JPS61237863A - Electronic control type internal-combustion engine - Google Patents

Abstract

PURPOSE:To enable a combustion to be always set to an optimum state, by providing a means, correcting a maximum pressure in a combustion engine and a fuel injection maximum pressure based on their respective set values, and a means, resetting each set value based on an effective heat generating rate, a fuel injection rate, etc. CONSTITUTION:In a CPU 19 which controls various valves including a fuel injection valve based on various operating parameter of an engine, a maximum pressure in a combustion chamber is corrected compared with a set value through control of the injection starting timing of a fuel injection valve on a basis of a pressure in a combustion chamber and a given horse power. Further, based on a fuel injection pressure and a given horse power, a fuel injection maximum pressure is corrected compared with a set value. Each set value is reset based on an effective heat generating rate, a fuel consumption rate, and the coefficient of effective combustion, determined by processing devices 101-103. Flow rate regulating valves 105 and 106 for cooling water and cooling oil, respectively, are controlled based on at least either the coefficient of effective combustion or a fuel consumption rate.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an electronically controlled internal combustion engine.

Conventional technology Electronically controlled internal combustion engines, for example, attempt to achieve optimal operation control of a diesel engine using an electronic computer, and specifically control the diesel engine's crank angle per revolution speed, torque, and pressure in each part of the engine. This data is then processed by a computer according to a predetermined program to determine optimal operating control conditions.
The obtained conditions are used as control command information to open and close the starting valve, scavenging valve, exhaust valve, fuel injection valve, etc. of the diesel engine in accordance with the crank angle.

FIG. 4 shows the overall configuration of an electronically controlled internal combustion engine.

A diesel engine usually has a plurality of cylinders (1) numbered from 91st to Nth, and each cylinder (1) has:
Start valve (2), scavenging valve (3), exhaust valve (4), respectively.
Equipped with fuel injection pressure 5). (6)-(11)
is an actuator that operates these parts (2) to (5). Fuel injection valve (May ζ is supplied with fuel oil from the fuel tank QO by the fuel pump (b). (6
) is the fuel pressure accumulator, aa is the fuel cutoff valve, a◆ is the check valve, O
I is a fuel flow meter.

On the other hand, the rotation angle of the crankshaft (g) is detected by the encoder α, and the rotation angle is detected by the input port Qη and the data bus (to).
The data is then input to a central processing unit (hereinafter referred to as CPU). Note that the detection output of the encoder Ql is also sent to the diesel engine control circuit (a) and the frequency/voltage converter (b) as crank angle information.

The signal converted into a voltage signal corresponding to the rotational speed of the frequency/voltage converter is input to the CPU (111) via the analog/digital converter (support) and the data bus Ql. pressure, temperature.

The exhaust gas composition and the like are also detected by sensors (Sl) to (Srs), and after the data is digitally converted by an analog/digital converter, it is input to CPUQl.

The CPU Ql reads the operating command input from the setting input/display device, and based on this operating command, calculates the crank angle per revolution speed, the pressure and temperature of each part of the engine, etc. input from the analog/digital converter, etc. By using data representing the operating state of the engine, such as the composition of exhaust gas, calculation of the control amount and operation amount for optimal control of the engine is executed according to a predetermined program. Then, from this calculation result, a control command for the fuel pump Ql is created and sent to the fuel pump Ql via a digital/analog converter.
). Furthermore, the CPU (11) calculates the starting valve (2) from the calculation result.

Control commands for each part of the air supply valve (3), exhaust valve (4), and fuel injection valve (5) are created and output to the diesel engine control circuit 4.

The diesel engine control circuit 4 reads the control command from the CPU (6) and sends control information corresponding to the crank angle information obtained from the encoder aQ to the 11th second drive circuit (to)@. The first drive circuit (to) is
A control valve that controls the actuation timing of the actuator (9) is controlled to operate the fuel injection valve (5). 1i
The drive circuit (to) No. 2 is the actuator (6) (7)
The control valves (to) @ (7) that control the operation timing of (8) are operated to operate the start valve (2), the scavenging valve (3), and the exhaust valve (47), and also to operate the fuel cutoff valve Q. In this example, the actuator (6)
~ (9) As a driving power source, a hydraulic oil pump OIζ
Therefore, the hydraulic pressure generated is used, and a pulsation prevention and hydraulic oil pump 6υ is installed on the outlet side of the hydraulic pump (b).
) is installed in the pressure accumulator to reduce the power required.

