JPS628622B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a low temperature starting device using a fuel injection timing control device for a diesel engine.

Conventionally, this type of low-temperature starting device uses engine rotational speed, fuel injection amount (fuel injection pump easy position, etc.), fuel injection pump rotational phase angle (angular difference between piston top dead center position and fuel injection timing), The input information of the four conditions of air temperature and outside air temperature is input into the microcomputer of the fuel injection timing control device, and this computer controls the fuel injection angle control device to achieve the optimal starting conditions, controlling the rotation of the timing gear and the fuel injection. The phase difference with the pump rotation is set.

However, among the above-mentioned input information, the outside temperature requires an outside air temperature detection element and its lead wire, and has the disadvantage of complicating the hardware, such as needing to be set at a location that is not affected by the engine temperature.

The present inventors discovered that the time from the time when the engine is started by the starter motor and then begins to rotate on its own to the time when the engine reaches the engine rotational speed at which smooth ignition is achieved in all cylinders is significantly different from the outside temperature when the temperature is low. Noting that there is a correlation, the present invention was completed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a low-temperature starting device that is simple, has fewer failures, and is highly reliable.

The present invention provides engine rotational speed, fuel injection amount,
In a low-temperature starting device equipped with an arithmetic circuit that automatically controls fuel injection timing of an engine at low temperatures, including a rotational phase angle of a fuel injection pump and an outside air temperature as input information, the arithmetic circuit has a rotational speed of the engine. The present invention is characterized in that it includes a calculation means for calculating a continuous combustion time of the engine from the above and detecting a parameter corresponding to the above-mentioned outside air temperature from the above-mentioned continuous combustion time.

A detailed explanation will be given below based on the drawings.

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. In the figure, a diesel engine 1 includes a detection circuit 2 that detects the rotational speed of the engine, and a detection circuit 4 that detects the rack position of the fuel injection pump 3.
and a detection circuit 5 that detects the rotational phase angle of the fuel injection pump 3.

Outputs are taken out as electrical signals from each of these detection circuits 2, 4, and 5, and guided to an input interface 9 of a microcomputer 8. This input interface 9 converts these electrical signals into a predetermined information signal level and sends it to a central processing unit (hereinafter referred to as "CPU") 10. CPU10
A storage device 11 is connected to. This storage device 1
1 stores the correlation between the time from when the engine starts to rotate under its own power at startup until all the cylinders are in a smooth ignition state and the outside temperature.

The CPU 10 processes the outputs from each of the detection circuits 2, 4, and 5 as input information, and provides a control output to the hydraulic control valve 14 via the output interface 12. This hydraulic control valve 14 changes the hydraulic pressure to a fuel injection angle control device 17 inserted between a timing gear 16 and the rotating shaft of the fuel injection pump 3, and controls the timing gear 16 so as to advance the fuel injection timing at low temperatures. rotation and fuel injection pump 3
control the rotation and phase difference.

The characteristic configuration of the present invention is that the change over time of the electric signal from the detection circuit 2 that detects the rotational speed of the engine is replaced by the outside air temperature detection signal, which has been conventionally used as input information, based on the stored contents of the storage device 11. be.

FIG. 2 is a diagram showing the starting characteristics of a diesel engine in winter when the outside temperature is relatively high, with time plotted on the horizontal axis and engine rotational speed on the vertical axis.

In FIG. 2, current is applied to the starter motor at point A, and the engine starts rotating. From point A to point B in FIG. 2 is a so-called cranking state, in which no ignition occurs in the cylinder of the diesel engine, and the engine continues to be rotated by the starter motor. When some of the cylinders cause the first explosion and ignite at point B, the starter motor is disconnected and a so-called continuous explosion state continues. Point C in FIG. 2 is a so-called complete explosion state, where all cylinders are in a complete and smooth ignition state, and the rotational speed of the engine increases.

Assuming that the time period in which the continuous bombing occurs from point B to point C (hereinafter referred to as "multiple bombing time") is T, the continuous bombing time T shows a strong correlation with the outside air temperature.

FIG. 3 is a diagram showing the relationship between continuous detonation time and outside temperature, with the horizontal axis representing the outside air temperature and the vertical axis representing the detonation time.
As shown in FIG. 3, when the outside air temperature is as low as -20°C to 0°C, the outside air temperature can be substituted for the continuous detonation time T.

In addition, in this example, an example was shown in which the continuous explosion time is calculated using the outside air temperature, but it is not necessarily necessary to calculate the outside air temperature, and since the continuous explosion time T is a function of the outside air temperature, it can be calculated directly and rationally. It can also be used for calculations.

As described above, according to the present invention, a memory device is provided that stores in advance the engine continuous explosion time with respect to the outside temperature at low temperature, and the engine continuous explosion time is counted and calculated based on the change in the engine over time. By calculating the outside air temperature, the fuel injection timing control device can be controlled under three conditions: engine rotational speed, fuel injection amount, and rotational phase angle of the fuel injection pump.

As a result, it is possible to obtain a low-temperature starting device that has a low failure frequency, is highly reliable, has a simple number of hardware components, and is inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an apparatus according to an embodiment of the present invention. Figure 2 shows the starting characteristics of a diesel engine. FIG. 3 is a diagram showing the relationship between continuous combustion time of a diesel engine and outside temperature. 1... Diesel engine, 2... Detection circuit (rotational speed), 3... Fuel injection pump, 4... Detection circuit (Rack position), 5... Detection circuit (fuel injection pump rotational phase angle), 8... Microcomputer, 9...Input interface, 10...Central processing unit (CPU), 11...Storage device, 12...
Output interface, 14...Hydraulic control valve, 1
6...Timing gear, 17...Fuel injection angle control device.

Claims (1)

[Claims] 1. A low-temperature starting device equipped with an arithmetic circuit that automatically controls engine fuel injection timing at low temperatures, including engine rotational speed, fuel injection amount, rotational phase angle of a fuel injection pump, and outside air temperature as input information, A low-temperature starting device characterized in that the arithmetic circuit includes arithmetic means for calculating a continuous combustion time of the engine from the rotational speed of the engine and detecting a parameter corresponding to the outside air temperature from the continuous combustion time.