JPH0128276Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel regulating device for a diesel engine.

For large marine diesel engines that have a built-in discharge valve, suction valve, and relief valve in their fuel pumps, the opening and closing timing of the fuel intake valve is usually fixed, and the relief valve depends on the engine load (or rotational speed). It is possible to change the opening and closing timing by
The engine is operated by manipulating the opening and closing timing of this valve. In other words, the eccentric shaft for driving the relief valve and the output shaft of the governor, which is installed on the machine side and controls the relationship between engine speed and load, are connected via a link mechanism, and the drive shaft is connected to the output shaft of the governor, which is installed on the machine side and controls the relationship between engine speed and load. The timing is controlled by the governor according to the engine load (or rotational speed).
The rotational speed instruction to the speed governor is performed by transmitting the required propeller rotational speed instruction of the ship to the control cylinder using a pneumatic or hydraulic signal and increasing or decreasing the stroke of the cylinder.

In this case, the relationship between the maximum internal cylinder pressure of the engine and the load is as shown in FIG. On the other hand, in some conventional large marine engines, the opening and closing timing of the intake valve is manually changed under specific loads normally used on ships.
By increasing the maximum cylinder pressure, the effective work of the engine is increased, ultimately reducing fuel consumption for the specified engine load. This effect is noteworthy when aiming for an energy-saving engine, but
Manual operation of the fuel injection system is accompanied by risks due to individual differences in skill and operational judgment among operators. Furthermore, since the load on the engine changes during the voyage, manual operations each time are complicated.

The purpose of the present invention is to focus on the above-mentioned points and to provide a fuel adjustment device for a diesel engine that automatically varies the opening and closing timing of the intake valve according to the engine load. The regulating shaft of the escape valve of the fuel pump is connected to the output end of a speed governor, and the speed governor adjusts the timing of opening and closing of the escape valve, thereby adjusting the flow rate of fuel discharged from the fuel pump. A positioner device that receives an engine load signal corresponding to the magnitude of the engine load and outputs a displacement according to the input signal, and a lift curve corresponding to the engine load is set and a displacement signal from the positioner device is input. and a link mechanism connected between the cam device and a shaft for adjusting the opening/closing timing of the suction valve of the fuel pump to adjust the opening/closing timing of the suction valve in accordance with the lift of the cam device. .

In this case, it is possible to obtain the relationship between the maximum cylinder pressure and the engine load as shown by the solid line in Figure 2, which eliminates the drawbacks of the conventional manual method and reduces the engine's fuel consumption. becomes possible.

Furthermore, no large marine diesel engine has been found equipped with an automatic timing change device for load motion, and the present invention is unprecedented.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is an explanatory diagram showing one embodiment of the device according to the present invention.

In the figure, numeral 1 is an input signal for instructing timing advance and a pneumatic signal for instructing engine speed, and numeral 2 is a known positioner device comprising a known pneumatic positioner 2a and a known air cylinder 2b.

3 is a lever that is connected to the cylinder of the air cylinder 2b; 4 is a cam that is connected to the lever 3 and moves horizontally on a fixed guide (not shown) as the cylinder moves horizontally; 5 is a spring (not shown)
The roller is pressed against the cam 4 by a roller shaft (not shown) and a vertical rod 5a for the roller is connected to transmit the vertical displacement of the cam 4. The cam 4 has an eccentric shaft that controls the opening/closing timing of the intake valve (connected to the intake valve eccentric shaft 10) of the fuel pump in response to the displacement output from the positioner device 2 (displacement corresponding to the engine load). A lift curve corresponding to 10 rotations) is set.

6 is an amplifier, and the input shaft of the amplifier and the vertical roller rod 5a are connected by a lever 6a. Reference numeral 7 denotes a link, which is connected to the output shaft of the amplifier 6 by pin coupling.

8 is a horizontal link for automatic timing advance, 10 is an eccentric shaft for the suction valve, and 9 is a lever, which is fixed to the shaft end of the eccentric shaft 10 for the suction valve with a key or serration, and is connected to the horizontal link 8 by a pin. .

The operation in the case of the above configuration will be described.

