JPS58110839A - Fuel supply device for engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a fuel supply device for an engine.

In particular, the present invention relates to an engine fuel supply device in which fuel supply can be electronically controlled.

Generally, when a mixture is supplied to each cylinder of a multi-cylinder engine through a hemanifold, it is necessary to sufficiently atomize the fuel in order to equalize the air-fuel ratio in each cylinder.

Therefore, in conventional engine fuel supply devices, various studies have been made, such as increasing the fuel pressure and injecting the fuel from minute holes, but there is still a problem that atomization of the fuel is insufficient.

Furthermore, increasing the fuel pressure requires an expensive high-pressure fuel pump and also requires safety considerations.

The present invention aims to solve these problems, and provides an engine that is capable of achieving sufficient fuel atomization even at low fuel pressures, and that is also capable of achieving an optimal air-fuel ratio depending on the operating conditions of the engine. The purpose is to provide a fuel supply device for

Therefore, the engine fuel supply device of the present invention includes a variable venturi that can maintain a constant flow velocity in the venturi section of the engine intake system, and a fuel supply passage that can supply fuel having a predetermined pressure into the engine intake system. In addition, the amount of fuel (f
an air-fuel ratio adjustment mechanism that adjusts the air-fuel ratio by adjusting the fuel flowrate), and a control means that outputs an air-fuel ratio adjustment control signal according to the operating state of the engine is connected to the air-fuel ratio adjustment mechanism. It is characterized by

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
1 to 11 show a fuel supply system for an engine as a first embodiment.
FIG. 3 is an explanatory diagram showing details of the fuel supply section, FIG. 4 is an output characteristic diagram to explain its operation, and FIG. 5 is a graph showing an example of engine rotation fluctuation. Fig. 6 is a fuel consumption-air-fuel ratio characteristic diagram, Fig. 7 is a block diagram including other control means, Fig. 8 is a partial sectional view showing a modification of the fuel injection section, and Fig. 9 is a fuel injection diagram. FIG. 10 is a partial sectional view showing another modification of the section.
11 is a partial sectional view showing still another modification of the fuel injection section. .

As shown in FIGS. 1 and 2, a rotation speed detection section (rotation speed sensor) 1 for detecting the rotation speed N of the engine E is provided.

Further, a throttle opening degree detection section (throttle opening degree sensor) 2;)'-- serving as a load detection section is provided, so that the load state of the engine E can be detected based on the throttle valve 250 opening degree .theta.

Furthermore, an oxygen concentration detection section (027 sensor) 4 is provided that detects the oxygen concentration in the exhaust gas in the exhaust passage 3 of the engine E to detect air-fuel ratio information, and the temperature of the engine E (for example, the cooling water temperature TW). A temperature detection section (temperature sensor) 5 is provided to detect the lubricating oil temperature.

Also, a rotational fluctuation detection unit (ΔN sensor) that receives a signal from the rotational speed sensor 1 and detects a rotational fluctuation ΔN of the engine E.
6 is provided.

Further, an acceleration detection section (acceleration sensor) 7 is provided which receives a signal from the throttle opening sensor 2 and detects acceleration dθ/di (including deceleration). It is configured as a differentiation circuit that differentiates and outputs the signal from 2.

Furthermore, as shown in FIGS. 1 and 3, a fuel supply section 9 that can supply fuel to the intake system (intake passage) 8 of the engine E is provided, and in this embodiment, this fuel supply section 9 is a third
It is constructed as a capretor equipped with a variable venturi 10 as shown in the figure.

That is, as shown in FIG. 3, a differential pressure responsive motor 11 is attached to the outer wall of the venturi portion of the carburetor. chamber 13
The diaphragm 12 is displaced by the differential pressure caused by the atmospheric pressure acting on the chamber 14 and the pressure (negative pressure) in the intake passage 8 acting on the other chamber 14, and the biasing force of the spring 15 in the chamber 14. However, a movable portion 16 is attached to the diaphragm 12. The movable portion 16 protrudes or retracts toward the intake passage 8 as the diaphragm 12 is displaced.

A space 16a with a vent opening into the intake passage 8 is formed in the movable part 16. and a check valve 17 that allows.

The diaphragm 12 communicates with the chamber 14 via an orifice 18 provided in parallel with the check valve 17 .

Further, the chamber 13 communicates with the atmosphere via a passage 19.

