阅读说明：本技术 用于控制燃料计量系统的方法 (Method for controlling a fuel metering system ) 是由 T.赫格斯 于 2019-07-17 设计创作，主要内容包括：描述了一种用于控制燃料计量系统的方法。在马达起动之前为提高燃料温度而给流量控制阀通电。(methods for controlling a fuel metering system are described.)

1. Method for controlling a fuel metering system, characterized in that a flow control valve is energized for increasing the fuel temperature before the motor is started.

2. The method of claim 1, wherein the energizing of the flow control valve is initiated by remote unlocking of the vehicle or touching a switch.

3. Method according to any of the preceding claims, characterized in that the drive shaft of the high-pressure pump is placed in a position at shut-down in which the delivery chamber of the high-pressure pump is as large as possible.

4. The method of any , wherein the flow control valve is energized in a pulsed manner.

5. The method of any of the preceding claims, wherein the energizing is based on a predicted start of the motor.

6. The method of any of the preceding claims, wherein the energizing is based on temperature.

7. Computer program configured for carrying out all the steps of of the method according to any one of of claims 1 to 6.

8. A machine-readable storage medium having stored thereon a computer program according to claim 7.

9. A controller configured to perform all the steps of of the method of any of of claims 1-6.

10. Program code together with processing instructions for creating a computer program that can be run on a controller, wherein the program code produces a computer program according to claim 7 if the program code is converted into a computer program that can be run in accordance with the processing instructions.

Technical Field

The invention relates to a method for controlling a fuel metering system.

Background

Methods for controlling fuel metering systems are known. For combustion motors with high-pressure injection systems, cold start requests for the motor are made by pressure buildup in the fuel reservoir. In this case, after a long shutdown phase, the temperature of the fuel corresponds to the temperature of the environment. However, the cold fuel does not completely evaporate when it is injected into the combustion chamber, as a result of which wetting of the piston or the combustion chamber wall can occur. Thereby, more soot particles are generated during the combustion process. The amount of carbon black particles should be kept as low as possible.

Disclosure of Invention

In contrast, the method according to the invention, which has the features of the independent claim, has the advantage that the amount of soot particles can be significantly reduced during cold starting, this is achieved by energizing the flow control valve of the high-pressure pump before the motor is started, by energizing the flow control valve before the start of the internal combustion engine, heat is generated in the valve, which heats up the fuel in the high-pressure pump, the flow control valve forms units with the high-pressure pump, the flow control valve controls the fuel flow into the delivery chamber of the high-pressure pump, the flow control valve serves here as a regulator for regulating the pressure in the rail.

It is particularly advantageous that the energization of the flow control valve is initiated by remote unlocking of the vehicle and/or by contact of a switch at . with these signals, an upcoming start of the combustion engine can be easily identified.

In , a particularly advantageous embodiment provides that the drive shaft of the high-pressure pump is brought into a position when the internal combustion engine is shut down, in which position the delivery chamber of the high-pressure pump is as large as possible.

It is particularly advantageous to operate the flow control valve in a pulsed manner (getaktet), thereby protecting the assembly from overloading, it is also particularly advantageous for the heating of the flow control valve to be carried out as a function of temperature, point being particularly advantageous if the flow control valve and therefore the fuel are heated as a function of temperature during start-stop operation.

In a further aspect, the invention relates to novel program codes together with processing instructions for creating a computer program capable of running on a controller, in particular a source code with compilation instructions and/or linking instructions, wherein the program codes, when converted, i.e. in particular compiled and/or linked, according to the processing instructions, into a computer program capable of running, produce a computer program for carrying out all the steps of of the described method.

Drawings

Embodiments of the invention are illustrated in the drawings and are explained in detail in the following description. In the drawings:

FIG. 1 illustrates the major elements of a fuel metering system; and is

Fig. 2 shows a flow chart for explaining the manner of processing according to the present invention.

Detailed Description

Fig. 1 shows the main elements of a fuel metering system of a fuel supply system of an internal combustion engine. The track is denoted by 100. From the rail 100, the fuel reaches the combustion chamber of the internal combustion engine through an injector, not shown. The pressure P in the rail 100, also referred to as the rail pressure, is detected by the sensor 105. The rail 100 is connected to a delivery chamber 130, i.e. a high-pressure pump, via a pressure-limiting valve 110 and an outlet valve 120. The fuel in the delivery chamber 130 is compressed by the piston 140. For this purpose, the piston is driven by the camshaft or crankshaft of the internal combustion engine via a drive and expands and contracts the conveying chamber 130 by its back and forth movement.

