JPS6339398Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention provides a carburetor, especially a main fuel chamber in which main fuel for normal operation is stored, a fuel jet communicating with a fuel nozzle, and a lower part of the main fuel chamber that communicates with the main fuel chamber. The present invention relates to a carburetor, which has a starting fuel chamber arranged and into which starting fuel is injected, and is configured to switch between using different fuels during starting and during normal operation, such as a carburetor for a kerosene engine.

Conventionally, in such a carburetor, a main fuel such as kerosene is stored in both the main fuel chamber and the starting fuel chamber before starting the engine and during normal operation, and when starting the engine, starting fuel such as gasoline is injected into the starting fuel chamber. The starting fuel is separated into layers in the upper part of the starting fuel chamber due to the difference in specific gravity between the two fuels, and the separated starting fuel is sucked in by a fuel jet and discharged from a fuel nozzle. However, with such conventional technology, it takes time to separate the starting fuel into layers, so when starting the engine immediately after injecting the starting fuel into the starting fuel chamber, the main fuel is separated from the fuel nozzle. It may be discharged,
Therefore, there was a risk that the engine operating state at the time of starting would become unstable.

The present invention was made to solve such conventional technical problems, and even if the engine is started immediately after the starting fuel is injected, the starting fuel is separated more quickly than the main fuel to the fuel nozzle side. An object of the present invention is to provide a carburetor which is capable of accurately supplying fuel and stably starting an engine.

In order to achieve this objective, the present invention includes a main fuel chamber in which the main fuel for normal operation is stored, a fuel jet communicating with the fuel nozzle, and a starting device located below the main fuel chamber and communicating with the main fuel chamber. In the carburetor, the starting fuel chamber has a starting fuel chamber, and a starting fuel having a specific gravity lower than the main fuel is injected into the starting fuel chamber when starting the engine. It is characterized by being vertically partitioned into an upper chamber that communicates with the jet and is connected to a starting fuel injection pipe, and a lower chamber that communicates with the upper chamber and the main fuel chamber, respectively.

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings. First, in FIG. A cylindrical fuel chamber body 3 with a bottom is attached to the fuel chamber body 3 via a seal member 4, and a fuel chamber 5 is formed by the carburetor main body 1 and the fuel chamber body 3. The inside of the fuel chamber 5 is divided into an upper main fuel chamber 6 and a lower starting fuel chamber 7. Before starting the engine and during normal operation, a main fuel such as kerosene is stored in the main fuel chamber 6 and starting fuel chamber 7, and the engine is operated normally using this main fuel. an amount of starting fuel, for example gasoline, is injected into the upper part of the starting fuel chamber 7;
This starting fuel is used to start the engine.

A bench lily 10 is provided in the middle of the intake passage 2. A chiyoke valve 12 is pivotally supported on the carburetor main body 1 on the upstream side of the bench lily 10 along the intake direction shown by an arrow 11, and A throttle valve 13 is pivotally supported on the carburetor body 1.

The fuel chamber body 3 includes an upper large-diameter portion 14 and a lower small-diameter portion 15 connected to each other via a stepped portion 16.
The small diameter portion 15 is formed so that the diameter becomes smaller toward the bottom. A cylindrical connecting portion 18 concentric with the small diameter portion 15 is integrally provided on the bottom portion 17 of the fuel chamber body 3.
It is extended upwards to the middle of 5. On the other hand, a cylindrical holder 19 that extends downward and can come into contact with the upper end of the connecting part 18 is integrally provided at the lower part of the carburetor main body 1 at a position corresponding to the bench lily 10. A female thread 20 is cut.
A bolt 21 is inserted into the connecting portion 18 from below, and by screwing this bolt 21 into the female thread 20 and tightening it, the carburetor main body 1 and the fuel chamber body 3 are connected.
are integrally combined.

The holder 19 has an annular chamber 2 between a fuel nozzle 22 facing the bench lily 10 of the intake passage 2 and an inner surface of the holder 19 that is integrally connected to the fuel nozzle 22.
A bleed pipe 23 forming a 4 is inserted. Further, a fuel jet 25 communicating with the lower end of the bleed pipe 23 is fixed to the inner surface of the holder 19 and has a female thread 2.
6, and is located below the fuel jet 25 in the holder 19 and above the starting fuel chamber 7, the inside of the holder 19, that is, the fuel jet 25, and the outside of the holder 19, that is, the starting fuel chamber 7. A pair of communication holes 2 for communicating with the upper part of 7.
7 is drilled on one diameter line. Said annular chamber 24
is connected to the upstream end of the intake passage 2 via a bleed passage (not shown).

