JP5018165B2 - Motorcycle - Google Patents

Description

  The present invention relates to a motorcycle in which an engine and an air cleaner disposed behind the engine are connected by an intake passage, and a rear cushion unit is disposed between the engine and the air cleaner.

  In general straddle-type motorcycles, for example, as disclosed in Patent Documents 1 and 2, an engine is mounted on the front half of the body frame, and a fuel tank is mounted above the front half of the body frame. A seating seat is provided, and an air cleaner is provided below the seating seat, and a rear cushion unit for buffering and suspending a rear wheel is disposed between the engine and the air cleaner in a substantially upright posture.

The engine is installed on the upper surface of the crankcase with the cylinder assembly being substantially upright or leaning forward, and the intake port that opens on the back side of the engine is connected to the air cleaner by an intake passage. It is desirable that the intake passage be as short and linear as possible to reduce the intake resistance of the engine and ensure a large passage cross-sectional area.
JP 05-085454 A JP 2006-193026 A

  However, since the rear cushion unit is installed between the engine and the air cleaner as described above, the rear cushion unit is obstructive and it is difficult to form the intake passage linearly. The intake passage must be straightened by disposing the intake passage above the upper mounting portion of the rear cushion unit as in a motorcycle.

  To do this, it is necessary to lower the position of the upper end of the rear cushion unit or increase the position of the air cleaner. According to the former, the total length of the rear cushion unit is shortened and the suspension stroke of the rear wheel is reduced. Therefore, according to the latter, the seating surface of the seating seat becomes high and the riding performance is impaired. Further, if the position of the lower end of the rear cushion unit is lowered to extend the entire length of the rear cushion unit, the minimum ground clearance of the vehicle body is lowered and off-road running performance is lowered.

  The present invention has been made in view of such matters, and the intake passage connecting the engine and the air cleaner is linearized and shortened as much as possible, and the passage area is enlarged to reduce the intake resistance. Another object of the present invention is to provide a motorcycle capable of improving the rough road running performance by increasing the suspension stroke and the minimum ground clearance of the vehicle body.

In order to achieve the above object, the motorcycle according to the present invention is equipped with a four-cycle engine having a cylinder assembly substantially upright in the front half of the body frame, and a rear cushion unit is arranged in a substantially upright posture behind the engine. In the motorcycle, an air cleaner is disposed behind the rear cushion unit and below the seating seat, and the intake port that opens at the rear of the cylinder assembly is connected to the air cleaner by an intake passage. A connecting pipe constituting a part of the air cleaner is connected to the downstream end of the air cleaner, and a bulging portion that bulges in the vehicle width direction is formed in the vicinity of the connecting portion of the connecting pipe with the air cleaner. The cross-sectional shape of a part of the connecting pipe that is continuous with the vertical axis is the horizontal axis The connecting pipe is formed so that at least a lower part of the bulging part of the connecting pipe covers the outer part of the coil spring of the rear cushion unit in a side view of the vehicle, and the connecting pipe has the vertically long part. The rectangular portions are arranged so as to overlap each other so as to cover the outer portion of the narrow part of the outer diameter of the damper chamber protruding upward from the upper end of the coil spring of the rear cushion unit in a side view of the vehicle, and the connecting The vehicle width direction dimension of the vertically long rectangular portion covering the outer portion of the thin outer diameter portion of the pipe projecting from the upper portion of the damper chamber is the same as that of the bulging portion of the connecting pipe covering the outer portion of the coil spring. The passage area in the vehicle width direction of the connecting pipe by setting it larger than the vehicle width direction dimension Characterized in that were expanded.

  Furthermore, the motorcycle according to the present invention is characterized in that the upper end portion of the rear cushion unit is attached to the vehicle body frame at a position higher than the upper end portion of the cylinder assembly.

  The motorcycle according to the present invention is characterized in that the intake passage is inclined rearward and upward with respect to a plane perpendicular to the axis of the cylinder assembly in a side view of the vehicle.

  According to the motorcycle of the present invention, the intake passage connecting the engine and the air cleaner and the upper portion of the rear cushion unit are overlapped in a side view of the vehicle, thereby straightening and shortening the intake passage. The passage area of the passage can be enlarged, and by making the rear cushion unit an inverted type, the diameter of the upper portion of the rear cushion unit can be reduced to increase the above effect.

