Title of Invention	A STRADDLE TYPE VEHICLE WITH IMPROVED RIGIDITY OF UNDERCOWL TO WITHSTAND AIR RESISTANCE DURING RUNNING OF THE VEHICLE
Abstract	A straddle-type vehicle is provided. The straddle-type vehicle includes an under cowl covering up both left and right sides of an engine attached to a body frame. The under cowl includes: a left side member covering up at least a part of the left side of the engine; a right side member covering up at least a part of the right side of the engine; and a front side member attached to the body frame, extending transversely on a front side of the body frame, and connecting the left side member with the right side member.

Title of Invention

A STRADDLE TYPE VEHICLE WITH IMPROVED RIGIDITY OF UNDERCOWL TO WITHSTAND AIR RESISTANCE DURING RUNNING OF THE VEHICLE

Abstract

A straddle-type vehicle is provided. The straddle-type vehicle includes an under cowl covering up both left and right sides of an engine attached to a body frame. The under cowl includes: a left side member covering up at least a part of the left side of the engine; a right side member covering up at least a part of the right side of the engine; and a front side member attached to the body frame, extending transversely on a front side of the body frame, and connecting the left side member with the right side member.

Full Text	Straddle-Type Vehicle This application claims priority from Japanese Patent Application No. 2007-338782 filed on December 28, 2007. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a straddle-type vehicle and particularly relates to an under cowl of a straddle-type vehicle. 2. Description of the Related Art Examples of the straddle-type vehicle include a vehicle equipped with a cowl to reduce air resistance during running. Examples of the cowl include an under cowl covering up peripheries of a cylinder block or a cylinder head of an engine. For example, Japanese Patent Application Publication No. 3-62590 discloses an under cowl configured so that a lower connection fin passing transversely across front sides of lower portions of a crankcase and an exhaust pipe is installed in lower portions of a pair of left and right side panel portions. More specifically, the side panel portions are bilaterally symmetric and a cooling air introduction port serving as a front opening portion that is open to a front surface of an engine is formed between front ends of the side panel portions. A lower portion of the front end of each side panel portion extends toward a front side of a lower portion of the exhaust pipe led out from front surfaces of the crankcase and the cylinder head of the engine. The lower connection fin is provided to be installed between front ends of the extension portions. SUMMARY OF THE INVENTION The straddle-type vehicle disclosed in the Japanese Examined Patent Publication No. 3-62590 has no safety-related problems but it is desired to improve rigidity of the under cowl enough to be able to withstand air resistance during running. It is also desired to contrive a shape of the under cowl so as to be able to introduce flowing air into the engine with high efficiency. A straddle-type vehicle according to the present invention includes an under cowl covering up both left and right sides of an engine attached to a lower portion of a body frame. The under cowl includes a left side member covering up at least a part of the left side of the engine and a right side member covering up at least a part of the right side of the engine. The under cowl also includes a front side member attached to the body frame, extending transversely on a front side of the body frame, and connecting the left side member with the right side member. The under cowl according to the present invention includes the front side member attached to the body frame, extending transversely on the front side of the body frame, and connecting the left side member with the right side member. Therefore, rigidity of the under cowl can be improved. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: Fig. 1 is a side view of a straddle-type vehicle according to one embodiment of the present invention; Fig. 2 is a side view showing a state in which an under cowl is detached from the straddle-type vehicle according to one embodiment of the present invention; Fig. 3 is a perspective view showing the under cowl of the straddle-type vehicle according to one embodiment of the present invention; Fig. 4 is a side view showing a left side member of the under cowl of the straddle-type vehicle according to one embodiment of the present invention; Fig. 5 is a front view showing a state in which the under cowl of the straddle-type vehicle according to one embodiment of the present invention is attached to a body frame; Fig. 6 is a side view showing a right side member of the under cowl of the straddle-type vehicle according to one embodiment of the present invention; and Fig. 7 is a front view showing a front side member of the under cowl of the straddle-type vehicle according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A straddle-type vehicle according to one embodiment of the present invention will be described hereinafter based on drawings. In the drawings, members or regions exhibiting the same functions are denoted by the same reference symbols, respectively. Further, the present invention is not limited to the following embodiment. Moreover, if expressions such as "front", "rear", "left", "right", "upper", and "lower" are used for the straddle-type vehicle, they are according to directions as seen from a rider in a state in which the rider rides on the straddle-type vehicle in an ordinary riding posture, respectively. Furthermore, a front side of the vehicle is denoted by "Fr", a rear side thereof is denoted by "Rr", a left side thereof is denoted by "L", and a right side thereof is denoted by "R" as necessary. Each drawing is shown on premise that the drawing is seen in a direction of reference symbols. As shown in Fig. 1, a straddle-type vehicle 1000 according to one embodiment of the present invention includes an under cowl 300 covering up both left and right sides of an engine 200 attached to a body frame 100. More specifically, in this embodiment, as shown in Fig. 1, the straddle-type vehicle 1000 includes a small-sized cowl 530 covering up a headlamp 520 attached to a handle 510. A fuel tank 540 is arranged on a rear side of a head pipe 101 of the body frame 100 to which the handle 510 is attached. Small-sized side cowls 550 are attached to positions closer to front side of both side portions of the fuel tank 540, respectively. Fig. 2 shows a state in which the under cowl 300 is detached from the straddle-type vehicle 1000. As shown in Fig. 2, the engine 200 is arranged below the fuel tank 540. In this embodiment, the engine 200 is attached to the body frame 100 in a space between a front wheel 601 and a rear wheel 602 of the straddle-type vehicle 1000 and below the fuel tank 540 . The engine 200 is arranged so that a crankcase 201 is located at a lower position and a cylinder 202 is located at an upper position. An oil reservoir 210 in which oil circulating in the engine 200 is accumulated is provided below the engine 200. A crankshaft is arranged in the crankcase 201 to be oriented in a vehicle width direction. The engine 200 is attached to the body frame 100 via a plurality of brackets 121, 122, and 123. In this embodiment, a lower portion of the engine 200 is attached to the brackets 121 and 123 and an upper portion of the cylinder 202 of the engine 200 is attached to the bracket 122. Although not shown, a pair of left and right brackets 122 is provided to attach the upper portion of the cylinder 202 to the body frame 100, respectively. In this engine 200, a plurality of fins are provided outside of the cylinder 202. Brackets (footrest brackets. 