JPS6124544B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application] The present invention relates to an electronic fuel injection device for an internal combustion engine.

[Prior art]

Most automobiles manufactured today have a fuel system that is controlled by a carburetor or by a fuel injection system.

Although carburetors have the advantages of low cost and low operating fuel pressure, there are many undesirable attributes associated with their use.
For example, the operation of a carburetor requires a continuous flow of fuel, and the amount of fuel is determined depending on the position of the throttle. It is well known that in an air stream flowing through the throat of a capletor, it is difficult to properly atomize fuel into the air stream.
If proper atomization is not performed, the fuel supply to each of the plurality of cylinders will be uneven, and the air-fuel mixture will be richer or leaner depending on the cylinder. These conditions result in increased waste gas emissions from the cylinder with a mixture that is either too rich or too lean for the stoichiometric point. Also, compared to fuel injection systems, carburetor systems are inherently imprecise in their fuel control, which can cause all cylinders to operate at sub-optimal points.

Additionally, capletor systems operate in an open-loop mode, which is common. In open-loop mode, the engine's exhaust gases are not examined, so the characteristics of the combustion occurring within the engine cannot be determined. This situation does not allow for an optimal air/fuel ratio and also results in significantly higher exhaust gas levels.

Fuel injection systems that overcome some of the defects of the carburetor system have also been commercialized. Such fuel injection systems allow for relatively precise control of the fuel delivered to the engine by the fuel supply system, thereby improving maneuverability without undesirable power surges, reducing exhaust gas levels, and Optimization of the system is easy and the system can be operated in closed loop mode.

As electronic fuel injection systems continue to grow in importance due to their suitability for economical fuel delivery and emission control, fuel injectors are subject to increasingly stringent regulations that regulate system operation. Conditions are required.

The preferred injector for modern internal combustion engine fuel injection systems is of the electromagnetically actuated solenoid type. Solenoid type injectors are relatively fast acting, accurate and can be easily combined with modern electronic air/fuel ratio control systems. Electronic control of the opening and closing of the injectors provides a powerful means of achieving air/fuel ratios according to a program or predetermined schedule for exhaust gas control. usually,
The injector is specially designed for single-point or multi-point systems.

In single-point systems, one injector is typically configured to inject fuel at the active injection point (generally, this is the air inlet of the throttle body connected to the plain section of the manifold). has been done. In such an arrangement, the injector must operate twice as fast as in a multi-unit system. An eight-cylinder engine requires twice as much fuel to be injected. That is, a high-velocity, high-capacity injector is required. A single point system suitable for two-plane manifolds is described in U.S. Pat. No. 4,142,683, ``Electric Fuel Injection Valve.''

In a multi-point system, fuel is injected locally at multiple injection points (eg, near the intake valve of each cylinder in a multi-cylinder engine). Fuel must be supplied to this system at relatively high pressure. This is because the fuel must enter the injector at one end, pass through a narrow passage, and then be metered and injected from an outlet orifice into the cylinder near the intake valve. This type of multipoint fuel injection system is described in U.S. Patent No.
Disclosed in No. 3788287.

With multi-point systems, there are many problems with hot starting the vehicle and handling hot fuel. Because,
This is because the injectors and the fuel supply lines to the injectors are located very close to the hot areas of the engine.
This results in fuel evaporation, lowering the amount of fuel injected per pulse due to vapor or bubble entrainment, and dilution of the air/fuel ratio. Additionally, multi-point fuel injection systems require high pressure fuel systems, which are inherently difficult to seal and encapsulate, and the need for high pressure pumps can result in high costs.

[Summary of the invention]

It is therefore an object of the present invention to reduce the amount of air/bubbles entrained in the fuel delivered to the injector by the resulting air/bubbles that are injected together with the fuel by the injector.
An object of the present invention is to provide a fuel injection device that can prevent dilution of the fuel ratio.