  Further, since the upper end portion of the rear cushion unit is attached to the vehicle body frame at a position higher than the upper portion of the cylinder assembly, the suspension stroke can be increased and the minimum ground clearance of the vehicle body can be increased to improve rough road running performance.

  In addition, the intake passage is inclined backward and upward with respect to a plane perpendicular to the axis of the cylinder assembly when viewed from the side of the vehicle, so that the curvature of the intake port in the cylinder assembly can be increased. Can contribute to the reduction of intake resistance.

  In addition, by connecting the connecting pipe portion, which has a relatively high degree of design freedom, among the members constituting the intake passage with the upper portion of the rear cushion unit, the cross-sectional shape of the connecting pipe is increased, thereby providing an intake passage. The passage area can be enlarged.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a left side view of a motorcycle to which the present invention is applied, FIG. 2 is a left side view showing the vicinity of the main part of the present invention, and FIG. 3 is a vertical cross section taken along line III-III in FIG. It is a figure which shows one Embodiment.

  The body frame 2 of the motorcycle 1 includes a head pipe 3, a main pipe 4, a front pipe 5, a down pipe 6, a center frame member 7, a reinforcing pipe 8, a seat pipe 9, a seat stay 10 and the like. It is prepared for. The members 4, 6, 7, 9, and 10 are a pair of left and right (symmetrical), and the reinforcing pipe 8 has an arc-shaped outer shape, and both ends thereof are connected to the left and right main pipes 4. It is connected to the front pipe 5 at the bottom of the shape. A bridge pipe (not shown) is bridged in the vehicle width direction at the upper ends of the left and right center frame members 7, and a cushion upper end mounting bracket 35 to be described later is formed at the center of the bridge pipe.

  The engine 12 is a DOHC type four-cycle engine having an intake camshaft and an exhaust camshaft (not shown), and members 4, 5, 6, 7 constituting the front half of the vehicle body frame 2 via a plurality of engine suspension brackets (not shown). It is mounted so as to be surrounded by 8. In this engine 12, for example, a single-cylinder cylinder assembly 14 is installed on the upper surface of a crankcase 13 in a substantially upright posture, and an exhaust port 15 is opened on the front of the cylinder assembly 14 and an intake port 16 is opened on the back. Yes.

  A fuel tank 18 is installed above the engine 12 so as to be sandwiched between the left and right main pipes 4. A seat 19 is placed on the upper surface of the seat pipe 9 from the rear upper surface of the fuel tank 18. A rear fender 20 is installed behind the seating seat 19.

  A rear cushion unit 21 is disposed behind the engine 12 in a substantially upright (or slightly forward tilted) posture, and an air cleaner 22 is disposed behind the engine 12 and below the seating seat 19. When viewed from the side of the vehicle, the air cleaner 22 is surrounded by the center frame member 7, the seat pipe 9, and the seat stay 10, and there are a plurality of spaces between the air cleaner 22 and the intake port 16 of the engine 12 (cylinder assembly 14). They are connected by an intake passage 23 formed by connecting members. Both sides of the air cleaner 22 are covered with a resin side cover 24.

  The intake passage 23 has a configuration in which an intake pipe 25, a throttle body 26, and a connecting pipe 27 are sequentially connected from the engine 12 side toward the air cleaner 22 side. The intake passage 23 is disposed so as to be inclined rearwardly with respect to the plane A perpendicular to the axis of the cylinder assembly 14 in a vehicle side view (see FIG. 2). A radiator 29 for cooling the engine 12 is installed on both the left and right sides of the front pipe 5 of the body frame 2, and both left and right sides thereof are covered with a resin radiator cover 30.

  A front fork that supports a front wheel (not shown) is pivotally supported on the head pipe 3 of the vehicle body frame 2 together with a handlebar, a front fender, and the like, while a pivot shaft 31 extending in the vehicle width direction is installed below the center frame member 7. The front end of the swing arm 32 is pivotally supported on the pivot shaft 31, and a rear wheel (not shown) is pivotally supported on the rear end of the swing arm 32 so that the power of the engine 12 is rearened via a chain (not shown). Transmitted to the wheel. Generally, the chain is disposed along the swing arm 32 on the left side of the vehicle body.

  The rear cushion unit 21 has an upper end connected to a cushion upper end mounting bracket 35 (see FIG. 1) provided on the vehicle body frame 2 (bridge pipe not shown) at a position higher than the upper end of the cylinder assembly 14. On the other hand, the lower end portion is connected to a cushion lower end mounting bracket 36 provided near the base end portion of the swing arm 32 via a plurality of link members (not shown).

  The rear cushion unit 21 is an inverted type, and as shown in FIGS. 3 and 4, the piston rod 40 advances and retreats in the axial direction of the rear cushion unit 21 from the lower end of the damper chamber 39 of the shock absorber constituting the main body. A coil spring 41 is wound around 39 and the piston rod 40. The height of the upper end of the coil spring 41 is located in the middle of the damper chamber 39. For this reason, the outer diameter D2 of the damper chamber 39 protruding upward from the upper end of the coil spring 41 is much thinner than the outer diameter D1 of the coil spring 41.

  Of the members 25, 26, 27 constituting the intake passage 23, the connecting pipe 27 portion is a thin portion in which the upper portion of the damper chamber 39 protrudes from the upper portion of the rear cushion unit 21, that is, the upper end of the coil spring 41. It is arranged so as to overlap with the vehicle side view (part of the outer diameter D2), that is, the upper part of the rear cushion unit 21 and the connecting pipe 27 are arranged close to each other in the vehicle width direction. . The rear cushion unit 21 is disposed near the center in the vehicle width direction, and the connecting pipe 27 is disposed on the left side of the upper portion of the damper chamber 39 of the rear cushion unit 21, for example.

  As shown in FIG. 4, the cross-sectional shape of the portion of the connecting pipe 27 that is juxtaposed with the upper part of the rear cushion unit 21 in the vehicle width direction is a vertically long shape in which the vertical axis dimension H is larger than the horizontal axis dimension W. Is formed.

  In addition, the connecting pipe 27 is provided with a bulging portion 23a that bulges in the vehicle width direction in the vicinity of the connection portion with the air cleaner 22, and the intake characteristics can be changed by changing the volume of the bulging portion 23a. . The bulging portion 23a has a height dimension equivalent to the height dimension of the air cleaner 22, and reduces the level difference when the air in the air cleaner 22 flows into the connecting pipe 27. Air retention is suppressed.

  An exhaust pipe 44 is connected to the exhaust port 15 of the engine 12 and is connected to an exhaust muffler 45 disposed at the rear of the vehicle body. As described above, the chain for transmitting the power of the engine 12 to the rear wheel is disposed on the left side of the vehicle body and swings up and down together with the swing arm 32 and the rear wheel. The exhaust muffler 45 is routed on the right side of the vehicle body.

  As shown in FIG. 3, a reservoir tank 47 of the rear cushion unit 21 is installed on the opposite side of the intake passage 23 from the connecting pipe 27 with respect to the upper part of the rear cushion unit 21, that is, on the right side. An exhaust pipe 44 is passed through. The exhaust pipe 44 needs to be piped downward as much as possible so as not to interfere with the legs of the rider seated on the seat 19. Further, in order to arrange the exhaust pipe 44 without projecting in the vehicle width direction, the exhaust pipe 44 is accommodated between the right center frame member 7 and the rear cushion unit 21. In this way, by arranging the intake passage 23 (air cleaner 22) and the exhaust pipe 44 (exhaust muffler 45) separately on the left and right sides of the vehicle body, the heat of the exhaust is prevented from reaching the intake passage 23 and the air cleaner 22. it can.

  As described above, in the motorcycle 1 according to the present invention, the damper chamber 39 having the narrowest outer diameter in the entire length of the rear cushion unit 21 protrudes upward from the upper end of the coil spring 41 in the intake passage 23 of the air cleaner 22. The air intake passage 23 is prevented from projecting outward in the vehicle width direction, and the air intake passage 23 is straightened as much as possible to reduce the air intake resistance. Can do.

  In addition, among the members constituting the intake passage 23, a portion of the connecting pipe 27 having a relatively large degree of freedom in shaping is arranged side by side in the vehicle width direction with respect to the upper portion of the rear cushion unit 21, and the cross section of the connecting pipe 27 Since the shape is a vertically long shape in which the vertical axis dimension H is larger than the horizontal axis dimension W, the passage area of the intake passage 23 can be expanded to further reduce the intake resistance. And, since the cross-sectional shape of the connecting pipe 27 is gradually changed from a rectangle to a circle from the intake upstream side to the intake downstream side, a sudden change in the cross-sectional shape of the intake passage 23 can be suppressed, and the intake resistance can be further reduced. .

