JPH03151555A - 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 controlling according to the operating condition of the engine a control valve for controlling communication between an amount of fuel increasing passage which is connected to each air intake of a multiple carburetor and which has an amount of fuel increasing pump interposed therein, and a return passage. 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 71A to 71D disposed opposite to the air intake 2 of each carburetor A1 to A4 is provided and a control valve 23 which opens the amount of fuel increasing passage 21 and blocks communication between the passage 21 and a return passage 22 when the throttle valve 9 is open for more than a predetermined degree and the rotating speed of an engine is within a fixed range is interposed in the passage 21.

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 an effective opening area of an intake passage passing through the carburetor body. 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 types of carburetors that mechanically control the opening and closing of the effective opening area of the intake airway 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
Indicated in gazettes, 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, for example,
This is shown in Publication No. 754, etc.

The aforementioned butterfly type multiple carburetor mechanically controls the opening and closing of the effective opening area of the intake tract using a throttle valve.

The sliding throttle valve type multiple carburetor has 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 air flow velocity flowing through the intake tract becomes low, and each fuel nozzle hole that opens into the intake tract The negative airway pressure applied to the air is weakened. (approaching atmospheric pressure)
According to this, it becomes difficult to suck out sufficient fuel from each fuel injection hole into the intake tract, leading to dilution of the mixture, which is not desirable. This phenomenon becomes more pronounced as the diameter of the intake duct is increased in order to improve the output of the engine.

As a conventional technology aimed at solving this problem, an air control valve 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, in order to rapidly increase the rotation from a low opening state, the throttle valve is raised rapidly, as in the case of engine fitting operation. If you look at the sudden acceleration of an engine when the throttle valve is opened suddenly, an increased amount of air is immediately supplied to the engine due to the sudden opening of the throttle valve, but the supply of fuel is temporarily delayed due to air inertia. This is not desirable as 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 suction and airway negative pressure applied to the opening of the needle jet is increased, thereby making it possible to suck out a larger amount of fuel into the intake airway 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 the 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 purpose of the present invention is to provide a fuel increasing device that can suppress the dilution of the air-fuel mixture in a carburetor during high-opening, low-speed operation and acceleration operation of three engines, and actively enrich the air-fuel mixture. 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 constituting the multiple carburetor; A fuel increase pump that sucks fuel in the tank through a suction passage and discharges it through a discharge passage; A fuel increase passage connected to the discharge passage of the fuel increase pump; Branched from the fuel increase passage and connected to the fuel tank. A continuous return passage; The fuel increase passage is connected to the fuel increase passage by a control signal from a control circuit that receives the output of a throttle valve opening sensor that detects the opening of the throttle valve and the output of a rotation sensor that detects the rotation speed of one engine. A control valve that disconnects communication between the fuel increase passage and the return passage when the fuel increase passage is opened, and connects the fuel increase passage and the return passage when the fuel increase passage is closed; A fuel increase distribution passage is connected to the downstream fuel increase passage, and the other end is connected to the intake passage of each carburetor constituting the multiple carburetor including an intake pipe.

[Effect]

When the opening of the throttle valve is above a certain degree and within a certain rotational speed range of the engine, the control valve is operated by a control signal from the control circuit to open the fuel increase passage and cut off communication between the fuel increase passage and the return passage. As a result, the fuel pressurized by the fuel increase pump can be injected and supplied from the fuel increase passage through the fuel increase distribution path into the intake passage of each carburetor constituting the multiple carburetor.

On the other hand, when the opening of the throttle valve is below a certain degree and the engine speed is outside a certain rotation speed range, the control valve is operated by a control signal from the control circuit to close the fuel increase passage and connect the fuel increase passage and the return passage. Therefore, injection and supply of fuel from the fuel increase passageway to the intake passage of each carburetor via the fuel increase distribution passage is suppressed.

〔Example〕

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 four-speed carburetor.

