KR20040041364A - An air intake valve seat in engine - Google Patents

Abstract

PURPOSE: An intake valve seat for an engine is provided to reduce smoke and NOx in burning by increasing vortex of intake airflow at the end of suction stroke with chamfering the lower part of the intake valve seat. CONSTITUTION: An intake valve seat(10) is placed in a suction port(31) of a cylinder head communicated with an intake port(20), and a chamfer(11) is processed in the intake valve seat by offsetting the lower part of the intake valve seat for the inside of a combustion chamber from the center of the suction port. Vortex is generated in flowing suction air into the combustion chamber through the intake valve from the intake port with the offset chamfer in the lower part of the intake valve seat. Flow rate is increased with decreasing the gap between the intake valve and the suction port with closing the intake valve at the end of suction stroke.

Description

An air intake valve seat in engine}

The present invention relates to an intake valve seat of an engine, and more particularly, to an intake valve seat of an engine having a structure capable of increasing the vortex strength of the intake air flow at the end of the intake stroke.

In general, an engine includes a combustion system including an intake machine that sucks air, a combustion chamber that mixes and burns the sucked air together with fuel, and a combustion head generated after combustion by the combustion system and a cylinder head and a cylinder head block. It consists of a cooling system for cooling the exhaust system and the combustion system for exhausting the outside.

As shown in FIG. 1, the intake system of the dual engine includes an intake manifold 1 for sucking external air and an intake port for supplying air sucked by the intake manifold 1 to each combustion chamber of the engine ( It consists of the cylinder head 4 provided in 2a, 2b and the cylinder head block 3, and connected with the intake port 2a, 2b.

Here, the cylinder head 4 has an intake valve which closes the intake port by the force of the spring and opens and closes in accordance with the operation of the engine (in accordance with the movement of the cam shaft connected to the crankshaft) while supplying the intake gas into the combustion chamber. It is provided.

The intake valve is composed of four parts, such as a valve head, a valve face, a valve stem, and a stem end. As can be seen from FIG. 2, the inlet port 5 of the cylinder head 4 includes the valve of the intake valve described above. An intake valve seat 6 having a structure as shown in Figs. 3A and 3B is provided in close contact with the face to prevent leakage of the combustion chamber pressure and to maintain complete airtightness.

On the other hand, one of the most important things when developing an engine combustion system is the swirling flow of air drawn into the combustion chamber. This is because the vortex flow of the intake air must be large enough to smoothly mix the air and the fuel, thereby reducing the smoke in the main operation region.

In the related art, as shown in FIG. 1, a pair of intake ports 2a and 2b are provided per combustion chamber, and an intake port-2a called a helical port is twisted spirally near the cylinder head 4. Intake port-2b, called a tangential port, is arranged so that intake air flows in a tangential direction from the edge of the combustion chamber so that the flow direction of intake air itself forms a vortex.

For reference, each cylinder head is provided with an exhaust port as well as an exhaust port and a peripheral device thereof. In FIGS. 1 to 3, the exhaust port, the exhaust port, and the exhaust valve seat are omitted to avoid unnecessary substrates.

By the way, since the vortex of the intake flow by the intake port as described above can be formed only when a certain amount or more of air flows. The strength of the vortex is almost linearly proportional to the amount of intake valve opening.

That is, when the opening amount of the intake valve is small, the vortex strength is very small and insignificant, whereas when the opening amount of the intake valve is large, the vortex strength is very strong.

Therefore, in the middle of the intake stroke, as the opening amount of the intake valve increases, the vortex strength increases, but as the intake valve closes toward the end of the intake stroke, the flow rate of air decreases and the vortex of air sucked in from the intake port Gradually get smaller.

As a result, when the intake valve is closed and the compression stroke starts, the vortex strength of the intake flow decreases considerably compared to the middle of the intake stroke, so that the mixture of air and fuel is not smooth at the time of fuel injection, thereby effectively reducing the smoke. There was no problem.

Accordingly, the present invention has been made to solve the problems of the prior art as described above, by forming a chamfer in the set direction on the surface facing the inner side of the combustion chamber, the engine made to strengthen the vortex of the intake flow at the end of the intake stroke Its purpose is to provide an intake valve seat.

