JP2003083184A - Intake device for multi-cylinder internal combustion engine - Google Patents

Abstract

(57) [Summary] [Problem] To provide an intake manifold having a divided structure in which the intake manifold is reduced in weight while ensuring airtightness at a divided surface in an intake passage and is less likely to be restricted by the shape of the intake passage. Provided is an intake device for a multi-cylinder internal combustion engine. SOLUTION: An intake manifold of an intake device for a multi-cylinder internal combustion engine includes a vertically divided lower outer member 31 and an upper outer member 32, and a vertically divided lower inner member 41,
It is composed of an intermediate inner member 43 and an upper inner member. In the intake passages 21 juxtaposed in the axial direction of the crankshaft, a division surface V along the intake passages 21 of the upper outer member 32 and the upper inner member 42 is formed by the upper outer member 32 and the upper inner member Upper outer member 32 of 42
It is constituted by a mating surface at a fitting portion H6 having a single stepped portion T6 formed only at the center, and crosses the center line N of the intake passage 21 when viewed from the axial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for a multi-cylinder internal combustion engine, and more particularly to an intake manifold which is composed of divided components and each intake passage has a division surface along the intake passage. Regarding the intake device.

[0002]

2. Description of the Related Art Conventionally, as this type of intake device, one disclosed in Japanese Patent Application Laid-Open No. 8-4607 is known.
In this intake manifold of an internal combustion engine, a surge tank is formed by an intermediate part provided between an upper part and a lower part, and a plurality of intake pipe passages communicating with the surge tank are formed by the upper part and the intermediate part. . The upper part and the intermediate part are divided along the center line of the intake pipe passage, and the dividing surfaces formed in steps on the partition walls of the upper part and the intermediate part are fitted to each other to prevent intake air leakage from the dividing surface. Is suppressed. Further, with respect to the partition wall located in the center, the concave dividing surface formed on the partition wall of the upper part and the convex dividing surface formed on the partition wall of the intermediate part are fitted.

[0003]

By the way, in the above-mentioned prior art, at the fitting portions of the upper part and the intermediate part, the dividing surfaces of the upper part and the intermediate part are each formed in a stepped shape, or a plurality of stepped parts are formed. Since it is formed in a concave shape or a convex shape, the passage walls (respective partition walls) in which the fitting parts of both parts are formed are the intake walls over the entire length of the center line and the entire width of the partition wall in the vertical direction. There was a problem that the intake manifold became heavier than the other passage walls of the pipe passage (that is, the wall thickness became thicker), the waste meat increased, and the intake manifold became heavy. Further, when viewed from the axial direction, since the dividing surface overlaps the entire center line, the intake pipe passages that are adjacent in the axial direction are formed with a relatively large deviation in the left-right direction, particularly at the intake port side end of the internal combustion engine. In the intake manifold described above, the center lines of the adjacent intake pipe passages are also relatively displaced from each other, which may make it difficult to manufacture the intake manifold.

The present invention has been made in view of such circumstances, and the inventions according to claims 1 to 4 are:
An air intake system for a multi-cylinder internal combustion engine that includes an intake manifold that has a divided structure in which the air intake manifold is lightweight while ensuring the airtightness on the split surface in the intake passage, and is not easily restricted by the shape of the intake passage. The purpose is to provide. The invention according to claim 3 is intended to further improve the assembling property of the intake manifold having the divided structure, and the invention according to claim 4 further facilitates formation of the positioning portion and intake pressure. It is an object of the present invention to suppress the deterioration of airtightness at the fitting portion due to the action of.

[0005]

According to the invention described in claim 1, the intake manifold having a plurality of intake passages arranged in parallel in the axial direction of the crankshaft is composed of divided constituent members. In the intake system for a multi-cylinder internal combustion engine, the constituent members include a first outer member and a second outer member that are vertically divided, and an inner member that is arranged inside the first and second outer members. , The plurality of intake passages are formed by at least the first outer member and the inner member, and the dividing surfaces of the first outer member and the inner member in each of the intake passages along the intake passage are mutually It is constituted by a mating surface at a fitting portion having a single step portion formed on only one of the first outer member and the inner member to be fitted, and in addition, from the axial direction. When in an intake system for a multi-cylinder internal combustion engine which crosses the center line of the intake passage.

According to the invention described in claim 1, the following effects are exhibited. That is, in each of the plurality of intake passages arranged side by side in the axial direction, the dividing surface along the intake passage is
Since the first outer member and the inner member are configured by the mating surface of the fitting portion having the stepped portion, the contact area of both members at the fitting portion can be increased, and The leakage of intake air can be prevented or suppressed, and the airtightness on the split surface is ensured.

Since the fitting portion has the single step portion formed on only one of the first outer member and the inner member, the thickness of the other member without the step portion can be reduced. Therefore, as compared with a member in which a step is formed in both members to be fitted to each other, the passage wall in which the fitted portion is formed has a small amount of padding, and the intake manifold is lightweight. .

Further, when viewed from the axial direction, the dividing surface crosses the center line of the intake passage, so that the fitting portion is separated from the center line of the intake passage and the fitting portion is located in a wide range outside and inside. Since it can be provided, even in the intake manifolds axially adjacent to each other and the intake manifolds whose center lines are relatively largely displaced in the left-right direction, an intake manifold having a split surface along the intake passages of the first outer member and the inner member can be provided. An intake device for a multi-cylinder internal combustion engine that can be manufactured and that has an intake manifold having a split structure that is not easily restricted by the shape of the intake manifold can be obtained.

Further, since the fitting portion can be provided in a wide range outside and inside away from the center line of the intake passage, since the fitting portion has the step portion, the fitting portion becomes thicker than other portions. The intake manifold is provided by arranging the joint portion at a position away from the center line to reduce the thick passage wall and at the same time increase the passage wall of the intake passage formed by the member not provided with the step portion. The weight reduction of can be promoted.

