JPS6035134A - Fuel injection equipment of internal-combustion engine - Google Patents

Abstract

PURPOSE:To hold the rate of fuel injection always at its optimum level by equipping a fuel injection device with an oil-hydraulic timer to correct the changing ignition timing, wherein the injection amount is controlled by the relative rotation of a plunger with a ring valve while the ignition timing is controlled by displacement of the plunger of said valve in the axial direction. CONSTITUTION:A fuel injection pump 1 has a plurality of single cylinder units 4, each of which presses forward the fuel through the action of a plunger 16 reciprocated by a cam shaft 19, and the relative rotation and axial directed displacement of a ring valve 18 fitted on said plunger 16 with respect thereto will provide adjustment of the amount of fuel injection and the rate thereof, respectively. Said axial directed displacement of ring valve 18 is performed by an injection rate adjustment rack 25 and an eccentric pin 26. At the exterior end of the above-mentioned cam shaft 19, an oil-hydraulic timer is mounted, which shall conduct a specified delay or advance of the ignition angle by changing the rotational phase angle between the cam shaft 19 and the drive shaft on engine side. This will accomplish a feedback control in compliance with the amount of change in said adjustment rack 25 as well as the operating conditions of the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel injection device for an internal combustion engine.

(Prior art) In conventional fuel injection systems for internal combustion engines, the fuel injection rate was set to a constant value throughout the entire operating range of the engine.
For example, the blue-white smoke phenomenon during low-speed and low-load operation has been improved.
11y If the fuel injection rate is set high in order to improve the engine's operating characteristics, the noise will increase during high-speed/high-load operation, and cavitation erosion may occur in the injection pipe or nozzle, which may cause problems such as engine operating characteristics. There was a problem in that it was difficult to maintain the motor in good condition throughout its entire operating range.

(Object of the Invention) The present invention provides a fuel injection device for an internal combustion engine, which allows the engine to maintain good operating characteristics throughout its entire operating range by adjusting the fuel injection rate according to the engine's operating condition. It was made for the purpose of providing.

(Structure of the Invention) The fuel injection device for an internal combustion engine of the present invention enables fuel to be fed under pressure by reciprocating a plunger within a barrel, and an annular valve having an oil relief port is inserted into the outside of the plunger. , the annular valve and the plunger are appropriately rotated relative to each other to change the timing of communication between the oil escape port of the annular valve and a lead portion of an oil passage formed across the top surface and side peripheral surface of the plunger. A suitable number of single-cylinder pump units that control the amount of fuel injected are assembled into the pump body, and each of the single-cylinder pump units is driven by each cam of a camshaft disposed within the pump body. A hydraulic timer device is installed that operates to control the injection timing of each pump single-cylinder unit by changing the rotational phase angle between the camshaft of the fuel injection pump and the engine-side drive shaft, and the hydraulic timer device The operation of each cam is controlled by a solenoid valve, and the annular valve is appropriately displaced in the axial direction of the plunger according to the operating state of the engine by an electronic side rail type injection rate adjusting actuator. The fuel injection rate of each of the pumps can be adjusted by changing the operating speed range, and the solenoid valve and the injection rate adjusting actuator can be controlled to adjust the fuel injection timing and the optimum fuel injection timing for the operating condition of the engine. This system is characterized by feedback control based on engine speed, load, etc. so that the fuel injection rate is always maintained.

(Example) In a plunger-type fuel injection pump, there is a correlation between the rotation angle of the cam, the cam speed, and the plunger lift as shown by the cam speed concave line and the plunger lift curve L2 in FIG. Therefore, now, for example, cam angle 2
The fuel injection pump, which was operating within the operating range of the first gI range A of 0 to 30, was changed to a cam angle ll0-. 10, the cam speed at the start of injection changes from speed V to speed V, and the fuel injection rate changes by a value corresponding to the amount of change in the cam speed. It will be elevated. For this reason, during low-speed and low-load operation, where better operating characteristics can be obtained by setting a relatively high fuel injection amount, the engine is operated at a low cam angle range with a low cam speed, and the fuel injection rate is relatively low. The higher the speed, the better the driving characteristics.
If the engine is operated in a cam angle range with a high cam speed during high-load operation, better operating characteristics can be obtained throughout the entire operating range of the engine.

