JPH0240033A - Throttle valve for butterfly type carburetor - Google Patents

Abstract

PURPOSE:To completely suppress the occurrence of icing and to sharply improve atomizing performance of fuel by a method wherein the throttle valve of a butterfly type carburetor is formed by a synthetic resin material containing a conductive material. CONSTITUTION:A butterfly type throttle valve 8 is screwedly mounted on a throttle valve shaft 9, pivotally supported in a bearing hole 1A of a carburetor body 1, by means of screws 10. The throttle valve 8 is formed by a composite resin material in which a resin material, e.g. polyamide series, forms a base material and powder or fibers of a conductive material, e.g. carbon, is contained in the base material. In a state in which the ambient temperature of an engine is low, an operator closes an on-off switch 13 and charges the throttle valve 8 with a current. The throttle valve 8 itself is caused to self-generate heat. This constitution enables complete suppression of the occurrence of icing and sharp improvement of atomizing performance of fuel.

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, and in particular, the invention relates to a carburetor that controls the concentration and amount of air-fuel mixture supplied to an internal combustion engine. This invention relates to a throttle valve for a so-called butterfly type carburetor that is controlled to open and close by using the same method.

[Conventional technology]

Conventionally, the throttle valve of a butterfly-type carburetor has a throttle valve shaft rotatably supported on the carburetor body, and the butterfly-type throttle valve is attached to this throttle valve shaft. By rotating the throttle valve, the throttle valve rotates within the intake tract, thereby controlling the effective opening area of the intake tract.

Conventionally, this type of throttle valve has often been integrally molded from polyamide resin or the like.

This has advantages over throttle valves made of metal materials, such as the light weight of synthetic resin materials, excellent contact resistance, and the fact that they are formed by molding and do not require processing. This is for the purpose of not using points.

[Problem to be solved by the invention]

However, although throttle valves made of synthetic resin materials have the above-mentioned nine excellent functions, they have lower thermal conductivity than throttle valves made of metals such as aluminum and copper, resulting in the following problems: has.

By the way, the thermal conductivity of aluminum is 2.3 cal /see/ crrf/ 'C/cm
The thermal conductivity of polyamide resin is 0.4 ca/see/crrf/'C/cm.

Generally, the air that flows through the air cleaner into the intake duct of the carburetor body contains some water vapor, and when this intake air is cooled, the throttle valve is also cooled, and the humidity of the air is reduced. It becomes supersaturated with respect to the temperature set, and water is deposited and forms a mist on the surface of the throttle valve.

On the other hand, in the carburetor body, atomized gasoline fuel continuously flows through the intake duct inside the carburetor and collides with the throttle valve, which is cooled by the latent heat of vaporization of the atomized gas. .

When the temperature of this throttle valve drops below 0°C,
The above-mentioned mist of water condenses into ice, which adheres to the surface of the throttle valve and blocks the effective area of the intake duct or the low-speed fuel injection hole that opens near the throttle valve. This may reduce the intake air amount and low-speed fuel amount, leading to engine malfunction. (So-called icing phenomenon) When the throttle valve is made of synthetic resin material, its thermal conductivity is lower than that of metal, so although it is difficult to cool down in the early stages of operation, the temperature drops below -0'C. If the temperature decreases, it is difficult to transfer and receive heat from the outside, so a temperature rise cannot be expected, and icing is more likely to occur than with a metal throttle valve.

[Means to solve problems]

The butterfly type vaporizer throttle valve of the present invention has been developed in view of the above-mentioned problems, and has the two excellent performance features of synthetic resin materials, and has good icing resistance. In order to achieve the above object, the throttle valve is made of a synthetic resin material containing an electrically conductive material, and an electric current is passed through the throttle valve.

[Effect]

By directly passing an electric current through the synthetic resin material containing a conductive material, the throttle valve itself generates heat, increasing the temperature of the throttle valve. Regardless of the temperature drop due to latent heat of vaporization, the temperature can always be maintained at a constant temperature or higher.

〔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). Reference numeral 3 denotes a float base body disposed below the carburetor body 1, and a float chamber 4 is formed by the four parts of the carburetor body 1 and the float base body 3.

A constant fuel level is formed in the float chamber 4 by the cooperation of the float 5, a valve seat (not shown), and the float pulp.

Is one end of 6 an intake duct? The main nozzle is open inward, and the other end is connected to a constant liquid level in the float chamber 4 via a main jet 7. Reference numeral 8 denotes a butterfly-type throttle valve, and this throttle valve 8 is screwed with a screw 10 to a throttle valve shaft 9 rotatably supported in a bearing hole IA of the carburetor main body l. In particular, this throttle valve 8 is made of a composite resin material having a base material of a resin material such as polyamide, and containing powder or fiber of a conductive material such as carbon in the base material. It is.

A current is passed through this throttle valve 8,
As a specific example of this method, a conductive sleeve 11 is fitted into the bearing hole IA of the carburetor main body 1, a throttle valve shaft 9 made of a conductive material is slidably held in the sleeve 11, and the throttle valve shaft 9 made of a conductive material is slidably held in the sleeve 11. The throttle valve f8 is attached to the valve stem 9 with a screw 10, and the sleeves 11 and 11 at both ends of this
are connected by an electric circuit.

Note that 12 is a power source arranged in the electric circuit, 13 is an open/close switch, and 14 is a bypass hole as a low-speed fuel injection hole that opens into the intake passage 2 in correspondence with the throttle valve 8.

When a negative pressure is generated in the intake passage 2, the fuel stored in the float chamber 4 is sucked out into the intake passage 2 from the main nozzle 7 and fuel injection holes such as the bypass hole 14.

According to the throttle valve of the headfly type carburetor according to the present invention, the engine can be operated in November, December, March, or April when the ambient temperature of the engine is relatively low and the humidity is relatively high. During operation, the driver closes the on/off switch 13 in the electric circuit of the throttle valve 8 to allow current to flow through the throttle valve 8.

According to this, since the synthetic resin forming the throttle valve 8 contains a conductive material, the entire throttle valve 8 generates heat by itself, thereby raising the temperature of the throttle valve 8.

Therefore, even if the throttle valve 8 receives the latent heat of vaporization of the fuel, the temperature of the throttle valve 8 will not drop below 0°C.
Even if humid air containing supersaturated humidity flows through the intake passage 2, no ice is formed on the surface of the throttle valve 8, and icing on the throttle valve 8 can be completely suppressed.

The temperature rise of the throttle valve 8 with respect to the current applied to the throttle valve 8 can be determined by appropriately selecting the content ratio of the conductive material contained in the synthetic resin material as the base material or the type of the conductive material. And, as a conductive material,
For example, iron, copper, chromium, carbon, tungsten, nickel chromium.

Examples of the synthetic resin material used as the base material include polyacetal, polyolefin, polystyrene, polycarbonate, and polyamide, which must be appropriately selected depending on the purpose.

Furthermore, if the open/close switch 13 is replaced with a manual switch and is replaced with a heat-sensing switch that closes only when the engine ambient temperature is below a certain temperature, the throttle valve 8 can be automatically warmed to a certain temperature when the engine ambient temperature is low. [Effects of the Invention] As described above, the butterfly type carburetor throttle valve of the present invention provides the following effects.

■Synthetic resin is used because it has the advantages of throttle valves made of synthetic resin materials, such as light weight and good corrosion resistance, but also allows the throttle valve mouth body to self-heat and prevent the temperature of the throttle valve from dropping. This completely prevents icing on the throttle valve.

■According to the self-heating of the throttle valve mouth body, the fuel flowing in the intake tract collides with the throttle valve whose temperature has increased.
In particular, the fuel atomization performance can be greatly improved even when the throttle valve is opened at a low degree and the engine ambient temperature is low.

■If the open/close switch placed in the electrical circuit of the throttle valve is a heat-sensitive switch, the throttle valve will be automatically energized and heated when the temperature of the intake air drawn into the intake tract is below a certain temperature. This method requires no skill at all.

[Brief explanation of the drawing]

The figures show an embodiment of the throttle valve of the 7-toughfly type carburetor according to the present invention, in which Fig. 1 is a longitudinal cross-sectional view, and Fig. 2 is a longitudinal cross-sectional view taken along line II-II in Fig. 1. . 1 , Carburetor main body 2 , Intake path 8 , Throttle valve 9 , Throttle valve shaft

Claims (5)

[Claims] (1) In a butterfly type carburetor throttle valve that is attached to a throttle valve shaft rotatably supported by the carburetor body and controls opening and closing of the intake passage that passes through the carburetor body, the throttle valve is electrically conductive. A throttle valve for a butterfly type vaporizer made of synthetic resin material containing a material. (2) In a butterfly type carburetor throttle valve that is attached to a throttle valve shaft rotatably supported by the carburetor body and controls opening and closing of the intake passage passing through the carburetor body, the throttle valve is electrically conductive. A throttle valve of a butterfly type vaporizer, which is formed of a synthetic resin material containing a material and in which an electric current is passed through the throttle valve. (3) In a butterfly type carburetor throttle valve that is attached to a throttle valve shaft rotatably supported by the carburetor body and controls opening and closing of the intake passage that passes through the carburetor body, the throttle valve is electrically conductive. A throttle valve for a butterfly type carburetor, which is made of a synthetic resin material containing a resin material, and has an on/off switch for controlling opening/closing of a current flowing to the throttle valve in an electric circuit that supplies current to the throttle valve. (4) The throttle valve for a butterfly type carburetor according to claim 3, wherein the opening/closing switch is a manual changeover switch. (5) The throttle valve for a butterfly type vaporizer according to claim 3, wherein the opening/closing switch is a heat-sensitive switch that automatically closes the electric circuit only when the temperature is below a certain temperature.