JP2002097984A - Fuel quantity adjusting device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent feeding of a larger quantity of fuel than necessary, preventing generation of black smoke at the start of an engine by setting the minimum necessary quantity of initial fuel supply 4-2 adaptable for the environmental change or mechanical secular change of the engine. SOLUTION: When the engine is started, the quantity of initial fuel supply 4-1 is decided based on a temperature-fuel supply quantity map. When the start of the engine is not completed, the quantity of fuel supply is gradually increased (5). Then, when the start of the engine is completed, the temperature-fuel supply quantity map is modified. The new quantity of initial fuel supply 4-2 is made to be smaller than the quantity of fuel supply 6 at the completion of the start of the engine by a prescribed value under the previous condition of temperature of the start of the engine. At the next start of the engine, the quantity of initial fuel supply 4-2 is decided based on the modified temperature-fuel supply quantity map.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel metering device for an engine.

[0002]

2. Description of the Related Art Conventionally, as a fuel supply device for an engine,
Some fuel supply amounts are adjusted at the time of starting according to the engine temperature. In this type of apparatus, the amount of fuel supplied at the time of starting is set to be relatively large in order to perform a reliable start even when there is an environmental change other than the engine temperature or a mechanical aging of the engine.

[0003]

In the above prior art, since the fuel supply amount at the time of starting is set to be relatively large, more fuel than necessary is supplied at the time of starting, and black smoke is easily generated.

An object of the present invention is to provide an engine fuel supply device which can solve the above problems.

[0005]

As shown in FIG. 1, a temperature sensor (1), a start completion detecting means (2) and a controller (3) are provided.

The temperature sensor (1) detects an engine temperature based on one of a cooling water temperature, an engine oil temperature, a cooling exhaust air temperature, an engine wall temperature, and an engine ambient temperature, and a start completion detecting means (2). ) Detects the completion of the start of the engine, and when the start of the engine is started, the controller (3) determines the initial state shown in FIG. 2 based on the temperature-fuel supply map as shown in FIG. When the fuel supply amount (4-1) is determined and the engine start is not completed, the fuel supply amount is gradually increased (5) as shown in FIG. , As shown in FIG.
The fuel supply amount map is corrected so that the new initial fuel supply amount (4-2) is smaller by a predetermined amount than the fuel supply amount (6) at the time of the start completion under the previous start start temperature condition, An engine fuel metering device for determining an initial fuel supply amount (4-2) based on a corrected temperature-fuel supply amount map at the time of the next engine start.

(Invention of claim 2) The fuel metering device for an engine according to claim 1 is provided with an atmospheric pressure sensor (7) as shown in FIG. 1, and a controller (3) based on the atmospheric pressure. The temperature-fuel supply map is corrected by the following procedure. If the atmospheric pressure is decreasing, the initial fuel supply amount (4-2) shown in FIG.
A fuel supply device for an engine, wherein, when the atmospheric pressure is increasing, the initial fuel supply amount (4-2) is shifted to an increasing side.

[0008]

Operation and Effect of the Invention (Invention of claim 1) The invention of claim 1 has the following operation and effects. As shown in FIG. 2 (B), the temperature-fuel supply map is corrected based on the fuel supply amount (6) at the time of the start completion, and a new initial fuel supply amount ( 4-2) is reduced by a predetermined amount from the fuel supply amount (6) at the completion of the start, and at the next engine start, based on the corrected temperature-fuel supply amount map, the initial fuel supply amount ( In order to determine 4-2), even if there is an environmental change or a mechanical aging change of the engine, the minimum necessary initial fuel supply to adapt to the change
(4-2) is set. Therefore, unnecessary fuel is not supplied at the time of starting, and the generation of black smoke can be suppressed. If the starting is not completed with the initial fuel supply amount (4-1), the fuel supply amount is gradually increased (5), so that the engine start does not fail.

(Invention of claim 2) The invention of claim 2 has the following effect in addition to the effect of the invention of claim 1. If the atmospheric pressure decreases and the air becomes thinner,
In order to shift the initial fuel supply amount (4-2) to the decreasing side and vice versa, to shift the initial fuel supply amount (4-2) to the increasing side, an appropriate fuel supply amount according to the air amount is required. Can be set, and generation of black smoke and failure in starting due to a change in atmospheric pressure can be prevented.

[0010]

Embodiments of the present invention will be described with reference to the drawings. 1 to 3 are views for explaining an embodiment of the present invention. In this embodiment, a fuel metering device for a diesel engine is used.