The present invention has been made with attention to the above points, and includes controlling the injection amount by rotating the plunger and the annular valve relative to each other, and controlling the injection timing by displacing the annular valve in the axial direction of the plunger. The injection timing control mechanism of the so-called annular valve type fuel injection pump is used as it is as an injection rate adjustment groove that changes the range of use of the cam, while changing the injection timing caused by vertical displacement of this annular valve. This is corrected by a hydraulic timer device that changes the rotational phase angle of the camshaft, thereby controlling the fuel injection rate so that it is always at the optimum value depending on the operating state of the engine.

The fuel injection device for an internal combustion engine of the present invention will be explained based on the embodiment shown in FIGS. It has a hydraulic timer device 2 that adjusts the injection timing of the pump and the fuel injection pump.

As shown in FIG. 2, the fuel injection pump 1 is capable of pumping fuel by fitting the plunger 6 into the barrel 15 so that it can slide and rotate freely, and by reciprocating the plunger 6 within the barrel 15. At the same time, an annular valve/I with an oil escape date 29 is slidably and relatively rotatably attached to the outside of the plunger/B, and the annular valve/I is appropriately connected to the plunger/B via the metering rack 21. The timing of communication between the lead part 2/ex of the oil passage 2/ formed across the top surface/lc and side peripheral surface/4b of the plunger/B and the annular valve/ by relative rotation is determined. The amount of fuel to be injected is controlled by changing the amount of fuel to be injected, and the annular valve is displaced in the axial direction of the plunger by an injection rate adjusting rack 23 via an eccentric bin and a cam during pressure feeding of fuel. In other words, by changing the usage range (cam speed range), in other words, by changing the pre-stroke of the plunger/B), the pump single-cylinder unit L is adjusted to adjust the fuel injection rate by changing the pump body 3.
A number of pumps (t in the illustrated embodiment) are installed in the pump, and a simple unit for each pump is installed.

t... is disposed at the lower part of the pump body 3, and each cam/'1 of the cam shaft/9. /'l... are respectively driven. Incidentally, by vertically displacing the annular valve /r, the fuel injection timing naturally changes177'', but the amount of unnecessary injection timing adjustment by this annular valve /lr can be eliminated by the hydraulic timer device described in the previous section. Correction control is performed so as not to affect the operating characteristics of the engine in any way. Therefore,
Only the fuel injection rate is controlled by the vertical displacement of the annular valve /r. Also, in Fig. 2, the code /7 is a delivery valve;
O is a plunger spring, and 2r is an uneven ratio adjustment bin for adjusting the unevenness of the injection amount between each pump single cylinder unit +, +, . . . .

Both the metering rack 2II and the injection rate adjustment rack 25 of the fuel injection pump are driven by an electronically controlled actuator that operates according to the operating state of the engine. That is, the metering rack 2 is connected to the first linear solenoid B installed on the outside of the pump body 3, as shown in FIG. ing.

The first and second linear solenoids 6 and q detect the operating state of the engine detected by the load sensor 3/ mounted on the engine side and the rotation speed sensor 32, and the seventh position sensor j mounted on the first linear solenoid B. and the amount of displacement of the first and second linear solenoids t and q detected by the second position sensor r attached to the second linear solenoid (in other words, the amount of displacement of the metering rack 2Il and the injection rate adjustment rack 2I) ), its operation is feedback-controlled by the controller 30 so as to maintain the optimum injection amount and optimum fuel injection rate at all times in response to the ever-changing operating state of the engine. The second linear solenoid moves the annular valve downward to reduce the pre-stroke of the plunger as the operating state of the engine shifts from low speed and low load operation to high speed and high load operation. The operating direction is set so that it operates in the direction in which it is forced to move. Therefore, as the operating state of the engine shifts from low-speed, low-load operation to high-speed, high-load operation, the fuel injection chamber is gradually lowered. For this reason, the blue-white smoke in the exhaust that was generated due to an insufficient fuel injection rate during low-speed, low-load operation is reduced as much as possible, and the blue-white smoke generated due to an excessive fuel injection rate during high-speed, high-load operation is reduced as much as possible. The occurrence of problems such as cavitation erosion in the injection system, which occurs during engine operation, is suppressed as much as possible, and as a result, it becomes possible to maintain the engine's operating characteristics favorably over its entire operating range.