So is the pressure regulating valve, (Incorporated) is the oil tank, and Ol is the flow regulating valve.

FIG. 5 shows a conventional example of a control block diagram of the fuel injection valve (5) and the fuel pump C1η out of the above-mentioned "predetermined program". The combustion chamber pressure processing device 111 in the central processing unit 4 is connected to the combustion chamber pressure processing device 111 through an analog/digital converter.

Signals (pz) from the combustion chamber pressure sensor (Sy) # and the scavenging chamber pressure sensor (Sa). h(ps)D is input, a signal from encoder 4 is input to the rotation speed processing device, and a signal (1) f from the fuel injection pressure sensor (S9) is input to the fuel injection pressure processing bag [1531]. D is input.

In the combustion chamber pressure treatment device, the combustion chamber pressure pz is the sixth
As shown in figure (a), the pressure of the compression wire is P
The maximum C1 combustion pressure Pm, the expansion pressure Pexp at a specific crank angle during the expansion process, and the corresponding crank angles i0c, θm, and θexp are read out. At the same time, the indicated mean effective pressure Pi is calculated.

These waveform processes are performed in the same cylinder (1) in several tens to several 1
This is done by averaging the waveforms of 00 cycles. The rotational speed processing device 6 calculates the rotational speed of the engine, divides the crank angle, and sends the signals to the fuel injection pressure processing device and the fuel injection pressure processing device.

In the fuel injection pressure processing device (2), the waveform is processed as shown in FIG. 6(b), and the crank angle of corresponding to the fuel injection start pressure pfos, the maximum injection pressure pfm, and the fuel injection start pressure 1'fo. , and the crank angle θ of the fuel injection path
fe is read.

Next, in the indicated horsepower processing device, the indicated mean effective pressure P
From i and engine speed n.

Perform the calculation. Here, Vs - displacement (cylinder stroke volume) 1lI - 1: 2 cycles - 1/2: 4 cycles. Comparison of maximum pressure in the combustion chamber, correction processing device - The maximum pressure Pm in the combustion chamber is stored as a standard value. This value is set so that the thermal efficiency is the best (the fuel consumption rate is the lowest) in a relatively high output range.1For example, in recent marine In a large two-stroke diesel engine, the maximum pressure (Pm) is set as shown in Figure 7.Generally speaking, the higher the maximum pressure Pm is, the better the thermal efficiency will be, but it is naturally determined by the mechanical strength of the engine, etc. There is a limit to the end-of-compression pressure Pc in the combustion chamber.
The limit is set at 1.6 to 1.7 times. The signal of the maximum pressure Pm inputted from the combustion chamber pressure processing device mortar to the combustion chamber maximum pressure comparison/correction processing bag @- is compared with the set maximum pressure (Pm)m, and the pressure Pc at the end of compression is determined as shown in the figure. The correction amount is determined in consideration of the horsepower Ni condition. From the combustion chamber maximum pressure comparison/correction processing device, the stored maximum pressure (Pm) m (A
, B, C・''), and the correction signal is set to Pm/PC≦1.6~ as mentioned above.
The limit is set to fall within the limits of 1.7. This correction signal is input to the diesel engine control circuit (1), and a signal for correcting the fuel injection start timing is output to the first drive circuit in accordance with the crank angle information obtained from the encoder (1). and the fuel injection valve (6)
The control valve (goods) is designed to perform corrective control. In addition, the maximum set pressure (Pm) m (A, B, C3 shown in Fig. 8)
It is also possible to reset settings from a setting input processing device with a display device.

On the other hand, the maximum injection pressure is compared and compared by the correction processing device, and corrected by the pressure deviation-correction signal characteristic shown in Figs. I get a signal. This correction signal is sent to the fuel pump aη via a digital/analog converter (Incorporated) to control the ejection flow rate of the fuel pump (Ill).

