JP5807446B2 - Engine cooling structure - Google Patents

Description

  The present invention relates to a cooling structure for an engine mounted on a motorcycle.

  As an engine cooling structure, there is known an engine cooling structure in which traveling air is applied to cooling fins formed outside a cylinder and air-cooled (see, for example, Patent Document 1). In the engine cooling structure described in Patent Document 1, the engine is suspended at the lower part of the frame so that the cylinder is tilted forward. Cooling fins extending in the front-rear direction (vehicle width direction) are formed on the upper and lower surfaces of the cylinder, and cooling fins extending in the vertical direction are formed on the left and right side surfaces of the cylinder. Various devices are disposed between the frame and the cylinder, and a gap through which the traveling wind blows toward the back is narrow.

  In this engine cooling structure, the traveling wind from the front of the vehicle body hits the cooling fins and blows backward to cool the cylinder. In this case, the traveling wind that has entered between the frame and the cylinder flows along the cooling fins on the upper surface of the cylinder, and the flow is hindered by equipment and the like as it enters the interior. The traveling wind that has lost its destination is divided into left and right parts and flows downward along the cooling fins on the left and right side surfaces of the cylinder. As described above, in the engine cooling structure described in Patent Document 1, the cooling efficiency is enhanced by forming the cooling fins so as to follow the flow of the traveling wind escaping from the upper surface of the cylinder to the left and right side surfaces.

JP 2003-138936 A

  By the way, when the engine is suspended on the frame so that the cylinder is tilted forward, the traveling wind easily escapes backward through the space between the frame and the cylinder. In the motorcycle described in Patent Document 1, by arranging the devices so as to narrow the space between the frame and the cylinder, the driving wind is guided to the left and right side surfaces of the cylinder to improve the cooling efficiency. The layout is limited and can only be applied to certain specific vehicles. In order to ensure cooling efficiency, it is conceivable to form a large cooling fin, but there is a problem that the engine becomes large and the weight of the engine increases.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an engine cooling structure that ensures cooling efficiency with a simple configuration in an engine suspended on a frame so that a cylinder is tilted forward. .

The engine cooling structure of the present invention includes a frame extending rearward from the head pipe, an engine suspended on the frame so as to tilt the cylinder forward under the frame, and between the frame and the cylinder. comprising a baffle plate provided to guide the traveling wind from the front to the cylinder, and a cooling fin extending in the vertical and horizontal directions around the outer wall of the cylinder, the air guide plate, running wind The direction is parallel to the cooling fin, and the traveling air is guided to the cylinder .

According to this configuration, since the traveling wind from the front is guided to the cylinder by the air guide plate, the flow rate of the traveling wind flowing around the cylinder can be increased to ensure the cooling efficiency of the cylinder. Further, it is not necessary to form large cooling fins, and the engine can be reduced in size and weight while cooling efficiency is ensured. Further, since the traveling wind is guided to the cylinder along the cooling fin, the cooling efficiency of the cylinder can be further increased.

  In the engine cooling structure of the present invention, an air intake member that takes in air into the transmission case of the engine is provided on one side in the vehicle width direction with respect to the frame extending in the longitudinal direction of the vehicle body. The intake member is provided so as to protrude from the side wall of the vehicle body at the center side. According to this configuration, since the wind guide plate is provided in the center of the vehicle body, the traveling wind can be effectively guided to the cylinder. Further, since the traveling wind guided to the wind guide plate does not escape from the intake member side, the flow rate of the traveling wind hitting the cylinder can be increased to further increase the cooling efficiency of the cylinder.

  In the engine cooling structure of the present invention, the air guide plate is formed integrally with a side wall of the air intake member on the vehicle body center side. According to this configuration, an increase in component costs can be suppressed by integrally molding the side wall of the air intake member on the vehicle body center side and the air guide plate. Moreover, a wind guide plate can be easily shape | molded by making the protrusion direction of a wind guide plate into a die cutting direction.

  Further, in the engine cooling structure of the present invention, a recess is provided on the side wall of the air intake member on the center side of the vehicle body so as to form a guide surface that guides traveling air with the air guide plate on the base end side of the air guide plate. It is done. According to this configuration, the flow rate of the traveling wind guided to the cylinder by the recess can be increased, so that the cooling efficiency of the cylinder can be further increased.