The pressure limiting valve 110 is designed such that it releases the connection between the rail and the delivery chamber 130 when the pressure in the rail 100 exceeds a certain threshold value, the outlet valve 120 is designed such that it releases the fuel flow when the pressure in the delivery chamber 130 is greater than the pressure in the rail 100, alternatively, the pressure limiting valve 110 can also be connected to a tank or other line in a low-pressure region, another connection connects the delivery chamber 130 to an electrically operated flow control valve 150, this flow control valve 150 connects the tank 160 to the delivery chamber 130, the region between the delivery chamber 130 and the tank 160 is generally referred to as a low-pressure region, the rail 100, the delivery chamber 130 and the region between them are generally referred to as a high-pressure region, preferably, a delivery pump is arranged in said tank 160, which delivers fuel from the tank 160 to the delivery chamber 130 via the flow control valve 150.

The amount of flow into the delivery chamber 130 is controlled by manipulation of the electrical flow control valve 150. Or to control the pressure build-up in the delivery chamber 130. For example, it can thus be provided that the flow control valve 150, in its currentless state, is continuously opened and releases the fuel flow between the tank and the delivery chamber. If the flow control valve is closed during the compression phase of the piston, a pressure can build up and a corresponding amount of fuel can be delivered into the rail depending on the moment of closing.

The flow control valve 150 forms a unit of construction with the high pressure pump, the flow control valve controls the flow of fuel into the delivery chamber 130 of the high pressure pump, the flow control valve is a regulator for regulating the pressure in the rail 100.

For this purpose, a control 170 is provided, which actuates the flow control valve 150 as a function of the rail pressure P in the rail 100. During the suction phase of the high-pressure pump, the piston 140 enables fuel in the low-pressure region to flow from the tank line into the delivery chamber 130. During the suction phase of the high-pressure pump, the piston moves downward in fig. 1 as shown. In the delivery phase of the upward movement of the piston, the medium is compressed and as such is brought to a higher pressure level. Fuel having a high pressure is delivered into the rail 100 via the outlet valve 120 and provided to the injectors.

However, it can also be provided that the flow control valve 150 is closed in the absence of current. In this case, the valve is opened by energization and pressure buildup is started by the end of energization.

A pressure limiting valve 110 is provided in order that the pressure in the rail 100 does not rise above a certain value. Which opens a connection between the rail 100 and the delivery chamber 130 or other areas in the low-pressure area when a certain pressure is present.

According to the invention, the particle count is reduced by additional control of already existing components in the internal combustion engine with high-pressure injection. Before starting the internal combustion engine, fuel is supplied to a supply chamber of the high-pressure pump by the low-pressure pump. The flow control valve of the high-pressure pump is now energized before the motor is started. The delivery chamber is closed and the lost energy of the flow control valve is transmitted to the fuel via the pump housing. The fuel heats up and is then delivered to the rail as the motor starts. The fuel is injected into the combustion chamber at an elevated temperature where it is more readily vaporized.

It is particularly advantageous to adjust the drive shaft of the high-pressure pump when the internal combustion engine is shut down in such a way that the largest possible volume is available in the delivery chamber of the high-pressure pump. In fig. 1, this means that the piston 140 moves down as far as possible in order for the delivery chamber 130 to reach its maximum volume.

In step , it is recognized that the motor vehicle is about to start, which can be achieved, for example, by a signal from a remote control for unlocking the vehicle.

, the driver's vehicle is opened or should be opened upon the presence of a signal from a remote control or contact, it can be provided in a further refinement that further signals are evaluated for detecting an imminent start of the internal combustion engine.

In hybrid vehicles, it can also be provided that the start of the program is derived from the operating mode prediction, for example from the navigation data, by means of the predicted combustion motor start, in order to be able to thus perform a sufficient fuel warm-up.

In a subsequent step 210, the prefeed pump, not shown, fills the delivery chamber 130 of the high-pressure pump with fuel via the open flow control valve 150. A subsequent query 220 checks whether the fuel temperature has exceeded the target value. If this is not the case, the flow control valve 150 is manipulated in a subsequent step 230 for increasing the temperature of the fuel. This means that the energization is only performed at low temperatures. In particular, in start-stop operation, the current is only supplied when the temperature falls below a threshold value. Thereby, unnecessary heating processes and thus unnecessary energy consumption can be avoided.

This actuation is preferably carried out in such a way that the flow control valve does not change its state. For this purpose, in particular pulsed excitation is used. In this case, the energization is so short that the flow control valve does not change its state, but introduces as much energy as possible and thus lost power into the flow control valve.

Subsequently, it is checked in query 240 whether a motor start has been performed. If this is not the case, the query is re-executed 220. If this is the case, in step 250, the usual actuation of the flow control valve is switched over for pressure regulation.