JP2824663B2 - Fuel supply device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply device for an internal combustion engine that supplies two types of fuel, gasoline and hydrogen, according to operating conditions.

2. Description of the Related Art There is known an internal combustion engine that uses two types of fuels, gasoline and hydrogen.

This apparatus includes gasoline supply means for supplying gasoline and hydrogen supply means for supplying hydrogen. At least when the residual hydrogen pressure is a predetermined pressure, the supply of hydrogen is stopped and only gasoline is supplied, and good ignition of hydrogen is performed. By utilizing the characteristics, lean combustion of gasoline is realized.

[Problems to be Solved by the Invention] Conventionally, since the flammable range of gasoline is relatively narrow, the amount of air is generally controlled by a throttle valve. By the way, even in the region where hydrogen is supplied, if the amount of air is similarly controlled by the throttle valve, the good ignitability of hydrogen cannot be fully utilized, and there is room for improvement in fuel efficiency.

The present invention has been made in view of these circumstances,
It is an object of the present invention to provide a fuel supply device for an internal combustion engine that effectively supplies gasoline and hydrogen to improve fuel efficiency.

[Means for Solving the Problem] In order to solve the problem, the invention according to claim 1 is
A fuel supply device for an internal combustion engine, comprising gasoline supply means for supplying gasoline, and hydrogen supply means for supplying hydrogen, wherein at least the residual hydrogen pressure is at or below a predetermined pressure, the supply of hydrogen is stopped to supply only gasoline, In an operation region where the supply of hydrogen is stopped, a throttle valve that opens and closes the intake passage is linked to an accelerator, and in other operation regions, a control unit that keeps the throttle valve fully open is provided.

Further, the invention according to claim 2 comprises a gasoline supply means for supplying gasoline and a hydrogen supply means for supplying hydrogen. At least when the residual hydrogen pressure is lower than a predetermined pressure, the supply of hydrogen is stopped and only gasoline is supplied. In a fuel supply device for an internal combustion engine, a bypass passage communicating with an intake passage before and after a throttle valve that opens and closes an intake passage in conjunction with an accelerator is provided, and an on-off valve that opens and closes this passage is provided in the bypass passage. In the operating region where the supply of the fuel gas is stopped, the control device is provided with a control unit that keeps the on-off valve fully closed in the other operating regions.

[Operation] In the invention described in claim 1, the throttle valve is linked to the accelerator in the operation region where the supply of hydrogen is stopped, and only gasoline is supplied. In the other operation regions, the throttle valve in the intake passage is fully opened. Hold and supply hydrogen.

Further, in the invention according to claim 2, in the operation region in which the supply of hydrogen is stopped, the on-off valve of the bypass passage is kept fully closed,
The throttle valve is interlocked with the accelerator to supply only gasoline, and in other operating regions, the on-off valve of the bypass passage is kept fully open, and the intake passage is communicated before and after the throttle valve to supply hydrogen.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram of a fuel injection device for an internal combustion engine according to the present invention.

In the drawings, reference numeral 1 denotes a water-cooled internal combustion engine. A cylinder head 3 is mounted on a cylinder block 2 mounted on a crankcase (not shown), and a head cover 4 is provided on the cylinder head 3. A combustion chamber 6 is defined by the cylinder block 2, the cylinder head 3 and the piston 5, and the cylinder head 3 is provided with a spark plug 7. The spark plug 7 is sparked at a predetermined timing by the control device 8, and ignites the air-fuel mixture compressed in the combustion chamber 6.

The piston 5 is connected to a crankshaft 10 via a connecting rod 9 and rotates the crankshaft 10 by reciprocating the piston 5. The rotation of the crankshaft 10 is detected by the engine speed detecting means 11, and the engine speed information is sent to the control device 8.

The cylinder head 3 is provided with an intake system 12 and an exhaust system 13, and a surge tank 15 is provided in an intake pipe 14 of the intake system 12.
An air cleaner 16 is connected further upstream, and the intake system 12 is opened and closed by an intake valve 17 provided on the cylinder head 3. A throttle valve 18 is provided upstream of the surge tank 15 in the intake pipe 14, and the throttle valve 18 is opened and closed by a servomotor 19. The servo motor 19 is the control device 8,
It is controlled according to the operating state. The air cleaner 16 is provided with intake air amount detection means 44, which detects the amount of intake air and sends it to the control device 8.

