JPH10110661A - Fuel injection nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To directly measure a fuel injection quantity, an injection ratio, and an injection time so as to always secure an optimal injection characteristic by arranging an injection quantity direct detection mechanism, which is provided with an optical system radiating/receiving the light to be cut off by means of a vane when a turbine is rotated by fuel flow, in a nozzle holder main body. SOLUTION: Pressurized fuel is fed from a fuel injection pump P to a pressurized fuel port 104 via a fuel passage 60 in an inlet connector 4 in a fuel injection nozzle 1. When the fuel pushed into an oil sump 301, a needle valve 4 is lifted and an injection hole 35 is opened, so that the fuel is injected into a combustion chamber %. In this process, in an instant when the fuel injection is started, a fuel flow rate of the flowing fuel reaches about 40m/s at most in the fuel passage 60, so that a turbine 6c in an injection quantity direct detection mechanism 6 is rotated by means of this fuel flow force. In this way, the light transmitted from a light inlet hole to a light outlet hole is intermittently shut off by means of a vane of the turbine 6, and on the basis of the obtained output, a fuel injection quantity is found by means of a controller 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a fuel injection nozzle.

[0002]

2. Description of the Related Art In an internal combustion engine, a fuel injection pump and a fuel injection nozzle are used together as a system for supplying fuel to a combustion chamber in an atomized state. On the other hand, there is an urgent need for measures against exhaust gas in diesel engines. Important factors that affect the properties of the exhaust gas are the fuel injection amount and the injection timing, and controlling these factors more accurately has become a major issue. Conventionally, control has been performed by calculating the injection amount from the control rack position and the engine speed, and calculating the injection timing from an injection timing detection sensor mounted on a timer actuator. However, each of these methods is a method of indirectly capturing the fuel injection amount and the injection timing, and does not always match the injection amount actually injected from the injection nozzle. It has been difficult to obtain an accurate injection amount and injection timing due to the influence of a change with time and time.

[0003]

SUMMARY OF THE INVENTION The present invention has been made by research to solve the above-mentioned problems, and the first object of the present invention is to provide a fuel injection system having a relatively simple and compact structure. It is an object of the present invention to provide a fuel injection nozzle capable of directly measuring a quantity or an injection rate and an injection timing and controlling the injection characteristics optimal for an engine state. A second object of the present invention is not only to directly measure the fuel injection amount or the injection rate and the injection timing, but also to control the injection hole area in accordance with the engine load and the number of revolutions. It is an object of the present invention to provide a fuel injection nozzle capable of reliably realizing improvement of output, improvement of output / fuel efficiency, and reduction of combustion noise and NOx.

[0004]

SUMMARY OF THE INVENTION In order to achieve the first object, the present invention provides a nozzle holder body, a nozzle body provided with an injection hole at a tip thereof, and a nozzle body accommodated in the nozzle body slidably in the axial direction. A needle valve that has a pressure receiving surface and is opened by applying fuel pressure to the pressure receiving surface to inject fuel from the injection hole, and that the nozzle holder body can rotate so that a blade faces the fuel passage. A turbine, an optical axis hole provided so as to intersect the blade at a position displaced from the rotation center of the turbine, and intercepted by the blade when the turbine is rotated by a fuel flow, and a light beam passing through the optical axis hole. An injection amount direct detection mechanism having an optical system for entering and exiting is provided. Further, in order to achieve the second object, the fuel injection nozzle of the present invention forms a hole for leading pressurized fuel at the tip of the nozzle body, and injects the pressurized fuel into an enclosure defining the hole. A plurality of injection holes are provided at intervals in the circumferential direction, a rotary valve is disposed in the hole, and the rotary valve is rotated by an actuator provided on the nozzle holder body so as to change the injection hole opening area. Includes those that are

[0005]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 10 show an embodiment in which the present invention is applied to a fuel injection nozzle of a variable injection hole type. In FIG. 1, reference numeral 1 denotes a nozzle holder main body, 2 denotes a driving head which is oil-tightly fitted and fixed to an upper end portion of the nozzle holder main body 1 via an O-ring, and 3 is connected to a lower end of the nozzle holder main body 1. Nozzle body, retaining nut 5
To the nozzle holder main body 1. Reference numeral 4 denotes a needle valve (nozzle needle) inserted in the nozzle body 3, and reference numeral 6 denotes an injection amount direct detection mechanism attached to a fuel passage portion of the nozzle holder body 1.

