JPH088276Y2 - Diesel engine fuel injector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a fuel injection device for supplying fuel to a diesel engine, and in particular, when the number of ignited cylinders reaches a predetermined number, the injectors of unignited cylinders are stopped and a fixed amount The present invention relates to a fuel injection device that prevents white smoke and odors from being emitted while ensuring engine output.

[Prior Art] As a fuel injection device of an engine for supplying fuel to an injector, a mechanical fuel injection pump (row type, rotary type, etc.) ("Automotive Engineering Complete Book 5" (diesel engine) ... Sankaido Publishing Co., Ltd.), A fuel injection pump (unit type) in which the controller controls the injection amount is known.

Conventionally, these fuel injection pumps pressure-feed fuel to all injectors arranged for each cylinder so as to keep the engine rotation speed constant, and the engine is preferably driven by the fuel injected from these injectors. Is configured as follows.

[Problems to be Solved by the Invention] However, in a diesel engine that spontaneously combusts due to evaporation of fuel, even if the same fuel is supplied to each cylinder by each injector, at the time of low temperature starting Since the degree of fuel evaporation (ignitability) and ignition delay differ for each cylinder, cylinders that cause ignition (ignition cylinders) and cylinders that do not cause ignition (unignited cylinders) can be created. , The engine is operated by the cylinder that has ignited, but at this time, since the fuel supply to the cylinder that does not ignite is continued, a considerable amount of unburned fuel is discharged from the cylinder that does not ignite for a long time. There is a problem that it will end up.

[Means for Solving the Problems] The present invention is intended to solve the above problems, and an injector provided to supply fuel to each cylinder of an engine and an ignition provided to the engine to detect ignition of each cylinder. The ignition sensor provided, the temperature sensor provided to detect the engine temperature in the engine, and the number of cylinders that are ignited based on the detection signal of the ignition sensor at low temperature start, and the total number is When the required engine output at cold start is equal to or exceeds the number that can be obtained, the injectors that were supplying fuel to the unignited cylinders are stopped, and the fuel supply to the unignited cylinders is cut off. When the temperature reaches a temperature at which no ignition can occur in all cylinders, a controller is provided which operates all injectors and supplies fuel to all cylinders. It

[Operation] When the controller sums up the number of cylinders that are ignited based on the detection signal of the ignition sensor and the totaled number is equal to or exceeds the number that can obtain the engine output required at the cold start, , The fuel supply to the unfired cylinders is stopped by stopping the injectors supplying the fuel to the unfired cylinders.
Therefore, no unburned fuel is discharged from the unignited cylinder. The temperature of the entire engine rises and the temperature of the non-ignited cylinder rises due to the warm-up of the ignited cylinder that has been ignited and continues to be supplied with fuel. The controller operates all the injectors to supply fuel to all the cylinders when the engine temperature reaches a temperature at which no ignition can occur in all the cylinders.

[Embodiment] A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

Reference numeral 1 shown in FIG. 1 is a 6-cylinder engine, and unit injectors 2 to 7 for atomizing and supplying fuel to the respective cylinders A to F of the engine 1 are provided.
Is attached. On the other hand, each cylinder A to F of the engine 1
In each of the exhaust passages 8 to 13 connected to
Ignition sensors 14 to 19 such as thermocouples that detect the ignition of F are attached, and a temperature sensor 20 that detects the temperature of the cooling water is attached to the cooling water circulation system of the engine 1.

As shown in FIG. 2, each of the unit type injectors 2 to 7 in the embodiment slidably accommodates a plunger 22 cam-driven according to the rotation speed of the engine 1, and the plunger 22 The fuel supplied in response to the drive is pressurized and sent to a fuel supply passage 23, which will be described later, and the cam 24
A nozzle holder 27 that forms a fuel chamber 26 for introducing a leak fuel into a fuel return passage 25 described later with a minimum lift value of, and a nozzle body 28 that is integrally accommodated at the tip side of the nozzle holder 27, From the body 28 formed in the holder 27 and the fuel supply passage 29 for guiding fuel from a fuel injection pump (not shown) to the fuel supply passage 23 in the body 28 and from the body 28. Of the fuel return passage 25 for returning the leaked fuel to the fuel injection pump side, and when one of the fuel return passages 25 is opened, the other solenoid valve 31 is closed.

