JP2021105356A - Fuel injection injector - Google Patents

Abstract

To improve the sureness of an operation, in an injector which can change an injection direction of atomized fuel according to an engine temperature.SOLUTION: An injector 13 has a constitution in which a nozzle plate 26 is arranged at a tip of a body. The nozzle plate 26 is composed of a base plate 26a in which a fuel injection hole 25 is formed, an outside-temperature sensing deformation part 26b joined to an upper edge of the base plate, and an inside-temperature sensing deformation part 26c joined to a lower end edge of the base plate 26a. The temperature sensing deformation parts 26b, 26c are bimetals which are obtained by pasting two pieces of metal plates. At a warmup operation, fuel is set so as not to progress toward a lower face of an intake port. Therefore, a port wet phenomenon of a warmup drive seat can be prevented. When a temperature of an engine is raised to a certain level, the base plate 26a is changed in a posture in a downward direction by the deformation of the temperature sensing deformation parts 26b, 26c. Accordingly, atomized fuel can be sent into a cylinder while riding on high-velocity intake air.SELECTED DRAWING: Figure 3

Description

The present invention relates to a fuel injection injector used in an internal combustion engine.

In a spark-ignition internal combustion engine such as a gasoline engine, an injector is used for fuel injection, and there are a port injection method in which fuel is injected into an intake port and a direct injection method in which fuel is injected into a cylinder. Of these, the port injection method has the advantage of being excellent in mixing fuel and intake air, and has the advantage of being able to reduce the cost of the injector as compared with the direct injection method.

On the other hand, as a problem of the port injection method, there is a port wet phenomenon in which fuel adheres to the inner surface of the intake port. To further describe this point, the atomized fuel injected from the injector changes direction according to the flow of intake air. Therefore, when the injector is placed above the intake port, the axis of the injector is located on the lower surface of the intake port. However, since the flow velocity of the intake air increases or decreases depending on the opening of the throttle valve, the straightness of the fuel exceeds the flow of the intake air in the low speed rotation region such as during warm-up operation, and the atomized fuel is the intake port. It is easy to adhere to the bottom surface.

In other words, since the engine temperature is low during warm-up operation, it is difficult for fuel to evaporate when it adheres to the intake port. Therefore, the port wet phenomenon should be prevented especially during warm-up operation, but the intake air flow velocity is low. It was difficult to prevent the port wet phenomenon.

As a countermeasure against such a situation, in Patent Document 1, the nozzle plate provided at the tip of the injector is made of bimetal, and the nozzle plate is warped and deformed by the temperature to inject fuel when the engine temperature is low. A configuration is disclosed in which the angle is small and the fuel injection angle (spread angle) increases when the temperature of the engine rises to a certain extent.

Japanese Unexamined Patent Publication No. 2008-14156

It can be said that the port wet phenomenon at low engine temperature can be reduced by changing the fuel injection angle as in Patent Document 1, but in order to change the injection angle due to the warp deformation of the nozzle plate, the nozzle plate may be made considerably thicker. It is presumed that the degree of warpage deformation must be increased considerably, and it is unclear whether or not the desired effect can be obtained.

The present invention has been made against the background of such a situation, and while it is common with Patent Document 1 that the fuel injection mode is automatically changed according to a change in engine temperature, it has an effect of suppressing the port wet phenomenon. It is intended to improve certainty.

The injector of the present invention includes two independent configurations. The first invention is as described in claim 1.
"A body mounted on the cylinder head or the intake manifold with the axis facing the intake port and a nozzle plate arranged at the tip of the body are provided, and a fuel injection hole is opened in the nozzle plate. ing"
In the basic configuration
"At least the outer peripheral portion of the nozzle plate is divided into an inner temperature-sensitive deformed portion located on the side of the intake port and an outer temperature-sensitive deformed portion located on the side of the intake port, and the inner side thereof. By making the thermal expansion rate of the temperature-sensitive deformed portion and the outer temperature-sensitive deformed portion different, when the temperature is raised until the temperature-sensitive deformed portion is deformed, the warp deformation of the inner temperature-sensitive deformed portion and the outer temperature-sensitive deformed portion is performed. The angle between the axis of the intake port and the injection axis of the atomized fuel is set to be large due to the difference between the two. "
It has the feature.

