JPH07683Y2 - Fuel injection control device for diesel engine - Google Patents

Description

[Detailed Description of the Invention] Purpose of the Invention [Industrial field of application] The present invention adjusts the amount of fuel supplied to a diesel engine by a mechanical link mechanism, and also controls the maximum amount of the fuel to operate the diesel engine. The present invention relates to a fuel injection control device for a diesel engine that regulates according to the state.

[Prior Art] Conventionally, a fuel injection control device for injecting and supplying fuel to a diesel engine controls the amount of fuel to be injected and supplied to the diesel engine by linking to the operation amount of the accelerator, and therefore has the following configuration. ing.

Along with recent advances in electronic technology, a so-called electrical link mechanism that detects the accelerator operation amount with some sensor and drives the fuel increase / decrease member based on the detection result to control the fuel injection supply amount Fuel injection control devices have been developed. The fuel injection control device that employs this kind of electrical link mechanism can control the fuel supply amount more precisely by including various sensors that detect not only the accelerator operation amount but also other diesel engine operating states. Has features. For example, Japanese Utility Model Application Laid-Open No. 58-152536 discloses a technique for forcibly shutting off fuel during deceleration operation to achieve deceleration performance reliably and quickly.
Japanese Patent No. 164645 discloses a technique for improving fuel efficiency and preventing white smoke by reducing the fuel injection amount to less than the basic injection amount during deceleration.

On the other hand, as a more general configuration, a fuel for directly adjusting the fuel amount according to the accelerator operation by mechanically linking a fuel increasing / decreasing member for increasing / decreasing the fuel amount to be injected and injected to the diesel engine according to the displacement amount and the accelerator, There is an injection control device. Those employing this mechanical link mechanism have the features that they are simpler in construction, stronger against electromagnetic noise, and cheaper than the fuel injection control device of the electrical link mechanism. On the other hand, it is difficult to precisely adjust the fuel supply amount according to the operating state of the diesel engine other than the accelerator operation amount, and a boost compensator and the like have been proposed to cope with this. This is the maximum value of the fuel supply amount determined based on the displacement amount of the fuel increasing / decreasing member when the diesel engine is operated in a severe environment where the atmospheric pressure changes greatly or when the diesel engine is equipped with a supercharger. Regulated by the atmospheric pressure introduced to the boost compensator,
When the intake pressure is low, the maximum value is made small to suppress the occurrence of smoke, and when the supercharging pressure is high, the maximum value is made large so that the output can be increased.

[Problems to be Solved by the Invention] A fuel injection control device that employs a mechanical link mechanism as described above has a simple structure and is strong against electromagnetic noise. It is used in a wide range of fields because it can inject and supply a fuel amount suitable for operating conditions.

However, the adjustment of the fuel supply amount by the boost compensator is limited to the fluctuation of the atmospheric pressure or the operating condition of the supercharger, and only slightly changes the fuel supply amount based on the accelerator operation amount. That is, in the fuel injection control device that employs the mechanical link mechanism, the accelerator operation amount mechanically directly connected to the fuel increase / decrease member becomes the main control amount that determines the fuel injection amount, and has priority over the accelerator operation amount. It does not have a mechanism that drastically changes the fuel injection amount.

For this reason, when the accelerator operation amount is accidentally increased and the fuel supply amount to the diesel engine becomes excessive, there is no way to correct it, and the accelerator operation is required to be performed carefully. For example, even if the brake is operated in a state where the accelerator operation amount is large, the output torque of the diesel engine continues to be large and the operation is continued at a speed at which the output torque and the brake performance are in balance.
Such a situation may occur when the accelerator and the brake are operated at the same time, or when the driver operates the accelerator and the instructor operates the brake in a driving vehicle for driving a car. Such an operating state of the diesel engine is not preferable for the maintenance of the diesel engine and the brake mechanism and for further improving safety.

The present invention has been made to solve the above problems, and provides a fuel injection control device having a simple structure, which is strong against electromagnetic noise and has an inexpensive mechanical link mechanism. It is an object of the present invention to provide a fuel injection control device for a diesel engine, which is further improved in operability and safety by giving priority to the braking command of.

