JP2000161030A - Intake valve for internal combustion engine - Google Patents

Abstract

(57) Abstract: An intake valve that opens and closes a communication portion between an intake passage of an internal combustion engine and a combustion chamber, and is formed between the intake passage and the intake valve in an initial stage of opening the intake valve. The intake air flowing through the throttled intake passage is not disturbed, the intake resistance is reduced, the intake air flow rate is increased, and the intake efficiency is increased. SOLUTION: A valve body 1 of an intake valve V has a tapered bulge extending radially from a seat face portion 4 seated on a valve seat 30 of an intake passage 27 toward an outer peripheral edge of the valve body 1. In the initial stage of opening the intake valve V, the downstream side of the throttle intake passage Pv has a passage cross-sectional area that is gradually increased so that the intake air flowing therethrough is not disturbed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake valve for controlling opening and closing of an opening end of an intake passage on a combustion chamber side in an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, an intake valve of an internal combustion engine is generally formed in a poppet shape with an umbrella-shaped valve body and a valve rod integrally extending from a center portion of the valve body (see FIG. 1). JP 1
-315608).

[0003] As shown in FIG. 10, the outer peripheral edge of the valve body 01 of a conventional intake valve V ', as not the valve diameter is large, the seat surface 030 _first valve seat 030 of the intake passage 027 side seating is cut so as to be substantially parallel to the 'longitudinal center line C'-C' of the intake valves V from where the outer edge of the sheet off Ace surface 04 _1.

[0004]

In the conventional intake valve, as shown in FIG. 10, at the initial stage of opening, the inner wall surface of the intake passage 027 having the valve seat 030 and the outer edge of the intake valve V '. Is large in the downstream passage just after the minimum throttle passage section of the throttle intake passage Pv ′ between the intake passage Pv ′ and the intake passage Pv ′. This causes the intake resistance to increase, resulting in an increase in intake pressure loss. As a result, the intake flow rate decreases, leading to a decrease in the intake efficiency of the engine.

The present invention has been made in view of the above circumstances, and the pressure loss of the intake air in the initial stage of opening the intake valve is reduced by making only a slight improvement to the valve body of the intake valve to reduce the amount of intake air. It is an object of the present invention to provide a novel intake valve for an internal combustion engine in which the amount is increased to thereby improve the intake efficiency of the engine.

[0006]

According to a first aspect of the present invention, there is provided an intake valve for an internal combustion engine for opening and closing a communication portion between an intake passage and a combustion chamber, the valve being an umbrella-shaped valve. The valve body comprises a main body and a valve rod integrally extended from the top of the valve body, and the valve main body is formed from a seat face portion having a seat face surface capable of seating on a seat surface of a valve seat provided in an intake passage. It is characterized by having a tapered bulging portion that extends radially toward the outer peripheral edge of the valve body, and according to such a feature, at the initial stage of opening the intake valve, the inner wall surface of the intake passage and On the downstream side of the minimum throttle section of the throttle intake passage formed between the throttle valve and the outer peripheral surface of the valve body of the intake valve, the flow of intake air flowing through the throttle intake passage is such that the passage cross-sectional area gradually increases. Air intake resistance is reduced by preventing turbulence , Thereby achieving the increase of the intake air flow rate, with increasing the intake efficiency, thereby improving the engine performance.

In order to achieve the above object, according to a second aspect of the present invention, in the first aspect, the outer surface of the bulging portion has a conical surface that is continuous with a seat face surface of the seat face portion. And a round surface that is continuous with the conical surface, wherein the lower edge of the round surface is connected to the bottom surface of the valve body. According to such characteristics, the invention according to claim 1 and It has the same effect.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 5 show a first embodiment of the present invention. FIG. 1 is an overall front view of an intake valve of the present invention, and FIG.
FIG. 3 is a partially cutaway enlarged view of a portion surrounded by a virtual line as viewed in the direction of arrows 2 in FIG. 1, FIG. 3 is an enlarged sectional view of a part of a valve seat, and FIG. FIG. 5 is a cross-sectional view showing the state, and FIG. 5 is an enlarged view of a portion surrounded by an imaginary line taken along line 5 in FIG.

In the following embodiments, the vertical relationship between the intake valves will be described with the valve stem side being “up” and the valve body side being “down”.