A first hole 100a to a third hole 100c whose diameters are gradually increased from the lower end to the upper end are formed in the axis of the nozzle holder body 1, and the first hole 100a
The push rod 10 is located in the region from
1 is slidably inserted. Also, the third hole 100c
An adjusting screw 102 screwed with the female screw of the third hole 100c is fitted in an area extending from the second hole 100b to the second hole 100b. A nozzle spring 103 is interposed between the adjusting screw 102 and the push rod 101. I have. The nozzle body 3 has a stepped portion 30 which is fitted to the bottom of the blind hole of the retaining nut 5 at a middle portion in the longitudinal direction of the outer surface, and a cylindrical main portion 31 extending below the stepped portion 30 and extending through the retaining nut 5. The main portion 31 is formed with a tip portion 32 for forming an injection hole via a tapered portion. On the other hand, a guide hole 300 concentric with the first hole 100a of the nozzle holder main body 1 and an oil reservoir 301 having a larger diameter than the guide hole 300 are formed in the axis of the nozzle body 3 from the upper end to the lower end. Further, a guide hole 302 having a smaller diameter than the guide hole 300 is formed below the oil reservoir 301. At the lower end of the guide hole 302, as shown in FIGS. 3, 4A and 4B, a conical seat surface 303 is formed, and the pressurized fuel is guided following the seat surface 303. A bottom hole 34 is defined by the wall at the tip. Nozzle holder body 1
The pressurized fuel port 104 is provided on one side of the oil reservoir 301 through passage holes 105 and 305 formed in the nozzle holder body 1 and the nozzle body 3.
And pressurized fuel is guided there.

An inlet connector 6 a is connected to the pressurized fuel port 104, and the inlet connector 6 a is connected to a fuel injection pump P by a fuel supply pipe 600.
The injection amount direct detection mechanism 6 according to the present invention includes a pressurized fuel port 104.
Is provided at an appropriate position in an area extending from the vicinity of the oil reservoir 301 to the oil sump 301, but in this embodiment, it is incorporated in the inlet connector 6a. More specifically, as shown in FIG. 2A, a fuel passage 60 communicating with the pressurized fuel port 104 is formed in the inlet connector 6a.
A stepped hole 61 is provided in an intermediate portion of the fuel passage 60 so as to be orthogonal to the hole axis of the fuel passage 60, and the holder 6b is inserted into the stepped hole 61. The holder 6b has a small-diameter shaft 62 reaching the fuel passage 60. The shaft 62 has a slit groove 620 having a required depth from the front end surface, and the slit groove 620 has a predetermined height level. A shaft hole 621 is drilled through the diameter of the shaft 62 in the part of
The optical axis hole 6 is located at a lower level than the shaft hole 621.
22 is penetrated so as to penetrate the shaft 62.
A tangential flow type turbine 6c having a plurality of, for example, eight blades 63 at regular intervals is arranged on the outer circumference of the slit groove 620. The turbine 6 c has a minute shape with a diameter of 1 mm or less and a blade width of 0.14 mm. The tip of the blade 63 reaches, for example, about １ ／ of the diameter of the fuel passage 60, and the through-hole 622 It is rotatably supported by a support shaft 6d fitted in the shaft hole 621 so as to be located behind the tip. The diameter of the optical axis hole 622 is the blade 63
Dimensions are equal to or slightly smaller than the width of As shown in FIG. 2C, the inlet connector 6a is provided with a pair of light introducing holes 64 and light emitting holes 65 coaxially with the optical axis hole 622. An optical fiber cable 640 for light emission from a light source 6e such as a launcher is guided to form a light emitting portion.
A light receiving optical fiber cable 650 is guided to the light outlet hole 65 to form a light receiving portion. The light receiving optical fiber cable 650 is electrically connected to the controller 12 including a CPU via the binarization processing means 2f. By connecting, the injection amount signal (or injection rate signal) and the injection timing detection signal are fed back. The binarization processing means 2f is a means for converting the light quantity / time signal detected by the light receiving section into data of 0 or 1 at a certain shresh hold level of the light quantity.

The needle valve 4 has an engaging portion 41 at the upper end thereof for engaging with the push rod 101, a guide portion 40 on the outer periphery which is in sliding contact with a guide hole 300, and an oil sump 301 at the end of the guide 40. A pressure receiving portion 42 for receiving the fuel pressure in the inside is provided.
, A thin shaft portion 43 for forming a cylindrical fuel passage A with the guide hole 302 is provided. At the lower end of the thin shaft portion 43, a conical seat surface 44 that comes into contact with and separates from the seat surface 303 is formed. As shown in FIGS. 3 and 4 (a) and 4 (b), the inside of the wall defining the hole 34 is a tapered conical surface 341 smoothly connected to the seat surface 303, and the lower end of the conical surface 341. Is a hemispherical end wall. In a region corresponding to the conical surface 341 defining the hole 34, a plurality of injection holes 35 communicating with the hole 34 are arranged at equal intervals on the same circumference as shown in FIGS. Has been established. The number of the injection holes 35 is five in this embodiment, and radially extends at intervals of 62 ° on the circumference. The axis of each injection hole 35 may be perpendicular to the nozzle axis, but in this embodiment, it has a predetermined inclination angle with respect to the nozzle axis. Injection hole 3
The cross-sectional shape perpendicular to the axis of 5 is circular in the embodiment,
It may be a polygon. In the case of a polygonal cross-sectional shape, the amount of change in the injection hole area per unit rotation angle can be increased.