  ADVANTAGE OF THE INVENTION According to this invention, in the engine suspended by the flame | frame so that a cylinder may be tilted ahead, cooling efficiency is securable with a simple structure.

1 is a right side view showing an appearance of a motorcycle according to the present embodiment. 1 is a left side view showing an appearance of a motorcycle according to the present embodiment. It is a left view which shows the peripheral part of the engine which concerns on this Embodiment. It is a right view which shows the peripheral part of the engine which concerns on this Embodiment. It is sectional drawing which follows the AA line of FIG.3 and FIG.4 of the engine which concerns on this Embodiment. It is explanatory drawing of the manufacturing method of the cover of the air cleaner for belt rooms which concerns on this Embodiment. It is explanatory drawing of the driving | running | working wind which flows around the cylinder which concerns on this Embodiment.

  Hereinafter, the present embodiment will be described in detail with reference to the accompanying drawings. In the following, an example in which the engine cooling structure according to the present invention is applied to a business type motorcycle will be described, but the application target is not limited to this and can be changed. For example, the engine cooling structure according to the present invention may be applied to an engine of another type of motorcycle.

  With reference to FIG.1 and FIG.2, the structure of the whole motorcycle which concerns on this Embodiment is demonstrated. FIG. 1 is a right side view of the motorcycle according to the present embodiment, and FIG. 2 is a left side view of the motorcycle according to the present embodiment. In FIGS. 1 and 2, the front of the vehicle body is indicated by an arrow FR, and the rear of the vehicle body is indicated by an arrow RE.

  As shown in FIGS. 1 and 2, a business type motorcycle 1 is configured by mounting various covers as a vehicle body exterior on a vehicle body frame (not shown) made of steel or aluminum alloy. The motorcycle 1 is provided with a leg shield 21 that protects the driver's suspension in the front, and a center frame cover 22 is provided behind the leg shield 21 and below the seat 8. Further, side frame covers 23 are provided on the left and right rear sides of the motorcycle 1.

  A front fork 31 is rotatably supported in front of the vehicle body via a steering shaft (not shown). A handlebar 32 for steering the front wheel 3 is provided above the front fork 31. A brake lever 33 is disposed in front of the handle bar 32 and a head lamp 34 is provided in front of the handle bar 32. A front fender 35 that covers the upper part of the front wheel 3 is installed at the lower part of the front fork 31 while the front wheel 3 is rotatably supported. The front wheel 3 is provided with a brake disc 36 and a caliper 37 that holds the brake disc 36 therebetween.

  A swing arm 41 is supported below the side frame cover 23 so as to be swingable in the vertical direction, and a suspension 42 is attached between the vehicle body frame and the swing arm 41. The rear wheel 4 is rotatably supported at the rear portion of the swing arm 41. On the left side of the rear wheel 4, a rear sprocket (driven sprocket) and a chain cover 43 for storing the chain are provided. The power of the engine 10 is transmitted to the rear wheel 4 by the rear sprocket and chain. A tail lamp 44 and a rear fender 45 are provided at the rear of the side frame cover 23.

  An air cleaner 140 (see FIGS. 3 and 4) is disposed inside the center frame cover 22. The leg shield 21 is formed such that traveling wind flows inside the center frame cover 22 through a gap with the front fender 35, and air is taken into the air cleaner 140. The air taken into the air cleaner 140 is sent to the engine 10 disposed on the lower rear side of the leg shield 21 through the intake pipe 141 (see FIGS. 3 and 4).

  Above the engine 10, a belt chamber air cleaner (intake member) 180 and an intake duct 181 for taking in outside air as cooling air are provided (see FIGS. 3 and 4). The air taken in from the belt chamber air cleaner 180 is sent to the belt chamber of the continuously variable transmission via the suction duct 181. A discharge duct (not shown) for discharging the air taken into the belt chamber is provided behind the engine 10.

  The engine 10 is suspended from the vehicle body frame in a state where the cylinder is tilted forward in a substantially horizontal direction. Air is taken into the engine 10 through the air cleaner 140 and the intake pipe 141, and air and fuel are mixed by the fuel supply device and supplied to the combustion chamber. The combustion gas after combustion is discharged as exhaust gas from the muffler 102 through the exhaust pipe 101 extending rearward on the right side surface of the engine 10.

