JPS62228652A - Rotary shaft for carburetor - Google Patents

Abstract

PURPOSE:To protect a shaft from being broken due to a high temperature caused through backfire by forming the rotary shafts of a gate valves in a carburetor from synthetic resin material while applying metallic galvanization onto the outer circumference at a sliding section. CONSTITUTION:A throttle valve 4 in a carburetor 1 and the shafts 8, 9 of gate valves in a choke valve 5 are formed from synthetic resin such as copolymer, acetal, etc. Glass fibers are contained as reinforcing material in the synthetic resin as required. Said shaft is chemically etched to improve the tightly contacting force, then ionic material is adsorbed through a sensitization and palladium is deposited through activation thereafter copper is galvanized chemically. Furthermore, copper sulfate galvanization is performed through electrical under coat galvanization followed by nickel galvanization and finish galvanization of chrome alloy so as to produce a heat-resistant shaft.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention relates to a vaporizer that controls the concentration and amount of air-fuel mixture supplied to an engine, and particularly relates to a butterfly-type on-off valve (e.g. It relates to a rotating shaft used to attach a throttle valve, choke valve).

``Prior art'' A butterfly-type on-off valve that opens and closes the intake passage that passes through the carburetor body is generally equipped with a throttle valve and a choke valve, and these are rotatably supported on the carburetor body. It is attached to the rotating shaft. This rotating shaft is made of free-cutting steel.
It is formed from a metal material such as stainless steel or a copper rod, or a synthetic resin material such as polyphenylene or sulfide.

"Problems to be Solved by the Invention" Among such conventional rotating shafts, those made of metal materials are excellent in heat resistance and sliding abrasion resistance, but because of their high specific gravity, it is difficult to reduce the weight of the product. It had the disadvantage of being difficult. On the other hand, rotating shafts made of synthetic resin have a low specific gravity and can reduce the risk of mold breakage of the entire product, but special consideration must be given to the heat generated by backfire from the engine.

This is because the rotating shaft is arranged approximately perpendicular to the intake duct, so the packfire blown back from the engine flows back upstream along the intake duct, and the tip of this flame crosses the intake duct. Direct contact with the blocking rotating shaft. The tip of this flame is the hottest, and if this flame comes in contact with the rotating shaft over a long period of time, especially the surface of the rotating shaft that opens toward the engine, distortion will occur in the rotating shaft, causing operational problems. Not desirable.

In addition, if a reinforcing material such as glass fiber is contained inside the synthetic resin material, if the reinforcing material is deposited on the sliding surface of the rotating shaft, friction may occur during the rotation of the rotating shaft, which is undesirable. There is.

``Means for Solving the Problems'' The rotating shaft of the vaporizer according to the present invention was created in view of the above-mentioned problems. The purpose is to obtain a rotating shaft that is not affected by wear due to durability caused by precipitation of reinforcing material placed inside the resin material on the surface, and in order to achieve the above objective, the rotating shaft is molded from a synthetic resin material and The outer circumference of the rotating shaft is plated with metal.

``Function'' According to such a rotating shaft, even if the rotating shaft that opens into the intake duct receives the flame from the backfire generated in the engine, the 5 rotating shaft is metal-plated, so it temporarily has high thermal conductivity. Since heat can be dissipated overall through the metal plated surface, thermal properties can be improved.

In addition, even if the reinforcing material is deposited on the surface of the synthetic resin material, since the upper part is further metal-plated, the reinforcing material does not come into direct contact with the inner surface of the shaft hole of the carburetor body, which supports the rotating shaft. This can improve the durability of the shaft.

"Embodiment" Hereinafter, one embodiment of the rotating shaft of the carburetor according to the present invention will be described with reference to the drawings.

Reference numeral 1 denotes a carburetor main body through which an intake passage 2 passes, and a venturi portion V is formed in the middle part of the intake passage 2. A main nozzle 3 for sucking out fuel from a float chamber (not shown) opens in a portion V of the venturi. A butterfly-type throttle valve 4 is arranged in the intake passage z on the engine side (lower side in the figure) than the venturi part V, while the venturi part V
Intake path z closer to the air cleaner (upper side in the diagram)
A butterfly type choke valve 5 is arranged inside.

On the other hand, 6 is a shaft hole for a throttle, which is bored approximately perpendicular to the carburetor body 1, and above it, a shaft hole 7 for a choke, which is also bored approximately perpendicular to the carburetor body 1, is bored. . A rotary shaft 8 for a throttle is rotatably disposed in the shaft hole 6 for the throttle, and a rotary shaft 9 for a choke is rotatably disposed in the shaft hole 7 for the choke. A throttle valve 4 is attached to the rotating shaft 8 for the throttle, and a choke valve 5 is attached to the rotating shaft 9 for the choke.

The above is a rotation shaft of a conventionally known carburetor, and the present invention particularly has the following configuration in order to achieve the above object.

That is, the rotating shafts 8 and 9 are made of copolymer or acetal.

It is made of a synthetic resin material such as polyphenylene sulfide, or a reinforcing member such as glass fiber is contained in the synthetic resin material, and the outer periphery of the rotating shafts 8 and 9 formed of such synthetic resin material is further plated with metal. It is something.

The rotating shaft 8.9 made of a synthetic resin material may be metal plated, for example, by the following method.

Therefore, the surface of the rotating shaft 8.9 may be plated with any metal, but hard chrome plating is generally easy to implement.

When the surface of the rotating shaft 8.9 is plated with metal in this way, when the backfire from the engine comes into contact with the outer circumference of the rotating shaft 8.9, the flame will spread over the metal surface with high thermal conductivity. As a result, part of the flame does not concentrate on a part of the rotating shafts 8, 9, and the rotating shafts 8, 9 are not deformed even during long-term use. No part of it melts.

Furthermore, when glass fibers, etc. are contained in the synthetic resin material, the glass fibers, etc. may be deposited on the surface of the rotating shaft. Therefore, substances contained in glass fibers and the like do not directly appear on the surface.

"Effects of the Invention" As described above, the rotating shaft of the carburetor according to the present invention has the following effects.

■Even if the rotating shaft receives a packfire that occurs in the engine, the temperature of the flame can be diffused around the entire circumference of the rotating shaft using highly thermally conductive metal-plated metal members (chrome, etc.). Since the rotary shaft is not exposed to high temperatures and the temperature is lowered, stable rotation controllability can be ensured even when the rotary shaft is used for a long period of time.

(Even if a multi-resin material is filled with inclusions and those inclusions are precipitated on the rotating part of the rotating shaft, the precipitated inclusions are covered with metal plating so that they do not connect with the holes during rotation. Frictional force can be reduced at intervals, and a rotating shaft with excellent durability can be provided.

■If the entire vaporizer is made of resin material, the base material of the rotating shaft is synthetic resin material and only its surface is metal plated, so the synthetic resin material continues to have good effects on the entire vaporizer. Can be inherited.

[Brief explanation of drawings]

The figure is a longitudinal cross-sectional view showing one embodiment of the rotating shaft of the carburetor according to the present invention. 8.9. , , is the axis of rotation.

Claims (1)

[Claims] A rotating shaft rotatably supported by a carburetor body through which an intake passage passes through, and to which an on-off valve for opening and closing the intake passage is attached, the rotating shaft being molded from a synthetic resin material. The rotating shaft of the carburetor is formed by metal plating the outer periphery of the sliding valve.