JP2023050551A - Air cleaner structure in saddle-riding type vehicle - Google Patents

Abstract

To provide an air cleaner which achieves high intake efficiency.SOLUTION: An air cleaner has: a first case part (37) forming a purification chamber (33); and a second case part (35) forming an unpurified chamber (32). The first case part (37) has a substantially hemispherical shape, and an upstream end opening (57) of a connecting tube (43) faces a top part (39) having a substantially hemispherical shape of the first case part (37).SELECTED DRAWING: Figure 1

Description

The present invention relates to an air cleaner structure for a saddle type vehicle.

A straddle-type vehicle has a structure in which external air is filtered by a filter such as an air cleaner element in an air cleaner and then sent to an internal combustion engine.
Patent Literature 1 discloses an air cleaner having a substantially hemispherical cover portion below a fuel tank. This air cleaner discloses a mode in which an opening is provided immediately after the connecting tube is inserted into the purification chamber.

JP 2015-132233 A

However, the above air cleaner structure leaves room for improvement in intake efficiency.
SUMMARY OF THE INVENTION The present invention has been made in view of the circumstances described above, and an object of the present invention is to improve the intake efficiency of an air cleaner.

The saddle type vehicle has an unpurified chamber and a purified chamber separated by an air cleaner element. A connecting tube for introducing outside air into the power unit is inserted into the purified chamber, and a first case portion forming the purified chamber. In the air cleaner having a second case portion forming an uncleaned chamber, the second case portion has a substantially hemispherical shape, and the connecting tube has an upstream end opening toward the top of the substantially hemispherical shape of the first case portion. An air cleaner structure for a saddle-ride type vehicle is provided.

Since the air that gathers at the top of the hemispherical first case portion can be efficiently introduced into the internal combustion engine, it is possible to reduce intake resistance and improve intake air volume.

1 is a side view of a saddle-ride type vehicle; FIG. FIG. 2 is a partially cutaway enlarged view of a portion indicated by arrow 3 in FIG. 1; It is a cross-sectional view of the air cleaner structure. FIG. 3 is a sectional view taken along IV-IV in FIG. 2; 3. It is a 90 arrow directional view of FIG. FIG. 6 is a sectional view taken along line VI-VI of FIG. 5; 100 arrow directional view of FIG. 3. FIG. FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 7; 4 is a view in the direction of arrow 4 of FIG. 2 in a state where a part of the first case portion is omitted; FIG. FIG. 10 is a schematic diagram showing the result of a simulation experiment on the flow of outside air inside the air cleaner 31. FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description, directions such as front, rear, left, right, and up and down are the same as the directions with respect to the vehicle body unless otherwise specified. In each figure, FR indicates the front of the vehicle body, UP indicates the upper side of the vehicle body, and LH indicates the left side of the vehicle body.

[Embodiment]
FIG. 1 is a side view of a straddle-type vehicle 10 according to an embodiment of the invention.
A straddle-type vehicle 10 includes a body frame 11, a power unit 12 supported by the body frame 11, a front fork 14 supporting a front wheel 13 in a steerable manner, a swing arm 16 supporting a rear wheel 15, and a passenger seat. The vehicle includes a seat 17 .
The saddle-ride type vehicle 10 is a vehicle in which an occupant sits astride a seat 17 . The seat 17 is provided above the rear portion of the body frame 11 .

The body frame 11 includes a head pipe 18 provided at the front end of the body frame 11 , a front frame 19 positioned behind the head pipe 18 , and a rear frame 20 positioned behind the front frame 19 . A front end portion of the front frame 19 is connected to the head pipe 18 .
Seat 17 is supported by rear frame 20 .

The front fork 14 is supported by a head pipe 18 so as to be steerable left and right. The front wheel 13 is supported by an axle 13 a provided at the lower end of the front fork 14 . A steering handle 21 gripped by a passenger is attached to the upper end of the front fork 14 .

