JPH05256199A - Fuel quantity increasing device for multiple carburetor - Google Patents

Abstract

PURPOSE:To inhibit mixture from becoming lean in an engine, during high-opening low-speed operation and during accelerating operation and positively make the mixture rich in a specific operating region where the mixture becomes lean, in a fuel quantity increasing device for a multiple carburetor. CONSTITUTION:A fuel quantity increasing device for a multiple carburetor is formed of carburetors 1 provided with throttle valves 9 for mechanically controlling the opening/closing of the effective opening area of intake passages 2, and venturi parts 11; fuel inflow passages 19 for applying pressure to the fuel in a fuel tank T by a fuel pump P or the like so as to feed the fuel to float chambers 5; a fuel quantity increase passage 20 branched from each fuel inflow passage 19; a control valve 21 for controlling the opening/closing of the fuel quantity increase passage 20 by a control signal from a control circuit 30 receiving the output of a throttle valve opening sensor 27 and a vehicle speed sensor 28; and fuel increase quantity distribution passages 20A-20C branched from the fuel quantity increase passage 20 and connected to the respective intake passages 2 of the carburetors 1. When the opening of the throttle valves 9 is the fixed value or more and the vehicle speed is within a range of the fixed vehicle speed determined in relation to the opening of the throttle valves 9, the control valve 21 is put in action by the control signal from the control circuit 30 to open the fuel quantity increase passage 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vaporizer for controlling the amount and concentration of air-fuel mixture supplied to an engine.
A plurality of carburetors that mechanically control the opening and closing of the effective opening area of the intake passage that penetrates the carburetor body with a throttle valve operated by an accelerator wire, for example, two, three, four, in the horizontal direction, The present invention relates to a fuel increasing device for a multiple vaporizer arranged vertically or in a V shape.

[0002]

2. Description of the Related Art There are the following two types of carburetors which mechanically control the opening / closing of an effective opening area of an intake passage by a throttle valve operated by an accelerator wire. Firstly, a valve shaft is rotatably supported by the carburetor main body across an intake passage passing through the carburetor main body, and a disc-shaped butterfly valve is attached to the valve shaft. A venturi portion is formed in the intake passage upstream of the butterfly valve, and a fuel injection hole is formed in the venturi portion. The fuel injection hole opens below the constant liquid surface of the float chamber. Here, when the driver operates the accelerator wire to rotate the valve shaft, the butterfly valve controls the opening and closing of the effective opening area of the intake passage. (Usually called a butterfly type vaporizer, a butterfly type multiple vaporizer using a plurality of such vaporizers is disclosed in, for example, Japanese Utility Model Publication No. 52-57307.)

Secondly, a sliding valve guide cylinder is provided continuously from the middle part of the intake passage penetrating the carburetor main body to the side, and a cylindrical or rectangular throttle valve is provided in the sliding valve guide cylinder. The venturi portion is formed by the bottom of the throttle valve and the intake passage, and a fuel injection hole is formed in the venturi portion. Here, when the driver operates the throttle wire to move the throttle valve in the sliding valve guide cylinder, the throttle valve controls the opening / closing of the effective opening area of the intake passage (the area of the venturi portion). (Usually called a sliding throttle valve type carburetor, and a sliding throttle valve type multiple carburetor using a plurality of such carburetors is shown in, for example, Japanese Utility Model Publication No. 53-38754.) With the throttle valve, the effective opening area of the intake passage,
The butterfly-type multiple vaporizer and the sliding throttle valve-type multiple vaporizer that mechanically control the opening / closing of the (Venturi portion) have the following problems.

First, when the throttle valve is opened to a high opening and the engine speed is low (high opening low speed operation), the flow velocity of the air flowing through the venturi portion becomes low, and the fuel opening to the venturi portion is opened. The Venturi negative pressure applied to the nozzle hole is weakened. According to this (close to the atmospheric pressure), it becomes difficult to suck sufficient fuel from the fuel injection hole to the venturi portion, which causes a lean mixture, which is not preferable. The phenomenon of leaning of the air-fuel mixture in the high opening and low speed operation becomes more remarkable as the diameter of the intake passage is increased (the diameter of the venturi portion is increased) in order to improve the output of the engine. As a conventional technique aiming to solve the above, a single carburetor is arranged with an air control valve on the upstream side of the throttle valve, and at the time of high opening low speed operation, the output of the throttle valve opening sensor and A technique is known in which the air control valve is controlled in the closing direction by the output of the engine rotation speed sensor. (Shown in Jitsukai Sho 60-70761.)

Secondly, when the throttle valve is suddenly accelerated to a high opening degree in order to rapidly increase the rotation speed from a low opening state, as in the idling operation of the engine, during a rapid acceleration operation of the engine. As a result, the engine is immediately supplied with the increased amount of air by the sudden opening of the throttle valve, but the fuel supply is temporarily delayed by the air inertia, resulting in the lean mixture. Not preferred. This leaning phenomenon of the air-fuel mixture becomes more prominent as the diameter of the intake passage is increased (the diameter of the venturi portion is increased). As a conventional technique aiming to solve the above,
The diaphragm is used to divide the housing into a pump room and an atmosphere room.
In the pump chamber, an intake side check valve is placed inside, and an acceleration fuel inflow path connected to the float chamber and a discharge side check valve inside are placed, and acceleration connected to the intake passage of each carburetor. Open the fuel discharge path, press this diaphragm toward the pump chamber side when the throttle valve opens suddenly to pressurize the pump chamber, and vaporize the acceleration fuel stored in the pump chamber through the acceleration fuel discharge path. There is a so-called acceleration pump device technology in which the fuel is injected and supplied into the intake passage of the device. (Shown in Jitsuko Sho 53-32183.)

[0006]

According to such a conventional technique, there are the following inconveniences. First of all, Shokai Sho 60-70
According to the technology of No. 761, during high speed low speed operation,
Although the throttle valve is kept open at a high opening, the air control valve controls the intake passage in the closing direction by the output signal from the control unit to reduce the effective opening area of the intake passage upstream of the throttle valve. Is. According to this, the intake passage negative pressure in the intake passage including the throttle valve on the engine side of the air control valve rises, and the opening of the needle jet as the main fuel system opening to the venturi section on the engine side from the air control valve. The intake passage negative pressure applied to the portion is increased, so that a larger amount of fuel than the needle jet can be sucked out into the intake passage, and thus leaning of the air-fuel mixture can be prevented. However, since the air control valve operates to close the intake passage and reduces the effective opening area of the intake passage, the amount of air supplied to the engine is reduced, which is not preferable in improving the output of the engine. .. In particular, one of the purposes of adopting the multiple vaporizer is to improve the output of the engine, which is particularly inconvenient in the multiple vaporizer. Further, the air control valve needs to be arranged in each carburetor, which increases the number of parts and the number of assembling steps, which is not preferable, and further hinders the design freedom of the entire carburetor.

