JPS58133429A - Controller of fuel injection quantity in diesel engine - Google Patents

Abstract

PURPOSE:To reduce the generation of smoke, by providing a correction controller operated in accordance with the atmospheric pressure and engine speed to a fuel injection quantity controller to reducibly control a maximum injection quantity both in accordance with the atmospheric pressure and to a fixed quantity further at high revolution. CONSTITUTION:When speed of an engine is 2,500rpm or less, a rotary switch 2 is turned off, and a solenoid 81 is not excited to place a metallic plate 62 in a plane state. Now at high altitude, a tapered part 72c of a working rod 72 turns a control lever 57 in the direction of an arrow head Y to adapt the upper part of a tension lever 28 to one end 57a and limit the movement in the direction of an arrow head X. That is, a stroke of a plunger 12 is limited to prevent excessive supply of fuel. When the speed of the engine increases to at least 2,500rpm, the switch 2 is turned on to excite the solenoid 81 and increase the displacement of the rod 72 further turn the lever 57 to a fixed quantity in the direction of the arrow head Y. Accordingly, the movement of a lever 18 in the direction of the arrow head X is controlled to further reduce a maximum injection quantity of fuel to a fixed amount.

Description

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

In diesel engines, the density of the air decreases at high altitudes, so there is a problem in that the amount of intake air is insufficient for the injected fuel at maximum load, resulting in smoke.

Conventionally, diesel engine fuel injection amount control devices to solve this problem control the amount of fuel injection by controlling the opening/closing position of a cut-off port provided on the plunger by displacing a control sleeve fitted with a granjani. A control sleeve for a distributed fuel injection pump.

A cam activated by an atmospheric pressure detection mechanism that detects atmospheric pressure is activated via a governor lever and a correction lever to move the control sleeve in the direction of reducing the maximum fuel injection amount in high areas where atmospheric pressure is low. Therefore, a method has been proposed in which the amount of smoke is reduced (Japanese Patent Application No. 111122/1982).

By the way, diesel engine smoke! The amount is the first
As shown in the figure, the number is higher in highlands (indicated by line B) than in lowlands (indicated by polygonal line A), and if the engine speed increases at high altitudes,
As shown by line B, the amount of intake air is insufficient for the injected fuel, and the amount of smoke generated increases, for example, at an engine speed of 220 Or, p, m, the smoke target value shown by straight line C is exceeded. become.

However, the conventional diesel engine fuel injection amount control device described above only controls the maximum fuel injection amount according to atmospheric pressure, so the amount of smoke increases when the engine rotates at high speeds at high altitudes. However, the disadvantage is that smoke cannot be sufficiently reduced.

In view of the above circumstances, an object of the present invention is to reduce the maximum injection amount of fuel when the atmospheric pressure is low and to reduce the maximum injection amount of fuel according to the atmospheric pressure state and the rotating part of the engine, and to reduce the maximum injection amount of fuel when the atmospheric pressure is low and Sometimes the object is to provide a fuel injection amount control device for a diesel engine.

For this reason, the present invention inputs both the outputs of an atmospheric pressure detector and an engine rotation detector into a correction control device that corrects and controls a maximum injection amount regulating device that regulates the maximum injection amount of fuel, and makes the correction described above. The control device corrects and controls the maximum injection amount control device to reduce the maximum injection amount when atmospheric pressure is low and also to reduce the maximum injection amount when the rotation is high than when the rotation is low. It is characterized by controlling the maximum injection amount according to atmospheric pressure and engine speed to reduce smoke generation even at high altitudes and high engine speeds.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

In Fig. 2, l is a diesel engine's distribution fuel injection pump, and 2 is a rotary switch that turns on when the number of revolutions of the diesel engine exceeds a certain value (for example, 2 s o o r, p, m). The rotation detector 3 is an atmospheric pressure detector attached to the above-mentioned distribution type fuel injection pump 1.

In the distribution type fuel injection pump 1, 10 is a housing forming a pump chamber 11 into which fuel is supplied;
2 is a plunger that distributes and pressure-feeds the fuel in the pump chamber 11; 13 is a drive shaft 14 integrated with the plunger 12;
The cam disk 13 is rotatably driven at a speed of 1/2 of the engine rotation speed, and the cam disk 13 is provided with face cams 13a of the same number as the number of cylinders of the engine, and a plunger spring (not shown) drives the plunger. 12 and cam disc 13 are urged toward the roller rod 5 side,
The 7-eighth cam 13a of the cam disk 13 is pressed against the fixed roller 15 to cause the plunger 12 to reciprocate by the amount of cam lift. The plunger 12 includes a suction slit 12a communicating with the suction port 16 of the housing 10, a central oil passage 12b, a distribution slit 12C1 communicating with the discharge passage 17 of the housing 10, and a pump chamber 1.
A cut-off port 12d opening into each plunger 12 is provided, and a cut-off sleeve 18 for opening and closing the cut-off port 12d is slidably fitted around the outer periphery of the plunger 12. When the plunger 12 is retracted, the suction slit 12a and the suction port 16 match, so that the plunger 12 sucks the fuel in the pump chamber 11 supplied from the tank into the tip chamber 19, and then the plunger 12
2 rotates and advances, the suction port 16 is closed and compressed, and the distribution slit 12C and the discharge passage 17 match, so that the compressed high-pressure fuel is transferred to the delivery pulp 20.
When the plunger 12 moves further forward.

