JPH0861172A - Intake air manifold - Google Patents

Abstract

PURPOSE: To prevent fuel leakage caused by breaking in the vicinity of a connecting part of a branching pipe part with an engine body, reduce a weight increase, and enhance castability and workability. CONSTITUTION: In an intake air manifold 1 having a surge tank part 2 and a branching pipe part 3 extending by bending toward one side surface of a cylinder head 5 from this surge tank part 2, a cross-sectional shape of a part in the vicinity of a connecting part of the branching pipe part 3 with the cylinder head 5, is formed in a shape having thick parts 15 projecting in a shoulder shape to both side parts on the bending directional inside of the branching part 3, and cross-sectional performance is enhanced without causing undulations on an outside surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake manifold for an automobile engine, and more particularly to an intake manifold for preventing fuel leakage due to breakage during a collision.

[0002]

2. Description of the Related Art Conventionally, an intake manifold of an automobile engine is reinforced with stays and reinforcing ribs to increase its strength, thereby preventing a branch pipe of the intake manifold from being damaged and causing fuel leakage in the event of a collision. It is thought to do. An example thereof will be described with reference to FIG.

In FIG. 4, 21 is a surge tank unit 2.
2 is an intake manifold having a branch pipe portion 23 that is curved and extends from the surge tank portion 22 toward one side surface of the cylinder head 25. One end of the surge tank portion 22 and the cylinder head of the branch pipe portion 23. 25 is connected by a stay 24 to a position near the connecting portion, the middle portion of the branch pipe portion 23 is supported by the vehicle body 27 or the engine body by the support bracket 26, and the bending direction of the middle portion of the branch pipe portion 23. Reinforcing ribs 2 extending in the longitudinal direction of the branch pipe portion 23 on the inner outer surface.
8 is provided to project, and the wall thickness of the branch pipe portion 23 is increased as necessary.

It is disclosed in Japanese Utility Model Laid-Open No. 4-111552 that reinforcement of the intake manifold by strengthening with a stay to prevent the branch pipe from being cracked or damaged. A reinforcing rib is provided on the outer surface of the branch pipe. Those are disclosed in Japanese Utility Model Publication No. 4-34455.

[0005]

However, even if the rigidity of the intake manifold 21 is increased by various means as described above, a particularly large bending moment is generated in the vicinity of the connection portion of the intake pipe portion 23 with the cylinder head 25 at the time of collision. Acting,
Therefore, there is a problem that the fear of fuel leakage due to breakage of this portion cannot be completely eliminated.

Therefore, the cylinder head 2 of the intake pipe portion 23
It is conceivable to increase the wall thickness t of the pipe wall in the vicinity of the connecting portion with 5, as shown in FIG. 5 (a). However, if the overall wall thickness is increased, unnecessary weight increase is caused. The problem occurs. In Japanese Utility Model Laid-Open No. 63-45058, there is disclosed a cross-sectional shape of the intake pipe in which the wall thickness of the intake pipe along the vibration direction accompanying the operation of the engine is made thicker than other portions. However, according to this, in the vicinity of the connection portion with the cylinder head 25, the thickness of both side portions becomes large, and the upper and lower thicknesses on which a large bending stress acts are thin, so that the effect is not sufficiently exerted.

Further, as shown in FIG. 5 (b), the cylinder head 2 of the intake pipe portion 23 on which a particularly large compressive stress acts.
It is conceivable to provide ribs 29 on the outer surface of the upper portion in the vicinity of the connection portion with 5, but die cutting becomes difficult and castability deteriorates, and workability of the injector hole processed in this portion deteriorates. Problems arise.

In view of the above conventional problems, the present invention can enhance the strength of the branch pipe portion in the vicinity of the connection portion with the engine body to prevent the occurrence of fuel leakage due to breakage, and the weight increase is small, and the casting An object is to provide an intake manifold that does not deteriorate in workability and workability.

[0009]

According to the present invention, there is provided an intake manifold having a surge tank portion and a branch pipe portion curved and extending from the surge tank portion toward one side surface of an engine body. The cross-sectional shape of the portion near the connecting portion with the engine body is characterized in that it has a thick portion projecting like a shoulder on both sides on the inner side in the bending direction of the intake pipe portion.

[0010]

[Operation] At the time of collision, a large load is applied to the surge tank toward the engine body, which causes a bending moment to act on the intake pipe. Therefore, the portion near the connecting portion of the branch pipe to the engine body is bent by the bending moment. Compressive stress acts on the inside in the direction, tensile stress acts on the outside in the bending direction, and in particular, large compressive stress acts on the inside portion in the bending direction of the intake pipe portion due to the bending moment and the collision load. Since the thick portions protruding like shoulders are provided on both sides of the shoulder, sufficient strength can be ensured, and breakage can be reliably prevented, and the risk of fuel leakage due to breakage can be eliminated. Also, since the wall thickness is only partially increased, the weight increase is small, and since the thick part is formed so as to project like shoulders on both sides,
There are no undulations on the outer surface, the castability does not deteriorate, and it does not hinder the processing of the injector hole. Further, since there is no undulation on the outer surface, there is no fear that water will accumulate, and the drainage is good.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described with reference to.

In FIGS. 1 and 2, reference numeral 1 denotes an intake manifold, which is curved and extended from a surge tank portion 2 and one side surface of a cylinder head 5 constituting the engine body from the surge tank portion 2. A plurality of branch pipes 3a, 3b,
And a branch pipe portion 3 composed of 3c. Reference numeral 4 is a mounting flange for the cylinder head 5 provided at the tip of the branch pipe portion 3. Appropriate branch pipes 3a, 3 in the branch pipe portion 3
A support piece 6 is provided on the outer peripheral side of the intermediate curved portion of b, and is supported by a support bracket 7 mounted on the vehicle body 8 side. The support bracket 7 may be attached to an engine body such as a cylinder block (not shown).

Reinforcing ribs 9 are provided on the inner peripheral side of the intermediate curved portions of the branch pipes 3a, 3b, 3c of the branch pipe portion 3 from the support position of the support bracket 7 toward both sides in the longitudinal direction of the branch pipes 3a, 3b, 3c. It is projected. Further, a mounting projection 10 is provided on one side of the mounting flange 4 of the branch pipe portion 3 with respect to the cylinder head 5, and a mounting seat 11 is provided outside the position near the connection portion of the branch pipe 3c with the surge tank portion 2 on one side. Is provided,
The mounting protrusion 10 and the mounting seat 11 are connected by a stay 12.

Further, ribs 13 are provided on the outer peripheral side of the intermediate curved portions of the respective branch pipes 3a, 3b, 3c so as to extend from the vicinity of the curved portion to the surge tank portion 2, and the surge tank portion 2 and the stay 12 are fixed to each other. A notch 14 is formed in the rib 13 at a position between them. As shown in detail in FIG. 3, the notch 14 has an opening angle θ of 90 ° or less and a depth h of the rib 13.
It is preferable that the height of H is H and h = H / 2 to H.

Further, in the vicinity of the connecting portion of each branch pipe 3a, 3b, 3c with the cylinder head 5, as shown in FIG.
As shown in (c), in the cross-sectional shape, the intake pipe portion 3
Thick portions 15 projecting like shoulders are formed on both sides on the inner side in the curving direction. In addition, the cross-sectional shape of the intake passage through which the intake air flows is formed as it is.

In the above structure, the middle portion of the branch pipe portion 3 is supported by the vehicle body 8 or the engine body via the support bracket 7, and the portion near the surge tank portion 2 is near the connecting portion with the cylinder head 5. Since the position and the stay 12 are connected to each other, the rigidity of the branch pipe portion 3, particularly the connecting portion with the cylinder head 5 can be increased.

Further, the surge tank portion 2 collides with a cowl portion (not shown) in the front portion of the vehicle compartment as the engine body moves during a collision from the front, and as shown by a white arrow in FIG. When a large external force F acts, a bending moment acts on the intake pipe portion 3, and in the portion near the connection portion of the branch pipe portion 3 with the cylinder head 5, the bending moment causes a compressive stress to the inner portion in the bending direction. Tensile stress acts on the outside portion in the direction, and in particular, a large compressive stress acts on the inside portion in the bending direction of the intake pipe portion 3 due to the bending moment and the external force F.
Sufficient strength can be ensured by providing thick portions 15 protruding in a shoulder shape on both sides in the vicinity of the connecting portions of b and 3c with the cylinder head 5.
In the illustrated example, the cross-sectional performance was improved by 40%, and the strength was significantly improved.

Therefore, even if a large external force F acts as described above at the time of a collision from the front, the branch pipe portion 3 can be prevented from being broken at the connection portion with the cylinder head 5, and each branch pipe 3a, It is possible to reliably prevent the fuel from leaking out from the fuel injection device (not shown) arranged at the connecting portion of the cylinder heads 3b and 3c.

Moreover, the rib 13 is provided between the intermediate portion of the branch pipe portion 3 and the surge tank portion 2 and the notch 14 is provided in the rib 13 between the surge tank portion 2 and the fixed position of the stay 12. When the external force F acts on the surge tank portion 12 due to the collision from the front as described above, the surge tank portion 2 in the intake manifold 1, the stay 12 of the branch pipe portion 3 and the support bracket 7 are supported, and the reinforcement rib 9 is supported. As shown by the arrow, a tensile force FA acts between the reinforced portion and the reinforced portion, and the tensile force FA causes stress to concentrate at the position where the notch 14 is formed, resulting in fracture at that portion. Can absorb collision energy. for that reason,
The invasion of the cowl portion into the vehicle compartment can be suppressed, and the occupant can be protected. In addition, the rib 13 is provided and the notch 1 is formed in the rib 13.
By providing No. 4, it is possible to change the wall thickness while minimizing the increase in weight, and it is possible to effectively cause stress concentration.

Further, since the thick portion 15 projecting from the connecting portion of the branch pipe portion 3 with the cylinder head 5 is only partially provided in a shoulder shape, the weight increase is small, and the rib is further provided. Unlike the case of projecting, no undulation occurs on the outer surface, so that the castability does not deteriorate, and there is no obstacle during machining of the injector hole. Further, since there is no undulation on the outer surface, there is no fear that water will accumulate, and the drainage is good.

[0021]

As described above, according to the intake manifold of the present invention, even if a large compressive stress due to a bending moment and a collision load acts on the inside portion of the intake pipe in the bending direction at the time of a collision, it projects like a shoulder on both sides. By providing a thick portion that protects the wall, sufficient strength can be secured, breakage can be reliably prevented, and the risk of fuel leakage due to breakage can be eliminated, and the wall thickness can be partially increased. Since it only has to be attached, the weight increase is small, and since the thick part is formed by protruding shoulders on both sides, there is no undulation on the outer surface,
Castability does not deteriorate, there is no hindrance during the processing of the injector hole, and there is no fear of water accumulation due to the fact that there is no undulation on the outer surface, and great effects such as good drainage are exhibited.

[Brief description of drawings]

FIG. 1 shows an intake manifold of one embodiment of the present invention,
(A) is a side view, (b) is a sectional view taken along the line BB of (a),
(C) is a CC cross section of (a).

FIG. 2 is a view as viewed in the direction of arrows AA in FIG. 1;

FIG. 3 is an enlarged view of part D in FIG.

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

FIG. 5 is a diagram showing each example of a connecting portion reinforcing means in a conventional example.
FIG. 9 is a cross-sectional view taken along the line EE of FIG.

[Explanation of symbols]

 1 Intake Manifold 2 Surge Tank 3 Branch Pipe 5 Cylinder Head (Engine Body) 15 Shoulder-Thickened Wall

Claims (1)

[Claims] 1. An intake manifold having a surge tank portion and a branch pipe portion curvedly extending from the surge tank portion toward one side surface of the engine body, in the vicinity of a connection portion of the branch pipe portion with the engine body. An intake manifold characterized in that a lateral cross-sectional shape of the portion has a thick portion projecting like a shoulder on both sides on the inner side in the bending direction of the intake pipe portion.