132) to which each footrest 131 is attached are attached to a lower portion of the body frame 100. Further, attachment portions 133 to which the under cowl 300 is attached are provided in the left and right footrest brackets 132, respectively. Moreover, as shown in Fig. 1, an operation pedal 250 performing transmission operation from a position at which each footrest 131 is attached toward a front side is provided. In this embodiment, the under cowl 300 includes a left side member 301, a right side member 302, a front side member 303, and a stay 304 as shown in Fig. 3. As shown in Fig. 1, the left side member 301 covers up at least a part of a left side of the engine 200. More specifically, in this embodiment, the left side member 301 covers up a left side of a cylinder portion of the engine 200 and a front side portion of a left side of the crankcase 201. The region is formed into a gently curved shape slightly projecting outward. Further, a lower portion of the left side member 301 extends forward of the lower portion of the body frame 100 and has a vertical width smaller as they get closer to the front side, thus being designed so that it appears to a person seeing the straddle-type vehicle 1000 that the straddle-type vehicle 1000 sharply hurtles. As shown in Fig. 4, connection portions 311 and 312, 314, and 316 connected to a front side member 303, a stay 304 and a left attachment portion 133 (see Fig. 2), respectively are provided inside of the left side member 301. The connection portions 311 and 312 connected to the front side member 303 are provided at two places of a front side of the lower portion of the left side member 301 and an intermediate region thereof, respectively. Although not shown, spring nuts are attached to the connection portions 311 and 312 and screwed with the front side member 301 and the left side member 304, respectively. The connection portions 311 and 312 are reinforced by ribs. The connection portion 314 attached to the stay 304 is provided in an upper portion of the left side member 301. In this embodiment, the connection portion 314 is formed out of a protrusion having a return on a tip end. A connection portion 316 connected to the left attachment portion 133 (see Fig. 2) is provided on a rear side of the lower portion of the left side member 301. In this embodiment, a through-hole for fastening the connection portion 316 to the left attachment portion 133 (see Fig. 2) is formed in the connection portion 316. The through-hole is formed out of a horizontally long hole so as to absorb attachment error. The connection portion 316 is attached to the left attachment portion 133 (see Fig. 2) by a rubber mount using a rubber grommet. As shown in Fig. 3, the right side member 302 is formed to be substantially bilaterally symmetric about the left side member 301 and covers up at least a part of a right side of the engine 200. In this embodiment, although not shown, the right side member 302 covers up a right side of the cylinder portion of the engine 200 and a front side portion of a right side of the crankcase 201. Furthermore, a lower portion of the right side member 302 extends forward of that of the body frame 100. In this embodiment, as shown in Fig. 5, a region 321 into which an exhaust pipe 317 connected to the engine 200 is inserted is formed inside the right side member 302. As shown in Fig. 6, the region 321 projects outward and forms a recess inside. As shown in Fig. 5, connection portions 322 and 323, 324, and 32 6 connected to the front side member 303, the stay 304, and the right attachment portion 133 (see Fig. 2) , respectively are provided inside the right side member 302. The connection portions 322 and 323 connected to the front side member 303 are provided on a front side of a lower portion of the right side member 303. A hole for locking a screw that fastens the front side member 303 to the right side member 302 is formed in the connection portion 322 and a periphery of the hole is reinforced by a rib. Further, an engagement piece is provided on the connection portion 323. The connection portion 324 connected to the stay 304 is provided in an upper portion of the right side member 302. In this embodiment, the connection portion 324 is formed out of a protrusion having a return formed on a tip end. The connection portion 326 connected to the right attachment portion 133 (see Fig. 2) is provided on a rear side of the lower portion of the right side member 302. In this embodiment, a through-hole for fastening the connection portion 326 to the right attachment portion 133 (see Fig. 2) is formed in the connection portion 32 6. The through-hole is similar in configuration to that of the connection portion 316 of the left side member. In this embodiment, the left side member 301 and the right side member 302 are resin molded parts and molded using a pair of metal molds forming inside and outside, respectively. In other words, each of the respective regions of the left side member 301 and the right side member 302 such as the connection portions and the ribs stated above is formed into a shape that enables each region to be cut away in a cutting direction of the metal molds. The left side member 301 and the right side member 302 can thereby be molded by the pair of metal molds without a complicated cutting structure. As shown in Fig. 5, the front side member 303 is attached to the body frame 100, extends transversely on the front side of the body frame 100, and connects the left side member 301 with the right side member 302. In this embodiment, as shown in Fig. 5, the front side member 303 includes a rib 331, first winged portions 332 and 333, and second winged portions 334 and 335. An attachment portion 341 attached to the body frame 100 is provided on the rib 331. In this embodiment, a fastening hole for fastening the attachment portion 341 to the bracket 