JPH03151556A - Amount of fuel increasing device of multiple carburetor - Google Patents

Abstract

PURPOSE:To prevent mixture from becoming lean when an engine is operated at low speed with a throttle valve wide open by providing an amount of fuel increasing passage for supplying fuel from inside a fuel reservoir to each air intake of a multiple carburetor, and interposing in the passage an amount of fuel increasing pump which is controlled according to the operating condition of the engine. CONSTITUTION:A throttle valve 9 to be manually controlled is slidably provided within the sliding valve guide tube 3 of the main body 1 of each carburetor A1 to A4 provided to respective cylinders. A needle 13 for controlling the area of a passage of a jet 14 communicated with a float chamber 5 is mounted to the throttle valve 9. Fuel is supplied from a fuel pump P to the float chamber 5 via a fuel inflow passage 17, etc. An amount of fuel increasing passage 21 through which an increased amount of fuel is supplied from an amount of fuel increasing pump 20 to each control jet 31A to 31D disposed opposite to the air intake of each carburetor A1 to A4 is provided, the amount of fuel increasing pump 20 having an air intake passage 20A connected to a fuel tank. The amount of fuel increasing pump 20 is so controlled by a control circuit 25 that when the throttle valve 9 is open for more than a fixed degree and also the rotating speed of an engine is within a fixed range the pump 20 is driven.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a carburetor that controls the amount and concentration of air-fuel mixture supplied to an engine, and particularly relates to a carburetor that controls the amount and concentration of air-fuel mixture supplied to an engine. Multiple carburetors, for example two or three, are mechanically opened and closed using throttle valves operated by accelerator wires.

This invention relates to a fuel increasing device for a multiple carburetor in which four carburetors are arranged horizontally, vertically, or in a V-shape.

[Conventional technology]

There are two main types of carburetors that mechanically control the opening and closing of the effective opening area of the intake tract using a throttle valve operated by an accelerator wire.

The first is one in which a valve shaft is rotatably supported by the carburetor body across an intake path that passes through the carburetor body, and a disc-shaped butterfly valve is attached to the valve shaft. By operating the accelerator wire, the valve stem is rotated, and the effective opening area of the intake tract is controlled by the butterfly valve, and a butterfly type multiple carburetor is usually used. For example, Utility Model 52-57307
This is shown in the No. 1 gazette, etc.

The second method is to provide a sliding valve guide cylinder above the middle part of the intake passage that passes through the carburetor body, and to allow a cylindrical or rectangular sliding throttle valve to slide freely within the sliding valve guide cylinder. It was placed,
By operating the accelerator wire, the sliding throttle valve is moved within the sliding valve guide cylinder, thereby controlling the opening and closing of the effective opening area of the intake tract with the sliding throttle valve.
A device using a plurality of such vaporizers is usually called a sliding throttle valve type multiple carburetor.
This is shown in Publication No. 754, etc.

The butterfly type multiple carburetor and sliding throttle valve type multiple carburetor which mechanically control the opening and closing of the effective opening area of the intake passage using the throttle valve described above have the following problems.

First, when the throttle valve is opened to a high opening and the engine speed is low (high opening and low speed operation).

The airflow velocity flowing through the intake tract becomes low, and the negative pressure in the intake tract applied to each fuel injection hole opening into the intake tract is weakened. (approaching atmospheric pressure) According to this, it becomes difficult to suck out sufficient waste from each fuel nozzle hole into the intake tract, and this high opening and low speed is undesirable as it leads to dilution of the air-fuel mixture. The phenomenon of leanness of the air-fuel mixture during operation becomes more pronounced as the diameter of the intake passage is increased in order to improve the output of the engine.

As a conventional technology aimed at solving this problem, an air control pulp is placed upstream of the sliding throttle valve, although it is a single carburetor, and during high opening and low speed operation, the throttle valve opening sensor A technique is known in which the air control valve is controlled in the closing direction depending on the output of the engine speed sensor and the output of the engine speed sensor. (This is shown in Utility Model Application No. 60-70761.) Second, the throttle valve is suddenly opened to a high degree in order to rapidly increase the rotation from a low opening state, like when the engine is idling. If you look at the sudden acceleration of an engine when the throttle valve opens suddenly, an increased amount of air is immediately supplied to the engine, but the supply of fuel is temporarily delayed due to air inertia, and as a result, This is not preferable because it leads to dilution of the air-fuel mixture.

This phenomenon of air-fuel mixture dilution becomes more pronounced as the diameter of the air intake passage increases.