A first partition member 28 and a second partition member 29 are installed in the fuel chamber 5, and the first partition member 28 divides the fuel chamber 5 into a main fuel chamber 6 and a starting fuel chamber 7. The starting fuel chamber 7 is divided into an upper chamber 8 and a lower chamber 9 by the second partition member 29 .

In FIG. 2, the first partition member 28 is made of synthetic resin, and includes a cylindrical portion 30 that is fitted into the upper end of the small diameter portion 15 of the fuel chamber body 3, and a cylindrical portion 30 that extends radially outward from the upper end of the cylindrical portion 30. An engagement flange 31 that engages with the step 16, a partition plate 32 that closes the lower end of the cylindrical part 30, and a holder 19 of the carburetor main body 1 that protrudes upward at the center of the partition plate 32. A cylindrical insertion portion 33 and a pair of cylindrical communication tube portions 34 and 35 that open on the upper surface of the partition plate portion 32 and extend downward.
are integrally formed.

The partition plate portion 32 is formed in a conical shape that slopes upward toward the center, and has both communication tube portions 34 and 35.
are arranged on both sides of the insertion part 33 on one diameter line of the partition plate part 32.

The synthetic resin forming the first partition member 28 is selected from one having oil resistance and water resistance in order to avoid deterioration due to moisture contained in fuel.

Both communication pipe portions 34, 3 in the first partition member 28
On the outer periphery in the middle of 5, there is an annular step 36 facing downward,
37 are formed respectively, and these step portions 36, 3
7 and the inner circumferential surface of the small diameter portion 15, the second partition member 29 is sandwiched. That is, the second partition member 29
is basically formed into a disk shape from a synthetic resin having oil resistance and water resistance, similar to the first partition member 28, and includes a pair of holes 38 and 39 through which both communication tube portions 34 and 35 are inserted, and a connecting portion. Hole 40 into which 18 is inserted
Equipped with Further, a pair of notches 41 and 42 are provided on the outer peripheral edge of the second partition member 29, and when the outer peripheral edge of the second partition member 29 comes into close contact with the inner surface of the small diameter portion 15, the two notches 41, 42 and small diameter part 1
Communication passages 43 and 44 that communicate the upper chamber 8 and the lower chamber 9 are formed between the upper chamber 8 and the inner surface of the lower chamber 5, respectively.
Furthermore, the opening areas of these communication passages 43 and 44 are set to be considerably larger than the opening area of the fuel jet 25.

A float 45 is housed in the main fuel chamber 6,
A float valve 46, which is driven to open and close by the float 45, is arranged to open and close a valve hole 47 formed in the carburetor body 1. Further, a starting fuel injection pipe 4 is provided on the upper side of the small diameter portion 15 in the fuel chamber body 3 in a manner corresponding to the opening direction of both communication holes 27 of the holder 19.
8 is integrally protruded from the lower side wall of the small diameter portion 15, and furthermore, a fuel discharge pipe 49 is integrally protruded from the lower side wall of the small diameter portion 15. Moreover, the fuel discharge pipe 49 is closed by screwing the cap 50 together.

An engagement protrusion 33a is provided protrudingly from the upper end of the insertion portion 33 in the first partition member 28.
a is engaged with an engaging portion 51 provided on the holder 19. These engaging protrusions 33a and engaging portions 51
is for regulating the position of the first partition member 28 around the holder 19, and when the engaging protrusion 33a engages the engaging portion 51, both communicating tube portions 3
4 and 35 are arranged in a direction perpendicular to an imaginary straight line connecting the starting fuel injection pipe 48 and the communication hole 27. In addition, in FIG. 1, for convenience of explanation, both communicating pipe portions 3 are shown.
4 and 35 are shown arranged on an imaginary straight line connecting the starting fuel injection pipe 48 and the communication hole 27.