The rotary valve 7 is arranged in the hole 34. The rotary valve 7 is rotated around a nozzle axis by driving a drive shaft system 8 penetrating through holes formed in the needle valve 4 and the adjusting screw 102 by an actuator 9 mounted on the driving head 2. It has become. To describe these structures in detail, as shown in FIG. 3, a first hole 45a is formed in the shaft center of the needle valve 4 in a relatively short range from the lower end, and an end region of the first hole 45a is formed. A conical surface 451 and a short hole 452 are provided.
The second hole 45b has a larger diameter than the hole 45a.
The second hole 45b reaches the upper end of the needle valve 4.
The second hole 4 is provided in the axis of the push rod 101.
A third hole 45c having substantially the same diameter as 5b is formed, and a fourth hole 45d is formed in the axis of the adjusting screw 102 from the lower end to the upper end. The diameter of the fourth hole 45d is appropriately smaller at the upper end region than at the other portions in order to prevent the drive shaft from blurring.

In this embodiment, the drive shaft system 8 includes a shaft body 8a reaching the drive head 2, a joint pin 8b and a joint 10
The rotary valve 7 is connected to the joint pin 8b via the joint 10. The shaft body 8a
Has a length from the fourth hole 45d to the lower end region of the second hole 45b. The joint pin 8b has a large-diameter portion 80 that freely fits in the second hole 45b. The upper end of the joint pin 8b and the lower end of the shaft main body 8a are connected to a joint portion 811, 8 of an Oldham type such as a type that allows axial play.
01 are connected so that the rotational force is transmitted. The joint 10 transmits rotational torque and holding torque to the rotary valve 7 while allowing the axial play of the rotary valve 7 caused by the lift of the needle valve 4, and uses an Oldham coupling. More specifically, the joint 10 has a cylindrical portion having a diameter that fits loosely into the first hole 45a, and a lower end of the cylindrical portion is connected to a rotor valve 7 to be described later so as to be relatively slidable in the axial direction. Are formed. At the upper end of the cylindrical portion of the joint 10, a conical surface 10c that seats on the conical surface 451 is formed as shown in FIGS. 3 and 4 (c), and fits into the short hole 452 from the upper end of the conical surface 10c. The short axis portion 10d extends, and the short axis
A projecting piece 10e is formed at the upper end of the projecting piece d.
e is engaged with a groove provided at the lower end of the large-diameter portion 80 so that torque is transmitted.

The actuator 9 is fixed in a space 200 provided in the driving head 2. Actuator 9
Is arbitrary as long as it has characteristics capable of rotating (preferably reversible rotation) and holding at a predetermined rotational position. For example, a stepping motor or a servo motor is used. The output shaft and the upper end of the shaft body 8a are directly connected or connected by a transmission element such as an eccentric pin or a gear. The shape of the rotary valve 7 is arbitrary. FIGS. 3 to 7 show one example (first example) of the rotary valve 7. The rotary valve 7 has a flat pressure receiving surface 74 on the upper end on which the pressure of the pressurized fuel acts when the needle valve 4 is opened. . At the center of the pressure receiving surface 74, a projection 7
0 are integrally formed, and the projection 70
The groove 10b is fitted so as to be relatively slidable in the vertical direction. The rotary valve 7 has, below the pressure receiving surface 74, a conical surface 72 that is tapered and inclined at an angle that matches the conical surface 341 of the hole 34. The conical surface 72 and the conical surface 341 form a friction sheet. A surface is made. The height of the conical surface 72 is limited so that the lower end does not contact the bottom wall of the hole 34. The rotary valve 7 has a plurality of fuel passages 73 each having one end opened to the pressure receiving surface 74. The fuel passages 73 are open so that the other ends thereof communicate with the injection holes 35 provided in the conical surface 341 of the hole 34. It is necessary that the cross section of the fuel passage 73 perpendicular to the axis has a size equal to or greater than the diameter of the injection hole 35. In the first example, the fuel passage 73 is formed of five grooves opened in the conical surface 72, and these grooves are circumferentially formed so as to correspond to the injection holes 35 provided in the conical surface 341 of the hole 34. They are formed at 62 ° intervals. In this example, each of the grooves is a groove bottom 735.
As shown in FIG. 7, each groove has a groove bottom 735 parallel to the nozzle axis.
2 may be substantially parallel to the inclination angle of 2, and the lower end of each groove ends at a position corresponding to immediately below the injection hole 35.