The swing arm 16 is supported by a pivot shaft 22 supported by the vehicle body frame 11 . The pivot shaft 22 is a shaft extending horizontally in the vehicle width direction. A pivot shaft 22 is inserted through the front end of the swing arm 16 . The swing arm 16 swings up and down around the pivot shaft 22 .
The rear wheel 15 is supported by an axle 15 a provided at the rear end of the swing arm 16 .

Power unit 12 is arranged between front wheel 13 and rear wheel 15 and supported by body frame 11 .
Power unit 12 is an internal combustion engine. The power unit 12 includes a crankcase 23 and a cylinder portion 24 that houses reciprocating pistons. An exhaust device 25 is connected to an exhaust port of the cylinder portion 24 .
The output of power unit 12 is transmitted to rear wheels 15 by a driving force transmission member that connects power unit 12 and rear wheels 15 .

The straddle-type vehicle 10 also includes a front fender 26 that covers the front wheels 13 from above, a rear fender 27 that covers the rear wheels 15 from above, a step 28 on which the passenger puts his or her feet, and a fuel for storing the fuel used by the power unit 12. and a tank 29 .
A front fender 26 is attached to the front fork 14 . The rear fender 27 and step 28 are provided below the seat 17 . The fuel tank 29 is supported by the vehicle body frame 11 .

FIG. 2 is a partially cut-away enlarged view of the arrow portion indicated by reference numeral 3 in FIG. An air cleaner 31 as an intake device is connected to the rear side wall of the cylinder portion 24 . The air cleaner 31 is arranged between the fuel tank 29 and the power unit 12 and behind the power unit 12 . The air cleaner 31 is supported by the rear part of the vehicle body frame 11 and arranged in front of the rear fender 27 .

The air cleaner 31 includes a first case portion 37 arranged above in FIG. 2, a second case portion 35 arranged below, and an air cleaner element separating the first case portion 37 and the second case portion 35. 41. The air cleaner 31 has an unpurified chamber 32 formed by the second case portion 35 and a purified chamber 33 formed by the first case portion 37 separated by the air cleaner element 41 . The air cleaner element 41 is a substantially plate-shaped dry or wet filter. The first case portion 37 has a substantially hemispherical shape.

A connecting tube 43 for introducing outside air into the power unit 12 is inserted into the purification chamber 33 . Here, the purification chamber 33 side of the connecting tube 43 is defined as the upstream side of the intake air, and the cylinder portion 24 side of the connecting tube 43 is defined as the downstream side of the intake air. The connecting tube 43 has an upstream end opening 57 facing the substantially hemispherical top portion 39 of the first case portion 37 .
A throttle body 45 is connected to the downstream end of the connecting tube 43 , and a fuel injection valve 47 is attached to the throttle body 45 . The cylinder portion 24 is connected to the downstream end portion of the throttle body 45 . Also, a resonator 50 may be connected to the connecting tube 43 .

As shown in FIG. 1, an exhaust device 25 is connected to the front side wall of the cylinder portion 24 . The exhaust system 25 includes an exhaust pipe 51 extending from the front side wall of the cylinder portion 24 through the front of the power unit 12 and below the power unit 12, and a catalytic converter 52 connected to the downstream end of the exhaust pipe 51 below the power unit 12. , and an exhaust muffler 53 connected to the downstream end of the catalytic converter 52 .

As shown in FIG. 2, an intake duct 40 for introducing outside air is inserted into the unpurified chamber 32 . A parabolic reflecting plate 49 is provided upstream of the intake duct 40 so as to face it. The reflecting plate 49 reflects outside air flowing from the front to the rear inside the cowl and guides it to the air intake duct 40 while the saddle-ride type vehicle 10 is running.

M3 is the center of the cross section where the intake duct 40 is inserted into the second case portion 35 . M2 is the center of the downstream end opening 55 of the intake duct. M4 is the center of the upstream end opening 57 of the connecting tube 43 . M1 is the center of the cross section where the connecting tube 43 is inserted into the first case portion 37 . In other words, M1 is the center of proximal end 61 .