According to a second aspect of the present invention, in the intake system for a multi-cylinder internal combustion engine according to the first aspect, the step portion is the first portion.
An inner portion of the dividing surface formed on the outer member and located inward of the center line when viewed from the axial direction,
The stepped portion is formed by bulging the portion having the outer surface of the first outer member outward in the axial direction.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, the following effect is exhibited. That is, the step portion formed on the first outer member is formed by bulging the portion having the outer surface of the first outer member in the axial direction to form the step portion. It is not necessary to increase the thickness of the outer member, and the stepped portion
Since it is in the portion forming the inner portion of the dividing surface, the dividing surface in the portion does not become unnecessarily large in the vertical direction, and the range in which the first outer member and the inner member overlap can be reduced. As a result, it is possible to reduce the weight of the intake manifold by reducing the useless meat on the passage wall.

According to a third aspect of the present invention, in the intake system for a multi-cylinder internal combustion engine according to the first or second aspect, the fitting portion in which the step portion is formed on the first outer member,
When viewed in the axial direction, a cross section along the axial direction has a groove shape at the outermost part of the outer portion of the dividing surface located outside the center line, with respect to the first outer member. The inner member has a positioning portion that restricts the movement of the inner member in the axial direction.

According to the invention of claim 3, in addition to the effects of the invention of the cited claim, the following effect is exhibited. That is, since the fitting portion has the concave groove-shaped positioning portion, the assembling property of the first outer member and the inner member is improved, and the positioning portion has
Since it is provided on the outermost part of the outer portion of the dividing surface located outside the center line, the passage wall that is thick because of the concave groove shape is formed even though the positioning portion has the concave groove shape. Since the inward extension can be suppressed, the increase in wall thickness due to the formation of the fitting portion is suppressed, and the intake manifold is lightened.

According to a fourth aspect of the present invention, in the intake system for a multi-cylinder internal combustion engine according to the third aspect, the step portion is formed on one side in the left-right direction from the positioning portion, and the inner member is provided with the step portion. The first step portion is in contact with one side surface in the axial direction, and the second step portion is formed on the other side in the left-right direction from the positioning portion and is in contact with the other side surface in the axial direction of the inner member. The positioning portion is formed by a portion where the first and second step portions overlap each other when viewed in the axial direction.

According to the invention of claim 4, in addition to the effect of the invention of claim 3, the following effect is exhibited. That is, since the step portion formed on the first outer member is composed of the first and second step portions extending in the left-right direction from the positioning portion, the thickness of the fitting portion can be reduced by fitting using the step portion. At the same time, the inner member as a whole will come into contact with the step on both sides in the axial direction.
Even when the intake pressure acts on the fitting portion from both sides in the axial direction, there is a portion where the inner member is pressed against the first outer member, so that the fitting portion is deformed due to the action of the intake pressure. Thus, it is possible to prevent the airtightness from degrading on the dividing surface. Further, the positioning portion can be easily formed by forming the first step portion and the second step portion in the portion overlapping in the axial direction.

In this specification, "axial direction" means the direction of the rotation axis of the crankshaft of the internal combustion engine unless otherwise specified, and "up and down" and "left and right" mean unless otherwise specified. When viewed from the axial direction of the internal combustion engine, it means "upper and lower" and "left and right" when the dividing surface of the outer member is a horizontal plane.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. Referring to FIG. 1, a multi-cylinder internal combustion engine to which an intake device of the present invention is applied is installed in a front portion of a vehicle body so that a rotation axis of a crank shaft (not shown) is oriented in the front-rear direction of the vehicle. It is an 8-cylinder internal combustion engine. The internal combustion engine includes a pair of left and right cylinder rows CL formed by eight cylinders 2 arranged side by side in the axial direction A1 (direction of the rotation axis of the crankshaft, see FIG. 2) alternately four by four. The CR has a V-shaped cylinder block 1, a pair of left and right cylinder heads 3 respectively connected to the left and right cylinder rows CL and CR, and both cylinder heads 3 are connected to each other to move between the cylinder heads 3. A pair of left and right head covers 4 that form a valve operating chamber that accommodates the valve device is provided. A pair of left and right banks B forming a V shape by the left and right cylinder rows CL, CR, the cylinder head 3 and the head cover 4.
L and BR are formed.

When the internal combustion engine is mounted on the vehicle and "upper, lower, left and right" of the vehicle is used as a reference, "upper and lower" with respect to the vehicle is the same as "upper and lower" in the specification. The "left and right" based on the vehicle is opposite to the "right and left" in the embodiments of the specification. Also, the left and right banks
The structures of BL and BR are basically the same, so in the following, the left bank BL will be mainly described and the right bank BR will be described.
Corresponding parts are designated by the same reference numerals.

A piston 5 reciprocally fitted in a cylinder hole 2a of each cylinder 2 rotatably drives the crank shaft rotatably supported by the cylinder block 1 via a connecting rod 6. The cylinder head 3 has a cylinder 2
A combustion chamber 7 formed of a recess formed at a position facing the cylinder hole 2a, and a pair of intake valve openings opening in the combustion chamber 7
An intake port 8 having 8a and an exhaust port 9 having a pair of exhaust valve ports 9a opening to the combustion chamber 7 are formed, and further driven by the valve operating device in synchronization with the crankshaft, A pair of intake valves 10 and a pair of exhaust valves 11 that open and close the intake valve openings 8a and both exhaust valve openings 9a at predetermined timings are provided.

Further, each intake port 8 is connected to the left and right banks.
In the space S formed between BL and BR, there is one opening 8b opened at the side surface of the cylinder head 3 on the space S side. The intake manifold M disposed in the space S and coupled to the cylinder head 3 has a size that suppresses the pressure fluctuation of the intake air caused by the opening and closing of the intake valve 10 while the intake air whose flow rate is controlled by the throttle valve 12 flows in. Intake collecting chamber 20 having a volume of 20 mm, and while being connected to the intake collecting chamber 20 at the upstream end,
It has eight intake passages 21 connected to the opening 8b of the intake port 8 at the downstream end. These intake passages 21 are on the left bank BL.
Left bank side intake passages connected to the intake ports 8 of
21L and four right bank side intake passages 21R connected to the intake ports 8 of the right bank BR. The left bank side intake passage 21L and the right bank side intake passage 21R are alternately arranged one by one in the axial direction A1. They are arranged side by side (see FIG. 2).