This object of the invention provides for fuel injection at an injection point of an internal combustion engine an electronically controlled injector comprising a valve member and located and independently formed at said injection point; an injector jacket supporting the injector at least in a portion containing the valve member, the injector jacket defining a pressure accumulation chamber defined by an inner wall of the injector jacket and partially surrounding the portion containing the valve member; forming an injector jacket, the accumulator chamber having an injector jacket adapted to allow pressurized fuel filled therein to be metered by the valve member and injected to the injection point; ,
The injector jacket has a fuel inlet transmission passage for receiving pressurized fuel and sending it to the pressure accumulation chamber, and a fuel outlet transmission passage directly connected to the pressure accumulation chamber for sending pressurized fuel from the pressure accumulation chamber. The fuel inlet transmission passage constitutes a fuel circulation route together with the fuel outlet transmission passage, and a substantially constant flow of fuel is flowed from the fuel inlet transmission passage through the pressure accumulation chamber to the fuel outlet transmission passage. The fuel circulation causes steam or bubbles mixed in the fuel to move toward the fuel outlet side transmission passage, and the mixed steam or bubbles to the fuel outlet side transmission passage. This is achieved by a fuel injector that is located at a higher position than the fuel inlet transmission passage so as to facilitate the movement of the fuel outlet transmission passage.

Further, according to the present invention, since the part of the injector that includes the valve member is in contact with the fuel filled in the pressure accumulation chamber, fuel can be injected without making the fuel in the pressure accumulation chamber very high pressure. Another advantage is that no high pressure fuel system is required.

〔Example〕

The invention will be explained in more detail below with reference to illustrated embodiments.

FIG. 1 shows the aperture mechanism main body 12 of a single point system.
FIG. 2 is a plan view of the injectors 8 and 10 installed therein, which can be quickly replaced. Each injector 8, 10 meters fuel into a respective air inlet 14, 16, which is a fuel injection point in a single point system. The air flowing through each air inlet is normally controlled by a pair of restrictor plates 18,20. The aperture plates 18, 20 are rotated in a direction opening the passageway to increase airflow when the aperture link 22 is operated.

Fuel enters the system from a fuel inlet port 25, which is connected to a pressurized fuel source (not shown), through a fuel inlet passageway 24, shown in phantom. A cam actuated fuel pump attached to the fuel line of the fuel tank, as found in conventional vehicles, may be a suitable source of fuel. As will be described later, the fuel source only needs to supply a fuel pressure of 6 to 1 kg/cm ² since this system is a low-pressure fuel injection device. The high pressure fuel sources normally used in previous electronic fuel injection systems are not required in this system, resulting in an economical cost for the overall system.

The fuel inlet passage 24 is connected to the fuel inlet transmission passage 26
The fuel inlet transmission passage is divided into two parts a and 28a, and these fuel inlet transmission passages communicate with pressure accumulation chambers 30 and 32. The fuel is transferred from the pressure accumulation chambers 30 and 32 to the fuel outlet side transmission passage 26.
b, 28b to the collection chamber 34 of the pressure regulator 37.

Fuel from the collection chamber 34 flows through a pressure regulating port 36 that connects with a fuel outlet passage 38 terminating in a fuel outlet port 40.
At the fuel outlet port 40, the fuel is returned to the fuel tank by conventional tubing or fittings.

The pressure regulator 37 controls the opening and closing of the pressure regulating port 36 to maintain a constant flow of circulating fuel, and the pressure regulator 37
The pressure of the fuel at 0.32 is kept substantially constant. Then, the injectors 8, 10 are connected to the grommet 4.
The fuel to be injected from the pressure accumulators 30, 32 to the air inlets 14, 16, respectively, is metered in response to electrical control signals from control cables 42, 44 passing through the air inlets 14, 16, respectively.
Ground cables 41 and 43 of the injectors 8 and 10 are connected to the throttle mechanism main body 12 through terminal posts 45.

Electrical control signals are sent from an electronic control unit and are used to determine the timing of opening and closing of each injector 8,10. Although a variety of electronic control units may be used to provide pulse width modulated control signals to the injector, a preferred timing and control unit for the illustrated single point system is disclosed in U.S. Pat. No. 4,142,683.

In FIG. 2, fuel inlet ports 25 are located below fuel outlet ports 40, which are connected by conventional fittings 23, 35 to conduits or fuel lines for circulating fuel. Upright tab 1
Reference numerals 1, 13, 15, and 17 are provided around the throttle mechanism main body 12, and are used to attach an air purifier.

3 and 4, the arrangement of one quick-changeable injector, such as injector 10, is shown.