121 by a bolt is formed in the attachment portion 341. As shown in Fig. 5, the rib 331 extends forward and downward from a region attached to the body frame 100. Further, left and right side surfaces 351 and 352 of the rib 331 are inclined outwardly to the left and the right in a width direction as they get closer to a rear portion, respectively. As shown in Fig. 7, the first winged portions 332 and 333 extend leftward and rightward from a tip end of the rib 331 in the width direction, respectively. The second winged portions 334 and 335 extend leftward and rightward from a proximal end of the rib 331, respectively above the first winged portions 332 and 333. Connection portions 361 and 362 connected to the left side member 301 and the right side member 302 are provided in intermediate portions of the left and right first winged portions 332 and 333, respectively. In this embodiment, screw holes for screwing the connection portions 361 and 362 are formed in the connection portions 361 and 3 62, respectively. Further, a tip end of the left first winged portion 332 is connected to a tip end of the left second winged portion 334 via a wall 363. The wall 363 has a shape proportional to an inner side surface of the left side member 301 and includes a connection portion 364 connected to the inner side surface of the left side member 301. In this embodiment, the left side member 301 and the front side member 303 are connected with each other by connecting the connection portions 311 and 312 of the left side member 301 shown in Fig. 4 to the connection portions 361 and 364 of the front side member 303 shown in Fig. 7. Moreover, in this embodiment, as shown in Fig. 7, a wall 3 65 connected to an inner side surface of the right side member 302 is provided on a tip end of the right first winged portion 333. The wall 365 has a shape proportional to the inner side surface of the right side member 302 and includes a connection portion 366 connected to the inner side surface of the right side member 302. In this embodiment, the right side member 302 and the front side member 303 are connected with each other by connecting the connection portions 322 and 323 of the right side member 302 shown in Fig. 6 to the connection portions 3 62 and 366 of the front side member 303 shown in Fig. 7. Furthermore, in this embodiment, the exhaust pipe 317 connected to the engine 200 extends to a front side of the engine 200 and, on the front side of the engine 200, extends rearward while forming a U-shaped curve. As shown in Fig. 5, a gap allowing the exhaust pipe 317 connected to the engine 200 to pass through is formed between the tip end of the right second winged portion 335 and the right side member 302. In this embodiment, the front side member 303 is a resin molded part and molded by a pair of metal molds that can cut away the front side member 303 longitudinally. In other words, each of the respective regions such as the rib 331, the first winged portions 332 and 333, and the second winged portions 334 and 335 is formed into a shape that enables each region to be cut away in a cutting direction of the metal molds. The front side member 303 can thereby be molded by the pair of metal molds without a complicated cutting structure. Next, as shown in Fig. 5, the stay 304 is attached to the body frame 100 above the front side member 303 and supports upper portions of the left side member 301 and the right side member 302. In this embodiment, the stay 304 is a rod-like member. A bracket 125 for attaching the stay 304 to an upper position than a position at which the front side member 303 is attached is attached to the body frame 100. Attachment pieces 372 are welded to a central portion 371 of the stay 304. The stay 304 is provided on the front side of the body frame 100 and the attachment pieces 372 are attached to the bracket 125 of the body frame 100 by means of bolts. Left and right side portions 373 and 374 of the stay 304 extend obliquely rearward and are connected to the connection portion 314 and 324 in the upper portions of the left side member 301 and the right side member 302 shown in Figs. 4 and 6, respectively. In this embodiment, the connection portions 314 and 324 in the upper portions of the left side member 301 and the right side member 302 are formed out of protrusions each having a return formed on a tip end, respectively. Due to this, although not shown, flanges are formed on both left and right ends of the stay 304 and fitting holes into which the protrusions of the connection portions 314 and 324 are fitted are formed in the flanges, respectively. A rubber ring (bush) is fitted into each of the fitting holes, thereby fitting the protrusion of each of the connection portions 314 and 324 into each fitting hole without slackening. This structure can facilitate attaching or detaching of the left side member 301 and the right side member 302 to or from the stay 304. A structure of the under cowl 300 according to this embodiment has been described so far. The under cowl 300 includes the left side member 301 covering up at least a part of the left side of the engine 200 and the right side member 302 covering up at least a part of the right side of the engine 2 00. Further, the under cowl 300 includes the front side member 303 attached to the body frame 100, transversely extending on the front side of the body frame 100, and connecting the left side member 301 with the right side member 302. In this embodiment, the front side member 303 connecting the left side member 301 with the right side member 302 is connected to the body frame 100. Due to this, as compared with an instance in which a member corresponding to the front side member is not connected to the body frame 100 as disclosed in the Japanese Examined Patent Publication No. 3-62590, the rigidity of the under cowl 300 can be secured. Furthermore, the under cowl 300 can be attached to the body frame 100 with high accuracy. Moreover, in this embodiment, the under cowl 300 is constituted by the three members, that is, the left side member 301, the right side member 302, and the front side member 303. Due to this, the under cowl 300 can be molded by a pair of simple metal molds without a complicated cutting structure. Further, the under cowl 30 0 can be coated in a state in which such members as the left side member 301, the right side member 302, the front side member 303, and the stay 304 are detached from the under cowl 300. Therefore, the respective members can be coated easily and beautifully according to rider's preference. Furthermore, in this embodiment, the under cowl 3 00 covers up both side portions of the engine 200 when viewed from a front side of the straddle-type vehicle 1000 as shown in Fig. 5. Due to this, flowing air can be introduced from a front side of the under cowl 300 into the both sides of the engine 200, making