JPH07119431A - Blow-by gas recirculating device for multiple cylinder engine - Google Patents

Abstract

PURPOSE:To mutually equalize the respective air-fuel ratios between cylinders by substantially equally carrying a blow-by gas to an intake passage directing each cylinder when the blow-by gas is sucked to a cleaner case. CONSTITUTION:This device has a plurality of intake passages 77 for allowing the front case 67 inner part of the cleaner case 63 of an air cleaner 27 to communicate with each cylinder. A blow-by gas 85 is sucked into the front case 67. A chamber 83 for introducing the blow-by gas 85 is formed in the cleaner case 63, and a plurality of communicating holes 82 for allowing the chamber 83 inner part to communicate with the front case 67 are formed. Each communicating hole 82 is arranged along the direction where the upper stream end opening 86 of each intake passage 77 is opened in the front case 67.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention allows blow-by gas generated when an engine is driven to pass through an intake air cleaner,
The present invention relates to a blow-by gas recirculation device for a multi-cylinder engine mounted on a motorcycle or the like, which is recirculated to the engine.

[0002]

2. Description of the Related Art Conventionally, some motorcycles have the following structure.

That is, a multi-cylinder engine is mounted on a motorcycle, and an air cleaner for intake air that is shared by these plural cylinders is provided. This air cleaner is composed of a cleaner case that forms the outer shell of the air cleaner, and an element provided between the intake air and the upstream side of the intake air inside the cleaner case. In addition, a plurality of intake passages are provided that allow the inside of the downstream side of the cleaner case to communicate with each of the cylinders.

The blow-by gas generated when the engine is driven is sucked into the cleaner case due to the negative pressure in the cleaner case on the downstream side, and from there, is further sucked into each cylinder through each of the intake passages. The mixed gas supplied separately from the above is used for combustion. Further, the combustion gas generated by this combustion is subsequently exhausted.

[0005]

By the way, in the above-mentioned conventional structure, the blow-by gas sucked into the cleaner case moves toward the intake passage closer to the sucked position,
There is a risk of large drift.

When such drift occurs, the air-fuel ratio varies among the cylinders. So, for example,
When the exhaust gas purification control is performed based on the air-fuel ratio, the amount of air-fuel ratio variation among the cylinders makes it difficult to control the air-fuel ratio, which causes a problem that exhaust gas purification is hindered.

[0007]

SUMMARY OF THE INVENTION The present invention has been made by paying attention to the above circumstances. When blow-by gas is sucked into a cleaner case, the blow-by gas is substantially equal to the intake passage toward each cylinder. The purpose is to make the air-fuel ratios among the cylinders equal to each other.

[0008]

A blow-by gas recirculation apparatus for a multi-cylinder engine according to the present invention for achieving the above object forms a chamber 83 for introducing a blow-by gas 85 into a cleaner case 63, and the inside of this chamber 83 is formed. Is formed in the front case (downstream side of the cleaner case) 67, and the upstream end opening 86 of each intake passage 77 opening in the front case (downstream side of the cleaner case) 67 is formed. The communication holes 82 are arranged along the lined direction.

[0009]

[Operation] The operation of the above configuration is as follows.

The terms in parentheses below correspond to the terms in the claims.

The blow-by gas 85 introduced into the chamber 83 is once dispersed in the chamber 83 by once colliding with the inner walls of the chamber 83.

Next, the blow-by gas 85 passes through the respective communication holes 82 and the front case (downstream of the cleaner case) 6
7 is drawn into the intake passages 7.
7, the blow-by gas 85 sucked into the front case (downstream side of the cleaner case) 67 through each of the communication holes 82 is It is made to flow substantially uniformly toward each of the intake passages 77 without being biased into any of the intake passages 77.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 1 in the drawing denotes a motorcycle, which is a vehicle, and an arrow Fr indicates the front thereof. The right and left described below means the direction toward the front. Further, G is a road surface on which the motorcycle 1 can travel.

The vehicle body frame 2 of the motorcycle 1 has a head pipe 3 at its front end, and a main frame 4 extends downward from the upper part of the head pipe 3 toward the rear lower side, and the extended end of the main frame 4 is extended. The seat pillar tube 5 extends further rearward and downward. On the other hand, a pair of left and right down tubes 7 extend rearward and downward from the lower part of the head pipe 3, and the extending ends of the down tubes 7 and the extending ends of the seat pillar tubes 5 are connected to each other.