Injector 10 is mounted in an injector jacket 48. A portion of the injector containing a valve member, which will be described later, is arranged in a space surrounded by the inner wall of the injector jacket 48, and its outer periphery and the injector jacket 4 are connected to each other.
A space created by the inner wall of 8 forms a pressure accumulation chamber 32. (As shown in FIG. 5, the injector 8 is mounted in an injector jacket 50.) The injector jacket 48 is laterally supported by a bridge structure 53 in coaxial relationship with the air inlet 16. . The bridge structure 53 has a lower wing 52 and an upper wing 54 as shown in FIG. In this embodiment, the fuel inlet transmission passage 28a and the fuel outlet transmission passage 28b located higher than this are the fourth
As shown, it is formed by apertures in each of the lower wing 52 and the upper wing 54. As shown in FIG. 3, the bridge structure 53 is streamlined and the aperture plate 2 in the air inlet 16
0 supports the injector jacket 48 above. Due to their elongated shape, the injector 10 and injector jacket 48 allow the air introduced into the air inlet to flow freely around them and have few protrusions that would create turbulence.

The aperture plate of each air inlet is controlled to open and close by rotating the aperture link 22 shown in FIG. 3 in response to the force applied to the pins 29 and 31. For example, a spring may be coupled to the pin 31 such that a force is applied to the right in the drawings to impart a torque on the aperture plate rod 33 in the direction of the aperture plate closing. If a similar rightward force is applied to pin 29 by an operator control cable connected to pin 29, an opening torque is applied to rod 33.

In FIG. 4, a fuel inlet transmission passage 28a and a fuel outlet transmission passage 28b are formed as holes.
is inclined upward at an angle of 15 to 20 degrees in this embodiment. This angle allows steam or air bubbles to pass through to the collection chamber 34 without remaining in the pressure accumulation chamber 32, the fuel inlet transmission passage 28a, and the fuel outlet transmission passage 28b. Importantly, even if the car is parked on a hill, this angle is sufficiently upward to allow the vapor to collect in the collection chamber 34 and be dissipated there, rather than being trapped in the fuel inlet transmission passage, the accumulator, or even the fuel outlet transmission passage. This is because the slope is steep.

The injector jacket 48 has upper and lower mounting openings 56, 58 to which the injector 10 can be directly mounted. Injector jacket 48 further includes a support shoulder 60 that supports a mounting ring 62 that is of a slightly larger diameter than the body of injector 10 and is press fit onto injector 10. O-ring 6
4 seals the joint between the installation ring 62 and the support shoulder 60 in a liquid-tight manner.

This provides a very tight hydraulic seal without imposing significant downward pressure on the injector to create a leak-tight assembly. A simple spring type clip 65 supported by screws 66 attaches the injector 10 to the injector jacket 48.
hold.

The lower mounting opening 59 accommodates a slightly smaller flange 57 of the cap 59 at the end of the injector. Cap 59 is provided with a larger flange 63 that serves as an abutment when injector 10 is inserted into injector jacket 48.
An O-ring 68 of an appropriate shape is attached to the flanges 57, 63.
The cap 59 is located in the recess formed by the cap 59 and seals the joint between the support shoulder 61 and the flange 63.

The injector 10 is relatively easily attached to the injector jacket 4.
It is clear that it can be attached and detached to 8. Injector 10
acts as an electronically controlled valve that receives and meters pressurized fuel from a fuel source via the pressure accumulator 32 without any particular difficulty. If an injector becomes inoperative, it can be replaced without disconnecting and reconnecting the fuel line. Further, a fuel inlet transmission passage 28a and a fuel outlet transmission passage 28b
will remain in place when the injector is replaced and does not need to be readjusted.

The structure of the sealed pressure accumulation chamber 32 is similar to that of the injector 10.
It has the advantage of supplying fuel at a substantially constant pressure to the fuel cell, and there is no substantial pressure drop even if the fuel injections are performed many times at high speed. The accumulator chamber 32 also has sloping fuel inlet transmission passages 28a and fuel outlet transmission passages 28b to help dispose of hot fuel. Accumulator chamber 32 is sized to allow steam and bubbles to rise into fuel outlet transfer passage 28b and away from valve tip 244 (FIG. 7) of injector 10. The inlet orifices 250, 252 (FIG. 7) to the valve member are arranged below the communication portion with the pressure accumulation chamber of the fuel inlet transmission passage 28a and the fuel outlet transmission passage 28b for performing this operation. Importantly, this prevents foam from accumulating in the valve member, which is difficult to remove once trapped. The amount of fuel retained in the valve member is relatively small for this reason.

