JPH07259571A - Engine intake system and manufacture thereof - Google Patents

Abstract

PURPOSE:To secure an intake system that is less in the number of part items and ease of manufacturing and assembling. CONSTITUTION:A joining part 11 being interconnected to plural intake ports of a multicylinder engine is formed in an inner surface of a vessel-form upper case 10, while plural pieces of grooves 13 corresponding to each of these intake ports. In addition, plural grooves 33 being connected to each of these grooves of the upper case 10 is formed in an inner surface of a vessel-form lower case 30 as well. Likewise, an intake expanding chamber is made up by means of blow forming, while an opening 22 is formed in an axial end on one side, and plural pieces of grooves 22 are parallelly installed on the outer surface, constituting a surge tank 20 there. In succession, the upper case 10 and the lower case 30 are joined together so as to house this surge tank 20, an intake air passage, whose one end is connected to these intake ports and the other end to an inner part of the surge tank 20, respectively, as mutually separated, is formed in space between the plural grooves of the lower case 30 and the plural grooves of the surge tank 20 as well as in space between the plural grooves of the upper case 20 and the plural grooves of the surge tank 20.

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 and a manufacturing method thereof, and more particularly to an intake system mounted on a multi-cylinder engine to improve output performance by utilizing an inertial effect of intake air and a manufacturing method thereof.

[0002]

2. Description of the Related Art Recently, a surge tank is provided in an intake system of an automobile engine. This is a tank of a predetermined capacity that is interposed between the intake pipe of the engine and the throttle body to define an intake expansion chamber, and can prevent intake pulsation and intake interference of each cylinder.

By the way, the pressure wave generated in the intake stroke of the engine propagates from the intake port through the intake pipe, is reflected at the open end of the surge tank, and returns to the intake port as a positive pressure wave immediately before the intake valve is closed. There is a phenomenon that it is pushed into the cylinder to improve the volumetric efficiency, which is called the inertial effect of intake air. In particular, in order to secure the inertial effect of intake air in the low engine speed range, a surge tank of a predetermined capacity is required and the intake passage must be of a predetermined length. In order to arrange these in a limited space inside the engine room, for example, as shown in Japanese Utility Model Laid-Open No. 58-20331, the intake port of each cylinder and the surge tank are connected by independent intake passages. An intake device that has been proposed has been proposed. Further, there is also known one in which an intake passage is formed around the surge tank by utilizing a part of the constituent wall of the surge tank.

In Japanese Patent Publication No. 3-53451, a part of the intake expansion chamber (surge tank) is positioned above the fuel injection valve in order to secure a sufficient volume of the intake expansion chamber (surge tank). In view of the difficulty in assembling the intake intake chamber, it is necessary to expand the intake expansion chamber so that it is located above the fuel injection valve. It has been proposed to insert a bolt, which is provided below the extension line of the center line of the fuel injection valve with respect to the expansion chamber, into which a dividing surface is provided and which fastens both dividing portions from below.

[0005]

In the above-mentioned conventional intake device, since the intake expansion chamber and the intake passage are formed by the common constituent wall, a plurality of middle parts are required to manufacture the constituent parts such as the case. It is necessary to use a casting method that combines a child and a resin molding method that uses a molten core,
The manufacturing cost is high, and the intake device is expensive after all. On the other hand, if each component has a structure that is easy to manufacture, the number of components increases, and assembly becomes difficult.

In view of the above, the present invention is directed to an engine intake device in which an intake passage for independently communicating and connecting each of a plurality of intake ports of a multi-cylinder engine and a surge tank is formed around the surge tank. It is an object of the present invention to provide an intake device for an engine, which has less fuel consumption and can be easily manufactured and assembled.

Another object of the present invention is to provide a manufacturing method capable of manufacturing the air intake device having the above structure with a simple die structure at a low cost.

