JPH0639052Y2 - Intake device for multi-cylinder internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an intake system for a multi-cylinder internal combustion engine.

[Conventional technology]

A butterfly valve for intake control is provided in the surge tank to divide the inside of the surge tank into a first surge tank internal chamber and a second surge tank internal chamber when the butterfly valve is fully closed, and the first surge tank is opened when the butterfly valve is fully opened. A multi-cylinder internal combustion engine is known in which the inner chamber and the second surge tank inner chamber are made to communicate with each other (see, for example, Japanese Patent Laid-Open No. 56-115818). In this internal combustion engine, the equivalent valve length of the intake passage is changed by fully opening or closing the butterfly valve according to the operating state of the engine, thereby utilizing the intake inertia effect to achieve high filling over the entire engine speed range. We try to ensure efficiency. By the way, in this internal combustion engine, if even a small amount of air leaks when the butterfly valve is fully closed, the intake inertia effect weakens and the charging efficiency cannot be sufficiently increased.
Therefore, in this type of internal combustion engine, high sealing performance is required when the butterfly valve is fully closed. In this respect, the butterfly valve can obtain a good sealing property, so that the butterfly valve is suitable for application to such an internal combustion engine.

However, as a practical matter, when attempting to arrange a butterfly valve in a surge tank, it is difficult to machine the valve seat and assemble the valve. Therefore, even if the butterfly valve is suitable, good sealing and assembling performance is required. In order to secure it, some kind of ingenuity is required. Therefore, in order to improve the sealability and assembly of the butterfly valve, a valve holder with a built-in butterfly valve is formed separately from the surge tank, and the valve holder is fitted in the notch formed in the surge tank. A known intake device is known (see Japanese Utility Model Laid-Open No. 61-48923).

[Problems to be solved by the invention]

However, this intake device has a structure in which the valve holder is simply fitted and fixed in the notch. Therefore, since a gap is created at the joint surface between the valve holder and the notch, air leaks through this gap. Thus, there is a problem that a sufficiently high filling efficiency cannot be secured because the intake inertia effect is weakened.

[Means for solving problems]

In order to solve the above problems, according to the present invention, the inside of the surge tank is separated from the first surge tank internal chamber by a partition wall extending in the longitudinal direction of the surge tank from one end surface to the other end surface of the surge tank. It is divided into two surge tank inner chambers, the first surge tank inner chamber is connected to the first cylinder group, and the second surge tank inner chamber is connected to the second cylinder group. The air intake duct is connected to connect each surge tank internal chamber to the air cleaner via the air intake duct, and an opening is formed on the other end surface of the surge tank, and a notch is formed in the partition wall around the opening. A valve holder integrally formed with a partition wall part that fits in the notch and forms a part of the partition wall and a lid part that closes the opening is formed separately from the surge tank, and the first part is formed in the partition wall part of the valve holder. Surge tank internal chamber and second In an intake system for a multi-cylinder internal combustion engine, a communication hole that communicates with the internal chamber of the fuel tank is formed, and an intake control valve that is controlled to open and close according to the operating state of the engine is arranged in the communication hole. A groove is formed in the central part that extends over the entire length of the outer peripheral wall surface, and a strip-shaped sealing member that extends over almost the entire length is inserted between the groove and the inner peripheral wall surface of the notch so that the belt-shaped sealing member is recessed. It is composed of a base portion that fits in the groove and a ridge that sealingly contacts the inner peripheral wall surface of the notch.

〔Example〕

First, the basic principle of the present invention will be briefly described with reference to FIGS. 9 and 10.