Each intake passage 21 is opened and closed by an intake control valve 24 provided in the intake passage 21 in accordance with the engine speed, so that the internal combustion engine is operated in a low speed range where the engine speed is below a predetermined value. When the engine is operated, it becomes an intake air supply passage to the corresponding intake port 8, and a long intake passage 22 set to an intake passage length that effectively exhibits the effect of inertia supercharging in the low speed rotation range, and an engine. When the internal combustion engine is operated in a high speed rotation range in which the rotation speed exceeds the predetermined value, it serves as an intake air supply passage to the corresponding intake port 8 and effectively exhibits the effect of inertia supercharging in the high speed rotation range. The short intake passage 23 is set to the passage length and has a shorter intake passage length than the long intake passage 22.

The intake collecting chamber 20 has a common collecting chamber 20C located at the center of the space S in the left-right direction and a common collecting chamber 20C.
Above, the left collecting chamber 20L and the right collecting chamber 20R are opposed to each other in the left-right direction so as to sandwich the common collecting chamber 20C. Each long intake passage 22 is connected to the common collecting chamber 20C at the upstream end and is connected to the intake port 8 at the downstream end. On the other hand, the upstream end of the short intake passage 23 provided with the intake control valve 24 that is fully closed in the low speed rotation range and fully opened in the high speed rotation range is connected to the right collecting chamber 20R in the left bank side short intake path 23. In the short intake passage 23 on the right bank side, the left collecting chamber 20L
Connected to.

Referring to FIGS. 2 and 3 together, the intake manifold M is formed by injection molding using a synthetic resin as a molding material, or by die casting using a light metal such as aluminum or magnesium or an alloy thereof as a molding material, and then divided. A main body having a multi-divided structure composed of the separated components. The main body is composed of an outer member 30 which is vertically divided, and an inner member 40 which is arranged inside the outer member 30 and vertically divided. Therefore, the intake manifold M is composed of the main body forming the main parts of the intake collecting chamber 20 and the intake passage 21, and various members described later that are connected to the main body.

The outer member 30 is vertically divided into a lower outer member 31 and an upper outer member 32, and has a horizontal dividing surface D1. The lower outer member 31 has a plurality of bolts attached to the cylinder head 3 through the gasket G1 at the left and right flanges 31f.
An outer wall 31a of the second passage P2 that is coupled by F1 (see FIG. 3) and is curved so as to be convex downward is formed, and the upper outer member 32 includes a plurality of bolts F2 on the lower outer member 31.
And a part of the outer wall 32a of the fourth passage P4 that is curved so as to be convex upward. To the upper outer member 32, a left cover 33L and a right cover 33R are coupled to the upper outer member 32 by a plurality of bolts F3 and stud bolts F4 so as to cover the left and right openings of the upper outer member 32 via seal members E1 ( (See FIG. 3),
Further, an upper cover 35 that closes an opening 34 provided at the center of the upper wall 32b of the upper outer member 32 in the left-right direction is coupled by a plurality of bolts F5 (see FIG. 3).

Referring to FIG. 2, at the central portion of the lower outer member 31 in the axial direction A1, a partition wall 31b is formed which has a predetermined width in each of the axial direction A1 and the lateral direction and which projects upward and extends in the lateral direction. The eight intake passages 21 are connected to the axial direction A1.
One side A2 (It will be "front" with respect to the vehicle.)
Four four second intake passage portion 21 ₂ and the shaft consisting of the intake passage 21 of the intake passage 21 first intake passage portion 21 ₁ made of the other side A3 (If based on the vehicle becomes "rear".) Of It is divided into two in the direction A1. Furthermore, the lower outer member 31 is connected to each intake port 8 together with an intermediate inner member 43 which will be described later.
A passage P5 is formed (see FIG. 1).

Further, the openings 36 formed between the first intake passage portion 21 at the upper outer member 32 ₁ and the second intake passage 21 ₂ is opposed in the vertical direction on the partition wall 31b, the partition wall 31b
Has a width in the axial direction A1 and a width in the left-right direction substantially equal to.
As shown in FIGS. 1 and 3, the upper outer member 32 includes
Four cylindrical left bank-side connecting portions 37L and right bank-side connecting portions 37R are integrally molded, and these connecting portions 37L and 37R are formed.
The four air funnels 38 provided with the intake control valve 24
A pair of left and right valve units 38L and 38R integrally molded with a
It is connected by a plurality of bolts F6.

The upper outer member 32 has a left collecting chamber wall 32cL and a right collecting chamber wall 3 which form a left collecting chamber 20L and a right collecting chamber 20R in cooperation with the left cover 33L and the right cover 33R, respectively.
2cR is provided, and the valve units 38L and 38R are housed in the left and right collecting chambers 30L and 32R, respectively. And the left cover 33L
Is provided with an intake inflow portion 33La for intake air to the intake manifold M, and a throttle body 13 as an intake introduction member is connected to the intake inflow portion 33La (see FIG. 1).
The intake air whose flow rate is controlled by 12 flows into the intake manifold M from the intake inflow portion 33La. In this way, the left and right covers
The 33L and 33R, the upper cover 35, and the valve units 38L and 38R are members that form the intake manifold M together with the main body.

Referring to FIGS. 1-3, the inner member 40
Is vertically divided into a lower inner member 41, an intermediate inner member 43, and an upper inner member 42, and the lower inner member 41 and the intermediate inner member 43 have a horizontal dividing surface D2.
43 and the upper inner member 42 have a horizontal dividing surface D3 that is coplanar with the horizontal dividing surface D1. The lower inner member 41 is fitted inside the lower outer member 31 to form an inner wall 41a of the second passage P2. The intermediate inner member 43 fitted to the upper end of the lower inner member 41 is fitted to the inner side of the lower outer member 31 and has the inlet portion 22a of the long intake passage 22 in cooperation with the upper inner member 42. A passage P1 and a third passage P3 that connects the second passage P2 and the fourth passage P4 are formed. The upper inner member 42 joined to the intermediate inner member 43 is fitted inside the upper outer member 32, and the inner wall 42a of the fourth passage P4.
And a part of the outer wall 42b of the fourth passage P4.

