JP5560150B2 - Engine intake system - Google Patents

Description

  The present invention relates to an intake device for an engine, and more particularly to an intake device for an engine in a straddle-type vehicle that is a small vehicle.

  With regard to a conventional engine intake device, for example, in an intake device of a four-cycle multi-cylinder engine of an automobile, an inertia supercharging method for increasing an intake air amount by using a dynamic effect of an intake air column is adopted. This obtains the inertia supercharging effect from the low speed operation region to the high speed operation region of the engine.

For this reason, conventionally, an intake device in which the effective intake pipe length is lengthened at low speeds and the effective intake pipe length is shortened at high speeds to change the effective intake pipe length between the low speed operation region and the high speed operation region. Is adopted.
As this type of intake device, a device disclosed in Patent Document 1 is connected to a low-speed surge tank at the upstream end of an intake passage connected to each cylinder, for example, and a high-speed surge tank is connected to the middle of the intake passage. In addition, a switching valve is provided at the connection portion.

  The switching valve is closed at a low speed and opened at a high speed. By operating this valve, the amount of intake air can be increased in both the low speed and high speed regions by making the effective intake pipe length longer at low speed and shorter at high speed.

Japanese Patent No. 3075737

The intake system for an engine disclosed in the above-mentioned patent document employs a diaphragm actuator having a relatively simple structure as a switching drive source.
However, the target vehicle of the above-mentioned patent document is a four-wheeled vehicle and has a relatively large intake system arrangement space.

However, in a small vehicle such as a saddle-ride type vehicle, securing a sufficient length of the intake pipe, and further, a space for installing a drive source for switching the air flow path are major issues.
In addition, when a drive source for switching the air flow path is provided, in order to guarantee a good operation of the drive source over a long period of time, it is desirable to provide a storage protective case or the like for protection. The structure in which the case is provided is currently difficult to provide in terms of space.

  The present invention has been made in view of the above problems, and in a small vehicle such as a saddle-ride type vehicle, a sufficient length of an intake pipe can be secured, and an installation space for a drive source for switching an air flow path is also provided. It is another object of the present invention to provide an engine intake device that can be secured and also has a storage protection structure for protecting a drive source.

In order to achieve the above object, the invention according to claim 1 is configured to be able to switch the path of the intake passage when the intake air is purified via the air cleaner and the mixed gas is supplied to the intake port of the engine. In the engine intake system,
A portion of the intake pipe connected to the intake port of the engine is disposed in the air cleaner case, a branch passage is provided in the middle of the intake pipe in the air cleaner case, and two openings are formed. An opening / closing drive device that opens or closes any one of the air cleaner case is provided in the air cleaner case ,
The opening / closing drive device includes a swingable swinging plate in which the opening / closing drive unit opens and closes any of the openings, and the swinging shaft of the swinging plate is arranged in the direction in which the intake pipe is disposed in the air cleaner case. It is characterized by being parallel to the passage axis .
In order to achieve the above object, the invention according to claim 2 is capable of switching the path of the intake passage when the intake air is purified via the air cleaner and the mixed gas is supplied to the intake port of the engine. In the engine intake system configured,
A portion of the intake pipe connected to the intake port of the engine is disposed in the air cleaner case, a branch passage is provided in the middle of the intake pipe in the air cleaner case, and two openings are formed. An opening / closing drive device that opens or closes any one of the air cleaner case is provided in the air cleaner case,
The passage axial line of the intake passage in the throttle body arranged on the upstream side of the intake port of the engine is configured to incline in a direction away from the air cleaner case toward the rear of the vehicle in plan view. To do.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect of the invention, the opening / closing drive device includes a fitting ring portion that fits into one of the openings, and an air cleaner case. An attachment portion main body having an attachment portion fixed to an inner wall and an opening / closing drive portion for opening and closing the opening of the fitting ring portion are configured as an integral structure as an assembly.