Next, the technique of Japanese Utility Model Publication No. 53-32183 is as follows.
The pump chamber is pressurized by the sudden opening operation of the throttle valve, and the acceleration fuel stored in the pump chamber is injected and supplied into the intake passage of each carburetor through the acceleration fuel discharge passage. However, it is difficult to set a long injection fuel injection time to supply the fuel for acceleration from the acceleration pump device into the intake passage of each carburetor (continuous injection from the initial stage to the final stage of acceleration). This is because the diaphragm that pressurizes the pump chamber of the acceleration pump device is mechanically connected to the throttle valve.To increase the acceleration fuel injection time, select the chamber volume of the pump chamber, Select a diaphragm spring that is compressed in the room to urge the diaphragm toward the atmosphere chamber, select the passage diameter of the acceleration fuel intake passage and the acceleration fuel discharge passage, or check the intake side check valve and the discharge side check valve. It takes a lot of time to select a valve closing spring for biasing against the seat, which hinders improvement in development efficiency. Even if the above-mentioned elements are selected, the compression stroke of the diaphragm is uniquely determined by the opening stroke of the throttle valve, so there is a limit to the extension of the acceleration fuel injection time from the initial stage to the final stage of acceleration. Is. Further, during the acceleration operation from the intermediate opening operation of the throttle valve, the diaphragm has already compressed the pump chamber and it is difficult to further compress the diaphragm, so that sufficient fuel for acceleration cannot be supplied. I was afraid.

The fuel amount increasing device for a multiple vaporizer according to the present invention has been made in view of the above, and is provided with a plurality of vaporizers for mechanically controlling the opening / closing of the effective opening area of the intake passage by a throttle valve. In the continuous vaporizer, it is possible to suppress the leaning of the air-fuel mixture during the middle, high opening, low speed operation and acceleration operation of the engine, and to positively thicken the air-fuel mixture in a specific operation region where the air-fuel mixture becomes lean. It is an object to provide a fuel increasing device.

[0009]

According to the fuel increasing device for a multiple vaporizer according to the present invention, in order to achieve the above object, the effective opening area of the intake passage passing through the vaporizer main body is mechanically adjusted by a throttle valve. Multiple vaporizers with open / close control and a plurality of vaporizers with a venturi portion formed in the intake passage; Fuel vaporized by fuel head difference or fuel pump pressurizing the fuel stored in the fuel tank Of the throttle valve opening sensor for detecting the opening of the throttle valve, which is disposed in the fuel increase passage, which is branched from the fuel inflow passage; A control valve for controlling the opening and closing of the fuel increase passage and the amount of fuel flowing in the fuel increase passage by a control signal from a control circuit to which the output and the output of a vehicle speed sensor for detecting the speed of the vehicle are input; Than Is branched from the fuel increase passage of the flow side,
And a fuel increase distribution passage connected to the intake passage of each carburetor; the throttle valve opening degree is equal to or greater than a certain opening degree, and the vehicle speed is controlled within a certain vehicle speed range determined with respect to the throttle valve opening degree. The control valve is operated by a control signal from the circuit to open the fuel quantity increasing passage.

[0010]

The control valve operates according to the control signal from the control circuit when the opening of the throttle valve is equal to or larger than a certain opening and the vehicle speed is within the range of the constant vehicle speed determined for the opening of the throttle valve. Open the fuel increase passage. According to this, the pressurized fuel in the fuel inflow passage is injected and supplied into the intake passage of each carburetor constituting the multiple vaporizer via the fuel increase passage and the fuel increase distribution passage, and the lean mixture is suppressed. To do. On the other hand, when the throttle valve opening is equal to or less than a certain opening degree and the vehicle speed is outside the constant vehicle speed pressure range defined for the throttle valve opening degree, the fuel increase passage is blocked and held by the control valve. Therefore, the injection and supply of fuel from each fuel increase distribution passage into the intake passage is suppressed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a fuel increasing device for a multiple vaporizer according to the present invention will be described below with reference to the drawings. (Note that, although the present embodiment shows a sliding throttle valve type triple vaporizer, the carburetor type may be a butterfly type carburetor, and is not limited to the number of carburetors. It is not limited to the placement, the vertical placement, the V-shape, and the like.) First, a single vaporizer C constituting a multiple vaporizer will be described with reference to FIG. Reference numeral 1 denotes a carburetor main body in which an intake passage 2 penetrates the inside thereof, and a sliding valve guide cylinder 3 is continuously provided upward from a substantially middle portion of the intake passage 2 and faces a lower recess of the carburetor main body 1. The float chamber main body 4 is disposed, and the lower recess and the float chamber main body 4 form a float chamber 5. A valve seat 6 is opened in the float chamber 5, and a float valve 7 for controlling the opening and closing of the valve seat 6 is arranged corresponding to the valve seat 6, and the float valve 7 is a float valve arranged in the float chamber 5. Opening / closing driving force is applied to the valve seat 6 by the movement of 8.

A throttle valve 9 for controlling the opening and closing of the effective opening area of the intake passage 2 is movably arranged in the sliding valve guide cylinder 3, and the throttle valve 9 rotates on the carburetor main body 1. The operation shaft 10 is freely supported mechanically by a link and a lever, and the operation lever 12 is integrally attached to the shaft end portion of the operation shaft protruding outside the carburetor body 1. An accelerator wire (not shown) to be pulled by a driver is attached to the operation lever 12. Therefore,
When the driver operates the accelerator wire, the operating lever 12 and the operating shaft 10 rotate, and this is transmitted to the throttle valve 9 via a lever, a link, etc., and the throttle valve 9 opens and closes the intake passage 2. become. Then, the venturi portion 11 is formed by the bottom portion 9A of the throttle valve 9 that opens into the intake passage 2 and the intake passage 2 that faces the bottom portion 9A. The opening area of the venturi portion 11 changes as the throttle valve 9 moves. (Forms a so-called variable venturi)