In this way, the movable part 16
is displaced to form the variable venturi 10, and the manner in which the movable portion 16 is displaced at this time is adjusted so that the gas flow rate passing through the venturi 10 is always approximately constant.

Note that a podensiometer used for feedback controlling the position of the variable venturi 10 may be attached to the motor 11.

By the way, on the venturi wall facing the movable part 16,
A nozzle opening 20 is formed so that fuel can be injected from a direction substantially perpendicular to the airflow flowing through the intake passage 8, and a fuel supply passage 22 is connected to the nozzle opening 20 in communication.

Further, the nozzle opening 20 is provided with a self-excited vibration valve 24 .

Furthermore, a fuel pump 2I is interposed in the fuel supply passage 22, and this pumps the fuel tank T through the fuel supply passage 22 from the nozzle opening 20 into the intake passage 8 at a predetermined pressure (sometimes higher than atmospheric pressure). pressure) can be supplied.

In addition, the fuel supply passage 22 communicating with the nozzle opening 20 includes
A duty control type solenoid valve (electromagnetic valve) 23 that constitutes the air-fuel ratio adjustment mechanism M is interposed.

By the way, as shown in FIGS. 1 and 2, each sensor 1, 2 .
A control means 28 is provided which outputs an air-fuel ratio adjustment control signal according to the operating state of the engine E based on the signals from the engines 4 to 7.

This control means 28, as shown in FIG.
, interface 35 for solenoid valve 23, first to
The first to third ROMs 36 to 38 serve as the third read memory (Read Memory), and the first to third read/write memories (Read/Write Memo)
ry) and a CPU 42 as a processor section.

In addition, each interface 29 to 35 and each ROM 36 to
38 and each RAM 39 to 41 are connected to the CPU 42 and I10.
They are connected by bus 43.

The input interfaces 29 to 34 differ depending on the type of sensor, but if the sensor is an analog signal detection type, the interface used is a combination of an A/D converter and a serial/parallel converter. If the sensor is of a digital signal detection type, a serial/parallel converter or the like is used as an interface.

In addition, since the output interface 35 supplies a serial pulse train signal to the duty-controlled solenoid valve 23, the output interface 35 is connected to
A parallel/serial converter or the like is used to convert parallel data from 3 into a serial signal.

Basically, the first ROM 36 stores a value corresponding to the fuel flow rate according to the engine speed N and the throttle opening θ as the engine load state [this value is actually the valve opening time T of one duty control (ms)] It has been converted to . ] This is a read-only memory that stores the data T in the form of a matrix map.The data T stored in this first ROM 36 will be the pace of fuel control from then on, so this data T can be used as pace data or pace map. That's what it means.

The second ROM 37 is a read-only memory that stores the correction coefficient value K (dθ/d t ) corresponding to the acceleration (dθ/d t ), and the third ROM 3B stores the engine temperature (cooling water temperature) TW. Correction coefficient value K (TW) according to
This is a read-only memory that stores .

The first RAM 39 is configured so that the fuel flow rate becomes the stoichiometric air-fuel ratio in a preset operating range such as the low-speed, low-load operating range as shown by reference numeral A in FIG.
Correction coefficient value KA (θ
, N) is a readable and writable memory that can store data in the form of a map of IJ racks.

The second RAM 40 is used for operating in other operating ranges different from the operating range A, such as high-speed operating ranges and high-output operating ranges as indicated by symbols B and C in FIG.

Correction coefficient value K to be stored in the first RAM 3 C1
.

Based on (θ, N), the first RO is
Correction coefficient value KC (for correcting the signal from M36)
This is a readable and writable memory that can store data (θ, N) in a STOCK type map.

Generally, in a multi-cylinder engine E, the explosion timing differs for each cylinder, so the engine speed N constantly fluctuates as shown in Figure 5. Then, a misfire occurs in the cylinder, and as shown by the symbol, large irregularities in the rotational speed N (specifically, a significant decrease in the rotational speed N) occur due to this misfire. By causing a misfire in this way, the fuel consumption becomes worse (as shown by the symbol E in Fig. 6).
Become.

Therefore, the mixture should be made lean to the extent that misfire does not occur, but the correction coefficient value KB (θ, N) for this purpose is the third
It is stored in the RAM 41 in a matrix-type map.

