JP2000130259A - Seal structure of intake manifold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve vibration isolating property and sound proofing property while holding high sealing performance by fitting and mounting a gasket composed of an elastic body to a flange in the radial direction formed on an attaching part of an intake manifold, mounting a fastening flange of a shape divided into two parts from its upper part, and fastening with a fastening tool. SOLUTION: A gasket 6 of a nearly turned-down U-shaped cross section which extends in the radial direction from an end edge of an intake manifold 1 to a flow passage, is held and mounted from a side surface, and a fastening flange 7 is attached from upward. The fastening flange 7 is formed in a shape divided into two parts whose divided surfaces are brought into continuously contact with each other so as to cover a flange 1a attached on the gasket 6. The intake manifold 1 is positioned in a full-float condition by the gasket composed of an elastic body and the fastening flange 7. It is thus possible to effectively reduce noise and vibration, and it is also improve heat insulating property without being brought directly contact a cylinder head 2 and the intake manifold 1 with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting an intake manifold of an engine and a mounting portion of a cylinder head, and more particularly to a sealing structure of an intake manifold for sealing and vibration-proofing a mounting portion of both members.

[0002]

2. Description of the Related Art Conventionally, the mounting portions of an intake manifold and a cylinder head of an engine have been made of a lightweight alloy or a synthetic resin in order to reduce the weight of the intake manifold. A soft gasket with a high degree of flexibility has been inserted between them, and various mounting structures have been developed and implemented with various shapes of mounting parts according to the insertion structure of such a soft gasket. . Taking an example based on the drawings, in the intake manifold 1 'made of a lightweight alloy, as shown in FIG. 4, the flange 1a of the intake manifold 1'
And a wide-area flat type gasket 3 which is in contact with the entire surface of the mounting surface of the cylinder head 2 and is fastened and fixed by a fastener 4 attached to the flange 1a of the intake manifold 1 '. On the other hand, in the intake manifold 1 made of synthetic resin, since the amount of distortion of the flange 1a is not small due to the synthetic resin material having poor hardness, as shown in FIG. It is mounted in an annular groove 1b formed in the flange 1a, and is fastened and fixed by a fastener 4 attached to the flange 1a. At this time, the flange 1a of the intake manifold 1 and the cylinder head 2 have a small metal contact area with the O-ring 5 and have insufficient rebound resilience. (FIG. 3 shows a state before tightening.)

[0003]

However, such an intake manifold structure cannot exhibit sufficient sealing performance and vibration damping performance. That is, in the structure shown in FIG. 4 in which the flat type gasket 3 is mounted on the flange 1a of the intake manifold 1 'made of a lightweight alloy, since the flat type gasket 3 comes in contact with a large mass and a large area, a sufficient surface pressure is applied. Has its flange 1
Since an excessive load is applied to the mounting portion (a), a high strength is required, and there is a disadvantage that it is absolutely disadvantageous in weight. Further, in the case of the intake manifold 1 made of synthetic resin using the odd-shaped O-ring 5, since the structure is such that the cylinder head 2 which is a hard member is metal-touched as described above, the vibration from the engine is directly transmitted, and the vibration preventing effect is obtained. Cannot be expected at all. The present invention has solved such a problem by full-floating the intake manifold, and has succeeded in obtaining vibration-proofing and soundproofing while maintaining high sealing performance.

[0004]

The present invention relates to a seal structure of an intake manifold for mounting and sealing an engine cylinder head 2 and an intake manifold 1 as shown in FIGS. Radial flange 1a formed on mounting part
A gasket 6 made of an elastic body and having a substantially U-shaped cross-section is fitted and mounted, and a flange 1a of the intake manifold 1 to which the gasket 6 is attached is covered from above, and is divided along a cylindrical portion into two fastening flanges. 7 is attached, and the intake manifold 1 is fixed with the fastener 4.

[0005]

DETAILED DESCRIPTION OF THE INVENTION As described above, according to the present invention, a gasket 6 is interposed between a cylinder head 2 of an engine and an intake manifold 1, and the gasket 6 is fastened to a flange 7 of the engine.
The intake manifold 1 is fixed in a full float state by being tightened from the outside, and a radial flange 1a is formed in a mounting portion of the intake manifold 1 in order to maintain the float state well, and the elastic body is The gasket 6 is formed to have a substantially U-shaped cross section, and the two-part tightening flange 7 covering the gasket 6 can be elastically and accurately mounted.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a gasket 6 having a substantially U-shaped cross section sandwiched and mounted on a flange 1a extending radially from the end edge of an intake manifold 1 with respect to a flow path, and tightening a fastening flange 7 from above. FIG. 2 shows the mounting state, in which the fastening flange 7 is connected to the cylindrical portion of the intake manifold 1 having a plurality of divided surfaces connected so as to cover the flange 1a to which the gasket 6 is mounted, as shown in FIG. It has a divided shape.
As the two-part shape, from a full cover shape covering the entire mounting portion of the intake manifold 1 as shown in FIG. 2 to a partial cover shape (not shown) partially covering only the flange 1 a and the gasket 6. There is no problem if any shape can be freely selected, and any shape can be used to restrain the flange 1a with the gasket 6 and to fix it softly and securely without displacement.

[0007]

As described above, in the seal structure of the intake manifold of the present invention, the intake manifold 1 is placed in a full float state by the gasket 6 made of an elastic body and the tightening flange 7, so that the sound and vibration are reduced. In addition, there is an advantage that the cylinder head 2 and the intake manifold 1 are not in direct contact with each other, so that the heat insulating property is excellent. In addition, since the intake manifold 1 has a flange 1a completely floating and fixed by a gasket 6 formed in a substantially U-shaped cross section, there is an elastic margin, so that the distortion of the intake manifold 1 can be reduced. It is advantageous in sealing performance because it can be regulated by. Of course, the two-part structure of the fastening flange 7 ties the cylindrical portion of the intake manifold 1 from both sides, so that the mounting workability is dramatically improved, and the followability to each manifold 1 or gasket 6 is also excellent, so that it is perfect. It has a simple sealed structure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a mounted state of an intake manifold.

FIG. 2 is a plan view showing an embodiment of a fastening flange.

FIG. 3 is a cross-sectional view showing a conventional mounting state of an intake manifold.

FIG. 4 is a cross-sectional view showing a conventional mounting state of an intake manifold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intake manifold 2 Cylinder head 3 Flat type gasket 4 Fastener 5 O-ring 6 Gasket 7 Fastening flange

Claims (1)

[Claims] In a seal structure of an intake manifold which is a mounting portion between an engine cylinder head and an intake manifold, a flange extending in a radial direction is formed on a mounting portion of the intake manifold,
A gasket having a substantially U-shaped cross section is fitted into this flange, and a two-part tightening flange that covers the flange from above and is divided along the cylindrical part is mounted from above, and tightened and fixed with a fastener. The seal structure of the intake manifold characterized by the following.