JPS6250064A - Production of variable swirl port - Google Patents

Abstract

PURPOSE:To easily form a variable swirl sport by installing a core provided with a partition plate in the part corresponding to the boundary between a main port part and auxiliary port part into a casting mold for a cylinder head and executing insert-casting integrally with the partition plate. CONSTITUTION:The core 15 is formed by mounting the partition plate 14 made of metal to the boundary part 13c between the space part 13a corresponding to the main port 3 and the space part 13b corresponding to the auxiliary port part 4 in a core mold 12 for forming the variable swirl port. The core 15 provided with the partition plate 14 is installed in the casting mold and a molten metal is poured into the old to insert-cast the plate 14 integrally with the cylinder head part. The production of the variable swirl port is thereby made easy and low in cost.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for forming a variable swirl port 1 having mutually independent main ports and sub ports in a cylinder head of an engine.

<Prior art> For example, the cylinder head of a direct injection diesel engine is provided with an intake port, and air introduced into the combustion chamber through the intake port is compressed there and mixed with fuel injected from an injection nozzle. , explosive combustion of fuel is achieved. It is well known that the better the air and fuel mixture in the combustion chamber, the better the combustion efficiency.For this reason, intake ports have traditionally been devised to forcefully form a swirl in the intake air to improve the mixing state. Things are being done to improve this.

By the way, the strength of the swirl formed in the combustion chamber affects, for example, engine performance, the amount of nitrogen oxides generated, fuel efficiency, etc., and the intake air at the optimum swirl ratio (combustion chamber) depends on the operating condition of the engine. It is desirable that the strength of the swirl can be adjusted because the ratio of the rotational speed of the engine to the rotational speed of the engine differs. Therefore, various intake boats (variable swirl boats) with variable swirl ratios have been proposed. However, the variable swirl boats that have been proposed so far have had the problem of reducing the amount of intake air by changing the swirl ratio.

Therefore, as shown in FIGS. 4 and 5, the main port 3 connected to the upstream side of the intake valve 2 of the cylinder head 1 and the main port 3 connected at a certain angle near the terminal end of the main port 3 are currently being used. A variable swirl port is considered, which includes a variable swirl port and an independent auxiliary boat 4, and the swirl ratio can be changed by changing the amount of air flowing through the auxiliary port 4 using a switching valve 6 provided on the intake manifold 5 side. ing.

According to this variable swirl port 1-, the main port 3 and the sub-port 4 are independent, and the sub-port 4 is raised, so that a sufficient amount of air can be secured even when changing the swirl ratio.

In the figure, 7 is a cylinder, 8 is a cylinder liner, 9 is a combustion chamber, 10 is an actuator that controls opening and closing of the switching valve 6 according to the engine speed, load, etc., and A is an actuator for controlling the air flowing in from the main port 3. Flow (main swirl), B is the flow of air flowing in from the sub port 4 (reverse swirl).

<Problems to be Solved by the Invention> The intake boat is formed using a boat-shaped core during casting of the cylinder head of the engine, but the above-mentioned variable swirl port has two independent main bodies in a limited space. Since it has a port 3 and a sub-port 4, its shape is complicated, and it is difficult to manufacture a core 11 as shown in FIG. 6 to form a variable swirl port by casting, which reduces manufacturing costs. There was a problem with the increase in

The present invention has been made to solve the above problems, and an object of the present invention is to enable variable swirl ports to be manufactured easily and at low cost.

Means for Solving the Problems> The configuration of the present invention that achieves the above object includes a main port connected to the upstream side of the intake valve and the main port connected at a certain angle near the terminal end of the main port. When manufacturing a variable swirl port consisting of a main port 1 and an independent sub port,
A core is formed by providing a partition plate at a portion corresponding to the boundary between one portion and the sub-port portion, and the core is placed in a mold of the cylinder head, and the partition plate is integrally cast. Features.

<Example> Next, a method for manufacturing a variable swirl port according to the present invention will be described with reference to FIG. 1.2.3.

The core mold 12 for forming the core has a space 13 corresponding to the main port 3 of the variable swirl port shown in FIG.
a, a space 13b corresponding to the sub-boat 4, and a groove 13c for attaching a partition plate, and the groove 1
A core 15 as shown in FIG. 2 is formed by attaching a metal partition plate 14 to 3c and filling it with molding sand.

The core 15 is placed at a predetermined position in a cylinder head mold, and hot water is poured into the mold to cast the partition plate 14 together with the cylinder head.

After the casting is completed, by removing the sand mold part of the core 15,
As shown in FIG. 3, a variable swirl port consisting of a main port 3 and a sub-port 4 separated by a partition plate 14 is formed.

<Effects of the Invention> According to the method for manufacturing a variable swirl port according to the present invention,
A complex-shaped variable swirl port consisting of a main port and a sub-boat independent of the main port can be manufactured easily and at low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an example of a core mold used in carrying out the present invention, FIG. 2 is a perspective view of the core, and FIG. 3 is a cross-sectional view of a variable swirl port manufactured by the method of the present invention. FIG. 4 is a perspective view of the variable swirl boat, FIG. 5 is a sectional view of the upper part of the engine equipped with the variable swirl boat, and FIG. 6 is a perspective view of the core of the variable swirl boat. In the drawing, 3 is a main port, 4 is a sub-port, 12 is a core type, 14 is a partition plate, and 15 is a core.

Claims (1)

[Claims] When manufacturing a variable swirl port consisting of a main port connected to the upstream side of the intake valve and a sub port independent of the main port connected at a certain angle near the terminal end of the main port, the main port part and the sub port are A variable variable valve characterized in that a partition plate is provided at a portion corresponding to a boundary between the parts to form a core, and the core is placed in a mold of a cylinder head and the partition plate is integrally cast. Swirl port manufacturing method.