As a conventional technique aimed at solving this problem, a diaphragm is used to divide the housing into a pump chamber and an atmospheric chamber, and the pump chamber is equipped with a suction side check valve that is connected to the float chamber. A check valve on the discharge side is disposed inside the acceleration fuel inlet passage, and an acceleration fuel discharge passage connected to the intake passage are opened, and this diaphragm is pressed toward the pump chamber side during the sudden opening operation of the throttle valve. There is a technique of a so-called acceleration pump device in which a pump chamber is pressurized and acceleration fuel stored in the pump chamber is injected and supplied into the intake passage of each carburetor through an acceleration fuel discharge passage. (This is shown in Utility Model Publication No. 53-32183.) [Problems to be Solved by the Invention] This conventional technique has the following problems.

First, according to the technology disclosed in Japanese Utility Model Application No. 60-70761, during high-opening, low-speed operation, the sliding throttle valve is kept open at a high opening, but the air control valve is controlled by the output signal from the control unit in the intake airway. is controlled in the closing direction to reduce the effective opening area of the intake tract upstream of the sliding throttle valve. According to this, the negative pressure in the intake tract including the sliding throttle valve on the engine side from the air control valve increases, and the needle jet as the main fuel system that opens into the intake tract on the engine side from the air control valve increases. The negative pressure applied to the opening of the intake tract is increased, which allows a larger amount of fuel to be sucked into the intake tract than with a needle jet, thereby preventing dilution of the air-fuel mixture.

However, since the air control valve operates in the direction of closing the intake tract and reduces the effective opening area of the intake tract, the amount of air supplied to each engine decreases, which is not desirable in terms of improving engine output. .

This is particularly a problem with multiple carburetors because one of the purposes of employing multiple carburetors is to improve the output of the engine.

Next, the technology of Utility Model Publication No. 53-32183 pressurizes the pump chamber by the sudden opening operation of the throttle valve, and injects the acceleration fuel stored in the pump chamber into the intake path of each carburetor through the acceleration fuel discharge path. According to this method, it is possible to supply a fixed amount of acceleration fuel, but it is difficult to set a long acceleration fuel injection time to be supplied from the acceleration pump device into each intake passage. This is due to the fact that the diaphragm that pressurizes the chamber is mechanically connected to the throttle valve.In order to lengthen the accelerated fuel injection time, the chamber volume of the pump chamber must be selected, and the diaphragm must be compressed in the pump chamber. Selection of a diaphragm spring that urges the air toward the atmospheric chamber.

Selection of passage diameters of the acceleration fuel intake passage and acceleration fuel discharge passage, selection of valve closing springs to press and bias the intake side check valve and discharge side check valve against each valve seat, etc. The work required a large amount of setup time, which hindered improvement in development efficiency. Further, even if each of the above-mentioned factors is selected, there is a limit to how long the accelerated fuel injection time can be extended.

[Means to solve the problem]

The fuel increasing device for a multiple carburetor according to the present invention was developed in view of the above-mentioned problems, and is a multiple carburetor fuel increasing device in which a plurality of carburetors are arranged to mechanically open and close the effective opening area of the intake duct using a throttle valve. The object of the present invention is to provide a fuel increasing device that can actively enrich the air-fuel mixture in a carburetor while suppressing the dilution of the air-fuel mixture during high-opening, low-speed operation and acceleration operation of the engine. It is.

According to the fuel increasing device for a multiple carburetor according to the present invention, a multiple carburetor is provided with a plurality of carburetors that mechanically open and close the effective opening area of the intake passage passing through the carburetor body using a throttle valve. and; A fuel inflow path that pressurizes the fuel stored in the fuel tank by a fuel head differential or a fuel pump and supplies it to the valve seat opening in the float chamber of each carburetor that constitutes the multiple carburetor; and; A control signal from a control circuit that receives the output of a throttle valve opening sensor that detects the opening of the valve and the output of a rotation sensor that detects the rotational speed of one engine is used to direct the fuel in the fuel tank through the suction passage. a fuel increasing pump that sucks in air and discharges the fuel into the fuel increasing passage through a suction passage; one end is connected to the fuel increasing passage, and the other end is connected to the intake passage of each carburetor forming the multiple carburetor including the intake pipe. It is characterized by comprising: a fuel increase distribution path;

[Effect]

When the opening of the throttle valve is above a certain degree and within a certain rotational speed range of the engine, the fuel increase pump is driven by a control signal from the control circuit to feed the fuel in the fuel tank to each fuel increase distribution path, while , the control circuit does not output a signal to drive the fuel increase pump when the opening of the throttle valve is below a certain level and when the engine speed is outside the constant rotation speed, so the fuel increase pump does not act as a pump, and each No fuel is supplied to the fuel increase distribution path.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fuel increasing device for a multiple carburetor according to the present invention will be described below with reference to FIG. Note that this embodiment is an embodiment of a sliding throttle valve type recurrent vaporizer.

