JP5691258B2 - Engine intake system - Google Patents

Description

  The present invention relates to an intake device for an engine applied to a scooter type motorcycle including a power unit in which an engine and a transmission device are integrally formed.

  2. Description of the Related Art Conventionally, a scooter type motorcycle employs a so-called swing-type power unit in which an engine and a transmission device (for example, a transmission) are integrally configured to pivotally support a rear wheel. In order to allow the engine and the transmission device to function as a swing arm, the power unit is pivotally supported by the vehicle body frame so that the front portion is swingable, and the rear portion is buffered and suspended at the rear end of the vehicle body frame. Therefore, the impact from the rear wheel can be absorbed by the entire power unit.

  Also, an intake port and an exhaust port are formed in the cylinder head of the engine, an engine intake system (engine intake device) that supplies a mixture of fuel and air to the intake port, and an engine exhaust that exhausts exhaust from the exhaust port The system is configured to be swingable in the vertical direction with respect to the vehicle body frame together with the power unit.

  Among these, in Patent Document 1, an air cleaner (main air cleaner) of an engine intake system is configured to be divided into two in the vehicle width direction, and a joining flange portion projecting outward to join the divided surfaces, A scooter type motorcycle is disclosed that is disposed directly under a seat rail in a body frame.

Japanese Unexamined Patent Publication No. 63-195086

  However, in the scooter type motorcycle described in Patent Document 1, since the joint flange portion of the air cleaner in the engine intake system is disposed directly below the seat rail, the air cleaner is not moved when the engine intake system is swung with the power unit. There is a possibility that the joint flange part may interfere with the seat rail. Therefore, in this engine intake air cleaner, the capacity of the air cleaner must be reduced in order to prevent interference with the seat rail.

  An object of the present invention is to provide an air intake device for an engine that can ensure a large capacity of an air cleaner.

In the present invention, a power unit in which an engine and a transmission device are integrally formed is supported by a pair of left and right body frames so as to be swingable, and is disposed between the power unit and the body frame so as to be swingable together with the power unit. In an engine air intake apparatus provided with an air cleaner that can be divided in the vehicle width direction, the air cleaner is defined by a clean side inside the vehicle width direction defined by an air cleaner body and a filter element, an air cleaner cover, and a filter element. It is divided into a dirty side on the outer side in the vehicle width direction and includes a joining flange portion projecting outward to join the divided surfaces , and this joining flange portion is a vehicle plan view, a range between the left and right of the vehicle body frame, the dirty-side of the car While that consists disposed at a position deviated from just below the frame, the air cleaner cover constituting the dirty side of the air cleaner, in the vehicle width direction outer side than the body frame positioned in the dirty-side of the air cleaner Rise The connecting portion of the inlet pipe that is provided and connected to the bulged position of the air cleaner cover at least partially overlaps the vehicle body frame in a plan view of the vehicle, or the vehicle is more than the vehicle body frame. The inlet pipe is configured to be positioned on the outer side in the width direction, and the inlet pipe extends from the connection portion of the air cleaner cover to the front of the vehicle by overlapping the body frame in a plan view of the vehicle. The suction port, which is the upstream end opening of the pipe, is The air cleaner is directed to the inner side in the vehicle width direction and is arranged directly below the vehicle body frame located on the dirty side of the air cleaner or on the vehicle width direction inner side than the vehicle body frame. An upstream portion of the outlet pipe connected to is opened in the clean side, and an inflow port which is an upstream end opening is arranged so as to be directed to the filter element .

  According to the present invention, the joint flange portion projecting outward to join the split surfaces of the air cleaner is disposed in a range sandwiched between the pair of left and right body frames in a plan view of the vehicle. For this reason, since the air cleaner of the engine intake device that swings with respect to the vehicle body frame together with the power unit can be prevented from interfering with the vehicle body frame, the capacity of the air cleaner can be secured to that extent.

1 is a left side view showing a scooter type motorcycle to which an engine intake system, which is an embodiment of an intake system for an engine according to the present invention, is applied. FIG. 2 is a left side view showing a body frame, a power unit, and an engine intake system in the scooter type motorcycle of FIG. 1. The III arrow line view of FIG.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the present invention is not limited to these embodiments.