The outline of this device is as follows. This device includes a fuel injection pump (8), a mechanical governor (9), and an electronic governor (10). Fuel injection pump (8)
Is a Bosch row-type pump, which is provided with a fuel metering rack (11) that slides in the fuel increase / decrease direction. The fuel metering rack (11) includes a mechanical input unit (12) and an electronic input unit (13).
And The fuel metering rack (11) is provided with an urging means.
In (15), the fuel is urged toward the fuel increasing side.

The structure of the mechanical governor (9) is as follows. The mechanical governor (9) has a speed control lever (1
4), a governor spring (16), a governor lever (17), and a governor force generating means (18). A governor lever (17) is interlocked to the speed control lever (14) via a governor spring (16). Governor force generating means
(18) is a flyweight that rotates at a speed proportional to the engine speed, and faces the governor lever (17). A mechanical output section is provided at the swinging end of the governor lever (17).
(19) is provided, which faces the mechanical input section (12) of the fuel metering rack (11) from the fuel increasing side. In the mechanical governor (9), the mechanical input unit (12) of the fuel metering rack (11) is connected to the mechanical output unit (1) by the urging force of the urging means (15).
9), governor spring force (20) and governor force
The governor lever (17) is swung by the unbalance force with (21), and the fuel metering rack (11) is metered.

The configuration of the electronic governor (10) is as follows. The electronic governor (10) is a set rotation speed detection sensor (22)
And a rotation speed sensor (25), a controller (3), and an actuator (23). Set rotation speed detection sensor (2
2) Detects the speed setting position of the speed control lever (14) and sends a target rotation speed detection signal to the controller (3). The rotation speed sensor (2) detects the actual rotation speed and transmits an actual rotation speed detection signal to the controller (3). controller
(3) compares the target rotation speed with the actual rotation speed and controls the output of the actuator (23). Actuator (2
3) is a linear solenoid whose output shaft end is an electronic output section (24). This electronic output unit (24)
Faces the electronic input unit (13) of the fuel metering rack (11) from the fuel increasing side. In this electronic governor (10),
The electronic input unit (13) of the fuel metering rack (11) is received by the electronic output unit (24) by the urging force of the urging means (15), and the fuel metering rack (11) is operated by the operation of the actuator (23). Measure.

The control characteristics of the electronic governor (10) and the metering characteristics of the mechanical governor (9) are as follows. FIG. 3 shows a characteristic diagram of the electronic governor and the mechanical governor. The horizontal axis indicates the rotation speed, and the vertical axis indicates the metering position. Mechanical governor (10)
(33) is a solid line, and the electronic governor
The electronic control characteristic diagram (34) according to (3) is indicated by a chain line. The mechanical metering characteristic diagram (33) includes a horizontal upper limit metering line (33a) and a sloping full load metering line (33b).
The full load metering line (33b) slopes downward from the high rotation side end of 3a) toward the high rotation side. Electronic control characteristic diagram (3
4) is vertical, and the upper end is a mechanical metering characteristic diagram (33)
Of the upper limit metering line (33a).

The functions of the electronic governor (10) and the mechanical governor (9) based on the above characteristics are as follows. During the electronic control operation by the electronic governor (10), the electronic control characteristic diagram
The control according to (34) is performed, and the electronic output unit (24) receives the electronic input unit (13), whereby the mechanical output unit (1) is received.
9) is separated from the mechanical input unit (12) so that the mechanical governor (9) does not act on the fuel metering rack (11), and the electronic governor (10) maintains the rotation speed at a constant value. When the load exceeds the full load, the metering is performed along the upper limit metering line (33a), and the mechanical output unit (19) receives the mechanical input unit (12), thereby controlling the fuel injection amount in the electronic control operation. And the electronic output section (24) is connected to the electronic input section.
(13) so that the electronic governor (10) does not act on the fuel metering rack (11).
The amount of fuel increase is restricted by the mechanical metering operation according to (9).

The electronic governor (10) also has the following control functions. That is, the electronic governor (10) is a temperature sensor.
(1), start completion detecting means (2) and atmospheric pressure sensor (7). The temperature sensor (1) detects an engine temperature based on an engine coolant temperature. The detection of the engine temperature may be performed based on one of the engine oil temperature, the cooling exhaust air temperature, the engine machine wall temperature, and the engine ambient temperature. The start completion detecting means (2) includes a rotational speed sensor (25).
Use as is. The controller (3) performs the processing shown in FIG. In step S1, it is determined whether or not the cell starter has been turned ON. If the determination is affirmative, the process proceeds to step S2. In step S2, the cooling water temperature is read. After step S2, the process proceeds to step S3. In step S3, as shown in FIG. 2B, based on the coolant temperature-fuel injection amount map,
The initial fuel injection amount (4-1) shown in (B) is determined, and the adjustment position of the fuel adjustment rack (11) is set by the actuator (23). The cooling water temperature-fuel injection amount map is shown in FIG.
As shown in a map curve (26) indicated by a solid line in (B), the fuel injection amount is set to decrease as the cooling water temperature increases. Reference numeral (35) in FIG. 3 is a mechanical adjustment characteristic diagram when the engine is started, and (36) is an electronic control characteristic diagram when the engine is started. After step S3, the process proceeds to step S4.