Reference numeral 1 denotes a carburetor main body through which an intake passage 2 passes, and a sliding valve guide cylinder 3 is connected upward from a substantially middle portion of the intake passage 2, and is opposed to a lower concave portion IA of the carburetor main body l. A float basic body 4 is arranged, and a float chamber 5 is formed by the lower recess IA and the float basic body 4.

A valve seat 6 opens in the float chamber 5, and a float valve 7 that opens and closes the valve seat 6 is disposed corresponding to the valve seat 6.
is applied with driving force to open and close the valve seat 6 by a float 8 disposed in the float chamber 5 .

A throttle valve 9 that controls opening and closing of the effective opening area of the intake passage 2 is movably disposed inside the sliding valve guide cylinder 3, and this throttle valve 9 is rotatably supported on the carburetor body 1. The operating shaft 10 is mechanically connected to the operating shaft 10 by a link 11 or the like, and an operating lever 12 is integrally attached to the shaft end of the operating shaft that protrudes outside the carburetor main body 1. An accelerator wire (not shown) that is operated by the driver is attached to the accelerator wire (not shown).

Therefore, when the driver operates the accelerator wire, the operating lever 12 and operating shaft 10 rotate, and this is transmitted to the throttle valve 9 via the link 11, so that the throttle valve 9 opens and closes the intake passage 2. become.

Further, a jet needle 13 is integrally attached to the bottom of the throttle valve 9, and this jet needle 13 is inserted into a needle jet 14 that opens into the intake passage 2.

The needle jet) 14 is connected to the main jet 1B via a mixing nozzle 15, and an annular acceleration well W is formed on the outer periphery of the mixing nozzle 15.
The fuel in the float chamber 5 is stored in this acceleration well W. On the other hand, the valve seat 6 is supplied with pressurized fuel stored in the fuel tank T via the fuel inlet passage 17, and the fuel tank T is located below the carburetor body l. When the fuel tank T is placed above the carburetor body 1, the fuel in the fuel tank T is pressurized by the fuel pump P and supplied to the fuel inlet passage I7.On the other hand, when the fuel tank T is placed above the carburetor main body 1, ) The fuel in the fuel tank T is pressurized by the fuel head difference and is supplied to the fuel inlet passage 17 . The position of this fuel tank T is not limited.

Therefore, when the liquid level in the float chamber 5 is lower than the set liquid level, the float valve 7 opens the valve seat 6 by the float 8, so that the valve seat 6 is
Fuel flows into the float chamber 5 through the float chamber 5, and when the liquid level in the float chamber 5 rises to a set constant level, the float valve 7 closes the valve seat 6 with the float 8, so that the fuel inflow path 17 from the float chamber 5 through the valve seat 6.
This stops the supply of fuel into the float chamber 5, thereby making it possible to always form a constant liquid level inside the float chamber 5.

A single carburetor A is formed by the above, and since this example is a quadruple carburetor, this single carburetor A consists of the first carburetor Al, the second carburetor A2, and the third carburetor A1. vaporizer A3. Fourth vaporizer A4. and 4 pieces are placed on the side. The operating shaft 10 of the first carburetor and the second. Third. 4th. The operating shaft 102.103 of the carburetor A2+A3A4.
10< is mechanically connected to the first vaporizer A
When the first operation lever 12 is rotated, the first operation lever 12 is rotated.
Second. Third. Fourth, vaporizer A I + A 2 +
Each throttle valve A3 + A4 opens and closes each intake passage synchronously.

In addition, the second. Third. Each fourth vaporizer A2. Since each component of A3A4 is the same as that of the first carburetor A1, the same reference numerals are used, and a brief explanation of the drawings will be omitted, and the numbers 0 and above indicate conventionally known carburetors.

Reference numeral 20 denotes a fuel increase pump that sucks in fuel from a fuel tank T or a fuel tank N in which fuel is stored inside, such as a float chamber 5, through an intake passage 20A and pressurizes and discharges it from a discharge passage 20B. , electrically driven.

21 is a fuel increase passage connected to the discharge passage 20B of the fuel increase pump 20. And the intake path of each carburetor from this fuel increase passage 21? Alternatively, fuel increase distribution paths 22A, 228, 22C, and 22D that are connected to an intake pipe (not shown) that connects the intake path 2 of the carburetor body 1 and the engine are branched.

23 is a throttle valve opening sensor that detects the opening of the throttle valve 9 with respect to the intake passage 2; 24 is a rotation sensor that detects the engine speed; the outputs of the throttle valve opening sensor 23 and the rotation sensor 24 are sent to the control circuit. 25, and a control signal for driving the fuel increase pump 20 is output from the control circuit 25 under constant conditions of the throttle valve opening and the engine rotation speed.