Reference numeral 1 denotes a carburetor body in which an intake passage 2 passes through, and a sliding valve guide cylinder 3 is connected upward from a substantially middle portion of the intake passage 2, and is opposed to the lower four parts IA of the carburetor body 1. 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 for controlling the opening and closing of the valve seat 6 is disposed corresponding to the valve seat 6. Furthermore, this float valve 7 is connected to a float disposed in the float chamber 5. 8 applies an opening/closing driving force to the valve seat 6.

A throttle valve 9 that controls the opening and closing of the effective opening area of the intake passage 2 is movably arranged inside the sliding valve guide cylinder 3. This throttle valve 9 is rotatably supported on the carburetor body l. The operating shaft 10 is mechanically connected to the operating shaft lO by a link II 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 l. 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 16 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 17. On the other hand, when the fuel tank T is placed above the carburetor main body 1 (see FIG. ) 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 AI, the second carburetor A2, and the third carburetor A. vaporizer A3. a fourth carburetor A4, arranged laterally, and
the operating shaft lO of the first vaporizer; Third. @4, vaporizer A2. The operating shafts 102, 103, 104 of A3A4 are mechanically connected, and when the operating lever 12 of the first carburetor A1 is rotated, the first... Second. Third
．． Each throttle valve of the fourth carburetor A+, A2, A3, and A4 opens and closes each intake passage synchronously.

In addition, the second. Third. The constituent parts of each of the fourth vaporizers A2+A3A4 are the same as those of the first vaporizer A1, so the same reference numerals are used and a brief description of each drawing is omitted.0 and above are conventionally known vaporizers.

20 is a fuel increase pump that sucks in fuel from a fuel tank N that stores fuel inside, such as the fuel tank T or the float chamber 5, through the suction passage 20A, and pressurizes and discharges it from the discharge passage 2QB; The pump type may be electric, mechanical, pulsating pressure, etc. 21 has one end as the fuel increase pump 2
This is a fuel increase passage connected to the discharge passage 20B of No. 0.

22 is a return passage branched from the fuel increase passage 21 and connected to the fuel tank T. Reference numeral 23 designates a control valve that opens and closes the fuel increase passage 21 and the return passage 22 as described below, and its specific structure will be explained below.

That is, 24 is an increase valve seat provided in the fuel increase passage 21, and 25 is a return valve seat provided at the opening of the return passage 22 to the fuel increase passage 21. portion 2B, a return valve portion 27 is placed facing the return valve seat 25, and this increase valve portion 26
and the return valve section 27 are integrally formed to form a valve section V, and when the increase valve section 26 closes the increase valve seat 24, the return valve section 27 opens the return valve seat 25. On the other hand, when the increase valve section 26 opens the increase valve seat 24, the return valve section 27 closes the return valve seat 25.

This valve portion V is attracted to the fixed core 29 by energizing the solenoid 2, and is integrally attached to the movable core 30 separated from the fixed core 28 by de-energizing the solenoid 28. (This control valve 23 does not have to be a solenoid valve, but can be appropriately selected as long as it has the function of electrically opening and closing the passage.) The fuel increase passage 21 is connected to the fuel increase pump 20 by the increase valve seat 24 of the control valve 23. It is divided into an upstream fuel increase passage 21A on the side, and a downstream fuel increase passage 21B on the opposite side from the fuel increase pump 20 (downstream from the increase valve seat 24), and from this downstream fuel increase passage 21B. A fuel increase distribution path 21C that is connected to an intake pipe (not shown) that connects the intake pipe 2 of each carburetor or the intake pipe 2 of the carburetor body l with the engine;
210, 21E, and 21F branch off.

31 is a throttle valve opening sensor that detects the opening of the throttle valve 9 with respect to the intake passage 2; 32 is a rotation sensor that detects the engine speed; the outputs of the throttle valve opening sensor 31 and the rotation sensor 32 are sent to the control circuit. 33, and a control signal for driving the control valve 23 is output from the control circuit 33 under predetermined conditions of the throttle valve opening degree and the engine rotation speed.

To give a specific example of the above-described conditions such as the throttle valve opening and the engine rotation speed under which the control signal for driving the control valve 23 is output from the control circuit 33, the opening of the throttle valve 9 is A control signal for driving the control valve 23 is outputted from the control circuit 33 when the engine is opened by 3/4 or more and the engine speed is within the range of 200 ORPM to 500 ORPM.