The injector 10 shown in FIG. 4 is a wide angle spray injector. A wide angular (in cross section) or hollow conical injection pattern has many advantages over a straight pattern when the injector 10 is mounted on the throttle plate coaxially with the air inlet 16 as shown. . Generally, air is introduced through an opening that becomes larger and larger as the aperture plate rotates. The opening is defined by the wall of the air inlet and the outer edge of the diaphragm plate. When fuel is injected in the form of a hollow cone pointing toward this opening, evaporation occurs due to the turbulence created by the air accelerated in the relatively narrow area between the throttle plate and the wall of the air inlet. and good results for fuel distribution.

If the angle of the conical pattern is too large, it will wet the wall of the air inlet, and if it is too small, it will be sprayed onto the aperture plate and liquefied. Therefore, a compromise must be made taking into account the distance of the injector from the aperture plate and the diameter of the air inlet. Generally, in this embodiment, a spray angle between 60° and 80° is believed to provide optimal effectiveness with respect to evaporation and mixing with the introduced air. Throttle mechanism bodies with air inlets of different dimensions have installation distances adjusted accordingly.

The diaphragm mechanism body further includes a vacuum sensing port 74 communicating with the air inlet 16 near the closed position of the diaphragm plate. A vacuum or pressure drop is created when the airflow is constricted between the restrictor plate 20 and the wall of the air inlet. This vacuum is standardized in a sealed metering chamber 76 and communicated through a tubular fitting 78 to a sensor. As shown in FIG.
The pressure sensor 83 is averaged with the vacuum level of
An integrated vacuum degree signal of the diaphragm mechanism body is supplied from the diaphragm.

FIG. 5 shows the injectors 8, 10 installed in each injector jacket 48, 50 and the air inlets 14, 1.
6 is shown. The injector jacket is streamlined and tapered to facilitate the flow of air passing around the circumference of the injector, which is coaxial with the injector jacket. The air is smoothly accelerated towards the air inlet at the morning glory-shaped taper portions 82,84. The area in this vicinity of the air inlet is sufficiently large that the annular portion occupied by the injector and injector jacket does not restrict the air flowing into the throttle body 12. Tapered portions 82 and 84 that are irregularly shaped portions
end in short connecting passages 86, 88 which transition into the constriction section of the generally cylindrical air inlet.

The morning glory-shaped tapered portions 82, 84 are separated by a smoothly widening separation center portion 90. Separate center section 90 extends approximately as high as the top of the injector jacket. The separation center 90 helps streamline the airflow and separates the incoming air into two streams, which can be controlled by individual throttle plates in the air inlets 14, 16. do the work. The airflow splitting and air inlet splitting prevents fuel splashing and uneven fuel distribution from the injectors mounted above the throttle plate. This is necessary if the injectors 8, 10 are operated individually at different times.

In FIG. 6 the pressure regulator 37 is shown in detail. The pressure regulator 37 has a valve that opens and closes the pressure regulating port 36 in response to changes in the pressure in the collection chamber 34 . The outlet pipe 92 contacts the flat side of the hemispherical valve body 91. The spherical portion of the hemispherical valve body 91 fits into a similarly shaped recess in the valve plate 94 and is retained therein by a crimp 96. The recess in the valve plate and the shape of the hemispherical valve body allow the valve plate to move in response to changing pressure conditions, but when the valve is closed, the outlet pipe 9
On the upper edge of 2 the hemispherical bulb body always lies flat.

The valve plate 94 is attached to a diaphragm member 98 that serves as a flexible pressure regulating member as well as a sealing member for the collection chamber 34, and the diaphragm member 98 is connected to a pressure regulator cover bolted to the throttle mechanism body 12. It is held by 100. A retaining plate 104 is threadedly attached to the valve plate 94 on the opposite side of the diaphragm member 98 and has an upright edge for retaining the compression spring 102. The compression spring 102 is held in compression by a spring retaining cup 108 that adjusts via an adjustment bolt 110 screwed into an upright boss 112 of the pressure regulator cover 100. By adjusting the adjustment bolt 110, the force exerted by the compression spring 102 on the diaphragm member 98 can be changed, and the hemispherical valve body 9
Hold 1.

