JPS60173355A - Manufacturing method of bypass hole in plastic carburetor - Google Patents

Abstract

PURPOSE:To secure an inexpensive and accurate carburetor, by molding plural bypass holes by means of casting formation, then blocking up some of useless bypass holes in time of molding a thermoplastic carburetor. CONSTITUTION:At the time of molding a carburetor body 1 with thermoplastics, plural bypass holes 6 interconnected to a bypass chamber 5 are molded by means of casting formation in advance. Next, after a throttle valve 4 is attached to the carburetor body, some of useless bypass holes are blocked up in taking account of a requisition characteristic of the carburetor and its matchability with the throttle valve. In time of closure, each of thermoplastic plugs is inserted into these useless bypass holes and heated, thus they are ingeniously closable.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vaporizer, and more particularly to a plastic vaporizer in which the main body of the vaporizer, which constitutes most of the constituent parts of the vaporizer, is made of a thermoplastic material.

In recent years, plastic materials have been adopted for the carburetor body, but this is because plastic materials are lighter in weight than metal materials such as zinc alloy die-casting materials or aluminum, which are conventionally used as materials for the carburetor body, and are corrosion resistant. It is used because of its excellent properties and low material cost.

However, while it has the various effects mentioned above, products made of plastic materials are extremely difficult to machine, such as drilling, and even if they could be machined, the life of the cutting tool would be extremely short or was extremely vague.

- Various holes and grooves are drilled in the main body of the mountain carburetor, and these holes and grooves are designed by appropriately selecting their direction and shape so that they can be cast out when designing the main body of the vaporizer. All of these can be molded by casting when forming the carburetor body.

However, the holes and grooves for these passages do not need to be changed every time the installed engine changes, but the control die that controls the amount of air, fuel, and mixture)
Alternatively, the bypass hole is optimally set and determined to suit each engine. These control jets can be used by selecting the control hole diameter and preparing them in advance, but the bypass holes that are drilled from the bypass chamber of the carburetor body into the intake tract are difficult to machine. In particular, a mold for bypass hole casting is required that has a hole diameter and position suitable for each engine, which increases the number of molds and increases product costs. .

The method of manufacturing a bypass hole in a plastic carburetor according to the present invention has been devised in view of the above-mentioned problems, and by obtaining a bypass hole that can be adapted to many engines with a single mold, an inexpensive plastic carburetor can be manufactured. The purpose is to obtain a vessel.

Hereinafter, an embodiment of the method for manufacturing bypass holes in a plastic vaporizer according to the present invention will be described with reference to FIG.

Reference numeral 1 denotes a carburetor main body through which an intake passage 2 passes.A shaft 3 is rotatably supported in the intake passage 2, and a throttle valve 4 is supported on the shaft 3. This vaporizer main body 1 is molded from a thermoplastic resin material such as polyphenylene sulfide (abbreviated as PP5), and has holes (not shown) provided in the vaporizer main body 1.
All passages, grooves, etc. are formed by casting during molding of the carburetor body l.

That is, 5 is a bypass chamber provided corresponding to the fully open position of the throttle valve 4, and this bypass chamber 5 has a plurality of bypass holes 6 penetrating the intake passage 2, which are integrally formed when the carburetor main body 1 is molded. It is cast and formed. The bypass hole 6 is composed of a plurality of bypass holes 6 as shown in FIGS. 2 and 3, and the hole diameter and the pitch between the holes are predicted and determined in advance. Then, when the wood carburetor is actually installed in the engine and the appropriate hole diameter and pitch of the bypass holes 6 are determined, unnecessary bypass holes 6 among the already drilled bypass holes 6 are closed. be.

This closing operation can be accomplished by inserting a plug 7 made of, for example, a thermoplastic material into the bypass hole 6, and melting and solidifying the plug 7 using a heat welding machine or the like.

In this way, when molding the carburetor main body l, a plurality of predicted bypass holes are punched out and drilled in advance, and then only the unnecessary bypass holes are closed to obtain the desired bypass holes. Therefore, the pore size is relatively small (for example, o,
This eliminates the need for machining a bypass hole (e.g. mm), making it possible to provide a bypass hole extremely easily and at low cost, which has been the biggest bottleneck in the past.

As described above, according to the method for manufacturing bypass holes in a plastic vaporizer according to the present invention, a plurality of bypass holes are integrally formed by casting during molding of the vaporizer main body, and then unnecessary bypass holes are formed from the bypass holes. Since the desired bypass hole is obtained by closing only the bypass hole, the bypass hole, which is considered to be the most difficult to manufacture in plastic vaporizers, can be provided very easily and at low cost.

Further, unnecessary bypass holes can be closed by thermal welding, thereby improving workability.・

[Brief explanation of the drawing]

The si diagram shows / in the plastic vaporizer according to the present invention.
A vertical sectional view showing an example of a method for manufacturing a hay pass hole, the second
FIG. 3 is a plan view showing an embodiment of a plurality of bypass holes. Engineering φ... Carburetor body 4th generation, ◆, Throttle valve 5ψ, --- bypass hole 6 ---, multiple bypass holes

Claims (1)

[Claims] 1) A carburetor body through which an intake passage passes is formed of a thermoplastic plastic material, and a bypass chamber is formed in correspondence with an end of a throttle valve rotatably disposed in the intake passage. At the same time, a plurality of bypass holes are formed in the bypass chamber so as to pass through the intake passage, and the bypass holes are integrally molded by casting when forming the carburetor main body, and then the plurality of bypass holes are eliminated. / Plasti made by blocking only the Heibus hole.
A method for manufacturing a bypass hole in a vaporizer made of carbon. 2) A carburetor main body through which an intake passage passes is formed of a thermoplastic plastic material, and a bypass chamber is formed corresponding to an end of a throttle valve rotatably disposed in the intake passage. A plurality of bypass holes are drilled through the intake duct, and the bypass holes are integrally cast and molded during molding of the carburetor body, and then only the unnecessary bypass holes of the plurality of bypass holes are made of thermoplastic material. A method for manufacturing a bypass hole in a plastic vaporizer, which is closed by thermally welding a plastic material.