The second invention is as described in claim 2.
"A body mounted on the cylinder head or the intake manifold with the axis facing the intake port, a nozzle portion arranged at the tip of the body and having a fuel injection hole formed, and a tip protruding from the nozzle portion. Equipped with a cylinder
The spread angle of the fuel ejected from the fuel injection hole is defined by the tip cylinder portion. "
In the basic configuration
"The tip tube portion is divided into an inner temperature-sensitive deformed portion located on the side of the intake port and an outer temperature-sensitive deformed portion located on the side of the intake port, and the inner temperature-sensitive deformed portion and the outer side. When the temperature is raised until the temperature-sensitive deformed portion is deformed by making the thermal expansion rate different from that of the temperature-sensitive deformed portion, the intake is caused by the difference in warp deformation between the inner temperature-sensitive deformed portion and the outer temperature-sensitive deformed portion. The angle between the center of the port and the center of the atomized fuel injection is set to be large. "
It has the feature.

In both inventions, the temperature-sensitive deformed portion may be made of bimetal, or the inner temperature-sensitive deformed portion and the outer temperature-sensitive deformed portion may be made of a single-layer metal plate.

Since the flow velocity of the intake air is low during warm-up operation when the engine temperature is low, the degree to which the atomized fuel injected from the injector is changed by the flow rate of the intake air is low. Therefore, when the engine temperature is low, the port wet phenomenon during warm-up operation can be prevented by setting the injector so that the axis of the injector is closer to the outlet of the intake port.

On the other hand, when the engine goes out of warm-up operation and the engine temperature rises to a certain extent, for example, in the case of an automobile, the flow rate of intake air becomes faster, but in claim 1, the outer temperature-sensitive deformed portion and the inner temperature-sensitive deformed portion and the inner temperature-sensitive deformation portion. Due to the difference in thermal deformation from the part, the attitude changes so as to increase the angle between the axis of the fuel injection direction and the intake port according to the temperature rise, so the flow velocity of the atomized fuel before reaching the intake port increases. It flows toward the cylinder on a fast intake. Therefore, the port wet phenomenon can be prevented.

As described above, in the invention of claim 1, the fuel injection direction is changed according to the temperature by changing the posture of the nozzle plate by using the temperature-sensitive deformed portion. However, the posture change of the nozzle plate and fog. Since the responsiveness to the injection direction of the chemical fuel is high, it is excellent in certainty that the injection direction of the atomized fuel is changed by a temperature change.

In claim 2, the injection direction of the atomized fuel is changed by changing the posture of the tip cylinder portion, but since the protruding length of the tip cylinder portion can be arbitrarily set, the injection direction of the atomized fuel is changed by changing the posture of the tip cylinder portion. Excellent in certainty of changing.

Therefore, in any of the inventions of claims 1 and 2, the warm-up operation state is released while setting the injection direction so that the atomized fuel does not adhere to the inner surface of the intake port during the warm-up operation in which the intake flow velocity is slow. When the operating region where the flow velocity of the intake air becomes high is reached, the injection direction of the atomized fuel automatically changes in the direction across the flow of the intake air, and the mixing property of the atomized fuel and the intake air can be improved. As a result, complete combustion can be realized by improving the mixing property of the atomized fuel and the intake air while preventing or significantly suppressing the port wet phenomenon during warm-up operation.

The inner temperature-sensitive deformed portion and the outer temperature-sensitive deformed portion may be formed of, for example, a single-layer metal plate having a different coefficient of thermal expansion. If both are composed of a bimetal composed of a plurality of metal plates having different coefficients of thermal expansion, there is an advantage that the warp deformation can be ensured and the change in the injection direction of the atomized fuel can be ensured.

