JPS6075749A - Carburetter - Google Patents

Abstract

PURPOSE:To enable increasing of air-fuel mixture only when occasion demands and to improve fuel consumption, by a method wherein a power fuel feed system is formed with a system, which is operated in response to a suction negative pressure value, and a system which is operated in response to a throttle valve, and the latter system is actuated when the throttle valve is almost fully opened. CONSTITUTION:A moving body 3 for throttle, which forms a varying venturi between a throat part 2 and the moving body, is vertically movably contained in a housing 1 having a vertically extending columnar air passage and the throat part 2 formed with upper and lower members 21 and 22, and is moved through a ring coupled with a shaft 31 at the lower end thereof. Further, a first power fuel feed system, which is connected to an annular orifice 4, being open to the narrowmost part of the throat part 2 and is actuated by means of a suction negative pressure, and a second power fuel feed system which is actuated through a lever 52 in response to the movement of the moving body 3. The second power fuel feed system is adapted to be actuated when a throttle is almost fully opened.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Technical Field 1. The present invention relates to an electric appliance that supplies an air-fuel mixture at a required mixture ratio to an internal combustion engine, particularly a carburetor for an automobile internal combustion engine.

1 Background Art 1 The load condition of an automobile's internal combustion engine fluctuates rapidly, so even if a carburetor is used, it is necessary to send a mixture with an appropriate mixture ratio to the internal combustion engine depending on the load condition and rotation speed. Because the main fuel supply system alone cannot always deliver a mixture with an appropriate mixture ratio, an auxiliary fuel supply system is generally installed, and when the load increases, the amount of fuel supplied is increased to create a rich mixture. For this purpose, additional fuel is supplied by a piston or Guia 7 ram that operates depending on the negative pressure value in the intake manifold between the carburetor and the internal combustion engine. However, in this conventional configuration, additional fuel was supplied only in response to the negative IJZ value, so the intake air was When the negative pressure value in the intake manifold is small because there is a large amount, for example, when driving at low speed in small or middle school, or when stepping on the accelerator pedal when climbing a hill that is not very steep, the air-fuel mixture becomes too rich and it becomes silent for a while. As the cost increases, the CO concentration in the 411' air also increases.To solve this problem, reducing the amount of additional fuel required at full load; 11 (1 problem) that it is not possible to supply

1. Purpose of the Invention] The present invention has been made in view of the above points, and its purpose is not only to be able to meet the need for a rich mixture, but also to provide the necessary mixture. To provide a carburetor that does not supply a mixture richer than the ratio, and therefore consumes less fuel and does not increase CO2 concentration in exhaust gas.

1 Disclosure of the Invention 1 The present invention provides an orifice opening at the inner circumferential edge of the throat B tos o -1 that protrudes into the air passage;
iii er: A first power fuel supply comprising a housing and a iiJ' moving body for a throttle arranged in the air passage, and increasing the amount of supplied fuel in response to the negative pressure value in the intake manifold. system and fully open the throttle (
It has the advantage of being equipped with a second power fuel supply system that increases the amount of fuel supplied near I, and at full load the throttle is fully opened (the second power supply system operates near I). 2
By supplying additional fuel from the power fuel supply system of the first power fuel supply system, which supplies additional fuel in accordance with the negative pressure value, the amount of additional fuel to be supplied can be reduced (can be set). It was made into a tongue.

To explain the present invention in detail based on the illustrated embodiment, the carburetor shown here has a cylindrical air passage that penetrates vertically, a throw part 2 that projects into this air passage, and an inner peripheral edge of the throat part 2. An annular orifice opening to the throat part 2 is disposed coaxially with the throat part 2 and movable reciprocally in the axial direction below the housing 1. A movable body 3 for a throttle forming a venturi is provided.) A float chamber 8 is provided on both sides of the housing 1. In the center of this housing 1, a movable body 3 having a conical part is disposed so as to be movable in the vertical and axial directions. ．．
A throat portion 2 is provided to narrow the cross-sectional area of a cylindrical air passage that protrudes inward to form an annular venturi between the air passage and the air passage 1 and passes through the center of the air passage 1 downward. Further, at the smallest inner diameter part of the funnel part 2, an annular orifice 4 is provided in the lower peripheral part of the housing 1 and communicates with the chamber 70 through a natural liquid reservoir 5. The negative pressure generated by the air flow flowing down the venturi between the throat part 2 and the moving body 3 opens the fuel reservoir (j) and the annular orifice. Fuel is sucked out into the air passage through the venturi 4.The moving tree 3 responds to the accelerator pedal and moves downward when the accelerator pedal is depressed, thereby increasing the venturi area.