In FIGS. 1 and 2, the intake valve V is formed in a poppet shape with an umbrella-shaped valve body 1 and a valve rod 2 integrally connected from the center of the top surface of the valve body 1. As clearly shown in FIG. 2, the top surface of the valve body 1 is formed as a multi-stage conical surface, and the upper edge of the top surface is formed at the base end of the valve stem 2 through a concave arcuate surface 3. Connected smoothly. A seat face portion 4 having a predetermined width in the axial direction of the valve stem 2 is provided at an intermediate portion in the thickness direction of the valve body 1. ₁ is formed, the taper angle of the sheet off Ace surface 4 ₁ is 90 °. The sheet off Ace surface 4, the intake passage 27 as described later, is detachably seated on the seat surface 30 ₁ of the valve seat 30 which is fitted and fixed to the combustion chamber 26 side opening end.

As clearly shown in FIG. 2, an umbrella-shaped valve body 1 is provided.
A swelling portion 5 which extends from the seat face portion 4 toward the radial outside of the valve body 1 in a tapered shape and forms an outer edge of the valve body 1 is integrally formed. The bulge portion 5, a conical surface 5 ₁ following the sheet off Ace surface 4 ₁ on its outer surface, a rounded surface 5 ₂ smoothly continuous to the conical surface 5 ₁ is formed. The bulging part 5
The lower edge protrudes below the bottom surface 6 of the valve body 1, and is smoothly connected to the bottom surface 6 of the valve body 1 via the curved concave surface 7. The taper angle of the conical surface 5 ₁ of the bulging portion 5 is 60 °, therefore the conical surface 5 _1, the taper angle is slightly radially outward relative to the seat off Ace surface 4 ₁ is 90 ° They are inclined downward, and ridge lines 8 are formed at their boundaries.

On the top surface of the valve body 1, another conical surface 10 is formed to connect from the upper edge of the seat face surface 4 toward the valve stem 2, and the taper angle of the other conical surface 10 is formed. Is 120 °. Further, another conical surface 11 is further formed than the upper edge of the other conical surface 10, and the taper angle of the further conical surface 11 is 144 °, and the upper edge thereof is the concave arc surface 3. And is smoothly connected to the base of the valve stem 2. The boundary between the sheet off Ace surface 4 ₁ and the other conical surface 10, ridge 12 is formed, also on the boundary between the still another of the conical surface 11 and the other conical surface 10 other ridge 13 is formed.

At the upper end of the valve stem 2 of the intake valve V, an annular groove 15 is formed as usual, and a spring seat plate 17 is formed in the annular groove 15 via a split cotter 16 as described later. It is fitted (see FIG. 4).

As shown in FIG. 3, an annular valve seat 30 corresponding to the valve body 1 of the intake valve V is fixed to the wall surface of the intake passage 27 opened and closed by the intake valve V by press fitting or the like. You. Of the valve seat 30, and an inner surface contiguous with the inner wall surface of the intake passage 27 is formed in multiple stages conical surface, the multi-stage conical surface, the sheet off Ace surface 4 ₁ of the valve body 1 can be seated so as to be separable The sheet surface 30 ₁ composed of a conical surface,
Upstream conical surface 3 that is continuous with the upstream side of the sheet surface 30 ₁
0 and ₂ and the downstream-side conical surface 30 ₃ continuous to the downstream side of the sheet surface 30 ₁ becomes more. The taper angle of the seat surface 30 ₁ is 90 °, the taper angle of the upstream inner surface 30 ₂ is 60 °, further taper angle of the downstream conical surface 30 ₃ is 100 °.

Next, of the intake valve V configured as described above,
FIGS. 4 and 5 show an example of a structure for attaching the internal combustion engine to the intake passage 27. FIGS.
This will be described with reference to FIG.

Engine block 2 of a four-cycle internal combustion engine
Reference numeral 0 designates a cylinder block 21 and a cylinder head 22 fixed on the deck surface of the cylinder block 21. A piston 25 is slidably fitted in a cylinder bore 24 formed in the cylinder block 21. The lower surface of the combustion chamber 2 facing the upper surface of the piston 25
6 are formed, and an intake passage 27 and an exhaust passage 28 communicating with the combustion chamber 26 are formed in a uniflow type. Of the intake passage 27, the open end of the combustion chamber 26 side, the annular valve seat 30 is provided integrally to the seat surface 30 ₁ of the valve seat 30, as described above, the intake valve V sheet off Ace surface 4 ₁ is seated to be separable.

