JPH03260333A - Intake device of engine - Google Patents

Abstract

PURPOSE:To obtain sufficient supporting rigidity, eliminate a gap of a communication part and prevent noises from leaking by connecting an intercooler to bilateral surge tanks on upper parts of bilateral banks at a communication passage and then supporting it. CONSTITUTION:An engine 1 is constructed in a shape of V-character, and surge tanks 5, 6 are arranged in upper parts of the bilateral tanks 2, 3. The surge tanks 5, 6 are respectively provided with branch pipes 7, 8 and communication pipes 9, 10, while the branch pipes are respectively provided with injectors 11a. An intercooler 12 which is arranged in a front part of the engine 1 has cooling parts 13, 14, a common inlet pipe 15, and both-end outlet pipes 16, 17. The both-end outlet pipes 16, 17 are connected to the communication pipes 9, 10 through a joint 28 made of, for example, thick rubber, and supported by means of the surge tanks 5, 6 or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an intake system for a ■-type engine in which surge tanks are provided above left and right banks, respectively.

(Prior art) In an engine, a mechanical supercharger is provided downstream of the throttle body in the intake passage, and the discharge port side of the mechanical supercharger is connected to a surge tank via an intercooler. This has been conventionally known as described in Japanese Patent No. 63-51121. In an engine equipped with such a mechanical supercharger and intercooler, as described in the above publication, a bypass passage is formed by bypassing the supercharger and intercooler, and a bypass control valve is installed in this bypass passage. Bypass # at low load
Normally, the control valve is opened to bypass the supercharger to perform natural intake, and when the load becomes high, the bypass control valve is closed to perform supercharging.

By the way, in a vehicle equipped with a supercharged engine,
In order to keep the engine room small, it is necessary to arrange the intake system, including the supercharger, as compactly as possible to increase the ease with which the engine can be mounted.

Therefore, particularly in the case of a V-type engine, it has been conventional practice to utilize the space between the left and right banks forming the V-shape and to dispose a supercharger in this space. In that case, one surge tank is provided above the left and right banks, and the intercooler is arranged in front of the supercharger in a direction perpendicular to the crankshaft, thereby making it possible to create a compact layout for the entire intake system.

(Problems to be Solved by the Invention) As described above, a supercharger is disposed in the space between the left and right banks of a V-type engine, one surge tank is provided above each of the left and right banks, and the supercharger When installing an intercooler in front of the engine in a direction perpendicular to the crankshaft, how to support and fix the intercooler is a major problem when installing the engine.

In the case of the intake system with the above configuration, the intercooler protrudes in front of the engine, but since there is not enough space at the front end of the engine, it is not recommended to fix the intercooler to the engine side using only mounting members such as brackets. difficult. Furthermore, it is necessary to avoid a support structure in which a load is applied to the supercharger through the connection with the intercooler, which is quite heavy.

Furthermore, in the configuration of the intake system as described above, it has conventionally been recommended to provide a gap of several millimeters where the passage on the intercooler side and the passage on the surge tank side meet, and cover this gap with rubber, etc. This was normal, but in that case, the problem was that the pulsating noise leaking from this gap was quite loud.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to increase the rigidity with which an intercooler, which is disposed in front of the engine in a direction orthogonal to the crankshaft, is supported on the engine side.

At the same time, the purpose is to prevent sound leakage from the connection portion of the intercooler.

(Means for Solving the Problems) The present invention provides dual support for the intercooler and prevention of sound leakage by rigidly connecting the intercooler to the communication passage of the surge tank provided above the left and right banks of a V-type engine. It solves two problems at once,
Its structure is as follows. That is, in the engine intake system according to the present invention, a surge tank is provided above the left and right banks arranged in the shape of a square, an intercooler is arranged in a direction perpendicular to the crankshaft, and the intercooler is connected to the left and right communication passages. In the engine which communicates with both surge tanks, the intercooler is connected and fixed to both surge tanks at the communication passage, and is supported by these surge tanks.

In the above configuration, it is preferable to interpose thick rubber at the connecting portion between the intercooler and the surge tank.

(Function) The intercooler is arranged in a direction perpendicular to the crankshaft, and is connected and fixed to the surge tanks provided above the left and right banks of the V-type device through their communication passages, so that it can be suspended from the left and right. Supported by Tasugi.

