CN1034361C - Improved Fuel Injection System of Internal Combustion Engine - Google Patents

Abstract

A fuel feeding device of an internal combustion engine comprises a main body, in which a fuel cavity is communicated with a cavity hole for selectively transferring fuel to a fuel metering means of the fuel cavity; a hole communicating with the interior of the main body between the cavity hole and the exterior of the main body; a valve means including a valve which is preferably cooperated with a hole for selectively opening and closing the hole, and a valve rod for selectively operating an electromagnetic means in the main body, the electromagnetic means being operatively connected with a valve rod to move the valve rod to the position for opening or closing the hole; and a means for supplying gas to the fuel cavity at least when the hole is opened to supply fuel to the fuel cavity. The valve rod protrudes to the fuel cavity from the cavity hole through the electromagnetic means and is communicated with the cavity hole and the fuel cavity through the channel of the valve rod, such that the fuel in the fuel cavity is transmitted to the hole through the channel of the valve rod and the cavity hole.

Description

Improved Fuel Injection System of Internal Combustion Engine

The present invention is a divisional patent application whose title of invention is "improved internal combustion engine fuel delivery device" and the application number is CN88102779.0, and the application date is March 31, 1988.

The present invention relates to a fuel injector type device of an internal combustion engine, wherein a certain amount of fuel is injected into each cylinder of the engine mixed with gas (such as air and other gases suitable for combustion). The invention also relates to a fuel injection system for an internal combustion engine having the device or injector described above.

Inject a fixed amount of fuel mixed with gas into the engine, and the pressure of the mixed gas is sufficient to make the fuel directly injected into the engine cylinder or the intake system through a valve control port, and the inhaled air enters the engine through the intake system. In the cylinder, the above-mentioned technology is already known. This form of fuel metering and injection process needs to provide fuel and gas to the fuel metering and injection system corresponding to each cylinder of the engine.

When designing the fuel metering and injection system, many factors in the working process must be considered, such as the weight of the fuel supply control valve with the valve stem. Because the dynamic load and rebound of the valve are important factors affecting the accuracy of fuel supply. Similarly, the wetting degree of the metered fuel to the pipe wall will also affect the change of the fuel supply amount between the cycles of the engine, and affect the engine's response to the change of the fuel metering.

The object of the present invention is to provide a fuel injection system with an improved arrangement for the fuel supply of an internal combustion engine, which is small and compact and whose operation meets the reliability, accuracy and longevity requirements of modern engines.

To this end, a fuel injection system for an internal combustion engine is provided, which includes:

A fuel delivery device for an internal combustion engine, comprising:

a body having a fuel cavity in communication with the nozzle cavity,

a dosing device for selectively delivering fuel to the fuel chamber,

a spout in the body communicating between the spout lumen and the exterior of the body,

The valve means includes a valve member adapted to cooperate with the spout for selectively opening and closing the spout, and having a valve stem mounted on the valve member,

an electromagnetic device selectively operable within the body, the electromagnetic device being operatively connected to the valve stem to move the valve stem to open or close the spout,

air supply means for supplying air to the fuel chamber at least when the nozzle is open for supplying fuel from the fuel chamber to the open nozzle,

The valve stem extends from the spout cavity to the fuel cavity through the electromagnetic device, and a passage through the valve stem communicates the spout cavity with the fuel cavity, so that the fuel in the fuel cavity is delivered to and through the valve stem passage and the spout cavity. through the spout.

The electromagnetic device is preferably a solenoid valve. The solenoid valve has a coil concentric with the valve stem, and the valve stem is equipped with an armature coaxial with it. The armature is preferably along or substantially within the annular space between the coil and the valve stem. The valve stem is preferably cylindrical, with a valve member fixed at one end, and fuel can flow in from the other open end. The valve member end connection is between the inner wall of the cylindrical valve stem and the inner cavity. Connected in this way, a large amount of fuel will not be enclosed in the part below the junction between the cylindrical valve stem and the inner cavity, and will not flow into the inner cavity. Fuel is preferably injected directly into the combustion chamber of the engine through the body bore.

