JPH0240065A - Carburetor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a carburetor that controls the concentration and amount of air-fuel mixture supplied to an internal combustion engine.

[Conventional technology]

Among the components of a carburetor, the largest component is the carburetor body, and an intake passage is provided through the carburetor body, with one end connected to the air cleaner and the other end connected to the engine.

Conventionally, a body integrally molded from polyamide resin or the like has often been used as the main body of the vaporizer.

This is achieved by taking advantage of the advantages of synthetic resin materials, such as their light weight, excellent corrosion resistance, and smooth intake tract inner surface roughness. It is designed to provide an excellent, lightweight, and highly efficient vaporizer.

[Problem to be solved by the invention]

However, although the vaporizer body made of synthetic resin material has the above-mentioned excellent performance 1 function, it has a lower thermal conductivity than the vaporizer body made of metal such as aluminum or zinc, so it has the following characteristics: There are problems.

By the way, the thermal conductivity of aluminum is 2.3 can/see/ am'/'C/cm, and the thermal conductivity of polyamide resin is 0.4 can/sec/ crrf/00/cm.
■When starting the engine at a relatively low engine ambient temperature, the engine temperature rises as the engine continues to operate, but as mentioned above, the thermal conductivity of the synthetic resin material is low. In addition, the temperature of the vaporizer body rises extremely slowly.

Therefore, the atomized fuel sucked out from the float chamber into the intake duct of the carburetor body tends to adhere to the inner wall of the intake duct, making it difficult to supply a highly vaporizable air-fuel mixture to the engine.

■When the engine ambient temperature rises and the engine finishes warming up, the carburetor body receives the sufficiently raised engine temperature via the intake pipe to increase the temperature of the carburetor body. At this time, since the thermal conductivity of the vaporizer main body is low, it is difficult for heat to be radiated from the vaporizer main body to the surroundings, and the vaporizer main body is maintained at a high temperature state. According to this, although the vaporization of the fuel in the intake passage of the carburetor body is improved, there is a risk that a paper lock phenomenon may occur in the relatively small diameter fuel passage formed in the shape of a grid in the carburetor body.

Further, the float chamber disposed near the carburetor main body is also affected by the heat of the vaporizer main body arranged above, and there is a risk that percolation of the fuel within the float chamber may occur.

[Means for Solving the Problem] [Operation] The carburetor used in the internal combustion engine according to the present invention was created in view of the above problems, and combines the advantages of synthetic resin materials and the advantages of metal materials. We aim to provide a vaporizer that also has the following features:
In order to achieve the above objective, an additive material having a thermal conductivity higher than that of the synthetic resin material as the base material is integrally contained in the synthetic resin material as the base material forming the carburetor body of the vaporizer. The vaporizer main body is formed from a composite synthetic resin material that has higher heat receiving and heat dissipating properties than synthetic resin materials.

〔Example〕

Hereinafter, one embodiment of 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, one side (left side in the figure) of this intake passage 2 is connected to an air cleaner (not shown), and the other side (right side in the figure) is connected to an engine ( (not shown). Further, a freely rotatable butterfly-type throttle valve 3 is disposed within the intake passage 2, and the effective opening area of the intake passage 2 is controlled by this throttle valve 3.

Reference numeral 4 denotes a float base body disposed below the carburetor body 1, and a float chamber 5 is formed by the concave portion of the carburetor body 1 and the float base body 4.

A constant fuel level is formed within the float chamber 5 by the cooperation of the float 6, a valve seat (not shown), and a float valve.

Reference numeral 7 designates a main nozzle whose one end opens into the intake passage 2 and whose other end communicates with a constant liquid level in the float chamber 5 via a main jet 8.

The above is a conventionally known carburetor, in which when negative pressure is generated in the intake passage 2, the fuel stored in the float chamber is sucked out into the intake passage 2 from the fuel injection hole such as the main nozzle. be.

In order to solve the above problems, the carburetor according to the present invention has a main body l as follows.

That is, the vaporizer main body 1 is formed of a composite resin material having a resin material such as polyamide resin as a base material and containing powder or fibers such as aluminum in the base material.