To describe a specific example of the conditions for the throttle valve opening 1 engine rotation speed control circuit 25 mentioned above, the throttle valve 9 is opened to 3/4 or more, and the engine rotation speed is A control signal for driving the fuel increase pump 20 is outputted from the control circuit 25 within the rotational speed range of 2000RPM to 500ORPM. The condition range is clearly shown in the shaded area in FIG. 2, and this condition range is appropriately set optimally during the carburetor setting work for the m interval.

Next, we will discuss its effect.

First, as when operating the throttle valve 9 at a low or medium opening,
To explain the operating state in which the opening degree is 3/4 or less at t/1, no matter how the engine speed changes, the throttle valve 9 does not open to a certain opening degree, so the control circuit 25 increases the amount of fuel. A control signal for driving the pump 20 is not output, so the fuel increase pump 20 is in an inactive state, and does not feed the fuel in the fuel tank N into the fuel increase passage 21, but rather increases the amount of fuel. Additional fuel is not supplied from the passage 21 to the intake passage 2.

In addition, during high opening operation in which the throttle valve 9 is opened further than the above-mentioned low opening operation, and the load applied to the engine is small or medium load, that is, high opening high speed, high opening medium speed, and high opening operation. At times, the rotational speed of one engine rose sufficiently due to the throttle valve 9 being opened to a high degree and the load being relatively small, reaching 5000RP! It maintains the rotation speed above If, and the engine rotation speed is within the set rotation speed range 2.
000 RPM to 500 ORPM [Since supination occurs, no control signal for driving is output from the control circuit 25 to the fuel increase pump 20.

Therefore, the fuel increase pump 20 does not supply fuel into the fuel increase passage 21.

That is, when the throttle valve 9 is in the normal operating state of the engine, such as low opening operation, medium opening operation, high opening medium speed operation, and high opening high speed operation 1 o'clock, the fuel is supplied to the fuel increase passage 21. Since fuel is not supplied from the fuel increase pump 20, the fuel increase distribution passages 22A, 22B, 2 are routed from the fuel increase passage 21.
Fuel is not supplied into the intake passage 2 through 2C and 22D, and the main jet 1B, needle jet 14, jet needle 13, or low-speed fuel system is used as the main fuel system of the carburetor. Fuel is sucked out into the intake passage 2 through a bypass hole and a pilot outleft hole (both not shown) to satisfy the operation of one engine.

The fuel increasing device for a multiple carburetor according to the present invention has the following special effects.

First, the throttle valve 9 is opened to a high opening degree, and the engine speed is relatively low when the throttle valve 9 is operated at a high opening degree and at a low speed. Such a situation is a state in which the throttle valve 9 is opened to a high opening degree and a high load is applied to the engine, such as when climbing a steep slope.

In this state, the throttle valve 9 is opened to a high opening degree, and the opening degree of the throttle valve 9 is opened to 3/4 or more. On the other hand, the engine speed also decreases from the normal speed during high opening operation of the throttle valve 9, from 2000 RPM to 5000 RPM.
It is in the rotation speed range of P. The opening state of the throttle valve 9 is detected by the throttle valve opening sensor 23, and its output is input to the control circuit 25.

On the other hand, the rotational speed of the engine is detected by a rotation sensor 24, and its output is input to a control circuit 25.

When each output from the throttle valve opening sensor 23 and the rotation sensor 24 is input to the control circuit 25, the control circuit 25
outputs a control signal for driving the fuel increase pump 20 to the fuel increase pump 20, and the fuel increase pump 20 that receives the control signal pumps the fuel in the fuel tank N through the suction passage 2OA. The fuel is sucked in and discharged from the suction passage 20B to the fuel increase passage 21 for feeding. Then, this fuel is distributed to each fuel increase distribution path 22A, 22B, 22C.
, 22D, through the first . 2nd゜3rd. It is immediately injected and supplied into each intake passage 2 of the fourth carburetor AH, A2, A3, and A4, and together with the main fuel in each carburetor and the fuel sucked out from the system into the intake passage z, This can prevent the air-fuel mixture in each carburetor from becoming diluted during high-opening, low-speed operation.

The increased fuel is supplied from this fuel increasing passage 21 to each intake passage 2 through the fuel increasing distribution paths 22A, 22B, 22C, and 22D of each carburetor when the throttle valve 9 is opened to 3/4. degree or more, and the engine speed is 200 ORP
This is performed continuously in the high opening and low speed operation state of the throttle valve 9 within the rotational speed range from M to 500 ORPM, and when the opening of the throttle valve 9 falls below the opening of 3 or when one engine The rotation speed is from 2000RPM to 500O
If either or both conditions are met, the output of the control signal from the control circuit 25 for driving the fuel increase pump 20 is stopped, and the fuel increase distribution path 22A is thereby stopped. , 22B , 22
This is to stop the supply of fuel from C and 22D to the intake passages 2 of each carburetor.