According to a fourth aspect of the present invention, in addition to the configuration of the first aspect of the present invention, the opening / closing drive device is provided with the intake air disposed along a longitudinal direction of the air cleaner case. An intake port provided in the middle of the pipe is arranged to be openable and closable.

  The invention according to claim 5 is characterized in that, in addition to the configuration of the invention according to any one of claims 1 to 4, the opening / closing drive device uses a diaphragm valve as its drive source.

  According to a sixth aspect of the present invention, in addition to the configuration of the first aspect of the present invention, the air cleaner case includes a unit swing engine and a vehicle body above the power transmission case. It is configured in a horizontally long shape disposed in the vehicle front-rear direction below the rear frame, and the intake pipe is disposed in the air cleaner case along the vehicle body front-rear direction.

  According to a seventh aspect of the invention, in addition to the configuration of the sixth aspect of the invention, the intake pipe is held along a corner portion formed by a side wall and a bottom wall of the air cleaner case. It is characterized by.

  According to an eighth aspect of the present invention, in addition to the configuration of the first aspect of the present invention, the intake pipe includes a curved portion at a portion that protrudes from the inside of the air cleaner case, An opening is provided outside the curved shape of the bending portion, and the opening / closing driving device is attached to open and close the opening.

The invention according to claim 9, in addition to the configuration of the invention according to any one of claims 1-8, the intake port of the engine, the air cleaner case than the longitudinal direction of the vehicle body center line in a plan view It is arranged on the side.

According to the first aspect of the present invention, by arranging a part of the intake pipe in the air cleaner case, the length of the intake pipe can be secured in the air cleaner case, and the opening / closing drive device is provided in the air cleaner case. By providing in a case, the arrangement space in a small vehicle can be ensured.
Further, since the opening / closing drive device is provided in the air cleaner case, the opening / closing drive device can be protected by the case, and a dedicated storage member for protecting the opening / closing drive device from the outside becomes unnecessary, and its installation Spaces can be omitted.
According to the first aspect of the present invention, the swing shaft of the swing plate for opening and closing the opening provided in the middle of the intake pipe is located upstream of the location where the swing shaft is provided. Since it is configured parallel to the direction of the intake pipe, when the branch passage is extremely shortened to reduce the dead space, the swing plate as the on-off valve is used as the main intake passage (when the intake pipe is used for a long time) Since the air resistance of the rocking plate can be reduced even when the rocking plate is in the open state, the air flow can be made smooth and the engine performance can be improved.
According to the second aspect of the present invention, by arranging a part of the intake pipe in the air cleaner case, the length of the intake pipe can be secured in the air cleaner case, and the opening / closing drive device is provided with the air cleaner. By providing in a case, the arrangement space in a small vehicle can be ensured.
Further, since the opening / closing drive device is provided in the air cleaner case, the opening / closing drive device can be protected by the case, and a dedicated storage member for protecting the opening / closing drive device from the outside becomes unnecessary, and its installation Spaces can be omitted.
According to the second aspect of the present invention, the passage axis of the intake passage in the throttle body disposed upstream of the intake port of the engine is away from the air cleaner case toward the rear of the vehicle in a plan view of the vehicle. By tilting, the intake pipe outside the case can be shaped to be greatly curved between the air cleaner case and the throttle body, and it can be inserted at an angle close to perpendicular to the side wall of the air cleaner case. The engine performance can be improved in a state where the effective intake pipe length for intake from the opening constituting the passage is short.

According to the third aspect of the present invention, the opening of the intake pipe can be positioned by fixing the opening / closing drive device. In addition, since the opening / closing drive unit is a unitized structure integrally including an opening / closing drive unit that opens and closes its own opening, fine adjustment of the opening / closing operation of the opening / closing drive device itself can be performed before mounting to the air cleaner case. It can be done in advance and is very easy to install in the case.

According to the fourth aspect of the present invention, the middle portion of the intake pipe that is long along the longitudinal direction of the air cleaner case can be positioned and fixed. It can be fixed well overall.

