JPS6341544Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved fuel injection amount control device for diesel engines (particularly for vehicles).

Conventionally, as a device for controlling the amount of fuel supplied to a vehicle diesel engine, a device has been used in which the depression angle of an accelerator pedal is directly transmitted to a fuel control lever in proportion.

However, with such conventional devices, even when transitioning from partial cylinder operation to full cylinder operation, the position of the accelerator pedal remains the same, so the position of the fuel control rack remains the same, and the output increases rapidly at the moment of transition. . For example, at the moment of switching from 4-cylinder operation to 8-cylinder operation, the output suddenly doubles.

Conversely, when shifting from full-cylinder operation to partial-cylinder operation, even if the accelerator pedal is in the same position, the output suddenly decreases (to 1/2 in the above example) for the same reason.

In this way, if the power output suddenly increases or decreases when changing from partial cylinder operation to full cylinder operation or vice versa, the vehicle may suddenly accelerate or decelerate even though the accelerator pedal position remains the same. This makes it difficult for the driver to control the vehicle and makes the ride uncomfortable.

This overcomes these shortcomings of conventional devices and allows the accelerator pedal to remain in the same position when transitioning from partial cylinder operation to full cylinder operation or vice versa.
In order to provide a fuel injection amount control device that does not cause sudden changes in output, the present inventor has already filed a utility model registration application (Utility Model Publication No. 63-019555).

The main part of the invention of that application is the movement amount correction mechanism of the fuel control rack of the fuel injection pump as shown in FIG. 1, and its effect is due to the governor characteristics as shown in FIG. In improvement.

In other words, the idling position A of the accelerator pedal
When the pedal is depressed from the position D to the cylinder number switching position D, the easy position is momentarily retracted to the state shown by curve C when transitioning from the partial cylinder operation state shown by curve B to full cylinder operation. . In other words, by instantly matching the maximum output value during partial cylinder operation with the minimum output value during all cylinder operation, it is possible to switch from partial cylinder operation to all cylinder operation, and from all cylinder operation to partial cylinder operation. It is configured so that the state changes.

However, as shown in Figure 4, if the engine is operated to obtain maximum output with the characteristic that the ease position is constant in the medium speed range, the change in intake air amount of the engine at a certain rotation speed A situation occurs where the fuel injection amount does not correspond. In other words, the amount of intake air does not necessarily remain constant from low to high speeds depending on the shape and dimensions of the intake pipe or engine specifications, depending on the engine speed, and therefore the fuel control rack position is kept constant. Then, the amount of fuel injection becomes excessive compared to the amount of intake air at a certain engine speed,
There is a risk that a rotational region that causes bottom complete combustion may occur.

The purpose of the present invention is to overcome the drawbacks of the conventional devices and the previous application, and to provide a system that can
The output does not change suddenly when the accelerator pedal remains in the same position, and the set rotational speed at which the fuel injection amount is excessive compared to the intake air amount is detected, and the fuel injection amount at that set rotational speed is adjusted. To provide a fuel injection amount control device for a diesel engine that can prevent incomplete combustion by automatically reducing the fuel injection amount in accordance with the intake air amount at the set rotation speed. There is a particular thing.

To achieve this objective, the present invention provides a rod that connects the accelerator pedal of a diesel engine and a fuel control lever of a fuel injection pump, which cuts off fuel supply to some cylinders at low loads, and a rod that connects the fuel control lever of a fuel injection pump. A displacement correction mechanism having a different length is incorporated, and when switching between partial cylinder operation and full cylinder operation, the displacement correction mechanism is activated and the fuel control lever is configured so that the output of the engine is maintained approximately constant. In addition, the present invention is characterized by providing means for detecting a set rotational speed at which the amount of fuel injection becomes excessive with respect to the amount of intake air, and controlling the amount of fuel injection at the set rotational speed.

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

Fig. 1 is an explanatory diagram of the main parts of a fuel injection amount control device according to an embodiment of the present invention, Fig. 2 is a system diagram of the same device, and Fig. 3 is a diagram showing the operating characteristics of a slide switch in the device of the present invention. , FIG. 4 is a governor characteristic diagram when no means for adjusting the operating position of the slide switch is provided, and FIG. 5 is a governor characteristic diagram of the device of the present invention.

In FIG. 1, an accelerator pedal 2 swingably supported by a vehicle body 1 swings between an idling position A and a full load position L. D located in the middle is the cylinder number switching position.