The engine speed is indicated in the ship's engine room or wheelhouse. At this time, the instruction signal, that is, the pneumatic pressure signal, is transmitted to the engine speed governor, and the signal (pneumatic pressure) line is branched to the automatic timing advance device. This is the above input signal 1 for .

That is, a signal having the same pressure as the engine load signal is applied to the automatic timing advance device of the present invention.

In the positioner device 2, input signal 1 is received,
A known positioner 2a sets an air pressure line, and an air cylinder 2b provides a cylinder stroke (horizontal displacement) corresponding to the input signal pressure, that is, a cylinder stroke corresponding to the designated rotation speed.

The horizontal displacement of the cylinder 2b causes the cam 4 to move horizontally, which is transmitted to a cam device consisting of the cam 4, the roller 5, and the vertical roller rod 5a, and the vertical displacement of the cam 4 is amplified by the amplifier 6, and the link 7, Eccentric shaft 1 for suction valve via horizontal link 8 and lever 9
By rotating 0, the opening/closing timing of the suction valve is changed according to the load.

The air pressure for engine load and engine speed indication signals is the fourth
The characteristics shown in the figure are obtained, and the cam 4 is affected by the engine load and the cam 4.
The vertical displacement has the characteristics as shown in FIG.

The present invention as described above has the following effects.

The device of this invention makes it possible to change the opening and closing timing of the intake valve according to the engine load situation, and automatically instructs the appropriate intake valve opening and closing timing in the normal operating load range of the ship, reducing engine fuel consumption. In other words, the operating costs of ships can be reduced, resulting in a large economic effect.

In another embodiment of the present invention, the structure of the device is the same as that of the previous embodiment, but the timing advance instruction input signal 1 is a scavenging pressure that changes depending on the engine load. The scavenging pressure always increases as the operating load of the engine increases, and changes as an increasing function as shown in FIG. The device of the above embodiment in which this scavenging pressure is used as an input signal has the same actions and effects as those described above for the same device.

In addition, as shown in FIG. 7, the cam device consists of a rotating cam 22 and a lever 21 fixed to a cam shaft instead of the horizontally moving cam 4 (see FIG. 3). may be provided.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the relationship between maximum cylinder pressure and engine load in a conventional engine, and Figure 2 shows the relationship between maximum cylinder pressure and engine load when equipped with the fuel adjustment device of the present invention. Line diagram, 3rd
The figure is an explanatory diagram showing one embodiment of the fuel adjustment device according to the present invention, Fig. 4 is a diagram showing the relationship between the air pressure for the engine speed indication signal and the engine load, and Fig. 5 is a diagram showing the relationship between the vertical displacement of the cam and the engine load. FIG. 6 is a diagram showing the relationship between scavenging pressure and engine load, and FIG. 7 is an explanatory diagram showing another aspect of the cam device. 1... Input signal for timing advance angle instruction, 2...
Positioner device, 3, 9...Lever, 4...Cam, 5...Roller, 6...Amplifier, 7...Link, 8...Horizontal link for automatic timing advance, 1
0... Eccentric shaft for suction valve.

Claims (1)

[Scope of utility model registration request] The adjustment shaft of the escape valve of a fuel pump having an intake valve, a discharge valve, and an escape valve is connected to the output end of a speed governor, and the speed governor adjusts the timing of opening and closing of the escape valve. In a diesel engine that adjusts the flow rate of fuel discharged from a pump, there is a positioner device that receives an engine load signal corresponding to the magnitude of the engine load and outputs a displacement corresponding to the engine load signal, and a positioner device that outputs a displacement corresponding to the engine load signal. When the displacement signal is input, the lift curve corresponding to the opening/closing timing of the intake valve of the fuel pump is adjusted in response to the displacement so that the closing timing of the intake valve is earlier in a predetermined normal load range than in a low load range. The set cam device includes a link mechanism that is connected between the cam device and the opening/closing timing adjustment shaft of the intake valve of the fuel pump and adjusts the opening/closing timing of the intake valve in accordance with the lift of the cam device. Features a diesel engine fuel adjustment device.