it possible to efficiently cool the engine 200. Moreover, as shown in Fig. 1, the under cowl 300 covers up a front side portion of the engine 200 when viewed from a lateral side of the straddle-type vehicle 1000. Due to this, the flowing air can be efficiently introduced from the front side of the under cowl 300 into the engine 200. The engine 200 can thereby be efficiently cooled. Further, in this embodiment, the under cowl 300 does not cover up a rear side portion of the engine 200 when viewed from the lateral side of the straddle-type vehicle 1000. Due to this, the air surrounding the engine 200 can be promptly released during running. The engine 200 can thereby be efficiently cooled. Furthermore, in this embodiment, the straddle-type vehicle 1000 includes the stay 304 attached to the body frame 100 above the front side member 303, and the stay 304 supports the upper portions of the left side member 301 and the right side member 302, respectively. Furthermore, in this embodiment, the lower portions 316 and 326 of the left side member 301 and the right side member 302, respectively are attached to the bracket attached to the body frame 100 (to be specific, the attachment portion 133 provided on the footrest bracket 312). This can further improve the rigidity of the under cowl 300 and attachment position accuracy. Additionally, in this embodiment, the front side member 303 includes the rib 331 extending forward and downward from the region attached to the body frame 100 and the first winged portions 332 and 333 extending leftward and rightward from the tip end of the rib 331 in the width direction. The first winged portions 332 and 333 are connected to the left side member 301 and the right side member 302, respectively. The left and right side surfaces 351 and 352 of the rib 331 are inclined outwardly to the left and the right in a width direction as they get closer to the rear portion, respectively. The front side member 303 also includes the second winged portions 334 and 335 extending leftward and rightward from the proximal end of the rib 331. The left second winged portion 334 is connected to the left side member 301. In this embodiment, shapes of the rib 331, the first winged portions 332 and 333, and the second winged portions 334 and 335 enable the rigidity of the under cowl 300 to be improved, the flowing air to be introduced into the periphery of the engine 200 during running, and the engine 200 to be efficiently cooled. In this embodiment, the gap allowing the exhaust pipe 317 connected to the engine 200 to pass through is formed in the front side member 303. Due to this, the under cowl 300 can be arranged without disturbing insertion of the exhaust pipe 317. The straddle-type vehicle according to one embodiment of the present invention has been described so far based on the drawings. However, the present invention is not limited to the above-stated embodiment. For example, the respective shapes of the left side member, the right side member, the front side member, and the stay, the attachment structure of the under cowl to the body frame, connection structures of the left side member, the right side member, the front side member, and the stay that constitute the under cowl and the like are not limited to the above-stated embodiment but can be variously changed. For example, in the above-stated embodiment, the front side member includes the second winged portions extending leftward and rightward from the rib, respectively and the left second winged portion is connected to the left side member. Alternatively, the right second winged portion may be connected to the right side member. Further, while the front side member includes the second winged portions extending leftward and rightward from the rib, the left and right second winged portions may be connected to the left side member and the right side member, respectively. Furthermore, the present invention is not limited to the above-stated embodiment but can be applied to various types of straddle-type vehicles. WE CLAIM: 1. A straddle-type vehicle comprising an under cowl covering up both left and right sides of an engine attached to a body- frame, wherein the under cowl includes: a left side member covering up at least a part of the left side of the engine; a right side member covering up at least a part of the right side of the engine; and a front side member attached to the body frame, extending transversely on a front side of the body frame, and connecting the left side member with the right side member. 2. The straddle-type vehicle as claimed in claim 1, wherein the under cowl covers up both side portions of the engine when viewed from a front side of the straddle-type vehicle. 3. The straddle-type vehicle as claimed in claim 1, wherein the under cowl covers up a front side portion of the engine when viewed from a lateral side of the straddle-type vehicle. 4. The straddle-type vehicle as claimed in claim 1, comprising a stay attached to the body frame above the front side member, and supporting upper portions of the left side member and the right side member. 5. The straddle-type vehicle as claimed in claim 1, wherein a lower portion of each of the left side member and the right side member is attached to a bracket attached to the body frame. 6. The straddle-type vehicle as claimed in claim 1, wherein the front side member includes: a rib extending forward and downward from a region attached to the body frame; and a first winged portion extending transversely from a tip end of the rib in a width direction, and wherein the first winged portion is connected to the left side member and the right side member. 7. The straddle-type vehicle as claimed in claim 6, wherein left and right side surfaces of the rib are inclined outwardly to the left and the right in a width direction as they get closer to a rear portion, respectively. 8. The straddle-type vehicle as claimed in claim 6, comprising a second winged portion extending transversely from a proximal end portion of the rib. 9. The straddle-type vehicle as claimed in claim 8, wherein the second winged portion is connected to the left side member and/or the right side member. 10. The straddle-type vehicle as claimed in claim 1, wherein a gap allowing an exhaust pipe connected to the engine to pass through is formed in the front side member. A straddle-type vehicle is provided. The straddle-type vehicle includes an under cowl covering up both left and right sides of an engine attached to a body frame. The under cowl includes: a left side member covering up at least a part of the left side of the engine; a right side member covering up at least a part of the right side of the engine; and a front side member attached to the body frame, extending transversely on a front side of the body frame, and connecting the left side member with the right side member.