When the cut-off port 12d moves to the side of the cut-off sleeve 18 and opens, the high-pressure fuel inside the plunger 12 is released into the pump chamber 11, its pressure is lowered, and injection ends.

This reciprocating motion of the plunger 12 is performed for the number of cylinders during one revolution of the plunger 12, and discharge passages 17 (only one is shown) provided at equal intervals around the outer circumference of the plunger 12.
The fuel is injected into each cylinder sequentially. Further, the fuel injection amount is increased or decreased by sliding the force cutoff sleeve 18 and changing the effective stroke amount of the plunger 12, that is, by adjusting the opening timing of the cutoff port 12d. When 118 moves to the left in the figure, the injection amount decreases.1-1 Conversely, when it moves to the right, the injection amount increases.

Further, reference numeral 21 denotes a bar 7 all speed pana built in the upper part of the pump chamber 11, and the operation of the governor 21 adjusts the movement of the cut-off sleeve 18 according to the engine speed, thereby controlling the fuel injection amount. This is to adjust the In the governor 21, 22 is a governor gear 2 that meshes with a drive gear 23 fixed to the drive shaft 14.
4, a governor shaft 25 rotatably supports the governor shaft 22; 25 is a flyweight in which a flyweight holder 26 is integrated with the governor gear 24 provided on the governor shaft 22; 27 is slidable along the governor shaft 22'2; The governor sleeve 27 is configured to slide due to the expanding operation of the flyweights 25 due to centrifugal force.

Furthermore, 28 and 29 are a tension lever and a start lever that are rotated following the movement of the governor sleeve 27, and the tension lever 28, the start lever 29it, and a common first lever fixed to the collector lever 30 are The start lever 29 is supported so as to rotate about the pin 31 as a fulcrum, and the tip of the governor sleeve 27 is in contact with the back surface of the start lever 29 . A pole head pin 32 is erected at the lower end of the start lever 29,
The Rad pin 32 to the ball is connected to the cut-off sleeve 18.
It engages with the pin hole 18a and cuts off according to the rotation of star trace/<-29! J-7-18 is configured to move. In addition, 33 is the start lever 2 mentioned above.
This is a stunite spring loaded between the tension lever 9 and the tension lever 28.

On the other hand, 34 is a control lever that is pivotally supported on the housing 10 via a shaft 35, and the control lever 34 is interlocked with an accelerator pedal 37 via a cable or a link 36, and is connected to the inner end of the shaft 35. One end of a yoke 39 is attached via an eccentric pin 38, and an idle pin 41 inserted into the upper end of the tension lever 28 via an idle spring 4o is connected to the other end of the yoke 39. 39 has a governor spring 42 and a partial load spring 4.
Two compression springs 3 and 3 are installed with a predetermined load, and as the angle of the control lever 34 increases, that is, as the amount of depression of the accelerator pedal 37 increases, the yoke 39 is pulled to the left in the figure. , the tension of the springs 42 and 43 within the yoke 39 acts to pull the tension lever 28 to the left. Note that the collector lever 30 is connected to the second pin 4.
4 to the housing 10, and is biased by a lower support spring 45, and its rotational position is adjusted by a full load adjustment screw 46.

Further, 57 has a roughly U-shape as an example of a maximum injection amount regulating device that regulates the maximum injection amount of fuel by regulating the rotation of the tension lever 28 in the fuel increasing direction indicated by the arrow X in FIG. This is a regulatory lever. This regulation lever 57
is rotatably supported on the housing lO by a pin 58.
, its one end 57a is opposed to the upper end of the tension lever 28, and the upper end of the tension lever 28 and the one end 57a of the regulating lever 57 are brought into contact with each other, thereby regulating the rotation in the direction of increasing the amount of fuel. ing.