Referring to FIG. 9, 3a, 3b, 3c, 3d, 3e, 3f are intake branch pipes,
Reference numeral 4 represents a surge tank. The first intake branch pipe groups 3a, 3b, 3c are connected to the first cylinder group whose intake strokes do not overlap with each other, and the second intake branch pipe groups 3d, 3e, 3f also do not overlap with each other in the intake strokes. It is connected to a cylinder group. The interior of the surge tank 4 is divided by a partition wall 5 into a first surge tank inner chamber 6 and a second surge tank inner chamber 7. The first surge tank internal chamber 6 and the second surge tank internal chamber 7 are made to communicate with each other through a communication hole 8 formed in the partition wall 5, and an intake control valve 9 is arranged in this communication hole 8. The first surge tank inner chamber 6 and the second surge tank inner chamber 7 are connected to an air cleaner 12 via an intake duct portion 10 and a throttle body 11, and a throttle valve 13 connected to an accelerator pedal is arranged in the throttle body 11. To be done.

FIG. 10 shows an operating state in which the intake control valve opens and an operating state in which the intake control valve closes. As shown in FIG. 10, the intake control valve 9 is closed during the engine high load and low speed operation. At this time, the branch portion 14 of the intake air flow in the intake duct portion 10 becomes a node of air column vibration due to the intake pulsation, and the frequency of the intake pulsation becomes relatively low. Therefore, at this time, as shown by the curve A in FIG. 10, when the engine speed is low, the charging efficiency is increased by the intake inertia effect, and the shaft torque is increased.
On the other hand, the intake control valve 9 is fully opened during engine high load and high speed operation. At this time, since the open ends of the intake branch pipes 3a, 3b, 3c, 3d, 3e, 3f serve as nodes of the air column vibration due to the intake pulsation, the frequency of the intake pulsation increases, and therefore the curve B of FIG. As shown, when the engine speed is high, the charging efficiency is increased by the intake inertia effect, and the shaft torque is increased.

Next, the intake device according to the present invention will be described with reference to FIGS. 1 to 6. In addition, in FIGS. 1 to 6, constituent elements similar to those in FIG. 9 are denoted by the same reference numerals. Referring to FIG. 6, a partition wall 5 is formed inside the surge tank 4 so as to extend in the longitudinal direction from the one end surface 4a of the surge tank 4 to the other end surface 4b in the central portion of the surge tank. The partition wall 5 extends beyond the end surface 4a on one side of the surge tank to the inside of the intake duct portion 10. A flange for attaching the throttle body 11 (Fig. 9) to the tip of the intake duct section 10.
15 are integrally formed. The inside of the surge tank 4 is vertically divided into two by a partition wall 5, a first surge tank internal chamber 6 is formed below the partition wall 5, and a second surge tank internal chamber 7 is formed above the partition wall 5. A first cylinder group, for example, 2 through the intake branch pipes 3a, 3b, 3c of the first surge tank internal chamber 6
The second surge tank internal chamber 7 is connected to the second cylinder, the fourth cylinder, and the sixth cylinder, and the second surge tank internal chamber 7 is connected to the second cylinder group through the intake branch pipes 3d, 3e, 3f, for example, the first cylinder, the third cylinder, and the fifth cylinder. Connected to.

A rectangular opening 16 is formed on the other end surface 4b of the surge tank 4, and a partition 17 around the opening 16 is provided with a notch 17 having a substantially U shape. Inner wall surfaces 18 on both sides of the notch 17 are tapered so as to expand outwardly on the other end surface 4b of the surge tank 4. On the other hand, as shown in FIGS. 1 to 3, a valve holder 19 having an intake control valve 9 is formed separately from the surge tank 4. The valve holder 19 is fitted in the notch 17 and forms a part of the partition wall 5.
A and a lid portion 19b that closes the opening 16 are integrally formed. A communication hole 8 is formed through the partition wall portion 19a,
An intake control valve 9 is arranged in the communication hole 8. The valve shaft 20 of the intake control valve 9 is rotatably supported in the valve holder 19. One end of the valve shaft 20 penetrates the lid portion 19b and projects outward, and the arm 21 is attached to the protruding end of the valve shaft 20.
Is fixed. The tip of the arm 21 is the lid of the valve holder 19.
The intake control valve 9 is connected to an actuator 22 supported by 19b, and the intake control valve 9 is controlled to open and close by this actuator 22.

