Control system for a diesel engine

Abstract

The utility model discloses a control system of diesel engine for solving the problem of engine cylinder dilution caused by diesel entering oil sump and engine oil through engine cylinder wall during the execution process of the post-injection step in the related art, diesel engine controller connection cylinder outside injection controller, through the cylinder outside injection controller control cylinder outside injection ware and inject diesel in the exhaust pipe of diesel engine, to realize the diesel injection when the cylinder outside injection ware installed on the diesel engine exhaust pipe regenerates, effectively avoid the diesel entering engine oil problem caused by the post-injection in cylinder, reduce the engine failure risk, improve the security of engine.

Description

Technical Field

[0001] This utility model relates to the field of automotive technology, and in particular to a control system for a diesel engine. Background Technology

[0002] Currently, some diesel engines produce a large amount of particulate matter in their exhaust. To protect the environment, diesel particulate filters (DPFs) are needed to capture these particles. Most current DPF regeneration processes involve the following steps: After the main injection, appropriate post-injection occurs through the diesel engine's in-cylinder injectors. The injected diesel fuel enters the oxidation catalyst (DOC) through the exhaust pipe to raise its temperature. The resulting high-temperature gas then enters the DPF, causing the diesel particulate matter attached to the DPF carrier to undergo an oxidation-reduction reaction.

[0003] During the post-injection process in the engine cylinder, some unburned post-injected diesel fuel will enter the oil pan through the engine cylinder wall and mix with the engine oil. The increased amount of diesel fuel entering the oil pan will lead to oil dilution, reduced lubrication capacity, and the risk of cylinder scoring and premature wear in the engine. Utility Model Content

[0004] The purpose of this invention is to provide a control system for a diesel engine to solve the problem in related technologies where, during the execution of the in-cylinder post-injection step, diesel fuel enters the oil pan through the engine cylinder wall and mixes with the engine oil, causing oil dilution, which leads to engine cylinder scoring and premature wear.

[0005] This utility model provides a control system for a diesel engine, the system including a diesel engine, an external injector, a diesel oxidation catalyst (DOC), and a diesel particulate filter (DPF);

[0006] The exhaust pipe of the diesel engine is connected to the intake pipe of the oxidation catalyst, and the exhaust pipe of the oxidation catalyst is connected to the intake pipe of the diesel particulate filter.

[0007] The diesel engine is equipped with a diesel engine controller, and the external injector is equipped with an external injection controller. The diesel engine controller and the external injection controller are connected via a bus.

[0008] The external injector is located on the side wall of the exhaust pipe of the diesel engine. Under the action of the external injection controller, the external injector injects diesel fuel into the exhaust pipe of the diesel engine.

[0009] In one possible implementation, the system further includes an in-cylinder injector;

[0010] The diesel engine controller is equipped with a selection switch; the selection switch is used to control the in-cylinder injector to perform in-cylinder injection or to control the out-of-cylinder injector to perform out-of-cylinder injection; in-cylinder injection refers to the in-cylinder injector injecting diesel fuel into the cylinder of the diesel engine, and out-of-cylinder injection refers to the out-of-cylinder injector injecting diesel fuel into the exhaust pipe outside the cylinder of the diesel engine.

[0011] In one possible implementation, the diesel engine controller is provided with a first enable switch, which is cascaded with the selection switch;

[0012] When the selection switch is set to external injection and the first enable switch is turned on, the diesel engine controller sends a signal to the external injector via the bus.

[0013] In one possible implementation, the diesel engine controller is provided with a second enable switch, which is cascaded with the first enable switch and the selection switch;

[0014] When the selection switch is set to external injection, the first enable switch is on, and the second enable switch is on, the diesel engine controller controls the external injector via the bus so that the external injector, under the action of the external injection controller, injects diesel fuel into the exhaust pipe of the diesel engine.

[0015] In one possible implementation, the diesel engine controller is provided with a third enable switch, which is cascaded with the second enable switch, the first enable switch, and the selection switch;

[0016] When the selection switch is set to external injection, the first enable switch is on, the second enable switch is on, and the third enable switch is on, the diesel engine controller obtains diesel injection feedback signals from the external injection controller via the bus.

[0017] In one possible implementation, the diesel engine controller is equipped with a diesel injection signal receiver and a diesel injection signal source address verifier;

[0018] Under the action of the diesel injection signal receiver, the diesel engine controller receives the hydrocarbon injection signal;

[0019] Under the action of the diesel injection signal source address verifier, the diesel engine controller verifies the source address of the diesel injection signal.

