JPS59176459A - Fuel feed controller for diesel engine - Google Patents

Abstract

PURPOSE:To lengthen service life by blocking fuel supply to a part of cylinders in multi-cylinder Diesel engine under light or intermediate load while alternatively exchanging the stopping cylinder and working cylinder when opening and stopping an exhaust valve thereby consuming all cylinders uniformly. CONSTITUTION:In a fuel injection pump 2 of 6-cylinder Diesel engine 1, a load sensor 4 is fixed to a load lever 3 to provide the detected value to input interface 7 of microcomputor 6. On the basis of output from the load sensor 4, the microcomputor 6 will close a fuel cut valve 12 and to open an air valve 13. Consequently fuel supply to injection pumps 2d, 2e, 2f is cut to open an exhaust valve 22 in first cylinder group by means of a decomp. shaft 24. Under intermediate load, a fuel cut valve 11 is closed while the air valve 13 is opened to stop second cylinder group.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to fuel supply control for a diesel engine that automatically cuts the fuel supplied to the cylinders of the diesel engine by a microcomputer in order to reduce driving fuel consumption. Regarding equipment.

[Description of prior art]

Conventionally, this type of control device has cut fuel supplied to a specific cylinder mainly when the load on the engine is light in order to reduce fuel consumption during driving. That is, in the case of a six-cylinder engine, for example, the conventional control device always cuts fuel to the half of the cylinders on the opposite side of the flywheel in order to reduce the torsional moment of the crankshaft. For this reason, the piston rings and cylinder liners of these cylinders wear out earlier than those of cylinders that do not have fuel cut, and the engine overballs or the parts of cylinders that have reached the end of their fuel life. There was a drawback that it was determined by

[Purpose of the invention]

The present invention solves this drawback. Even when the fuel supplied to the cylinders is cut, the parts of all the cylinders of the diesel engine wear uniformly, and the diesel engine It is an object of the present invention to provide a fuel supply control device for a diesel engine that does not shorten the overhaul time or life span.

[Features of the invention]

The present invention includes a load sensor that detects the load of a diesel engine as an electrical signal, and a fuel supply path for some of the cylinders of the engine and a fuel supply path for other cylinders that can be alternately blocked. When the fuel supply passages of all the cylinders of the engine are blocked, the rocker arms of some of the cylinders are pushed down, and the fuel supply passages of other cylinders are blocked. Exhaust valve opening means configured to push down the rocker arms of the other cylinders to open the exhaust valves; and exhaust valve opening means configured to take in the detection signal of the load sensor as input information and open the exhaust valve according to the magnitude of the load of the engine. The exhaust valve opening means is characterized by comprising a control means including a microcomputer that operates in synchronization with the exhaust valve opening means.

[Explanation based on examples]

An explanation will be given below based on the drawings of the embodiment.

FIG. 1 is a block diagram of a control device according to an embodiment of the present invention. 1st
In the figure, ■ is a six-cylinder diesel engine, and 2 is a fuel injection pump. A load sensor 4 is attached to a load lever 3 of the fuel injection pump 2. This load sensor 4 detects the load of the diesel engine 1 as an electrical signal. The detection signal of this load sensor 4 is guided to the input ink face 7 of the microcomputer 6. This input interface 7 converts this electrical signal into a predetermined information signal level and sends it to the CPU 8. CPU 8 has storage device 9
is connected. This recording device 9 records fuel cut information and exhaust valve opening information for each cylinder according to the magnitude of the engine load. It has been a. The output of CI) Ll 8 is connected via an output interface 10 to the control power of the lightning-opening fuel cut-off valve ILI2 and the sealing air valve 13.

The characteristic feature of the present invention is that this fuel Kantharz is
The main feature of this system is that it cuts fuel for the engine's cylinders using two systems. The fuel cartridges 11 and I2 are interposed between the feed pumps 14 and 15 of the fuel injection pump 2 and the filter 16, respectively. foot pump 14
supply fuel to the injection pumps 2a, 2b, and 2C, respectively, and the foot pump 15 supplies fuel to the injection pumps 2d, 2e, and 2f, respectively. 18 is a fuel tank. The injection pumps 2d, 2e, and 2f are connected to three cylinders (hereinafter referred to as "first cylinder group") located on the flywheel side of the engine.
That's what it means. ), the injection pumps 2a, 2b
, 2c is configured to inject fuel into the other three cylinders (hereinafter referred to as the "second cylinder group").

That is, each injection pump 2 is connected to a nozzle 21 of a cylinder 20, as shown in the enlarged sectional view of the main part in FIG. 22 is an exhaust valve, 23 is a rocker arm, and 24 is a decompression shaft.

Further, the air valve 13 is interposed between an air tank (not shown) and an air cylinder 26. This air cylinder 26 is
As shown in FIG.
The piston rod 27 is connected via a rod 28 and a decompression prepper 29 to a decompression shaft 24 on which a ratchet wheel 30 is pivoted so as to rotate by degrees. 31 is a nail.