It is a vertical sectional view of the main part of an internal combustion engine. (A) is an enlarged view of a main part of FIG. 1, (B) is a cross-sectional view of (A), a cross-sectional view taken along the line BB of (C), and (C) is a cross-sectional view taken along the line CC of (A) and (B). It is a figure. It is a figure which shows the action at the time of temperature rise. In the figure which shows the 2nd Embodiment, (A) is a vertical sectional view at a low temperature, (B) is a vertical sectional view at a high temperature. (A) is a view of the third embodiment viewed from the axial direction, and (B) is a sectional view taken along line BB of (A).

(1). Outline of Main Parts of Internal Combustion Engine Next, an embodiment of the present invention will be described with reference to the drawings. First, an outline of a main part of an internal combustion engine will be described with reference to FIG. This embodiment is applied to an injector of an internal combustion engine for a vehicle, and the internal combustion engine has a cylinder block 1 and a cylinder head 2 fixed to the upper surface thereof as main components of the engine body. A plurality of cylinders (cylinder bores) 3 are formed in the cylinder block 1, and a piston 4 is slidably fitted in each cylinder. The cylinder head 2 is formed with a recess 5 having a trapezoidal cross section that opens toward the cylinder 3.

A pair of intake ports 6 and exhaust ports 7 are formed in a pair of cylinder heads 2 on both sides of the cylinder head 2 with the crank axis in between, corresponding to each cylinder 3. Each intake port 6 is open to the intake side surface 2a of the cylinder head 2, but a pair of intake ports 6 may be assembled at the assembly port and the assembly port may be opened at the intake side surface 2a. The outlet (termination) of each intake port 6 is opened and closed by the intake valve 8. The intake valve 8 is urged in the closing direction by the spring 9.

An intake manifold 10 is fixed to the intake side surface 2a of the cylinder head 2, and each branch passage 11 of the intake manifold 10 communicates with the intake port 6.

The intake manifold 10 is provided with an upward flange 12, and an injector 13 corresponding to each intake port 6 is mounted on the flange 12. That is, an injector insertion hole 14 corresponding to the intake port 6 is provided in the flange 12 of the intake manifold 10, and the injector 13 is inserted into the injector insertion hole 14. Therefore, the injector insertion hole 14 is located above the branch passage 11 and the intake port 6.

Further, the extension line of the axial center O1 of the injector 13 extends around the lower end portion of the outlet of the intake port 6. Therefore, the axial center O1 of the injector 13 is inclined with respect to the axial center O2 of the branch passage 11 and the intake port 6, and the intersection angle (crossing angle) θ of both lines O1 and O2 is an acute angle. Although not shown, each injector 13 is connected to a long pipe (delivery pipe) in the crank axis direction, and fuel is supplied to the pipe from its end or the like. The exhaust port 7 is opened and closed by the exhaust valve 15.

(2). Injector Next, the details and mounting structure of the injector 13 will be described mainly with reference to FIG. The injector 13 includes a body (main body portion) 18 connected to the above-mentioned split pipe, and the body 18 includes a large diameter portion 19 connected to the split pipe, a small diameter portion 20 located on the tip side, and the like. It has an intermediate diameter portion 21 located between the two, and the intermediate diameter portion 21 is held in the injector insertion hole 14 via the O-ring 22. The small diameter portion 20 of the injector 13 penetrates to the cylinder head 2, and a recess 23 for allowing the small diameter portion 20 to enter is formed on the upper surface of the intake port 6.

As shown in FIG. 2, a fuel reservoir 24 is formed at the tip of the body 18, while a nozzle plate 26 having a fuel injection hole 25 opened is arranged at the tip of the body 18 to charge fuel. It is extruded at 27 to be ejected from the fuel injection hole 25. A supply passage 28 for supplying fuel to the fuel reservoir 24 is formed in the body 18, and fuel is injected by advancing the plunger 27 with an electromagnetic solenoid while the supply passage 28 is closed.