The construction described above brings many advantages to the operation of a fuel injection system having such a fuel delivery device. Having the fuel flow through a channel within the stem (as a barrel stem can provide) reduces the surface area that can affect the fuel. The fuel is injected into the engine from the metering point to the outlet of the body. This is particularly different from the existing structure, which passes through a circular passage. The wetting of the surface by the fuel affects the amount of reaction delay between the change in delivery rate at the fuel meter and the resulting change in the delivery rate of the fuel injected into the engine at the nozzle. In each injection cycle, as the fuel delivery rate changes, the thickness of the oil film deposited on the surface area where the fuel flows between the dosing point and the outlet point will also change. So if the surface area in contact with the fuel is reduced, the total amount of fuel including the change in film thickness will also be reduced. This advantage is reflected in the faster reaction time of the engine and in the reduced instability due to variations in the amount of fuel injected from engine cycle to cycle.

There are also advantages to using a solenoid valve arrangement. The structure of the prior art is that the fuel metering place is between the solenoid valve and the fuel delivery port, while the present invention arranges the solenoid valve assembly between the fuel delivery port and the metering place. This shortens the length of the valve stem, which reduces the weight of the valve stem and lowers the natural frequency, which in turn reduces the number of possible rebounds when the valve is closed. When the engine is working at a high load, a considerable amount of fuel will flow through the valve stem, which can produce a good cooling effect when the solenoid valve generates a high heat.

Similarly, the electromagnetic valve part is arranged between the fuel delivery port and the quantitative place where the fuel enters the engine, and the electromagnetic valve adopts a symmetrical shape, so that the fuel injection device or a part thereof can be packed into the engine cylinder head, thereby reducing the engine and fuel delivery. The overall height of the combined unit. This structural position can also rely on the heat from the cylinder head to heat up the fuel and help fuel atomization.

The main application of the above-described device for injecting fuel into an internal combustion engine is to inject fuel directly into individual cylinders of a multi-cylinder engine, as is widely used in motor vehicles.

Considering the production cost, usually only one pump is used to send the fuel in the fuel tank to each fuel injection device, and then send the return oil from each injection device back to the fuel tank through an appropriate oil return pipe . In order to reduce costs, often only one pressure regulator is used to control the pressure differential between the air supply and the fuel supply to the fuel injection device. Adopting this structure will inevitably lead to the need to use many fuel pipes to connect between the fuel injection device and the fuel pump, and between the fuel injection device and the pressure regulator, which will obviously increase the production cost. It should be noted that in this structure, the fuel and gas pipes must have appropriate end fittings, which are often threaded, so that the joints can effectively prevent leakage and protect the fuel injection device, fuel pump and pressure regulator. Complementary parts are provided with threads. The production and assembly of multiple threaded parts is another cost factor, as is the assembly of a large number of fuel and gas lines, which also affects the appearance of the unit.

Operational problems can also arise from the use of numerous fuel and gas lines. The plastic pipe is elastic, so the cross-section of the pipe changes with the pressure inside the pipe, making it difficult to control the pressure difference between the supplied fuel and gas to a specified value.

In the case of many engine applications, such as automobiles and marine external engines, the structural size of the engine and the corresponding accessories of the engine are very important factors. The reduction in the size of the engine itself is limited, so it is important to keep the effect of the accessories added on the main engine on increasing the overall size of the engine to a minimum.

In view of the structural, operational and cost deficiencies of the currently known fuel injection systems, it is an object of the present invention to provide an improved engine fuel injection system in which at least the above mentioned deficiencies have been overcome so that a more efficient operation can be obtained operating system, and also reduce the manufacturing cost of the system.

According to the above-mentioned viewpoint, it is suggested that the above-mentioned fuel injection device be combined into a fuel injection system for a multi-cylinder internal combustion engine as suggested by the present invention. Each cylinder of the internal combustion engine is equipped with a fuel injection device of that kind, and each fuel injection The device is integrally formed with a single rigid longitudinal monolith in which fuel supply pipes and gas supply pipes are formed, these pipes should extend along the lengthwise direction of the monolith, each fuel metering device communicates directly with the fuel supply pipe , each fuel chamber is provided in the integral piece and communicates with the gas supply pipe, so that when the hole is opened, the gas from the gas supply pipe carries the fuel from the fuel chamber to reach and pass through the valve stem passage and the nozzle cavity. The opening goes into the cylinder.