Next, the operation of this embodiment will be explained.
Before starting the engine, main fuel, such as kerosene, is stored in the main fuel chamber 6 and the starting fuel chamber 7, that is, the upper chamber 8 and the lower chamber 9. When starting the engine in this state, a required amount of starting fuel, such as gasoline, is injected into the upper chamber 8 from the starting fuel injection pipe 48. Since the opening areas of the communication passages 43 and 44 are set to be considerably larger than the opening area of the fuel jet 25, the injection pressure of starting fuel and
Due to the synergistic effect of the ascending force of the starting fuel (descending force of the main fuel) based on the specific gravity difference between the main fuel and the starting fuel, the main fuel that had previously filled the upper chamber 8 is removed from the communication passage 43. , 44 to the lower chamber 9, and an amount of main fuel corresponding to the expelled amount is guided from the lower chamber 9 to the main fuel chamber 6 via the communicating pipe portions 34, 35. Therefore, only the starting fuel is stored in the upper chamber 8, and this starting fuel is sucked into the fuel jet 25 and discharged from the fuel nozzle 22 into the intake passage 2. As a result, when starting the engine, the time required for layer separation, which is conventionally required, is no longer necessary, and the engine can be started immediately after the starting fuel is injected. Moreover, since the main fuel is prevented from mixing with the starting fuel as much as possible, stable starting operation can be performed.

After the engine is started, as the starting fuel is consumed, the main fuel is supplied from the lower chamber 9 to the upper chamber 8 via the communication passages 43 and 44, and the supplied amount is transferred from the main fuel chamber 6 to the communication pipe sections 34 and 35. It is supplied to the lower chamber 9 via. Therefore, when the starting fuel in the upper chamber 8 is consumed, the main fuel is subsequently sucked into the fuel jet 25, and the main fuel emulsified in the bleed pipe 23 flows from the fuel nozzle 22 into the intake passage 2. Normal operation is performed.

As described above, according to the present invention, there is a main fuel chamber in which the main fuel for normal operation is stored, a fuel jet that communicates with the fuel nozzle, and a starting fuel chamber that communicates with the main fuel chamber and is located below the main fuel chamber. In the carburetor, the starting fuel chamber has a starting fuel chamber, and a starting fuel having a specific gravity lower than the main fuel is injected into the starting fuel chamber at the time of starting the engine. It is partitioned vertically into an upper chamber that communicates with the engine and is connected to the starting fuel injection pipe, and a lower chamber that communicates with the upper chamber and the main fuel chamber, so that when the engine is started, the starting fuel injection pipe is connected to the When starting fuel is injected into the upper chamber of the fuel chamber, due to the synergistic effect of the injection pressure and the rising force of the starting fuel based on the difference in specific gravity between the main fuel and the starting fuel,
The main fuel in the upper chamber can be effectively expelled to the lower chamber while the upper chamber can be rapidly filled with starting fuel. Therefore, the time required for fuel layer separation, which is conventionally required when starting the engine, is reduced. This eliminates the need for starting fuel and allows starting operation to be performed immediately after injecting starting fuel.In addition, it effectively prevents the main fuel from being mixed into the starting fuel that flows from the upper chamber through the fuel jet to the fuel nozzle at the beginning of starting. This allows the engine to always start stably and reliably. Furthermore, even after the engine is started, residual starting fuel tends to collect in the upper chamber based on the difference in specific gravity, so the mixing ratio of starting fuel in the fuel flowing from the upper chamber to the fuel nozzle can be adjusted over time. It is possible to gradually reduce the fuel consumption, and therefore, the switching from the starting fuel to the main fuel can be smoothly performed without adversely affecting the operability of the engine.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which FIG. 1 is an overall vertical sectional view, and FIG. 2 is a perspective view of the first and second partition members in FIG. 1. DESCRIPTION OF SYMBOLS 1... Carburetor main body, 5... Fuel chamber, 6... Main fuel chamber, 7... Starting fuel chamber, 8... Upper chamber, 9...
... lower chamber, 22 ... fuel nozzle, 25 ... fuel jet, 28 ... first partition member, 29 ... second partition member, 48 ... starting fuel injection pipe.

Claims (1)

[Scope of claim for utility model registration] Main fuel chamber 6 where main fuel for normal operation is stored
and a fuel jet 25 communicating with the fuel nozzle 22.
and a starting fuel chamber 7 disposed below the main fuel chamber 6 in communication with the main fuel chamber 6, and the starting fuel chamber 7 contains starting fuel having a specific gravity lower than the main fuel. In the carburetor that is injected when starting the engine, the starting fuel chamber 7
is vertically partitioned into an upper chamber 8 that communicates with the fuel jet 25 and to which the starting fuel injection pipe 48 is connected, and a lower chamber 9 that communicates with the upper chamber 8 and the main fuel chamber 6, respectively. Characterized by a vaporizer. The carburetor according to claim 1, wherein each of the chambers is defined by a pair of partition members 28 and 29 attached to a single fuel chamber 5.