JPH08135531A - Intake manifold for engine - Google Patents

Abstract

PURPOSE: To reduce the installation height of connecting pipes for extraction of intake negative pressure and also reduce the affection of intake pulsation inside a surge tank in an intake manifold. CONSTITUTION: A part of the upper wall part of a surge tank 11 interconnected to the collective part of an intake pipe 7 is expanded toward the outside so as to form an expanded part 12. Also multiple connecting pipes 14 (straight pipes) are connected to the side walls of the expanded part 12, and interconnected to the inside of the swelled part 12. Then a negative pressure response actuator is connected to the connecting pipes 14 so as to take out intake negative pressure from the surge tank 11 as negative pressure source. Because the top end part of the connecting pipes 14 is extended along the upper outer wall surfaces of the surge tank 11, the installation height of the connecting pipes 14 is reduced. In addition, because the affection of intake pulsation inside the surge tank 11 becomes less apt to be transmitted to the connecting pipes 14 due to volume of interior of the swelled part 12, a uniform and stable intake negative pressure can be taken out from each connecting pipe 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine intake manifold having a surge tank.

[0002]

2. Description of the Related Art Generally, in an engine of an automobile (especially, an engine provided with a fuel injection device), a surge tank is provided at a collecting portion of an intake manifold to expand a volume of an intake passage to increase intake pulsation and intake air of each cylinder. Prevents interference.

In engines of automobiles and the like, negative pressure responsive actuators are often used as drive devices for engine control such as idle-up control. Various connection pipes are attached to the surge tank in order to take out the negative pressure in the surge tank as a drive source of this actuator.

By the way, as shown in FIG. 3, in general, the surge tank 4 of the intake manifold 3 mounted on the engine 2 of the automobile 1 is disposed on the uppermost part of the engine 2, and therefore, is located above the surge tank 4. When mounting the connecting pipe, it is necessary to consider the clearance with the engine hood 5.

Therefore, conventionally, as shown in FIG. 4, an L-shaped connecting pipe 6 is attached to the upper portion of the surge tank 5 of the intake manifold 4, and the tip of the connecting pipe 6 is provided along the outer wall surface of the surge tank 5. By extending in the horizontal direction, a clearance with the engine hood 5 is secured. In FIG. 4, 7 is an intake pipe communicating with the surge tank 4, and 8
Is a flange for connecting each intake pipe 7 to an intake port of a cylinder head (not shown), and 9 is a flange for connecting the surge tank 4 to a throttle body (not shown).

The connecting pipe 6 is bent by L as shown in FIG. 5 in order to make the mounting height as low as possible.
As shown in FIG. 6, an L-shaped welded portion 6a is often used rather than the L-shaped one.

[0007]

However, the above-mentioned conventional intake manifold 3 has the following problems.

Since a plurality of connecting pipes 6 are directly attached to each part of the surge tank 4, the influence of the intake pulsation in the surge tank 4 differs depending on the mounting position, and the negative pressure taken out from each connecting pipe 6 is likely to vary. , It is difficult to obtain a stable driving force for the negative pressure responsive actuator.

Further, the L-shaped connecting pipe 6 is more expensive than the straight pipe.
The manufacturing cost is high due to the use of. In particular, the welding shown in FIG. 6 is expensive, and there is a large problem of high manufacturing cost.

The present invention has been made in view of the above points, and it is possible to reduce the influence of intake pulsation in the surge tank on the connecting pipe, and the tip of the connecting pipe is provided outside the surge tank. An object is to provide an engine intake manifold that can be arranged along a wall surface.

[0011]

In order to solve the above-mentioned problems, the intake manifold of the engine according to the present invention of claim 1 bulges outward a part of the wall of the surge tank communicating with the intake pipe. The bulging portion is formed by connecting the connecting pipe to the bulging portion so as to communicate with the inside of the bulging portion.

The intake manifold for an engine according to a second aspect of the present invention is characterized in that, in addition to the structure of the first aspect, a connecting pipe is attached to a side surface portion of the bulging portion.

[0013]

According to the present invention, the connecting pipe is communicated with the inside of the surge tank through the bulging portion, so that the volume of the bulging portion allows the intake air in the surge tank. The influence of pulsation is less likely to be transmitted to the connecting pipe.

According to the invention of claim 2, in addition to the above, the tip of the connecting pipe extends along the outer wall surface of the surge tank.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. The same parts as those in the above-mentioned conventional example are designated by the same reference numerals and will be described with reference to FIG.