A structure with rigid longitudinal integral members discussed above provides fuel and gas to a plurality of fuel injection devices, each fuel injection device supplying a corresponding cylinder in a multi-cylinder internal combustion engine, which substantially reduces the number of cylinders required during installation. Number of fuel and air supply pipes. In detail, it is only necessary to use a single fuel supply pipe from the fuel pump and a single air supply pipe from the pressurized gas source to supply all fuel injection devices. Leaving aside the substantially improved appearance due to this construction, the reduction in the number and length of the flexible fuel and air supply pipes substantially reduces the variation in cross-section due to changes in the fluid pressure within these pipes impact on quantitative precision. In addition, the number of fuel and gas connections that need to be made is substantially reduced. This reduction in pipe connections contributes to space and cost savings as well as to reducing potential leak areas within the system.

In addition, the use of a rigid longitudinal monolith with multiple fuel injection devices, each corresponding to a cylinder in a multi-cylinder engine, allows the longitudinal monolith to act as a downward compression, and the fuel injection devices Fastened to relevant parts corresponding to each cylinder of the engine, each fuel injection device will have one end seated against the engine and communicate with the corresponding gap of the engine through a fuel delivery port at the one end, each fuel injection device The opposite ends of each fuel injection device are received in corresponding grooves in the rigid longitudinal monolith and provide a fixation for securing the rigid longitudinal monolith to the engine and securing each fuel injection device between the monolith and the engine. device. Therefore, there is no need to provide independently processed threaded holes at the connecting part of each fuel injection device and each cylinder; the longitudinal integral piece is fixed on the corresponding fuel injection device and the engine to ensure that the fuel injection device and the engine The number of threaded holes required for the required work correspondence between the two parts is not large.

The present invention will be described in detail below with reference to the accompanying drawings, which describe a practical structure of the fuel injection system of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a typical three cylinder engine incorporating the fuel injection system of the present invention.

Fig. 2 is a cross-sectional view of the fuel passage and the air passage installed at the fuel metering device and the injection system.

Fig. 3 is an axial sectional view of the fuel injection system and the interface of the oil and gas passages.

FIG. 4 is a view of the air control ring in the direction indicated by 4-4 in FIG. 2 .

Fig. 5 is a sectional view of the engine cylinder head equipped with oil and gas passages and fuel metering device and injection system.

Fig. 6 is a cross-sectional view of the pressure regulator installed on the oil and gas channels.

Fig. 7 is a partial sectional view of the voltage regulator along the direction indicated by 7-7 in Fig. 6 .

Figure 8 is a partial cross-sectional view of the switching mechanism for feeding fuel and gas into the fuel chamber.

Referring to Fig. 1, what is described here is a three-cylinder two-stroke engine basically adopting a traditional structure, which includes a cylinder block and a crankcase mechanism 1, a detachable cylinder head 2, and an intake system 4 in the cylinder block and the exhaust system 5 on the other side of the cylinder block. Spark plugs 7 are housed on the cylinder head 2, and each spark plug corresponds to an engine cylinder respectively. The fuel and air passage assembly 11 is mounted by bolts 8 approximately along the longitudinal centerline of the top end of the cylinder head.

As shown in FIG. 2, the engine fuel injection system includes a passage assembly 11 for supplying air and fuel. This assembly has a dosing device 10 and an injection system 12 for each cylinder. The channel assembly 11 is an elongate member within which an air line 13, an oil supply line 14 and an oil return line 15 extend longitudinally, these lines being closed at one end of the channel. As shown in Figure 1, an intake pipe connector 9 connected to the air pipe 13, an oil supply pipe connector 6 connected to the oil supply pipe 14, and a pressure regulator connected to the oil return pipe are arranged at appropriate positions. The oil return pipe connector 3 connected to the road 15 (the pressure regulator will be described in detail later).