Full Text

Straddle-Type Vehicle
This application claims priority from Japanese Patent
Application No. 2007-338782 filed on December 28, 2007.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a straddle-type vehicle
and particularly relates to an under cowl of a straddle-type
vehicle.
2. Description of the Related Art
Examples of the straddle-type vehicle include a vehicle
equipped with a cowl to reduce air resistance during running.
Examples of the cowl include an under cowl covering up
peripheries of a cylinder block or a cylinder head of an engine.
For example, Japanese Patent Application Publication No.
3-62590 discloses an under cowl configured so that a lower
connection fin passing transversely across front sides of lower
portions of a crankcase and an exhaust pipe is installed in lower
portions of a pair of left and right side panel portions. More
specifically, the side panel portions are bilaterally symmetric
and a cooling air introduction port serving as a front opening
portion that is open to a front surface of an engine is formed
between front ends of the side panel portions. A lower portion
of the front end of each side panel portion extends toward a

front side of a lower portion of the exhaust pipe led out from
front surfaces of the crankcase and the cylinder head of the
engine. The lower connection fin is provided to be installed
between front ends of the extension portions.
SUMMARY OF THE INVENTION
The straddle-type vehicle disclosed in the Japanese
Examined Patent Publication No. 3-62590 has no safety-related
problems but it is desired to improve rigidity of the under cowl
enough to be able to withstand air resistance during running.
It is also desired to contrive a shape of the under cowl so as
to be able to introduce flowing air into the engine with high
efficiency.
A straddle-type vehicle according to the present
invention includes an under cowl covering up both left and right
sides of an engine attached to a lower portion of a body frame.
The under cowl includes a left side member covering up at least
a part of the left side of the engine and a right side member
covering up at least a part of the right side of the engine.
The under cowl also includes a front side member attached to
the body frame, extending transversely on a front side of the
body frame, and connecting the left side member with the right
side member.
The under cowl according to the present invention
includes the front side member attached to the body frame,

extending transversely on the front side of the body frame, and
connecting the left side member with the right side member.
Therefore, rigidity of the under cowl can be improved.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
Fig. 1 is a side view of a straddle-type vehicle according
to one embodiment of the present invention;
Fig. 2 is a side view showing a state in which an under
cowl is detached from the straddle-type vehicle according to
one embodiment of the present invention;
Fig. 3 is a perspective view showing the under cowl of
the straddle-type vehicle according to one embodiment of the
present invention;
Fig. 4 is a side view showing a left side member of the
under cowl of the straddle-type vehicle according to one
embodiment of the present invention;
Fig. 5 is a front view showing a state in which the under
cowl of the straddle-type vehicle according to one embodiment
of the present invention is attached to a body frame;
Fig. 6 is a side view showing a right side member of the
under cowl of the straddle-type vehicle according to one
embodiment of the present invention; and
Fig. 7 is a front view showing a front side member of the
under cowl of the straddle-type vehicle according to one

embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A straddle-type vehicle according to one embodiment of
the present invention will be described hereinafter based on
drawings. In the drawings, members or regions exhibiting the
same functions are denoted by the same reference symbols,
respectively. Further, the present invention is not limited
to the following embodiment. Moreover, if expressions such as
"front", "rear", "left", "right", "upper", and "lower" are used
for the straddle-type vehicle, they are according to directions
as seen from a rider in a state in which the rider rides on the
straddle-type vehicle in an ordinary riding posture,
respectively. Furthermore, a front side of the vehicle is
denoted by "Fr", a rear side thereof is denoted by "Rr", a left
side thereof is denoted by "L", and a right side thereof is
denoted by "R" as necessary. Each drawing is shown on premise
that the drawing is seen in a direction of reference symbols.
As shown in Fig. 1, a straddle-type vehicle 1000 according
to one embodiment of the present invention includes an under
cowl 300 covering up both left and right sides of an engine 200
attached to a body frame 100. More specifically, in this
embodiment, as shown in Fig. 1, the straddle-type vehicle 1000
includes a small-sized cowl 530 covering up a headlamp 520
attached to a handle 510. A fuel tank 540 is arranged on a rear

side of a head pipe 101 of the body frame 100 to which the handle
510 is attached. Small-sized side cowls 550 are attached to
positions closer to front side of both side portions of the fuel
tank 540, respectively.
Fig. 2 shows a state in which the under cowl 300 is detached
from the straddle-type vehicle 1000. As shown in Fig. 2, the
engine 200 is arranged below the fuel tank 540. In this
embodiment, the engine 200 is attached to the body frame 100
in a space between a front wheel 601 and a rear wheel 602 of
the straddle-type vehicle 1000 and below the fuel tank 540 . The
engine 200 is arranged so that a crankcase 201 is located at
a lower position and a cylinder 202 is located at an upper
position. An oil reservoir 210 in which oil circulating in the
engine 200 is accumulated is provided below the engine 200. A
crankshaft is arranged in the crankcase 201 to be oriented in
a vehicle width direction. The engine 200 is attached to the
body frame 100 via a plurality of brackets 121, 122, and 123.
In this embodiment, a lower portion of the engine 200 is attached
to the brackets 121 and 123 and an upper portion of the cylinder
202 of the engine 200 is attached to the bracket 122. Although
not shown, a pair of left and right brackets 122 is provided
to attach the upper portion of the cylinder 202 to the body frame
100, respectively. In this engine 200, a plurality of fins are
provided outside of the cylinder 202. Brackets (footrest
brackets. 132) to which each footrest 131 is attached are