The condition range is clearly indicated by the shaded area in FIG. 2, but this condition range is appropriately set optimally during the setting work of the carburetor for the engine, and is not limited to the above conditions.

Next, we will discuss its effect.

First, as when operating the throttle valve 9 at a low or medium opening,
To explain this in an operating state where the opening degree is 374 or less, no matter how the engine speed changes, the throttle valve 9 is not opened to a certain opening degree, so the control circuit 33 sends a signal to the control valve 23 for driving. The control signal is not output, therefore, the control valve 23 is in an inoperative state, and the increase valve portion 2B of the valve portion V comes into contact with the increase valve seat 24 and closes the fuel increase passage 21.
On the other hand, the return valve portion 27 is separated from the return valve seat 25 and keeps the fuel increase passage 21 and the return passage 22 in communication.

Therefore, the fuel in the fuel tank N is discharged from the suction passage 20A of the fuel increase pump 20 to the discharge passage 20B, and
However, since the increase valve portion 26 keeps the increase valve seat 24 closed, the fuel fed into the fuel increase passage 21 returns to the fuel tank T via the return passage 22. Since the fuel is returned to the downstream side of the fuel increase passage 21, the fuel increase passage 2
From 1B to fuel increase distribution paths 21C, 21D, 21E
, each vaporizer A via 21F.

No additional fuel is supplied to the intake passages 2 of A2, A3*A4.

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'',
During operation, the engine speed increases sufficiently because the throttle valve 9 is opened at a high opening and the load is relatively small, and the engine speed is maintained at 5000 PPM or more. The rotation speed range is set to 20.
Since it is outside the range of 00 RpH to 5000 RPM, no control signal for driving is outputted from the control circuit 33 to the control valve 23.

Therefore, as described above, the control valve 23 keeps the fuel increase passage 21 closed. That is, in the normal operating state of one engine, which is the low opening operation of the throttle valve 9, the medium opening operation, and the high opening medium speed operation of the throttle valve 9, and the high opening high speed operation 1 o'clock, the fuel increase passage 21 is Since the fuel increase passage 21 is kept closed and is in communication with the return passage 22, the fuel increase passage 21 is connected to each carburetor A+, A2, A3.
, A4 fuel increase distribution path 21G, 210, 21E
, 21F, no additional fuel is supplied through the main jet 1B, needle jet 1 as a fuel system, which the carburetor normally has.
4. Fuel is sucked out into the intake passage 2 through the jet needle 13 or the bypass hole, pipe 0-, and doorlet hole (both not shown) as a low-speed fuel system, thereby satisfying the engine operation.

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 when operating the throttle valve 9 at a high opening, from 2000 PPM to 500 OR.
It is within the PM rotation speed range. The opening state of the throttle valve 9 is detected by the throttle valve opening sensor 31, and its output is input to the control circuit 33. On the other hand, the engine rotation speed is detected by the rotation sensor 32, and its output is used for control. It is input to the circuit 33.

When each output from the throttle valve opening sensor 31 and rotation sensor 32 is input to the control circuit 33, the control circuit 33
outputs a control signal for driving the control valve 23 to the control valve 23, and the control valve 23 that receives the control signal
In this case, the movable iron core 30 is attracted to the fixed iron core 29.

According to this, the return valve portion 27 comes into contact with the return valve seat 25 to cut off communication between the return passage 22 and the fuel increase passage 21, and the increase valve portion 26 separates from the increase valve seat 24.
The upstream fuel increasing passage 21A and the downstream fuel increasing passage 21B of the fuel increasing passage 21 are brought into communication.

Therefore, the pressurized fuel pressurized by the fuel increase pump 20 and supplied to the fuel increase passage 21 passes through the increase valve seat 26 into the downstream fuel increase passage 21B without returning from the return passage 22 into the fuel tank T. This fuel flows into the first . Second. Third. Fourth Qi (stop device A +, A
2, A3, Aa) It is immediately injected into the intake passage 2 at each intake, and together with the fuel sucked into the intake passage 2 from the main fuel system in each carburetor, it This can prevent dilution of the air-fuel mixture in each carburetor.