A jet needle 13 is integrally attached to the bottom portion 9A of the throttle valve 9, and the jet needle 13 is inserted into a needle jet 14 which is a fuel injection hole opening in the venturi portion 11. To be done. The needle jet 14 is connected to the main fuel jet 16 via a mixing nozzle 15 having an air bleed hole 15A, and an annular acceleration well W is formed on the outer circumference of the mixing nozzle 15 described above. In the acceleration well W, a liquid surface having substantially the same height as the constant liquid surface formed in the float chamber 5 is formed, and in the acceleration well W on the liquid surface, a main air passage communicating with the atmosphere is formed. Open. (Main air passage not shown)

On the other hand, the valve seat 6 has a fuel inflow passage 19
Fuel stored in a fuel tank T, which will be described later, is supplied in a pressurized state via the fuel tank T. When the fuel tank T is disposed below the carburetor main body 1, The fuel is pressurized by a fuel pump P, which will be described later, and supplied to the fuel inflow passage 19. On the other hand, when the fuel tank T is arranged above the carburetor body 1, the fuel in the fuel tank T is It is pressurized by and is supplied to the fuel inflow path 19. The position of the 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 fuel flows from the fuel inflow passage 19 into the float chamber 5 through the valve seat 6. When the liquid level in the float chamber 5 rises up to a set constant level, the float valve 7 closes the valve seat 6 with the float 8, so that the float valve 7 from the fuel inflow passage 19 via the valve seat 6 The supply of fuel to the inside of the float chamber 5 is stopped, whereby a constant liquid surface can be formed in the float chamber 5. The above is a conventionally known vaporizer.

In this embodiment, three such carburetors C are arranged laterally. This state is shown in FIG. 2, and for convenience sake, the first carburetor C1, the second carburetor C2, and the third carburetor C2 are shown from the right in the figure.
Let it be vaporizer C3. For example, an operation shaft 10 is connected to the throttle valve 9 in each vaporizer so as to open and close in synchronization. Further, the fuel inflow passage 19 of each vaporizer is connected to the fuel tank T, and the pressurized fuel is supplied into the fuel inflow passage 19.

Reference numeral 20 denotes a fuel amount increasing passage branched from the fuel inflow passage 19, and a control valve 21 for controlling the opening and closing of the fuel increasing passage 20 is arranged in the fuel increasing passage 20. In the control valve 21 according to the present embodiment, the movable iron core 23 is attracted to the fixed iron core 24 by energizing the solenoid 22, and the valve portion 25 integrally formed with the movable iron core 23 is provided in the fuel increase passage 20 in the valve seat 26. A normally-closed solenoid valve for opening the valve was used.
(This control valve 21 can be appropriately selected as long as it has a function of electrically opening and closing the passage (for example, a motor) without being a solenoid valve.) Then, the fuel increasing passage 20 downstream of the control valve 21 (specifically, In particular, the fuel amount increase distribution passages 20A, 20B, 20C branch from the fuel amount increase passages 20) downstream of the valve seat 26 toward the respective intake passages 2 of the carburetors C1, C2, C3. The opening positions of the fuel increasing distribution passages 20A, 20B, 20C to the intake passage 2 are within the range of the intake passage 2 or the intake pipe (not shown) connecting the intake passage 2 of the carburetor body 1 and the engine. Not limited. In this embodiment,
The fuel increasing distribution passages 20A, 20B, 20C are opened by a nozzle N upstream of the throttle valve 9 (left side in FIG. 2).

Reference numeral 27 is a throttle valve opening sensor for detecting the opening of the throttle valve 9 with respect to the intake passage 2. Reference numeral 28 is a vehicle speed for detecting the speed (hereinafter referred to as vehicle speed) of a vehicle equipped with an engine equipped with a carburetor. It is a sensor.

Throttle valve opening sensor 27 and vehicle speed sensor 28
The output of the control valve 30 is input to the control circuit 30, and the control circuit 30 controls the control valve 2 under the condition that the throttle valve opening and the vehicle speed are determined.
A control signal for driving 1 is output. A specific example of the conditions under which the throttle valve opening and the vehicle speed at which the control signal for driving the control valve 21 is output from the control circuit 30 will be described below. The control circuit 30 drives the control valve 21 to drive the control valve 21 in a state in which the opening is equal to or more than 8 and within a constant vehicle speed range (50 km / hour to 110 km / hour) determined for the throttle valve opening. The control signal is output. For example, when the throttle valve opening is 4/8, the vehicle speed is in the range of 50 km / hour to 70 km / hour,
When the throttle valve opening is 6/8, the vehicle speed is 50 km / h to 90
The vehicle speed is in the range of 50 km / hour, and in the throttle valve opening of 8/8, the vehicle speed is in the range of 50 km / hour to 110 km / hour. The above-mentioned condition range is clearly indicated by the hatched range in FIG. 3, but this condition range is appropriately set in the setting work of the carburetor for the engine and is not limited to the above condition.

Next, its operation will be described. First, a relatively low opening operation state in which the opening of the throttle valve 9 of each carburetor is 3/8 opening or less will be described. The throttle valve 9 is opened up to a certain opening (3/8 opening). Since it does not exist, the control circuit 30 does not output the control signal for driving to the control valve 21. Therefore, the control valve 21 is in the inoperative state, and the control valve 2
The first valve portion 25 keeps the valve seat 26 closed, so that the increased fuel is not supplied from the fuel increasing passage 20 and the fuel increasing distribution passages 20A, 20B, 20C to the intake passage 2 of each carburetor. During such low opening operation, the venturi section 1
1 is throttled to a small opening area by a throttle valve 9, and the flow velocity of the air flowing through the venturi portion 11 of this small opening and the intake passage downstream of the venturi portion 11 is increased and the intake air of the venturi portion 11 and the intake air downstream of the venturi portion 11 are Since the negative pressure of the passage is increased and maintained, the optimum fuel is sucked out into the venturi portion 11 and the intake passage 2 through the needle jet 14 as the main fuel system, the bypass hole (not shown) as the low-speed fuel system, and the pilot outlet hole. Since it is supplied to the engine, the engine can be operated well and a desired vehicle speed of a relatively low vehicle speed (less than 50 km / hour) can be obtained.

