JPH0119065B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel control device that controls the amount of fuel using an electronic control device.

A hot wire sensor is installed in the bypass air passage that quickly circulates through the intake passage, and by feeding back the output of this hot wire sensor, the amount of air flowing through the bypass passage is controlled to be approximately constant by an air regulating valve, and the fuel The present applicant has already developed a fuel control device and its correction device that control the amount of air by an electromagnetic device that drives the above-mentioned air regulating valve. No. Japanese Patent Application No. 188497 Japanese Patent Application No. 188498 Patent Application No. 188499 Patent Application No. 1884500 Patent Application No. 188501 Patent Application No. 188502 Patent Application No. 188644 It is proposed as.

These proposed fuel control devices had the disadvantage of poor acceleration characteristics. In other words, when the throttle valve is suddenly opened by pressing the access pedal, the amount of intake air increases rapidly, but because the control of the fuel metering valve is delayed, the amount of fuel cannot be rapidly increased. For this reason, there is a problem in that the air-fuel ratio temporarily becomes lean during sudden acceleration, and the output torque of the engine decreases.

The object of the present invention is to provide a device that improves the above-mentioned drawbacks, that is, a fuel control device that has excellent acceleration characteristics.

A feature of the present invention is to provide a fuel control device having the following configuration.

a bench lily portion formed in an intake passage that supplies air to the engine; a throttle valve provided in the intake passage downstream of the bench lily portion; a bypass air passage connecting the upstream of the bench lily portion and the bench lily portion; and the bypass air passage. A hot wire sensor detects the amount of air flowing through the passage, an air metering valve controls the amount of air flowing through the bypass air passage, and an outlet is provided between the bench lily portion and the throttle valve to collect fuel from the fuel pump. The air metering valve includes a fuel passage leading to the outlet, a fuel metering valve provided in the fuel passage and controlling the flow rate of fuel flowing through the fuel passage, and the air metering valve and the fuel metering valve provided at both ends thereof. a proportional electromagnetic device that displaces the fuel metering valve in a direction to increase the amount of fuel when the amount of air flowing through the bypass air passage is displaced in a direction to decrease the amount of air flowing through the bypass air passage; The air metering valve is controlled so that the amount of air flowing is substantially constant, and the auxiliary throttle valve is opened by the dynamic pressure of the air flow flowing through the intake passage through a notch near the outlet of the fuel passage; A fuel injection part fixed to a side surface of the intake passage located in the notch and having a small bench lily part, and a nozzle opening in the small bench lily part are further provided, and the fuel in the fuel passage is supplied from the fuel passage outlet to the nozzle. A fuel control device characterized in that the fuel is supplied to the intake passage through the small bench lily section.

By providing the auxiliary throttle valve in the above configuration, the air-fuel mixture becomes richer during acceleration, thereby preventing a decrease in engine torque. Its action is as follows.

During sudden acceleration, when the accelerator pedal is depressed, the throttle valve opens and intake air suddenly increases. On the other hand, the auxiliary throttle valve cannot be opened suddenly because of its inertial force. Therefore, the amount of air flowing through the small bench lily increases temporarily, and the negative pressure generated in the small bench lily causes fuel to be sucked out. Therefore, even if the operation of the proportional electromagnetic device is delayed, the amount of fuel supplied increases in accordance with the increase in the amount of air.

In this way, by providing the auxiliary throttle valve and the small bench lily, the present invention eliminates the conventional drawback that during sudden acceleration, the increase in fuel cannot keep up with the increase in air amount and the mixture becomes lean. This has the effect of improving acceleration characteristics.

An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, reference numeral 10 is a main body constituting a fuel supply device, through which an intake passage 12 passes. A throttle valve 14 is rotatably provided in the intake passage 12 in conjunction with an access pedal, and a bench lily portion 16 is further formed upstream of the throttle valve 14 . Upstream of bench lily part 16 and bench lily part 16
The narrowest part of the air passage is communicated with by a bypass air passage 18, and a hot wire sensor 20 is installed in the middle of the bypass air passage 18.
is located. The processing circuit 22 of the hot wire sensor 20 is integrally attached to the main body 10,
The output of this processing circuit 22 is input to a computer 26 which is also fixed to a holding portion 24 formed in the main body 10.