  According to the fifth aspect of the present invention, since the drive source is constituted by a diaphragm valve, it can be driven by negative pressure or the like, and the structure of the branch passage can be reduced with a simple structure without increasing the size of the apparatus structure. Can be opened and closed.

  According to the sixth aspect of the present invention, the air cleaner case can be enlarged horizontally in the vehicle front-rear direction, and the intake pipe can be arranged relatively long in accordance with the case shape and held by the case inner wall. Effective position regulation against vehicle body vibration can be performed.

  According to the seventh aspect of the present invention, since the lower side and the side surface of the intake pipe are held by the corners of the inner wall of the air cleaner case, the intake pipe can be securely held and fixed, and is effective against vehicle body vibration. Position regulation is possible.

  According to the eighth aspect of the present invention, the opening is provided in the bent portion of the intake pipe, so that not only the dead space of the branch passage is eliminated, but also the merging portion of the intake passage extends along the curved portion. Since the flow air resistance can be reduced, the air flow can be smoothed and the engine performance can be improved.

According to the ninth aspect of the present invention, when the intake port of the engine is disposed closer to the air cleaner case than the center line in the vehicle longitudinal direction in plan view of the vehicle, the inclination angle of the passage axis is further increased. In addition, the intake passage can be shortened and the entire intake passage can be made compact.

1 is a left side view of an embodiment of a saddle riding type vehicle according to the present invention. It is a perspective view for showing the inside of the case main part of the air cleaner case in the intake device of the engine concerning the present invention. It is a left side view for showing the inside of the case body of the air cleaner case in the engine intake device according to the present invention. It is a disassembled perspective view for showing the attachment structure of the filter attached to the case main body of the air cleaner case shown in FIG. 3, and a lid | cover. FIG. 3 is a plan view of a main part in a state in which a seat, a fuel tank, and the like are removed to show the engine intake device and the air cleaner case according to the present invention. It is a perspective view which shows the external appearance of the opening / closing drive apparatus in one Embodiment which concerns on this invention. It is a side view which shows the external appearance which looked at the opening-and-closing drive apparatus shown in FIG. 6 from the arrow X direction of FIG. FIG. 8 is a partially exploded perspective view for illustrating a mounting structure of a swing plate in the opening / closing drive device shown in FIGS. 6 and 7. It is an AA arrow directional cross-sectional view in FIG. It is a conceptual diagram which shows the schematic structure for demonstrating operation | movement of the intake device in this embodiment, and shows the case where an air path is long. It is a conceptual diagram which shows the schematic structure for demonstrating operation | movement of the intake device in this embodiment, and shows the case where an air path is short.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals, and Fr, Rr, U, D, R, and L shown in the drawings are the front direction, rear direction, upward direction, downward direction, and right direction of the vehicle in the embodiment. , Indicates the left direction.

FIG. 1 is a left side view of a low floor straddle-type vehicle according to an embodiment of the present invention.
A low-floor straddle-type motorcycle 1 as a low-floor straddle-type vehicle extends a down tube 22 obliquely downward from a head pipe 20, and includes a front frame 31 extending rearward and slightly downward from the middle stage of the down tube 22. The lower tube 23 extends horizontally from the lower end of the down tube 22, and further, a rear frame 32 (seat rail) that is a seat rail that is separated from the rear end of the lower tube 23 diagonally upward and left and right (front and back in the drawing). The body frame is composed of the above and the like.

  Further, the low floor saddle riding type motorcycle 1 includes a front wheel 18 that is rotatably provided at a lower end of a front fork 17 that is pivotably attached to a head pipe 20, a handle 10 that is provided at an upper end of the front fork 17, and a lower tube. 23, a power unit 25 of a so-called unit swing engine provided on a frame such as the rear end of the power unit 25 so as to be able to swing up and down via a pivot shaft 16, a rear wheel 19 provided rotatably at the rear end or rear of the power unit 25, and a power unit 25. A rear cushion 24 obliquely spanned between the rear end or rear and the rear frame 32; a front cowl 35 surrounding the front of the head pipe 20; a seal leg 26 surrounding the rear of the head pipe 20; A low floor portion 27 extending substantially horizontally and a side extending from the low floor portion 27 and surrounding the rear frame 32 A bar 28, this is supported by the frame 32 after being placed on the side cover 28 is configured to have a seat 6 extending back and forth, the.

