JP2959312B2 - Gas fuel combined system for diesel engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gaseous fuel combined system capable of reducing the generation of black smoke in exhaust gas in a diesel engine by using LPG, LNG or other gaseous fuel in an auxiliary manner.

[0002]

2. Description of the Related Art Conventionally, in a vehicle equipped with a diesel engine, in order to reduce the generation of black smoke in exhaust gas, LPG fuel is supplementarily used together with light oil, and an accelerator pedal depression amount is smaller than a predetermined value. In the same manner as the conventional diesel engine, the engine is driven by injecting only light oil, and when the accelerator pedal depression amount is larger than the predetermined value, the injection amount of the light oil is changed to a predetermined value corresponding to the predetermined value. And injects LPG corresponding to the amount of depression into the intake pipe instead of light oil and LPG in the engine.
A gas-fuel combined system in a diesel engine that drives the engine in a state in which is mixed is known.

As a method of limiting light oil in this type of system, a load lever stopper is interposed between an accelerator pedal and a load lever of a light oil injection pump so that even if the accelerator pedal depression amount exceeds a certain level, the load lever is stopped. Is configured not to move at the predetermined position, and the LPG injection amount corresponding to the further accelerator depression amount and the engine speed is detected by, for example, an accelerator pedal depression amount by an accelerator stroke sensor. It is configured to be controlled by a computer that is calculated based on the engine speed and the like. (Survey report on the possibility of using LPG fuel combined system for in-use diesel vehicles: 1989, Japan Automobile Transport Technology Association)

[0004]

However, in the above technology, the timing of switching between engine driving using only light oil and engine driving using light oil and LPG gas / liquid fuel is uniformly determined based on a predetermined value of the accelerator pedal depression amount. For example, if the above control is performed when the gas fuel tank becomes empty, only the light oil ejection amount at the switching time can be obtained even if the switching time is exceeded. As a result, it does not lead to an increase in engine load or rotation speed.

In the above system, in the case of an apparatus in which LPG is vaporized by cooling water of an engine, especially in winter, the temperature of the cooling water sufficient to vaporize LPG does not increase in the early stage of operation or in a cold region. In such a case, the same problem as described above arises.

In view of the above-mentioned drawbacks of the prior art, the present invention is configured so that the timing of switching between light oil and gas / liquid fuel can be arbitrarily adjusted according to the remaining amount of fuel, the environment or the operating condition, thereby effectively reducing the amount of exhaust gas contained in exhaust gas. An object of the present invention is to provide a gas-fuel combined system that can efficiently operate a diesel engine while reducing the generation of graphite. Another object of the present invention is to provide a gas-fuel combined system which can effectively prevent an accident such as engine runaway in the system.

[0007]

According to the present invention, in order to achieve the above technical object, there is provided an invention as set forth in claim 1 , wherein the timing of switching between light oil fuel only and gas / liquid fuel using both light oil and gas fuel. gaseous fuel combined system definitive to determinable constructed an internal combustion engine based on the depression amount of the accelerator pedal
And swings in conjunction with depression of the accelerator pedal.
Connected to the accelerator lever through the elastic member
A load lever for controlling the injection amount of the oil fuel ;
A load that enables arbitrarily variable control of the bar swing regulation position
Lever swing regulating means, and an engine containing the remaining amount of the gaseous fuel.
The engine operating state is detected and the accelerator pedal
Of the gaseous fuel detected.
Operating state of engine including remaining amount and accelerator pedal
The injection amount of the gaseous fuel and the volume
Drive unit including a load lever and a load lever swing restricting means
And control means for respectively controlling the movement of wood, the access
Lever and load lever
The elastic member is attached by depressing the accelerator pedal.
Only the accelerator lever can swing against the power
The accelerator and load levers.
The first and second return springs that urge in the return direction
Propose a gas fuel combined system characterized by having
You.

[0008] In order to more safely and surely control such invention, the invention according to claim 2 is based on claim 1.
The load lever swing restricting means includes a load lever.
Loader connected via a connecting rod to the
Arm and the load lever are engaged with the load arm.
A rotating member provided with a regulating member for regulating the swing position,
A step motor for variably controlling the rotation angle of the rotation member;
It consists of.

In the embodiment described later, a stepping motor is used as the load lever swing regulating means.
Without being limited to this, it is possible to use a rack-and-gear or an actuator that can be controlled to advance or retreat in multiple steps or steplessly.