Then, from this fuel increase passage 21 to each intake path via the fuel increase distribution path of each carburetor. The increased amount of fuel is supplied to the interior when the throttle valve 9 is in a high-opening, low-speed operation state where the opening of the throttle valve 9 is 3/4 or more and the engine rotational speed is within the rotational speed range of 200 ORPM to 500QRpHI. This is performed continuously when the opening of the throttle valve 9 becomes 3/4 or less, or when the engine speed is 200 OR.
If either or both of the following conditions are met, the output of the control signal from the control circuit 33 for driving the control valve 23 is stopped, and the control valve 23 returns to its original position. return valve part 2 again.
7 opens the return valve seat 25 and the increase valve part 2B
closes the fuel increase valve seat 24, which causes the fuel increase passage 2 to close.
1. Fuel increase distribution path 21C, 210, 21E, 21
This is to stop the supply of fuel from F to the intake passages 2 of each carburetor AI, A2 + A3, and A4.

The second condition is an acceleration operation in which the throttle valve 9 is rapidly opened from a low opening to a high opening, the throttle valve 9 is in a low opening state, and the engine is in a low speed operating state. From this state, the driver quickly opens the throttle valve 9 to a high opening state by pulling the accelerator wire, and performs accelerated operation.Here, when the throttle valve 9 is rapidly opened from a low opening state to a high opening state. Looking at the behavior of fuel supply to the intake passage 2 at , the behavior is as follows.

When the throttle valve 9 is held at a low opening, the engine speed is kept at idling speed (for example, 1200 RPM) or at a low speed. As the negative pressure in the intake passage increases, 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 outleft hole, and the engine is operated at a low opening and at a 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 is increased at once. The negative pressure at the tip of the needle jet 14 opening into the path 2 temporarily increases. According to this, the fuel stored in the acceleration well W is sucked out into the intake passage 2 through the mixing nozzle 15 and the engine 14, thereby increasing the rotational speed of the engine. In this state, the fuel in the acceleration well W is sucked out into the intake passage 2 through the needle jet 14 without being restricted by the main jet te, and has already been stored in the wake of the main jet 1B. This is because they are in a state where they are 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 above 50 QORPM. 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 l5 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 such a situation, in the present invention, 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 200 ORPM to 500 ORPM. The outputs of the sensor 31 and the rotation sensor 32 are input to the control circuit 33, and the control circuit 33 outputs a control signal for driving the control valve 23.

According to this, the return valve part 27 of the valve part (■) of the control valve 23
comes into contact with the return valve seat 25 and closes the return passage 22, and at the same time, the increase valve portion 2B opens the increase valve seat 24, so that the fuel increase passage 21. Fuel increase distribution path 21C, 21D
, 21E, 21F, the fuel pressurized by the fuel increase pump 20 is supplied to each vaporizer A t *A2, A3A,
This is injected into the air intake path z of the engine to prevent dilution of the air-fuel mixture and assist in increasing rotation during acceleration. When the engine speed exceeds 500 ORPM, the output of the control signal from the control circuit 33 to the control valve 23 is stopped, the return valve section 27 opens the return valve seat 25, and the increase valve section 2B opens the increase valve seat. 24, the fuel increase passage 21, fuel increase distribution passages 21C, 21D, 21E,
The fuel supply from 21F to each intake passage 2 is cut off, but since the engine speed has risen sufficiently to over 500 ORPM, there is a large intake passage load on the needle jet 14 as the main fuel system. Since pressure acts on the throttle valve 9
Fuel suitable for high-opening operation can be sucked into the intake passage 2 from the needle jet 14.

