JPH04301173A - Intake device for engine - Google Patents

Abstract

PURPOSE:To provide an intake device for engine which can improve fuel injection accuracy and intake filling efficiency of an engine, in which a fuel injection valve is provided in each separate intake passage. CONSTITUTION:In an intake device F of an engine E, in which a fuel injection valve 23 is provided in each separate intake passage 22, a collecting intake passage of the upstream of the separate intake passages 22 is formed as a chamber member 16 for internally pressurizing each fuel injection valve 23 and each separate intake passage 22. It is desired to load the engine E on a vehicle W so as to be transverse to the vehicle W and so that the upper part of the engine is inclined to the rear of the vehicle W, and the intake passage is located in the front side of the vehicle against the engine E, and a fuel discharge valve 23 is located inside of the chamber member 16 in the downstream of an air cleaner 17.

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 an engine.

0002

2. Description of the Related Art A fuel injection type engine in which a fuel injection valve is provided facing an intake passage has been known in the past. Here, fuel in the fuel tank is supplied to the fuel injection valve via a fuel supply passage. however,
In such a fuel injection type engine, since the fuel injection valve is usually arranged near the engine body, the temperature of the fuel injection valve or the intake passage around the fuel injection valve becomes high due to the heat received from the engine body. As a result, fuel vaporizes in the fuel injection valve or in the fuel supply passage in its vicinity, causing vapor lock, which results in the problem that fuel injection is not performed in accordance with the amount of intake air, and air-fuel ratio control is disturbed. Incidentally, even if vapor lock does not occur, there is a problem in that the specific gravity of the fuel decreases due to an increase in the temperature of the fuel, which disturbs the air-fuel ratio control. Note that there is also the problem that the intake air filling efficiency decreases due to an increase in the temperature of the intake air in the intake passage.

Therefore, the fuel injection valve is placed above the intake passage, and a surge tank or the like is placed below the intake passage to provide good ventilation around the fuel injection valve. An engine has been proposed that promotes cooling of the engine (for example, see Japanese Patent Laid-Open No. 2-86950).

0004

[Problems to be Solved by the Invention] However, since the running wind is not very strong in the engine room, in conventional engines such as the one disclosed in Japanese Patent Application Laid-Open No. 2-86950, it is necessary to close the fuel injection valve or intake passage sufficiently. cannot be cooled down. Additionally, vapor lock is generally most likely to occur in the fuel injection valve when the engine is warmly restarted, but at this time the vehicle has not yet started, so no airflow is available. Therefore, in the conventional engine described above, there is a problem in that the fuel injection valve cannot be cooled when cooling is most needed.

[0005] Furthermore, an engine has been proposed in which the fuel injection valve is disposed in a collective intake passage upstream of the independent intake passage, and the fuel injection valve is cooled by relatively high-speed intake air flowing within the collective intake passage. (For example, Utility Model Publication Heisei 1-1
(See Publication No. 48064). However, in an engine in which a fuel injection valve is provided in the independent intake passage of each cylinder, the pipe diameter of the independent intake passage is relatively small, and it is difficult to arrange the fuel injection valve in the independent intake passage.
The technique disclosed in Japanese Utility Model Application Publication No. 1-148064 cannot be applied as is.

The present invention has been made to solve the above-mentioned problems of the conventional art, and is to improve the accuracy of fuel injection in an engine in which a fuel injection valve is provided for each independent intake passage of each cylinder. An object of the present invention is to provide an engine intake device that can improve intake air filling efficiency.

[0007]

[Means for Solving the Problem] In order to achieve the above object, the first invention provides an engine in which a fuel injection valve is provided upstream of an independent intake passage provided for each cylinder. An intake device for an engine is provided, wherein the collective intake passage is formed as a chamber member that accommodates each fuel injection valve and at least a portion near the fuel injection valve of each independent intake passage.

[0008] Furthermore, a second invention is the engine intake system according to the first invention, wherein the engine is mounted on the vehicle in such a manner that the engine is placed horizontally with respect to the vehicle and the upper part of the engine is inclined toward the rear of the vehicle. To provide an intake device for an engine, characterized in that an intake passage system is arranged on the front side of a vehicle with respect to the engine.