[0010]

According to the technical means, only light oil and light oil /
The gas fuel switching time is not controlled uniformly,
For example, when the remaining amount of the gaseous fuel tank decreases, the switching time is delayed to increase the mixing amount of light oil, and when the gaseous fuel becomes empty, the switching time is further delayed, and only the light oil is used. On the other hand, when the remaining amount of the light oil fuel tank decreases, the switching time is advanced to increase the mixing amount of the gaseous fuel, and when the light oil fuel becomes empty, the switching is performed. If the timing is further advanced and engine combustion is performed using only gaseous fuel, smooth driving performance can be achieved in any case. Further, according to such means, the detected gaseous fuel
Engine operating status, including remaining fuel, and accelerator pedal
Position of the load lever in accordance with the
Since the injection amount of gaseous fuel can be controlled, gas oil and gas
Arbitrarily and quickly control the mixing ratio with the body fuel
it can. Due to this, the engine operating condition changes rapidly
Controllable with high response even in transient operation
Become. Further, the accelerator lever and the load lever
First and second return springs are provided and both levers are
Return spring by connecting the
If one of the rings breaks, the other return spring and the front
The load lever is urged in the return direction by the elastic member.
Therefore, runaway of the engine can be avoided. In addition,
The bar and the load lever are connected via a spring member
The load lever swings following the accelerator lever
During this time, only light oil is burned and then the accelerator is depressed.
As a result, only the accelerator lever swings against the elastic member.
In order to operate, the light oil fuel is
In this state, the injection amount of gaseous fuel can be controlled.

In the case of an apparatus for vaporizing gaseous fuel using cooling water of an engine, particularly in the winter, for example, in the early stage of operation or when the temperature of cooling water sufficient to vaporize LPG in a cold region has not risen, the above-mentioned condition is required. Similarly to the above, the engine cooling water temperature may be detected, the switching timing may be delayed until the cooling water temperature rises, and the engine combustion may be performed using only light oil.

Further, depending on environmental conditions such as a traffic congestion area, it may be necessary to advance the switching time and increase the mixing amount of gaseous fuel to take measures against exhaust gas. In such a case, it is also possible to control by manual operation. .

According to a second aspect of the present invention, the above-mentioned invention is further embodied .
It is possible to accurately control the load lever swing regulation position. this
Thereby, the invention according to claim 1 can be smoothly implemented.

[0014]

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention, but are merely illustrative examples. Not just. FIG.
4 to 4 show a gas-fuel combined system of a diesel engine according to an embodiment of the present invention, and FIG.
2 to 4 show an accelerator lever that swings in conjunction with an accelerator pedal and a load lever control mechanism that controls an injection pump governor. FIG. 2 is an overall front view of the control mechanism, and FIG. FIG. 4 is a bottom view showing a configuration of a control unit for restricting the rotation of the load lever.

In FIG. 1, 1 is a light oil fuel tank, 2 is a row type injection pump, 3 is an engine, 7 is an accelerator lever which swings in conjunction with an accelerator pedal, and 8 is an accelerator lever 7 via a cancel spring 11. The load levers are connected to control an injection pump governor (not shown), and return springs 9 and 10 are independently attached thereto. Then, the fuel filtered from the light oil fuel tank 1 through the feed pump 5 and the fuel filter (not shown) is sent to the injection pump 2, and a load control mechanism 20 described later is provided.
Until the load lever 8 is oscillated, the lever 8 oscillates via the accelerator lever 7 in accordance with the depression amount of the accelerator pedal, and the injection pressure controlled by an injection pump governor (not shown) The fuel is supplied from an injection pipe 6 to an injection nozzle in the engine 3 and injected into a fuel chamber.

On the other hand, reference numeral 21 denotes a gas fuel tank filled with a liquefied gas composed of LPG or LNG. For example, when the load lever 8 is restricted from swinging, an electromagnetic valve or other opening / closing valve 25 provided on the inlet side of the tank 21 is provided. A regulator 26 that is opened and the pressure of the vaporized gas vaporized by the cooling water of the engine 3 is controlled by the control unit 13.
The air is supplied between the intake pipe 23 provided with the air cleaner 22 and the intake manifold 24, and is guided into the combustion chamber together with the light oil fuel.

The control unit 13 includes an engine speed sensor 16, an accelerator sensor 17 for detecting a swing angle (accelerator depression angle) of an accelerator lever 7 corresponding to an engine load, a light oil fuel tank 1 and a gas fuel tank 2.
1, remaining amount sensors 14 and 15 respectively attached to the engine 1
The control signal is calculated and controlled as a detection signal of a water temperature sensor 29 for detecting the temperature of the cooling water based on a predetermined calculation program, and a control signal is transmitted to the load control mechanism 20 and the regulator 26.

Next, the load control mechanism will be described in detail with reference to FIGS. 2 to 4. In FIGS. 2 and 4, the accelerator lever 7 and the load lever 8 are pivoted by a common support shaft 19. While being pivotally supported, the lower end thereof is connected by a cancel spring 11, and the load lever 8 is integrally formed with the accelerator lever 7 until swinging is restricted by a restricting pin 31 described later by depressing an accelerator pedal.
Are configured to be swingable. Return springs 9 and 10 are independently attached to the accelerator lever 7 and the load lever 8, respectively. As a result, even if the cancel spring 11 falls off or is erroneously broken, the accelerator lever 7 is actuated by the biasing force of each of the return springs 9 and 10.
Since both the load lever 8 and the load lever 8 return to the idle side, the runaway of the engine 3 can be completely prevented. 8a is a return position regulating member at the time of return.