Reference numeral 61 denotes a correction control device that rotationally drives the regulation lever 57 and corrects and controls the amount of rotation thereof in accordance with atmospheric pressure and engine rotational speed, and is configured as follows. That is, first, the elastic metal plate 62 is brought into close contact with the upper end surface of the recess 10b formed in the upper part of the housing 10 so as to open upward, and is fixed by tightening bolts (not shown) from above through the bracket 63. At the same time, a through hole 64 for guiding the atmosphere is formed in the side wall of the fourth part iob to form an atmospheric pressure chamber 65 in the fourth part 10b. A bellows 3 as an atmospheric pressure detector is housed in the atmospheric pressure chamber 65, and the upper end surface of the bellows 3 is fixed to the lower surface of the metal plate 62, while the space between the lower end surface of the bellows 3 and the bottom surface of the fourth part 10b is A coil spring 67 is compressed in the bellows 3, and a certain amount of gas is sealed in the bellows 3, so that when the pressure in the atmospheric pressure chamber 65 is standard pressure, the axial dimension of the bellows 3 becomes a constant value. Moreover, the bellows 3 is expanded and contracted according to atmospheric pressure. Further, in the center of the lower end surface of the bellows 3, there is a large diameter part 72 of the actuation door 2, which is composed of a large diameter part 72a, a small diameter part 72b, and a tapered part 72C between them.
The upper end surface of a is fixed. The large diameter portion 72a is slidably fitted into the bottom surface of the recess 10b via a packing 73, so that the small diameter portion 72b and the tapered portion 72C protrude into the pump chamber 11. The small diameter portion 72b or the tapered portion 72C is adapted to come into contact with the other end of the regulating lever 57. Therefore, when the actuating rod 72 is displaced downwardly as shown by l in FIG.
By displacing one end 57a to the right in FIG. 2, the amount of rotation of the tension lever 28 in the direction of arrow X is restrained to a smaller extent.

On the other hand, a solenoid 81 is fixed to the upper part of the bracket 63, and a plunger 81a of the solenoid 81 is passed through a central hole 63a of the bracket 63 to come into contact with the center of the metal plate 62. The solenoid 81 is connected to a power source 83 via the rotary switch 2. Therefore, when the rotary switch 2 is turned on, the solenoid 81 is energized to project the plunger 81a and bend the metal plate 62 downward by a certain amount.

Therefore, the correction control device 61 operates the actuating rod 72 by expanding and contracting the bellows 3 according to the atmospheric pressure state, rotates the regulation lever 57 by a predetermined amount, and also maintains the engine speed at a constant value (2500 r, p, m) or more, the solenoid 81 is energized to cause the actuating rod 72 to further protrude downward by a certain amount via the metal plate 62 and the bellows 3, and the regulating lever 57 is moved further by a certain amount by the arrow Y. It is designed to rotate in the direction. The above operating rod 72
The downward correction amount, that is, the displacement Il! Figure 3 shows the relationship between altitude and altitude (corresponding to atmospheric pressure). Figure 3 middle MV,
indicates the amount of displacement of the actuating rod 72 when the engine speed is less than 250 Or, p, m, and the straight line V2 indicates the amount of displacement of the operating rod 72 when the engine speed is 250 Or, PJT1 or more, and the rotation switch 2
is on and the solenoid 81 is energized, indicating the amount of displacement of the operating door 2.

The fuel injection amount control device for a diesel engine configured as described above operates as follows.

It is now assumed that the engine rotational speed is 250 Or, p, m or less.

At this time, since the rotary switch 2 is off, the solenoid 81 is deenergized, and the metal plate 62 forms a flat surface as shown in FIG. 2 due to its elasticity. And Sakuho Roshi 72
As shown in the straight line ■ in Figure 3, the displacement amount 4 changes according to the altitude (atmospheric pressure and a certain relational force (tomorrow); for example, if the altitude is 〃: high), then the operating rod By rotating the regulating lever 57 by a certain amount in the direction of the arrow Y in FIG. 2 (I) in the center of FIG. 2 so that the tension lever 28 injects the maximum fuel when the engine is fully loaded, When attempting to rotate in the X direction, the tension lever 2 is attached to one end 57a of the regulating port/<-57, which is displaced according to the displacement of the actuating port/hand 72.
Since the upper part of the actuating rod 72 is brought into contact with the upper part i and movement in the direction of the arrow X is restricted, the maximum amount of fuel to be injected is regulated to be reduced in accordance with the amount of displacement of the actuating rod 72, that is, the altitude. In other words, the forward distance of the cut-off sleeve 18 to the right in FIG. 2 is regulated.
The effective stroke of the plunger 12 is regulated to decrease, thereby preventing excessive supply of fuel relative to the amount of intake air.

