JPH0570758B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reed valve used in a suction section for fuel from a carburetor in various engines, and particularly to a reed valve with greatly improved durability.

[Prior art and its problems]

Generally, in a two-stroke engine or the like, a reed valve device 1 as shown in FIGS. 3 and 4 is provided at a fuel intake portion from a carburetor.

This reed valve device 1 has a valve body 2 and is attached to a fuel intake section. This valve body 2 is formed into a cap shape having an inlet 3 for sucking in fuel and three outlets 4, 4 for discharging fuel, and is fixed in a proper position with a tightening device (not shown) such as a bolt. be done.
Further, on the outside of the support 5 in which each outlet 4 is bored, there is a thin plate-shaped resin or metal reed valve 6 that opens and closes each outlet 4, and the opening degree of this reed valve 6 is regulated from the outside. Curved metal stopper 7
are fixed with tightening bolts 8, 8, . . .

To further explain, if the reed valve 6 is made of resin, it is punched out of a thin plate material made of fibers impregnated with resin, or if it is made of metal, it is punched out of a thin metal plate material such as stainless steel by press punching. Three opening/closing movable parts 6a, 6a, . . . for opening and closing each outlet 4 extend from the base 6b and have a substantially E-shape. Further, the stopper 7 is formed in a substantially E-shape with three restraining parts 7a, 7a, . Further, around each outlet 4 of the support 5, a valve seat 9 made of a rubber cushion or the like that is compatible with each open/close movable part 6a of the reed valve 6 is provided.

In the reed valve device 1 formed in this way, each opening/closing movable part 6a of the reed valve 6 is moved outward during the exhaust and suction strokes in which the pressure of the suction part on the engine side is lower than the pressure on the carburetor side. 6, the fuel is moved from the fully closed state shown by the chain line in FIG. 6 to the fully open state shown by the solid line in FIG. 6, opening each outlet 4 and sucking the fuel into the combustion chamber of the engine. On the other hand, during the compression, explosion, and expansion strokes in which the pressure in the suction section on the engine side is higher than the pressure on the carburetor side, each opening/closing movable part 6a of the reed valve 6 changes from the fully open state shown by the solid line in the figure to the fully open state shown by the chain line in the figure. Return to , and fully close each outlet 4.

On the other hand, in order to meet today's demands for cost reduction, the valve body 2 is molded from a resin such as polybutylene terephthalate or phenol resin or a single metal such as aluminum without providing a valve seat 9 on the peripheral edge of the outlet 4. things are being done.

However, the conventional reed valve 6 of the valve body 2 which is not provided with the valve seat 9 is made of a thin plate material of resin or metal.
If the reed valve 6 is installed and used, the reed valve 6 will directly and violently collide with the resin or metal support 5 portion, and the reed valve 6 will quickly chip at the portion that comes into contact with the support 5.
The valve will no longer be able to open and close properly.
For example, there was an inconvenience that the vaporized fuel was not properly sucked.

[Purpose of the invention]

The present invention has been made in view of these points, and provides sufficient performance when the reed valve is attached to a valve body in which a valve seat made of cushion material is not provided at the abutting part. Demonstrates durability and can continue proper valve opening/closing operation over a long period of time.
Moreover, it is an object of the present invention to provide a reed valve that maintains a high natural frequency as a resin-made reed valve and has excellent operating characteristics.

[Summary of the invention]

The reed valve of the present invention is a reed valve formed of a thin plate-like base material, wherein the base material is made of resin, and an outlet portion of the valve body of the base material that is not provided with a valve seat made of cushion material. By forming a metal layer that is more durable than the base material on the part that comes into contact with the reed valve, and forming a resin part with a high natural frequency that is responsible for opening and closing operations on the base side of the metal layer, the durability of the reed valve is greatly increased. It is characterized by improved performance and superior operating characteristics.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

1 and 2 show one embodiment of the invention. The reed valve 11 of this embodiment is an improved version of the conventional resin reed valve, and a metal layer 13 is provided on the portion of the resin thin plate base material 12 that contacts the outlet 4 portion of the valve body 2. formed and composed. In this embodiment, the metal layer 13 is not provided on the entire surface of the base material 12, but only on a portion sufficient to completely close the outlet 4. As a result, a resin portion having a high natural frequency and responsible for the opening/closing operation is formed on the base side of the metal layer 13.