  FIG. 1 is a left side view showing a scooter type motorcycle to which an engine intake system, which is an embodiment of an intake system for an engine according to the present invention, is applied. FIG. 2 is a left side view showing a body frame, a power unit, and an engine intake system in the scooter type motorcycle of FIG. In the present embodiment, front / rear, left / right, and upper / lower expressions are based on the driver when riding the vehicle.

  As shown in FIGS. 1 and 2, a scooter type motorcycle 10 as a scooter type vehicle includes an underbone body frame 11. In the vehicle body frame 11, one down tube 13 made of steel pipe is extended rearward and downward from the rear portion of the head pipe 12 at the frontal head, and a cylindrical bridge pipe 14 is formed at the lower rear end of the down tube 13. Are extended and connected in the vehicle width direction, and a pair of left and right seat rails 15 extend rearward and obliquely upward from the bridge pipe 14.

  A tail bridge 16 is bridged between the rear ends of the pair of left and right seat rails 15. A link plate 17 is fixed to the bridge pipe 14 and the seat rail 15 at the lower center of the vehicle body frame 11 where the bridge pipe 14 and the seat rail 15 intersect.

  A front fork 18 is supported on the head pipe 12 so as to be rotatable left and right together with a handle bar 19, and a front wheel 20 is pivotally supported at the lower end of the front fork 18. On the other hand, a power unit 23 is pivotally supported on the link plate 17 at the center lower part of the vehicle body frame 11 via an engine suspension bracket 22 so as to be swingable in the vertical direction.

  The power unit 23 is generally used for a scooter. An engine 24 and a transmission device 25 are integrally formed, and a rear wheel 26 is directly supported on the rear portion of the transmission device 25. The transmission device 25 is a continuously variable transmission that changes the output of the engine 24 to a predetermined rotational speed, for example. A reaction unit 27 is bridged up and down between the rear portion of the transmission device 25 and the seat rail 15. By this reaction unit 27, the power unit 23 and the rear wheel 26 are suspended with their vertical swings buffered.

  A seat 28 is provided on the body frame 11 above the seat rail 15 so as to be openable and closable. An article storage box 29 capable of storing a helmet or the like is disposed below the seating seat 28 and above a cylinder assembly 32 (described later) in the power unit 23. By opening the seat 28, the upper opening 29A of the article storage box 29 is opened, and articles can be taken into and out of the article storage box 29. The front portion of the power unit 23 and the vehicle body frame 11 are covered with a synthetic resin frame cover 30 to improve the appearance and protect internal devices.

  The engine 24 is configured by a cylinder assembly 32 extending from the front of the crankcase 31 so as to be inclined forward in a substantially horizontal direction. A transmission device 25 is provided integrally from the left side of the crankcase 31 and extends rearward. The cylinder assembly 32 includes a cylinder 33, a cylinder head 34, and a head cover 35 that are sequentially stacked from the crankcase 31 side. A pair of left and right bearing boss portions 36 are integrally extended forward from the lower front portion of the crankcase 31.

  Above the power unit 23 and below the seat rail 15, an engine intake system 37 that supplies an air-fuel mixture (fuel / air mixture) to an intake port (not shown) of the cylinder head 34 is connected to the intake port. The The engine intake system 37 functions as an intake device for the engine and includes an air cleaner 38, an outlet pipe 39, a carburetor 40, and an intake pipe 41.

  The intake pipe 41 is connected to an intake port of the cylinder head 34 and is connected to a carburetor 40, and the carburetor 40 is connected to an air cleaner 38 via an outlet pipe 39. Clean air from which dust or the like has been removed by the air cleaner 38 is supplied to the carburetor 40 as intake air. The carburetor 40 mists a predetermined amount of fuel from a fuel tank (not shown) in accordance with the intake air amount to the intake port. And is supplied to the intake port together with the intake air.

  An exhaust port (not shown) is opened on the lower surface of the cylinder head 34. An exhaust pipe (not shown) extends rearward from the exhaust port, and an exhaust muffler (not shown) is connected to the rear end of the exhaust pipe. An engine exhaust system that exhausts exhaust from the engine is configured. The engine exhaust system and the engine intake system 37 swing with the power unit 23 in the vertical direction via the engine suspension bracket 22. The highest position of the air cleaner 38 when the engine intake system 37 is swung is shown by a two-dot chain line in FIG.