Specifically, the number of times a misfire occurs within a predetermined period of time (this corresponds to the number of times the rotational fluctuation ΔN exceeds a predetermined value ΔNs (this value is allowed to have a predetermined width)). ] Calculate and determine the correction coefficient value Kl (θ, N) that gives a certain value n (this value is also allowed to have a predetermined range), or A correction coefficient KB (θ, N) is calculated and determined so that the value ΔN1 becomes a certain value ΔN1.

The CPU 42 controls the timing of extracting signals from each sensor 1, 2, 4 to 6 via the interfaces 29 to 34 and the 10 bus 43, and
The solenoid valves 23a to 23c control the reading of data in the M36 to 38 via the I10 bus 43, control the writing and reading of data to the first to third RAMs 39 to 41 via the I10 bus 43, control the signal output to the I10 bus 43 and the interface 35, read out data from the ROMs 36 to 38 and RAMs 39 to 41 based on the signals from each sensor 1, 2° 4 to 6, and perform appropriate arithmetic processing. This is the main control unit that can perform the following functions.

Next, a specific example of air-fuel ratio control by this control means 28 will be explained.

In response to the signals from the first rotation speed sensor and the throttle opening sensor 2, pace data T is read from the corresponding address in the first ROM 36, and from this data T, the CPU 42 determines whether the engine E is currently running. What kind of operating region is it in? (Specifically, the operating region is marked A in Fig. 4.
It is determined in which region, B or C).

Then, the CPU 42 controls the ROMs 36 to 38 and the RAM so that the air-fuel ratio is appropriate according to the operating range A to C.
Data is read from 39 to 41 and the output (air-fuel ratio adjustment control signal) TD to the solenoid valve 23 is easily calculated.

Here, in operating region A (low speed, low load operating region), it is desirable to operate at a stoichiometric air-fuel ratio mainly from the viewpoint of exhaust gas purification, and in operating region B (high speed operating region), it is desirable to operate at a stoichiometric air-fuel ratio, mainly from the viewpoint of reducing fuel consumption. It is desirable to operate with a lean air-fuel mixture with an air-fuel ratio of about 18, and in operating region C (high-output operating region), the air-fuel ratio should be about 11 to 13, mainly from the viewpoint of improving output and preventing burnout of spark plugs, etc. It is desirable to operate with a rich mixture.

Therefore, in this example, the CPU 42 calculates the following output TD according to the operating ranges A to C.

First, in driving region -8, T, = T, · KA (θ, N) fist K (TW) · K (dθ
/dt) tll is performed and 1. Driving area B
Then, TD−TlllIKll(θ, N) −K('r
w) −K(dθ/d t ) 12+ calculation is performed, and in operating region C, TD=T, ・Kc(θ, N
)−K(Tw)−K(dθ/dt)+31 is performed.

In the above formula, T is the data in the first ROM 36.

K (dθ/d t ) is the data in the second ROM 37, K
(T, ) is data in the third ROM 38.

KA (θ, N) is the data in the first RAM 39, Kc
(θ, N) is the data in the second RAM 40, K, (θ
.

N) is data in the third RAM 41.

Note that T, , K(dθ/d t ), and K(Tw) are fixed data written in advance in the ROM, but KA
(θ, N) IKm (θ, N), Kc (θ, N)
is data written into each RAM after being calculated by the CPU 42 to an appropriate value according to the operating state. Therefore K
A(θ, N), Kl(θ, N) and IKc(θ, N) are rewritten at predetermined intervals depending on the operating state.

Further, in FIG. 4, the characteristic indicated by the symbol θ□ is the output characteristic when the throttle opening is θ.

In this way, an appropriate output To is outputted to the LUID valve 23 as an air-fuel ratio adjustment control signal according to each operating range A to C, but it is also in an accelerated operating state (including a decelerated operating state).
As can be seen from the above equations +11 to +131, the output TD should be different between the acceleration operation state and the constant speed operation state, but the cases of the acceleration operation state and the constant speed operation state will be briefly explained.

First, in the case of accelerated driving, the driving conditions change rapidly, so it is necessary to read and process data from memory with extremely high responsiveness. The value is fixed to 1 (for example, 1) and arithmetic processing is quickly performed.

That is, the fixed data Tll corresponding to the output is the first RO
As well as being read out immediately from M36.

The fixed data K (dθ/d t ) corresponding to the acceleration is the second
It is quickly read out from the ROM 37, immediately subjected to signal processing, and output. This is the same in any operating range A to C. At this time, temperature data K ('rw) from the third ROM 38 is also used, but other data KA (θ, N), Kl (θ, N).

Kc (θ, N) is fixed at an appropriate value as described above.

As a result, even in such an accelerated driving state, fine-grained and responsive fuel control, that is, air-fuel ratio control, can be performed.

Furthermore, in the case of constant speed operation, there is little or only a gradual change in the operating condition, so that the writing and reading of data to and from the writable and readable memo IJ-(RAM) is appropriately performed. In addition, in the case of ideal constant speed operation, there is a possibility that the acceleration becomes zero and the output TD becomes zero, so in such a case, set an appropriate value (for example, 1
) in the second ROM 37 so that the correction coefficient value K(
dθ/dz) is set.

By the way, the lRO is adjusted so that the fuel flow rate becomes the stoichiometric air-fuel ratio.
Correction coefficient value KA (θ
. However, the calculation of the correction coefficient KC (θ, N) for correcting the signal from the first ROM 36 to obtain a different air-fuel ratio takes more time than the above calculation.

Therefore, 1. For example, in operating region C, 4 rotations per 20 revolutions.
~5 rotations, the first R is based on the signal from the 02 sensor 4.
Correction coefficient value Ka(θ, N) to be stored in AM 39
(This value is 1, which can be obtained instantaneously) is used to adjust the signal T from the first ROM' 36 so that the stoichiometric air-fuel ratio is achieved.
, and during these 4 to 5 rotations, the above correction coefficient KA (
θ, N), the first ROM3
Correction coefficient value K for correcting signal TI from 6. (θ
. Based on the signal, the above correction coefficient value Kc(θ, N)
using the first ROM 36 to create a rich mixture.
A correction is made to the signal T from .

In addition, regarding the operating region B, similarly, several times (for example, 4 to 5 rotations) out of a predetermined number of rotations (for example, 20 rotations) are operated at the stoichiometric air-fuel ratio.

The remaining times (eg 15-16 revolutions) are operated with a lean mixture.

Also, in the constant speed driving state in driving region B.

In order to improve fuel efficiency, it is preferable to operate with a mixture as lean as possible without causing a misfire, but for this reason ΔN
According to the signal from the sensor 6, the CPU 42 calculates a correction coefficient value KS (θ, N) that can achieve the optimal lean mixture as described above, and the correction coefficient value obtained in this way is used. The numerical value K11 (θ, N) is written into the third RAM 41, and then read out from the third RAM 41 and used for calculating the output TD.

In this case, the correction coefficient value Ka is adjusted so that the air-fuel ratio is gradually increased until the number of misfires occurs reaches a predetermined value n.
(θ+N) is updated in the third RAM 41,
The correction coefficient value K11 (θ, N) is updated until the number of misfires finally reaches a predetermined value n.

Furthermore, the output TD is also corrected according to the engine temperature TW, and the correction coefficient value K(Tw
) is, for example, K(TW
L) K (TWM) and 50 for 10-50°C
If the temperature is above ℃, it is set as K (TwH) and the third
It is stored in ROM 38. The above correction coefficient value K
The way to set (Tlv) is that the lower the engine temperature, the lower the engine temperature.
The mixture is designed to be rich.

In this way, the output TD that has been appropriately processed according to the engine operating state is supplied to the solenoid valve 23 as a control signal for adjusting the air-fuel ratio through the T10 bus 43 and the interface 35 in a form that has been subjected to pulse width modulation, etc. It will be done.

Then, the solenoid valve 23 is subjected to duty control according to the output TD to turn on and off the fuel supply passage 22, so that the flow rate of the fuel supplied from the self-excited vibration valve 24 of the nozzle opening 20 is appropriately controlled. As a result, the engine E is operated at an appropriate air-fuel ratio depending on its operating state.

Note that the reference numeral 44 in FIG. 1 indicates an air cleaner.

Further, the fuel flow rate control means 28' may be configured as shown in FIG. In other words, what is shown in FIG.
~3rd ROM 36-38 is sensor 1.2.5.7
1 to 3 according to these signals.
Fixed data T at the corresponding address in ROM 36-38.

K(dθ/dt) and K(TW) are output, and other functions are almost the same as those of the previous embodiment.

Note that in FIG. 7, the same reference numerals as in FIG. 2 indicate substantially the same parts.

Furthermore, the correction coefficient value KA (θ,
N) Instead of storing lKe(θ, N) and KC(θIN) in RAM, correction coefficient values KA(θ) and KB(θ) are determined according to only θ or only N.