As shown in FIG. 6, the notches 17 are formed on both inner peripheral wall surfaces 18 that are tapered so as to expand outward, and the notches 17
The inner peripheral wall surface 23 located at the innermost portion of the
As shown in FIGS. 1 and 2, the partition wall portion 19a of the valve holder 19 has a tip outer peripheral wall surface 24 formed at the tip end of the partition wall portion 19a and a width gradually narrowing toward the tip outer peripheral wall surface 24. And both outer peripheral wall surfaces 25 that are tapered. Sixth
As shown in the drawing, the connection between the inner peripheral wall surface 18 on both sides of the notch 17 and the inner peripheral wall surface 23 on the inner side is rounded, and as shown in FIGS. Partition part 19a
The connection between the outer peripheral wall surface 25 on both sides and the tip outer peripheral wall surface 24 is also rounded.

The lid portion 19b of the valve holder 19 is fastened to the other end surface 4b of the surge tank 4 by bolts. At this time, the partition wall portion 19a
A small gap is formed between both outer peripheral wall surfaces 25 and both inner peripheral wall surfaces 18 of the notch 17, and a small gap is also formed between the tip outer peripheral wall surface 24 of the partition wall portion 19a and the inner peripheral wall surface 23 of the notch 17. Thus, the dimensions of the partition wall portion 19a and the notch 17 are determined.

As shown in FIG. 1 to FIG. 3 and FIG. 7, a concave groove 26 having a U-shaped cross section is formed in the central portion of the outer peripheral wall surfaces 24, 25 of the partition wall portion 19a. A band-shaped seal member 27 made of, for example, a rubber gasket is provided in the groove 26.
Is inserted. As shown in FIGS. 4, 5, and 7, the band-shaped sealing member 27 has a base portion 27a having a substantially rectangular shape.
And a ridge 27b having a semicircular cross section integrally formed on the outer peripheral surface of the base 27a. As shown in FIG. 7, the base portion 27a of the band-shaped seal member 27 is fitted into the groove 26, and the protrusion 27b of the band-shaped seal member 27 is arranged so as to be able to contact the inner peripheral wall surfaces 18 and 23 of the notch 17. To be done. Therefore the partition part 1
When 9a is fitted in the notch 17, the outer peripheral surface of the base portion 27a of the band-shaped seal member 27 is pressed onto the bottom wall surface of the groove 26, and the protrusion 27b of the band-shaped seal member 27 has a recessed notch 17 Are pressed against the inner wall surfaces 18 on both sides of. As shown in FIG. 7, the width of the base portion 27a of the band-shaped sealing member 27 is narrower than the width of the concave groove 26. On the other hand, as shown in FIGS. 1 and 4, a plurality of protrusions 28 are integrally formed on the inner peripheral surface of the band-shaped seal member 27, and these protrusions 28 are formed on both side outer peripheral wall surfaces 25 of the partition wall portion 19a. It is fitted in each projection receiving hole formed above. Therefore, the band-shaped seal member 27 is
It is firmly held in the concave groove 26 of a.

Since the base portion 27a of the band-shaped seal member 27 is fitted in the groove 26 in this way, the band-shaped seal member 27 is displaced when the partition wall portion 19a of the valve holder 19 is fitted in the notch 17,
Alternatively, the belt-shaped seal member 27 can be held in the regular position shown in FIG. 7 without being twisted, and thus even after the fitting. Further, when the valve holder 19 is fitted, the ridges 27b of the band-shaped seal member 27 come into contact with the inner peripheral wall surfaces 18 on both sides of the notch 17, so that the band-shaped seal member 27 is covered on both inner peripheral wall surfaces of the notch 17.
Substantially in line contact with 18. Therefore, when the valve holder 19 is fitted, the frictional resistance between the band-shaped seal member 27 and the inner peripheral wall surfaces 18 on both sides of the notch 17 is small, and thus the partition wall portion 19 of the valve holder 19 is installed.
The a can be easily fitted in the notch 17.