To explain more precisely, )1 housing 1 is formed from part 2) unung 11 and lower part 1 unong 12, and the second part j of part 1 unong 11 has air 1.
Nona (not shown) is connected and the lower No-ung 12
The intake manifold DI/redoka C is connected to the lower part of the intake manifold via a base 69. The slot portion 2 is integrated inwardly with the upper inlet member 21 and the inner surface of the lower/1 housing 12. A lower throat member 22 protrudes from the annular orifice 4.
An annular expansion chamber 20 located around the outer periphery of the orifice 4 is formed as a gap between the upper throat member Z1 and the lower throat member 22. Also, the throat member 2
1 has an inner diameter that becomes smaller as the inner diameter goes downward (), and the inner surface of the lower housing 12 is also the tip of the lower throat member 22, and is formed so that the inner diameter gradually becomes wider (・Therefore, the cross-sectional area of the air passage at the opening 1'' of the orifice 4 is the smallest.The fuel reservoir 9 provided in the lower part of the lower part 12 wraps around the air passage. Although it is annular, it is divided into a plurality of parts in the circumferential direction, and each fuel reservoir 9 communicates with the 70-dochian 7 to -8. From these fuel reservoirs 9 to the orifice 4; heating charge 0 (supplied from the fuel tube 19 hanging down from the lower surface of the upper housing 11 and the main engine at the upper end of this fuel tube 19); and the other end is the expansion chamber 20.
through an expansion channel 26 that opens at the periphery of the tube. Here, the main jet 25 and the expansion passage 26, which have large inner diameters, are aligned in a straight line in the axial direction, but between them there is an annular ring formed in the upper part of the lower housing 12. A gap is traversed by the groove and the upper housing 111 which is connected to the outside by a perforated air pipe 28. Also, this gap is simply the main jet 25
In addition to the connecting part between the main jet 25 and the expansion passage 26, it is annular that surrounds the air passage in the middle of the housing 1.
When fuel is sucked up to 6, air is also sucked in at the same time.
1, and functions as an air vent 27. In other words, the air bleed part 5
It consists of . In the figure, 29 is a cooling water flow path that prevents icing by passing cooling water for the internal combustion engine, and 81 in -8 is a float, 82
83 indicates a needle valve, and 83 indicates an adjustment screw.

The movable body 3 has a shaft 31 that is press-fitted between the lower ends of the lower housing 12 and removed and is slidably supported in the axial direction by a no-boat 30.
The lower end of the shaft 31 is connected to the throttle shaft 38 via a link 39. The rotation of the throttle shaft 38 causes the movable body 3 to move down by 1", increasing the area of the venturi during downward movement.

Next, the first power fuel supply system 401 shown in FIGS. 1 and 3 will be explained. This is two intake mantles.
In response to the negative pressure value t in 6, the power piston 41 is spring-biased in both directions and becomes a power piston.
Power valve 42 and valve seat 4 driven by
3. The fuel tube 47 is composed of a valve portion including a spring 44 and the like, and a fuel tube 47 whose lower end is inserted into a fuel hole 45 formed in the lower housing 12.

The fuel hole 45 is connected to the 70-chamber 8 through the valve part, and the fuel tube 47 is connected to the orifice 41 through the same structure as the fuel tube 19.
Then, additional fuel (±) flows from the float chamber 8 through the nozzle section, where air is mixed in at the air bleed section 5 and sent to the IJ station 4.

Second power 1. The t I f Jli m system 50 is a mechanical type that opens and closes in response to the operation of the Thronrele and supplies additional fuel to the orifice 4 through the luer section.
A1), as shown in FIG. ”] A piston 51 which is arranged to be movable up and down in the opening 11 and is biased by a spring to a lower end force fJd, and which is used as a nozzle to control the flow of fuel in the tension passage 26; −
and a lever 52 which is pivotally supported on the 1-plane of the no.
). When the movable body 3 is in the L position, the piston 51
is in the position where it has been pushed and moved downward, and when the movable body 3 is lowered, the piston 51 moves by force C'1. In addition, this carburetor also has an acceleration pump (not shown) which is activated by depressing the accelerator pedal as an auxiliary fuel supply system. 60 is a fuel path from the acceleration pump. A nozzle for injecting fuel sent through 61, comprising: 1. part) 1
It is arranged on the inner surface of the housing 11. Reference numeral 63 is an air pipe that connects the upper space of the float tube 1'-8 with the outside.