  Further, since the intake passage 23 is inclined rearwardly with respect to the plane A perpendicular to the axis of the cylinder assembly 14 when viewed from the side of the vehicle, the intake port 16 is generally formed in a forward downward direction toward the combustion chamber. On the other hand, the angle of the intake passage 23 is formed as coaxial as possible, and the intake passage 23 can be linearized over the entire length including the intake port 16, and the intake resistance can be greatly reduced in this respect as well. . Further, since the curvature of the intake port 16 can be increased by inclining the intake passage 23 rearwardly with respect to the surface A, the intake resistance in the intake port 16 can be reduced, and the intake efficiency can be further improved. it can.

  On the other hand, since the upper end of the rear cushion unit 21 is mounted on the vehicle body frame 2 (cushion upper end mounting bracket 35) at a higher position than the upper end of the cylinder assembly 14, the suspension stroke is increased and the minimum ground clearance is increased. The rough road running ability of 1 can be improved.

  The exhaust pipe 44 is arranged side by side in the vehicle width direction so as to overlap with the coil spring 41 of the rear cushion unit 21 when viewed from the side of the vehicle, but the exhaust pipe 44 is connected to the intake passage 23 (connecting pipe 27). The diameter is much smaller than that of the coil spring 41. Therefore, even if the coil spring 41 is arranged at a level next to the coil spring 41, there is no overhanging to the side of the vehicle body, and it is provided inside the center frame member 7 with a margin. Can do.

1 is a left side view of a motorcycle to which the present invention is applied. The left view which shows the principal part vicinity of this invention. The figure which shows one Embodiment of this invention by the longitudinal cross-section in alignment with the III-III line of FIG. FIG. 4 is a longitudinal sectional view taken along line IV-IV in FIG. 2.

Explanation of symbols

1 Motorcycle 2 Body frame
12 engine
13 Crankcase
14 Cylinder assembly
16 Intake port
18 Fuel tank
19 Seating seat
21 Rear cushion unit
22 Air cleaner
23 Air intake passage
25 Intake pipe
26 Throttle body
27 Connecting pipe
39 Damper room
40 Piston rod
41 Coil spring
44 Exhaust pipe
47 Reservoir tank A Surface perpendicular to the axis of the cylinder assembly H Vertical dimension of the connecting pipe W Horizontal dimension of the connecting pipe

Claims (3)

A four-cycle engine with a cylinder assembly that is substantially upright is mounted in the front half of the body frame, and a rear cushion unit is placed in a substantially upright position behind the engine, and air is placed behind the rear cushion unit and below the seating seat. In a motorcycle in which a cleaner is disposed and the intake port that opens at the rear of the cylinder assembly is connected to the air cleaner by an intake passage, a connecting pipe that forms a part of the intake passage is disposed downstream of the air cleaner. A bulging portion that bulges in the vehicle width direction is formed in the vicinity of the connecting portion of the connecting pipe connected to the air cleaner, and the cross-sectional shape of the connecting pipe that continues to the bulging portion is the vertical axis. Forms a vertically long rectangular section whose dimensions are larger than the horizontal axis dimensions and The rear cushion unit is configured such that at least a lower part of the bulged portion of the pipe pipe covers the outer side of the coil spring of the rear cushion unit as viewed from the side of the vehicle, and the vertically long rectangular portion of the connecting pipe is viewed from the side of the vehicle. The damper springs are arranged so as to cover the outer portions of the narrow outer diameter portions of the damper chambers protruding upward from the upper ends of the coil springs, and the connecting pipes are externally protruded above the damper chambers. By setting the vehicle width direction dimension of the vertically long rectangular part covering the outer part of the thin part of the diameter larger than the vehicle width direction dimension of the bulging part covering the outer part of the coil spring of the connecting pipe, A motorcycle characterized in that the passage area of the connecting pipe in the vehicle width direction is enlarged . The motorcycle according to claim 1 , wherein an upper end portion of the rear cushion unit is attached to the vehicle body frame at a position higher than an upper end portion of the cylinder assembly. 3. The motorcycle according to claim 1 , wherein the intake passage is disposed so as to be inclined rearwardly upward with respect to a plane orthogonal to the axis of the cylinder assembly in a side view of the vehicle.

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