Configuration of the Invention [Means for Solving the Problems] The fuel injection control of the diesel engine of the present invention made to achieve the above-mentioned object is a fuel that mechanically interlocks the amount of fuel to be injected and supplied to the diesel engine. The maximum amount of fuel to be injected and supplied to the diesel engine is regulated in accordance with the displacement amount of the maximum supply amount regulating member driven by the atmospheric pressure introduced into the control pressure chamber, while determining the displacement amount of the increasing / decreasing member. In a fuel injection control device for a diesel engine, which supplies and injects a fuel amount according to an operating state of the diesel engine, a brake operating unit for operating a brake system of a vehicle, and the brake operating unit is operated to operate the brake system. Is activated, the air pressure introduced into the control air pressure chamber is adjusted to reduce the maximum amount of the fuel amount. Characterized in that it comprises a and.

The fuel injection control device of the diesel engine to which the present invention is applied may be any type that can perform fuel injection to the cylinders of the diesel engine, and may be of a distributed type, a column type, or the like.
Further, the fuel increasing / decreasing member may be any of conventionally proposed structures such as a spill ring and a control rack.
The maximum supply amount regulating member is a member that regulates the maximum amount of fuel injection determined by the fuel increasing / decreasing member, and refers to a member such as a stopper that regulates the displacement of a spill ring, a control rack, or the like. The maximum value of the fuel supply is determined by driving the member by the air pressure introduced into the control air pressure chamber.

Further, as the brake operating means, for example, in a diesel engine mounted on a vehicle, a main brake, a sub
Brake, parking brake, etc. are applicable.

[Operation] According to the fuel injection control device for a diesel engine of the present invention having the above configuration, when the brake operating means is operated and the brake system is operated, the atmospheric pressure adjusting means adjusts the atmospheric pressure introduced into the control atmospheric pressure chamber. , Adjusting the amount of displacement of the maximum supply control member to reduce the maximum amount of fuel.

In this way, since the maximum supply amount of fuel is reduced, the braking performance of the vehicle is improved and the fuel is not shut off even if the accelerator pedal is depressed, so that the brake operation means is not operated. That is, the acceleration performance is good when the brake system is deactivated.

In the present invention, when the vehicle is instructed to travel by the accelerator and the vehicle is instructed to be braked by the brake operation means at the same time, the braking performance by the brake system is maintained while maintaining the continued travel by the accelerator (in this case, fuel cutoff is not performed). In order to secure it, the maximum fuel supply is reduced.

Therefore, for example, when the braking is applied by the brake pedal attached to the passenger seat of the automobile training vehicle, the vehicle can be stopped quickly and surely even if the accelerator pedal is depressed. In addition, even in other vehicles, when simultaneous operation of the accelerator and the brake occurs, the braking instruction of the brake can be prioritized to improve safety.

Hereinafter, in order to more specifically describe the fuel injection control device for a diesel engine of the present invention, a detailed description will be given with reference to embodiments.

[Embodiment] FIG. 1 is a system schematic configuration diagram of a vehicle for driving education training equipped with the fuel injection control device of the embodiment. Therefore, the vehicle of this embodiment is provided with a pair of accelerator pedal AC and brake pedal BP1 in its driver's seat, and also with brake pedal BP2 in the front passenger seat on which the instructor sits. The brake pedals BP1 and BP2 have the same general structure as the conventional one, which adjusts the hydraulic pressure of a brake system (not shown) that suppresses the rotational force of the drive wheels according to the amount of depression.

Further, as shown in the figure, the diesel engine 1 serving as a drive source of the vehicle is provided with a turbocharger 3 in its intake system, and is configured to be supplied with fuel by a fuel injection pump 7 equipped with a boost compensator 5. There is. The output of the diesel engine 1 operating in this way is transmitted through the transmission 12 directly connected to the crankshaft 10 to the drive wheels 14,15.
Is transmitted to the vehicle and becomes the driving force of the vehicle.

