JP2000097109A - Starting device for carburetor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing cost of a starting device, as well as to feed an adequate air-fuel mixture for starting to the engine, even though a carburetor is in the inclined condition. SOLUTION: While the first starting fuel passage P1 which consists of a starting fuel jet 6 including a mixing pipe M is formed on a straight line, the first starting fuel passage is provided about at the center of a fuel liquid level X-X formed in a float chamber 4, and the starting fuel jet 6 is opened under the constant liquid level. While the second starting fuel passage P2 including a starting fuel nozzle 11 is provided on about a straight line, it is crossing connected to the upper side P1a of the first starting fuel passage P1 from the oblique direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carburetor for controlling the concentration and amount of an air-fuel mixture supplied to an engine. The present invention relates to a starting device for a vaporizer supplied to a fuel cell.

[0002]

2. Description of the Related Art A first example of a conventional carburetor starting device is shown in FIG.
Is shown in Reference numeral 1 denotes a carburetor body through which an intake passage 2 penetrates. The intake passage is opened and closed by a throttle valve (not shown). The intake passage is an upstream intake passage connected to an air cleaner by the throttle valve. And a downstream intake passage connected to the engine. The air cleaner and the engine are not shown.
Reference numeral 3 denotes a float chamber main body disposed below the carburetor main body 1. The float chamber 4 is formed by the carburetor main body 1 and the float chamber main body 3, and a fuel inflow (not shown) flows into the float chamber 4. A constant fuel liquid level XX is formed by the cooperative action of the valve seat hole connected to the path, the float valve that opens and closes the valve seat hole, and the float that applies an opening / closing operation force to the float valve. The starting device S includes the following. 5 is the fuel level X
A first starting fuel passage formed substantially in the vicinity of the center of −X, specifically, substantially in the vicinity of the center of the intake passage 2 and formed on a straight line in the vertical direction in FIG. The fuel jet 6 is arranged, and the mixing pipe M is arranged on the downstream side.
(Here, upstream and downstream are defined in the direction of fuel flow.) That is, the starting fuel jet 6 is located near the center of the fuel level XX and below the fuel level XX in the floating chamber 4. The opening is located at the position. Reference numeral 7 denotes a starting valve chamber which is provided on the side of the carburetor main body 1 and is vertically formed and has a bottom 7A. A starting air passage 8 and a starting air-fuel mixture passage 9 are opened on the side wall of the starting valve chamber 7, and the starting air passage is connected to an intake passage upstream of a throttle valve (not shown). Is connected to an intake passage downstream of the throttle valve. A second starting fuel passage 10 extending vertically is formed in the bottom 7A of the starting valve chamber 7 concentrically with the starting valve chamber 7, and is arranged downstream of the second starting fuel passage 10. The fuel nozzle 11 opens at the bottom 7A of the starting valve chamber 7. Reference numeral 12 denotes a start valve which is slidably disposed in the start valve chamber 7, and a needle 13 inserted into the start fuel nozzle 11 is integrally attached to the start valve 12. The start valve is opened and closed by a wax 14 as a heat-sensitive member. Reference numeral 15 denotes a third starting fuel passage connecting the downstream of the first starting fuel passage 5 and the upstream of the second starting fuel passage 10, and is formed obliquely from the left side of the carburetor main body 1 in the figure. The opening at the left end of the vaporizer main body 1 is closed by a plug 16. According to the first conventional example, in a state where the temperature of the engine atmosphere machine is low, the starting valve 12 is pulled up by the wax 14,
The starting valve 12 is pulled upward in the starting valve chamber 7. Therefore, the starting air passage 8, the starting air-fuel mixture passage 9, and the starting fuel nozzle 11 are opened into the starting valve chamber 12,
When the engine is started in such a state, a negative pressure generated in the intake passage downstream of the throttle valve acts in the starting valve chamber 7. According to the above, the fuel in the float chamber 4 is sucked into the mixing pipe M under the control of the starting fuel jet 6 and mixed with the air supplied from the bleed hole in the mixing pipe M. The second starting fuel passage 1 is connected via the first starting fuel passage 5 and the third starting fuel passage 15.
The fuel reaches the starting fuel nozzle 11 of 0, and the fuel further restricted by the annular gap formed by the starting fuel nozzle 11 and the needle 13 is supplied into the starting valve chamber 7. And
In the starting valve chamber 7, fuel supplied through the starting fuel nozzle 11 and air supplied through the starting air passage 8 are mixed to form a starting air-fuel mixture. The mixture is supplied into the intake passage downstream of the throttle valve through the mixture passage 9, whereby a concentrated and increased starting mixture suitable for cold starting can be supplied to the engine.