The above problems to be solved by the invention are the optimal control methods for conventional electronically controlled internal combustion engines, but as mentioned above, the set maximum combustion pressure (Pm) m and the maximum fuel injection pressure (Pfm) m It is also based on data from sea operations in the early stages of service, and cannot take into account all the contamination and changes in characteristics of various parts due to aging of the engine, and changes in the properties of fuel oil. Therefore, for a diesel engine that has been running for a year or when the fuel oil used has changed, when operating with these standard setting values of (Pm)m and (Pfm)m, 1 is truly optimal control (the operating cost of the engine is There was a problem in that it was not possible to determine whether or not the minimum value was reached while driving.

Therefore, the present invention compensates for these drawbacks and provides an optimal Ill.
(7) Make it possible to obtain indicators for control while driving.

In particular, it attempts to optimally set target combustion conditions when the properties of fuel oil change.

Means for Solving the Problems and Description: In order to solve the problems, the present invention calculates the opening/closing timing of valves that need to be opened and closed during operation of an internal combustion engine.

An electronically controlled internal combustion engine that controls the opening and closing operations of the valves based on the calculation result and the detected crank angle is configured to set the injection start timing of the fuel injector among the valves based on the combustion chamber pressure and indicated horsepower. Means for correcting the maximum pressure in the combustion chamber with respect to its set value by controlling the fuel injection pressure and indicated horsepower.

means for correcting the maximum fuel injection pressure with respect to the set value based on the set value; A means for resetting the engine cooling water flow rate adjustment valve and a cooling oil flow rate adjustment valve based on the effective combustion coefficient,
and means for controlling based on at least one of the effective combustion coefficient and the indicated fuel consumption rate.

Function: Not only is it possible to optimally control the engine by controlling the fuel injection start timing and fuel injection pressure, but also the set value of the maximum pressure in the combustion chamber and the set value of the maximum fuel injection pressure can be adjusted. This resetting control makes it possible to set the conditions for the pot type without confirming that fuel consumption is at its minimum.Moreover, by also controlling the cooling water flow rate adjustment valve and the cooling oil flow rate adjustment valve, Not only can the optimal controlled operation of one engine be carefully examined, but also the optimal controlled operation can be realized more strictly.

Embodiment One embodiment of the present invention will be described below with reference to FIGS. 1 to 8.

FIG. 1 is a diagram showing the conventional one shown in FIG. 6, which is added by the present invention, and all the functions explained in FIG. 6 are retained. The explanation of that part will be omitted.

The newly added items are the fuel oil flow rate sensor (Sso) attached to the fuel flow meter (to), the fuel oil temperature sensor (Su) - the combustion chamber wall member temperature sensor (Stx) ~ (
Sss), engine cooling water inlet and outlet temperature sensor (Sll)
(517), engine cooling oil inlet and outlet temperature sensor (Ssa
) (St, ), an exhaust gas temperature sensor (Ss), and a low-speed νD converter (22a) for various temperature sensors. Additionally, the CPU (newly added to the ill is a fuel flow processing device (10G)).

Effective heat release rate processing device (101), fuel injection rate processing device (1G, effective combustion coefficient ηb/indicated fuel consumption rate bi
A processing device (108), and a cooling water and cooling oil temperature comparison and correction processing device (104). Furthermore, the installed equipment is an engine cooling water flow rate adjustment valve (105).
and an engine cooling oil flow rate adjustment valve (106).

First, a signal from the fuel oil flow rate sensor (Ss) is input to the fuel flow rate processing device (1GG) in CPU U via the analog/digital converter@. At the same time, the signal from the fuel oil temperature sensor (Su) is also sent to the low speed A/D converter L22a.
) is input to the fuel flow rate processing device (Zoo), and the fuel flow rate per unit time is calculated by the processing device (Zoo).

The combustion chamber wall member temperature sensor is as follows: (Ss) is the cylinder cover temperature, (Su) is the cylinder cover temperature, (S14)
(516) detects the piston temperature and (516) the exhaust valve temperature. (Sss) (Sty) are sensors that detect the engine cooling water inlet and outlet temperatures, and (Ssa) (Sss) are sensors that detect the engine cooling oil inlet and outlet temperatures, respectively.

(No. 5 is the exhaust gas temperature sensor. These (Ssz)
~(Ss- and [S,] are the low-speed A/D converters (
22a), it is input to the cooling water and cooling oil temperature comparison and correction processing device (104).