The fuel injection pump 7 is of a distribution type and is driven by rotation of a drive shaft 20 driven by the diesel engine 1. The fuel injection pump 7 is a well-known one that includes a feed pump, a timer mechanism, and a mechanical governor mechanism (not shown). That is, when the accelerator pedal AC provided in the vehicle is depressed, the tension of the control spring 24 is increased via an adjusting lever (not shown) mechanically linked to the accelerator pedal AC, and the spill ring 26 is increased in the injection amount increasing direction ( (To the right in the figure)
Move to. On the other hand, the governor mechanism is actuated by the increase in the rotation speed of the drive shaft 20 to move the governor sleeve 28 to the right, and the spill ring 26 is moved in the injection amount decreasing direction (left in the drawing). The position of the spill ring 26 is determined as the balance of these two opposing forces, and the fuel injection amount is adjusted to the optimum value.

Next, the configuration of the boost compensator 5 provided above the fuel injection pump 7 will be described.

The boost compensator 5 is a boost pressure chamber as shown in the figure.
A diaphragm 5c that separates 5a from a constant pressure chamber 5b that is kept at a constant pressure, a spring 5d that biases the diaphragm 5c toward the boost pressure chamber 5a, a push rod 5e that slides according to the movement of the diaphragm 5c, and a push rod. 5e It is composed of a connecting pin 5f or the like that comes into contact with the taper portion formed at the tip portion from the side surface. The supercharging pressure chamber 5a is selectively communicated with an intake port 32 of the diesel engine 1 or a vacuum pump 34 via a pressure switching valve (hereinafter referred to as VSV) 30. That is, the supercharging pressure chamber 5a communicates with the intake port 32 when the operation switch 30a of the VSV 30 is opened, and the vacuum pump 34 replaces the intake port 32 when the operation switch 30a is closed. Connect to 5a. In this way, the operation switch 30a for changing the object communicating with the supercharging pressure chamber 5a is
Another brake pedal BP provided in the passenger seat mentioned above
It is linked to 2 and is configured to close in cooperation with the depression operation of the brake pedal BP2.

The boost compensator 5 operates differently as follows according to the difference of the object communicating with the supercharging pressure chamber 5a.

First, a case where the brake pedal BP2 is not operated, that is, a case where the vehicle driven by the diesel engine 1 is in a normal traveling state will be described. At this time, the boost pressure chamber
5a communicates with the intake port 32 of the diesel engine 1,
As the turbocharger 3 operates and the intake pipe pressure increases, the pressure in the supercharging pressure chamber 5a rises, and the diaphragm 5c of the boost compensator 5 resists the biasing force of the spring 5d to the side of the constant pressure chamber 5b (see the figure below). Direction). Along with this, the push rod 5e also moves downward, so that the connecting pin 5f that is in contact with the tapered portion moves to the bush rod 5e side. At the other end of the connecting pin 5f of the boost compensator 5, the bent portion 35 of the control arm 35 is provided.
a is abutted. Therefore, when the connecting pin 5f is moved to the push rod 5e side, the control arm 35 rotates clockwise around the fulcrum Ra. The other end of the control arm 35 serves as a stopper portion of the tension lever 40 that is biased by the control spring 24 in the governor direction. Therefore, as the control arm 35 rotates, the maximum position of the tension lever 40 at full load is displaced in the governor direction. As a result, the other end of the tension lever 40, which is rotatable around the fulcrum Rb, moves in the direction of arrow B when fully loaded. Since this end of the tension lever 40 is fitted to the spill ring 26 externally fitted to the plunger 41 for pumping fuel, the spill ring 26 also moves in the direction of arrow B, and the end of fuel injection at full load is completed. Is delayed, and the fuel injection amount increases as a result.

On the other hand, when the brake pedal BP2 provided in the passenger seat is stepped on from the normal operating state as described above, the VSV 30 operates by closing the operation switch 30a, and the supercharging pressure chamber 5a and the vacuum pump 34 And are communicated. Therefore, the pressure in the supercharging pressure chamber 5a becomes a negative pressure adjusted by the vacuum pump 34, and contrary to the above, the push rod 5e moves upward and the connecting pin 5f moves in the opposite direction.
Therefore, the spill ring 26 is displaced in the direction of arrow A to accelerate the end timing of fuel injection at full load, and the fuel injection amount is reduced.

The fuel that is pumped by the reciprocating motion of the plunger 41 until the overflow occurs due to the spill ring 26 whose position is determined in this way is the delivery valve provided corresponding to each cylinder.
Fuel is injected into each cylinder via a fuel injection nozzle 48 provided in each cylinder via 47.