  The power unit 25 includes the engine 12 at the front end of the power transmission case 41 that houses the speed reduction portion, and is an important power transmission component that decelerates the driving force generated by the engine 12 and transmits it to the rear wheel 19.

The intake device 40 for supplying air to the engine 12 includes an air cleaner case 50 including an air filter and the like, in the vehicle longitudinal direction between the power transmission case 41 of the unit swing engine and the rear frame 32 of the vehicle body frame. Is provided as a horizontally long case.
An intake pipe 70 for supplying air from the air cleaner case 50 to the engine 12 is provided.

Although detailed explanation is omitted, 33 is a front fender, 37 is a headlamp, 34 is a rear fender, 29 is an exhaust pipe, 36 is a stand, 47 is a silencer, 38 is a rear combination lamp, and 39 is a rear seat. A grab rail held by a passenger sitting in
The occupant M gets on the seat 6 so as to keep his riding posture by placing his / her feet on the low floor portion 27 and grasping the handle 10.

The intake device 40 of the engine 12 which is a characteristic part in the present embodiment will be sequentially described.
As shown in FIGS. 8 and 9, the intake device 40 exemplified in the present embodiment cleans the intake air via an air cleaner 53 provided in the air cleaner case 50 as shown in FIGS. 8 and 9. The mixed gas is supplied to the intake port 12 b of the engine 12 through the body 56.
In this intake, the path of the intake passage can be switched by an opening / closing drive device 60, which will be described later, disposed in the air cleaner case 50.

In the intake device 40 of this embodiment, the intake pipe 70 connected to the throttle body 56 has a case internal intake pipe 71 on the case body 51 side of the air cleaner case 50, as shown in FIGS. 2 and 3. It is disposed along the longitudinal direction of the vehicle body.
The air cleaner case 50 has a structure in which an air cleaner 53 and a lid 52 are attached to the case body 51 shown in FIGS. 2 and 3 as shown in FIG. That is, in this embodiment, the air cleaner 53 and the lid 52 are fixed to the opening side of the case main body 51 shown in FIG. Further, the lid 52 is configured such that a duct 5 forming a case air inlet is attached to the inside of the cover member 8.

In the intake pipe 70 according to the present embodiment, an opening 73 on the front end side is provided on the rear side of the case (rear side in the longitudinal direction of the vehicle body) in the air cleaner case 50, and an opening 74 on the branch passage 76 (see FIG. 10). It is provided on the front side of the case (the front side in the vehicle longitudinal direction).
In the present embodiment, the branch passage 76 is configured to be an extremely short branch flow path so that it slightly protrudes from a curved portion 70a described later. In short, it is sufficient that a fitting ring portion 67 of the opening / closing drive device 60 described later can be fitted, and the shorter the length, the better.

The opening 73 is an opening at the tip of the in-case intake pipe 71, and the in-case intake pipe 71 is slightly curved inward on the case rear side of the air cleaner case 50 and opens toward the inside of the case. ing.
On the other hand, the opening 74 is an opening located on the front side of the case of the air cleaner case 50, and is provided outside the curved portion 70a that is curved so that the in-case intake pipe 71 is connected to the outside-case intake pipe 72 outside the case. . And this opening part 74 is comprised so that it can open and close by the opening-and-closing drive device 60 mentioned later attached in the air cleaner case 50. FIG.