Incidentally, this fuel increase passage 21. Fuel increase distribution path 21C,
From 21D, 21E, and 21F, the amount of increased fuel injected into the intake passage 2 is determined by setting work with the engine, but for example, with a single carburetor, a small amount of fuel of about 5 cc/min can be used. For this reason, a control jet 34 having a passage diameter smaller than the effective passage diameter of the fuel increase passage 21 is disposed in the downstream side fuel increase passage 21B on the downstream side of the control valve 23 (on the side discharging to the intake passage 2). The fuel increase passage 21 is controlled by the control jet 34 . Fuel increase distribution path 21C, 210,
By controlling the amount of fuel injected into each intake passage z from 21E and 21F, it becomes easy to accurately control the increased amount of fuel suitable for high opening, low speed operation, and acceleration operation.

In addition, each fuel increase distribution path 2IC, 21D, 21E
, 21F has fuel increase distribution paths 21C, 21D, 21
E, distribution path control jets 71A, 71B, ? having a passage diameter smaller than the effective passage diameter of 21F? IC,
71D, the fuel increase distribution path 2IC, 210
, 21E, and 21F to the intake passage 2 of each carburetor, it is possible to control the amount of injected fuel more accurately than when the control jet 34 is arranged in the fuel increase passage 21. Among them, it is possible to change the passage diameter of the distribution path control jets 71A, 718, 7IC, and 71D for each carburetor, and when the cooling between cylinders is different, etc. When it becomes necessary to change the solubility of the air-fuel mixture for each vaporizer constituting the multiple vaporizer, the distribution path control jets 71A and 71B
, ? The requirements of the engine can be met by optimally selecting the passage diameters of the IC and 71D.

In addition, fuel increase distribution paths 2IC, 21D, 21E,
When the other end of 21F is opened to each intake passage 2 to the intake passage 2A on the engine side from the throttle valve 9 and the intake pipe (not shown) that connects the carburetor and the engine, it opens to the engine and the fuel supply. The distance between the engine and the engine is shortened, there is no collision of increased fuel with the throttle valve, throttle valve shaft, jet needle, etc., and additional fuel can be supplied to the engine in an extremely short period of time. This can further improve the performance of the engine.

Additionally, if a foreign object gets caught between the increase valve portion 26 and the increase valve seat 24 of the control valve 23, fuel will not continue to be supplied from the fuel increase passage 21 into the intake passage 2 while the engine is operating. However, the fuel increase passage 21 and the fuel increase distribution passage 2
A leak passage 40 connected to the fuel tank T is branched from 1G, 21D, 21E, and 21F, and a normally closed on-off valve 41 is arranged in the leak passage 40, and if the on-off valve 41 is opened under such a situation, the amount of fuel can be increased. Passage 21, fuel increase distribution path 21G, 210, 21E,
Is the fuel for increasing the amount that can be used on 21F in each intake duct? The fuel was not supplied into the fuel tank T and was able to flow out into the fuel tank T. In particular, the effective passage diameter of the leak passage 40 is changed to that of the fuel increase passage 21. Fuel increase distribution path 21C, 210
, 21E, and 21F, the fuel in the fuel increase passage 21 can be reliably and immediately extracted. Note that the on-off valve 41 is not limited to a solenoid valve, but may be a zero manual valve.

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 into an acceleration pump chamber 52 and an atmospheric chamber 53, and one end of the acceleration pump chamber 52 is connected to the inside of the float chamber 5, and a suction side check valve 54 is arranged inside. Acceleration fuel intake path 55 and acceleration fuel discharge path 5B
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 the pump lever 59.

Further, acceleration nozzles 80A, 80B, 60C, which open to the intake path 2 of each carburetor, are provided in the acceleration fuel discharge path 56.
Acceleration fuel discharge distribution path 81A connected to 80D, BIB
, 81C, BID will be notified. Furthermore, 62A,
62B, 132C.

820 is an acceleration fuel discharge distribution path 81A, 81B,
These are the discharge side valves located 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 passage 56 to the acceleration fuel discharge distribution passage 131A.
, BIB, 61C, 810 through each vaporizer acceleration nozzle 130A, 60B, 80C, 800
The gas is injected and supplied into the intake passage z of each carburetor. The other end of the fuel increase distribution passage 2IC, 210, 21E, 21F communicating with the fuel increase passage 21 similar to the embodiment shown in FIG. 1 is connected to the discharge side check valve 82A, 82B of each carburetor.