The area between the idling position A and the cylinder number switching position D (represented by the angle θ ₁ ) corresponds to an idling range and a low negative range, and this range is a range of partial cylinder operation.

The area between the cylinder number switching position D and the full load position L (represented by the angle θ ₂ ) corresponds to a high load area, and this area is the range of all cylinder operation.

The accelerator pedal 2 is connected via a rod 3 to a fuel control lever 4 of a governor 11 of a fuel injection pump 10. A movement amount correction mechanism, such as a solenoid 5, is provided in the middle of the rod 3, and by operating this, the length of the rod 3 can be adjusted in two stages.

Further, a movement amount correction mechanism, such as a solenoid 7, is provided on the fuel control lever 4, and by operating this, the length of the rod 8 can be adjusted in two stages. The tip 3a of the rod 3 and the tip 8a of the rod 8 are connected, and the movement of the accelerator pedal 2 is transmitted via the rods 3 and 8 to the fuel control lever 4, which controls the fuel control shaft 6 fixed thereto. Rotate. Rotation of the shaft 6 moves a fuel control rack (not shown) to adjust the fuel injection amount.

In FIG. 2, the first fuel injection pump 9 and the second
A fuel injection pump 10 is installed on the engine,
One side of this second fuel injection pump 10 is a governor 11
is provided, and this operation is transmitted to the control of the second injection pump 9 via the control rack of this pump 10 and a link (not shown) between the pumps 10 and 9, and furthermore, from the engine. When the injection pump 10 is driven, this rotation is also transmitted to the fuel injection pump 9 via a gear (not shown).

As the accelerator pedal 2 swings, the contact 2a that rotates integrally with the accelerator pedal 2 slides on the slide switch 12. 13 is the power supply, solenoids 5, 7, 1
7. Power is supplied to the slide 12, solenoid valve 14, and controller 19. Until the contactor 2a reaches the position _A0 (corresponding to the idling position A) on the slide switch 12 to the position _D0 (corresponding to the cylinder number switching position D), the slide switch 12 is
It is in the off state, and is in the on state from when it reaches the position D ₀ until it reaches the position L ₀ (corresponding to the full load position L). This operating characteristic is shown in FIG.

When the slide switch 12 is in the OFF state, that is, in partial cylinder operation, the solenoid valve 14 is in the "closed" state, and in the embodiment shown in FIG. 2, fuel F is supplied only to the second fuel injection pump 10. At this time, the solenoids 5 and 7 are also not supplied with power, so the rods 3 and 8 are retracted and in a short state, and the movement of the accelerator pedal 2 is transmitted to the fuel control lever 4 as is. That is, the first
In the figure, the rod 8 (i.e., fuel control lever ₄ ) swings from position A' to position D' (angle θ ₁ ') corresponding to the idling range and low load range (angle θ 1 ). .

When the accelerator pedal 2 is depressed, the contact 2a also rotates and the slide switch 1
2 exceeds the position D ₀ , the state is turned on, the solenoid valve 14 is opened, and the first fuel injection pump 9 also receives fuel F.
will be supplied. At the same time, the solenoids 5 and 7 are also actuated to extend the rods 3 and 8. In Figure 1, the tip positions of rods 3 and 8
D' momentarily moves to position D'', and thereafter gradually moves to position L' corresponding to full load position L (angle θ ₂ ').

The governor characteristics of such a control device (which is not provided with means for adjusting the operating position of the slide switch 12) are shown in FIG.

In FIG. 4, straight line A shows the rack position at idling, straight line B shows the rack position immediately before the number of cylinders is changed, straight line C shows the rack position immediately after the cylinder number is changed, and line D shows the rack position at full load. d ₁ and d ₂ represent the moving distance of the rack position corresponding to the angles θ ₁ and θ ₂ , respectively.

The structure shown in FIG. 1 can prevent a sudden change in output when shifting from partial cylinder operation to full cylinder operation or vice versa.

However, with only the above mechanism, at rotational speeds where the amount of fuel injection is excessive relative to the amount of intake air, the combustion state may deviate from the optimum value, causing incomplete combustion and generating black smoke. As mentioned above.

Therefore, in the present invention, the contact position of the slide switch 12 that is contacted by the contactor 2a moved by the accelerator pedal 2 is detected at a set rotational speed at which the amount of fuel injection becomes excessive with respect to the amount of intake air of the engine. The feature is that the fuel injection amount at the set rotational speed can be controlled.