As shown in FIG. 3, a third virtual plane VC including the plate-shaped air cleaner element 41 and parallel to the main surface of the air cleaner element 41 and a second virtual plane VV perpendicular to the third virtual plane VC are assumed. At this time, it is assumed that the second virtual plane VV is placed at approximately the midpoint of the longitudinal length of the air cleaner element 41 . At this time, a plane parallel to the third virtual plane VC and containing M1 is defined as a first virtual plane VH.
A spherical surface C is assumed centering on the intersection of the line of intersection between the first virtual plane VH and the second virtual plane VV and the longitudinal section of the air cleaner 31 . The spherical surface C may include at least part of the inner peripheral surface of the first case portion 37 . The center M4 of the upstream end opening 57 of the connecting tube 43 is in a solid surrounded by the spherical surface C, the first virtual plane VH and the second virtual plane VV. On the inner peripheral surface P facing the spherical surface C, the upstream end opening 57 of the connecting tube 43 faces the top portion 39 which is a portion surrounded by the first virtual plane VH and the second virtual plane VV.

It is desirable that the entire upstream end opening 57 of the connecting tube 43 is within a solid surrounded by the spherical surface C, the first virtual plane VH, and the second virtual plane VV.

The first case portion 37 has a substantially hemispherical shape upward from the first virtual plane VH. When viewed from the side, the first virtual plane VH is considered as the X axis, and the second virtual plane VV is considered as the Y axis. is in the positive Y-axis direction, at least a portion of the upstream end opening 57 of the connecting tube 43 is located in the second quadrant.
It is desirable that the entire upstream end opening 57 of the connecting tube 43 is located in the second quadrant.

According to this configuration, the intake air that gathers at the top portion 39 of the hemispherical first case portion 37 can be more efficiently introduced into the internal combustion engine. Therefore, the air intake resistance is reduced and the amount of intake air to the internal combustion engine is improved.

A connecting tube 43 is inserted into the purification chamber 33 from a base end portion 61 provided on the vehicle front side of the first case portion 37 . As viewed from the side of the vehicle, the center M4 of the upstream end opening 57 of the connecting tube 43 extends substantially parallel to the air cleaner element 41 from the center M1 of the base end portion 61 where the connecting tube 43 is inserted into the first case portion 37. It is provided on the top portion 39 side of the first virtual plane VH.
According to this configuration, the intake air that gathers at the top portion 39 of the hemispherical first case portion 37 can be more efficiently introduced into the internal combustion engine.

Assuming that the second imaginary plane VV is perpendicular to the air cleaner element 41 and is positioned midway between the longitudinal length of the first case portion 37 as viewed from the side of the vehicle, at least a portion of the upstream end opening 57 of the connecting tube 43 is , is provided at a position farther from the base end portion 61 than the second virtual plane VV.
According to this configuration, the intake duct can be arranged as long as possible inside the unpurified chamber 32 . Therefore, in the medium and low speed range, the pulsating effect of the intake air can be utilized to the maximum, increasing the amount of intake air and improving drivability.

The connecting tube 43 has a bent portion 59 extending from the base end portion 61 toward the top portion 39 of the first case portion 37 .
According to this configuration, the connecting tube 43 can be extended longer than a structure in which the connecting tube 43 has a straight shape. Then, the air that gathers at the top portion 39 of the hemispherical first case portion 37 can be efficiently introduced into the internal combustion engine. In addition, since the connecting tube 43 is long, the pulsation effect is likely to occur, and the intake air volume can be improved.

