JPS588921Y2 - exhaust port liner - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an exhaust port liner for an internal combustion engine.

A cylindrical port liner is inserted into the exhaust port with a gap between it and the inner wall surface of the exhaust port in order to maintain the temperature inside the exhaust port at a high temperature and help purify the exhaust gas that is exhausted. Forming a layer is performed.

The temperature difference within this exhaust port is significant, so the exhaust port liner is thermally expanded and contracted.

Exhaust port liners with various structures have been proposed in the past, but all of them are internally designed to actively allow thermal expansion and contraction in the axial direction, but there are no means to actively absorb thermal expansion and contraction in the radial direction. Not considered.

Therefore, there was a problem in that the exhaust port liner was distorted and deformed.

The present invention relates to a port liner provided in order to eliminate the above-mentioned problems.

Embodiments of the present invention will be described below with reference to the drawings.

1 is a cylinder head, 2 is an exhaust port provided in the cylinder head 1, 3 is an exhaust valve seat, 4 is an exhaust valve, and 5 is a gasket 10 that also serves to hold a port liner at the exhaust outlet of the front exhaust port 2. The exhaust manifold is connected via the exhaust manifold.

6 is an exhaust port liner according to the present invention.

This exhaust port liner 6 is a cylindrical body inserted into the exhaust port 2 with a gap between it and the inner wall circumferential surface, and one end is regulated to abut against the exhaust port wall surface, and the other end is slidable. It is movably supported in abutment.

For example, as shown in the figure, one end 8 on the exhaust valve 4 side is brought into contact with the wall surface of the exhaust port 2, and the other end 9 on the exhaust outlet side is slidably supported in contact with the inner peripheral wall surface of the exhaust outlet. , is fitted into the gasket 10 so as to be relatively movable.

Although not shown, a configuration opposite to the above may also be used.

Further, in order to stably support the exhaust port liner 6 in the radial direction, a bullet support piece 11 is provided on the outer circumferential surface of the exhaust port liner 6 and is supported on the inner wall surface of the exhaust port 2 by five pieces.

The port liner according to the present invention has the same structure as the port liner 6 described above, but has a large number of axially long slits 7 formed at appropriate intervals in the peripheral wall thereof.

Since the present invention has the above-mentioned structure, the exhaust port 2 has an air insulation layer formed by the exhaust port liner 6, and maintains the temperature of the exhaust gas passing through the exhaust port liner 6 at a high temperature and releases it into the cooling water. The amount of heat can be reduced.

As this high-temperature exhaust gas passes through, the exhaust port liner 6 is affected by heat and expands and contracts.

In the illustrated example, the other end 9 of the exhaust port liner 6 is slidably supported in contact with the exhaust outlet of the exhaust port 2, so that the expansion and contraction in the axial direction can be sufficiently absorbed by the other end 9. do.

Furthermore, expansion and contraction in the radial direction is actively absorbed by the slits 7 formed in the peripheral wall of the exhaust port liner 6.

In this way, the exhaust port liner according to the present invention has a large number of axially long slits in its peripheral wall, so it can actively absorb expansion and contraction in the radial direction due to the thermal effects of particularly large temperature differences. This has the advantage of preventing deformation or damage to the exhaust port liner.

Additionally, the exhaust port liner of the present invention is different from the casting method when the cylinder head is cast, or the method where it is fastened together with the exhaust manifold, and can be installed in the specified position by simply inserting the cylinder-shaped liner into the exhaust port. Because of this, the installation work is easy and it has versatility so that it can be immediately applied to the exhaust port of a conventional cylinder head.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the cylinder head exhaust port section equipped with the exhaust port liner of the present invention, and Figure 2 is the same as Figures 1 - ■.
FIG. 1...Cylinder head, 2...Exhaust port, 6...Exhaust port liner, 7...
·slit.

Claims (1)

[Scope of utility model registration request] A cylindrical port that has a gap between the exhaust port provided in the cylinder head and the circumferential surface of the inner wall, has one end in contact with the exhaust port wall surface, and the other end is slidably supported in contact with the exhaust port wall surface. An exhaust port liner characterized in that a long slit is provided in the peripheral wall of the port liner in the axial direction.