That is, in FIG. 2, the Arcel pedal 2
A solenoid 17 having a rod 16 is connected to a panel 15 on which a slide switch 12 is mounted and mounted so as to coincide with the center of swing of the switch.
In addition, a rotation speed sensor 18 is provided in the second fuel injection pump 10, and the detection signal is sent to the controller 19.
is input. The controller 19 is set so that, when a rotational speed signal of a certain predetermined value is input, the solenoid 17 is operated so that its actuator moves in and out in response to the output signal.

The controller 19 is configured to experimentally determine the load position at which the maximum output state during partial cylinder operation is optimized according to the engine speed, and to generate an adjustment signal for the rack position when switching from partial cylinder operation to full cylinder operation, or vice versa.

Therefore, as shown in FIG. 5, for example, when the rotational speed reaches a rotational speed v ₁ that is close to the rotational speed v ₂ at which the amount of injected fuel is most excessive relative to the amount of intake air, the solenoid 17 is activated. If it is set to
The contact position between 2 and the contactor 2a is shifted. As a result, the operating position of the slide switch 12 also moves as shown by the chain line in FIG. 3, and the rack position begins to move by the mechanism described above.

Then, as the engine speed increases, the rack position D' is gradually moved to the low load side, and when the rotation speed reaches the rotation speed v ₂ at which the amount of injected fuel is most excessive relative to the amount of intake air, the position D' of the panel 15 is changed. The movement toward the low load side due to rotation is maximum. Therefore, the amount of fuel injected at the rotational speed _v2 is reduced and incomplete combustion is prevented.

In addition, when the rotation speed becomes more than v ₂ , controller 1
Based on the output signal from 9, the solenoid 17 rotates the panel 15 to return it to its original position, so that the rack position gradually begins to return to its original position, and at rotational speed v ₃ , the rack position returns to its original state. .

As explained above, the fuel injection amount control device of the present invention connects the fuel control lever 4 and the accelerator pedal 2 with the rod 3, and the rod 3 and the control lever 4 are provided with a length adjustment mechanism.
This length adjustment mechanism is operated by a signal from a slide switch 12 that operates in response to the movement of the accelerator pedal 2 so that the output is the same when changing from partial cylinder operation to full cylinder operation or vice versa. Furthermore, the panel 15, which is the support board for the slide switch 12, is configured to automatically rotate in response to a signal associated with a change in engine speed, so even if the number of cylinders changes. It is possible to alleviate sudden changes in output, and also to detect the set rotational speed at which the amount of injected fuel is maximum relative to the amount of intake air, and to control the amount of fuel injection at that set rotational speed. , the amount of injected fuel is automatically reduced in accordance with the amount of intake air at the set rotational speed to prevent incomplete combustion and obtain the best combustion state.

Therefore, it is possible to facilitate the driver's steering control, improve ride comfort, and improve fuel consumption efficiency.

It should be noted that although the device is used to change the operating load of the movement amount correction mechanism according to the rotational speed by changing the contact position between the contact 2a linked to the accelerator pedal 2 and the slide switch 12, the present invention is not limited to this. It is also possible to attach a load detection pick-up to the fuel control lever 4 or the like to change from partial cylinder to full cylinder operation or vice versa, and to change the position of this pick-up according to the rotational speed. .

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the main parts of a fuel injection amount control device according to an embodiment of the present invention, Fig. 2 is a system diagram of the same device, and Fig. 3 is a diagram showing the operating characteristics of a slide switch in the device of the present invention. , FIG. 4 is a governor characteristic diagram when no means for adjusting the operating position of the slide switch is provided, and FIG. 5 is a governor characteristic diagram of the device of the present invention. 2... Accelerator pedal, 4... Fuel control lever, 5, 7... Solenoid (travel correction mechanism), 9, 10... Fuel injection pump, 11... Governor, 12... Slide switch, 17... Solenoid .

Claims (1)

[Scope of utility model registration request] A rod connecting an accelerator pedal of a diesel engine that cuts off fuel supply to some cylinders at low load and a fuel control lever of a fuel injection pump, and a movement correction mechanism that changes the length of each of the fuel control levers are incorporated, At the time of switching between partial cylinder operation and full cylinder operation, the movement amount correction mechanism is activated and the fuel control lever is configured so that the output of the engine is maintained approximately constant,
A fuel injection amount control device for a diesel engine, comprising means for detecting a set rotational speed at which the fuel injection amount becomes excessive with respect to the intake air amount, and controlling the fuel injection amount at the set rotational speed.