Next, the throttle valve 9 is opened from the relatively low opening operation state below the 3/8 opening degree, and the load state applied to the engine during the medium to high opening state above 3/8 opening state is further opened. When the load is light or medium, the engine speed is
Since the throttle valve 9 is opened to the middle and high openings and the load is not relatively large, the throttle valve 9 rises appropriately, and as a result, the flow velocity of the air flowing through the venturi portion 11 of each carburetor is increased. The negative pressure in the part 11 is sufficiently high,
The proper fuel corresponding to the negative pressure is needle jet 14
Since it is more sucked into the intake passage 2, a proper vehicle speed can be obtained according to the opening degree of the throttle valve. Specifically, referring to FIG. 2, the vehicle speed exceeds 70 km / hour at the throttle valve opening 4/8, the vehicle speed exceeds 95 km / hour at the throttle valve opening 6/8, and the throttle valve opening 8 At / 8,
The vehicle speed exceeds 110 km / hour. That is, in such an operating state, the vehicle speed with respect to the throttle valve opening degree shown in FIG. 2 increases to a vehicle speed outside the shaded range. Therefore, a control signal for driving is not output from the control circuit 30 to the control valve 21, and the control valve 21 keeps the fuel quantity increasing passage 20 closed. As described above, when the throttle valve 9 is in the middle and high opening operation and the load applied to the engine is small and the operation is in the middle load, the fuel increase passage 20 and the fuel increase distribution passages 20 are provided.
Although the fuel amount is not increased from A, 20B, and 20C, the negative pressure of the venturi portion 11 is sufficiently increased as described above, so that the optimum fuel is sucked out from the needle jet 14 as the main fuel system to the venturi portion 11. Is supplied to the engine to satisfy the operation of the engine, and a desired medium or high vehicle speed can be obtained according to the throttle valve opening.

The fuel amount increasing device for the multiple vaporizer according to the present invention has a special function in the following. First, the first
In the operating state, the throttle valve 9 is opened to a high opening in a medium opening of 3/8 or more, but the vehicle speed is not sufficiently increased. Such a situation is a state in which the throttle valve 9 is opened to a medium or high opening degree and a high load is applied to the engine, and for example, a state where a steep slope is climbed up or a load is fully loaded. In such a state, the throttle valve 9 is opened to a medium or high opening of 3/8 or more, while the rotational speed of the engine is decreased due to the high load and the flow velocity of the air flowing through the venturi portion 11 is decreased. Is decreased, and the negative pressure of the venturi portion 11 is decreased, so that the needle jet 1
The amount of fuel sucked into the intake passage 2 from No. 4 is reduced and the air-fuel mixture is diluted, so that an appropriate vehicle speed with respect to the throttle valve opening cannot be obtained. For example, when the throttle valve opening is 4/8, the vehicle speed is less than 70 km / hour, when the throttle valve opening is 6/8, the vehicle speed is less than 95 km / hour, and the throttle valve opening is 8 /
In 8, the vehicle speed is less than 110 km / hour, and so on. When this state is reached, the opening state of the throttle valve 9 is detected by the throttle valve opening sensor 27 and its output is input to the control circuit 30, while the vehicle speed is detected by the vehicle speed sensor 28 and its output. Is input to the control circuit 30.

When the outputs from the throttle valve opening sensor 27 and the vehicle speed sensor 28 are input to the control circuit 30, the control circuit 30 sends a control signal for driving the control valve 21 to the control valve 21. In the control valve 21 that receives the control signal, the movable iron core 23 is attracted to the fixed iron core 24, and the valve portion 25 opens the valve seat 26. According to this, a part of the pressurized fuel supplied into the fuel inflow passage 19 is separated from the fuel inflow passage 19, and the fuel amount increase distribution passages 20A, 20B,
20C, and is immediately injected and supplied into each intake passage 2 of each carburetor C1, C2, C3. Together with the fuel sucked into the venturi section 11 from the needle jet 14 as the main fuel system. The throttle valve suppresses leaning of the air-fuel mixture during high-load operation in which the throttle valve is opened to medium and high openings. The vehicle speed rises to an appropriate vehicle speed according to the throttle valve opening. The supply of the increased fuel from the fuel increasing passage 20 into the intake passage 2 is performed in a constant vehicle speed range in which the opening of the throttle valve 9 is equal to or greater than 3/8 and the throttle valve opening is determined. Inside (in other words, the vehicle speed has not risen to an appropriate vehicle speed with respect to the throttle valve opening).
For example, a throttle valve opening of 4/8 is a constant vehicle speed range from a vehicle speed of 50 km / hour to a vehicle speed of 70 km / hour, and a throttle valve opening of 6/8 is a vehicle speed of 50 km / hour to a vehicle speed of 95 k.
It is a constant range up to m / hour, and a constant range from a vehicle speed of 50 km / hour to a vehicle speed of 110 km / hour when the throttle valve opening is 8/8. Then, when the opening degree of the throttle valve 9 becomes equal to or less than 3/8 opening degree, or outside the constant vehicle speed range defined for the throttle valve opening degree (in other words, the vehicle speed appropriate for the throttle valve opening degree). If either condition or both conditions are met, the output of the control signal from the control circuit 30 for driving the control valve 21 is stopped,
The control valve 21 returns to its original position and the valve portion 25 allows the valve seat 2
6 is closed, whereby the fuel supply from the fuel increase passage 20 and each fuel increase distribution passage 20A, 20B, 20C to the intake passage 2 of each carburetor is stopped.