A branch arm 7a is extended from the accelerator lever 7 near the support shaft 19, and an accelerator sensor 17 is connected to the branch arm 7a via a connecting rod 35 and a rotating arm 35a. The step angle can be detected. The load lever 8 is connected to a load arm plate on the stepping motor 30 side via a connecting rod 33.

Next, the mechanism of the stepping motor 30 will be described with reference to FIGS. The stepping motor 30 is configured to be rotatable by a predetermined angle based on a control signal from the control unit 13, and the rotation plate 3 having a motor shaft on which a restriction pin 31 for the load lever 8 is provided.
2 is provided on the shaft. The rotating plate 32 is provided with the regulating pin 3.
1 extends on the opposite side, one end of a connecting rod 36 is pivotally supported on the extending portion 32a, and the rotation angle of the stepping motor 30 can be detected by the position sensor 38 via the connecting rod 36 and the rotation arm 37. Constitute.
The load arm plate 34 has a center portion pivotally supported by a shaft 34a concentrically with the rotary plate 32, and is configured to be swingable. The arm portion extends from the center portion, and a load lever Eight connecting rods 33 are supported. The rotation arm of the load arm plate 34 engages the side surface of the arm with the regulation pin 31 so that the angle can be regulated.

Next, the operation of the embodiment will be described. First, in a normal fuel supply system, the stepping motor 30 is moved to a predetermined angular position (hereinafter referred to as a first regulated angular position) based on a control signal from the control unit 13.
Then, when the accelerator pedal is depressed, the load lever 8 swings together with the accelerator lever 7 via the cancel spring 11, and the swing of the load lever 8 causes the injection of the injection pump governor (not shown). Pressure control is performed, and the fuel sent from the light oil fuel tank 1 to the injection pump 2 is supplied from the injection pipe 6 to the injection nozzle in the engine 3 at the injection pressure controlled by the injection pump governor, and the engine fuel chamber Injected to.

On the other hand, the accelerator sensor 17 detects the depression angle of the accelerator, and operates the opening / closing valve 25 provided on the inlet side of the gas fuel tank 21 until the depression angle reaches an angle position corresponding to the first restriction angle position. Do not open. As a result, when the depression amount of the accelerator pedal is smaller than the angle position corresponding to the first regulation angle position, the engine 3 is driven by injecting only light oil as in the conventional diesel engine 3. When the depression amount of the accelerator pedal exceeds an angular position corresponding to the first regulating angular position, the load arm plate 34 swinging with the load lever 8 via the connecting rod 33 rotates, and the side surface of the arm portion is rotated. Engages with the regulating pin 31 of the rotating plate 32, and the load lever 8 is regulated to swing.

On the other hand, at the time when the swing is restricted, the solenoid valve and other on-off valves 25 provided on the inlet side of the tank 21 are opened, and the accelerator lever 7 is connected to the load lever 8 via the cancel spring 11. Further, even if the angle of the load lever 8 is restricted, the accelerator lever 7 further swings against the elastic force of the cancel spring 11, and the swing angle (stepping angle) is detected by the accelerator sensor 17,
The regulator 26 is pressure-controlled in accordance with the depression angle via the control unit 13 to supply a predetermined amount of liquefied gas vaporized by the cooling water of the engine 3 to the intake pipe 23 side, and the light oil fuel Is guided into the combustion chamber.

As a result, the liquefied gas corresponding to the stepping amount is burned in the engine 3 in a state where the light oil and the LPG are mixed, so that the engine 3 can be driven by gas-liquid mixing. In the above configuration, when the remaining amount of the liquefied gas in the gaseous fuel tank 21 decreases, the control unit 13 detects this through the remaining amount sensor 15 and controls the stepping motor 30 in proportion to the remaining amount. By rotating the control lever 1 counterclockwise from the position shown in FIG. 3 from the position shown in FIG. 3, the swing restriction position of the load lever 8 can be delayed, whereby the switching timing from light oil to gas-liquid fuel can be delayed. , Which saves gaseous fuel. When the remaining amount of the liquefied gas in the gas fuel tank 21 further decreases, the stepping motor 30 is further rotated counterclockwise to a position where the load lever 8 is not restricted, and the engine 3 is driven only with light oil.