The nozzle plate 26 is arranged at the bottom of a circular recess 29 formed at the tip of the body 18, and four fuel injection holes 25 are opened in the nozzle plate 26. However, the number and position of the fuel injection holes 25 can be arbitrarily set. For example, it is possible to leave only one in the center. Since the fuel injection port 30 at the tip of the body 18 has a tapered shape that spreads forward, the atomized fuel is ejected toward the intake port 6 while diffusing at a predetermined injection angle (spread angle).

The nozzle plate 26 embodies the first aspect, and includes a circular substrate 26a in which a fuel injection hole 25 is formed, a semicircular outer temperature-sensitive deformed portion 26b that surrounds the substrate 26a from above, and a substrate 26a. It is composed of a semicircular inner temperature-sensitive deformed portion 26c that surrounds from below, and the substrate 26a and the inner peripheral edges of the temperature-sensitive deformed portions 26b and 26c are integrally joined by welding or the like, and the temperature-sensitive deformed portion 26b. The outer peripheral edge of, 26c is held by the ring body 32 at the bottom of the circular recess 29 in the body 18. The temperature-sensitive deformed portions 26b and 26c may be joined to the inner peripheral surface of the circular recess 29 by welding or brazing.

The temperature-sensitive deformed portions 26b and 26c are bimetals in which a high expansion coefficient metal plate 33 and a low expansion coefficient metal plate 34 are laminated, respectively, and in the outer temperature-sensitive deformed portion 26b, the low expansion coefficient metal plate 34 is circularly concave. The high expansion coefficient metal plate 33 is arranged on the bottom side of the circular recess 29 in the inner temperature-sensitive deformation portion 26c. Further, for example, when the temperature of the temperature-sensitive deformed portions 26b and 26c is about room temperature, the entire nozzle plate 26 is set to have a flat posture. In order to allow the nozzle plate 26 to be deformed, an annular protrusion 35 that can come into contact with the substrate 26a from the back side is provided on the bottom surface of the circular recess 29 in the body 18, and an annular space 36 is formed outside the annular projection 35. ..

In the above configuration, when the nozzle plate 26 is flat, the axial center O1 of the injector 13 is set to pass through the lower part of the outlet of the intake port 6 as described above. Therefore, the atomized fuel ejected from the injector 13 is carried on the intake air to the cylinder without adhering to the lower surface of the intake port 6 even if the flow velocity of the intake air is slow in the warm-up operation state. This makes it possible to prevent the port wet phenomenon during warm-up operation.

On the other hand, when the engine temperature rises, the heat of the combustion gas is transferred to the body 18 of the injector 13 via the cylinder head 2, and the heat of the heated cooling water is transferred from the cooling jacket to the body of the injector 13 via the cylinder head 2. The temperature of the nozzle plate 26 rises as it is transmitted to 18, but when the temperature of the nozzle plate 26 rises to a certain extent, the temperature-sensitive deformed portions 26b and 26c made of bimetal begin to warp and deform. ..

That is, since the high expansion rate metal plate 33 is located on the front surface side and the low expansion rate metal plate 34 is located on the back surface side of the outer temperature-sensitive deformed portion 26b, as shown in FIG. Is warped and deformed so as to be separated from the bottom surface of the circular recess 29, while the inner temperature-sensitive deformed portion 26c has a high expansion rate metal plate 33 located on the back surface side and a low expansion rate metal plate 34 located on the back surface side. As the temperature rises, the inner peripheral portion warps and deforms so as to approach the bottom surface of the circular recess 29, and the inner temperature-sensitive deformed portion 26c and the outer temperature-sensitive deformed portion 26b warp and deform in opposite directions. The substrate 26a changes its posture so that its perpendicular line is inclined downward with respect to the axial center O1 of the injector 13.