Second, during the acceleration operation in which the throttle valve 9 is rapidly opened from a low opening to a middle opening and a high opening, the throttle valve 9 is in a low opening state, and the engine is running at a low speed. The vehicle is running and the vehicle speed is low. From this state, the driver pulls the accelerator wire to rapidly open the throttle valve 9 to a medium or high opening state and perform acceleration operation. Here, the behavior of the fuel supply to the intake passage 2 of each carburetor when the throttle valve 9 is rapidly opened from the low opening state to the middle opening state is as follows. When the throttle valve 9 is in a low opening state, the engine speed keeps idling rotation (for example, 1200 RPM) or low rotation speed. In such a state, the fuel is a low speed fuel system such as a bypass hole and a pilot outlet hole (Fig. (Not shown) is sucked into the intake passage 2 to perform the low opening low speed operation of the engine. Next, when the throttle valve 9 is rapidly opened to a medium or high opening state from the low opening state of the throttle valve 9, the amount of air flowing through the intake passage 2 of each carburetor is increased at once. According to this, the tip negative pressure of the needle jet 14 opening into the intake passage 2 temporarily rises slightly. According to this, the fuel stored in the acceleration well W is sucked into the venturi portion 11 from the needle jet 14 through the mixing nozzle 15 to increase the engine speed. In this state, the fuel in the acceleration well W is sucked out to the Venturi portion 11 via the needle jet 14 because the suction passage negative pressure applied to the opening portion of the needle jet 14 temporarily rises slightly.
This is because the inflow of the main jet 16 is not restricted, and the main jet 16 is already stored in the accelerating well W downstream of the main jet 16 and is easily sucked out. However, even if the fuel in the acceleration well W is sucked out, the stored fuel in the acceleration well W is limited, so that the engine speed cannot be increased significantly.
That is, even if the throttle valve 9 is opened to a medium or high opening degree, it is difficult to immediately increase the vehicle speed according to the throttle valve opening degree. By increasing the capacity of the acceleration well W, it is possible to increase the number of revolutions during acceleration and increase the vehicle speed, but the inner and outer diameters of the mixing nozzle 15 improve the drivability in other operating regions. This is because the capacity of the accelerating well W is inevitably limited because it is determined in consideration. In such a state, in the present invention,
The throttle valve opening is 3/8 or more, and it is opened to a high opening or more, and the engine speed does not increase significantly even if it is higher than idling speed. Does not rise to the appropriate vehicle speed according to (cannot rise)
Therefore, the outputs of the throttle valve opening sensor 27 and the vehicle speed sensor 28 that detect them are input to the control circuit 30, and the control circuit 30 outputs a control signal for driving to the control valve 21. According to this, since the valve portion 25 of the control valve 21 immediately opens the valve seat 26, the fuel pressurized from the fuel increasing passage 20 and the fuel increasing distribution passages 20A, 20B, 20C is in the intake passage 2 of each carburetor. Is injected and supplied to the vehicle, which suppresses the leaning of the air-fuel mixture during the acceleration operation, assists the rotation increase during acceleration, and increases the vehicle speed according to the throttle valve opening. When the fuel is supplied from the fuel increase passage 20 and the fuel increase distribution passages 20A, 20B, 20C, the engine speed is sufficiently increased and the vehicle speed is appropriately increased according to the throttle valve opening. The output of the control signal to the control valve 21 is stopped from 30 and the fuel supply from the fuel increase passage 20 and each fuel increase distribution passage 20A, 20B, 20C is cut off, but the engine speed is sufficient. Since the vehicle speed has risen to the appropriate level and the vehicle speed has also risen appropriately in accordance with the throttle valve opening, a large negative pressure acts on the needle jet 14 as the main fuel system. The compatible fuel could be sucked out from the needle jet 14 into the intake passage 2 of each carburetor. The acceleration operation described above will be described with reference to a specific example with reference to FIG. 3. When the throttle valve opening is 2/8 and the vehicle speed is 30 km / hour, the throttle valve 9 is rapidly opened to 4/8 opening and the vehicle speed is 60 km / hour. When it rises only until time, the outputs of the throttle valve opening sensor 27 and the vehicle speed sensor 28 are input to the control circuit 30, and the control circuit 30 outputs a signal for driving the control valve 21. According to this, the fuel increase passage 20 and each fuel increase distribution passage 20A, 20B, 20
Fuel is immediately supplied to the intake passage 2 from C, leaning of the air-fuel mixture is suppressed, the engine speed is increased, and the vehicle speed can be increased according to the throttle valve opening. And the vehicle speed is 70km /
When the time is exceeded, the output from the vehicle speed sensor 28 to the control circuit 30 is stopped, so that the control circuit 30 causes the control valve 2 to stop.
The output to No. 1 is stopped, and the fuel supply to the intake passage 2 of each carburetor from the fuel increase passage 20 and each fuel increase distribution passage 20A, 20B, 20C is stopped.

Further, even during the intermediate acceleration operation in which the throttle valve 9 is rapidly opened from the intermediate opening, for example, the 4/8 opening to the 8/8 opening (fully opened), the negative pressure of the venturi section 11 is temporarily reduced. There is a case where the vehicle speed does not increase to a desired speed because the increase in the rotation speed is suppressed and the vehicle speed does not increase to a desired speed. Even in such a state, the control valve 21 performs the above operation by the signal output from the control circuit 30. Can be improved. Explaining with a specific example with reference to FIG. 2, when the throttle valve opening is 4/8 and the vehicle speed is 75 km / hour, the throttle valve 9 is opened to 8/8 opening (fully opened) and the vehicle speed increases only up to 95 km / hour, Outputs from the throttle valve opening sensor 27 and the vehicle speed sensor 28 are input to the control circuit 30, and a signal for driving the control valve 21 is output from the control circuit 30, whereby the control valve 21 opens the fuel quantity increase passage 20. Immediately, fuel is supplied toward the intake passage 2 to prevent leaning of the air-fuel mixture, and thus the rotation of the engine is increased and the vehicle speed can be increased according to the throttle valve opening. When the vehicle speed exceeds 110 km / hour, the output from the vehicle speed sensor 28 to the control circuit 30 is stopped, so that the output from the control circuit 30 to the control valve 21 is stopped, and the fuel increase passage 20 and each fuel increase distribution path are stopped. 20A,
The supply of fuel to the intake passage 2 of each carburetor is stopped from 20B and 20C.

Further, the control signal output from the control circuit 30 to the control valve 21 is a drive pulse having an energization time Ti, and the opening of the throttle valve 9 is 3/8 or more and the vehicle speed is the throttle valve opening. Within the fixed vehicle speed range specified for
When the opening of the throttle valve 9 is in a constant opening state, the energization time Ti is shortened according to the increase of the vehicle speed, and the fuel increase passage 20 and the fuel increase distribution passages 20A, 20B, 20C are directed to the intake passage 2. When the vehicle speed is constant, the energization time Ti is lengthened in accordance with the increase in the opening degree of the throttle valve 9 to increase the fuel amount passage 20, each fuel amount increase distribution passage 20A. , 20B, 20C to increase the amount of fuel supplied to each intake passage 2. This fuel control state is clearly shown in FIG. 3. In FIG. 3, the amount of fuel supplied from the control valve 21 is the smallest in the mesh range (referred to as a large flow rate), and the fuel amount in the solid hatching range follows the mesh range. The amount of fuel in the hatched area indicated by the dotted line is larger than that in the hatched area indicated by the solid line (called the small flow rate). According to the above, for example, 8/8 of the throttle valve 9
When the opening is constant, the vehicle speed is from 50km / h to 110k
While rising up to m / hour, the amount of fuel supplied to each intake passage 2 via the fuel increase passage 20 and each fuel increase distribution passage 20A, 20B, 20C is gradually reduced to a large flow rate, a medium flow rate, and a small flow rate. In particular, the negative pressure of the venturi portion 11 is low, and the venturi portion 1 is
It is difficult to suck fuel into the vehicle (for example, vehicle speed 55 km /
(A state of time), it is possible to perform a large amount of fuel increase correction, while the needle jet 14 sucks fuel into the venturi section 11 in a better state than the above state (for example, a vehicle speed of 105 km / hour). In this case, it is possible to carry out a small amount of fuel increase correction, and there is an extremely great effect in terms of operability of the engine, emission of harmful exhaust gas, and fuel economy.

