JPS58106136A - Regulating device of fuel injection quantity in diesel engine - Google Patents

Abstract

PURPOSE:To simultaneously further easily perform altitude compensation and supercharged pressure correction of a supercharger, by providing a negative pressure control valve, which generates negative pressure in accordance with an intake air quantity, and negative pressure controller operating an injection quantity regulating member in accordance with said negative pressure. CONSTITUTION:A driving shaft 2 of a fuel injection pump 1 is driven by a Diesel engine 3. An injection quantity regulating lever 41 is operated by a negative presure responsive controller 55, and a level of negative pressure is controlled by a solenoid opening and closing valve 61 and arithmetic device 63. The arithmetic device 63 receives output signals of an intake air quantity 64, temperature detector 65 and speed detector 67. In this way, altitude compensation and correction of supercharged pressure of a supercharger can be simultaneously further easily performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection amount adjustment device for a diesel engine, and particularly to a fuel injection amount adjustment device that takes into account a decrease in air amount at high altitudes and an increase in air amount in a supercharged engine. - In diesel engines, the maximum injection amount is set by the injection pump's full-load screw in order to keep the smoke concentration below a certain value in the high-load range. In injection pumps with altitude compensation, the full-load stop is moved by a bellows that responds to atmospheric pressure, and in diesel engines with a turbocharger, the full-load stop is moved via a diaphragm that responds to boost pressure. Although a maximum injection amount is determined, fluctuations in rotational speed are handled by a mechanical governor, and depending on the rotational speed, the required injection amount may not match. In addition, the system tends to be too complicated to perform altitude compensation and boost pressure correction for a turbocharged engine at the same time.

SUMMARY OF THE INVENTION An object of the present invention is to obtain a required injection amount at each rotation speed in accordance with each rotation speed, and to simultaneously and easily perform altitude compensation and supercharging pressure correction of a supercharger.

In order to achieve this objective, according to the present invention, a negative pressure is generated according to the intake air amount or engine operating parameters related thereto, and this negative pressure is used to control the injection amount adjusting member by superimposing the operation according to the rotation speed. operate. The specific configuration of this device includes a device that detects the amount of air, a computing unit that generates an output electric signal representing the amount of fuel according to the air amount signal, and a device that detects the magnitude of negative pressure according to the output electric signal. A negative pressure control valve to be controlled and a negative pressure responsive operating device to operate an injection amount adjusting member according to this negative pressure are provided.

An embodiment of the present invention will be explained with reference to the drawings. In Fig. 1, 1 is a fuel injection pump, the drive shaft 2 of which is driven by a diesel engine 3, and the drive shaft 2 is driven by a diesel engine 3. By rotating the centrifugal weight 7 of the centrifugal force governor 6, the sliding sleeve 8 is moved to the right in the axial direction according to the rotation speed, and the sliding sleeve 8 is distributed on the circumference of the plunger operating ring 9 located at the end of the shaft. on a plurality of rollers 10,
Front cam 1 with the same number of cam ridges as the number of cylinders in engine 3
1 is rotated together and reciprocated in the axial direction. The cam 11 is pressed against the roller 10 by a spring 12. A pump plunger 17 is pressed against the opposite end surface of the cam 110, and every rotation of the drive shaft 2 and therefore the cam 110,
The plunger 17 performs one rotational movement and the same number of axial reciprocating movements as the number of cam ridges. The plunger 17 has the same number of suction vertical grooves 19 as the number of engine cylinders and one distribution vertical groove 2o around its periphery, and a central shaft hole 21 communicating with the distribution vertical groove 20 is open at the end surface and is close to the cam 11. It communicates with a spill port 22 that opens into the housing space 13. Pump cylinder 23 into which plunger 17 fits
has one suction hole 24 and as many distribution holes 25 as there are cylinders of the engine. Further, a spill ring 26 is fitted on the plunger 17 so as to be movable in the axial direction so as to close and open the spill port 22. Suction hole 24
communicates with the housing space ] 3 via a suction passage 31 .

While being driven by the drive shaft 2 and rotating, it moves in the axial direction due to the joint action of the cam 11 and the roller 10. When the plunger 17 moves to the left, one suction vertical groove 19 and the suction hole 24 coincide with each other. As the plunger 17 moves further to the left, the housing space 1 is pressurized by a fuel supply pump (not shown) to a pressure proportional to the engine speed.
3 passes through the suction passage 31 and enters the suction hole 2.
4 and flows into the pressure chamber 32 on the end face of the plunger through the suction longitudinal groove 19. Cam 11 and plunger 17
begins to rotate and move to the right from the left end position,
Since the distribution longitudinal groove 20 communicating with the pressure chamber 32 via the central shaft hole 21 coincides with one distribution hole 25 and the spill port 22 is closed by the spill ring 26, the fuel in the pressure chamber 32 is is pushed by the plunger 17 and the center shaft hole 2
1. Push open the delivery valve 33 from the vertical groove 20 and the distribution hole 25 to reach the injection nozzle 34, from which it is injected into the cylinder 35 to which it belongs. When the spill port 22 opens out of the spill ring 26 as the plunger 17 moves to the right, the high pressure fuel in the pressure chamber 32 now returns from the central shaft hole 21 through the spill port 22 to the housing space 13, thereby causing fuel injection. ends. In other words, this spill ring 2
6 controls the end of fuel injection and therefore the fuel injection amount.