As shown in FIGS. 1 and 2, the intake manifold 10 according to this embodiment includes one or a plurality (three in the figure) connected to an intake port of a cylinder head (not shown) of an engine. A surge tank 11 having a substantially bottomed tubular shape is provided at the base end portion (collection portion) of the intake pipe 7. A flange 8 for connecting these to the cylinder head is provided at the tip of the intake pipe 7.

A bulging portion 12 having a substantially L-shaped top surface is formed on the upper portion of the surge tank 11 by bulging a part of the wall portion upward. Inside the bulging portion 12, the surge tank 11 is formed. A sub chamber 13 (see FIG. 2) communicating with the inside is formed. On the side wall of the bulging portion 12, a plurality of (two in each of the two side portions in the figure, and one in total, three in total) connecting pipes 14 (straight pipes) are provided.
Is attached and communicates with the sub chamber 13. The tip of the connecting pipe 14 extends along the upper outer wall surface of the surge tank 11. A flange 9 for connecting a throttle body (not shown) is provided at the opening of the surge tank 11.

The operation of the present embodiment configured as above will be described below.

Various negative pressure responsive actuators (not shown) for performing idle-up control and the like are connected to the connecting pipe 14 attached to the bulging portion 12 so that the negative suction pressure in the surge tank 11 is negative. Take it out as a drive source for the pressure-responsive actuator.

Since the connecting pipe 14 is attached to the side surface of the bulging portion 12 and extends horizontally along the upper outer wall surface of the surge tank 11, it is possible to attach the connecting pipe 14 in each direction. Also, the mounting height of the connecting pipe 14 can be lowered to ensure a sufficient clearance with the engine hood 5. Further, since the connecting pipe 14 is an inexpensive straight pipe, the manufacturing cost can be reduced.

Since the connecting pipe 14 is communicated with the inside of the surge tank 11 through the sub chamber 13 in the bulging portion 12, the influence of intake pulsation in the surge tank 11 is influenced by the volume of the sub chamber 13. It becomes difficult to be transmitted to, and stable intake negative pressure can be taken out. Further, by attaching a plurality of connecting pipes 14 to the bulging portion 12 and communicating the inside of the surge tank 11 via the sub chamber 13, a constant intake negative pressure can be taken out from each connecting pipe 14. In this way, since it is possible to reduce the influence of intake pulsation in the surge tank 11 and secure a stable negative pressure flow rate, it is possible to stabilize the operation of the negative pressure responsive actuator and perform accurate engine control. it can.

The shape of the bulging portion 12 and the volume of the sub-chamber 13 are not limited to those in this embodiment, but can be arbitrarily set in consideration of the number and direction of the connecting pipes 14 to be attached. Further, in the above-described embodiment, the case where the negative pressure is taken out from the connection pipe as the drive source of the negative pressure responsive actuator is explained. The same can be applied to the case of connecting and supplying bypass air or the like from the connecting pipe into the surge tank.

[0023]

As described in detail above, according to the intake manifold of the engine of the present invention, since the connecting pipe is attached to the bulging portion provided in the surge tank, the intake air in the surge tank is increased depending on the volume inside the bulging portion. The influence of pulsation is less likely to be transmitted to the connecting pipe. As a result, there is an excellent effect that a stable intake negative pressure can be taken out from the connecting pipe. Further, by attaching the connecting pipe to the side surface of the bulging portion, the tip of the connecting pipe can be extended along the outer wall surface of the surge tank.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is a partially cutaway view of an essential part of an embodiment of the present invention, taken along the arrow A in FIG.

FIG. 3 is an explanatory view showing a layout of an intake manifold of an automobile engine.

FIG. 4 is a perspective view of a conventional intake manifold.

FIG. 5 is a side view of an L-shaped connecting pipe manufactured by bending.

FIG. 6 is a side view of an L-shaped connecting pipe manufactured by welding.

[Explanation of symbols]

 7 Intake pipe 10 Intake manifold 11 Surge tank 12 Bulging part 14 Connection pipe

Claims (2)

[Claims] 1. A part of a wall portion of a surge tank communicating with an intake pipe is bulged outward to form a bulging portion, and a connecting pipe is attached to the bulging portion to communicate with the inside of the bulging portion. The engine intake manifold characterized by 2. The intake manifold for an engine according to claim 1, wherein a connecting pipe is attached to a side wall of the bulging portion.