In addition, as shown in FIG.
It is also possible to form a plurality of protrusions 27c on the outer peripheral surface of 27a.

The outer peripheral wall surface 25 on both sides of the partition wall portion 19a and the outer peripheral wall surface 24 at the tip end
By rounding the connection portion with the inner peripheral wall surface 18 on both sides of the notch 17 and the inner peripheral wall surface 23 on the inner side of the notch 17, these connection portions can be reliably sealed.

Further, by forming the inner peripheral wall surfaces 18 on both sides of the notch 17 in a concave shape, even if the partition wall portion 19a is slightly inclined, the protrusions 27b of the band-shaped seal member 27 are securely pressed onto the inner peripheral wall surfaces 18 on both sides of the notch 17. Therefore, the sealing property can be improved.

[Effect of device]

By inserting a seal member on the outer peripheral wall surface of the partition wall of the valve holder and the inner peripheral wall surface of the notch, it is possible to reliably seal between them. Further, the seal member is fitted in the concave groove of the partition wall of the valve holder, and the projection of the seal member contacts the inner peripheral wall surface of the notch, so that the seal member is not displaced or twisted. The partition wall can be easily fitted into the notch with a small insertion force.

[Brief description of drawings]

1 is a plan view of a valve holder, FIG. 2 is a perspective view of a valve holder, FIG. 3 is a side view of a valve holder, FIG. 4 is a plan view of a band-shaped seal member, and FIG. 5 is a side view of a band-shaped seal member. 6 and 6 are perspective views of a surge tank, FIG. 7 is a cross-sectional view showing a partition wall fitted in a notch, and FIG. 8 is a cross-sectional view of another embodiment similar to FIG. 7, FIG. 9 is a diagram schematically showing the entire intake system, and FIG. 10 is a diagram showing the opening / closing region of the intake control valve and the axial torque. 4 ... surge tank, 5 ... bulkhead, 6 ... first surge tank internal chamber, 7 ... second surge tank internal chamber, 8 ... communication hole, 9 ... intake control valve, 16 ... opening, 17 ... notches,
19 …… Valve holder, 26 …… Concave groove, 27 …… Band-shaped sealing member,
27a …… base, 27b, 27c …… projection.

Claims (1)

[Scope of utility model registration request] 1. The inside of the surge tank is divided into a first surge tank internal chamber and a second surge tank internal chamber by a partition wall extending in the longitudinal direction of the surge tank from one end surface to the other end surface of the surge tank. Then, the first surge tank inner chamber is connected to the first cylinder group, the second surge tank inner chamber is connected to the second cylinder group, and the intake duct portion is connected to the one end face of the surge tank. The surge tank inner chamber is connected to the air cleaner through the intake duct portion to form an opening on the other end face of the surge tank and a notch is formed in the partition wall around the opening, and the notch is formed in the notch. A valve holder integrally formed with a partition wall part that is fitted to form a part of the partition wall and a lid part that closes the opening is formed separately from the surge tank,
An intake control valve is formed in a partition wall portion of the valve holder to form a communication hole that communicates the first surge tank internal chamber and the second surge tank internal chamber with each other, and opening / closing control is performed in the communication hole according to an operating state of the engine. In the intake system for a multi-cylinder internal combustion engine in which a plurality of cylinders are arranged, a groove is formed in the central portion of the outer wall surface of the partition wall portion and extends over the entire length of the outer wall surface, and between the groove and the inner wall surface of the notch. A strip-shaped seal member extending over substantially the entire length thereof is inserted into the groove, and the strip-shaped seal member includes a base portion fitted in the groove and a ridge that sealingly contacts the inner peripheral wall surface of the notch. Intake device for multi-cylinder internal combustion engine.