As one base material 12 of this reed valve 11,
It is preferable to use a thin plate material having a high natural frequency, such as glass fiber or carbon fiber impregnated with a resin material. The other metal layer 13 may be made of a material having greater durability than the base material 12, and metal foil may be used as the base material 1.
It may be formed by adhering to the base material 12, or by other known means such as vapor deposition of metal on the base material 12. Further, the material of the metal foil, which is a type of the metal layer 13, may be selected from crystalline metal foil such as stainless steel foil, non-crystalline metal foil such as amorphous alloy, etc. depending on design conditions. In other words, although amorphous metal foil is more expensive than crystalline metal,
It has excellent mechanical properties such as hardness and strength, as well as excellent chemical stability (corrosion resistance), so it is best to consider these properties and select one that meets the design conditions.

Next, the operation of this embodiment will be explained.

The reed valve 11 of this embodiment has an outlet 4 of the valve body 2.
Since the metal layer 13 is formed only on the opening/closing movable part 14a which is sufficient to fully close the opening/closing part 14a, and the base part 14b is made of resin, the reed valve 11 itself has a high natural frequency as a resin reed valve. While maintaining this, the metal layer 13 significantly improves durability. Therefore, even if the valve body 2 to which the reed valve 11 is mounted is made of a single piece of resin or metal, chipping or the like may occur at the opening/closing movable portion 14a that comes into violent contact with the valve body 2. Therefore, extremely good valve opening/closing operation can be maintained for a long period of time. Moreover, the opening/closing operation of each movable part 14a is performed with good responsiveness based on the high natural frequency of the resin base material 12 portion on which the metal layer 13 is not formed, and the operating characteristics as a reed valve are improved. It will be extremely expensive. As a result, the reed valve of this embodiment can be applied to parts that require high-speed operation.

Further, in the above embodiment, when the metal layer 13 made of metal foil is bonded to the base material 12, the metal layer 13
Small through holes may be formed here and there at positions that do not reduce the sealing performance to increase the adhesive force between the two.

Note that the present invention is not limited to the above-mentioned embodiments, and can be modified as necessary.

〔Effect of the invention〕

Since the reed valve of the present invention is constructed and operates in this manner, it can be used by being attached to a valve body that does not have a valve seat made of cushion material at the abutting part of the reed valve. It exhibits sufficient durability and can continue proper valve opening/closing operation over a long period of time, and also maintains a high natural frequency as a resin reed valve, resulting in excellent operating characteristics. Furthermore, it has advantages such as low cost.

[Brief explanation of drawings]

1 and 2 show an embodiment of the reed valve of the present invention, FIG. 1 is a perspective view of one embodiment, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG. FIG. 4 is a perspective view showing a reed valve device equipped with a conventional reed valve, and FIG. 4 is a sectional view taken along the line - in FIG. 3. DESCRIPTION OF SYMBOLS 1...Reed valve device, 4...Outlet, 5...Support, 11...Reed valve, 12...Base material, 13...
...Metal layer.

Claims (1)

[Scope of Claims] 1. In a reed valve formed of a thin plate-like base material, the base material is made of resin, and an outlet portion of the valve body of the base material is not provided with a valve seat made of cushion material. A reed valve characterized in that a metal layer having greater durability than the base material is formed in a part that comes into contact with the base material, and a resin part with a high natural frequency responsible for opening and closing operation is formed on the base side of the metal layer. 2. The reed valve according to claim 1, wherein the metal layer is made of a crystalline metal or an amorphous metal.