The fuel dosing device 10 is commercially available and will not be described in detail here. Among commercially available dosing devices, "Multec" brand dosing devices manufactured by the Rochester Division of General Motors Corporation are suitable. An oil inlet 16 and an oil outlet 17 are opened on the body 18 of the dosing device 10, and the fuel flows in and out therefrom. The metering hole is opened on the area indicated by 19, and the metering hole sends the fuel to the pipeline 20 in (detailed later).

The body 18 of the dosing device 10 is installed in a horizontal hole 26 formed by the outer wall 21 of the channel assembly 11, and an "O"-shaped sealing ring 22 is arranged between the body 18 and the hole 26. There is a hole 27 on the inner wall 25 between the air channel 13 and the fuel channel 14 , and there is also an "O"-shaped sealing ring 23 between the hole 27 and the body 18 . The position of the region 19 where the measuring hole of the dosing device 10 is located corresponding to the channel 20 is determined by the pressure plate 28 . The pressing plate 28 is installed in the groove 29 of the body 18, and is pressed against the end wall 21 at an appropriate position by a bolt or a set screw (not shown in the figure). The body 18 of the dosing device passes at 34 through the dividing wall of the passages 14 and 16 in a high precision fit to reduce fuel leakage therebetween.

Injection system 12 (as shown in Figure 3) has a housing 30, also has a cylindrical sleeve 31 on the housing 30, stretches out a spout 32 from the bottom of cylindrical sleeve, and communicates with cavity 33 in the spout. A poppet member 34 cooperating with the orifice 32 is secured to a cylindrical valve stem 35 . The cylindrical valve rod 35 is installed in the inner cavity 33 through the guide rib 36 and can slide therein. The guide ribs are equally spaced on the circumference of the valve stem 35 .

The casing 30 is coaxial with the cylindrical valve stem 35 , and the electromagnetic coil 40 is installed in the casing 30 and is located between the bottom plate 37 and the cover plate 38 of the casing 30 . It can be seen from the gap 39 that the electromagnetic armature 41 installed on the upper end of the cylindrical valve stem 35 can move in a limited axial direction. The spring 42 pushes the armature 41 upwards to ensure that the valve member 34 can close the spout 32 under normal conditions. The lower part of the valve stem 35 is provided with a relatively small hole 43 , which makes the inside of the valve stem 35 always communicate with the inner chamber 33 . After the electromagnetic coil 40 is energized, the armature 41 is pulled down to close the gap 39 , and then the valve stem 35 and the valve element 34 are displaced to open the nozzle 32 .

The cover plate 38 at the upper end of the housing is in the hole 45 of the channel assembly 11 , so that the tube 46 installed in the channel assembly 11 is located in the hole 48 at the upper end of the armature 41 . A tube 46 is sealed with an interference fit in the channel 20 of the channel assembly 11 in the wall 25 , and the tube 46 feeds fuel from the channel 20 into the opening at the upper end of the valve stem 35 .

One end of the dosing device 10 is in the hole 27 in the wall 25 of the channel assembly 11, and there is an air flow control ring 75 at this end. The annular flange 74 of the air flow control ring 75 is sleeved on the body 18 of the dosing device. On the outer surface of the flange 74 there is an annular groove 77 which communicates with the channel 78 and communicates with the fuel chamber 80 of the ring 75 through a series of small holes 79 . As shown in FIG. 4 , the ring 75 has a central fuel passage 81 at one end, the passage space of which is defined by a lining 82 . Three equally spaced arms 84 secure the bushing 82 to the circumference of the ring 75 . The space defined between the circumference of the ring 75 , the central bush 82 and the three arms 84 forms three arcuate holes 85 through which the air from the air channel 13 flows.