FIGS. 8 and 9 show another example of the rotary valve 7 used in the above embodiment. In this example,
The fuel passage 73 is formed of a hole instead of a groove,
A plurality (5 in this example) of lateral holes 730 that can communicate with 5
Are formed radially on the circumference at predetermined intervals (in this example, every 62 °), and a plurality of vertical holes 731 are formed from the pressure receiving surface 74 of the rotary valve 7 to the horizontal hole 730. The fuel passage 73 needs to have a diameter equal to or greater than the diameter of the injection hole 35. Other structures are the same as those shown in FIGS. 3 to 7, and corresponding parts are denoted by the same reference numerals and description thereof will be omitted.

FIGS. 10 (a) and 10 (b) show an example in which the embodiment of the present invention is applied to select one of a plurality of diameters of injection holes by rotating a rotary valve 7. FIG. In this example, four first injection holes 35 provided in the radial direction from the conical surface 341 are provided at intervals of 90 ° on the circumference.
It has an injection hole 35a, and four second injection holes 35b formed by shifting the phase of the first injection hole 3a by 45 ° on the circumference. The first injection hole 35a is the second injection hole 35a. The hole diameter is smaller than the injection hole 35b. Although the rotary valve 7 of the first example is used as an example, the rotary valve 7 may have a structure of the second example or the third example shown in FIGS.

In each of the embodiments, the hole 34 does not necessarily have to have a conical surface as a whole. That is, a straight cylindrical surface parallel to the nozzle axis may be formed from the end of the sheet surface 303 to the intermediate portion, and the tapered conical surface 341 may be formed from the end of the straight cylindrical surface.
In this case, the rotary valve 7 also has a straight cylindrical surface parallel to the nozzle axis from the pressure receiving surface 74 to the intermediate portion, and a conical surface 72 is formed from the end thereof. This is also included in the present invention. In any case, the inclination angle between the conical surface 341 of the hole 34 and the conical surface 72 of the rotary valve 7 will usually be selected from the range of 50 to 70 °. In the drawing, it is 60 °. In FIGS. 3 to 9, the number of the injection holes 35 and the number of the fuel passages 73 are respectively five, but are not limited thereto, and may be four or six or more. 10 (a) and 10 (b) also show that the number of the injection holes 35 is eight in total, and the fuel passage 7 of the rotary valve 7 is provided.
Although three are four, more or less may be used. For example, three first injection holes 35a and two second injection holes 35b may be provided, and three fuel passages 73 of the rotary valve 7 may be provided. In addition, the injection hole 35 has a large diameter instead of two types,
There may be three types, medium and small. The drive shaft system 8
Also, the joint pin 8b may be omitted and the shaft body 8a and the joint 10 alone may be used. In this case, the upper end of the joint 10 is engaged with the lower end of the shaft main body 8a so as to be relatively slidable in the axial direction.

It is preferable that the rotary valve 7 be rotated by the actuator 9 during a period in which no axial force is applied to the drive shaft system 8 by the engine cylinder pressure, that is, during an intake stroke or an exhaust stroke of the engine. In order to perform such rotation timing control, the actuator 9 is electrically connected to a controller 12 composed of a CPU. The input portion of the actuator 9 has a rotation speed detection sensor 120 (or a rotation angle detection sensor) of an engine or a fuel injection pump and a fuel injection pump. Load detection sensors 121 such as rack sensors are connected. As a result, the signal from the rotation speed detection sensor 120 is always input to the controller 12, and the drive signal is output to the actuator 9 when it is determined that the engine is in the above-described stroke. Then, a signal from the load detection sensor 121 is input at the same time, and a predetermined drive amount (drive rotation angle) is applied to the actuator 9 by a predetermined map formed in advance from data of the load and the number of rotations, for example, at low speed / low load → medium speed・
Drive control is performed such that the rotation angle gradually increases in the order of medium load → high speed / high load. The rotary valve 7 is provided with a series of operations in a flow chart as shown in FIG. 11 before, during, and after the injection by the actuator 9, but the pressure acting on the pressure receiving surface 74 of the rotary valve 7. Depending on the pressure of the pressurized fuel
Since the conical surface 72 and the conical surface 341 of the hole 34 are maintained in position by frictional force, the rotary valve 7 can be rotated even during fuel injection.

