In this case, since the water generated in the engine 10 can be collected in the pair of oil / water separation chambers provided in the magnet cover 160 and the clutch cover 150, the water generated in the engine 10 can be collected more efficiently. It becomes.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, in the above embodiment, the case where the oil / water separation chamber 155 is configured by a space formed by the inner wall surface 156a, the inner bottom surface 156b and the partition wall portion 157 of the clutch cover 150, and the wall surface portion 222 of the gasket 220 will be described. doing. However, the configuration of the oil / water separation chamber 155 is not limited to this, and can be changed as appropriate. For example, a normal gasket that does not have the wall surface portion 222 may be used, and a wall portion that extends to a position corresponding to the wall surface portion 222 may be provided in the clutch cover 150. Even in the case of such changes, the same actions and effects as in the above embodiment can be obtained.

  Moreover, in the said embodiment, the case where the oil-water separation chamber 155 is formed in the edge part of the vehicle front side in the clutch cover 150 is demonstrated. However, the position where the oil / water separation chamber 155 is formed is not limited to this, and can be changed as appropriate. For example, it can be provided at an appropriate place (for example, near the center or the rear end of the clutch cover 150) according to the layout in the engine 10 of the motorcycle 1.

  The oil / water separation structure for a small vehicle engine according to the present invention can efficiently recover moisture generated in the engine without requiring a complicated structure, and is a small size used for traveling in a cold region, for example. It is useful as an oil / water separation structure for a vehicle engine.

1 Motorcycle 2 Main frame (frame)
DESCRIPTION OF SYMBOLS 10 Engine 110 Crankcase 111 Crank chamber 112 Crankshaft 113 Support piece 120 Cylinder 130 Cylinder head 140 Head cover 150 Clutch cover 151 Recessed part 152 Oil injection port 153 Oil amount check window 154 Drain hole 155 Oil water separation chamber 156a Inner wall surface 156b Inner bottom surface 157 Partition wall 157a Upper end 160 Magnet cover 161 Recessed portion 170 Oil pan 180 Clutch mechanism 190 Power generator 200 Cooling water hose 210 Oil filter 211 Oil pump 220 Gasket 221 Outer peripheral portion 222 Wall surface portion

Claims (6)

A crankcase that pivotally supports the crankshaft, a pair of engine covers that cover the outside of the crankcase in the vehicle width direction, and an oil / water separation chamber that collects water droplets condensed in the crankcase,
The oil / water separation chamber of the engine for a small vehicle is characterized in that the oil / water separation chamber opens upward at a lower end portion of at least one engine cover and is provided by using a part of an inner wall surface of the engine cover. .   2. The oil / water separation structure for a small vehicle engine according to claim 1, wherein the oil / water separation chamber is formed at an end portion of the pair of engine covers on the vehicle front side.   And further comprising a gasket disposed on a joint surface between the crankcase and the engine cover, and extending upward from an inner bottom surface of the engine cover, and having a partition portion that partitions a space in the engine cover. The oil / water separation chamber is provided in a space formed by an inner wall surface, an inner bottom surface and the partition wall portion of the engine cover, and a wall surface portion of the gasket provided to face the inner wall surface of the engine cover. The oil-water separation structure for a small vehicle engine according to claim 1 or 2.   The upper end portion of the partition wall portion and the upper end portion of the flat portion of the gasket are arranged at a position substantially equal to or higher than the oil level height in a state where a standard amount of engine oil is maintained. Item 4. An oil-water separation structure for a small vehicle engine according to Item 3.   5. The small vehicle according to claim 3, wherein a support piece is provided on a part of the crankcase so as to support a wall surface of the gasket with an upper end of the partition wall. Engine oil / water separation structure.   6. The oil / water separation structure for a small vehicle engine according to claim 5, wherein a part of a fastening member for fixing the engine cover to the crankcase is received by the support piece.

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