62C, 82D and acceleration nozzles 80A, 80B,
Each acceleration fuel discharge distribution path etA between 80C and flOD
, 1318, BtC, 81D.

According to this structure, the fuel increase distribution path 21C from the fuel increase passage 21 during high opening low speed operation and acceleration operation,
The increased amount of fuel is supplied to each carburetor via 210, 21E, and 21F in the same manner as in the first embodiment, but during acceleration operation, especially at the beginning of acceleration, the fuel is supplied from the acceleration well W. In addition, since the accelerating fuel from the accelerator 50 could also be supplied, the start-up of rotation at the beginning of acceleration could be done even more smoothly, and in addition, with conventional accelerators, a lot of time was spent on setting. The injection time of acceleration fuel is determined by opening the control valve 23 in response to an output signal from the control circuit 33, and controlling the injection time of the fuel increase passage 21 and the fuel increase distribution passage 21.
C, 21D, 21E, 21F, acceleration fuel discharge distribution passages 61A, GIB, 81C, 1lllD that open into each intake passage 2 from acceleration nozzles [lOA, 130
Since fuel was supplied to B, 80G, and 800, 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 21C, 210, 21E, 2
In particular, the other end of 1F is connected to the discharge side check valves 82A, 82B,
82C, 82D and acceleration nozzle 1liOA, 80B
, 80C, 800, each acceleration fuel discharge distribution path 8
1A, IIIB, 81C, and 81D, each discharge side check valve 82A, 82B,
A fuel increase passage 21, a fuel increase distribution passage 2IC, 21D, 21E, 21F are used for the pressing load of each check valve spring that presses 82C and 82D against each discharge valve seat.

The fuel pressure flowing therein is not subject to any restrictions.

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

When the fuel increase distribution passages 21C, 210, 21E, and 21F are opened in the acceleration fuel discharge passage 56 on the acceleration pump chamber 52 side from 82D, the fuel increase distribution passage 21, the fuel increase distribution passage 21
c.

21D, 21E, 21F, the acceleration fuel discharge distribution path GIA, 81B, unless the pressure of the fuel flowing therein is greater than the pressing load of the check valve spring.
81C.

It is not possible to supply additional fuel via 810, and it is necessary to further increase the discharge pressure of the fuel pump P.

Furthermore, the openings of the fuel increase distribution passages 21C, 210, 21E, and 21F that open to each intake passage 2 of each carburetor body 1 are drilled within a limited carburetor structure, so there is less freedom in design. Although few, acceleration fuel discharge distribution passages 81A, 81B, 81C, 8 are connected to the already drilled acceleration nozzles BOA, 80B, 80C, 800.
According to the use of 1D, the fuel increase distribution path 21C, 2
It becomes easy to route 1D, 21E, and 21F.

〔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. # actively fuel without! ! It is possible to prevent dilution of the mixture in each carburetor by supplying pressurized fuel from the fuel increaser pump to each carburetor from the volume passage, and this is especially useful when increasing output using multiple carburetors. This made it possible to significantly improve engine performance.

■When there is no need to supply additional fuel from the fuel increaser into the intake passage, the fuel flowing into the fuel increase passage returns to the fuel tank via the return passage, which increases the engine atmosphere temperature and increases the fuel consumption. Even if paper occurs in the fuel increase passage, the vapor can be discharged into the fuel tank, making it difficult for paper lock to occur.

■The fuel to be increased into the fuel increase passage is not dependent on the fuel pressure from the fuel tank or the discharge pressure from the fuel pump, but is based on the discharge pressure of the specially provided fuel increase pump, so the fuel increase passage and fuel increase distribution This allows the injection pressure of the increased amount of fuel from the road into the intake tract to be freely set, and in particular it is possible to set it to the high pressure side. According to this, it is possible to improve fuel atomization and supply speed. I was able to do that.