A muffler 21 is connected to the exhaust pipe 20 of the exhaust system 13, and the exhaust pipe
Numeral 20 is opened and closed by a valve (not shown) to discharge combustion gas.

The internal combustion engine 1 is provided with a fuel supply device A, which is provided with a gasoline supply means 30 for injecting gasoline.
And hydrogen supply means 31 for injecting hydrogen. Gasoline is supplied from a fuel tank 33 to a fuel injector 32 constituting the gasoline supply means 30 via a pump 34.
The pressure of the supplied gasoline is adjusted to be constant by the pressure regulator 35.

The hydrogen injector 36 of the hydrogen supply means 31 is provided on the cylinder head 3, and the hydrogen injector 36 is provided with a hydrogen cylinder.
From 37, hydrogen is supplied under pressure regulation by the regulator 38. The residual hydrogen pressure of the hydrogen cylinder 37 is detected by the pressure detecting means 39 and sent to the control device 8, and when the remaining amount of hydrogen falls below a predetermined pressure, the valve 40 is closed and the supply to the hydrogen injector 36 is stopped. It has become. The hydrogen injector 36 is mounted between the intake valve 17 and the spark plug 7 and near the spark plug 7 so that hydrogen injected from the hydrogen injector 36 can be easily burned.

The operation of the accelerator 41 by the driver is detected by a sensor 42, and the operation state of the accelerator 41 is detected by the sensor 42 and sent to the controller 8. When the residual hydrogen pressure is equal to or higher than a predetermined pressure, gasoline By the operation of the supply means 30 and the hydrogen supply means 31, gasoline and hydrogen are supplied.

When the residual hydrogen pressure is equal to or higher than a predetermined pressure, gasoline and hydrogen are supplied in a normal driving region used for general driving, and only hydrogen is supplied at a low load including idling, and only gasoline is supplied at a high load. May be.

Further, under the control of the control device 8, in the operation region where the residual hydrogen pressure is equal to or lower than the predetermined pressure, the supply of hydrogen is stopped and only gasoline is supplied. In an operation region in which the supply of hydrogen is stopped, including the case where the supply of hydrogen is stopped at a high load, the throttle valve 18 is interlocked with the accelerator 41, and these constitute control means. As described above, when the hydrogen is exhausted, the supply of hydrogen is stopped, the supply amount of gasoline is increased to the engine flammable range, and the operation is enabled.

On the other hand, the throttle valve 18 is kept fully open via the servomotor 19 in an operation region other than the operation region for supplying gasoline and hydrogen and the operation region for supplying only hydrogen, that is, the operation region for stopping the supply of hydrogen. In this operation region, a large amount of air is sucked in because the intake passage is fully opened. However, since the ignitability of hydrogen is good, even a lean mixture can be burned.
At this time, since the intake passage is fully opened, the pump loss of the internal combustion engine 1 is reduced, and the fuel efficiency is improved.

2 and 3 are flowcharts showing the operation of the fuel supply device for an internal combustion engine according to the present invention.

FIG. 2 shows a routine executed at regular intervals. In step a, the residual hydrogen pressure is measured, and it is determined whether the residual hydrogen pressure is equal to or higher than a predetermined specified pressure (step b). Determines whether the servo motor 19 is energized (step c). If it is not energized in step c, the servo motor 19 is energized (step d). If the servo motor 19 is energized, the opening of the throttle valve 18 is measured (step e), and the engine speed is further reduced. Measure (step f). Then, from the obtained throttle valve opening and the engine speed, the hydrogen injection amount and timing are calculated (step g), and the gasoline injection amount and timing are further calculated (step h). Transition.