A rotation angle detecting mechanism 1 is provided in the drive shaft system.
1 is provided. The rotation angle detection mechanism 11 detects the rotation angle for each fuel injection, sends this rotation angle signal to the controller 12 as a feedback signal, and when there is an error from the set rotation angle in the rotary valve 7, This is a means for causing the drive signal to be output to the driver 9 for correction. The rotation angle detection mechanism 11 is optional such as a potentiometer, an encoder, and a collimator. In this embodiment, a potentiometer is used, and a rotating member 110 is fixed to the shaft body 8a, and the rotating member 110 and the rotating member 112 fixed to the shaft of the potentiometer body 111 are connected directly or by a transmission element such as a belt. doing. When using a collimator,
While a regular polygonal (pentagonal in this example) reflecting piece corresponding to the number of injection holes is fixed to the shaft main body 8a, a light source for irradiating light to the reflecting piece is attached to the wall of the driving head 2; A light-receiving portion composed of a light-electric conversion element, that is, a light-receiving element array, may be attached along the inner wall of the driving head 2 from near the light source. The light receiving unit is provided over an angle range (72 ° in this example) obtained by dividing at least 360 ° by the number of injection holes, and the output side is connected to the coat roller 12. The drive shaft system to which the rotation angle detection mechanism 11 is attached is not necessarily limited to the shaft main body 8a. An output shaft coaxial with the shaft main body 8a may be provided on the side opposite to the shaft main body of the actuator 9, and the rotating element of the rotation angle detecting mechanism 11 may be attached to the output shaft.

An injection amount direct detection mechanism 6 characterized by the present invention.
Is sent to the controller 12 via the binarization processing means 6f, and the turbine speed signal (injection amount signal) and the injection timing detection signal measured during the fuel injection from the injection hole 35 are sent to the controller 12. Feedback is performed to calculate the injection amount and the injection rate, and it is determined whether or not each injection is appropriate, and the appropriate injection amount and injection rate set according to the combustion state are corrected or set. The rotation angle of the rotary valve 7 is corrected so that the appropriate injection amount and injection rate match the correction. The injection amount direct detection mechanism 6 is preferably provided at the fuel injection nozzle of each cylinder.

Although the present invention is suitable for a variable injection hole type using a rotary valve 7, the present invention is not limited to this, and it has a conventional structure, that is, the needle valve 4 is inserted into the nozzle body 3. Nozzle spring 10
3, the needle valve 4 is urged against the seat surface 303 to close the valve. When the fuel pressure passing through the fuel passage A from the oil reservoir 301 exceeds the urging force of the nozzle spring 103, the needle valve 4 is urged from the seat surface 303. Needless to say, the present invention is also applicable to a type in which the valve is separated and opened to spray from the injection hole 35. Although the structure of the rotary valve 7 is not limited,
Preferably, (i) the enclosure defining the hole has a conical surface,
The injection hole is open to this conical surface, (ii) the rotary valve has a pressure receiving surface at the upper end for receiving the pressure of pressurized fuel, and the outer surface has a conical surface having an angle according to the inclination angle of the conical surface of the hole. Further, the rotary valve is provided with a plurality of fuel passages one end of which is open to the pressure receiving surface at intervals in the circumferential direction,
Each fuel passage has a configuration that is opened at a conical surface corresponding to the injection hole on the hole side. Further, as a control system, a drive shaft system connecting the rotary valve and the actuator has a rotation angle detection mechanism, and an output side of the rotation angle detection mechanism is connected to a controller for driving the actuator, and The actuator is driven by a signal from the detection mechanism during non-fuel injection or / and during fuel injection, and the rotation angle of the rotary valve is corrected.

[0019]

Next, the operation of the embodiment of the present invention will be described. In the first embodiment, the pressurized fuel is supplied by the fuel injection pump P
Through the fuel supply pipe 600 and the fuel passage 60 of the inlet connector 6a to the pressurized fuel port 104, and is pushed into the oil reservoir 301 through the passage holes 105 and 305.
From there it goes down the annular fuel passage 106. This fuel pressure simultaneously acts on the pressure receiving surface 42 of the nozzle needle 4 located in the oil reservoir 301. When the fuel pressure reaches a pressure exceeding the set force of the spring 103, the needle valve 4 is lifted,
The seat surface 44 at the lower end of the needle valve is the nozzle body 3
The valve is separated from the seat surface 303 and is opened. FIG. 4 shows the state at this time, and the pressurized fuel enters the hole 34 and flows into the fuel passage 73 of the rotary valve 7. When the fuel pressure decreases, the needle valve 4 is pushed down by the urging force of the spring 103 and is closed.