The effective heat release rate processing device (101) receives the signal (Pz) from the combustion chamber pressure processing device and calculates the effective heat release rate dQe/dθ using a linear equation.

Here, is the specific heat ratio of the combustion gas, V is the cylinder volume, and A
is the heat equivalent of work.

On the other hand, the fuel injection rate processing bag [(102) receives the signal (p[) from the fuel injection pressure processing device.

The fuel injection rate dB/dθ is calculated using the following equation.

Here, C is the flow coefficient, A is the injection area of the fuel injection valve, and T
B is the specific weight of the fuel, and g is the acceleration of the power.

Then, in the effective combustion coefficient η, indicated fuel consumption rate bi processing device (1Gg), first, the effective heat release rate processing device (
101). Effective heat release rate dQe7dθ
and the fuel injection rate dB/dθ which is the output from the fuel injection rate processing device (102), and the effective combustion coefficient ηb is calculated by a linear equation.

Here, Hu is the lower calorific value of the fuel, and σcs and θfs are the crank angles at the start of combustion and the start of injection.

Figure @2 shows the effective heat release rate d calculated in this way.
Fe/dθ, fuel injection rate, dB/dθ, effective combustion coefficient η
An example of b is shown below. These serve as indicators for evaluating the combustion state of the engine.

Further, the effective combustion coefficient ηbe at the end of effective combustion where the effective heat release rate dQe/dθ becomes 0 is ηbeQE/B-Hu...(V) where θce is given by the crank angle at the end of effective combustion. Here, B is θfc is the crank angle of the fuel injection path. FIG. 8 shows an example of the effective combustion coefficient ηbe at the end of effective combustion. Heat loss during the combustion period by (l-ηbe),
It is possible to evaluate the amount of unburned fuel at the end of effective combustion, but in the case of large diesel engines, combustion is close to complete and there is almost no unburned fuel, so (l-η
be' may be used as an evaluation index of heat loss during the combustion period. Figure 8 shows ηbe with respect to the indicated mean effective pressure Pi using the engine speed n as a parameter. As Pi increases at a constant engine speed n (for example, n), the amount of fuel supplied increases and the effective heat amount increases. This indicates that the heat loss is relatively reduced and ηbe becomes larger. Furthermore, it is shown that when Pi is constant and n increases, ηbe increases because the combustion period becomes shorter and heat loss decreases.

Next, as another function of the effective combustion coefficient ηb/indicated fuel consumption rate bi processing device (10 g), the indicated horsepower Ni obtained by the indicated horsepower processing device - and the indicated horsepower Ni obtained by the fuel flow rate processing device (Zoo) are calculated. Fuel flow rate per unit time Qf
The indicated fuel consumption rate bi may be determined using the following equation.

However, rB is the specific weight of the fuel, Huy is the lower calorific value of the fuel used, and is given by the fuel flow rate per unit time Qf ('/h) obtained by the fuel flow rate processing device (100), and the formula (Vll). There is an on relationship with the injected fuel amount B (g/C, cle), and Qf is
It is also used for examining and correcting the flow coefficient C on the right side of Equation 110.

In parallel with these calculation processes, as described above, the maximum pressure in the combustion chamber is compared, the maximum pressure Pm in the combustion chamber is adjusted by the correction processing device, and the maximum injection pressure Pfm is adjusted by the comparison and correction processing device for the maximum injection pressure. adjustments will be made.

However, the fuel properties and lower calorific value are set at the standard setting value (Pm).
m (Pfm) In cases where these values are different from those at the time of request, it cannot be determined whether or not the engine is being operated with the minimum fuel consumption just by adjusting Pm and Pfm.

Therefore, the above index (a) effective heat release rate dQ/dθ, (
0) Fuel injection rate dB/dθ, ? 1) using the effective combustion coefficient ηb, and (e) the effective combustion coefficient ηbe at the end of effective combustion, and (e) the indicated fuel consumption rate bt, the reference setting value (Pm)m, (Pf
m) It becomes possible to reset m and drive with the lowest fuel consumption.

First, (a) dQ/alj %(COdB/dθ, (
/jrtbli gi 2 It is processed and displayed on the display device as shown in Figure 1c.