In step b, it is determined whether or not the residual hydrogen pressure is equal to or higher than a predetermined specified pressure. If the residual pressure is equal to or lower than the specified pressure, it is determined whether or not the servo motor 19 is energized (step i).
If the power is supplied, the power supply to the servo motor 19 is stopped (step j). If the servomotor 19 is not energized, the intake air amount is measured (step k), and the engine speed is further measured (step l). Then, based on the obtained intake air amount and the engine speed, the gasoline injection amount and timing are calculated (step m), the hydrogen valve is closed (step n), and the hydrogen injection amount is set to zero (step m). o) Move to the next program.

FIG. 3 shows a routine executed for each crank angle. In step a, it is determined whether or not it is the hydrogen injection timing, and in the case of the injection timing, a predetermined amount of hydrogen is injected (step b). If it is not the hydrogen injection timing, it is determined whether or not it is the gasoline injection timing (step c). If it is the injection timing, a predetermined amount of gasoline is injected (step d), and the program proceeds to the next program.

FIG. 4 is an overall configuration diagram of another embodiment of the fuel injection device for an internal combustion engine according to the present invention.

In this embodiment, the same components as those shown in FIGS. 1 and 2 have the same configuration and the same function, and therefore, the description is omitted.

The throttle valve 18 provided in the intake passage is operated by operating the accelerator 50, and a bypass passage 51 communicating the intake passage is provided before and after the throttle valve 18. The bypass passage 51 is provided with an on-off valve 52 for opening and closing this passage.
Are driven by the actuator 53. This actuator
Numeral 53 is controlled by the control device 8 and, similarly to the embodiment shown in FIGS. 1 to 3, in the operation region where the supply of hydrogen is stopped, the on-off valve 52 is kept fully closed, and the throttle valve 18 is turned on the accelerator 50. To supply only gasoline.

At this time, since the bypass passage 51 is fully open, the pump loss is reduced as in the above-described embodiment, and the fuel efficiency is improved.

In the other operation regions, the on-off valve 52 is kept fully open, the throttle valve 18 is linked to the accelerator 50, and gasoline and hydrogen or only hydrogen are supplied. Note that in both of the above embodiments,
The description has been given of the case where hydrogen is directly injected into the combustion chamber 6, but the present invention can be similarly applied to a case where hydrogen is injected into the intake passage.

Also, in the embodiment shown in FIGS. 1 to 3 and the embodiment shown in FIG. 4, the hydrogen injector 36 is provided near the ignition plug 7, but as shown in FIG. 5 and FIG. The injection direction of the hydrogen injector may be adjusted so that when hydrogen is injected, the hydrogen gas is directed to the spark plug.

FIG. 5 shows an embodiment in which the combustion chamber is attached to a wedge-type combustion chamber of a four-cycle internal combustion engine.
An intake opening 61 and an exhaust opening 62 are formed in one of the 60,
On the other hand, an ignition plug 63 and a hydrogen injector 64 are provided. When the solenoid coil 65 is energized by the drive signal, the hydrogen injector 64 opens the supply valve 66 against the spring 67 and injects hydrogen from the supply passage 68. This is an example in which it is attached to a wedge-type combustion chamber, but the same applies to other bathtub type, hemispherical type, multispherical type, and pent roof type.

FIG. 6 is a cross-sectional view of a combustion chamber of a two-stroke internal combustion engine. A combustion chamber 73 is formed by a cylinder block 70, a cylinder head 71 and a piston 72.
63 and a hydrogen injector 64 are provided. The installation of the two-cycle internal combustion engine in the combustion chamber has a higher degree of freedom than the installation in the combustion chamber of the four-cycle internal combustion engine because the intake and exhaust valves are not installed.

7 and 8 show an embodiment showing the supply ratio between hydrogen and gasoline.

The embodiment shown in FIG. 7 shows a specific control example in a case where only hydrogen is supplied at a low load and only gasoline is supplied at a high load. In this case, the high-load region where only gasoline is supplied is extremely narrow, and the throttle valve is fully opened in the entire region if the residual hydrogen pressure is equal to or higher than a predetermined value. In this embodiment, the supply amount of hydrogen is gradually reduced as the load increases.

In the embodiment shown in FIG. 8, the hydrogen supply amount is set to an amount necessary to maintain idling and is constant regardless of the engine load. In this embodiment, since it is not necessary to control the supply amount of hydrogen, the control is simple and cost reduction is possible.

9 to 11 show an embodiment of a method for inputting a drive signal of the hydrogen injector.

FIG. 9 shows a circuit diagram for obtaining a drive signal, and FIG. 10 shows a waveform diagram of this circuit. The hydrogen injector 80 is constituted by an electromagnetic type, and generates a signal which triggers at a constant crank angle. Thus, the pickup 82 is attached to the internal combustion engine 81, and a pickup signal is output from the rotation of the crankshaft 83. The pickup signal is shaped into a pulse by a pulse generation circuit 84 to generate a pulse having a predetermined time width, and a driving signal having a predetermined time width for driving the hydrogen injector 80 is output by the driving circuit 85 based on the pulse. .

FIG. 11 shows an embodiment in which the drive signal of the hydrogen injector is extracted from the primary ignition signal. The primary ignition signal is an igniter
The igniter 90 detects the primary ignition signal to determine the ignition timing and the primary coil energizing time of the ignition coil 91. Based on the ignition signal of the igniter 90, the ignition coil 91
Generates a high voltage to spark the spark plug 92.

The primary ignition signal input to the igniter 90 is also input to a pulse generation circuit 93. The pulse generation circuit 93 shapes the waveform to generate a pulse having a fixed time width. A drive signal having a predetermined time width for driving the drive is output.

[Effects of the Invention] As described above, according to the first and second aspects of the present invention, in the operation region for supplying hydrogen, the intake passage and the bypass passage are fully opened, so that a large amount of air is sucked. However, due to the good ignitability of hydrogen, even a lean mixture can be burned. Also, at this time, since the intake passage and the bypass passage are fully opened, the pump loss is reduced, and the fuel efficiency is improved.

[Brief description of the drawings]

1 is an overall configuration diagram of a fuel injection device for an internal combustion engine of the present invention, FIGS. 2 and 3 are flowcharts showing the operation of the fuel injection device for an internal combustion engine of the present invention, and FIG. 4 is an internal combustion engine of the present invention. 5 and 6 are diagrams showing the state of attachment of a hydrogen injector, and FIGS. 7 and 8 are diagrams showing the supply ratio between hydrogen and gasoline. FIGS. 9 to 11 show an embodiment of a method for inputting a drive signal of a hydrogen injector. In the drawings, reference numeral 1 denotes an internal combustion engine, 6 denotes a combustion chamber, 8 denotes a control device, 14 denotes an intake pipe, 18 denotes a throttle valve, 19 denotes a servomotor,
A is a fuel supply device, 30 is gasoline supply means, 31 is hydrogen supply means, 51 is a bypass passage, 52 is an on-off valve, and 53 is an actuator.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F02D 19/02-19/08 F02D 9/02 F02D 41/02 F02M 21/02

Claims (2)

(57) [Claims] 1. A gasoline supply means for supplying gasoline,
A hydrogen supply means for supplying hydrogen, wherein at least the residual hydrogen pressure is equal to or lower than a predetermined pressure, in a fuel supply device for an internal combustion engine that supplies hydrogen and stops supplying hydrogen only, in an operation region where the supply of hydrogen is stopped. A fuel supply device for an internal combustion engine, comprising: a control unit that links a throttle valve that opens and closes an intake passage to an accelerator and holds the throttle valve in a full open state in other operation regions. 2. Gasoline supply means for supplying gasoline,
A hydrogen supply means for supplying hydrogen, wherein at least when the residual hydrogen pressure is equal to or lower than a predetermined pressure, in a fuel supply device for an internal combustion engine that supplies hydrogen and stops supplying hydrogen, the intake passage is opened and closed in conjunction with an accelerator. A bypass passage communicating the intake passages before and after the throttle valve is provided, and an on-off valve for opening and closing this passage is provided in the bypass passage, and the on-off valve is fully closed in an operation region in which the supply of hydrogen is stopped,
A fuel supply device for an internal combustion engine, comprising: control means for keeping the on-off valve fully open in other operation ranges.