  As shown in FIGS. 6 and 7, the opening / closing drive device 60 in this embodiment includes a fitting ring portion 67 that fits into the opening 74 of the branch passage 76 and is supported by the inner wall of the air cleaner case 50. It is comprised as an assembly of the attachment part main body 66 provided with the part 68, and the opening-and-closing drive part 61 which opens and closes the opening 67a of the fitting ring part 67, and both members are appropriately assembled and integrated.

In the opening / closing drive device 60, the attachment main body 66 is composed of two parts.
That is, as shown in FIG. 6, from the opening cylindrical part 66b which has the fitting ring part 67 (part fitted to the opening part 74), and one side (left direction in FIG. 4) of this opening cylindrical part 66b. It is composed of a drive source holding portion 66a that protrudes in a direction opposite to the protruding direction of the fitting ring portion 67 (upward in the drawing) and holds a drive source described later.

For example, three attachment portions 68 for fixing the attachment portion main body 66 in the air cleaner case 50 are provided, one of which is on the opening cylindrical portion 66b side and two of the drive source holding portions 66a. On the side.
The mounting structure of the mounting portion main body 66 is shown in the cross section of FIG. In other words, the attachment portion 68 is in contact with attachment protrusions 51e (three locations corresponding to the attachment portion 68) protruding inward from the side wall 51b of the case body 51 from the outside of the case body 51. It is fixed by a set screw 90.
Further, in this fixed state, the fitting ring portion 67 is fitted into the opening 74 of the branch passage 76.

  In this embodiment, the opening / closing drive unit 61 of the opening / closing drive device 60 includes a swingable swinging plate 80 that opens and closes the opening 67a of the fitting ring 67, a diaphragm valve 59 as a drive source, and a diaphragm. The link rod 64 transmits the movement of the valve 59 to the swing plate 80.

  As shown in FIG. 8, the swing plate 80 has a pair of swing shafts 81 (only one of which is shown in FIG. 8) provided on the swing axis C. Is dropped into the bearing recess 66d, and the stop plate 69 is fixed by a plate screw 69a from above. By such a structure, it is held rotatably.

  Further, the rocking plate 80 penetrates with the tip end of the link bar 64 bent at a position appropriately deviated from the rocking axis C. Therefore, the rocking plate 80 rotates in a predetermined direction (arrow Y direction) by moving the link bar 64 in a direction (arrow O direction and arrow S direction) intersecting the rocking axis C. The opening 67a is closed or opened.

  In this embodiment, the piping 88 of the diaphragm valve 59 is connected to the upstream side of the throttle valve 57 via a solenoid valve 58s, a surge tank 58t, and a one-way valve 58o, as shown in FIGS. That is, the solenoid valve 58s is turned on and off based on the throttle opening and the engine speed based on the control unit signal, the surge tank 58t makes the pressure fluctuation constant, and the one-way valve 58o takes out only the negative pressure. Can do.

As in the present embodiment, when the drive source is configured by the diaphragm valve 59, a pipe 88 for supplying a negative pressure is integrally provided in the case body 51 as a configuration for driving the diaphragm valve 59. The structure is connected via a joint 88a.
Therefore, the opening 74 of the branch passage 76 can be opened and closed with a simple structure without increasing the structure for driving the drive source.

  With this configuration, the swing plate 80 swings in the range of 90 degrees and opens and closes the opening 67a by the operation of the link bar 64 (the direction of the arrow O and the direction of the arrow S) as described above. Is called. The swing axis C of the swing plate 80 is configured to be parallel to the longitudinal direction of the in-case intake pipe 71. That is, the swing axis C is parallel to the intake air flow in the upstream intake pipe 71 in the case, and the swing plate 80 stands to open the opening 67a (90 degrees from the state shown in FIG. 8). In the rotated state), it is configured not to be resistant to the air flowing through the in-case intake pipe 71.

  In such a mounting structure of the opening / closing drive device 60, for example, first, the fitting ring portion 67 is fitted into the opening portion 74 of the branch passage 76 when mounting. This fitting structure may be a structure in which the fitting ring portion 67 is fitted to either the outside or the inside of the opening 74.