[0008]

In order to achieve the above object, an intake system for an engine according to the present invention has an intake passage for independently connecting each of a plurality of intake ports of a multi-cylinder engine and a surge tank. In an engine intake device formed around the surge tank, a joint portion that communicates with the plurality of intake ports is formed, and a plurality of grooves corresponding to each of the plurality of intake ports are formed on an inner surface. And a container-like lower case formed by forming a plurality of grooves connected to each of the plurality of grooves of the upper case on the inner surface thereof, to integrally form an intake expansion chamber, and A surge tank having an axial end formed with an opening and a plurality of grooves arranged side by side on the outer surface, the upper case and the lower case being joined so as to accommodate the surge tank, One end communicates with the plurality of intake ports between the plurality of grooves of the upper case and the plurality of grooves of the surge tank, and between the plurality of grooves of the upper case and the plurality of grooves of the surge tank. The other end portion is configured to form mutually independent intake passages that communicate with each other inside the surge tank.

Further, in the method for manufacturing an intake device according to the present invention, a joint portion for communicating with a plurality of intake ports of a multi-cylinder engine is formed on the inner surface of a container-shaped upper case, and each of the plurality of intake ports is formed. To form a plurality of grooves corresponding to the, the inner surface of the container-shaped lower case, to form a plurality of grooves to be connected to each of the plurality of grooves of the upper case, to form an intake expansion chamber by blow molding, An opening is formed at an axial end, and a plurality of grooves are provided on the outer surface side by side to form a surge tank, the upper case and the lower case are joined so as to accommodate the surge tank, and the plurality of grooves of the lower case are formed. And a plurality of grooves of the surge tank, and between the plurality of grooves of the upper case and the plurality of grooves of the surge tank, one end communicates with the plurality of intake ports and the other end. But It is obtained by the forming mutually independent intake passage communicating with serial surge tank.

In the above method for manufacturing an air intake device, the upper case and the lower case may be formed by die casting of aluminum and the surge tank may be formed by blow molding of synthetic resin, or all of them may be formed by synthetic resin. Good.

[0011]

In the engine air intake system of the present invention, when the upper case and the lower case are joined in a state where the surge tank is housed, a plurality of grooves formed on the inner surfaces of the upper case and the lower case and the outer surface of the surge tank are formed. Independent intake passages are formed between the plurality of grooves formed in
One end of each intake passage communicates with the intake port, and the other end communicates with the surge tank. Thus, when the intake device having the above configuration is mounted on the engine and a pressure wave propagates from the intake port to the surge tank through the intake passage in the intake process of the engine, the surge tank has an axial opening in the opening. And returns to the intake port as a positive pressure wave immediately before the intake valve closes. As a result, intake air is filled in the cylinder, and good volume efficiency is obtained.

Further, in the method for manufacturing an intake device according to the present invention, first, the inner surface of the container-shaped upper case is formed with the joint portion which is connected to the plurality of intake ports of the multi-cylinder engine so as to communicate with each other. A plurality of grooves corresponding to Next, a plurality of grooves connected to each of the plurality of grooves of the upper case are formed on the inner surface of the container-shaped lower case. In addition, an expansion chamber is formed by blow molding, an opening is formed at one end in the axial direction, and a plurality of grooves are juxtaposed on the outer surface to form a surge tank. When the upper case and the lower case are joined so as to accommodate the surge tank, between the plurality of grooves of the lower case and the plurality of grooves of the surge tank, and between the plurality of grooves of the upper case and the plurality of grooves of the surge tank, In between, the mutually independent intake passages, one end of which communicates with the plurality of intake ports and the other end of which communicates with the surge tank, are formed.

The upper case and the lower case may be formed by die casting of aluminum, and the surge tank may be formed by blow molding of synthetic resin. Alternatively, all may be made of synthetic resin, and in this case, the upper case and the lower case can be easily joined by vibration welding, for example.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show an intake device according to an embodiment of the present invention, which is mounted on a four-cylinder engine (not shown). FIG. 1 is an exploded view of the air intake system of the present embodiment, which is composed of an upper case 10, a surge tank 20 and a lower case 30, and the upper case 10 and the lower case 30.
The lower case 30 is joined to the upper case 10 by the bolts BT in a state where the surge tank 20 is housed in the space defined by.