[0003] A second example of a conventional carburetor starting device is shown in FIG.
Is shown in The same components as those in FIG. 2 are denoted by the same reference numerals, and description thereof is omitted. A characteristic of the example of FIG. 3 is that the first starting fuel passage and the second starting fuel passage in the first conventional example are unified into a single starting fuel passage 1.
That it was 5. And that the starting fuel passage 15 is arranged vertically apart from the center of the fuel level. It is.

[0004]

According to the first example of the conventional carburetor starting device, when the carburetor is tilted left and right, the fuel liquid level XX is equal to the tilted liquid level such as X1-X1 and X2-X2. Form a surface. However, in any inclined liquid level state, the starting fuel jet 6 is arranged to be opened below the fuel liquid level, and the starting fuel nozzle 11 or the third starting fuel passage 15 is disposed above the fuel liquid level. According to the above, it is possible to supply a proper starting air-fuel mixture even when the vaporizer is tilted,
The fuel in the float chamber 4 does not overflow into the intake passage through the starting mixture passage 9. On the other hand, focusing on the starting fuel passage, the first starting fuel passage 5 is vertically arranged substantially at the center of the intake passage 2, and the second starting fuel passage 10 is vertically arranged on the side of the carburetor body 1. Therefore, the third starting fuel passage 15 for connecting the two starting fuel passages 10 and 5 is required. According to the above, the work for working the third starting fuel passage 15 and the work for press-fitting the plug 16 for closing the opening of the third starting fuel passage 15 are required, and the manufacturing cost cannot be reduced.

Further, according to the second example of the conventional carburetor starting device, there is a problem when the carburetor is tilted left and right. That is, in the state of the inclined liquid level X1-X1, the starting fuel jet 6 is located above the fuel liquid level X1-X1, and cannot supply the starting fuel. On the other hand, in the state of the inclined liquid level X2-X2, the starting fuel jet 6 and the starting fuel passage 15 including the starting fuel nozzle 11 are arranged below the fuel liquid level X2-X2, whereby the fuel in the float chamber 4 is mixed. Air passage 9
Spills into the intake passage through the, and a good engine start cannot be obtained.

The carburetor starting device according to the present invention has been made in view of the above-mentioned problems, and can supply a proper starting air-fuel mixture to the engine even when the carburetor is in an inclined state. It is an object of the present invention to provide a starting device for a carburetor capable of reducing its manufacturing cost.

[0007]

According to a first aspect of the present invention, there is provided a starting apparatus for a carburetor, comprising:
A starting air passage connected to an intake passage upstream of the throttle valve and a starting air-fuel mixture passage connected to an intake passage downstream of the throttle valve are opened, and a mixing pipe and a starting fuel jet are provided at the bottom of the throttle valve chamber. A starting device for a carburetor that opens and closes a starting fuel nozzle connected below the constant liquid level of the float chamber and controls the opening and closing of the starting air passage, the starting air-fuel mixture passage, and the starting fuel nozzle with a starting valve disposed in the starting valve chamber. A first starting fuel passage formed of a starting fuel jet including the mixing pipe is formed in a straight line, and the first starting fuel passage is disposed substantially at the center of a fuel level formed in the floating chamber, and the starting fuel nozzle is disposed. The second starting fuel passage including the second starting fuel passage is disposed on a straight line and crosses the first starting fuel passage obliquely from the first starting fuel passage.

[0008]

A first starting fuel passage formed of a starting fuel jet including a mixing pipe is formed in a straight line, and the first starting fuel passage is disposed substantially at the center of a fuel level formed in a floating chamber. It is possible to supply an appropriate starting air-fuel mixture to the engine even in the inclined state. Further, since the second starting fuel passage including the starting fuel nozzle is arranged on a substantially straight line and crosses the first starting fuel passage obliquely from the first starting fuel passage, the machining operation can be reduced, and the press-in operation of the plug is not required, and the manufacturing is not required. Cost reduction can be achieved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vaporizer starting device according to the present invention will be described below with reference to FIG. In addition, the same reference numerals are used for the same structural parts as those in the related art, and the description is omitted. P
Reference numeral 1 denotes a first starting fuel passage, which is substantially the center of the fuel level XX (in other words, the center of the intake passage 2) and is formed linearly in the vertical direction in the figure. The starting fuel jet 6 is arranged on the upstream side of the first starting fuel passage P1, and the mixing pipe M is arranged on the downstream side. The starting fuel jet opens at a position below the fuel level XX in the float chamber 4, and a plurality of bleed holes are formed in the mixing pipe M, and air is introduced inward from the outer periphery through the bleed holes. Is introduced. P2 is
The second starting fuel passage, which communicates from the bottom portion 7A of the starting valve chamber 7 in a straight line obliquely from the bottom 7A of the starting valve chamber 7 toward the upper side of the first starting fuel passage P1. The downstream of the second starting fuel passage opens into the starting valve chamber 7 via the starting fuel nozzle 11. Then, when the start valve 12 opens the start air-fuel mixture passage 9, the start air passage 8, and the start fuel nozzle 11 to start the engine, the start restricted by the start fuel jet 6 in the first start fuel passage P1. The fuel is mixed with air in the mixing pipe M to become an air-fuel mixture, and the air-fuel mixture in the second starting fuel passage P2 is passed through an annular gap formed by the starting fuel nozzle 11 and the needle 13 to the starting valve chamber 7. And then into the intake path via the starting mixture passage 9.