In the solenoid valve 31 of the embodiment, the spool 32 of the solenoid valve 31 that closes the fuel return passage 25 when not energized is returned by a return spring (not shown) to open the lower fuel return passage 25. At the same time, its fuel return passage 25
The fuel oil feeding passage 29 formed substantially parallel to the above is closed.

On the other hand, the nozzle holder 27 is formed in a tubular shape so as to slidably accommodate the needle valve 33, and the facing portion of the taper-shaped pressure receiving surface 34 of the needle valve 33 is depressed in the radial direction along the circumferential direction. By applying fuel oil pressure to the pressure receiving surface 34, the needle valve
A fuel pressure chamber 35 that moves 33 in the valve opening direction is formed. The fuel supply passage 23 is connected to the fuel pressure chamber 35.

By the way, in this embodiment, the ignition sensors 14 to 19 and the temperature sensor 20 are connected to the input section of the controller 21,
The injectors 2-7 are connected to the output of the controller 21.

Next, the control content of the controller will be described with reference to FIG.

Immediately after the starter is started, the controller 21 outputs the fuel to each of the injectors 2 to 7 in step 41 after the start 40 to inject fuel into all cylinders of the engine 1 to start the engine 1. Next, the controller 21 makes judgments 42, 44, ..., 52, respectively, on the basis of the detection signals from the ignition sensors 14 to 19 to judge the operating states of the respective cylinders A to F. If it is in the non-ignition state, when it is in the non-ignition state, that is, in NO, the flags (A = 1, B = 1, ..., F = 1) indicating the non-ignition in steps 54, 55, ... ), The number of ignited cylinders is counted in steps 43, 45, ..., 53 next to the above-mentioned judgments 42, 44 ,. At the same time, the controller 21 makes a judgment 57 when the number X of ignition cylinders is equal to or exceeds the number N capable of obtaining the engine output required at the cold start (for example, setting the total number of cylinders to 6 and idling at the cold start). When the number of operating cylinders N that obtains the required engine output is 2, the number of cylinders that can cut off the fuel supply is 4.) Judgment 58, 59, ..., 62
In Steps 63, 64, ..., 68 based on the above, the injector that was supplying the unfired cylinders is stopped, and the fuel supply to the unfired cylinders is cut off. As a result, it is possible to prevent the discharge of unburned fuel (white smoke) from the unignited cylinders and to prevent the discharge of odors, while ensuring the engine output required at the time of cold start and idling. After this, the controller 21 detects the cooling water temperature T ₀ in step 69,
Based on the detection signal from the temperature sensor 20, a determination 70 determines the operating state of the engine 1. That is, when it is determined that T ₀ ≦ T in the determination 70, the number of operating cylinders is fixed because it is during low temperature starting or idling, and the flow from determination 58 to step 68 is repeatedly executed.

If T ₀ > T in judgment 70, the temperature T ₀ of each of the cylinders A to F is maintained at a temperature at which the supplied fuel can be combusted without being ignited. 7 to 7 to inject fuel from the injectors 2 to 7 into all cylinders A to F of the engine 1 to increase the output of the engine 1 and preferably drive the engine 1.

[Effect of the Invention] As is clear from the above description, the present invention exhibits the following excellent effects.

At the time of cold start, while ensuring the required engine output, the fuel supply to the unfired cylinders was cut off so that the unfired cylinders could be warmed up. Can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view showing a preferred embodiment of the present invention, FIG. 2 is a sectional view of an injector, and FIG. 3 is a flow chart showing control of a controller. In the figure, 1 is an engine, 2 to 7 are injectors, 14 to 19 are ignition sensors, and 21 is a controller.

Claims (1)

[Scope of utility model registration request] 1. An injector provided to supply fuel to each cylinder of an engine, an ignition sensor provided to detect ignition of each cylinder of the engine, and an engine sensor provided to detect engine temperature. Temperature sensor,
At the time of cold start, the number of cylinders that are ignited based on the detection signal of the ignition sensor is totaled, and when the total number is equal to or exceeds the number that can obtain the required engine output at cold start, the Only the injectors that were supplying fuel to the ignited cylinders were stopped, and the fuel supply to the unignited cylinders was cut off.
After that, when the engine temperature reaches a temperature at which no ignition can occur in all cylinders, a diesel engine characterized by having a controller that operates all injectors to supply fuel to all cylinders Fuel injection device.