Further, for example, the throttle valve 9 is changed from 2/8 opening to 4 /
In the acceleration state in which the vehicle speed is 60 km / hour and is opened up to 8 degrees, a small amount of fuel increase correction can be performed. On the other hand, the throttle valve 9 changes from 2/8 degrees to 8/8 degrees. In the acceleration state in which the vehicle speed was released up to 60 km / hour, it was possible to correct the fuel increase in the flow rate larger than that in the acceleration state, and it was possible to achieve the appropriate fuel correction for the acceleration operation.

Further, the large flow rate within the mesh range described above,
When the control valve 21 is controlled by arbitrarily changing the energization time Ti within each range of the medium flow rate in the solid line hatching range and the small flow rate in the dotted line hatching range, the fuel increase passage 20 and the fuel increase distribution passages 20A, 20B are controlled. , 20C, the fuel supplied to the intake passage 2 can be controlled more precisely and finely. Further, the control valve 21 may be a linear electromagnetic valve in which the valve portion 25 moves linearly with respect to the valve seat 26 so that the opening area thereof can be continuously changed.

Reference numeral 31 is a pressure regulator for always maintaining the pressure of the fuel flowing in the fuel increasing passage 20 at a constant pressure, which is composed of a metal housing, the interior of which is constituted by a diaphragm and a fuel chamber and a spring. The fuel in the fuel increasing passage 20 upstream of the fuel inflow passage 19 or the valve seat 26 flows into the fuel chamber from the inlet and pushes up the valve through the diaphragm to balance the spring with the set pressure. The remaining fuel is returned to the fuel tank T, while the spring chamber is connected to the intake passage 2. According to this, since the fuel pressure flowing in the fuel increasing passage 20 is always kept constant, the controlled fuel amount is uniquely determined by opening the control valve 21, and the fuel increasing passage 20 and the fuel increasing distribution passage 20A. , 20B, 20C to the respective intake passages 2 could be accurately controlled.
(Note that the pressure regulator 31 itself is publicly known and the details are not shown.)

Considering the fuel amount increase passage 20, first, the inlet may be directly connected to the fuel tank T located above the carburetor without branching from the fuel inflow passage 19, or from the carburetor. Fuel tank T in the lower position
It may be directly connected to a fuel pump via a second pump (not shown), or the fuel increasing distribution passages 20A, 20 corresponding to the outlets thereof.
B and 20C may be the intake passages 2 or intake pipes (not shown), but when opened to the intake passages 2 on the downstream side (right side in FIG. 1) of the throttle valve 9, the fuel increase distribution passages are formed. The time required for the fuel supplied from 20A, 20B, 20C to each intake passage 2 to reach the engine is further shortened, and the fuel supplied into the intake passage 2 is reduced by the throttle valve 9 and the needle jet 1.
Since it does not collide with 4 etc., it can be smoothly supplied to the engine and the responsiveness can be improved. Furthermore, although the sliding throttle valve type carburetor is used in the above embodiment, the same effect can be obtained in a butterfly type carburetor.

Further, in the embodiment shown in FIG. 5, among the vaporizers forming the multiple vaporizer, the vaporizer equipped with the acceleration pump device is arranged, and the first vaporizer C1 and the second vaporizer are provided. Bowl C2
Uses the vaporizer shown in FIG. 1 and uses the third vaporizer C3 as a vaporizer equipped with an acceleration pump device. (Note that the same structural parts as those of the first embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals and the description thereof will be omitted.) First, a carburetor C3 equipped with an acceleration pump device will be described with reference to FIG. An acceleration pump device 50 has the following configuration. That is, 5
Reference numeral 1 denotes a diaphragm which is divided into an acceleration fuel pump chamber 52 and an atmosphere chamber 53. One end of the acceleration fuel pump chamber 52 is connected to the floating chamber 5 and an intake side check valve 54 is arranged inside the acceleration fuel pump chamber 52. A fuel intake passage 55 and an acceleration fuel discharge passage 58, one end of which is connected to the intake passage 2 through an acceleration nozzle 56 and in which a discharge-side check valve 57 is arranged, are opened, and the diaphragm 51 is opened to the atmosphere chamber 53. The diaphragm spring 59 that presses to the side is contracted. The opening operation of the throttle valve 9 is performed by the operation lever 12, the link 60, the pump lever 6
1 to the diaphragm 51. That is,
According to the opening operation of the throttle valve 9, the diaphragm 51 reduces the volume of the acceleration fuel pump chamber 52 by the pump lever 61 to pressurize the acceleration fuel pump chamber 52, whereby the diaphragm 51 is stored in the acceleration fuel pump chamber 52. The fuel for acceleration is injected and supplied into the intake passage 2 through the acceleration nozzle 56.

Then, a carburetor equipped with an acceleration pump device is used as the third carburetor C3 to form a multiple carburetor as shown in FIG. (The first vaporizer C1 and the second vaporizer C2 do not have an acceleration pump device) From the accelerated fuel discharge passage 58 of the third vaporizer C3 to the accelerated fuel distribution passages 58A, 58B, 58C.
Are branched, and each of these acceleration fuel distribution paths 58A, 58B,
58C is connected to each intake passage 2 of each carburetor C1, C2, C3 via an acceleration nozzle 56. A discharge-side check valve 57 is arranged in each of the acceleration fuel distribution paths 58A, 58B, 58C. Further, a fuel amount increase distribution passage 20A branched from the fuel amount increase passage 20 similar to that of the first embodiment shown in FIG.
The downstream outlets of 20B and 20C are the acceleration fuel distribution passages 58A and 58 between the acceleration nozzle 56 and the discharge side check valve 57.
B and 58C are opened respectively.