Passage 88 communicates air passage 13 with annular fuel chamber 80 adjacent liner 82 as shown in FIG. 2 . Thus, air from the air passage 13 can enter the fuel cavity 80 of the ring 75 through the passage 88 and the arcuate hole 85 . This part of the air can further pass through the adjacent orifice area 19 through the liner 82 and into the fuel passage 81 . It can be seen that when the fuel injection system is in working condition, the air can flow out from the air channel 13, forming a radially inward airflow around the area 19 of the metering mechanism 10, sending a certain amount of fuel from the area 19, and then the air continues Move along the axial direction, enter the channel 20 through the channel 81 , and then enter the hollow cavity of the valve stem 35 through the tube 46 . This movement of the air flow prevents fuel loss because some air flows back into the air passage 13 via the passage 88.

Groove 77, hole 79 and channel 78 provide a substantially unrestricted flow path for air from air channel 13 to hole 49 in cover plate 38. Air can enter the hollow valve stem 35 through the hole 49 , and can also flow between the outer surface of the armature 41 and the sleeve 47 , and enter the cavity 33 through the gap 39 . This communication between air passage 13 and cavity 33 ensures that there is an air flow in cavity 33 with sufficient pressure to prevent the accumulation of inflow or return flow of fuel from cavity 33 through armature 41. When this happens, the dosing accuracy of the fuel supplied to the engine is reduced.

The outward edge of the sleeve 47 at 58 rests on the base of the aperture 49 of the cover plate 38 . The lower portion of the sleeve 47 fits between the neck 50 of the housing 30 and the extension 51 of the sleeve 31, the overlapping portions of these three parts being welded together to form a solid fuel-air interface.

The above-mentioned device can be used on a multi-cylinder machine of the kind shown in FIG. 1 . This multi-cylinder engine has a fuel and air passage assembly 11 which includes a fuel metering device 10 and an injection system 12 corresponding to each cylinder. As shown in Figure 5, the sleeve 31 of the injection system 12 is installed in the appropriate stepped hole 57 on the engine cylinder head 2, so that the fuel sprayed from the nozzle 32 directly enters the combustion chamber in the cylinder. The sealing ring 16 on the sleeve 31 is pressed against the appropriate surface of the cylinder head for sealing. Tightening means such as bolts 8 secure the channel assembly 11 to the cylinder head 2 . The channel assembly 11 is thus combined with the injection system 12 which in turn is combined with the cylinder head. O-ring 52 in bore 49 forms a seal between channel assembly 11 and outer edge 58 of sleeve 47 to prevent fuel or air leakage between channel assembly 11 and injection system 12 .

As shown in FIG. 5 , there are cooling chambers and passages 53 , 54 and 55 on the cylinder head of the engine, as well as a spark plug hole 56 . The injection system 12 is installed in the stepped hole 52, and a part of the casing 30 of the injection system is exposed in the cooling cavity 54, so as to directly cool the injection mechanism, take away the heat generated by the electromagnetic coil 40, and limit the heat transfer from the combustion chamber to the injection system and quantitative devices.

FIG. 8 shows a modification of the air control ring 75 in FIG. 2 . In the configuration shown in this figure, sleeve 110 and fuel conduit 114 replace air control ring 74 and liner 82 of FIG. 2 .

It should be noted that the configuration of the sleeve 110 is an improvement over the type disclosed. There is an interference fit between the sleeve 110 and the hole 109 of the fuel dosing device 10 , and a slight press fit with the hole 111 of the channel assembly 11 is preferred. The “O” ring 112 prevents fuel from leaking out of the fuel supply passage 14 .

The nozzle of fuel dosing device 10 is contained at 113 places, and it just faces the fuel conduit 114 that is one with sleeve 110, and quantitative fuel just enters in the fuel chamber 120 like this. The fuel injection system 12 communicates with the cavity 120 , and the fuel in the cavity 120 flows into the injection system 12 . The structure of the injection system 12 is the same as that mentioned above in FIG. 2 .