The second condition is during acceleration operation in which the throttle valve 9 is rapidly opened from a low opening to a high opening, and the throttle valve 9 is in a low opening state and one engine is in a low speed operating state. From this state, the driver pulls the accelerator wire to rapidly open the throttle valve 9 to a high opening state and performs accelerated operation.

Here, the behavior of fuel supply to the intake passage 2 when the throttle valve 9 is rapidly opened from a low opening state to a high opening state is as follows.

When the throttle valve 9 is in a low opening state, the engine speed is maintained at idling speed (for example, 1200 RP) or at a low rotational speed, and in such a state, the fuel is kept in the low opening state of the throttle valve 9. Due to the increase in the negative pressure in the intake passage, fuel is sucked out into the intake passage 2 from a low-speed fuel system (not shown) such as a bypass hole or a pilot outlet hole, and the engine is operated at a low opening and low speed.

Next, when the throttle valve 9 is rapidly opened from the low opening state to a high opening, the amount of air flowing through each intake passage 2 increases at once. The negative pressure at the tip of the needle jet 14 opening into the passage 2 temporarily increases, and the fuel stored in the acceleration well W is sucked out from the needle jet 14 into the intake passage 2 via the mixing nozzle 15, and the engine increase the rotation speed.

In this state, the fuel in the acceleration well W is sucked out into the intake passage 2 via the second jet 14 without being restricted from flowing in by the main jet 16, and is already stored in the wake of the main jet 1B. This is because it is in a state where it is easily sucked out. However, even if the fuel in the acceleration well W is sucked out, the fuel stored in the acceleration well W is controlled, so the rotational speed of the engine is not significantly increased.

That is, even if the throttle valve 9 is opened to a high opening degree, it is difficult to increase the engine speed to 5000 PPM or more. Although it is possible to increase the increase in rotational speed during acceleration by increasing the capacity in the acceleration well W, the inner and outer diameters of the mixing nozzle 15 are determined by taking into consideration the operability in other operating ranges. This is because the capacity of the acceleration well W is inevitably limited.

In this situation, when using wood, the throttle valve 9
is opened to a high opening, and that the engine speed rises above idling speed but does not rise above 5000 RPM and remains within the speed range of 2000 PPM to 500 ORPM. The outputs of the sensor 23 and the rotation sensor 24 are input to the control circuit 25, and the control circuit 25 outputs a control signal for driving the fuel increase pump 20.

According to this, the fuel increase pump 20 starts driving, sucks the fuel in the fuel tank N through the suction passage 20A, and supplies it into the fuel increase passage 21 from the discharge passage 20B.

Therefore, from the fuel increase passage 21 to the fuel increase distribution path 22A.
, 22B, 22C, and 22D, an increased amount of fuel can be injected and supplied to each intake passage 2, thereby suppressing the dilution of the air-fuel mixture and assisting in increasing the rotational speed during acceleration. When the engine speed exceeds 500 ORPM, the control circuit 25 outputs a control signal to the fuel increase pump 20, and the fuel is supplied from the fuel increase passage 21. Since the rotational speed has sufficiently increased to 500 ORPM or more, a large negative pressure in the intake passage acts on the needle jet 14 as the main fuel system, so the needle jet 1 uses fuel that is compatible with the high opening operation of the throttle valve 9.
4 was able to be sucked out into the intake passage 2.

In addition, the fuel required is #! ! The amount of increased fuel injected into the intake passage 2 from the volume passage 21 is determined by setting work with the engine, but for example, a minute amount of fuel of about 5 cc/min may be sufficient for a single carburetor. A control jet 30 having a passage diameter smaller than the effective passage diameter of the fuel increase passage 21 is disposed within the fuel increase passage 21.
At the fuel increase passage 21, each fuel increase distribution passage 22A,
By controlling the amount of fuel injected into the intake path z through 22B, 22C, and 22D, it is possible to accurately control the increased amount of fuel that is suitable for high-opening, low-speed operation, and acceleration operation. be.

In addition, fuel increase distribution paths 22A, 22B, 22C
, 22D open to the intake passages 2 to the intake passage 2A on the engine side of the throttle valve 9 and the intake pipe (not shown) connecting the carburetor and the engine, thereby connecting the engine and the fuel increase distribution passage. The distance to the openings of 22A, 22B, 22C, and 22D is shortened, and the extra fuel does not collide with the throttle valve, throttle valve shaft, jet needle, etc., and the extra fuel can be delivered to the engine in a much shorter time. This allowed us to further improve the performance of the engine.