According to the above structure, the fuel increase passage 20 by the control valve 21 and each fuel increase distribution passage 20A, 20
The supply of the increased amount of fuel to B and 20C is similar to that of the first embodiment, but during acceleration operation, fuel is supplied from the acceleration well W to the intake passage 2 via the needle jet 14 especially at the initial stage of acceleration. In addition to the above, the acceleration fuel from the acceleration pump device 50 could be supplied together, so that the rise of rotation in the initial stage of acceleration could be performed more smoothly. That is, in the first embodiment, the fuel amount increase passages 20A, 20B, 20 are changed from the fuel amount increase passages 20 during the acceleration operation.
Looking at the behavior of the fuel supplied via C, the throttle valve 9 is mechanically opened from a low opening to 3/8 or more, and the vehicle speed is a constant vehicle speed determined with respect to the throttle opening. When the vehicle speed sensor 28 detects the vehicle speed, the vehicle speed sensor 28 detects the vehicle speed and inputs a signal to the control circuit 30, which outputs a signal to the control valve 21. Change in the negative pressure of the venturi section 11 → suction of fuel from the needle jet 14 due to the change in the negative pressure → increase in rotation → increase in vehicle speed → detection of the vehicle speed by the vehicle speed sensor 28 and a time delay occur, and the control valve There is a slight delay in the fuel supply from the fuel increase passage 20 to the intake passage 2 via 21. On the other hand, according to the second embodiment, when the throttle valve lever 12 is rotationally operated to start the acceleration operation, the rotation of the throttle valve lever 12 is synchronized with the diaphragm via the link 60 and the pump lever 61. 51, the acceleration fuel pump chamber 52 is compressed and compressed from the acceleration fuel pump chamber 52 to the acceleration fuel discharge passage 58 and the acceleration fuel distribution passage 58.
Since the accelerating fuel could be injected and supplied to the intake passage 2 of each carburetor through A, 58B, 58C and each accelerating nozzle 56,
It is possible to prevent the time delay of the fuel supply from the fuel quantity increasing passage 20 during the acceleration operation and to improve the acceleration performance in the initial stage of acceleration.

Further, the other ends on the downstream side of the fuel increasing distribution passages 20A, 20B, 20C branched from the fuel increasing passage 20 are respectively accelerated fuel distribution passages 58A, particularly between the discharge side check valve 57 and the acceleration nozzle 56. Due to the openings in 58B and 58C, the fuel increase distribution passages 20A, 20A, and 20A, due to the pressing load of the check valve spring S that presses the discharge side check valve 57 against the discharge valve seat.
The fuel pressure flowing in 20B and 20C is not restricted in any way. That is, the fuel amount increase distribution passages 20A, 2 are provided in the acceleration fuel discharge passage on the acceleration fuel pump chamber 52 side of the discharge side check valve 57.
When 0B and 20C are opened, the fuel increase distribution passage 20A,
If the pressure of the fuel flowing in 20B, 20C is not larger than the pressing load of the check valve spring S, it is impossible to supply the increased fuel through the acceleration fuel distribution passages 58A, 58B, 58C, and the fuel pump P discharges. Increase the pressure or make a sufficient difference between the fuel heads to increase the fuel quantity distribution passages 20A, 20
It is necessary to increase the pressure of fuel flowing in B and 20C.

Furthermore, since the openings of the fuel increasing distribution passages 20A, 20B and 20C which are opened to the intake passage 2 of the carburetor main body 1 are formed in the limited carburetor structure, the degree of freedom in design is small. However, the acceleration nozzle 5 that has already been drilled
According to the use of the acceleration fuel distribution passages 58A, 58B, 58C connected to No. 6, the fuel increase distribution passages 20A, 20B, 2
It becomes easy to rotate 0C.

In the first and second embodiments, the amount of the increased fuel injected and supplied from the fuel increase passage 20 into the intake passage 2 is determined by the setting work with the engine. Since a small amount of fuel of about 5 cc / min is sufficient, a passage diameter smaller than the effective passage diameter of the fuel increasing passage 20 is provided in the fuel increasing passage 20 on the downstream side (the side discharging to the intake passage 2) of the control valve 21. By disposing the control jet J and controlling the amount of fuel injected from the fuel increase passage 20 into the intake passage 2 by this control jet J, accurate control of the increased fuel becomes easy.

[0036]

As described above, the fuel quantity increasing device for a multiple vaporizer according to the present invention has the following effects. In a multiple carburetor that mechanically controls the opening and closing of the effective opening area of the intake passage with a throttle valve, the throttle valve opening is equal to or greater than a certain opening degree, and the vehicle speed is a constant vehicle speed determined with respect to the throttle valve opening degree. During the operation of the throttle valve in the range, middle and high opening low speed, etc., it positively vaporizes the fuel pressurized from the fuel increase passage and the fuel increase distribution passage without depending on the negative pressure of the venturi section. Since it is possible to prevent the mixture from being diluted by being supplied to the carburetor, the setting work of the carburetor is extremely easy and the engine performance can be remarkably improved. During acceleration operation of the engine, the engine speed does not rise sufficiently even though the throttle valve is open to medium or high opening, and a proper vehicle speed corresponding to the opening of the throttle valve cannot be obtained. In this case, the fuel positively pressurized from the fuel increase passage and the fuel increase distribution passage was supplied into each intake passage of each carburetor to prevent the lean mixture of the air-fuel mixture during the acceleration operation. It was possible to improve the performance. In addition, according to the use of the carburetor equipped with the acceleration pump device and the fuel increase device in combination, the acceleration fuel is supplied from the acceleration pump device, especially during the period from the initial stage to the middle stage of the acceleration. Since the pressurized fuel can be supplied to each carburetor from the fuel increasing passage, the acceleration of the engine can be further improved. The control of the amount of fuel in the fuel increase passage by the control valve is such that the opening of the throttle valve is constant when the throttle valve has a certain opening or more and the vehicle speed is within a constant vehicle speed defined for the throttle opening. In the open state, the fuel amount decreases as the vehicle speed increases, and when the vehicle speed is constant, the fuel amount increases as the throttle valve opening increases. The fuel control characteristics were able to meet the requirements of the engine within an extremely short time, and the engine performance could be significantly improved and the development efficiency could be significantly improved. Since one end of the fuel increase passage is opened to the fuel inflow passage and the other end of each fuel increase passage branched from the fuel increase passage is opened to each acceleration fuel distribution passage downstream from the discharge side check valve, it is already opened. Since the acceleration fuel distribution passage of the installed acceleration pump device can be used as a part of the fuel increase distribution passage, the degree of freedom in designing the carburetor can be increased. Furthermore,
The amount of fuel discharged from each fuel boost distribution channel does not affect the closing force of the discharge check valve, and the discharge pressure of the fuel does not affect the closing force of the discharge check valve. The discharge pressure of fuel can be optimally set. By opening the other end on the outlet side of the fuel increase distribution passage into the intake passage on the engine side from the throttle valve, the distance between the opening of the fuel increase distribution passage to the intake passage and the engine is shortened. Can be instantaneously supplied, and the collision of fuel with the jet needle, throttle valve, etc. after being injected into the intake passage can be reduced, so that the dynamic characteristics of the engine can be improved. By controlling the pressure of the fuel flowing through the fuel increase passage to a constant fuel pressure by the pressure regulator, the amount of fuel supplied from the fuel increase passage into the intake passage is uniquely determined by the control valve, so accurate fuel supply is ensured. Is made possible.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a single vaporizer that constitutes a multiple vaporizer and does not have an acceleration pump device.