  The engine suspension bracket 22 is formed by integrating a cylindrical vehicle body side bearing portion 43 and a similarly cylindrical engine side bearing portion 44 by a plurality of bridge members 45. The vehicle body side bearing portion 43 is rotatably supported by the left and right link plates 17 in the vehicle body frame 11, and the engine side bearing portion 44 is rotatably supported by the left and right bearing boss portions 36 of the crankcase 31 in the power unit 23. . Thus, the engine suspension bracket 22 is bridged between the power unit 23 and the link plate 17 of the vehicle body frame 11 and supports the power unit 23 so as to be swingable in the vertical direction with respect to the vehicle body frame 11.

  As described above, the engine intake system 37 is disposed above the power unit 23 and below the seat rail 15, that is, between the power unit 23 and the seat rail 15 in a vehicle side view. As shown in FIG. 3, it is configured to be divided into two along the vehicle width direction W.

  That is, the air cleaner 38 is configured by joining the air cleaner body 46 and the air cleaner cover 47 using the joining flange portions 46A and 47A, and the joining surface (divided surface) 48 between the air cleaner body 46 and the air cleaner cover 47. The filter element 49 is arranged on the side. The interior of the air cleaner 38 is separated into a clean side 50 and a dirty side 51 with the filter element 49 as a boundary.

  The clean side 50 of the air cleaner 38 is constituted by an air cleaner body 46 and a filter element 49, and the dirty side 51 is constituted by an air cleaner cover 47 and a filter element 49. An inlet pipe 52 capable of introducing outside air is connected to the air cleaner cover 47 in communication with the dirty side 51. The outlet pipe 39 is connected to the air cleaner body 46 in communication with the clean side 50. The outside air introduced from the inlet pipe 52 into the dirty side 51 is cleaned by the filter element 49 and flows into the clean side 50 as clean air, and flows from the clean side 50 through the outlet pipe 39 to the carburetor 40. Supplied.

  The joint flange portion 46A of the air cleaner body 46 and the joint flange portion 47A of the air cleaner cover 47 are configured to project outward to join the joint surfaces (split surfaces) 48 of the air cleaner body 46 and the air cleaner cover 47. These joining flange portions 46A and 47A are fastened with bolts and nuts (not shown). These joint flange portions 46A and 47A are arranged in a range X sandwiched between a pair of left and right seat rails 15 in the vehicle plan view shown in FIG. Accordingly, the joint flange portions 46A and 47A are arranged at positions out of the pair of left and right seat rails 15 that are off from directly below the seat rail 15A located on the dirty side 51 side. Further, the air cleaner cover 47 of the air cleaner 38 is provided so as to bulge outward in the vehicle width direction W from the seat rail 15A on the dirty side 51 side in the vehicle plan view.

  A connection portion 53 of the inlet pipe 52 connected to the air cleaner cover 47 partially overlaps the seat rail 15A on the dirty side 51 side in the vehicle plan view, and the remaining portion is more than the seat rail 15A on the dirty side 51 side. It is positioned outside the vehicle width direction W. However, the connecting portion 53 of the inlet pipe 52 may be positioned so as to entirely overlap the seat rail 15A on the dirty side 51 side, or in the vehicle width direction W with respect to the seat rail 15A on the dirty side 51 side. All may be located outside.

  The inlet pipe 52 extends from the connection portion 53 with the air cleaner cover 47 to the rear of the vehicle and is accommodated in the air cleaner cover 47 (dirty side 51) and the connection portion 53 with the air cleaner cover 47. And an exposed portion 52A that is exposed to the outside of the air cleaner cover 47.

  The exposed portion 52A of the inlet pipe 52 extends from the air cleaner 38 to the front side of the vehicle in a substantially horizontal direction in a side view of the vehicle shown in FIG. Further, the exposed portion 52A of the inlet pipe 52 is curved inward in the vehicle width direction W (center side in the vehicle width direction W) in the vehicle plan view shown in FIG. The mouth 54 is configured to be directed inward in the vehicle width direction W (center side in the vehicle width direction W).

  Further, the inlet 54 of the inlet pipe 52 is disposed directly below the seat rail 15A on the dirty side 51 side of the air cleaner 38 or inside the vehicle width direction W with respect to the seat rail 15A in the vehicle plan view. In the present embodiment, the inlet 54 of the inlet pipe 52 is disposed on the inner side in the vehicle width direction W than the seat rail 15A on the dirty side 51 side.