The waveform pattern can be observed successively.

For example, when the pattern shown by the broken line in FIG. 2 is obtained, it is compared with the pattern shown by the solid line when the reference setting values are determined, and the Pm and Pfm are reset so as to approach the pattern shown by the solid line.

However, (Pm)m has a setting limit as mentioned above.

There may be cases where it is not possible to approximate the solid line pattern. Therefore, next, in) the effective combustion coefficient η at the end of effective combustion
The heat loss during the combustion period is evaluated by bc, and the temperature of the cooling water and cooling oil of the combustion chamber members of the engine 1 is adjusted to reduce the heat loss during the combustion period and improve fuel consumption. For this purpose, the cooling water.

The cooling oil temperature comparison/correction processing device (104) compares the signals from the cooling water and cooling oil temperature sensors (S's) to (S+*) with the effective combustion coefficient '7be at the end of effective combustion.

As this ηbe approaches ηbe in Fig.
The configuration is such that a correction signal is sent to the digital/analog converter (2). However, in this case too, there is an upper limit to the temperature, and this upper limit is the temperature of the combustion chamber wall member, that is,
Cylinder liner, cylinder cover.

Piston and exhaust valve temperature sensors (Sz*) to (Ss)
determined by the temperature obtained by Note that if the temperature of these combustion chamber wall members is not detected, a guideline for determining the upper limit of the temperature limit can be obtained from the exhaust gas temperature obtained by the exhaust gas temperature sensor (S,).

Effects of the Invention As described above, according to the present invention, it is possible to carefully examine the optimum control operation of the engine using the conventional method, and also to realize the optimum control operation more strictly, thereby minimizing fuel consumption. This makes it possible to set various conditions while confirming that the conditions are correct.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of essential parts of an embodiment of the present invention. Figure Wiz and Figure 8 are diagrams explaining the processed waveforms in one embodiment of the present invention, Figure 4 is an overall configuration diagram of an electronically controlled internal combustion engine to which the configuration of the present invention is added, and Figure 6 is a block diagram of a conventional example. Fig. 6 is an explanatory diagram of the processing waveform in the conventional example, Fig. 7 is an explanatory diagram of the maximum pressure in the combustion chamber and compression path pressure in the combustion chamber, and Fig. 8 is a comparison of the maximum pressure in the combustion chamber, from the modified processing device. FIG. 9 is an explanatory diagram of the combustion injection maximum pressure. FIG. fH10 is an explanatory diagram of the output signal of the correction processing device for comparison of the maximum injection pressure. (5)-Fuel injection valve, (Foundation)...Crankshaft, QI-
・Encoder, wire...Central processing unit, (1)-・
Diesel engine, 4...Setting input/display device, -...
・Comparison of maximum pressure in combustion chamber, correction processing device, rn-・Comparison of maximum injection pressure, correction processing device, m-・Setting input processing device, @-・Display device, (101) ... Effective heat release rate processing device, (IH)--fuel injection rate processing device,
(10g)... Effective combustion coefficient ηb/indicated fuel consumption rate bf processing device, (104) --- Cooling water, cooling oil temperature comparison, correction processing device, (106) --- Engine cooling water flow rate adjustment valve % (1Gg) ・・・Engine cooling oil amount adjustment valve

Claims (1)

[Claims] 1. An electronically controlled internal combustion engine that calculates the opening and closing timing of a valve that needs to be opened and closed during operation of the internal combustion engine, and controls the opening and closing operation of the valve based on the calculation result and the detected value of the crank angle, Means for correcting the maximum pressure in the combustion chamber with respect to a set value by controlling the injection start timing of the fuel injection valve among the valves based on the pressure in the combustion chamber and the indicated horsepower; means for correcting the maximum fuel injection pressure with respect to the set value based on the set value of the maximum pressure in the combustion chamber, and the set value of the maximum pressure in the combustion chamber and the set value of the maximum fuel injection pressure based on the effective heat release rate, fuel injection rate, and effective combustion. and means for controlling the cooling water flow rate adjustment valve and the cooling oil flow rate adjustment valve of the engine based on at least one of the effective combustion coefficient and the indicated fuel consumption rate. An electronically controlled internal combustion engine.