1 is a schematic diagram showing an intake system of a general engine;

Figure 2 is a bottom view of the cylinder head shown in Figure 1,

3 (a) and 3 (b) are side cross-sectional and bottom views of the intake valve seat shown in FIG. 2, respectively,

4 is a bottom view of a cylinder head provided with an intake valve seat of an engine according to a preferred embodiment of the present invention;

(A) and (b) of FIG. 5 are side cross-sectional and bottom views of the intake valve seat shown in FIG. 4, respectively,

Figure 6 is a graph of the experimental results showing that Smoke and No _x is reduced when employing the intake valve seat according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: intake valve seat 11: chamfer

20: intake port 30: cylinder head

31: intake vent

The intake valve seat of the engine according to the present invention for achieving the above object is characterized in that the chamfering process in the set direction on the surface facing the inside of the combustion chamber.

The present invention is characterized in that, in the case of an engine provided with a plurality of intake valve seats per cylinder, the process is performed by differently setting the chamfer direction of each intake valve seat.

The present invention is further characterized in that the intake valve seats of the intake valve seats adjacent to each other have a difference of approximately 90 degrees between the intake valve seats of claim 2.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a bottom view of a cylinder head provided with an intake valve seat of an engine according to a preferred embodiment of the present invention, and FIGS. 5A and 5B are side cross-sectional views of the intake valve seat shown in FIG. 4 and 5, the intake valve seat 10 according to the embodiment of the present invention is provided in the inlet port 31 of the cylinder head 30 communicating with the intake port 20. do.

The intake valve seat 10 of the present invention has an offset in the setting direction D1 by a predetermined distance Δℓ from the center point of the intake port 31 with respect to its bottom surface, that is, the surface facing the inside of the combustion chamber. The chamfer 11 is processed, but it is preferable to process this chamfer 11 so that it may make a fixed angle (DELTA) (theta).

As described above, the vortex becomes strong at the moment when air sucked into the combustion chamber from the intake port 20 is introduced into the combustion chamber through the intake valve by the offset chamfer 11 processed on the bottom surface of the intake valve seat 10.

As such, the vortex caused by the offset chamfer 11 of the intake valve seat 10 is generated at a portion adjacent to the intake valve, and thus becomes stronger at the end of the intake stroke.

That is, when the intake valve is closed at the end of the intake stroke, the gap between the intake valve and the intake port 31 becomes smaller and the flow rate becomes faster, so that the vortex caused by the offset chamfer 11 of the intake valve seat 10 becomes stronger. Become.

As the vortex becomes strong at the end of the intake stroke by the offset chamfer 11 of the intake balance seat 10 as described above, the vortex of sufficient strength is maintained at the time of injection of the fuel, so that not only Smoke but also No _x is reduced. Proven through the actual experimental results shown in FIG.

For reference, when a plurality of intake valve seats 10, 10-b are provided in one cylinder head 30, the chamfers 11, 11 processed in each intake valve seat 10, 10-b. It is preferable to form the directions D1 and D2 in -b) so as to have a difference by a set angle along the rotational direction of the vortex, since the vortices formed from each intake port can form a stronger vortex without canceling each other.

The present invention is described above by illustrating specific embodiments, but the present invention is not limited to the above embodiments. Those skilled in the art can easily make various changes and modifications to the present invention, and it should be noted that such variations or modifications are included within the scope of the present invention as long as the features of the present invention are used.

As described above, the present invention can further increase the vortex of the intake flow at the end of the intake stroke by processing the chamfer by offsetting the bottom surface of the intake valve seat, that is, the surface facing the inner side of the combustion chamber in the set direction, thereby allowing combustion. In this case, it is possible to reduce the generation of pollutants such as smoke and No _x .

Claims (3)

In the intake valve seat provided in the cylinder head of the engine, An intake valve seat of an engine, characterized by chamfering in a set direction on a surface facing the inside of the combustion chamber. 2. The intake valve seat of an engine according to claim 1, wherein in the case of an engine provided with a plurality of intake valve seats per cylinder, the intake valve seat of the intake valve seat is processed with a different chamfer direction. 3. The intake valve seat of an engine according to claim 2, wherein the chamfer direction of each intake valve seat has a difference of set angles between intake valve seats adjacent to each other along the rotational direction of the vortex.