FIG. 3 is an external perspective view of the main part of the decompression shaft 24 of this embodiment. A 6 (flit) concave portion 24a is formed at the location where each rocker arm 23 of the decompression shaft 24 comes into contact. The corresponding recess 24a is provided 180 degrees out of phase with respect to the axis of the decompression shaft 24. Fig. 4 shows another example of the decompression shaft 24, in which a protrusion is provided in place of the recess 24a in Fig. 3. 24b is provided.

With this configuration, the operation of this embodiment will be explained with reference to FIGS. 5 to 7. The diesel engine 1 rotates and operates as follows depending on the magnitude of the engine load detected by the load sensor 4.

■ When load sensor 4 detects "light load" = CI)
U8 closes the fuel cartridge hull 12, which had been open, and at the same time opens the core hull 13. As a result, the fuel supplied to the injection pumps 2d, 2e, and 2f is cut,
The decompression shaft 24 is connected by a ratchet wheel 30 to the mouth of the first cylinder group, the car arm 23 and the exhaust valve 2.
2 rotates 90 degrees at a time until the position is pushed down, and then stops, as shown in Figure 5 (al), to stop the explosive combustion of the first cylinder group.For this reason, only the second cylinder group is caused to explode and burn. However, since the engine has a light load, the twisting moment applied to the crankshaft is small and poses no problem.

■ When load sensor 4 detects "medium load": CPU
8 closes the fuel cut valve 11, which had been open, and opens the air valve 13 at the same time. As a result, the injection pump 2a
, 2b, 2c is cut, and the decompressor 71-24 uses the ratchet wheel 30 to close the rocker arm 23 and exhaust valve 22 of the second cylinder group.
Rotate in 90 degree increments until you press down, stop, and press down on the fifth
As shown in Figure (bl), the explosive combustion of the 20th cylinder group is stopped, and the explosive combustion of the first cylinder group is performed.

■ When load sensor 4 detects "full load" = CI)
U8 maintains the fuel cup I valves 11 and 12 open, and maintains the air valve 13 closed. As a result, no fuel supplied to the injection pumps 28 to 2f is sent to the cylinder 1, and the decompression shaft I/24 is rotated by 90 degrees by the ratchet wheel 30 to the position where it does not push down the rocker arm 23 and exhaust valve 22 of the gold cylinder. Then, as shown in FIG. 5 [C], explosive combustion occurs in all cylinders.

FIG. 6 is a diagram showing the operating characteristics of the above device depending on the rotation angle of the decombination shaft 24.

In the above example, a ratcheso wheel is used as a means for rotating the decompression shaft by a predetermined angle, but other means such as a step motor may also be used.

In addition, the partial load classification is only light load, and every time the operating status repeats the cycle of light load to medium load - medium load - light load - medium load and full load, the 10th cylinder group and the second cylinder group It is also possible to adopt a system in which the fuel is cut off alternately during light loads.

Furthermore, although the embodiment has been explained using an in-line 6-cylinder engine, it is of course possible to use it in an in-line 4-cylinder V-type 8-cylinder engine, etc.

〔Effect of the invention〕

As described above, according to the present invention, two systems of fuel cut mechanisms are provided, and when the diesel engine is under light load, the cylinders that cut fuel are changed depending on the operating conditions, etc.
By configuring all cylinders to explode and burn normally under full load, the parts of the cylinders wear out evenly, and the overball timing and lifespan of the engine can be reduced without reducing fuel consumption, unlike conventional control devices. It has an excellent effect that does not speed up comparison.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a control device according to an embodiment of the present invention. FIG. 2 is a side view of the main part of FIG. 1 showing the rotation mechanism of the non-embodiment decombination shaft. FIG. 3 is an external perspective view of the main parts of the decompression shaft of this embodiment. FIG. 4 is an external perspective view of a main part of another embodiment of the decompression shaft 1-. FIG. 5 is a diagram showing the combustion situation of the diesel engine of this embodiment. FIG. 6 is a diagram showing the operating characteristics of the control device depending on the rotation angle of the non-embodiment decombining shaft 1-. ■... Diesel engine, 2... Fuel injection pump, 3
. . . Rotor lever, 4 . . . Load sensor, 6 .
Air valve, 14.15...foot pump, I6.
... Filter, I8 ... Fuel tank, 20 ... Cylinder, 21 ... Nozzle, 22 ... Exhaust valve, 23 ...
・Rocker arm, 24...decompression shaft l-12
6...Air cylinder, 27...Bis 1-rond,
29... Decompression lever, 30... Ratchet wheel, 31... Pawl. Patent applicant: Hino Motors Co., Ltd., 5. −1゜Representative Patent Attorney Nao Takashi Ide ゛Figure 3 Figure 4 Calculation of all cylinder groups Figure 5 Figure 6

Claims (1)

[Scope of Claims] (]) A load sensor that detects the load of a diesel engine as an electrical signal; a blocking means capable of blocking the fuel supply passages of some of the cylinders of the engine, when the fuel supply passages of some of the cylinders are occluded; an exhaust valve opening means configured to push down the rocker arms of other cylinders to open the exhaust valve when the engine is blocked; A fuel supply control device for a diesel engine, comprising control means including a microcomputer that operates the closing means and the exhaust valve opening means in synchronization.