On the other hand, an auxiliary throttle valve 28 is provided in the intake passage 12 between the throttle valve 14 and the bench lily portion 16, and is opened by the dynamic pressure of the airflow. A notch 28A is provided at one end of the auxiliary throttle valve 28, as shown in FIG.
is located. The fuel injection section 30 is comprised of a small bench lily 30A that opens in a direction that matches the air flow direction, and a number of nozzles 30B that open at right angles to the air flow direction. This fuel injection section 30 is communicated with a fuel tank 38 via a fuel passage 32, a fuel pressure regulator 34, and a fuel pump 36. A fuel orifice 40 and a fuel needle valve 42 for adjusting the opening area of the fuel orifice 40 are arranged in the middle of the fuel passage 32 . As shown in the figure, the fuel needle valve 42 has a plurality of flange portions 42A to form a labyrinth. On the other hand, an air orifice 44 and an air needle valve 46 for changing the opening area of the air orifice 44 are provided downstream of the hot wire sensor 20 in the bypass passage 18 . The fuel orifice 40, the fuel needle valve 42, the air orifice 44, and the air needle valve 46 are arranged on the same axis, that is, on the operating line of the air needle valve.
6, a proportional electromagnetic device 48 is also arranged on the same axis. Therefore, the output shafts 48A and 48B of the proportional electromagnetic device drive the fuel needle valve 42 and the air needle valve 46, respectively, where each needle valve 42 and 46 and each output shaft 48A,
48B is configured separately.

The output shaft 48A and the fuel needle valve 42 come into contact with each other due to the pressure of the fuel acting on the flange 42A of the fuel needle valve 42, and the displacement of the output shaft 48A is transmitted to the fuel needle valve 42, while the output shaft 48B and the air needle The valve 46 is abutted by a spring 54 and transmits the displacement of the output shaft 48B to the air needle valve 46. A bellow ram 50 is fixed to the output shaft 48A that drives the fuel needle valve 42, and by fixing the bellow ram 50 to the main body 10, fuel is prevented from leaking outside the main body 10. Furthermore, the air orifice 44 is configured to be movable in the same direction as the displacement direction of the air needle valve 46. That is, the air orifice 44 is fixed to an orifice holder 52, and by rotating the orifice holder 52, the air orifice 44 can be moved in the same direction as the displacement direction of the air needle valve 46. be. A load adjustment screw 56 is provided within the orifice holder 52 to change the set load of a spring 54 that applies a set load to the air needle valve 46.

On the other hand, a fuel return passage 58 is branched from the middle of the fuel passage 32 between the fuel orifice 40 and the fuel injection section 30.
8 communicates with a fuel reservoir 60 formed at the upper part of the fuel needle valve 42 and the fuel surface side of the bellow ram 50, and further communicates with the fuel tank 38 via a fuel return pipe (not shown). Here, the fuel return passage 58 extends in a direction opposite to the direction of gravity, that is, toward the top, and is structured to remove air bubbles generated in the fuel passage 32. A solenoid valve 62 is provided in the middle of the fuel return passage 58, and opens the fuel return passage 58 during deceleration to prevent fuel from being injected from the fuel injection section 30.

The upstream and downstream sides of the throttle valve 14 are connected by a correction air passage 64, and this correction air passage 64
There is a solenoid valve 66 that opens this passage when the cooler is activated.
A starting valve 68 is provided in parallel with the electrode valve 66 and closes this passage from fully open to fully closed in accordance with starting and warm-up operations. This starting valve 68
has a thermowax inside, which operates to reduce the air flowing through the correction air passage 64 as the engine temperature rises.