  On the other hand, the outlet pipe 39 connected to the air cleaner body 46 in the air cleaner 38 is formed such that a connection portion 55 with the air cleaner body 46 is bent toward the dirty side 51 in the air cleaner body 46 and is an upstream end opening. 56 is arranged so as to be directed to the filter element 49.

  With the configuration as described above, according to the present embodiment, the following effects (1) to (7) are obtained.

  (1) In the air cleaner 38, joint flange portions 46A and 47B projecting outward in order to join the joint surfaces (split surfaces) 48 of the air cleaner body 46 and the air cleaner cover 47 are a pair of left and right in a vehicle plan view. It is arranged in a range X sandwiched between the seat rails 15. The air cleaner 38 of the engine intake system 37 that swings with respect to the seat rail 15 together with the power unit 23 has the seat flange 15A when the joint flange portions 46A and 47A are disposed directly below the seat rail 15A on the dirty side 51 side. A large clearance (see clearance L in FIG. 2) is required between the two.

  On the other hand, in the present embodiment, the joint flange portions 46A and 47A are arranged in a range X sandwiched between the pair of left and right seat rails 15 in the vehicle plan view shown in FIG. It is in a position off from directly below 15A. For this reason, even if the clearance L between the air cleaner 38 and the seat rail 15 is set small, the air cleaner 38 does not interfere with the seat rail 15 (seat rail 15A) when swinging, as shown by a two-dot chain line in FIG. Can be prevented. As a result, a large capacity of the air cleaner 38 can be ensured accordingly.

  (2) The exposed portion 52A of the inlet pipe 52 in the air cleaner 38 is curved inward (center side) in the vehicle width direction W so that the suction port 54 is directed inward in the vehicle width direction W in the vehicle plan view. Has been. For this reason, it is possible to prevent dust from entering the air cleaner 38 from the outside of the vehicle through the inlet pipe 52 and intrusion of rainwater.

  (3) The exposed portion 52A of the inlet pipe 52 in the air cleaner 38 is configured to curve inward in the vehicle width direction W. When the exposed portion 52A of the inlet pipe 52 is linear, as shown in FIG. 2, since the seat rail 15 is inclined to the vehicle front side, the exposed portion 52A of the inlet pipe 52 is moved forward of the vehicle. When the air cleaner is extended, the exposed portion 52A may interfere with the seat rail 15 when the air cleaner swings.

  On the other hand, when the exposed portion 52A of the inlet pipe 52 is configured to be curved inward in the vehicle width direction W, even when the exposed portion 52A extends forward of the vehicle, the air cleaner 38 is swung. Interference with the seat rail 15 can be prevented. As a result, it is possible to easily adjust the pipe length of the exposed portion 52A of the inlet pipe 52, and intake noise by the inlet pipe 52 can be suitably reduced.

  (4) Since the suction port 54 of the inlet pipe 52 is disposed on the inner side in the vehicle width direction W than the seat rail 15A on the dirty side 51 side in the vehicle plan view shown in FIG. 3, when the air cleaner 38 swings, The diameter of the suction port 54 can be increased without considering that the suction port 54 interferes with the seat rail 15A on the dirty side 51 side. As a result, since the inflow resistance of the outside air flowing into the inlet pipe 52 can be reduced, the output of the engine 24 can be increased.

  (5) Since the air cleaner cover 47 of the air cleaner 38 to which the inlet pipe 52 is connected is provided to bulge outward in the vehicle width direction W from the seat rail 15A located on the dirty side 51 side of the air cleaner 38, the dirty The capacity of the side 51 and thus the capacity of the air cleaner 38 can be increased.

  (6) The inlet pipe 52 of the air cleaner 38 extends in a substantially horizontal direction from the air cleaner 38 to the front of the vehicle in a side view of the vehicle shown in FIG. When the inlet pipe 52 extends downward in front of the vehicle in a side view of the vehicle, mud easily enters from the inlet 54, and when the inlet pipe 52 extends upward in the front of the vehicle, the inlet It becomes easy for rainwater to enter from 54. On the other hand, since the inlet pipe 52 extends in a substantially horizontal direction from the air cleaner 38 to the front of the vehicle in a side view of the vehicle, the above-described mud and rainwater enter the inlet pipe 52 and eventually the air cleaner 38. Can be prevented.