[0020] In one possible implementation, the diesel engine controller is provided with a signal transmitter and a signal receiver, and the diesel engine controller performs signal transmission and reception operations under the action of the signal transmitter and the signal receiver.

[0021] In one possible implementation, the external injection controller is provided with a signal receiver and a signal transmitter, and the external injection controller performs signal transmission and reception operations under the action of the signal transmitter and the signal receiver.

[0022] In one possible implementation, a through hole for mounting a nozzle of an external injector is provided on the side wall of the exhaust pipe near the diesel engine.

[0023] In one possible implementation, the bus is a CAN bus.

[0024] In this invention, an external injection controller is connected to a diesel engine controller. The external injection controller controls the external injector to inject diesel fuel into the exhaust pipe of the diesel engine. This enables the external injector installed on the exhaust pipe of the diesel engine to inject diesel fuel during regeneration, effectively avoiding the problem of diesel fuel entering the engine oil caused by in-cylinder injection, reducing the risk of engine failure, and improving engine safety.

[0025] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of this invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments of this utility model will be briefly introduced below. Obviously, the drawings introduced below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic diagram of the control system of a diesel engine provided in an embodiment of this utility model;

[0028] Figure 2 A schematic diagram of the hardware structure of a diesel engine controller provided in an embodiment of this utility model. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0030] Furthermore, in the description of the embodiments of this utility model, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this utility model, "multiple" means two or more.

[0031] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0032] Currently, some diesel engines produce a large amount of particulate matter in their exhaust. To protect the environment, diesel particulate filters (DPFs) are needed to capture these particles. Most current DPF regeneration processes involve the following steps: After the main injection, appropriate post-injection occurs through the diesel engine's in-cylinder injectors. The injected diesel fuel enters the oxidation catalyst (DOC) through the exhaust pipe to raise its temperature. The resulting high-temperature gas then enters the DPF, causing the diesel particulate matter attached to the DPF carrier to undergo an oxidation-reduction reaction.

[0033] During the post-injection process in the engine cylinder, some unburned post-injected diesel fuel will enter the oil pan through the engine cylinder wall and mix with the engine oil. The increased amount of diesel fuel entering the oil pan will lead to oil dilution, reduced lubrication capacity, and the risk of cylinder scoring and premature wear in the engine.

[0034] In view of this, the present invention provides a control system for a diesel engine to solve the problem in the related art where, during the execution of the in-cylinder post-injection step, diesel fuel enters the oil pan through the engine cylinder wall and mixes with the engine oil, causing oil dilution, resulting in engine cylinder scoring and premature wear.

[0035] This utility model can be summarized as follows: a diesel engine controller is connected to an external injection controller, and the external injection controller controls the external injector to inject diesel fuel into the exhaust pipe of the diesel engine, so as to realize the diesel fuel injection during the regeneration of the external injector installed on the exhaust pipe of the diesel engine, effectively avoiding the problem of diesel fuel entering the engine oil caused by in-cylinder injection, reducing the risk of engine failure, and improving engine safety.

[0036] After introducing the embodiments of this utility model, the following is a brief description of the application scenarios to which the technical solutions of this utility model are applicable. It should be noted that the application scenarios described below are only for illustrating the embodiments of this utility model and are not intended to limit it. In specific implementation, the technical solutions provided by the embodiments of this utility model can be flexibly applied according to actual needs.

[0037] To facilitate understanding of the control system for the diesel engine provided in this embodiment of the present invention, further explanation will be provided below with reference to the accompanying drawings.

[0038] Figure 1 A schematic diagram of the control system of a diesel engine provided in an embodiment of this utility model is shown below. Figure 1 As shown, the system includes a diesel engine, an external injector, an oxidation catalyst (DOC), and a diesel particulate filter (DPF).

[0039] The exhaust pipe of the diesel engine is connected to the intake pipe of the oxidation catalyst, and the exhaust pipe of the oxidation catalyst is connected to the intake pipe of the diesel particulate filter.

[0040] The diesel engine is equipped with a diesel engine controller, and the external injector is equipped with an external injection controller. The diesel engine controller and the external injection controller are connected via a bus.

[0041] The external injector is located on the side wall of the exhaust pipe of the diesel engine. Under the action of the external injection controller, the external injector injects diesel fuel into the exhaust pipe of the diesel engine.