The fuel chamber 120 communicates with the air passage 13 through the hole 121 , the annular passage 122 around the fuel conduit 114 and the arc passage 124 therebetween. The outer walls of the hole 121 and the annular passage 122 are formed by the holes parallel to each other on the pre-opened fuel metering device 10 and the sleeve 110, and the arc-shaped passage 124 is formed by cutting off the partition walls of these two holes. This processing and forming method keeps the wall 125 between the two holes unchanged and extends to the overlapping portion of the fuel conduit 114, and at the same time forms a part of the tapered surface within an arc of 180°. It should be noted that the cavity 120, the hole 121, the annular passage 122 and the arc passage 124 are all for each dosing device 10 and the injection system 12, and the oil supply passage 14, the oil return passage 15 and the air supply passage 13 are also for each There are both dosing devices and injection systems. The ramp 126 can introduce fuel that bounces off the face into the injection system 12 instead of returning the fuel directly to the annular passage 122 .

In use, when in the fuel injection phase, an air flow flows out from the channel 13, enters the cavity 120 through the hole 121, the arc channel 124 and the annular channel 122, and then enters the fuel injection system 12 through the cavity 120, The air mixed with the fuel that has been sent into the chamber 120 by the fuel metering device 10 enters the fuel injection system 12, and then is injected into the engine cylinder through this.

Fuel, or at least a portion of it, is generally not injected into cavity 120 until fuel injection into the engine begins, ie, when there is substantially no air flow from air passage 13 into cavity 120 . The structure of the hole 121 and the channels 122 and 124 is as follows. All fuel which has a tendency to flow back from chamber 120 into air channel 13 flows through a spiral path. In the fuel flowing out from the dosing device 10, there are some oil particles rebounded from the wall of the chamber 120, and these oil particles are likely to be attached to the other surface of the chamber 120 or the annular passage 122, so that the kinetic energy of the oil particles is lost, and/ Or lead the fuel to a path that prevents it from leaking into the air channel 13 . As on annular passage 122, the function of the annular passage is to provide a single inlet from which all fuel from chamber 120 can only enter on its way to air passage 13.

The advantage of this action is that there is a substantially unrestricted flow area to allow air to flow into the cavity, while oil particles can only flow in the opposite direction through a very small orifice.

This method of preventing fuel leakage from passage 20 in FIG. 2 and chamber 120 in FIG. 8 to air passage 13 can improve the quantitative accuracy of the amount of fuel injected into the engine, thereby improving engine fuel efficiency and emission control level, At the same time, it is possible to avoid accumulation of fuel in the air passages and the resulting problem of cleaning the air passages.

Because the fuel enters the channel 20 from the dosing device 10 to overcome the air pressure in the cavity, which is roughly the pressure in the air channel 13, so it is necessary to adjust the fuel pressure according to the air pressure so that the quantitative accuracy of the fuel meets the requirements. . Multiple dosing devices and injection systems are housed in an integral channel assembly 11, so a single pressure regulator in channel assembly 11 regulates the pressures of all the dosing devices and injection systems to desired values.

Figure 6 is a drawing of a typical voltage regulator. The pressure regulator 60 has a body 61 having a fuel portion 62 and an air portion 63 which are held together by a forged edge 64 . Fuel portion 62 is an interference fit with bore 56 . The hole 56 passes through the outer wall 21 of the channel assembly 11 and also through the portion of the wall 74 between the oil supply channel 14 and the oil return channel 15 . The oil return channel 15 communicates with the central cavity of the fuel part 62 through the hole 59 on the peripheral wall of the fuel part 62 . There is an "O" shaped sealing ring 65 between the fuel portion 62 of the body 61 and the wall of the channel assembly 11. The fuel portion 62 may also partly pass through the portion of the wall 25 between the fuel supply passage 14 and the air passage 13 , while the air portion 63 passes through the other portion of the wall 25 into the air passage 13 .

Two opposing shoulders of the fuel portion 62 and the air portion 63 grip a diaphragm 66 to separate the fuel from the air. In its normal working condition, the diaphragm is flexible. A preloaded spring 67 presses against a pressure plate 68 . The pressure plate is fastened to the diaphragm 66 . The force exerted by the spring can be adjusted by the adjustment plug 69 . There is a hole in the center of the adjustment plug, which is used to communicate with the inside of the air passage 13 and the air part 63 .