Further, if the fuel increase pump 20 is operated continuously for some reason, it will continue to supply fuel throughout the engine operation, but the fuel increase passage 21 or the fuel increase distribution passages 22A, 22B, From 22C and 22D,
The leak passage 40 connected to the atmosphere or the fuel tank T is branched, and a normally closed on-off valve 41 is disposed in the leak passage 40. Under such circumstances, the on-off valve 4! If the fuel increasing passage 21 is opened, the fuel for increasing the number of stitches flowing through the fuel increasing passage 21 will not be supplied into the intake passage 2, and will not be supplied to the atmosphere or the fuel tank T.
It was possible to make it flow inside. In particular, the effective passage diameter of the leak passage 40 is determined by adjusting the effective passage diameter of the fuel increase passage 21 and the fuel increase distribution passages 22A, 22B, 22G, 22D.
If the effective passage diameter is made larger than the effective passage diameter, the fuel in the fuel increase passage 21 can be reliably and immediately extracted. Furthermore, on-off valve 4
1 is not limited to a solenoid valve, but may be a manual valve.

In addition, each fuel increase distribution path 22A, 22B, 22
C, 22D are fuel increase distribution paths 22A, 22B,
Distribution path control jets 31A, 31B, 31C, which have a passage diameter smaller than the effective passage diameter of 22C, 22D,
310, when arranged, the fuel increase distribution path 22A, 22
B, 22G, and 22D can control the increased amount of fuel supplied to the intake passage 2 of each carburetor, compared to placing the control jet 30 in the fuel increasing passage 21, making it possible to control the amount of injected fuel more accurately. Among them, the distribution path control jets 31A, 31B, 31G,
It is now possible to change the passage diameter of the 31D for each carburetor, and when the cooling is different between cylinders, etc., the concentration of the mixture can be changed for each carburetor that makes up the multiple carburetor. 1 distribution path control jet 31A when it becomes necessary to change the
, 31B.

The requirements of the engine can be met by optimally selecting the respective passage diameters of 31G and 31D.

Moreover, what is shown in FIG. 3 shows an embodiment in which a carburetor having an accelerator is combined with an increase device according to the present invention, which will be described below. (For structures that are the same as those in FIG. 1, the same reference numerals are used and explanations are omitted.) 50 is an accelerator, which has the following configuration.

That is, 51 is a diaphragm that divides the acceleration pump chamber 52 and the atmospheric chamber 53, and the acceleration pump chamber 52 has an acceleration pump chamber 52 connected to the inside of the float chamber 5 at one end and a suction side check valve 54 disposed therein. Fuel intake passage 55 and acceleration fuel discharge passage 56
When the diaphragm 51 is opened, the diaphragm 51 is moved into the atmospheric chamber 53.
A diaphragm spring 57 that presses toward the side is compressed. The opening operation of the throttle valve 9 is controlled by the operation lever 12. Link 58. It is applied to the diaphragm 51 via a pump lever 59.

Acceleration nozzles t30A, 60B, 80G are provided in the acceleration fuel discharge passage 56 and open to the intake passage 2 of each carburetor.
, acceleration fuel discharge distribution path 81A connected to 80D,
81B, 81C, and 61D will be contacted. In addition, 82A
, 62B, 82C.

82D is the acceleration fuel discharge distribution path 61A, 61B,
These are discharge side check valves arranged at 81G and 81D.

That is, when the throttle valve 9 opens, its rotation is transmitted to the pump lever 59 via the link 58, and the diaphragm 51 is moved into the acceleration pump chamber 5 by the pump lever 61.
The acceleration pump chamber 52 is pressurized by reducing the volume of the acceleration pump chamber 52, thereby transferring the acceleration fuel stored in the acceleration pump chamber 52 from the acceleration fuel discharge path 56 to the acceleration fuel discharge distribution path 81A.
, 81B, 131C, 81D to each carburetor acceleration nozzle Jl/60A, 80B, 80C, EI
OD is injected and supplied into the intake passage 2 of each carburetor.

A fuel increase passage 21 similar to the embodiment shown in FIG.
Fuel increase distribution paths 22A, 22B, 2 connected to
The other ends of 2G and 22D are discharge side check valves 62A of each vaporizer.

62B, 82C, 62D and acceleration nozzle 130A,
The acceleration fuel discharge distribution passages 81A, 81B, BIC, and 81D between the fuel pumps 80B, 80C, and 800 are opened.

According to this structure, the fuel increase distribution path 22A is connected from the fuel increase passage 21 during high opening, low speed operation and during acceleration operation.
, 22B, 22C, and 22D to supply the increased amount of fuel to each carburetor is the same as in the first embodiment, but
During acceleration operation, in addition to the fuel supply from the acceleration well W, especially at the beginning of acceleration, the acceleration fuel from the accelerator 50 can also be supplied, so that the start-up of rotation at the beginning of acceleration can be performed even more smoothly. Furthermore, the fuel increase pump 20 is driven by the output signal from the control circuit 25, and the fuel increase pump 20 is driven by the output signal from the control circuit 25, and the fuel increase passage 21. Fuel increase distribution paths 22A, 22B, 22C, 22D, acceleration fuel discharge distribution paths 81A, 131B, 81C,
An acceleration nozzle 60A that opens into each intake passage 2 from the BID,
Since fuel was supplied to the SOB, BOC, and HD, the desired acceleration fuel could be accurately supplied from the beginning to the end of acceleration, making it possible to further improve acceleration performance.