According to the fuel injection pump 7 of the diesel engine of the present embodiment configured and operated as described above, the following effects are obvious.

First, a case where the brake pedal BP2 provided in the passenger seat is not operated will be described. At this time, as in the conventional case, the fuel injection pump 7 is operated by the depression amount of the accelerator pedal AC.
The amount of fuel ejected from the diesel engine 1 is determined, and the diesel engine 1 can be freely controlled. Further, when the turbocharger 3 operates, the air supply pipe pressure is guided to the supercharging pressure chamber 5a of the boost compensator 5, and the push rod 5e
The effect of the boost compensator 5 is the same as that of the conventional one unless the amount of fuel injection at full load is increased and corrected to suppress the generation of smoke. Therefore, if the fuel injection amount is shown with respect to the rotation speed of the fuel injection pump 7,
As shown by the solid line in FIG. 2, similar characteristics to the conventional one can be obtained.

Next, a case where the brake pedal BP2 provided in the passenger seat is operated will be described. When the brake pedal BP2 is depressed, the operation switch 30a is closed in conjunction with this operation, and the VSV 30 operates to generate the air pressure introduced into the supercharging pressure chamber 5a from the intake pipe pressure up to that time in the vacuum pump 34. Change to negative pressure. Therefore, the push rod 5e of the boost compensator 5 is displaced upward and the fuel injection amount of the full load path is reduced and corrected, thereby reducing the fuel supply amount to the diesel engine 1. That is, if the brake pedal BP2 provided in the passenger seat is operated, the amount of fuel supplied to the diesel engine 1 is suppressed to a small amount even if the accelerator pedal AC is largely operated, and the driving force transmitted to the drive wheels 14 and 15 is reduced. Can be reduced. Therefore, the depressing operation of the brake pedal BP2 effectively exerts the restraining force of the brake mechanism (not shown) that is originally operated, and the vehicle can be stopped within a short time. If the fuel injection amount in this state is illustrated, it will be understood that the characteristic shown by the alternate long and short dash line in FIG. 2 is obtained, and the maximum fuel injection amount can be uniformly suppressed. Generally, the operation of the brake BP2 provided in such a passenger seat occurs in an emergency situation, and it is desirable to regulate the fuel amount so as to operate the braking force to the maximum as described above. On the other hand, the operation of the brake pedal BP1 provided in the driver's seat is frequently executed in a normal driving state, and there is a possibility of re-acceleration in which the accelerator pedal AC is operated immediately after the brake operation. Therefore, in the present embodiment, the brake pedal BP1 provided in the driver's seat is not linked with the boost compensator 5, and the deterioration of reacceleration due to the deregulation of the maximum fuel injection amount by the boost compensator 5 is avoided. That is, in the present embodiment, by switching the pressure introduced into the supercharging pressure chamber 5a only when the brake pedal BP2 in the passenger seat is operated, the drivability during normal operation and the emergency braking property during the operation of the brake pedal BP2 are set. Compatibility can be achieved.

As described above, according to the fuel injection pump 7 of the present embodiment, the accelerator compensator 5 has a simple structure in which the VSV 30 and the operation switch 30a are added to the boost compensator 5 provided conventionally, and the structure is inexpensive and resistant to electromagnetic noise. The amount of fuel to be injected and supplied to the diesel engine 1 can be adjusted to an appropriate amount by prioritizing the braking command by the brake operation over the operation amount of the pedal AC, and the diesel engine 1 can be operated more comfortably and safely. .

In the above embodiment, the example in which the fuel injection pump 7 of the embodiment is mounted on the vehicle for driving education is explained, but the brake pedal BP1 and the operation switch mounted on a normal vehicle and provided in the driver's seat. You may interlock with 30a.
Also in this case, the accelerator pedal AP and the brake pedal BP1
Even when both and are simultaneously operated, the braking command by the brake operation is prioritized, the amount of fuel supplied to the diesel engine 1 can be reduced, and the braking force can be effectively exerted. Further, instead of the vacuum pump 34, the supercharging pressure chamber 5a may be simply opened to the atmosphere, and the same effect can be obtained.