The upper case 10 is formed into a container shape, for example, by die casting of aluminum, and has a flange portion 11 formed at a side end thereof to be joined to an intake port portion (not shown) of the engine. Four openings (representatively represented by 12) of four intake passages corresponding to the intake ports of the four cylinders are formed in the flange portion 11 and communicate with the inner space of the upper case 10. As shown in FIG. 3, four grooves (representatively represented by 13) are formed inside the upper case 10. It should be noted that the flange portion 11 is provided with a plurality of bolt holes (representatively represented by 14) for joining to the engine.

The lower case 30 is also formed in a container shape by die casting of aluminum and has four grooves (typically 33
The grooves 33 are formed in parallel with each other, but these grooves 33 are gathered on one side in the axial direction of both cases as compared with the grooves 13 of the upper case 10. Further, a flange portion 31 joined to an intake cylinder (not shown) equipped with a throttle valve (not shown) is formed at one axial end of the lower case 30. An intake air inlet 32 is formed in the flange portion 31, and the intake air inlet 32 communicates with the inner space of the lower case 30. In addition, a plurality of bolt holes (representatively represented by 34) for joining the intake cylinder are formed in the flange portion 31, and bolt holes (representatively represented) are formed in the peripheral portion of the main body portion where the groove 33 is formed. Are represented by 35).

In the surge tank 20 provided between the upper case 10 and the lower case 30, the intake expansion chamber ER is formed by blow molding of synthetic resin, and the opening 22 is formed at one end in the axial direction. With the intake expansion chamber ER
Four grooves (representatively represented by 23) are arranged side by side on the outer periphery of the. As shown in FIG. 4, an opening 20a is formed in a direction orthogonal to the groove 23 (axial direction of the surge tank 20).

Thus, as shown in FIG. 1, the surge tank 2
0 to accommodate the upper case 10 and the lower case 30
Are joined and fixed by the bolts BT, the state shown in FIGS. 3 and 4 is obtained. That is, between the groove 13 of the upper case 10 and the groove 23 of the surge tank 20, and between the groove 23 of the surge tank 20 and the groove 33 of the lower case 30,
Four intake passages AP independent of each other are formed. One end of the intake passage AP communicates with each opening 12 that communicates with each intake port, and the other end communicates with the inside of the surge tank 20 through the opening 21a of the surge tank 21. Since the opening 22 of the surge tank 20 and the opening 32 of the lower case 30 communicate with each other, the intake cylinder (not shown) communicates with the inside of the surge tank 20 through the openings 22 and 32, and the intake passage It communicates with the opening 12 of the flange portion 11 through the AP, and eventually communicates with each intake port.

As described above, the upper case 10, the surge tank 20, and the lower case 30 are joined to form an intake device, and when this intake device is mounted on the engine through the flange portion 11, a pressure wave generated in the intake process is generated. Is propagated from the intake port (not shown) to the intake expansion chamber ER in the surge tank 20 via the intake passage AP, and the surge tank 20
It is reflected by the opening 22 of and returns to the intake port. If this timing is synchronized immediately before the intake valve (not shown) is closed, it returns to the intake port as a positive pressure wave, and the inertial effect of intake is obtained, and the volumetric efficiency of intake is improved.

As described above, in this embodiment, since the surge tank 20 is formed by blow molding, it can be easily set to a predetermined capacity. In addition, the intake passage AP includes the groove 23 of the surge tank 20, the groove 13 of the upper case 10, and the groove 33 of the lower case 30.
Since the shape of these grooves 13, 23, 33 which are formed between and can be easily made into a desired shape, the inertial effect of intake can be easily ensured while minimizing the overall size. The shape can be obtained.

