CN105863862B - A kind of fuel injector, co-rail oil injection system and fuel injecting method - Google Patents

Abstract

The invention relates to the technical field of engine fuel injection, and provides a fuel injector, a common rail fuel injection system and a fuel injection method. Wherein, the fuel injector includes a parallel first oil passage and a second oil passage; the first common end of the first oil passage and the second oil passage are connected to the common rail pipe, and the second common end is connected to the fuel injection port ; The first on-off valve is set on the first oil channel, and the pressure-reducing valve and the second on-off valve are set on the second oil channel, both of the first on-off valve and the second on-off valve are connected to the controller. The scheme realizes the adjustment of fuel injection pressure by designing two oil channels. When the post-spray is used, the oil is injected through the second oil channel, and the injection pressure is reduced through the pressure reducing valve on the oil channel, so as to prevent the high injection pressure diesel from washing the cylinder wall and take away the lubricating oil film, thereby effectively protecting the engine and Reduce the risk of scuffing. In addition, the fuel injector can also control the fuel injection pressure of the pre-injection, so as to realize the change of the fuel injection law, improve the combustion efficiency and reduce the fuel consumption.

Description

Fuel injector, common rail fuel injection system and fuel injection method

technical field

The invention relates to the technical field of engine fuel injection, in particular to a fuel injector, a common rail fuel injection system and a fuel injection method.

Background technique

Engines face the challenge of ever-tightening emissions regulations and ever-lowering emission limits. As emission regulations tighten, particulate filters are required to further reduce particulate emissions.

Taking the diesel engine as an example, the post-injection is used to control the regeneration of the particle trap. Since the rail pressure of the injector at a certain operating point is fixed, that is, the post-injection pressure of the injector is the same as the pressure of the main injection. The problem caused by this is that the high injection pressure diesel sprayed on the cylinder wall during post injection will cause oil dilution. Easy to cause oil dilution. The dilution of the engine oil will destroy the performance of the engine oil, reduce the kinematic viscosity, and cause the diesel engine to scuff; in severe cases, it will also lead to a drop in engine oil pressure, loss of component functions, and a decrease in engine reliability.

Contents of the invention

(1) Technical problems to be solved

The technical problem to be solved by the present invention is to provide a fuel injector and a common rail fuel injection system with adjustable fuel injection pressure.

(2) Technical solution

In order to solve the above technical problems, the present invention provides a fuel injector, including a parallel first oil passage and a second oil passage, and a controller; the first oil passage and the second oil passage The first common end of the common rail is connected to the common rail pipe, and the second common end is connected to the fuel injection port; the first on-off valve is arranged on the first oil passage, and the pressure reducing valve and the second oil passage are arranged on the second oil passage. On-off valve, the first on-off valve and the second on-off valve are connected to the controller; the controller includes a first judging module, a second judging module and a signal sending module; the first judging module is used to judge For the working condition of the particle trap, the second judging module is used to judge the fuel injection timing, and both the first judging module and the second judging module send judging data to the signal sending module; the signal The sending module sends control signals to the first on-off valve and the second on-off valve according to the judgment data.

Preferably, the controller is an automobile-specific microcomputer controller.

Preferably, the first switch valve is a high-pressure solenoid valve, and the second switch valve is a low-pressure solenoid valve.

The present invention also provides a common rail fuel injection system, including the above fuel injector.

The present invention also provides a fuel injection method for a common rail fuel injection system, comprising the following steps:

S1. Judging the working condition of the particle filter through the first judging module, when it is in the regeneration working condition, enter S2, otherwise enter S3;

S2. Judging the fuel injection timing through the second judging module:

During the main injection, the signal sending module sends an opening signal to the first on-off valve, and sends a closing signal to the second on-off valve;

During post-spraying, the signal sending module sends a closing signal to the first on-off valve, and sends an opening signal to the second on-off valve;

S3. Judging the fuel injection timing through the second judging module:

During the main injection, the signal sending module sends an opening signal to the first on-off valve, and sends a closing signal to the second on-off valve;

During pre-spraying, the signal sending module sends a closing signal to the first on-off valve and an opening signal to the second on-off valve.

(3) Beneficial effects

The technical solution of the present invention has the following beneficial effects: the fuel injector of the present invention includes a first oil passage and a second oil passage connected in parallel; the first common end of the first oil passage and the second oil passage connected to the common rail pipe, and the second common end is connected to the fuel injection port; the first oil passage is provided with a first on-off valve, and the second oil passage is provided with a pressure reducing valve and a second on-off valve. Both the first on-off valve and the second on-off valve are connected to the controller; the controller includes a first judging module, a second judging module and a signal sending module; the first judging module is used to judge the working condition of the particle trap , the second judging module is used to judge the fuel injection timing, and both the first judging module and the second judging module send judging data to the signal sending module; A control signal is sent to the first on-off valve and the second on-off valve. The scheme realizes the adjustment of fuel injection pressure by designing two oil channels. When the post-spray is used, the oil is injected through the second oil channel, and the injection pressure is reduced through the pressure reducing valve on the oil channel, so as to prevent the high injection pressure diesel from washing the cylinder wall and take away the lubricating oil film, thereby effectively protecting the engine and Reduce the risk of scuffing. In addition, the fuel injector can also control the fuel injection pressure of the pre-injection, so as to realize the change of the fuel injection law, improve the combustion efficiency and reduce the fuel consumption.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the structural representation of the fuel injector of the present application;

Fig. 2 is a schematic flow chart of the working principle of the fuel injector of the present application;

In the figure: 1. The first oil passage; 2. The second oil passage; 3. The first on-off valve; 4. The second on-off valve; 5. The pressure reducing valve.