attached to a lower portion of the body frame 100. Further,
attachment portions 133 to which the under cowl 300 is attached
are provided in the left and right footrest brackets 132,
respectively. Moreover, as shown in Fig. 1, an operation pedal
250 performing transmission operation from a position at which
each footrest 131 is attached toward a front side is provided.
In this embodiment, the under cowl 300 includes a left
side member 301, a right side member 302, a front side member
303, and a stay 304 as shown in Fig. 3.
As shown in Fig. 1, the left side member 301 covers up
at least a part of a left side of the engine 200. More
specifically, in this embodiment, the left side member 301
covers up a left side of a cylinder portion of the engine 200
and a front side portion of a left side of the crankcase 201.
The region is formed into a gently curved shape slightly
projecting outward. Further, a lower portion of the left side
member 301 extends forward of the lower portion of the body frame
100 and has a vertical width smaller as they get closer to the
front side, thus being designed so that it appears to a person
seeing the straddle-type vehicle 1000 that the straddle-type
vehicle 1000 sharply hurtles.
As shown in Fig. 4, connection portions 311 and 312, 314,
and 316 connected to a front side member 303, a stay 304 and
a left attachment portion 133 (see Fig. 2), respectively are
provided inside of the left side member 301. The connection

portions 311 and 312 connected to the front side member 303 are
provided at two places of a front side of the lower portion of
the left side member 301 and an intermediate region thereof,
respectively. Although not shown, spring nuts are attached to
the connection portions 311 and 312 and screwed with the front
side member 301 and the left side member 304, respectively. The
connection portions 311 and 312 are reinforced by ribs. The
connection portion 314 attached to the stay 304 is provided in
an upper portion of the left side member 301. In this embodiment,
the connection portion 314 is formed out of a protrusion having
a return on a tip end. A connection portion 316 connected to
the left attachment portion 133 (see Fig. 2) is provided on a
rear side of the lower portion of the left side member 301. In
this embodiment, a through-hole for fastening the connection
portion 316 to the left attachment portion 133 (see Fig. 2) is
formed in the connection portion 316. The through-hole is
formed out of a horizontally long hole so as to absorb attachment
error. The connection portion 316 is attached to the left
attachment portion 133 (see Fig. 2) by a rubber mount using a
rubber grommet.
As shown in Fig. 3, the right side member 302 is formed
to be substantially bilaterally symmetric about the left side
member 301 and covers up at least a part of a right side of the
engine 200. In this embodiment, although not shown, the right
side member 302 covers up a right side of the cylinder portion

of the engine 200 and a front side portion of a right side of
the crankcase 201. Furthermore, a lower portion of the right
side member 302 extends forward of that of the body frame 100.
In this embodiment, as shown in Fig. 5, a region 321 into which
an exhaust pipe 317 connected to the engine 200 is inserted is
formed inside the right side member 302. As shown in Fig. 6,
the region 321 projects outward and forms a recess inside.
As shown in Fig. 5, connection portions 322 and 323, 324,
and 32 6 connected to the front side member 303, the stay 304,
and the right attachment portion 133 (see Fig. 2) , respectively
are provided inside the right side member 302. The connection
portions 322 and 323 connected to the front side member 303 are
provided on a front side of a lower portion of the right side
member 303. A hole for locking a screw that fastens the front
side member 303 to the right side member 302 is formed in the
connection portion 322 and a periphery of the hole is reinforced
by a rib. Further, an engagement piece is provided on the
connection portion 323. The connection portion 324 connected
to the stay 304 is provided in an upper portion of the right
side member 302. In this embodiment, the connection portion
324 is formed out of a protrusion having a return formed on a
tip end. The connection portion 326 connected to the right
attachment portion 133 (see Fig. 2) is provided on a rear side
of the lower portion of the right side member 302. In this
embodiment, a through-hole for fastening the connection portion

326 to the right attachment portion 133 (see Fig. 2) is formed
in the connection portion 32 6. The through-hole is similar in
configuration to that of the connection portion 316 of the left
side member.
In this embodiment, the left side member 301 and the right
side member 302 are resin molded parts and molded using a pair
of metal molds forming inside and outside, respectively. In
other words, each of the respective regions of the left side
member 301 and the right side member 302 such as the connection
portions and the ribs stated above is formed into a shape that
enables each region to be cut away in a cutting direction of
the metal molds. The left side member 301 and the right side
member 302 can thereby be molded by the pair of metal molds
without a complicated cutting structure.
As shown in Fig. 5, the front side member 303 is attached
to the body frame 100, extends transversely on the front side
of the body frame 100, and connects the left side member 301
with the right side member 302.
In this embodiment, as shown in Fig. 5, the front side
member 303 includes a rib 331, first winged portions 332 and
333, and second winged portions 334 and 335. An attachment
portion 341 attached to the body frame 100 is provided on the
rib 331. In this embodiment, a fastening hole for fastening
the attachment portion 341 to the bracket 121 by a bolt is formed
in the attachment portion 341. As shown in Fig. 5, the rib 331

extends forward and downward from a region attached to the body
frame 100. Further, left and right side surfaces 351 and 352
of the rib 331 are inclined outwardly to the left and the right
in a width direction as they get closer to a rear portion,
respectively.
As shown in Fig. 7, the first winged portions 332 and 333
extend leftward and rightward from a tip end of the rib 331 in
the width direction, respectively. The second winged portions
334 and 335 extend leftward and rightward from a proximal end
of the rib 331, respectively above the first winged portions
332 and 333. Connection portions 361 and 362 connected to the
left side member 301 and the right side member 302 are provided
in intermediate portions of the left and right first winged
portions 332 and 333, respectively. In this embodiment, screw
holes for screwing the connection portions 361 and 362 are
formed in the connection portions 361 and 3 62, respectively.
Further, a tip end of the left first winged portion 332 is
connected to a tip end of the left second winged portion 334
via a wall 363. The wall 363 has a shape proportional to an
inner side surface of the left side member 301 and includes a
connection portion 364 connected to the inner side surface of
the left side member 301. In this embodiment, the left side
member 301 and the front side member 303 are connected with each
other by connecting the connection portions 311 and 312 of the
left side member 301 shown in Fig. 4 to the connection portions

