JPH0116340B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a starting valve of 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. A brake is applied to the movement of the opening piston 5 to lower the rotation 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 opening/closing timing of the starter valve 4 has been uniquely determined by the cam 6 regardless of the engine speed and the like.

However, originally there is an optimal timing for opening and closing the starter valve depending on the operating condition such as the engine 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 had to do work in the opposite direction during 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.

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a starter valve control device that can control the opening and closing of a starter valve at optimal timing.

The starting valve control device of the present invention inputs the engine speed and starting air pressure and commands the optimum opening/closing timing of the starting valve corresponding to the engine speed by correcting the delay time of the starting valve corresponding to the starting air pressure. and an arithmetic control section that commands the optimum opening/closing timing of the blow valve corresponding to the engine speed, and an operating section that opens and closes the starting valve and the blow valve according to instructions from this arithmetic control section. It has a function of detecting the valve opening operation and performing feedback control of the starting valve opening/closing timing based on the difference between the actual operation timing and the calculated timing.

An embodiment of this invention apparatus will be described 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 stroke during braking to the outside of the cylinder during the expansion stroke, thereby increasing the braking performance. 12 is the starting valve 2
This is a detector that detects the opening operation of the 13 is an angle detector for detecting the absolute position of the crank angle, for example, a rotary encoder, and the explosion top dead center of the No. 1 cylinder is taken in as data, and in the case of other cylinders, it is calculated by calculation based on that. There is. This data is sampled at intervals of approximately 5 degrees of crank angle, and the engine speed is calculated from the travel time during that time. Also, the starting valve 2 is a solenoid valve A.
It is designed to be activated by opening and closing.

The calculation control section is composed of a calculation section and a control section. In the arithmetic unit, the optimal opening/closing timing of the starter valve 2 according to the engine speed is preset for starting and braking, and the optimal opening/closing timing of the blow valve 11 for braking is preset in the calculation section using a numeric keypad. Then, by inputting the engine speed and starting air pressure, the optimum opening/closing timing of the starting valve corresponding to the engine speed is corrected and outputted with the delay time of the starting valve corresponding to the starting air pressure, and the engine speed of the blow valve is output. It is designed to output the optimal opening/closing timing corresponding to the The control section performs correction calculations based on the above output based on the starting air pressure at the optimum timing, and issues commands to the actuating section for opening and closing the starting valve 2 and the blow valve 11. At this time, regarding the starting valve 2, the control section I performs a comparison operation between the crank angle from the crank angle detector 13 and the calculated value. A command is given, and if the condition does not hold, it continues to judge whether the above formula holds in the next calculation. The control section makes a similar judgment regarding the blow valve 11. On the other hand, the control section inputs the opening signal of the starter valve 2 from the detector 12, detects the timing at which the actuating section actually operates, and calculates the Calculate the difference from the calculated timing. Then, the corrected delay time is detected from the engine speed at that time, and feedback is provided to the calculation of the next optimal opening/closing timing. As a result, the optimal value is automatically corrected at all times in any situation.

Therefore, the delay in transmission of operating air pressure can be automatically corrected, and the starter valve 2 and the blow valve 11 can always be opened and closed at the optimum timing.
1, the braking ability can be improved. This minimizes air usage and also reduces starting and braking times. This means that the starting air tank can be made smaller, and the capacity of the air compressor can also be made smaller, 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, increasing safety in ship operation.

Next, a fifth modification of the opening/closing drive method of the starting valve 2 will be described.
This will be explained with reference to FIG. Fig. 5 shows a hydraulic drive system, in which hydraulic pipes are connected above and below the piston 2a of the starter valve 2, and hydraulic pressure is supplied through the electro-hydraulic servo valves _C1 and _C2 to operate the starter valve 2. It is driven to open and close. Also, Figure 6 shows the electromagnetic drive system.
The valve shaft 2b of the starter valve 2 extends above the cylinder head 1, and the starter valve 2 is driven by a solenoid D provided at the top of the cylinder head 1.

Since the starting valve control device of the present invention is as described above, it is possible to control the opening and closing of the starting valve and the blow valve at optimal timing. This makes it possible to improve the starting performance and braking (reversing) performance of the engine.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams of different conventional starting valve control devices, FIGS. 3 and 4 are illustrations of an embodiment of the inventive device, and FIG. 3 is an explanatory diagram of the actuating part; FIG. 4 is a control flow sheet, and FIGS. 5 and 6 are explanatory diagrams of modified examples of different operating parts. 2...starting valve, 11...blow valve.

Claims (1)

[Claims] 1 Input the engine speed and starting air pressure to command the optimum opening/closing timing of the starting valve corresponding to the engine speed by correcting the delay time of the starting valve corresponding to the starting air pressure, and also command the engine speed of the blow valve. It consists of an arithmetic control section that commands the corresponding optimum opening/closing timing, and an actuation section that opens and closes the above-mentioned starting valve and blow valve according to the commands from this arithmetic control section. A starting valve control device for a diesel engine that has a function of feedback controlling the opening and closing timing of the starting valve based on the difference between the operating timing and the calculation timing.