JPS637261B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a starting and braking control device for a diesel engine.

A conventional starting valve control device has a configuration as shown in FIG. 1, for example. Each cylinder head 1
A starting valve 2 that can be opened against the force of a spring is provided at the cylinder head, and compressed air from a starting air pipe 3 is sent to the cylinder head 1 through a control valve 4, and the starting valve 2 is pushed down to cause the piston 5 of each cylinder to move. I pressed it down one after another to start and rotate it. In this case, the control valve 4 is the cam 6
It is designed and manufactured to open when the piston is at a predetermined position (normally between the vicinity of the top dead center and the vicinity of the bottom dead center of the expansion stroke). When braking in reverse (reverse rotation), the engine speed is gradually lowered, the camshaft 7 is slid, and the control valve 4 is opened when the piston 5 is between the bottom dead center and the top dead center of the compression stroke. Braking is applied to the movement of the opening piston 5 to lower the rotation speed and stop it.
Furthermore, as shown in FIG. 2, a plurality of cylinders are treated as one block and controlled by a common control valve 4. In any case, conventionally the starting valve 4
The opening/closing timing of the cam 6 was uniquely determined by the cam 6 regardless of the engine speed, etc.

However, originally there is an optimal timing for opening and closing the starter valve depending on the operating conditions such as the engine rotation speed. Therefore, in the past, the timing was not necessarily optimal, resulting in a lot of wasted air usage and time consuming for starting and braking. Additionally, the compressed air supplied during braking sometimes did work in the expansion stroke, reducing braking performance.
Furthermore, the transmission time of the air signal from the control valve 4 to the cylinder head 1 changes depending on the pressure of the working air.
Further, in the case of FIG. 2, there were many problems such as the fact that the transmission time differed depending on the distance from the control valve 4 to each cylinder, so it was difficult to open and close the starter valve at the optimum timing.

This invention was made in view of the above-mentioned circumstances, and its purpose is to enable opening/closing control of a starting valve and blow valve at optimal timing with a simple configuration without using a computer or the like. It is intended to provide a control device.

The control device of the present invention includes a crank angle detector, a converter that determines the engine speed based on a signal from the detector, a starting valve open detector, a starting air pressure detector, and a crank angle detector that determines the engine speed. and a computing unit that corrects the opening/closing angle of the starting valve and the blow valve based on the starting air pressure and the starting air pressure, and a computing circuit that corrects the correction angle based on the difference between the actual opening angle of the starting valve and the reference opening angle. It is something.

An embodiment of this invention apparatus will be explained below with reference to FIGS. 3 and 4. In the figure, reference numeral 11 denotes a blow valve that is provided using a passage for an acupressure device valve provided in the cylinder head 1 in order to improve braking performance during braking, and is opened and closed by a solenoid valve B. This blow valve 11 discharges an appropriate amount of compressed air introduced into the cylinder during the compression process during braking to the outside of the cylinder during the expansion process, thereby increasing the braking performance. Further, the starting valve 2 is operated by opening and closing the solenoid valve A. 12 is a detector that detects the opening operation of the starter valve 2; Reference numeral 13 denotes an angle detector of, for example, a rotary encoder, which detects the absolute position of the crank angle. If the resolution of this detector 13 is ²¹⁰ , it can be expressed in 1024 combinations. The signal is output in 10 bits. 14
is an F/V converter that determines the engine rotational speed using a pulse signal using the lower bit from the angle detector 13, and the output is obtained as a voltage signal proportional to the rotational speed. Reference numeral 10 denotes a pressure detector provided in the starting air tank to detect the pressure of starting air.

Reference numerals 16 and 17 are registers A and B for opening angle and closing angle, respectively, which determine the correction value of the transmission delay time corresponding to the starting air pressure. Correction coefficients corresponding to the starting air pressure are predetermined in the register A 16 and the register B 17, respectively, and the starting air pressure is inputted and the correction coefficient is sent to the computing unit 18 by a switching signal from the switching logic 20. It's summery. This calculator 18 inputs the engine rotation speed from the F/V converter 14, outputs a correction coefficient proportional to the rotation speed, and also outputs a correction coefficient proportional to the rotation speed.
The correction coefficient based on the starting air pressure from 17 is D/A.
Convert and perform calculations on both. The output from this calculator 18 is sent to an A/D converter 19, where it is digitally converted to determine the correction angle. 21 and 22 are register D for valve opening and random access memory A
It is. The register D21 inputs A/A to the actual crank angle input from the crank angle detector 13.
The correction angle of delay or advance from the D converter 19 is added or subtracted. In this case, the crank angle detector 13
In order to eliminate the need to mechanically precisely align the zero point of the crankshaft with the zero point of the crankshaft, an adder 15 for zero shifting is provided. RAMA22 stores the reference valve opening angle, and register D2
The calculated angle from 1 is compared with this reference angle, and if they are the same, an open signal is output to solenoid valve A or B.
In addition, a register E23 with the same configuration as above for valve closing,
A RAMB 24 is provided and adapted to be switched by switching logic 20. On the other hand, an arithmetic circuit is provided that corrects the correction angle based on the difference between the actual opening angle of the starter valve and the reference opening angle. That is, the reference valve opening angle is stored in the register A16 as well as in the RAMA22. Also, using the signal from the starter valve open detector 12, the crank angle detector 13
The actual valve opening angle is detected based on the signal and input to the register A16. Then, the register A16 sends a signal to the calculator 18 to correct the next correction angle based on the difference between the actual valve opening angle and the reference valve opening angle.
It is starting to be released in As a result, the starting valve 2 and the blow valve 11 are always opened and closed at the reference angle. Note that signals from the RAMA 22 and the RAMB 23 are configured to open and close the solenoid valves A and B through a buffer 31, a monomulti 32, and a power amplifier 33, respectively.

Therefore, it is possible to automatically correct the transmission delay of the operating air pressure and also to correct it based on the engine speed, so that the starter valve 2 and the blow valve 11 can always be opened and closed at the reference angle, and the blow valve 11 is also provided. By doing so, braking ability can be improved. This minimizes air usage and also reduces start-up and control times. Therefore, the starting air tank can be made smaller,
In addition, the capacity of the air compressor can also be reduced, which contributes to reducing the cost of the entire plant. Furthermore, when braking, the engine can be reversed in a shorter time than before, resulting in a shorter stopping distance and time for the ship, which improves ship maneuvering safety.

Since the control device of the present invention is as described above, it is possible to always open and close the starter valve and the blow valve at the reference angle with a simple configuration without using a computer or the like. This makes it possible to improve the starting performance and braking (reversing) performance of the engine.

[Brief explanation of the drawing]

FIGS. 1 and 2 are explanatory diagrams of different conventional control devices, FIGS. 3 and 4 are illustrations of an embodiment of the inventive device, and FIG. 3 is an explanatory diagram of the operating section, and FIG. 1 is a block diagram of a control device. 2... Starting valve, 10... Starting air pressure detector,
11... Blow valve, 12... Starting valve open detector,
13... Crank angle detector, 14... Converter,
18...Arithmetic unit.

Claims (1)

[Claims] 1 includes a crank angle detector, a converter that determines the engine speed based on the signal from this detector, a starting valve open detector, and a starting air pressure detector, and a A control device for a diesel engine, comprising: a computing unit that corrects the opening/closing angle of a starting valve and a blow valve; and a computing circuit that corrects the correction angle based on the difference between the actual opening angle and the reference opening angle of the starting valve.