In order to change the fuel injection amount by operating the spill ring 26 according to the engine speed, one arm of an injection amount adjustment lever 41, which will be described later and can swing around a fixed shaft 40, is provided with a swinging mechanism via a fulcrum 42. A speed-dependent double-armed lever 43, which can be supported, engages at one end in the spill ring 26 and at the other end in the sliding sleeve 8 of the vane 6, and the rotational speed of the engine and therefore of the governor 6 is becomes higher, the centrifugal weight 7 opens outward and pushes the sliding sleeve 8 to the right, and the rotation speed-dependent lever 43
is swung clockwise to move the spill ring 26 to the left, opening the spill port 22 earlier and reducing the fuel injection amount.

Furthermore, a shaft 45 rotatably supported in the pump housing
is an acceleration lever 46 connected to an acceleration pedal (not shown)
The other end of the tension spring 48, which is coupled at the center of its upper end and has one end hooked to an eccentric pin 47 at its lower end, is attached to the free end of an acceleration responsive lever 49 that is swingably supported around a fulcrum 42. ing. A compression spring 50 is provided between the levers 49 and 43. Acceleration lever 4
6 to the position shown in the figure to bring the eccentric pin 47 to the leftmost position, the acceleration responsive lever 49 is activated via the tension spring 48 and the rotational speed responsive lever 43 is activated via the spring 50.
is swung counterclockwise around the fulcrum 42 to move the spill ring 26 to the right, thereby maximizing the fuel injection amount.

Now, FIG. 1 shows the positions of the levers 43 and 49 corresponding to the injection amount at a specific rotation speed, but by swinging the injection amount adjustment lever 41 around the fixed shaft 40,
According to the position of the spill ring 26, the injection amount can be further varied.

In order to operate this injection amount adjustment lever 41 with negative pressure, a diaphragm operator 55 is provided as a negative pressure responsive operator, and the diaphragm 56 is connected to the other arm of the lever 41, and the diaphragm and the operator case are connected to each other. The negative pressure chamber 57 defined by the negative pressure chamber 57 is connected to a negative pressure source 60 such as a vacuum pump via a throttle 58 and a constant pressure valve 59. □Aperture 5
8 and the diaphragm operating device 55, one port of an electromagnetic on-off valve 61 operated by current pulses as a negative pressure control valve for controlling the magnitude of negative pressure is connected, and the other port is connected to a throttle 62. It leads to the atmosphere through A computing unit 63 that controls the electromagnetic on-off valve 61 receives electrical output signals from an intake air amount detector 64, a temperature detector 65, and a rotation detector 67 as control inputs. In this case, the air amount detector 6
A pressure sensor that detects the absolute pressure within the intake pipe is used as the temperature sensor 65, and an intake air temperature sensor is used as the temperature detector 65.

Note that as the engine rotation detector 67, an electromagnetic pickup that detects the number of teeth of a gear is used.

Now, the amount of intake air is calculated in the calculator 63 from the absolute pressure in the intake pipe and the rotational speed detected by the pressure sensor 64, and this air amount is corrected by the intake air temperature detected by the intake air temperature sensor 65. The amount of fuel required to keep the smoke level below a certain value with respect to the detected air amount is calculated from the diagram in FIG. 2 showing the relationship with the amount of air.

And the relationship between fuel amount and negative pressure determined in advance (
(Fig. 3), and from the relationship of the negative pressure duty ratio of the electromagnetic on-off valve 61 (Fig. 4), which is also determined in advance, find the duty ratio of the current pulse required to energize the on-off valve 61. , gives a current pulse of this duty ratio to the on-off valve 61. The electromagnetic on-off valve 61 releases the negative pressure from the negative pressure source 60 to the atmosphere through the throttle 62 at an opening degree according to this duty ratio, and sends the negative pressure determined by this duty ratio to the negative pressure chamber 57 of the diaphragm operating device 55. the fuel injection pump 1 via the injection amount adjustment lever 41 according to this negative pressure.
determine the fuel injection amount.

FIG. 5 shows another embodiment, in which a diaphragm operating device 55 is connected to a negative pressure source 60 via an electromagnetic on-off valve 61' as a negative pressure control valve and a constant pressure valve 59, and is connected to a negative pressure source 60 through a throttle 66. It leads to the atmosphere.