In addition, fuel increase distribution paths 22A, 22B, 22G
, 22D, especially the discharge side reverse valve 62A, 8
2B, 82G, 82D and acceleration nozzle BOA,
80B, 80C, 600, each discharge side check valve 82A, 82B opens to each acceleration fuel discharge distribution path BIA, BIB, 81C, 810.
, 82G, 820 are applied to the suppression load of each check valve spring that presses each discharge valve seat.
, fuel increase distribution paths 22A, 22B, 22C, 2
2D, the fuel pressure flowing through it is not subject to any restrictions.

That is, each discharge side check valve 82A, 82B, 8
2C.

Fuel increase distribution paths 22A, 22B, 22C, 22 are connected to the acceleration fuel discharge path 5B on the acceleration pump chamber 52 side from 620.
When D is opened, the fuel increase passage 21 and the fuel increase distribution passage 22A.

22B, 22C, 22D, unless the pressure of the fuel flowing through them is greater than the pressing load of the check valve spring, the acceleration fuel discharge distribution passages 81A, BIB, 8
1C.

It is not possible to supply additional fuel via 81D, and it is necessary to increase the discharge pressure of the fuel increase pump 20.

Furthermore, the openings of the fuel increase distribution passages that open to the respective intake passages 2 of each carburetor body 1 are drilled in a limited carburetor structure, so there is little freedom in design. However, the acceleration nozzle 60A has already been drilled.

By using the acceleration fuel discharge distribution paths 61A, BIB, 81C, and flID connected to 60B, 80C, and EIOD, it becomes easy to route the fuel increase distribution path.

〔Effect of the invention〕

As described above, the fuel increasing device for multiple carburetors according to the present invention provides the following effects.

■In a multiple carburetor in which multiple carburetors are arranged to mechanically open and close the effective opening area of the intake tract using a throttle valve, dependence on the negative pressure in the intake tract during low-speed operation with a high opening of the throttle valve. Instead, the fuel booster pump actively supplies pressurized fuel from the fuel booster passage to each carburetor to prevent dilution of the air-fuel mixture in each carburetor. This made it possible to significantly improve engine performance by increasing output.

■Fuel for increase is fed into the fuel increase passage.

The injection pressure of the increased amount of fuel from the fuel increasing passage into the intake duct can be freely set because the injection pressure of the increased amount of fuel from the fuel increasing passage into the intake tract can be set freely, and the injection pressure of the increased amount of fuel from the fuel increasing passage into the intake duct can be set freely, rather than depending on the fuel pressure from the fuel tank or the discharge pressure from the fuel pump. This allows for improved fuel atomization and improved fuel atomization.
This made it possible to speed up the supply speed.

■During engine acceleration, if the engine speed cannot rise sufficiently even though the throttle valve is opened to a high opening, pressure is actively applied from the fuel increase passage and each fuel increase distribution passage. By supplying the same fuel to each carburetor, it was possible to prevent the air-fuel mixture from becoming diluted during acceleration operation, thereby improving the acceleration performance of the engine.

(This is because a control jet with a diameter smaller than the effective diameter of the fuel increase passage is placed in the fuel increase passage.

Since minute fuel control is possible, fuel control suitable for high throttle valve opening, low speed operation, and acceleration operation can be easily performed.

■By opening the other end of each fuel increase distribution path into the intake duct on the engine side from the throttle valve of each carburetor, fuel can be instantly supplied to the engine, improving the dynamic characteristics of the engine. It is something that can be achieved.

■By arranging a distribution path control jet having a passage diameter smaller than the effective passage diameter of the fuel increase distribution path in each fuel increase distribution path of the capacitor carburetor, it is possible to control the increase fuel amount supplied to each carburetor. In particular, by changing the passage diameter of each distribution path control jet for each carburetor, the optimum mixture concentration required by each carburetor can be controlled.

■By branching the leak passage from the fuel increase passage or fuel increase distribution passage and arranging a normally closed on-off valve in the leak passage, the fuel flowing through the fuel increase passage or fuel increase distribution passage can be removed when not needed. If the leak passage can be removed and the effective passage diameter of the leak passage is larger than the effective passage diameter of the fuel increase passage and the fuel increase distribution passage, the supply of increased fuel from the fuel increase passage and the fuel increase distribution passage can be instantly stopped. It is something.