A cylindrical valve guide 32 is fixed to the upper wall of the intake passage 27, and the valve rod 2 of the intake valve V provided in the intake passage 27 is slidably penetrated through the valve guide 32. A compression spring is provided between a spring seat plate 17 fitted into an annular groove at the upper end of the valve rod 2 of the intake valve V via a cotter and a spring seat surface 18 provided on the cylinder head 22. A valve spring 19 is interposed. The intake valve V opens and closes the intake passage 27 by the cooperation of the valve mechanism (not shown) and the valve spring 19 as usual.
2 is slid up and down.

The exhaust passage 28 is provided with an exhaust valve (not shown) for opening and closing the passage 28.

When the intake valve V closes the intake passage 27, the resilient force of the valve spring 19 causes the seat face surface 4 of the valve body 1 to move as shown by the chain line in FIG.
₁ is closely seated on the seat surface 30 ₁ of the valve seat 30 to close the intake passage 27.

When the intake valve V is opened by a valve mechanism (not shown) in the intake stroke of the engine, the intake air in the intake passage 27 is reduced by the negative intake pressure generated in the cylinder bore 24 as the piston 25 descends. Combustion chamber 26 through intake passage 27
Is flowed into.

As shown by the solid line in FIG. 5, in the initial stage of opening of the intake valve V, the intake air passes through a throttle intake passage Pv formed between the intake passage 27 and the valve body 1 to form the combustion chamber 26. When flowing to the intake valve V, the valve body 1 of the intake valve V is formed into a special shape as described above, so that the intake flow flowing through the throttle intake passage Pv is not disturbed, the intake resistance is reduced, and the intake flow rate is reduced. Can be increased.

Referring now to FIG. 5, the flow of intake air when this intake valve V is employed will be discussed. The valve body 1 has a seat face portion 4 with a lower edge toward an outer edge. bulge portion 5 which is extended is formed Te has especially a subsequent conical surfaces 5 ₁ to the sheet off Ace surface 4 ₁ of the outer surface of the expanded portion 5 the seat off ace unit 4, and a rounded surface 5 ₂ followed by Thus, in the initial stage of opening the intake valve V, the throttle intake passage Pv formed by the inner surface of the valve seat 30 and the outer surface of the valve body 1 of the intake valve V is located downstream of the minimum passage cross-sectional area Zmin. In this case, a section Z in which the passage cross-sectional area gradually increases can be formed, whereby a rapid change in the passage cross-sectional area is eliminated, and therefore, the conventional intake valve V is added to the intake air flowing through the throttle passage Pv. Inspiration like when used Turbulence prevents to rise to (see FIG. 10), thereby increasing the intake air flow rate by reducing the resulting intake resistance.

FIG. 6 shows a second embodiment of the intake valve for an internal combustion engine according to the present invention.
An example is shown. In the second embodiment, the lower edge of the bulging portion 5 formed on the valve body 1 is smoothly connected to the flat bottom surface 6 of the valve body 1 without protruding below the bottom surface of the valve body 1. In the second embodiment, the thickness of the valve body 1 does not increase due to the provision of the bulging portion 5.

According to the second embodiment, the intake valve V
This is applied when there is no increase in the weight of the piston and the recess for the valve escape formed on the top surface of the piston cannot be deepened.

The second embodiment is also different from the first embodiment.
The same operation and effect as those of the embodiment can be obtained.

FIG. 7 shows a third embodiment of the intake valve for an internal combustion engine according to the present invention.
An example is shown. In the third embodiment, the taper angle of the conical surface 5 ₁ of the bulging portion 5 which is extended from the sheet off ace portion 4 of the valve body 1, and its sheet off Ace surface 4 ₁ of the taper angle and the same angle for example 90 °, Furthermore the lower edge of the curved surface 5 ₂ of the bulge portion 5 is smoothly connected to the flat bottom surface 6 of the valve body 1. In the third embodiment, the thickness of the valve body 1 is thicker than that of the second embodiment, and the diameter of the valve body 1 is further increased.

The third embodiment is also similar to the first embodiment.
The same operation and effect as those of the embodiment can be obtained.

FIG. 8 shows a fourth embodiment of the intake valve for an internal combustion engine according to the present invention.
An example is shown. The fourth embodiment is a case of forming the valve body 1, a conical surface 5 ₁ of the bulging portion 5 which is extended from the seat off ace surface 4 ₁ of the sheet off ace portion 4 in a multistage surface, the conical surface of the multi-stage 5 _1, sheet off ace surface 4 first conical surface 5 ₁ a of the taper angle toward from _one to the rounded surface 5 ₂ 80 °, the second conical surface 5 ₁ b and the tapered angle of the taper angle is 70 ° is 60 ° Of the third conical surface 5c.