Since the intercooler is rigidly connected to the surge tank, there is no need to provide a gap between them that would cause sound leakage. In addition, by interposing thick rubber in the connection part, the connection between the intercooler and the surge tank,
A rigid connection with less sound leakage is possible.

(Example) Examples will be described below based on the drawings.

FIG. 1 is a plan view of a ■-type engine according to an embodiment of the present invention, FIG. 2 is a rear view thereof, and FIG. 3 is a side view thereof. In this embodiment, the engine 1 is a V-type six-cylinder engine, and when viewed from the front, the three cylinders in the left bank 2 and the right bank 3 are such that each cylinder in the left bank 2 is connected to each cylinder in the right bank 3. In contrast, they are arranged so as to be offset by a predetermined amount from each other in the crankshaft direction. A Lysholm type supercharger 4 is disposed in the space between the left and right banks 2 and 3 in the direction of the crankshaft.

Surge tanks 5 and 6 are provided above the left and right banks 2.3, respectively, and extend in the crankshaft direction.

And each surge tank 5.6 has left and right banks 2.3
Branch pipes 7 and 8 forming independent intake passages to each cylinder between the cylinders.
A communication pipe 9. is provided at the end of the engine front example, which constitutes a communication path with an intercooler to be described later. The lO is extended forward. In addition, each cylinder branch pipe 7.8
An injector mounting hole 11a is provided in each of the injector mounting holes 11a, and an injector 11 for fuel injection is disposed therein.

An intercooler 12 is disposed in front of the engine 1 in a direction perpendicular to the crankshaft. intercooler 12
There are two cooling parts 13.1 corresponding to the left and right banks 2.3.
4, which are arranged substantially symmetrically with respect to the engine center.

And a common inlet pipe 15 is provided at the center position,
Outlet pipes 16 and 17 are provided at both left and right ends. The inlet pipe 15 is connected to a discharge pipe 18 provided from the top of the supercharger 4 toward the front.

The supercharger 4 has an inlet portion 19 at the rear end in the longitudinal direction, and a throttle body 20 is connected to the inlet portion 19.

In the inlet portion 19, the side connecting the throttle body 20 is offset toward the left bank 2 with respect to the engine center, and the connecting surface is inclined toward the right bank 3. The throttle body 20 as a whole is offset toward the left bank 2, and its link mechanism 21 is disposed horizontally toward the offset space behind the left bank 2.

Further, an air bypass valve 22 is connected to the inlet portion 19, and a portion immediately downstream of the throttle body 20 is connected to the discharge 'f18 of the supercharger 4 via the air bypass valve 22 and a bypass passage pipe 23 connected to the air bypass valve 22. It is communicated. Furthermore, an intercooler bypass passage pipe 24 is connected to the connection part of the air bypass valve 22 with the bypass passage pipe 23, and an intercooler bypass valve 25 is provided downstream of the connection part.

The intercooler bypass passage pipe 24 is connected from above to a downstream position of the air bypass valve 22, and is bent into a dogleg shape and branches into two parts, including the left and right surge tanks 5,
The intercooler side communication pipes 9 and 10 are integrally formed with the intercooler side communication pipes 9 and 10.

The tip of each of the above-mentioned communicating tubes 9. It is connected from above to connecting portions 9a and 10a that branch and rise from below the tip of the IO. In FIG. 1, 26 indicates the position of the EGR inlet, and 27 indicates the position of the PCV inlet. EGR introduction port 26
and PCV inlet 27 is for EGR gas or PCV
so that the gas mixes well with air before being introduced into the engine.
It is necessary to provide it at a position upstream of the surge tanks 5 and 6.

Both end outlet pipes 16.17 of the intercooler 12 are connected to the communication pipe 9. of the left and right surge tanks 5.6. They are rigidly bolted to the IOs through joints 28 made of thick rubber and supported by these surge tanks 5.6 and brackets (not shown) separately fixed below. A duct 31 that extends beyond the radiator 29 located at the front and opens at the vehicle grille 30 is provided to cover the front surface of the intercooler 12, and a membrane-like rubber seal is bolted to the inner surface of the rear end of the duct 31. 32 seals the gap between the duct 31 and the intercooler 12.