That is, according to the present embodiment, the surge tank can be formed into a free shape by blow molding, and the surge tank has a simple structure in which the case is divided into two cases, and each case has a core or the like. Since it can be easily manufactured by die casting without using it, an inexpensive product can be obtained. In the present embodiment, the upper case 10 and the lower case 30 are manufactured by die-casting of aluminum, but they may be manufactured by resin molding, and in this case, they can be easily manufactured. Instead, both cases can be easily joined by vibration welding or the like.

[0022]

Since the present invention is configured as described above, it has the following effects. That is, in the intake system for an engine of the present invention, it has a surge tank integrally formed with the intake expansion chamber, a plurality of grooves formed on the inner surface of each of the upper case and the lower case, and the outer surface of the surge tank. It is configured so that mutually independent intake passages are formed between the formed plurality of grooves, and since the intake passage inertia effect is obtained by the intake passages, it is easy to manufacture, small and inexpensive. An intake device can be provided.

Further, according to the method for manufacturing an intake device of the present invention, mutually independent intake passages are formed by joining the upper case and the lower case so as to accommodate the surge tank formed by blow molding. Therefore, the intake device can be manufactured at low cost with a simple die structure.

In particular, if the surge tank is formed by blow molding of synthetic resin, it is easy to manufacture,
If the upper case and the lower case are also made of synthetic resin, they can be manufactured more easily.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an air intake device according to an embodiment of the present invention.

FIG. 2 is a plan view of an air intake device according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of an air intake device according to an embodiment of the present invention,
It is the sectional view on the AA line of FIG.

FIG. 4 is a cross-sectional view of an intake device according to an embodiment of the present invention,
It is the BB sectional view taken on the line of FIG. 2 and FIG.

[Explanation of symbols]

 10 Upper Case 20 Surge Tank 30 Lower Case 13, 23, 33 Groove AP Intake Passage ER Intake Expansion Chamber

Claims (4)

[Claims] 1. An intake system for an engine, wherein an intake passage for connecting each of a plurality of intake ports of a multi-cylinder engine and a surge tank independently to each other is formed around the surge tank. And a container-like upper case formed by forming a plurality of grooves corresponding to each of the plurality of intake ports on the inner surface, and connecting to each of the plurality of grooves of the upper case. A container-shaped lower case having a plurality of grooves formed on the inner surface and an intake expansion chamber are integrally formed, an opening is formed at one axial end, and a plurality of grooves are provided side by side on the outer surface. A surge tank, the upper case and the lower case are joined so as to accommodate the surge tank, between the plurality of grooves of the lower case and the plurality of grooves of the surge tank, and the upper case. Between the plurality of grooves of the surge tank and the plurality of grooves of the surge tank, one end of which communicates with the plurality of intake ports and the other end of which communicates with the inside of the surge tank. An intake system for an engine, characterized in that 2. An inner surface of a container-shaped upper case is formed with a joint portion communicating with and connected to a plurality of intake ports of a multi-cylinder engine, and a plurality of grooves are formed corresponding to each of the plurality of intake ports. On the inner surface of the container-shaped lower case, a plurality of grooves that are connected to each of the plurality of grooves of the upper case are formed, while forming an intake expansion chamber by blow molding, and forming an opening at one axial end, A plurality of grooves are juxtaposed on the outer surface to form a surge tank, the upper case and the lower case are joined so as to accommodate the surge tank, and the plurality of grooves of the lower case and the plurality of grooves of the surge tank are formed. And between the plurality of grooves of the upper case and the plurality of grooves of the surge tank, one end communicates with the plurality of intake ports and the other end communicates with the inside of the surge tank. Germany A method for manufacturing an intake device, which comprises forming an upright intake passage. 3. The method for manufacturing an intake device according to claim 2, wherein the upper case and the lower case are formed by die casting of aluminum, and the surge tank is formed by blow molding of synthetic resin. 4. The method for manufacturing an intake device according to claim 2, wherein the upper case, the lower case and the surge tank are formed of synthetic resin.