Then, as shown in FIGS. 2 and 3, the lower inner member 41 has end walls 41b, 4 at both ends in the axial direction A1.
1c; first part 41 ₁ of one side A2 having 41d, 41e and the other side
It is divided into the second part 41 _{2 of} A3. Of these, both end walls 41b, 41e in the axial direction A1 of the first and second portions 41 ₁ , 41 ₂ ; 41
d and 41c are respectively on a single step T1 of the fitting portion H1 formed on both end walls 31d and 31e of the lower outer member 31 in the axial direction A1 and in the axial direction A1 of the partition wall 31b. Both end walls 31b
Single step T2 of the mating part H2 formed on 1 and 31b2 respectively
Is fitted to. Here, the step portions T1; T2 are formed by the bulging portions formed by bulging the end walls 31d, 31e; 31b1, 31b2 having a substantially uniform thickness outwardly in the axial direction A1. It The first and second parts 41 ₁ and 41 ₂ having the same specifications have inner walls, respectively.
Three plate-shaped partition walls 41f extending from 41a toward the lower outer member 31 are provided so as to project, and the end portions 41f1 of these partition walls 41f are formed in an arc shape on the inner surface of the outer wall 31a of the lower outer member 31, Second by four each formed by being fitted into the fitting portion H3 having the groove K3 whose cross section in the axial direction A1 is concave.
The passages P2 are arranged side by side in the axial direction A1.

The intermediate inner member 43 is provided on the first side A2.
1 part 43₁And the second part 43 of the other side A3 _TwoDivided into two and
Those first and second parts 43 of one specification₁， 43_TwoIs left-right
The lower wall 43a of the common collecting chamber 20C is formed at the center of the. That
First part 43₁Has an end wall 43b on one side A2 and the other on the other side.
An opening 43c that opens in the axial direction A1 is provided on the side A3.
In the second part 43_TwoTo the axial direction A1 on one side A2
An opening 43d is provided, and an end wall 43e is provided on the other side A3. this
Therefore, the first and second parts 43₁， 43_TwoIs the maximum in the axial direction A1.
The large distance is approximately equal to the predetermined width in the axial direction A1 of the partition wall 31b.
And a width 44 in the left-right direction is almost equal.
Be done. The first and second portions 43 of the intermediate inner member 43₁，
43_TwoIs the first wall of the lower inner member 41 at the end walls 43b and 43e.
2 part 41₁, 41_TwoRespectively coupled with bolts F7
In this state, the lower outer member 31 is fitted. Also, the lower out
The lower inner member 41 and the intermediate inner member 43 are
When mated, lower outer member 31 is
The pair of left and right projecting portions 31c at the ends of the intermediate inner member 43
1, the second part 43₁， 43_TwoThe corresponding protrusion 43f of the bolt F
8 (see FIGS. 2 and 3).

The upper inner member 42 is the first portion of the one side A2.
42 ₁ and the second portion 42 ₂ of the other side A3, the first and second portions 42 ₁ and 42 ₂ having the same specifications are jointed with a part of the inner wall 42a in the left-right central portion. In the common meeting room 20C upper wall 4
Form 2f. The end wall 42b and the second member 42 _{and second} end wall 42e of the other side A3 of the first portion 42 ₁ of the one side A2 is both end walls 32d, 3 respectively in the axial direction A1 of the upper outer member 32
Fitted in a single step T4 of the fitting portion H4 formed in 2e, the end wall 42c on the other side A3 of the first portion 42 ₁ and the second member 42 ₂
The end wall 42d of the one side A2 is the upper outer member 32, respectively.
Fitting part H5 formed on both edges of the opening 36 of the opening 36 in the axial direction A1
Is fitted to a single step T5. Here, the step T4 has an outer surface 32S exposed to the outside of the intake passage 21 of the upper outer member 32.
And end walls 32d and 32e having a substantially uniform thickness are formed by bulging portions formed by bulging outward in a stepwise manner in the axial direction A1.

After that, the pair of left and right protrusions 32f at both ends of the upper outer member 32 in the axial direction A1 correspond to the corresponding protrusions 42g of the first and second portions 42 ₁ , 42 ₂ of the upper inner member 42. is coupled by a bolt F8 (Fig. 2, is shown only the first portion 42 ₁ in Figure 3.). As a result, the end walls 42c and 42d are located with a gap 45 in the axial direction A1 substantially equal to the predetermined width of the partition wall 31b in the axial direction A1 and a width in the left-right direction being substantially equal to each other. Immediately below the end walls 42c, 42d, there is a gap 46 in which the maximum distance in the axial direction A1 is substantially equal to the predetermined width in the axial direction A1 of the partition wall 31b, and the width in the left-right direction is also substantially equal. Openings 42h and 42k that open in the axial direction A1 are provided, respectively.

Furthermore, the first upper inner member 42, the second portion 42 _1, 42 _2, three plate-shaped partition wall 42m extending from the inside wall 42a to the upper outer member 32 is provided projecting The front end portion 42m1 of the partition wall 42m extends from the outer wall 32a of the upper outer member 32 to the inner wall 4 of the upper inner member 42.
Each of the four fourth passages P4 formed by being fitted into the positioning portion T7 of the fitting portion H6 described later of the partition wall 32m (see FIGS. 1 and 3) extending toward 2a has the axial direction A1. Will be installed side by side. Here, the outer walls 31a, 32a, the inner walls 41a, 42a, the end walls 31d, 31e, 31b1, 31b2, 32d, 32e, 42c, 42d and the partition walls 32m, 41f, 42m are passage walls of the intake passage. Configure
The end walls 31d, 31e, 31b1, 31b2, 32d, 32e, 42c, 42d and the partition walls 32m, 41f, 42m form a passage wall in which the fitting portions H1 to H5 are formed.