On the other hand, when the remaining amount of light oil in the light oil fuel tank 1 is reduced, this is detected by the remaining amount sensor 14 and, conversely, the stepping motor 30 is rotated clockwise to rotate the load lever 8. The swing regulation position is advanced so that the switching time from light oil to gas-liquid fuel can be made earlier, leading to saving of light oil fuel. Since the control unit 13 also detects the temperature of the cooling water of the engine 3 by the water temperature sensor 29, the temperature of the cooling water sufficient to vaporize the LPG in the early stage of operation or in a cold region is not increased particularly in winter. In this case, the stepping motor 30 is further rotated counterclockwise to a position where the load lever 8 is not restricted, the engine 3 is driven only with light oil, and when the cooling water rises, the stepping motor 30 is returned to the original position. You only have to return.

Depending on environmental conditions such as traffic congestion areas, it may be necessary to advance the switching timing and increase the amount of gaseous fuel mixed to take measures against exhaust gas. Therefore, the rotation angle control of the stepping motor 30 must be manually controlled. It is preferable to provide an operating means for operation on the driver's seat side as shown in FIG.

[0028]

As described above, according to the present invention, light oil and ki /
The switching timing of the liquid fuel can be arbitrarily adjusted according to the remaining fuel, the environment or the operating condition .
However, smooth driving performance can be achieved. This makes it possible to efficiently operate the diesel engine while effectively reducing the generation of graphite in the exhaust gas. That is, according to the present invention,
If the operation of the engine includes the remaining amount of the detected gaseous fuel,
Depending on the condition and the accelerator pedal depression amount.
Bar swing regulation position and gas fuel injection amount can be controlled respectively
The mixing ratio of light oil and gaseous fuel
One can be controlled quickly. For this reason, engine operation
High response even in the transient operation state where the
Control becomes possible with the answer. In addition, the accelerator
First and second return springs on bar and load lever
And both levers are connected by an elastic member.
Therefore, if one of the return springs breaks, the other
Load lever by return spring and the elastic member
-Is urged in the return direction to avoid engine runaway
it can. In addition, between the accelerator lever and the load lever
Follows the accelerator lever because it is connected via a spring member
While the load lever swings, only light oil is burned.
Then, depressing the accelerator against the elastic member
Corresponds to the amount of depression because only the accelerator lever swings
Control the gaseous fuel injection amount with light oil fuel restricted.
You can control. Further, according to the invention of claim 2,
By using a step motor, the load lever
Can be accurately controlled. As a result,
Item 1 can be smoothly implemented.

[Brief description of the drawings]

FIG. 1 is an overall view showing a gas-fuel combined system of a diesel engine according to an embodiment of the present invention.

FIG. 2 is an overall front view showing a load control mechanism of an accelerator lever that swings following an accelerator pedal and a load lever that controls an injection pump governor.

FIG. 3 is a side view of a main part of FIG. 2 showing a configuration of an accelerator lever and a load lever.

FIG. 4 is a bottom view showing the configuration of a control unit that controls the rotation of the load lever shown in FIG. 2;

[Explanation of symbols]

 Reference Signs List 1 light oil fuel tank 2 injection pump 3 engine 7 accelerator lever 8 load lever 9, 10 return spring 11 cancel spring 13 control unit 14, 15 remaining amount sensor 17 accelerator sensor 21 gas fuel tank 26 regulator 29 water temperature sensor 30 stepping motor 31 regulating pin

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F02D 1/00-45/00 F02M 21/00-45/04

Claims (2)

(57) [Claims] 1. Light oil fuel only, and light oil and gas fuel in combination
Switch the gas / liquid fuel switch
Configured so that it can be determined based onFor internal combustion enginesWillingness
In the combined fuel system,An accelerator that swings in conjunction with depression of the accelerator pedal
The fuel oil is connected to the lever through an elastic member.
A load lever to control the firing rate, The load regulating position of the load lever can be variably controlled.
Load lever swing restricting means, Detecting an operating state of the engine including the remaining amount of the gaseous fuel;
While detecting the depression amount of the accelerator pedal,
The engine operation including the detected remaining amount of the gaseous fuel
Depending on the rolling state and the amount of depression of the accelerator pedal,
The injection amount of the gaseous fuel, the load lever and the load
Control the movement of the driving members including the lever swing restricting means, respectively.
Control means, The accelerator lever and the load lever are controlled by the swing restriction.
When the accelerator pedal is depressed beyond the
Only the accelerator lever swings against the urging force of the elastic member
As well as possible, Urges the accelerator lever and load lever in the return direction
That the first and second return springs are provided. Feature
Gas fuel combined system. 2. The apparatus according to claim 2, wherein said load lever swing restricting means comprises:
Connected to the load lever via a connecting rod
And the load arm engaged with the load arm.
A rotation provided with a regulating member that regulates the swing position of the
A moving member and a step for variably controlling the rotation angle of the rotating member.
2. The gas-fuel combined system according to claim 1, comprising a pump.