In this state, if the engine speed exceeds 250 or pm, even if the maximum fuel injection amount is regulated to be reduced according to the altitude, the amount of intake air will be insufficient and smoke will occur. However, at this time, the rotary switch 2 is turned on, the solenoid 81 is energized, and the downward correction amount we of the operating door 2 is 250 Or, as shown by the straight line v2 in FIG. PJn or less (indicated by straight line v0), the regulating lever 57 is further rotated by a certain amount (corresponding to the stroke of the plunger 81a of the solenoid 81) in the direction of the arrow Y in FIG. Tension lever 28 at full engine load
When trying to rotate in the direction of the arrow X in Figure 2 to inject the maximum amount of fuel, the above restriction is applied.
a to tension lever 28 (7) ~ 1% ＼ nihehe
＼X＼NN Since the cursed part comes into contact with the eagle and its movement in the direction of arrow A certain amount of weight loss is regulated. As a result, even when the engine is running at high speed, excessive fuel supply is prevented and smoke generation is prevented.

FIG. 4 shows the main parts of another embodiment, and the parts not shown are the same as those in FIG. 2.

In FIG. 4, reference numeral 2 indicates a rotation sensor as an example of a rotation detector for detecting the engine rotation speed, 3 indicates an atmospheric pressure sensor, 90 indicates a computer, and 91 indicates a plunger 92 as an operating rod by an amount proportional to the current value. The operating rod 92 of the proportional solenoid 91 has a tapered portion 92b connected to the other end 57 of the regulating lever 57 as a maximum injection amount regulating device having exactly the same structure as the above embodiment.
b, and rotates the regulation lever 57 with its tapered portion 92a in accordance with the amount of displacement of the plunger 92, thereby regulating the maximum injection amount of fuel.

On the other hand, the computer 90 stores in advance information representing the injection amount at maximum load that does not cause smoke to exceed a certain value according to the atmospheric pressure and engine speed. The amount of displacement l of the actuating rod 92 (shown in FIG. 5) is stored in advance, which is to be decreased when the atmospheric pressure is low and also to be decreased when the rotation is high compared to when the rotation is low. In addition, in Figure 5, the straight lines W□, W2゜W
...The rotation goes from low to high in the order of Wn. Then, the computer 90 reads out the information (displacement amount 4) based on both the signals from the atmospheric pressure sensor 3 and the rotation sensor 2, and uses this information to apply a predetermined current to the proportional solenoid 91 via an interface circuit (not shown). Applying electricity and protruding the actuating rod 92 by a predetermined amount (j?),
The maximum amount of smoke injected is regulated according to atmospheric pressure and engine speed to prevent smoke from being produced even at high altitudes and high speeds.

In this embodiment, the computer 90 and the proportional solenoid 91 constitute a correction control device.

The correction control device used in the present invention is not limited to the above-mentioned embodiment, but can be configured in various ways.
It may be of a structure that performs this only when the atmospheric pressure is below a certain level.

As is clear from the above description, the diesel engine fuel injection amount control device of the present invention uses a correction control device that operates based on the outputs of both the atmospheric pressure detector and the rotation detector to control the maximum injection amount regulating device. Through correction control, the maximum injection amount is reduced when atmospheric pressure is low, and the maximum injection amount is also reduced at high speeds compared to low speeds, so the amount of smoke generated can be reduced, especially at high altitudes. Can reduce smoke generation at high speeds.

[Brief explanation of drawings]

Fig. 1 is a graph showing smoke characteristics, Fig. 2 is a sectional view of an embodiment of the present invention, and Fig. 3 is a graph showing the relationship between altitude and displacement of the operating rod using the engine speed as a parameter in the above embodiment. The characteristic diagram shown in FIG. 4 is a sectional view of the main part of another embodiment,
FIG. 5 is a characteristic diagram showing the relationship between the altitude and the displacement amount of the actuating rod using the engine speed as a parameter in the above embodiment. ■...Distribution type fuel injection pump, 2...Rotation detector, 3...Atmospheric pressure detector, 57...Maximum injection amount regulating device, 61...Correction control device . Patent applicant Toyo Kogyo Co., Ltd. Agent Patent attorney Aoyama Aoyama and two others Figure 1 Rotation speed (rpml Figure 2 2)

Claims (1)

[Claims] (1) An atmospheric pressure detector that detects the atmospheric pressure state, a rotation detector that detects the engine rotation state, a maximum injection amount regulation device that regulates the maximum injection amount of fuel, and the rain detected by the above-mentioned rain detector. Depending on the atmospheric pressure and rotational conditions, the correction amount for the maximum injection amount regulating device is set in the direction of decreasing the maximum injection amount when the atmospheric pressure is low, and the above correction amount is set in the direction of reducing the maximum injection amount when the atmospheric pressure is low. Correction control of the maximum injection amount regulating device is performed by setting the maximum injection amount to be reduced more than the maximum injection amount.