■If the other end of each fuel increase distribution path is opened to each acceleration fuel discharge distribution path between each discharge side check valve of the accelerator and each acceleration nozzle, especially from the initial stage to the middle stage of acceleration and then to the final stage. while,
In addition to supplying fuel from the accelerator, pressurized fuel can be supplied from the fuel increase distribution path, and by using the already installed accelerated fuel discharge distribution path of each carburetor, it is possible to simply route the passage. Further, since the pressure of the increased fuel is not equally affected by the closing force of the discharge side check valve, it is easy to set the discharge pressure.

[Brief explanation of the drawing]

Fig. 1 is an overall system diagram including a vertical cross-sectional view of a carburetor showing an embodiment of the fuel increasing device for multiple carburetors according to the present invention, and Fig. 2 shows the relationship between throttle valve opening and engine speed. A line diagram showing an example of the range in which the control circuit outputs an output for driving the control valve, and FIG. 3 is an overall system diagram including a vertical cross-sectional view of a multiple carburetor showing another embodiment. 2. Intake path 5. Float chamber 6.
,,,valve seat 9,,,throttle valve 17. ．． ．． ．．
Fuel inflow path 20. ,,,fuel increase pump 21,,,
, Fuel increase passages 22A, 22B, 22C, 22D, Fuel increase distribution passage 23, Throttle valve opening degree sensor 24, Rotation sensor 25. ,,,control circuit 30
, , Control jets 31A, 31B, 31G, 31D, , Distribution path control jet 40, , Leak passage 41. ,,, on-off valve 5
0, , , Accelerator 5G, , , Acceleration fuel discharge passage f30A, 80B, 80G, l1iOI), , Acceleration nozzle 81A, BIB, 810, 610. ,, acceleration fuel discharge distribution path [12A, 62B, 82G, 820 . ,,Discharge side check valve T,,,Fuel tank P,,,Fuel pump W=,,,Acceleration well A,,,First carburetor A
2. , second vaporizer A3. , third vaporizer A41. 4th vaporizer

Claims (8)

[Claims] (1) A multiple carburetor in which a plurality of carburetors are arranged to mechanically open and close the effective opening area of the intake passage passing through the carburetor body using a throttle valve; A fuel inflow path that is pressurized by a head differential or a fuel pump and is supplied to a valve seat opening in the float chamber of each carburetor that constitutes a multiple carburetor; and a throttle valve opening sensor that detects the opening of the throttle valve. Based on a control signal from a control circuit that receives the output and the output of a rotation sensor that detects the engine speed, the fuel in the fuel tank is sucked through the suction passage and sent to the fuel increase passage through the suction passage. A fuel increasing pump for discharging fuel; A fuel increasing distribution passage whose one end is connected to the fuel increasing passage and the other end is connected to the intake passage of each carburetor constituting the multiple carburetor including the intake pipe; A multiple carburetor that drives a fuel increase pump in accordance with a control signal from a control circuit at an opening degree or higher and within a certain rotation speed range of the engine, and feeds the fuel in the fuel tank to each fuel increase distribution path. fuel increase device. (2) A multiple carburetor according to claim 1, wherein a control jet having a passage diameter smaller than the effective passage diameter of the fuel increase passage is disposed in the fuel increase passage connected to the discharge passage of the fuel increase pump. Fuel increase device. (3) The fuel supply system according to claim 1, wherein the other end of each fuel increase distribution passage is opened to an intake path including an intake pipe on the engine side from the throttle valve of each carburetor constituting the multiple carburetor. Fuel increase device for continuous carburetor. (4) A patent claim in which a distribution passage control jet having a passage diameter smaller than the effective passage diameter of the fuel increase distribution passage is arranged in each fuel increase distribution passage connected to the intake path of each carburetor constituting a multiple carburetor. A fuel increasing device for a multiple carburetor according to item 1. (5) A fuel increasing device for a multiple carburetor according to claim 4, wherein the passage diameter of the distribution path control jet is changed for each carburetor constituting the multiple carburetor. (6) A leak passage connected to the atmosphere or a fuel tank is branched from the fuel increase passage or the fuel increase distribution passage, and a normally closed on-off valve is disposed in the leak passage.
Fuel increase passage for the multiple carburetor described in Section 1. (7) The fuel increasing device for a multiple carburetor according to claim 6, wherein the effective passage diameter of the leak passage is larger than the effective passage diameter of the fuel increasing passage or the fuel increasing distribution passage. (8) Accelerate fuel in the acceleration pump chamber by rapidly opening the throttle valve at the other end of each fuel increase distribution path. A discharge side check valve of an accelerator that injects fuel into the intake duct of each carburetor constituting a multiple carburetor through each acceleration nozzle from each acceleration fuel discharge distribution path equipped with a discharge side check valve inside. 2. A fuel increasing device for a multiple carburetor according to claim 1, which is opened in each acceleration fuel discharge distribution path between the acceleration nozzle and the acceleration nozzle.