As described above, the outer member is divided into the upper and lower parts.
30 and inner member 40 make each long intake passage 22 first
To fifth passages P1 to P5, each short intake passage 23 is formed from the air funnel 38a, the connecting portions 37L and 37R, part of the fourth passage P4 and the fifth passage P5, and the common collecting chamber 20C.
Are formed by the partition wall 31b, the lower wall 43a, the upper wall 42f, and the gaps 44 and 46. Therefore, the long intake passage 22 and the short intake passage 23 share a part of the fourth passage P4 and the fifth passage P5, and the short intake passage 23 is connected to the connecting portions 37L, 3L.
It joins the long intake passage 22 on the intake downstream side of the 7R and is located above the intake passage 21. Furthermore, the long intake passage 22 having the second passage P2 that is convex downward and the fourth passage P4 that is convex upward is curved from the common collecting chamber 20C to the intake port 8 while the common collecting chamber 20C is centrally located. And extends in a spiral shape to cover the common collecting chamber 20C so as to surround the entire circumference, and the short intake passage 23 includes the left and right collecting chambers 20L, 20L.
It is located between 0R and covers the upper part of the common collecting chamber 20C.

As shown in FIGS. 1 and 4, in each intake passage 21, the fourth and fifth passages P4, P5 are located outside the first passage P1, and the intake passage 21L on the left bank side is provided. Intake port side end portion P4a of the fourth passage P4 that is the left end portion and the fifth passage P
5 is a fourth passage P4 which is the right end portion of the left bank side intake passage 21L
Is located farther from the center plane CP in the left-right direction of the intake manifold M than the third passage-side end portion P4b and the third passage P3, and, conversely, is the right end portion of the right bank-side intake passage 21R. Intake port side end P4a of the fourth passage P4a and the fifth passage P5
Is the fourth passage P4 which is the left end portion of the intake passage 21R on the right bank side.
Is located farther in the left-right direction from the center plane CP of the intake manifold M than the third passage side end portion P4b and the third passage P3.
Therefore, the intake passages 21 on the left bank side adjacent in the axial direction A1
In the L and right bank-side intake passages 21R, the intake passages 21 are arranged laterally offset at the left and right ends of the intake passages 21L and 21R.

Further, in this embodiment, at the left end portion of the intake manifold M, the intake port side end portion P4a of the fourth passage P4 of the left bank side intake passage 21L is the right bank side intake passage 21R.
Is located to the left of the center line N of the fourth passage P4 of the long intake passage 22 at the third passage-side end P4b of the fourth passage P4, which is the left end of the intake passage M, and to the right at the right end of the intake manifold M. Intake port side end P4a of the fourth passage P4 of the bank side intake passage 21R
Is the fourth passage P4 which is the right end of the left bank side intake passage 21L.
Is located to the right of the center line N at the third passage-side end portion P4b, and on the plane including the horizontal dividing surface D1, the intake port-side end portion of the fourth passage P4 of the left bank-side intake passage 21L. P4a hardly overlaps the third passage side end portion P4b of the fourth passage P4 of the right bank side intake passage 21R, and the intake port side end portion P4a of the fourth passage P4 of the right bank side intake passage 21R is left. Bank side intake passage 21L
The fourth passage P4 does not substantially overlap the third passage-side end portion P4b.

Then, between the left and right collecting chambers 20L and 20R, and between the outer wall 32a and the upper wall 32b and the upper cover 35,
A first communication passage 51 is formed that always connects the left and right collecting chambers 20L and 20R. The first communication passage 51 is located immediately above the short intake passage 23, that is, with the outer wall of the fourth passage P4 forming the long intake passage 22 and the short intake passage 23 arranged side by side in the axial direction A1 as a passage wall. , The passage wall, the upper wall 32b, the upper cover 35, and the axial direction A
The short intake passages 23Le and 23Re (see FIG. 2) located at both ends in 1 are formed by end walls 32n (see FIGS. 2 and 3) extending from the outer wall 32a to the upper wall 32b. As a result, the first communication passage 51 is formed so as to cover a part of the intake passage 21 located at both ends in the axial direction A1 in the axial direction A1.

In the first communication passage 51, the second communication passage 52 in the vertical direction formed by the gap 45 divides the fourth passage P4 into two in the axial direction A1. The opening 36 communicates with the central portion. This allows the intake air from the left and right collecting chambers 20L and 20R to be quickly supplied to the common collecting chamber 20C when intake is performed through the long intake passage 22 in the low speed rotating region, and also in the high speed rotating region. When the intake is performed through the short intake passage 23, the first communication passage 51 and the second communication passage 51 are connected so that the intake air is quickly distributed from the left collecting chamber 20L to which the throttle body 13 is connected to the right collecting chamber 20R. The passage area of the passage 52 is set.

Further, referring to FIG. 3, the upper outer member
A bracket 60, to which two diaphragm type actuators for driving the intake control valve 24 are attached, is connected to 32 via a gasket G2, and the operating shafts of both actuators are connected to the four intake control valves 24 on the left and right respectively. ,
The intake control valves 24 are simultaneously opened and closed.

Further, referring to FIG. 1, a fuel injection valve 61 for injecting fuel toward the intake port 8 is mounted on the flange 31f of the lower outer member 31, and is located immediately above the fuel injection valve 61. A delivery pipe 62 that supplies fuel to the fuel injection valve 61 extends in the axial direction A1.

By the way, as shown in FIGS.
In the fourth passage P4 of each intake passage 21 formed by the upper outer member 32 and the upper inner member 42, the dividing surface V along the fourth passage P4 of the upper outer member 32 and the upper inner member 42 is the upper outer member. The partition wall 32m of 32 and the partition wall 42m of the upper inner member 42 are configured to mate with each other at a fitting portion H6.
Therefore, in the division plane V, the partition walls 32m, 4
Since the two meters are in surface contact with each other, leakage of intake air is suppressed and airtightness is secured.