A pair of left and right seat rails 8 extend rearward and upward from the rear end of the body frame 2, and the seat rails 8 are supported by the seat pillar tubes 5 by a back stay 9.

A front fork 11 is rotatably supported on the head pipe 3. A front wheel 12 is supported on the lower end of the front fork 11, while a handle 13 is attached to the upper end of the front fork 11. A pair of left and right brackets 11a, 11a are provided on the upper portion of the front fork 11 so as to project forward, and a headlamp 14 is supported by these brackets 11a.

A rear arm 16 is pivotally supported by a pivot shaft 15 so as to be vertically swingable in the middle of the seat pillar tube 5 in the vertical direction. The rear wheel 1 is attached to the swinging end of the rear arm 16.
7 is supported, and a shock absorber 18 is installed between the seat rail 8 and the rear arm 16.

An in-line four-cylinder engine 20 is provided in a space surrounded by the main frame 4, the seat pillar tube 5, and the down tube 7. This engine 20
Has a crankcase 21 and four left and right cylinders 22 projecting from the crankcase 21, and is supported by the vehicle body frame 2. A power transmission device 24 is connected to the crankcase 21, and the rear wheel 17 is connected to an output shaft 25 of the power transmission device 24 by a chain transmission mechanism 26.

A carburetor 27 and an air cleaner 28 are connected to the rear surface of each cylinder 22. On the other hand, one end of an exhaust pipe 29 is connected to the front surface of each cylinder 22 of the above, and the other end of each exhaust pipe 29 is connected to the down tube 7 of the same.
It extends rearward through the vicinity of the lower side and is connected to the front end of the collecting pipe 31. A silencer 32 is connected to the rear end of the collecting pipe 31. In the above case, four exhaust pipes 2
9, one end side of each exhaust pipe 29 at both left and right ends is located near the outer side of the left and right down tube 7, and one end side of each intermediate exhaust pipe 29 is located between the left and right down tubes 7. .

A fuel tank 34 is supported on the main frame 4. On the other hand, the seat rail 8 has a seat 35 and a tandem seat 36 integrally formed with each other in the front and rear.
And are supported. A rider can sit on the seat 35, and a footrest 37 for the rider is provided on a bracket 38 attached to the lower portion of the seat pillar tube 5 so as to project therefrom. In addition, the tandem seat 36
A passenger can sit on the vehicle, and a tandem footrest 39 for the passenger is provided on the bracket 38. A grip 40 is gripped by the passenger.

A hydraulically operated wet multi-plate clutch 4 for connecting and disconnecting the power transmission from the engine 20 to the power transmission device 24.
1 is provided and the clutch 41 is normally urged to engage. On the other hand, the left and right ends of the handle 13 are grips 42. These grips 42
A clutch lever 43 is provided near the front of the left grip 42, and the clutch lever 43 is pivotally supported by the handle 13 so as to be rotatable back and forth, and is normally rotated forward by a spring.

A hydraulic pipe 44 for connecting the clutch lever 43 and the clutch 41 is provided. And
When the clutch lever 43 is gripped by the hand holding the grip 42 and rotated to the grip 42 side, this operation is transmitted to the clutch 41 via the pressure oil in the hydraulic pipe 44, and the clutch 41 It is designed to disconnect.

When driving the motorcycle 1 by driving the engine 20, first, the clutch lever 43 is rotated toward the grip 42 to disengage the clutch 41.

Next, when the engine 20 is started, the fuel in the fuel tank 34 is supplied to the carburetor 27 and mixed with the intake air 45 sucked through the air cleaner 28, which is used for combustion in the engine 20. It The power of the engine 20 generated by this is generated by the connection operation of the clutch 41 and the power transmission device 24 and the chain transmission mechanism 26.
It is transmitted to the rear wheels 17 via the, and the motorcycle 1 can run.

A main stand 47 is pivotally supported by a pivot shaft 46 on the rear end of the down tube 7 so as to be vertically rotatable. When the main stand 47 is rotated upward, the main stand 47 is brought into the storage posture as shown in FIG. On the other hand, if the main stand 47 is rotated downward and the rotating end of the main stand 47 is grounded on the road surface G, the motorcycle 1 is self-supporting on the road surface G by the main stand 47 and the front wheels 12. To be made.