Next, the piping 88 of the diaphragm valve 59 is set so as to come out of the case, and then the mounting body 66 is fixed in the case by the mounting screw 90, and the mounting is completed.
As described above, the opening / closing drive device 60 is an integrated structure in which the attachment structure portion and the drive device portion are assembled in advance, and is so-called unitized, so that the attachment is simple. The tube 70 can be easily fixed to the air cleaner case 50.

After fixing the intake pipe 70, as described above, the air cleaner 53 shown in FIG. 4 is set and the lid 52 is covered, and the screw 14 is screwed into the screw hole 54 shown in FIG.
As shown in FIG. 1, the intake device 40 assembled in this way is attached above the power transmission case 41 of the engine 12 and between the rear frame 32 of the vehicle body.

  In the present embodiment, the intake pipe 70 is fixed to the corner portion SB where the in-case intake pipe 71 is in contact with both the side wall 51b and the bottom wall 51a of the air cleaner case 50 inside the air cleaner case 50 by fixing the opening / closing drive device 60. It is held so as to be pressed. The bottom wall 51a is provided with ribs 51d, and the contact with the bottom wall 51a of the case internal intake pipe 71 is actually the ribs 51d.

Further, in the present embodiment, as shown in FIGS. 10 and 11, the passage axis C2 of the intake passage 72a in the throttle body 56 disposed on the upstream side of the intake port 12b of the engine 12 is It is configured to incline with respect to the rearward direction away from the air cleaner case 50, that is, with respect to the passage axis C 1 of the outer case intake pipe 72.
According to such a configuration, the outside-case intake pipe 72 has a shape that is largely curved between the air cleaner case 50 and the throttle body 56 and is inserted at an angle close to orthogonal to the side wall 51b of the air cleaner case 50. Can be made. As a result, the engine performance can be improved in a state where the effective intake pipe length for intake from the opening 74 is short.

  Further, in the present embodiment, as shown in FIG. 5, the intake port 12b of the engine 12 is disposed on the air cleaner case 50 side of the vehicle longitudinal direction center line C0 in the vehicle plan view. With this configuration, even when the inclination angle of the passage axis C2 is increased, the intake passage can be shortened and the entire intake passage can be made compact. Thereby, for example, the capacity of the storage box can be increased.

The operation of the engine intake device 40 applied to the low floor straddle-type motorcycle 1 configured as described above will be described with reference to FIGS. 10 and 11.
10 and 11 are conceptual diagrams showing a schematic configuration of the intake device 40 in the present embodiment, and there are portions that are different from the actual shape, positional relationship, and the like. In particular, the diaphragm valve 59 shown in FIG. 10 and FIG. 11 is illustrated in a lateral direction to make the concept of the invention easier to understand, although it is different from the actual one. For convenience of explanation, the branch passage 76 has a structure protruding from the bending portion 70a as shown in FIGS. 10 and 11, but in reality, the swing plate 80 is directly disposed on the bending portion 70a. A configuration is more preferable.

In order to obtain the inertia supercharging effect from the low speed operation region to the high speed operation region of the engine, as shown in FIG. 10, the effective intake pipe length is increased at low speeds. On the other hand, at high speed, the effective intake pipe length is shortened as shown in FIG.
In the present embodiment, as described above, in the intake device 40, by arranging the in-case intake pipe 71 in the air cleaner case 50, the arrangement space of the intake pipe 70 in the small vehicle is secured, and the branch passage 76 is formed. Opening and closing the opening 74 switches the air passage.

  First, in the case of the low speed shown in FIG. 10, the pressure variable chamber 62 in the diaphragm valve 59 is opened to the atmosphere through the pipe 88 by the operation of the solenoid valve 58s controlled based on the throttle opening and the engine speed. It becomes a state. That is, when the pressure variable chamber 62 is opened to the atmosphere, the flexible membrane 65 is lowered by the urging force of the compression spring 63, and the link rod 64 connected to the flexible membrane 65 is lowered, whereby the branch passage 76 is formed by the swing plate 80. The side opening 74 is closed.