FIG. 2 is an overall system diagram including a vertical cross-sectional view showing a first embodiment of a fuel increasing device for a multiple vaporizer in which a plurality of vaporizers shown in FIG. 1 are arranged.

FIG. 3 is a diagram showing an example of a range in which an output for driving is output from a control circuit to a control valve in relation to a throttle valve opening and a vehicle speed.

FIG. 4 is a diagram showing another example of a range in which an output for driving is output from the control circuit to the control valve in the relationship between the throttle valve opening and the vehicle speed.

FIG. 5 is an overall system including a vertical cross-sectional view showing a second embodiment of a fuel increasing device for a multiple carburetor in which a carburetor having an acceleration pump device is arranged in the carburetor forming the multiple carburetor. It is a figure.

FIG. 6 is a vertical cross-sectional view of a single vaporizer including the acceleration pump device shown in FIG.

[Explanation of symbols]

 2 Intake passage 5 Float chamber 6 Valve seat 9 Throttle valve 11 Venturi part 14 Needle jet 19 Fuel inflow passage 20 Fuel increase passage 20A, 20B, 20C Fuel increase distribution passage 21 Control valve 27 Throttle valve opening sensor 28 Vehicle speed sensor 30 Control circuit 31 Pressure Regulator 50 Acceleration Pump Device 56 Acceleration Nozzle 57 Discharge Side Check Valve 58 Acceleration Fuel Discharge Path 58A, 58B, 58C Acceleration Fuel Distribution Path T Fuel Tank P Fuel Pump J Control Jet

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area F02M 13/02 G 9038-3G

Claims (6)

[Claims] 1. A multiple carburetor in which a plurality of carburetors, in which a venturi portion is formed in the intake passage, are arranged and the effective opening area of the intake passage passing through the carburetor body is mechanically controlled by a throttle valve. A fuel inflow passage for pressurizing the fuel stored in the fuel tank by a fuel head difference or a fuel pump and supplying it to a valve seat opening in the floating chamber of each carburetor; and an increase in fuel amount branched from the fuel inflow passage. A fuel passage by means of a control signal from a control circuit which is arranged in the fuel quantity increasing passage and which receives the output of a throttle valve opening sensor for detecting the opening of the throttle valve and the output of a vehicle speed sensor for detecting the speed of the vehicle. A control valve for controlling opening and closing of the fuel increase passage and controlling the amount of fuel flowing in the fuel increase passage; and a fuel increase distribution passage branched from the fuel increase passage downstream of the control valve and connected to the intake passage of each carburetor; When the throttle valve opening is equal to or greater than a certain opening degree and the vehicle speed is within a certain vehicle speed range determined with respect to the throttle valve opening, the control valve is operated by the control signal from the control circuit to increase the fuel increase passage. Fuel increase device for multiple carburetors that opens. 2. A carburetor in which an effective opening area of an intake passage passing through the carburetor main body is mechanically controlled by a throttle valve and a venturi portion is formed in the intake passage, and an intake passage passing through the carburetor main body. Throttle valve that mechanically controls the opening and closing of the effective opening area of the valve, the venturi portion formed in the intake passage, and the acceleration fuel pump chamber that is mechanically compressed in conjunction with the opening operation of the throttle valve. A carburetor having an accelerating pump device for injecting accelerating fuel from an accelerating fuel discharge passage, and a multiple carburetor comprising: an accelerating fuel branching passage branched from the accelerating fuel discharge passage and connected to an intake passage of each carburetor. And; a fuel inflow passage for supplying the fuel stored in the fuel tank to a valve seat opening in the floating chamber of each carburetor by pressurizing the fuel with a fuel head difference or a fuel pump; a fuel branched from the fuel inflow passage Increase passage And; the fuel is output by a control signal from a control circuit, which is arranged in the fuel increase passage and receives the output of a throttle valve opening sensor for detecting the opening of the throttle valve and the output of a vehicle speed sensor for detecting the speed of the vehicle. A control valve for controlling opening and closing of the fuel increase passage and controlling the amount of fuel flowing in the fuel increase passage; and a fuel increase distribution passage branched from the fuel increase passage downstream of the control valve and connected to the intake passage of each carburetor; And the opening of the throttle valve is equal to or greater than a certain opening, and the vehicle speed is within the range of the constant vehicle speed determined with respect to the opening of the throttle valve,
A fuel increasing device for a multiple carburetor in which a control valve is operated by a control signal from a control circuit to open a fuel increasing passage. 3. The control of the amount of fuel in the fuel increasing passage by the control valve is carried out when the opening of the throttle valve is a certain opening or more,
In addition, when the vehicle speed is within a constant vehicle speed range determined with respect to the throttle valve opening, and the throttle valve opening is in a constant opening state, the fuel amount decreases as the vehicle speed increases, and the vehicle speed becomes constant. In the state, the fuel amount increasing device for a multiple vaporizer according to claim 1 or 2, wherein the fuel amount is increased in accordance with an increase in the opening of the throttle valve. 4. The fuel amount increasing apparatus for a multiple carburetor according to claim 2, wherein the fuel increasing distribution passage is opened to each acceleration fuel distribution passage downstream of the discharge side check valve. 5. The fuel amount increasing device for a multiple vaporizer according to claim 1, wherein an outlet side of the fuel amount increasing distribution passage is opened in each intake passage on the engine side of the throttle valve. 6. The fuel amount increasing device for a multiple vaporizer according to claim 1, wherein the fuel pressure flowing through the fuel amount increasing passage is controlled to a constant fuel pressure by a pressure regulator.