  Next, a schematic configuration of the engine cooling structure according to the present embodiment will be described. 3 is a left side view showing the peripheral portion of the engine according to the present embodiment, FIG. 4 is a right side view showing the peripheral portion of the engine, and FIG. It is sectional drawing which follows A line.

  As shown in FIGS. 3 to 5, the engine 10 is suspended below a main frame (frame) 2 that extends rearward from a head pipe (not shown) that supports the steering shaft. The engine 10 includes a crankcase 110 in which a crankshaft (not shown) is disposed so that the rotation shaft is parallel to the vehicle width direction. The crankcase 110 includes a right crankcase 110R and a left crankcase 110L that are divided into left and right at a joint surface substantially perpendicular to the vehicle width direction.

  A cylinder 120 and a cylinder head 130 are attached in front of the crankcase 110. The cylinder 120 is arranged so that its axial direction C is substantially horizontal. A piston (not shown) is accommodated in the cylindrical space in the cylinder 120 so as to be able to reciprocate in the cylinder axis direction. Around the outer wall of the cylinder 120, cooling fins 121 extending in the vertical direction and the horizontal direction (vehicle width direction) are provided. Exhaust heat of the cylinder 120 is promoted by the traveling wind hitting the cooling fins 121.

  An air cleaner 140 for taking in air flowing from the front of the leg shield 21 is disposed on the upper front side of the cylinder head 130. The air cleaner 140 is connected to the cylinder head 130 via the intake pipe 141. The air taken in by the air cleaner 140 is supplied to the combustion chamber in the cylinder 120 through the intake pipe 141. A magneto cover 150 that divides the magneto chamber is attached to the left joint surface of the left crankcase 110L. A transmission case 160 that forms a belt chamber of a continuously variable transmission is attached to the right joining surface of the right crankcase 110R, and a belt cover 170 is attached to the right joining surface of the transmission case 160. .

  Above the transmission case 160, a belt chamber air cleaner 180 for taking cooling air into the belt chamber is disposed. The belt chamber air cleaner 180 is connected to the transmission case 160 via a suction duct 181. The air taken in from the belt chamber air cleaner 180 is sent to the belt chamber via the suction duct 181, cools the belt chamber, and then is discharged outside through a discharge duct (not shown).

  The belt chamber air cleaner 180 is made of synthetic resin and is arranged on the right side of the main frame 2 extending in the front-rear direction at the center in the vehicle width direction. The belt chamber air cleaner 180 is configured by attaching a cover (side wall) 180b to a cleaner body 180a having an open left side so as to cover the opening on the left side. A wind guide plate 180 c is provided on the cover 180 b between the main frame 2 and the cylinder 120 to guide the traveling wind from the front of the vehicle body to the cylinder 120.

  The air guide plate 180c is formed in a substantially L shape in side view by an upper plate portion 185 extending in the front-rear direction and a side plate portion 186 extending downward from the rear end of the upper plate portion 185. Due to the shape of the air guide plate 180c, the traveling wind from the front is guided by the upper plate portion 185 and the side plate portion 186, and the direction of the traveling wind flowing from the front to the rear is converted downward. In this case, the air guide plate 180c protrudes directly below the main frame 2, that is, to the central portion in the vehicle width direction. For this reason, traveling wind from the front is guided toward the cylinder 120 located below the main frame 2 by the air guide plate 180c.

  As described above, the cooling fin 121 extending in the left-right direction and the up-down direction is provided on the outer wall of the cylinder 120. The cooling fin 121 is formed in parallel to a plane orthogonal to the axial direction C of the cylinder 120. The side plate portion 186 of the air guide plate 180 c is formed in parallel to the cooling fins 121 and guides the traveling air from the front along the cooling fins 121. Here, the term “parallel” includes not only a completely parallel state but also a state in which the traveling wind deviates from the parallel state to the extent that the running wind flows along the cooling fins 121.

  The traveling wind guided to the cylinder 120 by the air guide plate 180 c passes along the cooling fins 121 to the lower side of the cylinder 120. At this time, since the direction of the traveling wind guided to the cylinder 120 by the air guide plate 180c is along the cooling fin 121, the resistance of the cooling fin 121 is reduced, and the flow rate of the traveling wind flowing through the cooling fin 121 is increased. . Thereby, the exhaust heat of the cylinder 120 is promoted, and the cooling efficiency of the cylinder 120 is enhanced.