361 and 364 of the front side member 303 shown in Fig. 7.
Moreover, in this embodiment, as shown in Fig. 7, a wall
3 65 connected to an inner side surface of the right side member
302 is provided on a tip end of the right first winged portion
333. The wall 365 has a shape proportional to the inner side
surface of the right side member 302 and includes a connection
portion 366 connected to the inner side surface of the right
side member 302. In this embodiment, the right side member 302
and the front side member 303 are connected with each other by
connecting the connection portions 322 and 323 of the right side
member 302 shown in Fig. 6 to the connection portions 3 62 and
366 of the front side member 303 shown in Fig. 7. Furthermore,
in this embodiment, the exhaust pipe 317 connected to the engine
200 extends to a front side of the engine 200 and, on the front
side of the engine 200, extends rearward while forming a
U-shaped curve. As shown in Fig. 5, a gap allowing the exhaust
pipe 317 connected to the engine 200 to pass through is formed
between the tip end of the right second winged portion 335 and
the right side member 302.
In this embodiment, the front side member 303 is a resin
molded part and molded by a pair of metal molds that can cut
away the front side member 303 longitudinally. In other words,
each of the respective regions such as the rib 331, the first
winged portions 332 and 333, and the second winged portions 334
and 335 is formed into a shape that enables each region to be

cut away in a cutting direction of the metal molds. The front
side member 303 can thereby be molded by the pair of metal molds
without a complicated cutting structure.
Next, as shown in Fig. 5, the stay 304 is attached to the
body frame 100 above the front side member 303 and supports upper
portions of the left side member 301 and the right side member
302. In this embodiment, the stay 304 is a rod-like member.
A bracket 125 for attaching the stay 304 to an upper position
than a position at which the front side member 303 is attached
is attached to the body frame 100. Attachment pieces 372 are
welded to a central portion 371 of the stay 304. The stay 304
is provided on the front side of the body frame 100 and the
attachment pieces 372 are attached to the bracket 125 of the
body frame 100 by means of bolts. Left and right side portions
373 and 374 of the stay 304 extend obliquely rearward and are
connected to the connection portion 314 and 324 in the upper
portions of the left side member 301 and the right side member
302 shown in Figs. 4 and 6, respectively. In this embodiment,
the connection portions 314 and 324 in the upper portions of
the left side member 301 and the right side member 302 are formed
out of protrusions each having a return formed on a tip end,
respectively. Due to this, although not shown, flanges are
formed on both left and right ends of the stay 304 and fitting
holes into which the protrusions of the connection portions 314
and 324 are fitted are formed in the flanges, respectively. A

rubber ring (bush) is fitted into each of the fitting holes,
thereby fitting the protrusion of each of the connection
portions 314 and 324 into each fitting hole without slackening.
This structure can facilitate attaching or detaching of the left
side member 301 and the right side member 302 to or from the
stay 304.
A structure of the under cowl 300 according to this
embodiment has been described so far. The under cowl 300
includes the left side member 301 covering up at least a part
of the left side of the engine 200 and the right side member
302 covering up at least a part of the right side of the engine
2 00. Further, the under cowl 300 includes the front side member
303 attached to the body frame 100, transversely extending on
the front side of the body frame 100, and connecting the left
side member 301 with the right side member 302. In this
embodiment, the front side member 303 connecting the left side
member 301 with the right side member 302 is connected to the
body frame 100. Due to this, as compared with an instance in
which a member corresponding to the front side member is not
connected to the body frame 100 as disclosed in the Japanese
Examined Patent Publication No. 3-62590, the rigidity of the
under cowl 300 can be secured. Furthermore, the under cowl 300
can be attached to the body frame 100 with high accuracy.
Moreover, in this embodiment, the under cowl 300 is constituted
by the three members, that is, the left side member 301, the

right side member 302, and the front side member 303. Due to
this, the under cowl 300 can be molded by a pair of simple metal
molds without a complicated cutting structure. Further, the
under cowl 30 0 can be coated in a state in which such members
as the left side member 301, the right side member 302, the front
side member 303, and the stay 304 are detached from the under
cowl 300. Therefore, the respective members can be coated
easily and beautifully according to rider's preference.
Furthermore, in this embodiment, the under cowl 3 00
covers up both side portions of the engine 200 when viewed from
a front side of the straddle-type vehicle 1000 as shown in Fig.
5. Due to this, flowing air can be introduced from a front side
of the under cowl 300 into the both sides of the engine 200,
making it possible to efficiently cool the engine 200.
Moreover, as shown in Fig. 1, the under cowl 300 covers
up a front side portion of the engine 200 when viewed from a
lateral side of the straddle-type vehicle 1000. Due to this,
the flowing air can be efficiently introduced from the front
side of the under cowl 300 into the engine 200. The engine 200
can thereby be efficiently cooled. Further, in this embodiment,
the under cowl 300 does not cover up a rear side portion of the
engine 200 when viewed from the lateral side of the
straddle-type vehicle 1000. Due to this, the air surrounding
the engine 200 can be promptly released during running. The
engine 200 can thereby be efficiently cooled.