The hydraulic timer device 2 is connected to the camshaft 19 of the fuel injection pump.
It is attached to the outer end of the camshaft/9 and the engine drive Ni/2, and is operated by receiving the pressure of hydraulic oil supplied from the hydraulic pump 33 via the solenoid valve //.
By appropriately changing the rotational phase angle between the
It is designed to have a retardation effect. This hydraulic timer device 2, that is, the solenoid valve // has a displacement 11 of 25 (i.e. ,
As mentioned above, based on the advance and retard angles (1 bit) changed by the vertical displacement of the annular valve, fuel injection is performed at an appropriate timing for the engine's rotational speed, which sometimes fluctuates from time to time. Its operation is feedback-controlled by the controller 30. Therefore, as mentioned above, even though the injection timing is changed accordingly when adjusting the fuel injection rate, the injection timing is always set to the optimum value for the engine operating condition, and the engine operating characteristics are Well maintained throughout the entire operating range.

(Effects of the Invention) The fuel injection device for an internal combustion engine of the present invention is a fuel injection device having a fuel injection pump configured to perform fuel control using an annular valve inserted into a plunger. By appropriately displacing the cam in the axial direction of the plunger to change the pre-stroke of the plunger, that is, the usage range of the cam, the fuel injection rate can be adjusted. It is possible to suppress and reduce as much as possible the occurrence of blue-white exhaust smoke caused by excessive fuel injection rate or capitation erosion caused by excessive fuel injection rate at high speeds and high-speed loading. This has the effect of making the driving characteristics good over the entire driving range.

[Brief explanation of the drawing]

Fig. 1 is a front view of a fuel injection device for an internal combustion engine according to an embodiment of the present invention, Fig. 2 is a vertical sectional view taken along the line I-■ of Fig. M1, and Fig. 3 is a correlation diagram of cam speed and plunger lift with respect to cam angle. be. l...Fuel injection pump 2...Hydraulic timer device 3...Pump body T...Pump single cylinder unit 9...Injection rate adjustment actuator//... ...
Solenoid valve/2... Drive shaft/4'... Cam 15... OO barrel/O... Plunger/f... Annular valve/R... Cam shaft 2/... ...Oil passage 2q...Oil escape day

Claims (1)

[Scope of Claims] l. Fuel can be pumped by reciprocating the plunger (/B) within the barrel (15), and
An annular valve (/lr) having an oil release date (29) is fitted on the outside of the plunger (l), and the annular valve (/l) and the plunger (/6) are appropriately rotated relative to each other. Annular valve C
A pump unit that controls the amount of fuel injection by changing the communication timing of the lead part (j/a)' formed in several phases of the plunger (/B) and the oil release date (29) of HI> Assemble an appropriate number of cylindrical units (4') into the pump body (3), and attach each pump simple unit (1).
, (4') . . . are arranged in the pump body (3), each cam (/4') of the camshaft (19). (/4') The camshaft (/q) of the fuel injection pump (1) is actuated by hydraulic oil, and the camshaft (/q) and the engine side drive shaft C/ Hydraulic timer device fl!(,
2) is installed so that the operation of the hydraulic timer device (2) can be controlled by a solenoid valve (//), while the annular valve (/l) is installed with an electronically controlled injection rate adjusting actuator (9). By appropriately displacing the plunger (L) in the axial direction according to the operating condition of the engine and changing the operating speed range of each of the cams (/R, (/L), etc.), each of the pump single cylinders :x=knit 4')
, (4') so as to be able to adjust the fuel injection rate of . and a fuel injection device for an internal combustion engine, characterized in that feedback control is performed based on the engine rotation speed, load, etc. so that the fuel injection rate is always maintained.