The pressure plate 68 carries a valve disc 70 which cooperates with a sleeve 71 which defines an aperture 72 . There is a threaded hole 73 on the body 61, and the oil return connector 3 is screwed into the hole, so that the released fuel can flow back into the fuel tank. As specifically described in Figure 7, there is a ball head 90 integrated with it on the valve disc 70, the ball head is placed in the conical chamber 91 of the pressure plate 68, the baffle plate 92 clamps the ball head 90, assembled in chamber. The forged edge 93 of the pressure plate 68 secures the barrier over its entire circumference. A groove is opened on the baffle plate 92 from the central hole 94 to the periphery, so that the neck 95 of the valve disc 70 enters in the central hole 94 . The pushing effect of the spring 96 makes the ball head 90 lean against the pressing plate 92 to ensure the centering of the valve disc 70 . This structure improves the sealing accuracy of the valve disc 70 with the outlet sleeve 71 .

It should be understood that the construction of the pressure regulator described above could also be modified to have a sleeve 71 mounted on the diaphragm 66 and a stationary valve disc.

During use, if the fuel pressure is lower than a predetermined value due to the combined effect of the air pressure on the diaphragm 66 and the spring 67, the valve disc 70 will stop at the position for closing the orifice 72 (as shown). If the pressure continues to increase until it is sufficient to overcome the combined air pressure on the diaphragm 66 and the load of the spring 67, then the diaphragm first bends to the right as shown in the figure, and then pushes the valve disc to move, opening the outlet 72, and release The fuel just returns in the fuel tank through hole 72.

Therefore, the pressure regulator with the above-mentioned structure can basically be installed in the channel assembly 11, so that the external dimensions of the engine and the fuel system will not be increased. At the same time, in this structure, since there is a certain amount of fuel in the channel assembly, the pressure fluctuation generated when the pressure regulator is working can be suppressed.

It should be understood that the fuel injection system described above can be used with various types of internal combustion engines, whether four-stroke or two-stroke. The engine employing the above-mentioned fuel injection system is particularly suitable as an engine of various means of transportation, such as an engine of an airplane, a vehicle, and a ship, and when used on a ship, it can be used as an external marine engine.

Claims (5)

1. A fuel injection system for an internal combustion engine, comprising: a body (18) having therein a fuel chamber (80) communicating with a nozzle lumen (33), a dosing device (10) for selectively delivering fuel to the fuel chamber (80), a spout (32) in the body (18), which establishes communication between the lumen (33) and the exterior of the body (18), The valve means (34, 35) has a valve member (34) adapted to cooperate with the spout (32) to selectively open and close the spout (32), and also has a The valve stem (35) on the valve member (34), A selectively operable electromagnetic device (40, 41) within the body (18), which is operatively connected to the valve stem (35) to move the valve member (34) to open and close the spout (32), air supply means for supplying air to the fuel chamber (80) at least when the nozzle (32) is open for supplying fuel from the fuel chamber (80) to the open nozzle (32) and through the nozzle (32), It is characterized in that the valve stem (35) extends from the nozzle cavity (33) to the fuel chamber (80) through the electromagnetic device (40, 41), and a valve stem (35) extends the nozzle cavity (33) A passage (20) communicating with the fuel chamber (80) so that fuel from the fuel chamber (80) is delivered to the open nozzle (32) through the valve stem passage (20) and the nozzle lumen (33) and through the nozzle (32). 2. The fuel injection system according to claim 1, characterized in that the electromagnetic device (40, 41) has a stationary electromagnetic coil (40), which is concentrically mounted on the valve stem (35) Around, also have an armature (41) that is fixed on this valve rod (35). 3. The fuel injection system according to claim 2, characterized in that the armature (41) is located substantially in the annular space between the valve stem (35) and the electromagnetic coil (40). 4. The fuel injection system according to claim 1, characterized in that the valve stem (35) is hollow and has a small hole (43) on its wall near the valve member (34), so that fuel flows from The interior of the hollow valve stem (35) passes into the spout cavity (33). 5. An injection system for an internal combustion engine having a device as claimed in any one of claims 1 to 4 for injecting fuel into an internal combustion engine.

Images