The air bypass valve 22 is constituted by a diaphragm-type pressure-responsive valve, and opens when the engine is under low load.
It gradually closes when the boost pressure exceeds a predetermined value, and becomes fully closed when the load is high. Further, the intercooler bypass valve 25 is also constituted by a diaphragm type pressure-responsive valve, and opens when the load is low. and,
It begins to close from the lower load side than the air bypass valve 22, and becomes fully closed when it enters the supercharging region. As a result, in the non-supercharged region, air is taken by bypassing the supercharger 4, and an increase in pressure loss is prevented. In addition, especially in the low load range,
Intercooler 2 is also bypassed for intake air.

Therefore, during low load, the supercharger 4 is stopped and drive loss is reduced, and the air bypass reduces pressure loss.Furthermore, the intake temperature increases, atomization is improved, and combustion-like suspension is reduced. As a result, fuel efficiency and emissions (HC) are improved. On the other hand, when the load is high, the intercooler bypass valve 25 is fully closed, and sufficiently cooled air is supplied to the engine.
Abnormal combustion is prevented and the reliability of the supercharger is ensured.

A communication pipe 9 between the outlet pipe 16.17 of the intercooler 12 and the surge tank 5.6. The detailed structure of the joint 28 interposed in the connecting portion with the IO is as shown in FIG. 4 (front view) and FIG. 5 (AA cross-sectional view in FIG. 4). That is, this joint 28 has an inner diameter that is approximately the same as the inner diameter of the outlet pipe 16.17 of the intercooler 12 and the communication pipe 9.10 of the surge tank 5.6, and has boss portions 41λ and 41b at symmetrical positions on the outer periphery. The ring-shaped thick rubber 41 is used as a base material, and one stud bolt 42a, 42b is erected near one side of the rubber at the left and right boss portions 41a, 41b. An iron plate 42 is baked, and the boss portions 41a, 41b are formed on the other side.
An iron plate 43 having boss portions 43a and 43b is baked at a position rotated by 90 degrees with respect to the above. This joint 2
8 is sandwiched between the end surfaces of the communication pipes 9 and 10 and the outlet pipe 16.17 of the intercooler 12, with the side surface having the stud bolts 42a and 42b facing the surge tank 5.6 side, and the communication pipe 9.10 side means the above stud bolt 42
a, 42b and the nut 44, and the bolt 46 is fixed by the nut 44 through the holes 45a, 45b of the boss portions 43a, 43b on the other side from the outlet pipe 16.17 side.
Fixed at 7. The intercooler 12 has its outlet pipe 1
6°17 is a joint 2 made of thick rubber 41 as described above for the communication pipe 9.10 of the surge tank 5.6.
By being rigidly connected via 8, it becomes suspended by the surge tank 5.6, and sufficient support rigidity is obtained. Moreover, by adopting such a connection structure, there is no gap between the intercooler 12 and the surge tank 5.6, and leakage of discharge sound is prevented.

(Effects of the Invention) Since the present invention is configured as described above, sufficient support rigidity can be obtained by supporting the intercooler by the surge tanks located above the left and right banks, and at the same time, the intercooler can be supported by the surge tanks located above the left and right banks. It is possible to prevent sound leakage by eliminating the gap in the communication part with the surge tank.

[Brief explanation of drawings]

FIG. 1 is a plan view of a V-type engine according to an embodiment of the present invention, FIG. 2 is a rear view of the same, FIG. 3 is a side view of the same, FIG. 4 is a front view of a joint in the embodiment, and FIG. The figure is A in Figure 4.
-A sectional view. l: Engine, 2: Left bank, 3: Right bank, 4: Supercharger, 5.6 = Surge tank, 9, 10: Communication pipe, 12:
Intercooler, I6, 17: Outlet pipe, 28: Joint, 41: Rubber. Figure 4

Claims (2)

[Claims] (1) An engine in which a surge tank is provided above the left and right banks arranged in a V shape, an intercooler is arranged in a direction perpendicular to the crankshaft, and the intercooler is communicated with both surge tanks through communication passages on the left and right sides. An intake system for an engine, wherein the intercooler is connected and fixed to both surge tanks at a portion of the communication passage, and is supported by both surge tanks. (2) The intake system for an engine according to claim 1, wherein a thick rubber is interposed at the connecting portion between the intercooler and the surge tank.