When the fuel pressure in the collection chamber 34 begins to rise above the initial set pressure, the hemispherical valve body 91 is raised from its contact position with the outlet pipe 92 and passes through the fuel outlet passage 38, and the compression spring 102 pushes the hemispherical valve body 91 up. Reduce the pressure until you press down to close the valve.

The stronger the compression force of the compression spring 102, the more
Although the pressure developed in the system is higher, the system is generally kept at the lower pressure of a normal fuel pump.

The collection chamber that regulates the system pressure is the accumulator chamber 3.
0.32 pressure is not substantially changed.

The throttle mechanism body is particularly effective when attached to two plain manifolds. For example, when installed in a V8 (8 cylinder) engine that has a first manifold plane connected to cylinders 1, 4, 6, and 7 and a second manifold plane connected to cylinders 2, 3, 5, and 8. , air inlet 14 supplies a mixed charge of air and fuel to the first manifold plane, while air inlet 16 supplies a mixed charge of air and fuel to the first manifold plane.
Supply to manifold plane.

The timing of the control signal pulses to the injectors 8, 10 will now be described. In a V8 engine, when the crankshaft is at a 45 degree angle between two revolutions of the crankshaft and before the pistons of the cylinders pass through top dead center, each of the eight cylinders sequentially rotates 1, 2,
It must be supplied as 3, 6, 5, 7, 8. In other words, if the crankshaft is initially positioned at an angle of 135 degrees before the top dead center of cylinder 1, the injector 8 will pulse at 90 degrees, 270 degrees, 450 degrees, 430 degrees of the crankshaft. Similarly, the injector 10 is located at 180° and 360° of the crankshaft.
Rhythm at ゜, 540゜, 720゜.

Additionally, the duration or width of each pulse is calculated by the electronic control unit to ensure that each cylinder receives the appropriate amount of fuel/air mixture depending on engine operating conditions, such as throttle opening, air temperature, emissions control, etc. Supply accordingly.

The foregoing is discussed in detail in US patent application Ser. No. 778,806.

FIG. 7 shows a quick-replaceable injector 10.
has an injector housing 210 with a large solenoid coil member mounting hole 213 for slidably mounting the solenoid coil member. The solenoid coil member includes a plastic or molded bobbin 212 with a coil 214 wound thereon.
A substantially cylindrical coil core 224 is received and mounted in the bore 215 of the bobbin 212 and locks the bobbin 212 within the mounting bore 213 by means of its own flange 223 located on the shoulder 221. Flange 223 is secured by ends 225 and 227 to securely hold the coil member within mounting hole 213.

The coil core 224 is inserted into the hole 215 of the bobbin 212.
The coil 214 is preferably made of a material that concentrates the magnetic velocity of the core into a coaxial magnetic field that extends substantially the entire length of the coil 214 and forms a concentrated magnetic pole at one end of the coil. Thus, in terms of strength and durability, the coil core 224 is made from a material with low residual magnetism, such as soft iron. The coil is further connected to a set of terminals. One of them is coil core 22
A terminal 226 passes through the flange 223 of 4 and is molded into a hard plastic mold 228.
The terminal, shown as , is bent in the mold at right angles to the longitudinal axis of the injector so that it is lower than the injector. Appropriate rings 217, 219
seals the bobbin hole 215 and the attachment hole 213, respectively.

At the other end of the injector is a valve member having a needle valve body 242 and an armature 230. Of the portion of the injector that accommodates this valve member, that is, the portion containing the valve member, the circumferential portion from the mounting ring 62 to the cap 59 forms the boundary of the pressure accumulation chamber 32, as described with reference to FIG. . That is, the pressure accumulator chamber 32 is defined by the inner wall of the injector jacket 48 and partially surrounds the valve member containing portion of the injector. Returning to Figure 7, armature 2 made of magnetically attractable material
30 reciprocates within the armature opening 231 and moves the needle valve body 242 along with it. The needle bulb body 242 has a chamfered surface 246 created by drawing a circular collar.
and further flat parts 245, 247 with cut out collars.
Depending on the valve port 2 of the valve housing 240
41 and placed inside. The needle valve body 242 further includes a valve tip 24 that rests on a valve seat 251 that tapers conically toward an outlet or metering orifice 253.
Contains 4.