Therefore, the air is supplied from the opening 73 to the intake port 12b of the engine 12 through the in-case intake pipe 71, the state where the effective intake pipe length is long is maintained, and the intake air amount can be increased by the inertia supercharging effect.
A throttle body 56 having a throttle valve 57 is arranged immediately upstream of the intake port 12b.

In the case of high speed shown in FIG. 11, negative pressure is supplied via the one-way valve 58 o and surge tank 58 t by the operation of the solenoid valve 58 s, and the pressure variable chamber 62 in the diaphragm valve 59 is negative pressure via the pipe 88. It will be in the state made.
That is, when the pressure variable chamber 62 has a negative pressure, the flexible membrane 65 rises against the urging force of the compression spring 63. When the link rod 64 moves up in conjunction with the flexible membrane 65, the swing plate 80 rotates 90 degrees, and the opening 74 on the branch passage 76 side opens.

Therefore, most of the air is supplied from the opening 74 to the intake port 12 b of the engine 12 through the branch passage 76. Thereby, the state where the effective intake pipe length is shortened is maintained, and the intake air amount is increased due to the inertia supercharging effect.
Further, the fact that the swing shaft 81 is parallel to the intake air flow in the upstream intake pipe 71 in the upstream side means that the air flow in the intake pipe 71 in the case when the swing plate 80 is open. Since the air resistance becomes smaller, the air flow becomes smoother and the engine performance can be improved.

  Further, in the present embodiment, since the opening 74 is arranged close to the curved portion 70a of the intake passage, it is possible to eliminate a dead space (a space that hinders the air flow) of the air flow. Smooth air flow. In addition, since the confluence portion of the intake passage is located in the curved portion 70a, the air flow can be smoothed by switching the effective intake pipe length, and the engine performance can be improved.

  Further, since the outside-case intake pipe 72 has a large curved shape and is inserted at an angle close to orthogonal to the side wall 51b of the air cleaner case 50, the intake air flow from the opening 74 can be easily flowed, and effective intake air can be obtained. Engine performance can be improved when the pipe length is short.

Further, since the opening / closing drive unit 61 is disposed in the air cleaner case 50, it is protected from the outside.
Furthermore, in the present embodiment, the intake pipe 70 can be positioned and fixed at the opening 74 of the branch passage 76 at the same time by fixing the opening / closing drive device 60.

  Further, the air cleaner case 50 is firmly positioned and fixed at the inlet portion in the case along the substantially entire length in the longitudinal direction, and the long region of the intake pipe 70 is firmly held and fixed by the corner portions of the case inner walls 51a and 51b. Therefore, the position can be effectively controlled against vertical and horizontal vibrations of the vehicle body, and a favorable state for airflow can be secured.

Although the embodiment of the present invention has been described above, the low floor straddle type motorcycle has been described as an example. However, the straddle type vehicle of the present invention is not limited to the low floor straddle type vehicle described above, The present invention can be applied to a saddle riding type tricycle, a low floor saddle riding type four wheel vehicle, and a saddle riding type vehicle having another structure.
In the present invention, the shape and structure of the air cleaner case 50, the attachment main body 66 of the opening / closing drive device 60 and the diaphragm valve 59 shown in the above embodiment can be changed as appropriate.

  In the embodiment, the opening / closing drive device 60 is installed so as to open / close the opening 74 in the middle portion of the intake pipe 70, but the opening / closing drive device 60 opens / closes the opening 73 at the tip of the intake pipe 70. It is good also as a structure attached to.