In the present invention, the injection amount detecting mechanism 6 is incorporated here utilizing the inlet connector 6a, and the blade 63 of the turbine 6c faces the fuel passage 60. When the needle valve 4 is closed, the fuel in the fuel passage 60 has a low pressure and is almost stationary. For this reason, the turbine 6 c is not rotated but is very slowly rotated in the forward and reverse directions.
The light beam transmitted through the light-outgoing hole 65 through 2 is kept almost blocked by the blade 63 of the turbine 6c, or remains almost transmitted. Then, as described above, the seat surface 4 at the lower end of the needle valve
4 is separated from the seat surface 303 of the nozzle body 3, the valve is opened, and at the moment when the pressurized fuel starts to be injected from the injection hole 35, the fuel flows through the fuel passage 60 at a flow velocity that reaches a maximum flow velocity of 40 m / s. . This fuel flow causes the turbine 6c to rotate in the fluid flow direction, thereby causing the beam introduction hole 6 to rotate.
The light beam transmitted through the optical axis hole 622 to the light outlet hole 65 from the nozzle 4 is intermittently (pulsed) blocked by the blade 63 of the turbine 6c, and the flow velocity and the number of light beams blocked are in a proportional relationship. This output is taken as a feedback signal from the binarization processing means 6f to the controller 12, whereby the injection amount is directly obtained, and the fuel injection period is calculated from the rise and the end of the pulse. The injection rate is calculated by differentiating the number of pulses during the period. Then, the controller 12 corrects the calculation result and the data of the injection amount, the injection rate, and the injection timing that are set corresponding to the engine speed and the load, or corrects the calculation result with the injection amount, the injection rate, and the injection timing. Are compared,
The driving of the fuel injection pump P is controlled so as to reduce the deviation.

Since the turbine 6c is minute, it does not have resistance to the flow of fuel and has a small pressure loss, so that the fuel injection characteristics are not affected. In addition, the response is good because the viscous resistance and the inertial force are reduced. In addition, an external force that hinders the rotation of the turbine is generated with magnetism and capacitance. However, since the turbine rotation speed is detected by blocking the light passing through the optical axis hole 622, no external force other than the fluid force is applied to the turbine 6c. Further, since the rotating shaft of the turbine 6c is lubricated by the fuel flow, shaft wear does not occur, and stable rotating characteristics are maintained for a long time. Thus, the injection amount and the injection rate which is an unsteady flow during the injection period can be accurately detected.

Next, a description will be given of a case in which the fuel injection of the injection hole variable type is performed using the rotary valve 7 as in the embodiment. In FIG. 11, at the start time, even if the needle valve 4 is closed, each fuel passage 7 of the rotary valve 7 is closed.
3 is not necessarily aligned with the injection holes 35 penetrating the surrounding wall of the hole 34, and each injection hole 35 is shielded by a conical portion between the fuel passages 73. At this start time, the drive signal is not sent from the controller 12 to the actuator 9, and the mode is set to the holding mode. And
When an information signal of the rotation speed (or rotation angle) and load of the engine or the fuel injection pump is sent from the rotation speed detection sensor 120 and the load sensor 121 to the controller 12 during the intake stroke or the exhaust stroke of the engine, these correspond to these. A rotation angle is calculated. Then, a driving amount signal corresponding thereto is sent to the actuator 9, the driving force of the actuator 9 is transmitted to the shaft main body 8a, and the rotational torque is transmitted to the joint pin 8b.
Is transmitted from the joint 10 to the rotary valve 7, and the rotary valve 7 rotates, for example, clockwise by a required rotation angle.

During this rotation, no load is applied to the rotary valve 7 in the axial direction.
4 is not in strong contact with the conical surface 341, and therefore can be easily and smoothly rotated to a desired rotation angle. At this time, the rotation angle detection mechanism 11 detects the actual rotation angle position of the shaft main body 8a, that is, the rotary valve 7. The rotation angle detection signal is fed back to the controller 12, and the controller 12 determines whether there is an error from the set angle. If there is an error, a drive signal is sent from the controller 12 to the actuator 9, whereby the shaft body is 8a is minutely driven, and the position of the rotary valve 7 is corrected. When the position is determined at the set rotation angle,
A holding signal is output from the controller 12 to the actuator 9, and the rotary valve 7 is held at that position.

FIGS. 5A and 5B show a state in which the rotary valve 7 is rotated so that the edge of the fuel passage 73 is located at a half position of the diameter of the injection hole 35, that is, the opening of the injection hole is halved. The state is shown. In this state, the conical surface 72 of the rotary valve 7 is positioned so as to divide the injection hole 35. FIGS. 6A and 6B show a state in which the rotary valve 7 is further rotated to align the fuel passage 73 with the injection hole 35, and the opening of the injection hole 35 is fully opened. In this state, when the fuel pressure gradually increases and reaches the injection timing determined based on the detection signal fed back from the injection amount direct detection mechanism 6, a signal is sent from the controller 12 to the fuel injection pump P. When the needle valve 4 is opened by the fuel pressure, the high pressure fuel is supplied to the pressure receiving surface 74 of the rotary valve 7.
Through each fuel passage 73 from each opening of the nozzle hole 35 of the set opening degree
And is sprayed. During this injection, the fuel injection pressure acts on the pressure receiving surface 74 at the upper end of the rotary valve 7. As a result, the rotary valve 7 is pressed down in the axial direction, and the outer peripheral conical surface 72 comes into strong surface contact with the conical surface 341 of the hole 34 to be in a surface sealing state, where a fixing force is generated by frictional force. The fixing force due to the friction is higher than the force for moving the rotary valve 7 in the rotation axis direction by the injection pressure applied to the injection hole 35. For this reason, when the needle valve 4 is closed, the rotary valve 7 rotated by a predetermined angle to change the injection hole is firmly fixed at that position when the needle valve 4 is opened, that is, when fuel is injected.