[0042] In this invention, an external injection controller is connected to a diesel engine controller. The external injection controller controls the external injector to inject diesel fuel into the exhaust pipe of the diesel engine. This enables the external injector installed on the exhaust pipe of the diesel engine to inject diesel fuel during regeneration, effectively avoiding the problem of diesel fuel entering the engine oil caused by in-cylinder injection, reducing the risk of engine failure, and improving engine safety.

[0043] Furthermore, this embodiment of the invention uses two controllers to control the diesel engine and the external injector respectively, eliminating the need to integrate the control logic of the external injector into the diesel engine controller, thus reducing the workload of using the engine controller.

[0044] Figure 2 A schematic diagram of the hardware structure of the diesel engine controller provided in the embodiment of this utility model is shown below. Figure 2 As shown, the diesel engine controller includes a cascaded selection switch, a first enable switch, a second enable switch, a third enable switch, a diesel injection signal receiver, and a diesel injection signal source address verifier.

[0045] In another possible implementation, the control system of the diesel engine also includes in-cylinder injectors;

[0046] The diesel engine controller is equipped with a selection switch;

[0047] The selector switch is used to control the in-cylinder injector for in-cylinder injection or to control the out-of-cylinder injector for out-of-cylinder injection.

[0048] In-cylinder injection refers to the injection of diesel fuel into the cylinder of a diesel engine by an in-cylinder injector, while out-of-cylinder injection refers to the injection of diesel fuel into the exhaust pipe outside the cylinder of a diesel engine by an out-of-cylinder injector.

[0049] Since the control logic for external injection described above also applies to internal injection, this embodiment of the invention switches between internal and external injection via a selector switch, eliminating the need to develop two separate control logic architectures for external and internal injection, thus reducing hardware development costs.

[0050] In one possible implementation, the diesel engine controller is provided with a first enable switch, which is cascaded with a selector switch;

[0051] When the selector switch is set to external injection and the first enable switch is turned on, the diesel engine controller sends a signal to the external injector via the bus.

[0052] In one possible implementation, the diesel engine controller is provided with a second enable switch, which is cascaded with the first enable switch and the selector switch;

[0053] When the selector switch is set to external injection, the first enable switch is on, and the second enable switch is on, the diesel engine controller controls the external injector via the bus so that the external injector, under the action of the external injection controller, injects diesel fuel into the exhaust pipe of the diesel engine.

[0054] In one possible implementation, the diesel engine controller is provided with a third enable switch, which is cascaded with a second enable switch, a first enable switch, and a selector switch;

[0055] When the selector switch is set to external injection, the first enable switch is on, the second enable switch is on, and the third enable switch is on, the diesel engine controller obtains the diesel injection feedback signal from the external injection controller via the bus.

[0056] The selection switch is equivalent to an injection mode switch, through which the present invention realizes the switching between in-cylinder injection mode and out-of-cylinder injection mode; the first enable switch is an out-of-cylinder injection bus control enable switch, which is equivalent to a bus switch. When this switch is turned on, the signal is transmitted through the bus; otherwise, the signal cannot be transmitted through the bus; the second enable switch is a diesel injection bus transmission enable switch, which is equivalent to a signal transmission switch. When this switch is turned on, the diesel injection signal is transmitted through the bus; the third enable switch is a diesel injection feedback value bus receiving enable switch, which is equivalent to a signal receiving switch. When this switch is turned on, the diesel engine controller receives the diesel injection feedback signal from the out-of-cylinder injection controller from the bus. The diesel injection feedback signal contains the diesel injection feedback value.

[0057] Since the above four switches are cascaded, in order to realize the function of any one of the switches, it is necessary to turn on the current switch and the switches between the current switches. For example, in order to control the external injector to inject diesel fuel into the exhaust pipe through the external injection controller, the selector switch needs to be set to external injection, the external injection bus control enable switch needs to be turned on, and the diesel injection feedback value bus transmission enable switch needs to be turned on in order to control the external injector to inject diesel fuel into the exhaust pipe.

[0058] This invention controls the process of injecting diesel fuel into the exhaust pipe via an external injector using multiple cascaded switches, ensuring the accuracy of the external fuel injection process and accurately controlling the amount of fuel injected. Simultaneously, the external injector injects less diesel fuel into the exhaust pipe, resulting in higher precision in DOC temperature control and better facilitating the oxidation-reduction reaction of particulate matter by the DPF.