Furthermore, a third invention provides an engine intake system according to the second invention, wherein each fuel injection valve is disposed within a chamber member downstream of the air cleaner. provide.

0010

[Examples] Examples of the present invention will be explained in detail below. As shown in FIGS. 1 to 3, in an FF type (front engine/front drive) vehicle W, a 4-cylinder engine E having first to fourth cylinders #1 to #4 is installed horizontally, that is, the engine The cylinder E is mounted so that the cylinder arrangement direction faces the width direction of the vehicle W. Further, this horizontally mounted engine E is arranged so that its upper part is inclined toward the rear of the vehicle (to the right in FIG. 1). In the following, for convenience, the front direction of the vehicle W (left side in FIG. 1) is simply referred to as "front", and the rear direction (right side in FIG. 1) of vehicle W is simply referred to as "rear".

The engine E is provided with a cylinder block 1 and a cylinder head 2, the upper surface of the cylinder head 2 is covered by a cylinder head cover 3, and the lower surface of the cylinder block 1 is provided with an oil pan 4. The crankshaft 5 is rotatably supported by the cylinder block 1, and the power of the crankshaft 5 is transmitted to the front wheel drive shaft 11 via a transmission (not shown) and a front differential (not shown). It is meant to be transmitted. Further, a part of the power of the crankshaft 5 is transmitted to the air conditioner 8 and the alternator 9 via the crank pulley 6 and the V-belt 7. In addition,
A radiator 12 is arranged slightly in front of the engine E.

As mentioned above, since the engine E is arranged with its upper part tilted rearward, a relatively large space is formed below the bonnet 13 and in front of the engine E, which becomes wider in the front and rear as it goes upward. There is. Therefore, the air intake device F is arranged by effectively utilizing the wide upper part of this space.

The intake device F takes in air from the opening at the front end of the air duct 14, and takes this air into the surge tank 21 through the front chamber member 15, the rear chamber member 16, and the connecting pipe 19 in this order. Furthermore, the air in the surge tank 21 is supplied to the corresponding cylinder through each independent intake passage 22 provided for each cylinder. Note that the air taken into the intake device F is
The air is filtered by an air cleaner (element) 17 disposed within the rear chamber member 16 to remove floating dust in the air.

The specific structure of the intake device F will be explained below. In the intake device F, the rear chamber member 16, the connection pipe 19, the surge tank 21, and the independent intake passage 22 are as follows:
It is integrally formed of resin to form an assembly S, and this assembly S is assembled using a plurality of mounting bolts 25 at the positions between each cylinder of the engine E, that is, at the parts where the independent intake passages 22 are not arranged. , is attached to the front side of the cylinder head 2. Note that, in order to improve the adhesion between the resin assembly S and the metal cylinder head 2, an O-ring 26 is disposed on the connection surface between the two. Here, the assembly S
The installation work to the cylinder head 2 is performed by inserting the mounting bolts 25, tools (not shown), etc. from the front end opening of the rear chamber member 16 before installing the air cleaner 17 to the rear chamber member 16. .

A front chamber member 15 made of resin is attached to the front end opening of the rear chamber member 16. Note that the front chamber member 15 is attached after the air cleaner 17 is attached to the rear chamber member 16.

The air duct 14 is made of resin, and is fixed to the lower surface of the bonnet 13 with a mounting portion 14a. Therefore, the air duct 14 and the front chamber member 15 are not directly connected. however,
When the air duct 14 and the front chamber member 15 are respectively attached to predetermined positions, the rear end of the air duct 14 and the front end of the front chamber member 15 are brought into contact with each other. A sealing member 28 is arranged on the connection surface between these, and the air duct 14 and the front chamber member 1
5 are closely connected. In addition,
In this way, since most of the intake device F is made of resin, its weight can be reduced.

In the assembly S, the rear chamber member 16
is formed into a relatively large box shape, and a surge tank 21 is disposed near the lower end of this rear chamber member 16 . Each independent intake passage 22 branches from the surge tank 21, rises almost upward, curves with a relatively large curvature so as to be convex forward or upward, and extends rearward, and then extends toward the rear. It is connected to the intake port 27 in the head 2. In this way, since the curvature of each independent intake passage 22 is relatively large, the length of the intake path is somewhat long. The reason why the intake path length of each independent intake passage 22 is set to be somewhat long in this way is to effectively obtain an inertial effect in a predetermined rotation range of the engine E. As described above, since the engine E is arranged at an angle and a relatively large space is formed between the front side surface of the engine and the bonnet 13, it is easy to set the curvature of each independent intake passage 22 to be large. Can be done.