1 Low floor type saddle riding type motorcycle (saddle riding type vehicle)
DESCRIPTION OF SYMBOLS 10 Handle 12 Engine 32 Rear frame 40 Engine intake device 50 Air cleaner case 59 Diaphragm valve 60 Opening / closing drive device 61 Opening / closing drive unit 64 Link rod 66 Mounting portion main body 67 Fitting ring portion 68 Mounting portion 70 Intake pipe 73, 74 Opening portion 76 Branch passage 80 Swing plate 81 Swing shaft

Claims (9)

The engine intake device (40) configured to be able to switch the path of the intake passage when the intake gas is purified via the air cleaner (53) and the mixed gas is supplied to the intake port (12b) of the engine (12). In
A part of the intake pipe (70) connected to the intake port (12b) of the engine (12) is disposed in the air cleaner case (50), and the intake pipe (70) in the air cleaner case (50) is in the middle. A branch passage (76) is provided to form two openings (73, 74), and an opening / closing drive device (60) for opening / closing one of the openings (73, 74) is provided in the air cleaner case (50). ) in the provided,
The opening / closing drive device (60) includes a swingable swing plate (80) in which the open / close drive unit (61) opens and closes any of the openings (73, 74), and the swing plate (80). The swinging shaft (81) of the engine is configured in parallel to the passage axis (C2) in the direction in which the intake pipe (70) is disposed in the air cleaner case (50). 40). The engine intake device (40) configured to be able to switch the path of the intake passage when the intake gas is purified via the air cleaner (53) and the mixed gas is supplied to the intake port (12b) of the engine (12). In
A part of the intake pipe (70) connected to the intake port (12b) of the engine (12) is disposed in the air cleaner case (50), and the intake pipe (70) in the air cleaner case (50) is in the middle. A branch passage (76) is provided to form two openings (73, 74), and an opening / closing drive device (60) for opening / closing one of the openings (73, 74) is provided in the air cleaner case (50). )
The air cleaner case (C2) of the intake passage (72a) in the throttle body (56) arranged on the upstream side of the intake port (12b) of the engine (12) faces the rear of the vehicle in a plan view. 50) An intake device (40) for an engine, which is configured to be inclined in a direction away from 50). The opening / closing drive device (60) includes a fitting ring portion (67) fitted into one of the openings (73, 74) and a mounting portion (68) fixed to the inner wall of the air cleaner case (50). An attachment body (66) comprising:
An opening / closing drive part (61) for opening and closing the opening (67a) of the fitting ring part (67);
The intake system (40) for an engine according to claim 1 or 2 , characterized in that is configured as a unitary structure. The opening / closing drive device (60) is disposed so as to be able to open and close the opening (74) provided in the middle of the intake pipe (70) disposed along the longitudinal direction of the air cleaner case (50). The engine intake device (40) according to any one of claims 1 to 3, wherein the intake device (40) is an engine.   The engine intake device (40) according to any one of claims 1 to 4, wherein the opening / closing drive device (60) uses a diaphragm valve (59) as a drive source.   The air cleaner case (50) has a horizontally long shape in which the engine (12) is a unit swing engine and is disposed in the vehicle front-rear direction above the power transmission case (41) and below the rear frame (32) of the vehicle body. The engine intake device (40) according to any one of claims 1 to 5, wherein the intake pipe (70) is disposed in the air cleaner case (50) along a longitudinal direction of the vehicle body. ).   The said intake pipe (70) is hold | maintained along the corner | angular part (SB) comprised by the side wall (51b) and bottom wall (51a) of the said air cleaner case (50). An intake device (40) for an engine according to claim 1.   The intake pipe (70) is provided with a curved portion (70a) at a portion protruding from the inside of the air cleaner case (50), and the opening (74) is provided outside the curved shape of the curved portion (70a). The engine intake device (40) according to any one of claims 1 to 7, wherein the opening / closing drive device (60) is mounted to open and close the opening (74). The intake port of the engine (12) (12b) is, the longitudinal direction of the vehicle body center line in a plan view from claims 1 8, characterized in that it is arranged on the side of (C0) the air cleaner case than (50) Engine intake system (40) according to any one of the preceding claims.

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