Detailed ways

Embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but should not be used to limit the scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", " The orientations or positional relationships indicated by "vertical", "horizontal", "top", "bottom", "inner" and "outer" are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and Simplified descriptions, rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and thus should not be construed as limiting the invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral Ground connection; it can be mechanical connection or electrical connection; it can be direct connection or indirect connection through an intermediary. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

Please refer to FIG. 1 , the fuel injector of this embodiment includes a first oil channel 1 and a second oil channel 2 connected in parallel, and a controller. Wherein, the first common ends of the first oil channel 1 and the second oil channel 2 are connected to a common rail pipe, and high-pressure oil is connected from the common rail pipe. The second common end of the first oil channel 1 and the second oil channel 2 is connected to the oil injection port, and oil is injected from the oil injection port.

Wherein, the first oil passage 1 and the second oil passage 2 may also be respectively connected to one fuel injection port, so that multiple fuel injection ports need to be provided on the fuel injector.

In this embodiment, in order to control the oil pressure injected from the fuel injection port, a first switch valve 3 is provided on the first oil channel 1, and a pressure reducing valve 5 and a second switch are provided on the second oil channel 2. valve 4. Wherein, both the first on-off valve 3 and the second on-off valve 4 are connected to the aforementioned controller.

Obviously, the first oil channel 1 passes through the high-pressure oil directly connected from the common rail, so it is a high-pressure oil circuit. The second oil channel 2 is provided with a pressure reducing valve 5, and the high pressure oil fed in from the common rail becomes low pressure oil after passing through the pressure reducing valve 5, so the second oil channel 2 is a low pressure oil circuit. On this basis, the controller controls the on-off of the first on-off valve 3 and the second on-off valve 4, thereby realizing the simultaneous control of high-pressure and low-pressure fuel injection inside the injector.

Wherein, the controller includes a first judging module, a second judging module and a signal sending module. The first judging module is used to judge the working condition of the particle trap, the second judging module is used to judge the fuel injection timing, and both the first judging module and the second judging module send judging data to Signal sending module. The signal sending module synthesizes the judgment data of the first judging module and the second judging module, and sends control signals to the first on-off valve 3 and the second on-off valve 4 .

The scheme realizes the adjustment of fuel injection pressure by designing two oil channels. When post-spraying is used, fuel is injected through the second oil channel 2, and the injection pressure is reduced through the pressure reducing valve 5 on the oil channel, so as to prevent high injection pressure diesel from washing the cylinder wall and taking away the lubricating oil film, thereby effectively protecting the engine and reduce the risk of cylinder scuffing. In addition, the fuel injector can also control the fuel injection pressure of the pre-injection, so as to realize the change of the fuel injection law, improve the combustion efficiency and reduce the fuel consumption.

In this embodiment, the controller is preferably a microcomputer controller dedicated to automobiles.

In addition, the first switch valve 3 is preferably a high-pressure solenoid valve, and the second switch valve 4 is preferably a low-pressure solenoid valve. Of course, the first on-off valve 3 and the second on-off valve 4 are not limited to the cases listed in this embodiment, and any type of on-off valve disclosed in the art can be used as long as the oil channel can be switched on and off.

This embodiment also provides a common rail fuel injection system, including the above fuel injector.

Use the above-mentioned common rail fuel injection system for fuel injection, see Figure 2, including the following steps:

S1. Judging the working condition of the particle filter through the first judging module, when it is in the regeneration working condition, enter S2, otherwise enter S3;

S2. Judging the fuel injection timing through the second judging module:

During the main injection, the signal sending module sends an opening signal to the first on-off valve 3 and a closing signal to the second on-off valve 4;

During post-spraying, the signal sending module sends a closing signal to the first on-off valve 3 and an opening signal to the second on-off valve 4;

S3. Judging the fuel injection timing through the second judging module:

During the main injection, the signal sending module sends an opening signal to the first on-off valve 3 and a closing signal to the second on-off valve 4;

During pre-spraying, the signal sending module sends a closing signal to the first on-off valve 3 and an opening signal to the second on-off valve 4 .