Referring to FIGS. 4 to 8, the fitting portion H6 is a step portion T6 (FIGS. 4 to 7) formed at the tip portion 32m1 of the partition wall 32m.
And positioning section T7 (see FIGS. 4 and 8) and step section
It is fitted with T6 and the positioning part T7, and is constituted by a tip part 42m1 of a plate-shaped partition wall 42m having a flat surface without a step. Of these, the step T6, when viewed from the axial direction A1,
As shown in FIG. 4, a first step T6a (see also FIG. 5) including a single step located on the right side, which is one side in the left-right direction from the positioning section T7, and positioning. The second step portion T6b (see also FIG. 6) includes a single step portion located on the left side, which is the other side in the left-right direction from the portion T7. In this embodiment, the positioning portion T7 located on the center plane CP in the left-right direction of the intake manifold M has the first and second step portions T6 when viewed in the axial direction A1, as shown in FIG.
It is formed in the part where a and T6b overlap. In this overlapping portion, the first step T6a and the second step T6b serve as both side walls in the axial direction A1, and the cross section along the axial direction A1 has a groove shape,
The amount of protrusion of the positioning portion T7 from the outer wall 32a (the vertical width of the side wall) is made smaller than the amount of protrusion of the other portions of the first and second stepped portions T6a, T6b. On the other hand, within a range in which the upper inner member 42 can be restricted from moving in the axial direction A1, it is set to a value as small as possible,
The increase in the wall thickness of the partition wall 32m due to the groove shape is suppressed.

Further, the position of the positioning portion T7 is determined from the viewpoint of the effectiveness of the positioning function in consideration of the symmetry of the intake manifold M and the shape of the partition wall 42m of the upper inner member 42, and the increase in the wall thickness of the partition wall 32m. From the viewpoint of suppression, it is set at a position close to the outer wall 32a, and in this embodiment, it is provided on the outermost V1a of the outer portion V1 of the dividing surface V, which will be described later, on the center plane CP.

As shown in FIG. 4, the dividing surface V crosses the center line N when viewed from the axial direction A1.
With the intersection V0 where the dividing plane V intersects the center line N as a boundary, the dividing plane V is located outside the center line N and is located outside the center line N, and the outside portion V1 and the center line N. And an inner portion V2 located further inward than the center line N.

Explaining the dividing surface V further, as described above, the left bank side intake passage 21L and the right bank side intake passage 21R are alternately arranged side by side in the axial direction A1, and further, in the axial direction A1.
At the left and right ends of the left bank-side intake passage 21L and the right bank-side intake passage 21R that are adjacent to each other, the intake passages 21 are arranged to be displaced in the left-right direction. Therefore, as shown in FIG.
In the left bank side intake passage 21L and the right bank side intake passage 21R, which are the two intake passages 21 adjacent to each other in the axial direction A1, regarding the fourth passage P4, the central portion including the center plane CP of the intake manifold M is , When viewed from the axial direction A1, the 4th
Overlapping portions 71 (hatched portions indicated by alternate long and short dash lines) where the passages P4 overlap with each other are formed, and the left and right ends of the fourth passages P4 of both the intake passages 21L and 21R, when viewed from the axial direction A1, have the fourth passages P4. A non-overlapping portion 72 (hatched portion of the chain double-dashed line) that does not overlap is formed.

Looking at the relationship between the dividing surface V (solid line hatching portion) and the overlapping portion 71 and the non-overlapping portion 72, most of the outer portion V1 is included in the overlapping portion 71 and the inner portion V2 of the outer portion V1 is included. Most are contained in the non-polymerized portion 72. In the overlapping portion 71, as shown in FIGS. 5 and 6, the first and second step portions T6
The part of the partition wall 32m, which is the passage wall where a and T6b are formed,
It has a thick portion 32m2 that is thicker (that is, thicker) than the other passage wall of the upper outer member 32 (for example, the outer wall 32a) and the partition wall 42m of the upper inner member 42.
On the other hand, in the non-polymerized portion 72, as shown in FIG.
The part 32m3 of the partition wall 32m (also the passage wall) where the step T6b is formed is the same as the partition wall 32m of the upper outer member 32.
1 is a portion having an outer surface 32S exposed to the outside of 1, and in the portion 32m3 of the second step T6b, the upper outer member 32 has an axial direction A
Stepwise bulge 32m4 formed by bulging outward in step 1
Is formed. Therefore, the second step in the non-overlapped portion 72
The T6b is formed with substantially the same wall thickness as the other passage walls of the upper outer member 32 and the partition wall 42m of the upper inner member 42 without increasing the wall thickness of the partition wall 32m. And the first step T
As shown in FIG. 5, 6a contacts a side surface 42m2 on the left bank side intake passage 21L side, which is one side surface of the partition wall 42m in the axial direction A1, and the second step T6b is shown in FIG. As described above, the right bank side intake passage 2 which is the other side surface of the partition wall 42m in the axial direction A1
It contacts the side surface 42m3 on the 1R side.

Incidentally, the description so far has been made on the cross section when the left bank side intake passage 21L is on the front side and the right bank side intake passage 21R is the rear side. Therefore, in FIG. 4, most of the first step portion T6a is shown. It is located on the right side of the center plane CP, and most of the second step T6b and the inner part V2 are located on the left side of the center plane CP.
Right bank intake passage 21R is in front, left bank intake passage 21L
In the cross-section when the inside is at the back, most of the first step T6a is located on the left side of the center plane CP, and most of the second step T6b and the inner part V2 are on the right side of the center plane CP. Will be located in.