According to the carburetor starter according to the present invention, the first starter fuel passage P1 including the starter fuel jet 6 and the mixing pipe M is located substantially at the center of the fuel level XX and a straight line in the vertical direction. As it was formed above, when the vaporizer was tilted,
The starting fuel jet 6 is always below the inclined fuel liquid levels X1-X2 and X2-X2, so that the starting fuel can be supplied satisfactorily. Further, according to the above, the upper part P1a of the first starting fuel passage P1 is located substantially at the center of the fuel liquid level XX and can be arranged at a position where the liquid level change in the height direction is small, and the inclined liquid level X1-X2 is always available. , And X2-X2, the fuel in the floating chamber 4 is inclined and the fuel in the floating chamber 4 is moved to the first starting fuel passage P1,
It does not overflow into the intake passage 2 via the second starting fuel passage P2. According to the above, at the time of starting in the inclined state of the carburetor, a properly controlled starting air-fuel mixture can be supplied to the engine, so that a remarkable improvement in startability can be achieved.

Also, according to the fact that the second starting fuel passage P2 is formed obliquely downward and cross-connected to the upper part P1a of the first starting fuel passage P1, the starting fuel passage can be simplified and the number of processing steps can be reduced. Since the number of plugs can be reduced and the plug press-in operation becomes unnecessary, it is effective in reducing the manufacturing cost of the starting device. Although the second starting fuel passage P2 in this embodiment has a single angle for ease of description, the second starting fuel passage P2, the starting valve 12, and the wax 14 can be freely designed by forming a double angle. The degree can be increased. Also, the second
According to the formation of the starting fuel passage P2 in an oblique direction,
The vertical height of the starting valve 12, the wax 14, and the like can be reduced. Although the starting device S in this embodiment has been described as a wax-type automatic starting device, the present invention
Not only wax type automatic starter, but also related to driving method of start valve, such as one that opens and closes start valve manually by using lever or wire, one that drives start valve by electric signal using solenoid or motor, etc. And can be applied to all starting devices.

[0012]

As described above, according to the starting apparatus for a carburetor according to the present invention, the first starting fuel passage composed of the starting fuel jet including the mixing pipe is formed linearly and the first starting fuel passage is floated. Since the second starting fuel passage including the starting fuel nozzle was disposed substantially on a straight line while being disposed substantially at the center of the fuel level formed in the chamber, and crossed obliquely with the first starting fuel passage, Even when the carburetor is tilted, a good starting air-fuel mixture can be supplied to the engine, so that the startability of the engine can be remarkably improved. Further, the man-hour for processing the starting fuel passage can be reduced and the plug press-in operation can be eliminated. Therefore, the manufacturing cost can be effectively reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main part of an embodiment of a starting device for a vaporizer according to the present invention.

FIG. 2 is a longitudinal sectional view of a main part showing a first example of a conventional starting device for a carburetor.

FIG. 3 is a vertical sectional view of a main part showing a second example of a conventional evaporator starting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 4 Float room 6 Starting fuel jet M Mixing pipe 7 Starting valve room 8 Starting air passage 9 Starting mixture passage P1 First starting fuel passage P2 Second starting fuel passage S Starting device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G006 AE05 AE08 AE12 BA03 BB22 BC05

Claims (1)

[Claims] 1. A starting air passage connected to an intake passage upstream of a throttle valve and a starting air-fuel mixture passage connected to an intake passage downstream of a throttle valve are opened in a side wall of the starting valve chamber. A starting valve which opens a starting fuel nozzle connected to the bottom of the float chamber below a constant liquid level through a mixing pipe and a starting fuel jet at a bottom portion, and arranges the starting air passage, the starting mixture passage, and the starting fuel nozzle in the starting valve chamber. In the starting device for a carburetor, the opening and closing of which is controlled, a first starting fuel passage formed of a starting fuel jet including the mixing pipe is formed in a straight line, and the first starting fuel passage is formed in a floating chamber. And a second starting fuel passage including the starting fuel nozzle is arranged on a straight line and crosses the first starting fuel passage obliquely from the first starting fuel passage.