Wherein, the first judging module judges the working condition of the particle trap. When the particle filter is in the regeneration mode, it is necessary to periodically regenerate the particle filter with after-spray. At this time, the second judging module is used to judge the timing of fuel injection. Generally, it is judged according to the stroke of the piston in the engine cylinder that it is currently in the period of main injection or post injection. To achieve different fuel pressure controls for the main injection and the post injection, it needs to be realized by disconnecting the first switch valve 3 and turning on and off the second switch valve 4 . specifically:

During the main injection, the first switch valve 3 is controlled to be turned on, the second switch valve 4 is turned off, and the high-rail pressure fuel enters the engine cylinder through the first oil channel 1;

During post-spraying, the first on-off valve 3 is controlled to be disconnected, the second on-off valve 4 is turned on, and the high-rail pressure fuel enters the engine cylinder through the second oil channel 2 . When the high-rail pressure fuel enters the second oil passage 2, the pressure of the fuel decreases through the pressure reducing valve 5 . Therefore, the fuel injector adopts a lower fuel injection pressure during post injection, which can avoid fuel dilution caused by high injection pressure fuel scouring the cylinder wall.

When the particulate filter is in the non-regenerating condition, it is not necessary to carry out post-injection fuel injection at this time, only to perform main-injection fuel injection, or to combine main-injection and pre-injection. Wherein, the second judging module judges the fuel injection timing. At this time, the second judging module first judges the load of the engine: if the load is low, it is necessary to combine the pre-injection with the main injection; otherwise, only the main injection is required. When it is necessary to combine the pre-injection and the main injection, the second judging module further judges whether it is in the pre-injection or the main injection period according to the stroke of the piston in the engine cylinder. Similarly, different fuel pressure controls for main injection and pilot injection need to be realized by disconnecting the first on-off valve 3 and on-off of the second on-off valve 4 . specifically:

During the main injection, the first on-off valve 3 is controlled to be turned on, and the second on-off valve 4 is turned off, so that the high-rail pressure fuel enters the engine cylinder through the first oil channel 1;

During pre-injection, as mentioned above, the first on-off valve 3 is controlled to be disconnected, and the second on-off valve 4 is turned on, so that the high-rail pressure fuel enters the second oil passage 2 and passes through the pressure reducing valve 5 to reduce the fuel pressure. Among them, the use of lower fuel pressure during pre-injection can realize changes in fuel injection rules, improve combustion efficiency and reduce fuel consumption.

The above embodiments are only used to illustrate the present invention, but not to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications or equivalent replacements of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all should cover Within the scope of the claims of the present invention.

Claims (5)

1. A fuel injector, characterized in that it comprises a first oil passage and a second oil passage connected in parallel, and a controller; the first common part of the first oil passage and the second oil passage One end is connected to the common rail pipe, and the second common end is connected to the fuel injection port; the first on-off valve is provided on the first oil channel, and the pressure-reducing valve and the second on-off valve are provided on the second oil channel, so Both the first on-off valve and the second on-off valve are connected to the controller; the controller includes a first judging module, a second judging module and a signal sending module; the first judging module is used to judge the particulate trap working condition, the second judging module is used to judge the fuel injection timing, and both the first judging module and the second judging module send judging data to the signal sending module; When the particulate filter is in regeneration mode and the fuel injection timing is the main injection, the signal sending module sends an opening signal to the first on-off valve and a closing signal to the second on-off valve; when the particle When the trap is in regeneration mode and the fuel injection timing is post-spray, the signal sending module sends a close signal to the first on-off valve and an open signal to the second on-off valve; When the particulate filter is in a working condition other than the regeneration working condition, and the fuel injection timing is the main injection, the signal sending module sends an open signal to the first switch valve, and sends a close signal to the second switch valve. signal; when the particulate filter is in a working condition other than the regeneration working condition, and the fuel injection timing is pre-injection, the signal sending module sends a closing signal to the first on-off valve, and sends a closing signal to the second on-off valve Send an open signal. 2. The fuel injector according to claim 1, wherein the controller is a microcomputer controller dedicated to automobiles. 3. The fuel injector according to claim 1, wherein the first on-off valve is a high-pressure solenoid valve, and the second on-off valve is a low-pressure solenoid valve. 4. A common rail fuel injection system, characterized in that it comprises the fuel injector according to any one of claims 1 to 3. 5. The method for injecting fuel by the common rail fuel injection system according to claim 4, is characterized in that, comprising the following steps: S1. Judging the working condition of the particle filter through the first judging module, when it is in the regeneration working condition, enter S2, otherwise enter S3; S2. Judging the fuel injection timing through the second judging module: During the main injection, the signal sending module sends an opening signal to the first on-off valve, and sends a closing signal to the second on-off valve; During post-spraying, the signal sending module sends a closing signal to the first on-off valve, and sends an opening signal to the second on-off valve; S3. Judging the fuel injection timing through the second judging module: During the main injection, the signal sending module sends an opening signal to the first on-off valve, and sends a closing signal to the second on-off valve; During pre-spraying, the signal sending module sends a closing signal to the first on-off valve and an opening signal to the second on-off valve.