Further, as shown in FIG. 3, a fuel bypass passage 70 is formed in the fuel passage 32, and a solenoid valve 72 that opens during acceleration is provided in the middle of this fuel bypass passage 70.

Next, the relationship between the signals input to the computer 26 and the output signals will be explained with reference to FIG.

The computer 26 has a hot wire sensor 20.
The signal H/W from H/W and the setting level Ref which is compared with this signal, the signal TH of the throttle valve opening sensor (not shown) for detecting the acceleration state, and the idle opening switch (not shown) for detecting the deceleration state. A signal I〓 of a rotation speed sensor (not shown), a signal N of a rotation speed sensor (not shown), a signal C _ON of a cooler switch that detects cooler operation, etc. are input. It goes without saying that operating parameters of other engines may be input for various other corrections. Next, the output is a proportional electromagnetic device 48, an electromagnetic valve 6 that stops fuel during deceleration.
2. It is sent to a solenoid valve 66 that supplies correction air when the cooler is activated, and to a solenoid valve 72 that increases the amount of fuel when accelerating. Here, the signal sent to the proportional electromagnetic device 48 is a duty pulse signal whose ON time per cycle is controlled, and the signals sent to the other electromagnetic valves are ON or OFF signals. As shown in FIG. 5, the signal sent to the proportional electromagnetic device 48 is such that the signal H/W of the hot wire sensor 20 input to the comparator (including a differential amplifier) 74 converges to the set level Ref. It's a signal. In other words, the signal is such that the proportional electromagnetic device 48 controls the opening area determined by the air needle valve 46 and the air orifice 44 so that the amount of air flowing through the bypass air passage 18 is substantially constant.

Next, the operation of the fuel control device as described above will be explained.

Now, when the engine is operated, air flows through the intake passage 12, and a pressure difference is generated between the bench lily portion 16 and the upstream side of the bench lily portion 16. Therefore, air flows from upstream of the bench lily portion 16 to the bench lily portion 16 via the bypass air passage 18. The hot wire sensor 20 detects the amount of air based on this air flow. By the way, hot wire sensor 20
The signal H/W is at the setting level Ref as shown in Figure 5.
Since the throttle valve 14 is closed and the vent lily negative pressure generated in the vent lily 16 becomes smaller, the value of the signal H/W of the hot wire sensor 20 becomes smaller than the set level Ref (the vent lily The computer 26 causes the amount of air passing through the opening determined by the air needle valve 46 and the air orifice 44 to reach the set level Ref. A duty pulse is applied to the proportional electromagnetic device 48 to move the air needle valve 46 downward in FIG. At this time,
The opening area determined by the fuel needle valve 42 and the fuel orifice 40 is changed to a value that reduces the amount of fuel by the amount of air taken into the engine when the throttle valve 14 is closed. Of course, the shape of the fuel needle valve 42 is determined so that the air-fuel ratio at this time is close to the stoichiometric air-fuel ratio.

Next, when the throttle valve 14 is opened and the amount of air taken into the engine increases, the negative pressure generated in the vent lily portion 16 increases, and as a result, the amount of air passing through the bypass air passage 18 increases. Therefore, the value of the signal H/W of the hot wire sensor 20 becomes greater than the set level Ref, and the
6 sets the air needle valve 46 to the first position so that the amount of air passing through the opening determined by the air needle valve 46 and the air orifice 44 approaches the set level Ref.
A duty pulse is applied to the proportional electromagnetic device 48 to raise it upward in the figure. At this time, the opening area determined by the fuel needle valve 42 and the fuel orifice 40 is changed to a value that increases the amount of fuel by the amount of air taken into the engine when the throttle valve 14 is opened. Of course, as described above, the shape of the fuel needle valve 42 is selected so that the air-fuel ratio at this time is close to the stoichiometric air-fuel ratio.