Therefore, the injection hole 35 of the hole 34 is shielded at the rotation angle given to the rotary valve 7, and the injection hole area can be arbitrarily changed without any step. For example, when the load is low, the fuel injection pressure is increased with a decrease in the injection hole area, and the injection period becomes longer. This can promote the atomization of the spray and increase the excess air ratio of the spray,
NOx is reduced. Also, at high load,
As the injection hole area increases, the fuel injection pressure decreases, shortening the injection period. As a result, the spray at a required flow rate at the time of a high load is uniformly dispersed and supplied as a whole, and stable high-output combustion is performed. Further, since the rotary valve 7 is fixed only by the fuel injection pressure, the actuator 9 can be small in size and torque, thereby avoiding an increase in the size of the injection nozzle and arranging and mounting it on the engine. Can be easier.

When the rotary valve 7 moves due to an external force stronger than the holding force during fuel injection and the position shifts, the position shift is detected by the rotation angle detecting mechanism 11 after the injection when the needle valve 4 is closed. Is detected. Since the feedback signal is sent to the controller 12, it is corrected by driving the actuator 9 by a signal from the coat roller 12, and the rotary valve 7 is returned to the set rotation angle position at the time of the previous injection, and is maintained in this state. As described above, since the position of the rotary valve 7 can be constantly detected and corrected, the variation of the spray for each injection can be reduced. During such fuel injection, in the injection amount direct detection mechanism 6, the turbine 6c is rotated by the fuel flow force as described above, and the rotation is transmitted to the optical axis hole 62.
2 is detected by interruption of the blade 63 of the optical axis that transmits light, and is continuously fed back to the controller 12 as an injection amount signal and an injection timing signal, whereby the injection rate is calculated by the controller 12, and the rotary valve 7 at the next injection is Is calculated, and the injection timing is corrected. After fuel injection, the rotary valve 7
Is returned to the original position set before the injection, and is kept in that state to prepare for the next injection. Therefore, according to the present invention, the injection rate and the injection amount can be accurately controlled in accordance with the state of the engine in synergy with the use effect of the rotary valve 7, and optimal combustion can be realized.

According to the conical rotary valve 7 used in the embodiment of the present invention, since the position of the rotary valve 7 can be fixed only by the fuel injection pressure, the holding torque T ₂ of the rotary valve and the rotation of the rotary valve are rotated. Torque T ₁
In other words, if T ₂ −T ₁ is a small range, T ₂
And by providing a small torque only from the outside over the difference △ T of T _1, it is possible to even during fuel injection by rotating the rotary valve 7 more alert change the opening area of the injection hole 35,
This makes it possible to easily control the injection rate of the pilot or the like. In addition, since the rotary valve 7 and the hole 34 are surface-sealed by the conical surfaces 72 and 341, a so-called inter-injection fuel, in which a part of the fuel flows in the circumferential direction between the hole 34 and the outer peripheral surface of the rotary valve. Leaks are also prevented,
Spraying is performed with an appropriately distributed spray amount. 3 and 4, the conical surface 10C of the joint 10 and the first hole 4
Since the seat is in contact with the conical surface 451 of 5a, the fixing of the rotary valve 7 is further ensured by the frictional force caused thereby. Further, fuel leakage upward through the outer periphery of the joint pin 8b is prevented by the face seals of the conical surfaces 10C and 451. Therefore, spraying can be performed while maintaining the injection pressure at the desired pressure. In the case where the fuel passage 73 of the rotary valve 7 is formed as a groove, there is an advantage that the processing of the fuel passage 73 is facilitated and the cost can be reduced. Further, when the groove bottom is made parallel to the conical surface 72, the area of the pressure receiving surface 74 can be increased as compared with the case where the groove bottom is made parallel to the nozzle axis. Can be made larger.