  The cover 180b has a recess 180d corresponding to the air guide plate 180c. The concave portion 180d is formed so as to extend the base end side of the upper plate portion 185 and the side plate portion 186 of the air guide plate 180c to the inner side of the cleaner body 180a. Therefore, the traveling wind is guided to the cylinder 120 not only by the wind guide plate 180c but also by the recess 180d on the proximal end side of the wind guide plate 180c. As described above, the guide surface that guides the traveling air to the cylinder 120 is formed by the air guide plate 180c and the recess 180d, so that the flow rate of the traveling air that is guided to the cylinder 120 is increased and the cooling efficiency of the cylinder 120 is increased. Yes.

  The belt chamber air cleaner 180 is provided so as to partition the right side of the main frame 2. The engine cooling structure according to the present embodiment has a structure in which traveling air is not released from the right side by the belt chamber air cleaner 180. For this reason, the flow rate of the traveling wind guided to the cylinder 120 by the air guide plate 180c is increased, and the cooling efficiency of the cylinder 120 is further enhanced.

  Here, with reference to FIG. 6, the manufacturing method of the cover of the air cleaner for belt rooms is demonstrated. FIG. 6 is an explanatory diagram of a cover manufacturing method according to the present embodiment.

  As shown in FIG. 6, the cover 180b and the air guide plate 180c are formed by injection molding using molds 190a and 190b. The molds 190a and 190b are combined with each other in a liquid-tight state to form a space corresponding to the cover 180b. In this case, a substantially L-shaped space corresponding to the air guide plate 180c is formed in the mold 190a. The space corresponding to the air guide plate 180c extends in the same direction as the direction in which the molds 190a and 190b are removed.

  In this state, the cover 180b and the air guide plate 180c are integrally formed by filling the space formed in the molds 190a and 190b with molten resin. As described above, the cover 180b and the air guide plate 180c are integrally formed, so that an increase in component costs can be suppressed. In addition, since the air guide plate 180c extends along the drawing direction of the molds 190a and 190b, the air guide plate 180c can be easily manufactured by the molds 190a and 190b.

  With reference to FIG. 7, traveling wind for cooling the cylinder will be described. FIG. 7 is an explanatory diagram of the traveling wind flowing around the cylinder according to the present embodiment. 7A is a schematic view of the cylinder as viewed from the side, and FIG. 7B is a cross-sectional view of FIG. 7A.

  As shown in FIG. 7A, the traveling wind W from the front of the vehicle is divided into upper and lower parts by the cylinder head 130 and flows rearward along the upper and lower surfaces of the cylinder 120. Exhaust heat of the cylinder 120 is promoted by running wind W from the front of the vehicle hitting the cooling fins 121 and blowing backward. In this case, the traveling wind W that has entered between the cylinder 120 and the main frame 2 is guided by the wind guide plate 180 c and the recess 180 d, and the flow direction is changed downward so as to face the cylinder 120.

  Cooling fins 121 a extending in the left-right direction (vehicle width direction) are formed on the upper and lower surfaces of the cylinder 120, and cooling fins 121 b extending in the up-down direction are formed on the left and right side surfaces of the cylinder 120. The cooling fins 121a and 121b are formed in parallel to the air guide plate 180c. Therefore, the traveling wind is blown from the air guide plate 180c toward the cylinder 120 in a direction along the cooling fins 121a and 121b.

  As shown in FIG. 7B, the traveling wind blown to the cylinder 120 is divided in the left-right direction (vehicle width direction) on the upper surface of the cylinder 120 and flows along the cooling fins 121a, and the left and right side surfaces of the cylinder 120 are moved to the cooling fins 121b. Along the bottom. In this case, since the traveling wind is blown from the air guide plate 180c along the cooling fins 121a and 121b, the resistance of the cooling fins 121a and 121b to the traveling wind W is reduced. As a result, the flow rate of the traveling wind passing through the cooling fins 121a and 121b is increased, and the cooling efficiency of the cylinder 120 is enhanced.