KC (θ); KA (N), K#), Kc
(Nl may be stored in RAM, and the correction coefficient values KA, KB, and Kc as constants are fixed regardless of θ and N.
It may also be stored in AM.

Furthermore, the nozzle opening 20 may be constructed as a single-hole nozzle 26 as shown in FIG.
Similarly, a pipe 27 with a slit 27a as shown in the figure may be inserted to inject fuel from a direction substantially perpendicular to the air flow.

It is also possible to provide a spiral nozzle 45 in the nozzle opening 20 that supplies fuel through a spiral passage 45a as shown in FIG. 11, so that the fuel is injected from a direction substantially perpendicular to the air flow. be.

12 to 14 are explanatory diagrams showing the details of the fuel supply section in the engine fuel supply device as the second to fourth embodiments of the present invention, and the same as those in FIGS. 1 to 11 are shown in FIGS. 12 to 14. Symbols indicate almost similar parts.

In the second embodiment shown in FIG. 12, three parallel passages 46a having different cross-sectional areas are provided in a portion of the fuel supply passage 22 in front of the nozzle opening 2o.

A passage portion 46 consisting of 46b and 46c is formed, and an on/off control type solenoid valve 47a as an air-fuel ratio adjustment mechanism M is provided in each of the parallel passages 46a to 46C.

47b and 47C are installed.

Note that the ratio of the cross-sectional areas of the parallel passages 46a to 46C is, for example, 1.
:2:3, which means that these three passages 4
The on/off state of 6a to 46c is controlled by solenoid valves 478 to 4.
By controlling at 7C, the fuel flow rate can be reduced to at least 6
Can be adjusted in stages.

The on/off control of each of the solenoid valves 47a to 47b is performed by an air-fuel ratio adjustment control signal from the control means 28'' depending on the operating state K of the engine E (see FIG. 4).

Here, the control means 28'' is obtained by replacing the interface 35 of the control means 28.28' with another appropriate interface, for example, as this interface,
A combination of appropriate gate circuits is used to appropriately distribute and supply on/off signals to the solenoid valves 47a to 47C.

Therefore, also in the case of this second embodiment, the engine E can be operated at an appropriate air-fuel ratio depending on its operating state.

In the third embodiment shown in FIG. 13, a pipe 49 with a slit 48 is inserted into the nozzle opening 20, and the pipe 49 is connected to an electromagnetic drive mechanism 50 constituting the air-fuel ratio adjustment mechanism M. The drive control of the pipe 49 is based on the operating state of the engine E from the control means 28'' (
Specifically, this is carried out using air-fuel ratio adjustment control signals corresponding to the operating conditions indicated by symbols A, B, and C in FIG.

Note that the tip of the pipe 49 is connected to the guide portion 16 of the movable portion 16.
b is slidably inserted into the pipe 4.
9 does not move unless the movable part 16 is driven by the drive mechanism 50, even if the movable part 16 moves according to the state of negative pressure in the intake passage 8. That is, the pipe 49 and the movable part 16 are not seen in conjunction with each other.

Further, the slit 48 is formed at a position where fuel can be injected from a direction substantially perpendicular to the airflow flowing in the intake passage 8, and furthermore, the slit cross-sectional area is smaller closer to the movable part 16, and vice versa. The distance from the movable part 16 increases.

Therefore, the amount of fuel injected from the slit 48 increases as the pipe 49 protrudes, and decreases as the pipe 49 retracts.

Furthermore, the control means 28/// control means 28.28'
The interface 35 is replaced with another suitable interface. For example, this interface supplies a continuously changing current signal (including when viewed as an average value) to the coil of the electromagnetic drive mechanism 50. It is conceivable to include a D/A converter that can transmit data.

Therefore, also in the case of this third embodiment, the above-mentioned first and second
As in the embodiment, the engine E can be operated at an appropriate air-fuel ratio depending on its operating state.

The fourth embodiment shown in FIG. 14 has a nozzle opening 20 with an electromagnetic part and a moving mechanism that constitute an air-fuel ratio adjustment mechanism.

51 (This drive mechanism 51 is also equipped with a linear solenoid coil.) A needle valve 52 driven by VC is provided, and the drive control of this needle valve 52 is performed by a control means having almost the same configuration as the control means 28''. 28'', which corresponds to the operating state of the engine E (see FIG. 4).