The valve port 241 is an opening along the central axis of the valve housing 240 that is attached to the valve member port 243 in the injector housing 210.The valve housing 240 is attached to a C-shaped spacer 234 molded to a precise thickness. As such, it is spaced apart from the shoulder of the injector housing 210. The distance between the end of the valve port 241 and the valve housing 240 is a precise length to provide a precise gap between the edges of the valve collar 254 and the spacer 234. In this way, an accurate movement distance of the needle valve body can be ensured without performing any special processing on the armature screwed into the threaded end 232 at the end of the needle valve body 242.

Valve tip 244 is pressed against valve seat 251 by the pressure of closing spring 216 against washer 218 attached to end pin 291 of adjustment rod 220. The adjusting rod 220 forces the closing spring against the armature 230, and the armature acting against it is subjected to different spring forces depending on the compression distance of the spring.

In this embodiment, the closing spring is compressed to optimal seating without applying significant pressure to maintain high speed operation of the injector. Once the closing spring is adjusted to the correct compression, the injector housing is tightened to hold the adjustment rod in position. Plug 257 is used to seal the adjustment rod once such calibration has been performed. The opening time of the injector, which preferably depends on the coil, should be approximately the same as the closing time. Generally, the greater the pressure on the closing spring, the faster the valve member will close.

In operation, when current is supplied to terminal 226, the magnetic flux in coil 214 begins to increase and become concentrated in coil core 224. The magnetic field created by this magnetic flux concentration attracts armature 230 against the downward force of closing spring 216, and when that force is overcome, the armature begins to move upward in FIG. Armature 230 moves due to the presence of air gap D, set distance d, and spacing between bulb collar 254 and spacer 234. When the valve collar 254 contacts the surface of the spacer 234, the valve collar stops the movement of the needle valve body and the valve seat 2
51 metering orifice is fully opened. Fuel entering inlet orifices 250, 252 enters valve port 241, flows along valve tip 244 and exits through metering orifice 253.

Valve housing 240 has a cap 59 attached to its end. Cap 59 is
An O-ring 68 and a circular recess are provided to seal the inside surface of the mounting opening 58 (FIG. 4). The injector is further provided with a mounting ring 62 in which an O-ring 64 is provided to seal this portion of the injector to the mounting opening. These have already been described in connection with the injector jacket and will not be discussed in further detail.

In US patent application Ser. No. 778,806, it is shown that the injector of a multi-unit system typically injects fuel twice per engine cycle and is subjected to a fuel load of 1/8. However, the injector of a single point system as described above must inject fuel four times for each engine cycle and is responsible for half of the total fuel requirement. Thus each injector must deliver fuel twice in half the time in a single point system. Therefore, single point systems require high volume injectors that operate at high speeds. When a valve that can be used in any system is used in a single point system,
It is clear that there are restrictions on movement.

Valve tip 244 has two chamfered conical surfaces 260, 261 which enhance the high speed operation of the injector of FIG. Conical surface 260 seals valve seat 251 and is of a more gentle slope than conical surface 261 to provide a relatively strong, very narrow seal on valve seat 251 . Therefore, when the needle valve body opens, only a very short opening distance is required to reach the maximum area of fuel flow.

Since the inlet orifices 250, 252 are located adjacent to the valve tip 244, no substantial restriction of fuel flow needs to be considered. In high flow, low pressure systems, this injector has little loss of injector capacity due to pressure drop in the restricted passage.

In this regard, injector 10 has been described above as a single point system. However, an injector receiving fuel from an accumulator is equally advantageous in a multi-unit system, as shown in the embodiment of FIG.

The injector of FIG. 8 is shown mounted in an injector jacket 300 having an upper mounting opening 302 and a lower mounting opening 304 and similar to the injector jacket used in single point systems.
The injector 10 is inserted into the mounting opening and the shoulder 3
06,308 and sealed from fluid leakage from the mounting opening. The injector jacket further includes clips 310, 312 which are of conventional size and are mounted on opposite sides of the injector jacket.
a hook end 314 that snaps into the rim of the injector;
It has 316.