Furthermore, the maximum pressure of fuel injection may be controlled more finely by appropriately controlling the negative pressure of the vacuum pump 34.
For example, it may be considered that the supercharging pressure chamber 5a is configured to selectively and partially communicate with the intake pipe to the vacuum pump and / or the atmospheric pressure. With such a configuration, when the brake is operated, the negative pressure of the vacuum pump 34 is introduced while maintaining the communication between the supercharging pressure chamber 5a and the intake pipe, or when the brake is operated, the negative pressure of the vacuum pump and the orifice are introduced. The introduction pressure to the intake pressure chamber 5a is precisely adjusted by, for example, introducing both the above-mentioned atmospheric pressure. A simpler configuration can be achieved by simply providing an atmosphere opening orifice in the passage between the vacuum pump 34 and the VSV 30. As an example, if the above-mentioned configuration is applied to a training vehicle, the vacuum pump 34 is directly connected to the supercharging pressure chamber 5a when the passenger side brake is operated.
The negative pressure may be introduced, and the negative pressure of the vacuum pump 34 may be diluted with the atmospheric pressure within a range in which the re-accelerating property is allowable when the driver's seat side brake is operated, and may be introduced as a slightly higher appropriate pressure.

Another example is a parking brake and activation switch 30.
A configuration in which a is linked is also conceivable. In this case, the maximum amount of fuel supplied to the diesel engine 1 is regulated during parking or when the parking brake is operating, so that the engine is rotated at a high speed due to an erroneous operation of the accelerator pedal AP. Can be prevented. In the above embodiment, the boost compensator 5 is used for description, but the structure is not limited to the one that operates in conjunction with the turbocharger 3, and a simple atmosphere correction device may be used.

In the above embodiment, the pressure of the boost pressure chamber 5a of the boost compensator 5 is adjusted to a constant negative pressure by the vacuum pump 34 simultaneously with the operation of the brake pedal BP2, and the maximum fuel injection amount is suppressed to a predetermined value. However, the brake pedal BP is not limited to such a configuration.
Set the prescribed delay time from step 2 and set the boost pressure chamber 5a
Change the introduction pressure to the, or adjust the increase or decrease of the introduction pressure according to the operating state of other diesel engine 1,
It may be embodied in various forms without departing from the gist of the present invention.

Effects of the Invention As described in detail above with reference to the embodiments, according to the fuel injection control device for a diesel engine of the present invention, when both the driving instruction by the accelerator and the braking instruction by the brake operating means occur at the same time, the accelerator The maximum fuel supply amount is reduced in order to ensure the braking performance of the brake system while maintaining the continuation of travel due to (the fuel cutoff is not performed at this time).

Since the maximum supply of fuel is reduced, the braking performance of the vehicle is improved even when the accelerator pedal is depressed, and the fuel is not shut off, so the acceleration performance when the brake system is deactivated. Is good. Further, when simultaneous operation of the accelerator and the brake occurs, the braking instruction of the brake can be prioritized to improve safety.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a fuel injection control device for a diesel engine according to a first embodiment of the present invention, and FIG. 2 is an explanatory diagram showing effects of the same embodiment. 1 ... Diesel engine, 3 ... Turbocharger 5 ... Boost compensator 5a ... Boost pressure chamber, 5b ... Constant pressure chamber 5e ... Push rod, 7 ... Fuel injection pump 12 ... Transmission, 26 ... Spill ring 30 ... Negative pressure switching valve, 34 ... Vacuum pump

Claims (1)

[Scope of utility model registration request] 1. A fuel amount injected and supplied to a diesel engine,
It is determined according to the displacement amount of the fuel increasing / decreasing member mechanically interlocked with the accelerator, and is injected and supplied to the diesel engine according to the displacement amount of the maximum supply amount regulating member driven by the atmospheric pressure introduced into the control pressure chamber. In a fuel injection control device for a diesel engine, which regulates the maximum amount of fuel and injects and supplies the fuel amount according to the operating state of the diesel engine, a brake operation means for operating a brake system of a vehicle, and the brake operation. An air pressure adjusting means for adjusting the air pressure introduced into the control air pressure chamber and decreasing the maximum amount of the fuel when the brake system is activated by operating the means. Characteristic diesel engine fuel injection control device.