In the case of this fourth embodiment as well, almost the same effects and advantages as those of the above-mentioned embodiments can be obtained.

Further, in this fourth embodiment, a duty control type solenoid valve 53 is interposed in the fuel supply passage 22 on the fuel tank side of the needle valve 52.
3 is provided to correct the amount of fuel injected through the needle valve 52, for example, in an operating range where a small fuel flow rate is required.

In the case of this fourth embodiment as well, the fuel is injected in a direction substantially perpendicular to the airflow.

Incidentally, in each of the embodiments described above, the nozzle opening 20 can also be provided upstream of the variable venturi 10.

Further, in each of the embodiments described above, the ΔN sensor 6 and the acceleration sensor 7 can be provided independently of the sensors 1 and 2, and the CPU 42 can also have the functions of the ΔN sensor 6 and the acceleration sensor 7.

As detailed above, the engine fuel supply device of the present invention has the advantage that sufficient fuel atomization can be performed even at low fuel pressure by skillfully combining the variable venturi and the electronic control means for fuel supply. In addition to this, it also has the advantage of achieving the optimum air-fuel ratio depending on the operating condition of the engine.

[Brief explanation of drawings]

1 to 11 show a fuel supply system for an engine as a first embodiment of the present invention, and FIG. 1 is an overall configuration diagram thereof;
FIG. 2 is a block diagram thereof, FIG. 3 is an explanatory diagram showing details of its fuel supply section, and FIG. 4 is an output characteristic diagram for explaining its operation. Fig. 5 is a graph showing an example of engine speed fluctuation, Fig. 6 is a fuel consumption-air-fuel ratio characteristic diagram, Fig. 7 is a block diagram including other control means, and Fig. 8 is a modification of the fuel injection section. FIG. 9 is a partial sectional view showing another modification of the fuel injection part, FIG. 1θ is a sectional view taken along the line X-X in FIG. 9, and FIG. FIGS. 12 to 14 are explanatory diagrams showing details of the fuel supply section in the engine fuel supply apparatus as second to fourth embodiments of the present invention, respectively. FIG. 1. Rotation speed sensor, 2. Throttle opening sensor as load detection section, 3. Exhaust passage, 4. 02 sensor as oxygen concentration detection section, 5. Temperature sensor, 6. Rotation fluctuation detection ΔN sensor as part, 7... acceleration sensor,
8... Intake passage as engine intake system, 9... Fuel supply section, 10... Variable pentu IJ, 11... Differential pressure responsive venturi! 2.Diaphragm, 13.14.-Channo ξ 15.φ spring, 16.Movable part, t6a.
Space, 16b--Guide part, 17--Check valve,
18... Orifice, 19... Passage, 20... Φ nozzle opening. 21...Fuel pump, 22...Fuel supply passage, 23...
Solenoid valve, 24...Self-excited vibration valve. 25...throttle valve, 26...single hole nozzle, 27 fist...
Vibrator, 27a...slit, 28°2B', 2 gigs,
28", 28"...control means, 29-35...interface, 36-38--first to third ROMs as first to third read memories, 39-41...first to third glue 1st to 3rd RAM as read/write memory
, 42 CPU as a processor section, 43...11
077% 44--Air cleaner, 45...Spiral nozzle, 45a...Spiral passage, 46...Passway portion, 46a~
46c... Parallel passage. 47a-47c...Solenoid valve, 48...Slit,
49...pipe, 50.51--electromagnetic drive mechanism, 52
...Needle valve, 53..Solenoid valve, E..Engine, M..Air-fuel ratio adjustment mechanism, T..Fuel tank. Sub-Agent Patent Attorney Yoshi Iinuma Sangyo 1 Figure 4 Figure 3 Figure 4 Figure 13 Figure 25 Figure 14 Figure 5

Claims (1)

[Claims] A variable venturi that can maintain a constant flow velocity in a venturi section of an engine intake system, and a fuel supply passage that can supply fuel having a predetermined pressure into the engine intake system, the fuel supply passage being connected to the fuel supply passage. An air-fuel ratio adjustment mechanism is provided that adjusts the air-fuel ratio by adjusting the amount of fuel flowing, and a control means is connected to the air-fuel ratio adjustment mechanism that outputs a control signal for adjusting the air-fuel ratio according to the operating state of the engine. A fuel supply device for an engine, characterized in that: