JPH022921Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention is designed to connect the cylinder head side surface and the intake/exhaust manifold in a same-flow type engine in which both the intake port and the exhaust port are provided on the side surface of the cylinder head on the same side. This invention relates to an improvement of the intake/exhaust manifold gasket interposed between the intake and exhaust manifold gaskets.

(Prior Art) Generally, in this type of same flow type engine, the intake and exhaust manifold gaskets are
For example, as disclosed in Japanese Utility Model Application Publication No. 52-155853, it is integrally formed in order to improve assemblability, and an intake port and an exhaust port are provided at the portions corresponding to the intake port and exhaust port, respectively. It is something that

(Problem to be solved by the invention) By the way, the above-mentioned intake/exhaust manifold gasket not only prevents gas leaks, but also prevents thermal deformation of the cylinder head, that is, a large amount of gas is removed from the exhaust manifold which has become hot due to receiving a large amount of heat from the exhaust gas. Absorbs heat
It also has the purpose of preventing heat conduction to the cylinder head via the exhaust manifold gasket.
For this reason, at least the portion of the intake/exhaust manifold gasket that corresponds to the exhaust port side must be formed of a heat insulating material.

On the other hand, in recent years, as part of engine exhaust gas purification, blow-by gas in the crankcase is introduced into the combustion chamber of the engine and combusted. Usually, there is a structure near the combustion chamber of the intake manifold that communicates with the crankcase. One end of the blow-by gas introduction passage is open. However, blow-by gas contains moisture and mist-like oil, so when blow-by gas flows into the intake manifold from the introduction passage when the engine is cold, it is rapidly cooled by the intake air and condenses and freezes. However, there was a problem in that the opening of the blow-by gas introduction passage to the intake manifold was blocked. In order to solve this problem, there is a need for a heat source that thaws or prevents blow-by gas from condensing and freezing at the intake manifold opening.

The purpose of this invention is to prevent the heat of the exhaust manifold from being reversely conducted to the cylinder head via the intake/exhaust manifold gasket in a same flow type engine, and to transfer the heat of the cylinder head and exhaust manifold to the intake manifold. By making the heat conductive to
To suppress thermal deformation of a cylinder head as much as possible, and to thaw or prevent blow-by gas from condensing and freezing without adding a separate heat source.

(Means for Solving the Problems) In order to achieve this object, the present invention has been developed to improve the intake/exhaust manifold gasket interposed between the cylinder head side surface and the intake/exhaust manifold in the above-mentioned same flow type engine. The purpose is to make the constituent materials different for each part.

Specifically, the solution of the present invention is provided between the cylinder head side surface and the intake/exhaust manifold in a same-flow type engine in which both the intake port and the exhaust port are provided on the same cylinder head side surface, An intake/exhaust manifold gasket is formed with an intake port and an exhaust port that communicate with the intake port and the exhaust port, respectively, and the joint surface side with the side surface of the cylinder head on the exhaust port side is formed of a heat insulating material, and the exhaust port side is made of a heat insulating material. The joint surface side with the exhaust manifold on the port side, the joint surface side with the cylinder head side surface and the joint surface side with the intake manifold on the intake port side are made of a material with good thermal conductivity, and at least the joint surface with the cylinder head side surface is formed. It is assumed that the intake port side and the exhaust port side of the surface are integrally formed.

(Function) This prevents heat conduction from the exhaust manifold to the cylinder head with the heat insulating material, and also conducts the heat of the cylinder head and exhaust manifold to the intake manifold through the material portion with good thermal conductivity. By effectively heating the gas, it is possible to prevent the opening of the blow-by gas introduction passage from being blocked.

(Effect of the invention) Therefore, according to the invention, the intake/exhaust manifold gasket in a same-flow type engine has a heat insulating material on the joint surface with the side surface of the cylinder head on the exhaust port side, and a heat insulating material on the side of the joint with the side surface of the cylinder head on the exhaust port side. The joint surface side with the cylinder head, the joint surface side with the cylinder head side surface on the intake port side, and the joint surface side with the intake manifold on the intake port side are formed of a material with good thermal conductivity, and at least the joint surface with the cylinder head side surface is on the intake port side. Since the cylinder head and the exhaust port side are integrally formed, thermal deformation due to heat conduction from the exhaust manifold of the cylinder head can be suppressed as much as possible, and the heat of the exhaust manifold and cylinder head can be effectively transferred to the intake manifold. It is possible to thaw or prevent the blowby gas from condensing and freezing at the opening of the blowby gas introduction passageway to the intake manifold without additionally installing any heat source. Therefore, it is possible to maintain engine performance, improve durability, and improve reliability of blow-by gas processing performance all at once at low cost.

(Example) Hereinafter, an example as a specific example of the technical means of the present invention will be described based on the drawings.

