JPH0452465Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an intake system for an internal combustion engine, and more particularly, to an intake system for an internal combustion engine that can uniformly distribute fuel to a plurality of cylinders.

(Prior art) When a single point injection type fuel injection device or a common carburetor is used for multiple cylinders as a fuel supply system for an internal combustion engine having multiple cylinders, the Since fuel and air are mixed, it is known that if a drift occurs in the intake air flow, it will adversely affect the distribution to each cylinder.

and an upstream intake passage for guiding fresh air from the air cleaner, a fuel supply device having an intake passage extending substantially perpendicular to the upstream intake passage, and an intake manifold connected to the fuel supply device and having a plurality of branch passages. In an internal combustion engine equipped with this, drifting tends to occur due to the directivity of the intake air, especially in the upstream intake passage from the air cleaner to the fuel supply device, and it is difficult to uniformly distribute fuel to each cylinder.

Therefore, as disclosed in Japanese Utility Model Application Publication No. 62-43133, an intake chamber having a required volume is provided at the downstream end of the upstream intake passage, and the inlet and outlet of the intake chamber are oriented approximately at right angles to each other. It is conceivable to open it.

(Problem that the invention aims to solve) However, simply providing an intake chamber with such a structure still makes it difficult to eliminate the directivity of the intake air, causing uneven flow in the intake air flow and making it difficult to uniformly distribute fuel to each cylinder. difficult to do.

Figure 9 is a cross-sectional plan view of the main part of the intake system,
The figure shows a cross-sectional front view of the same main part.

91 is the engine, 92 is the intake manifold, 93
94 is an intake chamber, and 95 is a tube connected to an air cleaner.

As shown in FIGS. 9 and 11, when the inlet 96 of the intake chamber 94 is opened in the A direction, the air-fuel mixture to the first cylinder 91-1 and the second cylinder 91-2 is rich, and 3. 4th cylinder 91-3, 91-4
The mixture tends to become lean. Further, even if the inlet 96 is opened in the B direction, C direction, and D direction, variations occur in the components of the air-fuel mixture to each cylinder.

The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide an intake system for an internal combustion engine that can uniformly distribute and supply fuel to each cylinder.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes: an upstream intake passage 15 that guides fresh air from the air cleaner 7; and an intake passage extending substantially perpendicularly to the upstream intake passage 15. 19; an intake manifold 3 connected to the fuel supply device 5 and having a plurality of branch passages 13; an inlet 37 connected to the upstream intake passage 15; Connecting outlet 45
an intake chamber 9 having an inlet port 37 and an outlet port 45 of the intake chamber 9;
is an intake system for an internal combustion engine whose openings are substantially perpendicular to each other, the outlet port 45 is formed at a location offset from the imaginary extension of the axis of the inlet port 37, and within the intake chamber 9, A baffle plate 51 is provided which hits the intake air flow from the inlet 37 and causes turbulence.

(Function) The arrangement structure of the outlet 45 and the baffle plate 51 eliminate the directivity of the intake air, prevent the occurrence of drift, and uniformly distribute fuel to each cylinder.

(Embodiment) Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a plan view of the intake device, and FIG. 2 is a sectional front view of the same essential parts.

1 is a 4-cylinder engine, 3 is an intake manifold, 5
7 is a fuel supply device, 7 is an air cleaner, 9 is an intake chamber, the air cleaner 7 is disposed in front of the engine 1, and the intake manifold 3 is disposed on the side of the engine 1.

The intake manifold 3 includes a gathering portion 11 and a gathering portion 11.
It is provided with four branch paths 13 branching from.

A fuel supply device 5 is disposed on the gathering portion 11 of the intake manifold 3, an intake chamber 9 is disposed on the fuel supply device 5, and the air cleaner 7 and the intake chamber 9 are connected by a tube 15.

The fuel supply device 5 is of a fuel injection type, and the throttle body 17 of the fuel supply device 5 has an intake passage 19 extending in a direction perpendicular to the direction in which the tube 15 extends.

In the throttle body 17, a main injector 23 is installed upstream of the throttle part 21 of the intake passage 19, and a throttle valve 25 and a secondary injector 27 that operate at high speed are installed downstream of the throttle part 21 of the intake passage 19. This is an atomization adjustment valve that is opened and closed by a pressure actuator 31.

The intake chamber 9 is composed of a case 33 and a lid 35.

FIG. 3 is a plan view of the case, and FIGS. 4 and 5 are sectional views taken along lines - and - in FIG. 3.

The case 33 includes a cylindrical body 37 defining an inlet,
An open recess 39 is formed at the top.

The recess 39 includes a substantially cylindrical cylindrical portion 41 and a bulging portion 43 extending into the bulging cylinder 37 in a tangential direction of the cylindrical portion 41 .

The outlet 45 is connected to the bottom wall 47 of the cylindrical body 3 on the cylindrical part 41 side.
It opens at a location offset from the axis of 7.

A convex portion 55 is formed on the bottom wall 47 on the side of the cylindrical portion 41 on an extension of the axis of the cylindrical body 37 .

A baffle plate 5 is installed near the bulge 43 of the cylindrical portion 41 so as to divide the space into a space on the side of the cylinder 37 and a space on the side of the outlet 45.
Place 1.

The baffle plate 51 connects the middle part to the bottom wall 47 with screws 53.
, and both ends thereof are fitted into the grooves 59 of the peripheral wall 57 of the recess 39 .

The baffle plate 51 is arranged substantially orthogonally to the axis of the cylinder 37, as shown in a plan view in FIG. 6, and in FIGS. 7 and 8 by the arrows in FIG. It has a first plate part 61 facing the projection plane of the body 37, and a second plate part 63 arranged in a direction intersecting the axis of the cylinder body 37 and located outside the projection plane of the cylinder body 37. Approximately V-shaped.

The lower edge of the first plate portion 61, the bottom wall 47, and the recess 39
the peripheral wall 57 of the convex portion 55, the front surface 55A of the convex portion 55,
A space portion 67 is defined by the front standing wall 65 of the second plate portion 63, and the lower edge of the second plate portion 63, the bottom wall 47, and the recessed portion 3
A space 71 is defined by the peripheral wall 57 of 9 and the front standing wall 69 of the convex part 55, and the upper edge of the baffle plate 51 and the front standing wall 69 of the convex part 55
5 and the peripheral wall 57 of the recess 39 define a space 73.

Then, the space on the side of the cylinder 37 and the space on the side of the outlet port 45 are communicated with each other through the spaces 67, 71, 73,
The first plate part 61 and the second plate part 63 are configured so as to collide with the vertically intermediate portion of the intake air flow from the air intake valve 7.

The space part 71 is formed larger than the space part 67, and the sum of the space part 71 and the space part 73B above the second plate part 63 is divided into the space part 73A above the space part 67 and the first plate part 61. form larger than the sum of

In addition, in order to efficiently remove the directivity of the intake air flow, the outer edge of the lower edge of the first plate portion 61 is provided with an edge that hits the intake air flow along the outer wall 75 of the cylinder 37 where the flow velocity is considered to be high. 77 is formed into a bulge. Furthermore, for the same reason, a convex portion 81 that protrudes upward is formed on the bottom wall 47 near the peripheral wall 57, and a convex portion 8 with a larger protrusion amount than the convex portion 81 is formed downstream of the convex portion 81 in the intake air flow.
3 is formed.

The cylindrical body 37 is connected to the end of the tube 15 and has an outlet port 4.
5 is connected to an intake passage 19 of the fuel supply device 5.

Next, the effect will be explained.

When the engine 1 is started, fresh air flows into the intake chamber 9 from the cylinder 37 via the air cleaner 7 and the tube 15.

A part of the fresh air from the cylinder end 37 is then transferred to the first plate part 6.
Part of the fresh air that hits the second plate 63 and is disturbed by the first plate 61 hits the second plate 63 and is further disturbed, passing through the spaces 67, 71, 73 and flowing into the bulge. 43
The fuel reaches the cylindrical portion 41 side, has its directivity removed, and is fed into the fuel supply device 5 from the outlet 45 without causing drift.

Therefore, according to this embodiment, the directivity of the intake air in the intake path from the air cleaner 7 to the fuel injection device 5 can be eliminated, uneven flow can be prevented, and fuel can be evenly distributed to each cylinder.

Furthermore, in the embodiment, the sum of the space portion 71 and the space portion 73B above the second plate portion 63 is formed to be larger than the sum of the space portion 67 and the space portion 73A above the first plate portion 61. The amount of intake air flowing into the cylindrical portion 41 from the axial direction of the cylindrical body 37 is equal to the amount of intake air flowing into the cylindrical portion 41 from the direction intersecting the axial center of the cylindrical body 37, or the amount of intake air flowing from the axial direction of the cylindrical body 37 The amount of intake air flowing from the direction intersecting the axis of the cylindrical body 37 can be larger than the amount of intake air, the directivity of the intake air can be removed by the baffle plate 51 more efficiently, and the occurrence of drift can be effectively prevented.

In the embodiment, the baffle plate 51 is divided into a portion 61 facing the projection surface of the introduction port and a portion 6 located outside the projection surface.
Although the baffle plate 51 is formed into a V-shape in plan view, the location and shape of the baffle plate 51 are not limited to the structure of the embodiment and may be arbitrary.

Furthermore, the baffle plate 51 is not limited to being formed of a plate as the term suggests, but may be of any type as long as it hits the intake air flow and causes disturbance.

(Effects of the invention) As is clear from the above explanation, according to the invention, in an internal combustion engine having multiple cylinders, the directivity of the intake air flow in the intake passage is removed, the drift is prevented, and the flow is directed to each cylinder. can achieve uniform fuel distribution.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the intake device, FIG. 2 is a cross-sectional front view of the same essential parts, FIG. 3 is a plan view of the case, and FIGS. 4 and 5 are sectional views taken along lines - and - in FIG. Figure 6 is a plan view of the baffle plate, Figures 7 and 8 are the
9 is a sectional plan view of the main part of a conventional intake system, FIG. 10 is a sectional front view of the main part, and FIG. 11 shows the direction of intake air flow and the mixture components of each cylinder. This is a chart showing the relationship between In the figure, 1 is the engine, 3 is the intake manifold, and 5
7 is a fuel supply device, 7 is an air cleaner, 9 is an intake chamber, 37 is an inlet, 45 is an outlet, and 51 is a baffle plate.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) An upstream intake passage that guides fresh air from the air cleaner, a fuel supply device having an intake passage extending substantially perpendicular to the upstream intake passage, and a connection to the fuel supply device. an intake manifold having a plurality of branch passages; an intake chamber having an inlet connected to an upstream intake passage; and an outlet connected to an intake passage of a fuel supply device; In an intake system for an internal combustion engine in which the outlets are opened in directions substantially perpendicular to each other, the outlet is formed at a location offset from an imaginary extension of the axis of the inlet, and the inlet is located within the intake chamber. An intake system for an internal combustion engine, characterized in that it is provided with a baffle plate that impinges on and causes turbulence in the intake air flow flowing from the engine. (2) The baffle plate has a baffle plate portion 61 that is substantially perpendicular to the imaginary extension of the axis of the inlet and faces the projection plane of the inlet, and a baffle plate portion 61 that is outside the projection plane of the inlet. The baffle plate portions 63 are arranged in different directions so as to divide the inside of the intake chamber into an inlet side space and an outlet side space, and the baffle plate portions 63 are located outside the projection plane of the inlet.
The space portion that communicates the inlet side space and the outlet side space where is located communicates the inlet side space and the outlet side space where the baffle plate portion 61 facing the projection plane of the inlet is located. The intake device for an internal combustion engine according to claim 1, wherein the air intake device is larger than the space portion of the utility model.