  (7) Since the outlet pipe 39 (FIG. 3) in the air cleaner 38 is configured to bend toward the dirty side 51 in the clean side 50, the space of the clean side 50 is effectively used to increase the length of the outlet pipe 39. Therefore, the intake noise by the outlet pipe 39 can be reduced. Further, since the outlet pipe 39 is bent in the clean side 50 and the inflow port 56 thereof is directed to the filter element 49, the intake resistance by the outlet pipe 39 can be reduced, and the output of the engine 24 can be increased. .

  As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to this. For example, the inlet pipe 52 may be further extended forward of the vehicle, and the suction port 54 may be positioned below the seating seat 28, thereby further preventing dust and rainwater from entering the inlet pipe 52. . Further, the inlet pipe 52 may be configured integrally with the air cleaner cover 47.

10 Scooter type motorcycle 11 Body frame 15, 15A Seat rail (body frame)
23 Power unit 24 Engine 25 Transmission device 37 Engine intake system (engine intake device)
38 Air Cleaner 39 Outlet Pipe 46 Air Cleaner Body 47 Air Cleaner Cover 46A, 47A Joint Flange 48 Joint Surface (Divided Surface)
50 Clean Side 51 Dirty Side 52 Inlet Pipe 52A Inlet Pipe Exposed Portion 53 Inlet Pipe Connection 54 Inlet Pipe Inlet W W Width X Range

Claims (4)

A power unit in which an engine and a transmission device are integrally formed is supported swingably on a pair of left and right body frames,
In an engine air intake apparatus that is disposed between the power unit and the vehicle body frame, is provided so as to be able to swing with the power unit, and includes an air cleaner that can be divided in the vehicle width direction.
The air cleaner is divided into a clean side inside the vehicle width direction defined by the air cleaner body and the filter element, and a dirty side outside the vehicle width direction defined by the air cleaner cover and the filter element. A joining flange portion projecting outward to join the two surfaces, and the joining flange portion is a range sandwiched between the pair of left and right body frames in a plan view of the vehicle, and on the dirty side side while that consists disposed at a position deviated from just below the vehicle body frame,
The air cleaner cover constituting the dirty side of the air cleaner is provided to bulge outward in the vehicle width direction from the vehicle body frame located on the dirty side of the air cleaner, and is connected to the bulged position of the air cleaner cover. The inlet pipe connecting portion is configured such that at least a part of the vehicle body frame overlaps the vehicle body frame or is positioned on the outer side in the vehicle width direction than the vehicle body frame,
The inlet pipe has an exposed portion upstream from the connection portion of the air cleaner cover, and extends in front of the vehicle by overlapping the body frame in a plan view of the vehicle.
The inlet opening which is the upstream end opening of the inlet pipe is oriented inward in the vehicle width direction in the vehicle plan view and directly below the vehicle body frame located on the dirty side of the air cleaner or in the vehicle width direction from the vehicle body frame Arranged inside,
Furthermore, an upstream portion of an outlet pipe having a downstream end connected to an intake pipe of an engine is opened in the clean side, and an inflow port which is an upstream end opening is arranged to face the filter element. Engine intake system. The inlet pipe extends from the connection portion with the air cleaner cover toward the front of the vehicle in a substantially horizontal direction in the vehicle side view and is exposed to the outside of the air cleaner cover, and the connection portion between the air cleaner cover and the vehicle 2. The engine intake device according to claim 1, wherein the engine intake device is configured to include a portion to be accommodated that extends rearward and is accommodated in the dirty side behind the air cleaner cover . In the vehicle body frame, one down tube made of a steel pipe extends rearward and downward from the rear part of the head pipe, and a cylindrical bridge pipe extends in the vehicle width direction at the lower rear end of the down tube. The pair of left and right seat rails are connected and configured to extend obliquely rearward and upward from the bridge pipe, and the power unit is disposed below the rearward and upwardly extending seat rail. The engine intake system according to claim 1 or 2. The power unit includes a rear cushion that is pivotally supported by the front lower portion of the body frame via an engine suspension bracket so as to be swingable in the vertical direction, and the rear portion is constructed between the seat rail constituting the body frame. The air cleaner is suspended by being cushioned by the unit in the vertical direction, and the air cleaner includes a front side and a top side of the power unit in a range surrounded by the seat rail and a rear side of the rear cushion unit. The engine intake device according to any one of claims 1 to 3, wherein the engine intake device is arranged at an upper portion .

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