Figures 1 and 2 show a same-flow type four-cylinder engine, where 1 is the cylinder head, 2a,
2b, 2c, and 2d are formed in a row horizontally on the left and right sides of the cylinder head 1 in FIG.
intake ports. 3a, 3b, 3c, 3d
are the intake ports 2a to 2 on the side of the cylinder head 1 on the same side as the intake ports 2a to 2d, respectively.
There are four exhaust ports that are formed adjacent to the lower part of d and open into the combustion chamber (not shown) in pairs with the corresponding intake ports 2a to 2d. Further, reference numeral 4 denotes an intake manifold whose downstream end is connected and communicated with each of the above-mentioned intake ports 2a to 2d through four branch parts 4a to 4d, respectively, and 5 which has an upstream end connected to each of the above-mentioned intake ports 2a to 2d through four branch parts 5a to 5d, respectively. This is an exhaust manifold connected and communicated with exhaust ports 3a to 3d. Then, the intake air is transferred to each intake port 2a on one side of the cylinder head 1 by the intake manifold 4.
2d to a combustion chamber (not shown), and exhaust gas is discharged to the atmosphere from exhaust ports 3a to 3d on the side of the cylinder head 1 on the same side via an exhaust manifold 5. It consists of

Further, as shown in FIG. 2, 6 is a blow-by gas introduction passage that opens at the center of the upper end of the cylinder head cover 7 (only halfway shown) and communicates with the engine crankcase, and the other end 4 through the gas reservoir chamber 6a as shown in FIG.
Each branch passage 4a to 4d of the intake manifold 4 and the intake port 2a to 2d are connected to each other by the four communication ports 6b to 6e.
The blow-by gas is distributed from the gas reservoir chamber 6a to a combustion chamber (not shown) and combusted.

As shown in FIG. 2, an intake/exhaust manifold gasket 8 is interposed between the side surface of the cylinder head 1 and the intake/exhaust manifolds 4, 5. As shown in FIG. 4, the intake/exhaust manifold gasket 8 has intake ports 8a to 8d communicating with the intake ports 2a to 2d, respectively, and exhaust ports 8e to 8h communicating with the exhaust ports 3a to 3d, respectively.
and are formed in a two-layered structure as shown in FIG. The joint surface side with the side surface of the cylinder head 1 and the joint surface side with the intake manifold 4 on the side of the intake ports 2a to 2d, and the exhaust port 3
The joint surface side with the exhaust manifold 5 on the sides a to 3d is formed of a material 10 with good thermal conductivity such as composite material or thermally expandable graphite.

Therefore, in the above embodiment, the exhaust ports 3a to 3 of the intake/exhaust manifold gasket 8
Since the joint surface side with the side surface of the cylinder head 1 on the d side is formed of the heat insulating material 9, the exhaust manifold 5
Heat conduction from the cylinder head to the cylinder head 1 side is prevented, and thermal deformation of the cylinder head 1 can be suppressed as much as possible. In addition, the side of the intake/exhaust manifold gasket 8 on the side of the intake ports 2a to 2d that is joined to the side surface of the cylinder head 1 and the side that is joined to the intake manifold 4 is made of a material 10 having good thermal conductivity.
Since the cylinder head 1 side is formed of The openings 6a to 6e to the intake manifold 4, that is, the communication ports 6a to 6e, are not blocked, and therefore good blow-by gas processing performance can be maintained over a long period of time. Moreover, the exhaust port 3a of the intake/exhaust manifold gasket 8
The joint surface side with the exhaust manifold 5 on the 3d side is formed of a material 10 with good thermal conductivity, and the intake manifold 4 on the intake ports 2a to 2d side is made of a material 10 with good thermal conductivity.
Since it is formed integrally with the joint surface side with the exhaust manifold 5, the heat from the exhaust manifold 5 can also be effectively used to heat the intake manifold 4, and the above-mentioned blow-by gas treatment performance can be more reliably maintained over a long period of time.

In the above embodiment, the intake/exhaust manifold gasket 8 has a two-layered structure, but the structure can be simplified as shown in FIG. It is also possible to have a single-layer structure in which `` is also used as a pedestal for the heat insulating material 9 ''. In this case, as in the above embodiment, the heat of the exhaust manifold 5 is transferred to a material with good thermal conductivity.
This is preferable in that it is conducted to the intake manifold 4 through the air outlet 0' and can reliably thaw or prevent the blow-by gas from condensing and freezing.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a side view of a same-flow type engine, Fig. 2 is a front view of the same, and Fig. 3 is an enlarged plan view showing the opening of the blow-by gas introduction passage to the intake manifold. , FIG. 4 is a front view of the intake/exhaust manifold gasket, FIG. 5 is a sectional view taken along the line -- in FIG. 4, and FIG. 6 is a view equivalent to FIG. 5 showing a modification of the intake/exhaust manifold gasket. . DESCRIPTION OF SYMBOLS 1...Cylinder head, 2a-2d...Intake port, 3a-3d...Exhaust port, 4...Intake manifold, 5...Exhaust manifold, 6...Blow-by gas introduction passage, 6b-6e...Communication port, 8, 8'...
Intake/exhaust manifold gasket, 8a to 8d...
Intake port, 8e to 8h...Exhaust port, 9,9'...Insulation material,
10,10'...Material with good thermal conductivity.

Claims (1)

[Scope of utility model registration request] In a same-flow type engine in which both the intake port and the exhaust port are provided on the side surface of the cylinder head on the same side, the intake air is interposed between the side surface of the cylinder head and the intake/exhaust manifold, and communicates with the intake port and the exhaust port, respectively. An intake/exhaust manifold gasket is formed with an inlet and an exhaust port, and the side where the exhaust port side is connected to the side surface of the cylinder head is made of a heat insulating material, and the side where the exhaust port side is connected to the exhaust manifold is made of a heat insulating material. In addition, on the intake port side, the joint surface side with the side surface of the cylinder head and the joint surface side with the intake manifold are formed of a material with good thermal conductivity, and at least the joint surface side with the cylinder head side surface is made of a material with good thermal conductivity. An intake/exhaust manifold gasket characterized by being integrally formed.