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

■By arranging a control jet with a smaller diameter than the effective diameter of the fuel increase passage in the fuel increase passage, it is possible to perform minute fuel control and is suitable for high throttle valve opening, low speed operation, and acceleration operation. The desired control jet can be easily selected.

- By opening the other end of each fuel increase distribution path into the intake path on the side of the engine from the throttle valve, fuel can be instantly supplied to the engine, thereby improving the dynamic characteristics of the engine.

■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 in the fuel increase passage can be removed when it is not needed. Moreover, if the effective passage diameter of the leak passage is made larger than the effective passage diameter of the fuel increase passage, the supply of increased fuel from the fuel increase passage can be stopped instantaneously.

■If the other end of each fuel increase distribution path is opened to each acceleration fuel discharge path between each discharge side check valve and each acceleration nozzle of the accelerator, especially during the initial, middle, and final stages of acceleration. In addition to supplying fuel from the accelerator, pressurized fuel can be supplied from the fuel increase passage, and by using the already provided acceleration fuel discharge passage, it is easy to route the passage. Since the discharge pressure of the fuel increase pump is not equally affected by the closing force of the discharge control valve, the discharge pressure can be easily set.

[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 duct 5... Float chamber 6...
・/<Lubesheet 9. , , Throttle valve 17 , , Fuel inflow path 20. ,,,Fuel increase pump 21,,,Fuel increase passage 22. ,,, return passage 210, 210
．． 21E, 21F, ..., Fuel increase distribution path 23, ...
Control valve 31, Throttle valve opening sensor 32, Rotation sensor 33. ,,,control circuit 34
, , control jet 40 , , leak passage 41. ,,, on-off valve 50,
, , Accelerator 5B, , Acceleration fuel discharge passages 60A, 130B, 80C:, +300. ,, acceleration nozzles 131A, 81B, 131C, BID, , acceleration fuel discharge distribution passages 82A, 82B, 82C, 820, , discharge side check valves 71A, 71B, 710, 710. ,,Distribution path control jet T,,,Fuel tank p,,,Fuel pump W,,,Acceleration well A10. First vaporizer A20. Second vaporizer A31. Third vaporizer A41
．． 4th vaporizer

Claims (7)

[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 that opens into the float chamber of each carburetor that constitutes the multiple carburetor; A fuel increase pump that discharges via the discharge passage; A fuel increase passage that is connected to the discharge passage of the fuel increase pump; A return passage that branches from the fuel increase passage and is connected to the fuel tank; Detects the opening degree of the throttle valve. When the fuel increase passage is opened, communication between the fuel increase passage and the return passage is cut off by a control signal from a control circuit that receives the output of the throttle valve opening sensor and the output of the rotation sensor that detects the engine rotation speed. , one end communicating with the fuel increase passage and the return passage when the fuel increase passage is blocked; one end connected to the downstream fuel increase passage divided by the control valve disposed in the fuel increase passage, and the other end connected to the intake pipe a fuel increase distribution path connected to the intake path of each carburetor constituting a multiple carburetor including; The signal operates the control valve, opens the fuel increase passage and cuts off communication between the fuel increase passage and the return passage, and prevents the control circuit from operating when the opening of the throttle valve is below a certain degree and outside the constant rotation speed range of the engine. A fuel increase device for a multiple carburetor which operates a control valve in response to a control signal to close a fuel increase passage and communicate the fuel increase passage with a return passage. (2) The 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 downstream fuel increase passage downstream of the control valve. fuel increase device. (3) The other end of each fuel increase distribution path is opened to an intake path including an intake pipe on the engine side from the throttle valve.
A fuel increasing device for a multiple carburetor as described in . (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) In response to the rapid opening operation of the throttle valve at the other end of each fuel increase distribution path, the acceleration fuel in the acceleration pump chamber is transferred from each acceleration fuel discharge distribution path equipped with a discharge side check valve inside to each acceleration nozzle. The accelerating fuel discharge distribution path between the discharge side check valve and the accelerating nozzle of the accelerating device that injects the fuel into the intake passage of each of the multiple carburetors constituting the multiple carburetor through the accelerating device. A fuel increasing device for a multiple carburetor according to scope 1.