  As shown in FIG. 7C, a guide plate 195 may be provided on the left and right sides of the cylinder 120 in order to further increase the cooling efficiency of the cylinder 120. The guide plate 195 makes it difficult for the traveling wind passing through the cooling fins 121b to escape sideways, and the flow rate of the traveling wind passing through the cooling fins 121b can be increased. The guide plate 195 may be provided on either the left or right side of the cylinder 120.

  As described above, according to the engine cooling structure of the present invention, since the traveling wind from the front is guided to the cylinder 120 by the wind guide plate 180c, the flow rate of the traveling wind flowing around the cylinder 120 is increased. 120 cooling efficiency can be promoted. Further, it is not necessary to form the cooling fins 121 large, and the engine 10 can be reduced in size and weight while ensuring the cooling efficiency. In particular, since the traveling wind is guided to the cylinder 120 along the cooling fins 121 by the air guide plate 180c, the cooling efficiency of the cylinder 120 is enhanced.

  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 air guide plate is integrally formed with the cover of the belt chamber air cleaner, but the present invention is not limited to this configuration. The air guide plate and the cover may be formed separately. Further, the method for forming the air guide plate and the cover is not limited to injection molding.

  Moreover, in the said embodiment, although it was set as the structure by which a baffle plate is provided in the air cleaner for belt rooms, it is not limited to this structure. In a motorcycle on which an engine is mounted so that the cylinder is tilted forward, the air guide plate may be provided between the frame and the cylinder. For example, a wind guide plate may be provided in the lower part of the frame, or a wind guide plate may be provided in the suction duct.

  Moreover, in the said embodiment, although the baffle plate was formed in the side view substantially L-shape by the upper-plate part and the side-plate part, it is not limited to this structure. The shape of the air guide plate is not particularly limited as long as the air guide plate has a shape that guides the traveling air to the cylinder. For example, the side plate portion of the air guide plate may not be formed in parallel to the cooling fin.

  Moreover, in the said embodiment, although it was set as the structure by which a recessed part is provided in a cover so that the guide surface which guides driving | running | working wind with a wind guide plate may be formed, it is not limited to this structure. If the traveling airflow with a sufficient flow rate can be supplied to the cylinder by the air guide plate, the cover does not have to be formed with a recess.

  Moreover, in the said embodiment, although it was set as the structure which has a single baffle plate, it is good also as a structure which has several baffle plates. For example, a plurality of wind guide plates may be provided in the belt chamber air cleaner to increase the flow rate of the traveling wind guided to the cylinder.

  Moreover, in the said embodiment, although it was set as the structure which the cooling fin extended in the up-down direction and the left-right direction, it is not limited to this. For example, the cooling fins may extend in an oblique direction with respect to the left and right side surfaces of the cylinder. In this case, it is preferable that the side plate portion of the air guide plate is also formed obliquely along the cooling fin.

  The engine cooling structure according to the present invention is useful as, for example, a scooter engine cooling structure.

1 Motorcycle 2 Main frame (frame)
10 Engine 120 Cylinder 121 Cooling Fin 130 Cylinder Head 180 Belt Room Air Cleaner (Intake Member)
180a Cleaner body 180b Cover (side wall at the center of the vehicle body)
180c Air guide plate 180d Concave portion 181 Suction duct 185 Upper plate portion 186 Side plate portion 190a, 190b Mold

Claims (4)

A frame extending backward from the head pipe;
Below the frame, an engine suspended on the frame so as to tilt the cylinder forward,
A wind guide plate provided between the frame and the cylinder so as to guide the traveling wind from the front to the cylinder ;
A cooling fin extending in the vertical and horizontal directions around the outer wall of the cylinder ,
The cooling structure for an engine according to claim 1, wherein the air guide plate is formed so as to guide the traveling air to the cylinder so that the traveling air is directed parallel to the cooling fin . An intake member that takes air into the transmission case of the engine on one side in the vehicle width direction with respect to the frame extending in the longitudinal direction of the vehicle body;
The engine cooling structure according to claim 1 , wherein the air guide plate is provided so as to protrude from a side wall of the air intake member on the vehicle body center side. The engine cooling structure according to claim 2 , wherein the air guide plate is formed integrally with a side wall of the air intake member on a vehicle body center side. 4. The recess according to claim 3 , wherein a recess is provided on a side wall of the air intake member on the center side of the vehicle body so as to form a guide surface for guiding traveling air with the air guide plate on the base end side of the air guide plate. The engine cooling structure described.

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