The down tube 7 on the left side which is the vehicle body
A side stand 50 is vertically rotatably supported by a pivot shaft 49 extending in the left-right direction at the lower part of the. The side stand 50 also allows the motorcycle 1 to stand on the road surface G.

At the rear portion of the seat rail 8, a standing handle 51 made of a circular pipe having a U-shape in side view is provided in a protruding manner, and a resin rear side cover 52 is provided to cover the standing handle 51 from the outside. As described above, when the motorcycle 1 is to be made to stand by the main stand 47 or the side stand 50, the standing handle 51 can be gripped.

A luggage carrier device 5 is provided at the rear of the vehicle body of the motorcycle 1.
4 are provided. The luggage carrier device 54 will be described.

The upper surface of the tandem seat 36 is a loading platform 55.
Is also used for. Below the left and right sides of the platform 55,
Fixed front and rear hooks 56 and 57 are provided respectively. Of these hooks 56 and 57, the front hook 56 is fixed to the upper rear portion of the back stay 9, and the rear hook 57
Is fixed to the standing handle 51, and both hooks 56 and 57 project downward.

Movable hooks 58 are provided below the left and right side portions of the cargo bed 55 and behind the rear hooks 57. The luggage 61 can be bound on the cargo bed 55 by the string-like body 60 that is hooked on the hooks 56, 57, and 58 so as to be freely detachable.

1 and 3 to 7, the air cleaner 28 is shared by the plurality of cylinders 22 and has a resin cleaner case 6 forming an outer shell thereof.
3, and an element 64 provided between the intake air 45 and the downstream side in the cleaner case 63,
The element 64 has a U-shape in a side view.

The cleaner case 63 is composed of a rear case 66 which is an upstream side of the cleaner case 63 and a front case 67 which is a downstream side of the cleaner case 63. A flange 68 is detachably attached to the right side wall of the rear case 66 with a bolt 69, and an inlet pipe 70 projects leftward from the flange 68. The projecting end of the inlet pipe 70 is located inside the element 64 at the left-right center of the rear case 66. An inlet cover 72 is detachably attached to the outer surface of the flange 68 with a bolt 73. The upstream end of the inlet cover 72 opens downward so that rainwater does not enter, and the downstream end communicates with the right end of the inlet pipe 70.

Four communication pipes 75 are attached to the upper portion of the front wall 74 of the front case 67 at substantially equal intervals in the left-right direction. Each of the communication pipes 75 is connected to the corresponding cylinder 22 via the carburetor 27, and the inside of each of the communication pipes 75 serves as an intake passage 77. in this case,
Although the inner diameters of the communication pipes 75 are substantially the same, the communication pipes 75 at the left and right ends of the four communication pipes 75 are shorter than the communication pipe 75 at the middle portion. This allows
The intake air 45 is supposed to flow through the communication pipes 75 almost evenly.

At the lower front portion of the front case 67, a recess 78 is formed which extends linearly to the left and right and opens rearward. The recess 78 includes a lower surface of the front wall 74, an upper surface plate 78a integrally formed on the front case 67, which faces the upper and lower surfaces,
It is composed of a bottom plate 78b. A resin cover plate 79 is provided which closes the rear end opening of the recess 78 so as to be openable and closable. The cover plate 79 is removably screwed to the left and right boss portions 80 protruding in the recess 78 with bolts 81. The space inside the recess 78 closed by the cover plate 79 serves as a chamber 83.

The cover plate 79 is formed with four small communicating holes 82 in the left-right direction. A gas inlet 87 is formed substantially in the center of the left and right of the chamber 83, and the gas inlet 87 and the inside of the crankcase 21 are connected by a suction tube 84.

When the engine 20 is driven, the outside air is sucked into the rear case 66 as the intake air 45 through the inlet cover 72 and the inlet pipe 70. Then, when it is sucked into the front case 67, it is filtered through the element 64. Then, the filtered intake air 45 is drawn into the engine 20 side through each intake passage 77. On the other hand, due to the negative pressure in the front case 67, the blow-by gas 85 generated in the crank case 21 is first sucked into the chamber 83, and further passes through each communication hole 82 to the front case 67.
Inhaled into. Here, the air is mixed with the intake air 45, passes through the intake passages 77 and the carburetor 27, and
Inhaled into.