In the straddle-type vehicle 10, the first inner diameter D1 of the bent portion 59 of the connecting tube 43 is larger than the second inner diameter D2 on the upstream side thereof.
According to this configuration, it is possible to reduce the intake resistance due to the bent portion. Therefore, drivability at low and medium speeds can be improved.
An intake duct 40 is inserted into the unpurified chamber 32 from the vehicle rear side of the second case portion 35 . The air intake duct 40 is attached in a direction facing the connecting tube 43, and the distance between M3 and M2 in FIG. The distance between M4 and M1 in FIG. 3 is defined as the length L2 between the center of the upstream end opening 57 of the connecting tube 43 and the wall surface 72 of the first case portion. The lengths of L1 and L2 are substantially the same.
According to this configuration, intake efficiency can be improved. As a result, the amount of air intake increases, improving drivability.

The downstream end opening 55 of the air intake duct 40 opens perpendicularly to the axial direction of the opening. By opening in this way, for example, the flow in the direction of the slope 80 becomes smooth.

FIG. 4 is a sectional view taken along line IV-IV in FIG. A part of the reflector 49 is omitted in FIG.
A double pipe portion 67 is provided along the outer circumference 63 of the upstream end opening 54 of the intake duct 40 . After being reflected by the reflecting plate 49 , the outside air is rectified by the double pipe portion 67 and introduced into the unpurified chamber 32 through the upstream end opening 54 of the intake duct 40 .

5 is a view taken along arrow 90 in FIG. 3 showing the upstream end opening 54 of the intake duct 40. FIG. The double pipe portion 67 is provided in an arc shape so as to surround the upstream end opening portion 54 of the intake duct 40 . FIG. 6 is a sectional view taken along line VI-VI in FIG.
Rectifying action to prevent turbulence caused by the collision of the intake air directly entering the upstream end opening 54 and the intake air trying to enter the upstream end opening 54 of the intake duct 40 from the direction along the outer periphery of the intake duct 40. occurs.
Since the intake air can be rectified by the double pipe portion 67, the efficiency of intake air from the intake duct 40 can be improved. Therefore, the output is improved.

7 is a view along arrow 100 in FIG. 3 showing the downstream end opening 55 of the intake duct 40. FIG.
A double pipe portion 69 is provided along the outer periphery 63 of the downstream end opening 55 of the intake duct. In other words, the double pipe portion 69 is provided in an arc shape so as to surround the downstream end opening 55 of the intake duct 40 . FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG.
According to this configuration, the double pipe portion 69 suppresses the flow of intake air flowing rearward of the opening 55 and enhances the rectifying action and the intake noise reducing action of suppressing the occurrence of turbulence in the vicinity of the opening 55 . Moreover, according to such a configuration, the intake efficiency can be improved. Therefore, the amount of intake air is increased to improve drivability.

FIG. 9 is an arrow view indicated by reference numeral 4 in FIG. 2 with a part of the first case portion 37 omitted. A double tube portion 71 is provided along the outer circumference 65 of the upstream end opening 57 of the connecting tube. Outside air introduced from the unpurified chamber 32 reaches the purified chamber 33 after being filtered by the air cleaner element 41 .

The filtered outside air flows toward the top portion 39 along the hemispherical inner peripheral surface P of the first case portion 37 . Outside air is rectified by the double tube portion 71 and sucked from the upstream end opening 57 of the connecting tube 43 . Specifically, the outside air flow that tries to enter the upstream end opening 57 of the connecting tube 43 from the back side of the double tube portion 71 having a large outer diameter and the outside air that is directly sucked into the upstream end opening 57 of the connecting tube 43 The flow of air is less likely to collide, and the intake efficiency is improved. Outside air is taken in from an upstream end opening 57 of the connecting tube 43 that opens near the top 39 and is finally led to the power unit 12 .

According to this configuration, since the intake air can be rectified by the double pipe portion 71, the intake efficiency can be improved. Therefore, the output is improved.

10A and 10B are schematic diagrams showing results of a simulation experiment on the flow of outside air inside the air cleaner 31. FIG.
Outside air sucked from the upstream end opening 54 of the air intake duct 40 is guided from the air intake duct 40 to the uncleaned chamber 32 .
At this time, the outside air collides with the slope 80 and diffuses in the unpurified chamber 32, flows from the downstream end opening 55 of the intake duct toward the air cleaner element 41, and also flows from the downstream end opening of the intake duct 40. There is also a flow that goes around the back of 55. The outside air is filtered by the air cleaner element 41 and introduced into the purification chamber 33 .

The filtered outside air flows along the inner peripheral surface P of the first case portion 37 toward the top portion 39 . Of course, there is a flow from the air cleaner element 41 directly toward the upstream end opening 57 of the connecting tube, a flow along the slope 82 toward the top portion 39, and the like.
Since outside air is led to the power unit 12 from the upstream end opening 57 of the connecting tube opened near the top 39, there is an excellent effect that the intake efficiency is better than that of the conventional configuration.

(Configurations supported by the above embodiments)
The above embodiment supports the following configurations.

(Configuration 1)
In the air cleaner structure, an unpurified chamber and a purified chamber are partitioned by an air cleaner element, a connecting tube for introducing outside air to the power unit is inserted into the purified chamber, and a first case portion forming the purified chamber. In the air cleaner having a second case portion forming the unpurified chamber, the first case portion has a substantially hemispherical shape, and the connecting tube extends toward the top portion of the substantially hemispherical shape of the first case portion and upstream thereof. An air cleaner structure for a saddle-ride type vehicle, characterized in that an end opening is exposed.

According to such a configuration, the air that gathers at the top of the hemispherical first case portion can be efficiently introduced into the internal combustion engine. Therefore, intake resistance can be reduced and the amount of intake air can be improved.

(Configuration 2)
When viewed from the side of the vehicle, the center of the upstream end opening of the connecting tube is a first imaginary line extending parallel to the air cleaner element from the center of the base end where the connecting tube is inserted into the first case. The air cleaner structure for a straddle-ride type vehicle according to (configuration 1), wherein the air cleaner structure is provided on the top portion side of the plane.

According to such a configuration, the intake air that gathers at the top of the hemispherical first case portion can be more efficiently introduced into the internal combustion engine. Therefore, it is possible to reduce intake resistance and improve the amount of intake air.

(Composition 3)
Assuming that a second imaginary plane perpendicular to the air cleaner element is positioned midway between the longitudinal length of the first case portion in a vehicle side view, at least a portion of the upstream end opening of the connecting tube is: The air cleaner structure for a straddle-type vehicle according to (configuration 1) or (configuration 2), wherein the air cleaner structure is provided at a position farther from the base end portion than the second imaginary plane.

According to such a configuration, the intake duct can be arranged with the maximum length inside the air case cover. Therefore, in the medium and low speed range, the pulsating effect of the intake air can be utilized to the maximum, increasing the amount of intake air and improving drivability.

(Composition 4)
The air cleaner structure for a straddle-type vehicle according to any one of (Configuration 1) to (Configuration 3), wherein a double pipe portion is provided along the outer periphery of the connecting tube.

According to such a configuration, a rectifying action is generated to prevent turbulence caused by collision between the intake air directly entering the opening and the intake air trying to enter the opening from the direction along the outer circumference of the connecting tube. Since the intake air can be rectified by the double tube portion, the intake efficiency from the connecting tube can be improved. Therefore, the output is improved.

(Composition 5)
The saddle riding according to any one of (Configuration 1) to (Configuration 4), wherein the connecting tube has a bent portion extending from the base end portion toward the top portion of the first case portion. air cleaner structure in a model vehicle.

According to such a configuration, the connecting tube can be stretched longer than a structure in which the connecting tube has a straight shape. Then, the air that gathers at the top of the hemispherical first case portion can be efficiently introduced into the internal combustion engine. In addition, since the connecting tube is long, the pulsation effect is likely to occur, and the intake volume can be improved.

(Composition 6)
The air cleaner structure for a straddle-type vehicle according to (Configuration 5), wherein the inner diameter of the bent portion of the connecting tube is larger than the inner diameter of the upstream side thereof.

With such a configuration, it is possible to reduce intake resistance due to the bent portion. Therefore, drivability at low and medium speeds can be improved.

(Composition 7)
An intake duct for introducing outside air is inserted into the second case portion (35), and a double pipe portion is provided along the outer periphery of the air duct (Configuration 1) to (Configuration 6) ).

According to such a configuration, the flow of intake air flowing rearward of the opening is suppressed, and the rectifying action and intake noise reducing action of suppressing the occurrence of turbulent flow near the opening are enhanced. Therefore, since the intake air can be rectified, the intake efficiency of outside air through the intake duct can be improved. Therefore, the output is improved.

In addition, the above-described embodiment shows one mode to which the present invention is applied, and the present invention is not limited to the above-described embodiment.
For example, the positional relationship between the purified chamber 33 into which the connecting tube 43 is inserted and the unpurified chamber 32 into which the intake duct 40 is inserted may be reversed in the vertical direction. In other words, the portion of the hemispherically shaped purification chamber 33 designated as the top 39 may be located on the lower side of the vehicle.

REFERENCE SIGNS LIST 10 saddle type vehicle 31 air cleaner 32 unpurified chamber 33 purified chamber 35 second case portion 37 first case portion 39 top portion 40 intake duct 41 air cleaner element 43 connecting tube 55 downstream end opening of intake duct 57 upstream end opening of connecting tube Part 59 Bent part 61 Base end part 63 Outer circumference 65 Outer circumference 67 Double pipe part 71 Double pipe part 72 Wall surface D1 First inner diameter D2 Second inner diameter L1 Length L2 Length M1 Center M4 Center P Inner peripheral surface VH First virtual Plane VV Second virtual plane VC Third virtual plane

Claims (7)

An unpurified chamber (32) and a purified chamber (33) are separated by an air cleaner element (41), and a connecting tube (43) for introducing outside air to the power unit (12) is inserted into the purified chamber (33). and an air cleaner having a first case portion (37) forming the purified chamber (33) and a second case portion (35) forming the unpurified chamber (32),
The first case portion (37) has a substantially hemispherical shape,
An air cleaner for a straddle-type vehicle, wherein the connecting tube (43) has an upstream end opening (57) facing a substantially hemispherical top (39) of the first case (37). . When viewed from the side of the vehicle, the center (M4) of the upstream end opening (57) of the connecting tube (43) is the base end ( The saddle according to claim 1, characterized in that it is provided on the top (39) side of a first imaginary plane (VH) extending from the center (M1) of the air cleaner element (41) in parallel with the air cleaner element (41). Air cleaner for ride-on vehicles. Assuming that a second imaginary plane (VV) perpendicular to the air cleaner element (41) is positioned midway between the longitudinal length of the first case portion (37) in a vehicle side view, the connecting tube (43) At least part of the upstream end opening (57) of is provided at a position farther from the base end (61) than the second virtual plane (VV) An air cleaner in a saddle-riding vehicle as described. An air cleaner for a saddle type vehicle according to any one of claims 1 to 3, characterized in that a double pipe portion (71) is provided along the outer circumference (65) of the connecting tube (43). . From claim 1, characterized in that said connecting tube (43) has a bent portion (59) extending from said base end (61) toward said top portion (39) of said first case portion (37). The air cleaner for a saddle-ride type vehicle according to any one of claims 4 to 5. Straddle type according to claim 5, characterized in that the first inner diameter (D1) of the bend (59) of the connecting tube (43) is larger than the second inner diameter (D2) on the upstream side thereof. Air cleaner in vehicles. An intake duct (40) for introducing outside air is inserted into the second case part (35), and a double pipe part (67) is provided along an outer circumference (63) of the intake duct (40). An air cleaner for a saddle-ride type vehicle according to any one of claims 1 to 6, characterized by:

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