In the embodiment shown in FIG. 10, for controlling the rotational position of the rotary valve 7, that is, selecting the injection hole 35, a drive signal is sent from the controller to the actuator 9 during the intake stroke or the exhaust stroke, and the engine or the fuel injection pump is driven. The output shaft is driven to a required rotation angle in accordance with the rotation speed (or rotation angle) and the load, and is transmitted to the shaft main body 8a. For example, when the engine is started at a low load and at a low speed, the rotary valve 7 is rotated, and FIG.
(B), whereby each fuel passage 73
Communicate with the first injection holes 35a each having a small diameter, and the second injection holes 35b are shielded. Also, when the engine is under high load and high speed, the rotary valve 7 is rotated to maintain the state shown in FIG. 10A, whereby each of the horizontal holes 730 of the fuel passage 73 has a large diameter second injection hole 35b. And the first injection hole 35a is shielded. By the above-described switching of the injection holes, the fuel injection pressure is increased with a decrease in the injection hole area at a low load, and the injection period is lengthened. As a result, promotion of atomization of spray and increase of excess air ratio of spray can be expected, and NOx can be reduced. In addition, when the load is high, the fuel injection pressure is reduced as the injection hole area increases, and the injection period is shortened. As a result, the spray at a required flow rate at the time of a high load is uniformly dispersed and supplied as a whole, and stable high-output combustion is performed.

[0029]

According to the first aspect of the present invention described above, the fuel injection amount and injection timing can be directly measured and fed back to the control system by a relatively simple and compact structure, so that it is optimal for the state of the engine. An excellent effect is obtained in that the injection control and the combustion control can be performed.
According to the second aspect, it is possible to control the injection hole area in accordance with the load and the rotation speed of the engine in synergy with the direct measurement of the injection amount and the injection timing of the fuel. And an excellent effect of reliably realizing improvement of combustion noise and reduction of NOx.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing one embodiment of a fuel injection nozzle according to the present invention.

2A is a sectional view of an injection amount direct detection mechanism according to the present invention, FIG. 2B is a partially enlarged view of the same, and FIG. 2C is an enlarged view along the line ZZ.

FIG. 3 is a partially enlarged view of FIG. 1;

4A is a partially enlarged view showing a state where the needle valve is opened from a closed state of the needle valve in FIG. 1, and FIG. 4B is a partially enlarged view thereof.

FIG. 5 (a) is a view when FIG.
FIG. 2B is a cross-sectional view taken along line XX, and FIG. 2B is a front view showing one injection hole in the state of FIG.

FIG. 6A is a view showing a state in which the injection hole is fully opened;
FIG. 2B is a cross-sectional view taken along a line, and FIG. 2B is a front view showing one injection hole in the state of FIG.

FIG. 7 is a perspective view of the rotary valve in FIGS. 3 to 6;

FIG. 8 is a partially enlarged cross-sectional view showing an example in which another rotary valve is used.

9 is a perspective view of the rotary valve in FIG.

FIG. 10A is a cross-sectional view of a state where an injection hole having a large diameter is selected, which is applied to an injection hole selection type fuel injection nozzle;
(B) is a cross-sectional view showing a state where an injection hole having a small diameter is selected.

FIG. 11 is a flowchart illustrating an example of control according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle holder main body 3 Nozzle body 4 Needle valve 6 Injection amount direct detection mechanism 6c Turbine 7 Rotary valve 9 Actuator 12 Controller 34 Hole 35 Injection hole 60 Fuel passage 63 Blade 622 Optical axis hole

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02M 61/04 F02M 61/04 A 61/10 61/10 H 61/18 330 61/18 330C // F02M 45/00 45 / 00 C 47/00 47/00 Z (72) Inventor Jun Mizuno 3-13-26 Yayumicho, Higashimatsuyama-shi, Saitama Pref. Inside Zexel Higashimatsuyama Plant (72) Inventor Takao Iwasaki 3-chome Yayumicho, Higashimatsuyama-shi, Saitama No. 13-26 Inside Zexel Higashi Matsuyama Plant

Claims (2)

[Claims] 1. A nozzle holder body, a nozzle body having an injection hole provided at a tip thereof, housed in the nozzle body slidably in an axial direction, and having a pressure receiving surface at a tip thereof, wherein fuel pressure acts on the pressure receiving surface. A nozzle valve that opens and injects fuel from the injection hole, and furthermore, a turbine that is rotatably disposed on the nozzle holder body so that a blade faces the fuel passage; and a position displaced from a rotation center of the turbine. An injection amount direct detection mechanism provided with an optical axis hole provided so as to intersect with the blade and interrupted by the blade when the turbine is rotated by the fuel flow, and an optical system for entering and exiting a light beam into and from the optical axis hole is provided. A fuel injection nozzle characterized in that: 2. A hole for introducing pressurized fuel is formed at the tip of the nozzle body, and a plurality of injection holes for jetting pressurized fuel are provided in the surrounding wall defining the hole at circumferential intervals. 2. The fuel according to claim 1, wherein a rotary valve is disposed in the hole, and the rotary valve is rotated by an actuator provided on the nozzle holder body to change the injection hole opening area. Injection nozzle.