JPH06249091A - Intake system of internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce noises radiated from an intake collector by restraining the vibrational transmission from a cylinder head to the intake collector, particularly the transmission of vibration in the region exceeding a specified frequency. CONSTITUTION:An intake collector 4 and intake manifold are casted separately from each other. The head side flange 13 of the intake manifold 5 is secured fixedly to the side of a cylinder head 2. An elastic seal member 15 is interposed in the connection of the collector side flange 12 of the intake manifold 5 and the intake collector 4. The intake collector 4 is elastically supported on the collector side flange 12 by bolts having a rubber bushing disposed thereon. A radiation plate 23 made of a metal plate having a proper mass is interposed in the intermediate part of the elastic seal member 15 in the direction of thickness. The radiation plate 23 serves as an intermediate mass body in an vibration system for supporting the intake collector 4 to restrain the vibration transmission to the intake collector 4 in a region over the resonance frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an intake system for an internal combustion engine in which an intake collector and an intake manifold are separate members.

[0002]

2. Description of the Related Art In an internal combustion engine such as a fuel injection type gasoline engine, an intake system provided with an intake collector having a relatively large volume is often used. As shown in Japanese Utility Model Laid-Open No. 60-45864, the intake collector and the intake manifold may be cast as separate members, but these intake collector and intake manifold are generally plate-shaped. It is rigidly connected and fixed by a plurality of bolts via a gasket, and similarly, it is also rigidly connected and fixed by a plurality of bolts between the intake manifold and the cylinder head through a plate-shaped gasket.

[0003]

However, in such a conventional intake system, since vibration on the cylinder head side is transmitted to the hollow intake collector via the intake manifold, a large radiation is generated in the intake collector. There is a problem that sound is generated. Particularly, in the V-type internal combustion engine, the surface area of the upper surface of the intake collector is large, so that the radiated sound generated from the intake collector becomes more remarkable.

It has been attempted to suppress the vibration transmission by interposing an elastic member in the middle of the intake system from the cylinder head to the intake collector, such as using an elastic member as a gasket between the cylinder head and the intake manifold. However, since the spring constant of the elastic member cannot be made extremely small from the standpoint of securing the support strength of the intake system and the sealing performance, it is sufficient to reduce the vibration transmission in the frequency region of 1 kHz or higher, which is a problem for the radiated sound of the engine. Is difficult to achieve.

[0005]

Therefore, the present invention aims to improve the vibration isolation performance by elastically supporting the intake collector and disposing an intermediate mass body in a seal member between the intake manifold and the intake manifold. That is, the present invention comprises an intake manifold composed of a plurality of branch portions, one end of which is attached to the cylinder head, and an intake collector attached to the other end of the intake manifold and supported by the intake manifold. In an intake device for an internal combustion engine, a sealing member having elasticity is interposed on a joint surface between the intake manifold and the intake collector, and an elastic member is arranged on a bolt connecting the two to elastically support the intake collector, and It is characterized in that a metal plate having an appropriate mass is interposed at an intermediate portion in the thickness direction of the seal member.

[0006]

In the above construction, the intake collector is elastically supported on the intake manifold by the elastic member and the seal member arranged on the bolt. This elastic support structure can be modeled as a kind of spring-mass system by a seal member corresponding to a spring and an intake collector corresponding to a mass body, but in the thickness direction of the seal member corresponding to a spring. By arranging a metal plate that will be an intermediate mass body in the middle part,
Vibration transmission from the cylinder head side to the intake collector is reduced in the frequency region above the resonance frequency.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to an intake system for a V-type 6-cylinder internal combustion engine. In this V-type internal combustion engine, cylinder heads 2 are mounted and fixed on the left and right banks of a cylinder block 1, and a cylinder head cover 3 is attached to the upper surface thereof. The intake port (not shown) is arranged inside the V bank of each cylinder head 2, and an intake collector 4 and an intake manifold 5 that form an intake device are provided between the V banks. In addition, outside the V bank of each cylinder head 2,
The exhaust manifold 6 is connected.

FIG. 2 is an exploded perspective view of the intake device located between the V banks. The intake collector 4 has an elongated box shape along the cylinder row direction and has six intake outlets on the lower surface (not shown). Is formed, and a flange surface is processed so as to surround the intake outlet. Further, the inside of the intake collector 4 is partitioned into a pair of volume chambers corresponding to the left and right banks, respectively, and intake intake pipes 7 are provided at the front and rear ends of the intake collector 4 so as to communicate with the volume chambers.
Is provided. A throttle chamber (not shown) is attached to the intake air introduction pipe 7, and an air duct made of synthetic resin is further connected. Also, this intake collector 4
A plurality of through holes 8 are formed in the peripheral portion of the.

The intake collector 4 and the cylinder head 2 described above.
The intake manifold 5 that connects to the intake ports is formed by integrally casting six branch portions 11 corresponding to each cylinder, and the collector-side flange 12 attached to the intake collector 4 is common to the left and right banks. The base end of each branch portion 11 is connected to the collector-side flange 12. A head side flange 13 is connected to the tip of each branch portion 11 which is divided into three right and left portions. The head side flange 13 is integrated for each of the three cylinders in the left and right banks, and as shown in FIG.
It is adapted to be fixed to the side surface of the cylinder head 2 by a plurality of bolts 14 via a gasket (not shown).

An elastic seal member 15 integrated for all cylinders is interposed between the joint surface of the intake manifold 5 and the intake collector 4, that is, between the collector side flange 12 and the flange surface of the lower surface of the intake collector 4. ing. The intake collector 4 and the collector side flange 12 pass through the through hole 8 of the intake collector 4 and the through hole 16 of the elastic seal member 15 and the screw hole 19 of the collector side flange 12.
Are connected to each other by a plurality of bolts 17 that are screwed together. An elastic rubber bush 18 is interposed between the head of the bolt 17 and the intake collector 4. That is, the intake collector 4 is elastically supported by the intake manifold 5 by the elastic seal member 15 and the rubber bush 18. The intake collector 4 is not supported by other stays or the like so as to allow elastic displacement with respect to the intake manifold 5.

As shown in FIGS. 2 and 3, the elastic seal member 15 interposed between the intake collector 4 and the intake manifold 5 has a collector-side elastic material layer 21 formed by molding a rubber material such as NBR into a gasket shape and Manifold side elastic material layer 22
And a heat dissipation plate 23 made of a metal plate sandwiched between the two.
It has a layered structure. That is, the metal heat dissipation plate 23 is provided in the middle portion in the thickness direction of the elastic seal member 15 made of rubber material.
Is intervening. The collector-side elastic material layer 21 and the manifold-side elastic material layer 22 are formed to have the minimum required geometrical dimensions corresponding to the shapes of the flange surface of the lower surface of the intake collector 4 and the collector-side flange 12, respectively. On the other hand, the heat dissipation plate 23 includes both elastic material layers 21,
It is formed in a substantially rectangular shape wider than 22, and has a size capable of covering substantially the entire lower surface of the intake collector 4. Further, a plurality of fins 24 are formed on both side portions protruding from both elastic material layers 21 and 22. This fin is formed by forming a substantially U-shaped cut in the heat dissipation plate 23 and bending it downward, and is formed so as to face the vehicle traveling wind indicated by arrow A as shown in FIG. ing.

The collector-side elastic material layer 21, the manifold-side elastic material layer 22 and the heat radiating plate 23 are previously integrated by baking or bonding.

In the structure of the above embodiment, the intake collector 4 is elastically supported as described above, and the heat radiating plate 23 which can be freely displaced with respect to the intake collector 4 is arranged in the thickness direction of the elastic seal member 15. Since it is arranged in the intermediate portion, the heat dissipation plate 23 functions as an intermediate mass body in the spring-mass system. Therefore, the heat dissipation plate 2 which is an intermediate mass body
In the region on the higher frequency side than the resonance frequency of 3, the heat dissipation plate 23 vibrates in the opposite phase to the vibration of the intake collector 4, so that the vibration transmissibility is greatly reduced. Specifically, the vibration isolation performance can be improved in a region of approximately 1 kHz or higher where human hearing characteristics are sensitive.

FIG. 4 shows the intake collector 4 in the conventional structure in which the intake collector 4 is rigidly connected to the intake manifold 5.
3 shows the difference between the vibration level of No. 1 and the vibration level in the configuration of the above embodiment. That is, in the region where the difference is 0 dB or more, the elastic seal member 1 including the heat dissipation plate 23 is provided.
There will be 5 effects. In FIG. 4, assuming that the mass of the intake collector 4 is M (for example, 2 kg) and the mass of the heat dissipation plate 23 is m, the mass ratio μ (= m / M) is 0.2 and 0.3. And two characteristics are shown, and in either case, the intake collector 4 is in the region of 1 kHz to 2 kHz.
The vibration level of is greatly reduced. Where the intermediate mass m
As shown in the figure, the larger the weight of the intermediate mass body m, the greater the effect of. It becomes extremely easy to secure.

Since the heat dissipation plate 23 is hidden under the lower surface of the intake collector 4, the influence of noise generated by the vibration of the heat dissipation plate 23 is very small. Further, it does not occupy a large storage space.

Further, in the above structure, since the heat dissipation plate 23 for promoting heat dissipation is located between the intake manifold 5 and the intake collector 4, the heat transferred from the cylinder head 2 side to the intake collector 4 can be reduced and the intake air temperature can be suppressed. As a result, the filling efficiency can be improved. Further, the heat dissipation plate 23 also functions as a heat shield plate that shields the radiant heat from the exhaust pipe (particularly, the connecting pipe at the end of the internal combustion engine that connects the pair of left and right exhaust manifolds 6) and suppresses the temperature rise of the intake collector 4. it can. The heat sink 23
In order to enhance the heat dissipation effect due to, it is preferable to use a material having a relatively high heat transfer coefficient for the manifold-side elastic material layer 22 and a material having a relatively low heat transfer coefficient for the collector-side elastic material layer 21. Alternatively, a heat insulating material layer may be further interposed between the collector-side elastic material layer 21 and the heat dissipation plate 23.

Next, FIG. 5 shows an embodiment in which the present invention is applied to an in-line type internal combustion engine. Also in this embodiment, the elastic seal member 15 is interposed between the intake manifold 5 and the intake collector 4, and the intake collector 4 is elastically supported via the bolt using the rubber bush (not shown). A heat radiating plate 23 having fins 24 is arranged in the middle of the elastic seal member 15 in the thickness direction.
In the example of FIG. 5, the internal combustion engine is mounted on a vehicle in a so-called horizontal position, so that the fins 24 are formed in the width direction of the intake collector 4.

[0019]

As is apparent from the above description, according to the intake system for an internal combustion engine of the present invention, the intake collector is elastically supported with respect to the intake manifold, and the elastic seal member between the two is arranged in the thickness direction. By providing a metal plate that serves as an intermediate mass body in the intermediate portion, 1 kHz which becomes a problem as engine noise without excessively reducing the spring constant of the elastic seal member
Vibration transmission can be suppressed in the above region. Therefore, the radiated sound from the intake collector, which occupies a relatively large specific gravity as the noise of the internal combustion engine, can be reduced.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a V-type internal combustion engine equipped with an intake device according to the present invention.

FIG. 2 is an exploded perspective view of an intake device in this V-type internal combustion engine.

FIG. 3 is a perspective view of the elastic seal member as seen from the intake manifold side.

FIG. 4 is a characteristic diagram showing a vibration transmissibility to an intake collector in this embodiment in comparison with a conventional one.

FIG. 5 is a front view showing an embodiment in which the present invention is applied to an in-line type internal combustion engine.

[Explanation of symbols]

 2 ... Cylinder head 4 ... Intake collector 5 ... Intake manifold 15 ... Elastic seal member 17 ... Bolt 18 ... Rubber bush 21 ... Collector side elastic material layer 22 ... Manifold side elastic material layer 23 ... Heat sink

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location F16F 15/08 Q 9138-3J F16J 15/12 F 8207-3J

Claims (1)

[Claims] 1. An internal combustion engine comprising: an intake manifold including a plurality of branch portions, one end of which is attached to a cylinder head; and an intake collector attached to the other end of the intake manifold and supported by the intake manifold. In an intake device for an engine, an elastic seal member is provided on a joint surface between the intake manifold and the intake collector, and an elastic member is arranged on a bolt connecting the two to elastically support the intake collector. An intake device for an internal combustion engine, wherein a metal plate having an appropriate mass is interposed in an intermediate portion in the thickness direction of the seal member.