Furthermore, in this embodiment, the straddle-type
vehicle 1000 includes the stay 304 attached to the body frame
100 above the front side member 303, and the stay 304 supports
the upper portions of the left side member 301 and the right
side member 302, respectively. Furthermore, in this
embodiment, the lower portions 316 and 326 of the left side
member 301 and the right side member 302, respectively are
attached to the bracket attached to the body frame 100 (to be
specific, the attachment portion 133 provided on the footrest
bracket 312). This can further improve the rigidity of the
under cowl 300 and attachment position accuracy.
Additionally, in this embodiment, the front side member
303 includes the rib 331 extending forward and downward from
the region attached to the body frame 100 and the first winged
portions 332 and 333 extending leftward and rightward from the
tip end of the rib 331 in the width direction. The first winged
portions 332 and 333 are connected to the left side member 301
and the right side member 302, respectively. The left and right
side surfaces 351 and 352 of the rib 331 are inclined outwardly
to the left and the right in a width direction as they get closer
to the rear portion, respectively. The front side member 303
also includes the second winged portions 334 and 335 extending
leftward and rightward from the proximal end of the rib 331.
The left second winged portion 334 is connected to the left side
member 301. In this embodiment, shapes of the rib 331, the first

winged portions 332 and 333, and the second winged portions 334
and 335 enable the rigidity of the under cowl 300 to be improved,
the flowing air to be introduced into the periphery of the engine
200 during running, and the engine 200 to be efficiently cooled.
In this embodiment, the gap allowing the exhaust pipe 317
connected to the engine 200 to pass through is formed in the
front side member 303. Due to this, the under cowl 300 can be
arranged without disturbing insertion of the exhaust pipe 317.
The straddle-type vehicle according to one embodiment of
the present invention has been described so far based on the
drawings. However, the present invention is not limited to the
above-stated embodiment.
For example, the respective shapes of the left side member,
the right side member, the front side member, and the stay, the
attachment structure of the under cowl to the body frame,
connection structures of the left side member, the right side
member, the front side member, and the stay that constitute the
under cowl and the like are not limited to the above-stated
embodiment but can be variously changed. For example, in the
above-stated embodiment, the front side member includes the
second winged portions extending leftward and rightward from
the rib, respectively and the left second winged portion is
connected to the left side member. Alternatively, the right
second winged portion may be connected to the right side member.
Further, while the front side member includes the second winged

portions extending leftward and rightward from the rib, the left
and right second winged portions may be connected to the left
side member and the right side member, respectively.
Furthermore, the present invention is not limited to the
above-stated embodiment but can be applied to various types of
straddle-type vehicles.

WE CLAIM:
1. A straddle-type vehicle comprising an under cowl covering
up both left and right sides of an engine attached to a body-
frame, wherein the under cowl includes:
a left side member covering up at least a part of the left
side of the engine;
a right side member covering up at least a part of the
right side of the engine; and
a front side member attached to the body frame, extending
transversely on a front side of the body frame, and connecting
the left side member with the right side member.
2. The straddle-type vehicle as claimed in claim 1,
wherein the under cowl covers up both side portions of
the engine when viewed from a front side of the straddle-type
vehicle.
3. The straddle-type vehicle as claimed in claim 1,
wherein the under cowl covers up a front side portion of
the engine when viewed from a lateral side of the straddle-type
vehicle.
4. The straddle-type vehicle as claimed in claim 1,
comprising a stay attached to the body frame above the front
side member, and supporting upper portions of the left side

member and the right side member.
5. The straddle-type vehicle as claimed in claim 1,
wherein a lower portion of each of the left side member
and the right side member is attached to a bracket attached to
the body frame.
6. The straddle-type vehicle as claimed in claim 1,
wherein the front side member includes:
a rib extending forward and downward from a region
attached to the body frame; and
a first winged portion extending transversely from a tip
end of the rib in a width direction, and
wherein the first winged portion is connected to the left
side member and the right side member.
7. The straddle-type vehicle as claimed in claim 6,
wherein left and right side surfaces of the rib are
inclined outwardly to the left and the right in a width direction
as they get closer to a rear portion, respectively.
8. The straddle-type vehicle as claimed in claim 6,
comprising a second winged portion extending transversely from
a proximal end portion of the rib.

9. The straddle-type vehicle as claimed in claim 8,
wherein the second winged portion is connected to the left
side member and/or the right side member.
10. The straddle-type vehicle as claimed in claim 1,
wherein a gap allowing an exhaust pipe connected to the
engine to pass through is formed in the front side member.

A straddle-type vehicle is provided. The straddle-type vehicle includes an under cowl covering up both left and right sides of an engine attached to a body frame. The under cowl
includes: a left side member covering up at least a part of the left side of the engine; a right side member covering up at least a part of the right side of the engine; and a front side member attached to the body frame, extending transversely on a front side of the body frame, and connecting the left side member with the right side member.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=7V8zRfKy2Te/0bcFKVKq7Q==&loc=wDBSZCsAt7zoiVrqcFJsRw==

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Patent Number

272339

Indian Patent Application Number

2045/KOL/2008

PG Journal Number

14/2016

Publication Date

01-Apr-2016

Grant Date

30-Mar-2016

Date of Filing

24-Nov-2008

Name of Patentee

YAMAHA HATSUDOKI KABUSHIKI KAISHA

Applicant Address

2500 SHINGAI, IWATA-SHI, SHIZUOKA

Inventors:

#	Inventor's Name	Inventor's Address
1	TAKAAKI MIYAZAKI	C/O YAMAHA HATSUDOKI KABUSHIKI KAISHA 2500 SHINGAI, IWATA-SHI, SHIZUOKA 438-8501

PCT International Classification Number

B62k11/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2007-338782	2007-12-28	Japan