[0059] In one possible implementation, the diesel engine controller is equipped with a diesel injection signal receiver and a diesel injection signal source address verifier.

[0060] Under the action of the diesel injection signal receiver, the diesel engine controller receives the diesel injection signal;

[0061] Under the action of the diesel injection signal source address verifier, the diesel engine controller verifies the source address of the diesel injection signal.

[0062] This embodiment of the invention defines the hardware receiving port of the controller that receives the diesel injection signal through a diesel injection signal receiver to prevent other controllers from receiving the signal; by verifying the controller address contained in the diesel injection signal through a diesel injection signal source address verifier, it can prevent control and tampering by other external controllers.

[0063] In order to enable the controller to receive messages sent by other devices, based on the above embodiments, in this utility model, the diesel engine controller is provided with a signal transmitter and a signal receiver. Under the action of the signal transmitter and the signal receiver, the diesel engine controller performs signal transmission and reception operations; the external injection controller is provided with a signal receiver and a signal transmitter. Under the action of the signal transmitter and the signal receiver, the external injection controller performs signal transmission and reception operations.

[0064] In one possible implementation, a through hole for mounting a nozzle of an external injector is provided on the side wall of the exhaust pipe near the diesel engine.

[0065] In one possible implementation, the bus is a CAN bus.

[0066] In summary, this invention connects a diesel engine controller to an external injection controller, which in turn controls the external injector to inject diesel fuel into the exhaust pipe of the diesel engine. This enables the external injector, installed on the exhaust pipe of the diesel engine, to inject diesel fuel during regeneration, effectively avoiding the problem of diesel fuel entering the engine oil caused by in-cylinder injection, reducing the risk of engine failure, and improving engine safety.

[0067] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A control system of a diesel engine, characterized by, The system includes a diesel engine, an external injector, a diesel oxidation catalyst (DOC), and a diesel particulate filter (DPF). The exhaust pipe of the diesel engine is connected to the intake pipe of the oxidation catalyst, and the exhaust pipe of the oxidation catalyst is connected to the intake pipe of the diesel particulate filter. The diesel engine is equipped with a diesel engine controller, and the external injector is equipped with an external injection controller. The diesel engine controller and the external injection controller are connected via a bus. The external injector is located on the side wall of the exhaust pipe of the diesel engine. Under the action of the external injection controller, the external injector injects diesel fuel into the exhaust pipe of the diesel engine. The system also includes an in-cylinder injector; The diesel engine controller is equipped with a selection switch; the selection switch is used to control the in-cylinder injector to perform in-cylinder injection or to control the out-of-cylinder injector to perform out-of-cylinder injection; in-cylinder injection refers to the in-cylinder injector injecting diesel fuel into the cylinder of the diesel engine, and out-of-cylinder injection refers to the out-of-cylinder injector injecting diesel fuel into the exhaust pipe outside the cylinder of the diesel engine. The diesel engine controller is provided with a first enable switch, a second enable switch, and a third enable switch, wherein the third enable switch is cascaded with the second enable switch, the first enable switch, and the selection switch; When the selection switch is set to external injection, the first enable switch is open, the second enable switch is open, and the third enable switch is open, the diesel engine controller controls the external injector via the bus so that the external injector injects diesel fuel into the exhaust pipe of the diesel engine under the action of the external injection controller; the diesel engine controller also obtains diesel fuel injection feedback signals from the external injection controller via the bus.

2. The system of claim 1, wherein, The diesel engine controller is equipped with a diesel injection signal receiver and a diesel injection signal source address verifier. Under the action of the diesel injection signal receiver, the diesel engine controller receives the diesel injection signal; Under the action of the diesel injection signal source address verifier, the diesel engine controller verifies the source address of the diesel injection signal.

3. The system of claim 1, wherein, The diesel engine controller is equipped with a signal transmitter and a signal receiver. Under the action of the signal transmitter and the signal receiver, the diesel engine controller performs signal transmission and reception operations.

4. The system of claim 1, wherein, The external injection controller is equipped with a signal receiver and a signal transmitter. Under the action of the signal transmitter and the signal receiver, the external injection controller performs signal transmission and reception operations.

5. The system of claim 1, wherein, A through hole for mounting a nozzle for an external injector is provided on the side wall of the exhaust pipe near the diesel engine.

6. The system of claim 1, wherein, The bus in question is a CAN bus.

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