However, in this carburetor, mainly the fuel tube 7
19 to the air bleed section 5 (the fuel force that reaches the orifice 4 after being mixed with air), the air is sucked out by the negative pressure generated by the air flow flowing down the venturi and flows through the air path. The mixture is then sent to the internal combustion engine. When the throttle is opened, that is, when the movable body 3 is moved downward, the area of the vent 1) increases and a large amount of air-fuel mixture is supplied. When the negative pressure in the intake manifold 6 is considerably high, the power piston 41 in the first power fuel supply system 40 is pulled up against its spring I, and the power pulse 742 moves upward to close the valve. No fuel is routed through this part 7 to close the intake manifold 6, so when a lean mixture is created or the negative pressure in the intake manifold 6 is reduced, such as when power is required. , Power Piston 41 Kahane)=
Since it moves downward in one force and pushes down the power pulp 42 to open the valve part, the fuel is also sent to the orifice 1 through the - pulp part and the fuel deyu 747, and a relatively rich mixture is created. It is something that is formed. It should be noted that the valve part in this first power heating supply system 40 is quite narrowed down, and the fact that there is an air bleed part 5 at the opening of the orifice and 4, and there are many additions. It does not supply fuel.

At full load, it is necessary to supply a rich air-fuel mixture to the internal combustion engine, and at this time, because the negative pressure in the intake manifold is small, the first power fuel supply system described in 4-5 also cannot supply fuel. However, since this first power supply system limits the amount of additional fuel supplied as described above, this supply system alone cannot produce the rich mixture required. As shown in FIG. 2, when the rontle is fully opened, the lever 52 connected to the lowered movable body 3 releases the depression of the piston 51, so the piston 51 moves upward and opens its pulp section. For this purpose, the fuel is supplied to the main fuel g (not only supplied through each fuel tube 19 as a channel but also sent to the orifice 4 through the fuel tube 55,
In particular, since the fen 1 of the pallet 7 in the second power fuel supply system 50 is not so narrowed, it is possible to create a rich air-fuel mixture that is centered at full load.

1 Effects of the Invention 1 As described above, in the present invention, the power fuel supply system for obtaining a rich air-fuel mixture includes a first system that operates in response to the negative pressure value in the intake manifold, and a first system that operates in response to the throttle. This system has two systems: a second power supply system that operates, and in particular, the second power fuel supply system is operated at full throttle (nearly 1), so the fuel supply at full load is controlled by the first system. This can be supplemented by the second power fuel supply system, and for this purpose, the amount of power in the first power fuel supply system, which operates frequently, can be reduced significantly, thus reducing the need for low-speed driving in the car. When the negative pressure in the intake manifold is small, the gas mixture tends to be destroyed when the accelerator pedal is depressed at 1 o'clock, such as when climbing up a not-so-steep hill. It is.

[Brief explanation of drawings]

FIG. 1 is a cutaway exploded perspective view of one embodiment of the present invention, and FIG. 2 is the same 1. FIG. 3 is a partial sectional view of the same as above, FIG. 1 is a plan view of the lower housing, 1 is a housing,
2 is the throat part, 3 is the movable body, 4 is the orifice, ・10
5o indicates the first power fuel supply system, and 5o indicates the second power fuel supply system. Agent Attorney 1: Stone 1'1. ] Ai 7 @ Figure 3 Figure 4

Claims (2)

[Claims] (1) A housing having a throat portion projecting into the air passage and an orifice opening at the inner peripheral edge of the throat portion, and a movable throttle rod disposed within the air passage. At the same time, a first power fuel supply system that increases the amount of supplied fuel according to the negative pressure value in the intake manifold, and a second power fuel supply system that increases the amount of supplied fuel near full throttle opening. A vaporizer comprising: (2) The second power fuel supply system is comprised of a pallet 7 that is disposed in the fuel path between the fuel reservoir and the orifice and opens and closes in response to the movement of the movable rod.
'1 The vaporizer according to claim 1.