The injector jacket 300 for a multi-point system is threaded 315, which is made at a point proximate to the intake valve of the cylinder, i.e., the point of injection, and which engages a threaded opening. Ru,
Fuel is supplied to the pressure accumulator chamber 317 in the usual manner through a conduit 318 serving as a fuel inlet transmission passage that fits into the nipple 320. Nipple 320 is screwed into a bored and internally threaded section of the injector jacket. Similarly, the fuel outlet side transmission passage is connected to the conduit 3.
It is formed by 19. Low pressure fuel is supplied to the inlet orifice 322 according to the operation of the needle valve body.
324, 326, and is injected into the cylinder via a metering orifice. In a multi-cylinder engine, each cylinder has an injector jacket 300 connected to a pressurized fuel source and has an injector inserted into the injector jacket; fuel is passed from the fuel source via a fuel inlet transmission passage. Pressure accumulation chamber 317
The fuel then flows to the next injector via the fuel outlet transmission passage. The pressure regulator continuously circulates fuel from injector to injector.

Furthermore, in FIG. 8, a conduit 319 as a fuel outlet transmission passage and a conduit 3 as a fuel inlet transmission passage are shown.
18, but the fuel outlet transmission passage can be arranged above the fuel input transmission passage. In this way, one injector design can be used in either single-point or multi-point systems, which is one of the key advantages of the present invention.
It is one. Injectors for multi-point systems generally have inferior timing and response times than those for single-point systems, so injectors for single-point systems can be The device can be used in multipoint systems.

〔effect〕

The invention provides the advantage of preventing vapors or bubbles entrained in the fuel from reaching the inlet orifice of the injector valve member. Furthermore, there is also the advantage that it can be configured with a low pressure fuel system.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a single point fuel injector for a multi-cylinder, two-plane manifold having quick-change injectors according to the present invention; FIG. 2 is a rear view of the single point fuel injector shown in FIG. 1; 3 is a front view of the single-point fuel injection device shown in FIG. 1, FIG. 4 is a cross-sectional view of the single-point fuel injection device shown in FIG. 1 Single-point fuel injection device shown in Figure 5
6 is a sectional view taken along line 6-6 of the single point fuel injector of FIG. 1; FIG. 7 is a sectional view of an example of the quick-change injector of the present invention cross section,
FIG. 8 is a sectional view for explaining the application of the present invention to a multi-point system. 8, 10... Injector, 28a... Fuel inlet transmission passage, 28b... Fuel outlet transmission passage, 30, 32
...Accumulation chamber, 48,50...Injector jacket,
250, 252... Entrance orifice, 253...
Exit (metering) orifice.

Claims (1)

[Scope of Claims] 1. A fuel injection device for fuel injection at an injection point of an internal combustion engine, comprising: an electronically controlled injector including a valve member; an independent injector located at the injection point; an injector jacket configured to support the injector at least in a portion thereof containing the valve member; an injector jacket forming an injector jacket, the pressure accumulator being such that pressurized fuel filled therein can be metered by the valve member and injected into the injection point; Equipped with; a fuel inlet transmission passage for receiving pressurized fuel and sending it to the pressure accumulation chamber; and a fuel outlet transmission passage 28b directly connected to the pressure accumulation chamber for sending pressurized fuel from the pressure accumulation chamber.
the injector jacket has, and the fuel inlet transmission passage and the fuel outlet transmission passage constitute a fuel circulation route, and the fuel inlet transmission passage passes through the pressure accumulation chamber to the fuel outlet. A substantially constant movement of fuel is maintained to the side transmission passage, and the fuel circulation causes steam or bubbles mixed in the fuel to move toward the fuel outlet side transmission passage, and the mixed vapor is removed. The fuel injection device is characterized in that the fuel outlet side transmission passage is located at a higher position than the fuel input side transmission passage so as to encourage the movement of bubbles or bubbles to the fuel outlet side transmission passage. 2. In the device according to claim 1,
The valve member of the injector has an inlet orifice located below either the fuel inlet transmission passage or the fuel outlet transmission passage, and the valve member has an inlet orifice located below either the fuel inlet transmission passage or the fuel outlet transmission passage to prevent entrained steam or bubbles from entering the fuel outlet transmission passage. The fuel injection device is designed to encourage the movement of the fuel. 3. In the device according to claim 1,
The relationship in which the fuel outlet side transmission passage is located at a higher position than the fuel inlet side transmission passage is achieved by two straight holes inclined at an angle of at least 15° with respect to the horizontal. Injection device.