In this way, the inner temperature-sensitive deformed portion 26c and the outer temperature-sensitive deformed portion 26b are warped and deformed in the opposite directions, so that the substrate 26a constituting the nozzle plate 26 is tilted toward the intake port 6 to change its posture. Therefore, the perpendicular line of the substrate 26a is tilted downward with respect to the axial center O1 of the injector 13. Then, the angle θ between the axial center O3 of the injection of the atomized fuel and the axial center O2 of the intake port 6 becomes large, but the flow velocity of the intake air becomes high and the inner surface of the intake port 6 rises to fog. It is possible to prevent the port wet phenomenon because it is easy to evaporate even if the chemical fuel adheres.

Since the injection direction of the atomized fuel is automatically changed by the action of the bimetal, no control mechanism is required and the cost can be suppressed.

(3). Other Embodiments Next, other embodiments shown in FIGS. 3 and 4 will be described. The second embodiment shown in FIG. 4 embodies claim 2. A valve seat 38 on which the ball-shaped valve body 37 is seated is arranged at the tip of the inside of the body 18, and the body 18 is formed. One fuel injection hole 25 is opened in the central portion of the tip of the fuel injection hole 25. Further, the ball-shaped valve body 37 is fixed to the tip of the valve rod 39, and the fuel is ejected from the fuel injection hole 25 by retracting the valve rod 39.

A tip cylinder portion 40 that regulates the injection angle of the atomized fuel is fixed to the tip surface of the body 18. That is, the injection angle (spread angle) of the atomized fuel is defined by the atomized fuel ejected while diffusing from the fuel injection hole 25 hitting the tip edge of the tip cylinder portion 40. Therefore, the injection angle of the atomized fuel is inversely proportional to the protruding height of the tip cylinder portion 40.

The tip tubular portion 40 is composed of a half-split outer temperature-sensitive deformed portion 40a and an inner temperature-sensitive deformed portion 40b that overlap each other to form a cylinder, and both temperature-sensitive deformed portions 40a and 40b have a high expansion coefficient. It is composed of a bimetal composed of a laminate of a metal plate 33 and a low expansion coefficient metal plate 34. That is, in the outer temperature-sensitive deformed portion 40a, the inner peripheral side is a low expansion rate metal plate 34 and the outer peripheral side is a high expansion rate metal plate 33, while in the inner temperature-sensitive deformed portion 40b, the inner peripheral side is a high expansion rate metal plate. At 33, the outer peripheral side is a low expansion rate metal plate 34.

In this embodiment, when the tip cylinder portion 40 is heated to a certain extent by raising the engine temperature, the low expansion rate metal plate 34 is pushed downward by the high expansion rate metal plate 33 in the temperature-sensitive deformed portions 40a and 40b. By inclining, the posture of the tip tubular portion 40 changes so as to incline the axial center O4 downward as a whole. Therefore, the radius θ formed with the axial center O2 of the intake port 6 becomes large, but when the intake port 6 is removed from the warm-up operation range, the intake air flow velocity is increased, so that the atomized fuel does not adhere to the intake port 6. ， It is sent to the cylinder by being put on the intake air with a high flow velocity. Therefore, the same effect as that of the first embodiment is obtained.

The third embodiment shown in FIG. 5 embodies claim 1. In this embodiment, the outer temperature-sensitive deformed portion 26b and the inner temperature-sensitive deformed portion 26c are single-layer metal plates having a large coefficient of thermal expansion. It is composed of. Then, although one fuel injection hole 25 is formed in the center of the substrate 26a, the outer temperature-sensitive deformed portion 26b and the inner feeling are in a state where the axial center of the fuel injection hole 25 coincides with the axial center O1 of the injector 13. The thermal deformation portion 26c is inclined so as to move away from the bottom surface of the circular recess 29 as it goes downward.