Each independent intake passage 22 has a surge tank 21
The rear chamber member 1 except for the vicinity of the rising part from
It is located within 6. And the rear chamber member 16
Inside, a fuel injection valve 23 is provided for each independent intake passage 22, and each fuel injection valve 23 is inserted into a fuel injection valve mounting hole 24 formed at the rear end of the rear chamber member 16. Fixed. Since each fuel injection valve 23 is disposed within the rear chamber member 16 in this manner, it is effectively cooled by the high-speed air flowing within the rear chamber member 16. Therefore, the temperature rise of the fuel in the fuel injection valve 23 or the fuel supply passage (not shown) is suppressed, vapor lock is prevented from occurring, or the specific gravity of the fuel is prevented from decreasing, and fuel injection is performed accurately. It will be done. Moreover, the air in each independent intake passage 22 is cooled, and the intake air filling efficiency is increased. Note that since the fuel injection valve 23 is disposed downstream of the air cleaner 17 where the air flow velocity is particularly high, the cooling effect of the fuel injection valve 23 is enhanced. Further, since floating dust in the air is removed by the air cleaner 17, dust does not adhere to the fuel injection valve 23, thereby increasing its durability.

[0019]

According to the first aspect of the invention, the fuel injection valve and the independent intake passage are disposed within a chamber member constituting a collective intake passage, and are cooled by intake air flowing at high speed. Therefore, the temperature rise of the fuel in the fuel injection valve or the fuel supply passage around the fuel injection valve is suppressed, vapor lock or a decrease in specific gravity of the fuel is prevented, and fuel injection is performed accurately. Furthermore, since the air in each independent intake passage is cooled, the intake air filling efficiency is increased.

According to the second invention, basically the same operation and effect as the first invention can be obtained. Furthermore, since the engine is installed in the vehicle horizontally with the upper part of the engine tilted toward the rear of the vehicle, a relatively large space is formed in front of the engine. Since the intake device is arranged at the front, the layout of the intake device becomes easy. Furthermore, since the shape of the independent intake passage can be set relatively freely, its path length can be set to a predetermined length that provides a good inertia effect.

According to the third invention, basically the same operation and effect as the second invention can be obtained. Furthermore, since the fuel injection valve is disposed downstream of the air cleaner where the flow velocity of intake air is particularly high, the cooling effect of the fuel injection valve is further enhanced. Further, since the air from which dust has been removed by the air cleaner comes into contact with the fuel injection valve, dust does not adhere to the fuel injection valve, thereby increasing its durability.

[Brief explanation of drawings]

FIG. 1 is a partially sectional side elevational explanatory view of an engine equipped with an intake device according to the present invention.

FIG. 2 is a front elevational explanatory view of the intake system of the engine shown in FIG. 1;

FIG. 3 is an explanatory cross-sectional view taken along line A-A of the intake device shown in FIG. 2;

[Explanation of symbols]

E...Engine F...Intake device W...Car 1...Intake device 14...Air duct 15...Front chamber member 16... Rear chamber member 17...Air cleaner 22...Independent intake passage 23...Fuel injection valve

Claims (3)

[Claims] Claim 1: In an engine in which a fuel injection valve is provided for each independent intake passage provided for each cylinder, a collective intake passage upstream of the independent intake passage is connected to each fuel injection valve and each independent intake passage. An intake device for an engine, characterized in that it is formed as a chamber member that contains at least a portion near a fuel injection valve. 2. In the engine intake system according to claim 1, the engine is mounted on the vehicle with the engine placed horizontally relative to the vehicle and the upper part of the engine is inclined toward the rear of the vehicle, and the intake passage system is An engine intake device characterized in that it is arranged on the front side of a vehicle with respect to the engine. 3. The engine intake system according to claim 2, wherein each fuel injection valve is disposed within a chamber member downstream of the air cleaner.