JPH0634101U - Engine intake and exhaust valves - Google Patents

Abstract

(57) [Abstract] [Purpose] Prevents uneven wear between the intake and exhaust valves and the valve seat, improves exhaust efficiency, improves fresh air introduction, and smoothes combustion. In the intake valve 2 arranged facing the combustion chamber 12 of the cylinder head 1, the stem 3 is centered on the valve surface facing the intake port 11 between the valve head portion 2a and the stem 3. Grooves 4 are formed in a radial direction on a predetermined circumference at predetermined intervals.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an engine intake / exhaust valve improvement.

[0002]

[Prior art]

 The intake / exhaust valve of the engine may cause compression leakage due to uneven wear between the intake / exhaust valve and the valve seat due to carbon deposits or improper contact with the valve sheet over time. As a device for preventing this uneven wear, as disclosed in Japanese Patent Laid-Open No. 1-104114, a guide plate is provided on the port side of the valve head portion, and the swirl generated in the port causes the guide plate to rotate the valve. In particular, it is known that the valve and the valve seat are worn as uniformly as possible.

[0003]

[Problems to be solved by the device]

 However, it is technically difficult to provide a guide plate for such an intake / exhaust valve, and there are problems in terms of size and weight, and there is a problem that it cannot be easily adopted.

Therefore, an object of the present invention is to provide an intake / exhaust valve for an engine, which can easily prevent uneven wear between the intake / exhaust valve and the valve seat and improve intake / exhaust efficiency.

[0005]

[Means for Solving the Problems]

 According to the present invention, in an intake / exhaust valve arranged facing a combustion chamber of a cylinder head, a predetermined circle centered on the stem is formed on the valve surface facing the port between the valve head and the stem. Grooves are formed in a radial direction on the circumference at predetermined intervals.

[0006]

[Operation] The intake or exhaust swirl passing through the port is blown to the groove engraved on the valve surface, and the groove is pushed around the valve axis by the blown swirl to give rotation to the intake or exhaust valve. Prevents uneven wear with the valve seat to ensure smooth rotation.

[0007]

【Example】

 This embodiment shows an example in which the present invention is applied to an intake valve of an engine. As shown in FIGS. 1 to 4, an intake valve 2 is provided in an intake port 11 of a cylinder head 1 and a cam (not shown) is provided. The stem 3 reciprocates following the shaft, and the outer peripheral portion of the umbrella portion 2a of the intake valve 2 comes into contact with and separates from the valve seat 10 of the cylinder head 1 to send fresh air into the combustion chamber 12.

On the umbrella portion 2 a facing the intake port 11 of the intake valve 2, crescent-shaped grooves 4 are radially arranged on a concentric circle centered on the stem 3.

The groove 4 is a crescent shape surrounded by a semicircular collision portion 4a formed in a predetermined depth in a wall shape at a right angle from the surface of the umbrella portion 2a and a straight portion 4c on the surface of the umbrella portion 2a. The groove 4 is formed on the same circumference with a predetermined interval from the straight portion 4c to the bottom of the collision portion 4a.

The collision portion 4a of the groove 4 is provided so as to face the swirl generated in the intake port 11. In this embodiment, the intake valve 2 is rotated by the swirl in the clockwise direction in the plan view of FIG. As shown in FIG. 3, the cross section of the intake valve 2 viewed from the end is formed by the groove 4 having the collision portion 4a on the left side and the straight portion 4c on the right side.

With the above-mentioned configuration, the operation will be described.

When the intake valve 2 opens and separates from the valve seat 10 with the start of the intake stroke, intake air accompanied by swirl is sucked into the combustion chamber from the intake port 11, and at this time, the swirl forms the inclined portion 4 b of the groove 4. The intake valve 2 is given a rotational force in the clockwise direction by being guided by and colliding with the collision portion 4a.

When the intake stroke ends, the intake valve 2 is seated on the valve seat 10 and stops rotating due to the swirl. Since the position at which the umbrella portion 2a contacts the valve seat 10 is slightly changed, the intake valve 2 can evenly contact the valve seat 10 to prevent uneven wear.

Similarly, a valve guide (not shown) of the cylinder 1 that slides and guides the stem 3 also changes its sliding position at each suction stroke, and the stem 3 and the valve guide are evenly worn all around.

In this way, the swirl generated during the intake stroke collides with the groove 4 and thereby imparts a rotational force to the intake valve 2 and the stem 3, so that the intake valve 2, the valve seat 10 and the stem 3 are provided. The valve guide gradually changes the contact position to prevent uneven wear and carbon accumulation, and the groove 4 formed in the intake valve 2 allows the intake valve 2 to be made lighter, allowing the valve system to follow. It is possible to improve the sex.

In addition, although the groove 4 is provided in the intake valve 2 in the above-mentioned embodiment, although not shown, a similar groove 4 may be provided in the exhaust valve. In this case, the exhaust gas flowing out to the exhaust port is The swirl rotates the exhaust valve to prevent uneven wear and improve exhaust efficiency.

Further, although the groove 4 is formed in a crescent shape in the above-mentioned embodiment, it is not shown in the figure, but it may be formed by a groove provided with an inclined portion 4b for introducing a swirl and a collision wall 4a with which the swirl collides. The same actions and effects as above can be obtained.

[0018]

[Effect of device]

 As described above, according to the present invention, the swirl generated during the intake / exhaust stroke collides with the groove provided in the valve umbrella portion, thereby imparting a rotational force to the intake / exhaust valve, and the intake / exhaust valve and valve seat as well as the stem and valve. Since the guide gradually changes the contact position, it is possible to prevent uneven wear and carbon accumulation, and because grooves are formed in these valves, it is possible to reduce the weight of the valves and the followability of the valve train. In addition, the intake and exhaust strokes of the intake and exhaust strokes become smoother, and the intake and exhaust efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a perspective view of a valve showing a flow of intake air.

[Explanation of symbols]

 2 Intake valve 2a Umbrella part 3 Stem 4 Groove 4a Collision part 4b Inclined part 11 Intake port

Claims (1)

[Scope of utility model registration request] 1. An intake / exhaust valve arranged facing a combustion chamber of a cylinder head, wherein a predetermined circumference centered on the stem is provided on a valve surface facing a port between a valve head portion and a stem. An intake / exhaust valve for an engine, characterized in that grooves are formed in a radial direction on the top at predetermined intervals.