The fourth embodiment is also similar to the first embodiment.
The same operation and effect as those of the embodiment can be obtained.

FIG. 9 shows a fifth embodiment of the intake valve for an internal combustion engine according to the present invention.
An example is shown. The fifth embodiment is a case of forming the outer surface of the bulge portion 5 which is extended from the seat off ace surface 4 ₁ of the valve body 1 in a convex curved outward.

The fifth embodiment is also similar to the first embodiment.
The same operation and effect as those of the embodiment can be obtained.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments, and various embodiments are possible within the scope of the present invention. For example, in the above embodiment, the case where the present invention is applied to an internal combustion engine having a four-cycle uniflow type intake and exhaust passage has been described.
Of course, this can be applied to other types of internal combustion engines, and the taper angles of the seat face surface and the conical surface of the bulging portion are not limited to those of the above embodiment.

[0034]

As described above, according to the present invention, the valve body of the intake valve extends radially from the seat face portion having the seat face surface toward the outer peripheral edge of the valve body. In the initial stage of the opening of the intake valve, the downstream side of the throttle intake passage defined by the valve body and the valve seat gradually decreases in cross-sectional area of the passage. The intake air flow therethrough can be increased so that the intake air flow does not become turbulent, thereby reducing the intake air resistance, increasing the intake air flow rate and improving the intake efficiency, and thereby improving the engine performance. be able to.

[Brief description of the drawings]

FIG. 1 is an overall front view of an intake valve of the present invention.

FIG. 2 is a partially broken enlarged view of a portion surrounded by a virtual line as viewed from the direction of arrows 2 in FIG.

FIG. 3 is an enlarged sectional view of a part of a valve seat.

FIG. 4 is a sectional view showing a state in which the intake valve is attached to a cylinder head of the internal combustion engine.

FIG. 5 is an enlarged view of a portion surrounded by a virtual line as viewed from the direction of arrow 5 in FIG. 4;

FIG. 6 is a sectional view of a part of a valve body of an intake valve (second embodiment);

FIG. 7 is a sectional view of a part of a valve body of an intake valve (third embodiment);

FIG. 8 is a sectional view of a part of a valve body of an intake valve (fourth embodiment);

FIG. 9 is a sectional view of a part of a valve body of an intake valve (fifth embodiment);

FIG. 10 is a diagram showing a flow of intake air by a conventional intake valve.

[Explanation of symbols]

1 Valve body 2 Valve stem 4 Seat face 4 ₁ ----- sheet off Ace surface 5 ......... bulged portion 5 ₁ .......... conical surface 5 ₂ ......... Earl Surface 26 ... Combustion chamber 27 ... Intake passage 30 ... Valve seat 30 ₁ ...・ Seat surface Pv ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Throttle intake passage

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Naomi Kurosaki 143 Hagadai, Haga-cho, Haga-gun, Tochigi Prefecture Inside PSG Corporation (72) Inventor Masayuki Inoue 143 Hagadai, Haga-gun, Haga-gun Tochigi Prefecture Inside PSG Corporation (72) Inventor Hideyuki Takiguchi 143 Hagadai, Haga-cho, Haga-gun, Tochigi Prefecture Inside PSG Co., Ltd.

Claims (2)

[Claims] 1. An intake valve for an internal combustion engine, which opens and closes a communication part between an intake passage (27) and a combustion chamber (26), comprising an umbrella-shaped valve body (1) and a valve body (1). The valve body (1) comprises a valve stem (2) integrally extending from the top, and the valve body (1) is provided with a valve seat (3) provided in an intake passage (27).
0) having a seat face surface (4 ₁ ) which can be seated on the seat surface (30 ₁ ) of the valve body (1). An intake valve for an internal combustion engine, comprising a bulging portion (5). 2. An outer surface of the bulging portion (5) has a conical surface (5 ₁ ) continuous with the seat face surface (4 ₁ ) of the seat face portion (4) and a conical surface (5 ₁ ). and a continuous curved surface (5 _2), the lower edge of the curved surface (5 _2), characterized in that it is connected to the bottom (6) of the valve body (1), claim 1, wherein Intake valves for internal combustion engines.