By repeating the above steps, bypass air passage 1
By applying feedback so that the amount of air passing through the air valve 8 remains approximately constant using an electromagnetic device that controls the air needle valve, changes in the amount of air taken into the engine are detected and the air needle valve is driven. By controlling the fuel needle valve using an electromagnetic device, the air-fuel ratio of the air-fuel mixture supplied to the engine is controlled to approximately the stoichiometric air-fuel ratio. Note that it is also possible to control the air-fuel ratio to a value other than the stoichiometric air-fuel ratio by changing the value of the set level.

In the embodiment shown in FIG. 1, the throttle valve 14 suddenly opens during sudden acceleration when the accelerator pedal is suddenly depressed, but the auxiliary throttle valve 28 is configured to open due to the dynamic pressure of the intake air as described above. This auxiliary throttle valve 28 cannot be opened suddenly because of its inertial force. Therefore, the amount of air flowing through the small bench lily 30A increases rapidly. Therefore, the negative pressure in this vent lily increases, and the amount of fuel sucked out thereby increases. The increase in the amount of intake air is detected by the hot wire sensor 20 and proportional electromagnetic device 48.
The fuel needle valve 42, which is a fuel metering valve, is further moved in the direction of opening. Although this movement is slightly delayed relative to the increase in air, as described above, the fuel is sucked out using the negative pressure generated in the small bench lily, so that regardless of this delay, the delay in fuel supply can be suppressed. Therefore, during sudden acceleration, the air-fuel mixture becomes lean temporarily, and the problem can be solved when the torque decreases. Furthermore, when the amount of intake air is small, the auxiliary throttle valve 28 is closed, so air flows through the small bench lily, and the flow rate of the small bench lily is extremely high compared to the flow rate of intake air when there is no auxiliary throttle valve 28. Become. Since fuel is supplied to this high velocity air stream, atomization of the fuel is improved.

As described above, the present invention can prevent a temporary lean state of the air-fuel mixture during rapid acceleration, thereby preventing torque shortages and providing a fuel control system with excellent acceleration characteristics.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a fuel control device according to the present invention, FIG. 2 is a cross-sectional view along the line shown in FIG. A block diagram showing input and output, and FIG. 5 is a diagram showing a comparator for comparing a hot wire sensor and a set level. 12... Intake passage, 16... Bench lily part, 1
8... Bypass air passage, 20... Hot wire sensor, 32... Fuel passage, 40... Fuel orifice, 42... Fuel needle valve, 44... Air orifice, 46... Air needle valve, 48... Proportional Electromagnetic device.

Claims (1)

[Claims] 1. A bench lily part 16 formed in the intake passage 12 that supplies air to the engine, a throttle valve 14 provided in the intake passage downstream of the bench lily part, and a bypass air passage 18 connecting the upstream part of the bench lily part and the bench lily part. , a hot wire sensor 20 for detecting the amount of air flowing through the bypass air passage, an air metering valve 46 for controlling the amount of air flowing through the bypass air passage, and an outlet between the bench lily portion and the throttle valve. a fuel passage 32 that guides fuel from the fuel pump 36 to the outlet; a fuel metering valve 42 that is provided in the fuel passage and controls the flow rate of fuel flowing through the fuel passage; Proportional electromagnetic devices 48 are provided at both ends to displace the fuel metering valve in a direction to increase the amount of fuel when the air metering valve is displaced in a direction to decrease the amount of air flowing through the bypass air passage. The air metering valve is controlled so that the amount of air flowing through the bypass air passage becomes approximately constant based on the output of a wire sensor, and the air metering valve has a notch 28A near the outlet of the fuel passage to control the air flow flowing through the intake passage. an auxiliary throttle valve 28 that opens by dynamic pressure; a fuel injection section 30 that is fixed to the side surface of the intake passage located in the notch and has a small bench lily portion 30A; and a nozzle 30B that opens in the small bench lily portion. The fuel control device further comprises: the fuel in the fuel passage passes through the nozzle from the fuel passage outlet, and further passes through the small bench lily portion to be supplied to the intake passage.