Next, the operation and effect of the embodiment configured as described above will be described. When the internal combustion engine is operated, the intake air whose flow rate is controlled by the throttle valve 12 flows from the intake air intake inflow portion 33La to the left collecting chamber 20L and the first communication passage 51.
Through the right collecting chamber 20R and further through the second communication passage 52 into the common collecting chamber 20C. When the internal combustion engine is operating in the low speed rotation range, the intake control valve
Since 24 is fully closed, the intake air that has flowed into the intake collecting chamber 20 reaches the respective intake ports 8 from the common collecting chamber 20C through the long intake passage 22 and is further supplied with fuel from the fuel injection valve 61. It is also supplied to the combustion chamber 7. At this time, since the intake air is supplied to the combustion chamber 7 through the long intake passage 22 having the intake passage length that effectively obtains the effect of inertial supercharging in this engine operating range, the intake air is highly efficient under high volume efficiency. Torque is obtained. Further, when the internal combustion engine is operating in the high speed rotation range, the intake control valve 24 is in a fully open state, so the intake air that has flowed into the intake collecting chamber 20 corresponds to the collecting chambers from the left and right collecting chambers. The fuel is supplied to the combustion chamber 7 together with the fuel supplied from the fuel injection valve 61, reaching each intake port 8 through the connected short intake passage 23. Also at this time, since the intake air is supplied to the combustion chamber 7 through the short intake passage 23 having the intake passage length with which an effective inertia supercharging effect is obtained in this engine operating range, the intake air is highly efficient under high volume efficiency. Torque is obtained.

Then, in each of the plurality of intake passages 21 arranged in parallel in the axial direction A1, the divided surface V of the upper outer member 32 and the upper inner member 42 along the fourth passage P4 of the intake passage 21.
Is composed of the mating surface of the fitting portion H6 having the step T6 into which the upper outer member 32 and the upper inner member 42 are fitted, so that the contact area of both members 32, 42 at the fitting portion H6 is Can be increased, and the leakage of intake air from the dividing surface V can be prevented or suppressed, and the airtightness on the dividing surface V can be ensured.

Since the fitting portion H6 has the single stepped portion T6 formed only in the upper outer member 32, the wall thickness of the partition wall 42m of the upper inner member 42 in which the stepped portion is not formed can be reduced. Therefore, the partition wall which is the passage wall in which the fitting portion H6 is formed is compared with the one in which the stepped portion is formed in the upper outer member and the upper inner member that are fitted to each other.
The intake manifold M is made lighter by reducing the 32m and 42m flesh.

Moreover, when viewed from the axial direction A1, the division plane V
Crosses the center line N of the fourth passage P4 of the intake passage 21 with the intersection V0 as a boundary, so that the dividing surface V passes through the fourth passage of the intake passage 21.
Since the fitting portion H6 can be provided in a wide range outside and inside of the center line N of P4, the intake passage 21 adjacent to the axial direction A1 and the center line N thereof are relatively large in the left-right direction. For example, in the left bank-side intake passage 21L and the right bank-side intake passage 21R that are adjacent to each other in the axial direction A1, on the plane including the horizontal dividing surface D1, the intake port side of the fourth passage P4 of the left bank-side intake passage 21L The end P4a hardly overlaps the third passage side end P4b of the fourth passage P4 of the right bank side intake passage 21R, and the intake port side end P4a of the fourth passage P4 of the right bank side intake passage 21R is , 4th passage of left bank side intake passage 21L
Even in the intake manifold M that hardly overlaps the third passage side end portion P4b of P4, the intake manifold M having the dividing surface V along the fourth passage P4 between the upper outer member 32 and the upper inner member 42 is manufactured. Therefore, it is possible to obtain the intake system of the multi-cylinder internal combustion engine including the intake manifold M having the divided structure that is not easily restricted by the shape of the intake manifold M.

Furthermore, when viewed from the axial direction A1, the intake passage
In the overlapping portion 71 where the fourth passages P4 of 21 overlap with each other, the fitting portion H6 can be provided at an outer position apart from the center line N. Therefore, since the fitting portion H6 has the first step portion T6, another passage is formed. The fitting portion H6, which is thicker than the wall 32m2, is provided at a position away from the center line N to reduce the number of thick partition walls 32m, and at the same time, the upper inner member 42 having no step is provided. By increasing the number of partition walls 42m formed by, it is possible to promote the weight reduction of the intake manifold M.

At the non-overlapping portion 72, the upper outer member 32
The second stepped portion T6b formed in the step is formed by a stepped bulging portion 32m4 formed by bulging a portion 32m3 having the outer surface 32S of the upper outer member 32 stepwise in the axial direction A1. By doing so, the upper outer member 32 is formed to form the second step T6b.
Of the non-overlapping portion 72, the second step T6b is in a portion forming the inner portion V2 of the dividing surface V, and the inner portion V2 is larger than the center line N. Horizontal division plane D1
Since it is close to the plane including the above, the dividing surface V in this portion does not become unnecessarily large in the vertical direction, and the range in which the upper outer member 32 and the upper inner member 42 overlap can be reduced. The weight of the intake manifold M can be reduced by reducing the amount of mess on the partition wall 32m.

Since the fitting portion H6 has the positioning portion T7 in the shape of a groove, the assembling property of the upper inner member 42 with respect to the upper outer member 32 is improved, and the positioning portion T7 is seen in the axial direction A1. At this time, since the positioning portion T7 has a concave groove shape because it is provided on the outermost V1a of the outer portion V1 of the dividing surface V located outside the center line N, the positioning portion T7 has a concave groove shape. Since the thick wall portion 32m2 of the partition wall, which has a large wall thickness, can be suppressed from extending inward, an increase in wall thickness due to the formation of the fitting portion H6 is suppressed, and the intake manifold M is lightened. .

The step T6 formed on the upper outer member 32 is
First and second stepped portions T6 extending in the left-right direction from the positioning portion T7
It consists of a and T6b.
While the wall thickness of the fitting portion H6 is reduced by fitting using the stepped portions T6a and T6b, the partition walls 42m of the upper inner member 42 in the fitting portion H6 as a whole are on both side surfaces in the axial direction A1. 42m2, 4
Since it comes into contact with the stepped portion T6 at 2 m3, there is a portion where the partition wall 42m is pressed against the upper outer member 32 even when the intake pressure acts on the fitting portion H6 from both sides in the axial direction A1. Therefore, it is possible to prevent the airtightness of the divided surface V from being lowered due to the deformation of the fitting portion H6 due to the action of the intake pressure.
Further, the positioning portion T7 includes a first step portion T6a and a second step portion T6.
By forming 6b in the portion overlapping in the axial direction A1,
It can be easily formed.