In step S4, it is determined whether the engine has been started. Specifically, the determination is made based on whether or not the engine speed has reached a predetermined start completion speed. If the determination is negative, as shown in FIG. 2 (C) and FIG.
At 5, the fuel injection amount is gradually increased (5), and the process returns to step S4. This cycle is repeated until the engine speed reaches the start completion speed. When the engine speed reaches the start completion speed, the determination in step S4 is affirmed, and the process proceeds to step S6. In step S6, the temperature-fuel injection amount map is corrected based on various conditions such as the fuel injection amount at the completion of the start. Specifically, as shown in the modified map curve (26a) shown by the dashed line in FIG. 2B, under the above-mentioned start start temperature condition and under the start start temperature condition of a predetermined temperature range including this start start temperature, a new Initial fuel supply (4-2)
The fuel supply amount is reduced by a predetermined amount from the fuel supply amount (6) when the start is completed. As a result, at the next engine start,
Based on the modified coolant temperature-fuel supply map,
The initial fuel supply amount (4-2) is determined. The atmospheric pressure sensor (7) detects the atmospheric pressure of the place where the engine is used, and the controller (3) determines the initial fuel supply amount (4-2) when the atmospheric pressure is decreasing. If the atmospheric pressure is increasing by shifting to the decreasing side, the initial fuel supply amount (4-2) is shifted to the increasing side.

In the above embodiment, an example of application to a diesel engine has been described, but the present invention can also be applied to a spark ignition type engine.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a fuel metering device for a diesel engine according to an embodiment of the present invention.

FIG. 2 is a view for explaining the function of the apparatus shown in FIG. 1; FIG.
FIG. 2B is a graph showing the relationship between the cooling water temperature and the fuel injection amount, and FIG. 2C is a graph showing the change over time in the fuel injection amount.

FIG. 3 is a diagram showing mechanical adjustment characteristics and electronic control characteristics of the apparatus of FIG. 1;

[Explanation of symbols]

(1) temperature sensor, (2) start completion detecting means, (3) controller, (4-1) initial fuel supply amount (initial fuel injection amount), (4-1) new initial fuel supply Amount (new initial fuel injection amount), (5) ... increase, (6) ... fuel supply amount at the completion of startup
(Fuel injection amount at the time of starting completion), (7) ... atmospheric pressure sensor.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yamaichi 3-8, Chikushinmachi, Sakai-shi, Osaka F-term in Kubota Sakai Coastal Plant (reference) 3G301 HA02 JA00 JA24 KA01 LB14 MA11 MA16 NC02 NC08 ND25 ND30 NE01 NE03 NE06 PA09Z PC10Z PE01Z PE08Z

Claims (2)

[Claims] 1. A temperature sensor (1) and a start completion detecting means (2)
And a controller (3). The temperature sensor (1) includes a cooling water temperature, an engine oil temperature,
The engine temperature is detected based on one of the cooling exhaust air temperature, the engine wall temperature, and the engine ambient temperature, the start completion detecting means (2) detects the completion of the engine start, and the controller (3) controls the engine When the start is started, the initial fuel supply amount (4-1) is determined based on the temperature-fuel supply amount map, and if the start of the engine is not completed, the fuel supply amount is gradually increased (5). When the start of the engine is completed, the temperature-fuel supply map is corrected, and the new initial fuel supply (4-2) is changed to the fuel supply amount (6 ), And at the next engine start, the initial fuel supply amount (4-2) is determined based on the corrected temperature-fuel supply amount map. Metering device. 2. The fuel metering device for an engine according to claim 1, further comprising an atmospheric pressure sensor, wherein the controller corrects the temperature-fuel supply map based on the atmospheric pressure. When the atmospheric pressure is decreasing, the initial fuel supply amount (4-2) is shifted to the decreasing side, and when the atmospheric pressure is increasing, the initial fuel supplying amount (4-2) is shifted to the increasing side. A fuel supply device for an engine, comprising: