JPH025723A - Fuel injection control system for fuel injection valve - Google Patents

Abstract

PURPOSE:To optimuly control the air-fuel ratio by controlling the valve opening time of a fuel injection valve in accordance with a temperature difference between the surface temperature of the fuel injection valve and the temperature of fuel. CONSTITUTION:When a water temperature sensor 2 detects a high temperature of an engine 1, a first temperature detector 12 detects a temperature TI of the outer surface of the forward section of a fuel injection valve 6, and further a second temperature detector 20 detects a fuel temperature TF in a fuel pipe 18. These detected values are computed by an ECU 30 which accordingly delivers a drive pulse by which the time of valve opening exceeds a normal valve opening time if the value of TI-TF is greater than a predetermined value. Further, a drive pulse by which the time of valve opening is equal to a normal value is delivered if TI-TF is less than the predetermined time. Accordingly, it is possible to feed an optimum fuel amount during restart at a high temperature at which vapors are possibly produced, and it is possible to prevent the fuel to be fed from becoming overritch in such a case that the temperature of the surface of the forward section of the fuel injection valve 6 is low so that vapors are not produced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel injection control system that improves the high-temperature restartability of an internal combustion engine (hereinafter referred to as engine b) equipped with a fuel injection valve. .

When an engine that has been operated for a relatively long period of time is stopped, the cooling function stops and the temperature of the engine drops slightly after the engine is stopped. Thus, when the temperature rises, the fuel Q'
1fi=, and vapor may be generated in the fuel. If the engine is started again with vapor generated in the fuel, the vapor may be injected from the fuel injection valve.
The engine will not be supplied with the required amount of fuel. In other words, the air-fuel ratio in the combustion chamber becomes lean, and the engine may not start or may stall.

The present invention relates to an improvement for solving the problem that occurs when restarting at 'r1 temperature.

(Conventional technology and its problems) In order to avoid improving the high-4 restartability of the engine, the fuel pressure (hereinafter also referred to as fuel pressure) is adjusted so that the air-fuel ratio does not become lean.
There is a known means for increasing the temperature compared to the normal starting time (for example, see Japanese Utility Model Publication No. 18675Q of 1983).

Utility Model Application Publication No. 61-18437, etc.).

The above means controls the temperature of the fuel in the fuel pipe (hereinafter referred to as fuel temperature).
(c)) and increases the fuel pressure when the fuel temperature exceeds a predetermined value to suppress the generation of vapor and increase the amount of injected fuel.

The generation of vapor itself depends on temperature. However, the generation of vapor that affects the amount of fuel injected, that is, the generation of vapor that squirts in the fuel injection valve, particularly at its tip, does not simply depend on the fuel temperature.

It is true that vapor is generated when the fuel temperature is high, but as long as this vapor is generated in the fuel vibrator, it will return to the fuel tank via the return pipe, and it will have a negative effect on fuel injection-4 in particular, and it will be worse than J3. 【stomach. Even if the fuel temperature is high, if the fuel injection valve is also polished at the same temperature, it can be said that no new vapor is generated in the fuel injection valve. Therefore, in any case where the amount is increased just because the fuel temperature is high, over-rich condition occurs.

(Problems to be Solved by the Invention) Therefore, the present invention provides an injection control system for a fuel injector that solves the above-mentioned problems when restarting an engine at a high temperature and realizes an optimal air-fuel ratio. is the issue to be solved.

(Means for Solving the Problems) The above problems are solved by means (1) and (2) described below.

■A fuel injection valve that injects and supplies fuel to the internal combustion engine,
a fuel vibrator connected to the fuel injection valve to supply fuel to the fuel injection valve; a first temperature detection means for detecting a surface temperature of the fuel injection valve; and a first temperature detection means for detecting the temperature of the fuel in the fuel injection valve. a second temperature detecting means, a starting temperature detecting means for detecting a starting temperature of the internal combustion engine and detecting whether or not the starting temperature of the internal combustion engine is a high-4 starting temperature; When a start is detected, I
T A valve opening time for controlling the opening time of the fuel injection valve according to the temperature difference between the surface temperature detected by the first temperature detection means and the fuel temperature detected by the second temperature detection means 11a. Injection υ of the fuel injection valve that controls the control means
control system.

■A fuel injection valve that injects and supplies fuel to the internal combustion engine;
1. A fuel vibrator connected to the fuel injector to supply fuel to the fuel injector; and a fuel vibrator connected to the fuel pipe to keep the fuel pressure in the fuel pipe constant relative to the reference pressure.
Blefushi 11 regulator that adjusts to a convex pressure,
a conductive path for introducing the 11η reference pressure into the pressure regulator; and a conductive path located in the middle of the conductive path,
, 4 and 11: a switching valve for switching to atmospheric pressure or injection DA atmospheric pressure, and a first valve for detecting the surface temperature of the fuel injection valve.
a second temperature detecting means for detecting the fuel temperature in the fuel pipe; and a starting temperature detecting means for detecting a starting temperature stone of the direct internal combustion engine and detecting whether or not the starting of the internal combustion engine is a high temperature starting. temperature detection means, and when a high temperature start of the internal combustion engine is detected by the starting temperature detection means, a surface temperature of the fuel injection valve detected by the first temperature detection means and the second temperature detection means; When the detected temperature difference in the fuel temperature inside the fuel vibrator exceeds a predetermined temperature difference, the switching valve is switched, and 1) the reference 11 introduced into the a/reschare V generator is switched to atmospheric pressure. λJ valve injection control system that controls the fuel injection valve control means and the fuel injection valve control means.

(for production) First, the operation of the above means (2) will be described.

When the starting temperature detection means confirms that the internal combustion engine is to be started at a high temperature, the surface temperature of the fuel injector detected by the first temperature detection means and the fuel Fl detected by the second temperature detection means are The opening time of the fuel injection valve is controlled by the temperature difference.

Therefore, for example, if the temperature difference is greater than or equal to a predetermined value,
Even if the valve opening time a, II is controlled to be longer than usual and vapor is generated in the fuel injection valve, the air-fuel ratio of the internal combustion engine will not become lean. Furthermore, if the temperature a difference is less than a predetermined value, fuel injection is performed at the normal valve opening time, and the air-fuel ratio of the internal combustion engine does not become too steep.

As mentioned above, the vapor that affects fuel injection is the vapor generated in the fuel injection valve, and this vapor depends on the temperature difference between the fuel temperature in the fuel pipe and the fuel temperature in the fuel pipe. Therefore, the effect of vapor generation can be almost eliminated by the above-mentioned action.

Next, we will discuss the effect of the means (2).

When a high temperature start of the internal combustion engine is confirmed by the starting temperature detection means, the surface temperature of the fuel injector detected by the first temperature detection means and the fuel temperature detected by the second temperature detection means are detected. If the temperature difference between the
Preflexi 1 by the switching valve control means? Increase the fuel pressure of the fuel injector by introducing the popular L regulator. This makes it possible to prevent vapor generation by increasing the fuel pressure only when there is a large difference between the surface temperature of the fuel injector and the fuel temperature in the fuel vibrator, that is, when vapor is likely to occur in the fuel injector. , the air-fuel ratio at restart (J
Can be optimized.

(Example) A first example according to the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram of an injection control system for a fuel injection valve according to a first embodiment of the present invention. In the figure, 1 is an engine, and a water temperature sensor 2 for detecting water temperature is attached to a cooling water passage 3 of the engine 1. A fuel injection valve 6 is provided in the intake manifold 4 . There is a surge tank 8 in the L flow of the intake manifold 4.
A pressure sensor 10 is provided through a passage 34 .

The fuel injection valve 6 has a fuel pipe 18. Fuel filter 22.
Fuel damper 24. Fuel is supplied from a fuel tank 28 via a fuel pump 26 or the like. The fuel pipe 1 is connected to the fuel chamber 16b of the pressure regulator 16. Blessy t below! The configuration of the regulator 16 will be explained with reference to FIG. The pressure regulator 16 has a structure in which a reference pressure chamber 16a and a fuel chamber 16b are separated by a diaphragm 16. Diaphragm 16 CJ is always lit r1'+ by spring 16f etc.
A constant force is applied to the i 16 b side. fuel chamber 1
6b includes a return pipe 32 in addition to the fuel pipe 118.
The return vibe 32 is connected to the fuel tank 2.
Connected to 8. When the fuel J1 in the fuel chamber 16b becomes higher than the reference pressure in the semi-pressure chamber 16a plus the pressure by the urging force of the spring 16f, etc., the diaphragm 16q is displaced and the fuel It operates to connect the pipe 18 and the return vibe 32. Thereby, when the fuel pressure in the fuel u16b or the fuel pipe 18 exceeds a predetermined value, excess fuel is released to maintain the predetermined pressure. Note that the predetermined pressure here refers to the standard pressure 〒16
It changes depending on the pressure inside a. Illustrated 37 is the reference pressure chamber 16
It is a communication pipe for introducing reference 1f: into a, and the injection atmosphere pressure of the fuel injection valve 6 is the reference pressure? i! The surge tank 8 is interposed between the pressure regulator 16 and the surge tank 8 so as to be introduced into the pressure regulator 16a.

As shown in detail in FIG. 3, a first temperature detector 12 is attached to the tip of the fuel injection valve 6. As shown in FIG. Further, a second temperature detector 20 is attached to the fuel pipe 18. These 2=a detectors determine the fuel injection valve 6
The surface temperature of the tip of the fuel vibrator 18 and the fuel temperature inside the fuel vibrator 18 can be measured.

Reference numeral 30 in FIG. 1 is an engine electronic control IT device (hereinafter referred to as ECU), which receives signals from each sensor and detector and controls the fuel injection valve 6 and the like. That is, the water temperature sensor 2 is connected to the input terminal of the E CLJ 30 via the signal line 54, and the pressure sensor 10 is connected to the signal line 52.
Via the signal line 56, the first temperature sensor 12
A second temperature detector 20 is electrically connected via a signal line 62. On the other hand, the fuel injection valve 6 is electrically connected to the output side terminal of the ECU 3O via a signal line 58.

FIG. 5 shows the temperature of the fuel injector 6 measured by the first temperature detector 12.
surface temperature (TI) at the tip of the second temperature detection 3
20 shows the range (R) in which the fuel injection valve 6 is controlled by the ECU 30 based on the relationship with the fuel temperature (T1) in the fuel vibrator 18 measured at 20. 1J rope 15, T-
In region 1 where T[≧C, E CLJ 30 controls the injection valve 6 to open for the normal valve opening time J:6. Specifically, a drive signal having a longer pulse 1j than that normally applied for starting (ie, starting in a region other than the IR) is outputted to the signal line 58. This means that the degree of vapor generation at the tip of the fuel injector 6 is T.
It is based on the fact that it is determined by the temperature difference C from 1 and the fuel property. In addition, the size of C is determined appropriately depending on the fuel properties, and by changing C, it can be applied to various fuels! can do.

Next, the functions and effects of the first embodiment will be described.

It is now assumed that the engine 1, which has been operated for a long time, is in a stopped state and the cooling water passage 3 is at a high temperature.

When the engine 1 is restarted in this state, the high temperature state of the engine 1 is detected by the water temperature hint 2. At this point, the first temperature detector 12 detects the surface temperature (T1) of the tip of the fuel injection valve 6. Roughly speaking, the second temperature sensor detects the amount of fuel 1ffl (T, ) in the fuel pipe 118.
is detected. These temperature information are each E CtJ
If the value of T - T is greater than a predetermined value C, then (1) a driving pulse is given to the fuel injection valve 6 for a period longer than the normal valve opening time. Further, if the value of T-T[ is smaller than the predetermined value C, a drive pulse with a normal valve opening time is applied. Therefore, when restarting at a high temperature where vapor is generated, it is possible to supply the optimum amount of fuel, and conversely, the surface temperature of the tip of the fuel injector 6 is low and no vapor is generated. In such cases, the fuel supply will not overlap. Therefore, the air-fuel ratio at the time of restarting the engine 1 can be optimized. Note that the predetermined value 11111C is a value that should be changed depending on the fuel properties, and can be adapted to the shape of the C fuel by changing the predetermined l1rIC.

Next, a second embodiment of the present invention will be described mainly with reference to FIGS. 2 and 5.

FIG. 2 is a schematic diagram of the injection control system of the second embodiment (fuel injection). In the following, the same reference numerals are given to the same components as those of the first embodiment shown in FIG. 1, and detailed explanation thereof will be omitted.

The second embodiment differs from the first embodiment in that a switching valve 14 is provided in the communication pipe that introduces the reference JJ into the reference pressure chamber 16a of the refrigeration unit 1 fregulator 16 (T14). However, the communication state between the conduction path 38 and the conduction path 42 is controlled via the switching valve 14. Note that this switching valve 14 is electrically connected to the output side terminal of the ECU 3O via a signal line 60.

FIG. 5 is an explanatory diagram of the operation of the switching valve 14. Figure (a) illustrates a state in which the switching valve 14 is not energized. The switching valve 14 has three boats. In other words,
The switching valve 14 is connected to the bow 1-1 of the pressure regulator 16.
6c through the conduction path 42, and a boat 171b which communicates with the leege tank 8 through the conduction path 38, and the popular boat 14j. Also, the switching valve 14 includes a spring 14C whose end is fixed to the housing 14k, a valve 14d attached to the other end of the spring 14G, and a valve 1/1. It has a small hole 14i integrated with d, and is composed of a branzil 14h made of ferromagnetic material, a solenoid coil 14f, and an iron plate 140 that is magnetized by the solenoid coil 1711° when energized. .

Note that an air passage 14e is formed within the solenoid coil 14f.

The spring 14c is always connected to the valve 14d for air ventilation ff11.
The solenoid coil 1/If is energized so as to close the solenoid coil 4e and prevent the introduction of atmospheric air from the boat 14j. Therefore, normally the conduction path 38 on the boat h 14 b side and the conduction path 42 on the boat 1/Ia side are in communication. Therefore, the reference pressure chamber 1 of the pressure regulator 16
6a, the RK/J in the surge tank 8 (introduced,
The difference between the fuel pressure of the fuel injection valve 6 and the injection atmospheric pressure is adjusted to be constant.

When the switching valve 14 receives a drive signal from the ECU 3O and is energized, it operates as shown in FIG. 3(b). However, when the solenoid coil 14r is energized, the plunge p14h is attracted to the magnetized iron plates 1 to 14G, opening the air passage 14e. On the other hand, the valve 14d closes the bow)-14,b. Therefore, the popularity introduced from Boh 111 J is small hole 141. The air is introduced into the reference pressure chamber 16a of the pressure regulator 16 through the air passage 1/It-3° boat 1/Ia, etc.

Therefore, by the pressure regulating action of the pressure regulator 16, the fuel pressure in the fuel chamber 16b side is adjusted and increased, and the fuel pressure in the fuel injection valve 6 is also increased.

Next, the functions and effects of the second embodiment will be described. In the second embodiment, after detecting a high temperature restart of the engine 1 in the first embodiment, each temperature information (T and TF) is converted to E CLJ 3
The process is the same up to the point where it is taken in to 0. In the second embodiment, the switching valve 14 can suppress the generation of vapor at the tip of the fuel injection valve 6 by increasing the fuel pressure of the fuel injection valve 6, and can also control the fuel supply to the engine 1. can be multiplied. In other words, only when the temperature difference between the T, J and T taken into the ECU 3O is greater than a predetermined value C, the ECU 3O allows the three-way valve 14 to pass through 111, thereby reducing the pressure regulator 16. : Air is introduced into the multi-quasi-pressure chamber 16b, pressure regulator 16
The fuel pressure of the fuel injection (J) valve 6 is increased to 127 by the pressure adjustment action of
I'm here. In the second embodiment as well, the fuel supply m is increased and corrected as in the first embodiment. In addition,
The control according to the fuel f1 state by the predetermined 1+OC is the first
This is similar to the example.

Note that the control of the ECU 3O is not limited to the control of only the first embodiment or the control of only the second embodiment, but is also a combination of both, thereby realizing fine optimization of the air-fuel ratio during a high temperature restart.

Also in this case, as mentioned in the first embodiment, the predetermined value C
It is also assumed that control according to Iζ can be performed depending on the fuel properties.

(Effects of the Invention) According to the present invention having the above configuration, the following effects are expected.

When the engine is restarted at a high temperature, the vapor generated in the fuel injector is predicted from the temperature difference between the fuel temperature in the fuel pipe and the surface temperature of the fuel injector, and the fuel j1. Since the injection of the fuel injection valve is controlled by controlling the valve opening time, the air-fuel ratio of the engine can be appropriately controlled. Therefore, good startability and stability of the engine can be maintained even when restarting at a high temperature.

41. Even if the engine fuel is alcohol fuel, or a fuel other than gasoline is used, injection control based on the temperature difference between the fuel temperature and the surface temperature of the fuel injector can be done by taking this temperature difference into account to determine the difference in fuel properties. It is expected that it will also be able to respond to λ1.

Furthermore, conventionally, as a countermeasure against high-temperature restart, the shapes of valve J3 of the fuel injection valve and the seat that the valve contacts have been devised, but in the present invention, there is no need to make any improvements to the structure of the fuel l1la4 valve itself. Since there is no such thing, the effect of cost reduction can be expected.

[Brief explanation of the drawing]

1 is a schematic block diagram of a first embodiment of the present invention, FIG. 2 is a schematic block diagram of a second embodiment of the present invention, and FIG. 3 is a schematic block diagram of a second embodiment of the present invention. FIG. 4 is an installation diagram of the second humidity detector, and FIG. 5(a) is a configuration diagram of the pressure regulator. (b) is an explanatory diagram of disturbance of the three-way valve, and FIG. 6 is a diagram of the relationship between the surface temperature of the fuel injection valve and the fuel temperature. 1...Engine 2...Water temperature sensor 9 6...Fuel injection valve 8...Rige tank 12...First temperature detector 14...Three-way valve 16...Blessy t/regulator 18...・Fuel pipe 30...ECL no.

Claims (2)

[Claims] (1) A fuel injection valve that injects and supplies fuel to the internal combustion engine; a fuel pipe that is connected to the fuel injection valve and supplies fuel to the fuel injection valve; and detecting the surface temperature of the fuel injection valve. a first temperature detection means; a second temperature detection means for detecting a fuel temperature in the fuel pipe; and a second temperature detection means for detecting a starting temperature of the internal combustion engine and detecting whether or not the starting of the internal combustion engine is a high temperature starting. starting temperature detecting means; when the starting temperature detecting means detects a high temperature start of the internal combustion engine, the surface temperature detected by the first temperature detecting means and the fuel detected by the second temperature detecting means; An injection control system for a fuel injection valve, comprising: a valve opening time control means for controlling an opening time of the fuel injection valve according to a difference between temperature and humidity. (2) a fuel injection valve that injects and supplies fuel to the internal combustion engine; a fuel pipe that is connected to the fuel injection valve and supplies fuel to the fuel injection valve; and a fuel pipe that is connected to the fuel pipe and supplies the fuel a pressure regulator that adjusts the fuel pressure in the pipe to a pressure higher than a reference pressure by a certain pressure; a conduit passage for introducing the reference pressure into the pressure regulator; a switching valve for switching the pressure to atmospheric pressure or injection atmosphere pressure; a first temperature detection means for detecting the surface temperature of the fuel injection valve; a second temperature detection means for detecting the temperature of the fuel in the fuel pipe; starting temperature detecting means for detecting a starting temperature of the internal combustion engine and detecting whether or not the starting of the internal combustion engine is a high temperature starting; and when the starting temperature detecting means detects a high temperature starting of the internal combustion engine, the first switching the switching valve when a temperature difference between the surface temperature of the fuel injection valve detected by the temperature detection means and the fuel temperature in the fuel pipe detected by the second temperature detection means is a predetermined temperature difference or more; An injection control system for a fuel injection valve, comprising switching valve control means for switching a reference pressure introduced into the pressure regulator to atmospheric pressure.