In the above case, the communication holes 82 are arranged along the left-right direction in which the upstream end openings 86 of the intake passages 77 opening in the front case 67 are lined up. Also,
As shown in FIG. 1, the communication holes 82 have substantially the same diameter and are arranged at substantially equal intervals on the left and right. Further, the same as above, the communication holes 82 are laterally offset from the gas inlet 87,
In addition, they are located directly below the respective intake passages 77.

Therefore, the blow-by gas 85 sucked into the chamber 83 once collides with the inner walls of the cover plate 79 and the like in the chamber 83,
It is dispersed in the chamber 83 as a whole.

Next, the blow-by gas 85 is sucked into the front case 67 through each communication hole 82 and further flows toward each intake passage 77. As described above, each communication hole 82 is The blow-by gas 85 sucked into the front case 67 through each of the communication holes 82 is arranged because the upstream end openings 86 of the intake passage 77 are arranged in a line.
Is prevented from being unbalanced in any of the intake passages 77, and is made to flow substantially uniformly toward each of the intake passages 77.

On the other hand, a drainage hole 88 is formed at the lower end of the left side portion of the front wall 74, and a notch 89 is formed in the lower portion of the cover plate 79 located behind the drainage hole 88.
A drain tube 90 having one end connected to the drain hole 88 and the other end extending downward is provided, and a filter 91 is provided in the middle of the drain tube 90.

Then, the water 92 accumulated in the cleaner case 63 is drained through the notch 89, the drain hole 88, the drain tube 90, and the filter 91.

Although the above is based on the example shown in the drawings, the diameter of each communication hole 82 is made different by making the diameter of the one in the middle of the left and right smaller and the diameter of the one at both ends larger. The flow of the blow-by gas 85 may be made uniform.

[0044]

According to the present invention, a chamber for introducing blow-by gas is formed in the cleaner case, and a plurality of communication holes for communicating the inside of this chamber with the downstream side of the cleaner case are formed, whereby the cleaner case The communication holes are arranged along the direction in which the upstream end openings of the intake passages opening in the downstream side are lined up.

Therefore, the blow-by gas introduced into the chamber once collides with the inner walls of the chamber and is dispersed in the chamber as a whole.

Next, the blow-by gas is sucked into the downstream side of the cleaner case through the communication holes. As described above, the communication holes are formed along the direction in which the upstream end openings of the intake passages are arranged. Since the blow-by gas sucked into the downstream side of the cleaner case through each of the communication holes is not distributed to any of the intake passages, the blow-by gas is evenly distributed toward each of the intake passages. Shed

Therefore, since the blow-by gas sucked into the cleaner case flows into the intake passage toward each cylinder substantially evenly, the air-fuel ratios between the cylinders are made equal to each other.

[Brief description of drawings]

FIG. 1 is a view taken along the line 1-1 of FIG.

FIG. 2 is an overall side view of the motorcycle.

FIG. 3 is an overall side surface partial cross-sectional view of the air cleaner.

FIG. 4 is an overall front view of an air cleaner.

FIG. 5 is an overall plan view of an air cleaner.

FIG. 6 is an overall rear view of the air cleaner.

7 is a view taken along line 7-7 of FIG.

[Explanation of symbols]

 1 Motorcycle 20 Engine 22 Cylinder 27 Vaporizer 28 Air Cleaner 45 Intake Air 63 Cleaner Case 64 Element 66 Rear Case (Upstream of Cleaner Case) 67 Front Case (Downstream of Cleaner Case) 77 Intake Passage 82 Communication Hole 83 Chamber 85 Blow-by gas 86 opening

Claims (1)

[Claims] 1. An air cleaner for intake air which is shared by a plurality of cylinders, and a cleaner case which forms an outer shell of the air cleaner, and an element which is provided in the cleaner case between above and downstream sides of the intake air. A blow-by of a multi-cylinder engine, which is configured by In the gas recirculation device, a chamber for introducing the blow-by gas is formed in the cleaner case, and a plurality of communication holes are formed for communicating the inside of the chamber with the downstream side of the cleaner case. The communication holes are arranged along the direction in which the upstream end openings of the intake passages are arranged. Blow-by gas feedback device for a multi-cylinder engine.