Further, in this embodiment, as shown in (A), the outer temperature-sensitive deformed portion 26b and the inner temperature-sensitive deformed portion 26c have vertical widths toward both ends when viewed from the direction of the axial center O1 of the injector 13. It has a crescent shape so that it becomes smaller. Further, as shown in (B), the substrate 26a has a hemispherical protrusion 41 protruding toward the body 18, while the hemispherical protrusion 41 rotatably fits into the tip of the body 18. The recess 42 is provided, and the substrate 26a is allowed to change its posture in a state where the hemispherical protrusion 41 and the hemispherical recess 42 are in surface contact with each other.

In this embodiment, the outer temperature-sensitive deformed portion 26b and the inner temperature-sensitive deformed portion 26c are thermally expanded and warped and deformed while also expanding in the width direction (vertical direction). When the outer temperature-sensitive deformed portion 26b and the inner temperature-sensitive deformed portion 26c are stretched and warped, the substrate 26a changes its posture so as to change its perpendicular line downward. Therefore, as in the first embodiment, the injection direction of the atomized fuel can be automatically changed downward in accordance with the temperature rise of the internal combustion engine.

Although the embodiments of the present invention have been described above, the present invention can be embodied in various ways. For example, even when the temperature-sensitive deformed portion is made of bimetal as in the first embodiment, it is possible to set the temperature-sensitive deformed portion in an inclined posture in a non-heated state as in the third embodiment. be. The injector can also be placed below the intake port. In this case, the fuel injection direction may be set to rise due to the temperature rise of the engine. Further, the injector may be attached to the cylinder head.

The present invention can be embodied in an injector for fuel injection of an internal combustion engine. Therefore, it can be used industrially.

2 Cylinder head 6 Intake port 10 Injector manifold 13 Injector 14 Injector insertion hole 18 Body 20 Small diameter part 25 Fuel injection hole 26 Nozzle plate 26a Board 26b Outer temperature sensitive deformation part 26c Inner temperature sensitive deformation part 27 Plunger 29 Circular recess 33 Bimetal High expansion rate metal plate to form 34 Low expansion rate metal plate to make up bimetal 37 Valve body 38 Valve seat 39 Valve rod 40 Tip tube 40a Outer temperature-sensitive deformed part of the tip tube 40b Inner temperature-sensitive deformed part of the tip tube O1 Injector axis O2 Intake port 6 axis O3 Fuel injection direction axis

Claims (2)

A body mounted on the cylinder head or the intake manifold with the axis facing the intake port and a nozzle plate arranged at the tip of the body are provided, and a fuel injection hole is opened in the nozzle plate. The configuration is
At least the outer peripheral portion of the nozzle plate is divided into an inner temperature-sensitive deformed portion located on the side of the intake port and an outer temperature-sensitive deformed portion located on the side of the intake port. By making the thermal expansion rates of the temperature-sensitive deformed portion and the outer temperature-sensitive deformed portion different, when the temperature is raised until the temperature-sensitive deformed portion is deformed, the warp deformation of the inner temperature-sensitive deformed portion and the outer temperature-sensitive deformed portion is caused. Due to the difference, the angle between the axis of the intake port and the injection axis of the atomized fuel is set to be large.
Injector for fuel injection. A body mounted on the cylinder head or intake manifold with the axis facing the intake port, a nozzle portion arranged at the tip of the body to form a fuel injection hole, and a tip cylinder protruding from the nozzle portion. It has a part and
The spread angle of the fuel ejected from the fuel injection hole is defined by the tip cylinder portion.
The tip tube portion is divided into an inner temperature-sensitive deformed portion located on the side of the intake port and an outer temperature-sensitive deformed portion located on the side of the intake port, and the inner temperature-sensitive deformed portion and the outer feeling. When the temperature is raised until the temperature-sensitive deformed portion is deformed by making the thermal expansion rate different from that of the temperature-sensitive deformed portion, the intake port is caused by the difference in warp deformation between the inner temperature-sensitive deformed portion and the outer temperature-sensitive deformed portion. The angle between the axis of the fuel and the injection axis of the atomized fuel is set to be large.
Injector for fuel injection.

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