JPH0322516Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake port device for a four-valve cylinder head of an internal combustion engine.

In an internal combustion engine, an intake port serves to introduce a large amount of fresh air into a combustion chamber, and also improves combustion efficiency by swirling the entire air flowing into the combustion chamber. In order to accomplish this, it has conventionally been common practice to form the final portions of the two intake ports, that is, the passages just before they flow into the cylinder, into a spiral shape to give a swirling flow to the intake air (referred to as a spiral port).

In this case, there was a problem in that the amount of air flowing into the combustion chamber was reduced due to energy loss due to the swirling flow type.

The present invention was developed in view of the above circumstances, and its purpose is to be able to supply a large amount of incoming air into the combustion chamber, and to reduce the inflow resistance of air between the inlet and outlet of the intake port. It is an object of the present invention to provide an intake port device for a cylinder head that is capable of

Hereinafter, the present invention will be explained with reference to the drawings.

In the drawing, 1 is a cylinder head body, and the cylinder head body 1 is provided with two intake ports 2, 3 and an exhaust port 4. 5 in the drawing is the combustion chamber,
6 is the cylinder center line.

One intake port 2 is a spiral port that gives a swirling flow to the intake air, and the other intake port 3
is a tangential port through which air enters tangentially to the combustion chamber 5.

Further, the two intake ports 2 and 3 are arranged substantially perpendicular to the longitudinal direction of the engine when the cylinder head body 1 is viewed from above.

That is, the axes of the inlet portions 2a and 3a of the intake ports 2 and 3 are perpendicular to the cylinder center line 6 (angle A° = B° = 90°), and the outlet of one intake port 2 is , is located perpendicular to the cylinder center line 6 and on the intake port side in front of the cylinder center line 6, and is located on a line perpendicular to the cylinder center line 6 from the cylinder center, and the outlet of the other intake port 3 is It is located on the same line as the cylinder center line 6.

In the drawings, 7 is a cylinder block, 8 is a piston, 9 is a cylinder liner, 10 is a head cover, and 12 and 13 are intake valves.

As shown in FIG.
As shown in FIG. 5, the air flows in from the outer periphery of both sides of the intake valve 12.

Air first flows into the intake port 2 perpendicularly to the center of the cylinder, and as it approaches the combustion chamber 5, air flows into the combustion chamber 5 while turning from the outer periphery of one side of the intake valve 13, as shown in FIG.

That is, one of the air flowing in from the two intake ports 2 and 3 is given a swirling flow by the spiral port, and the remaining air is given a swirling flow by the flow velocity in the tangential direction of the combustion chamber 5.

Then, the intake port 2 with this arrangement,
The details of the airflow state around each intake valve obtained in step 3 are shown in FIG. That is, if the velocity vector of air entering the cylinder from intake port 2 (spiral port) is indicated by 20, and the velocity vector of air entering the cylinder from intake port 3 (tangential port) is indicated by 21, then the velocity vectors of both are As clearly understood from the comparison of directions, it is understood that the present invention has a structure in which collisions between both airflows are minimized. Now, if we observe the function of each airflow that enters the cylinder from each port, the air that enters the cylinder from intake port 2 (spiral port) will not collide with the air that enters from the other port, so basically To efficiently create the swirling airflow required within a cylinder. On the other hand, the air entering the cylinder from intake port 3 (tangential port) does not collide with the air entering from the other port and induces a swirling flow, so a sufficient amount of air enters the cylinder. It plays the role of compensating for the inflow of air. As described above, the present invention ensures generation of sufficient swirling flow and inflow of a sufficient amount of air while minimizing turbulence caused by collisions between airflows.

In addition, in this invention, two intake ports 2,
The axes of the inlet portions 2a, 3a of No. 3 are made substantially perpendicular to the center of the cylinder in order to shorten the length of the port and to avoid an increase in passage resistance due to extreme bending.

As described in detail above, the present invention provides a diesel engine which has two intake valves 12, 13 of the same shape and two exhaust valves of the same shape facing the combustion chamber in the cylinder head body 1. Intake ports 2 and 3 are provided, one intake port is made into a spiral port that gives a swirling flow to the intake air, and the other intake port 3 is made into a tangential port that allows air to flow in tangentially to the combustion chamber 5. , the respective inlet portions 2a, 2b of the intake ports 2, 3 are made to communicate with each other, and the axes of the respective inlet portions 2a, 3a of the intake ports 2, 3 are made perpendicular to the cylinder center line 6, and one The outlet of the intake port 2 is perpendicular to the cylinder center line 6 and
A cylinder characterized by being located on a line perpendicular to the cylinder center line 6 from the cylinder center on the more front side of the intake port, and the outlet of the other intake port 3 being located on the same line as the cylinder center line 6. This is the head's intake port device.

Therefore, one of the air flowing in from the two intake ports 2 and 3 is given a swirling flow by the spiral port, and the rest is given a swirling flow by the flow velocity in the tangential direction of the cylinder. Since these two airflows have velocity vectors that minimize collision with each other, the airflow flowing through the spiral port efficiently creates the required swirling airflow within the cylinder.

In addition, since the air flowing through the tanzel shear port does not need to induce a swirling flow by itself, the amount of intake air can be increased with less energy loss (compared to the case of two spiral ports). These have the effect of swirling the entire amount of air flowing into the combustion chamber, which improves combustion efficiency. Further, the axes of the inlet portions 2a and 3a of the intake ports 2 and 3 are perpendicular to the cylinder center line 6, and the outlet of one intake port 2 is perpendicular to the cylinder center line 6 and also perpendicular to the cylinder center line. 6, located on the line perpendicular to the cylinder center line 6 from the cylinder center,
By locating the outlet of the other intake port 3 on the same line as the cylinder centerline 6, the length of the port can be shortened and an increase in passage resistance due to extreme bending can be avoided, and the air between the inlet and the outlet can be reduced. Inflow resistance can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a cylinder head equipped with an intake port device according to the present invention, and FIG.
3 is an explanatory diagram of the configuration of an embodiment of the present invention; FIG. 4 is an explanatory diagram of an intake port device in a multi-cylinder; FIG. 5 is an explanatory diagram of inflow of intake air into a tangential port; FIG. 6 is a schematic diagram showing velocity vectors of an embodiment according to the present invention. 1 is the cylinder head body, 2 and 3 are intake ports, and 5 is the combustion chamber.

Claims (1)

[Scope of utility model registration request] In a diesel engine that has two intake valves 12 and 13 of the same shape and two exhaust valves of the same shape facing the combustion chamber in the cylinder head, two intake ports 2 and 3 are provided in the cylinder head body 1, and one The intake port 2 is made into a sparral port which gives a swirling flow to the intake air, and the other intake port 3 is made into a tangential port which lets air flow into the combustion chamber 5 in a tangential direction. Entrance part 2a, 3
a in communication with each other, the axes of the respective inlet portions 2a and 3a of the intake ports 2 and 3 are made perpendicular to the cylinder center line 6, and the outlet of one intake port 2 is made perpendicular to the cylinder center line 6. It is located vertically and on the intake port side in front of the cylinder center line 6, and is located on a line perpendicular to the cylinder center line 6 from the cylinder center, and the outlet of the other intake port 3 is on the same line as the cylinder center line 6. An intake port device for a cylinder head, characterized in that: