JP2535339Y2 - Secondary air introduction device for engine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting portion of an injection valve for supplying secondary air for burning unburned components in exhaust gas of an internal combustion engine.

[0002]

2. Description of the Related Art A conventional secondary air injection valve is generally provided separately from an exhaust manifold. However, in a small engine, the space for mounting the injection valve is narrow, and it is difficult to set a mounting surface having a sufficient area on the cylinder head, and from the inner circumference to the outer circumference of the gasket provided on the mounting surface. However, there is an inconvenience that the distance, that is, the seal width cannot be sufficiently obtained.

[0003]

SUMMARY OF THE INVENTION The present invention simplifies the structure of the mounting portion and the gasket in the case where the secondary air injection valve and the exhaust manifold are arranged close to each other, and sufficiently increases the seal width of the gasket. The task is to take it.

[0004]

In order to solve the above-mentioned problems, the present invention provides an engine in which an exhaust manifold mounting surface is provided at an exhaust outlet on a side surface of a cylinder head. A series of gaskets provided near the outlet and provided with a mounting surface for a secondary air injection valve connected to the inlet on an extension of the mounting surface of the exhaust manifold, and common to the mounting portion of the exhaust manifold and the injection valve. These are mounted on the mounting surface using

[0005]

With the above means, a common gasket can be used for the mounting portion of the injection valve and the exhaust manifold, and the seal width of the gasket can be made large even in a portion where both mounting portions are close to each other. Airtightness can be obtained.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a V-type engine embodying the present invention, 2 and 3 are left and right cylinders, 4 and 5 are their cylinder heads, 6 and 7 are exhaust outlets, and 8 is an exhaust manifold connected to the exhaust ports. , 9 are mufflers, 10 and 11 are flanges for connecting the exhaust manifold 8 to the exhaust outlets 6 and 7, and 12 is a crankshaft.

As shown in FIG. 2, a secondary air injection valve 13 is disposed close to the flange 11 through a narrow boundary A, and the injection valve 13 and the flange 11 are connected to a common series of gaskets 14. Is attached to the cylinder head 5 by using. In the figure, 11a is a screw for fixing the flange 11, and 13a is a screw for fixing the injection valve 13.
As shown in FIG. 3, a mounting surface 15 is formed flat on the side surface of the cylinder head 5, and the injection valve 13 and the flange 11 of the exhaust manifold 8 are mounted on the mounting surface 15 via the gasket 14.

[0008] The injection valve 13 is, as shown in FIG.
4 and a valve case 17 integrally with a mounting portion 16
A cover 19 having an inflow port 18 is fixed thereto with screws 20, a valve seat 21 is interposed between the valve case 17 and the cover 19, and a valve hole 22 is formed in the valve seat 21. A lead 23 is attached to the valve hole 22, and an outlet 24 is formed in the bottom of the valve case 17. The injection valve 13 is connected to the mounting portion 16 with the screw 1.
3a and attached on the gasket 14 by tightening.
The flange 11 of the exhaust manifold 8 serves as a mounting portion of the exhaust manifold, and is fixed by screws 11a. A narrow boundary portion A shown in FIG.
Are used as a series which is not divided at the boundary portion A.

As shown in FIG. 4, an exhaust port 25 is provided in the cylinder head 5 and is opened and closed by an exhaust valve 26. The exhaust port 25 curves in the direction of the crankshaft 12, The mounting surface 15 formed on the side surface of the cylinder head 5 opens as an outlet 7 to which the flange 11 of the exhaust manifold 8 is connected. A secondary air inlet 28 is provided at a position connecting the outlet 24 of the injection valve 13 and the side surface of the exhaust port 25 to penetrate the cylinder head 5.
A fresh air is introduced from a hose 30 via a hose 30.

When the engine 1 operates, the exhaust port 2
Due to the high pressure in the valve 5, the reed 23 comes into close contact with the valve seat 21 and closes the valve hole 22, but when the pressure of the exhaust gas becomes negative, the valve hole 22 is opened to allow fresh air to flow into the exhaust gas, and Combustion of unburned components can be promoted.

In the above embodiment, the injection valve 13 is provided only on the cylinder 3 side.

[0012]

As described above, according to the present invention, the mounting surface for mounting the exhaust manifold and the secondary air injection valve on the cylinder head is provided as a series of planes, and the gasket is provided on both the exhaust manifold and the injection valve. Since a series of parts is provided, positioning at the time of processing the mounting surface can be performed only once, so that processing can be performed quickly, and the number of parts can be reduced since only one gasket is required. Furthermore,
Even if the exhaust manifold and the injection valve are arranged close to each other, the gasket is not divided at the boundary between the two members, so that the seal width is not narrowed and sufficient airtightness can be maintained.

[Brief description of the drawings]

FIG. 1 is a front view of an engine embodying the present invention.

[Fig. 2] Enlarged front view of main parts

FIG. 3 is a cross-sectional view of the same.

FIG. 4 is a longitudinal sectional view of the same.

[Explanation of symbols]

4, 5 Cylinder head 8 Exhaust manifold 1
3 Injection valve 14 Mounting surface 15 Gasket 25
Exhaust port 28 Secondary air inlet A boundary

Claims (1)

(57) [Scope of request for utility model registration] 1. An engine in which an exhaust manifold mounting surface is provided at an exhaust outlet on a side surface of a cylinder head, an inlet for secondary air communicating with an exhaust port is provided near the exhaust outlet, and the secondary air is connected to the inlet. A mounting surface for a secondary air injection valve is provided on an extension of the mounting surface of the exhaust manifold, and these are mounted on the mounting surface using a series of gaskets common to a mounting portion of the exhaust manifold and the injection valve. A secondary air introduction device for an engine.