Further, the lower inner member 41, the upper inner member 42 and the intermediate inner member 43 which constitute the inner member 40 are
First and second parts 41 ₁ , 41 ₂ ; 42 ₁ , with the same specifications, respectively
Since it is composed of 42 ₂ ; 43 ₁ and 43 ₂ , members are made common and maintenance is possible for each member, which is advantageous in terms of maintenance.

In the following, an embodiment in which a part of the configuration of the above-described embodiment is modified will be described.
In the above embodiment, each intake passage 21 is composed of a long intake passage 22 and a short intake passage 23 that are switched according to the engine speed, but each intake passage 21 is a single intake passage. It may be configured. Also, the single step T6 is not the upper outer member 32 but the upper inner member.
It may be formed only on 42.

In the above embodiment, the dividing surface V relates to the fourth passage P4 formed by the upper outer member 32 and the upper inner member 42, but the intake passage formed by the lower outer member and the lower inner member. It may be a divided surface V formed along the.

The internal combustion engine may be a V-type internal combustion engine other than the 8-cylinder engine, or may be a multi-cylinder internal combustion engine other than the V-type internal combustion engine.

[Brief description of drawings]

1 is a cross-sectional view of an intake device for a V-type internal combustion engine that is an embodiment of the present invention, and is a cross-sectional view taken along line I-I of FIG.

FIG. 2 is a sectional view taken along line II-II of FIG.

3 is a schematic exploded perspective view of an intake manifold of the intake device of FIG.

FIG. 4 is a view similar to FIG. 1 seen from the axial direction, and is a view for explaining adjacent intake passages.

5 is a sectional view taken along line VV of FIGS. 1 and 4. FIG.

6 is a sectional view taken along line VI-VI in FIGS. 1 and 4. FIG.

FIG. 7 is a sectional view taken along line VII-VII in FIGS. 1 and 4.

FIG. 8 is an enlarged view of a portion VIII in FIG.

[Explanation of symbols]

1 ... Cylinder block, 2 ... Cylinder, 3 ... Cylinder head, 4 ... Head cover, 5 ... Piston, 6 ... Connecting rod, 7 ... Combustion chamber, 8 ... Intake port, 9 ... Exhaust port, 10
... intake valve, 11 ... exhaust valve, 12 ... throttle valve, 13 ... throttle body, 20 ... intake collecting chamber, 20C ... common collecting chamber, 20L ...
Left collecting chamber, 20R ... Right collecting chamber, 21 ... Intake passage, 22 ... Long intake passage, 23 ... Short intake passage, 24 ... Intake control valve, 30 ... Outer member, 31 ... Lower outer member, 32 ... Upper outer member , 32
m4 ... bulge, 33L, 33R ... cover, 32S ... outer surface, 34 ... opening, 35 ... cover, 36 ... opening, 37L, 37R ... connection, 38
L, 38R ... valve unit, 40 ... inner member, 41 ... lower inner member, 42 ... upper inner member, 43 ... intermediate inner member, 44,
45, 46 ... Gap, 51, 52 ... Communication passage, 60 ... Bracket, 61 ...
Fuel injection valve, 62 ... Delivery pipe 71 ... Overlapped portion, 72 ... Non-overlapped portion, CL, CR ... Cylinder row, BL, BR ... Bank, A1 ...
Axial direction, A2 ... One side, A3 ... Other side, S ... Space, M ... Intake manifold, D1 to D3 ... Horizontal dividing surface, G1, G2 ... Gasket, F1 to F8 ... Bolt, H1 to H6 ... Fitting part, T1, T2, T4, T
5, T6 ... Step, T6a ... First step, T6b ... Second step, T7 ... Positioning section, K3 ... Groove, P1 to P5 ... Passage, E1 ... Seal member, CP
… Center plane, N… Center line, V… Division plane, V1… Outer part, V1
a ... outermost part, V2 ... inner part.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02M 35/10 301P 301R (72) Inventor Nobuyuki Imai 1-4-1 Chuo Wako, Saitama Prefecture Stock Company Honda Technical Research Institute (72) Inventor Kenji Yokotsuka 22-30 Honmachi, Wako City, Saitama Prefecture F-term in Mets Co., Ltd. (reference) 3G031 AA24 AA28 AB07 AB08 AC01 AC03 AC04 BA07 BA14 BA15 BB05 DA03 DA05 DA32 DA36 EA02 FA03 GA05 GA13 HA01 HA02 HA04 HA10 HA11

Claims (4)

[Claims] 1. An intake system for a multi-cylinder internal combustion engine, wherein an intake manifold having a plurality of intake passages arranged in parallel in the axial direction of a crankshaft is composed of divided constituent members. A first outer member and a second outer member that are divided, and an inner member that is arranged inside the first and second outer members, wherein the plurality of intake passages include at least the first outer member and the first outer member. An inner member, and the first member in each of the intake passages.
A split surface of the outer member and the inner member along the intake passage has a single step formed on only one of the first outer member and the inner member that are fitted to each other. An intake device for a multi-cylinder internal combustion engine, wherein the intake device is configured by a mating surface of a portion and crosses a center line of the intake passage when viewed from the axial direction. 2. The step portion is formed in the first outer member, and is an inner portion of the dividing surface located inward of the center line when viewed from the axial direction, and the step portion is The portion having the outer surface of the first outer member is formed by bulging outward in the axial direction.
An intake system for a multi-cylinder internal combustion engine as described above. 3. The fitting portion, in which the step portion is formed in the first outer member, is located outside the center line when viewed from the axial direction. The outermost portion has a positioning groove that has a groove-shaped cross section along the axial direction and restricts the inner member from moving in the axial direction with respect to the first outer member. An intake system for a multi-cylinder internal combustion engine according to claim 2. 4. The first step part, which is formed on one side in the left-right direction from the positioning part and is in contact with one side surface of the inner member in the axial direction, and the step part is left-right from the positioning part. A second step portion formed on the other side in the axial direction and in contact with the other side surface in the axial direction of the inner member, the positioning portion, when viewed in the axial direction, includes the first and the first The intake system for a multi-cylinder internal combustion engine according to claim 3, wherein the two-stage portions are formed by overlapping portions.