In the embodiment shown in FIG. 6, an electromagnetic switching valve 61'' is used instead of the electromagnetic on-off valve as the negative pressure control valve, and the negative pressure operating device 55 controls the switching valve 61#, the throttle 58, and the constant pressure valve 59. via to a negative pressure source 60 or to the atmosphere.

In the above embodiment, the negative pressure control valves 61, 61', and 61'' were opened, closed, or switched depending on the duty ratio of the current pulse, but the negative pressure was bleed to the atmosphere depending on the magnitude of the DC current. You can also control the size.

FIG. 7 shows a negative pressure control valve that controls the negative pressure caused by such bleed. A hollow bleed base piece 74 is connected to a movable magnetic core 73 facing a fixed magnetic core 72 of an electromagnetic coil 71, and a diaphragm 75 connects the valve case. The diaphragm 75 forms an atmospheric chamber 76 communicating with the atmosphere and a negative pressure extraction chamber 77 within the valve case.

The internal space of the bleed base piece 74 communicates with the atmospheric chamber via the hole 78. Depending on the magnitude of the DC current supplied to the electromagnetic coil 71, the attractive force of the movable magnetic core 73 changes, and therefore the force that tries to move the bleed base piece 74 changes, but the negative pressure that balances that force is negative pressure. As shown in FIG. 8, for example, as shown in FIG. 8, a negative pressure proportional to the current is generated in the extraction chamber 77, and this negative pressure 55. In this case, the computing unit 63 only needs to have a computing function that generates the negative pressure shown in FIG. 3 in proportion to the direct current.

Furthermore, in order to ensure that the position of the injection amount adjustment lever 41 correctly corresponds to the required fuel amount calculated by the calculator 63 after detecting the air amount, the negative pressure applied to the diaphragm 56 of the diaphragm operating device 55 is detected. A sensor or a position sensor for detecting the amount of movement of this diaphragm 56 is provided, and the output of this negative pressure sensor or position sensor is sent to a computing unit 6.
It is also possible to perform feedback control so that the sensor output is equal to the memorized value by comparing it with a negative pressure value or a position value representative of the amount of fuel corresponding to the amount of air stored in advance in step 3. Ru. In this case, the electromagnetic on-off valves 61, 6
1' or an embodiment using an electromagnetic switching valve 61'', the constant pressure valve 59 is not required.

In order to determine the amount of air, either the displacement of the valve in the intake passage is converted into an electrical signal and this is corrected using air temperature or atmospheric pressure, or the atmospheric pressure and intake pipe pressure are detected and used to calculate the air temperature and dust. By correcting this, an output signal as an engine operating parameter related to the air amount can be obtained from the calculator 63.

In this way, according to the present invention, the fuel injection amount is adjusted according to the intake air amount, so the injection amount can be adjusted in consideration of a decrease in the amount of air at high altitudes or an increase in the amount of air in a supercharged engine. Altitude compensation and supercharging pressure correction can be performed simultaneously and easily using a single mechanism 55-63. As a result, the smoke concentration in the high load range can be suppressed to a desired value or less, thereby improving the operating performance of the engine and reducing the formation of harmful exhaust gases.

In the above-mentioned embodiment, the maximum injection amount adjustment lever (-41 position) was set by the diaphragm operating device 55, but the 9th position
In the illustrated embodiment, the position of the maximum injection amount adjusting lever 41 is set by a full load screw 85, and the position of the acceleration responsive lever 49 is set by a diaphragm operating device 55. That is, one arm 87a of the approximately L-shaped arm 87, which is swingably supported around a fulcrum 86, is engaged with a bottle on the diaphragm 56 of the diaphragm operating device 55, and the other arm 87b is engaged with the acceleration response lever (-49) as a stopper.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the fuel injection amount adjusting device according to the present invention, FIGS. 2 to 4, and 8 are diagrams for explaining its operation, and FIGS. FIG. 7 is a longitudinal sectional view of another embodiment of the negative pressure control valve, and FIG. 9 is a schematic diagram of still another embodiment. 111. Fuel injection pump, 6...Centrifugal governor, 17.
... Pump plunger, 22 ... Spill port, 26
... Spill ring, 41 ... Maximum injection amount adjustment lever, 4
3... Rotation speed responsive lever, 55... Diaphragm operator, 60... Negative pressure source, 61, 61'... Solenoid on/off valve, 61#... Solenoid switching valve, 63... Calculation vessel,
64...Pressure sensor, 65...Intake air temperature sensor Patent applicant Toyota Motor Corporation Figure 3 Fuel quantity No. 416ζl August 11 Simba (111

Claims (1)

[Claims] In a device that adjusts the amount of fuel injection by operating a fuel adjustment member that changes the end timing of fuel injection depending on the rotation speed, it generates negative pressure according to the amount of intake air or engine operating parameters related to this. A fuel injection amount adjustment device for a diesel engine, characterized in that a negative pressure is used to operate an injection adjustment member in addition to an operation according to the rotation speed.