According to this, the thermal conductivity of the vaporizer body l is 0.4 can/sec/cm, which is the thermal conductivity of the polyamide resin material.
It is possible to obtain a higher thermal conductivity compared to 10C/cm, and how high this thermal conductivity is determined is determined by considering the temperature rise characteristics of the engine and the environmental temperature in which it will be used. In order to increase the thermal conductivity, it is sufficient to appropriately set the type or mixing ratio of the selected high thermal conductivity material to obtain the optimum thermal conductivity.

According to the above, when the engine is operated and the temperature rises, the engine temperature is transmitted to the carburetor main body 1 in a short time and
As a result, the fuel flowing through the intake passage 2 of the carburetor body 1 is efficiently atomized on the warmed inner wall of the intake passage 2, which improves the mixing of air and fuel and improves engine performance. The combustibility of the fuel can be improved, and the performance can be improved.

On the other hand, as mentioned above, the temperature of the carburetor body increases as the engine temperature rises, but due to its increased thermal conductivity, the heat dissipation from the carburetor body to the surroundings also increases, and the carburetor This prevents the temperature of the main body l from increasing significantly.

Therefore, fuel paper is less likely to form in small-diameter passages such as the fuel passage of the main nozzle 7, and the fuel paper lock phenomenon can be completely prevented.

Furthermore, since the conductivity of heat from the carburetor body 1 to the float chamber 5 is reduced, the temperature of the fuel in the float chamber 5 does not increase significantly, so that the percolation phenomenon of the fuel in the float chamber 5 can be suppressed. It is.

In addition, the synthetic resin material as the base material of the vaporizer main body 1 on the wood flow side may be either thermoplastic or thermosetting.
For example, polyacetal, polyolefin, polystyrene, polycarbonate, polyamide, etc. can be selected according to the purpose, and additional materials with higher thermal conductivity than the base material include iron, copper, chromium, carbon, tungsten, etc. It will be selected by

Further, although a butterfly type throttle valve is used as the throttle valve, a cylindrical piston type sliding throttle valve may also be used.Furthermore, it will be even more effective if the present invention is applied not only to the carburetor body but also to the float basic body at the same time. be.

〔Effect of the invention〕

As described above, the carburetor for an internal combustion engine according to the present invention provides the following effects.

■While it has the advantages of a vaporizer using synthetic resin materials, such as light weight, good corrosion resistance, and good tube inner surface roughness, it also has a temperature rise characteristic that quickly increases the temperature when it receives heat from the outside. Since we were able to provide an excellent carburetor body, we were able to improve the atomization performance of the fuel within the intake pipe, making it possible to further improve the operability of the engine. In particular, we were able to see a significant improvement in drivability from starting when the engine ambient temperature was low to completing warm-up.

■While the engine is running, the heat received by the carburetor body from the engine is absorbed by the carburetor body's self-heat dissipation effect (due to its high thermal conductivity), which enables sufficient heat dissipation. Since the temperature rise of the main body was suppressed to around 60°C, the paper lock phenomenon in the fuel passage drilled in the carburetor main body was completely suppressed, and the performance was further stabilized. This is what was created.

Furthermore, since the heating of the fuel in the float chamber was also reduced, it was possible to suppress a rise in fuel temperature, thereby making it possible to prevent the percolation phenomenon of the fuel in the float chamber.

[Brief explanation of the drawing]

Figure VJ1 is a system diagram of the entire engine showing one embodiment of the carburetor in the internal combustion engine according to the present invention. 1. Carburizer body 2. Intake path 4. Float basic body 5. Float chamber.

Claims (2)

[Claims] (1) A carburetor body through which an intake passage passes through, and which is equipped with a throttle valve that controls the effective opening area of the intake passage; A float chamber formed by storing a constant liquid level inside; A carburetor for an internal combustion engine, which is capable of sucking fuel in a float chamber into an intake tract via a fuel passage by negative pressure generated in the intake tract, wherein the carburetor body is formed of a synthetic resin material and the synthetic resin A vaporizer comprising a material containing an additive material having a thermal conductivity higher than that of the synthetic resin material as a base material. (2) The vaporizer according to claim 1, wherein the additive material is a metal.